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 .
Election/Restrictions
Applicant’s election without traverse of Invention I, claims 1-19 in the reply filed on 08/03/2026 is acknowledged.
Claim 20 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 08/03/2026.
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.
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.
Claims 1-4, 7, 11, 13-14, 16, and 18-19 are rejected under 35 U.S.C. 103 as being unpatentable over Park et. al., U.S. Pat. Pub. 2023/0395554, hereafter Park, in view of Mizuno, U.S. Pat. 8,791,564, hereafter Mizuno, in view of Sack et. al., “Optimization of Lead Free SMT Reflow & Rework Process Window”, Presented at IPC Printed Circuits Expo/Apex 2006, hereafter Sack, and further in view of Boyd et. al., U.S. Pat. Pub. 2016/0351526, hereafter Boyd
Regarding claim 1, Park discloses (see Figs 5,6, par. [0077]-[0086]) a method of attaching a plurality of discrete power modules (DPMs) [20] to a substrate [111], the method comprising:
positioning (Fig. 12) the substrate [130] such that a bottom surface of the substrate [130[ opposes a top surface of a base plate [420];
placing (Fig. 6) a plurality of solder pre-forms [130] (par. [0085]) on a top side of the substrate [111]; placing each DPM [20] of the plurality of DPMs on a top surface of a corresponding solder pre-form [130] of the plurality of solder pre-forms [130];
performing a reflowing process (par. [0088]);
Park fails to explicitly disclose:
performing the reflowing process that includes:
melting the solder pre-form by providing heat to the substrate via the base plate;
measuring, via at least one sensor, measured temperatures of a plurality of temperature zones of the DPMs during the reflowing process;
determining, via a controller, whether the measured temperatures of the plurality of temperature zones are below a threshold temperature during the reflowing process; and
maintaining the measured temperatures of the plurality of temperature zones below the threshold temperature during the reflowing process.
However, Mizuno discloses (Fig. 2, col. 6, lines 39-46, Col. 7, line 6)
performing the reflowing process that includes:
melting the solder pre-form [15] by providing heat to the substrate [20] via the base plate [203];
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to modify the reflow process of Park with the teachings of heating from below the substrate with a hot base plate because Mizuno teaches (Col. 7, lines 6-14) that such a modification decreases thermal stress during the soldering process, which reduces warpage.
Park in view of Mizuno fails to explicitly disclose
measuring, via at least one sensor, measured temperatures of a plurality of temperature zones of the DPMs during the reflowing process;
determining, via a controller, whether the measured temperatures of the plurality of temperature zones are below a threshold temperature during the reflowing process; and
maintaining the measured temperatures of the plurality of temperature zones below the threshold temperature during the reflowing process.
However, Sack discloses (p. S24-01-2, top paragraph, Fig. 3, Table 4 on p. S24-01-4)
measuring, via at least one sensor, measured temperatures of a plurality of temperature zones of the DPMs during the reflowing process (Sack discloses multiple temperature zones measured by multiple temperature sensors, thermocouples);
determining whether the measured temperatures of the plurality of temperature zones are below a threshold temperature during the reflowing process (p. S24-01-2, top paragraph, Table 1, the temperature is limited from above to avoid thermal damage); and
maintaining the measured temperatures of the plurality of temperature zones below the threshold temperature during the reflowing process (245 and 250 degrees Celcius, to avoid thermal damage).
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to monitor temperatures during reflow process and keep said temperature below the threshold, as taught by Sack, because Sach teaches (p.S24-01-2, top paragraph) that this is done to avoid thermal damage to sensitive components during the reflow process.
Park in view of Mizuno in view of Sack fails to explicitly disclose determining via a controller.
However, Boyd discloses (claim 39, par. [0027]) using an on-device controller to control and monitor the heating process.
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to use a controller to monitor and control the soldering process, as taught by Boyd, because Boyd teaches (par. [0048] that the board controller maintains a desired temperature of the reflow process.
