Electronics Forum | Thu Sep 02 08:57:29 EDT 1999 | Scott
I am using a 18 mil and below water soluble solder paste (89.5-25-80). I have never used this type of paste. The PCB has a fine pitch component of which I cannot prevent bridging. The paste coverage on the pad looks like it is slumping. It is not a n
Electronics Forum | Wed Sep 08 11:04:41 EDT 1999 | Timothy O'Neill
| I am using a 18 mil and below water soluble solder paste (89.5-25-80). I have never used this type of paste. The PCB has a fine pitch component of which I cannot prevent bridging. The paste coverage on the pad looks like it is slumping. It is not a
Electronics Forum | Sat Jul 28 03:05:35 EDT 2001 | Frank
Hi guy Does anyone have experiance with printing problem between solder paste water soluble 62/36/2 and gold plating PCB? I do have problem about insufficient solder after printing although I used the same printing parameter as when I print with ano
Electronics Forum | Sun Jul 29 08:36:39 EDT 2001 | davef
You have provided very little information. Two similar possibilites come to mind: poor pad solderability protection and old boards. POOR SOLDERABILITY PROTECTION: Maybe the nickel plating under the gold is oxidized, contaminated, or otherwise very
Electronics Forum | Sun Jul 29 23:58:08 EDT 2001 | Frank
Hi Dave Thanks for your information. The problem that I found is paste not stick well on pads ( solder paste printing process). When the table move down (PCB saperate from stencil) some of paste stick on aperture instead pads. Solder paste : Delta
Electronics Forum | Mon Jul 30 21:12:32 EDT 2001 | davef
"Poor release" (paste hanging-up in the stencil holes) could have three main (or combination of) causes: 1 Equipment: Stencil is too thick. Specifically, a 6 thou stencil should be OK, providing you don�t violate the area and aspect ratios in the fi
Electronics Forum | Mon Jul 30 01:34:46 EDT 2001 | mugen
Best thing to do, is consult your solder paste supplier, bring him/her in, and ask for their humble professional opinion? If they refuse, strongly consider switching to a supplier, with responsive "humble professional opinions" to share, one that spr
Electronics Forum | Tue Jul 31 00:48:55 EDT 2001 | Frank
Sorry I forgot to provide enough information. Stencil thickness is 6 mil Aperture width is 10 mil Aspect ratio (aperture area / wall area) = 0.72 Solder paste mesh size, type 3 (-325 +500) With this aspect ratio we can printing without any probl
Electronics Forum | Tue Feb 23 12:56:03 EST 2010 | vleasher
Is there any harm in washing SMT soldered with NoClean paste? The PCA has some large thru-hole connectors that we would prefer to do as water soluble on out selective solder but the SMT consists of LGA's and other low parts that we would not be able
Electronics Forum | Tue Feb 23 16:45:36 EST 2010 | dyoungquist
Davef is right on as usual. We are doing exactly what you do. Some smt with no clean paste then the plate through connectors on our selective solder machine using water soluble flux. We then clean with a ultrasonic water process. We do see the re
