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
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-6 & 11 are rejected under 35 U.S.C. 103 as being unpatentable over Trichy et al. (US 2019/0221449) [Hereinafter Trichy] & Trichy et al. (US 2020/0343107) [Hereinafter Trichy_2020].
Regarding claim 1, Trichy teaches A method, comprising:
filling a first material [fig. 7, filler 81/811/800, para 30/36] having a first density in a housing [fig. 7, housing 7, para 15] to form a liquid or gel-like first pre-layer [fig. 4, 811, para 35],
wherein the housing comprises sidewalls (fig. 7, 7), and
a substrate [fig. 7, substrate 10, para 16] with at least one semiconductor body arranged thereon is arranged in or forms a ground surface of the housing (fig. 7, 7), and
wherein the first pre-layer (fig. 4, 811) partly fills the housing (fig. 7, 7) and completely covers the substrate (fig. 7, 10; wherein the layer 811 completely covers the top surface of the substrate) and the at least one semiconductor body [fig. 7, semiconductor body 20, para 19] arranged thereon;
filling a second material [fig. 7, layer 801, para 30] different from the first material and having a second density in the housing (fig. 7, 7),
the first density being higher than the second density, to form
a liquid or gel-like second pre-layer [wherein the layer 801 includes casting material i.e. silicone gel], wherein
the first pre-layer (fig. 7, 811/800) forms between the second pre-layer (fig. 7, 801) and the substrate (fig. 7, 10); and
performing a curing step [para 37],
forming
a solid first layer [fig. 7; wherein layer 800 becomes solid upon curing] and a solid second layer [fig. 7, layer 801],
wherein the second layer permanently adheres to the first layer [fig. 7].
Trichy fails to explicitly disclose the curing step simultaneously curing the first material and the second material.
However Trichy_2020 teaches the curing step simultaneously curing the first material and the second material [para 46, the filler and casting material which form layers 800 & 801 are cured simultaneously].
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention to cure the first and second material simultaneously to create a seamless bond across the layer boundary.
Regarding claim 2, Trichy/Trichy_2020The method of claim 1, wherein:
filling the first material in the housing comprises filling a first silicone material in the housing; and
filling the second material in the housing comprises filling a second silicone material in the housing.
[Trichy teaches the layer 801 and 800 both may comprise silicon material in para 30/33].
Regarding claim 3, Trichy/Trichy_2020 teaches The method of claim 1,
wherein filling the first material in the housing and filling the second material in the housing are performed successively [Trichy, fig. 7, para 39-41].
Regarding claim 4, Trichy/Trichy_2020 teaches The method of claim 3,
wherein in a first step, the second material is filled in the housing, and, in a subsequent second step, the first material is injected underneath the second pre-layer formed by the second material.
[Trichy teaches in para 39-40 that the order/orientation of the first and second material is interchangeable and therefore may be rearranged as desired by design. Therefore, it would be obvious to one of ordinary skill to insert the first material underneath the second material as a design preference.].
Regarding claim 5, Trichy/Trichy_2020 teaches The method of claim 1,
wherein the curing step comprises heating at least the first pre-layer and the second pre-layer to temperatures of up to 150°C [Trichy_2020 teaches in para 44 heating the filler 81 and casting compound 5 between 30 and 150° C].
Regarding claim 6, Trichy/Trichy_2020 teaches The method of claim 1, wherein a difference between the first density and the second density is at least 0.005 g/cm3, or at least 0.1 g/cm3.
Trichy_2020 teaches para 6 wherein the casting material has a lower density than the inorganic filler. Para 29 teaches the casting material to be a polymer such as silicone gel. Para 30 discloses exemplary filler material and further states “if the density ρf of the filler 81 is 0.9 g/cm3 , the density ρcc of the casting compound 5 is <0.9 g/cm3 , or even <0.5 g/cm3”.
Therefore, it would be obvious to one of ordinary skill wherein a difference between the first density and the second density is at least 0.005 g/cm3, or at least 0.1 g/cm3.
Regarding claim 11, Trichy/Trichy_2020 teaches The method of claim 1,
wherein the first material (Trichy, fig. 7, 800) comprises a first base polymer mixed with a filler (Trichy, fig. 7, 81), and
the second material (Trichy, fig. 7, 801) comprises a second base polymer [Trichy, para 33], and
wherein the filler increases a density of the first base polymer to the first density [Trichy_2020, para 30].
Claim(s) 7-8 & 12 are rejected under 35 U.S.C. 103 as being unpatentable over Trichy & Trichy_2020 as applied to claims 1-6 & 11 and further in view of Fujisawa et al. (US 2017/0355804) [Hereinafter Fujisawa].
Regarding claim 7, Trichy/Trichy_2020 teaches The method of claim 1,
wherein the first material (fig. 7, 81/811/800) comprises a first base polymer, and
the second material (fig. 7, 801) comprises a second base polymer.
While Trichy notes the second material may comprise a casting material such as a non-reactive, soft or hard cross-linking polymer.
Trichy/Trichy_2020 fails to explicitly disclose the second material comprising a second base polymer that is different from the first base polymer.
However, Fujisawa teaches “Curable organopolysiloxane compositions cure to form cured products having excellent heat resistance, cold resistance, electrical insulating properties, weather resistance, water repellency, and transparency, and therefore, the compositions are used in a wide range of industrial fields. . . in order to achieve higher power density, driving must be possible even in high temperature conditions where the temperature of the chip surface during operation is 250° C. Therefore, there is strong demand for development of a sealing material that can withstand those temperatures . . .”
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the polymer material to comprise PPMS which is an organopolysiloxane composition to provide excellent heat resistance for the device.
