Electronics Forum | Wed Mar 14 09:07:34 EST 2001 | blnorman
We just ran a study to try to determine this. We exposed the paste to 85% humidity to simulate worst case manufacturing. At various times we removed the paste from the chamber and tested it for tack, solder balling, wetting (copper coupon), and vis
Electronics Forum | Wed Mar 14 17:52:49 EST 2001 | davef
6 Work Life Test 6.1 Obtain a stencil with 15 to 20 rows of a series of 0.025 by 0.050 inch apertures spaced 0.050, 0.040, 0.025, 0.015, 0.010, 0.010, 0.025, 0.040, 0.050 inches apart. See Appendix 1. Source of supply: Metal Etching Technology.
Electronics Forum | Wed Mar 14 22:41:03 EST 2001 | CAL
There are also Process monitoring tools that mount directly to your blades and monitor the paste. Impedance Spectroscopy is the process monitoring theory behind the tool. It works by having good sample data logged that the monitoring tool can compare
Electronics Forum | Thu Nov 03 08:34:25 EST 2005 | Slaine
Hi We currently use a small amount of Alloy : 43Sn 43Pb 14Bi Flux: RMA-51AC, Metal : 88.5%. We use it for reworking a product and only consume about 100g per year, we are in the middle or ordering in some more paste but the MOQ is 500g. Is it possibl
Electronics Forum | Wed Dec 09 09:47:32 EST 2009 | dyoungquist
I am curious as to why you need to mix.... We use a 500g cartridge with air gun. Our process is remove the cartridge from the fridge, allow it to warm up to room temperature before inserting into air gun, then apply bead of paste to the stencil. N
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 Feb 23 03:22:47 EST 2011 | pkannan
(Corrected the Subject line - sorry for Spelling ) You are very right. There are 2 major factors 1) There is going to be Flux separation. This is basically due to fact that metal particles are heavier than the Flux vehicle system, and due to gravity
Electronics Forum | Sat Feb 19 10:27:38 EST 2011 | kahrpr
Just a thought. What is the real shelf life of the past? Do manufactures low ball the self life to sell more paste. If the past is perfectly good one day before the expiration date is it still bad one day after I doubt it. Right or wrong I have seen
Electronics Forum | Wed Feb 23 00:45:49 EST 2011 | tsvetan
Does someone with technical knowledge knows what exactly happend with the solder paste after the shelf life pass? What we have seen is sometimes flux separation which disapear after a good mix, and change of viscosity i.e. drying. The tin, silver and
Electronics Forum | Thu Apr 03 17:25:49 EDT 2008 | alexs
Hi All, I have some question about expired solder paste. What would be some of the effects regarding assembly quality. Is there any changes in flux composition toward the end of shelf life? Thanks in advance for any replies.
