Electronics Forum | Tue Feb 22 01:38:42 EST 2005 | JSS
We r using QFPs of 0.5mm pitch and r not getting any soldering prob at the end.But some new customer insists upon the thickness check of the solder paste after printing. At present we don't hv thickness checking system.We r controlling the amount of
Electronics Forum | Wed Mar 02 05:14:07 EST 2005 | ABHI
Guys, Solder paste height worries all of us as we encounter the non wets after reflow. More so in fine pitch QFP's. The non wets are not always caused by solder paste height. Many other contributors. Even the pad geometry on te board can contribute t
Electronics Forum | Mon Feb 21 18:13:23 EST 2005 | gpaelmo
As davef states above, you would like to have flat surfaces below 25 mil. We are a contract manufacturer also and we've done thousands of 15 mil QFP's with HASL finish with no problems. Your success will depend on quality of PCB supplier providing th
Electronics Forum | Mon Feb 28 12:01:30 EST 2005 | Bob R.
We use QFNs in automotive products and have done a good bit of experimenting with pad designs, paste patterns, stencil thickness, and thermal via patterns. All of them have an effect on assembly and thermal cycle reliability. There is not a yes or
Electronics Forum | Wed Mar 02 18:46:02 EST 2005 | Austinj
The tendancy always has been "when in doubt, touch it up"... this is not the way to "verify the process" and is not the best strategy for multiple reasons (unessecary rework, additional labor costs, as well as making the solder joint more brittle, [i
Electronics Forum | Sun Mar 06 20:08:38 EST 2005 | mrduckmann2000
Davef, You have a good question. If we had perfect design engineers out there that would use the proper component spacing and not put SMT parts between and around thru-hole parts - glue and wave would work perfectly. I have done this with great su
Electronics Forum | Fri Mar 18 19:17:37 EST 2005 | valuems
Hello PMD Don't feel like that, we live with these MPM's. And we have over 10 years experience. Also never mess with the down stop on any MPM and you will be better off. Most of mpm's machines have a down stop of .0750 and it should never be cha
Electronics Forum | Mon Apr 04 09:45:55 EDT 2005 | Homer
IPC may help, otherwise there are many factors: Are the PTH clinched or straight? If straight, what length protrusion? What direction are the parts running thru wave? Is product on a pallet? Not to mention your soldering process: What type of mach
Electronics Forum | Tue Apr 12 08:25:43 EDT 2005 | davef
Q1 Can anyone explain to me what is the clean and non clean solder? A1 The trend away from CFCs has lead many users to evaluate switching to no-clean soldering processes. The term "no-clean" is actually a common misnomer when used to describe a flux
Electronics Forum | Wed Apr 13 04:09:15 EDT 2005 | simmcircuits
Hi, I need help with our MPM UP2000, the stencil and the lamp boards won't turn off completely, they are both on at the same time. Turning it on would only make it brighter, turning it off will just lose the brightness but the lamps are still on. I h
