Electronics Forum | Thu Sep 02 14:42:52 EDT 1999 | JohnW
| We are assembling double side pcs reflowing (smt) on top and by wave on bottom. | After first step (smt) we dispense glue on the bottom side putting one or two glue dots under small components and we cure in oven before wave. | After wave solderin
Electronics Forum | Tue Sep 07 12:51:02 EDT 1999 | Brad Kendall
| | We are assembling double side pcs reflowing (smt) on top and by wave on bottom. | | After first step (smt) we dispense glue on the bottom side putting one or two glue dots under small components and we cure in oven before wave. | | After wave so
Electronics Forum | Tue Oct 16 18:42:32 EDT 2001 | mparker
I go with DaveF's advice. You are probably curing the glue too fast. Another phenomenon that I have experienced was during glue cure and solder paste reflow simultaeously. A good reason to run a glue cure profile seperately from solder paste reflow
Electronics Forum | Mon Dec 22 14:15:41 EST 2008 | ck_the_flip
As Emil says, it's 100% the glue! Your paste is not designed to hold parts on at wave solder. Reflow is MUCH hotter than glue, so I doubt you're not adequately heat-curing it. Possibly, the glue cure is "too hot" and maybe making the material brit
Electronics Forum | Tue Oct 16 09:17:10 EDT 2001 | davef
Look at "Microcanyons", Circuits Assembly magazine, December 1998. There D Pauls & T Munson describe adhesive on boards that was cured too rapidly and formed a skin that trapped volatiles and solvents. The volatiles and solvents created long voids i
Electronics Forum | Wed Apr 05 22:42:28 EDT 2000 | Dave F
George: I would think so. We use an old Vitronics (822??) IR reflow oven to clue SMT adhesives. Gp get 'em!!! Dave F
Electronics Forum | Wed Feb 09 21:29:28 EST 2000 | Dave F
Charlie: People cure glue using their paste reflow profile all the time. And most of them are happy. Personally, I�m with Dean and Travis. It�s possible to as you suggest, it�s appealing not to mess with your oven profile, but it just doesn�t s
Electronics Forum | Mon Dec 22 20:16:17 EST 2008 | davef
The first question in solving the "ol' SMT component loss after second-side wave operation" problem is: So, what makes you think the components actually came-off in the wave and not during some previous 'handling'? Putting that aside, we'll play thi
Electronics Forum | Tue Feb 08 16:09:09 EST 2000 | dean
Generally speaking with most electronic grade epoxies: 1. Cure time is a function of temperature. 2. Polymer bonds begin to quickly break down above certain temperatures (product specific). I believe aprox 170-180C. The strength of the bond de
Electronics Forum | Wed Oct 17 10:21:08 EDT 2001 | genglish
Cheers guys for your rapid response, I investigated the problem further today, eventually I cam round to curing the adhesive in a sandwich of microscope slides resting on the PCA in question (hopefully mimicking the heat transfer), the adhesive is sp
