Electronics Forum: non-wetting and pad (Page 1 of 35)

non-wetting

Electronics Forum | Fri May 17 15:51:32 EDT 2002 | davef

First thing that comes to mind is that your �dip & look� testing at 240�C clearly doesn�t represent the in-use application of 215�C. So, what are the test results at 215�C? Other questions are: * Can we assume that the solderability of other compon

non-wetting on gold land pad

Electronics Forum | Wed Oct 27 19:50:59 EDT 1999 | chris

Hi What is the possible cause of non-wetting of solder paste to the gold land pad. What we observed in the surface of the non-wet pad is an organic FM, and using FTIR we found out that it is a flux. It is possible that the cause of non-wetting is

Re: non-wetting on gold land pad

Electronics Forum | Thu Nov 04 21:36:36 EST 1999 | chris

Hi John, Thanks to your reply, just one question is it possible that the solder paste ( flux material )applied to the pads cause the non-wet. regards Chris

Re: non-wetting on gold land pad

Electronics Forum | Fri Nov 05 10:01:04 EST 1999 | Dave F

Chris: You can have more than "one question!!!" Anyhow, yes crappy solder paste can cause non-wetting, but before you go there understand why the paste is wetting some surfaces, but not others. Ta Dave F

Re: non-wetting on gold land pad

Electronics Forum | Thu Oct 28 09:25:35 EDT 1999 | Dave F

Chris: Typical non-wetting causes are: * Poorly controlled soldering process * Incorrect material * Surface contamination * Insufficient preheat * Misapplied solder mask * Shadowing Without intending to insult you, all of the causes of non-w

Re: non-wetting on gold land pad

Electronics Forum | Thu Oct 28 20:45:38 EDT 1999 | chris

Hi Dave, We suspect that the organic FM causes the non-wetting problem. FTIR analysis confirm that the FM is a flux residue. Dave we only used FTIR to detect organic contaminants, we also used SEM/EDX to determined the elemental composition of the

Re: non-wetting on gold land pad

Electronics Forum | Fri Oct 29 09:36:42 EDT 1999 | Dave F

Chris: Thanks. SMTnet has a "Library." Buried deep within it is a listing of terms. The following is from that listing: Shadowing. When a component blocks the heat or solder wave flow from certain areas of the printed circuit board, resulting in

Re: non-wetting on gold land pad

Electronics Forum | Fri Oct 29 10:02:28 EDT 1999 | John Thorup

Chris A lot of people have reported sudden, fab lot related problems with Ni/Au pads. These are usually characterized by a discoloration of the gold and called cheerful names like "black pad disease". This can be a process problem at your fab house

HASL PCB non-wetting

Electronics Forum | Mon Mar 16 01:06:25 EST 1998 | Victor Ng

Dear all, Recently I have a problem of non-wetting at our wave soldering process. It appears only on the SMT pads for the chip components (at the solder side) of the HASL PCB. With all the same parameters on the wave soldering machine, i

black and grey pad

Electronics Forum | Sat Oct 06 05:33:47 EDT 2001 | spchua

I had recently encounter the "black and grey" pads problems for the BGA pad after the convection re-flow. The pads shows in in "black and grey" color and a litter solder in it, and it happen in ramdom, when applied heat and solder on the "black and g

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