- Shenzhen Root Technology Co., Ltd. v. Willow Blossom Holdco Limited And Willow Innovations, Inc.All claims unpatentablePTAB · Sep 25, 2026 · IPR2025-00554 · APJ Barry L Grossman · IPR · Final written decision
Claims 17–19 and 21–33 are unpatentable as obvious under each asserted § 103 ground.
RulingsFinal written decision- Skill levelSkill level petitioner adoptedDecided for petitioner
“Factors pertinent to a determination of the level of ordinary skill in the art include: (1) educational level of the inventor; (2) type of problems encountered in the art; (3) prior art solutions to those problems; (4) rapidity with which innovations are made; (5) sophistication of the technology; and (6) educational level of workers active in the field. Env’t Designs, Ltd. v. Union Oil Co., 713 F.2d 693, 696–697 (Fed. Cir. 1983) (citing Orthopedic Equip. Co. v. All Orthopedic Appliances, Inc., 707 F.2d 1376, 1381–82 (Fed. Cir. 1983)). Not all such factors may be present in every case, and one or more of these or other factors may predominate in a particular case. Id. Moreover, these factors are not exhaustive but are merely a guide to determining the level of ordinary skill in the art. Daiichi Sankyo Co. v. Apotex, Inc., 501 F.3d 1254, 1256 (Fed. Cir. 2007). In determining a level of ordinary skill, we also may look to the prior art, which may reflect an appropriate skill level. Okajima, 261 F.3d at 1355.” slip op. at 17
- Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther
“according to the Phillips standard,” and that “no formal claim constructions are necessary for purposes of resolving controversies in this proceeding. Pet. 3. We agree. Given the lack of dispute on this record, we do not perceive the need to construe any claim limitation. Claims must be construed “only to the extent necessary to resolve the controversy.” AstraZeneca AB v. Mylan Pharms. Inc., 19 F.4th 1325, 1345 (Fed. Cir. 2021) (quoting Vivid Techs., Inc. v. American Science & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (“Because we need only construe terms ‘that are in controversy, and only to the extent necessary to resolve the controversy,’ we need not construe the claim preambles here where the construction is not ‘material to the [obviousness] dispute.’” (citations omitted)).” slip op. at 18
- Expert testimonyPetitioner expert creditedDecided for petitioner
“We find Mr. Bauer’s testimonial evidence persuasive and undisputed as to why a person of ordinary skill, a degreed engineer with two years of experience designing human breast pump equipment, would modify Furrer to use a battery as a power source, and have a reasonable degree of confidence that it would work successfully.” slip op. at 26
- Obviousness (§103) › Motivation to combine / reasonable expectation of successMotivation foundReasonable expectation foundDecided for petitioner
“We find Mr. Bauer’s testimonial evidence persuasive and undisputed as to why a person of ordinary skill, a degreed engineer with two years of experience designing human breast pump equipment, would modify Furrer to use a battery as a power source, and have a reasonable degree of confidence that it would work successfully. Concerning the proposed combination of Furrer and Alvarez, Mr. Bauer testifies why a person of ordinary skill would combine Furrer and Alvarez, explaining that: a POSITA6 would have turned to the teachings of Alvarez to implement Furrer’s vacuum pump using a conventional pump controller having a portable, battery-powered pump to not only increase portability and to allow the user to move about when using the device but also to provide improved control for the system. Ex. 1003 ¶ 138. Mr. Bauer also testifies: a POSITA would have recognized that Alvarez advantageously provides details for such a conventional vacuum pump suitable for safely and controllably delivering negative pressure using a “[c]ontroller 115 [that] “houses the power source and drive mechanism for pumping device 100, and also contains hardware for various functions, such as controlling pumping device 100, milk production quantification, and communication with other devices. 6 “POSITA” is a patent law acronym for a “person of ordinary skill in the art.” Id. ¶ 139 (citing Ex. 1005 ¶ 69). Mr. Bauer further explains that Alvarez discloses that a “pump unit2100 [disclosed in Alvarez] preferably include[es] a controller and processor 2104 as well as a motor 2102 for actuating the device.” Id. (citing Ex. 1005 ¶ 115); see also id. ¶¶ 140–142 (providing “second,” “third,” and “fourth” reasons why a person of ordinary skill would have been motivated to combine Furrer and Alvarez). Mr. Bauer concludes from his analysis that “a person skilled in the art” slip op. at 26
Patent outcomesUS 11,806,454 unpatentableClaim construction§ 103 obviousnesscites Phillips · KSR · GrahamPatents in suitUS 11,806,454 - Shenzhen Root Technology Co., Ltd. v. Willow Blossom Holdco LimitedAll claims unpatentablePTAB · Jul 30, 2026 · IPR2025-00560 · APJ Barry L Grossman · IPR · Final written decision
Claims 1–29 are unpatentable under each asserted obviousness ground, including Chang and Fang, because Petitioner proved unpatentability by a preponderance of the evidence.
