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 | Mon Apr 23 19:12:23 EDT 2001 | relensky
Thanks for the instructions. I was missing the reflow part... Omikron is the method our board house offers. We have been through the plating thickness problem and tin depletion conditions. Beyond those issues, I have been trying a few different n
Electronics Forum | Mon Feb 07 13:40:41 EST 2000 | Dave F
Jose: Those are good guesses. Without knowing more, ask yourself: 1 There is probably adequate heat available, but that portion of the substrate that�s not soldering well is not receiving proper heating. Why is the component getting so hot, relati
Electronics Forum | Thu Aug 23 15:45:48 EDT 2001 | slthomas
So, we've already addressed the tombstoning on these guys by adopting the mfr's (Pana.) recommendations for pad size and spacing. Problem is, we have pretty bad wetting of some of these parts. The rest of the board we use them on looks great, nice
Electronics Forum | Wed Dec 19 09:56:20 EST 2001 | guicho_v
I'm new in SMT world, and I've got my 1st challenge: I'm having de-wetting issues with a specific IC 160 pins MQFP (six location, failure is random), where one pin has de-wetting (solder reflow OK, and there is evidence of having contact the past and
Electronics Forum | Tue Jul 30 08:37:39 EDT 2002 | davef
When you talk about 'poor wetting', 'dewett', 'no wets', etc.; are you seeing solder pulling back or away from the pad? Please describe the condition. Dewetting. The condition in the solder joint in which the liquid solder has not adhered intimate
Electronics Forum | Wed Nov 06 16:31:59 EST 2002 | slthomas
I would also consider paste control (don't take it personally...I always have to get after people about this one), time on the stencil, time between print and reflow, solderability of the component leads, paste volume (that one really got us once....
Electronics Forum | Tue Apr 01 08:59:06 EST 2003 | rdr
Hi all, I've got a question that hopefully someone can provide insight. We have a gold immersion assembly that we believe is experiencing fractures or non wetting on a certain BGA. To be sure that it is a fracture and not a wetting issue I would li
Electronics Forum | Mon Dec 22 19:43:43 EST 2003 | Dean
I have seen this affect on Immersion Tin and OSP. 70 to 90 % of the solder wicks to the lead and forms a "single" homogenous solder mass. This even though the pad was 100 % covered with paste... Evaluated different solder paste...did find variatio
Electronics Forum | Tue Feb 03 12:39:20 EST 2004 | paul_bmc
We had the data at the time and it was quite high. More false calls then anything. I do not have the data anymore it since has been archived. When the system was introduced we had 1 engineer and 2 operators trained for programming and running the
