Managing Your PCB Design Project There is no question about it. Coming up with innovative ideas for circuits can be a great deal of fun and extremely satisfying. Quite often, the PCB design step is where a promising project gets bogged down. Here are some tips to take you from beginning to end for a board design. Schematic Refinements Putting as much information on the schematic as possible before starting the board design is an excellent strategy. Letting the drawings show the flow will improve many schematics. The signal can be traced from input to output by following the schematic from left to right in this way. Modularizing is the second thing. Power supply and signal processing are functions which should be separated on the page or moved onto different pages altogether. Also, consider placing specific part and packaging information for each component as part of the identification tags. Component Placement With the up-front work done in the schematic stage, a designer can jump straight to component placement. Start by placing the external or inter-board connectors. These are typically the critical components that must be coordinated with the project housing or other PCBs. Then position the large components. A great deal of spacing for isolation between parts, trace placement between parts, and thermal management is necessary. Direction can be taken from the schematic. Debugging is much easier if the signal flows from one side of the board to the other. High generation components, like power supply transformers, must not be placed near sensitive input components, such as first stage amplifiers; this is very important. Component Alignment A very good strategy for component placement is to utilize standard alignments. Place all ICs in the exact same direction, either vertically or horizontally for example. Pin 1 markers need to all be pointing in the same direction. All polarized components, such as electrolytic capacitors and diodes need to follow a similar philosophy. To indicate the positive leads, use square pads. Design the Ground Plane and Place Power Traces Most two-sided PCBs place all of the components on one side of the board and reserve the second side for the ground plane. This helps regulate noise and coupling problems by ensuring that every ground point on the component side of the board can connect straight to ground. It also allows the ground plane to terminate fields from high-generation components like power supply transformers. It is typically a good idea to place pads on the ground plane as well. The ground plane is not going to act like a heat sink in the soldering phase of assembly as a result. It also makes it a lot easier to rework ground joints if required. The next thing is the placement of power traces. They can be made wider to address larger current requirements. Bypass capacitors which control power supply noise need to be placed as close to the power pins of critical components (ICs) as possible.
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Managing Your PCB Design Project Trace Routing Completion By incorporating the signal trace, designer are able to complete their boards. A good design guide is to use 10 mil traces with 10 mil separation on a 10 mil snap grid. Through the performance of an automatic check against the schematic, a lot of software packages allow the designer to validate correct placement. Trust the Experts Once designers jump in and design a circuit, they often end up enjoying it as much as coming up with the design in the first place. Consider using the design services of the fab house if this is not the case. Many can start with only a schematic, or even just a description of the functions, and produce a manufacturable PCB design. There is no question about it. Coming up with innovative ideas for circuits can be a great deal of fun and extremely sat...
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