Regarding claim 16, Park discloses (see Figs 5,6, par. [0077]-[0086]) a method of attaching a plurality of discrete power modules (DPMs) [20] to a substrate [111], the method comprising:
positioning (Fig. 12) the substrate [130] such that a bottom surface of the substrate [130[ opposes a top surface of a base plate [420];
placing (Fig. 6) a plurality of solder pre-forms [130] (par. [0085]) on a top side of the substrate [111]; placing each DPM [20] of the plurality of DPMs on a top surface of a corresponding solder pre-form [130] of the plurality of solder pre-forms [130];
performing a reflowing process (par. [0088]);
Park fails to explicitly disclose:
performing the reflowing process that includes:
melting the solder pre-form by providing heat to the substrate via the base plate;
measuring, via at least one sensor, measured temperatures of a plurality of temperature zones of the DPMs during the reflowing process;
determining, via a controller, whether the measured temperatures of the plurality of temperature zones are below a threshold temperature during the reflowing process; and
maintaining the measured temperatures of the plurality of temperature zones below the threshold temperature during the reflowing process by at least one of dynamically adjusting a power supplied to the base plate to lower a base plate temperature of the base plate, and dynamically adjusting a hold time of the power supplied to the base plate.
However, Mizuno discloses (Fig. 2, col. 6, lines 39-46, Col. 7, line 6)
performing the reflowing process that includes:
melting the solder pre-form [15] by providing heat to the substrate [20] via the base plate [203];
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to modify the reflow process of Park with the teachings of heating from below the substrate with a hot base plate because Mizuno teaches (Col. 7, lines 6-14) that such a modification decreases thermal stress during the soldering process, which reduces warpage.
Park in view of Mizuno fails to explicitly disclose
measuring, via at least one sensor, measured temperatures of a plurality of temperature zones of the DPMs during the reflowing process;
determining, via a controller, whether the measured temperatures of the plurality of temperature zones are below a threshold temperature during the reflowing process; and
maintaining the measured temperatures of the plurality of temperature zones below the threshold temperature during the reflowing process by at least one of dynamically adjusting a power supplied to the base plate to lower a base plate temperature of the base plate, and dynamically adjusting a hold time of the power supplied to the base plate.
However, Sack discloses (p. S24-01-2, top paragraph, Fig. 3, Table 4 on p. S24-01-4)
measuring, via at least one sensor, measured temperatures of a plurality of temperature zones of the DPMs during the reflowing process (Sack discloses multiple temperature zones measured by multiple temperature sensors, thermocouples);
determining whether the measured temperatures of the plurality of temperature zones are below a threshold temperature during the reflowing process (p. S24-01-2, top paragraph, Table 1, the temperature is limited from above to avoid thermal damage); and
maintaining the measured temperatures of the plurality of temperature zones below the threshold temperature during the reflowing process (245and 250 degrees Celcius, to avoid thermal damage).
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to monitor temperatures during reflow process and keep said temperature below the threshold, as taught by Sack, because Sach teaches (p.S24-01-2, top paragraph) that this is done to avoid thermal damage to sensitive components during the reflow process.
Park in view of Mizuno in view of Sack fails to explicitly disclose determining via a controller;
maintaining the measured temperatures by at least one of dynamically adjusting a power supplied to the base plate to lower a base plate temperature of the base plate, and dynamically adjusting a hold time of the power supplied to the base plate.
However, Boyd discloses (claim 39, par. [0027]) using an on-device controller to control and monitor the heating process;
Maintaining (par. [0048]) the measured temperatures by at least one of dynamically adjusting a power supplied to the base plate to lower a base plate temperature of the base plate, and dynamically adjusting a hold time of the power supplied to the base plate.
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to use a controller to monitor and control the soldering process, as taught by Boyd, because Boyd teaches (par. [0048] that the board controller maintains a desired temperature of the reflow process.
