referring to expert testimony that 13 technology to perform claimed function “was available at the relevant time and would have 14 been known to a person skilled in the art”
How later courts described this case
- referring to expert testimony that 13 technology to perform claimed function “was available at the relevant time and would have 14 been known to a person skilled in the art”
- “Whether or not the specification adequately sets forth 24 structure corresponding to the claimed function necessitates consideration of that 25 disclosure from the viewpoint of one skilled in the art.”
- “Extrinsic evidence, such as 24 expert testimony, may be useful in claim construction, but it should be considered in the 25 context of the intrinsic evidence.”
- referring to expert testimony that 11 circuitry in controller corresponded to “monitoring means”
Written by the judges who cited it.
The opinion
1
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7
8 UNITED STATES DISTRICT COURT
9 SOUTHERN DISTRICT OF CALIFORNIA
10
11 POWER DENSITY SOLUTIONS, LLC, Case No.: 24-cv-2122-RSH-JLB
12 Plaintiff,
CLAIM CONSTRUCTION ORDER
13 v.
14 GOOGLE LLC,
15 Defendant.
16
17
18 Plaintiff Power Density Solutions, LLC (“Power Density”) alleges defendant
19 Google LLC (“Google”) infringes U.S. Patent No. 6,552,901 (“the ’901 Patent”). The
20 Parties have submitted two disputed terms for construction. The Court held a claim
21 construction hearing on August 14, 2025. Having considered the Parties’ briefing and oral
22 arguments, the Court construes the disputed claims as follows.
23 I. BACKGROUND
24 A. Generally
25 Plaintiff is a California limited liability company. ECF No. 1 (“Compl.”) ¶ 2.
26 Plaintiff owns, by assignment, the ’901 Patent. Id. On November 12, 2024, Plaintiff
27 brought the instant action against defendant Google, alleging the cooling system used in
28
1 version 3 of Google’s Tensor Processing Units infringes independent Claims 1 and 16, and
2 dependent Claims 17-19, of the ’901 Patent. Id. ¶¶ 8, 10; ECF Nos. 1-3; 34 at 11.
3 On May 19, 2025, in accordance with the Patent Local Rules, the Parties filed their
4 Joint Claim Construction Hearing Statement, Chart, and Worksheet. ECF No. 27. On June
5 30, 2025, the Parties filed their Opening Claim Construction Briefs. ECF Nos. 34, 35. On
6 July 18, 2025, the Parties field their Responsive Claim Construction Briefs. ECF Nos. 36,
7 37.
8 B. The Asserted Patent
9 The ’901 Patent is entitled: “Apparatus and System for Cooling Electronic Circuitry,
10 Heat Sinks, and Related Components.” The patent “relates generally to the cooling of
11 electronic circuitry, integrated circuit boards, heat sinks, and power electronic components
12 to increase their power density.” ’901 Patent, col. 1:15–17.
13 As background, the ’901 Patent explains that the performance of most electronic
14 devices is constrained by thermal limitations. Id. at col. 1:15–25. These limitations “have
15 a direct effect on efficiency, power density, packaging and the architectural configuration
16 for these components in their operating environment.” Id. at col. 1:23–25. Prior art methods
17 of cooling components on an integrated circuit board have included: (1) “traditional spray-
18 cooling designs,” whereby a coolant is directed towards these components; (2) placing a
19 “cooling body” in contact with the electronic device; and (3) filling a “liquid cooled circuit
20 package” during operation. Id. at cols. 2:4–31; 3:4–18. According to the ’901 Patent, these
21 prior art systems exhibited certain inefficiencies. For example, in a traditional spray-
22 cooling system, inefficiencies result from evaporated vapors having to escape in the
23 direction of the coolant vapors being sprayed. Id. at col. 3:8–11.
24 The invention of the ’901 Patent purports to teach a more effective system and
25 method of removing latent heat from electronic components. Id. at col. 1:45–49. To do so,
26 the ’901 Patent describes a system and method for supplying a cooling fluid capable of
27 phase change to “passageways within an integrated circuit board and/or its components
28 and/or heat sinks.” Id. at col. 2:61–63; see also Abstract. The cooling fluid “passes through
1 the passageways and exits through ports or nozzles on the surface of the integrated circuit
2 board, components or heat sink.” Id. at col. 2:63–65. The components of the circuit board
3 may therefore be cooled “by both conductive cooling as the fluid passes through the core
4 of the component, circuit board, or heat sink and by evaporative cooling as the liquid
5 changes phase at or near the surface of the component circuit board, or heat sink.” Id. at
6 cols. 2:66–3:3; see also id. at Abstract.
7 II. LEGAL STANDARD
8 A. Claim Construction Generally
9 “It is a ‘bedrock principle’ of patent law that ‘the claims of a patent define the
10 invention to which the patentee is entitled the right to exclude.’” Phillips v. AWH Corp.,
11 415 F.3d 1303, 1312 (Fed. Cir. 2005) (quoting Innova/Pure Water, Inc. v. Safari Water
12 Filtration Sys., 381 F.3d 1111, 1115 (Fed. Cir. 2004)).
13 A determination of infringement therefore “involves a two-step analysis. ‘First, the
14 claim must be properly construed to determine its scope and meaning. Second, the claim
15 as properly construed must be compared to the accused device or process.’” Omega Eng’g,
16 Inc. v. Raytek Corp., 334 F.3d 1314, 1320 (Fed. Cir. 2003) (quoting Carroll Touch, Inc. v.
17 Electro Mech. Sys., Inc., 15 F.3d 1573, 1576 (Fed. Cir. 1993)).
18 The first step, commonly known as claim construction, is presently before the Court.
19 The Court construes patent claims ultimately as a matter of law, although “subsidiary
20 factfinding is sometimes necessary.” Teva Pharm. USA, Inc. v. Sandoz, Inc., 574 U.S. 318,
21 326 (2015); Markman v. Westview Instruments, Inc., 517 U.S. 370, 388 (1996) (“[J]udges,
22 not juries, are the better suited to find the acquired meaning of patent terms.”). “Ultimately,
23 the interpretation to be given a term can only be determined and confirmed with a full
24 understanding of what the inventors actually invented and intended to envelop with the
25 claim.” Phillips, 415 F.3d at 1316 (quoting Renishaw PLC v. Marposs Societa' Per Azioni,
26 158 F.3d 1243, 1250 (Fed. Cir. 1998)). Accordingly, a claim should be construed in a
27 manner that “stays true to the claim language and most naturally aligns with the patent’s
28 description of the invention[.]” Id.
