United States Court of Appeals 

for the Federal Circuit ______________________

POWER INTEGRATIONS, INC.,

Appellant

v.

SEMICONDUCTOR COMPONENTS INDUSTRIES, 

LLC, DBA ON SEMICONDUCTOR,

Appellee

______________________

2018-1607

______________________

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in No. IPR2016-

00809.

______________________

Decided: June 13, 2019

______________________

FRANK SCHERKENBACH, Fish & Richardson, PC, Boston, MA, argued for appellant. Also represented by 

MICHAEL R. HEADLEY, HOWARD G. POLLACK, NEIL WARREN, 

Redwood City, CA; JOHN WINSTON THORNBURGH, San Diego, CA. 

 MICHAEL HAWES, Baker Botts, LLP, Houston, TX, argued for appellee. Also represented by ROGER FULGHUM; 

BRETT J. THOMPSEN, Austin, TX; LAUREN J. DREYER, Washington, DC. 

______________________
POWER INTEGRATIONS, INC. v. SEMICONDUCTOR 

COMPONENTS

2

Before PROST, Chief Judge, REYNA and STOLL,

Circuit Judges.

PROST, Chief Judge.

Semiconductor Components Industries, LLC, doing 

business as ON Semiconductor (“ON”), petitioned for inter 

partes review (“IPR”) of several claims of U.S. Patent No. 

6,212,079 (“the ’079 patent”). The Patent Trial and Appeal 

Board (“Board”) determined that the IPR was not timebarred by 35 U.S.C. § 315(b) and that the challenged claims

were invalid. ON Semiconductor Corp. v. Power Integrations, Inc., No. IPR2016-00809, Paper 67 (P.T.A.B. Sept. 

22, 2017). Power Integrations, Inc. (“Power Integrations”) 

appeals the Board’s decision.

For the reasons explained below, we hold that this IPR

is time-barred under § 315(b). We therefore vacate the 

Board’s final written decision and remand with instructions to dismiss IPR2016-00809. 

I

A

Power Integrations owns the ’079 patent, which relates 

to switched mode power supplies. ’079 patent col. 1 ll. 7, 

11–26. These power supplies function to convert high-voltage alternating current into low-voltage direct current to 

power electronic devices. Id. The ’079 patent discloses a 

“switching regulator” to help conserve power and maintain 

output regulation at low loads without skipping cycles. Id.

col. 1 ln. 65–col. 2 ln. 35. 

B

In 2005 and 2006, Fairchild Semiconductor Corporation and Fairchild (Taiwan) Corporation (collectively, 

“Fairchild”) challenged several claims of the ’079 patent in 

two ex parte reexaminations, which were consolidated. 

J.A. 87. On May 5, 2009, the U.S. Patent and Trademark 
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3

Office (“PTO”) confirmed the validity of the challenged 

claims as amended and 22 new claims. J.A. 86–92. 

Then, on November 4, 2009, Power Integrations sued 

Fairchild for infringement of the ’079 patent and two other

patents. J.A. 1103–12. Fairchild was served with the complaint for infringement on November 6, 2009. In March 

2014, a jury found claims 31, 34, 38, and 42 of the ’079 patent not invalid and infringed. J.A. 1033–35. The jury 

awarded damages of $105 million. J.A. 1035. Following 

our decision in VirnetX, Inc. v. Cisco Systems, Inc., 767 F.3d 

1308 (Fed. Cir. 2014), the district granted Fairchild’s motion for a new trial on damages for infringement of the ’079 

patent. In the second damages trial in December 2015, a 

jury applied the entire market value rule and awarded 

damages of $139.8 million. J.A. 1038–39. 

Fairchild appealed, and we affirmed the jury’s verdict 

of infringement of the ’079 patent. Power Integrations, Inc. 

v. Fairchild Semiconductor Int’l, Inc., 904 F.3d 965, 974 

(Fed. Cir. 2018), cert. denied, 139 S. Ct. 1265 (2019). We 

concluded, however, that the entire market value rule 

could not be used to calculate damages in this case, vacated 

the damages award, and remanded for further proceedings. 

Id. at 977–80. On May 6, 2019, the district court granted 

the parties’ joint motion to release and return Fairchild’s 

posted bond of $146,480,598 and any accrued interest. To 

date, there has been no further action in the district court 

proceeding.

