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 .
This action is responsive to Applicant’s response to election/restriction, amendment, and remarks filed 04/01/2026.
Claims 1-3 and 7-10 are currently pending.
The Drawings filed 08/31/2023 are approved by the examiner.
Applicant’s election without traverse of Group I, claims 1-3 and 7-10, in the reply filed on 04/01/2026 is acknowledged.
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
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 1-3 and 7-10 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 1 recites a “liquid alloy thermal paste” with a variety of components. The claim recites a product-by-process limitation where “a viscous and paste-like liquid mixture is obtained as the liquid alloy thermal paste” is obtained by stirring a particular liquid alloy and trace element. The addition of the word “like” to the otherwise definite expression extends the scope of the expression so as to render it indefinite. It is unclear what the differences are between a “paste” and something that is “paste-like”. Does something that is “paste-like liquid” include properties or structure that one skilled in the art would not consider (i.e., beyond) a “paste” or “liquid”?
Independent claim 7 is also indefinite for the same recitation of “paste-like”, and claims 2, 3, and 8-10 are also indefinite for their dependency on one of independent claims 1 or 7.
Additionally, claim 7 recites the presence of a multi-metal liquid alloy that is a ternary liquid alloy, a quaternary liquid alloy, or a quintuple liquid alloy (i.e., a three-, four-, or five-component alloy composition) including a liquid metal and plurality of solid metals. The liquid metal component thereof is recited to include gallium, i.e., one element, and the solid metal component thereof is recited to include indium, tin, copper, and a metal element of group IVA or VA elements (i.e., one of additional tin with a case of double inclusion, lead, or bismuth, which are the only group IVA/VA metal elements), i.e., three or four elements (i.e., three elements when the group IVA element is tin by double inclusion or four elements when the group IVA/VA element is either lead or bismuth). This means there can only be four (1+3 liquid+solids) or five (1+4) components in the alloy. It is seriously unclear how the multi-metal liquid alloy can be a ternary (three component) liquid alloy because the claims requires the alloy comprise four or five components.
Claims 8-10 are also rejected for their dependency on claim 7.
For purposes of further examination, claim 7 is construed as requiring a quaternary or quintuple liquid alloy as that component because a ternary (three component) liquid alloy is impossible given the express requirement of four or five components.
In claim 8, the limitation “wherein the copper is a spherical or irregularly shaped particle copper with a particle size of …” renders the claim indefinite. Note the product-by-process limitations recited in parent claim 7. The final product of claim 7’s limitations is a multi-metal alloy thermal paste. The final product is clearly some sort of an alloy. An alloy is a homogenous mixture, i.e., single phase, of chemical elements. An alloy comprising a discrete particle as a component within the alloy, i.e., a heterogeneous mixture as implied by the copper particle limitation, is not an alloy. It is seriously unclear how the alloy can comprise the copper as particles as discrete copper particles within the alloy would render it not a component of the alloy as previously recited and required by the parent claim. It is unclear if the limitations of claim 8 further limit and/or include all the limitations of parent claim 7.
In an attempt to ascertain the scope of claim 8, it is noted the specification indicates the copper particle is actually a precursor material of the composition alloy. See [0097]-[0098] describing a quintuple alloying step S708 is to add 0.1 to 10 wt. % of copper to the dispersed quaternary liquid alloy and stir to form a quintuple liquid alloy, which is a product-by-process limitation describing how the alloy is made rather than structure of the final alloy composition. The specification describes the final alloy does not comprise discrete copper particles.
There is ultimately a great deal of confusion and uncertainty as to the proper interpretation of claim 8 due to an alloy (single phase composition) comprising copper cannot comprise the copper as discrete particles, and a person of ordinary skill in the art would not be apprised as to the scope of the invention. Where there is a great deal of confusion and uncertainty as to the proper interpretation of the limitations of a claim, it would not be proper to reject such a claim on the basis of prior art. As stated in In re Steele, 305 F.2d 859, 134 USPQ 292 (CCPA 1962), a rejection under 35 U.S.C. 103 should not be based on considerable speculation about the meaning of terms employed in a claim or assumptions that must be made as to the scope of the claims. See MPEP 2173.06. Please note that if the claim is amended to recite the copper particle limitation as a product-by-process of the origin/precursor of claim 7’s copper, the limitation would not further distinguish beyond the limitations of claim 7 because the final composition is a single phase by recitation of an alloy.