1 “In determining the proper construction of a claim, the court has numerous sources
2 that it may properly utilize for guidance.” Vitronics Corp. v. Conceptronic, 90 F.3d 1576,
3 1582 (Fed. Cir. 1996). These sources “include both intrinsic evidence (e.g., the patent
4 specification and file history) and extrinsic evidence (e.g., expert testimony).” Id. It is well-
5 settled that in construing an asserted claim, a court “look[s] first to the intrinsic evidence
6 of record, i.e., the patent itself, including the claims, the specification and, if in evidence,
7 the prosecution history.” Id. (citation omitted); see also Vederi, LLC v. Google, Inc., 744
8 F.3d 1376, 1382 (Fed. Cir. 2014) (“In construing claims, this court relies primarily on the
9 claim language, the specification, and the prosecution history.”).
10 The claim construction inquiry “begins and ends in all cases with the actual words
11 of the claim.” Scanner Techs. Corp. v. ICOS Vision Sys. Corp. N.V., 365 F.3d 1299, 1303
12 (Fed. Cir. 2004) (internal quotations omitted); see also Vitronics, 90 F.3d at 1582 (“[W]e
13 look to the words of the claims themselves, both asserted and nonasserted, to define the
14 scope of the patented invention.”). The words of a claim should generally be “given their
15 ordinary and customary meaning.” Vitronics, 90 F.3d at 1582. “[T]he ordinary and
16 customary meaning of a claim term is the meaning that the term would have to a person of
17 ordinary skill in the art [“POSITA”] in question at the time of the invention, i.e., as of the
18 effective filing date of the patent application.” Phillips, 415 F.3d at 1313. “In some cases,
19 the ordinary meaning of claim language as understood by a person of skill in the art may
20 be readily apparent even to lay judges, and claim construction in such cases involves little
21 more than the application of the widely accepted meaning of commonly understood
22 words.” Id. at 1314. “However, in many cases, the meaning of a claim term as understood
23 by persons of skill in the art is not readily apparent.” O2 Micro Int’l Ltd. v. Beyond
24 Innovation Tech. Co., 521 F.3d 1351, 1360 (Fed. Cir. 2008).
25 “[S]econd, it is always necessary to review the specification to determine whether
26 the inventor has used any terms in a manner inconsistent with their ordinary meaning.”
27 Vitronics, 90 F.3d at 1582. “The specification acts as a dictionary when it expressly defines
28 terms used in the claims or when it defines them by implication.” Id. “Usually, [the
1 specification] is dispositive; it is the single best guide to the meaning of a disputed
2 term.” Id.
3 “Third, the court may also consider the prosecution history of the patent, if in
4 evidence.” Id. The prosecution history consists of the “complete record of all proceedings
5 before the Patent and Trademark Office, including any express representations made by
6 the applicant regarding the scope of the claims.” Id. “[B]ecause the prosecution history
7 represents an ongoing negotiation between the PTO and the applicant, rather than the final
8 product of that negotiation, it often lacks the clarity of the specification and thus is less
9 useful for claim construction purposes.” Phillips, 415 F.3d at 1317. “Nonetheless, the
10 prosecution history can often inform the meaning of the claim language by demonstrating
11 how the inventor understood the invention and whether the inventor limited the invention
12 in the course of prosecution, making the claim scope narrower than it would otherwise be.”
13 Id.
14 “In most situations, an analysis of the intrinsic evidence alone will resolve any
15 ambiguity in a disputed claim term.” Vitronics, 90 F.3d at 1583. A court is also authorized,
16 however, to consider extrinsic evidence in construing claims, such as “expert and inventor
17 testimony, dictionaries, and learned treatises.” Markman v. Westview Instruments, Inc., 52
18 F.3d 967, 980 (Fed. Cir. 1995) (en banc), aff'd, 517 U.S. 370. Although a court may
19 consider evidence extrinsic to the patent and prosecution history, such evidence is
20 considered “less significant than the intrinsic record” and “less reliable than the patent and
21 its prosecution history in determining how to read claim terms[.]” Phillips, 415 F.3d at
22 1317–18 (internal quotation marks and citations omitted); see also Biagro W. Sales, Inc. v.
23 Grow More, Inc., 423 F.3d 1296, 1302 (Fed. Cir. 2005) (“Extrinsic evidence, such as
24 expert testimony, may be useful in claim construction, but it should be considered in the
25 context of the intrinsic evidence.”).
26 Extrinsic evidence may not be “used to contradict claim meaning that is
27 unambiguous in light of the intrinsic evidence.” Phillips, 415 F.3d at 1324. In cases where
28 it is necessary for a court to consult extrinsic evidence “in order to understand, for example,
1 the background science or the meaning of a term in the relevant art during the relevant time
2 period,” and such subsidiary facts “are in dispute, courts will need to make subsidiary
3 factual findings about that extrinsic evidence.” Teva, 574 U.S. at 331–32.
4 B. Means-Plus-Function Claims, 35 U.S.C. § 112, ¶ 6
5 Under 35 U.S.C. § 112, ¶ 6:
6 An element in a claim for a combination may be expressed as a means
7 or step for performing a specified function without the recital of
structure, material, or acts in support thereof, and such claim shall be
8 construed to cover the corresponding structure, material, or acts
9 described in the specification and equivalents thereof.
10 35 U.S.C. § 112, ¶ 6 (pre-AIA).1
11 “Section 112 ¶ 6 offers patent applicants two options: (1) recite, in the claim, a
12 function without reciting structure for performing the function and limit the claims to the
13 structure, materials, or acts disclosed in the specification (or their equivalents), in which
14 case § 112 ¶ 6 applies, or (2) recite both a function and the structure for performing that
15 function in the claim, in which case § 112 ¶ 6 is inapplicable.” Dyfan, LLC v. Target Corp.,
16 28 F.4th 1360, 1365 (Fed. Cir. 2022). “Limitations that invoke § 112 ¶ 6 are generally
17 known as ‘means-plus-function’ [claims].” Id. The statutory provision “represents a quid
18 pro quo by permitting inventors to use a generic means expression for a claim
19 limitation provided that the specification indicates what structure(s) constitute(s) the
20 means.” Atmel Corp. v. Info. Storage Devices, 198 F.3d 1374, 1381 (Fed. Cir. 1999).
