Jan,
Mass removals and remarkings happen all the time.  It is commonplace for
semiconductor companies to demark and remark their components.  It happens
when: Customer requires custom markings after parts are already marked,
wrong markings, permanency problems (lots of em), stolen chips you don't
want traced back to you (just kidding), even upscreening where another
company may purchase components and test them at extended temperatures then
apply their own markings.

This is in addition to the proprietary design stuff like Ian and Justin are
doing.

This is another reason why I believe components should have a cleanliness
requirement.  You are correct in that there is a lot of handling in manual
demarking.  These days it has become big business.  These component
demarking houses have automatic in-line demarking systems.  It is a
reasonably controllable process, however, my concern lies in how do they
insure the parts are clean.  I don't think most are washing the components,
I believe it is just an air shower and most of the vendors have never heard
of an Ionograph.

Next time you analyze that foreign material, try checking for walnut shells.

-----Original Message-----
From: PELCHAT_JM <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>; Russ <[log in to unmask]>
Date: Tuesday, September 08, 1998 4:13 AM
Subject: Re[2]: [TN] IC coating


>
>        I'm really not trying to be wise, but what would be the reasons
>        for removing IC marking?
>
>        How on earth would one control mass removals and remarkings?
>        My QA mindset just shuddered.
>
>        Jan Pelchat
>        (Stone's throw from Keene)
>
>
>______________________________ Reply Separator
_________________________________
>Subject: Re: [TN] IC coating
>Author:  Russ <[log in to unmask]> at 0UTG0ING
>Date:    9/8/98 12:26 AM
>
>
>Justin,
>Try Markem Corp. in Keene, New Hampshire, USA.  They make the inks used to
>mark the components and they have "body coating" inks.
>
>http:www.markem.com
>
>The markings sometimes can be (barely) read through not because the inks
are
>not dark enough but because of thickness issues.  If you want no
>traceability on your components then use microabrasive blasting.  For
>ceramic use aluminum oxide, for gold use sodium bicarbonate, and for
plastic
>I think you use walnut shells.  Be sure your system is ESD safe and mask
the
>leads or else you will ruin the solderability.  There are several companies
>in California who specialize in removing markings in high volume.  HGM in
>San Jose, California is one I remember.  They also do body coating and
>re-marking.  Prime Solutions in Fremont or Milpitas, California is another.
>Regards, Russ
>
>-----Original Message-----
>From: Justin Braime <[log in to unmask]>
>To: [log in to unmask] <[log in to unmask]>
>Date: Monday, September 07, 1998 4:30 PM
>Subject: [TN] IC coating
>
>
>>Morning all,
>>I'm looking at hiding the identity of some ICs on a particular product,
and
>>currently the suggestion is to grind off the top of the IC (ouch!!) , am I
>>right in thinking there is some kind of coating that will do the same
>>thing, and that is not removable??? If anybody knows of any particular
>>product can they please let me know......
>>
>>Thanks in advance
>>
>>Justin Braime
>>Production Engineering
>>Alpine Electronics of New Zealand Ltd
>>------------------------------------------------------------
>>15a Vestey Drive, Mt Wellington,
>>Private Bag 14921, Panmure,
>>Auckland, New Zealand.
>>Phone: +64-9-573 7100
>>Fax: +64-9-572 7101
>>-------------------------------------------------------------
>
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