RulingsFinal written decision- Expert testimonyPetitioner expert creditedDecided for petitioner
“Additionally, we note that Patent Owner did not cross-examine Mr. Ryan Bauer, who provided a detailed, 169-page expert report providing, on behalf of Petitioner, his opinions about the issues in this proceeding. See Exhibit 1003. Mr. Bauer’s testimonial evidence in this proceeding remains unrebutted.” slip op. at 3
- Skill levelSkill level petitioner adoptedDecided for petitioner
“Petitioner asserts that a person of ordinary skill in the art would have had “bachelor’s degree in mechanical engineering or a similar field and at least two years of experience designing human breast pump equipment. More education could substitute for experience and vice versa.” Pet. 8 (citing Ex. 1003 ¶¶ 15–18). Mr. Bauer’s Declaration testimony states he considered some of the factors listed above. Ex. 1003 ¶ 17. Mr. Bauer testifies that based on his background and experience, in his opinion, the level of ordinary skill is as stated by Petitioner. Id. at 18. Based on the prior art, the sophistication of the disclosed technology in the ’381 patent, and Mr. Bauer’s undisputed testimony, we adopt Petitioner’s definition of the level of ordinary skill.” slip op. at 17
- Claim Construction › Threshold & procedure › Whether a term needs construction (O2 Micro)No construction neededOther
“Petitioner asserts that the Examiner construed the term “self- contained, in-bra wearable device” to mean “complete, or having all that is needed, in itself’ and is capable of being worn in a bra.” Pet. 8 (citing Ex. 1005, 2290).14 According to Petitioner, “[Patent Owner] did not dispute this construction, and Petitioner applies it herein.” Id. Petitioner contends that all other terms “should receive their plain and ordinary meaning.” Id. We do not perceive the need to construe any claim limitation. Claims must be construed “only to the extent necessary to resolve the controversy.” AstraZeneca AB v. Mylan Pharms. Inc., 19 F.4th 1325, 1345 (Fed. Cir. 2021) (quoting Vivid Techs., Inc. v. American Science & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999); see also Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 868 F.3d 1013, 1017 (Fed. Cir. 2017) (“Because we need only construe terms ‘that are in controversy, and only to the extent necessary to resolve the controversy,’ we need not construe the claim preambles here where the construction is not ‘material to the [obviousness] dispute.’” (citations omitted)).” slip op. at 17
- Obviousness (§103) › Motivation to combine / reasonable expectation of successMotivation foundReasonable expectation foundUnpatentable
“(3) 1[a][1] a diaphragm configured to prevent milk from reaching an air pump by forming a seal around its outer edge; Petitioner relies on Fang for the disclosure of a diaphragm, as stated in this clause. Pet. 25–26. Petitioner asserts the proposed combination of elements suggest a breast pump device that would have used a diaphragm pump including first and second diaphragm housing components and an elastic diaphragm, “in accordance with Fang’s suggestions.” Id. at 25. As also asserted by Petitioner, Fang discloses that flexible diaphragm 7 (i.e., a membrane) is configured to prevent milk from reaching the pump. Id. at 26 (citing Ex. 1009 ¶ 19 (“The elastic diaphragm 7 is used to prevent milk from flowing into the air pump main unit 8.”). Mr. Bauer testifies: The flexible diaphragm [diaphragm 7 in Fang] forms a watertight and airtight seal around its outer edge. In doing so, the diaphragm prevents the passage of milk from reaching the air pump and facilitates generation of negative pressure during operation. Fang also explains that the elastic diaphragm 7 deforms away from the nipple tunnel when a vacuum is created on a pumping chamber, which then creates negative air pressure in the nipple tunnel when a vacuum is created on a pumping chamber.” slip op. at 28
Patent outcomesUS 11,813,381 unpatentableClaim construction§ 103 obviousnesscites Phillips · KSR · GrahamPatents in suitUS 11,813,381 - Samsung Display Co., Ltd. v. Pictiva Displays International Ltd.All claims unpatentablePTAB · Jul 22, 2026 · IPR2024-01095 · APJ Garth D Baer · IPR · Remand
On remand, the Board maintained its finding that claims 2 and 17 are unpatentable under §103 over Diekmann and Ma, and Suzuki and Ma.
