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 .
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
The following title is suggested: Improved Bonding Wires and Connectors in Semiconductor Device Packages, and Semiconductor Device
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 1-3, and 5-6 are rejected under 35 U.S.C. 102(a)(1) as being clearly anticipated by Takada; Mitsuo et al. (US 2022/0122937; hereinafter Takada).
Regarding claim 1, Takada discloses a semiconductor device comprising:
a semiconductor element (2; Fig 2; ¶ [0091]);
a first lead (one of 4; Fig 2; ¶ [0091]) electrically connected to the semiconductor element; and
a connecting member (one of bonding wires 5; Fig 2; ¶ [0091]); connected to the semiconductor element and the first lead, wherein
the connecting member includes a core (copper core material; ¶ [0049]) containing a first material (copper {Cu} alloy; ¶ [0092,0049]) and a surface layer (palladium {Pd} layer; ¶ [0058]), the surface layer covering the core and containing a first metal (Pd),
the first material includes an alloy in which at least a third metal (platinum {Pt}, for example {Table 1, example 12}, from among a group disclosed to be preferably selected from; ¶ [0051-53]) is added to a second metal (Cu; ¶ [0049]) and has a higher corrosion resistance than the second metal (it is known in the art {and disclosed by the Applicant} that Pt has a higher corrosion resistance than Cu), and
the third metal has a highest proportion among the metals added (in Table 1, example 12, at least, has Pt as the third metal in a highest proportion among added metals, being the only metal added to the core in the example) and has an atomic number greater than the second metal (The atomic number of Pt is 78, and of Cu is 29, as is readily known by consulting a Periodic Table. )
Regarding claim 2, Takada discloses the semiconductor device according to claim 1, wherein the second metal is Cu (as applied to claim 1).
Regarding claim 3, Takada discloses the semiconductor device according to claim 1, wherein the third metal is Pt (as applied to claim 1).
Regarding claim 5, Takada discloses the semiconductor device according to claim 1, wherein the first metal is Pd (as applied to claim 1).
Regarding claim 6, Takada discloses the semiconductor device according to claim 1, wherein the connecting member is a wire (as applied to claim 1).
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 4 is rejected under 35 U.S.C. 103 as being unpatentable over Takada; Mitsuo et al. (US 2022/0122937; hereinafter Takada) in view of Matsuura; Masamitsu (US 2023/0068748; hereinafter Matsuura).
Regarding claim 4, Takada discloses the semiconductor device according to claim 1, wherein a Pd coating is added to a copper wire to prevent oxidation (¶ [0005]).
Takada does not specifically disclose wherein the first metal (Pd) has a greater bonding strength to the first lead than the first material (Cu alloy).
In the same field of endeavor, Matsuura discloses that a palladium plating is added to a copper bonding pad to improve bond strength of the bonding pad to a wire. Accordingly, it would have been obvious to a person having ordinary skill in the art that Pd has a greater bonding strength to a lead than Cu, and that the Pd coating added to the copper wire as disclosed by Takada would have the same property.
Claims 7-8 and 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Takada; Mitsuo et al. (US 2022/0122937; hereinafter Takada) in view of Jeon; Oseob et al.. (US 2007/0001278 A1; hereinafter Jeon) and Otremba; Ralf et al. (US 2016/0293549; hereinafter Otremba).
Regarding claim 7, Takada discloses the semiconductor device according to claim 1, but does not disclose further comprising: a second semiconductor element; a second lead electrically connected to the second semiconductor element; and a second connecting member connected to the second semiconductor element and the second lead and configured such that a current flowing therein is smaller than a current flowing in the connecting member, wherein the second connecting member consists solely of a second core containing a second material.
In the same field of endeavor, Jeon discloses a semiconductor device comprising:
a semiconductor element (power transistor 606; Figs 24A-24C; ¶ [0323-324]), a first lead (source lead 610a; Figs 24B-24C; ¶ [0328]), and a connecting member (one of source wires 616a; Figs 24B-24C; ¶ [0328]);
a second semiconductor element (control IC 604; Figs 24A-24C; ¶ [0314,0323-324]); a second lead (control lead 610b; Figs 24B-24C; ¶ [0330]) electrically connected to the second semiconductor element; and a second connecting member (one of bonding wires 616(e); Figs 24B-24C; ¶ [0330]) connected to the second semiconductor element, wherein Jeon discloses the bonding wires may be formed of a metal such as copper and may be, for example, coated copper (¶ [0123]), but not disclose further structural detail of the bonding wires.
