Electronics Forum | Tue Jan 15 10:53:18 EST 2013 | boriskilk
We wouldn't advocate extending the soldermask beyond the component body but yes to ganging for fine pitch. To ensure we don't run into issues with flaking our preference is not to add solder mask when the space between pins is less than 6 mil.
Electronics Forum | Tue Jan 08 09:23:18 EST 2013 | lock_2002
This is a question regarding soldermask between pins of fine pitch devices. The majority of our production designs end up with at least 2-3 mils of copper thickness on the external layers due to blind vias, wrap plating requirements, etc. Our curre
Electronics Forum | Thu Sep 07 03:47:07 EDT 2006 | vicknesh28
I have been getting non wets on fine pitch QFP packages on random leads during reflow process. I noticed that every time there is some flux residue left between the non-wet lead and the solder pad. No residue was not observed on the rest of the good
Electronics Forum | Wed Sep 18 18:48:33 EDT 2002 | davef
Fabs can produce a solder mask web between 20 pitch leads, but I've never seen a web for 16 pitch leads. Although, I would like know a supplier that can lay-down a fine web. Minimum solder mask web width is about 0.004 thou. An absolute mininum o
Electronics Forum | Wed Sep 18 12:35:56 EDT 2002 | stepheno
Fourth - > back to design of PCB. Are there solder dams of > mask between the pads? If yes, that helps. If > not, pay close attention to stencil aperture > width and be sure that the aperture deposits less > paste by 1-2 mils per pad, centered o
Electronics Forum | Tue Dec 11 11:59:00 EST 2012 | sarason
The issue is surface tension around the connector. Your tip needs to have more surface tension than the pins of the connector as it forms a cluster when being soldered. When I used to solder superfine connectors with a metcal iron it had a horses hoa
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 | Mon Aug 23 10:11:55 EDT 2010 | flipit
Hi, I have never been able to find an acceptable dispense process for dispensing small dots of solder paste. I currently have an auger screw automated dispense system and can not accomplish 0.010" dot sizes. In addition, stencil printing is much m
Electronics Forum | Wed Sep 18 18:41:17 EDT 2002 | davef
People have made good comments. Additional points are: * Your bridging is probably being caused by one or more of the following: [1] printing too much paste, [2] smearing the paste during placement or subsequent handling, or [3] paste slump during t
Electronics Forum | Wed Sep 18 12:31:16 EDT 2002 | dragonslayr
My suggestion is to conduct a Design For Manufacturing (DFM)study on the assembly in question. Pay particular attention to the pad sizes, component lead dimensions and satisfy yourself that those two factors are correct. Given that pads match compone