Regarding claim 8, Trichy/Trichy_2020 teaches The method of claim 7,
the second base polymer (fig. 8, 801) is polydimethylsiloxane (PDMS) [Trichy, para 28 teaches the casting compound polymer material to be silicone gel or silicon rubber which is PDMS].
Trichy/Trichy_2020 fails to explicitly disclose wherein the first base polymer is polymethylphenylsiloxane (PPMS).
However, Fujisawa teaches “Curable organopolysiloxane compositions cure to form cured products having excellent heat resistance, cold resistance, electrical insulating properties, weather resistance, water repellency, and transparency, and therefore, the compositions are used in a wide range of industrial fields. . . in order to achieve higher power density, driving must be possible even in high temperature conditions where the temperature of the chip surface during operation is 250° C. Therefore, there is strong demand for development of a sealing material that can withstand those temperatures . . .”
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the polymer material to comprise PPMS which is an organopolysiloxane composition to provide excellent heat resistance for the device.
Regarding claim 12 Trichy/Trichy_2020 teaches The method of claim 11,
the second base polymer (fig. 8, 801) is polydimethylsiloxane (PDMS) [Trichy, para 28 teaches the casting compound polymer material to be silicone gel or silicon rubber which is PDMS].
Trichy/Trichy_2020 fails to explicitly disclose wherein the first base polymer is polymethylphenylsiloxane (PPMS).
However, Fujisawa teaches “Curable organopolysiloxane compositions cure to form cured products having excellent heat resistance, cold resistance, electrical insulating properties, weather resistance, water repellency, and transparency, and therefore, the compositions are used in a wide range of industrial fields. . . in order to achieve higher power density, driving must be possible even in high temperature conditions where the temperature of the chip surface during operation is 250° C. Therefore, there is strong demand for development of a sealing material that can withstand those temperatures . . .”
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the polymer material to comprise PPMS which is an organopolysiloxane composition to provide excellent heat resistance for the device.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Trichy & Trichy_2020 as applied to claims 1-6 & 11 and further in view of Hiromoto et al. (WO2022181281A1) [Hereinafter Hiromoto].
Regarding claim 13, Trichy/Trichy_2020 teaches The method of claim 1,
wherein the first material has a viscosity of at least 450 mPa∙s, or at least 2000 mPa∙s, and/or
the second material has a viscosity of at least 450 mPa∙s, or at least 2000 mPa∙s.
While Trichy notes the first and second materials to comprise silicone gel or silicone rubber.
Trichy/Trichy_2020 fails to explicitly disclose wherein the first material has a viscosity of at least 450 mPa∙s, or at least 2000 mPa∙s, and/or
the second material has a viscosity of at least 450 mPa∙s, or at least 2000 mPa∙s.
However, Hiromoto teaches “contains a silicone gel, and the viscosity of the encapsulant composition at 23°C is 2000 mPa·s or less.”
Therefore it would have been obvious to someone of ordinary skill in the art before the effective filing date of the claimed invention for the materials to comprise silicone gel with a viscosity of 2000 mPa∙s. or less to ensure.
Claim(s) 14-17 are rejected under 35 U.S.C. 103 as being unpatentable over Trichy.
Regarding claim 14, Trichy teaches A power semiconductor module arrangement, comprising:
a substrate [fig. 7, substrate 10, para 16] arranged in or forming a ground surface of a housing (fig. 7, 7),
the housing comprising sidewalls (fig. 7, 7);
at least one semiconductor body [fig. 7, semiconductor body 20, para 19] arranged on the substrate (fig. 7, 7);
a solid first layer partly [fig. 7, 800] filling the housing (fig. 7, 7) and completely covering the substrate (fig. 7, 10) and the at least one semiconductor body (fig. 7, 20) arranged thereon; and
a solid second layer [fig. 7, layer 801, para 30] arranged adjacent to the first layer (fig. 7, 800),
wherein the first layer (fig. 5, 800) is arranged between the second layer (fig. 5, 801) and the substrate (fig. 5, 10),
wherein the first layer (fig. 5, 800) comprises a first material [para 30; wherein layer 800 includes the casting material and the filler],
wherein the second layer (fig. 5 801) comprises a second material that is different from the first material [para 33; wherein layer 800 only contains the casting material], and
wherein the second layer permanently adheres to the first layer [fig. 5].
Regarding claim 15, Trichy teaches The power semiconductor module arrangement of claim 14,
wherein the first layer (fig. 5, 800)and the second layer (fig. 5, 801) each comprise a silicone material [para 30 & 33; wherein both layers comprise silicone gel or silicone rubber. Para 40 discloses curing steps].
Regarding claim 16, Trichy teaches The power semiconductor module arrangement of claim 15,
wherein the first layer and the second layer are cured silicone layers [para 30 & 33; wherein both layers comprise silicone gel or silicone rubber].
Regarding claim 17, Trichy teaches The power semiconductor module arrangement of claim 14,
wherein the second layer (fig. 5, 801) is arranged distant from a top of the housing (fig. 5, 7).
Allowable Subject Matter
Claims 9-10 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:
Regarding claim 9, Trichy/Trichy_2020 teaches The method of claim 1,
wherein the first material comprises a first base polymer.
The prior art of record fails to explicitly disclose the
second material comprises a second base polymer and isopropanol, and
wherein the isopropanol contained in the second material reduces a density of the second base polymer to the second density and evaporates during the curing step.
Thereby claim 9 contains allowable subject matter in light of the additional limitations recited therein and would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 10 contains allowable subject matter at least based upon dependency on claim 9.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to FELIX B ANDREWS whose telephone number is (703)756-1074. The examiner can normally be reached Monday - Friday 8:00 am - 5:00 pm ET.
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/FELIX B ANDREWS/Examiner, Art Unit 2812
/William B Partridge/Supervisory Patent Examiner, Art Unit 2812
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