Accordingly, it would have been obvious for a person having ordinary skill in the art to have combined the disclosures Takada with that of Jeon. One would have been motivated to do this in order to include the palladium-coated copper alloy bonding wire of Takada, which can maintain bonding reliability in-high temperature and high-humidity environments (Takada; ¶ [0012]), in the semiconductor device of Jeon having more than one semiconductor element. One would have had a reasonable expectation of success because of the materials of Takada are consistent with those disclosed by Otremba in the similar endeavor.
Takada and Jeon do not disclose the second connecting member is configured such that a current flowing therein is smaller than a current flowing in the connecting member, wherein the second connecting member consists solely of a second core containing a second material.
In the same field of endeavor, Otremba discloses a semiconductor device comprising a wire (including, for example copper alloy, that may or may not include a coating; ¶ [0046]) that may be configured (smaller thickness / diameter) such that a current flowing therein is smaller than a current flowing through another wire (¶ [0046]) due to different current requirements for a gate electrode (smaller current) as compared to a source electrode (larger current). Accordingly, it would have been obvious to a person having ordinary skill in the art to have combined the disclosures of Otremba with that of Takada in view of Jeon and configured the connecting member and second connecting member for the case where the semiconductor element includes different leads having different current carrying requirements, such as may be the case of the control lead 610b of Jeon used for the control IC as compared to the source lead 610a used for the power transistor 606. One would have had a reasonable expectation of success because of the similarity in devices and materials disclosed by each of Takada, Jeon and Otremba.
None of Takada, Jeon and Otremba discloses the second connecting member consists solely of a second core containing a second material. However, both Otremba and Jeon disclose that the wire(s) may or may not have a coating (that is, a surface layer, similar to that disclosed by Takada). It would have been obvious to a person having ordinary skill in the art, having chosen to use connecting members with different configurations (bonding wires having different thickness / diameter) to have used for the second, less demanding (lower current, smaller diameter) connecting member a second material that does not have the Pd coating of Takada. One may have been motivated to do this in order to reduce the cost of the second connecting member by eliminating the expensive Pd, and reserving the more expensive connecting members for the connections that most require or benefit from them. One would have had a reasonable expectation of success because uncoated bonding wire is well-known in the art, disclosed by both each of Otremba and Jeon, and because it is common to consider and trade off a variety factors including cost, performance, and reliability.
Regarding claim 8, Takada in view of Jeon and Otremba discloses the semiconductor device according to claim 7, wherein the semiconductor element is a transistor (power transistor 606, as applied to claim 7), and the second semiconductor element is a driver IC (control IC 604, as applied to claim 7) that drives and controls the transistor.
Regarding claim 11, Takada in view of Jeon and Otremba discloses the semiconductor device according to claim 7, but does not disclose wherein the second material consists solely of the second metal (Takada; Cu, as applied to claim 1) to which no other metals are added. However, each of Takeda (¶ [0005], examples 1-11 of Table 1), Jeon (¶ [0123]) and Otremba (¶ [0046]) disclose a copper core to which no other metals are added. One may have been motivated to use Cu to which no other metals are added in order to further reduce the cost of the second connecting member by eliminating the expensive Pt, it being known at the time of the invention that both Pd and Pt were significantly more expensive than Cu, and reserving the more expensive connecting members for the connections that most require or benefit from them. One would have had a reasonable expectation of success because Cu bonding wire is well known in the art, and because it is common to consider and trade off a variety factors including cost, performance, and reliability.
Regarding claim 12, Takada in view of Jeon and Otremba discloses the semiconductor device according to claim 7, wherein the second material contains a fourth metal having a higher electrical resistivity than the second metal. However, Takada discloses that one of the following metals is preferably added to the copper core material to improve bonding reliability: Au, Pd, Pt, Rh, Ni, In, and Ga (Takada; ¶ [0051]), and each of the listed materials has a higher resistivity than Cu (as is readily known by consulting a material properties reference). Accordingly, it would have been obvious to a person having ordinary skill in the art to have added one of the listed metals to Cu to form the second material. One would have been motivated to do this, with a reasonable expectation of success, because of Takada’s disclosure.
Regarding claim 13, Takada in view of Jeon and Otremba discloses the semiconductor device according to claim 12, but does not specifically disclose wherein the fourth metal is Au. However, it would have been obvious for a person having ordinary skill in the art to have chosen Au from Takada’s list of preferred metals to add to the Cu core. One may have been motivated to do this because Au has the lowest resistivity of any of the materials on the list (as is readily known by consulting a material properties reference), thereby enabling one to maintain a resistance of the connecting member closest to that of Cu to which no metals are added, while improving bonding reliability (as explained for claim 12.) One would have had a reasonable expectation of success because of Takada’s disclosure.
