Prosecution Insights
Last updated: April 19, 2026
Application No. 17/660,186

ELECTROFORMED HEAT EXCHANGER WITH EMBEDDED PULSATING HEAT PIPE

Final Rejection §103
Filed
Apr 21, 2022
Examiner
WITTENBERG, STEFANIE S
Art Unit
1795
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Raytheon Company
OA Round
4 (Final)
54%
Grant Probability
Moderate
5-6
OA Rounds
3y 2m
To Grant
73%
With Interview

Examiner Intelligence

Grants 54% of resolved cases
54%
Career Allow Rate
361 granted / 667 resolved
-10.9% vs TC avg
Strong +19% interview lift
Without
With
+19.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
59 currently pending
Career history
726
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
51.2%
+11.2% vs TC avg
§102
17.6%
-22.4% vs TC avg
§112
29.2%
-10.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 667 resolved cases

Office Action

§103
DETAILED ACTION Status of Claims Claims 1-20 are pending. Claims 11-20 are withdrawn from consideration. 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 . Status of Objections and Rejections The previous grounds of rejection under 35 U.S.C. 103 stand. 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) 1-2, 4-8 and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Takeda et al. (JP 60-165383), in view of Oyama (US 5,453,173) and in further view of Lin et al. (US 6,679,316). Regarding claim 1, Takeda discloses a method of electroforming to form a mold [0001] “The present invention…to provide a molding die produced by electroforming” (= a method comprising): Electroforming to form a copper layer (3) onto a surface having a non-planar shape (page 2 “A copper layer 3 is electrodeposited”) (= using electroforming to deposit a first portion of material that includes a surface having a non-planar shape; Figure 1 depicts the layers such as the copper layer as being non-planar due to the shape of the surface (1) (e.g. stepwise or tiered)); Providing pipe (4) as depicted in Figure 2 (= obtaining a preformed tube comprising multiple capillary pathways and multiple bends, the capillary pathways joined to one another via the multiple bends and including central portions that extend substantially parallel to each other); Welding a pipe (4) disposed in a serpentine shape alone the rear side of the cavity (1) (Figure 3) (= placing the preformed tube onto the surface of the first portion of material); Electroforming metal layer (7) (Figure 5) to form heat exchanging device (page 3, “exchanges heat”, page 2 “heat uniformity”) (= using electroforming to deposit a second portion of material over the first portion of material and over the preformed tube to form a heat exchanger); The pipe (4) forms a portion of a pipe of the heat exchanger. Regarding the phrase “wherein the preformed tube forms at least a portion of a pulsating heat pipe within the heat exchanger, the pulsating heat pipe configured to transport thermal energy through the heat exchanger”, this phrase does not further limit the claimed method. The phrase does not contain any further method step or material. Any reference to pulsating is directed towards the manner of operating the heat exchanger. Takeda fails to disclose the claimed bending the preformed tube into the non-planar shape. In the same or similar field of forming 3D structures through electroforming, Oyama discloses wherein a non-planar surface is covered with a stainless steel mesh network body (6) that has been formed by knitting stainless steel wires (Col. 5 lines 8-12). The network body (6) is deformed (= bending) onto the non-planar surface and thereafter electroforming is carried out to form electroformed coating (11) and an intermediate product (12) (Col. 5 lines 24-36) (Figures 3-5). Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to produce a method comprising bending a preformed object such as a tube because Oyama teaches that 3D structures obtained through electroforming can be shaped with a surface and thereafter carry out electroplating to form a 3D structure. Takeda in view of Oyama fail to disclose wherein non-central portions of the capillary pathways extend from the central portions to the bends separate from one another to provide space for the bends and wherein, within the preformed tube, the multiple capillary pathways extend between a warm end of the heat exchanger and a cool end of the heat exchanger and are configured to generate a self-sustaining oscillatory flow within the multiple capillary pathways. In the same or similar field of thermal spreaders (e.g. heat exchangers), Lin discloses a thermal spreader including channels (20) arranged boustrophedonically as depicted in Figure 1. The channels include straight portions (22 = central portions) and end turn portions (24 = non-central portions). The distance S is greater than the distance D for producing the optimum operation (Figures 1-2, Col. 3 line 66 – Col. 4 line 12). Lin discloses that the structure provides for a compact design (Col. 1 lines 38-41) and smaller device yet capable of achieving improved thermal spreading (Col. 2 lines 4-6). Lin discloses that the passive thermal spreader is self contained (= self-sustaining) (Col. 1 lines 65-67). Lin further discloses that the liquid is driven along channels from the warmer evaporator section generally designated E (Figure 4) to the cooler condenser section generally designated C (Col 4 lines 60-65). PNG media_image1.png 368 492 media_image1.png Greyscale Figure 4 of US 6,679,316. Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to produce a method comprising wherein non-central portions of the capillary pathways extend from the central portions to the bends separate from one another to provide space for the bends because Lin discloses a thermal spreader design that is more compact in size yet achieves greater thermal spreading ability by utilizing elongated central parallel portions connected with non-central portions that have a greater distance or spacing leading to the bending portion. Lin discloses the device as self-contained and wherein the pathways extend from a warmer end (E) to a cooler end (C). Regarding claim 2, Takeda discloses electroplating the copper layer (3) over a cavity formed (cavity 1 and molded portion 2) (= mandrel). Regarding claim 4, the fill tubes (27) of Lin are located outside of the thermal spreader body (Figure 4). Regarding claim 5, Takeda discloses wherein the electroplated portions encase all or substantially all of the pipe (Figure 5). Regarding claim 6, Takeda discloses wherein the heat exchanger has a non-planar shape (see all Figures) which is produced by the electroplated layers. Regarding claim 7, Oyama discloses the preformed material (i.e. network body) including stainless steel (Col. 5 lines 9-12). Regarding claim 8, Takeda discloses pipe (4) which is beneath the top portion (= hypodermic) and narrow tubing (= needle tubing). The claimed needle does not require a specific dimension, shape or other limiting element. Regarding claim 10, Takeda discloses wherein the pipe (4) has a circular cross-sectional shape (Figures 3-5). Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Takeda et al. (JP 60-165383), in view of Oyama (US 5,453,173), in view of Lin et al. (US 6,679,316) and in further view of Tajiri et al. (US 2022/0282391). Regarding claim 3, Takeda in view of Oyama and Lin fails to disclose dissolving the mandrel after the heat exchanger is formed. In the same or similar field of producing heat exchangers using electroforming (title), Tajiri discloses a method comprising a consumable mandrel (58) which defines the shape of the heat exchanger (100) and wherein the mandrel can be removable from the finished electroformed component [0026]. Tajiri teaches removing the consumable material of the mandrel to expose a new inner surface or revealed surface and removal with an etchant [0034]. Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to produce a method comprising dissolving a mandrel after forming the heat exchanger because in a similar method to Takeda in view of Oyama, Tajiri discloses removing a mandrel after heat exchanger production to expose a new inner surface or revealed surface. It would have been obvious to modify the method of Takeda in view of Oyama and Lin in order to expose a surface or reveal a new surface. Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Takeda et al. (JP 60-165383), in view of Oyama (US 5,453,173), in view of Lin et al. (US 6,679,316) and in further view of Joardar (US 2017/0356700). Regarding claim 9, Takeda in view of Oyama and Lin fails to disclose bending the heat exchanger to achieve a final shape for the heat exchanger. In the same or similar field of producing heat exchangers, Joardar discloses that heat exchangers have conventional bent shapes (e.g. 60) to produce coils [0035]. Joardar discloses forming the microchannels prior to bending [0020]. Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to produce a method comprising bending the heat exchanger to achieve a final shape for the heat exchanger because Joardar discloses that bending of a heat exchanger is a conventional process step to produce the desired coil shape. It would have been obvious to modify the method of Takeda in view of Oyama and Lin with a bending step to produce the final product comprised of the desired bent or coiled shape. Response to Arguments Applicant's arguments filed 9 December 2025 have been fully considered but are not persuasive. The Applicant refers to Lin’s channels and states that Lin does not disclose the channels extending between a warm end and a cool end. The Examiner respectfully disagrees. Lin discloses that the liquid is driven along the channels from the warmer evaporator section (E) to the cooler section (C) as depicted in Figure 4. Lin also describes the device as being self contained as stated above and therefore self-sustaining. Conclusion THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEFANIE S WITTENBERG whose telephone number is (571)270-7594. The examiner can normally be reached Monday - Friday, 7:00 am -4:00 pm EST. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Luan Van can be reached at (571) 272-8521. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Stefanie S Wittenberg/Primary Examiner, Art Unit 1795
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Prosecution Timeline

Apr 21, 2022
Application Filed
Oct 17, 2024
Non-Final Rejection — §103
Jan 15, 2025
Response Filed
Feb 07, 2025
Response after Non-Final Action
Apr 22, 2025
Final Rejection — §103
Jun 25, 2025
Response after Non-Final Action
Jul 23, 2025
Request for Continued Examination
Jul 24, 2025
Response after Non-Final Action
Sep 05, 2025
Non-Final Rejection — §103
Nov 25, 2025
Applicant Interview (Telephonic)
Nov 25, 2025
Examiner Interview Summary
Dec 09, 2025
Response Filed
Mar 10, 2026
Final Rejection — §103 (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

5-6
Expected OA Rounds
54%
Grant Probability
73%
With Interview (+19.3%)
3y 2m
Median Time to Grant
High
PTA Risk
Based on 667 resolved cases by this examiner. Grant probability derived from career allow rate.

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