Regarding claim 2, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Mizuno further discloses (Col.6, lines 54-67) ` wherein the maintaining the measured temperatures below the threshold includes dynamically adjusting a power supplied to the base plate to lower a base plate temperature of the base plate.
Regarding claim 3, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Sack further discloses (p. S24-01-12, Table 7) temperature and soak time as important variables for creating a BGA connection.
The limitation “wherein the maintaining the measured temperature below the threshold further includes dynamically increasing a hold time of the base plate temperature” is further obvious over the combination of references because when the soldering temperature is lowered, time to make a reliable BGA connection must be increased.
This limitation represents a predictable feedback adjustment of a known reflow-profile parameter.
Regarding claim 4, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Sack further discloses (p. S24-01-12, Table 7) temperature and soak time as important variables for creating a BGA connection.
The limitation ”wherein the maintaining the measured temperature below the threshold includes dynamically decreasing a hold time of a base plate temperature of the base plate” is further obvious over the combination of references because continued heating after sufficient solder-reflow exposure unnecessarily increases package temperature.
It would therefore have been obvious to shorten or terminate the heating when measured temperatures show that sufficient thermal exposure has occurred or that continued heating would approach component-temperature maximum.
This limitation represents a predictable feedback adjustment of a known reflow-profile parameter.
Regarding claims 7 and 18, ` Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above.
Park further discloses (Fig. 12, par. [0102], [0103]) further comprising: placing an alignment fixture [410] such that the plurality of DPMs [20] are between the alignment fixture [410] and the substrate [111]; and
applying a force (par. [0104]-[0105]) to the alignment fixture [410] toward the substrate [111] such that the alignment fixture clamps the plurality of DPMs to the substrate during the reflowing process.
Regarding claim 11, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above.
“wherein the bottom surface of the substrate contacts the top surface of the base plate during the reflowing process” is further obvious over the combination of references.
Mizuno further discloses (Fig. 2) placing a workpiece [1] on a hot plate [203].
Applying Mizuno’s arrangement to Park (Fig. 6) places the bottom surface of the substrate [111] of park on the upper surface of the hot plate [203].
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to modify the reflow process of Park with the teachings of heating from below the substrate with a hot base plate because Mizuno teaches (Col. 7, lines 6-14) that such a modification decreases thermal stress during the soldering process, which reduces warpage.
Regarding claim 13, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Park in view of Mizuno in view of Sack in view of Boyd fails to explicitly disclose
wherein the at least one sensor includes at least one non-contact sensor.
However, both contact and non-contact temperature sensors were known in the art prior to effective filing date of the instant application.
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to employ a non-contact infrared sensor in the process of Park in view of Mizuno in view of Sack in view of Boyd without making mechanical modification to the module/preform stack because this simplifies the process and removes unnecessary components from the stack.
Regarding claims 14 and 19, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Sack further discloses (Fig. 3) wherein the at least one sensor includes three sensors (thermocouples) and the plurality of temperature zones includes three temperature zones, wherein each sensor of the three sensors is positioned to measure a corresponding one of the three temperature zones (Fig. 3 shows more than 3 temperature zones, so the limitation is met).`
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Park et. al., U.S. Pat. Pub. 2023/0395554, hereafter Park, in view of Mizuno, U.S. Pat. 8,791,564, hereafter Mizuno, in view of Sack et. al., “Optimization of Lead Free SMT Reflow & Rework Process Window”, Presented at IPC Printed Circuits Expo/Apex 2006, hereafter Sack, in view of Boyd et. al., U.S. Pat. Pub. 2016/0351526, hereafter Boyd, and further in view of Heinrich et. al., U.S. Pat. Pub. 2022/0310435, hereafter Henrich.
Regarding claim 5, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Park in view of Mizuno in view of Sack in view of Boyd fails to explicitly disclose further comprising:
dispensing a tacking agent:
a) between the top side of a substrate and the plurality of solder pre- forms to retain the plurality of solder pre-forms on the substrate; or
b) between each DPM and the top surface of the corresponding solder pre-forms of the plurality of solder pre-forms to retain the DPMs on the plurality of solder pre-forms; or
c) (a) and (b).
