# Trash?



## acpeacemaker (Dec 20, 2011)

Sorry, my pictures aren't as good as they should be, my camera was dropped. The white part is a ceramic board? So I was thinking bad news when I seen it. I have 240 of these and all of them have different things on them. About half appear to have gold traces on the white part. They came from Motorola power packs for cb's.-Andrew


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## Smack (Dec 20, 2011)

NO, definitely not trash. Looks like AU, AG and PD values there.


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## acpeacemaker (Dec 20, 2011)

Don't get me wrong I don't want to throw it away. I was more worried about the white ceramic board possibly being affiliated with beryllium , but wasn't sure.


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## Geo (Dec 20, 2011)

you should be able to process the metal off the ceramic without breaking the ceramic so there shouldnt be a problem with that. the hazard is when you break,crush,grind or mill the ceramic.


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## acpeacemaker (Dec 20, 2011)

Thank you, what about under torch? I've been using a mini oven lately and give big props to whom ever posted it. It has worked wonders.


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## Geo (Dec 20, 2011)

not sure about very high temps, but ceramic is used because of its ability to withstand high temperatures. ordinary porcelain on the other hand can not withstand thermal shock and will shatter with explosive force either from the heating or rapid cooling. ceramics come in different colors but porcelain is mainly white and is used in electronics for its insulating abilities as it has high resistance to electricity. try to determine if the parts are ceramic or porcelain before you apply heat.


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## goldsilverpro (Dec 20, 2011)

That's a hybrid circuit and they are commonly made from alumina. If the gold traces are fairly dull or matte, it is a thick film circuit. If bright and shiny, a thin film circuit that is worth less. If gray traces are present, they are likely Pt.


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## acpeacemaker (Dec 20, 2011)

Thank you GSP, a lot of them are dull to a matte. There are grey traces as well. I was wondering about trying to get someone else to recover the values from these boards. I found out I have a little more than originally stated. I have a little over 500 of them.


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## Harold_V (Dec 21, 2011)

goldsilverpro said:


> If gray traces are present, they are likely Pt.


That's interesting, Chris. I've not heard of them. Can you say more?

Harold


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## acpeacemaker (Dec 21, 2011)

I forgot to mention these yesterday with this. There's another board in these packs that contain three of these on each. Ranging from dime to nickel size. (Picture) The gold tabs are buried in solder, but still has that white ceramic feel.


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## goldsilverpro (Dec 21, 2011)

Harold_V said:


> goldsilverpro said:
> 
> 
> > If gray traces are present, they are likely Pt.
> ...



My knowledge of these circuits is mainly based on my once working for a company, many years ago, that sold thick film pastes. I have not kept up with the technology, although I read a little before making this post. We once sent a couple of drums of the circuits out to a PGM refiner. These were the flat white ceramic thick film circuits only, with no components mounted on them, unlike the circuits in the photos. If I remember right, they yielded about $80/pound at about a $400 gold market. However, the value was probably higher since the refiner most likely screwed us.

Here's what little I know.

The ceramic substrates are usually made from alumina, beryllia, or aluminum nitride, although alumina is probably the most common. The alumina substrates are made by adding about 4% glass powder (frit) to the powdered alumina. Some sort of liquid is added. From this "dough", greenware is produced of the desired thickness and size. This is fired to drive off the liquid and melt the glass. The glass bonds the ceramic particles together to form the rigid ceramic substrate.

There are 2 types of circuits made directly on these substrates - thin film and thick film. The thin film circuits are made by applying gold and other metals to the substrates by vacuum metallization techniques. The thick film circuits are made by silk-screening glass-containing (2%-10%) metallic pastes to the substrates. They are then fired to drive off the solvents and melt the glass. The melted glass bonds with the glass in the substrate. I just found a reference that said the thin film metallization averaged about .1 microns thick (4 microinches), whereas thick film thicknesses can range from 5 microns (200 microinches) to 50 microns (2000 microinches). Quite a difference! All of the thin film circuits I've seen have bright shiny metallization, whereas the thick film metallization is much more matte. Also, with thick film metallization, you can probably "feel" the raised thickness with your finger.

