Electronics Forum | Tue Apr 11 10:30:46 EDT 2000 | Jeremy Smith
I am having a problem with some joints on a 100 pin pqfp and few different soics on one particular board. When viewed a 8x with a "Mantis" inspection scope the joints look as though they wetted to the ic leg but when probed the leg will pop loose.
Electronics Forum | Mon Apr 17 19:30:27 EDT 2000 | Boca
All of the above is good stuff. To add, I have seen this several times if the assembly is wavesoldered. Heat from the wave can partially reflow the top side SM solder joints and weaken them. To test, check joint strength before wave and then after
Electronics Forum | Fri Jun 08 17:22:51 EDT 2007 | naynayno
We have been producing an IMS assembly with SMT dpak's for some time. However, we recently encountered a new problem by chance - the parts can be flicked off with a finger nail. I state by chance because the solder joints are wetted and shiny with
Electronics Forum | Tue Apr 11 14:59:05 EDT 2000 | Glenn Robertson
Jeremy - What's the process flow on these modules? Are they wave soldered? What is the board finish (ENG, HASL, etc.)? Glenn Robertson
Electronics Forum | Tue Apr 11 20:26:16 EDT 2000 | Dave F
Jeremy: Parts assembler make leads of either Alloy 42 (Invar, whatever) or copper. The solderability of these leads are protected with eutectic or non-eutectic tin/lead solder, palladium or some palladium alloy, or gold. Cuppla things to consider:
Electronics Forum | Tue Apr 11 16:42:56 EDT 2000 | Chad Notebaert
I�m thinking �Poor intermatallic� It could be a few things. Lets start at the beginning. -Is your paste a 63/37 mixture? -Have you monitored you screen printing, Verify Solder deposition, Are you getting enough paste? -You say the solder looks like i
Electronics Forum | Fri Jun 08 18:27:03 EDT 2007 | jmelson
This is probably an inner plated layer of the component that did not bond well. It may be a component that either has the wrong surface finish for lead-free or can't handle the temperatures. Many times I have seen a similar-looking layer when the l
Electronics Forum | Tue Nov 28 09:21:58 EST 2006 | Michael Sanders
Is anyone aware of any articles, white papers, etc., that discuss the gap between the lead and the pad after a SM joint is soldered? In particular, I am looking for a formula for that "gap" for various components.
Electronics Forum | Tue Nov 28 09:37:39 EST 2006 | GS
Have you seen IPC-A-610 D ? regards GS
Electronics Forum | Tue Nov 28 15:41:51 EST 2006 | realchunks
Try IPC-SM-782.