Appropriate correction/clarification is required.
Claim Interpretation
In addition to the foregoing, the Office makes the additional notes of claim interpretation.
The claims recite a liquid alloy component and a trace element component “wherein by stirring the liquid alloy and the trace element to reform, a viscous and paste-like liquid alloy mixture is obtained as the liquid alloy thermal paste” which describes a process of making the liquid alloy thermal paste (that the liquid alloy thermal paste is made by stirring and reforming, i.e., melting and/or heating, the recited liquid alloy and trace element components) and is a product-by-process limitation. The claims also recite the liquid alloy and multi-metal liquid alloy (the liquid metal and the solid metals) components are themselves “alloyed or eutecticized by mixing the liquid metal and plurality of solid metals” which again describes a process of making the subject alloy (that is then used in another product-by-process limitation, Id.) and is a product-by-process limitation. Note the claims nest product-by-process limitations inside product-by-process limitations.
Product-by-process limitations are not limited to the recited step(s) except to the extent they suggest structure of the composition. Here, the claim 1 merely requires an alloy comprising gallium, indium, and tin in the recited relative proportions and 0.01-0.5 wt.% of any one of the recited trace element species, which is the structure suggested by the recited step(s). Similarly, claim 7 merely requires an alloy comprising gallium, indium, tin, copper, and one of lead, relatively additional tin, or bismuth in the recited relative proportions and 0.01-0.5 wt.% of any one of the recited trace element species, which is the structure suggested by the recited step(s). The claims do expressly require a process of reforming or melting nor separately alloying or eutecticizing any components.
Note that the claims are much more broad than apparent because the trace element permits double inclusion of gallium, indium, or tin because the trace element is recited that it may be selected to individually be gallium, indium, or tin which are already previously required in the final alloy. In this situation, for example, an amount of 70 wt.% gallium reads on the claim because 69.9 wt.% can be counted as reading on the liquid alloy component and 0.1 wt.% can be counted as reading on the trace element component. Similarly, for example, an amount of 20 wt.% indium reads on both components for substantially the same reason, etc. Similarly regarding the additional group IVA element (lead or tin) required in claim 7, tin may read on the tin and group IVA element components of the multi-metal liquid alloy and the trace element component. If this interpretation is incorrect, then the claims are seriously indefinite because it would be unclear how the compositions could simultaneously comprise a large amount of one element (e.g. 60-80 wt.% gallium, 5-15 wt.% tin, etc.) and a small/trace amount of the same element (e.g., 0.01-0.5 wt.% gallium as the trace element, 0.05-5 wt.% of tin as a metal element of Group IVA, etc.)
"[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985).
"The Patent Office bears a lesser burden of proof in making out a case of prima facie obviousness for product-by-process claims because of their peculiar nature" than when a product is claimed in the conventional fashion. In re Fessmann, 489 F.2d 742, 744, 180 USPQ 324, 326 (CCPA 1974).
Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing an nonobvious difference between the claimed product and the prior art product. In re Marosi, 710 F.2d 799, 803, 218 USPQ 289, 292-33 (Fed. Cir. 1983).
"[T]he lack of physical description in a product-by-process claim makes determination of the patentability of the claim more difficult, since in spite of the fact that the claim may recite only process limitations, it is the patentability of the product claimed and not of the recited process steps which must be established. We are therefore of the opinion that when the prior art discloses a product which reasonably appears to be either identical with or only slightly different than a product claimed in a product-by-process claim, a rejection based alternatively on either section 102 or section 103 of the statute is eminently fair and acceptable. As a practical matter, the Patent Office is not equipped to manufacture products by the myriad of processes put before it and then obtain prior art products and make physical comparisons therewith." In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972).
Additionally, the claimed recitations of a “thermal paste” in the preambles are merely intended use limitations. However, a liquid alloy is required (but this is met by the relatively large amount of gallium required in the body of the claim). See MPEP 2111.02. In the event these terms somehow limit the claim, they would be intrinsic, if not inherent, of the recited compositions. A composition comprising mainly of metals would be expected to be thermally conductive. A composition comprising a substantial amount of gallium would be expected to be capable of being present as a liquid alloy at relatively low temperatures (i.e., near room temperature or below) and capable of exhibiting viscous and/or paste properties at a certain temperature around its melting point.
