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 § 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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 6 – 9 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 6 includes “wherein the lead frame comprises electrical contact points to terminals of the semiconductor die,” It is unclear what “contact points” means. For the instant examination, the Examiner interprets it as “connection points.”
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims [ 1, 4, 10, 13-16, 19, and 20 ] are rejected under 35 U.S.C. 102(a)(1)&(a)(2) as being anticipated by Kassim.
Regarding claim 1, Kassim discloses:
A semiconductor package with a dual sided heat dissipation structure, (Kassim; Fig. 4B; [0057] the heat dissipation surface 116; Fig. 4C; the outer surface 224 of the die pad 204 can interface with a heat sink; 116 is the heat dissipation surface [0057]; Fig. 2A, where 116, 126, 102 together from one thick metal, which is a heat sink connected to one side of the die 212. the outer surface 224 of the die pad 204 can interface with a heat sink; 224 is on second side of the die. Therefore it is a dual sided heat dissipation structure.) the semiconductor package comprising: a semiconductor die having a first side and a second side, the second side being opposite to the first side; (Kassim; Fig. 2; [0044] A semiconductor die 212; where 116, 126, 102 together from one thick metal, which is a heat sink connected to one side of the die 212; where 224 is on second side of the die 212) a heat spreader on the first side of the semiconductor die; a lead frame on the second side of the semiconductor die; and a die clip positioned between the semiconductor die and a portion of the lead frame, wherein the die clip and the lead frame are joined at connection points. (Kassim; Fig. 2; [0044] A semiconductor die 212; Fig. 4B; [0057] the heat dissipation surface 116; [0043] a lead frame 202; a plurality of leads 206, where the leads are connected to surface terminal 214. A surface terminal attached to a pad or board is almost always a solder junction. Fig. 2A, clip 100, attach pad 102; die pad 204)
Regarding claim 4, Kassim teaches the limitation of claim 1 as discussed above.
Kassim discloses:
wherein the semiconductor package is free from solder between the lead frame and the die clip. (Kassim; Fig. 2; [0044] A semiconductor die 212; [0043] a lead frame 202; die clip 100; Fig. 2A. Between lead frame 202 and clip 100 is free from solder.)
Regarding claim 10, Kassim teaches the limitation of claim 1 as discussed above.
Kassim discloses:
wherein the lead frame comprises a lead, and at least a portion of the lead that extends beyond the heat spreader is flat. (Kassim; Fig. 6A 228 [0058]: “each of the leads 206 extend along a single plane)
Regarding claim 13, Kassim teaches the limitation of claim 1 as discussed above.
Kassim discloses:
the heat spreader is electrically connected to a drain terminal of the semiconductor die.
(Kassim; Fig. 2A; [0030]; heat dissipation pads 116; where 116, 126, 102 together from one thick metal, which is a heat sink connected to one side of the die 212; leads are connected to surface terminal 214. A surface terminal attached to a pad or board is almost always a solder junction.)
Regarding claim 14, Kassim teaches the limitation of claim 1 as discussed above.
Kassim discloses:
the die clip is positioned within a footprint of the lead frame. (Kassim; Fig. 2A; [0044] A semiconductor die 212; A die clip 100, 126 is part of it. [0043] a lead frame 202)
Regarding claim 15, Kassim discloses:
joining a die clip with a lead frame at a plurality of connection points; (Kassim; Fig. 2; [0044] A semiconductor die 212; [0043] a lead frame 202; a plurality of leads 206)
and after the joining, soldering the die clip to a semiconductor die, (Kassim; Fig. 2; a surface terminal 214; a surface terminal attached to a pad or board is almost always a solder junction.) wherein the die clip and the lead frame are on an opposite side of the semiconductor die than a heat spreader after the soldering. (Kassim; Fig. 2A; clip 100; a lead frame 202; heat dissipation surface 116.)
Regarding claim 16, Kassim teaches the limitation of claim 15 as discussed above.
Kassim discloses:
wherein the joining comprises welding. (Kassim; Fig. 2; a surface terminal 214; a surface terminal attached to a pad or board is almost always a solder junction.)
Regarding claim 19, Kassim teaches the limitation of claim 15 as discussed above.
Kassim discloses:
further comprising reflowing solder to connect the heat spreader and the semiconductor die prior to the soldering. (Kassim; Fig. 2; a surface terminal 214; a surface terminal attached to a pad or board is almost always a solder junction.; A semiconductor die 212; heat dissipation surface 116.)
Regarding claim 20, Kassim teaches the limitation of claim 15 as discussed above.
Kassim discloses:
pre-molding the heat spreader prior to the soldering. (Kassim; Fig. 2; heat dissipation surface 116.)
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 [ 2, 5, 18] are rejected under 35 U.S.C. 103 as being unpatentable over Kassim et al. US 20220139811 A1 (hereinafter Kassim) and in view of Hamner et al. US 20230369784 A1 (hereinafter Hamner)
Regarding claim 2, Kassim teaches the limitation of claim 1 as discussed above.
Kassim does not disclose:
wherein the die clip comprises openings at the connection points.
Hamner discloses:
wherein the die clip comprises openings at the connection points. (Hamner; [0095] FIG. 28 In the illustrated embodiment, the ground connection members 390 are openings for soldering or laser welding to the cable shields 160 of the cables 104.)
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add Hamner’s design into Kassim’s design. The reason for having openings would be for soldering or laser welding.
Regarding claim 5, Kassim teaches the limitation of claim 1 as discussed above.
Kassim does not disclose:
wherein the connection points provide alignment points between the lead frame and the die clip for welding the die clip and the lead frame.