C

On November 18, 2015, ON entered into an agreement 

to merge with Fairchild. J.A. 143–44. But the merger did 

not close immediately. See J.A. 143. Several months later, 

while the merger was still pending, ON filed a petition for 

IPR challenging claims 31, 32, 34, 38, 39, and 42 of the ’079 
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patent.1 J.A. 137–202. This petition for IPR was filed on 

March 29, 2016, more than one year after Fairchild was 

served with the complaint alleging infringement of the ’079 

patent. The Fairchild-ON merger closed several months 

later, on September 19, 2016. J.A. 281–82. The Board instituted the IPR four days after that, on September 23, 

2016. J.A. 103–31. 

Power Integrations argued in both its Patent Owner 

Preliminary Response and its Patent Owner Response that 

this IPR should be time-barred under § 315(b) because ON 

and Fairchild were in privity at the time of filing and 

Fairchild had been served with a complaint for infringement more than one year before the petition was filed. 

J.A. 218–20, 369–72. The Board rejected this argument in 

its institution decision and again in its final written decision. 

In its institution decision, the Board focused its 

§ 315(b) analysis on whether ON and Fairchild were in 

privity when Fairchild filed its petition. Power Integrations argued that the existence of a merger agreement and 

a confidentiality agreement stating that ON and Fairchild 

“share[d] a common legal and commercial interest” and 

“are or may become joint defendants in proceedings” 

showed that they had a common interest in annulling the 

jury’s $139.8 million damages award against Fairchild for 

infringing the ’079 patent. J.A. 218–19. ON had disclosed 

the merger agreement in its IPR petition but noted that the 

merger was not closed at the time it filed the petition and 

that the merger was dependent on several uncertain conditions occurring. J.A. 143. ON also asserted that Fairchild 

 

1 ON also filed two additional petitions for IPR 

against the ’079 patent and nine petitions for IPR against 

five of Power Integrations’ other patents. J.A. 277–78. ON 

filed all of these petitions after its merger with Fairchild 

was announced but before it closed. 
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had no role in the decision to file the IPR petition, had no 

control over the content of the IPR petition, and did not pay 

for the IPR petition. J.A. 143–44. The Board determined 

that there was insufficient evidence of record to establish 

control and therefore insufficient evidence to establish 

privity between Fairchild and ON at the time the petition 

was filed. J.A. 113–14. The Board thus held that the IPR 

was not time-barred by § 315(b) and instituted the IPR.

J.A. 115, 130. 

After institution, Power Integrations requested authorization to file a motion under 37 C.F.R. § 42.51(b)(2) for

additional discovery on the relationship between ON and 

Fairchild. J.A. 289–90. ON objected to providing the additional discovery. J.A. 1903. The Board applied the factors 

enumerated in Garmin International, Inc. v. Cuozzo Speed 

Technologies LLC, No. IPR2012-00001, Paper 26 at 6–7 

(P.T.A.B. Mar. 5, 2013), which govern requests for additional discovery, and denied Power Integrations’ request 

for authorization to file a motion for additional discovery. 

J.A. 290–92. In denying the request, the Board determined 

that “Patent Owner has expressed no more than a suspicion (mere speculation) that such evidence exists and 

would be uncovered by additional discovery” and therefore 

had not met the first Garmin factor. J.A. 292. The Board 

also concluded that even if Power Integrations had established the first Garmin factor, it would not grant the request for additional discovery because the requests were 

overly broad. Id. 

In its Patent Owner Response, Power Integrations 

again argued that ON was in privity with Fairchild (an undisputedly time-barred party) at the time ON filed the petition. J.A. 369–72. The Board rejected this argument for 

the same reasons it had rejected it in its institution decision. J.A. 10–13. It again focused on the issue of control 

and held that there was insufficient evidence of record to 

show that Fairchild exercised, or could have exercised, control over the IPR petition. Id.
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Power Integrations next asserted that ON was acting 

as Fairchild’s proxy in filing the IPR petition. J.A. 369–72.

The Board rejected this argument as well, finding that 

Power Integrations offered mere speculation, not evidence, 

that ON filed the petition as Fairchild’s proxy. J.A. 15–17. 

The Board determined that ON had its own interest in the 

IPR proceeding because it had a multi-billion-dollar merger with Fairchild pending at the time it filed the petition. 

J.A. 17. 

Finally, Power Integrations argued that the IPR was 

time-barred by § 315(b) because Fairchild, a barred party, 

was an admitted real party in interest (“RPI”) before institution. J.A. 364–69. Fairchild became an RPI at least by 

the time its merger with ON closed—four days before institution. J.A. 364–66. Two other panels of the Board had 

previously issued nonprecedential decisions holding that

only privity relationships up until the time an IPR petition 

is filed are relevant for purposes of the § 315(b) time-bar. 

See ARRIS Grp., Inc. v. TQ Delta LLC, No. IPR2016-00430, 

Paper 9 at 6 (P.T.A.B. July 1, 2016); Synopsys, Inc. v. Mentor Graphics Corp., No. IPR2012-00042, Paper 60 at 12 

(P.T.A.B. Feb. 19, 2014). The Board in this case similarly 

held that RPI and privity relationships for purposes of the 

§ 315(b) time-bar are only relevant up to the date the petition is filed. J.A. 14–15; see also J.A. 11–12 (“Panels of the 

Board have interpreted [§] 315(b) (and our associated rule 

37 C.F.R. § 42.101(b)) to mean that ‘it is only privity relationships up until the time a petition is filed that matter.’” 

