PCB Layout Guide
Designing your board is very important and exiting stage in the PCB development. There are many limitations and requirements that need you need to remember when designing it. Making a mistake in the design phase will cause starting all over again and result in starting another production if it is not caugt in the design phase. This article will take you through the basic of PCB Layout and guide you through the important steps to remember. At the end of the article we have summed up of the most common mistake done by PCB designers, in order to avoid you making them in your board.
What does the PCB Layout files contain?
The final PCB Layout files should be your Gerber files. The Gerber files is a 2D vector image that has been the industry standard for PCB fabrication data for a long time. The Gerber files describe how the board looks, the location of the holes, vias, lines, copper, silkscreen, outline etc. The Gerber files contains each image file for each individual filetype, additional layer will also have their individual files. A simple way to understand what Gerber files is, to see the Gerber files as the recipes for the manufacture to make the board.
What should you consider when designing your board?
When you need to have your board designed and be ready for production you must clarify the need and functionality of the board. In order to get an overview of your board and its functions it is recommended to make a schematic of your design. With this schematic it will be easier to understand the design and be a guide for the traces and where component should be placed. It can also be used to explain for the designer your needs or it can be used as a check-up of the finished design. Furthermore, it is always good to have a reference and overview of the idea.
When designing the board, you need to know the limitation as size, thickness, shape and its capabilities. What capabilities should the board have, should it have Bluetooth, Wi-Fi, NFC, etc. These capabilities will have impact in the way you are designing your board, because each technology is requiring special design rules. Therefore, it is important to understand the design rules of the technology that are applied to the board when designing it.
If you are an experienced PCB designer you can make the design yourself. Another option is that you can outsource it to an experienced designer, depending on your skills, the designer might route your board more efficacy, which is good if you have real estate or design rule issues.
- Manufacture specification:
- When you are routing your board, it is good to know your manufactures specification on trace spacing, number of layers, trace widths etc. If you design your board, and the manufacture can’t produce your board you might end up reroute your board design or find new manufacture.
- Avoid using multiple hole size:
- When designing your board, we recommend not to use too many different holes size. Different holes in your design will result in that the manufacture have to use different drills. This will in the end make your board more expensive.
- Make sure your material is on stock:
- Make sure if you design a complex board that required material is on stock. If you are using a unique material that is not on stock at your manufacture, you must add up extra lead time in your planning. Some material can add up surprisingly a lot of days extra.
- Always make a DFM Analyse:
- Making a DFM analyse is always something we recommend our customers, if there any mistake in your design, for example that could short circuits your board, is good to know before your board has been produced.
- Back up:
- Always back up your latest design. There is nothing worse than redo your work from beginning because you did not have a backup. With all the cloud option that’s available today, it is the worst thing that can happen to your work and add unnecessary extra time for getting your finished board.
- Doing holiday season, the manufactures will be busy, have in mind if there are any upcoming holidays in your manufacturing country to avoid extra lead time. In some cases, the holiday might have a huge impact in other countries, this will add extra days to manufacture, simply because the huge increase in demand.
Creating your Layout files for the first time, can be time consuming and result in that you have to redesign the board a couple of time, but in the long run it will help you to create better boards. There are plenty of help to get from experts, that only work to help with PCB layout. Seeking help for the couple of first projects is normal and will help you get a better understanding of the PCB Layout universe.