Electronics Forum | Fri Oct 24 06:55:48 EDT 2008 | clampron
Good Morning WS, If you experieced the solder balls after reflow of a bare board through the oven, then the source of the solder is either the oven or the board. I have had boards with untented via's that were HASL'd that had entrapped solder and fl
Electronics Forum | Fri Jul 27 13:51:53 EDT 2018 | vlad_saviuk
Hi, have some question: during solder paste printing I'm faced with problems on the edge of the PCB - solder balls on gold pads. During analisys we checked everything - change squeegee preasure, different cleaning cycles, squeegee speed - no effect.
Electronics Forum | Mon Nov 02 22:57:02 EST 1998 | Kelly Gossman
Micheal, What does your profile look like for the wave? What profile does your flux say you need? My guess is it is not your profile, our testing with solder balls found that the mask on the boards was the largest contributor to solder balls. Wha
Electronics Forum | Tue Nov 04 12:58:17 EST 2008 | smt123
I have to agree with Patrick here. This image appears to show a board that is NOT HASL as there is what appears to be a copper pad in the upper portion of the image. But then again the arrow tip appears to be white and I woudl expect that to be red s
Electronics Forum | Mon Nov 02 13:24:18 EST 1998 | Ryan Jennens
| Well my process is I'm running my belt speed at 3.50fpm and about 215 to 225 degrees top side. I got my main wave down to a little less than half the board thickness. I'm not using a hot air knife cause we thought it might create more of a problem
Electronics Forum | Wed Nov 04 02:53:53 EST 1998 | Earl Moon
| Micheal, | | What does your profile look like for the wave? What profile does your flux say you need? My guess is it is not your profile, our testing with solder balls found that the mask on the boards was the largest contributor to solder balls
Electronics Forum | Mon Nov 02 17:45:46 EST 1998 | ChrisK
In my experience, solder balls are normally caused by only a few things. In order of likelyhood: 1) Water based fluxes (VOC-Free)not having the water carrier completely dried from the board before going into the solder. I.E, too fast conveyor spee
Electronics Forum | Fri Mar 25 10:50:01 EDT 2011 | grahamcooper22
3 deg / sec) then the flux can slump from the paste and solder is carried with it off the pad and will form balls. Finally, are your pcbs dry ? Pass a bare one through the reflow oven before you print any paste on it, let it cool and then process as
Electronics Forum | Thu Jul 17 04:42:47 EDT 2003 | sanjeevc
Hi! One technique: 1. Remove all balls 2.Make > a mask(stensil)for reballing.The holes of the > mask must be 0.8-0.9 the size of the pads. 3. > Reball chips 4. Reflow chips Good luck Hi Yes,we have done quite a bit of reballing of BGAs with
Electronics Forum | Wed Jul 09 10:55:51 EDT 2003 | Veronica
Hi Reman01, I have done that before when I was in Motorola. What kind of ball are you trying to repair? How many pieces of BGA chip do you need to repair a day? If it is not too many, you can do it by yourself. It is a lot, such as 100 to 1000 piece