Additionally, the metal, the metal oxide, the metal nitride, and the carbon-based material species of claims 3 and 10 are construed as limiting the metal, metal oxide, metal nitride, and carbon-based material components of the thermal conductive particle of claims 2 and 9.
Claim Rejections - 35 USC § 102 & 103
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.
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.
Claims 1 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Inage et al. (JP S60-135549 A). Citations to the reference are with respect to the submitted English language machine translation of reference unless specified otherwise.
Inage et al. teach a quaternary or higher multicomponent alloy having a melting point below 15°C comprising 1-45 wt.% In, 1-30 wt.% Sn, 0.05-25 wt.% one or more components selected from Ba, Cd, Sb, Mg, Ca, Li, Bi and Pd and optionally one or more of Ag, Al, Zn, Au and Cu, and the balance Ga (abstract). The amounts of In and Sn overlap the recited ranges of indium and tin. Because the amount of Ga is the balance of the composition, the amount of Ga possible in the reference also overlaps the recited range of gallium, Also note that an exemplary base alloy (i.e., before addition of the 0.05-25 wt.% one or more additional components) consists of 68 wt.% Ga, 24 wt.% In, and 8 wt.% Sn (bottom p.3), which is within the recited ranges of gallium, indium, and tin.
While Inage et al. fail to meet the claimed 0.01-0.5 wt.% trace element of claims 1 and 7, the 0.1-10 wt.% copper of claim 7, and 0.05-5 wt.% of a group VA metal element (i.e., bismuth, the only group VA metal) of claim 7 under the meaning of anticipation, the claimed limitations are nevertheless met by the teachings of the reference under a prima facie case of obviousness. Inage et al. teach and motivate provision of any one or more of Sb, Bi, and Al reading claim 1’s trace element, Sb and Al reading on claim 7’s trace element as well as Cu reading on claim 7’s copper and Bi reading on claim 7’s group VA metal (Id.). The total amount of the additional components is between 0.05-25 wt.% (Id.), which in its totality overlaps and encompasses the claimed trace element, copper, and group VA metal ranges thereof. Inage et al. further teaches these additional components are adding in “trace amounts” to the trielement GaInSn (bottom p.2), preferable addition of copper obtains an alloy with a melting point of 15°C or lower like the instantly claimed invention (top p.3), addition of Sb or Si has an improved diffusion rate over the base GaInSn alloy (p.3), and addition of Bi prevents a rapid change in solidification temperature (p.3).
Accordingly, at the time of the effective filing date it would have been obvious to a person of ordinary skill in the art to arrive at the claimed limitations from the cited teachings of the reference as Inage et al. teach adding trace amounts of any one or more of copper, antimony, bismuth, aluminum, silicon in a total concentration of as little as 0.05 wt.% and up to 25 wt.% to the GaInSn alloy, preferably a 68 wt.% Ga, 24 wt.% In, and 8 wt.% alloy, in order to obtain a multicomponent alloy with a melting point below 15°C and optionally an adjusted/improved diffusion rate and/or change in solidification temperature with a reasonable expectation of success.
Please also note the breadth of the claimed trace element, as described in the Claim Interpretation section, above. Additional rationale to the composition requiring less components than what might be apparent exists. For example, claims 1 and 7 do not necessarily require a discrete trace element as they may be read on by gallium, indium and tin by double inclusion. Also, claim 7 does not necessarily require a discrete metal element of group IVA element because tin may read on both the tin component and the group IVA metal element by double inclusion.
Any remaining claim limitations are optional or are merely product-by-process limitations that are met by the disclosed structure of the reference. See the Claim Interpretation section of record.
Claims 2, 3, 9, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Inage et al. (JP S60-135549 A) as applied to claims 1 and 7 above, and further in view of Ren et al. (CN 108192576 A) or Cai et al. (CN 108329830 A). Again, citations to the references are with respect to the submitted English language machines translation of references unless specified otherwise.
The disclosure of Inage et al. is relied upon as set forth above.
Inage et al. teach a gallium based alloy having a melting point below 15°C comprising 1-45 wt.% In, 1-30 wt.% Sn, 0.05-25 wt.% one or more components selected from Ba, Cd, Sb, Mg, Ca, Li, Bi and Pd and optionally one or more of Ag, Al, Zn, Au and Cu, and the balance Ga, meeting the claimed alloys of the independent claims, as described above.