However, Heinrich discloses (Figs 2A, 2B, par. [0019]) further comprising:
dispensing a tacking agent [321], [322]:
between [321] the top side of a substrate [10] and the plurality of solder pre-forms [30] to retain the plurality of solder pre-forms [30] on the substrate [10]; or
between [322] each DPM [20] and the top surface of the corresponding solder pre-forms [30] of the plurality of solder pre-forms to retain the DPMs on the plurality of solder pre-forms; or
(a) and (b). (See above)
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to use tacking agents of Heinrich in the method of Park because Heinrich teaches (par. [0002]) that the tacking agents prevent damage during transport between different manufacturing facilities.
Claims 6 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Park et. al., U.S. Pat. Pub. 2023/0395554, hereafter Park, in view of Mizuno, U.S. Pat. 8,791,564, hereafter Mizuno, in view of Sack et. al., “Optimization of Lead Free SMT Reflow & Rework Process Window”, Presented at IPC Printed Circuits Expo/Apex 2006, hereafter Sack, in view of Boyd et. al., U.S. Pat. Pub. 2016/0351526, hereafter Boyd, and further in view of Song et. al., U.S. Pat. 10,263,407, hereafter Song.
Regarding claims 6 and 17, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Park in view of Mizuno in view of Sack in view of Boyd fails to explicitly disclose
further comprising placing a tray between the substrate and a plurality of busbars electrically coupled to each of the DPMs of the plurality of DPMs, wherein the tray provides at least one of:
electrical insulation between the busbars and the substrate; and reaction support for a clamp force applied to the busbars.
However, Song discloses (Fig. 3)
further comprising placing a tray [330] between the substrate [310] and a plurality of busbars [100] electrically coupled to each of the DPMs (transistors [315]) of the plurality of DPMs, wherein the tray [330] provides at least one of:
electrical insulation (Col. 22, lines 32-33) between the busbars and the substrate [310].
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to include busbars and an insulating tray to make insulated power connections to the power module.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Park et. al., U.S. Pat. Pub. 2023/0395554, hereafter Park, in view of Mizuno, U.S. Pat. 8,791,564, hereafter Mizuno, in view of Sack et. al., “Optimization of Lead Free SMT Reflow & Rework Process Window”, Presented at IPC Printed Circuits Expo/Apex 2006, hereafter Sack, in view of Boyd et. al., U.S. Pat. Pub. 2016/0351526, hereafter Boyd, and further in view of Lombardi et. al., U.S. Pat. Pub. 2012/0070940, hereafter Lombardi.
Regarding claim 8, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Park further discloses (inherent, all materials have a coefficient of thermal expansion)
wherein the substrate is a material having a first coefficient of thermal expansion and the alignment fixture is a material having a second coefficient of thermal expansion.
Park in view of Mizuno in view of Sack in view of Boyd fails to explicitly disclose
the second coefficient of thermal expansion being within ± 7.0 * 10⁻⁶ m/(m * °C) of the first coefficient of thermal expansion.
However, Lombardi discloses (claim 4) the second coefficient of thermal expansion being within ± 7.0 * 10⁻⁶ m/(m * °C) of the first coefficient of thermal expansion.
It would have been obvious to one of ordinary skill in the art prior to effective date of the instant application to match thermal expansion coefficients within a range provided by Lombardi, because Lombardi teaches (par. [0001]) that such CTE matching eliminates cracking or delamination of the assembly.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Park et. al., U.S. Pat. Pub. 2023/0395554, hereafter Park, in view of Mizuno, U.S. Pat. 8,791,564, hereafter Mizuno, in view of Sack et. al., “Optimization of Lead Free SMT Reflow & Rework Process Window”, Presented at IPC Printed Circuits Expo/Apex 2006, hereafter Sack, in view of Boyd et. al., U.S. Pat. Pub. 2016/0351526, hereafter Boyd, and further in view of Breingan et. al., U.S. Pat. Pub. 2015/0122876, hereafter Breingan.
