Electronics Forum | Sat Jun 25 00:52:31 EDT 2005 | ktron
Hi all, Recently I had problem with printing the lead free solder paste, almost every board has bridging especially on the fine pitch locations. Anyway this problem never happens when we use leaded solder paste. So I would like to ask if there are a
Electronics Forum | Wed Nov 07 11:56:44 EST 2001 | mparker
Pad spacing is just one element to consider. Your pad spacing is determined by the pitch (center to center distance between the leads). There are several good resources to find the appropriate pitch per device. Search the archives here or refer to th
Electronics Forum | Thu Jun 16 00:24:29 EDT 2005 | mskler
Hi everybody, Can some body tell me that what stencil thicknes is required for the 16mil QFP. I am getting bridging as well as dry at QFP pins. What type of solder 1. Viscocity 2. mesh size 3. flux contents Should be used for this type
Electronics Forum | Thu Jun 16 08:31:15 EDT 2005 | jh0n!
The most part I have the most difficulty with is a 16mil QFN. We found that reducing stencil thickness to 4mil, and reducing aperatures for the IC by 20%, and setting local fiducials to the IC helped immensely. We used to get 75% or more bridged ou
Electronics Forum | Thu Jun 16 22:14:51 EDT 2005 | davef
16 thou pitch parts: Use a 5 thou laser cut electropolished stencil with 0.008"x0.045" apertures and type 3 solder paste. Bridges Connecting or Partially Connecting Adjacent Leads or Lands * Excessive solder paste * Excessive component placement pre
Electronics Forum | Mon Aug 23 03:12:57 EDT 2010 | grahamcooper22
Possible route causes of bridging on fine pitch ICs are; too much paste (stencil aperture wrong), poor print quality (paste smudges during printing), pcb pads not flat depending on the solderable coating, paste has poor cold slump properties, too muc
Electronics Forum | Sat Aug 21 15:07:34 EDT 2010 | jry74
I have a problem with solder bridging between IC leads, especially fine pitch leads. If we lessen the apature ratio and/or decrease stencil thickness, I have more of a chance for unsoldered or insufficent joints. I am looking for any information th
Electronics Forum | Mon Aug 23 17:43:18 EDT 2010 | davef
SAG: Questions on solder mask webbing with fine pitch parts are: * What is the minimum pitch that you can use webbing between fine pitch pads? * What solder mask do you use?
Electronics Forum | Wed Sep 01 08:05:28 EDT 2010 | sachu_70
Solder mask between pads in case of fine-pitched device footprint may not be a practical solution to implement. Cheers !!!
Electronics Forum | Fri Aug 13 13:50:53 EDT 1999 | Brian Wycoff
| | | | | | Hello | | | | | | | | | | | | Having a problem with bridging on 20mil pitch qfp, only on the lead groups where squeegee goes over width of apertures. Using MPM sp-200 semi-auto, chem-etch stencil, 9-10mil width opening | | | | | | 100 du
