Electronics Forum | Wed Aug 01 10:28:24 EDT 2001 | btaylor
We have this problem with our High Temp. solder lines. Tombstoning is actually the term used in our facility. We found that the component termination width was a main contributor also profile ramp rates. Visual inspection will catch most of these rej
Electronics Forum | Mon Feb 07 13:00:06 EST 2000 | Jose RG
Hi, Last Friday, we had a new defect in our line. We found a nice and shiny solder fillet completelly attached to some component leads (in a SPLCC 84) but the solderjoints were not solder to the pads. (Hasl finishing) Any idea ?? Some contamination
Electronics Forum | Sun Jan 30 03:06:50 EST 2000 | Roni H.
Hi, The major reason is that the flux is still "wet", you should fix the temp. profile (specialy preheat zone) so the evaporation of flux carriers will be better (anyway not to much !). Recommended: 1st preheat zone heating to ~70C , 2nd&3rd prehea
Electronics Forum | Thu Jan 27 14:16:14 EST 2000 | Tuan Bui
I've tried Indium NC-SMQ92(96.5Sn 3.5Ag) on these MCMs and achieved only marginal wetting on pads and parts. The good wetting is what I try to achieve, shiny is what my engineers want (Prototype environment). Does pre-cleaning the PWBs in ultrasonic
Electronics Forum | Tue Jan 18 12:44:24 EST 2000 | Russ
I have found that reducing the amount of metal in the joint makes a difference, we have reduced the aperture sizes to provide a minimal amount of paste. just enough to hold the part during handling. You may also want to try and slow the initial ram
Electronics Forum | Wed Jan 12 09:30:33 EST 2000 | Jim Schultz
I need your help. I have been battleing tombstoned 0603 resistors for many months now. I have been working on the profile, the placement accuracy of the chipshooter, and the print accuracy. I am writing in the hopes that someone out there has some
Electronics Forum | Wed Jan 05 16:21:17 EST 2000 | g cronin
hi glenn i have had nothing but good experiences with Heller. As far as i have seen they have very even heat characteristics, great profiling and overall low maintenance. I am very happy with heller and they are my oven of choice right now.. greg
Electronics Forum | Mon Jan 03 14:00:06 EST 2000 | John Anderson
Has anyone had luck with 0201 cap board design, solder printing and reflow? IPC-SM-782 does not provide much help. I am particularly interested in attach pad design, stencil aperture design and thickness, solder paste (mesh, metal content, etc.), and
Electronics Forum | Tue Dec 21 00:10:00 EST 1999 | Edmund
Currently i am producing a board using dloble reflow process. The bottom side is mostly 0603 chips and some SOIC. The top side is mostly QFP and some heavy component. During the double reflow process , the capacitor chip on the bottom side drop(same
Electronics Forum | Sat Dec 18 01:53:46 EST 1999 | sin
If i have problem with tombstone, first i would look at the placement of my components. if placement is 50% greater on the pad, it would be ok to reflow. even you have bad profile, you would have some other problem not tombstone. then i look at
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