Using Wet SMD component (drop in water)

[MarkPham]

Hi everyone

Could you help with your experience for Using the Wet SMD component (drop in water)?

Can we continue use them for the assembly? What actions should be taken prior using?

What is the potential risk, hidden risk if we use the wet component?

I really need you sharing of exprience to learn.

Thank and Best regards

[Psi]

What parts are they?
How long have they been wet/underwater?

I can see its plastic tape, so that's good, it's not paper tape

They should be baked to fully dry them off, but chances are good they are probably fine to use if that is done.

One issue is if the water was dirty and got inside each parts compartment through the air holes in the bottom of the tape. It may cause things to get a bit sticky in there and interfere with the PnP machines ability to cleanly removal parts from the tape. And also interfere with soldering if the bottom of the chip is covered in dried on dirt.

There are some parts that might be damaged by water getting inside, MEMS stuff maybe. But usually parts are pretty well sealed up, so as long as they are dried and have not rusted the parts are fine.  It's more the tape itself and any dirt that was in the water that I would be concerned about.

If you have a microscope you could unravel some tape and have a look, see if the parts are still rattling around in their compartment's. That would tell you if water got that far in or not.

[mariush]

Label says TLV840 TLV840 Nano-Power Ultra-Low Voltage Supervisor with Adjustable Reset Time Delay:  https://www.ti.com/lit/ds/symlink/tlv840.pdf

Yeah, they should be fine after baking them for a few hours

[MarkPham]

Hi Psi

Thanks for your advice. The part that I'm asking are SOT components from TI with MSL 1

Best regards

[wraper]

That tape has a hole under each component, so every component likely got wet. They're probably useable if reel is put in the oven to dry quickly. I'd take some samples and inspect under microscope to see if there is no corrosion or lead tarnishing, test solderability. Even if apparently fine, I would not use the anywhere in anywhere safety critical or where they just can cause expensive device to fail though.

[Doctorandus_P]

In general, electronic parts don't get damaged by water. It's common to wash PCB's with water, some even put old and dirty PCB's in a dishwasher to clean them.

The important thing is to make sure the PCB's are dried completely before power is applied. Water (when dirty) is conductive, and this leads to all kinds of nasty effects when combined with electricity.

The biggest problem I see here is solderability. Water will accelerate corrosion of the tin plating on the pins of the IC's, and this will reduce solderability. In the end it probably comes down to whether the cost of extra rework offsets the cost of buying a new reel of parts.