DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments with respect to the rejection of claims 1 and 17 under 35 U.S.C. 102(a)(1) over Campbell (US 2014/0085822) have been fully considered and are persuasive as applied to the claims as amended. The portions of Campbell relied upon describe wicking of the dielectric fluid by capillary force and evaporation of the fluid within the porous wick structures (Campbell, para. 0088-0089), and do not disclose the newly recited limitations “wherein the non-conductive liquid permeates through the foam heat sink, and wherein the heat transfer path comprises convection of the non-conductive liquid through the foam heat sink.” Therefore, the rejection of claims 1, 3, 4, 8, 10-14, 16, 17, 19 under 35 U.S.C. 102(a)(1) has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of Pfister (US 6,888,720), as set forth below. Applicant’s amendment necessitated the new grounds of rejection presented in this Office action.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claim 15 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 15 recites “wherein the foam heat sink is comprised of a closed cell foam.” Claim 1, from which claim 15 depends, as amended recites “wherein the non-conductive liquid permeates through the foam heat sink, and wherein the heat transfer path comprises convection of the non-conductive liquid through the foam heat sink.” A closed cell foam comprises sealed cells that do not permit a liquid to permeate through the foam. It is therefore unclear how the foam heat sink of claim 15 can simultaneously be comprised of a closed cell foam and be permeated through by the non-conductive liquid with the heat transfer path comprising convection of the non-conductive liquid through the foam heat sink as required by claim 1. The metes and bounds of claim 15 cannot be ascertained, rendering the claim indefinite. Clarification or correction is required.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 3, 4, 8, 10-14, 16, 17, 19 are rejected under 35 U.S.C. 103 as being unpatentable over Campbell (US 2014/0085822) in view of Pfister (US 6,888,720).
Re claim 1:
Campbell discloses
An electronic cooling system (700’ in fig. 11), comprising:
an enclosure (702 in fig. 11) in which an electronic component (721 in fig. 11) is removably housed, the electronic component comprising a data storage device (para. 0059);
a non-conductive liquid (730 in fig. 11; para. 0067) that immerses or wets the electronic component (fig. 11); and
a foam heat sink (1100 in fig. 11; para. 0086, 0088) attached to a heat emitting surface of the electronic component (surface of the 1101’s in fig. 11), the foam heat sink permeated by the non-conductive liquid such that a convection heat transfer path between the electronic component and the non-conductive liquid is provided (the 1100’s are permeated by 730 and provide a heat transfer path between the 1101’s and 730 in fig. 11; para. 0088), and such that a porosity of the foam heat sink increases a coolant heat absorption rate from the heat emitting surface to the non-conductive liquid (the pores of 1100 increase the coolant heat absorption rate from the surfaces of the 1101’s to 730 in fig. 11).
Campbell does not explicitly disclose wherein the non-conductive liquid permeates through the foam heat sink, and wherein the heat transfer path comprises convection of the non-conductive liquid through the foam heat sink.
Pfister discloses a system for cooling electronic components wherein foam heat sinks (22 in figs. 1-3) are each thermally coupled to a corresponding electronic component (14 in figs. 1-3) with a thermally conductive adhesive (col. 3, ll. 20-28), wherein a cooling fluid permeates through the foam heat sink (the cooling fluid passes through the open microcellular pores of the graphitic foam product 22; col. 5, ll. 38-48; each foam product may include through bores 68 to facilitate the passage of the cooling fluid through the foam product; col. 6, ll. 28-32), and wherein the heat transfer path comprises convection of the fluid through the foam heat sink (as the cooling fluid passes through the open microcellular pores of the graphitic foam product, the heat from the graphitic ligaments is transferred to the cooling fluid; col. 5, ll. 38-48; as the cooling fluid passes through the graphitic foam products 22, it absorbs the heat generated by the circuit components 14; col. 6, ll. 18-27; the system is suitable for use when air, water or any other conventional heat exchange fluid is employed as the cooling fluid; col. 6, ll. 15-18).
Thus it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the electronic cooling system of Campbell wherein the non-conductive liquid permeates through the foam heat sink, and wherein the heat transfer path comprises convection of the non-conductive liquid through the foam heat sink as taught by Pfister, in order to transfer the heat conducted into the interconnected network of foam ligaments directly to the liquid flowing through the pores of the foam, thereby increasing the heat absorbed by the non-conductive liquid from the heat emitting surface with predictable results.