Hamner discloses:
wherein the connection points provide alignment points between the lead frame and the die clip for welding the die clip and the lead frame. (Hamner; [0095] FIG. 28 In the illustrated embodiment, the ground connection members 390 are openings for soldering or laser welding to the cable shields 160 of the cables 104.)
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add Hamner’s design into Kassim’s design for soldering or laser welding.
Regarding claim 18, Kassim teaches the limitation of claim 15 as discussed above.
Kassim does not disclose:
Wherein the die clip comprises a plurality of openings at the connection points.
Hamner discloses:
wherein the die clip comprises openings at the connection points. (Hamner; [0095] FIG. 28 In the illustrated embodiment, the ground connection members 390 are openings for soldering or laser welding to the cable shields 160 of the cables 104.)
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add Hamner’s design into Kassim’s design for soldering or laser welding.
Claims 3, 6, 11, 17 are rejected under 35 U.S.C. 103 as being unpatentable over Kassim et al. US 20220139811 A1 (hereinafter Kassim) and in view of Muto et al. US 20080012045 A1 (hereinafter Muto)
Regarding claim 3, Kassim teaches the limitation of claim 1 as discussed above.
Kassim does not disclose:
wherein the lead frame comprises a gate lead and a Kelvin source lead, a first connection point of the connection points joins the die clip and the gate lead, and a second connection point of the connection points joins the die clip and the Kelvin source lead.
Muto discloses:
wherein the lead frame comprises a gate lead (Muto; [0150] FIG. 39 the gate electrode for external connection of the semiconductor device 10) and a Kelvin source lead, a first connection point of the connection points joins the die clip and the gate lead, and a second connection point of the connection points joins the die clip and the Kelvin source lead. (Muto; FIG. 4 [0094] an electrode for Kelvin detection 24; an electrode for Kelvin detection 26; clip 20; gate electrode 23 )
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add Muto’s design into Kassim’s design. The reason for doing this would be to measure resistance.
Regarding claim 6, Kassim teaches the limitation of claim 1 as discussed above.
Kassim discloses:
wherein the semiconductor die comprises a field effect transistor, wherein the lead frame comprises electrical contact points to terminals of the semiconductor die, and wherein the terminals of the semiconductor die comprise a source terminal, a gate terminal, and a drain terminal. (Kassim; Fig. 2; [0044] A semiconductor die 212; [0043] a lead frame 202; a plurality of leads 206; [0046] devices include power diodes and power transistor devices such as MOSFETs (metal-oxide semiconductor field-effect transistors) IGBTs (insulated gate bipolar transistors), HEMTs (high electron mobility transistors). In these embodiments, the first surface terminal 214 can be a load terminal of the device (e.g., source, emitter, anode, etc.). In a vertical device configuration, the semiconductor die 212 may comprise a second load terminal (e.g., drain, collector, cathode, etc.) that is disposed on a rear surface of the semiconductor die 212 and electrically connected to the die pad 204, e.g., by a soldered connection.)
Kassim does not disclose:
a Kelvin source terminal,
Muto discloses:
a Kelvin source terminal, (Muto; [0150] FIG. 39 the Kelvin detection circuit to be connected to the electrode for Kelvin detection.)
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add Muto’s design into Kassim’s design. The reason for doing this would be to measure resistance. power transistor devices such as MOSFETs need to be low resistance to be efficient. When overheated, resistance increases.
A Kelvin detector has four terminals (two pairs), one pair for voltage, one pair for current. From Ohm’s law: R=V/I.
Regarding claim 11, Kassim teaches the limitation of claim 1 as discussed above.
Kassim does not disclose:
a thermistor die, wherein the lead frame comprises a thermistor lead electrically connected to a terminal of the thermistor die.
Muto discloses:
a thermistor die, wherein the lead frame comprises a thermistor lead electrically connected to a terminal of the thermistor die. (Muto; Fig. 4; [0094] the semiconductor chip 15, which are connected to the electrodes for temperature detection. Power transistor devices such as MOSFETs need to be low resistance to be efficient. When overheated, resistance increases.)
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add Muto’s design into Kassim’s design. The reason for doing this would be to detect temperature.
Regarding claim 17, Kassim teaches the limitation of claim 15 as discussed above.
Kassim does not disclose:
the semiconductor die comprises a field effect transistor, and the lead frame comprises a gate lead and a Kelvin source lead.
Muto discloses:
the semiconductor die comprises a field effect transistor, and the lead frame comprises a gate lead and a Kelvin source lead. (Muto; [0150] FIG. 39; the gate electrode for external connection of the semiconductor device 10; the Kelvin detection circuit to be connected to the electrode for Kelvin detection.)
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add Muto’s design into Kassim’s design. The reason for doing this would be to measure resistance.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Kassim et al. US 20220139811 A1 (hereinafter Kassim) and in view of Xiaochun et al. US 20050199985 A1 (hereinafter Xiaochun)
Kassim teaches the limitation of claim 1 as discussed above.
Kassim does not disclose:
die attach solder positioned between the heat spreader and the first side of the semiconductor die.
Xiaochun discloses:
die attach solder positioned between the heat spreader and the first side of the semiconductor die. (Xiaochun; Fig. 1; [0024] lead frame 140; clip 102; [0025] solder 154.)
Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to add Xiaochun’s design into Kassim’s design. The reason for doing this would be to improve conductivity.
Claims 7, 8, 9 are 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.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to WEI LI whose telephone number is (571)270-0313. The examiner can normally be reached 8:30-5:00.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Brent Fairbanks can be reached at 4089187532. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/WEI LI/Examiner, Art Unit 2899
/Brent A. Fairbanks/Supervisory Patent Examiner, Art Unit 2899
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