Electronics Forum | Tue Mar 13 17:29:18 EDT 2007 | Oswaldo Rey
I placed a Maxim MAX16810 38 pin TQFN with a power pad ground on the bottom of the chip on a prototype board FR4 doble sided. Vias of 0.6 mm where placed underneath part, 6 vias in total. Solder was placed with an air operated syringe, land pattern w
Electronics Forum | Thu Nov 08 07:33:23 EST 2007 | hussman
Why? Just use IPC on finished solder joints as your guide. I've seen groups of people puts hundreds of hours into this task and then tell me a 3 mil stencil is all I need. After reflow, none of the solder joints meet IPC Class 1 and a lot of tombs
Electronics Forum | Thu Nov 17 15:57:41 EST 2011 | olddog
Hi Bobpan, Regarding "second", the results of the test are no difference - still rejects the part. I tried 2 mils, 3 mils, 5 mils, 7 & 9. I changed the tolerances fron about 15% to 20%+. By the way, I did put on the new nozzle and it is still the sa
Electronics Forum | Tue Sep 10 08:42:26 EDT 2013 | rway
Most of our product are mixed technology. I don't consider thru-hole components as "pesky." Perhaps from a manufacturing point of view they are due to the extra handling and machine requirements. But from a reliability stand-point, thru-hole is mu
Electronics Forum | Thu Aug 13 14:10:01 EDT 2015 | markhoch
Hi Sam, I have a feeling that what you're trying to communicate is that your DPAK's are skewing off the pad during reflow. This is caused by a thermal "mismatch" where the solder paste on one side of the DPAK becomes molten before the other, then th
Electronics Forum | Mon Jan 11 04:42:38 EST 2016 | buckcho
You can do the so called "Golden Sample" with defects from the process. The making of the defects on the board is very important to be as much close to the real ones from the production. How I do it - after the printer I remove paste on some pads, so
Electronics Forum | Sat Jul 16 18:24:11 EDT 2016 | aemery
Scratches do not necessarily mean bad! Usually the forcer motor fails before a platen. The motors become weak or don't evenly distribute the supplied air, which causes them to tilt and drive into the platens. Mechanical misalignment of the VY forcer
Electronics Forum | Mon Jun 01 19:41:03 EDT 1998 | Steve Gregory
(snip)...The solder is on the pads and the part is aligned to the pads with in 10% before going into the IR oven. Our problem is when the board comes out of the oven we have a strange skewing problem that I have never seen before. The part is not tw
Electronics Forum | Tue Sep 21 09:49:50 EDT 2004 | Pomponio Magnus
Has anyone ever seen the distributions that result when plotting percent voiding? (Typically a BGA will have enough balls that you can get oogles of data.) I have seen this and seem to be noticing a pattern. First, they are not all normal, so your
Electronics Forum | Fri Feb 11 18:51:16 EST 2005 | primus
The operators use SET SEQ and SET SEG. I know all about getting these wrong, because if you forget the "Q" or the "G" you get SET SE which is SET SENSOR. That REALLY messes up our BEC! But then again, I believe our BECs are all calibrated wrong anywa
