Electronics Forum | Wed Apr 30 12:30:14 EDT 2003 | Guillermo
Hello, I would like to ask for cooments/advices about the inspection of small solder deposits inspection (aprox 4 mills). We tried with X ray and Scanning acoustic microscope but it looks like due to the small size, we could not be sure to get all t
Electronics Forum | Wed Jun 11 16:05:28 EDT 2003 | stepheno
We looked at some systems but didn't buy any. What we use is a little mirror. I believe Metron makes it. It is a small diamond shaped mirror with beveled sides and a handle. Used with a microscope, you can see a lot. They are around $100.00. Some
Electronics Forum | Wed Jul 09 11:58:03 EDT 2003 | sam
When we try another test by using less solder paste, we found under the microscope that the solder was actually stick on the LED gold surface, but not having good wetting. By this finding, we can basically conclude that it was poor solderability caus
Electronics Forum | Thu Aug 14 17:29:15 EDT 2003 | Andrea
We use these but we hand solder. The resistor is basically a wire inside the encapsulant. When we noticed the bowing, we tested about 200 that were on different CCA's. They were all fine. If they want to use these under the wave solder, be sure to lo
Electronics Forum | Fri Sep 12 09:10:23 EDT 2003 | Norm Morikawa
Around 1989 I had this probelmm with a SMT CCA that would not solder in one area consistently. I had it cross sectioned by the bare board supplier and found that under their metallurgical microscope the thickness of this HASL bare board could not be
Electronics Forum | Mon Apr 26 17:12:14 EDT 2004 | babe
Take a solder iron with some wire solder and attempt to tin the leads of the component. Look under magnifier or microscope. Did they wet? If not try fluxing them with liquid flux and then soldering again. Did they wet? If they did not then you may wa
Electronics Forum | Tue May 31 10:44:16 EDT 2005 | Scott B
We have found that when the HASL thickness is less than 5 microns the tin in the HASL reacts with the copper leaving a SnCu surface with poor solderability and microscopic grainy Pb islands. The IPC does not specify minimum HASL thickness but we now
Electronics Forum | Wed Aug 24 04:07:31 EDT 2005 | Khoo Meng Tze, Freescale Malaysia
Hi, I am doing a research on the solder ball joint strength of lead free PBGA package. Coming across a dozen of literatures and journals(and the industry itself), I have found out that the method of measuring intermetallic compound(IMC) formation is
Electronics Forum | Tue Sep 13 09:12:12 EDT 2005 | stepheniii
I couldn't find any sanctioned procedure for dragging a pick across the leads to check for opens. I've never been a big fan of this anyways. Other than visually inspecting under a microscope and touching the leads that look suspect is there anything
Electronics Forum | Tue Jan 10 17:10:35 EST 2006 | mdemos1
JAX: Thanks for the reply. We did send one of the boards back to the bare board supplier and they do concede that it is black pad. When you inspect the assembled board under a microscope, you can easily move the entire solder joint away from the p
