Electronics Forum | Tue Nov 11 16:30:08 EST 2008 | naynayno
Occasionally solder mask thickness is believed to be the cause of gasketing challenges during paste printing. We currently specific IPC-SM-840 on our fab drawings but this provides no limits or guidelines on thickness. I do not want to cause an unr
Electronics Forum | Fri Jul 28 14:34:13 EDT 2000 | Gary Simbulan
Belive it or not, these boards were run through a Centech batch mode Vapor Phase machine. Single stage top side IR preheat. Vapor temp 218 C. Solder paste is an SN62 RMA.The boards were FR4 8 layer w/ solder mask, fairly conventional as might be e
Electronics Forum | Thu Sep 20 07:18:42 EDT 2018 | proceng1
Has anyone else been experiencing this lately? We have had a rash of boards that come in properly vacuum sealed. We store them in the hot room until we are ready to build, and we get bubbles under the solder mask. We've had 4 different jobs, all di
Electronics Forum | Tue Nov 11 17:35:08 EST 2008 | davef
SM-840, is a material qualification document only, with all the test requirements applicable only to a defined test coupon, not to production boards. So, it's useless for what you're trying to accomplish. As assemblers use A-610 - Acceptability Of E
Electronics Forum | Tue Mar 18 11:53:58 EDT 2014 | sara_pcb
Our contract manufacturing agency have procured pcbs from approved vendor. After assembly we found solder mask separated from the PCB on the epoxy area as patches. The top side is intact. also over the pcb tracks, the mask got damaged. In what c
Electronics Forum | Wed Mar 19 08:38:13 EDT 2014 | davef
I can't picture much of what you're saying, not for nothing, I'm just not connecting. During assembly, solder mask can affected by heat and chemicals. Typically this would be during: * Soldering * Cleaning I will tell you this: Not to defend assem
Electronics Forum | Tue Mar 25 11:43:48 EDT 2014 | sara_pcb
It is Solder Mask on Bare copper, The land finish is HASL as per MIL-PRF-55110G which accepts trace of HASL as acceptable. Wetting is acceptable. regards, R.Saravanan
Electronics Forum | Fri Jun 19 10:03:46 EDT 1998 | Earl Moon
| Has anyone had experience with placing BGA on gold plated boards. I thought I read a while ago there was a problem with embrittlment causing cracked joints. If anyone has experience with this your feedback would be great. | Mike Mike, We and ind
Electronics Forum | Tue Mar 14 07:59:41 EST 2000 | JAX
Emmanuel, The discussion on what finish to use whether it be HASL, Immersion gold over nickel, Organic Solderability Preservatives, ect...... is still ongoing. This is not the only decision you need to make. Do you plan on Soldermask Defined Pads? Wh
Electronics Forum | Tue Mar 14 07:59:41 EST 2000 | JAX
Emmanuel, The discussion on what finish to use whether it be HASL, Immersion gold over nickel, Organic Solderability Preservatives, ect...... is still ongoing. This is not the only decision you need to make. Do you plan on Soldermask Defined Pads? Wh
