• Posco Co., Ltd. v. ArcelormittalAll claims unpatentable
  PTAB · Jul 16, 2026 · IPR2025-00371 · APJ Brian D Range · IPR · Final written decision

  Claims 1–25 are unpatentable as obvious under § 103 over the asserted combinations of Takagi, Cornette, Suehiro, GMW14400, Laurent, and Vaissiere.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “Petitioner contends that a person of ordinary skill in the art (POSITA) “would have had an undergraduate degree in materials science, manufacturing engineering, mechanical engineering, or equivalent knowledge, training, or experience, with two years of experience working in metallurgy.” Pet. 6 (citing Ex. 1003 ¶ 15). Patent Owner does not challenge Petitioner’s definition of a POSITA for this proceeding. PO Resp. 8. Because the parties agree and because Petitioner’s proposal is reasonable and consistent with the ’227 patent specification and the prior art, we adopt Petitioner’s proposal. See Okajima v. Bourdeau, 261 F.3d 1350, 1355 (Fed. Cir. 2001) (the prior art may reflect an appropriate level of skill in the art).” slip op. at 8

  • Claim Construction › Intrinsic evidence (Phillips canons) › Plain and ordinary meaning to a POSITAPlain and ordinary meaningDecided for patent owner

    “1. superficial layer The only independent claim at issue, claim 1, recites a “Superficial layer.” Ex. 1001, 15:6. Patent Owner argues that, based on plain and ordinary meaning, the term “superficial layer” refers to a “surface layer” or “top layer.” PO Resp. 8–9. Petitioner does not dispute this construction. See Pet. Reply 21–22 (arguing that the relevant layer of the Suehiro reference is a superficial layer because it is outermost and present at the surface). Because the parties are in agreement and because that agreement is consistent with plain language, claim language, and the ’227 specification, we construe “superficial layer” as referring to a surface layer or top layer.” slip op. at 10

  • Claim Construction › Extrinsic evidence (dictionaries, experts)Term construed petitioner constructionDecided for petitioner

    “defined stoichiometry” (Ex. 2037, 527) but the word may also be a “generic term for phases . . . which may have a narrow or extended compositional stability range” (id.). The first glossary meaning is consistent with Patent Owner’s position. The second, broader, glossary meaning is consistent with Petitioner’s position. Some of the extrinsic sources before us support the broad definition, and some support the narrow definition. See PO Sur-Reply 3–4 (arguing that Dr. Miles admitted that various treatises distinguish intermetallic compounds from alloys and solid solutions). Thus, neither Dr. Miles or Dr. Raabe is “wrong scientifically” in how they use the term “intermetallic” in this proceeding. Id. at 2 (noting that Dr. Miles agreed that Dr. Raabe’s construction is not wrong scientifically). As explained below, however, only one of these meanings is appropriate here. To decide which possible meaning applies to the ’227 patent, we focus on the patent claims and specification. Claim 1 indicates that the intermetallic layer has a “mean composition” (emphasis added). Ex. 1001, 15:1–10. This indicates, albeit weakly, that iron composition across the layer may vary rather than having ordered stoichiometry—consistent with Petitioner’s position. The specification also indicates that “intermetallic alloying” is a possibility—again, consistent with Petitioner’s position. Ex. 1001, 2:47–50. Meanwhile, nothing in the ’227 specification explicitly (or implicitly) suggests that “intermetallic layer” must be limited to elements atomically joined with defined stoichiometry in an ordered crystal structure. We also find that Dr. Miles’s testimony regarding the meaning of “intermetallic” is more credible than Dr. Rabbe’s testimony. Dr. Rabbe, in deposition, stated that Figure 2 of the challenged patent “does not show a layer that meets [his] construction of intermetallic.” Ex. 1078, 129:21–24. The ’227 patent, however, states that Figure 2 includes an “Al-rich Intermetallic layer.” Ex. 1001, Fig. 2, 3:60–64 (“FIG 2. Illustrates a coating … which does not correspond to the invention. This succession of layers (interdiffusion layer and intermetallic layer) yields inferior results in resistance spot welding.”). Also, Dr. Raabe previously referred to a layer of Takagi as having “intermetallic phase layering and structure.” Pet. Reply 4 (citing Ex. 1076 ¶ 166; Ex ¶ 1075, 17) (emphasis omitted). Thus, Dr. Raabe’s construction of “intermetallic” for this proceeding does not fully account for the ’227 patent usage of the word “intermetallic” and does not fully account for Dr. Raabe’s prior usage of the word “intermetallic.” Patent Owner argues that Petitioner’s construction “erases the meaningful distinction” between the claimed layers. PO Resp. 11. Patent Owner further argues that Petitioner’s construction renders the word “intermetallic” superfluous because allowing the intermetallic layer to be “merely a multi-element alloy erases the meaningful distinction among these layers.” Id. We disagree. The word intermetallic serves to require that the layer be composed of two or more metals or a metal and a metalloid. The word intermetallic also serves as a label to differentiate each of the four claimed layers. For example, in claim 1, the word “intermetallic” is used much like the words “interdiffusion” and “intermediate” to give each of the four layers (each having differently mean compositions) different labels.” slip op. at 16

  • Novelty / Anticipation (§102) › Prior-art status of a reference › Printed publication / public accessibilityPrinted publication establishedDecided for petitioner

    “Because IHS was a company that created an online database with the purpose of providing (selling) standards including General Motors standards to the public, we determine that a person of ordinary skill in the art would have known to look to this database and would have been able to find GMW14400. Patent Owner presents no evidence to the contrary. Because a preponderance of the evidence supports Petitioner, we determine Petitioner establishes GMW14400 is qualifies as prior art.” slip op. at 21

  Patent outcomesUS 11,326,227 unpatentable
  Claim construction§ 102 anticipation§ 103 obviousnesscites KSR · Graham
  Patents in suitUS 11,326,227
• Posco Co., Ltd. v. ArcelormittalAll claims unpatentable
  PTAB · Jul 16, 2026 · IPR2025-00370 · APJ Brian D Range · IPR · Final written decision

  Claims 1–30 are unpatentable as obvious under § 103 over the asserted combinations of prior art.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “Petitioner contends that a person of ordinary skill in the art (POSITA) “would have had an undergraduate degree in materials science, manufacturing engineering, mechanical engineering, or equivalent knowledge, training, or experience, with two years of experience working in metallurgy.” Pet. 6 (citing Ex. 1003 ¶¶ 13–16). Patent Owner does not challenge Petitioner’s definition of a POSITA for this proceeding. PO Resp. 8. Because the parties agree and because Petitioner’s proposal is reasonable and consistent with the ’602 patent specification and the prior art, we adopt Petitioner’s proposal. See Okajima v. Bourdeau, 261 F.3d 1350, 1355 (Fed. Cir. 2001) (the prior art may reflect an appropriate level of skill in the art).” slip op. at 8

  • Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededDecided for patent owner

    “1. superficial layer All independent claims at issue, claims 1, 21, and 24, recite a “superficial layer.” Ex. 1001, 15:11, 16:60, 17:21. Patent Owner argues that, based on plain and ordinary meaning, the term “superficial layer” refers to a “surface layer” or “top layer.” PO Resp. 8–9. Petitioner does not dispute this construction. See Pet. Reply 21–22 (arguing that the relevant layer of the Suehiro reference is a superficial layer because it is outermost and present at the surface). Because the parties are in agreement and because that agreement is consistent with plain language, claim language, and the ’602 specification, we construe “superficial layer” as referring to a surface layer or top layer.” slip op. at 10

