Electronics Forum | Mon Jan 13 06:28:15 EST 2003 | johnw
Hi folk's, I'm looking for some help full suggestions here... I've got a ceramic BGA with tn/lead / bismuth balls on it that is over collapsing due to the weight of the momponnet vs the ablity of theball to suppot them. We've spok eto the component
Electronics Forum | Thu Jan 16 03:43:42 EST 2003 | johnw
1st off for the forum folk, I don't like the fact that the new system only let's you see the posting your replying too, I'd rather be able to see the thread..... Anyhoo, why this alloy?, it's because it's the device manufacturers preferred and the c
Electronics Forum | Mon Jan 13 21:52:16 EST 2003 | davef
Haaaaaa!!!! You contractors get all the fun don't ya??? Consider: * Replacing the balls on the corners of the devices with balls composed of a "hard solder", yano something like 90/10. * Shimming to prevent excessive collapse of a heavy BGA during
Electronics Forum | Tue Feb 09 10:03:05 EST 2021 | grahamcooper22
Just wondering, what do companies who have a stand alone reflow oven use to allow their pcbs to safely exit off the reflow machine conveyor belt or pcb rails ? I've seen home made ramps that the pcb slides down.....but is there any other option ?
Electronics Forum | Wed Oct 10 20:35:17 EDT 2001 | djarvis
Stephen, I don't understand this at all mate. 1. If you don't place a QFP and get bridging across the bare pads, you were gonna get absolutely horrendous bridging if you did put one down. That points to poor printer set up or stencil design or both
Electronics Forum | Wed Apr 12 21:04:10 EDT 2000 | Dave F
Ashok: You still didn�t tell me why you want additional drying of your boards, but what the hey, we all have our dark secrets. Anywho, let�s consider some options for reducing the moisture of your cleaned boards: OPTION 1 - Up-Grading Your Cleaner
Electronics Forum | Thu Mar 28 13:19:14 EDT 2019 | davef
There is no industry standard for BTC stand-off height. "IPC-7093A Design and Assembly Process Implementation for Bottom Termination SMT (BTC) Components" just finished "Final Draft for Industry Review" in December 2018. It mentions stand-off height
Electronics Forum | Wed Nov 12 04:34:17 EST 2008 | kywl
Hi all, Assuming that i were to design a PCB and there are multiple components, what is the minimum spacing required to ensure that i won't have problems in my SMT process later on? Also, is there a minimum component stand-off height spec as well?
Electronics Forum | Tue Oct 03 11:35:51 EDT 2000 | aaronho
Screen printing has much lower profile than dispensing. So it is suitable for chips without body stand-off, (Even sot23 has stand-off). But is is much faster. Dispensers can not catch up with some chip shooters.
Electronics Forum | Wed Jul 12 21:35:56 EDT 2000 | Dave F
John: I agree. We keep out lead stand-off below 60 thou.
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