Hi Technetters - Per Steve's comment on Solder Paste quality - I think it is the same with any product out there that is, for the most part, a commodity - there is the good, the bad and the ugly. The sad fact is, you have to evaluate and qualify the solder paste you are about to use for the environment you are using it in (as Steve well knows). You wouldn't purchase a car based on sales rep and spec sheet hype - you have to test it yourself. Over time, your company will be making quite an investment in solder paste that will be consumed in production. As someone who has done countless solder paste evaluations and taught workshops of solder paste testing over the last 12 years, I can assure you that not all solder pastes are the same. There are some great formulations out there that are robust and accommodate a wide range of environmental factors with great tacktime and worklife. On the other hand, there is a lot of crap out there. For example, some solder pastes do a great job at generating solder balls (without any help from other deficiencies in the process). But, if a company is producing a substandard solder paste, how do they stay in business? Because very few users take the time and effort to evaluate solder paste. Sometimes, when I come in to a client to do a Process Audit, I can immediately tell that they never did valid solder paste qualification testing. If they had, they would never be using the solder paste that they are. In lieu of solder paste evaluations, there are two main reasons users give me for using the paste they are using. 1: "We've been using this paste ever since I was here and I've been here for 5 years. It seems to work so why change..." I call this the "Legacy Syndrome". 2. "We like the sales rep - he gets us tickets to the _____ games, etc." This is called "The Salesman Gives Good Lunch" excuse. Solder paste must be evaluated before selection and incorporation into a process. The candidate supplier should also have a good support reputation. This is not always the case. By the way - just because the batch of solder paste contains a Certificate of Compliance (C of C) doesn't guarantee quality either. Lot's of time, less scrupulous companies will just stick one in there without actually testing the batch. One additional note - with the advent of lead-free solder alloys and finishes, the situation will get worse before it gets better. Fortunately for us, there are some excellent suppliers out there - it's those other ones you better watch out for. Caveat emptor. Phil Zarrow ITM Consulting Durham, NH USA www.ITMconsulting.org --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------