Electronics Forum | Tue Sep 25 12:49:58 EDT 2001 | Hussman
Been there - done that. Makes a mess on that 2nd reflow process- doesn't it!?!?!? This is caused by design. If the open via is located in the land area, it will flow thru the via and cause pumps on the opposite side. You can have your vias filled
Electronics Forum | Sat Oct 06 08:27:24 EDT 2001 | davef
Yes, some solder masks do not tent well, because the material is too thin. That�s the trade-off. Thin masks: * Conform well to [don't bleed onto] fine pitch features. * Tent vias poorly, requiring an additional "plugging" step. As you imply, if th
Electronics Forum | Mon Oct 15 17:28:14 EDT 2001 | Brian W.
Boy, does this sound familiar. I agree with Dave, especially his point about board side taping. The kapton tape has a thickness of approximately 2mils. You artificially increase your paste thickness with this method. It also can be a cause for br
Electronics Forum | Thu Oct 25 04:52:17 EDT 2001 | Vai
I'm running intrusive reflow. What happened was when the board went thru' the first reflow ( which is secondary side ), at Post reflow, I can see the solder joint quality is very good smooth and shiny. But when we proceed with the 2nd reflow, at Post
Electronics Forum | Fri Nov 09 07:29:02 EST 2001 | henriksn
Hi, I would just like to add, that in our prototype production we often mount doublesided pcb's with components ranging from 0402 to BGA-280 to QFP-100. Of course we also mount and solder the side with the BGA's and QFP's last. Like the others here,
Electronics Forum | Thu Nov 15 07:59:53 EST 2001 | John S
My company is in the process of evaluating dispensing/screen printing vendors for a new production line that will build a mixed through hole and smt board in high volume. DEK recently came out with a system that uses a thick plastic stecil with mach
Electronics Forum | Fri Nov 16 10:53:30 EST 2001 | Carol Stirling
Hello Everyone, Our board supplier changed our board surface finish on a prototype to flat solderable tin (FST) because of the PWB thickness (.125"). The pads seem to be contaminated, particularly on second side pass through reflow. The solder appea
Electronics Forum | Mon Dec 03 03:42:15 EST 2001 | ianchan
Hi, actually this point was raised a cuppa times, from the past discussion forums... thats why I posed this questions once again *yawn* to find out any new delvelopments in relation to paste Volume giving accuracy??? Obviously it doesn't seem to h
Electronics Forum | Fri Dec 07 09:43:04 EST 2001 | Russ Steiner
I have a mixed technology PCB that has SMT all on bottom, TH parts on both sides (Yes, I realize that's bad. Can't be avoided.) We have designed a 10-up panel, 2 x 5 array. There are 50 leads per bd, 500 per panel. How much time is reasonable to a
Electronics Forum | Tue Dec 11 18:32:30 EST 2001 | edmentzer
Does anyone have experience with different colors of solder mask. I am interested to know if a clear or light color mask is better in the reflow process. Most of the boards we do have a green solder mask. It seems to me that I read somewhere that
