Electronics Forum | Mon Dec 11 15:12:20 EST 2000 | accuspec
we are using alphametals no clean 95sn/5ag CL775 paste. After reflow there are solder balls on the board. mainly are around the cap. We are using a conceptronic concept 60 air. There are 4 zones with 8 chambers. We are not sure what the profile
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 | Fri Mar 25 05:33:18 EDT 2011 | Nigel, RAKON
We have the occasional solder fine but the main issue I have is with small - large balls of solder around an 0402 capacitor. Our LF paste data sheet states a %rH of 25 - 70, I have recorded an average for March of 14.9 - 38.5 %rH. Every other requirm
Electronics Forum | Fri Mar 25 04:28:54 EDT 2011 | grahamcooper22
Are the solder balls what we would call ' mid chip ' solder balls where a single or sometimes a few larger solder balls are positioned somewhere along the side of the chip or are they the solder paste powder particles spread around the pads ?
Electronics Forum | Thu May 06 10:28:27 EDT 2004 | Bryan She
Modify your stencil aperture shape...reduce the solder paste deposited on pad,will reduce the solder balls.Be sure your reflow profile are good before doing this.rising slope is very important. This is my opinion.thanks. Bryan
Electronics Forum | Mon Jul 16 19:36:09 EDT 2001 | steven
I hv no choice as per customer's request to remove the solder balls. Can i just use water to clean away the solder balls since i'm using RMA solder paste and not the water soluable paste?
Electronics Forum | Mon Jul 16 19:27:27 EDT 2001 | eliishee
I have no choice, as per customer's request to remove the solder balls. Can i use water to clean away the solder ball since i'm using RMA solder paste not the water soluable paste.
Electronics Forum | Fri Mar 25 08:54:59 EDT 2011 | mosborne1
Have you checked your reflow profile? You need top make sure that you are with the specification of the solder paste. We currntly use the Kic thermal profiling device.
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 | Thu Jul 05 10:45:01 EDT 2001 | dougie
Steven, There is a load of info on this if you check through the archives. Quick pointer though are: Solder balls are caused by paste creeping under the component at placement. The part is placed and the paste is squashed under the component, when t
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