Electronics Forum | Fri Jul 04 12:32:33 EDT 2003 | sam
I need some advice about a problem that happened in a SMT LED: The failure symphoms of this SMT LEDs is that the LED body itself seemed to be functional, but when soldering on the products, it showed good wetting and soldering, LEDs are bright and l
Electronics Forum | Fri Aug 08 12:46:02 EDT 2003 | davef
When I was a salty old fart in the Navy, we sent the babes from the turnip patch off on snipe hunts. Shear tests are [in my opinion] senseless. The shear stress you measure depends more on the shear rate and on the point where the force is applied
Electronics Forum | Tue Sep 09 20:32:10 EDT 2003 | davef
The maximum ratio of gold weight to solder alloy weight can be calculated, to help prevent a problem from excessive gold-tin intermetallic compound (i.e., AuSn4). For the equation and its derivation, please refer to "The Use of Capillary Action Measu
Electronics Forum | Fri Sep 19 11:39:38 EDT 2003 | joeherz
We have recently started building a new assembly that is exhibiting some strange behavior. We are seeing what look like blow holes in wave soldered joints. When the joints are touched up, the solder in the barrel will actually bubble up from the ho
Electronics Forum | Mon Oct 06 12:37:18 EDT 2003 | ramanandkini
It was a nice discussion. What I did here was a thermal shock test 1 hour@ +90 deg.c and immediately 1 hour @ -40 deg.c. The second test I did was a high humudity test for a week. After each test, I carried out a peel test with scotch tape. Those bo
Electronics Forum | Tue Oct 14 11:34:04 EDT 2003 | Axl
As far as solder paste goes search no further! I have worked for some huge CM's as a Process Engineer and a lot of them have put thousands of hours of Engineering time and evaluation just to come up with the same answer every time. For no-clean it is
Electronics Forum | Thu Nov 06 07:54:50 EST 2003 | davef
First, skewing is a perfectly acceptable condition, providing the amount of skewing is not excessive. A-610 provides guidance. Second, this part is a land grid device. Land grid devices [ie, BCC�, LGA, QFN, MicroLeadFrame�, etc] are essentially BGA
Electronics Forum | Fri Jan 02 17:47:21 EST 2004 | gpaelmo
Yes, We have done away with masking with kapton 8 yrs ago. As long as the goldfingers are leading edge you can use one of these: 1. rubber goldfinger boot/glove - contact east use to carry them...don't know if they still do. 2. fiberglass glove - ma
Electronics Forum | Mon Feb 16 15:47:54 EST 2004 | Jim
I have about 200 PCB's from which a 20mil pitch QFP must be removed, cleaned and re-used (will place them back in trays for the P&P machine to place the parts on new boards). My intitial concern is: how can we remove the parts in an efficient manner?
Electronics Forum | Tue Feb 17 10:08:17 EST 2004 | russ
Do you have a bake oven that will reach 200C? You could bring a batch of boards up to temp and then start the pluckin'. A sfar as the solder goes if you apply flux to the leads they remove very clean as far as solder goes. To remove the flux we pl
