Author Topic: making silver grease?  (Read 1790 times)

0 Members and 1 Guest are viewing this topic.

Offline coppercone2Topic starter

  • Super Contributor
  • ***
  • Posts: 9443
  • Country: us
  • $
making silver grease?
« on: November 12, 2021, 07:04:58 pm »
So I have silver powder that I wanted to use for making ceramic PCB but I also thought to try to make some silver laiden grease. I could make a gram or so to apply with a micro applicator, maybe to some IGBT pads. My silver is between 2000 to 4000 mesh.

I moreso then anything wanted to create a sample before buying MG Chemicals 8463. I see they use a silane. I have seen other conductive silver grease made with mineral oil. I thought to mix it with CRC Silicone grease in a little cup by weight, 2/3 silver to 1/3 grease. Do you think that will make a OK grease?

Does the silver need to be like fumed or mixed with carbon, akin to carbon-coated-aluminum (german dark) for it to work in such a grease mixture? I see its added into the mix, but I suspect it maybe has to do with improving silver flow and protecting it from oxidation as a coating more so then a filler/cut.

My goal is to do contact resistance tests on crimps at high currents with precise equipment.

 

Offline wraper

  • Supporter
  • ****
  • Posts: 16855
  • Country: lv
Re: making silver grease?
« Reply #1 on: November 12, 2021, 07:15:30 pm »
Quote
maybe to some IGBT pads.
I don't see a point. Best thermal pastes don't use any silver, are cheaper and are not conductive. They is no point in silver paste other than bragging about its price or if you really need it to be electrically conductive.
Quote
My goal is to do contact resistance tests on crimps at high currents with precise equipment.
How is it supposed to help?
« Last Edit: November 12, 2021, 07:18:38 pm by wraper »
 

Offline coppercone2Topic starter

  • Super Contributor
  • ***
  • Posts: 9443
  • Country: us
  • $
Re: making silver grease?
« Reply #2 on: November 12, 2021, 07:20:20 pm »
Because I want to study it, its for the contact pads not the thermal pads, the spring contacts. I am also curious how much connection losses are reduced by such expensive additives.

This is meant to be a electrical contact improver.

https://www.mgchemicals.com/products/grease-for-electronics/electrically-conductive-grease/contact-grease/

https://www.cool-amp.com/conducto-lube

I have miliohm LCR meter and other tools needed to do a high current test. I also had to refinish the pads so 'pitted' might be an issue there. Seems like the 'proper' choice.

I am sure you can see my interest in making a sample of something similar when I already have spare silver and materials on hand?
« Last Edit: November 12, 2021, 07:28:06 pm by coppercone2 »
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 6972
  • Country: ca
Re: making silver grease?
« Reply #3 on: November 12, 2021, 07:46:02 pm »
Also consider lifetime, what happens a year from now. Silver oxidizes and that could be the worst aging mechanism. I think the base grease is critical, that it lasts.
In the electrical industry, there is:
Sanchem electrical contact grease NO-OX-ID
KOPR-SHIELD, contains colloidal copper.
For aluminum conductors, NOOXAL or NO-OX-ID-A, contains fine zinc particles which break through the Al oxide film.

When I looked at thermal compounds they are mainly zinc oxide in silicone oil.
In the PC industry, they have very little silver, just enough to add that to the product name.
Arctic Silver 5
?% Silver
5% Boron Nitride (aka white graphite, a ceramic powder)
30-40% Zinc Oxide
5% Aluminum Oxide
Base DiPhenylamine as "Synthetic polymer" Polyol Ester

Coolermaster HTK-002-U1
30% Aluminum Oxide
20% Zinc Oxide
14% Silicon dioxide
3% Titanium Dioxide
1.2% Calcium carbonate
3% Magnesium Oxide
Base steric acid, palmitic acid

Thermal Grizzly Kryonaut
65% Aluminum Powder
25% Zinc Oxide
10% Silicones

MG Chemicals 860 Silicon Heat Transfer Compound
70% Zinc Oxide
3% Silica Powder
Base silicone oil?
 

Offline coppercone2Topic starter

  • Super Contributor
  • ***
  • Posts: 9443
  • Country: us
  • $
Re: making silver grease?
« Reply #4 on: November 12, 2021, 07:49:13 pm »
http://images.salsify.com/image/upload/s--s1s21HSB--/tjpydfunckf8xbzzsubh.pdf

That grease is 90% the same ingredient as the MG-CHEMICALS silver grease. I thought if I mixed that with silver powder it would be good.

The silver powder is shiny and reacts with bleach to clump up and turn black when exposed. Will amorphous fumed silica interfere with anything?
 

Offline TimFox

  • Super Contributor
  • ***
  • Posts: 7948
  • Country: us
  • Retired, now restoring antique test equipment
Re: making silver grease?
« Reply #5 on: November 12, 2021, 08:31:27 pm »
A little pedantry:
Silver does not oxidize under normal conditions:  silver tarnish is a sulfide, Ag2S, from reaction with sulfur compounds in the atmosphere (from various industrial processes, etc.).
See  https://byjus.com/questions/what-is-the-chemical-formula-for-corrosion-in-copper-and-silver/
 

Online jpanhalt

  • Super Contributor
  • ***
  • Posts: 3472
  • Country: us
Re: making silver grease?
« Reply #6 on: November 12, 2021, 09:23:04 pm »
Like wraper said, it is completely unclear what you want to accomplish.

If you want a highly thermally conductive and electrically non-conductive "grease" there are products on the market or DIY with BN (boron nitride).  It is cheap and readily available (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723785/ ).  Many other citations are easily found.

If you want something that does both (i.e., is electrically conductive) use a solder.
 

Offline coppercone2Topic starter

  • Super Contributor
  • ***
  • Posts: 9443
  • Country: us
  • $
wat
« Reply #7 on: November 12, 2021, 09:54:30 pm »
https://www.cool-amp.com/conducto-lube

*Reduce Resistance *Prevent Data Errors *Prevent Power Interruptions *Prevent Power Failures
Provides electrical & thermal conductivity, lubrication & protection.
* Contains PURE SILVER * Prevents galling that will freeze joints * Lubricates switches * Eliminates hot spots in hinge joint switches caused by poor contact * Prevents clips of disconnected switches from overheating & losing tension * Increases conductivity * Contains no graphite, mercury or cyanide * Temperature range is -25 to at least 500 F *

i don't know why this is unclear. i linked the products I want to mimic in the beginning of the thread.
« Last Edit: November 12, 2021, 09:56:06 pm by coppercone2 »
 

Offline coppercone2Topic starter

  • Super Contributor
  • ***
  • Posts: 9443
  • Country: us
  • $
Re: making silver grease?
« Reply #8 on: November 14, 2021, 07:03:31 pm »
I will make 2g of 30% silver mineral oil mix and attempt to make 2g of 30% silver CRC-Silicone mix, when I find some vials

Does anyone know if mineral oil is compatible with a resin 3d printed SLA container? I thought to make a micro lip-balm style container for it. Or maybe I will just keep it in syringes
« Last Edit: November 14, 2021, 07:35:53 pm by coppercone2 »
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf