Electronics Forum | Mon Dec 13 00:48:33 EST 1999 | armin
Hi All I have a 0.7 mm diameter hole for vias, what�s the minimum annular ring for this hole diameter? What�s the term unsupported and supported holes refer to in IPC-2221 9.1.2 Annular Ring Requirements? I have a proto-type PCB (designed by our R&
Electronics Forum | Thu Apr 15 10:05:50 EDT 2010 | dwonch
Hi all, Long story ahead.... We are having issues with board vendors on some of our higher layer count (thick) boards. Specifically under BGAs with high aspect ratio vias (14:1). We are using ENIG finish and a lead free process. Basically we get t
Electronics Forum | Wed Feb 14 21:14:45 EST 2001 | davef
BGA Shorting 1 Damaged mask in between the BGA pad and via on the substrate. 2 Poor print registration. 3 Poor via segregation from the pads? Are they tented or is there just a dam in between? 4 Review the profile. You can run into a number of p
Electronics Forum | Mon Mar 15 16:07:32 EST 1999 | Earl Moon
| | After rmoving a BGA (plastic)to correct unexplained shorts | | I installed another BGA using flux only. | | Checking on an X Ray machine and found two shorts. | | | | can anyone give a good explenation ? | | | | Thanks | | | | Ron | | | Ron,
Electronics Forum | Tue Jun 05 03:56:52 EDT 2001 | JohnW
Flip Chip/uBGA Underfill Visual Standards The aim of this document is to produce some draft text and then select photographs to make up a draft visual standard for inspection. There is also a need to produce some reference material for C Scan image
Electronics Forum | Thu Feb 07 20:53:51 EST 2002 | davef
Regardless of the technique used for the mounting pad shape or definition, isolation of the plated through hole [PTH] from the mounting pad is important. If the PTH is contained within the mounting pad, solder will wick down the PTH. The amount of
Electronics Forum | Thu Jan 06 08:03:47 EST 2005 | davef
On solder in vias: It looks like the via are not solder masked well and pick-up solder either: * Solder coating ... OR * During leveling It's possible that the design specifies openings in the solder mask for these via. On solder in the unsupporte
Electronics Forum | Fri Mar 19 08:51:57 EST 1999 | Justin Medernach
| | | After rmoving a BGA (plastic)to correct unexplained shorts | | | I installed another BGA using flux only. | | | Checking on an X Ray machine and found two shorts. | | | | | | can anyone give a good explenation ? | | | | | | Thanks | | | | |
Electronics Forum | Mon Apr 02 20:47:22 EDT 2001 | davef
Cuppla questions for ya ... Where are the shorts [above the mask or between the mask and the laminate]? On the board, what material is between the copper traces and the mask? What type of solder mask(s) used by your suppliers? What are they using
Electronics Forum | Fri Sep 10 11:45:09 EDT 1999 | Scott S. Snider
| scott. | I appreciate your sincere answer. | would tell me the hint about printer if i's possible | To tune our smt process we have to know what is the major X's | for defect. To know major X's with DOE we need a good measurement equipment.