21 C. Indefiniteness
22 A patent must “conclude with one or more claims particularly pointing out and
23 distinctly claiming the subject matter which the applicant regards as [the] invention.” 35
24
25
26
1 35 U.S.C. § 112 was amended by the America Invents Act (“AIA”), which took
27 effect on September 16, 2012. Kyocera Senco Indus. Tools Inc. v. Int’l Trade Comm’n, 22
F.4th 1369, 1379 n.8 (Fed. Cir. 2022). As the application resulting in the ’901 Patent was
28
1 U.S.C. § 112, ¶ 2 (pre-AIA). A claim fails to satisfy this statutory requirement and is thus
2 invalid for indefiniteness if its language, when read in light of the specification and the
3 prosecution history, “fail[s] to inform, with reasonable certainty, those skilled in the art
4 about the scope of the invention.” Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898,
5 901 (2014). Indefiniteness is a “question of law that may contain underlying facts.”
6 Berkheimer v. HP Inc., 890 F.3d 1369, 1370 (Fed. Cir. 2018). “[A] party challenging patent
7 validity on indefiniteness grounds carries the burden of proof.” Bosch Auto. Serv. Sols.,
8 LLC v. Matal, 878 F.3d 1027, 1040 (Fed. Cir. 2017).
9 “Indefiniteness must be proven by clear and convincing evidence.” Sonix Tech. Co.
10 v. Publ’ns Int’l, Ltd., 844 F.3d 1370, 1377 (Fed. Cir. 2017). “[A] claim is
11 not indefinite merely because it poses a difficult issue of claim construction; if the claim is
12 subject to construction, i.e., it is not insolubly ambiguous, it is not invalid
13 for indefiniteness.” Bancorp Servs., L.L.C. v. Hartford Life Ins. Co., 359 F.3d 1367, 1372
14 (Fed. Cir. 2004). “That is, if the meaning of the claim is discernible, even though the task
15 may be formidable and the conclusion may be one over which reasonable persons will
16 disagree, we have held the claim sufficiently clear to avoid invalidity on indefiniteness
17 grounds.” Id. (internal quotation marks omitted).
18 III. ANALYSIS
19 A. Agreed Upon Constructions
20 The Parties have agreed upon the following constructions:
21
Limitation Agreed Construction
22 “means for supplying cooling fluid Construed as a means-plus-function term
23 capable of phase change to said under 35 U.S.C. § 112, ¶ 6
interior passageway” (Claims 1 Function: supplying cooling fluid capable of
24 and 16) phase change to said interior passageway
25
Structure: pump in combination with a
26 manifold or supply line
27
28
1 Alternate Structure: the evaporator side of a
heat pipe and a reservoir of cooling fluid
2
having a heat differential between them
3
“means for collecting and Construed as a means-plus-function term
4 recycling said cooling fluid” under 35 U.S.C. § 112, ¶ 6
5 (Claims 1 and 16”) Function: collecting and recycling said
cooling fluid
6
Structure: environmental housing with a
7 manifold, a radiator, an intercooler, a
8 compressor, a filter, a pump, and/or a
regulator
9
“standard size slot in a standard Plain and ordinary meaning
10
case for containing electronic
11 components” (Claim 18)
12 “exterior surface of said heat sink” Plain and ordinary meaning
(Claims 1 and 16)
13
14
The Court adopts the Parties’ agreed upon constructions for these terms. See
15
MyMail, Ltd. v. Am. Online, Inc., 476 F.3d 1372, 1378 (Fed. Cir. 2007).
16
B. Disputed Constructions
17
1. “means for adjusting the rate at which said cooling fluid passes
18
through said interior passageway […] so that substantially no cooling
19 fluid is vaporized within said interior passageway” (Claims 1 and 16)
20
The term “means for adjusting the rate at which said cooling fluid passes through
21
said interior passageway so that substantially no cooling fluid is vaporized within said
22
interior passageway” appears in Claims 1 and 16 of the ’901 Patent.
23
Claim 1 of the ’901 Patent recites:
24
1. A method for cooling a heat sink comprising:
25
providing a heat sink with at least one interior passageway within said
26 heat sink and at least one secondary passageway in fluid
communication with said at least one interior passageway connecting
27
said interior passageway to an exterior surface of said heat sink;
28
1 providing means for supplying cooling fluid capable of phase change
to said interior passageway;
2
3 providing means for adjusting the rate at which said cooling fluid
passes through said interior passageway;
4
5 adjusting the rate at which said cooling fluid passes through said
interior passageway so that substantially no cooling fluid is vaporized
6
within said interior passageway; and
7
providing means for collecting and recycling said cooling fluid.
8
9 ’901 Patent, Claim 1 (emphasis added).
10 Claim 16 of the ’901 Patent recites:
11 1. A system for cooling an electronic component comprising:
12
at least one electronic component;
13
a heat sink attached to said at least one electronic component;
14
15 said heat sink having at least one interior passageway within said heat
sink and at least one secondary passageway in fluid communication
16
with said at least one interior passageway connecting said interior
17 passageway to an exterior surface of said heat sink;
18
means for supplying cooling fluid capable of phase change to said
19 interior passageway;
20
means for adjusting the rate at which said cooling fluid passes through
21 said interior passageway so that substantially no cooling fluid is
vaporized within said interior passageway; and
22
23 means for collecting and recycling said cooling fluid.
24 Id., Claim 16 (emphasis added).
25 The Parties agree the “means for adjusting the rate at which said cooling fluid passes
26 through said interior passageway so that substantially no cooling fluid is vaporized within
27 said interior passageway” is a means-plus-function term under 35 U.S.C. § 112, ¶ 6 (pre-
28 AIA). ECF No. 27-1 at 2. The Parties also agree the term’s function is “adjusting the rate
1 at which said cooling fluid passes through said interior passageway [so that substantially
2 no cooling fluid is vaporized within said interior passageway].” Id. The Parties dispute,
3 however, whether the ’901 Patent discloses an adequate structure that is clearly linked to
4 this function.
