Electronics Forum | Mon Jul 16 14:48:16 EDT 2001 | mparker
Just received "Circuits Assembly", July 2001 issue. An article regarding solder balls and aperture design, beginning on page 40. This DOE had aperture, reflow profile and no clean pastes (3 types) as attributes. It is advocated that a U-shaped a
Electronics Forum | Thu Feb 01 12:50:38 EST 2001 | slthomas
I side (not that we every actually choose sides here) with the other poster re: reducing solder volume. There is a solder manufacturer that advertises regularly in trade mags. that there are "Absolutely! NONE....NIL....NADA.....mid chip beading/mic
Electronics Forum | Wed Dec 15 10:47:57 EST 1999 | Christopher Lampron
I agree with Wolfgang. We are currently reducing appertures by approx. 10% even on the chip components. This still gives us an adequate fillet volume and very greatly reduces the probability of solder balling/beading. We generally refer to the manufa
Electronics Forum | Thu Mar 28 17:54:57 EST 2002 | slthomas
I realize that this is sort of off-topic, but do you have scads of solder beads (mid-chip solder balls, whatever you like to call them) with that stencil design? If not, would you mind sharing which paste it is that you are using? Email if you like
Electronics Forum | Thu Feb 08 12:02:15 EST 2001 | slthomas
After reading the variety of responses, I feel moved to ask if you're you talking about what are occasionally referred to as solder beads (mid-chip solder balls, attached to the waste line of your chip caps and resistors) or the solder balls that ten
Electronics Forum | Thu Feb 21 03:25:58 EST 2008 | jlawson
I have seen smt chip varistors with Pd/Ag teminations that had poor wetting in terms of good fillet in LF (sac305) soldering. We found that the solder tended to be attracted to the plating on the part and off the actual pad (silver Immersion). This c
Electronics Forum | Thu Aug 05 08:39:26 EDT 1999 | Wayne Sanita
| | | Hello, If you are using no-clean and they are entrapped in the flux it is also IPC accepted but i havent found a customer yet who agrees with that. Im sure you have checked your profile. I had the same problem with chip components but after c
Electronics Forum | Wed Feb 16 09:19:22 EST 2000 | MARK ALDER
Please check Circuit Assembly March 1998, article "Solder balls and aperture shapes" and August 1999 "Guiding stencil design". They can be contacted at www.circuitassembly.com The main cause of mid chip solder balls is the volume of paste that is p
Electronics Forum | Tue Feb 13 07:26:26 EST 2001 | doctord
Bill, I can give you suggestions. First and foremost. Print a board and look under a microscope. Are you printing exactly on the pads? If you print on the mask, no matter how good we got the profile, no matter what paste we would get solder balls. Mo
Electronics Forum | Sat Jun 12 00:34:00 EDT 2004 | kanwal324
Hi ! The main problem being faced currently is formation of solder balls - to be precise, these are micro solder beads generally found attached with bodies of SOTs, Chip Caps, Chip Resistors, between pins of SOICs (50 mil) - lying on PCB surface,
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