DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of Invention II (original claims 15-20 and new claims 21-34) in the reply filed on 04/16/2026 is acknowledged.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 11/13/2023 has been considered by the examiner.
Claim Objections
Claim 22 is objected to because of the following informalities: missing the article “the” before “lead”. Appropriate 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.
Claim(s) 15-18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Krishnan et al. (US Pub. 2012/0018864) in view of Kassim et al. (US Pub. 2022/0139811).
Regarding independent claim 15, Krishnan teaches a method (Fig. 21; para. 0059-0060) comprising:
sintering a semiconductor die (310) to a die attach pad (DAP) (310) in a lead frame structure (302) (para. 0059);
connecting the semiconductor die to a lead post of a lead (306) with a clip (318) (para. 0059); and
encapsulating the semiconductor die in a mold body (326) with the lead extending from the mold body as an external terminal of a package (Fig. 21) (para. 0060).
Krishnan is silent with respect to connecting to a source contact pad formed on the semiconductor die, specifically.
Kassim teaches connecting a source contact pad (214) formed on a semiconductor die (212) to a lead post of a lead (206) with a clip (100) for the purpose of forming a power device package (Fig. 2; para. 0044-0045).
It would have been obvious to one of ordinary skill in the art at the time of filing to substitute the semiconductor die of Krishnan with the semiconductor die of Kassim to arrive at the claimed invention for the purpose of providing a power device package.
Re claim 16, Krishnan teaches wherein sintering the semiconductor die to the DAP includes: disposing a silver particle paste between the semiconductor die and the DAP (para. 0059, para. 0028); and applying pressure on the semiconductor die (para. 0059).
Re claim 17, Krishnan in view of Kassim teaches wherein connecting the source contact pad on the semiconductor die to a lead post of a lead with a clip includes sintering a first end of the clip to the source contact pad (Krishnan para. 0059).
Re claim 18, Krishnan in view of Kassim teaches wherein sintering the first end of the clip to the source contact pad includes: disposing a silver sinter preform on a top of first end of the clip abutting the source contact pad; and applying pressure to a backside of semiconductor die on which the source contact pad is formed (Krishnan para. 0059).
Re claim 20, Krishnan in view of Kassim teaches wherein the semiconductor die includes a silicon carbide (SiC) power transistor (Kassim para. 0045).
Claim(s) 19, 21-25 are rejected under 35 U.S.C. 103 as being unpatentable over Krishnan et al. (US Pub. 2012/0018864) in view of Kassim et al. (US Pub. 2022/0139811) and Lee et al. (US Pub. 2021/0159157).
Re claim 19, Krishnan teaches wherein connecting a source contact pad formed on the semiconductor die to the lead post of the lead with the clip further comprises soldering a second end of the clip to the lead post of the lead (para. 0059), instead of welding, as claimed.
Lee teaches that it is known that clips may be connected to leads through welding (para. 0050).
It would have been obvious to one of ordinary skill in the art at the time of filing to predictably substitute the soldering method of Krishnan with the welding method of Lee for the purpose of connecting the lead to clip. It is considered obvious to substitute one known method with another to obtain predictable results (MPEP 2143, I, B). Furthermore, welding provides the advantage of forming a stronger bond than soldering.
Regarding independent claim 21, Krishnan teaches a method (Fig. 21; para. 0059-0060) comprising:
sintering a semiconductor die (310) to a die attach pad (310) of a lead frame (302) (para. 0059);
sintering a first end of a clip (318) having a first end to the semiconductor die (para. 0059);
soldering a second end of the clip to a lead post of a lead (306) (para. 0059); and
encapsulating the semiconductor die in a mold body (326) (para. 0060).
Krishnan is silent with respect to sintering to a device contact pad on the semiconductor die, specifically.
Kassim teaches connecting a first end of a clip (100) to a device contact pad (214) formed on a semiconductor die (212) for the purpose of forming a power device package (Fig. 2; para. 0044-0045).
It would have been obvious to one of ordinary skill in the art at the time of filing to substitute the semiconductor die of Krishnan with the semiconductor die of Kassim to arrive at the claimed invention for the purpose of providing a power device package.
Krishnan teaches wherein the second end of the clip and the lead are soldered together (para. 0059) instead of welded together, as claimed.
Lee teaches that it is known that clips may be connected to leads through welding (para. 0050).
It would have been obvious to one of ordinary skill in the art at the time of filing to predictably substitute the soldering method of Krishnan with the welding method of Lee for the purpose of connecting the lead to clip. It is considered obvious to substitute one known method with another to obtain predictable results (MPEP 2143, I, B). Furthermore, welding provides the advantage of forming a stronger bond than soldering.
Re claim 22, Krishnan teaches wherein [the] lead extends outside the mold body to form an external terminal (Fig. 21).
Re claim 23, Krishnan in view of Kassim teaches wherein the device contact pad is a source contact pad and wherein the external terminal is an external source terminal (Kassim para. 0044-0046).
Re claim 24, Krishnan in view of Kassim teaches wherein the device contact pad is a first device contact pad, and the lead is a first lead and wherein the method includes: coupling a second device contact pad of the semiconductor die to a lead post of a second lead via wire bond (Kassim para. 0048).
Re claim 25, While Krishnan in view of Kassim teaches are silent with respect to wherein the second device contact pad is a gate contact pad and wherein the second lead extends outside the mold body to form an external gate terminal; however, such features are shown by Lee in Fig. 7 and para. 0060.
It would have been obvious to one of ordinary skill in the art at time of filing to form the gate connection as taught by Lee to the combination of Krishnan and Kassim to arrive at the claimed invention for the purpose of providing the gate voltage to the power device of Kassim.
Allowable Subject Matter
Claim 26 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claims 27-34 are allowed.
The following is a statement of reasons for the indication of allowable subject matter: there is no teaching, suggestion, or motivation from the prior art of record, nor does the prior art of record otherwise make obvious the limitations of…
Re claim 26, …disposing the lead frame in a tray with the semiconductor die facing the tray, the tray holding the clip, the first end of the clip being aligned with the device contact pad…
Re claims 27-34, …disposing the lead frame in a tray with the at least one semiconductor die facing the tray, the tray holding at least one clip having a first end aligned with a contact pad of the at least one semiconductor die…
…in combination with the other limitations.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MOLLY KAY REIDA whose telephone number is (571)272-4237. The examiner can normally be reached M-F 8:30-5:00PM.
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/MOLLY K REIDA/Examiner, Art Unit 2899
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