Just would like to correct my item # 7 on the processes each unit will undergo.Curing is "2 hours" minimumn not 8 hours - sorry.. Any inputs - please read my message below. >From: Enrique Lodangco <[log in to unmask]> >Reply-To: "TechNet E-Mail Forum." <[log in to unmask]>, Enrique >Lodangco <[log in to unmask]> >To: [log in to unmask] >Subject: [TN] Epoxy (clear or black) wicking on leads? How to control and > and possible root causes. >Date: Sun, 5 Sep 1999 01:49:53 +0800 >MIME-Version: 1.0 >From [log in to unmask] Sat Sep 04 10:49:14 1999 >Received: from [209.42.15.76] by hotmail.com (2.1) with ESMTP id >MHotMailB99AA6970074D82197BAD12A0F4C88770; Sat Sep 04 10:49:14 1999 >Received: from jefry ([209.42.15.79])by mail.ipc.org (8.8.8+Sun/8.8.8) with >ESMTP id MAA01480;Sat, 4 Sep 1999 12:47:51 -0500 (CDT) >Received: from IPC.ORG by IPC.ORG (LISTSERV-TCP/IP release 1.8d) with spool >id 2570732 for [log in to unmask]; Sat, 4 Sep 1999 12:34:20 -0500 >Received: from mail.ipc.org (209.42.15.76:34609) by IPC.ORG (LSMTP for >Windows NT v1.1b) with SMTP id <[log in to unmask]>; Sat, 4 Sep >1999 12:24:20 -0500 >Received: from mail2.info.com.ph (mail2.info.com.ph [203.172.11.151]) by > mail.ipc.org (8.8.8+Sun/8.8.8) with ESMTP id MAA01357 for ><[log in to unmask]>; Sat, 4 Sep 1999 12:34:56 -0500 (CDT) >Received: from ericlodangco ([203.172.28.52]) by mail2.info.com.ph >(8.9.1a/8.9.1) with SMTP id BAA316810 for <[log in to unmask]>; Sun, 5 > Sep 1999 01:37:55 +0800 >X-Priority: 3 >X-MSMail-Priority: Normal >X-Mailer: Microsoft Outlook Express 5.00.2314.1300 >X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300 >Message-ID: <018c01bef6fd$e85388e0$0bc5c5c5@ericlodangco> >Sender: TechNet <[log in to unmask]> > >Hi to all of you! > >I'm one of the new members of this forum and for a start I just would like >to know more about controlling epoxy wicking (capillary effect) on IC >leads. > >We are currently assembling module devices (Non Volatile SRAM's) for one of >our customers. Our biggest problem now is on how to control this phenomenon >during encapsulation process. This customer of ours have been doing this >for almost 10 years but problem was not eliminated. They just recently >transferred these operations (consigned everything) to us together with the >said problem. > >To give you a background: > >1. We manufacture these SRAM's or modules using leadframes (tin plated, >alloy 42 base metal) as the leads. >2. Major processes these units undergo - (1) Screen printing, (2)Manual >loading of DIPs and Lead frames onto the PCB (3) Reflow Soldering (4) >Aqueous Cleaning (5) Manual soldering of batteries or crystal on PCB (6) >Encapsulation - using part A and B epoxy (catalyst and resin) mixed and >dispensed on a tub (using an encapsulation machine) where the unit will be >inserted (7) then cured in the oven for a minimum of 8 hours @ 70ºC. > >IF we are to consider that there are no handling issues and machine problem >- >a. how do we control this phenomenon? >b. What are the possible root causes of this phenomenon (wicking or >capillary effect) during encapsulation process? >c. How do I know if it is a material problem? >d. Effects of temperature and humidity on these Lead frames? > > >Any inputs will be highly appreciated.. Thanks. > >For your attention: > >Eric Lodangco >FASTECH ADVANCED ASSEMBLY >Philippines > ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################