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 .
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.
Claim(s) 1-4, 6, 8-14, 16, and 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 20130001759 (Kim et al) and US 20180090417 (Gutala et al).
As to Claim 1, Kim teaches a power module package comprising:
a power module (Kim Fig 9) comprising a first lead frame (comprising 110 + 130), a second lead frame (142), and at least one chip at least partially between the first lead frame and the second lead frame (top-leftmost chip 152 between 130 and 142);
a first heat spreader attached to the first lead frame (top 170); and
a second heat spreader also attached to the first lead frame (bottom 170) such that the first lead frame, the first heat spreader and the second heat spreader form an enclosure defining a cavity containing the at least one chip (cavity between claimed elements contains the at least one chip), with an outer surface of the enclosure formed by the first lead frame, the first heat spreader and the second head spreader covered by molding compound material (part of outer surface covered by 160).
Kim does not explicitly teach wherein the enclosure comprises an inlet configured to allow a cooling medium to flow into the cavity and an outlet configured to allow the cooling medium to flow out of the cavity.
Gutala teaches a device similar to that of Kim, and explicitly teaches an enclosure (Gutala Fig 5 enclosure between 505 and 102) comprising an inlet configured to allow a cooling medium to flow into a cavity (fluid inlet 122 allows flow into cavity) and an outlet configured to allow the cooling medium to flow out of the cavity (fluid outlet 124 allows flow out of cavity).
It would have been obvious to one of ordinary skill in the art at the time of filing to combine the power module package without a flowing cooling medium taught by Kim with the inlet and outlet allowing for coolant flow within the module taught by Gutala in order to enhance heat dissipation away from the device improving performance of the package (Gutala ¶0041).
As to Claim 2, the combination of Kim and Gutala teaches the power module package according to claim 1. Kim further teaches wherein the first lead frame (110+130) comprises one or more fins on a first side (fin 130 on top side of package); and one or more further fins on a second side opposite the first side (fin 110 on bottom side of package).
As to Claim 3, the combination of Kim and Gutala teaches the power module package according to claim 2. Kim further teaches wherein the one or more fins are in contact with the first heat spreader (130 contacts top 170); and
wherein the one or more further fins are in contact with the second heat spreader (110 contacts bottom 170).
As to Claim 4, the combination of Kim and Gutala teaches the power module package according to claim 1. Gutala, as applied to claim 1, further teaches wherein the power module package is configured such that the cooling medium is in direct contact with the at least one chip (Gutala Fig 5 direct contact between coolant and chip ¶0041).
As to Claim 6, the combination of Kim and Gutala teaches the power module package according to claim 1. Kim teaches the package further comprising a die attach adhesive layer attaching the at least one chip to the first lead frame (devices attached to lead frames by solder paste ¶0041).
As to Claim 8, the combination of Kim and Gutala teaches the power module package according to claim 1. Kim further teaches:
wherein the power module further comprises a third lead frame (120) arranged such that the at least one chip is at least partially between the first lead frame and the third lead frame (top-left chip in Kim Fig 9 between 130 and 120).
As to Claim 9, the combination of Kim and Gutala teaches the power module package according to claim 8. Kim further teaches:
wherein the power module further comprises a fourth lead frame (141), and at least one further chip (bottom-left chip in Kim Fig 9) at least partially between the first lead frame and the fourth lead frame (chip between 142 and 130).
As to Claim 10, the combination of Kim and Gutala teaches the power module package according to claim 9. However, the combination does not explicitly teach the power module comprising a fifth lead frame arranged such that the at least one further chip is at least partially between the first lead frame and the fifth lead frame. However, it would have been obvious to one having ordinary skill in the art at the time of filing that the lead frame portions 110/120/130 in Kim Fig 9 could have been duplicated such that there is a fifth lead frame also positioned between third lead frame 120 and first lead frame portion 130. In such a situation, the at least one further chip would then be partially between first lead frame portion 110 and that fifth lead frame.
Such duplication of parts would have been obvious to those having ordinary skill at the time of filing, as such a person would have understood the duplication of those parts would not have led to a new and unexpected result (see MPEP §2144.04.VI.C).
