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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 1/19/16 has been entered.
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 1-10 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.
With respect to claim 1, the limitation “purely a first active metal” is ambiguous because the relative term "purely" is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree. It is unclear what purity is implied? Instead, the term “solely” appears to be more appropriate. Due to lack of guidance, one of ordinary skill in the art would not be reasonably apprised of the scope of the limitation. Therefore, the recited vague language fails to clearly set forth the scope, rendering the claims indefinite. For purpose of examination and in accordance with broadest reasonable interpretation consistent with the specification, the claims are taken to mean: the first metal material is a first active metal.
Appropriate correction is requested.
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.
Claims 1-6 are rejected under 35 U.S.C. 103 as being unpatentable over Keusseyan et al. (US 5033666, hereafter “Keusseyan”) in view of Schwobel et al. (US 2022/0411339, hereafter “Schwobel”).
Regarding claim 1, Keusseyan discloses a method for producing an active metal ceramic substrate (col. 2, lines 50-60; see examples), comprising:
coating/printing a first solder paste (first conductor composition) prepared by mixing a first metal material and a first organic medium onto a side surface of a ceramic substrate (col. 3, lines 35-40) to form a first sub-layer (first metallization layer) (col. 3, lines 46-62; col. 7- example 1; col. 10- example 4; claim 1- steps a) to c); wherein the first metal material is a first active metal (platinum, palladium– col. 4, lines 55-57; claim 4, also see Schwobel reference below), and does not contain silver (Ag); wherein a thickness of the first solder layer is 10 microns (col. 7, line 39), within about 5-20 microns (col. 3, line 58);
coating/printing a second solder paste (second conductor composition- col. 5, lines 34-45) prepared by mixing a second metal solder material (copper or gold) and a second organic medium onto a side surface of the first sub-layer that is away from the ceramic substrate, and drying the second solder paste to form a second solder layer (second metallization layer) (col. 3, lines 3-13; col. 7- example 1; col. 10- example 4; claim 1- steps e) to f); wherein the second solder metal material includes copper (Cu), and the second metal solder material does not contain silver (Ag); wherein a thickness of the second sub-solder layer is between about 25 microns (col. 7, line 63); and disposing a conductive metal layer (metallized component- col. 5, line 63 thru col. 6, line 10) onto a side surface of the second sub-layer that is away from the first sub-layer, so as to form the active metal ceramic substrate (assembly/package- col. 7, lines 10-19). Keusseyan discloses thickness of the second sub-layer (second metallization layer) in the range of about 10-30 microns (col. 5, lines 29-30), greater than the thickness of the first sub-layer (first metallization layer), which is about 5-20 microns (col. 3, line 58)- the thickness ranges overlap with recited ranges. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), MPEP 2144.05.
Keusseyan differs from the claim with respect to the second metal solder material also including tin (in addition to copper) and a second active metal. However, such constituents are known in the metal bonding art. Similar to Keusseyan, Schwobel (also drawn to method of producing a metal-ceramic substrate- abstract) discloses applying a solder metal material to a side surface of a ceramic substrate [0018]. Schwobel teaches that the solder metal material can be selected from several types of metals and metallic alloys, including tin-copper, tin-bismuth, tin-antimony, and indium-tin alloys [0025] and includes an active metal selected from titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V) and hafnium (Hf) [0026], which are identical to the active metals employed in Applicant’s invention. Specifically, the active metal assists to produces a connection between the solder and ceramic by chemical reaction [0026]. Schwobel teaches that the solder material can be in the form of a paste and also contains organic medium [0031-0032]; exemplary solder material is a standard paste containing copper, tin and titanium as active metal [0081-0082]. After heating, an integral bond is formed between the ceramic body and the metal foil via the solder material using active metal [0048]. Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to utilize solder paste(s) including active metal(s) similar to Schwobel in the method of Keusseyan because doing so would enable to form an integral bond via chemical reaction, thereby resulting in improved connection with the ceramic substrate. Moreover, the claim would have been obvious because the substitution of one known element for another (copper, copper-tin, tin-based or indium-based solder alloys) would only have yielded predictable results to one of ordinary skill in the art. KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 (2007) (See MPEP 2143- exemplary rationales). Thus, Keusseyan as modified by Schwobel discloses solder paste(s) including at least one active metal (Ti, Zr, Ta, etc.), and the second solder material/paste including copper, tin, as well as one active metal.
As to claims 2-3, Keusseyan discloses performing a brazing/sintering process to braze the conductive metal layer onto the ceramic substrate through the first solder layer and the second solder layer, wherein an operation temperature is about 600-800 °C (col. 5, lines 30-33; claim 7) - this falls within the claimed range of brazing/sintering process of between 600 °C and 900°C. Examiner maintains prior official notice with respect to utilizing vacuum during brazing/sintering process since it is conventional and doing so would prevent oxidation of the surfaces being joined. It is also noted that “high-temperature” renders claim 2 indefinite in scope and any temperature meets claim 2.