(quoting Synopsys, No. IPR2012-00042, Paper 60 at 12)).

Because the Board determined that Fairchild was not an 

RPI at the time the petition was filed and rejected Power 

Integrations’ privity and proxy arguments, it concluded 

that the IPR was not time-barred. 

Having found the IPR not time-barred, the Board proceeded to address the merits of the challenged claims and 

found them unpatentable as obvious over the combination 

of Japanese Unexamined Patent Application Publication 
POWER INTEGRATIONS, INC. v. SEMICONDUCTOR 

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No. JP H10-323028 (“Oda”) and Japanese Unexamined Patent Application Publication No. JP S59-144366 (“Nakamura”). 

Power Integrations timely appealed. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(4)(A).

II

On appeal, Power Integrations argues that this IPR 

was time-barred under § 315(b). As our court has previously held, when the PTO institutes an IPR, its rejection of 

a time-bar challenge under § 315(b) is reviewable. Wi-Fi 

One, LLC v. Broadcom Corp., 878 F.3d 1364, 1374 (Fed. 

Cir. 2018) (en banc). Power Integrations argues that privity and RPI relationships arising after filing but before institution should be considered for purposes of the § 315(b) 

time-bar. Under Power Integrations’ interpretation of 

§ 315(b), this IPR would be time-barred because Fairchild, 

a time-barred party, became an RPI after ON filed this petition but before institution. ON contends that privity and 

RPI relationships for purposes of § 315(b) should be assessed only at the time the IPR petition is filed and that 

this IPR is not time-barred.

Making things even more intersting, in a motion filed 

after the principal briefing in this appeal was completed, 

ON contended that Power Integrations is precluded from 

challenging the Board’s § 315(b) determination because it 

did not appeal the Board’s final written decision reaching 

the same § 315(b) determination in another IPR. Power 

Integrations responded that its challenge is not precluded 

because an exception to issue preclusion applies in this 

case. 

We begin by addressing ON’s motion and then turn to 

the merits of the appeal. 
POWER INTEGRATIONS, INC. v. SEMICONDUCTOR 

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A

1

In its motion, ON argues that issue preclusion bars 

Power Integrations’ § 315(b) challenge because in a different IPR proceeding (IPR2016-01594) on a different patent 

(U.S. Patent No. 8,115,457), Power Integrations did not appeal the Board’s final written decision, which reached the 

same § 315(b) determination as the Board decision underlying this appeal. Motion to Preclude Challenge to § 315(b) 

Determination at 2–4 (Oct. 9, 2018), ECF No. 66 (“Motion”).2 We disagree. 

The Supreme Court has long recognized that, under 

certain conditions, a tribunal’s resolution of an issue can 

preclude the party that lost on that issue from later contesting the same issue in another case:

[W]hen an issue of fact or law is actually litigated 

and determined by a valid and final judgment, and 

the determination is essential to the judgment, the 

determination is conclusive in a subsequent action 

between the parties, whether on the same or a different claim. 

B & B Hardware, Inc. v. Hargis Indus., Inc., 135 S. Ct. 

1293, 1303 (2015) (quoting Restatement (Second) of Judgments § 27 (1980)); see also Worlds Inc. v. Bungie, Inc., 903 

F.3d 1237, 1247 (Fed. Cir. 2018); Papst Licensing GmbH & 

 

2 The Board issued its final written decision in the 

IPR underlying this appeal on September 22, 2017, and 

Power Integrations filed a notice of appeal on February 23, 

2018. The Board issued its final written decision in 

IPR2016-01594 on February 14, 2018. Power Integrations 

filed a request for rehearing on March 16, 2018, which the 

Board denied on April 26, 2018. The time to appeal in 

IPR2016-01594 has since expired. 
POWER INTEGRATIONS, INC. v. SEMICONDUCTOR 

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Co. KG v. Samsung Elecs. Am., Inc., No. 2018-1777, 2019 

WL 2219683, at *4 (Fed. Cir. May 23, 2019).3

But this principle is subject to certain well-known exceptions. B & B Hardware, 135 S. Ct. at 1303 (referring to 

exceptions stated in Restatement (Second) of Judgments 

§ 28). As the Supreme Court explained in B & B Hardware, 

the Restatement allows for exceptions to issue preclusion 

even when the basic requirements for issue preclusion are 

satisfied. Id. at 1303, 1309−10. One of those exceptions is 

a lack of opportunity or incentive to litigate the first action. 