Claims 9-10 are rejected under 35 U.S.C. 103 as being unpatentable over Takada; Mitsuo et al. (US 2022/0122937; hereinafter Takada) in view of Otremba; Ralf et al. (US 2016/0293549; hereinafter Otremba).
Regarding claim 9, Takada discloses the semiconductor device according to claim 1, further comprising:
a second lead (another of 4; Fig 2; ¶ [0091]) electrically connected to the semiconductor element; and
a second connecting member (another of 5; Fig 2; ¶ [0091]) connected to the semiconductor element (2; Fig 2) and the second lead.
Takada does not disclose the second connecting member is configured such that a current flowing therein is smaller than a current flowing in the connecting member, wherein the second connecting member consists solely of a second core containing a second material.
In the same field of endeavor, Otremba discloses a similar semiconductor device comprising a wire (including, for example copper alloy, that may or may not include a coating; ¶ [0046]) that may be configured (smaller thickness / diameter) such that a current flowing therein is smaller than a current flowing through another wire (¶ [0046]) due to different current requirements for a gate electrode (smaller current) as compared to a source electrode (larger current). Accordingly, it would have been obvious to a person having ordinary skill in the art to have combined the disclosures of Otremba with that of Takada and configured the connecting member and second connecting member of Takada for the case where the semiconductor element includes different leads having different current carrying requirements. One would have had a reasonable expectation of success because of the similarity in devices and materials disclosed by each of Takada and Otremba.
Neither Takada nor Otremba discloses the second connecting member consists solely of a second core containing a second material. However, Otremba discloses that the wire(s) may or may not have a coating (that is, a surface layer, similar to that disclosed by Takada). It would have been obvious to a person having ordinary skill in the art, having chosen to use connecting members with different configurations (bonding wires having different thickness / diameter) to have used for the second, less demanding (lower current, smaller diameter) connecting member a second material that does not have the Pd coating of Takada. One may have been motivated to do this in order to reduce the cost of the second connecting member by eliminating the expensive Pd, and reserving the more expensive connecting members for the connections that most require or benefit from them. One would have had a reasonable expectation of success because uncoated bonding wire is well-known in the art, is disclosed Otremba, and because it is common to consider and trade off a variety factors including cost, performance, and reliability.
Regarding claim 10, Takada discloses the semiconductor device according to claim 1, but does not disclose wherein the semiconductor element is a transistor.
In the same field of endeavor, Otremba discloses a similar semiconductor device comprising a transistor (having a gate and a source; ¶ [0046]; for example a HEMT, high electron mobility transistor; ¶ [0047-48]), but does not disclose material construction details of its bonding wires (¶ [0046]). Accordingly, it would have been obvious to have combined the disclosure of Takada with that of Otremba. One would have been motivated to do this in order to include the palladium-coated copper alloy bonding wire of Takada which can maintain bonding reliability in-high temperature and high-humidity environments (Takada; ¶ [0012]). One would have had a reasonable expectation of success because of the materials of Takada are consistent with those disclosed by Otremba in the similar endeavor.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Takada; Mitsuo et al. (US 2022/0122937; hereinafter Takada) in view of Oda Taizo et al. (JP 2018/078229; hereinafter Oda).
Regarding claim 14, Takada discloses the semiconductor device according to claim 1, further comprising a resin member (encapsulated in a commercially available resin; ¶ [0131,0137]) covering the connecting member.
Takada does not disclose the resin member has a sulfur content of 5 ppm or more.
In the same field of endeavor Oda discloses a bonding wire for semiconductor device wherein the bonding wire undergoes a HAST evaluation similar to that of Takada (¶ [0132-138]) and is encapsulated in a “low-concentration sulfur containing resin” having sulfur content of 2ppm and in a “high-concentration sulfur containing resin” having sulfur content of 16 ppm, comprising a range of sulfur content from 2-16 ppm, overlapping the claimed range of greater than 5 ppm. It would have been obvious to a person having ordinary skill in the art that sulfur content of the resin of Takada may be greater than 5 ppm, due to Oda’s disclosure and since such sulfur content is common in resin encapsulants the art.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Nishiyama Yuto et al. (JP-2021027116-A)
Yamada, Takashi et al. (JP-5912008-B1)
Togashi Akira (JP-2011003745-A)
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/B.A.K./Examiner, Art Unit 2817
/ELISEO RAMOS FELICIANO/Supervisory Patent Examiner, Art Unit 2817