Electronics Forum | Fri Mar 26 10:35:52 EDT 2010 | grahamcooper22
Hi Krish, thanks for your detailed reply. Sorry I assumed you may be using a solder paste to solder the BGA to the pcb. Either solder paste or Gel flux is best for resoldering BGA to pcb. Are you using Gel flux ? Most popular long term storage for mo
Electronics Forum | Wed Jan 26 10:43:32 EST 2011 | grahamcooper22
From our experience with our gel fluxes the depth of the flux cavity can be 30% ~ 70% of the ball diameter. You'll probably need to do some tests to find the optimum for your process. If you have really fast movement on pick and placement machine the
Electronics Forum | Tue Mar 16 18:11:54 EDT 2021 | grahamcooper22
I am wondering, I have an application for assembling a 0.4mm WLCSP to a pcb....the solder sphere size is 0.26mm...would you print paste in the normal printing process and then place the device and reflow...or would you use a fluxing station on the pi
Electronics Forum | Wed Sep 21 16:25:43 EDT 2005 | GS
IPC-7525 tells you how to make stencil apertures for BGA IPC-7095 tells you how much should be the paste volume in order to get a reliable BGA solder joint. How are your PCB finisced? (HASL, ENIG, OSP, etc?) In case of not HASL, it could be necessa
Electronics Forum | Wed Jun 15 10:38:41 EDT 2016 | laynefelix
Hi everyone..i am new here. I am hardware design engineer and as per my experience PCBAs came out cold soldered after being reflowed the first time with ALPHA WS-820. The flux gel ALPHA WS 609 was supposed to be applied only onto the terminations of
Electronics Forum | Wed Aug 12 12:32:56 EDT 1998 | Rich Croteau
Have an SRT w/preheat, 18 layer board all copper, 456 BGA needs to be removed and replaced. The manufacturer is Chip Express and during reflow it warps up or down. Causing either opens or shorts on the corners. I was using gel flux with multiple p
Electronics Forum | Tue Dec 21 11:46:29 EST 2004 | KEN
Are you adding liquid flux? Or paste "Gel" flux? If liquid flux: This, in my mind, is an unacceptable technique. Why? 1. Can not control metals content. 2. Probably not adding the same chemestry flux...as paste flux has many different addi
Electronics Forum | Wed Feb 23 17:24:06 EST 2005 | Austinj
Solder spattering, solder balls, components "popping" off pads........ Not a serious chemical reaction, however, as replied to by KEN on 12/21/04 in a similar article: "Are you adding liquid flux? Or paste "Gel" flux? If liquid flux: This, in my m
Electronics Forum | Fri Jul 18 14:36:17 EDT 2008 | proy
I have a QFN which we are adding after process. (it was not available the day we ran the 4 prototypes.) We have removed most of the solder on all the pads, My plan was that a LITTLE solder on the center pad would wet and center the device (using a g
Electronics Forum | Mon Jun 06 12:51:17 EDT 2016 | wlsmt
My operator applied flux gel ALPHA WS-609 on MG P/N FTH101XAP (CAP ALUM 100UF 50V 20% SMD) before aqueous washing the PCBAs. Solder paste used was ALPHA WS-820. Now the caps have yellow stains. Any solution to this is appreciated. Tks
