Electronics Forum | Tue Jan 15 15:53:14 EST 2008 | jmelson
I only build my own products, so it has to meet my needs for QA only. I am doing some 20 mil lead pitch (0.5mm) and will soon be doing a 0.4 mm pitch part. I have more magnification on my microscopes (40X) but almost never need to go that high. If
Electronics Forum | Tue Jan 29 14:19:29 EST 2008 | operator
Well, here it is. My responsibilities: 1.All Documentation (build packets, processes docs, etc...Even some administrational docs) 2. Oven profiling and everything that goes with it (customer interaction, board& component baking ) 3. ESD program et
Electronics Forum | Tue Feb 12 17:57:42 EST 2008 | chef
I must ask the silly question- are you sure you deposited the correct amount of paste? Depending on aperature design-the voiding could come from a stencil that has its holes partially built up with old paste. If paste volume is guaranteed, then what
Electronics Forum | Wed Jun 18 09:13:44 EDT 2008 | realchunks
You're barking up the wrong tree. Solder "splashes" are generally caused by your print being off pad a bit. They are called solder fines. I've never seen a placement machine have the capability to push paste around using it's kiss-off from the noz
Electronics Forum | Sat Jun 21 23:15:07 EDT 2008 | mika
Also keep in mind that the CCGA column length tolerance is at minimum +/- 0.13mm from most part manufactures and they don't collapse in the same way as a BGA, therefore the paste height deposit could be critical in some rare circumstances. Board warp
Electronics Forum | Mon Aug 18 11:20:08 EDT 2008 | pjc
Stencil apertures are cut to deposit solderpaste onto the annular ring, provided its wide enough. Then you can place a solder preform if needed to ensure there is enough solder to fill the barrel. Here is some information on solder preforms: http://
Electronics Forum | Sat Sep 27 10:40:24 EDT 2008 | hussman
Hello all, Just had a problem where the solder paste does not want to stick to the pad, thru the stencil. We have run this board for years with no problem, and this new lot of boards is giving us problems. I know it's a board problem because they
Electronics Forum | Thu Oct 02 17:00:44 EDT 2008 | davef
Is that accurate? If so, what are your aspect & area ratios? [Similar to the JerryS comment above.] * You say, � � and the average height is very high: nearly 200 pct.� => Our troop can make paste that height too. They snap the stencil-off a fast as
Electronics Forum | Mon Nov 17 09:47:25 EST 2008 | cisridn
I would not recommend doing BGA soldering with only a hot air gun. I have done it in the past, but the boards would eventually come back from the field because the solder joints did not form correctly and the BGA would have to be reworked again. I
Electronics Forum | Tue Mar 03 03:02:17 EST 2009 | emmanueldavid
25% out of Lands in PCB, Insufficient/Inconsistent Alloy deposition which causes for poor Tackiness between Device Spheres & Paste deposited. Also note that Aperture Opening Designs in Your Stencil draws a huge role for these defects. 4. Placement: P
