Electronics Forum | Mon Sep 20 17:46:21 EDT 1999 | Dave F
| I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | The stencil is 6 mil thick, laser cut and electo-polished. | The apertures are 12 mil in diameter with 20 mil pitch. | We are usi
Electronics Forum | Tue Sep 21 12:10:23 EDT 1999 | Mario
| I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | The stencil is 6 mil thick, laser cut and electo-polished. | The apertures are 12 mil in diameter with 20 mil pitch. | We are usi
Electronics Forum | Mon Apr 13 17:03:40 EDT 1998 | EFData
We are having some difficulty soldering a 240 pin Altera device. We use Alpha WS-609, a very generic profile for that solder paste, and a 6 mil stencil with laser cut apertures (1:1 ratio). This is a 20 mil pitch device (aperture size is 10 mils X 75
Electronics Forum | Thu Sep 13 17:57:59 EDT 2001 | davef
You're correct. It is curious. Possible angles to look at are: 1 WS609 loves moisture in the air. In high humidity shops, this paste hakes-on liquid. If this is the case, you should also see slumping, resulting in fine pitch bridging, and solder
Electronics Forum | Wed Apr 30 20:33:15 EDT 2003 | davef
Haaaa!!!! Yes, we�ve seen things like that. We found that a high input impedance amplifier worked fine in a room with a controlled environment and worked poorly in the sweat-shop portion of our plant. We were using good ol� WS609, straight water w
Electronics Forum | Mon Jul 19 21:25:28 EDT 2004 | davef
It seems like the flux is burning-up before the metal begins to flow on this slightly odd component. Alpha talks about alternate reflow recipes for WS609, as follows: * A straight ramp up profile is preferred for reflowing low to medium thermal mass
Electronics Forum | Thu Feb 10 10:28:56 EST 2000 | Russ
Okay, Okay, here is the rest of the story! These boards were definitely plated, reworked to HASL, The component that is the most succeptable is a 160 pin QFP .5mm pitch. This component has nickel/iron lead frame. Significantly reduced apertures (1
Electronics Forum | Thu Feb 10 22:41:20 EST 2000 | Dave F
Russ: Now that�s a good story. Nuff said on the Vegas trip, that explains everything. Especially when you say "it must have something to do with ..." I love WS609. It�s been berry, berry good to me. Intermetalic Layer (IL). A compound formed a
Electronics Forum | Wed Sep 22 21:23:03 EDT 1999 | se
| | I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | | The stencil is 6 mil thick, laser cut and electo-polished. | | The apertures are 12 mil in diameter with 20 mil pitch. | | We
Electronics Forum | Thu Sep 23 12:47:48 EDT 1999 | Earl Moon
| | | I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | | | The stencil is 6 mil thick, laser cut and electo-polished. | | | The apertures are 12 mil in diameter with 20 mil pitch.
.gif)
winsouce.jpg)