Motoyo Wajima <[log in to unmask]> さんは書きました：
>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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