According to Restatement (Second) of Judgments 

§ 28(5)(c), issue preclusion does not apply when: 

(5) There is a clear and convincing need for a new 

determination of the issue . . . (c) because the party 

sought to be precluded, as a result of the conduct of 

his adversary or other special circumstances, did 

not have an adequate opportunity or incentive to 

obtain a full and fair adjudication in the initial action.

As the Supreme Court recognized, “[i]ssue preclusion 

may be inapt if ‘the amount in controversy in the first action [was] so small in relation to the amount in controversy 

 

3 Issue-preclusion principles can apply in a second 

action even when the first “action” was before an agency. 

See B & B Hardware, 135 S. Ct. at 1302–03 (“[I]ssue preclusion is not limited to those situations in which the same 

issue is before two courts. Rather, where a single issue is 

before a court and an administrative agency, preclusion 

also often applies.”). In particular, Board decisions in IPR 

proceedings can trigger issue preclusion. MaxLinear, Inc. 

v. CF CRESPE LLC, 880 F.3d 1373, 1376 (Fed. Cir. 2018) 

(“The TTAB, at issue in B & B Hardware, and the Board, 

in this case, are indistinguishable for preclusion purposes.”); Papst, 2019 WL 2219683, at *4.
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in the second that preclusion would be plainly unfair.’” 

B & B Hardware, 135 S. Ct. at 1309 (alteration in original) 

(quoting Restatement (Second) of Judgments § 28 cmt. j). 

As the Court explained: “After all, ‘[f]ew . . . litigants would 

spend $50,000 to defend a $5,000 claim.” Id. (alterations 

in original) (quoting 18 Charles Alan Wright & Arthur R. 

Miller, Federal Practice and Procedure § 4423 (2d ed. 

2002)). 

Our court has also recognized that the lack-of-incentive-to-litigate exception may justify not applying issue 

preclusion, even when the basic requirements are satisfied. 

See Kroeger v. U.S. Postal Serv., 865 F.2d 235, 239–40 (Fed. 

Cir. 1988) (“[C]ollateral estoppel has been deemed unfair 

when the party that would be bound lacked incentive to litigate the issue in the first proceeding because its stake in 

that proceeding was minimal in comparison with its stake 

in the second.”); Soverain Software LLC v. Victoria’s Secret 

Direct Brand Mgmt., LLC, 778 F.3d 1311, 1316 (Fed. Cir. 

2015) (“[T]he issue of incentive to litigate arises where 

‘[t]he stakes in the first action may be so small that extensive effort is not reasonable if the risk is limited to the first 

action.’” (quoting 18 Wright & Miller, supra, § 4423)). 

2

We agree with ON that Power Integrations raises the 

same § 315(b) time-bar argument in this appeal that it did 

in the non-appealed IPR on a different patent, Motion at 5–

7, and actually litigated that issue in the non-appealed 

IPR, id. at 7–8. We also agree with ON that the Board’s 

§ 315(b) determination in the non-appealed IPR was essential to the final decision in that proceeding. Id. at 8–9. We 

conclude that ON has established the basic requirements 

for issue preclusion, and Power Integrations has not substantively disputed that conclusion. See Power Integrations’ Opposition to Motion to Preclude at 6–13 (Oct. 19, 

2018), ECF No. 67 (“Opposition”). 
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We conclude, however, that Power Integrations has established that the lack-of-incentive-to-litigate exception 

applies here and justifies rejecting ON’s issue preclusion 

argument. The disparity in incentives to appeal the 

§ 315(b) issue between the IPR underlying this appeal and 

the non-appealed IPR are significant. See Response at 9–

10. Fairchild, which has since merged with ON, has been 

found to infringe the patent underlying the appealed IPR 

decision but not the patent underlying the non-appealed 

IPR decision.4 Indeed, a first jury awarded $105 million in 

damages and a second jury awarded $139.8 million in damages for infringement of the patent underlying this appeal. 

Moreover, ON and Fairchild entered their merger agreement one month before the second damages trial, and ON 

filed the petition for IPR three months after the second 

damages verdict.5 In contrast, there is no infringement 

finding or damages award associated with the patent underlying the non-appealed IPR decision. 

We are therefore persuaded by Power Integrations’ argument that it had a considerably greater incentive to continue litigating the § 315(b) issue in the IPR underlying 

this appeal than it had in the non-appealed IPR concerning 

a patent unassociated with any infringement finding or 

damages award.6 See Papst, 2019 WL 2219683, at *5

 

4 Fairchild was found not to infringe the ’457 patent 

in a district court action in the District of Delaware. Judgment, Fairchild Semiconductor Corp. v. Power Integrations 

Inc., No. 1:12-cv-00540-LPS (D. Del. Aug. 7, 2015), ECF 

No. 427.

