Electronics Forum | Fri Mar 05 02:59:59 EST 2010 | grahamcooper22
Hi, Do you have a picture on one of these leads where the solder has covered the lead ? As this is a gull wing device I wouldn't expect solder to cover it. I expect to see a toe fillet / wetting around the sides of the lead and a heel fillet. If your
Electronics Forum | Wed Mar 03 23:07:59 EST 2010 | davef
If your "engineer reviewed the reflow profile and said this was not related to reflow conditions," then what does he think it's related to? We think that a increased effort to improve the thermal recipe to solder this part is required, because: * S
Electronics Forum | Fri Mar 05 04:19:03 EST 2010 | aungthura
Ya, that could be happened bcoz of reflow profile.I think, in this case, each lead got the different temperature during the reflow process. If the solder had melted properly,the hot lead would have attracted the solder to cover itself.
Electronics Forum | Wed Mar 03 01:48:57 EST 2010 | 89jeong
Hello Sir. Our customer asked me why the solder did not cover the surface of the potocopuler lead. There are 2 ea of photocopuler on pcb and the leads are totally 8ea. But only one is showing this problem. When i reviewed the reflow profile, there
Electronics Forum | Wed Mar 03 18:42:29 EST 2010 | 89jeong
Hello Graham Copper. Thanks for yr comment. I will review the pad size and component placement with our engineer. It looks that the placement of lead is wrong. But what i want to hear from you is about solder lump on the right.As you can see, the sol
Electronics Forum | Mon Mar 08 05:03:24 EST 2010 | grahamcooper22
Hi, I fully agree with isd.jww. The difference in the solder joint appearance of the 2 joints highlighted could be down to a few reasons...reflow profile (I know you've checked, but have you stuck a thermocouple on this actual joint ? ), contaminatio
Electronics Forum | Wed Mar 03 10:52:57 EST 2010 | isd_jwendell
I agree with Graham. What isn't clear is the cause; Was the PCB layout not correct for the device, or was the component not placed properly.
Electronics Forum | Fri Mar 05 21:38:29 EST 2010 | 89jeong
Hello Guys. Many thanks for your interest in this matter. I believe we can solver this. The affected part is Photo coupler and has the same metallization. FYI, i attached another picture. You can compare the solder fillet of leads. The affected posit
Electronics Forum | Wed Mar 03 06:13:23 EST 2010 | grahamcooper22
The picture shows that the heel of the device lead is not on the pad. Either bad placement or wrong pad dimensions. I imagine most customers would reject this joint as only a small part of the lead is actually in the solder. With no heel fillet the j
Electronics Forum | Sat Mar 06 17:45:29 EST 2010 | isd_jwendell
Unfortunately, what you are calling a good fillet is not a good fillet. Solder on the top of the IC lead does not help to make a good connection. The most important fillet is the one located at the heel (think of the IC lead where it meets the PCB as