A question on depopulating cell phone boards....

[Meh1]

This might seem like something obvious and forgive me if it has already been discussed..from what I can glean from the forum the preferred method of depopulating cell phone boards is one of a couple methods: torch, sand bath, or heat gun..I am wondering could, cell phone boards be depopulated in a diluted sulfuric acid bath?..considering it does remove several annoying things from the final product like tin and lead without touching any PMs..Maybe I have a special case because this acid even though dilute is not only easily obtainable but inexpensive where I live..any suggestions and or experience trying this method?..Regards and happy new years -John

 

[martinbardill]

hello, im no expert so you may want another opinion. i believe that hot sulphuric will dissolve tin, i think the lead will show up as a powder. there are many methods, the key is finding the one that's right for you. try a couple of methods then decide from there. sulphuric will also react with metals higher than hydrogen in the reactivity series, allways use caution when using hot sulphuric .

 

[Pantherlikher]

It's a matter of what way is cheapest to depopulate boards.
Chemicals or fuel of some sort, like electricity...

BS.
Looking up my electric bill for comparison shopping...

 

[Geo]

the problem with depopulating cell phones chemically is the wide range of different metals involved. one acid will work on some of the metals while another will work on some of the other metals but no one acid will work for all of the different metals.lets say you wanted to dissolve the solder to remove the components with hcl.it will not dissolve the tin until all the steel is dissolved first.if you used a sulfate to remove the lead, it would leave the tin (not to mention that solder on cell boards are high silver content solder).sulfuric acid will just make a mess out of your material and then you would still have to figure out a way to finish the job with the mess you have created.

i tried as many different combinations as i could think of and decided a sand bath was the fastest and most economical way to depopulate cell phone boards.

 

[Meh1]

Thanks for the input..I see what you are saying..the solder would be only partially removed because of the high silver content..leaving me with components still attached..and boards soaked with acid....makes sense..thanks for the advice..-Regards John

 

[Geld Konig]

With this proceedure you certainly lose part or all gold plated in the holes on the cell phone board.
I think, it will be more difficult to get back this gold lost in the solution with Sn, Pb, and other metals.
Note: This gold plated under the CIs and others components in the board.