Detailed Action
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 § 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.
Claims 21 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by U.S. Pat. Pub. No. 20130005083 to Liu et al. (Liu).
Regarding Claim 21, Liu discloses a method of forming a semiconductor device, comprising:
providing a lead frame 40 comprising a conductive material [0039]; and
machining the lead frame to form (Fig. 9 for example):
a first die attach pad and a second die attach pad (32.1-32.4),
a source clip 712 connected to the first die attach pad by at least a first source clip connecting bar 722 and connected to the second die attach pad [0053],
a gate clip 710 connected to the die attach pad by a gate clip connecting bar 610,
a source lead 42.1-42.3, and
a gate lead ([0015], see also Fig. 10 showing source-gate leads).
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- are rejected under 35 U.S.C. 103 as being unpatentable over Liu in view of U.S. Pat. No. 5528079 to McIver.
Regarding Claim 1, Liu teaches a semiconductor device comprising:
a die attach pad connected at a first position (source region) to a source clip by a first source clip connecting bar, and connected at a second position (gate region) to a gate clip by a gate clip connecting bar;
a die positioned on the die attach pad;
a source lead; and
a gate lead (see above rejection of Claim 21);
wherein the source clip is bent over at least a portion of the die attach pad [0045] such that at least a portion of the source clip provides electrical contact at least a portion of the die [0053]; and
wherein the gate clip is bent over at least a portion of the die attach pad [0040] such that at least a portion of the gate clip provides electrical contact between at least a portion of the die [0053].
Liu does not explicitly teach that at least a portion of the clip provides electrical contact between at least a portion of the die and the lead. However, in analogous art, McIver in related art of semiconductor die package, further discloses wherein at least a portion of the clip provides electrical contact between at least a portion of the die and the lead (3:20-25; one end 10a of clip 10 is bonded to the metallized top of semiconductor die 4 by the same technique of solder bonding; the other end 10c of clip 10 is bonded to the second lead 8 in similar fashion; the sections 10a and 10c are parallel and are connected by a curved section 10b).
It would have been obvious to one having ordinary skill in the art before the filing of the application since at least a portion of the clip provides electrical contact between at least a portion of the die and the lead, as disclosed by McIver, in the semiconductor device, as disclosed by Liu, to improve the heat dissipation and reduce costs as taught by McIver 1:21-33.
Regarding Claim 2, Liu and McIver teach the semiconductor device of claim 1 wherein the first source clip connecting bar between the die attach pad and the source clip (Liu [0053]) but does not explicitly teach that the clip connecting comprises a curved portion. However, McIver further teaches that the clip connecting comprises a curved portion (col. 3, In 22-25- The sections 10a and 10c are parallel and are connected by a curved section 10b. The other end 10c of clip 10 is bonded).
Regarding Claim 3, Liu and McIver teach the semiconductor device of claim 1 wherein the gate clip connecting bar between the die attach pad and the gate clip (Liu [0053]) but does not explicitly teach that the clip connecting comprises a curved portion. However, McIver further teaches that the clip connecting comprises a curved portion (col. 3, In 22-25- The sections 10a and 10c are parallel and are connected by a curved section 10b. The other end 10c of clip 10 is bonded).
Regarding Claim 4, Liu and McIver teach the semiconductor device of claim 1 wherein the die attach pad, the source clip, and the first source clip connecting bar are integrally formed (Liu [0053]).
Regarding Claim 5, Liu and McIver teach the semiconductor device of claim 1 wherein the die attach pad, the gate clip, and the gate clip connecting bar are integrally formed ([0053] The other die attach pad receive solder paste Then a conductive epoxy is applied to the source and gate regions. Gate clips 710, 711 connect the gate to leadless gate contact pads; [0052] a leadless contact bar 610. The bar has four external leadless contact pads; [0003] The control circuit and the gate drivers may themselves be integrated into a single circuit and packaged in one or more small size packages).
Regarding Claim 6, Liu and McIver teach the semiconductor device of claim 2 wherein the first source clip connecting bar (FIG.49, 722; [0053] the other die attach pad receive solder paste Then a conductive epoxy is applied to the source and gate regions; the source clip 712 connects the sources to a source bar 722).
Regarding Claim 7, Liu and McIver teach the semiconductor device of claim 3 wherein the gate clip connecting bar (FIG.45, 610; [0052] a leadless contact bar 610. The bar has four external leadless contact pads; para [0053]- Gate clips 710, 711 connect the gate to leadless gate contact pads) and McIver teaches that the clip connecting has a portion having a U, C or arc shape (Fig. 5).
Regarding Claim 8, Liu and McIver teach the semiconductor device of claim 1, further comprising a second source clip connecting bar connecting the die attach pad to the source clip at a third position (FIG.27, 342.2) spaced apart from the first position (FIG.27, 342.1).
Regarding Claim 9, Liu and McIver teach the semiconductor device of claim 8 wherein the die attach pad, the source clip, and the second source clip connecting bar are integrally formed [0053].
Regarding Claim 10, Liu and McIver teach the semiconductor device of claim 8, wherein the second source clip connecting bar between the die attach pad and the source clip [0053]. McIver further teaches that the clip connecting comprises a curved portion (col. 3, In 22-25- The sections 10a and 10c are parallel and are connected by a curved section 10b. The other end 10c of clip 10 is bonded).
