From the MAKE Flickr pool
Karl W. shares a pic of his newly acquired artifact –
This ceramic wafer is a real mystery to me. I purchased it from a Ebay seller in Kfar Saba, Israel and during the shipment it cracked on the upper edge of it. It’s about 4″ x 4″ and just a bit thicker than a normal silicon wafer. I was thinking it could have been a early attempt at making small ICs, before silicon?
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I’d love it if anyone could give me more information on what this is, it seems like quite a rare item from what I can tell.
A larger version of the image can be seen here.
14 thoughts on “Ceramic IC”
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These are still made today and are called Thick-Film ceramics. You can also combine them with standard surface-mount components to make a “hybrid” device. They can include LASER-trimmed components, and allow a surprising freedom of materials. Useful for a number of applications, Corintech in the UK can manufacture them (amongst many others)
Dave is spot on. If you magnify the image you can see that the resistors (black areas ) have dark lines in them which show the trimmed areas. The resistors are printed with conductive ink to have a lower resistance than desired and then trimmed in an automated process with a laser and an ohmmeter.
Yup, I’m with you guys. The last company I worked for did this kind of work. It’s not common these days, but it’s still around.
Good eye and comment. However, hybrids are widely utilized in high-reliability applications. You will find these little guys in space, geothermal, military, drilling and aviation applications where the environments are harsh and the cost of failure is high.
At the University of New Mexico in the 1970s we had a lab where we made these under the direction of Dr. Roy Colclaser. Students created masks out of Rubylith and used a machine to screenprint the components on the substrate. Pins were soldered to the edges for connections off the ceramic. In those days we did not have laser trimmers. IIRC, the most commonly made circuit was an R-2R DAC.
What they said :)
The ceramic is most likely Aluminum Oxide (crushed sapphire) but could be Beryllium Oxide (be careful!).
My guess is that this is some kind of sensor or sensor interface to a differential amplifier. The top and bottom halves look somewhat symmetric.
If you want to dice out the parts, you’ll need a dicing saw similar to this:
http://mightyohm.com/blog/2009/07/tonys-diamond-chop-saw-part-1/
-Tony
To my first career as an auto service technician. I specialized in electronic engine control troubleshooting and repair. We had a Ford as I remember that developed a cold fault no-start condition. You could put a hair dryer on the module and the car would start and run, park it overnight and it would be dead in the morning. Out of curiousity, I canopenered it to find one of these Thick Film circuits inside. There was a hairline fracture that would open when the board shrank.