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 .
Status of the Claims
The status of the claims as filed in the reply dated 4/2/2026 are as follows:
Claims 1, 9, and 21 are amended,
Claims 14-20 are canceled,
Claims 1-13 and 21-25 are currently pending.
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.
4. Claim(s) 1-4, 6, 7, 9, 10, 13, and 21-25 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bennett et al. (U.S. Patent No. 4,653,572, “Bennett”) in view of Wang et al. (U.S. Patent Publication No. 2016/0033212, “Wang”, previously cited).
Regarding claim 1, Bennett discloses a method of achieving high heat transfer during cooling (fig 2), the method comprising:
providing an aluminum body (col 1, lines 9-40) having an inner surface enclosing a channel (fig 2), the inner surface comprising roughness features (see annotated fig 2 below) and cavities (see annotated fig 2 below);
transporting a refrigerant through the channel, the refrigerant absorbing heat from a thermal load and undergoing flow boiling (col 1, lines 9-40),
wherein the aluminum body comprises an aluminum tube (col 1, lines 9-40),
wherein the tube comprises aluminum about an entire perimeter of the tube (fig 2), and wherein the channel has a diameter (fig 2) configured to enhance nucleation site density during flow boiling, wherein the roughness features and cavities extend about an entire perimeter of the inner surface in an irregular arrangement (as evident in figure 2 shown below).
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Bennett does not explicitly discloses the inner surface comprising microscale roughness features and microcavities. Wang, however, discloses a heat transfer tube (fig 1) wherein the inner surface comprising microscale roughness features (“Si microstructure”) and microcavities (between the Si microstructures) configured to enhance nucleation site density during flow boiling (¶0032). Wang teaches that these microstructure increases heat exchange efficiency and reduces pressure drop (¶0078). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Bennett to provide the microscale roughness feature in place of the roughness features in order to optimize heat exchange efficiency and pressure drop in the tube.
Bennett, as modified, does not explicitly disclose wherein the heat is transferred to the refrigerant at an average heat transfer coefficient of at least about 10 kW/(m2*K) at a mass flux of about 300 kg/(m2*s). Rather, Wang teaches a heat transfer coefficient of at 50 kW/(m2*K) at higher mass fluxes (see figure 7b). However, since Wang teaches improving the heat transfer coefficient of a surface, the exact heat transfer coefficient at a give mass flux is considered a result-effective variable, i.e. a variable which achieves a recognized result. In this case the recognized result is that the size and shape of the roughness feature will determine the heat transfer coefficient (see ¶0038). It would not be inventive to vary the dimensions of the roughness features in order to achieve a heat transfer coefficient of at least about 10 kW/(m2*K) at a mass flux of about 300 kg/(m2*s) and thus it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to do so.
Regarding claim 2, the combination of Bennett and Wang discloses all previous claim limitations. Bennett, as modified, further discloses wherein the microcavities have a linear size in a range from about 2 microns to about 30 microns (see ¶0040 of Wang).
Regarding claim 3, the combination of Bennett and Wang discloses all previous claim limitations. Bennett, as modified, further discloses wherein the microscale roughness features have a height in a range from about 1 microns to about 15 microns (¶0040 of Wang).
Regarding claim 4, the combination of Bennett and Wang discloses all previous claim limitations. However, they do not explicitly disclose wherein the average heat transfer coefficient is stable within +/−5% for at least 28 days. However, Wang does teach that the stability of heat exchange increases due to the roughness features (¶0057). Thus it would have been obvious to a person of ordinary sill in the art for Bennett, as modified, to ensure that the heat transfer coefficient remain stable within +/−5% for at least 28 days in order to improve the reliability of the device.
Regarding claim 6, the combination of Bennett and Wang discloses all previous claim limitations. However, they do not explicitly disclose wherein the refrigerant comprises a hydrochlorofluorocarbon, a hydrofluoro-olefin, a hydrofluorocarbon, and/or a zeotropic refrigerant blend. However, the Examiner takes Official Notice that the use of hydrochlorofluorocarbon as refrigerant is old and well known in the art of heat exchangers and it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Bennett, as modified, to have the refrigerant to be hydrochlorofluorocarbon in order to optimize the heat exchange.
Regarding claim 7, the combination of Bennett and Wang discloses all previous claim limitations. However, they do not explicitly disclose wherein the aluminum body comprises an enhancement factor Øe.f. of at least about 2 at the mass flux of about 300 kg/(m2*s), where Øe.f.=(
h
-
structured/
h
-
plain)/(ΔPstructured/ΔPplain). However, since Wang teaches improving the heat transfer coefficient (see ¶0038), it would be obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Bennett, as modified, to improve the heat transfer coefficient such that Øe.f. is at least about 2 at the mass flux of about 300 kg/(m2*s).