Regarding Claim 11, Liu and McIver teach the semiconductor device of claim 10, whereinthe second source clip connecting bar (para [0040]- Tie bars 46.1-46.8 and 47.1-47.8 (FIG. 7) connect the lead frames 40) and McIver further teaches that the clip connecting has a portion having a U, C or arc shape (Fig. 5).
Regarding Claim 12, Liu and McIver teach the semiconductor device of claim 11, wherein the first source clip connecting bar and the second source clip connecting bar are configured to hold the source clip in position (Claim 1).
Regarding Claim 13, Liu and McIver teach the semiconductor device of claim 1, comprising an encapsulation material 84 encapsulating the die attach pad, the die, the source clip, the gate clip, at least a portion of the source lead, and at least a portion of the gate lead.
Regarding Claim 11, Liu and McIver teach a semiconductor device comprising:
a die attach pad 32.1- 32.4 comprising a source clip connection bar 722;
a source clip 712 comprising the source clip connection bar;
a gate clip 710, 711 comprising the gate clip connection bar 610;
a die positioned on the die attach pad ([0037] surface 31 surface has four die attach pads 32.1-32.4 for holding the dies in place);
a source lead 42.1-42.03; and
a gate lead ([0015]- FIG. 10 is a matrix of a plurality of source and gate lead frames); wherein the source clip is positioned over at least a portion of the die attach pad such that at least a portion of the source clip provides electrical contact at least a portion of the die [0053]; and
wherein the gate clip is positioned over at least a portion of the die attach pad such that at least a portion of the gate clip provides electrical contact between at least a portion of the die [0053] but does not explicitly teach a first portion of a clip connection, and a second portion of a clip connection, wherein at least a portion of the clip provides electrical contact between at least a portion of the die and the lead.
However, in analogous art, McIver teaches a first portion of a clip connection 10a, and a second portion of a clip connection 10c, wherein at least a portion of the clip provides electrical contact between at least a portion of the die and the lead (3:10-25; one end 10a of clip 10 is bonded to the metallized top of semiconductor die 4 by the same technique of solder bonding).. It would have been obvious to one having ordinary skill in the art before the filing of the application, a first portion of a clip connection, and a second portion of a clip connection, wherein at least a portion of the clip provides electrical contact between at least a portion of the die and the lead, as taught by McIver, in the semiconductor device, as disclosed by Liu, to improve the heat dissipation and reduce costs 1:21-33.
Regarding Claim 20, Liu and McIver teach the semiconductor device of claim 14, further comprising an encapsulation material 84 encapsulating the die attach pad, the die, the source clip, the gate clip, at least a portion of the source lead, and at least a portion of the gate lead (Fig. 15).
Claims 22-23 are rejected under 35 U.S.C. 103 as being unpatentable over Liu as applied to claim 21 above, and further in view of U.S. Pat. Pub. No. 20200068735 to Suwa et al. (Suwa) and McIver.
Regarding Claim 22, Liu teaches the method of claim 21, further comprising:
attaching a die to the second die attach pad ([0037] surface 31 surface has four die attach pads 32.1-32.4 for holding the dies in place);
the second source clip connecting bar ([0053] the source clip 712 connects the sources to a source bar 722); and
bending the source clip over at least a portion of the die attach pad such that at least a portion of the source clip provides electrical contact at least a portion of the die [0053.
LIU does not explicitly teach cutting the connecting bar; wherein at least a portion of the clip provides electrical contact between at least a portion of the die and the lead. However, in analogous art, Suwa teaches cutting the connecting bar [0148]. It would have been obvious to one having ordinary skill in the art before the filing of the the invention, cutting the connecting bar, as disclosed by Suwa, in the semiconductor device, as disclosed by Liu, to improve the productivity, as taught by Suwa [0133].
McIver further teaches that at least a portion of the clip provides electrical contact between at least a portion of the die and the lead 3:20-25. It would have been obvious to one having ordinary skill in the art before filing of the invention, wherein at least a portion of the clip provides electrical contact between at least a portion of the die and the lead, as taught by McIver, in the semiconductor device, as taught by Liu, to improve the heat dissipation and reduce costs 1:21-23.
Regarding Claim 23, Liu, Suwa and McIver teach the method of claim 22, further comprising: bending the gate clip over at least a portion of the die attach pad ([0040] after removal, the ends of the gate and source members are bent at an angle of 45 degrees so that the leadless contact ends of the gate and source members are in a plane parallel but spaced from the plane that includes the contacts to the sources and gates) such that at least a portion of the gate clip provides electrical contact at least a portion of the die [0053] and McIver further teaches that at least a portion of the clip provides electrical contact between at least a portion of the die and the lead 3:20-25.
Allowable Subject Matter
Claims 15-19 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.
The following is a statement of reasons for the indication of allowable subject matter: The cited prior art does not explicitly teach that the first portion of the source clip connection bar has an end face having a dimension matching a dimension of an end face of the second portion of the source clip connection bar, in context with superseding claim 14. Claims 16-19 are similarly allowed.
Conclusion
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/EVREN SEVEN/Primary Examiner, Art Unit 2812
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