Electronics Forum | Fri Jul 15 16:53:56 EDT 2005 | davef
Questions are: * Are you sure there was solder on the pad prior to placing the component? * Is there solder on the lead, but not on the pad?
Electronics Forum | Wed Sep 07 09:34:15 EDT 2005 | PWH
Does anyone know of an IPC standard that deals with drilled holes in a PCB in relation to pad location? We have a PCB where the holes are very close to (through the edge of in some cases) a SMT component pad on a PCB.
Electronics Forum | Fri Sep 09 11:37:27 EDT 2005 | ???
Try home-plated the stencil apertures, and make "V" shape home-plated outside edges of two pads instead of between two pads.
Electronics Forum | Tue Nov 01 09:00:07 EST 2005 | russ
Is an RQFP a Qfp with the center pad for heat dissipation? If so, you may be shifting when this center pad reflows and lifts the part.
Electronics Forum | Mon Nov 14 14:59:32 EST 2005 | davef
Additional questions are: * Does the problem appear with pasted/soldered only boards, in addition to those with components? * What is the size of the unsoldered area? What is the size of the pad? * Where is the solder mask, relative to the pad? * Wha
Electronics Forum | Thu Dec 08 22:47:32 EST 2005 | davef
Satisfactory solder paste should: * Be aligned with all pads * Conform to the stencil pad-aperture size * Have a smooth, flat void-free surface
Electronics Forum | Wed Dec 14 21:19:36 EST 2005 | davef
Heavens to Murgatroyd, we agree with Russ that "black pad" could be the cause of your solderability problem, but oxidized nickel is an additional explanation. While its often easy for assembler to jump this conclusion, it sounds like you've been bla
Electronics Forum | Fri Jan 13 08:53:53 EST 2006 | chunks
Wave not touching the thru-hole part. Adhesive on the pad. Board mask smear on the pad. Ring contaminated. Ring not plated correctly.
Electronics Forum | Fri Jan 13 11:57:51 EST 2006 | james
I am reworking some BGAs and just trying to find the easiest way to do it. Can you use tacky flux without solder on the pads to reflow? or do you have to have solder on the pads before placing the BGA to reflow? Any info is appreciated. thanks
Electronics Forum | Thu Mar 09 04:04:48 EST 2006 | dougs
one point to remember is to have a large stencil reduction on the thermal pad, you need to reduce the solder volume by about 35%, if you don't you risk the solder from the thermal pad shorting out the other leads or the solder volume causing the comp
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