Electronics Forum | Mon Mar 10 15:20:41 EST 2003 | MA/NY DDave
Hi Well I don't have all the titles right handy, yet let me give a few places for you to check. All my books aren't exactly at my finger tips. Author: Tumalla (??spelling) He is now at Georgia Tech Author: Lasky, Seraphim Author: Ning-Cheng Lee or
Electronics Forum | Thu Mar 06 18:21:29 EST 2003 | ppwlee
Mike, What is the most common method for monitoring and calculating machine capability for: - Reflow oven, I currently run a carrier monthly to monitor its temperature profile and would like to simplify the process. - P&P machines: We don't have a
Electronics Forum | Fri Mar 07 14:48:34 EST 2003 | gdstanton
Pretty much everything under the sun. For example if Company A wanted to hire Company B to build printed circuit cards designed by Company A; What type of T & C might Company B seek in their contract/agreement with Company A? The following things c
Electronics Forum | Tue Mar 11 12:43:27 EST 2003 | MA/NY DDave
Hey Frank, We got lucky. An article just appeared in one of our industry's magazines. Now you still have to read these articles carefully since the proponents sell the equipment yet it does support both opinions. Except it says (before PnP) and (p
Electronics Forum | Thu Mar 13 15:22:47 EST 2003 | ruggi
Ditto on the profile/reflow oven...a couple years ago, we had a huge increase in the number of tombstones found post-reflow. Profiling the oven showed a decent curve with some innocuous minor deviations, and further investigation of the oven found 2
Electronics Forum | Fri Mar 14 04:42:24 EST 2003 | emeto
Hi, About Thombstone defects: 1.Placement accuracy-main reason 2.Soldering-should be right on pads.The print should have regular shape.The quontity of the solder on both pads on one component have to be equal. 3.Reflow: the profile have to be made v
Electronics Forum | Tue Mar 18 11:51:24 EST 2003 | slthomas
I like this answer! Part geometry, part mass, land pattern, print accuracy, reflow profile, placment accuracy, and aperture shape all play a role. If you use a homeplate to reduce solder balling, have high profile/low mass parts AND place more to
Electronics Forum | Tue Mar 18 16:41:04 EST 2003 | russ
Here is what I have been finding lately. We switched to a 22mil square pad on 40 mil centers (from the IPC "75/25"). ALL OF OUR TOMBSTONES HAVE GONE AWAY! (at least for now) we did not change profiles, paste, or any other parameter. Obviously placem
Electronics Forum | Thu Mar 20 12:04:42 EST 2003 | Ren� Sandoval
Hello Garcia: For my experience in Tombstone problems I recommend you to check the next points: -Use Solder paste with 2% silver -Use 5 mils Th Stencil -In some machines , for 0402 or smaller componentes , you require an special holder for the feed
Electronics Forum | Fri Mar 21 20:21:41 EST 2003 | Grant
Hi, I can verify that, and we have done 2 or more reflows with prototypes, using vapor phase reflow, and because there is no oxygen, the result is good, and you cannot tell the difference between the first reflow, and the 3rd. We are getting a vap
