Electronics Forum | Fri Oct 18 12:40:35 EDT 2013 | robertwillis
Back in the mists of time there were two papers on the use of Parylene Coating and the improved thermal cycling results in 1990. It was on LCCC then shortly after on BGA. Does anyone know of results of recent trials or have a copy of the BGA papers.
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 Mar 19 21:01:49 EST 2003 | Rob
I would suggest creating a special reflow profile, heating the board up to 130C about 50 c below eutectic point (183C). Then applying heat to only the BGA, this will prevent thermal shock to surrounding components.
Electronics Forum | Fri Jan 14 17:09:21 EST 2005 | Bob R.
Whether or not conformal coating creates a reliability problem if it bridges the gap between the board and bottom of the part depends on the properties of the coating. A low modulus coating is fine, but one thats modulus increases at colder temperat
Electronics Forum | Mon Dec 05 12:41:40 EST 2005 | stepheniii
thermal cycling chemical reactions (can occur slowly) they were only touching before and not really a solid solder joint
Electronics Forum | Thu Jul 09 11:13:00 EDT 1998 | justin medernach
| IS IT BETTER FOR SOLDER PASTE TO SPREAD OUT AS FAR AS POSSIBLE ON BARE COPPER, OR FOR IT TO KEEP THE SHAPE OF THE PRINT? I'VE BEEN DOING SOME SOLDER PASTE EVALUATIONS, AND I'M TRYING TO EVALUATE THE RESULTS. I'M NOT SURE THAT BECAUSE A PASTE MAY
Electronics Forum | Tue Aug 22 16:02:07 EDT 2000 | Dr. Ning-Cheng Lee
If the thermal mass of the products is small, a tent-shaped profile is recommended, with peak temperature around 240C. The hottest spot on board should be less than 250C. However, if the thermal mass of the product is large, such as a large server PC
Electronics Forum | Tue Jun 05 21:14:10 EDT 2001 | davef
You aren't going to post our stuff on your "Hey, I'm the wizard site", are you? Board fab, Pad coatings, OSP 1 OSPs: Imidazole (Via Systems) is good. Entek (Enthone) works, but requires strict thickness control in fab. 2 Enthone CU56 allows one t
Electronics Forum | Mon Feb 08 09:03:49 EST 2010 | woodsmt
Looking for methods for detecting BGA microcracks without cross sectioning. Currently evaluating a new package and will be putting together a thermal stress eval. We would like to perform intermediate inspections for cracks. Once all cycles are don
Electronics Forum | Tue May 26 14:50:07 EDT 1998 | Dave F
| | I'm reviewing my board fab spec. It calls for a minimum SnPb thickness of 50 microinches on HASL PWB's. I've looked at other specs that call out anything from 30 to 80 microinches, and others that just say the copper pad must be covered and sol
.gif)