RulingsRemand decision- RemandDecided for petitioner
“that is both n-doped and comprised of 8-hydroxy-quinolinolato-lithium (Liq). The district-court defendant’s first invalidity challenge relied primarily on Clix2, which lacked an n-doped ETL. Paper 48, 2, Paper 50, 3. Thus, the asserted combination required modifying Clix2’s non-doped ETL by adding an n-dopant. Clix2’s missing n-doped ETL appeared to be a focus at trial. See Ex. 2034, 917:1–18, 920:8–14. Here, in contrast, Petitioner proposed a more modest modification to materially different primary references, Suzuki and Diekmann, which both already have n-doped ETLs. See Paper 50, 2–3; Paper 54 8–9. As we explained in our Final Written Decision, because Patent Owner did not contest that Liq acts as an n-dopant in Ma, Petitioner’s combinations were obvious because they merely “substitute one known n-dopant for another to further the same goal of improving ETL conductivity.” Paper 54, 12. That simple-substitution analysis would not be the same when n-doping Clix2’s non-doped ETL. For this reason, we agree with Petitioner that the district-court Clix2-based combination “is a different combination with a materially different motivation-to-combine analysis,” as compared to the Diekmann/Suzuki and Ma combinations that are at issue here. Paper 50, 3.” slip op. at 2
- Obviousness (§103) › Motivation to combine / reasonable expectation of successUnpatentableMotivation foundUnpatentable
“Dependent claims 2 and 17 require an electron transport layer (ETL) that is both n-doped and comprised of 8-hydroxy-quinolinolato-lithium (Liq). The district-court defendant’s first invalidity challenge relied primarily on Clix2, which lacked an n-doped ETL. Paper 48, 2, Paper 50, 3. Thus, the asserted combination required modifying Clix2’s non-doped ETL by adding an n-dopant. Clix2’s missing n-doped ETL appeared to be a focus at trial. See Ex. 2034, 917:1–18, 920:8–14. Here, in contrast, Petitioner proposed a more modest modification to materially different primary references, Suzuki and Diekmann, which both already have n-doped ETLs. See Paper 50, 2–3; Paper 54 8–9. As we explained in our Final Written Decision, because Patent Owner did not contest that Liq acts as an n-dopant in Ma, Petitioner’s combinations were obvious because they merely “substitute one known n-dopant for another to further the same goal of improving ETL conductivity.” Paper 54, 12. That simple-substitution analysis would not be the same when n-doping Clix2’s non-doped ETL. For this reason, we agree with Petitioner that the district-court Clix2-based combination “is a different combination with a materially different motivation-to-combine analysis,” as compared to the Diekmann/Suzuki and Ma combinations that are at issue here. Paper 50, 3.” slip op. at 2
- Obviousness (§103) › Graham factors (scope of art, differences, level of skill)UnpatentableUnpatentable
“that is both n-doped and comprised of 8-hydroxy-quinolinolato-lithium (Liq). The district-court defendant’s first invalidity challenge relied primarily on Clix2, which lacked an n-doped ETL. Paper 48, 2, Paper 50, 3. Thus, the asserted combination required modifying Clix2’s non-doped ETL by adding an n-dopant. Clix2’s missing n-doped ETL appeared to be a focus at trial. See Ex. 2034, 917:1–18, 920:8–14. Here, in contrast, Petitioner proposed a more modest modification to materially different primary references, Suzuki and Diekmann, which both already have n-doped ETLs. See Paper 50, 2–3; Paper 54 8–9. As we explained in our Final Written Decision, because Patent Owner did not contest that Liq acts as an n-dopant in Ma, Petitioner’s combinations were obvious because they merely “substitute one known n-dopant for another to further the same goal of improving ETL conductivity.” Paper 54, 12. That simple-substitution analysis would not be the same when n-doping Clix2’s non-doped ETL. For this reason, we agree with Petitioner that the district-court Clix2-based combination “is a different combination with a materially different motivation-to-combine analysis,” as compared to the Diekmann/Suzuki and Ma combinations that are at issue here. Paper 50, 3.” slip op. at 2
Patent outcomesUS 11,828,425 unpatentable§ 103 obviousnessPatents in suitUS 11,828,425 - Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentablePTAB · 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 unpatentableClaim construction§ 103 obviousnesscites Phillips · KSR · GrahamPatents in suitUS 10,230,009 - Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentablePTAB · 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 · GrahamPatents in suitUS 10,230,009 - Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentablePTAB · 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 unpatentableClaim construction§ 103 obviousnesscites Phillips · KSR · GrahamPatents in suitUS 10,230,009 - Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentablePTAB · 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 unpatentableClaim construction§ 103 obviousnesscites Phillips · KSR · GrahamPatents in suitUS 9,722,104 - Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentablePTAB · 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 unpatentableClaim construction§ 103 obviousnesscites Phillips · KSR · GrahamPatents in suitUS 9,722,104 - Runergy Alabama Inc. / Runergy USA Inc. et al. v. Trina Solar Co., Ltd.All claims unpatentablePTAB · 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 unpatentableClaim construction§ 103 obviousnesscites Phillips · KSR · GrahamPatents in suitUS 9,722,104 - Bio-Rad Laboratories, Inc. v. California Institute Of TechnologyNo claims unpatentablePTAB · Mar 23, 2026 · IPR2024-01451 · APJ Tawen Chang · IPR · Final written decision
Claims 1–19 were not shown unpatentable: Larson did not establish the claimed detection in a single sample volume, and the asserted obviousness combinations did not cure the deficiencies.