Inage et al. fail to teach further addition of a thermal conductive particle, as claimed.
However, Ren et al. teach a liquid metal heat interface material comprising la liquid metal, alumina particles, and zinc particles (abstract). The alumina and zinc particles each read on the claimed thermal conductive particle comprising either a metal or a metal oxide and the species thereof. Regarding the liquid metal, Ren et al. teach it is selected from low melting point alloys, preferably gallium-based alloys, (p.3). The blend of the liquid metal and the particles obtains a thermal interface material striking a balance between good heat conductivity, insulation, stability, and price (abstract and p.2). Ren et al. teach the blend comprising the low melting point alloy and particles form a paste at room temperature (p.3).
Alternatively, Cai et al. teach a heat conductive composite thermal interface material comprising a low melting point alloy, a high heat conducting powder, and graphene (abstract). The high heat conducting powder is preferably copper, silver, magnesium oxide, zinc oxide, diamond, or graphite (top p.3), which reads on the claimed thermal conductive particle comprising any of a metal, metal oxide, or carbon-based material and the species thereof. The graphene also reads on the claimed thermal conductive particle comprising a carbon-based material and species thereof. Regarding the low melting point alloy, Cai et al. teach it can comprise any one or more of gallium, indium, and tin (p.2). Cai et al. teach the blend comprising the low melting point alloys and particles have a high coefficient of heat conductivity, can be directly coated on a heating component, has a simple production method, easy operation, stable performance, and a good radiating effect.
Accordingly, at the time of the effective filing date it would have been obvious to a person of ordinary skill in the art to provide Inage et al.’s low melting point gallium based alloy as the low melting liquid metal alloy of Ren et al. in order to obtain a liquid metal heat interface material with a reasonable expectation of success. Similarly, at the time of the effective filing date it would have been obvious to a person of ordinary skill in the art to provide Inage et al.’s low melting point gallium based alloy as the low melting point metal alloy of Cai et al. in order to obtain a thermal interface material with a reasonable expectation of success.
Provision of a known material when the art recognizes its suitably for an intended purpose supports a prima facie obviousness determination. In the present case, the Ren et al. and Cai et al. secondary reference call for liquid and/or gallium-based metal alloys with low melting points and Inage et al. clearly teach such a corresponding alloy. At the time of the effective filing date it would have been obvious to provide the gallium-based alloy of Inage et al. as the low melting point / gallium-based alloy in Ren et al. or Cai et al. based on its melting point which Ren et al. and Cai et al. each teach as suitable for their intended purposes. Selection of a known gallium-based alloy with a particular melting temperature to make a composition calling for a generic gallium-based alloy with such particular melting temperature is prima facie obvious. See, for example, In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
Claims 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Freyermuth et al. (EP 2058081 A2). Citations to the reference are with respect to the submitted English language machine translation of reference unless specified otherwise.
As to claim 1, Freyermuth et al. teach a liquid metal paste comprising a molten metal (abstract). The paragraph at the top of p.3 discloses, “The liquid metal is preferably an alloy containing gallium in a range of 60 to 75 wt%, indium in a range of 15 to 24 wt%, and tin in a range of 8 to 17 wt%. Such an alloy has proven to be particularly suitable because it has a melting point of less than 10 ° C and can be processed so easily to the paste of the invention. Preferably, therefore, the melting point of the liquid metal is at most 15°C, especially at most 10°C. Preferably, antimony or antimony compounds are contained at most in an amount of up to 0.5 wt.%, since otherwise the wetting of the contact points by the paste can be impaired.” The disclosed preferred concentrations of gallium and indium fall within the relative ranges claimed. The disclosed preferred concentration of tin strongly overlaps the relative range claimed. The disclosed range of up to 0.5 wt.% antimony also meets and overlaps that of the claimed trace element.
While the cited teachings of the reference do not meet the claim under the meaning of anticipation (the amount of tin overlaps the claimed range and is not necessarily within the claimed range, one would need to select/provide antimony and the potential amount of antimony overlaps the claimed range and is not necessarily within the claimed range), the cited teachings of the reference nevertheless meet the claimed limitations under a prima facie case of obviousness due to the overlapping scope/nature of the cited teachings. Also, at the time of the effective filing date it would have been obvious to a person of ordinary skill in the art to provide a trace amount (0.5 wt.% or less) of antimony to the preferred GaInSn alloy in order to maintain the wetting properties of the paste with a reasonable expectation of success.
