Electronics Forum | Mon May 20 10:49:12 EDT 2002 | geoff_goring
Are we saying then that IMC can occur at the solder / Cu pad join on the PCB when finished assembled? In our case we are being told that this process is starting before assembly. Is it fundamentally the same thing. i.e. will the Tin diffuse with th
Electronics Forum | Fri Jun 14 14:30:36 EDT 2002 | davef
Assuming you are talking about solderable surfaces: People specify various materials to protect the solderability of the pads on the board. Gold, actually, Electroless Nickel - Immersion Gold [ENIG], is popular. * Board fabricators like it because
Electronics Forum | Tue Jul 16 10:15:12 EDT 2002 | robbied
Hi, we have recently had some customer returns where the 44 pin j-lead ASIC devices exhibit green corrosion from the copper under the tin plating on the leads. These boards were in the field for around 4 years, with innadequate conformal coating pro
Electronics Forum | Wed Jul 24 22:45:54 EDT 2002 | davef
WS609 is a wonderful paste. J-STD-001, 4.2 states words to the effect that for Class 3 products Type H or M fluxes should only be used for tinning operatins. Most water soluable fluxes are either H or M. I believe that you can use Type H or M flux
Electronics Forum | Wed Aug 21 20:11:34 EDT 2002 | mitch
We are going to begin using a 64 pin 10mm QFP with 0.5mm lead pitch. I was recently asked if we need to purchase our PCB with E3 coating instead of tinned pads when using the .5 pitch. The concept being suggested is that the E3 coating will give us b
Electronics Forum | Tue Sep 03 22:32:04 EDT 2002 | davef
Naw, alcohol and solvents won't do dip. Hold-off on: * Destructive testing. [Athough this will convince you to move on to other things.] * Rework of the solder connections. [Although this will correct the problem.] Consider investigating your aque
Electronics Forum | Tue Sep 24 14:38:53 EDT 2002 | Jim M.
The EMS company i work for assembles a small PCB board that requires 10 solid press fit pins installed. The pins are Phosphor Bronze, CDA-510 Alloy, Grade A, 3/4 hard with a finish of .00012 min tin/lead over .00005 min nickel.I would like these pla
Electronics Forum | Thu Nov 21 06:36:30 EST 2002 | Ben
I'm doing SMT of lead-free solder BGA on FR4 Ni-Au PCB. The solder paste I'm using is Sn/Ag/Cu and reflow with peak temp at 240C. I found there are voids(1-2) in almost every solder joint(500 micron in dia) under xray. And the void size is violate th
Electronics Forum | Thu Dec 19 20:40:08 EST 2002 | jonfox
One common practice, depending on what is on the other side of the PCB and how much heat you need to draw away from the part, is to manufacture a pseudo-heatsink into the board itself. It looks like a large tinned pad but has a dense array of vias f
Electronics Forum | Thu Dec 19 20:45:47 EST 2002 | jonfox
One common practice, depending on what is on the other side of the PCB and how much heat you need to draw away from the part, is to manufacture a pseudo-heatsink into the board itself. It looks like a large tinned pad but has a dense array of vias f
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