Unknown PCB Contaminant

[The Mythical Knights]

Having a "small" issue at work with contaminants on PCBs. I've included a photo of the issue. As you can see the lead-free paste didn't adhere to the pads consistently or at all and there is clearly some sort of film on the board preventing proper soldering. Not all panels and PCBs of the same design have this issue but the percentage is super high. 

[bob345]

May be possible that the boards where not properly cleaned by the manufacturer after production. Try rinsing then in a bath of 99.9% isopropanol with about 10% acetone or ethanol. That should get off almost any film left over from manufacturing. You could have bad solder paste as well. The bad flux in old solder paste can cause issues like this In my experience. Do the pads wet fine with standard lead free or leaded solder?

[r4tch3t]

2 hours ago, The Mythical Knights said:

Having a "small" issue at work with contaminants on PCBs. I've included a photo of the issue. As you can see the lead-free paste didn't adhere to the pads consistently or at all and there is clearly some sort of film on the board preventing proper soldering. Not all panels and PCBs of the same design have this issue but the percentage is super high. 

I'd  ask for replacements from the manufacturer as they are not up to standard. If you can't wait for replacements a quick dunk in IPA and a scrub with a toothbrush should clean then up good.

[The Mythical Knights]

12 hours ago, r4tch3t said:

I'd  ask for replacements from the manufacturer as they are not up to standard. If you can't wait for replacements a quick dunk in IPA and a scrub with a toothbrush should clean then up good.

Still kinda new in some fields. What is ipa? 

[The Mythical Knights]

12 hours ago, r4tch3t said:

I'd  ask for replacements from the manufacturer as they are not up to standard. If you can't wait for replacements a quick dunk in IPA and a scrub with a toothbrush should clean then up good.

Never mind. Alcohol. Got it lol

[The Mythical Knights]

Alcohol doesn't work 

[markr54632]

Does a quick run over with a ceramic pen help?

[The Mythical Knights]

20 hours ago, markr54632 said:

Does a quick run over with a ceramic pen help?

Not sure what a ceramic pen is

[markr54632]

I meant a fiberglass scratching brush. Unfortunately I have been calling these the wrong thing for ages now.

[The Mythical Knights]

5 hours ago, markr54632 said:

I meant a fiberglass scratching brush. Unfortunately I have been calling these the wrong thing for ages now.

Woops lol. The boards have already been sent down the line by now but if I see that again I have some things to try. We had somebody scrub them with alcohol before running through smt which helped but wasn't perfect. Time is always against me... 

[PineyCreek]

On 1/23/2019 at 6:42 PM, r4tch3t said:

I'd  ask for replacements from the manufacturer as they are not up to standard. If you can't wait for replacements a quick dunk in IPA and a scrub with a toothbrush should clean then up good.

@r4tch3t

Lol, the first time I read your comment I didn't connect it to isopropyl alcohol.  I was asking myself why anyone would use a pale ale to clean electronics.