  • Claim Construction › Intrinsic evidence (Phillips canons) › Plain and ordinary meaning to a POSITATerm construed petitioner constructionDecided for petitioner

    “defined stoichiometry” (Ex. 2037, 527) but the word may also be a “generic term for phases . . . which may have a narrow or extended compositional stability range” (id.). The first glossary meaning is consistent with Patent Owner’s position. The second, broader, glossary meaning is consistent with Petitioner’s position. Some of the sources before us support the broad definition, and some support the narrow definition. See PO Sur-Reply 3–4 (arguing that Dr. Miles admitted that various treatises distinguish intermetallic compounds from alloys and solid solutions) Thus, neither Dr. Miles or Dr. Raabe is “wrong scientifically” in how they use the term “intermetallic” in this proceeding. Id. at 2 (noting that Dr. Miles agreed that Dr. Raabe’s construction is not wrong scientifically). As explained below, however, only one of these meanings is appropriate here. To decide which possible meaning applies to the ’602 patent, we focus on the patent claims and specification. The claims indicate that the intermetallic layer has a “mean iron composition” (emphasis added). Ex. 1001, 15:6–10. This indicates, albeit weakly, that the iron composition across the layer may vary rather than having ordered stoichiometry— consistent with Petitioner’s position. The specification also indicates that “intermetallic alloying” is a possibility—again, consistent with Petitioner’s position. Id. at 2:50–54. Meanwhile, nothing in the ’602 specification explicitly (or implicitly) suggests that “intermetallic layer” must be limited to elements atomically joined with defined stoichiometry in an ordered crystal structure. We also find that Dr. Miles’s testimony regarding the meaning of “intermetallic” is more credible than Dr. Raabe’s testimony. Dr. Raabe, in deposition, stated that Figure 2 of the challenged patent “does not show a layer that meets [his] construction of intermetallic.” Ex. 1078, 129:21–24. The ’602 patent, however, states that Figure 2 includes an “Al-rich Intermetallic layer.” Ex. 1001, Fig. 2, 3:57–61 (“FIG 2. Illustrates a coating . . . which does not correspond to the invention. This succession of layers (interdiffusion layer and intermetallic layer) yields inferior results in resistance spot welding.”). Also, Dr. Raabe previously referred to a layer of Takagi as having “intermetallic phase layering and structure.” Pet. Reply 4 (citing Ex. 1076, 166; Ex. 1075, 17) (emphasis omitted). Thus, Dr. Raabe’s definition of “intermetallic” does not fully account for the ’602 patent usage of the word “intermetallic” and does not fully account for Dr. Raabe’s prior usage of the word “intermetallic.” Patent Owner argues that Petitioner’s construction “erases the meaningful distinction” between the claimed layers. PO Resp. 11. Patent Owner further argues that Petitioner’s construction renders the word “intermetallic” superfluous because allowing the intermetallic layer to be “merely a multi-element alloy erases the meaningful distinction among these layers.” Id. We disagree. The word intermetallic serves to require that the layer be composed of two or more metals or a metal and a metalloid. The word intermetallic also serves as a label to differentiate each of the four claimed layers. For example, in claim 1, the word “intermetallic” is used much like the words “interdiffusion” and “intermediate” to give each of the four layers (each having differently defined mean iron compositions) different labels.” slip op. at 16

  • Obviousness (§103) › Motivation to combine / reasonable expectation of successMotivation foundReasonable expectation foundDecided for petitioner

    “have had reason to combine teachings of Takagi and Cornette with a reasonable expectation of success. Pet. 11–20 (citing, e.g., Ex. 1003 ¶¶ 28– 42; Ex. 1016 ¶ 35; Ex. 1014, 9; Ex. 1025, 5:17–20; Ex. 1026, 7; Ex. 1034 ¶ 13). In particular, Petitioner argues that Takagi discloses a pre-coating thickness of 10–20 µm but does not explicitly disclose a post hot-stamping coating thickness corresponding to the pre-coating thickness. Pet. 11. Cornette teaches that the hot-stamping thickness causes coating expansion from 25 µm to about 40 µm, an increase of 60%. Id. (citations omitted). Petitioner and Dr. Miles reason that, when hot stamping Takagi’s product, the thickness would be 32 µm. Id. (citing Ex. 1003 ¶ 32); see also Pet. Reply 20–21. Thus, Patent Owner argues that Cornette evidences Takagi’s finally coating thickness without requiring modification of Takagi. Petitioner further argues that Takagi and Cornette teach that post hot- stamping thickness could be varied and optimized as a result effective variable. Id. at 12–13; see also Pet. Reply 17–18. Cornette teaches, for example, that “[t]he average [pre-coating] layer thickness showing the best compromise between corrosion protection and weldability is 25 µm” and links this pre-coating thickness to a final thickness of “about 40 µm at the steel surface.” Ex. 1014, 9. Petitioner also argues that it would have been obvious to fill in other details of Takagi including, for example, selecting USIBOR 1500 steel, based on the teachings of Cornette. Pet. 14. Patent Owner argues that there is no reason to combine Takagi with the teachings of Cornette. PO Resp. 26. Patent Owner makes seven related arguments. Patent Owner first argues that the Petitioner’s position is speculative and lacks basis. Id. at 26–27. We disagree. Cornette evidences a final coating thickness for Takagi, and the references also suggest that final coating thickness is result effective. Second, Patent Owner argues that there would have been no incentive to seek a motivation to seek a thicker coating post-hot stamping. Id. at 28– 35. This argument does not undermine Petitioner’s position that Takagi, by itself, would have reached a thicker coating after stamping as evidenced by Cornette. Pet. 11–12. Petitioner takes the position, with evidence, that practice of Takagi alone would reach the recited thickness. No motivation to modify Takagi is required under this position.” slip op. at 25

  Patent outcomesUS 10,961,602 unpatentable
  Claim construction§ 102 anticipation§ 103 obviousnesscites KSR · Graham
  Patents in suitUS 10,961,602
• Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentable
  PTAB · Apr 15, 2026 · IPR2025-00187 · APJ Debra L Dennett · IPR · Final written decision

  Claims 1–17 are unpatentable under § 103, principally because Chang in view of Jin renders them obvious; the Jin/Feldmann grounds were not shown.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “Petitioner contends that a person of ordinary skill in the art would have been someone with an advanced degree involving the disciplines of electrical engineering, applied physics, chemistry, or materials science, and at least two years of experience designing, developing, or researching in the field. Alternatively, that person would have had a bachelor’s degree in electrical engineering, applied physics, or materials science, and at least three years of experience designing, developing, or researching in the field. Pet. 4 (citing Ex. 1003 ¶ 49).” slip op. at 10

  • Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther

    “Petitioner contends that “[n]o claim construction is believed to be necessary to resolve this Petition.” Pet. 24. Patent Owner does not address claim construction. See generally Resp.; Sur-reply. For purposes of this Decision, we need not expressly construe any claim terms. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (holding that “only those terms need be construed that are in controversy, and only to the extent necessary to resolve the controversy”); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (citing Vivid Techs. in the context of an inter partes review).” slip op. at 11

