Transition to Layout
Once you’ve finished and cleaned up your schematics, you now have a complete set of electrical drawings you can use to prepare your PCB. What happens next is making the transition into a PCB layout. We’re finally to the point where we can start to place real components into a board and creating a new design.
However, there are some tasks to take care of first. The typical workflow in PCB design is to create an unpopulated board first, and then place the components onto the board. By “unpopulated,” we mean the board does not have any components on it. We’ll look at how to do this first, then we can start importing components into the board.
Creating an Unpopulated Circuit Board
This step is as simple as it sounds: you’re creating a new PCB layout file in your project. This PCB layout file will, by default, have no components and will generally have a square or rectangular shape. When a new PCB layout file, there are two tasks involved:
- Define the board size and shape. The default board shape and dimensions need to be changed to fit your design requirements. The board size and shape are usually defined in advance by another engineer, or they may be constrained by the size of your enclosure.
- Define the PCB stackup. You’ll need to select the number of layers you need and choose plane and signal layers. You’ll also need to define the thickness of the laminate layers in your PCB stackup.
It’s common to do some work before creating the PCB to determine the board size and number of layers you need. If you do these tasks first, you typically won’t need to change the board shape or the layer stack later. However, people sometimes make mistakes, or your project requirements might change, and you might need to change the stackup or board shape. ECAD software will allow you to change these aspects of the board later as needed.
ECAD software will allow you to define just about any board shape you want, including curved boards.
In Altium Designer, you can create a new PCB layout file with the “Add New to Project” feature. Open up DemoProject from your Altium 365 Workspace, and add a new PCB to your project. Save this new board in your project folder with the File → Save command, or hit Ctrl+S. Once you’ve created the new PCB, you can start the above tasks.