Electronics Forum | Mon Jan 15 08:01:14 EST 2007 | pyro747
The wave process, Flux (NR 330) 3 zones preheat top and bottom side convection, with solder pot at 260 C. PCB is ran in a selective wave pallet.
Electronics Forum | Fri Aug 10 04:19:05 EDT 2001 | wister
There are lots of voids at solder joint of chips,the thickness of multilayer pcb is 3.2mm,top side have lots of chip component and bottom side has several BGA and QFPs.For top side profile,the preheat time is about 100s,soak time is about 75s,time ov
Electronics Forum | Sun Sep 17 09:02:53 EDT 2006 | davef
Just as you will not find such a specification for SnPb solder, you will not find such a standard for SAC. We talked about solder strength several times previously here on SMTnet. Search the fine Archives for others comments. For instance: http://
Electronics Forum | Tue Jan 16 11:24:47 EST 2007 | realchunks
I think John is right. I've seen the same thing (I think, without a picture who knows)on heavy heatsink parts. But I've also seen this happen on larger parts that move right after being wave soldered. I'm talking within a second or two of being so
Electronics Forum | Tue Aug 14 17:55:01 EDT 2001 | Boysen
Are you using a water soluble paste? Older generations of water soluble paste are notorious for voiding. Some of the new generation water soluble fluxes allow a much wider process window.
Electronics Forum | Thu Nov 15 01:05:02 EST 2001 | jamstart
I think for x-ray, it really depend what package you are looking at. For CSP, it should be at least min 90KV, min 5 micro focus size. CSP definitely need a higher mag and resolution.
Electronics Forum | Mon Jan 15 13:31:11 EST 2007 | John S.
Since it is in a pallet, I would be sure the preheat temperature is correct across the entire assembly. We've seen large temperatue delta's across assemblies that are soldered in pallets. Could be overheated even or contact time too long. Interest
Electronics Forum | Wed Jan 14 23:08:19 EST 1998 | Ron Costa
Place your components directly on the PCB without using solder paste,unless your using high temp. solder spheres then you should use paste. If eutectic solder spheres are used try fluxing the BGA area and attach it directly to the board. This will re
Electronics Forum | Fri Aug 10 15:30:38 EDT 2001 | davef
More and more pople are seeing voids in solder connections other than BGA balls than ever before. Thats because they never looked [never had the means to look] before. Now, they can't stand it and, like that zit that their mother told them not to m
Electronics Forum | Fri Aug 10 13:09:49 EDT 2001 | Hussman
Hey Wister, Assuming you are talking about BGA voids, and you just want to try and optimize your profile, you could try a "straight ramp profie". This is where the soak temp is constantly being elivated until you hit reflow. I find this helped me
