PCB Via-hole (VIA) Symbol

A PCB via-hole (VIA) symbol consists of graphics, which make up the representation of the PCB via-hole object. A PCB via-hole symbol is an ordinary symbol object, there is no any difference between a via-hole symbol and other symbols used by CADint PCB.

However, a PCB via-hole must meet three conditions to be fully accessible as a via-hole object:

• the name of the PCB via-hole symbol must be constructed as VIA.XXX (main type symbol is VIA see Symbol Naming Conventions),
  
  
• at least one graphics primitive must be placed on any of Copper layers (usually a filled circle primitive),
  
  
• the PCB via-hole symbol must be stored in the VIAPADSTACKS PCB symbol library class.

  The PCB via-hole symbol is used to display a PCB via-hole object on the PCB document.

  A PCB via-hole symbol consists of graphics, which represent the physical via-hole. The following is an example of a PCB via-holes types supported on the PCB document:

  

  Figure The Via-hole types in CADint PCB (6-layers board).

  On the multi-layer board, you can use a Copper Inner layer to define shapes of the Via-hole on all inner-layers of the PCB board. This layer is a generic inner layer and shapes placed on this layer are repeated on all copper inner-layers.

  CADint supports the following via-holes types: Through via-hole, blind top, buried and blind bottom via-hole.

  A type of via-hole is dynamically retrieved from the contents of the Via-hole's padstack definition (only copper layers).

  To build a via-hole of the proper type, place graphics primitives on copper layers which should be interconnected on the PCB board (Remember that shapes placed on the Copper Inner layer will be repeated on all inner layers).

  Below is an example of the through via-hole definition and its mapping to 6-layer PCB board:

  

  Figure The Through Via-hole mapping (6-layers PCB board).

  Below is an example of the definition of the blind top via-hole and its mapping to 6-layer PCB board:

  

  Figure The Blind Via-hole mapping (6-layers PCB board).

  Below is an example of the definition of the blind top via-hole and its mapping to 6-layer PCB board:

  

  Figure The Buried Via mapping (6-layers PCB board).

  Below is an example of the definition of the blind bottom via-hole and its mapping to 6-layer PCB board:

  

  Figure The Blind Via-hole mapping (6-layers PCB board).