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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Fibers In Solder Joints

Views: 1246

Shep

#43774

Fibers In Solder Joints | 6 September, 2006

I'm using an EKRA X5 printer. My QC department has been rejecting boards for "fibers" in solder joints. After investigation, I have determined that the fibers are coming from the stencil cleaner paper. I'm using JNJ Industries p/n 5404EK paper. After several cleanings of the stencil, fibers have been seen in the apertures of the stencil, which of course get transferred to the PCB. Does anyone know of a different stencil cleaner paper or some other method of cleaning that will leave zero fibers on the stencil? I know this is probably an impossible task, but the "suits" in my company are all upset about this "devastating and catastrophic" finding.

reply »

#43777

Fibers In Solder Joints | 6 September, 2006

I don't remember ever having that problem with my EKRAs, but you might look at how much fluid you're dispensing on to the cleaning medium if this is occurring while you're using wet cleaning cycles. It could be getting saturated to the point of weakness. I also don't remember if there is a height/pressure adjustment for the wiper. Is it possible it's coming up too high, or with too much force, forcing the paper through the apertures? Also, is your vacuum working properly? It should be pulling most of that stuff out of there.

I don't remember where I got my rolls but it wasn't a JNJ line. FWIW, I really liked the EPAC products but went with something else that was quite a bit cheaper with decent results.

reply »

Shep

#43778

Fibers In Solder Joints | 6 September, 2006

Thanks Steve. I do know that my vacuum and height/pressure are as they should be. You make a good point about the saturation of the paper. I will certainly check that.

reply »

greg york

#43816

Fibers In Solder Joints | 7 September, 2006

normally one side is hydroentangled the other is not there is only one correct side which should be lint free and the other full of lint.that is wny people should never use rolls on both sides. Im of course talking typically (not sure of jnj brand) this is but can be seen easily under 60x mag cheers greg york england

reply »

FPC* - Fluid Pressure Control - Dispensing Pump

SMT in-printer dispensing