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 | Tue Oct 16 17:38:42 EDT 2001 | lileubie
Depending on the type of teflon material, thickness, and reflow profile requirements, these will have a direct bearing on your maximum process allowable PCB pallet size. You'll want to be careful on how big the PCB or pallet is. Larger teflon PCBs
Electronics Forum | Mon Dec 31 08:59:36 EST 2001 | Don Adams
The second pass in the wave is pretty extreme and will probably aggravate the conditions which caused warpage in the first place. Areas to look for problems, The lay up of the boards at fabrication or the materials used can lead to warpage. Work wi
Electronics Forum | Wed Jan 02 12:32:24 EST 2002 | cebukid
What is the rule-of-thumb on wave profiling Ceramics? I've used 2 methods: 1.) putting the T/C on the lead, and get a pretty good delta (within 50-80 deg. before hitting chip wave), well within manufacturer's spec. 2.) Right on the part body.
Electronics Forum | Wed Jan 02 13:31:55 EST 2002 | PeteC
The rule-of-thumb is to follow the flux mfg.'s recommended profile to achieve their specified top side PCB temperature before making contact with the wave. Typical top side PCB temps are 100-120deg.C. Your wave contact time should be around 2 seconds
Electronics Forum | Tue Jan 08 14:54:10 EST 2002 | Yannick
Hi, I experience some trouble with my solder joint recently. And I'm wondering if someone could help me with this. First I use a thermocouple wich I must tape to the board to profile my temperature. I want to buy the Temprobe from Saunder Tech
Electronics Forum | Tue Jan 22 18:53:37 EST 2002 | barry
Hi all, or anyone. We recently purchased some smd equip. to do our own inhouse assy. Though we did purchase a training package it was short and sweet. What I was wonderin is their any tips on oven profiling, we were told that 90% of our product would
Electronics Forum | Thu Mar 07 19:19:41 EST 2002 | dason_c
Ron, you need to check all the thermal couples are in good shape and clean before ask the outside service to do the calibration. After the machine calibrated and I suggest that you run 2 profiles and all the heating zone set at the same temperture,
Electronics Forum | Tue Apr 09 08:44:43 EDT 2002 | davef
Read IPC-7530 "Guidelines for Temperature Profiling for Mass Soldering Processes (Reflow & Wave)". There is no advantage in dropping off much faster than 4�C/sec. In fact, you risk fracturing your newly formed solder connections due to board warping
Electronics Forum | Mon Jul 01 15:37:56 EDT 2002 | pjc
Possible cause can be design related- if the solder land is too small. Check w/ IPC SM-782 Solder Land Design Guide Another is board finish. I have seen problems like this with Gold finished PWBs- which creates a more brittle solder joint.Another pos