  • Expert testimonyPatent owner expert creditedDecided for patent owner

    “gap-T isolation region would prevent shorting and that extending the tunnel oxide layer the edge “could trap impurities and create negative fixed oxide charges, which could then create a p-type inversion in the n-type base substrate, leading to a leakage path to the p-type emitter on the front of the solar cell” (Ex. 1003 ¶ 116 (emphasis added)) but are not convinced by his equivocal testimony. Notably too, neither Jin nor Feldmann discuss issues relating to trapped impurities and Petitioner, as well as Dr. Banerjee, fail to direct our attention to any record evidence to support their contentions. Rather, we are persuaded by Dr. Peckerar’s testimony that as a general rule in semiconductor process technology, a bare silicon surface should not be left unpassivated after processing. Elemental silicon is highly chemically reactive. As such, the bare surface is a “magnet” for defects and contamination. Leaving the tunnel oxide in place across the entire substrate backside would reduce this problem. Ex. 2001 ¶ 142. Dr. Peckerar further explains that a person of ordinary skill in the art would have known how to avoid shorting and leakage. In particular, he testifies that the manner by which charge is transported through a tunnel oxide can be controlled by adjusting manufacturing parameters such as time, temperature, thickness, and ambient impurities. A POSITA would plainly have adjusted these parameters to ensure that the tunnel oxide operates as intended (i.e., minimizes recombinant losses while transporting charge carriers to the backside of the solar cell) while avoiding undesirable leakage current. Because unwanted leakage charge can be avoided via other means during manufacture, there would have been no reason to reduce the physical extent of the tunnel oxide. Ex. 2001 ¶ 152 (referring to Ex. 2001 ¶¶ 149–151). Moreover, Dr. Peckerar testifies that “Dr. Banerjee also appears to be arguing that incorporation of impurities into the oxide will produce a MOSFET-like structure, with the contaminated oxide acting as a MOS gate leading to enhanced leakage,” but, for that to occur, “the source and drain areas would need to be of the same type.” Ex. 2001 ¶ 159. Here however, “the tunnel oxide layer is located between an n-type polysilicon layer and p-type frontside emitter layer” so “[n]o MOSFET-like structure can form because the source and drain are of different types.” Ex. 2001 ¶ 159. Neither Petitioner nor Dr. Banerjee address or dispute this testimony. See generally Reply; Ex. 1037. We credit Dr. Peckerar’s testimony in this regard. Without an apparent reason to modify the teachings of Jin and Feldmann to” slip op. at 19

  • Obviousness (§103) › Motivation to combine / reasonable expectation of success › HindsightNot shown unpatentableMotivation not foundNot shown unpatentable

    “On this complete trial record, we agree with Patent Owner. It is improper to base a conclusion of obviousness upon facts gleaned only through hindsight. “The invention must be viewed not after the blueprint has been drawn by the inventor, but as it would have been perceived in the state of the art that existed at the time the invention was made.” Sensonics, Inc. v. Aerosonic Corp., 81 F.3d 1566, 1570 (Fed. Cir. 1996) (citing Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1138 (Fed. Cir. 1985)). Therefore, “to establish a prima facie case of obviousness based on a combination of elements disclosed in the prior art, the [Petitioner] must articulate the basis on which it concludes that it would have been obvious to make the claimed invention.” Id. Impermissible hindsight is inferred when the specific understanding or principle within the knowledge of one of ordinary skill in the art that would motivate one (with no knowledge of the claimed invention) to make the proposed combination has not been explained. In re Rouffet, 149 F.3d 1350, 1358 (Fed. Cir. 1998).” slip op. at 17

  Patent outcomesUS 10,230,009 unpatentable
  Claim construction§ 103 obviousnesscites Phillips · KSR · Graham
  Patents in suitUS 10,230,009
• Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentable
  PTAB · Apr 15, 2026 · IPR2025-00917 · APJ Debra L Dennett · IPR · Final written decision

  Claims 1–17 are unpatentable under § 103 over Chang and Jin, alone or with Seo or Watanabe; the Jin and Feldmann grounds were not shown.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “In light of the record before us, we adopt Petitioner’s proposal regarding the level of ordinary skill in the art. Based on our review of the ’009 patent and the prior art of record, we determine that the definition offered by Petitioner comports with the qualifications a person would have needed to understand the ’009 patent and the prior art.” slip op. at 10

  • Expert testimonyPatent owner expert creditedDecided for patent owner

    “We acknowledge Dr. Banerjee’s testimony that the combination of Jin’s gap-T isolation region would prevent shorting and that extending the tunnel oxide layer the edge “could trap impurities and create negative fixed oxide charges, which could then create a p-type inversion in the n-type base substrate, leading to a leakage path to the p-type emitter on the front of the solar cell” (Ex. 1003 ¶ 116 (emphasis added)) but are not convinced by his equivocal testimony. Notably too, neither Jin nor Feldmann discuss issues relating to trapped impurities and Petitioner, as well as Dr. Banerjee, fail to direct our attention to any record evidence to support their contentions. Rather, we are persuaded by Dr. Peckerar’s testimony that as a general rule in semiconductor process technology, a bare silicon surface should not be left unpassivated after processing. Elemental silicon is highly chemically reactive. As such, the bare surface is a “magnet” for defects and contamination. Leaving the tunnel oxide in place across the entire substrate backside would reduce this problem. Ex. 2001 ¶ 142. Dr. Peckerar further explains that a person of ordinary skill in the art would have known how to avoid shorting and leakage. In particular, he testifies that the manner by which charge is transported through a tunnel oxide can be controlled by adjusting manufacturing parameters such as time, temperature, thickness, and ambient impurities. A POSITA would plainly have adjusted these parameters to ensure that the tunnel oxide operates as intended (i.e., minimizes recombinant losses while transporting charge carriers to the backside of the solar cell) while avoiding undesirable leakage current. Because unwanted leakage charge can be avoided via other means during manufacture, there would have been no reason to reduce the physical extent of the tunnel oxide. Ex. 2001 ¶ 152 (referring to Ex. 2001 ¶¶ 149–151). Moreover, Dr. Peckerar testifies that “Dr. Banerjee also appears to be arguing that incorporation of impurities into the oxide will produce a MOSFET-like structure, with the contaminated oxide acting as a MOS gate leading to enhanced leakage,” but, for that to occur, “the source and drain areas would need to be of the same type.” Ex. 2001 ¶ 159. Here however, “the tunnel oxide layer is located between an n-type polysilicon layer and p-type frontside emitter layer” so “[n]o MOSFET-like structure can form because the source and drain are of different types.” Ex. 2001 ¶ 159. Neither Petitioner nor Dr. Banerjee address or dispute this testimony. See generally Reply; Ex. 1037. We credit Dr. Peckerar’s testimony in this regard.” slip op. at 19

  • Obviousness (§103) › Motivation to combine / reasonable expectation of success › HindsightMotivation not foundNot shown unpatentableNot shown unpatentable

    “On this complete trial record, we agree with Patent Owner. It is improper to base a conclusion of obviousness upon facts gleaned only through hindsight. “The invention must be viewed not after the blueprint has been drawn by the inventor, but as it would have been perceived in the state of the art that existed at the time the invention was made.” Sensonics, Inc. v. Aerosonic Corp., 81 F.3d 1566, 1570 (Fed. Cir. 1996) (citing Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1138 (Fed. Cir. 1985)). Therefore, “to establish a prima facie case of obviousness based on a combination of elements disclosed in the prior art, the [Petitioner] must articulate the basis on which it concludes that it would have been obvious to make the claimed invention.” Id. Impermissible hindsight is inferred when the specific understanding or principle within the knowledge of one of ordinary skill in the art that would motivate one (with no knowledge of the claimed invention) to make the proposed combination has not been explained. In re Rouffet, 149 F.3d 1350, 1358 (Fed. Cir. 1998).” slip op. at 17

