Electronics Forum | Wed Nov 04 17:18:30 EST 2009 | davef
It will be very difficult to apply the proper amount of solder with a stencil to bump a ball that is the proper size. A low volume ball is less reliable than a customary sized ball. There are: * Reballing service providers * Reballing preforms * For
Electronics Forum | Thu Dec 09 07:21:10 EST 2010 | scottp
You won't have 2 mil height because the solder doesn't remain brick shaped. It's a dome. In the past I tried doing some calculations using the formula for the volume of a spherical section and also tried using a simulation program that accounts for
Electronics Forum | Thu Feb 07 13:53:06 EST 2013 | dyoungquist
IR reflow worked well for leaded solders but is not recommended for lead free reflow soldering. Your darker components (ICs) absorb more heat from IR than lighter colored ones (Rs & Cs). When getting all solder joints up to the proper lead free pea
Electronics Forum | Thu Dec 31 01:09:18 EST 1998 | Kelvin Chow
Dear Micheal, SIR test is used to characterize fluxes by determining the degration of electrical insulation resistance of rigid printed wiring board specimens after exposure to the specified flux. (IPC TM-650 #2.6.3.3 http://www.ipc.org/html/tm2.6.h
Electronics Forum | Thu Dec 31 14:20:35 EST 1998 | Michael Allen
Kelvin, Yes, we're referencing the same spec. I performed the test under the Class 2 conditions (except that I used a 100V bias rather than 50V...but my water-washed microBGAs still passed). Regarding the omegameter test: we have this instrument,
Electronics Forum | Thu Aug 19 22:59:48 EDT 1999 | Jeff Ferry
| I'm trying a second time to post this very important message, to me, concerning Air-Vac's following creation. Does any own and use this stuff successfully to remove solder from 20 layer and up MLB's with .020" diameter holes? Also, is any of the ad
Electronics Forum | Tue Sep 22 12:25:31 EDT 1998 | Chrys
| | Hi Jacqueline! | | Do these joints that you're having problems with happen to be on fine pitch solder joints? Are the fillets staying attached to the foot and separating from the pads cleanly? | | If that is true, are there many vias concen
Electronics Forum | Thu Apr 17 10:44:24 EDT 2008 | rculpepp
I'd suspect contamination also, possibly from the board supplier. Sr. Tech's post mentioned what looks like a blister on the board, in the upper right of the Q19 photo. This could very well be a contaminate from the PWB fab shop. I've seen similar pr
Electronics Forum | Thu Jul 20 13:28:13 EDT 2000 | Bob Willis
On all the trials I have done I have made no changes to the stencil thickness or apertures than the normal changes we make for our process. I have not changed any thing in terms on volume of solder for more reliable joints. I fact I have not read any
Electronics Forum | Thu Jun 11 09:34:11 EDT 1998 | Mike Moninger
I'm surprised there hasn't been a response to this. This technique has been around for some time, as it was used early on for memory boards and the like. The pins come on a reel with a carrier strip or strips. Machines are available from the manufact
