Hydrochloric Acid Removes SMD Components from PCB

I wish I could buy hydrochloric acid at my hardware store.

So, did it dissolve the solder on the components?

Can't find Muriatic acid? ive seen it at most hardware stores in the US, Homedepot and Lows included.

Never thought about using it to take components off a board, but seems like it should work.

I have heard of using a dilute solution of HCL for etching a PCB, so it makes sense that it would take the parts off. I wonder how PCB etchant (Ferric Chloride) would work.

I agree that heat and gravity may be better at removing parts, as that is how the parts are put on in the first place, and it won't even destroy the board.

Can't get hold of Ferric Chloride unless I made some up.

I figured on using heat, but my clandestine operation in the backshed is going unnoticed by the missus

Ferric Chloride is easily obtainable from Jaycar (Soanar or Electus) or better Tricky Dick's stores. I saw some in the new Jaycar in Mackay last week.

CraziestOzzy,

If the purpose is to reuse those parts for some other project, or to sell as good, I don't think I would trust your method of removal. First, there is probably going to be solderability problems with the component leads that have been etched back by the acid, second, I would be very concerned about acid ingress into the parts. If any acid got into the parts, it might be OK for a time, and then fail at some later date. I have seen what we call a "toaster oven" used as a small, cheap solder reflow station for PCB's. Perhaps you can pick up a used one of those to use for your recycling. Just don't let the missus use it to cook your breakfast! Here a picture of what I'm talking about:

Good luck, and be careful with that acid!

Tom

One more thing I forgot to mention. Your HCL acid "soup" is going to have a lot of nasty stuff in it after you use it to remove those parts. Disposing of this responsibly is not going to be easy. It's going to have lead in it, and could very well have leached some of the nasty stuff out of the components and the PCB itself. Please don't just dump that stuff in a ditch somewhere!

Tom

Yeah, thanks. I checked some IC's out by breaking them open. The acid did not go past the case to wreak havoc in the gutz. It would seem that the "oxidation" layer sealed any possible leaks if there were any gaps to start with. I do think that some sealant would be of benefit just to be on the safe side though, as I may not be able to see any penetration that may have ocurred..

The stuff I am getting from the PCB's is for personal use, so no need to fear

You are right about the oven, will go hunting at second hand shops for one of those babies.

Playing with acid is nasty business and is a one off thing for me. Was just toying with the idea and seems to work, although some components on PCB's don't agree with HCL.

I am storing the waste liquid and leaving to evapourate, Then going to play with some anode/cathodes and see what happens when I use some electrolysis ideas on the gunk.

Hi,

you will have the chlorides of copper and tin and lead in your soup, may be also some aluminum, iron and nickel.

This is not readily recaptured - let it crystallise slowly so that the stuff comes in different fractions, collect these separately and sell to a local ceramist for coloring the workpieces.

Be aware of the very corrosive evaporate: this pure HCl and later some water - not wanted to be anywhere to attack any metal. Burning some PVC-insulated cabling will destroy within days complete factories by corrosion - HCl generated.

Better to neutralise the remaining acid up to pH 7 by ammonia (add slowly) or other caustic material (calcium-, sodium-, potassium-hydroxide) or soda or baking powder.

If no pH measuring instrument available then use litmus or any other red-blue flower-color. Put a drop of the color onto white paper to watch the color-change.

Last time I had to neutralise some nitric-acid I used a drop of red wine as indicator - worked perfectly.

RHABE

Yes, the vapors are dangerous and potentially lethal both in the short and long term if proper precautions are NOT taken.

yeah cool....I am happy to have the brew evaporate and then top up and mix again to get some substantial fractional layers.

The other thought is to slowly add the acid liquid into a water/baking soda combo to neutralize it. I would never consider adding the neutralizer to the acid...can be dangerous if not done properly.

Have to look into using red wine for an indicator...one drop for me...one for the soup...one drop for me...

Hi,

if you add the powder slowly then no problem.

Foaming is not severe and persisting as long as the stuff is not glue-like.

Red wine: one to 10 drops for test, rest of bottle for me!

RHABE

The acid did dissolve the solder. Also dissolved other stuff

Hello bhankiii, If there is no Hardware Store selling it, and I have to admit it is not that easy to get hold of because of the danger. Try and builders yard. We used to get it in 2.5 Litres , and used it to clean stone as we were renovating buildings. You should be able to get it perhaps in smaller amounts in good Artist' shops. Take care......................................

Well you certainly live up to your name (I personally would have used directed heat and gravity to carefully remove the parts).

Just out of curiosity, what was the purpose of the exercise?

I had the idea of removing components without heating them up. Somewhere I read that most solders are composed of stuff that also coincidentally readily dissolves in HCL. I have stacks of PCB's in my junk box (junk room) and attempts at heating with hot air gun LINK and LINK were not so great and messy when dealing with large pin count IC's.

Ideas of using the oven would not have been very popular as I feared I may become a eunuch if the missus found out what I was cooking.

Yeah, you should've heard the earful I got when I was oven curing some newly painted auto parts.

You could remove the components like they do in China. Just get you a 20-gallon bucket and build a fire in it. Toast the CCAs over the fire and pull them off, wash them in the river, and using a broom, scrub them on the riverbank. Oh yeah, then carefully sand off the markings and replace them with some of your own and sell to the lowest bidder. Oh yeah, they are absolutely MIL-SPEC, NASA certified, and ready to fly in satellites. You betcha good buddy.

rofl....funny bugger

...you have exposed my dastardly scheme...

...further to my hidden agenda of flogging acid drenched electronic components into the world market, are these humble discrete components and non-SMD IC's. Four hours soaking time and the little suckers just pulled right out

Use a hot air blower, at my intern ship at an LCD company we used a paint remover hot air blower just a few seconds of hot air and a hit on the PCB and the components would fall off. it was all about timing