PCB Design Process & Workflow
There are 11 steps to the PCB design process & work flow which we cover in the pcb design guide.
Step 1: Finalize your Circuit Design – Everything starts with the circuit design. Without a circuit there is no need for a pcb. In the old days most circuits were hand drawn and later captured electronically. In today’s world of modern computing, the circuit design is capture directly into a schematic. For the sake of clarity we’ve added this as step 1 in the pcb design guide.
Step 2: Choose PCB Design Software – Many times electrical engineers don’t have a choice when it comes to choosing the pcb design software. Their companies have invested thousands into software packages and all their legacy design are captures in those packages, and therefore are “stuck”. However the hobbiest has several choices. Its important to choose a package that is first and foremost easy to use, but also capable of completing the pcb design as some packages won’t be able to handle the complexity.
Step 3: Capture Your Schematic – As mentioned earlier its likely that the circuit design is being captured electronically from the start. In general “capturing the schematic” is the process by which each component is drawn electronically and are interconnected with each other.
Step 4: Design Component Footprints – Once the schematic is complete its time to draw the physical outline of each of the components. These outlines are what are placed on the pcb in copper to allow the components to be soldered to the printed wiring board.
Step 5: Establish PCB Outline – Each project will have restrictions related to the board outline. This should be determined in this step since an idea of component count and area should be known.
Step 6: Setup Design Rules – With the pcb outline and pcb footprints complete is just about time to start the placement. Before placement thought you should setup the design rules to ensure that components or traces aren’t to close together. This is only one example as there are probably hundreds of different rules that can be applied to a pcb design.
Step 7: Place Components – Now its time to move each component onto the pcb and begin the tedious work of making all those components fit together. This is where you’ll find that pcb design is really a jigsaw puzzle.
Step 8: Manual Route Traces – It’s necessary to manually route critical traces. Clocks. Power. Sensitive analog traces. Once that’s complete you can turn it over to Step 9.
Step 9: Using the Auto Router – There are a handful of rules that will need to be applied for using an autorouter, but doing so will save you hours if not days of routing traces.
Step 10: Run Design Rule Checker – Most pcb design software packages have a very good setup of design rule checkers. Its easy to violate pcb spacing rules and this will pinpoint the error saving you from having to respin the pcb.
Step 11: Output Gerber Files – Once the board is error free it’s time to output the gerber files. These files are universal and are needed by the pcb fabrication houses to manufacture your printed circuit board.