Prosecution Insights
Last updated: April 19, 2026
Application No. 18/722,001

DRIVING DEVICE OF SEMICONDUCTOR SWITCHING ELEMENT AND POWER CONVERSION DEVICE

Non-Final OA §102§103§112
Filed
Jun 20, 2024
Examiner
ZHANG, JUE
Art Unit
2838
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Hitachi, Ltd.
OA Round
1 (Non-Final)
83%
Grant Probability
Favorable
1-2
OA Rounds
2y 7m
To Grant
93%
With Interview

Examiner Intelligence

Grants 83% — above average
83%
Career Allow Rate
825 granted / 993 resolved
+15.1% vs TC avg
Moderate +10% lift
Without
With
+10.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
19 currently pending
Career history
1012
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
34.2%
-5.8% vs TC avg
§102
49.9%
+9.9% vs TC avg
§112
8.9%
-31.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 993 resolved cases

Office Action

§102 §103 §112
DETAILED ACTION This office action is in response to the application filed on 06/20/2024. Claims 1-14 are pending. 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 . Priority Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, or 365(c) is acknowledged. Receipt is acknowledged of papers submitted under 35 U.S.C. 119(a)-(d), which papers have been placed of record in the file. Drawing The drawing submitted on 06/20/2024 is acknowledged and accepted by the examiner. Information Disclosure Statement The information disclosure statements (IDS) submitted on 06/20/2024 has been considered by the examiner. 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 8 and 11 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 8, Applicant recite the limitations “…the rated current …” at line 6 of claim 8 and at line 7 of claim 11 without proper antecedence basis. It is not clear what or which “rated current” Applicant is intended to refer to. And there is no evidence in the specification of the meaning of “the rated current”. Therefore, the metes and bounds of the claim are unclear. Applicant’s correction and/or clarification is required. 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 1, 8-9, 11, 14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Shu et al. (NPL_IEEE_Active Current Source IGBT Gate Drive With Closed-Loop di/dt and dv/dt Control, hereinafter Shu). Claim 1, Shu teaches a driving device of semiconductor switching element (e.g., IGBT, see Fig. 1-13), comprising: a gate driving circuit unit (e.g., the PWM driver) that drives a semiconductor switching element (e.g., the IGBT, see Fig. 1, 3-4) and a feedback current control unit (e.g., the circuits comprising VCCS1, VCCS2) that applies a feedback current (e.g., Ifb1 and/or Ifb2), which is calculated by multiplying a change rate of electricity to be applied by the gate driving circuit unit to the semiconductor switching element (e.g., Eq. 1, Eq. 2, see pages 3790) by a predetermined gain (e.g., the gain of the amplifier, see Fig. 3-4) to a gate of the semiconductor switching element gain (e.g., the corresponding gain at Turn-on and/or turn-off of IGBT respectively, see Fig. 3-4), wherein the change rate of electricity is a time change rate of at least one of a voltage or a current to be applied to the semiconductor switching element (e.g., see pages 3789-3790, Fig. 3-5), and the feedback current control unit changes the gain according to an operation condition (e.g., ON or OFF of IGBT) of the semiconductor switching element to adjust a surge voltage of the semiconductor switching element (e.g., the overshoot during Turn-On or Turn-Off of the IGBT, see pages 3789-3790, Fig. 3-5). Claim 8, Shu teaches the limitations of claim 1 as discussed above. It further teaches that wherein the operation condition is a main current (e.g., Ic) the current to be applied to the semiconductor switching element and a maximum value of the main current (e.g., Ic=800A) is a value ranging from 1 to 2 times the rated current of the semiconductor switching element (e.g., Ic=400 or Ic-600A, see Fig. 16). Claim 9, Shu teaches the limitations of claim 1 as discussed above. It further teaches that wherein the operation condition is a junction temperature of the semiconductor switching element (e.g., the range of the junction temperature during operating of the driving circuit of Fig. 3-4, 6) and the junction temperature is within a range of a rated junction temperature of the semiconductor switching element (e.g., the junction temperature of the IGBT during the operation of the driving circuit of Fig. 3-4, 6 is implicitly taught, see Fig. 3-4, 6). Claim 11, Shu teaches the limitations of claim 8 as discussed above. It further teaches that wherein the gain is in a dead zone region (e.g., t0-t1) when the main current is a boundary current or less (e.g., Ic during t0-t1) and in a monotonously increasing region (e.g., t1-t2) when the main current is the boundary current or more (e.g., Ic during t1-t2), and the boundary current is a value ranging from 20 to 80% of the rated current (e.g., see Fig. 5, 16). Claim 14, Shu teaches the limitations of claim 1 as discussed above. It further teaches that power conversion device, comprising: the driving device of semiconductor switching element as claimed in Claim 1 and a plurality of the semiconductor switching elements (e.g., the IGBT module, see Fig. 3-5, 6). 