5 a. Clearly Linked
6 Google first contends the “means for adjusting” term is indefinite because the ’901
7 Patent specification fails to clearly link any structure to the recited function of “adjusting
8 the rate at which said cooling fluid passes through said interior passageway so that
9 substantially no cooling fluid is vaporized within said interior passageway.” ECF No. 35
10 at 8. Plaintiff responds that the patent specification clearly links the “manifold(s), pump(s),
11 tube sizing and the evaporator side of a heat pipe and a reservoir of cooling fluid having a
12 heat differential between them” as the corresponding structure for this term. ECF Nos. 34
13 at 17–20; 36 at 3–8.
14 “A structure disclosed in the specification is corresponding structure only if the
15 specification or prosecution history clearly links or associates that structure to the function
16 recited in the claim.” Chi. Bd. Options Exch., Inc. v. Int’l Sec. Exch., LLC, 677 F.3d 1361,
17 1367 (Fed. Cir. 2012) (internal quotation marks omitted). “While the specification must
18 contain structure linked to claimed means, this is not a high bar[.]” Biomedino, LLC v.
19 Waters Techs. Corp., 490 F.3d 946, 950 (Fed. Cir. 2007). For a patent to satisfy this
20 standard, a POSITA must be able “to recognize the structure in the specification and
21 associate it with the corresponding function in the claim[.]” Williamson v. Citrix Online,
22 LLC, 792 F.3d 1339, 1352 (Fed. Cir. 2015); Budde v. Harley-Davidson, Inc., 250 F.3d
23 1369, 1376 (Fed. Cir. 2001) (“Whether or not the specification adequately sets forth
24 structure corresponding to the claimed function necessitates consideration of that
25 disclosure from the viewpoint of one skilled in the art.”). As such, “a challenge to a claim
26 containing a means-plus-function limitation as lacking structural support requires a
27 finding, by clear and convincing evidence, that the specification lacks disclosure of
28
1 structure sufficient to be understood by one skilled in the art as being adequate to perform
2 the recited function.” Budde, 250 F.3d at 1376–77.
3 The Court “first examine[s] the specification for a clear link or association.”
4 Medtronic, Inc. v. Advanced Cardiovascular Sys., 248 F.3d 1303, 1312 (Fed. Cir. 2001).
5 Here, the ’901 Patent specification does not explicitly recite the phrase “adjusting the rate
6 at which said cooling fluid passes through said interior passageway.”
7 The ’901 Patent does, however, disclose supplying cooling fluid under pressure to a
8 manifold that is “adapted to supply cooling fluid.” See ’901 Patent, cols. 3:55–57 (“[S]uch
9 components may be individually mounted to a manifold adapted to supply cooling fluid to
10 the components.”); 3:62–63 (“Cooling fluid may be supplied to the heat sink by way of a
11 manifold[.]”); 5:53–54 (“Cooling fluid is provided under pressure to manifold 14.”); 6:65–
12 66 (“Cooling fluid is provided under pressure to manifold 100 by supply line 102.”); 8:47–
13 48 (“Cooling fluid is supplied under pressure to chamber 200 by supply line 206.”); 9:11-
14 13 (“Cooling fluid may be supplied under pressure to the interior of heat
15 sink 254 via supply line 256.”).
16 Two methods for pressurizing cooling fluid are described in the specification. The
17 first uses a pump. Id. at cols. 5:54–55 (“The fluid may be pressurized by a pump or other
18 conventional means.”); 6:66–67 (“The fluid may be pressurized by a pump or other
19 conventional means.”); 8:48–49 (“The fluid may be pressurized by a pump, temperature
20 differentiation, or other conventional means.”). The second is through the temperature
21 difference between the evaporator side of a heat pipe and a reservoir of cooling liquid. See
22 id. at cols. 5:57–62 (“[T]he cooling fluid is pressurized by the heat differential between the
23 evaporator side of the heat pipe (i.e. the manifold 14, heat sink 12 and circuit board 10)
24 and the reservoir of cooling fluid (not shown) that supplies the cooling fluid
25 to manifold 14.”); 7:2–5 (“[T]he cooling fluid is pressurized by the heat differential
26 between the evaporator side of the heat pipe (i.e. the manifold 100) and the reservoir of
27 cooling fluid (not shown) that supplies the cooling fluid to manifold 100.”); 8:52–57
28 (“[T]he cooling fluid is pressurized by the heat differential between the evaporator side of
1 the heat pipe (i.e. chamber 200, circuit board or die 202, coils 206, and heat sink 204) and
2 the condenser or reservoir of cooling fluid (not shown) that supplies the cooling fluid
3 to chamber 200.”).
4 The ’901 Patent specification therefore identifies: (1) a pump; and (2) a heat pipe
5 and reservoir of cooling liquid as devices capable of pressurizing cooling liquid. Plaintiff
6 contends that a POSITA would have understood that the same structures that pressurize
7 cooling fluid would also “adjust[] the rate at which said cooling fluid passes through said
8 interior passageway so that substantially no cooling fluid is vaporized within said interior
9 passageway.” ECF Nos. 34 at 19 (“[A] POSITA will clearly understand that the flow rate
10 is changed by pressurization and the pump serves this purpose and is a structure to prevent
11 vaporization in the fluid system.”); 36 at 4 (“[A] POSITA would understand that the
12 pressure of the cooling liquid dictates its rate of flow within a given system.”). In support,
13 Plaintiff cites the opinions of its expert, Dr. Banerjee. ECF No. 34 at 19. Google responds
14 Dr. Banerjee’s testimony is not, by itself, sufficient to clearly link these structures to the
15 function of “adjusting the rate at which said cooling fluid passes through said interior
16 passageway so that substantially no cooling fluid is vaporized within said interior
17 passageway.” ECF No. 35 at 9.2
18 In the context of a means-plus-function claim under 35 U.S.C. § 112, ¶ 6, it is well-
19 established that “[t]here must be structure in the specification.” Atmel Corp. v. Info. Storage
20 Devices, 198 F.3d 1374, 1382 (Fed. Cir. 1999). Nevertheless, “[t]his conclusion is not
21 inconsistent with the fact that the knowledge of one skilled in the particular art may be used
22 to understand what structure(s) the specification discloses, or that even a dictionary or other
23
24
25
2 The Parties also contested at the claim construction hearing as to whether Dr.
26
Banerjee applied the correct legal standard in forming his opinions on indefiniteness.