As to claims 4-5, Keusseyan discloses thickness of the second solder layer (second metallization layer) in the range of about 10-30 microns (col. 5, lines 29-30), greater than the thickness of the first solder layer (first metallization layer), which is about 5-20 microns (col. 3, line 58)- the thickness ranges overlap with recited ranges, wherein a thickness ratio between the second solder layer (20 microns) and the first solder layer (5 micron) is about 4. Keusseyan further teaches that the thickness of the solder/metallization layer depends on the type and the melting temperature of the braze alloy as well as peak brazing temperature (col. 5, lines 22-30). It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to select desired thickness of the first solder layer and the second solder layer from disclosed ranges in the method of Keusseyan in accordance with heating temperature and the type of substrate/component beings brazed.
As to claim 6, Schwobel teaches that the solder material includes an active metal selected from titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V) and hafnium (Hf), wherein the active metal assists to produces a connection between the solder and ceramic by chemical reaction [0026]. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to incorporate any suitable active metal in the solder material of Keusseyan because doing so would enable to form an integral bond via chemical reaction, thereby resulting in improved connection with the ceramic substrate.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Keusseyan in view of Schwobel as applied to claim 1 above, and further in view of Sakuraba et al. (US 6221511, “Sakuraba”).
As to claim 7, Keusseyan or Schwobel does not mention the solder material viscosity. Examiner points out that viscosity is a temperature-dependent property and thus varies based on ambient conditions. Sakuraba (also directed to producing a metal-ceramic substrate by using brazing/soldering material) teaches that the braze paste includes 55-75 parts solvent & 25-45 parts binder by volume to make 10-14 parts by weight of the organic solvent to prepare the paste (col. 2, lines 40-46; col. 3, lines 30-38). If the organic vehicle is less than 10 parts by weight, the resulting viscosity tends to produce blurred printing. On the other hand, if the organic vehicle is more than 14 parts by weight, then resulting paste has very low viscosity with washout occurring (col. 3, lines 39-43). Reading this, artisan of ordinary skill would appreciate and understand the paste viscosity is a variable for achieving art-recognized result of sufficient coating on the ceramic substrate so that it prevents blurring or washout and forms the desired bonding layer. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to choose the instantly claimed paste viscosity through process optimization in the method of Keusseyan, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. MPEP 2144.05 (II).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Keusseyan in view of Schwobel as applied to claim 1 above, and further in view of Eguchi et al. (CA 1287557 C, “Eguchi”, of record).
As to claim 8, Keusseyan teaches that organic medium is conventional in the art and typically includes solvent, solutions of resin (paste forming agent) and thixotropic agent; the most widely used solvents includes alcohols, alcohols esters, terpenes, carbitol; most frequently used resin is ethyl cellulose; various combinations of these and solvents are formulated to obtain the viscosity and volatility requirements desired (col. 4, lines 20-37). Analogous to Keusseyan, Eguchi (also drawn to conductive copper paste composition- abstract) discloses a conductive paste comprising copper metal powder and organic medium including solvent, resin, and assortment of additives (pg. 3, lines 19-23). Eguchi teaches commonly known solvents such as butyl carbitol, butyl carbitol acetate, toluene, xylene, etc. for controlling the viscosity of the paste (pg. 9, lines 28); thixotropic agent (soldering accelerator- e.g. acid or metal salt) in the range of 0.1-2.5 wt%, (pg. 8, lines 10-25); and paste forming agent (resin component) in the range of 2-30 wt% (pg. 9, lines 19-22; see examples in Tables 1-3) with respect to the total organic medium. The weight ranges overlap with recited ranges. Given teachings of Keusseyan & Eguchi, it would have been obvious to one of ordinary skill in the art to select recited ratio of the agents and the solvent in the organic medium with the motivation of formulating desired viscosity, as suggested by both Keusseyan & Eguchi.
Claims 9-10 are rejected under 35 U.S.C. 103 as being unpatentable over Keusseyan in view of Schwobel & Eguchi as applied to claim 8 above, and further in view of Li et al. (CN 114952077 A, “Li”, of record).
As to claims 9-10, Schwobel discloses the metal solder material comprising active metal in the proportion of preferably 1-10% by weight [0027], which encompasses claimed range of 2-8 wt% active metal. Rejection of claim 8 above is incorporated herein concerning the organic medium. Schwobel discloses selecting from tin-copper alloys generally known to one skilled in the art [0025], which encompasses recited weight ranges of copper and tin. As evidence, Li teaches a composite solder paste comprising powder in following mass percentages: copper powder 20-50%, titanium 10-40% and tin 5-20% (abstract, [0007]). These amounts overlap with recited ranges. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), MPEP 2144.05. It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to select suitable amounts of copper, tin and titanium active metal from ranges taught by prior art for the purpose of providing a conductive solder material for forming the metallization layer in Keusseyan.
Response to Amendment and Arguments
Applicant's amendment and arguments filed 1/19/26 have been fully considered but they are not persuasive and moot in light of new ground(s) of rejection. Examiner points out that relative term “purely” renders the claim indefinite as explained above. Examiner also notes that proposal is presented below to advance prosecution.