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 set forth in Graham v. John Deere Co., 383 U.S. 1,148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103(a) 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 under 35 U.S.C. 103(a), the examiner presumes that the subject matter of the various claims was commonly owned at the time any inventions covered therein were made absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and invention dates of each claim that was not commonly owned at the time a later invention was made in order for the examiner to consider the applicability of 35 U.S.C. 103(c) and potential 35 U.S.C. 102(e), (f) or (g) prior art under 35 U.S.C. 103(a). Claims 7, 10 are rejected under 35 U.S.C. 103(a) as being unpatentable over Shu et al. (NPL_IEEE_Active Current Source IGBT Gate Drive With Closed-Loop di/dt and dv/dt Control, hereinafter Shu), in view of AKIYAMA et al. (US Patent or PG Pub. No. 20220416782, hereinafter ‘782). Claim 7, Shu teaches the limitations of claim 1 as discussed above. Shu further teaches that wherein the operation condition is a bus voltage (e.g., Vdc) to be applied to the semiconductor switching element (e.g., dv/dt and/or dv/dt being function of the voltage across 117, 119, see Fig. 3-7) Shu does not explicitly disclose that the maximum value of the bus voltage is a value ranging from 50 to 80% of the rated voltage of the semiconductor switching element. ‘782 discloses gate drive circuits of semiconductor switching elements (e.g., see Abstract; Fig. 1-2). It further discloses that when a surge applied to a main terminal of the semiconductor switching element exceeds an element withstand voltage which is a withstand voltage of the semiconductor switching element (e.g., the rated voltage of the semiconductor switching element) could causing a failure occurs, … and the permissible value permissible value of the peak value of the voltage Vds is a value lower than a withstand voltage of the semiconductor switching element (e.g., the rated voltage of the semiconductor switching element) by a predetermined margin, and is set to such a value that there is no possibility that the semiconductor switching element fails even though a voltage having the value is applied to the main terminal. (e.g., see Abstract, [0003][0050]). Therefore, It would have been obvious to one having ordinary skill in the art before the effective filing date to modify Shu by limiting the maximum value of the bus voltage being a margin value of the rated voltage of the semiconductor switching element as taught by ‘782 in order of being able to prevent the overvoltage failure of the semiconductor switching element. None of Shu nor ‘782 explicitly disclose that the margin value ranging from 50 to 80% of the rated voltage of the semiconductor switching element is ranging from 50 to 80% of the rated voltage. However, it has been held that when the general details of a range or measurement of degree are disclosed in the prior art, providing a more precise range in the claims of the invention without explaining the criticality of the range is not sufficient to overcome the prior art. See In re Williams, 36 F.2d 436, 438 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.") In this case, Paragraph [0050] of ‘782 discloses the permissible value permissible value of the peak value of the voltage Vds is a value lower than a withstand voltage of the semiconductor switching element (e.g., the rated voltage of the semiconductor switching element) by a predetermined margin, and is set to such a value that there is no possibility that the semiconductor switching element fails even though a voltage having the value is applied to the main terminal. Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the disclosure of Shu to include an the margin value ranging from 50 to 80% of the rated voltage of the semiconductor switching element to prevent the possibility of the semiconductor switching element overvoltage failure. Doing so would require only routine skill in the art. Claim 10, the combination of Shu and ‘782 teaches the limitations of claim 7 as discussed above. Shu further teaches that wherein the gain is in a dead zone region (e.g., during t4-t6) when the bus voltage is a boundary voltage or less [e.g., Vce(on)] and in a monotonously increasing region (e.g., t6-t7) when the bus voltage is the boundary voltage or more (e.g., see Fig. 5). Shu does not explicitly disclose that the boundary voltage is a value ranging from 30 to 50% of the rated voltage. ‘782 further discloses that the permissible value permissible value of the peak value of the