  • Obviousness (§103) › Motivation to combine / reasonable expectation of successMotivation foundUnpatentableUnpatentable

    “Patent Owner focuses on Chang’s description in paragraph 76 of a single configuration in which the emitter area and back surface field area are not adjacent to each other, thus eliminating “the necessity of performing an isolation process when the emitter area [] and the back surface field are [] are formed to be adjacent to each other.” Resp. 42 (citing Ex. 1013 ¶ 76). In so doing, Patent Owner side steps Chang’s unambiguous definition that “‘entirely formed’ means that an element such as a layer is formed over an entire surface without an empty area or a non-coverage area, or is formed over an entire area excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like.” Ex. 1013 ¶¶ 45, 51, 56, 62 (emphasis added). Chang discloses that a first tunneling layer, a first portion of an emitter area, a second tunneling layer, and a back surface field area may each be “formed over an entire area excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like.” Id. Chang’s definition of “entirely formed” (“excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like”) implies use of a mask. See Chang ¶ 62; Tr. 15:20–17:11. Dr. Banerjee testifies that the need to electrically isolate the emitter region from the back surface field was well known in the field, and both Chang and Jin teach backside isolation regions. Ex. 1003 ¶¶ 73, 217 (citing Ex. 1023 § 1). Chang also discloses that the emitter area may be formed by thermal diffusion, ion implantation or the like. Ex. 1013 ¶ 98. Petitioner persuasively argues that Chang’s disclosure of thermal diffusion of the emitter layer would result in dopants diffused into not only the top surface of the substrate, but also the exposed lateral surfaces, a problem also noted in Jin. See Pet. 11–12; Reply 6–7; Ex. 1003 ¶ 71; Ex. 1009 ¶¶ 57–58. Jin discloses avoiding shorting of the emitter layer and back surface field layer by edge isolation on the back surface field layer using a mask to create a “gap-T.” Ex. 1009 ¶¶ 57–58, 83. Chang discloses excluding a tunneling layer and a base surface field area from periphery region and isolation region. Ex. 1013 ¶¶ 56, 62. Using a mask, as implied in Chang and explicitly disclosed in Jin, would “pre-designate” and/or “inevitably form” the regions where the tunneling layer and back surface field area are excluded. We credit Dr. Banerjee’s testimony that one of ordinary skill in the art reviewing Chang would therefore understand the importance of implementing the isolation region in Chang’s device, and would therefore be motivated to look to other references, such as Jin (which was assigned to the same original assignee as Chang, LG Electronics, EX1009-Jin, face; EX1013-Chang, face) to understand details regarding Chang’s isolation region.” slip op. at 32

  Patent outcomesUS 10,230,009 unpatentable
  § 103 obviousnesscites Phillips · KSR · Graham
  Patents in suitUS 10,230,009
• Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentable
  PTAB · Apr 15, 2026 · IPR2025-00006 · APJ Debra L Dennett · IPR · Final written decision

  Claims 1–17 are unpatentable under § 103, principally over Chang and Jin; the Board rejected the Jin and Feldmann combinations for lack of a reason to combine.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “In light of the record before us, we adopt Petitioner’s proposal regarding the level of ordinary skill in the art. Based on our review of the ’009 patent and the prior art of record, we determine that the definition offered by Petitioner comports with the qualifications a person would have needed to understand the ’009 patent and the prior art.” slip op. at 10

  • Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther

    “Petitioner contends that “[n]o claim construction is believed to be necessary to resolve this Petition.” Pet. 24. Patent Owner does not address claim construction. See generally Resp.; Sur-reply. For purposes of this Decision, we need not expressly construe any claim terms. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (holding that “only those terms need be construed that are in controversy, and only to the extent necessary to resolve the controversy”); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (citing Vivid Techs. in the context of an inter partes review).” slip op. at 11

  • Obviousness (§103) › Motivation to combine / reasonable expectation of success › HindsightNot shown unpatentableMotivation not foundNot shown unpatentable

    “However, Petitioner proposes to remove the tunnel oxide layer from the edge and offers little explanation of why the skilled artisan would apply Jin’s gap- T isolation region to both of Feldmann’s polysilicon and tunnel oxide layers. As noted above, Petitioner states that the skilled artisan would have included Jin’s gap-T isolation region in order to prevent shorting. Pet. 26. Petitioner’s reasoning is questionable—supported only by the conclusory testimony of Dr. Banerjee. Dr. Banerjee’s testimony offers no more evidentiary support than provided in the Petition. Compare Ex. 1003 ¶ 116 with Pet. 26). Petitioner cannot satisfy its burden of proving obviousness by employing “mere conclusory statements.” See Magnum, 829 F.3d at 1380. We acknowledge Dr. Banerjee’s testimony that the combination of Jin’s gap-T isolation region would prevent shorting and that extending the tunnel oxide layer the edge “could trap impurities and create negative fixed oxide charges, which could then create a p-type inversion in the n-type base substrate, leading to a leakage path to the p-type emitter on the front of the solar cell” (Ex. 1003 ¶ 116 (emphasis added)) but are not convinced by his equivocal testimony. Notably too, neither Jin nor Feldmann discuss issues relating to trapped impurities and Petitioner, as well as Dr. Banerjee, fail to direct our attention to any record evidence to support their contentions. Rather, we are persuaded by Dr. Peckerar’s testimony that as a general rule in semiconductor process technology, a bare silicon surface should not be left unpassivated after processing. Elemental silicon is highly chemically reactive. As such, the bare surface is a “magnet” for defects and contamination. Leaving the tunnel oxide in place across the entire substrate backside would reduce this problem. Ex. 2001 ¶ 142. Dr. Peckerar further explains that a person of ordinary skill in the art would have known how to avoid shorting and leakage. In particular, he testifies that the manner by which charge is transported through a tunnel oxide can be controlled by adjusting manufacturing parameters such as time, temperature, thickness, and ambient impurities. A POSITA would plainly have adjusted these parameters to ensure that the tunnel oxide operates as intended (i.e., minimizes recombinant losses while transporting charge carriers to the backside of the solar cell) while avoiding undesirable leakage current. Because unwanted leakage charge can be avoided via other means during manufacture, there would have been no reason to reduce the physical extent of the tunnel oxide. Ex. 2001 ¶ 152 (referring to Ex. 2001 ¶¶ 149–151). Moreover, Dr. Peckerar testifies that “Dr. Banerjee also appears to be arguing that incorporation of impurities into the oxide will produce a MOSFET-like structure, with the contaminated oxide acting as a MOS gate leading to enhanced leakage,” but, for that to occur, “the source and drain areas would need to be of the same type.” Ex. 2001 ¶ 159. Here however, “the tunnel oxide layer is located between an n-type polysilicon layer and p-type frontside emitter layer” so “[n]o MOSFET-like structure can form because the source and drain are of different types.” Ex. 2001 ¶ 159. Neither Petitioner nor Dr. Banerjee address or dispute this testimony. See generally Reply; Ex. 1037. We credit Dr. Peckerar’s testimony in this regard.” slip op. at 19