27 Reading Dr. Banerjee’s declaration and deposition testimony as a whole, the Court finds
Dr. Banerjee’s opinions support that a POSITA would understand there to be structures
28
1 documentary source may be resorted to for such assistance, because such resources may
2 only be employed in relation to structure that is disclosed in the specification.” Id.
3 Here, Dr. Banerjee testified that a POSITA would have understood that: (1) a pump
4 or a heat pipe can be used to adjust the pressure of cooling liquid being fed into an interior
5 passageway; and (2) changing the pressure of a liquid changes its flow rate:
6
A. So somebody who’s skilled in the art knows that a pump can change
7 the pressure of the inlet of a system and if the inlet pressure changes,
the flow rate also changes. That’s known to anybody skilled in the art.
8
9 ECF No. 34-5 at 65:3–7.
10 Q. Is that—is a heat pipe a way to pressurize the coolant in the system?
11
A. It is if you.
12
13 Q. How does that work?
14
A. If you take a heat—a heat pipe, you know, textbook, for example
15 there are lots of textbooks on heat pipes, when you vaporize the fluid
on one end of the heat pipe, that end is at a slightly marginally higher
16
pressure than the end of the heat pipe where the vapor is condensing
17 and so because of that pressure differential created by the temperature
differential the vapor flows from the hot end of the heat pipe to the cold
18
end of the heat pipe and so that’s a—a structure for achieving
19 pressurization in the system and creating a pressure differential that
causes the fluid to flow.
20
21 Id. at 73:16–74:7; see id. at 64:8–16; 65:12–16; 65:23–25; 70:1–6; 70:24–71:9; 74:8–
22 74:20; see also Banerjee Decl. at ¶ 22 (“The structures that support the regulation and
23 adjustment of the flow can be . . . pressurization by a manifold and/or pump . . . and
24 temperature differential . . . created by the evaporator side of a heat pipe and a reservoir of
25 cooling fluid having a heat differential between them.”).
26 In addition to Dr. Banerjee’s opinions, Plaintiff also cites patents issued prior to the
27 ’901 Patent that discuss the availability of pumps in the marketplace and describe how the
28 flow rate of a pump is related to liquid pressure. See ECF No. 34 at 20; U.S. Patent No.
1 5,719,444 at col. 6:59–61 (“The cooling condenser 33 and pump 35 of the cooling system
2 are of conventional design and available in the present day marketplace[.]”) (emphasis
3 added); U.S. Patent No. 5,983,997 at 8:3–5 (“This graph demonstrates that the flow rate of
4 the pump is typically inversely proportional to the pressure.”) (emphasis added). Finally,
5 Google’s own expert, Dr. King testified that a pump is a device “that provides a given flow
6 rate at a given pressure differential.” ECF No. 34-4 at 24:9–11.
7 Taken together, the record suggests that a POSITA would have understood that: (1)
8 a pump or a heat pipe can be used to change the pressure of a cooling fluid; and (2) that
9 variations in pressure would affect the cooling liquid’s flow rate. See Telcordia Techs., Inc.
10 v. Cisco Sys., 612 F.3d 1365, 1377 (Fed. Cir. 2010) (referring to expert testimony that
11 circuitry in controller corresponded to “monitoring means”); Tech. Licensing Corp. v.
12 Videotek, Inc., 545 F.3d 1316, 1339 (Fed. Cir. 2008) (referring to expert testimony that
13 technology to perform claimed function “was available at the relevant time and would have
14 been known to a person skilled in the art”).3
15 Google argues a pump is not “clearly linked” as a corresponding structure to the
16 “means for adjusting” term because the ’901 Patent does not set forth, in detail, how a
17 POSITA would use a pump to adjust flow rate. This argument is not persuasive. “The law
18 is clear that patent documents need not include subject matter that is known in the field of
19 the invention and is in the prior art, for patents are written for persons experienced in the
20 field of the invention.” S3 Inc. v. nVidia Corp., 259 F.3d 1364, 1371 (Fed. Cir. 2001).
21 Instead, under Federal Circuit precedent, “knowledge of one skilled in the art can be called
22 upon to flesh out a particular structural reference in the specification for the purpose of
23 satisfying the statutory requirement of definiteness.” Creo Prods. v. Presstek, Inc., 305
24 F.3d 1337, 1347 (Fed. Cir. 2002) (collecting cases). Here, Plaintiff submitted evidence a
25
26
27 3 At the hearing, Plaintiff’s counsel represented that Plaintiff was not relying on a
“manifold” or “tube sizing” as structures independent of a pump or heat pipe for the “means
28
1 POSITA would understand how to modify the operational parameters of a pump to set
2 different flow rates. Banerjee Decl. ¶ 23; ECF No. 34-5 at 115:4–24. Notably, Google does
3 not submit clear and convincing evidence that a POSITA would not have understood how
4 to do so.4
5 Google’s argument the Federal Circuit’s decision in Medtronic is “particularly on
6 point” is also unpersuasive. ECF No. 35 at 10. In Medtronic, plaintiff alleged infringement
7 of a patent directed to intravascular coronary stents. 248 F.3d at 1305. The independent
8 claims of the patent recited a stent with “means for connecting adjacent elements together.”
9 Id. at 1308. It was undisputed one corresponding structure of the recited function of
10 “connecting adjacent elements together” was the helical windings of a continuous wire. Id.
11 at 1310. The question before the Court of Appeals was whether additional structures—a
12 straight wire, wire hooks, and suture ties—were also clearly linked to the recited function.
13 Id. at 1311. The Court of Appeals held that while these additional structures were “capable
14 of performing the function recited in the means-plus-function limitation,” there was “no
15 clear link or association between the disclosed structures and the function recited in the
16 means-plus-function claim limitation” as: (1) the patent specification described the stent
17 only as a helically wound continuous-wire stent; and (2) the specification made clear the
18 function of the straight wire, wire hooks, and suture ties was to perform a different
19 function—“to prevent overstretch” and not “to connect adjacent elements of the helix
20 together.” Id. at 1312–13.