5 We issued a decision vacating the second damages 

verdict on July 3, 2018, almost a year after the final written 

decision in this IPR. See Power Integrations, 904 F.3d 965. 6 We have no occasion to consider the preclusive effect of IPR decisions in circumstances different than presented in this case. 
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(noting that the appellant presented no “legally significant 

disparity in incentives” to satisfy exception to issue preclusion). Accordingly, we conclude that giving preclusive effect to the Board’s § 315(b) determination in the nonappealed IPR is inappropriate in this case. See Kroeger, 

865 F.2d at 239–40; Soverain Software, 778 F.3d at 1316.7 

Because we find the lack-of-incentive-to-litigate exception to issue preclusion applicable in this case, we do not 

reach the additional exceptions that Power Integrations 

contends also apply. See Response at 10–13. We hold that 

issue preclusion does not bar Power Integrations from challenging the Board’s § 315(b) determination. ON’s Motion 

is accordingly denied. 

B

We now turn to the merits of this appeal. The primary 

issue is one of statutory interpretation and one of first impression: whether privity and RPI relationships arising 

 

7 In addition, we note that Power Integrations’ judicial efficiency argument is apt here. See Response at 9–10. 

We decline to apply issue preclusion, especially when a recognized exception is satisfied, in a way that would require 

Power Integrations to have appealed from every adverse 

IPR decision, even where there is little or no incentive, to 

preserve its ability to challenge a legal issue like the 

Board’s interpretation of § 315(b). See, e.g., Ferrell v. 

Pierce, 785 F.2d 1372, 1385 (7th Cir. 1986) (“[T]he government may disagree with a court’s interpretation of a decree 

yet believe that the ruling is too insignificant to warrant 

appeal. If we were to hold that the government is then 

foreclosed from challenging the judicial interpretation in a 

later case . . . the government would be forced to appeal 

every adverse ruling, even the ones it can live with, merely 

to protect itself. We decline to encourage such unnecessary 

litigation.”). 
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after filing but before institution should be considered for 

purposes of the § 315(b) time-bar. 

1

Statutory interpretation is an issue of law that we review de novo. Unwired Planet, LLC v. Google Inc., 841 F.3d 

1376, 1379 (Fed. Cir. 2016). “In statutory construction, we 

begin ‘with the language of the statute.’” Kingdomware 

Techs., Inc. v. United States, 136 S. Ct. 1969, 1976 (2016) 

(quoting Barnhart v. Sigmon Coal Co., 534 U.S. 438, 450 

(2002)). Our “first step ‘is to determine whether the language at issue has a plain and unambiguous meaning with 

regard to the particular dispute in the case.’” Barnhart, 

534 U.S. at 450 (quoting Robinson v. Shell Oil Co., 519 U.S. 

337, 340 (1997)). “It is a ‘fundamental canon of statutory 

construction that the words of a statute must be read in 

their context and with a view to their place in the overall 

statutory scheme.’” FDA v. Brown & Williamson Tobacco 

Corp., 529 U.S. 120, 133 (2000) (quoting Davis v. Mich. 

Dep’t of Treasury, 489 U.S. 803, 809 (1989)). 

2

35 U.S.C. § 315 governs the relationship between IPRs 

and other proceedings. Section 315(b) reads: 

(b) Patent Owner’s Action.—An inter partes review may not be instituted if the petition requesting the proceeding is filed more than 1 year after 

the date on which the petitioner, real party in interest, or privy of the petitioner is served with a 

complaint alleging infringement of the patent. The 

time limitation set forth in the preceding sentence 

shall not apply to a request for joinder under subsection (c). 

ON argues that privity and RPI relationships for purposes of the § 315(b) time-bar should be assessed only at 

filing, while Power Integrations argues that privity and 

RPI relationships arising after filing but before institution 
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should also be considered. While the parties argue for opposing interpretations of when privity and RPI relationships should be assessed, they both contend that the 

statute is clear and unambiguous in favor of their opposing 

interpretations. See Appellant’s Br. 27; Appellee’s Br. 32–

34, 37. 

We agree with Power Integrations that the best reading of § 315(b) requires consideration of privity and RPI relationships arising after filing but before institution.8 

Turning to the statutory language, § 315(b) states that 

an IPR “may not be instituted” if a stated condition is true. 

35 U.S.C. § 315(b) (emphasis added). That condition is “if 

the petition requesting the proceeding is filed more than 1 

year after the date on which the petitioner, real party in 

interest, or privy of the petitioner is served with a complaint alleging infringement of the patent.” Id. The 

Board’s decision under § 315(b) is whether to institute or 

not. The condition precedent for this decision is whether a 

time-barred party (a party that has been served with a 

complaint alleging infringement of the patent more than 

one year before the IPR was filed) is the petitioner, real 

party in interest, or privy of the petitioner. In other words, 

the statute specifically precludes institution, not filing. 

