Still learning.

[Dr_Code]

These are only examples of the types of material. I don't plan to process the three items and only the items.

From top to bottom: LCD board, RAM, and CPU board from a laptop. Scrach testing the traces show they are copper under the solder mask. Is it necessary to depopulate the boards with a hot sand bath, then hot lye to remove the solder mask, and then AP?

The LCD board does seem to have some sort of clear glue over the fingers. I assume this was to hold on the thin plastic part that attached it to the actual display. I am leaning towards the hot lye solder mask removal for that particular type of scrap.

I want to do things right, but on the other hand, no sense wasting chemicals and time on an unneeded steps.

 

[Geo]

if theres no gold under the mask, theres no need to remove it. the AP will work its way through the mask and etch the copper underneath. if the traces were gold plated, then it would need to be removed. if there is epoxy over the gold traces, it should be removed as best you can. at the end of the AP process, dont worry about trying to separate foils from solder mask. the solder mask will net effect the hcl/Cl process to dissolve the foils. take all solids left from AP and rinse well with clean hcl until it stays clear. bits of solder mask or plastic will do no harm. when you filter, be sure to rinse the trash really well.

 

[pimpneightez]

If it's copper under the solder mask there is really no need to put it in lye. I would just cut the visible gold traces out like with fingers. No need to add an extra step if there is no PM's. If there is gold underneath the solder mask definatly give them a lye bath but make sure it's hot lye it works much better.

 

[pimpneightez]

Dang beat me too it Geo! I'm glad we both agree.

 

[rheslin2]

also, once the ram cards have been in a/p for a while, a blast from a squirt bottle helps to knock out those little gold foil tubes. i pull them out and spray them over an empty container, as to not dilute the a/p too much

 

[Dr_Code]

Thanks again, everyone!

Good idea about spraying them over a seperate container. The little gold dots/tubes looked like they would be particularly pesky to try and remove. I could see myself ending up with a bucket full of mostly water.