Electronics Forum | Wed Jan 05 12:48:44 EST 2000 | Dave F
Millerin: You are generally correct about plugging and over plating vias, but in Michaels case, the via is blind. Plugging would trap air between the bottom of the via and the plug material, causing an air pocket. When heated to soldering temperat
Electronics Forum | Thu Oct 08 14:04:04 EDT 1998 | Kris Ewen
Manish, I've seen similar phenomenon when processing CSPs on our cards. In our case, we were placing the components over the opening to in-pad blind vias. Due to poor drilling and plating processes by our board suppliers, volatiles were outgassing
Electronics Forum | Tue Nov 20 12:48:40 EST 2001 | tony_sauve
We recently experienced a problem w/voids (up to 65%) in uBGA solder joints. The only joints that have the problem correlated to pads which had blind 0.006" via's in them. The via's only extend down 2 layers, of the 18. 21 BGA's on the PCB, only expe
Electronics Forum | Tue Mar 24 11:20:18 EST 1998 | Earl Moon
| Anyone have an idea how small a via must be to inhibit significant solder volume escaping into the via? Typically, micro vias are drilled and plated to about .003" diameter. To avoid significant solder "drain off," they should be drilled as shallow
Electronics Forum | Wed Mar 25 19:41:01 EST 1998 | Earl Moon
| We have successfully put .016" vias in .030" pads. | There is no drain off with .030" solder balls, since | the actual volume in the .002" depression is low. | We did notice random bubbles where, apparently, the | solder reflowed and trapped the a
Electronics Forum | Wed Mar 25 16:38:21 EST 1998 | Steve Joy
We have successfully put .016" vias in .030" pads. There is no issue with .030" solder balls, since the actual volume of the .002" via in pad is small compared to the ball+solder paste volume. We did notice random bubbles where, apparently, the sol
Electronics Forum | Wed Mar 25 16:36:10 EST 1998 | Steve Joy
We have successfully put .016" vias in .030" pads. There is no drain off with .030" solder balls, since the actual volume in the .002" depression is low. We did notice random bubbles where, apparently, the solder reflowed and trapped the air in the
Electronics Forum | Wed Apr 21 14:38:38 EDT 1999 | Justin Medernach
| Does anyone have any experience with soldering 50mil pitch BGA's that have a via in the pad, the size is .012 The via will be masked off on the bottom side of the board. Need to know what precautions or problems if any I might encounter. The proces
Electronics Forum | Wed Feb 05 13:08:20 EST 2003 | joeherz
You're correct that a thicker solder deposit will make bridging on fine pitch devices a bigger risk. Another alternative could be to slightly over-print the pads (onto the soldermask) ala pin-in-paste process. Basically adding enough solder to fill
Electronics Forum | Thu Aug 06 09:51:20 EDT 1998 | Bob Willis
This text may be of interest to any one with tin lead spots Guide to Solder Spots - A New Plague in Manufacture ? So what are solder spots ? They appear to be the next big problem in modern reflow assembly in fact in any process that involves solder
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