  • Obviousness (§103) › Motivation to combine / reasonable expectation of successUnpatentableMotivation foundUnpatentable

    “configuration in which the emitter area and back surface field area are not adjacent to each other, thus eliminating “the necessity of performing an isolation process when the emitter area [] and the back surface field are [] are formed to be adjacent to each other.” Resp. 42 (citing Ex. 1013 ¶ 76). In so doing, Patent Owner side steps Chang’s unambiguous definition that “‘entirely formed’ means that an element such as a layer is formed over an entire surface without an empty area or a non-coverage area, or is formed over an entire area excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like.” Ex. 1013 ¶¶ 45, 51, 56, 62 (emphasis added). Chang discloses that a first tunneling layer, a first portion of an emitter area, a second tunneling layer, and a back surface field area may each be “formed over an entire area excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like.” Id. Chang’s definition of “entirely formed” (“excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like”) implies use of a mask. See Chang ¶ 62; Tr. 15:20–17:11. Dr. Banerjee testifies that the need to electrically isolate the emitter region from the back surface field was well known in the field, and both Chang and Jin teach backside isolation regions. Ex. 1003 ¶¶ 73, 217 (citing Ex. 1023 § 1). Chang also discloses that the emitter area may be formed by thermal diffusion, ion implantation or the like. Ex. 1013 ¶ 98. Petitioner persuasively argues that Chang’s disclosure of thermal diffusion of the emitter layer would result in dopants diffused into not only the top surface of the substrate, but also the exposed lateral surfaces, a problem also noted in Jin. See Pet. 11–12; Reply 6–7; Ex. 1003 ¶ 71; Ex. 1009 ¶¶ 57–58. Jin discloses avoiding shorting of the emitter layer and back surface field layer by edge isolation on the back surface field layer using a mask to create a “gap-T.” Ex. 1009 ¶¶ 57–58, 83. Chang discloses excluding a tunneling layer and a base surface field area from periphery region and isolation region. Ex. 1013 ¶¶ 56, 62. Using a mask, as implied in Chang and explicitly disclosed in Jin, would “pre-designate” and/or “inevitably form” the regions where the tunneling layer and back surface field area are excluded. We credit Dr. Banerjee’s testimony that one of ordinary skill in the art reviewing Chang would therefore understand the importance of implementing the isolation region in Chang’s device, and would therefore be motivated to look to other references, such as Jin (which was assigned to the same original assignee as Chang, LG Electronics, EX1009-Jin, face; EX1013-Chang, face) to understand details regarding Chang’s isolation region.” slip op. at 32

  Patent outcomesUS 10,230,009 unpatentable
  Claim construction§ 103 obviousnesscites Phillips · KSR · Graham
  Patents in suitUS 10,230,009
• Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentable
  PTAB · Apr 15, 2026 · IPR2025-00918 · APJ Avelyn M Ross · IPR · Final written decision

  Claims 1–11 are unpatentable under § 103 over Chang and Jin; the Board rejected the Jin and Feldmann based grounds for lack of a reason to combine without hindsight.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “Petitioner contends that a person of ordinary skill in the art would have been someone with an advanced degree involving the disciplines of electrical engineering, applied physics, chemistry, or materials science, and at least two years of experience designing, developing, or researching in the field. Alternatively, that person would have had a bachelor’s degree in electrical engineering, applied physics, or materials science, and at least three years of experience designing, developing, or researching in the field.” slip op. at 9

  • Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther

    “Petitioner contends that “[n]o claim construction is believed to be necessary to resolve this Petition.” Pet. 23. And, Patent Owner does not address claim construction. See generally PO Resp. As neither party proposes an express construction for our consideration and because we determine that an express claim construction is not necessary for us to render a decision in this matter, we do not construe any claim terms. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (holding that “only those terms need be construed that are in controversy, and only to the extent necessary to resolve the controversy”); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (citing Vivid Techs. in the context of an inter partes review).” slip op. at 10

  • Obviousness (§103) › Motivation to combine / reasonable expectation of success › HindsightNot shown unpatentableMotivation not foundNot shown unpatentable

    “base a conclusion of obviousness upon facts gleaned only through hindsight. “The invention must be viewed not after the blueprint has been drawn by the inventor, but as it would have been perceived in the state of the art that existed at the time the invention was made.” Sensonics, Inc. v. Aerosonic Corp., 81 F.3d 1566, 1570 (Fed. Cir. 1996) (citing Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1138 (Fed. Cir. 1985)). Therefore, “to establish a prima facie case of obviousness based on a combination of elements disclosed in the prior art, the [Petitioner] must articulate the basis on which it concludes that it would have been obvious to make the claimed invention.” Id. Impermissible hindsight is inferred when the specific understanding or principle within the knowledge of one of ordinary skill in the art that would motivate one (with no knowledge of the claimed invention) to make the proposed combination has not been explained. In re Rouffet, 149 F.3d 1350, 1358 (Fed. Cir. 1998).” slip op. at 16

  • Obviousness (§103) › Motivation to combine / reasonable expectation of successUnpatentableMotivation foundUnpatentable

    “Patent Owner focuses on Chang’s description in paragraph 76 of a single configuration in which the emitter area and back surface field area are not adjacent to each other, thus eliminating “the necessity of performing an isolation process when the emitter area [] and the back surface field are [] are formed to be adjacent to each other.” PO Resp. 42–43 (citing Ex. 1013 ¶ 76). But, in so doing, Patent Owner side steps Chang’s unambiguous definition that “‘entirely formed’ means that an element such as a layer is formed over an entire surface without an empty area or a non-coverage area, or is formed over an entire area excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like.” Ex. 1013 ¶¶ 45, 51, 56, 62 (emphasis added). Chang discloses that a first tunneling layer, a first portion of an emitter area, a second tunneling layer, and a back surface field area may each be “formed over an entire area excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like.” Ex. 1013 ¶¶ 45, 51, 56, 62. Chang’s definition of “entirely formed” (“excluding pre-designated or inevitably formed regions such as periphery region, isolation region or the like”) implies use of a mask. See Ex. 1013 ¶ 62; Tr. 15:20– 17:11. Dr. Banerjee testifies that the need to electrically isolate the emitter region from the back surface field was well known in the field, and both Chang and Jin teach backside isolation regions. Ex. 1003 ¶¶ 70–81, 91–96, 200 (citing Ex. 1026 § 1 and stating that “[b]oth Chang and Jin likewise teach backside isolation regions”). Chang also discloses that the emitter area may be formed by “thermal diffusion, ion implantation or the like.” Ex. 1013 ¶ 98. Petitioner persuasively argues that Chang’s disclosure of thermal diffusion of the emitter layer would result in dopants diffused into not only the top surface of the substrate, but also the exposed lateral surfaces, a problem also noted in Jin. See Pet. 11–12; Pet. Reply 6–7; Ex. 1003 ¶ 71; Ex. 1009 ¶¶ 57–58. Jin discloses avoiding shorting of the emitter layer and back surface field layer by edge isolation on the back surface field layer using a mask to create a “gap-T.” Ex. 1009 ¶¶ 57–58, 83. Chang discloses excluding the second tunneling layer and a base surface field area from periphery region and isolation portion. Ex. 1013 ¶¶ 56, 62. Using a mask, as implied in Chang and explicitly disclosed in Jin, would “pre-designate” and/or “inevitably form” the regions where the tunneling layer and back surface field area are excluded. We credit Dr. Banerjee’s testimony that one of ordinary skill in the art “reviewing Chang would therefore understand the importance of implementing the isolation region in Chang’s device, and would therefore be motivated to look to other references, such as Jin (which was assigned to the same original assignee as Chang, LG Electronics, EX1009-Jin, face; EX1013-Chang, face) to understand details regarding Chang’s isolation region.” Ex. 1003 ¶ 201.” slip op. at 33