When the Board finds that an IPR is barred under § 315(b), 

it denies institution. It does not reject the petitioner’s filing. The focus of § 315(b) is on institution. The language 

of the statute, in our view, makes privity and RPI relationships that may arise after filing but before institution relevant to the § 315(b) time-bar analysis. 

This reading of the statutory language is consistent 

with our prior cases, which have characterized the § 315(b)

time-bar “[a]s a statutory limit on the Director’s ability to 

 

8 We do not address the impact of a change in RPI, 

privity, or ownership occurring after institution.
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institute IPR.” Wi-Fi One, 878 F.3d at 1374 (emphasis 

added); see also id. at 1373 (“[Section] 315(b) controls the 

Director’s authority to institute IPR . . . .”); id. at 1374 (“It 

sets limits on the Director’s statutory authority to institute . . . .”); Applications in Internet Time, LLC v. RPX 

Corp., 897 F.3d 1336, 1365 (Fed. Cir. 2018) (Reyna, J., concurring) (“Section 315(b) is the gatekeeper to deny institution of petitions from time barred petitioners, their real 

parties in interest, and their privies.”), cert. denied, 139 

S. Ct. 1366 (2019).

Our reading of the statute is also consistent with common law preclusion principles. The statutory terms “real 

party in interest” and “privy” are not defined in Title 35. 

However, they are well-established common law terms.

See Wi-Fi One, LLC v. Broadcom Corp., 887 F.3d 1329, 

1335 (Fed. Cir. 2018), cert. denied, 139 S. Ct. 826 (2019); 

WesternGeco LLC v. ION Geophysical Corp., 889 F.3d 1308, 

1317 (Fed. Cir. 2018), cert. denied, 139 S. Ct. 1216 (2019).

Where Congress “uses a common-law term in a statute, we 

assume the ‘term . . . comes with a common law meaning, 

absent anything pointing another way.’” Microsoft Corp. v. 

i4i Ltd. P’ship, 564 U.S. 91, 101 (2011) (quoting Safeco Ins. 

Co. of Am. v. Burr, 551 U.S. 47, 58 (2007)). Thus, as we 

have previously recognized, “[t]he use of the familiar common law terms ‘privy’ and ‘real party in interest’ indicate 

that Congress intended to adopt common law principles to 

govern the scope of the section 315(b) one-year bar.” Wi-Fi 

One, 887 F.3d at 1335. As we stated in Western-Geco, “[t]he 

legislative history [of the Leahy-Smith America Invents 

Act (“AIA”)] thus lends support to the conclusion that ‘privity’ in § 315(b) should be given its common law meaning.” 

889 F.3d at 1318 (citing 154 Cong. Rec. S9987 (daily ed. 

Sept. 27, 2008) (statement of Sen. Kyl) (“The concept of 

privity, of course, is borrowed from the common law of judgments.”)). We therefore look to common law preclusion 

principles for guidance. 
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“The basic premise of preclusion is that parties to a 

prior action are bound and nonparties are not bound.” 18A 

Wright & Miller, supra, § 4449 (3d ed. 2019). However, the

general rule against nonparty preclusion is subject to several exceptions. Taylor v. Sturgell, 553 U.S. 880, 893 

(2008). Early definitions of privity were narrow. See 18A 

Wright & Miller, supra, § 4449. But over time, the common

law term “privity” became “used more broadly, as a way to 

express the conclusion that nonparty preclusion is appropriate on any ground.” Taylor, 553 U.S. at 894 n.8. The 

legislative history of the AIA recognized that the term 

“privity” has acquired an expanded meaning that is focused 

on the “practical situation.” See 157 Cong. Rec. S1376 

(daily ed. Mar. 8, 2011) (statement of Sen. Kyl) (‘‘[P]rivity 

is an equitable rule that takes into account the ‘practical 

situation,’ and should extend to parties to transactions and 

other activities relating to the property in question.’’). 

Common law preclusion cases suggest that preclusion 

can apply based on privity arising after a complaint is filed. 

“Courts have repeatedly found privity where, after a suit 

begins, a nonparty acquires assets of a defendant-infringer.” Kloster Speedsteel AB v. Crucible Inc., 793 F.2d 

1565, 1583 (Fed. Cir. 1986) (emphasis added), overruled on 

other grounds by Knorr-Bremse Systeme Fuer Nutzfahrzeuge GmbH v. Dana Corp., 383 F.3d 1337 (Fed. Cir. 2004)

(en banc). As we explained in Kloster, the supporting rationale is that:

[i]f a third party may thus come into the acquisition 

of rights involved in pending litigation without being bound by the final judgment, and require a suit 

de novo in order to bind him, he might, pending 

that suit, alienate that right to another with the 

same result, and a final decree bearing fruit could 

never be reached. 

