Electronics Forum | Tue Nov 27 08:13:04 EST 2007 | davef
C1: is there any gap between the pad and terminal if we place the glue? R1: Yes, there is a gap, but it is easily bridged by the amount of solder in the wave. C2: Btw, my practice to print solder pate then punch glue then PNP component and finally
Electronics Forum | Tue Nov 27 20:05:31 EST 2007 | shy
Dback, Current method is by using dispenser machine to dispense the glue at PCB. This non-wetting is randomly and not repeating to the same location. My adhesive height is 0.01" to 0.035". Is this will cause the component to had a gap between the t
Electronics Forum | Wed Nov 28 01:28:32 EST 2007 | shy
Q1:What is the relation between component standoff and drop missing? A1:component standoff will identify either solder paste at SMT side can form the fillet at component terminal or not. Drop/missing component is totally out of the topics since i jus
Electronics Forum | Thu Nov 29 15:08:56 EST 2007 | jaimebc
Shy, You mentioned that you are using "dog bone" apertures for your chip components? It doesn't make sense to me. I thought that the "dog bone" was used for fine pitch devices, to keep the solder away from the center and avoid bridging. It doesn't
Electronics Forum | Mon Dec 03 20:30:58 EST 2007 | shy
Q: I thought you said that the parts that weren't wetting in reflow were the parts with epoxy. A: Yes you're correct. Q: The question I have is do they wet in wave solder, and if they do, why does it matter what happens to them in ref
Electronics Forum | Wed Dec 05 22:59:42 EST 2007 | er_pe
To be successful, and to yield quality products off any selective solder systems out there on the market today, DFX rules need to be enforced and followed. Lay-out is a one-shot process where as manufacturing of the PCBA is continuous. Obviously, muc
Electronics Forum | Fri Dec 07 08:57:24 EST 2007 | ck_the_flip
Well first of all, you can�t even go NEAR the machine unless you have no life - and you can PROVE it mathematically. The machine�s got an automatic �geek sensor�. Then, in order to turn the machine on, you have to solve a 1st order differential eq
Electronics Forum | Wed Nov 28 16:08:38 EST 2007 | jmelson
I've been using Xilinx TQFP's in the 44 and 144 lead sizes with no trouble. I don't even bake them before reflow and have never had any problem. The Xilinx parts are certainly NOT sensitive, I could not break one with my bare hands if I tried (I ha
Electronics Forum | Thu Nov 29 16:00:03 EST 2007 | jmelson
Desoldering often applies a LOT more heat and thermal stress to the part, and maybe mechanical forces while everything is hot, to get the part free of the board. So, a lot of damage might be done there, making post-mortem harder. Without the leads,
Electronics Forum | Fri Nov 30 11:04:23 EST 2007 | slthomas
Sounds like Mydata might be one you could look at, for example. I don't have experience with them but they do have "smart" feeder capability. Some machines use electronically controlled and motor driven feeders, some use pneumatic and/or mechanicall