  Patent outcomesUS 9,722,104 unpatentable
  Claim construction§ 103 obviousnesscites Phillips · KSR · Graham
  Patents in suitUS 9,722,104
• Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentable
  PTAB · Apr 15, 2026 · IPR2025-00186 · APJ Avelyn M Ross · IPR · Final written decision

  Claims 1–11 are unpatentable under § 103 over Chang and Jin; the Board found the combination disclosed the claimed isolation portion and supported the challenged claims.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “Petitioner contends that a person of ordinary skill in the art would have been someone with an advanced degree involving the disciplines of electrical engineering, applied physics, chemistry, or materials science, and at least two years of experience designing, developing, or researching in the field. Alternatively, that person would have had a bachelor’s degree in electrical engineering, applied physics, or materials science, and at least three years of experience designing, developing, or researching in the field. Pet. 4 (citing Ex. 1003 ¶ 49). Patent Owner does not address the level of ordinary skill in the art. See generally PO Resp; Sur-reply. In light of the complete trial record before us, we adopt Petitioner’s proposal regarding the level of ordinary skill in the art. Based on our review of the ’104 patent and the prior art of record, we determine that the definition offered by Petitioner comports with the qualifications a person would have needed to understand the ’104 patent and the prior art.” slip op. at 9

  • Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededNot reached

    “C. Claim Construction We construe claim terms according to the standard set forth in Phillips v. AWH Corp., 415 F.3d 1303, 1312–17 (Fed. Cir. 2005) (en banc); 37 C.F.R. § 42.100(b). Under Phillips, we give claim terms “their ordinary and customary meaning.” Phillips, 415 F.3d at 1312. “[T]he ordinary and customary meaning of a claim term is the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention.” Id. at 1313. “Importantly, the person of ordinary skill in the art is deemed to read the claim term not only in the context of the particular claim in which the disputed term appears, but in the context of the entire patent, including the specification.” Id. Petitioner contends that “[n]o claim construction is believed to be necessary to resolve this Petition.” Pet. 23. And, Patent Owner does not address claim construction. See generally PO Resp. As neither party proposes an express construction for our consideration and because we determine that an express claim construction is not necessary for us to render a decision in this matter, we do not construe any claim terms. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (holding that “only those terms need be construed that are in controversy, and only to the extent necessary to resolve the controversy”); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (citing Vivid Techs. in the context of an inter partes review).” slip op. at 10

  • Expert testimonyPetitioner expert discountedPatent owner expert creditedMixed

    “edge and offers little explanation of why the skilled artisan would apply Jin’s gap- T isolation region to both of Feldmann’s polysilicon and tunnel oxide layers. As noted above, Petitioner states that the skilled artisan would have included Jin’s gap-T isolation region in order to prevent shorting. Pet. 25. Petitioner’s reasoning is questionable—supported only by the conclusory testimony of Dr. Banerjee. Dr. Banerjee’s testimony offers no more evidentiary support than provided in the Petition. Compare Ex. 1003 ¶ 113, with Pet. 25. Petitioner cannot satisfy its burden of proving obviousness by employing “mere conclusory statements.” Magnum Oil, 829 F.3d at 1380. We acknowledge Dr. Banerjee’s testimony that the combination of Jin’s gap-T isolation region would prevent shorting and that extending the tunnel oxide layer the edge “could trap impurities and create negative fixed oxide charges, which could then create a p-type inversion in the n-type base substrate, leading to a leakage path to the p-type emitter on the front of the solar cell” (Ex. 1003 ¶ 113 (emphasis added)) but are not convinced by his equivocal testimony. Notably too, neither Jin nor Feldmann discuss issues relating to trapped impurities and Petitioner, as well as Dr. Banerjee, fail to direct our attention to any record evidence to support their contentions. Rather, we are persuaded by Dr. Peckerar’s testimony that as a general rule in semiconductor process technology, a bare silicon surface should not be left unpassivated after processing. Elemental silicon is highly chemically reactive. As such, the bare surface is a “magnet” for defects and contamination. Leaving the tunnel oxide in place across the entire substrate backside would reduce this problem. Ex. 2001 ¶ 142. Dr. Peckerar further explains that a person of ordinary skill in the art would have known how to avoid shorting and leakage. In particular, he testifies that the manner by which charge is transported through a tunnel oxide can be controlled by adjusting manufacturing parameters such as time, temperature, thickness, and ambient impurities. A POSITA would plainly have adjusted these parameters to ensure that the tunnel oxide operates as intended (i.e., minimizes recombinant losses while transporting charge carriers to the backside of the solar cell) while avoiding undesirable leakage current. Because unwanted leakage charge can be avoided via other means during manufacture, there would have been no reason to reduce the physical extent of the tunnel oxide. Ex. 2001 ¶ 152 (referring to Ex. 2001 ¶¶ 149–151). Moreover, Dr. Peckerar testifies that “Dr. Banerjee also appears to be arguing that incorporation of impurities into the oxide will produce a MOSFET-like structure, with the contaminated oxide acting as a MOS gate leading to enhanced leakage,” but, for that to occur, “the source and drain areas would need to be of the same type.” Ex. 2001 ¶ 159. Here however, “the tunnel oxide layer is located between an n-type polysilicon layer and p-type frontside emitter layer” so “[n]o MOSFET-like structure can form because the source and drain are of different types.” Ex. 2001” slip op. at 18

  • Obviousness (§103) › Motivation to combine / reasonable expectation of success › HindsightNot shown unpatentableMotivation not foundNot shown unpatentable

    “base a conclusion of obviousness upon facts gleaned only through hindsight. “The invention must be viewed not after the blueprint has been drawn by the inventor, but as it would have been perceived in the state of the art that existed at the time the invention was made.” Sensonics, Inc. v. Aerosonic Corp., 81 F.3d 1566, 1570 (Fed. Cir. 1996) (citing Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1138 (Fed. Cir. 1985)). Therefore, “to establish a prima facie case of obviousness based on a combination of elements disclosed in the prior art, the [Petitioner] must articulate the basis on which it concludes that it would have been obvious to make the claimed invention.” Id. Impermissible hindsight is inferred when the specific understanding or principle within the knowledge of one of ordinary skill in the art that would motivate one (with no knowledge of the claimed invention) to make the proposed combination has not been explained. In re Rouffet, 149 F.3d 1350, 1358 (Fed. Cir. 1998).” slip op. at 16

  Patent outcomesUS 9,722,104 unpatentable
  Claim construction§ 103 obviousnesscites Phillips · KSR · Graham
  Patents in suitUS 9,722,104
• Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentable
  PTAB · Apr 15, 2026 · IPR2025-00007 · APJ Avelyn M Ross · IPR · Final written decision

  Claims 1–11 are unpatentable under §103 over Chang and Jin because the combination teaches the claimed isolation portion and the claimed tapering.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedOther

    “Petitioner contends that a person of ordinary skill in the art would have been someone with an advanced degree involving the disciplines of electrical engineering, applied physics, chemistry, or materials science, and at least two years of experience designing, developing, or researching in the field. Alternatively, that person would have had a bachelor’s degree in electrical engineering, applied physics, or materials science, and at least three years of experience designing, developing, or researching in the field. Pet. 4 (citing Ex. 1003 ¶ 49). Patent Owner does not address the level of ordinary skill in the art. See generally PO Resp; Sur-reply. In light of the complete trial record before us, we adopt Petitioner’s proposal regarding the level of ordinary skill in the art. Based on our review of the ’104 patent and the prior art of record, we determine that the definition offered by Petitioner comports with the qualifications a person would have needed to understand the ’104 patent and the prior art.” slip op. at 9

  • Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther

    “Petitioner contends that “[n]o claim construction is believed to be necessary to resolve this Petition.” Pet. 23. And, Patent Owner does not address claim construction. See generally PO Resp. As neither party proposes an express construction for our consideration and because we determine that an express claim construction is not necessary for us to render a decision in this matter, we do not construe any claim terms. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (holding that “only those terms need be construed that are in controversy, and only to the extent necessary to resolve the controversy”); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (citing Vivid Techs. in the context of an inter partes review).” slip op. at 10

  • Obviousness (§103) › Motivation to combine / reasonable expectation of success › HindsightTeaching away not foundNot shown unpatentable

    “On this complete trial record, we agree with Patent Owner. It is improper to base a conclusion of obviousness upon facts gleaned only through hindsight. “The invention must be viewed not after the blueprint has been drawn by the inventor, but as it would have been perceived in the state of the art that existed at the time the invention was made.” Sensonics, Inc. v. Aerosonic Corp., 81 F.3d 1566, 1570 (Fed. Cir. 1996) (citing Interconnect Planning Corp. v. Feil, 774 F.2d 1132, 1138 (Fed. Cir. 1985)). Therefore, “to establish a prima facie case of obviousness based on a combination of elements disclosed in the prior art, the [Petitioner] must articulate the basis on which it concludes that it would have been obvious to make the claimed invention.” Id. Impermissible hindsight is inferred when the specific understanding or principle within the knowledge of one of ordinary skill in the art that would motivate one (with no knowledge of the claimed invention) to make the proposed combination has not been explained. In re Rouffet, 149 F.3d 1350, 1358 (Fed. Cir. 1998).” slip op. at 16

  • Expert testimonyPatent owner expert creditedPetitioner expert discountedDecided for patent owner

    “However, Petitioner proposes to remove the tunnel oxide layer from the edge and offers little explanation of why the skilled artisan would apply Jin’s gap- T isolation region to both of Feldmann’s polysilicon and tunnel oxide layers. As noted above, Petitioner states that the skilled artisan would have included Jin’s gap-T isolation region in order to prevent shorting. Pet. 25. Petitioner’s reasoning is questionable—supported only by the conclusory testimony of Dr. Banerjee. Dr. Banerjee’s testimony offers no more evidentiary support than provided in the Petition. Compare Ex. 1003 ¶ 113, with Pet. 25. Petitioner cannot satisfy its burden of proving obviousness by employing “mere conclusory statements.” Magnum Oil, 829 F.3d at 1380. We acknowledge Dr. Banerjee’s testimony that the combination of Jin’s gap-T isolation region would prevent shorting and that extending the tunnel oxide layer the edge “could trap impurities and create negative fixed oxide charges, which could then create a p-type inversion in the n-type base substrate, leading to a leakage path to the p-type emitter on the front of the solar cell” (Ex. 1003 ¶ 113 (emphasis added)) but are not convinced by his equivocal testimony. Notably too, neither Jin nor Feldmann discuss issues relating to trapped impurities and Petitioner, as well as Dr. Banerjee, fail to direct our attention to any record evidence to support their contentions. Rather, we are persuaded by Dr. Peckerar’s testimony that as a general rule in semiconductor process technology, a bare silicon surface should not be left unpassivated after processing. Elemental silicon is highly chemically reactive. As such, the bare surface is a “magnet” for defects and contamination. Leaving the tunnel oxide in place across the entire substrate backside would reduce this problem. Ex. 2001 ¶ 142. Dr. Peckerar further explains that a person of ordinary skill in the art would have known how to avoid shorting and leakage. In particular, he testifies that the manner by which charge is transported through a tunnel oxide can be controlled by adjusting manufacturing parameters such as time, temperature, thickness, and ambient impurities. A POSITA would plainly have adjusted these parameters to ensure that the tunnel oxide operates as intended (i.e., minimizes recombinant losses while transporting charge carriers to the backside of the solar cell) while avoiding undesirable leakage current. Because unwanted leakage charge can be avoided via other means during manufacture, there would have been no reason to reduce the physical extent of the tunnel oxide.” slip op. at 18

  Patent outcomesUS 9,722,104 unpatentable
  Claim construction§ 103 obviousnesscites Phillips · KSR · Graham
  Patents in suitUS 9,722,104
• Deltran USA LLC v. The Noco CompanyAll claims unpatentable
  PTAB · Mar 13, 2026 · IPR2025-00885 · APJ Avelyn M Ross · IPR · Final written decision

  Claims 1–11 are unpatentable under Richardson-based obviousness grounds; the Yu and Paparrizos grounds do not establish unpatentability.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “Petitioner contends that a person of ordinary skill in the art, “[a]s of the claimed priority date of July 3, 2014, . . . would have been a person with a bachelor’s degree in electrical engineering or its equivalent and two years of experience in the field of electrical engineering including some experience in design of battery charging systems.” Pet. 21 (citing Ex. 1003 ¶¶ 19–30). Patent Owner “does not propose a different level of skill in the art[.]” PO Resp. 16. In light of the record before us, we adopt Petitioner’s proposal regarding the level of ordinary skill in the art, because it is supported by the testimony of C. Arthur MacCarley and not disputed by Patent Owner.” slip op. at 11

  • Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther

    “As neither party proposes an express construction for our consideration and because we determine that claim construction is not necessary, we do not expressly construe any claim terms. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (holding that “only those terms need be construed that are in controversy, and only to the extent necessary to resolve the controversy”); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co. Matal, 868 F.3d 1013, 1017 (Fed. Cir. 2017) (citing Vivid Techs. in the context of an inter partes review).” slip op. at 11

  • PTAB / AIA Trials › §315(e) estoppelNot reached

    “arguments relating to whether the prior findings are “necessary to the determination” or whether estoppel applies to arguments relating to Richardson being inoperative. See Pet. Reply 27. Nor does Petitioner respond to our inquiry about whether collateral estoppel maybe applied on a limitation by limitation basis. See Pet. Reply 27. At the hearing, however, Petitioner confirmed that resolution of the issue is not necessary to our final determination. JUDGE ROSS: Do we even need to decide the collateral estoppel issue? I mean, it seems to me that if your petition clearly made out your case for the combination of Richardson and Zhao, then we don't even need to reach that. MR. CHANDRA: That’s exactly right, Your Honor. That is our position, as well. We believe collateral estoppel applies, but you don't need to decide that issue in order to find these claims unpatentable. As I mentioned before, these are the same references. We have fairly sought out all of the portions of Richardson, we cited to specific portions. Not just relying on collateral estoppel, but the teachings of the reference itself. So, while this is an issue, we believe that collateral estoppel should apply. It does not have to apply in order to find the challenged claims unpatentable. Tr. 19:9–20. We are persuaded, as discussed in Section II.G., that Petitioner has shown where Richardson in combination with Zhao meets each limitation of the claims of the ’203 patent. Accordingly, we need not address whether Petitioner has demonstrated sufficiently that collateral estoppel applies here.” slip op. at 14

