Electronics Forum | Mon Mar 14 18:32:46 EST 2005 | russ
what did your D.O.E. studies show you as the critical parameters? These are the ones that you need to measure. If you did not perform DOE than you probably should prior to putting an SPC chart out there. What type of measurement capabilities regar
Electronics Forum | Tue Mar 15 10:44:42 EST 2005 | jdengler
-If the aperture volume is the same, there will be more solder on the HASL finish joint due to the solder already present on the pad. This difference is not usually enough to cause insufficiant solder volume but will "look different". Sometimes an
Electronics Forum | Wed Mar 16 08:06:52 EST 2005 | zsolt
Grant is right, also for us was the easiest solution to us custom pallets. But you should also try to tweak preheat zones settings. The flux manufacturer should give you some basic temperatures where the flux gets activated. Also it is worth to make
Electronics Forum | Wed Mar 16 09:48:44 EST 2005 | jdengler
I'm with Russ on this one. Had a similar problem with a flex circuit that used gold contacts into a ZIF connector on a ridged PCB. After may test I finally convinced the customer to do some test on the ZIF connector. The end result was flux contam
Electronics Forum | Thu Mar 17 22:47:29 EST 2005 | davef
That would be our first guess, also. Get the stuff analyzed to be sure. Another clue is if the white stuff disappears when you hit it with hot air from a rework station. The hot air is activate the flux. Good troubleshooting tool, but you're subj
Electronics Forum | Thu Mar 17 09:30:59 EST 2005 | John S
We are moving into using fine pitch components in a double sided reflow process. In one of our test runs, we noted that some of the QFP's would move while reflowed on the bottom on the second pass and become defective. Is this being done widely wit
Electronics Forum | Thu Mar 17 11:07:08 EST 2005 | Dougs
I'd agree with Justin, we do double sided reflow on most of our boards with fine pitch QFP's both sides, you do have a problem somewhere else, what size is you board? Is it warping slightly? What kind of oven are you using? Is it convection? fans
Electronics Forum | Tue Mar 22 12:04:31 EST 2005 | John S
Thanks for the advice. In this scenario we are designing our own product. Currently we are building at a prototype level with no appreciable wait between reflow passes. The part in question is a 64 pin QFP. We use a BTU VIP 98 with edge conveyor.
Electronics Forum | Thu Mar 17 13:03:21 EST 2005 | Slow Ride
When it comes to solder paste, you should worry about volume. Granted height is a part of the equation, but you could have perfect height and still get defects. I wouldn't get too wrapped up in volume either, unless you're evaluating stencil height
Electronics Forum | Thu Mar 17 15:03:23 EST 2005 | debh
Has anyone ever tried to use "Reel Scan" (brand) barcoding with Juki machines. We currently have 730-2020 and 2050-2060 lines set up. Was wondering how the compatibility is. (I think I already know the 730 is out...) I'll be asking the vendor also, b