Regarding claim 9, Bennett discloses a surface-modified component for enhanced heat transfer during cooling (fig 2), the surface-modified component comprising:
an aluminum body (col 1, lines 9-40) having an inner surface enclosing a channel, the inner surface comprising roughness features (see annotated fig 2 below) and cavities (see annotated fig 2 below) extending around an entire perimeter of the inner surface in an irregular arrangement (as evident in fig 2).
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However, Bennett does not explicitly disclose the inner surface comprising microscale roughness features of about 1 microns to about 15 microns in height and microcavities of about 2 microns to about 30 microns in linear size,
wherein the inner surface comprises aluminum and native aluminum oxide, and wherein the aluminum body does not include an interface between the inner surface and a sub-surface region of the aluminum body.
Wang, however, discloses a heat exchange tube wherein the inner surface comprising microscale roughness features (“Si microstructure”) of about 1 microns to about 15 microns in height and microcavities of about 2 microns to about 30 microns in linear size (¶0038),
wherein the inner surface comprises aluminum and native aluminum oxide (¶0038), and wherein the aluminum body does not include an interface between the inner surface and a sub-surface region (inner section) of the aluminum body (as Wang does not teach any interface). Wang teaches that these microstructure increases heat exchange efficiency and reduces pressure drop (¶0078). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Bennett to provide the microscale roughness feature in place of the roughness features in order to optimize heat exchange efficiency and pressure drop in the tube.
Regarding claim 10, the combination of Bennett and Wang discloses all previous claim limitations. However, they do not explicitly disclose wherein the heat is transferred to the refrigerant at an average heat transfer coefficient of at least about 10 kW/(m2*K) at a mass flux of about 300 kg/(m2*s). Rather, Wang teaches a heat transfer coefficient of at 50 kW/(m2*K) at higher mass fluxes (see figure 7b). However, since Wang teaches improving the heat transfer coefficient of a surface, the exact heat transfer coefficient at a give mass flux is considered a result-effective variable, i.e. a variable which achieves a recognized result. In this case the recognized result is that the size and shape of the roughness feature will determine the heat transfer coefficient (see ¶0038). It would not be inventive to vary the dimensions of the roughness features in order to achieve a heat transfer coefficient of at least about 10 kW/(m2*K) at a mass flux of about 300 kg/(m2*s) and thus it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to do so.
Regarding claim 13, the combination of Bennett and Wang discloses all previous claim limitations. Bennett, as modified, further discloses wherein the inner surface of the aluminum body further comprises micro-fins (Si microstructures, Wang) comprising the microscale roughness features (fig 1, Wang).
Regarding claim 21, Bennett discloses a method of achieving high heat transfer during cooling (fig 2), the method comprising:
providing an aluminum body (col 1, lines 9-40) having an inner surface enclosing a channel, the inner surface comprising roughness features and cavities configured to enhance nucleation site density during flow boiling (see fig 2 below);
wherein the aluminum tube comprises aluminum about an entire perimeter of the tube, wherein the channel has a diameter (fig 2) wherein the aluminum body further comprise grooves having roughness features and cavities thereon (see annotated fig 2 below).
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However, Bennett does not explicitly disclose wherein the inner surface comprising microscale roughness features and microcavities configured to enhance nucleation site density during flow boiling;
transporting a refrigerant through the channel, the refrigerant absorbing heat from a thermal load and undergoing flow boiling,
wherein the inner surface of the aluminum body further comprises micro-fins comprising the microscale roughness features.
Wang, however, discloses wherein the inner surface comprising microscale roughness features (“Si microstructure”) and microcavities configured to enhance nucleation site density during flow boiling (¶0038);
transporting a refrigerant through the channel, the refrigerant absorbing heat from a thermal load (“Pt heater”) and undergoing flow boiling (¶0032),
wherein the inner surface of the aluminum body further comprises micro-fins (“Si microstructure”) comprising the microscale roughness features. Wang teaches that these microstructure increases heat exchange efficiency and reduces pressure drop (¶0078). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Bennett to provide the microscale roughness feature in place of the roughness features in order to optimize heat exchange efficiency and pressure drop in the tube.