There are 4 main uses for this thick film paste on the circuit - traces, bonding pads for ICs or other components, resistors, and capacitors. The metals used for traces and pads are such things as Au, Pt, Pt/Ag, Pd/Ag, and Cu. I don't think that Ag is used alone due to migration problems. The resistors are made from metal oxides, such as ruthenium oxide. The capacitors are some sort of non-PM dielectric material. Also, you will sometimes see colored overlay squares of fired-on non-PM glazes protecting certain portions of the circuit.

In modern times, they have developed copper pastes for traces. In the photos, the traces look more like copper than gold, but that may be the quality of the photo. Copper should be easily distinguished from gold by color.

As far as refining is concerned, they can get complicated. If only the ceramic circuit, with no mounted components, try aqua regia. The times I did this, all traces of metal were removed. At first glance, the Ag might be a problem.. However, since I believe the Pt/Ag and Pd/Ag are in there as separate powders, and not as alloys, I think all the Pt and Pd will leach into the AR. 

I have seen many many types of components mounted on these circuits. I can't see any absolute one way to refine these, although AR would work in some cases. You have to examine what's there and then make a best guess as to what you should do. In the photos, there are lots of different mounted parts plus solder and connector pins. Might require some experimentation. Do 1 or 2 at a time.

Like many other items, the values can be all over the map.


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## stihl88 (Dec 21, 2011)

Some of you may remember my thread on these? I still have to process these components, they are mostly thick and dull colored Gold tracks and dull Grey tracks also.
I could look at them all day, in comparison with todays technology these components are dripping with Gold, zoom in and you'll see what i mean...


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## ctgresale (Dec 21, 2011)

Since we're on the topic of white ceramic chip's, anyone have an idea how to get the gray backing off easily ? It's soft just like regular bathroom caulk. I've got allot that I need to be processed but very time consuming trying to get it to come off.

Thanks
Steve


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## Smack (Dec 22, 2011)

I'm not up to the task but someone should take these pic's and some other good ones and make a GRF calendar. It was obvious :roll:


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## Harold_V (Dec 22, 2011)

goldsilverpro said:


> Here's what little I know.


Thanks, Chris. We learn something every day on this forum.

I figured I'd never see anything with platinum traces, which is what really caught my attention. Imagine the cost of producing boards that way! 

Harold


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## cking (Dec 22, 2011)

At 20% yield by weight, and if the number 85 under the circled M is the year of manufacture - then you could figure out what the PM values of the year were and figure it out. I don't know what PT or AU was going for in 85, but it had to be less than $100-200?



Harold_V said:


> goldsilverpro said:
> 
> 
> > Here's what little I know.
> ...



The date codes are generally 4 digits. In those 1st 2 photos I see 8910. I think the manufacturing year was 1989.


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## joem (Dec 22, 2011)

Smack said:


> I'm not up to the task but someone should take these pic's and some other good ones and make a GRF calendar. It was obvious :roll:



I like this idea.
send me high rez pictures from your cameras ( not off the web - poor quality for printing) and I'll make a file you can view on screen or print off your own printer.
Once I get enough pictures and names to credit with I'll make one and post a link.
email to [email protected]


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## Harold_V (Dec 23, 2011)

cking said:


> I don't know what PT or AU was going for in 85, but it had to be less than $100-200?


Hell no! You can do a search and discover what they were selling for, but, rest assured, gold was more than $300 and platinum was likley more than $400/oz. 

Harold


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## cking (Dec 23, 2011)

Harold_V said:


> cking said:
> 
> 
> > I don't know what PT or AU was going for in 85, but it had to be less than $100-200?
> ...



Wow, forgot about the "crisis" years... gold hit almost 900 in 1980. I was a pup then. What I was remembering was gold hitting $250 in 1999. Been a wild ride. Mostly in the 1970s gold had been below $200 (lots of history in that decade too).


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## Smack (Dec 23, 2011)

Gold bounced around the low $300 dollar range in 1985.


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## trashmaster (Dec 23, 2011)

and it's bounced around (currently) alot    the last couple of months.


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