Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

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FLUXED WIRES

gdandrea

#6228

FLUXED WIRES | 26 October, 2000

PLEASE COULD YOU TELL ME IF THERE IS A WAY TO AVALUATE CORE FLUXED WIRES IN TERMS OF WETTABILITY/SOLDERABILITY (SOMETHING LIKE MENISCOGRAPH TEST) .I NEED A LAB TEST ALSO ONLY TO COMPARE DIFFERENT WIRES.... REALLY THANK YOU

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ptvianc

#6229

Re: FLUXED WIRES | 26 October, 2000

Performing a wetting balance test would be very difficult. The flux cored wire "configuration" is just not compatible with the methodology of the wetting balance test. If the wetting balance is a must, then you might ask the vendor for the flux formulation separate from the wire and perform the test as normal; HOWEVER, I don't think that this approach would well represent the conditions for use of cored wire on the shop floor. A good shop floor test would be the sessile drop test on a piece of copper. That is, place a controlled quantity of the wire on a piece of clean copper (degreased and lightly etched in a solution of 1:1 HCl and H2O). Then, place the copper coupon on a hot plate at the appropriate temperature. Then, simply observe the extent of wetting by the molten solder (the "sessile drop"). In addtion, you might also not the time it took the solder to completely wet after melting as well as any discoloration caused by charring of the flux.

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