As to Claim 11, Kim teaches a method of forming a power module package, the method comprising:
forming a power module (Kim Fig 9 formed by conventional means) comprising a first lead frame (comprising 110 + 130), a second lead frame (142), and at least one chip at least partially between the first lead frame and the second lead frame (top-leftmost chip 152 between 130 and 142);
forming a first heat spreader attached to the first lead frame (top 170); and
forming a second heat spreader also attached to the first lead frame (bottom 170) such that the first lead frame, the first heat spreader and the second heat spreader form an enclosure defining a cavity containing the at least one chip (cavity between claimed elements contains the at least one chip), with an outer surface of the enclosure formed by the first lead frame, the first heat spreader and the second head spreader covered by molding compound material (part of outer surface covered by 160).
Kim does not explicitly teach wherein the enclosure comprises an inlet configured to allow a cooling medium to flow into the cavity and an outlet configured to allow the cooling medium to flow out of the cavity.
Gutala teaches a device similar to that of Kim, and explicitly teaches an enclosure (Gutala Fig 5 enclosure between 505 and 102) comprising an inlet configured to allow a cooling medium to flow into a cavity (fluid inlet 122 allows flow into cavity) and an outlet configured to allow the cooling medium to flow out of the cavity (fluid outlet 124 allows flow out of cavity).
It would have been obvious to one of ordinary skill in the art at the time of filing to combine the method of forming a power module package without a flowing cooling medium taught by Kim with the inlet and outlet allowing for coolant flow within the module taught by Gutala in order to enhance heat dissipation away from the device improving performance of the package (Gutala ¶0041).
As to Claim 12, the combination of Kim and Gutala teaches the method according to claim 11. Kim further teaches wherein the first lead frame (110+130) comprises one or more fins on a first side (fin 130 on top side of package); and one or more further fins on a second side opposite the first side (fin 110 on bottom side of package).
As to Claim 13, the combination of Kim and Gutala teaches the method according to claim 12. Kim further teaches wherein the one or more fins are in contact with the first heat spreader (130 contacts top 170); and
wherein the one or more further fins are in contact with the second heat spreader (110 contacts bottom 170).
As to Claim 14, the combination of Kim and Gutala teaches the method according to claim 11. Gutala, as applied to claim 11, further teaches wherein the power module package is configured such that the cooling medium is in direct contact with the at least one chip (Gutala Fig 5 direct contact between coolant and chip ¶0041).
As to Claim 16, the combination of Kim and Gutala teaches the method according to claim 11. Kim teaches the package further comprising a die attach adhesive layer attaching the at least one chip to the first lead frame (devices attached to lead frames by solder paste ¶0041).
As to Claim 18, the combination of Kim and Gutala teaches the method according to claim 11. Kim further teaches:
wherein the power module further comprises a third lead frame (120) arranged such that the at least one chip is at least partially between the first lead frame and the third lead frame (top-left chip in Kim Fig 9 between 130 and 120).
As to Claim 19, the combination of Kim and Gutala teaches the method according to claim 18. Kim further teaches:
wherein the power module further comprises a fourth lead frame (141), and at least one further chip (bottom-left chip in Kim Fig 9) at least partially between the first lead frame and the fourth lead frame (chip between 142 and 130).
As to Claim 20, the combination of Kim and Gutala teaches the method according to claim 19. However, the combination does not explicitly teach the power module comprising a fifth lead frame arranged such that the at least one further chip is at least partially between the first lead frame and the fifth lead frame. However, it would have been obvious to one having ordinary skill in the art at the time of filing that the lead frame portions 110/120/130 in Kim Fig 9 could have been duplicated such that there is a fifth lead frame also positioned between third lead frame 120 and first lead frame portion 130. In such a situation, the at least one further chip would then be partially between first lead frame portion 110 and that fifth lead frame.
Such duplication of parts would have been obvious to those having ordinary skill at the time of filing, as such a person would have understood the duplication of those parts would not have led to a new and unexpected result (see MPEP §2144.04.VI.C).
Claim(s) 5 and 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kim and Gutala as applied to claims 1 and 11 above, and further in view of US 20190069444 (Wan et al).
As to Claim 5, the combination of Kim and Gutala teaches the power module package according to claim 1. Gutala, as applied to claim 1, further teaches wherein the cooling medium comprises a dielectric liquid (Gutala, coolant may be deionized water ¶0025).
