Pre-layout Stage

Parent page: Laying out Your PCB

This documentation section describes what is needed to get started with a PCB design. Refer to the pages below to learn about the following topics:

• Defining the Board Shape – the Board Shape, also referred to as the board outline, is a closed polygonal shape that defines the overall extents of the board. The Board Shape can be made up of a single Board Region (for a traditional rigid PCB) or multiple board regions (for a rigid-flex PCB).
• Defining the Layer Stack – in printed circuit board design, the layer stack defines how the layers are arranged in the vertical direction, or Z plane. Since it is fabricated as a single entity, any type of board, including a rigid-flex board, must be designed as a single entity.
• Blind, Buried & Micro Via Definition – vias are used to span, or connect between the copper layers. If the via passes from the top surface of the board to the bottom surface, it is called a through hole via, thruhole via, or thru via. It is also possible to create vias that span other layers, by creating the vias at specific points during the fabrication process. These types of vias fall into two groups: blind and buried vias, and microvias (µVias). All of these Via Types are supported in Altium NEXUS.
• Working with Object Specific Keepouts on a Board – as well as the board shape, you should also define a placement and routing boundary around the edge of the board. This is done by placing objects on the keepout layer. Objects placed on this layer  define 'no-go' zones for components and routing. Typically, you would define a shape just in from the edge of the board to restrict components and routing from being placed to close to the edge of the board. You can also define other routing and component keepouts areas for mechanical objects such as screw heads, or other mounting requirements.
• Defining, Scoping & Managing PCB Design Rules – the PCB editor uses the concept of Design Rules to define the requirements of a design. These rules collectively form an 'instruction set' for the PCB editor to follow. They cover every aspect of the design – from routing widths, clearances, plane connection styles, routing via styles, etc.
• Working with Rooms on a PCB – a room is a region that assists in the placement of components by defining an area where components can either be kept within or kept out. It can also be used to define design requirements for a specific board area different from those for the rest of the board.