Any remaining claim limitations are optional or are merely product-by-process limitations that are met by the disclosed structure of the reference. See the Claim Interpretation section of record.
As to claims 2 and 3, Freyermuth et al. teach the paste further comprises a particulate material, in particular graphite, copper, and/or silver (middle of p.3), which meets the claimed thermal conductive particle.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (CN 105671394 A). Citations to the reference are with respect to the submitted English language machine translation of reference unless specified otherwise.
Wang et al. teach a gallium liquid metal material with high thermal conductivity (Abstract). A preferred gallium-based liquid alloy comprises 60-85 wt.% gallium, 10-23 wt.% indium, 1-12 wt.% tin, and "further contains traces of bismuth" (bottom p.2). The disclosed concentrations of gallium, indium, and tin strongly overlap those claimed.
While Wang et al. does not quantify their amount of the trace amounts of bismuth, the disclosure nevertheless overlaps and meets the trace element of 0.01-0.5 wt.% as claimed.
At the time of the effective filing date it would have been obvious to a person of ordinary skill in the art to arrive at or within the claimed limitations from the disclosed teachings of the reference with a reasonable expectation of success because it directly teaches providing a trace amount of bismuth, a Group VA element, to a Ga-In-Sn liquid metal alloy composition. A person of ordinary skill in the art would understand and expect a trace amount of a component to be present in a small amount, e.g., somewhere between 0 and about 1 wt.%, which overlaps and encompasses that claimed.
Any remaining claim limitations are optional or are merely product-by-process limitations that are met by the disclosed structure of the reference. See the Claim Interpretation section of record.
Claim 1 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Lu (CN 110129592 A). Citations to the reference are with respect to the submitted English language machine translation of reference unless specified otherwise.
Lu teach a gallium-based liquid alloy, gallium-based liquid alloy mainly comprises the following components according to weight percentage: 65-80 % of gallium, 10-20 % of indium, 5-15 % of tin, 0.5-2 % of zinc, 0.05-2.0 % of iron and 0.005-0.1 % of sulphur (abstract). A preferred and exemplary gallium-based liquid alloy is, in weight percentages, 68% gallium, 19.5% indium, 9.7% tin, 1.5% zinc, 0.5% iron, 0.3% copper, 0.3% aluminum, and 0.2% sulphur (Example 2, p.7). The exemplary alloy anticipates the claimed liquid alloy thermal paste as it comprises components squarely within the claimed ranges. 68% gallium, 19.5% indium, and 9.7% tin are within the recited ranges of gallium, indium, and tin. The 0.3 wt.% aluminum in the alloy reads on the claimed trace element and concentration thereof.
Any remaining claim limitations are optional or are merely product-by-process limitations that are met by the disclosed structure of the reference. See the Claim Interpretation section of record.
Claim 7 is rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Lu (CN 110129592 A). Citations to the reference are with respect to the submitted English language machine translation of reference unless specified otherwise.
Lu teach a gallium-based liquid alloy, gallium-based liquid alloy mainly comprises the following components according to weight percentage: 65-80 % of gallium, 10-20 % of indium, 5-15 % of tin, 0.5-2 % of zinc, 0.05-2.0 % of iron and 0.005-0.1 % of sulphur (abstract). A preferred and exemplary gallium-based liquid alloy is, in weight percentages, 68% gallium, 19.5% indium, 9.7% tin, 1.5% zinc, 0.5% iron, 0.3% copper, 0.3% aluminum, and 0.2% sulphur (Example 2, p.7). The exemplary alloy anticipates the claimed liquid alloy thermal paste as it comprises components squarely within the claimed ranges. It is a multi-metal liquid alloy. 68% gallium, 19.5% indium, 9.7% tin, and 0.3% copper are within the recited ranges of gallium, indium, tin, copper. The 0.3 wt.% aluminum in the alloy reads on the claimed trace element and concentration thereof. The tin component also reads on the additional tin as a group IVA element by double inclusion. For example, in the exemplary alloy comprising 9.7 wt.% tin, 9.6 parts thereof can be quantified as the express tin of the solid metals in the liquid alloy and the remaining 0.1 part of tin can be quantified as the content of the group IVA metal element (note there are only two group IVA metal elements, tin or lead). This has been explained in the Claim Interpretation section of record.