21 Here, Google has not sufficiently explained how the instant case is analogous to
22 Medtronic, where “the patent specification disclosed multiple structures potentially
23 capable of performing the recited function, but the specification expressly discussed and
24
25
4 Google advances a similar argument that the ’901 Patent does not explain in detail
26
how a heat pipe would be utilized to adjust flow rate. ECF No. 35 at 14. At the hearing,
27 however, Google acknowledged that the patent discloses using a heat pipe to pressurize
cooling liquid. And as noted above, Dr. Banerjee opined how pressurizing cooling liquid
28
1 thus clearly linked only a subset of those structures to the recited function.” Freeman v.
2 Gerber Prods. Co., 120 F. App’x 322, 326 (Fed. Cir. 2005). Google does not, for example,
3 argue that some smaller subset of structures disclosed in the specification performs the
4 recited “adjusting” function. In light of these differences, the Court is unpersuaded that
5 Medtronic supports Google’s indefiniteness argument.5
6 b. Capable of Performing the Function
7 Google next contends that a pump cannot be the corresponding structure clearly
8 linked to the “means for adjusting” limitation, because a POSITA would have recognized
9 that a pump, by itself, cannot “adjust the rate at which cooling fluid passes through an
10 interior passageway so that substantially no cooling fluid is vaporized within said interior
11 passageway.” ECF No. 35 at 11–13.
12 In support, Google cites Dr. King’s declaration, who opines that to “adjust the rate
13 at which cooling fluid passes through an interior passageway” such that substantially no
14 cooling fluid is vaporized within said interior passageway, the linked structure must include
15 not only a pump, but also a feedback system with a sensor that monitors the amount of
16 vaporization in the interior passageways. King Decl. ¶ 20 (“Put another way, a pump could
17 not, alone, perform the features of the claimed function. At minimum, the structure would
18 also need a sensor to measure the amount of vaporization in the interior passageways, as
19 well as some type of feedback mechanism to transmit the sensor output back to the pump”).
20 ///
21 ///
22 ///
23 ///
24
25
5 Google’s reliance on the Federal Circuit’s Biomedino decision is also unpersuasive.
26
In Biomedino, the Federal Circuit found that a black-box figure in a patent specification
27 labeled “Control,” accompanied by a bare statement of known techniques, was insufficient
to clearly link a structure to a recited function. 490 F.3d at 950–52. The instant case does
28
1 Plaintiff responds that Google’s argument erroneously assumes that the ’901 Patent
2 discloses a system where the cooling liquid’s flow rate is constantly being adjusted during
3 operation:
4 Google argues that the ’901 Patent fails to disclose a feedback system
and sensors to measure vaporization and tailor the flow rate
5
accordingly. This [erroneously] assumes that constant adjustment is
6 required. Dr. Banerjee explained that the operational parameters of a
pump can be adjusted to a desired flow rate to avoid evaporation. In
7
other words, a POSITA is capable of evaluating the conditions of their
8 system—the size of the flow conduits, the cooling liquid used, the
highest possible temperature of electronic components, etc.—and
9
adjusting the pump parameters to set an appropriate flow rate to meet
10 the goal of avoiding vaporization within the internal passageway. If
conditions within the system change, the pump can be adjusted further.
11
12 ECF No. 36 at 7 (emphasis added) (internal citations omitted).
13 The Court agrees with Plaintiff. This is not what the Parties’ agreed-upon
14 construction for the recited function requires. See GE Lighting Sols., LLC v. AgiLight, Inc.,
15 750 F.3d 1304, 1317 (Fed. Cir. 2014) (rejecting attempt to import an “extraneous adjectival
16 modifier” into the claims). In light of Plaintiff’s clarification that the “means for adjusting”
17 limitation does not require the constant adjustment of flow rate, Google’s argument is
18 unpersuasive.
19 c. Court’s Construction
20 For the above reasons, the Court rejects both Parties’ proposed constructions.
21 Google has not met its burden of demonstrating by clear and convincing evidence that the
22 “means for adjusting the rate at which said cooling fluid passes through said interior
23 passageway so that substantially no cooling fluid is vaporized within said interior
24 passageway” term is indefinite.
25 The Court construes the term as follows: the claimed function is “adjusting the rate
26 at which said cooling fluid passes through said interior passageway [so that substantially
27 no cooling fluid is vaporized within said interior passageway]”; the corresponding structure
28
1 is a “pump, or the evaporator side of a heat pipe and a reservoir of cooling fluid having a
2 heat differential between them.”
3 C. “substantially no cooling fluid is vaporized within said interior
4 passageway” (Claims 1 and 16)
5 The term “substantially no cooling fluid is vaporized within said interior
6 passageway” appears in the “means for adjusting” limitations in Claims 1 and 16 of the
7 ’901 Patent. Specifically, Claim 1 recites a “means for adjusting the rate at which said
8 cooling fluid passes through said interior passageway . . . so that substantially no cooling
9 fluid is vaporized within said interior passageway.” ’901 Patent, Claim 1 (emphasis added).
10 Claim 16 recites a “means for adjusting the rate at which said cooling fluid passes through
11 said interior passageway so that substantially no cooling fluid is vaporized within said
12 interior passageway.” Id., Claim 16 (emphasis added).
13 Plaintiff proposes the “substantially no cooling liquid” term be construed according
14 to its plain and ordinary meaning. If a construction is instead required, Plaintiff proposes
15 that the term be construed as “no or minimal [cooling fluid is lost]; no or minimal
16 [vaporization].” ECF No. 27-1 at 4. Google contends that the term should be held indefinite
17 because it is a term of degree without sufficient guidance as to its scope. ECF Nos. 35 at
18 16–18; 37 at 11–14.
19 Under Federal Circuit precedent, claims involving terms of degree are not inherently
20 indefinite. See Sonix Tech, 844 F.3d at 1377 (“Because language is limited, we have
21 rejected the proposition that claims involving terms of degree are inherently indefinite.”);
22 see also Interval Licensing LLC v. AOL, Inc., 766 F.3d 1364, 1370 (Fed. Cir. 2014)
23 (“We do not understand the Supreme Court to have implied . . . and we do not hold today,
24 that terms of degree are inherently indefinite.”); see also Tinnus Enters., LLC v. Telebrands
25 Corp., 733 F. App’x 1011, 1022 (Fed. Cir. 2018) (“[T]his court has repeatedly confirmed
26 that relative terms such as ‘substantially’ do not render a patent claim per se indefinite.”).
