Electronics Forum | Fri Jan 15 08:11:34 EST 1999 | Jim Nunns
Our spec on voids is 30% ball diameter in the center. On the component to ball and pad to ball interface, we use 25%. To determine this spec, we asked around. I don't know of any studies that have been done to verify if this is OK Regards Jim |
Electronics Forum | Fri Jan 15 15:29:03 EST 1999 | Jason Hall
| Our spec on voids is 30% ball diameter in the center. On the component to ball and pad to ball interface, we use 25%. To determine this spec, we asked around. I don't know of any studies that have been done to verify if this is OK | | Regards | Ji
Electronics Forum | Sat Jan 16 03:06:36 EST 1999 | Wirat S.
| | Our spec on voids is 30% ball diameter in the center. On the component to ball and pad to ball interface, we use 25%. To determine this spec, we asked around. I don't know of any studies that have been done to verify if this is OK | | | | Regard
Electronics Forum | Fri Jan 15 13:35:03 EST 1999 | Terry Burnette
| I saw the problem of void in solder bump or in lead less component or some BGA. But I didn't have standard specification of that void is accept or reject? Do any body have the better idea or suggestion of the criteria ? | | Thank you, | Wirat
Electronics Forum | Fri Aug 06 10:27:05 EDT 1999 | Kenneth Hedman
| | I saw the problem of void in solder bump or in lead less component or some BGA. But I didn't have standard specification of that void is accept or reject? Do any body have the better idea or suggestion of the criteria ? | | | | Thank you, |
Electronics Forum | Mon May 10 16:37:01 EDT 2004 | davef
First some definitions, the two main types for solder masking near BGA pads are: 1 Pad, Non-Solder Mask Defined. In circuit board design, pads with spacing that does not allow solder (usually bumps) on the pads to contact the adjacent solder mask. [
Electronics Forum | Thu Jun 19 21:39:31 EDT 2008 | mika
Hi, we used to have a RoHS package with uBGA 380 Solder ball's 0.8 mm pitch approx 15x15 mm, bump size is 0.4mm on a 0.33mm pad. Suddenly we need to use another vendor for various reasons. However, the new bump size is 0.45mm according to specs and t
Electronics Forum | Fri Oct 07 09:19:54 EDT 2005 | Kris
the direction in which the solders cool in a BGA are also different than the rest of the boards as the joints " hidden" to ambient. Refer to an analogus phenomenon in the cookson application note. http://www.cooksonsemi.com/pdfs/How%20&%20Why%20Bum
Electronics Forum | Fri Sep 30 10:07:44 EDT 2005 | davef
Alternate explanations are: * Your reflow profile needs to be tweeked. * Bumps under a die look different than elsewhere on the package. Severe creases may indicate a problem, but creases of only a 0.001 to 0.002" deep should not pose any difficulti
Electronics Forum | Fri Apr 29 17:49:22 EDT 2005 | Woodsmt
I have used many of these devices recently and have used them several times over the last few years. I have been successful using a type 4 paste on a 5 mil stencil. The 13 mil round aperture should provide you with an area ratio just adequate for r
