Electronics Forum | Thu Dec 10 12:53:12 EST 2009 | deanm
Bryan, Dyoungquist is correct. You should not need to mix solder paste. Overmixing solder paste can adversely affect it. Follow these guidelines and you should be fine: 1. Keep unopened containers of paste in the refrigerator. 2. Take one container
Electronics Forum | Wed Jul 27 09:58:05 EDT 2011 | davef
Pressure printing systems Conventional stencil printing techniques have fundamental limitations as regards paste handling: The volume of paste available for printing is limited, so frequent replenishment is necessary Paste is difficult to c
Electronics Forum | Wed Apr 14 08:15:18 EDT 2004 | arcandspark
We have tried other stencils with different size openings but this company will not allow us time or money to run any experiments to define stencil criteria and printer settings, its just run, run, run. They really dont care about post reflow yields.
Electronics Forum | Fri Apr 04 14:49:51 EDT 2008 | tombstone
Flux seperation is a common problem observed due to expiration of paste. The symptom is a yellow layer of flux when you open the jar. Excess flux separation will cause priting problems such as smearing and slumping.
Electronics Forum | Fri May 21 15:50:41 EDT 1999 | John Thorup
We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendors
Electronics Forum | Tue Apr 13 08:25:15 EDT 2004 | arcandspark
I would have gone to a .004" stencil but again, the board designers, which we have no control over or are we allowed to give input to, have made the pads on all connectors and many other parts so small that we are almost seeing insuffecient solder us
Electronics Forum | Wed Mar 14 16:10:38 EDT 2012 | cobham1
We need to develop a method of putting solder paste on a stencil then putting the unused part back into the refrig. Reason we are thinking of this method is because we only run circuit boards twice a week. I dont want to waste entire jar of paste bec
Electronics Forum | Tue Feb 22 17:57:32 EST 2005 | Austinj
Most solder paste has a shelf life of 1 week at room temperature after opened, if resealed at the end of the shift/day. Most shelf lives are 4-6 months at 40F (refridgerated) or 1 month at room temp (unopened/sealed). Recommended stencil life is appr
Electronics Forum | Mon Apr 12 15:52:12 EDT 2004 | wgaffubar
I am using Indium 92J type 4 solder paste due to a BGA site with .008" pads and stencil opening of .009" square and .005" stencil thickness. When I try the type 3 we get insuffecient print. The aspect ratio tells me that I should be using a type 4. T
Electronics Forum | Fri Mar 29 10:11:02 EDT 2019 | cyber_wolf
“For a number of years now, work has been proceeding in order to bring perfection to the crudely conceived idea of a transmission that would not only supply inverse reactive current for use in unilateral phase detractors, but would also be capable of
.png)
.gif)
winsouce.jpg)
