Electronics Forum | Fri Jul 13 04:58:01 EDT 2007 | pavel_murtishev
Good afternoon, Heating/Cooling rates contribute to warpage most of all. Try to tweak you profile so that heating/cooling rate would be minimized. Try to switch cooling blowers off maintaining required peak/TAL. Check copper balance for this PWB, by
Electronics Forum | Fri Jul 13 17:01:50 EDT 2007 | sean10
Thanks for your inputs. The board construction seams to be balanced and boards comes back to flat after top side process. we'll be performing experiement variing the profile parameters. if that does not do it, any printing suggestings? Would more sq
Electronics Forum | Fri Jul 13 12:27:30 EDT 2007 | jseagle
As in more dwell? We see the same problem with through holes connected to power or ground planes. The solder reaches the plane and stops. We are having our boards re-designed to increase the thermal relief and expand the hole size. We are also tr
Electronics Forum | Tue Jul 17 10:25:59 EDT 2007 | hussman
You want to know which flux will over come thermal mass problems? That's easy - none.
Electronics Forum | Fri Jul 13 16:07:42 EDT 2007 | wana
Hello All. Can the experts in the lead free field guide me to the articles / data confirming that it is OK to use lead free components in the normal "leaded" (Pb) SMT process. And also if any changes in the process would be required to be made. Th
Electronics Forum | Mon Jul 16 10:28:08 EDT 2007 | wana
Thanks guys for the suggestions. But, what I am looking for is data, papers, articles to support this process of using lead free parts in leaded process. Again thanks for any help that you can provide.
Electronics Forum | Mon Jul 16 11:04:21 EDT 2007 | davef
You want published articles? Look here: http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLC,GGLC:1969-53,GGLC:en&q=leadfree+in+snpb
Electronics Forum | Thu Jul 19 09:23:52 EDT 2007 | patrickbruneel
Chris, To my knowledge the only difference between leaded and lead-free components is the termination plating. What has changed in the component design that makes them resistant to higher temperatures?
Electronics Forum | Mon Jul 16 16:42:40 EDT 2007 | pnguyvu
Hi Jacky, It seems you have solder bead problem, beading occurs when the solder paste brick splatter as a component is placed into it, after reflow, the splatter becomes a spherical solder ball. Hope this will help. Steve USA STENCILS
Electronics Forum | Fri Jul 20 16:39:18 EDT 2007 | john_smith
Jacky, we have had a similar problem. We needed to go to a smaller nozzle and also check your vacuume system and air kiss.Could be after placement when the machine blows air to insure the part is off the nozzle that it is effecting the solder brick.
