Hello e-mailer, jschreiner who left no official name in the forum. I got a feeling the heatsink covering the entire board is causing the unusual reflowed solder condition. No matter how good a convection reflow oven could be, metallic heatsinks adversely affect reflow temperature performance. You probably took into the consideration when profiling the board with the huge heatsink, however, one example; can you control the cool-down rate of board? There could be some other factors that hinder reflowing solder. I don't know that because of it is Friday and I wanna go home soon. Some solderology guru's maybe can answer it. I suggest you re-profile the board without the heatsink and reflow some boards. And see whether you get the same condition or not. regards Matthew Park NII-Norsat International Inc. >Date: Fri, 11 Sep 1998 16:36:40 EDT >Reply-To: "TechNet E-Mail Forum." <[log in to unmask]>, [log in to unmask] >From: Werner Engelmaier <[log in to unmask]> >Subject: Re: [TN] Soft Solder >To: [log in to unmask] > >Hi 'jschreiner', >Are you sure you have wetting to the leads? What you describe is not 'soft >solder', whatever that may be, but sounds like not metallurgical connection. >You should be able to tell, because if you do not have wetting, there will be >no solder on the lead surface that was nearest the pad. That could mean, (1) >the reflow profile is too low ( especially with a large heat sink in place you >shopuld be measuring it), (2) you have none solderable leads, because of (a) >contamination, (b) maybe Alloy 42 leads. > >Werner Engelmaier >Engelmaier Associates, L.C. >Electronic Packaging, Interconnection and Reliability Consulting >7 Jasmine Run >Ormond Beach, FL 32174 USA >Phone: 904-437-8747, Fax: 904-437-8737 >E-mail: [log in to unmask] > >################################################################ >TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. >For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 >################################################################ > > ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################