  • Strike new argumentNew argument consideredOther

    “Our Practice Guide states, that “[o]nce a trial is instituted, the Board may decline to consider arguments set forth in a preliminary response unless they are raised in the patent owner response.” Consolidated Trial Practice Guide (“Practice Guide”), 52 (Nov. 2019) (citing In re Nuvasive, Inc., 842 F.3d 1376, 1381 (Fed. Cir. 2016) (explaining that a patent owner waives an issue presented in its preliminary response if it fails to renew the issue in its response after trial is instituted)).12 In addition, in our Scheduling Order, we stated that “Patent Owner is cautioned that any arguments not raised in the response may be deemed waived.” Paper 9 at 10; see also Practice Guide, 94 (same). Patent Owner confirmed at the Oral Hearing its understanding that arguments raised in its Preliminary Response and not reasserted in its Patent Owner Response were not appropriate for consideration during trial. Tr. 4:10–6:17. Petitioner does not identify any particular argument raised in the Patent Owner Preliminary Response that is not present in the Patent Owner Response. But, in this Final Written Decision, we do not consider arguments made in the Patent Owner Preliminary Response and instead assess only those fairly presented in the Patent Owner Response.” slip op. at 15

  Patent outcomesUS 11,667,203 unpatentable
  Claim construction§ 102 anticipation§ 103 obviousnesscites Phillips · KSR · Graham
  Patents in suitUS 11,667,203
• Deltran USA LLC / Adc Solutions Auto LLC v. The Noco CompanyAll claims unpatentable
  PTAB · Mar 13, 2026 · IPR2024-01219 · APJ Avelyn M Ross · IPR · Final written decision

  Claims 1–11 are unpatentable as obvious over the Richardson-based grounds; the Yu and Paparrizos grounds do not establish unpatentability.

  RulingsFinal written decision

  • Skill levelSkill level petitioner adoptedDecided for petitioner

    “Petitioner contends that a person of ordinary skill in the art, “[a]s of the claimed priority date of July 3, 2014, . . . would have been a person with a bachelor’s degree in electrical engineering or its equivalent and two years of experience in the field of electrical engineering including some experience in design of battery charging systems.” Pet. 21 (citing Ex. 1003 ¶¶ 19–30). Patent Owner “does not propose a different level of skill in the art[.]” PO Resp. 16. In light of the record before us, we adopt Petitioner’s proposal regarding the level of ordinary skill in the art, because it is supported by the testimony of C. Arthur MacCarley and not disputed by Patent Owner.” slip op. at 11

  • Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededNot reached

    “Petitioner submits there are no formal claim constructions necessary in this proceeding[.]” Pet. 22. Patent Owner also “does not propose any terms need to be construed.” PO Resp. 15. As neither party proposes an express construction for our consideration and because we determine that claim construction is not necessary, we do not expressly construe any claim terms. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999) (holding that “only those terms need be construed that are in controversy, and only to the extent necessary to resolve the controversy”); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co. Matal, 868 F.3d 1013, 1017 (Fed. Cir. 2017) (citing Vivid Techs. in the context of an inter partes review). slip op. at 11

  • PTAB / AIA Trials › §315(e) estoppelNot reached

    “arguments relating to whether the prior findings are “necessary to the determination” or whether estoppel applies to arguments relating to Richardson being inoperative. See Pet. Reply 27. Nor does Petitioner respond to our inquiry about whether collateral estoppel maybe applied on a limitation by limitation basis. See Pet. Reply 27. At the hearing, however, Petitioner confirmed that resolution of the issue is not necessary to our final determination. JUDGE ROSS: Do we even need to decide the collateral estoppel issue? I mean, it seems to me that if your petition clearly made out your case for the combination of Richardson and Zhao, then we don't even need to reach that. MR. CHANDRA: That’s exactly right, Your Honor. That is our position, as well. We believe collateral estoppel applies, but you don't need to decide that issue in order to find these claims unpatentable. As I mentioned before, these are the same references. We have fairly sought out all of the portions of Richardson, we cited to specific portions. Not just relying on collateral estoppel, but the teachings of the reference itself. So, while this is an issue, we believe that collateral estoppel should apply. It does not have to apply in order to find the challenged claims unpatentable. Tr. 19:9–20. We are persuaded, as discussed in Section II.G., that Petitioner has shown where Richardson in combination with Zhao meets each limitation of the claims of the ’203 patent. Accordingly, we need not address whether Petitioner has demonstrated sufficiently that collateral estoppel applies here.” slip op. at 14

  • BurdenDecided for patent owner

    “With respect to Petitioner’s allegations that rest on AAPA, we determine Petitioner has failed to show that claims 2, 10, and 11 are unpatentable. Our rules require that a petition for inter partes review must base the asserted challenges on “prior art consisting of patents or printed publications.” 35 U.S.C. § 311(b); 37 C.F.R. § 42.104(b)(2) and (4). And, a petitioner who relies on applicant admitted prior art as the basis, or part of the basis, of a ground, runs afoul of § 311. Qualcomm, 134 F.4th at 1365; see also USPTO Memorandum, Enforcement and Non-Waiver of 37 C.F.R. § 42.104(b)(4) and Permissible Uses of General Knowledge in Inter Partes Reviews (Jul. 21, 2025), available at www.uspto.gov/sites/default/ files/documents/aapa_memo_final__signed.pdf. We acknowledge but reject Petitioner’s position that its combinations discussing AAPA do not “rely” on AAPA but rather rely on U.S. Patent No. 5,793,185 (“the ’185 patent”), described in the ’203 patent as prior art. Pet. Reply 26. A petition for inter partes review must identify, “in writing and with particularity, each claim challenged, the grounds on which the challenge to each claim is based, and the evidence that supports the grounds for the challenge to each claim.” 35 U.S.C. § 312(a)(3); 37 C.F.R. § 42.104 (b)(4). Here, Petitioner’s contention that the Grounds 2 and 5 actually rely on the ’185 patent when discussing AAPA is inconsistent with the Petition. In particular, the Petition does not cite to or direct our attention to any specific details from the ’185 patent to support its challenges. See generally Pet. 54–57, 76–77. Accordingly, Petitioner has failed to show, by a preponderance of the evidence, that claims 2, 10, and 11 would have been unpatentable over the combination of Richardson, Zhao, and AAPA as well as over the combination of Yu, Paparrizos, and AAPA. Petitioner’s alternative allegations based on Epower-20/Epower-21 are considered below.” slip op. at 18

  Patent outcomesUS 11,667,203 unpatentable
  Claim construction§ 102 anticipation§ 103 obviousnesscites Phillips · KSR · Graham
  Patents in suitUS 11,667,203

Holdings, summaries, rulings, issues, outcomes, winners and claim constructions shown for a decision were generated by a large language model reading the opinion. They are a guide to the decision, not the decision. Confirm every one against the court's own text before relying on it. Outcomes read from the patent owner’s side. Party names are extracted from the decision and are missing on about 900 short Director denials and scans, which carry the trial number instead.