Electronics Forum | Thu Apr 22 06:42:03 EDT 2004 | Chris Lampron
Adam, What is the pad finish on the flex circuit? Is this the only component that you are having problems with? (on this Flex)If this is the only problem area on the flex (assuming there is more than one component)then that would lead me towards the
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 | Fri Sep 17 07:33:56 EDT 2010 | scottp
Based on the last few pictures in the report, the root cause is lousy HASL. In fact, you don't have HASL - you've got SnCu intermetallic. Don't mess with your reflow profile, change paste, or monkey with anything else in your process. Have the boar
Electronics Forum | Mon Sep 13 22:32:41 EDT 2010 | genesan
Hi all good morning and need advice from expertise here. One of my customer complain that they have constantly issues with one of their product and ask us to do cross section.The report show there was “no wetting to the PCB copper pad” and cause the
Electronics Forum | Mon Sep 13 22:58:49 EDT 2010 | genesan
Hi all good morning and need advice from expertise here. One of my customer complain that they have constantly issues with one of their product and ask us to do cross section.The report show there was “no wetting to the PCB copper pad” and cause the
Electronics Forum | Fri Sep 17 03:03:29 EDT 2010 | grahamcooper22
Hi Gani, looking at the HASL icture and the poor wetting of the solder over the pads I would imagine that the HASL coating is very thin on the pads and in actual fact isn't 'solder' but is tin /copper intemetallic and this has poor solderability. It
Electronics Forum | Tue Sep 14 02:46:17 EDT 2010 | grahamcooper22
Hi Gani, Looking at the pictures in the report it looks as if there is a thin coating of solder on the pcb pad....but it looks like the BGA sphere was barely in contact with the pad. This could be caused by insufficient solder paste on this pad...may
Electronics Forum | Tue Sep 14 14:22:11 EDT 2010 | grahamcooper22
If the HASL was poor quality and very thin you would find this defect....but you would expect to see it on more pads also. Also, you'd expect to see your solder from your solder paste either dewetted on the pad or reflowed onto the BGA sphere making
Electronics Forum | Thu Sep 16 01:54:46 EDT 2010 | sachu_70
Hi Gani, Immersion Ag finish has lesser shelf life as it can get more easily oxidized on exposure. However, I see concern in your Reflow profile. A few questions: Have you compared your reflow profile to the solder paste manufacturer's recommended pr
Electronics Forum | Tue Sep 14 14:07:45 EDT 2010 | grahamcooper22
Hi Gani, HASL is normally very good for solderability providing there is a good consistent coating of HASL on the pcb pad. But it is not unusual to have a very thin coating of HASL on the pad and this is poor for solderability. You then have tin/copp
