[vcf-midatlantic] Can anyone identify this mystery IC

[Douglas Crawford]

Ah, so the red lines are not b/c/e?
That's what I was first thinking.
Here me trying to make some sense of it
https://i.imgur.com/gOZujMR.jpg

Red lines inputs?
Could the blue things be capacitors?
Maybe purple outputs?
 From this view... OR gates?

At least I have some agreement now that several learned eyes
see transistors. It might be enough for our purposes
to just have a good guess of how many transistors there
are, and be able to identify them.  What they are doing
is a less important detail for our purposes at this
point in the exhibit.

So how many do to think you see in each group?
We may never know for sure, but I'll probably run with
your number as an estimate.


On 8/21/2022 3:43 PM, Dave McGuire via vcf-midatlantic wrote:
> 
>    I think those are actually six small groups of transistors, not six 
> transistors.  Possibly inverters; these can be built in a CMOS chip with 
> two transistors, which would usually be physically adjacent.
> 
>               -Dave
> 
> On 8/21/22 15:35, Douglas Crawford via vcf-midatlantic wrote:
>> They are changing their tune, Dave :)
>>
>> One says:
>> " Metalization is hiding all the lower levels. Looks like a device 
>> with just 6 transistors."
>> Another responds:
>> "So it would be a *transistor* array, not a gate array then.
>> If so, then I’m confused as to why it would need so many pins if there 
>> are only 6 transistors.  Unless it was a prototyping part where all 
>> the transistors were individually made accessible."
>>
>> (I'm positing with them # pins is because possibly they're gates)
>>
>>
>>
>>
>> On 8/21/2022 12:50 PM, Dave McGuire via vcf-midatlantic wrote:
>>>
>>>    Yes, but we should be able to determine everything, or almost 
>>> everything we need to know from that layer.  We'd need better and 
>>> higher-resolution photos.
>>>
>>>               -Dave
>>>
>>> On 8/21/22 12:48, Douglas Crawford via vcf-midatlantic wrote:
>>>> Ah, now we are getting somewhere.
>>>> We can only guess then, from the remaining metalization layer
>>>> correct?  Educated guess?
>>>>
>>>> On 8/21/2022 12:43 PM, Dave McGuire via vcf-midatlantic wrote:
>>>>> On 8/21/22 12:39, Douglas Crawford via vcf-midatlantic wrote:
>>>>>> These are the transistors?
>>>>>> https://imgur.com/aLpqVpE
>>>>>
>>>>>    I'd need to look more closely, but those appear to be clusters 
>>>>> of transistors, six of them.  They are likely gates.
>>>>>
>>>>>> I got one additional response from another designer:
>>>>>> "Looks like some kind of gate array with only the metalization 
>>>>>> layer being clearly visible. I worked on alot of these in the late 
>>>>>> 70's. I have no explanation for the bonding pad structures."
>>>>>
>>>>>    Agreed; this has either had its passivation layer removed, or it 
>>>>> had never been applied.  I suspect the latter, as it would've been 
>>>>> removed with acid, and there isn't so much as a trace of debris 
>>>>> from that.
>>>>>
>>>>>              -Dave
>>>>>
>>>
>>>
> 
>