[CCTALK] RE: scanners & circuit boards..

From: Dwight K. Elvey <dwightk.elvey_at_amd.com>
Date: Thu May 16 11:51:12 2002

>From: "Douglas H. Quebbeman" <dougq_at_iglou.com>
>>>> I'd be more concerned with accidentally scratching the
>>> glass bed of the scanner due to sharp component leads.
>>
>> You can't scratch glass with metal. What you can do is leave
>> a thin trace of metal on the glass. Gewelers rouge will easily
>> remove this is nothing else will.

 This is not true. Try running your windshield wipers
without the rubber. Although, it may be true that glass
has a hardness greater than most metals, this doesn't
mean it won't get scratched. The problem is that it also
fractures easily ( sometimes at a microscopic level ).
The tiny chips embed in the metal surface and that scratches
the glass. This is a multiplying effect. Also, most oxides
of metal are harder than glass. And lastly, the quartz
windows of the EPROMs are harder than glass.

>>>
>>> I guess that there is a slight possibility of degrading the
>>> contents of an EPROM if its window isn'tcovered.
>>
>> Glass is opaque to UV so you won't erase EPROMs either.
>
>EPROMs don't have UV-opaque glass windows, they have
>UV-transparent quartz windows. So they can be erased,
>but not by casual exposure.

 I think he was talking about the glass on the scanner.
Dwight
Received on Thu May 16 2002 - 11:51:12 BST