Strictly speaking from a fabricators point of view, these are not the
same.
Via-in-Pad (VIP):  Is the via being drilled (or ablated) in the laminate
and later, a pad being imaged around that via.  WHILE,
Via-on-Pad (VOP): The via is formed by copper plating, conductive paste or
insulation displacement in a B-staged material and then the copper is
laminated on the prepreg.  When the pad is formed it is now "ON" (or over)
the via.  This type of via formation is seen in IPC TYPE V and TYPE VI HDI
(IPC-2226), most of the times of Japanese  origin like ALIVH,
Neo-Manhattan, etc, while the VIP is IPC TYPE I, II, III or IV.
No real differences for design, big differences in fabrication and for
assembly, VOP is always flat while VIP have a dimple unless they are
filled/over-plated.

Happy Holden
Westwood Associates




Sefika Ozkal <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
11/29/2004 02:05 AM
Please respond to
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Re: [TN] Via-on-pad / via-in-pad






Hello,

I have not seen any example of via-in-pad and via-on-pad yet. So I am not
sure if I can determine which one is via-on-pad and the other is
via-in-pad
because I can not imagine.
Do they have differences because of design, manufacture, or assemly?
Regards,
Sefika OZKAL
>
>   1. Via-on-pad / via-in-pad
> >
> Date:    Fri, 26 Nov 2004 14:40:57 +0200
> From:    Sefika Ozkal <[log in to unmask]>
> Subject: Via-on-pad / via-in-pad
>
> Hi,
>
> What is the difference between via-in-pad and
> via-on-pad? Can someone
> explain?
>
> Lovely day
>
> Sefika OZKAL
> ASELSAN INC.
> MGEO Division
> Tel:+ 90 312 84 75 300
> Fax:+90 312 84 75 320
> e-mail:[log in to unmask]

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