Bob,

We don't pin our coupons. We routinely section via as small as 8 mils
diameter and put multiple coupons in each mount. We actually still grind
and polish by hand (only use autopolishing for ceramics). I know it's
difficult but nothing beats good microsectioning technique and patience
along with well trained techs.

Paul Terranova
Analytical and Environmental Test Services Lab
Worldwide Module Components Group

 Digital Equipment Corp
 200 Forest Street
 Mail Stop: MRO3-1/D2
 Marlboro,  MA  01752

'    Phone: (508)467-3109
* Fax: (508)467-6796
* Email: [log in to unmask]


        -----Original Message-----
        From:   BOB HAYNES [SMTP:[log in to unmask]]
        Sent:   Tuesday, February 24, 1998 3:15 PM
        To:     [log in to unmask]
        Subject:        [TN] Microsections

        Ladies and Gentlemen,

        I have been asked by our Purchased Material Inspection (PMI)
        department to find out how other people are doing the required
        microsection on small holes. The "B" Coupon as required by
Para..7.3.5
        of IPC-D-275, has holes of the smallest diameter on the printed
        wiring board. These are  vias which are now 10 mils and below
and it
        is reported that these are very difficult to do a good
microsection
        on.

        Has anyone else experienced the same problem and if so what was
        your solution? Any feed back and suggestions would be greatly
        appreciated.

        Thanks in advance,

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