Electronics Forum | Thu Jan 29 06:58:40 EST 2004 | davef
Ramp / Soak: Tombstoning is occuring during reflow. You need to get more heat into the ground plane. Obviously a ramp aint gettin' it done. Further, without intending to disrespect your internal discussion, if a linear profile improved the situati
Electronics Forum | Wed Oct 24 11:14:44 EDT 2001 | Cemal Basaran
Dave; Thanks for responsding so fast. here are my answers. 1-WOW!!! How do people get these cool toys? I am with the University at Buffalo Electronic Packaging Lab. http://www.packaging.buffalo.edu We have pretty much everything that is sold on the
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 | Wed Sep 08 17:31:58 EDT 1999 | Earl Moon
| I am wave soldering a single sided through hole PCB array with (6) .040" round diameter pins that sit .5" off the PCB, and .080" apart. The problem being experienced is that solderballs are appearing on the end of the pins. I have tried decreasin
Electronics Forum | Fri Jun 26 08:00:45 EDT 1998 | John Klimek
I have a used Hollis machine that might suit your needs. The only problem is that it is an oil blanketed machine. It is a 7" Hollis Nova 175. Right now it is collecting dust. | | | | | | | | | | Is anyone aware of any papers/publications dealing
Electronics Forum | Fri Apr 17 14:08:44 EDT 1998 | Earl Moon
| Currently I am in the buisness of soldering bare die to the top surface of a copper heat sink. Is any one else | have some exprience in this process that can help. We heat a copper slug through a contolled atmosphere, place a preform then a bare
Electronics Forum | Mon Apr 21 16:39:50 EDT 2003 | k_h
You might try reducing your solder paste volume. To much solder paste gives the part a pool to float in, nullifying the positive effect of surface tension. I use an aperture on stencil for the heat sink which is 5mils reduced on each side and a 25mil
Electronics Forum | Mon May 22 18:19:29 EDT 2006 | Steve
I have read some threads about poor wetting on palladium-silver (Pd-Ag) coated components. I followed the suggestions, but I am still having a problem. The part is an 0603 chip type (Vishay varistor). The Process: solder paste is lead-free Alpha Met
Electronics Forum | Fri Apr 06 10:43:57 EDT 2007 | flipit
Hi, Anyone seeing difficulty is soldering MLFs or QFN with lead free solder? I have an MLF with 3 rows of pads on each of the 4 sides of the part and then the large center ground plane in the middle. The part is 20 mil pitch. Had good luck with l
Electronics Forum | Wed Jun 04 11:09:06 EDT 2014 | clydestrum
Ok, I have an issue that is somewhat uniform in it's recurrence in that it keeps showing up on the same location on the board. The problem area is a group of traces on the exposed side, that keeps having solder mask peel occur. As you can see in the
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