voltage Vds is a value lower than a withstand voltage of the semiconductor switching element (e.g., the rated voltage of the semiconductor switching element) by a predetermined margin, and is set to such a value that there is no possibility that the semiconductor switching element fails even though a voltage having the value is applied to the main terminal. (e.g., see Abstract, [0003][0050]). Therefore, It would have been obvious to one having ordinary skill in the art before the effective filing date to modify Shu by limiting the maximum value of the bus voltage being a margin value of the rated voltage of the semiconductor switching element as taught by ‘782 in order of being able to prevent the overvoltage failure of the semiconductor switching element. None of Shu nor ‘782 explicitly disclose that the margin value ranging from 30 to 80% of the rated voltage of the semiconductor switching element is ranging from 30 to 80% of the rated voltage. However, it has been held that when the general details of a range or measurement of degree are disclosed in the prior art, providing a more precise range in the claims of the invention without explaining the criticality of the range is not sufficient to overcome the prior art. See In re Williams, 36 F.2d 436, 438 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.") In this case, Paragraph [0050] of ‘782 discloses the permissible value permissible value of the peak value of the voltage Vds is a value lower than a withstand voltage of the semiconductor switching element (e.g., the rated voltage of the semiconductor switching element) by a predetermined margin, and is set to such a value that there is no possibility that the semiconductor switching element fails even though a voltage having the value is applied to the main terminal. Therefore it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the disclosure of Shu to include an the margin value ranging from 30 to 80% of the rated voltage of the semiconductor switching element to prevent the possibility of the semiconductor switching element overvoltage failure. Doing so would require only routine skill in the art. Allowable Subject Matter Claims 2-6, 12-13 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 matters: For claims 2-6, 13, the prior art does not disclose or suggest, in combination with the limitations of the base claim and any intervening claims, primarily,… wherein the feedback current control unit having: an electricity change rate detector circuit unit that detects the change rate of electricity, a gain control circuit unit that forms a gain control signal based on the operation condition, a variable gain amplifier circuit unit that calculates the gain based on the gain control signal and multiplies the change rate of electricity by the gain, … a voltage-controlled current source circuit unit that converts an output from the variable gain amplifier circuit unit to the feedback current. For claim 12, the prior art does not disclose or suggest, in combination with the limitations of the base claim and any intervening claims, primarily, … wherein the feedback current control unit monotonously decreases an absolute value of the gain according to an increase in junction temperature of the semiconductor switching element. Examiner's Note: Examiner has cited particular columns and line numbers in the references applied to the claims above for the convenience of the applicant. Although the specified citations are representative of the teachings of the art and are applied to specific limitations within the individual claim, other passages and figures may apply as well. It is respectfully requested from the applicant in preparing responses, to fully consider the references in their entirety as potentially teaching all or part of the claimed invention, as well as the context of the passage as taught by the prior art or disclosed by the Examiner. In the case of amending the claimed invention, Applicant is respectfully requested to indicate the portion(s) of the specification which dictate(s) the structure relied on for proper interpretation and also to verify and ascertain the metes and bounds of the claimed invention. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JUE ZHANG whose telephone number is (571)270-1263. The examiner can normally be reached on M-F: 8:30AM-5:00PM If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Monica Lewis can be reached on 571-272-2838. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JUE ZHANG/ Primary Examiner, Art Unit 2838
Read full office action

Prosecution Timeline

Jun 20, 2024
Application Filed
Feb 05, 2026
Non-Final Rejection — §102, §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
83%
Grant Probability
93%
With Interview (+10.1%)
2y 7m
Median Time to Grant
Low
PTA Risk
Based on 993 resolved cases by this examiner. Grant probability derived from career allow rate.

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