Hi Matt,

Yes, the hole is drilled right thru the power and ground layers. For those
holes that do connect to one OR the other, most circuit designers use a
"thermal relief" pad on the connecting plane.

For those holes that do not connect to one of those planes, the designer
would use a "clearance pad" or, as some people call them, an "anti-pad" on
those layers. This "pad" (we are now creating a negative image) causes the
copper to be etched away, leaving a safe clearance around the drilled hole.

Hope this helps. Call if I can explain this further for you.

Charlie Barker
281/552-3328
[log in to unmask]



Hi guys,
 I wound up here thanks to Yahoo and I do have aquestion for you,
although I do not know if I am in any position to ask you to answer me.
If I need to sign up for something, could you fill me in.  Anyway my
question is this:  A via passes through a four layer board, is a hole
drilled in the ground and the power layers.  What is used to insulate the
ground and power layers from the solder that eventually will fill this
hole?  Is it a form of mask?  I thought mask prevented it from the top of
a layer (i.e. the top of the board), but not the width if a board is cut.
 Anyway, please get back to me on this.  Thanks.
     Matt
     [log in to unmask]


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