Sciencemadness Discussion Board

Motherboard RAM plastic, IDE plastic, PCI plastic

vmelkon - 6-6-2019 at 16:41

Hello, I desoldiered some motherboards.
I placed the RAM plastic (the sockets where you insert your RAM modules).
IDE plastic (the sockets where you insert your IDE cables).
PCI and PCI-ex slots.

I added them to HCl, 37% (10 M).
It looks like some of the plastic liquefied.
Does anyone know what these plastics are? Is it nylon?

The idea was to have the HCl react slowly with the nickel, tin, copper.

Twospoons - 6-6-2019 at 17:12

LCP is the likely material (liquid crystal polymer). It is rigid and good for moulding accurate detail.

DavidJR - 10-6-2019 at 09:27

Nylon does indeed dissolve in concentrated HCl, and it would not surprise me at all if it was in fact nylon that is used in the connectors.

Ubya - 10-6-2019 at 10:09

Quote: Originally posted by vmelkon  
Hello, I desoldiered some motherboards.
I placed the RAM plastic (the sockets where you insert your RAM modules).
IDE plastic (the sockets where you insert your IDE cables).
PCI and PCI-ex slots.

I added them to HCl, 37% (10 M).
It looks like some of the plastic liquefied.
Does anyone know what these plastics are? Is it nylon?

The idea was to have the HCl react slowly with the nickel, tin, copper.


If you just had a few motherboards it was wiser to remove the pins from the plastic, even if nothing happened to the plastic you still have to remove the plastic from the gold particles before adding acqua Regia (or anything that dissolves gold)

vmelkon - 10-6-2019 at 18:04

Quote: Originally posted by Ubya  
If you just had a few motherboards it was wiser to remove the pins from the plastic, even if nothing happened to the plastic you still have to remove the plastic from the gold particles before adding aqua Regia (or anything that dissolves gold)


But there are too many pins. I have a bunch of DIMM slots. Each has 190 to 200 pins. PCI slots have a lot as well. Maybe 100. There are AGP slots and PCI-Ex. There are USB headers and other headers. I also have HDD and cables like VGA, USB.

I have only seen people process RAM and they snip the connector part with a metal cutting scissor. Each RAM takes 10 sec to cut. That is easy.

Ubya - 11-6-2019 at 05:00

Quote: Originally posted by vmelkon  
Quote: Originally posted by Ubya  
If you just had a few motherboards it was wiser to remove the pins from the plastic, even if nothing happened to the plastic you still have to remove the plastic from the gold particles before adding aqua Regia (or anything that dissolves gold)


But there are too many pins. I have a bunch of DIMM slots. Each has 190 to 200 pins. PCI slots have a lot as well. Maybe 100. There are AGP slots and PCI-Ex. There are USB headers and other headers. I also have HDD and cables like VGA, USB.

I have only seen people process RAM and they snip the connector part with a metal cutting scissor. Each RAM takes 10 sec to cut. That is easy.


i know they are lots of pins, but with a pair of pliers and the right technique you can remove all the pins from each connector of a motherboard in 10 minutes (i dismantled 2 motherboards and removed all the pins this way)

RogueRose - 11-6-2019 at 05:44

I think the PCI, PCIe and RAM slots are usually glass reinforced nylon, PA6. I've also seen some of these parts semi dissolve in HCl.

As far as dissolving the pins, you should really take a look at the amount of gold that is used to cover these pins as it is a VERY small amount, MUCH less than what is on PCI cards or RAM cards. The pins seem to have about 5% total coverage of the entire pin in gold and it is much thinner than the plating on the cards. IIRC, these pins might also be a phosphor bronze that i've been told really messes up the extraction of gold.

The amount of HCl needed to dissolve all those pins is a lot compared to the amount of gold extracted. I'd venture a guess that you'd spend many times the value of the gold in HCl alone when working on these types of pins.

Twospoons - 11-6-2019 at 16:07

https://www.digikey.co.nz/products/en/connectors-interconnec...

A representative collection of PCIE connectors. Some are glass filled nylon, some are LCP, some use phosphor bronze. Most of them have bugger all gold (thats what 'Flash' means).

Look at the drawings for a particular part - the materials will be specified somewhere in a note.

[Edited on 12-6-2019 by Twospoons]