Ex Parte Arnd et alDownload PDFPatent Trial and Appeal BoardJun 7, 201613390700 (P.T.A.B. Jun. 7, 2016) Copy Citation UNITED STA TES p A TENT AND TRADEMARK OFFICE APPLICATION NO. FILING DATE 13/390,700 02/16/2012 23908 7590 06/09/2016 RENNER OTTO BOISSELLE & SKLAR, LLP 1621 EUCLID AVENUE NINETEENTH FLOOR CLEVELAND, OH 44115 FIRST NAMED INVENTOR KilianArnd UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www .uspto.gov ATTORNEY DOCKET NO. CONFIRMATION NO. ATODP0116US 7267 EXAMINER BAREFORD, KATHERINE A ART UNIT PAPER NUMBER 1718 NOTIFICATION DATE DELIVERY MODE 06/09/2016 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address( es): ipdocket@rennerotto.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte KILIAN ARND, JENS WEGRICHT, ISABEL-RODA HIRSEKORN, and HANS JURGEN SCHREIER Appeal2014-009106 Application 13/390,700 Technology Center 1700 Before ADRIENE LEPIANE HANLON, TERRY J. OWENS, and CHRISTOPHER C. KENNEDY, Administrative Patent Judges. OWENS, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE The Appellants appeal under 35 U.S.C. § 134(a) from the Examiner's rejection of claims 1 and 3-10. We have jurisdiction under 35 U.S.C. § 6(b). The Invention The Appellants claim an electroless plating method. Claim 1 is illustrative: 1. A method for electroless plating of tin and tin alloys comprising the steps of (i) providing a substrate having copper contact pads and a solder mask layer which exposes said copper contact pads, Appeal2014-009106 Application 13/390,700 (ii) depositing a sacrificial layer of copper by electroless plating directly onto the copper contact pads and (iii) depositing a tin or a tin alloy by electroless plating onto the sacrificial layer of copper deposited in step (ii) wherein the thickness ratio ranges from 0.3 to 0.8 and wherein the thickness ratio as defined herein is the ratio of the thickness of the sacrificial layer of copper directly after deposition in step (ii) and of the thickness of the tin or tin alloy layer deposited in step (iii). Schneble Lau Wang Mathew The References us 3,917,486 US 2006/0237097 Al US 7,148,569 Bl US 2009/0176366 Al The Rejections Nov. 4, 1975 Oct. 26, 2006 Dec. 12, 2006 July 9, 2009 The claims stand rejected under 35 U.S.C. § 103 as follows: claims 1 and 3-8 over \1/ang in vievv of ~v1athevv, claim 9 over \1/ang in vievv of Mathew and Schneble, and claim 10 over Wang in view of Mathew and Lau. OPINION We reverse the rejections. We need address only the sole independent claim, i.e., claim 1. 1 Wang covers a ball grid array's copper pad (310) with a thin layer of eutectic solder (63% Sn, 37% Pb, about 5-10 microns thick) or pure Sn solder (about 2-10 microns thick) and then a thicker layer of high-Pb solder (at least 80% Pb and at most 20 % Sn, about 10---50 microns thick) to protect 1 The Examiner does not rely upon Schneble or Lau for any disclosure that remedies the deficiency in the references applied to the independent claim (Final Act. 8-9). 2 Appeal2014-009106 Application 13/390,700 the copper pad from oxidation and enable it to form a solid physical bond with a solder ball (col. 1, 11. 47-55; col. 2, 11. 34--38; col. 3, 11. 13-32). The solder layers are applied by screen printing or plating (col. 2, 11. 13-22). The thin solder layer and copper pad form a Cu/Sn intermediate layer which is thin enough (e.g., less than 1 micron) to reduce the likelihood of it cracking (col. 2, 11. 39--46; col. 3, 11. 