The disclosed exemplary concentrations of the gallium-based liquid alloy fall within those claimed (or as at least implied as relatively present in the final paste).
In the event the cited teachings of the reference fail to meet the claimed liquid alloy mixture made from components comprising the multi-metal liquid alloy and trace element under the meaning of anticipation, the cited teachings of the reference nevertheless (both the preferred/exemplary and broad teachings) meet the claimed limitations under a prima facie case of obviousness due to the overlapping scope/nature of the cited teachings.
This rejection is made under 102/103 out of an abundance of caution due to the unusual product-by-process scope of the claim reciting concentrations of the precursor components, which can include multiples of the same by double inclusion, rather than directly reciting the concentrations of the final components.
Any remaining claim limitations are optional or are merely product-by-process limitations that are met by the disclosed structure of the reference. See the Claim Interpretation section of record.
Claims 2, 3, 9, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Lu (CN 110129592 A) as applied to claims 1 and 7 above, and further in view of Ren et al. (CN 108192576 A) or Cai et al. (CN 108329830 A). Again, citations to the references are with respect to the submitted English language machines translation of references unless specified otherwise.
The disclosure of Lu is relied upon as set forth above.
Lu teach a gallium-based liquid alloy, gallium-based liquid alloy mainly comprises the following components according to weight percentage: 65-80 % of gallium, 10-20 % of indium, 5-15 % of tin, 0.5-2 % of zinc, 0.05-2.0 % of iron and 0.005-0.1 % of sulphur, and a preferred, exemplary liquid alloy comprising, in weight percentages, 68% gallium, 19.5% indium, 9.7% tin, 1.5% zinc, 0.5% iron, 0.3% copper, 0.3% aluminum, and 0.2% sulphur, meeting the claimed alloys of the independent claims, as described above.
Lu et al. further teach their alloy has a melting temperature onset between -26.6 to 12.7 °C (abstract), which is certainly a low melting point for a metal alloy.
Lu fails to teach further addition of a thermal conductive particle, as claimed.
However, Ren et al. teach a liquid metal heat interface material comprising la liquid metal, alumina particles, and zinc particles (abstract). The alumina and zinc particles each read on the claimed thermal conductive particle comprising either a metal or a metal oxide and the species thereof. Regarding the liquid metal, Ren et al. teach it is selected from low melting point alloys, preferably gallium-based alloys, (p.3). The blend of the liquid metal and the particles obtains a thermal interface material striking a balance between good heat conductivity, insulation, stability, and price (abstract and p.2). Ren et al. teach the blend comprising the low melting point alloy and particles form a paste at room temperature (p.3).
Alternatively, Cai et al. teach a heat conductive composite thermal interface material comprising a low melting point alloy, a high heat conducting powder, and graphene (abstract). The high heat conducting powder is preferably copper, silver, magnesium oxide, zinc oxide, diamond, or graphite (top p.3), which reads on the claimed thermal conductive particle comprising any of a metal, metal oxide, or carbon-based material and the species thereof. The graphene also reads on the claimed thermal conductive particle comprising a carbon-based material and species thereof. Regarding the low melting point alloy, Cai et al. teach it can comprise any one or more of gallium, indium, and tin (p.2). Cai et al. teach the blend comprising the low melting point alloys and particles have a high coefficient of heat conductivity, can be directly coated on a heating component, has a simple production method, easy operation, stable performance, and a good radiating effect.
Accordingly, at the time of the effective filing date it would have been obvious to a person of ordinary skill in the art to provide Lu’s low melting point gallium based alloy as the low melting liquid metal alloy of Ren et al. in order to obtain a liquid metal heat interface material with a reasonable expectation of success. Similarly, at the time of the effective filing date it would have been obvious to a person of ordinary skill in the art to provide Lu’s low melting point gallium based alloy as the low melting point metal alloy of Cai et al. in order to obtain a thermal interface material with a reasonable expectation of success.
