At 08:50 AM 12/17/01 +1100, Ian Wilson wrote: >On 10:34 AM 17/12/2001 +1300, Wayne Trow said: >>We have recently had problems with our smt placement machines and reflow >>causing beading of the solder because of too much solder paste. I have been >>asked to reduce the paste apertures by 5% on all smt components.
Let me guess that the one specifying "5%" was not taking the trouble to find out exactly what reduction was necessary. Paste mask expansions are specified as oversize from pads. Applying a percentage to them will produce results not having a clear relationship to pad sizes. I don't think that is what the assembler actually needs. Rather, he needs the mask openings to have a specific relationship to the pad sizes. I'd find out what that is and define the masks accordingly. [EMAIL PROTECTED] Abdulrahman Lomax Easthampton, Massachusetts USA * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
