Electronics Forum | Wed Jun 18 08:57:45 EDT 2008 | more_sunshine
thanks for the post... but are you sure that the type of mask i mentioned is photoimageable and as i understood can be removed from desired places (pads/soldering areas) using uv and developer (which i don't know what material is it). and also the
Electronics Forum | Wed Jun 18 07:49:06 EDT 2008 | more_sunshine
hi i'm not experienced in creating pcbs but i have good background, and i have a bunch of questions. i have no access to world wide known pcb chemicals but i managed to get a cramolin positiv spray and i don't know if it is still usable or not? (di
Electronics Forum | Wed Jun 18 20:27:28 EDT 2008 | davef
No, we not sure if your solder mask is LPI. The article we linked was aimed at solder mask application methods. LPI is the most common mask in use today. So, what kind is it? Green tells you nothing. Solder mask can be a variety of colors.
Electronics Forum | Wed Jun 18 08:07:58 EDT 2008 | davef
Here is a link to a basic discussion of solder mask application methods: http://www.ami.ac.uk/courses/topics/0221_smp/index.html
Electronics Forum | Thu Jun 19 04:16:11 EDT 2008 | more_sunshine
actually this is my little problem, i don't know about the material except that it comes in a paste form and it has to be diluted with acetone and it has a green color. i wish that the compounds used to make a solder mask aren't that numerous to be d
Electronics Forum | Wed Sep 21 08:43:46 EDT 2005 | kmeline
We are having problems with a 1210 cap moving as far as a 1/4 inch from its pads during reflow. We have verified the placement before reflow. They will tombstone some of the time. There are smaller and larger parts around this location and none of th
Electronics Forum | Wed Sep 21 20:03:34 EDT 2005 | kevinbooth
I am going to agree with Rob a little. It is also possible that a internal ground plane might be under or connected to the pads of this cap thus causing a increase in temp to this part during reflow. This can cause parts on occasion to jump from the
Electronics Forum | Thu Jul 02 16:01:57 EDT 2009 | ewchong
thanks kpm. agree the cause of those pads lifting. all of them were no connects so they cannot be the cause of the electrical failure. when the bga was removed, all the solder balls on the pcb turned into conical shape due to the separation, except
Electronics Forum | Tue Jul 07 08:42:49 EDT 2009 | ewchong
kpm, you are probably right. under magnification those two pads show some exposed copper which means that they were contaminated or had insufficient solder paste before reflow.
Electronics Forum | Thu Jul 02 13:10:22 EDT 2009 | kpm135
On first glance it looks like those particular pads were not attached to any traces. If I had to guess I would say that your rework profile got hot enough to melt away the glue holding the pads to the board and they came away with your part when you
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