Once you have designed your printed circuit board, it’s time to send off the schematics to a fabricator, also called a PCB manufacturer. This is the point at which the project leaves your hands – there are no further chances to make changes or to catch errors. You cannot build in any additional functionality, troubleshoot your design work, or anything else. As you might imagine, this is a critical time in the creation of your board, so it pays to know a few things about working with a PCB manufacturer.
Before you send your design to the PCB manufacturer, there are a few things that you should do. Remember – this is your final chance to make sure that your board design lives up to your expectations. To that end, make sure that you:
- Print Out the Layout: Physically print the board design on paper and make sure that everything fits. If there is even a small amount out of tolerance, it’s time to address that.
- Check for Functionality: Make sure that your components are all in place, that your traces are properly sized, that you have no 90-degree angles (to avoid partial etching and the resulting shorts), and more. As much as you can, check functionality and placement one last time before sending the design out.
- Double Check Tolerances: Verify with your PCB manufacturer what their tolerances are and then ensure that your design meets those requirements. In most cases, you can simply build those tolerances into your design with your PCB software, such as our free PCB Artist software. Just run a quick manufacturability check based on those tolerances and you should be alerted to any issues, which can then be rectified.
- Double Check the Space Requirements: When adding components to your PCB, make sure that you leave enough space between them. You need to account for traces, but also to help alleviate heat buildup, to reduce resistance, and more. Don’t forget that you will also need to leave room for things like buttons and other components that are not part of the PCB layout, too. Accurate size estimation from the beginning stages is essential to success.
Know the PCB Manufacturing Process
It is important to understand the process followed by the PCB manufacturer once you send your design to them. After design, which is the part you handle, the next step is printing. The PCB manufacturer will check your design to ensure that it meets design tolerances. Note that this check does not necessarily mean that your board works to your expectations – most DFM checks are strictly to ensure that the board fulfills the tolerances necessary for manufacturing. (When you work with Advanced Circuits you can take advantage of our FreeDFM tool, to ensure your design is free of manufacturability issues.)
A plotter printer will then be used to print the PCB. This type of printer uses a transparent film to create a negative image of the board. Black and clear ink are used to represent traces and circuits, as well as non-conductive areas of the board (clear ink). With outer board layers, the colors are reversed, with black indicating non-conductive parts and clear ink used for components. A soldering mask is added, and then a registration hole is punched through the film to help align each one into the appropriate layer.
Next up, the manufacturer prints the copper layer for the board’s interior layers, then unnecessary copper is removed. Finally, the entire thing is sandwiched together into a single board and inspected, the layers are laminated, drilling takes place, and plating occurs. A final etching then occurs, followed by the application of the solder mask, silk-screening, and a final reliability test.
Of course, it helps if you have chosen the right PCB manufacturer in the first place. What should you consider when choosing one?
Choosing a PCB Manufacturer
You’ll find many important considerations when choosing a PCB manufacturer. There are numerous fabricators available, but they are by no means created equal. Some are budget-oriented options, while others are geared for working with major tech companies. Here are a few of the more critical considerations to make before choosing a partner:
- Lead Time: Some PCB manufacturers have very long lead times. Make sure you know the lead time requirements of any you are considering working with, as this will have a huge impact on your overall project.
- File Type: Make sure that the PCB manufacturer that you choose accepts the file type(s) that you want to send. Some of the more common types used today include KiCad, Gerber, and EAGLE.
- Minimum Time to Shipment: In addition to lead time, you’ll need to think about the company’s minimum time to shipment. Basically, this is a specified period that occurs before your order can be shipped. Some companies have very low requirements, but others have lengthy periods that may be a week or more.
- Order Quantity: How many boards do you need to print? Are you interested in one or two prototypes for testing? Do you need a full production run? Make sure that the PCB manufacturer you choose is able to meet your quantity requirements. Some companies will only print larger quantities, while others are more flexible.
- Software Availability: Ideally, you’ll work with a PCB manufacturer that makes design software available to you. At Advanced Circuits, we offer one of the most robust design tools in the industry – PCB Artist – free of charge. It can handle all of your design needs and seamlessly export the design when you’re ready to print.
Our Position as an Industry Leader
Ultimately, the right PCB manufacturer will help you bring your designs to life. Make sure that you check their reputation, the quality of their manufacturing process, their lead time and minimum time to shipment, minimum order quantity, and whether they offer access to free design software or not. At Advanced Circuits, we’re proud of our position as an industry leader, as well as our ability to offer our customers the flexibility they need. Whether you’re printing off a handful of prototypes, or you’re ready to go to market with a full production run, we can help.