Applicant argues (pg. 2 of Remarks):
In the Office Action, the Examiner notes that the previously-recited "first paste" was "not solely made of active metal alone" and was "open to other constituents such as gold or copper." On that basis, the Examiner considered Applicant's earlier arguments "not commensurate with the scope of the claims."
Applicant respectfully submits that this concern has now been addressed by the amendment to claim 1. By requiring that "the first metal material is purely a first active metal," the amended claim 1 now expressly excludes non-active metals such as copper, tin, gold, palladium, platinum, or rhodium (e.g., noble metals or inert metals) from the first metal material. Thus, the rejection can no longer rely on an interpretation in which other non-active metals are present in the first metal material of the claimed first paste.
In response, examiner submits that only the first metal material is made of active metal alone; the first paste still does not exclude other elements such as gold or copper. In other words, the first paste as a whole can include presence of other constituents. Therefore, Applicant’s argument that Keusseyan’s first conductive composition (paste) includes gold or Schwobel’s solder material includes copper is not convincing. It is also noted that recited second paste also includes copper and tin along with the active metal.
Applicant further argues (pg. 3 of Remarks):
Keusseyan does not teach or suggest using active metal (e.g. Ti, Zr, Ta, Nb etc.) as the sole metallic constituent of a first paste. Applicant acknowledges that Schwobel mentions these metals. However, the solder in Schwobel is provided a multi-layer solder foil, each first layer remains part of the composite multi-component Cu/Sn/active solder system. Copper and tin are essential components of Schwobel’s solder and there is no teaching to remove these metals from the first layer.
In response, examiner submits that 0.1-1.0% metal selected from palladium or platinum or rhodium in the first conductor paste (col. 4, lines 55-57; claim 4) in Keusseyan meets relatively broad “active metal” because it is not limited to specific list of metals in claim 1. Moreover, examiner points that Schwobel teaches active metal selected from titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V) and hafnium (Hf) [0026], which are identical to the active metals employed in Applicant’s invention. In response to argument that the references fail to show certain features of the invention, examiner notes that the features upon which applicant relies (i.e., having only active metal as the solder constituent of the first layer or removing all non-active metals) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Examiner contends that applicant’s arguments are not commensurate with the scope of the claims, which are open to other elements along with the active metal in both pastes.
Proposed Amendment(s)
In order to expedite prosecution, the following claim(s) drafted by the examiner appears to distinguish patentably over prior art reference(s) and is being presented to Applicant for consideration (support for amendment below is found in claims 6, 9 and original specification). Examiner notes that dependent claims should be corrected accordingly and further consideration and/or search will be required depending on nature of the amendment(s).
Schwobel discloses using an active metal such as titanium, zirconium, tantalum in the solder metal [0026]. However, prior art does not appear to disclose first sublayer made of only the first active metal & the organic medium, two different active metals, and specific weight ratios of tin and copper in the second metal material (from claim 9). Therefore, it is proposed to incorporate features of the first sublayer consisting of selective active metal(s) and weight amounts of tin & copper into claim 1 to clearly distinguish from the references. Claims 6 and 9 are also amended accordingly.
Claim 1. (Proposed) A method for producing an active metal ceramic substrate, comprising:
coating a first paste prepared by mixing a first metal material and a first organic medium onto a side surface of a ceramic substrate, and drying the first paste to form a first sub layer consisting of the first metal material and the first organic medium; wherein the first metal material is solely a first active metal selected from the group consisting of titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V), and hafnium (Hf), and does not contain a metal silver (Ag); wherein a thickness of the first sub layer is between 1 micrometer and 10 micrometers;
coating a second paste prepared by mixing a second metal material and a second organic medium onto a side surface of the first sub layer that is away from the ceramic substrate, and drying the second paste to form a second sub layer; wherein the second metal material includes a metal tin (Sn), different than the first active metal, and the second metal material does not contain silver (Ag), wherein the weight ratio of the metal tin (Sn), the metal copper (Cu), and the second active metal is 20 to 50 : 40 to 70 : 0.5 to 10 in the second metal material; wherein a thickness of the second sub layer is between 6 micrometers and 24 micrometers; and
disposing a conductive metal layer onto a side surface of the second sub layer that is away from the first sub layer, so as to form the active metal ceramic substrate.
Claim 6. (Proposed) The method according to claim 1, wherein 2), zirconium hydride (ZrH2), tantalum hydride (TaH2), niobium hydride (NbH), vanadium hydride (VH2), and hafnium hydride (H2Hf2).
Claim 9. (Proposed) The method according to claim 1,
Inquiry
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEVANG R PATEL whose telephone number is (571) 270-3636. The examiner can normally be reached on Monday-Friday 8am-5pm, EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Walker can be reached on 571-272-3458. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/DEVANG R PATEL/
Primary Examiner, AU 1735
Prosecution Insights