Motoyo Wajima <[log in to unmask]> さんのメッセージを転送します：
Hi Susan!
 It depends on the thickness of PWB and the drill diameter.

No.of Stack  Thickness of PWB    Drill Diameter   TotalAspectRatio
                (mils)              (mils)
   4         63(double sided)       24                 10.5
   3         31(multilayer)         12                  7.8
   2         63(multilayer)         16                  7.9
   2         39(multilayer)         12                  6.5
   1         63〜(multilayer)       12〜                5.3〜
Drill bit bending increase in higher aspect ratio.
Regards,
Motoyo Wajima
General Purpose Computer Division,Hitachi,Ltd.(JAPAN)

[log in to unmask] さんは書きました：
>One of my customers has a question regarding stack
>height for multilayer printed boards for drilling.
>
>When I was building boards, I drilled only one at a time.
>However, we were not producing high volumes of boards
>and all I can think of is why I wouldn't want to do it.
>
>Do any of you have experience drilling more than one
>panel of multilayers at a time?  What are your criteria
>for determining when to stack and how many?
>
>Thanks,
>Susan Mansilla
>Robisan Lab
>
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***********************************************
Motoyo Wajima
General Purpose Computer Division,Hitachi,Ltd.
1 Horiyamashita
Hadano-shi,Kanagawa-ken,259-13 Japan
E-mail:[log in to unmask]
Fax:+81-463-88-2935
***********************************************

***********************************************
Motoyo Wajima
General Purpose Computer Division,Hitachi,Ltd.
1 Horiyamashita
Hadano-shi,Kanagawa-ken,259-13 Japan
E-mail:[log in to unmask]
Fax:+81-463-88-2935
***********************************************

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