Reply to: RE>Re[2]: Ni/Au SMP mounting Dennis: I don't want to get caught up in a semantic misunderstanding. The use of the word "virtually" still leaves room for isolated exceptions without distorting the picture as a whole. Truevision purchases all of the components, PCBs, etc. for their products and provides complete kits to several assembly subcontractors. These assembly houses use a variety of solder pastes and fluxes (Kester, Alpha Metals, Delta, etc.) With the implementation of ENTECH fabs in the SAME kit as HASL PCBs, the assembly yield improvement with ENTECH was significant, especially for fine pitch QFPs (.016"-0.25" lead pitch). There was NO required change in stencils, paste or profiles. These assemblers are full aqueous houses with both SMT convection reflow and wave solder capability (our products require both). All of our assembly subcontractors prefer ENTECH-106 fabs to HASL fabs, without exception. No major assembly facility uses FREON for board cleaning any more. ENTECH will dissolve in FREON or IPA, leaving the bare copper without any protection from natural oxidation, thus reducing the board's solderability over time. If the potential user still uses FREON, ENTECH is NOT the copper coating of choice. Seagate (my former home) has converted their entire production to ENTECH-106A, using Kester NO-CLEAN paste. This means that >20,000 PCAs per day are being assembled in the hot and humid environment of Singapore without the use of aqueous cleaning and without assembly issues related to HASL PCBs. In all of the PCB assembly that I have witnessed over the past few years, I have not seen an incompatability of solder paste for SMT assembly with ENTECH-106A. Let there be no mistake. I have no ties with Enthone and only pass on the information because IT WORKS! The boards using ENTECH should be cheaper to build than HASL fabs (less thermal stress, less board warpage, etc.), the assembly houses will have fewer assembly-related problems, the component lands are flatter, the deposition of solder paste is more consistent from board to board, the fine-pitch QFP placement is more accurate with fewer solder bridges, etc. Each user needs to satisfy themselves that ENTECH is the best choice for their application. We already have! Bill Fabry Process/Quality Assurance Manager Truevision, Inc. [log in to unmask] -------------------------------------- Date: 1/9/96 7:33 AM To: Bill Fabry From: dmitchel Bill, Tell me more about your experience with Entek 106A. You say it is compatible "with virtually all solder pastes and solders (fluxes?) currently being used in SMT assembly". Even Enthone admits there may be some compatibility problems with their OSP and assembly materials. Regards, Dennis Mitchell [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Re: Ni/Au SMP mounting Author: [log in to unmask] at corp Date: 1/8/96 8:31 PM Reply to: RE>Ni/Au SMP mounting Doug: 100-150 micro-inches of Ni followed by 3-5 micro-inches of Au will do the job without causing solder joint embrittlement. If the object is flat pads for fine pitch components, why not specify the OSP coating ENTECH-106A by Enthone-OMI? It is cheaper than either NI/AU or HASL, requires less processing steps and thermal cycles, has >2 year of unassembled shelf life and most PCB vendors have it as a copper coating option. Also, there is NO process changes required for assembly. It is compatable with virtually all solder pastes and solders currently being used in SMT assembly. Bill Fabry [log in to unmask] -------------------------------------- Date: 1/8/96 7:34 PM To: Bill Fabry From: MR DOUGLAS C JEFFERY -- [ From: Doug Jeffery * EMC.Ver #2.10P ] -- Help, We have been looking into using electroless ni/au smp surfaces instead of solder..I was wondering if anyone had a recommendation on how much ni is required. Is it the same as a tab application? Is it minimual like the gold? How much ni do you have to have to prevent any migration? How much ni is too much? Thanks for your input... Doug Jeffery Electrotek ------------------ RFC822 Header Follows ------------------ Received: by rainbow.rasterops.com with SMTP;8 Jan 1996 19:34:14 -0800 Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI) id TAA02958; Mon, 8 Jan 1996 19:09:31 -0800 Resent-Date: Mon, 8 Jan 1996 19:09:31 -0800 Received: by ipc.org (Smail3.1.28.1 #2) id m0tZUJI-0000NuC; Mon, 8 Jan 96 21:01 CST Old-Return-Path: <[log in to unmask]> Date: Mon, 08 Jan 1996 22:04:23 EST From: [log in to unmask] (MR DOUGLAS C JEFFERY) X-Mailer: PRODIGY Services Company Internet mailer [PIM 3.2-334.50] Message-Id: <[log in to unmask]> To: [log in to unmask] Subject: Ni/Au SMP mounting Resent-Message-ID: <"P4rID.0._36.sfTym"@ipc> Resent-From: [log in to unmask] X-Mailing-List: <[log in to unmask]> archive/latest/2188 X-Loop: [log in to unmask] Precedence: list Resent-Sender: [log in to unmask] ------------------ RFC822 Header Follows ------------------ Received: by rainbow.rasterops.com with SMTP;9 Jan 1996 07:33:32 -0800 Received: from netcomsv.netcom.com by epic.truevision.com with smtp (Smail3.1.29.1 #2) id m0tZcpt-000NBBC; Tue, 9 Jan 96 07:07 EST Received: from zycon.com by netcomsv.netcom.com with SMTP (8.6.12/SMI-4.1) id HAA18353; Tue, 9 Jan 1996 07:29:54 -0800 Received: from corp.zycon.com ([89.0.0.198]) by zycon.com (4.1/SMI-4.1) id AA07862; Tue, 9 Jan 96 07:30:10 PST Received: from cc:Mail by corp.zycon.com id AA821201490; Tue, 09 Jan 96 07:32:46 PST Date: Tue, 09 Jan 96 07:32:46 PST From: "dmitchel" <[log in to unmask]> Message-Id: <[log in to unmask]> To: [log in to unmask] Subject: Re[2]: Ni/Au SMP mounting