Electronics Forum | Thu Nov 14 09:43:33 EST 2002 | MA/NY DDave
Hi I will only hit only a few and then bug out. Worked with one large EMS place that has the "fail first" approach to engineering and manufacturing. ( I know I know THEY all do). They didn't store the paste as the mfg suggested, they didn't control
Electronics Forum | Fri Nov 15 17:36:45 EST 2002 | jonfox
First of all, who are you buying it from? If it is not coming with any coverage (parts or tech support) from Tyco, don't make this your first one. They can adjust to just about anything you can program on them (big plus) but I would recommend havin
Electronics Forum | Thu Nov 21 06:36:30 EST 2002 | Ben
I'm doing SMT of lead-free solder BGA on FR4 Ni-Au PCB. The solder paste I'm using is Sn/Ag/Cu and reflow with peak temp at 240C. I found there are voids(1-2) in almost every solder joint(500 micron in dia) under xray. And the void size is violate th
Electronics Forum | Tue Dec 03 07:57:27 EST 2002 | pjc
Price of DEK 248 and MPM UP100 are about the same, $22-36K range. MPM UP100 has programmable squeegee pressure. Precise, repeatable results with less operator involvement. Pressure parameters saved in board program file. DEK 248 has manual microm
Electronics Forum | Wed Dec 18 12:49:04 EST 2002 | Mike F
I've used rice, too. The trick is to make the bag big enough to hold down the part or parts, but not so big it interferes with the top side heating of the parts around it. I've never actually used lead or steel shot, the heaviest fill material I ever
Electronics Forum | Wed Dec 18 15:38:59 EST 2002 | swagner
I have had a similar problem in the past, since I have never worked with a semiautomatic printer there could be a few things I recommend that will not work for you. 1. Make absolutly sure that you have proper support under all of the BGA's. 2. Print
Electronics Forum | Thu Jan 09 10:47:36 EST 2003 | Hussman
Depends on what you mean by shifting towards each other. Otherwise, 7 mil should be fine for 0603. I've used 6mil, 7mil and 8 mil without problems. Generally, stencil thickness won't have a bearing on "shifting" parts. Check placement. Make su
Electronics Forum | Fri Jan 17 04:07:12 EST 2003 | iman
A) Paste Printer : A1) identify the critical SMDs' pads. (choice should go to the BGA, CSP, MLF types...RES,CAP last in line...) A2) get a Paste measurement machine that measures readings of paste height (or better - volume) you are paste printing
Electronics Forum | Mon Jan 20 17:42:45 EST 2003 | jonfox
Double check the data sheets for your paste. Just as an example, ou Indium paste has a recommendation for the Heating, Liquidus, and Cooling stagees of reflow. They recommend a linear ramp up of 0.5 to 1.0 degree C. In the Liquidus stage, a peak t
Electronics Forum | Mon Mar 03 05:35:21 EST 2003 | Kelly
We just had this issue a couple months ago with a single sided FR-4 board which was scored. We found that the design was a factor but also the depth of the v-score. Since then we have re-designed the part further away from the score line. At the same
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