However, Kim and Gutala do not explicitly teach wherein the dielectric liquid is vaporized after absorbing heat generated from the at least one chip. Rather, Gutala is silent as to whether the liquid vaporizes after absorbing sufficient heat.
Wan teaches a device similar to that of Kim and Gutala, and explicitly teaches the benefits of vaporizing the coolant during operation (Wan ¶0022 discloses the heat-dissipation being optimized through such an evaporation/condensation cycle).
It would have been obvious to one of ordinary skill in the art at the time of filing to combine the package including a dielectric liquid taught by Kim and Gutala with the vaporization of the coolant after absorbing the heat taught by Wan in order to provide for improved heat-dissipation efficiency over keeping the coolant in liquid phase (Wan ¶0022).
As to Claim 15, the combination of Kim and Gutala teaches the method according to claim 11. Gutala, as applied to claim 11, further teaches wherein the cooling medium comprises a dielectric liquid which is vaporized after absorbing heat generated from the at least one chip (Gutala, coolant may be deionized water ¶0025).
However, Kim and Gutala do not explicitly teach wherein the dielectric liquid is vaporized after absorbing heat generated from the at least one chip. Rather, Gutala is silent as to whether the liquid vaporizes after absorbing sufficient heat.
Wan teaches a method similar to that of Kim and Gutala, and explicitly teaches the benefits of vaporizing the coolant during operation (Wan ¶0022 discloses the heat-dissipation being optimized through such an evaporation/condensation cycle).
It would have been obvious to one of ordinary skill in the art at the time of filing to combine the method including a dielectric liquid taught by Kim and Gutala with the vaporization of the coolant after absorbing the heat taught by Wan in order to provide for improved heat-dissipation efficiency over keeping the coolant in liquid phase (Wan ¶0022).
Claim(s) 7 and 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kim and Gutala as applied to claims 1 and 11 above, and further in view of US 20200251380 (Yu et al).
As to Claim 7, the combination of Kim and Gutala teaches the power module package according to claim 1. Kim further teaches a second solder layer bonding the second lead frame to the first lead frame (142 bonded to 130 through solder layer between chip and 130 ¶0041). However, their combination does not explicitly teach a first solder layer bonding the second lead frame to the at least one chip. Rather, Kim teaches direct bonding between the second lead frame and the at least one chip (¶0069).
Yu teaches a device similar to that of Kim and Gutala, and explicitly teaches the substitutability of solder in place of direct bonding (Yu ¶0051).
It would have been obvious to one of ordinary skill in the art at the time of filing to combine the second lead frame being connected to a chip by direct bonding taught by Kim and Gutala with the use of solder to connect the second lead frame and chip taught by Yu. The use of solder is known to be faster and easier to control than direct bonding methods, simplifying the assembly process.
As to Claim 17, the combination of Kim and Gutala teaches the method according to claim 11. Kim further teaches a second solder layer bonding the second lead frame to the first lead frame (142 bonded to 130 through solder layer between chip and 130 ¶0041). However, their combination does not explicitly teach a first solder layer bonding the second lead frame to the at least one chip. Rather, Kim teaches direct bonding between the second lead frame and the at least one chip (¶0069).
Yu teaches a device similar to that of Kim and Gutala, and explicitly teaches the substitutability of solder in place of direct bonding (Yu ¶0051).
It would have been obvious to one of ordinary skill in the art at the time of filing to combine the second lead frame being connected to a chip by direct bonding taught by Kim and Gutala with the use of solder to connect the second lead frame and chip taught by Yu. The use of solder is known to be faster and easier to control than direct bonding methods, simplifying the assembly process.
Response to Arguments
Applicant's arguments filed 11 December 2025 have been fully considered but they are not persuasive.
In response to applicant's argument that the enclosure of Kim cannot be reasonably combined with the enclosure of Gutala, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). In this case one of ordinary skill in the art would have been motivated to modify the module of Kim to be capable of containing a flowing coolant medium through the module as claimed.
Conclusion
THIS ACTION IS MADE FINAL. 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Corbyn D Mellinger whose telephone number is (703)756-5683. The examiner can normally be reached M-F 8-5 Eastern.
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/Corbyn D Mellinger/Examiner, Art Unit 2899
/ZANDRA V SMITH/Supervisory Patent Examiner, Art Unit 2899
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