35-52). Mathew forms a micropad (70) on a semiconductor device (52)'s active circuitry's electrical contact (54) by covering its exposed surface with a barrier layer (62) that blocks it from contact with to-be-applied copper and tin, depositing a copper stud ( 66) on the barrier layer by electro less plating, and then placing the semiconductor device in a tin immersion bath ( 68) to replace the copper with tin having a purity of at least 95%, preferably at least 99% (i-fi-f 20-22; Figs. 12, 13). The micropad typically is 1-3 microns in height (i-f 23) and "has improved shelf-life because the micropad is pure or substantially pure tin in composition" (i-f 31 ). "When the semiconductor device 52 is subsequently bonded at tin micropad 70 to another micropad of another integrated circuit, the tin will react at a relatively low bonding temperature with a copper micropad to become a solid and reliable intermetallic bond" (i-f 23). Establishing a prima facie case of obviousness requires showing that one of ordinary skill in the art would have had both an apparent reason or suggestion to modify the prior art and predictability or a reasonable expectation of success in doing so. See KSR Int 'l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007); In re Vaeck, 947 F.2d 488, 493 (Fed. Cir. 1991). The Examiner argues that it would have been prima facie obvious to one of ordinary skill in the art to apply Wang's thin pure Sn layer using 3 Appeal2014-009106 Application 13/390,700 Mathew's method (modified to exclude the barrier layer) due to Mathew's method being a known way to apply a tin plating layer having Wang's desired thickness (Final Act. 4--5; Ans. 3--4). The Examiner relies upon Mathew's silence as to a barrier layer when referring to one form of the method (i-f 34, 11. 1-8), statement that "[i]n another form a barrier layer is formed over the external contact prior to the step of forming a stud" (i-f 34, 11. 13-14), and claims wherein independent claim 1 does not recite a barrier layer but claim 4, which depends from claim 1, requires a barrier layer, as indicating that the barrier layer is optional (Final Act. 10-11; Ans. 9-11 ). The Examiner has not established that Mathew would have indicated to one of ordinary skill in the art any benefit in forming Wang's Cu/Sn intermetallic layer by, instead of plating tin onto a copper pad as done by Wang (col. 2, 11. 34--44), applying copper to the copper pad and then using immersion plating to replace the applied copper with tin. Thus, the Examiner has not established that one of ordinary skill in the art would have had an apparent reason or suggestion to modify Wang's method as proposed by the Examiner. As for predictability or reasonable expectation of success in using Mathew's method to apply Wang's pure Sn layer without using a barrier layer, the Examiner argues that in view of Mathew's disclosure that the replacement of copper with tin depends upon various factors including time and temperature (i-fi-f 16, 22), one of ordinary skill in the art would have understood that the replacement with tin of a copper layer applied to Wang's copper pad could be stopped before the copper in the pad has been replaced with tin (Ans. 17-18). 4 Appeal2014-009106 Application 13/390,700 Mathew discloses that tin replaces both the copper stud ( 66. 88) and an optional underlying copper seed layer (82) (i-fi-f 27, 30; Figs. 17, 18). The Examiner does not provide evidence that one of ordinary skill in the art would have had predictability or a reasonable expectation of success in applying a copper stud over Wang's copper pad and, using Mathew's tin immersion method without a barrier layer between the copper stud and the copper pad, replacing with tin the copper in the stud but not the copper in the pad. The Examiner has provided mere speculation to that effect, and such speculation is not sufficient for establishing a prima facie case of obviousness. See In re Warner, 379 F.2d 1011, 1017 (CCPA 1967) ("A rejection based on section 103 clearly must rest on a factual basis, and these facts must be interpreted without hindsight reconstruction of the invention from the prior art"). Accordingly, we reverse the rejections. DECISION/ORDER The rejections under 3 5 U.S. C. § 103 of claims 1 and 3-8 over Wang in view of Mathew, claim 9 over Wang in view of Mathew and Schneble, and claim 10 over Wang in view of Mathew and Lau are reversed. It is ordered that the Examiner's decision is reversed. REVERSED 5 Copy with citationCopy as parenthetical citation