Electronics Forum | Tue Jul 27 13:01:06 EDT 1999 | Mike Laroe
Looking for solder paste specification limits which have reliability data to support them. Currently, we are looking to define the min/max volume necessary to ensure a good joint on CBGA, PBGA, and Micro-BGA's. Any information will be greatly appre
Electronics Forum | Wed Feb 14 02:38:13 EST 2007 | Wayne
The middle of the BGA has to make sure it has 235 deg C (if you are using SAC paste), otherwise it will not form good joint.
Electronics Forum | Mon Jun 18 14:46:24 EDT 2007 | ck_the_flip
I have heard that with lead free soldering, the cooldown phase is NOT as critical as it is for Tin-Lead. -2�C per second cooldown is good enough to form a good solder joint with good grain structure.
Electronics Forum | Fri Jul 10 14:20:24 EDT 1998 | Bob Willis
Yes bright shiny joints are a myth as many people like dull joints as they are easier to inspect due to reduced reflection of light. The difference you are seeing in the joints is more likly to be a surface effect, flux or just you think its differen
Electronics Forum | Mon Jun 05 10:32:39 EDT 2000 | Khalid Saeed
It could be a gold finish problem. The recommened gold finish thickness is less than five micro inches. Gold thickness greater than five microi inches is significant contributor for causing embrittlement of the solder joints. Verify the reflow profil
Electronics Forum | Fri Dec 24 04:22:11 EST 1999 | Keith Stone
When you get to fine pitch you might want to try reducing the aperture on the long dimension of the pad only. If you reduce the width of the pad you can get solder paste left in the stencil giving insufficient or unsoldered joints. Reducing the lengt
Electronics Forum | Mon Feb 02 05:08:37 EST 2004 | heccles
Anybody seen problems with potted trimpots and reflow soldering - specifically poor wetting as a consequence of lead contamination from the potting compound. Regardless of reflow profile used (MIL -STD -202) cannot get a good joint formed ! If you us
Electronics Forum | Mon Aug 11 10:35:32 EDT 2008 | realchunks
What does your top side wetting look like? This is a perfect case where top side wetting will tell you when you have a good joint. Without seeingor knowing your process, I would suggest either more pre-heat or longer dwell in the solder. Either on
Electronics Forum | Mon Aug 30 16:14:58 EDT 1999 | Dave F
| I am building a board with T1/34 LED's in a 10X10 array there are 12 arrays in a panel. The LED's are body to body in the array, .1 spaced. The LEDS have been autoinserted on a Universal RAD III, so they are cut and clinched. The trouble I am havin
Electronics Forum | Thu Jul 09 11:32:16 EDT 1998 | Justin Medernach
| What should a good gold joint look like? We've run boards for our customers that look kinda dull but seemed to wet properly and the boards fired up just nicely! Should they look nice and shiny like our HASL boards or is "a shiny joint is a good joi