27 “[A] patentee need not define his invention with mathematical precision in order to comply
28 with the definiteness requirement.” Invitrogen Corp. v. Biocrest Mfg., L.P., 424 F.3d 1374,
1 1384 (Fed. Cir. 2005) (internal quotation marks omitted). Instead, “[c]laim language
2 employing terms of degree has long been found definite where it provided enough certainty
3 to one of skill in the art when read in the context of the invention.” Interval, 766 F.3d at
4 1370. “The claims, when read in light of the specification and the prosecution history, must
5 provide objective boundaries for those of skill in the art.” Id. at 1371; see Berkheimer v.
6 HP Inc., 881 F.3d 1360, 1364 (Fed. Cir. 2018) (“Our case law is clear that the objective
7 boundaries requirement applies to terms of degree.”). The standard “mandates clarity,
8 while recognizing that absolute precision is unattainable.” Nautilus, 572 U.S. at 899.
9 The Court looks first to the language of the claims to determine whether the meaning
10 of “substantially no cooling fluid is vaporized within said interior passageway” is
11 reasonably clear. See Berkheimer, 881 F.3d at 1363. “The word ‘substantially,’ when used
12 in a claim, can denote either language of approximation or language of magnitude.” Enzo
13 Biochem, Inc. v. Applera Corp., 599 F.3d 1325, 1333 (Fed. Cir. 2010). Here, as used in the
14 phrase “substantially no cooling fluid is vaporized within said interior passageway,” the
15 term “substantially” denotes magnitude because it purports to describe how much
16 vaporization occurs. See id.
17 Google contends the indefiniteness of this limitations is “confirmed” when
18 comparing independent Claim 1 with dependent Claim 2. ECF No. 37 at 11. Specifically,
19 Google argues the limitation that “substantially no cooling fluid is vaporized within said
20 interior passageway” is inconsistent with Claim 2’s limitation that “at least some of said
21 cooling fluid” is vaporized within the secondary passageway. Id. The Court does not agree.
22 Claim 1 recites at least two different passageways: (1) an interior passageway “within” the
23 heat sink; and (2) a secondary passageway that connects the interior passageway to the
24 exterior surface of the heat sink. See ’901 Patent, Claim 1. As Plaintiff notes, read together,
25 Claims 1 and 2 recite that while “substantially no cooling fluid is vaporized within said
26 interior passageway,” “at least some of the cooling liquid” is then vaporized in the
27 secondary passageway as the fluid leaves the interior of the heat sink. See’901 Patent,
28 Claims 1 and 2; ECF No. 34 at 25. This is consistent with the patent’s disclosure of
1 “promot[ing] internal cooling” of components “by conduction” while also providing for
2 the “cooling of the surface” of components “by evaporative and conductive cooling.” ’901
3 Patent at col. 2:31–37.
4 Notwithstanding the above, the Court agrees Claims 1 and 2 do not provide express
5 guidance as to what quantity of cooling fluid is vaporized within the interior passageway
6 such that “substantially no cooling fluid is vaporized.” Instead, the claim language provides
7 only that some quantity of liquid must remain in the interior passageway to permit some
8 level of vaporization in the secondary passageway.
9 The Court therefore looks next to the patent specification and file history. See
10 Berkheimer, 881 F.3d at 1364. The ’901 Patent specification provides that instead of
11 vaporizing near the heat sink, “to achieve maximum efficiency,” cooling fluid “should
12 begin to vaporize near the surface of the component or heat sink.” ’901 Patent, cols. 9:60–
13 63. If the system is operating at its “maximum operating capacity,” phase change should
14 occur “at or near the surface of an energized component at full load or at or near the surface
15 of a heat sink that is associated with a component operating at full load.” Id. at col. 10:17–
16 21. In contrast, if the system is operating “below its peak rating,” it performs “conductive
17 cooling i.e., without phase change.” Id. at col. 10:21–24.
18 In other words, the specification provides that when the system is operating below
19 its peak rating, cooling is conducted exclusively through conduction without phase change;
20 and even when the system is operating at its maximum capacity, phase change should only
21 occur at or near the surface of the component or heat sink (rather than in internal
22 passageways close to the heat sink). See id. at col. 10:17–24. This supports Plaintiff’s
23 proposed construction that the “substantially no” term is properly construed as “no or
24 minimal [cooling fluid is lost]; no or minimal [vaporization].”6
25
26
27 6 In this way, Plaintiff’s proposed construction contemplates real-world conditions,
where some miniscule amount of vaporization may be unavoidable. See In re Packard,
28
1 The prosecution history provides further support for Plaintiff’s proposed
2 construction. During the prosecution of the ’901 Patent, the Patent Office issued a non-
3 final office action rejecting Claim 1 of the ’901 Patent as being anticipated by U.S. Patent
4 No. 5,491,363 (“Yoshikawa”). ECF Nos. 34 at 25–27; 34-10 at 4. The Patent Office action
5 states the claim was rejected because Yoshikawa also taught “means . . . for supplying
6 cooling fluid capable of phase change to” an interior passageway “to conductively cool the
7 interior of [a] heat sink” and that the cooling liquid would “flow through [] other
8 passageways” in order “to cool” the “exterior surface” of the heat sink “at least partially
9 by evaporative cooling.” ECF No. 34-10 at 4. In responding to this rejection, the ’901
10 Patent applicant amended Claim 1 “to require that the rate at which cooling fluid passes
11 through the interior passageway is such that substantially no cooling fluid vaporizes within
12 the interior passageway.” ECF No. 34-11 at 7. The applicant concluded the method of
13 Claim 1 was, therefore, not anticipated by Yoshikawa because “at least some of the cooling
14 fluid vaporizes within the Internal Space of Yoshikawa.” Id. Google’s argument that the
15 distinction drawn in the prosecution history creates a “vast middle ground” is unpersuasive.
16 ECF No. 37 at 12–13. Instead, the amendment and accompanying explanation lend support
17 to Plaintiff’s position that the “substantially no” limitation excludes configurations where
18 a non-minimal amount of vaporization occurs in the interior passageway.
19 The Court finally looks to the extrinsic evidence. See Berkheimer, 881 F.3d at 1364.
20 Here, Dr. Banerjee opined that a POSITA would have understood the “substantially no”
21 limitation to mean “that no or minimal cooling fluid is lost . . . or no or minimal
22 vaporization . . . within the interior passageway of the heat sink.” Banerjee Decl. ¶ 26. In
23 contrast, Dr. King opined that the term is indefinite because a POSITA “would have to
24
25
26
751 F.3d 1307, 1313 (Fed. Cir. 2014) (The indefiniteness requirement “is not a demand for
27 unreasonable precision. The requirement, applied to the real world of modern technology,
does not contemplate in every case a verbal precision of the kind found in mathematics.”)
28
1 make a separate determination” of what the term means in different environments. King
2 Decl. ¶ 37. Dr. King does not opine, however, that a POSITA would be unable to make
3 these determinations. See King Decl. Instead, Dr. King opines that the patent disclosure
4 does not contain sufficient information to enable a POSITA to make these separate
5 determinations in each of these different environments:
6
A [POSITA] would further understand that there are complicated
7 physical links between vapor quantity, flow rate, temperature
8 distribution, heat flux, and other physical parameters in the system. The
vapor quantity is typically evaluated using sophisticated mathematical
9 modeling or detailed computer simulations. As such, “substantially” is
10 too vague of a descriptor to enable the design and operation of the
system without additional explanation or technical details.
11
12 Id. (emphasis added).
13 Enablement and indefiniteness are separate inquiries. See E-Numerate Sols., Inc. v.
14 United States, 170 Fed. Cl. 147, 154 (2024) (“Claim construction may contain
15 indefiniteness inquiries, but other invalidity arguments under § 112, such as lack
16 of enablement or lack of adequate written description, are separate and distinct.”); see
17 ON24, Inc. v. webinar.net, Inc., 698 F. Supp. 3d 1154, 1167 n.7 (N.D. Cal. 2023)
18 (“[I]ndefiniteness and enablement are distinct and different inquiries.”).7 “Even if the
19 written description does not enable the claims, the claim language itself may still be
20 definite.” Union Pac. Res. Co. v. Chesapeake Energy Corp., 236 F.3d 684, 692 (Fed. Cir.
21 2001).
22
23
24
7 “Enablement serves the dual function in the patent system of ensuring adequate
25 disclosure of the claimed invention and of preventing claims broader than the disclosed
invention.” MagSil Corp. v. Hitachi Glob. Storage Techs., Inc., 687 F.3d 1377, 1380–81
26
(Fed. Cir. 2012). The doctrine “prevents both inadequate disclosure of an invention and
27 overbroad claiming that might otherwise attempt to cover more than was actually
invented.” Id. at 1381. “Thus, a patentee chooses broad claim language at the peril of losing
28
1 Here, the Court declines to address Google’s enablement arguments (if any) at the
2 claim construction stage. See Haddad v. United States, 164 Fed. Cl. 28, 67 (2023)
3 (“[V]alidity arguments, such as lack of enablement and lack of written description, are not
4 proper to address during claim construction.”); ASM Am., Inc. v. Genus, Inc., No. C-01-
5 2190-EDL, 2002 WL 1892200, at *16 (N.D. Cal. Aug. 15, 2002) (“Because analysis of
6 enablement focuses on the adequacy of the specification in teaching a person of ordinary
7 skill in the art how to make and use the invention, it cannot be considered to be part of
8 claim construction.”).
9 Google’s reliance on the Federal Circuit’s Interval Licensing decision is also not
10 persuasive. ECF No. 35 at 17. Interval Licensing involved a claim related to displaying
11 content “in an unobtrusive manner that does not distract a user.” 766 F.3d at 1367. The
12 Court of Appeals held that the term “unobtrusive manner” was a “term of degree” that was
13 “highly subjective and, on its face, provides little guidance to one of skill in the art.” Id. at
14 1371. As the Court of Appeals later explained in Sonix Tech, Interval Licensing involved
15 a term that was “subjective in the sense that [it] turned on a person’s tastes or opinion.”
16 844 F.3d at 1378. This was because the term “unobtrusive manner” “implicates a person’s
17 individual focus, concentration, attentiveness, or similar mental state at a given moment,
18 or even opinions, affecting what is or is not distracting.” Id.
19 Google has not sufficiently explained how the Interval Licensing case is analogous
20 to this one. As Google’s own expert opined, the question of whether “substantially no
21 cooling fluid is vaporized within said interior passageway” can be measured. See King
22 Decl. ¶ 38 (“In principle, the vapor quantity could be monitored using sensing systems.”).
23 Unlike in Interval Licensing, “[t]his provides an objective baseline through which to
24 interpret the claims.” Sonix Tech, 844 F.3d at 1378 (holding that whether something is
25 “visually negligible” involved what could be seen by the normal human eye thereby
26 providing an “objective baseline” for interpreting claim language); see Polaris PowerLED
27 Tech., LLC v. VIZIO, Inc., No. SACV1801571JVSDFMX, 2019 WL 13043592, at *17
28 (C.D. Cal. Nov. 26, 2019) (“The term ‘zero’ denotes a specific value and the term of degree
1 || ‘approximately’ accounts for slight variations from that specified baseline.”).
2 For these reasons, the Court concludes Google has not demonstrated by clear and
3 || convincing evidence that the claim limitation “substantially no cooling fluid is vaporized
4 || within said interior passageway” is indefinite. The Court instead finds it appropriate to
5 adopt Plaintiffs alternative construction of this term as: “no or minimal [cooling fluid is
6 || lost]; no or minimal [vaporization].”
7 ITV. CONCLUSION
8 The Court construes the disputed terms as follows:
9 Agreed Construction
10 “means for adjusting the rate at Construed as a means-plus-function term
i which said cooling fluid passes under 35 U.S.C. § 112, 7 6
through said interior passageway | Function: “adjusting the rate at which said
12 so that substantially no cooling cooling fluid passes through said interior
B fluid is vaporized within said passageway [so that substantially no cooling
interior passageway” (Claims | fluid is vaporized within said interior
14 and 16) passageway]”;
15
Structure: “pump, or the evaporator side of a
16 heat pipe and a reservoir of cooling fluid
17 having a heat differential between them.”
18 “substantially no cooling fluidis | “no or minimal [cooling fluid is lost]; no or
vaporized within said interior minimal [vaporization]”
19 passageway” (Claims | and 16)
20
21 IT IS SO ORDERED.
22 || Dated: August 18, 2025 □
23 / A. AE C [oe
Hon. Robert S. Huie
United States District Judge
25
26
27
28
XA