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 | Tue Sep 26 09:27:10 EDT 2000 | Chris May
LarryK, It all depends upon your volume / problem. As Jax says, if this is a repeating problemo, get QA & Purchasing involved. Is it your stores ? Do they receive 100 off and "decant" 20 into a tube (manual handling error, training etc;). From your
Electronics Forum | Thu Sep 19 11:14:45 EDT 2002 | Jim M.
We had lots of problems with bridging on 15.8mm pitch, QFP17-160 at the start.The board was .032 thick, double sided-six boards to a panel. Here is the problems (not neccessarily in the biggest to little but as i remember them) and solutions that he
Electronics Forum | Thu Sep 07 07:41:06 EDT 2006 | Bubba
Check for coplaner leads if this just exists at reflow process, i.e. look at part before oven, turn on 3D at placement machine. If you see after wave solder, the wave could cause coplanarity issues on top as well if you are going slow enough to refl
Electronics Forum | Fri Aug 13 13:47:52 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 durometer
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
Electronics Forum | Wed May 17 14:02:06 EDT 2006 | russ
So, what is the pitch of the part and the pad size, also tell us the thickness of stencil. Russ
Electronics Forum | Wed May 17 13:48:37 EDT 2006 | dwelch123
I'm having trouble printing leads on a fine pitch part. The lead is only .008". I'm using a DEK 265 with metal squeegee and using WS200 multicore solder paste.The stencil is laser cut and polished. I've experimented with different pressures and diffe
Electronics Forum | Thu May 18 12:00:42 EDT 2006 | jdengler
I think he edited his original post.
Electronics Forum | Thu May 18 11:16:16 EDT 2006 | russ
Go 5 or 6 mil thick with stencil, i am not familiar with that pitch but I would recoomnd a 5mil. Was the thickness in this post before and i missed it? Russ
