Electronics Forum | Fri Feb 11 08:51:45 EST 2000 | HMAL
Dear Masdi, Perhaps you should check again your screen print process. Small amounts of solder paste under stencil can cause your problems. This paste is from previous printed pcb. When printing next pcb this paste attachs to places that it doesn't
Electronics Forum | Thu Dec 03 13:39:52 EST 1998 | Russ M
| | | | I have some 1.25 mils Al wire bonding chip on board process. After epxoy-based encapsulation, I do some aging test. How can I "see" or prove that there is a "wire break" exist due to the tension of thermal cycling? How can I know the failure
Electronics Forum | Tue Nov 05 09:57:45 EST 2013 | cuperpeter
Hello All, We have a problem with dewetting of solder paste. Problem is most visible on the pads without components (see attached pictures) and occurs randomly, 20% of PCB's. Pcb supplier sent us a cross-section of pads with thickness of Cu, Ni and
Electronics Forum | Tue Aug 25 13:30:35 EDT 2009 | rossi
It appears that the crack is between the paste and the ball. We physically pulled off the BGA by force and almost all the balls broke at the PCB. There was a thin layer of solder left on the pad. Maybe 1% of the balls stuck to the pad. I have attac
Electronics Forum | Fri May 15 14:41:25 EDT 1998 | Terry Burnette 512-933-5783
| We had some failures on an IC package that the manufacturer has put down to moisture inside the package, leading to popcorning. | This seems a bit odd, the package is a PLCC 84 which is quite thick. I have only seen this problem on thin packages. |
Electronics Forum | Tue Sep 14 21:03:42 EDT 2010 | genesan
Hi Sir, The diameter of the aperature is 17mil and thickness 6mil and since we are using Solder Paste Inspection i believe that should have a good paste deposit on this pad.Let say if no good paste it will more create insufficient solder which X-RAY
Electronics Forum | Wed Jun 29 17:38:16 EDT 2005 | GS
Several years ago, we had almost same pbm, best results have been obtained by using water soluble paste (those time the old AM1208). Any way, to get a good toe meniscus is not so easy. Talking about CTE, keep in consideration the internal die of TSO
Electronics Forum | Thu Dec 24 13:43:30 EST 1998 | Earl Moon
| | | Anyone ever attach gold bump flip chip to FR4 or Alumina substrates. Am trying to find a solder which is acceptable for use on gold. Am worried about gold imbrittlement since the gold bumps on the flip chip are .004"x.004"x.001" solid gold. T
Electronics Forum | Wed Aug 06 11:33:04 EDT 2008 | swag
We are having solder issues with this part. (See attached picture). Placement is good prior to reflow. All other parts are reflowing well and oven profile matches paste mfg. specs. well. This is non-ROHS, WS process. Any ideas on what might be h
Electronics Forum | Fri Jul 08 04:09:59 EDT 2011 | leadthree
I hope to get some feedback here. I have a SMD connector that reflow-solders quite poorly (I guess solder paste or profile issue). On the X-ray I see strange bubbles, does it mean there are voids under pin? Generally I am not satisfied with the sol