793 F.2d at 1583 (quoting J.R. Clark Co. v. Jones & Laughlin Steel Corp., 288 F.2d 279, 280 (7th Cir. 1961)). Thus, 
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common law principles lend support to our reading of the 

statutory text that privity relationships arising after an

IPR is filed but before institution should be considered in 

the § 315(b) time-bar analysis. 

Our view is further supported by the statute’s purpose, 

as demonstrated by its language. As we explained in Applications in Internet Time, in drafting § 315(b), Congress 

“chose language that bars petitions where proxies or privies would benefit from an instituted IPR, even where the 

petitioning party might separately have its own interest in 

initiating an IPR.” 897 F.3d at 1347 (emphasis added); see 

also id. at 1348 (stating that “the real-party-in-interest inquiry . . . bear[s] in mind who will benefit from having those 

claims canceled or invalidated” (emphasis added)). Against 

this backdrop, we decline to construe § 315(b) in a way that 

would have the Board, when deciding whether to institute, 

ignore the existence of RPIs or privies who would benefit 

from having an IPR instituted simply because they were 

not RPIs or privies when the petition was filed.

3

ON’s arguments for limiting evaluation of privity and 

RPI relationships to only the time of filing are unpersuasive. ON’s primary statutory interpretation argument is 

that the statutory language “tethers the analysis of any potential real party-in-interest and privy issues to the petition’s filing date” because of its focus on when “the petition 

requesting the proceeding is filed.” Appellee Br. 32–33.

But the “is filed” language in § 315(b) does not dictate finally determining RPI or privity relationships at filing. 

Rather, the “is filed” language merely marks the end of the 

one-year window that the petitioner has to file a petition 

for IPR. See Click-To-Call Techs., LP v. Ingenio, Inc., 899 

F.3d 1321, 1330 (Fed. Cir. 2018) (en banc in part) (stating 

that § 315(b) “unambiguously precludes the Director from 

instituting an IPR if the petition seeking institution is filed 

more than one year after the petitioner, real party in 
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interest, or privy of the petitioner ‘is served with a complaint’ alleging patent infringement’” (quoting § 315(b))).

ON argues that Wi-Fi One supports its statutory interpretation because we stated that “[n]othing in § 315(b) sets 

up a two-stage process for addressing the time bar: the 

time-bar determination may be decided fully and finally at 

the institution stage.” 878 F.3d at 1373; Appellee’s Br. 34–

35. We disagree. If anything, this statement bolsters the 

reading of § 315(b) that we set forth here. The “two 

stage[s]” referred to in Wi-Fi One are pre-institution and 

post-institution. In Wi-Fi One, we contrasted § 314(a), 

which concerns the pre-institution “preliminary” determination of whether the petitioner has a “reasonable likelihood” of prevailing on the issue of patentability, with 

§ 315(b), which concerns the time-bar determination. See 

878 F.3d at 1372–73. We concluded that § 314(a), while 

considered preliminarily pre-institution, is considered fully 

and decided finally post-institution and that, in contrast, 

the § 315(b) time-bar can be “decided fully and finally at 

the institution stage.” See id. Our use of “at the institution 

stage” rather than “at filing” in Wi-Fi One is entirely consistent with our holding here that privity and RPI relationships arising after filing but before institution may timebar institution under § 315(b). 

ON also raises several practical concerns with our 

reading of the statute. These practical concerns are unavailing and do not to justify departing from the most natural reading of the statute. See Pereira v. Sessions, 138 S.

Ct. 2105, 2118 (2018). First, ON contends that assessing 

privity and RPI relationships arising after filing but before

institution creates a “moving target” because the Board can 

make its institution decision anytime within three months 

after the Patent Owner Preliminary Response is filed or is 

due. Appellee’s Br. 36–37 (citing 35 U.S.C. § 314(b)). ON 

notes that the Board could possibly reach a different outcome on whether the IPR is time-barred depending on 

when it makes its institution decision relative to events 
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affecting the relationship between the petitioner and other 

entities. ON argues instead that “the filing date is the 

more appropriate date to analyze § 315(b) because it is 

fixed, giving the Board and the parties a known date for 

evaluating the time-bar issue.” See Appellee’s Br. 36–37. 