Re claim 17:
Campbell discloses
A method of cooling a data storage device (para. 0059) removably housed in an enclosure (702 in fig. 11), the method comprising:
immersing or wetting an electronic component (721 in fig. 11) with a non-conductive liquid (730 in fig. 11);
immersing or wetting a foam heat sink (1100 in fig. 11; para. 0086, 0088) attached to a heat emitting surface of the electronic component (surface of the 1101’s in fig. 11); and
transferring heat from the electronic component to the non-conductive liquid via the foam heat sink (heat is transferred from 721 to 730 via 1100 in fig. 11), a porosity of the foam heat sink increasing a coolant heat absorption rate from the heat emitting surface to the non-conductive liquid (the pores of 1100 increase the coolant heat absorption rate from the surfaces of the 1101’s to 730 in fig. 11).
Campbell does not explicitly disclose wherein the non-conductive liquid permeates through the foam heat sink, and wherein transferring heat from the electronic component to the non-conductive liquid comprises convection of the non-conductive liquid through the foam heat sink.
Pfister discloses a method of cooling electronic components wherein a cooling fluid permeates through a foam heat sink (22 in figs. 1-3) thermally coupled to a corresponding electronic component (14 in figs. 1-3) with a thermally conductive adhesive (col. 3, ll. 20-28; the cooling fluid passes through the open microcellular pores of the graphitic foam product 22; col. 5, ll. 38-48; through bores 68 facilitate the passage of the cooling fluid through the foam product; col. 6, ll. 28-32), and wherein transferring heat comprises convection of the fluid through the foam heat sink (as the cooling fluid passes through the open microcellular pores of the graphitic foam product, the heat from the graphitic ligaments is transferred to the cooling fluid; col. 5, ll. 38-48; as the cooling fluid passes through the graphitic foam products 22, it absorbs the heat generated by the circuit components 14; col. 6, ll. 18-27; the system is suitable for use when air, water or any other conventional heat exchange fluid is employed as the cooling fluid; col. 6, ll. 15-18).
Thus it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Campbell wherein the non-conductive liquid permeates through the foam heat sink, and wherein transferring heat from the electronic component to the non-conductive liquid comprises convection of the non-conductive liquid through the foam heat sink as taught by Pfister, in order to transfer the heat conducted into the interconnected network of foam ligaments directly to the liquid flowing through the pores of the foam, thereby increasing the heat absorbed by the non-conductive liquid from the heat emitting surface with predictable results.
Re claim 3:
Campbell discloses wherein the foam comprises a metal foam (para. 0088).
Re claim 4:
Campbell discloses wherein the non-conductive liquid evaporates as it removes heat from one or both of the foam heat sink and the electronic component (para. 0089).
Re claim 8:
Campbell discloses wherein the electronic cooling system comprises a two-phase immersion cooling system (para. 0089).
Re claim 10:
Campbell discloses further comprising a second foam heat sink (a second 1100 in fig. 11) attached to a wall (701 in fig. 11) of the enclosure, the second foam heat sink providing a second heat transfer path between the electronic component and the non-conductive liquid (the second 1100 provides a second heat transfer path between 1101 and 730 in fig. 11).
Re claim 11:
Campbell discloses wherein the non-conductive liquid is a dielectric liquid (para. 0067).
Re claim 12:
Campbell discloses wherein the data storage device comprises a random access memory module (para. 0059).
Re claim 13:
Campbell discloses wherein the data storage device comprises a solid state drive (para. 0059).
Re claim 14:
Campbell discloses wherein the data storage device comprises a hard disk drive (para. 0002).
Re claim 16:
Campbell discloses wherein the foam heat sink is comprised of an open cell foam (para. 0089 states that 1100 can wick dielectric fluid, therefore it must be open celled).
Re claim 19:
Campbell discloses wherein immersing or wetting the electronic component (1101 in fig. 11) and the foam heat sink (1100 in fig. 11) comprises immersing the electronic component and the metal foam heat sink (fig. 11), and wherein transferring heat from the electronic component to the non-conductive liquid comprises a phase change of the non-conductive liquid to a gas (para. 0089).
Claims 2, 5, 6 are rejected under 35 U.S.C. 103 as being unpatentable over Campbell (US 2014/0085822) in view of Pfister (US 6,888,720).Re claim 2:
Campbell discloses wherein the foam comprises material with compatibility to the non-conductive liquid (1100 is compatible with 730 in fig. 11).
Campbell does not explicitly disclose wherein the foam has a thermal conductivity of at least 15 W m⁻¹ K⁻¹.
However, it would obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the electronic cooling system of Campbell wherein the foam has a thermal conductivity of at least 15 W m⁻¹ K⁻¹, in order to ensure that the foam acts as a heat spreader rather than a heat trap, since it has been held that discovering an optimum value of a result effected variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980).Re claim 5:
The modified Campbell discloses wherein, the foam heat sink elevates an evaporation rate of the non-conductive liquid (1100 elevates the evaporation rate of 730 in fig. 11).
