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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Blow hole on pad after reflow oven

Views: 7486

#63501

Blow hole on pad after reflow oven | 12 January, 2011

Hello guys !

I have a problem, I am finding some blow holes in the solder join in a resistors pad, can this be because of high humidity in the board?

does baking the boards fix the problem?

thanks

reply »

#63507

Blow hole on pad after reflow oven | 12 January, 2011

How many % were affected? If a few,it can be caused bcoz of PCB coating. We had encountered it and PCB house replaced for faulty boards. Since then, we do test first if we hve to solder PCBs from this PCB house.

reply »

#63515

Blow hole on pad after reflow oven | 13 January, 2011

We've never seen the defect that you describe, but in wave soldering-land blowholes usually are caused by moisture in the board that out-gasses through the too thin plating of through holes. * Bandaid fix: bake the boards * Long-term fix: Obtain board with 1 thou plating on through holes

It would be interesting if there was a cause and effect in your boards that was similar to the one in PTH wave soldered boards.

reply »

#63577

Blow hole on pad after reflow oven | 20 January, 2011

Hi I hope this pictures helps this is the link

94427924@N00/5372753378/sizes/m/in/photostream/" target="_blank">http://www.flickr.com/photos/94427924@N00/5372753378/sizes/m/in/photostream/

reply »

#63579

Blow hole on pad after reflow oven | 20 January, 2011

Armando

Link does not work. Goes to a "page not found" error in flickr.

reply »

#63588

Blow hole on pad after reflow oven | 21 January, 2011

www.flickr.com/photos/94427924@N00/5372753378

hope this is better

reply »


XPS

#63594

Blow hole on pad after reflow oven | 21 January, 2011

Hi, in my experience, the humidity is trapped in the solder paste. Otherwise you can also try to : adjust preheat profile, and /or increase paste viscosity, and /or increase paste metal content (they are the most common causes).

reply »


aci

#63596

Blow hole on pad after reflow oven | 21 January, 2011

Try baking your boards first to remove the moisture. Moisture and boards that have not been drilled properly will cause pin hole or blow holes in PTH. Also take a look the surface of the pads before printing. You maybe contaminating the surfaces of the pads somehow. Maybe in storage?

reply »

#63609

Blow hole on pad after reflow oven | 23 January, 2011

Hi In my experience try to change component to another batch or anther manufacturer it is very often problem in reflow when components have strange finish

reply »

#63610

Blow hole on pad after reflow oven | 24 January, 2011

Hello!

I've had the same problem about one Jear ago. We had exessive building of voids in the solder joints. I recomment to take a pincer to break off some of the components. If the solder joint is good, the copper pad will stay at the solder joint on the component if you break off the component. If not, you can take a look at the structure of the solder joint. I guess, you will find more voids inside.

In my case, it was a trouble with condensing wather on the could solder paste. We solved the problem by changeing the solder paste handling.

reply »

Reflow Oven