At the outset, we disagree that the statutorily mandated three-month window for the Board to make an institution decision following the Patent Owner Response is too 

unpredictable for the parties to evaluate and address a

time-bar issue. While the exact date that the Board institutes within the three-month window is beyond the petitioner’s control, the terms and timeline of a possible merger 

are not. We also disagree with ON’s position that it would 

be difficult or burdensome for the Board to assess RPI and 

privity relationships arising after filing but before institution. Notably, the petitioner is required to identify all real 

parties in interest in its petition, 35 U.S.C. § 312(a)(2), and 

is under a continuing obligation to update the Board within 

21 days of any change to the RPI, 37 C.F.R. § 42.8(a)(3), 

(b)(1). This continuing obligation to provide notice would 

seem to make little sense unless it was relevant to the ongoing proceedings. Finally, while federal courts apply a 

“time-of-filing” rule for assessing jurisdiction at the time a 

complaint is filed, we decline to adopt a similar “time-offiling” rule for assessing the time-bar of § 315(b). See 

Grupo Dataflux v. Atlas Glob. Grp., L.P., 541 U.S. 567, 

570–71 (2004). Section 315(b) is not about federal-court jurisdiction; it is about preclusion in an agency proceeding. 

Thus, common law preclusion principles rather than federal-court juridical rules inform our reading of § 315(b).

We have considered the parties’ remaining statutory

interpretation arguments and find them unpersuasive. 

4

ON raises the issue of deference to the PTO’s interpretation of § 315(b). It argues that we should give the PTO’s 

regulation on time-bar determinations, 37 C.F.R. 
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§ 42.101(b), deference under Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984), or

at least give the Board’s interpretation of the regulation 

deference under Auer v. Robbins, 519 U.S. 452 (1997). Appellee’s Br. 38–40. 

The governing PTO regulation states:

A person who is not the owner of a patent may file 

with the Office a petition to institute an inter 

partes review of the patent unless:

. . . .

(b) The petition requesting the proceeding is filed 

more than one year after the date on which the petitioner, the petitioner’s real party-in-interest, or a 

privy of the petitioner is served with a complaint 

alleging infringement of the patent . . . .

37 C.F.R. § 42.101. We do not, however, give Chevron deference to an agency regulation that merely parrots the 

statutory language. See Gonzales v. Oregon, 546 U.S. 243, 

257–58 (2006); Click-To-Call, 899 F.3d at 1338 (“The governing regulation [§ 42.101(b)] largely parrots 

§ 315(b) . . . .”). Nor do we give Auer deference to an 

agency’s interpretation of a parroting regulation. See Gonzales, 546 U.S. at 257 (“An agency does not acquire special 

authority to interpret its own words when, instead of using 

its expertise and experience to formulate a regulation, it 

has elected merely to paraphrase the statutory language.”). 

ON argues further that the Board’s nonprecedential

decisions interpreting § 315(b) are entitled to Chevron deference. Appellee’s Br. 38 (referring to Synopsys, No. 

IPR2012-00042, Paper 60 at 12, and ARRIS, No. IPR2016-

00430, Paper 9 at 6). Based on these facts and the similarity between the regulatory and statutory text, we decline 

to give Chevron deference to these nonprecedential Board 

decisions, which do not even bind other panels of the 
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Board.9 See Click-To-Call, 899 F.3d at 1341 (“[B]ecause the 

regulation merely parrots the statute, deference is not 

owed even to the Director’s interpretation of the regulation, 

much less to a Board panel’s interpretation.”); see also 

United States v. Mead Corp., 533 U.S. 218, 230–31 (2001); 

Aqua Prods., Inc. v. Matal, 872 F.3d 1290, 1320 (Fed. Cir. 

2017) (en banc) (plurality opinion) (“Because Chevron deference displaces judicial discretion to engage in statutory 

interpretation, it requires a relatively formal expression of 

administrative intent, one with the force and effect of 

law.”). 

Because there is no agency interpretation deserving of 

the requested deference, we resort to the traditional principles of statutory construction without deference to the 

PTO and adopt the most natural reading of § 315(b) explained above.

5

In light of the foregoing, we hold that this IPR was 

time-barred by § 315(b) because Fairchild was an RPI at 

the time the IPR was instituted, even though it was not an 

RPI at the time the petition was filed. 

In view of this holding, we need not reach the remaining issues raised in this appeal—including Power Integrations’ arguments pertaining to obviousness, commercial 

success, claim construction, and discovery. Nor do we address Power Integrations’ argument that, even if privity 

and RPI relationships should be determined only at filing 

for purposes of § 315(b), the IPR would still be time-barred 

because ON was acting as Fairchild’s proxy in filing the petition for IPR, or at least was in privity with Fairchild at 

the time the petition was filed. 

 

9 Indeed, this court has not yet opined on whether 

deference is warranted for precedential Board decisions. 
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III

For the foregoing reasons, we vacate the Board’s final 

written decision and remand for the Board to dismiss 

IPR2016-00809. 

VACATED AND REMANDED

COSTS

The parties shall bear their own costs.