This is putting the debate to rest. Thank you all for your responses. Cumulatively they have slain the dragon.
I'd like to take a moment to say how privileged I feel to be part of this micro-society and I'm very appreciative of everyone's contributions. I learn something new every day!
Ed Popielarski
Engineering Manager
970 NE 21st Ct.
Oak Harbor, Wa. 98277
Ph: 360-675-1322
Fx: 206-624-0965
Cl: 949-581-6601
https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&spn=0.011188,0.033023&ctz=420&t=m&z=16&iwloc=A
-----Original Message-----
From: Stadem, Richard D. [mailto:[log in to unmask]]
Sent: Tuesday, June 25, 2013 11:25 AM
To: TechNet E-Mail Forum; Ed Popielarski
Subject: RE: Tacky (gel) flux expiration and recertification
The rules for recertification of liquid fluxes in J-STD-004, and the test methods referenced therein, also apply to tacky flux. This is because nearly all tacky fluxes turn into a liquid above 100 deg. Fahrenheit. So unless your solder melts at less than 100 deg. Fahrenheit, you can use those methods to re-certify tacky fluxes.
I have recertified tacky fluxes many times, and monitored the DPMO during its use. I saw an improvement each time, with everything else being the same.
My experience at other clients (not here at GD) has been that if the syringes or sealed jars are kept refrigerated, there is really no change, except for a slight improvement towards the end of the 6-month re-cert period. The only ones I use are from Alpha. I have not had such good luck with others. WS1208, WS609, WS619, etc. are very good tacky fluxes, each with its own set of properties and uses. Do not confuse them with WS609 solder paste and WS619 solder paste, however. Alpha has a bad habit of labeling tacky fluxes with the same description as their solder pastes that use that flux.
After 8 or 9 months past expiration, it may turn grainy and is no good for stenciling purposes (I stencil tacky flux for certain processes, such as compliant lead attachment, laser ball attachment, PoP, etc.) but the wetting activation properties are still good.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ed Popielarski
Sent: Tuesday, June 25, 2013 11:02 AM
To: [log in to unmask]
Subject: [TN] Tacky (gel) flux expiration and recertification
Esteemed Colleagues,
An interesting debate has arisen regarding tacky flux expiration, as well as flux pens.
The expired tacky flux in question was dated the same as the solder paste bought at the same time. Not a coincidence, in my opinion, just an "easy solution" for the supplier.
The tacky flux is water soluble and packaged in unopened sealed 10 cc tubes. The flux pen dispensers are no-clean and again in unopened sealed packaging.
It was my intention to wait as long as possible to "age" the material (of course not using it on product) and do a side-by-side comparison with new material through the reflow oven on bare copper coupons to re-certify in house.
The procedures for paste recertification do not specifically call out tacky flux nor no-clean flux pens, so a little creativity will be required.
Any advice, warnings or recommendations would be greatly appreciated.
Ed Popielarski
Engineering Manager
[Description: FullLogo]
970 NE 21st Ct.
Oak Harbor, Wa. 98277
Ph: 360-675-1322
Fx: 206-624-0965
Cl: 949-581-6601
https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&spn=0.011188,0.033023&ctz=420&t=m&z=16&iwloc=A
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