Regarding claim 12, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Park in view of Mizuno in view of Sack in view of Boyd fails to explicitly disclose
wherein the bottom surface of the substrate is disposed a predefined distance above the top surface of the base plate during the reflowing process.
However, Breingan discloses (par. [0046], Fig. 6)
wherein the bottom surface of the substrate [10] is disposed a predefined distance [260] above the top surface of the base plate [310] during the reflowing process.
The distance controls thermal coupling between the hot plate and the workpiece, and therefore constitutes a known process variable. It would have been obvious to one of ordinary skill in the art to use non-contact proximity hot plate heating of Breingan, because such heating prevents thermal shock causing cracks, uneven heating, and surface contamination.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Park et. al., U.S. Pat. Pub. 2023/0395554, hereafter Park, in view of Mizuno, U.S. Pat. 8,791,564, hereafter Mizuno, in view of Sack et. al., “Optimization of Lead Free SMT Reflow & Rework Process Window”, Presented at IPC Printed Circuits Expo/Apex 2006, hereafter Sack, in view of Boyd et. al., U.S. Pat. Pub. 2016/0351526, hereafter Boyd, and further in view of CN 103779307, hereafter ‘307.
Regarding claim 15, Park in view of Mizuno in view of Sack in view of Boyd discloses everything as applied above. Park in view of Mizuno in view of Sack in view of Boyd fails to explicitly disclose
wherein the reflowing process occurs within at least one chamber and the reflowing process further includes:
filling the at least one chamber with a gaseous substance including HCOOH;
increasing a pressure of the gaseous substance to be between 750 and 1050 mbar in the at least one chamber; and
heating the base plate to increase the measured temperatures of the plurality of temperature zones to be between 215 and 265 degrees Celsius for a first hold time while the pressure is between 750 and 1050 mbar.
However, these steps are obvious over ‘307 (par. [0028]-[0032]), because ‘307 discloses
wherein the reflowing process occurs within at least one chamber and the reflowing process further includes (par. [0030]-[0032]):
filling the at least one chamber with a gaseous substance including HCOOH (formic acid);
increasing a pressure of the gaseous substance to be between 750 and 1050 mbar in the at least one chamber (par. [0032] discloses an overlapping range of 0-1000mbar); and
heating the base plate to increase the measured temperatures of the plurality of temperature zones to be between 215 and 265 degrees Celsius (par. [0031] discloses an overlapping range of 100-350 degrees Celcius) for a first hold time while the pressure is between 750 and 1050 mbar (par. [0032] discloses an overlapping range of 0-1000 mbar).
While the temperature and pressure ranges of ‘307 are different from claimed ranges, said ranges overlap, and thus are obvious over ‘307 (MPEP, 2144.05.I, and case law therein)
It would have been obvious to one of ordinary skill in the art prior to effective filing date of the instant application to modify the process of Park with the chamber and conditions of ‘307, because ‘307 teaches (par. [0006]) that this improve the product performance, reduces the production cost and reduces the environment pollution of a full clean-free soldering power module and its preparation method.
Allowable Subject Matter
Claims 9 and 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.
Regarding claim 9, the prior art of record fails to explicitly disclose or make obvious wherein the alignment fixture defines a plurality of apertures, each aperture of the plurality of apertures aligning with a corresponding DPM of the plurality of DPMs and being open through the alignment fixture such that the DPMs are visible through the apertures, wherein the alignment fixture contacts a plurality of perimeter regions of each DPM.
Claim 10 is dependent on claim 9 and thus includes all limitations of said claim.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VICTOR V BARZYKIN whose telephone number is (571)272-0508. The examiner can normally be reached Monday-Friday, 9am-5pm.
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/VICTOR V BARZYKIN/Examiner, Art Unit 2893
/Britt Hanley/Supervisory Patent Examiner, Art Unit 2893
