Electronics Forum | Fri Jan 21 10:40:15 EST 2000 | Dave Chapman
Having adjusted the profile speed slower and adjusting the temps to the recommended lower levels, amazingly the mid chips have almost disapeared (90%). It appears they have been trying to run a "1 profile fits all" on the ovens for Alpha 737 and UP78
Electronics Forum | Fri Oct 22 11:37:38 EDT 1999 | Brett Gordon
Working DFM SMT issues with respect to a client's artwork together with a heavily modified solder stencil, I was able to reduce 0402 tombstoning from 80% across the board to 3%. I winged the aperture reductions, but are there any "rules" or guidelin
Electronics Forum | Tue Oct 12 10:24:50 EDT 1999 | Jose RG
Hi, We are in the way to evaluate different solder pastes, improve our solder paste incoming inspection steps, re-define our stencil requirements and the following questions are open. Two questions, 1- Is anybody using/requiring 1000 Kcps or more
Electronics Forum | Tue Sep 21 11:28:26 EDT 1999 | Dave F
| I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | The stencil is 6 mil thick, laser cut and electo-polished. | The apertures are 12 mil in diameter with 20 mil pitch. | We are usi
Electronics Forum | Tue Sep 07 06:24:07 EDT 1999 | Steve Cheung
We are changing over to a No-Clean paste soon and l was wondering how other people tackle the issue of stencil and PCB cleaning in high-volume production. The paste we are using is Cobar 325RX and its pretty sticky stuff let me tell you! Our proble
Electronics Forum | Wed Aug 25 19:31:22 EDT 1999 | Dave F
| JUST WANDERING IF ANYONE IS PRINTING ADHESIVE ON THE BOTTOM SIDE OF BOARD WITH THROUGH HOLE COMPONENTS ALREADY PLACED. I'VE BEEN TOLD IT IS POSSIBLE BUT WANT TO LOOK INTO THIS PROCESS IN DEPTH. | Chad: You don't need to YELL!!! Anyhow, yes we ha
Electronics Forum | Fri Aug 20 16:00:20 EDT 1999 | Earl Moon
| Has anybody run across a good concise book or other source on solder paste, its characteristics, handling, storage, stencil design, printing and reflow? Yes I asking for the world! | | TX | Mark | As the world turns, or is/was that a soap my x/fu
Electronics Forum | Fri Aug 20 22:43:14 EDT 1999 | ScottM
| Has anybody run across a good concise book or other source on solder paste, its characteristics, handling, storage, stencil design, printing and reflow? Yes I asking for the world! | | TX | Mark | SMT Magazine published a supplement "Pathways to
Electronics Forum | Sat Aug 14 17:39:37 EDT 1999 | Gerry S.
One of the DFM suggestions I've seen is to remove the solder mask web, i.e. the mask between pads on 20-mil QFP devices. The rational is that if the mask is thicker than the pad the mask can prevent the stencil from making intimate contact with the
Electronics Forum | Fri Aug 06 03:51:06 EDT 1999 | Thomas
Could someone give recommendation on the stencil opening for printing epoxy on HAL FR4 PCB for 0805 and 0603 size chips capacitors and resisitors. My regular stencil manufacturer recommend the following: Thickness: 8 mils 0805 opening: Oblong 0.35 X