Provision of a known material when the art recognizes its suitably for an intended purpose supports a prima facie obviousness determination. In the present case, the Ren et al. and Cai et al. secondary reference call for liquid and/or gallium-based metal alloys with low melting points and Lu clearly teach such a corresponding alloy. At the time of the effective filing date it would have been obvious to provide the gallium-based alloy of Lu as the low melting point / gallium-based alloy in Ren et al. or Cai et al. based on its melting point which Ren et al. and Cai et al. each teach as suitable for their intended purposes. Selection of a known gallium-based alloy with a particular melting temperature to make a composition calling for a generic gallium-based alloy with such particular melting temperature is prima facie obvious. See, for example, In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
Claims 1-3 are rejected under 35 U.S.C. 102(a)(1) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Huang et al. (CN 114921676 A). Citations to the reference are with respect to the submitted English language machine translation of reference unless specified otherwise.
As to claim 1, Huang et al. teach a liquid metal-containing paste useful as a thermal interface material comprising a gallium-based liquid metal alloy and a metal powder (abstract). The gallium-based liquid metal alloy comprises 50-95 wt.% gallium, 0-50 wt.% indium, and 0-30 wt.% tin (Id.), which overlaps the claimed liquid alloy composition. A preferred liquid metal alloy comprises 69 wt.% Ga, 21 wt.% In, and 10 wt.% Sn (Embodiment 1, p.3), which falls within the claimed liquid alloy composition. These liquid metal alloys also meet the presence of 0.01-0.5 wt.% trace element including gallium or indium as group IIIA elements and/or tin as a group IVA element by double inclusion. For example, in the preferred alloy comprising 69 wt.% Ga, 68.9 parts of the Ga can be quantified as the content of the liquid alloy component and falls within the claimed range of gallium in said liquid alloy and the remaining 0.1 part of Ga can be quantified as the content of gallium as an additional "trace element" component and falls within the claimed range of gallium in said trace element. Other rationale separately exists for the indium and tin components (e.g., in the 21 wt.% In, under a double inclusion rationale, 20.9 parts can be the liquid alloy and 0.1 parts can be the "trace element", etc.). This has been explained in the Claim Interpretation section of record.
The disclosed preferred concentrations of the gallium-based liquid metal alloy fall within those claimed (or as at least implied as relatively present in the final paste).
In the event the cited teachings of the reference fail to meet the claimed liquid alloy mixture made from components comprising the liquid alloy and trace element under the meaning of anticipation, the cited teachings of the reference nevertheless (both the preferred/exemplary and broad teachings) meet the claimed limitations under a prima facie case of obviousness due to the overlapping scope/nature of the cited teachings.
This rejection is made under 102/103 out of an abundance of caution due to the unusual product-by-process scope of the claim reciting concentrations of the precursor components, which can include multiples of the same by double inclusion, rather than directly reciting the concentrations of the final components.
Any remaining claim limitations are optional or are merely product-by-process limitations that are met by the disclosed structure of the reference. See the Claim Interpretation section of record.
As to claims 2 and 3, Huang et al. teach the paste further comprises a thermal conductive particle which is a metal (an additional metal powder, Id. in the abstract). The metal powder is preferably copper (Embodiment 1, Id., and p.2).
Prior Art Cited But Not Applied
The following prior art is made of record and not relied upon but is considered pertinent to Applicant's disclosure:
Chang et al. ("Recoverable liquid metal paste with reversible rheological characteristic for electronics printing", ACS Appl. Mater. Interfaces, 2020, 12, 14125-14135) teach a liquid metal paste comprising eutectic Ga-In alloy (EGaIn) and nonmetallic SiO2 quartz particles (abstract). Chang et al. compare the GaIn-quartz paste to GaIn-Cu and GaIn-Ni pastes to show the EGaIn alloy can be easily recovered from the paste (e.g., Fig.3 & p.14128-14129) and fails to teach or suggest a liquid alloy comprising all of gallium, indium, and tin, and optionally copper as instantly claimed.
Fan et al. (US 2023/0197558 A1) teach a liquid metal paste configured to be applied as a thermal interface material between electronic components, include a liquid gallium or liquid gallium alloy and powder of metal particles (abstract).
The remaining references listed on Form 892 have been reviewed by the examiner and are considered to be cumulative to or less material than the prior art references relied upon or discussed above.
Correspondence
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/MATTHEW R DIAZ/Primary Examiner, Art Unit 1761
/M.R.D./
April 22, 2026
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