Bennett, as modified, does not explicitly disclose wherein the heat is transferred to the refrigerant at an average heat transfer coefficient of at least about 10 kW/(m2*K) at a mass flux of about 300 kg/(m2*s). Rather, Wang teaches a heat transfer coefficient of at 50 kW/(m2*K) at higher mass fluxes (see figure 7b). However, since Wang teaches improving the heat transfer coefficient of a surface, the exact heat transfer coefficient at a give mass flux is considered a result-effective variable, i.e. a variable which achieves a recognized result. In this case the recognized result is that the size and shape of the roughness feature will determine the heat transfer coefficient (see ¶0038). It would not be inventive to vary the dimensions of the roughness features in order to achieve a heat transfer coefficient of at least about 10 kW/(m2*K) at a mass flux of about 300 kg/(m2*s) and thus it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to do so.
Regarding claim 22, the combination of Bennett and Wang discloses all previous claim limitations. Bennett, as modified, further discloses wherein the inner surface of the aluminum body further comprises micro-fins (“Si microstructure”, Wang) the microscale roughness features.
Regarding claim 23, the combination of Bennett and Wang discloses all previous claim limitations. Bennett further discloses wherein the channel has a diameter (fig 2).
Regarding claim 24, the combination of Bennett and Wang discloses all previous claim limitations. Bennett, as modified, further discloses wherein the microscale roughness features and microcavities extend about an entire perimeter of the inner surface (see rejection of claim 1).
Regarding claim 25, the combination of Bennett and Wang discloses all previous claim limitations. Bennett further discloses wherein the tube comprises aluminum around the entire perimeter of the tube (fig 2).
5. Claim(s) 5 and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bennett and Wang as applied to claims 1 and 9 above, and further in view of Mazanec et al. (U.S. Patent Publication No. 2011/0009653, “Mazanec”. previously cited).
Regarding claim 5, the combination of Bennett and Wang discloses all previous claim limitations. However, Wang does not explicitly disclose wherein the channel has a diameter of at least about 3 mm and/or a length of at least about 1 m. Mazanec, however, disclose a heat exchanger (fig 1) with a channel (10) having a length of up to 3 meters (¶0051). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Bennett, as modified, to have the length of the channel to be 3 meters such as taught by Mazanec in order to optimize the heat exchange of the device.
Regarding claim 12, the combination of Bennett and Wang discloses all previous claim limitations. However, Wang does not explicitly disclose wherein the channel has a diameter of at least about 3 mm and/or a length of at least about 1 m. Mazanec, however, disclose a heat exchanger (fig 1) with a channel (10) having a length of up to 3 meters (¶0051). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Bennett to have the length of the channel to be 3 meters such as taught by Mazanec in order to optimize the heat exchange of the device.
6. Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bennett and Wang as applied to claim 1 above, and further in view of Miljkovic et al. (U.S. Patent Publication No. 2019/0330734, “Miljkovic”, previously cited).
Regarding claim 8, the combination of Bennett and Wang discloses all previous claim limitations. However, Wang does not explicitly disclose prior to providing the aluminum body, forming the inner surface comprising the microscale roughness features and microcavities, the forming comprising: cleaning the inner surface with an organic solvent and/or deionized water; after the cleaning, exposing the inner surface to a hydrochloric acid (HCl) solution comprising a HCl concentration of 2 M to 5 M; and after the exposing, rinsing the inner surface with deionized water and then drying, thereby obtaining the inner surface comprising the microscale roughness features and microcavities. Miljkovic, however, discloses a method including prior to providing the aluminum body, forming the inner surface comprising the microscale roughness features and microcavities, the forming comprising: cleaning the inner surface with deionized water (¶0017); after the cleaning, exposing the inner surface to a hydrochloric acid (HCl) solution comprising a HCl concentration of 2 M (¶0020); and after the exposing, rinsing the inner surface with deionized water and then drying (¶0019), thereby obtaining an inner surface comprising the microscale roughness features and microcavities. It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Bennett, as modified, to provide the steps of Miljkovic in order to efficient form the inner surface.
7. Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Bennett and Wang as applied to claim 9 above, and further in view of Garosshen (U.S. Patent Publication No. 2015/0075756, previously cited).
Regarding claim 11, the combination of Bennett and Wang discloses all previous claim limitations. However, they do not explicitly discloses wherein the aluminum body comprises an aluminum alloy having an alloy designation in a 1000 through 7000 series. Garosshen, however, discloses an evaporator tube which comprises an aluminum alloy having an alloy designation in a 1000 through 7000 series (¶0017). It would have been obvious before the effective filing date of the claimed invention for Bennett, as modified, to provide the alloy of Garosshen in order to provide optimal heat exchange of the heat exchanger.
Response to Arguments
Applicant's arguments filed 4/2/2026 have been fully considered but they are not persuasive.
Applicant argues (pages 6-8) that none of the cited references teaches the irregular microscale roughness features of the claims. However, newly cited Bennett is now relied upon to teach these limitations.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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/HARRY E ARANT/Primary Examiner, Art Unit 3763
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