RulingsFinal written decision- Skill levelSkill level petitioner adoptedDecided for petitioner
“Patent Owner states that, “[f]or purposes of this IPR proceeding, PO does not contest Petitioner’s description of qualifications for a person of ordinary skill in the art (POSA) set forth [above].” PO Resp. 23. In view of the above, and because Petitioner’s uncontested description of one of ordinary skill in the art is reasonable and consistent with the ’921 patent and the cited art, we adopt Petitioner’s definition of a POSA for purposes of this Decision, except that we replace the phrase “at least a year of experience in quantitative and/or dPCR and fluorescence-based analyte detection” with “around a year of experience in quantitative and/or dPCR and fluorescence-based analyte detection.” Pet. 9 (emphasis added).13” slip op. at 14
- Claim Construction › Intrinsic evidence (Phillips canons) › Plain and ordinary meaning to a POSITATerm construed patent owner constructionDecided for patent owner
“We begin with “the context in which a term is used in the asserted claim,” which can be “highly instructive.” Phillips, 415 F.3d at 1314. In this case, claim 1 recites that the claimed assay is “capable of unambiguously detecting the presence or absence of each of said at least M analytes, in any combination of presence or absence, in a single sample volume, . . . wherein the analytes are amplified in the single sample 15 In this regard, we note that Petitioner’s claim construction position is not predicated on the collection of droplets being reconstituted into its original, pre-partition form prior to amplification; rather, the droplets remain compartmentalized from each other in the PCR thermal cycling tube. Tr. 65:21–66:9 (Petitioner’s counsel explaining that the droplets do not combine in the PCR thermal cycling tube but, rather, are “suspended in an immiscible fluid and analyzed en masse”). indicates that the first instance of single sample volume, i.e., the single sample volume in which the presence or absence of each M analytes are to be detected, is the antecedent basis for the second instance of “single sample volume,” i.e., the single sample volume in which the analytes are amplified. Thus, as the parties appear to agree, the single sample volume in which amplification takes places must be the same single sample volume in which the presence or absence of analytes are to be detected. We are not persuaded that, when accorded its plain and ordinary meaning, a single sample volume divided into a collection of droplets would be considered the “same” single sample volume prior to its partition.” slip op. at 17
- Novelty / Anticipation (§102) › Anticipation standard (single reference, every element)Not shown unpatentableNot shown unpatentable
“With respect to the limitation, “wherein the analytes are amplified in the single sample volume,” Petitioner asserts that “Larson discloses PCR assays that amplify target polynucleotide in a single sample volume, specifically a portion of the reaction mixture that is subsequently partitioned into droplets.” Pet. 31 (emphasis added). There is no dispute that the amplification of the analytes in Larson occurs in the droplets. Larson ¶¶ 6–7 (explaining that “[d]igital PCR (dPCR) is an alternative quantitation method in which dilute sample are divided into many separate reactions” and that “[t]he template is amplified in the droplet for detection”) (emphasis added). Because the claims require that amplification of the analytes be in the same sample volume in which the at least M analytes, in any combination of presence or absence, is unambiguously detected, and because the pre-partition single sample volume is not the same single sample volume as the collection of droplets after partition under our claim construction set forth above, we find Petitioner has not shown, by a preponderance of evidence, that claims 1–10 and 13–19 are anticipated by Larson.17 Tr. 68:12–69:14 (Petitioner’s counsel” slip op. at 27
- Obviousness (§103) › Graham factors (scope of art, differences, level of skill)Not shown unpatentableNot shown unpatentable
“Although we agree with Petitioner that Larson contemplates scenarios in which droplets may contain more than one target molecule and does not require the exclusion of such multiple occupancy droplets in all embodiments, we are nevertheless not persuaded Petitioner has shown, based on a preponderance of evidence, that Larson renders obvious an assay capable of unambiguously detecting, in such multiple occupancy droplets, the presence or absence of each of at least M analytes, in any combination of presence or absence, when M is greater than F and F is at least 2.” slip op. at 32
Patent outcomesUS 11,827,921 not shown unpatentableClaim construction§ 102 anticipation§ 103 obviousnesscites Phillips · KSR · GrahamPatents in suitUS 11,827,921
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.