Electronics Forum | Mon Nov 12 10:57:36 EST 2001 | emmanuel
We are to use a PBGA 272 and a PBGA 388. Between 500 and 750 thermal shocks (-45�C/+125�C), we have noticed that some cracks appear in the solder joints. According to our component specialists, these cracks are due to the whole design (pcb, component
Electronics Forum | Wed Nov 21 04:46:27 EST 2001 | emmanuel
Yes, i confirm you that the BGA i'm refering to are Motorola BGA. The fractures that appear after 500 thermal cycles (-45�C/+125�C) are located in the solder joint/pad connection. We have been asked if this fractures are due to BGA & PCB design or to
Electronics Forum | Tue Nov 27 01:43:29 EST 2001 | Anders
The reason why we are using soldered PCB jumpers is that it is cheaper than dip-switches, 0 ohms resistors, etc. Field updating is also easier. We are producing different variants of some of our products. It would nice if we could presolder the PCB
Electronics Forum | Tue Nov 27 15:57:58 EST 2001 | mparker
rather than applying jumpers, try thinking it another way. Have all possible jumper connections pre-made by the fab design. Use an exacto or dremel to "open" the undesired paths by removing a bit of copper trace. total flexibility, only one fab make
Electronics Forum | Tue Nov 27 14:24:13 EST 2001 | mparker
Short term fixes can be: have the vias "plugged" with solder by the fab house. This works if your fab is HASL finish. Tent the vias with solder mask, top side only. You may get a flux entrapment issue in the vias with this manner. Long term fix can
Electronics Forum | Wed Jan 02 04:05:46 EST 2002 | ianchan
Well usually QA keeps the COC and x-section samples, for a designated minimum time period of 6 months, this time period is not set in stone and is defined by your ISO records retention period...each company bears varient importance to the retention o
Electronics Forum | Fri Jan 04 15:06:07 EST 2002 | davef
Been rootin' through my card file. Other sources I'm aware of, but can not substantially comment on are: * DI water generators: Unit design 714.282.8100 fax8188 * Remco Engineering: modular ion exchange systems * Advanced Separation Technologies: co
Electronics Forum | Thu Jan 24 11:47:15 EST 2002 | Joe B.
Are there any formalized standards for the properties of solder balls? Example properties: sphericity uniformity(variance) of the ball size distribution surface roughness surface oxidation or other surface treatments/contaminants ?? As someone rela
Electronics Forum | Tue Feb 19 18:35:05 EST 2002 | dougt
I was asked by a mechanical guy where the industry standard was for designing a chassis for an ISA/PCI backplane board that we are going to use. We typically use a chassis built by an outside manufacturer but they have decided to build our own. Wel
Electronics Forum | Tue Feb 26 07:55:23 EST 2002 | cyber_wolf
I know that there is an IPC spec. for board pad size design for BGA components. After a little research we have found that recommendations vary from component manufacturers to board houses. (These recommendations are different than what IPC says....
