Technically, all plated through holes are vias, or pathways of
     connection from one layer to another.  Those holes into which
     components leads will be soldered or otherwise mounted are termed
     "component holes".  Those holes whose sole purpose is layer to layer
     interconnection are termed "vias".  Component holes must be sized
     accordingly to accommodate the particular component leads.  Other
     requirements such as annular ring, plated copper through the hole,
     etc. will vary around the specific application.  Via holes are
     typically sized as small as possible (allowing for proper current
     carrying requirements) in order to not take up more real estate than
     is necessary.  Again, features such as annular ring, copper thickness,
     etc. will vary depending on the application of the circuit board.
     These requirements are not necessarily the same as for component holes
     on the same board.

     Hope this helps...Andy


______________________________ Reply Separator _________________________________
Subject: [TN] VIA HOLE and COMPONENT HOLE DEFINITION
Author:  "raymund b. honorio" <[log in to unmask]> at SMTPLink-Hadco
Date:    06/11/98 1:55 PM


What is the difference between a via hole and a component hole?  How do you
distinguish these two types of holes in a PCB?

thanks in advance for any information.

regina

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