Options for cleaning legs on PLCC chips?

[JezC]

Hi,

I've acquired a couple of old PLCC packaged items (one is a 68k CPU and the other looks to be a Blitter) but they have lots of contamination on the legs, so I was wondering what might be best to use to clean them up.

I'll probably experiment on the 68k processor first (as they're rather more available & cheap compared to the Blitter ) but so far I've stocked up with some IPA & was wondering about a fibreglass pencil?

I'll try and get some photos later this evening...

TIA

[PhilC]

@JezC Remember those old grey rubbers you used to have at school? the ones supposedly that could rub out pen but just wore a hole in the paper. I use a large one of those to get rid of light surface corrosion.

[JezC]

That's a good shout @PhilC - I might even have some of those in a box somewhere

[Steve]

I also recommend fibreglass pens for this, very effective.

[JezC]

I also recommend fibreglass pens for this, very effective.

Thanks @Steve - any specific type/size that you've found better than others?

[Steve]

@JezC

I think I've got this one:
VILLCASE Fiberglass Scratch Brush Pen, Fiberglass Nylon Pen, Precision Clean Pen Sweeping Brush for Cleaning Jewelry, Watch, Coin, Electronic, Removing Rust and Corrosion
https://amzn.eu/d/0IiFORv

[exxos]

DeoxIT ?

[stephen_usher]

DeoxIT ?

Unfortunately, if the tarnish is too thick that won't help so you need to remove the lead/tin oxide from the surface first with an abrasive of some kind. Galina (lead oxide) can be quite tough, cassiterite slightly less so.

[rubber_jonnie]

Personally I use a fibreglass pencil, but be aware that you get tiny shards of fibreglass as a side effect and they are unpleasant if they get in your skin, so make sure you clean up as you go along. Still the best for heavily contaminated legs IMHO.

Other than that, ink or model railway track cleaning rubbers (Are they still a thing?) followed by an IPA bath and some Electrolube or DeOxit to finish off.

[stephen_usher]

Yeah, track rubbers are still a thing. Peco still make the small, traditional ones.