Re claim 6:
The modified Campbell discloses wherein the foam heat sink inhibits formation of a gas barrier on the heat emitting surface (1100 inhibits formation of a gas barrier on the surface of 1101 because the foam physically breaks up coalescing vapor bubbles and uses capillary wicking to constantly pull liquid toward the hot surface which prevents the formation of the gas barrier).
Claims 7, 20 are rejected under 35 U.S.C. 103 as being unpatentable over Campbell (US 2014/0085822) in view of Pfister (US 6,888,720), and further in view of Campbell (US 2014/0085823).
Re claim 7:
Campbell (US 2014/0085822) does not explicitly disclose wherein the electronic cooling system comprises a single-phase immersion cooling system.
Campbell (US 2014/0085823) discloses wherein the electronic cooling system comprises a single-phase immersion cooling system (620 in fig. 7; para. 0038).
Thus it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the electronic cooling system of Campbell (US 2014/0085822) wherein the electronic cooling system comprises a single-phase immersion cooling system as taught by Campbell (US 2014/0085823), in order to have lower fluid costs and complexity.
Re claim 20:
Campbell (US 2014/0085822) does not explicitly disclose wherein immersing or wetting the electronic component and the foam heat sink comprises immersing the electronic component and the foam heat sink, and wherein transferring heat from the electronic component to the non-conductive liquid comprises forced or natural convection.
Campbell (US 2014/0085823) disclose wherein immersing or wetting the electronic component and the foam heat sink comprises immersing the electronic component and the foam heat sink (711 and 712 are immersed in fig. 8B, 8C), and wherein transferring heat from the electronic component to the non-conductive liquid comprises forced or natural convection (para. 0042).
Thus it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the electronic cooling system of Campbell (US 2014/0085822) wherein immersing or wetting the electronic component and the foam heat sink comprises immersing the electronic component and the foam heat sink, and wherein transferring heat from the electronic component to the non-conductive liquid comprises forced or natural convection as taught by Campbell (US 2014/0085823), in order to have lower fluid costs and complexity.
Claims 9, 18 are rejected under 35 U.S.C. 103 as being unpatentable over Campbell (US 2014/0085822) in view of Pfister (US 6,888,720), and further in view of Amos (US 2021/0321535).
Re claim 9:
Campbell does not explicitly disclose further comprising a plurality of spray nozzles, wherein each spray nozzle is configured to dispense the non-conductive liquid in a direction of the electronic component housed in the enclosure.
Amos further comprising a plurality of spray nozzles (2’s in fig. 2; para. 0124), wherein each spray nozzle is configured to dispense the non-conductive liquid (para. 0124) in a direction of the electronic component (12 in fig. 2) housed in the enclosure (110 in fig. 2).
Thus it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the electronic cooling system of Campbell further comprising a plurality of spray nozzles, wherein each spray nozzle is configured to dispense the non-conductive liquid in a direction of the electronic component housed in the enclosure as taught by Amos, in order to have direct targeting of hot spots.
Re claim 18:
Campbell does not explicitly disclose wherein immersing or wetting the electronic component and the foam heat sink comprises spraying the non-conductive liquid in a direction of the electronic component.
Amos discloses wherein immersing or wetting the electronic component (10 in fig. 2; para. 0124) and the foam heat sink (para. 0189) comprises spraying the non-conductive liquid in a direction of the electronic component (para. 0019).
Thus it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the electronic cooling system of Campbell wherein immersing or wetting the electronic component and the foam heat sink comprises spraying the non-conductive liquid in a direction of the electronic component as taught by Amos, in order to have direct targeting of hot spots.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Campbell (US 2014/0085822) in view of Pfister (US 6,888,720), and further in view of Liu (US 2022/0240365).
Re claim 15:
Campbell does not explicitly disclose wherein the foam heat sink is comprised of a closed cell foam.
Liu discloses wherein the foam heat sink is comprised of a closed cell foam (para. 0027).
Thus it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the electronic cooling system of Campbell wherein the foam heat sink is comprised of a closed cell foam as taught by Liu, in order for the foam to have more rigidity.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ZHENGFU J FENG whose telephone number is (571) 272-2949. The examiner can normally be reached on Monday – Friday 10am - 6pm EST. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jayprakash Gandhi can be reached on (571) 272-3740. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/ZHENGFU J FENG/Primary Examiner, Art Unit 2835 July 17, 2026
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