Electronics Forum | Fri Oct 06 08:22:05 EDT 2000 | jackofalltrades
BGA's are not difficult, but should be inspected no matter how careful you are. Here we have been doing bga's forever and x-ray 100%. Without an x-ray there is no good way to ensure the BGA is placed properly, without bridging or insufficients. If yo
Electronics Forum | Thu May 07 15:56:43 EDT 1998 | Terry Burnette
80ppm). The CTE of your board and solder joints will typically be 18-22ppm. We have seen cases were the coating fills the gap between the component and the board, then during temperature cycling the coating expands to the point of breaking the solder
Electronics Forum | Thu Oct 01 07:03:55 EDT 2009 | davef
We doubt that Humiseal 1A33 is causing opens in your assemblies. We'd guess the opens occur earlier in the process, but are not hard failures. So, you pass your tests. When applied, the conformal coat flows into the gap in the ball crack and insulate
Electronics Forum | Tue Sep 14 04:00:12 EDT 2010 | genesan
Hi Sir grahamcooper22, There should not a issue in stencil since i had open the aperature 1:1(one to one).Futhemore this is HASL pcb coating as now our customer had convert to immersion silver.I had do comparison between both and found HASL wetting n
Electronics Forum | Wed Aug 29 03:16:20 EDT 2018 | cannizzaro
It is recommended that the thickness of the stencil of 0.1mm, the steel mesh should be partially nano-coated. It is best not to dry easily, and the particles are not easy to be too large. I have tried ALLPCB for this kind of BGA in the past and they
Electronics Forum | Mon Apr 01 20:33:30 EST 2002 | davef
Regarding your underfil ... * What material did you use as an underfil? * What machine and technique did you use to apply the underfil? * What type of component were you underfilling? * What was the end-use environment?
Electronics Forum | Tue May 25 11:34:02 EDT 2010 | jmedernach
Hi, Use nitrile or latex gloves for handling your product from your pre-coating cleaning step onward. In my opinion, conformal coating should be isolated from the rest of the factory floor. I'm not saying you need a clean room or even a white room.
Electronics Forum | Wed Oct 30 09:43:01 EST 2002 | gregp
Larger tighter spaced balls will present a problem in sealing the vacuum cup. There will be more leakage in this case. It really depends upon the application. The BGA you mention should not be a major concern. The bigger problems are with bigger
Electronics Forum | Mon Nov 01 07:39:49 EST 2004 | Bob R.
Yes, you can place a BGA in flux and get good reflow. However, depending on BGA type and size you should expect a yield loss due to coplanarity issues. Having the paste on the pad definately helps your yield.
Electronics Forum | Mon May 14 20:35:06 EDT 2001 | davef
You're correct. The units should be micro inches. By the by, this gold always should be a hard gold (99.96%-99.97% pure) with a Knoop hardness range of 130 to 200 (optimum 170).
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