Whether you’re an expert engineer or an at-home inventor, you’ve likely designed PCBs that fail due to a short circuit or burnt-out component. PCB designs are incredibly intricate, and you’re not alone in your trial and error. Circumvent some of these hard lessons by checking out these tips to optimize your PCB layout for a better performing PCB.

Research                                                                                                                   

Before you begin drawing up the plans for your next PCB, pause for a moment to consider why. Is your goal to improve an existing circuit board? Are you dreaming of an entirely innovative concept? Whichever your reason, make sure you know your end goal and research whether there are existing circuit board templates that you can use. This pre-work will save you a ton of time and keep you from reinventing the wheel if a solution already exists. You’ll also avoid repeating the mishaps of others when designing your PCB layout.

Create a Blueprint

Once you’re set on the outcome you’re hoping to achieve, it’s time to put your ideas into something tangible. Start with a hand-drawn sketch to map out your circuit board. This will allow you to see the flow and catch any errors before adding in the complication of technology. You can also have colleagues or other PCB hobbyists review your circuit board layout ideas for input before creating your virtual design.

Use a (Free) PCB Software

With your blueprint in hand, you’re ready to start designing the layout of your PCB. The best way to create a PCB layout is by using free PCB design software, like Advanced Circuit’s PCB Artist. PCB design software, like PCB Artist, will give you access to a components library with over 500,000 parts. It’s incredibly easy to search for a previously used component, add it, and rearrange as needed for your PCB layout. Never pay money to use PCB design software, as there are so many excellent free choices on the market.

This digital blueprint that you create using a PCB software is called a schematic. In your schematic, you’ll place your components, connectors, connections, and power sources. Eventually, this will become your PCB design that a manufacturer will use to create your PCB.

Most free PCB design software also comes with a design rule check so you can be confident that your PCB layout works and can be produced by the manufacturer of your choice.

Placement

The placement of your components during the schematics stage is incredibly critical to the viability of your PCB. Typically, you want to start by placing your most essential elements first, and then go from there with any flairs or add-ons. Keep in mind that you don’t want to overcrowd your PCB. Placing components and active elements too close together can result in high temperatures. Overheating your PCB can cause components to burn and, ultimately, lead to your PCB failing.

You’ll also want to check with the manufacturer, and during the design, rule check to see if there are placement restrictions. In general, you want to leave at least 100 mils of space between any component and the edge of your PCB. You also want to evenly space out your components and organize so that like-components are oriented the same direction, as possible.

Routing

As you plan and design your PCB’s layout, you’ll want to consider the different routing options and specifications. On a finished PCB, the routing is the copper traces that run along the green board and indicate the flow of electricity between the components. The general rule of thumb is to make the route distance between elements as short and direct as possible. You also want to make sure that you make your traces wide enough to handle the high temperatures in an electrical circuit. When in doubt about your PCB overheating, you can always add in via, or holes, to channel electricity to the other side of the PCB.

Layers

Thanks to advances in our scientific understanding of electricity and circuits, we can now easily manufacture PCBs with multiple layers. The more layers you have on a PCB layout, the more complex your circuit will be. Extra layers allow you to add in more components and tends to have higher connectivity.

Multilayer PCBs appear in more sophisticated electrical devices, but if you find your PCB layout is becoming overcrowded, this could be an excellent way to problem-solve. Multilayer PCB designs do come with higher costs, but Advanced Circuits offers excellent deals on two and four-layer PCB fabrication.

PCB Manufacturer

You’ve put in the hard work and effort to design your PCB, so make sure you select a manufacturer that can bring your plan to life. Different PCB manufacturers use different fabrication processes and use varying qualities of components. It would be a shame to have an incredible PCB layout, only to receive a low-quality product with a lousy soldering job or faulty components. Choosing a manufacturer that uses surface mounting technology is your best bet for a PCB that precisely represents your PCB layout. This fabrication method is mostly automated and reduces the risk of human error when creating your physical PCB.

Create a Prototype

Even if you’re 100% confident in your PCB, it’s always a good idea to order a prototype. Even experts know that you’ll likely want to make tweaks to your PCB design once you see how your prototype performs in its given application. After testing out your prototype, you can go back to the drawing board and update your PCB layout for optimal output.

Advanced Circuits Can Help

Advanced Circuits is the third largest PCB manufacturer in the U.S. Their company has you covered from beginning to end in your PCB layout process. You can utilize their free PCB design software and file check to ensure your layout is bug-free and ready to go. Advanced Circuits has an incredibly accurate fabrication process that will ensure your PCB is delivered precisely as you designed it.

Layout is so critical to electronic products that in some PCB design teams, designs are passed to specialized layout technicians for implementing best practices and to avoid known placement considerations. In most cases, sophisticated computer aided design (CAD) software is utilized to maximize efficiency, detect potential design issues, and warn of obvious errors.

Some of the key factors in successful PCB layout are:

• Experience – design experience contributes greatly to quality results, for both simple and complex PCB designs.
• Tools – robust toolsets such as CAD and Design for Manufacturing (DFM) computer applications have become a must for designing today’s complex PCBs.
• Adherence to guidelines and best practices – there are many generally accepted guidelines and best practices that can be beneficial in developing PCB layout, all the way through the manufacturing and testing processes.

Guidelines for PCB Layout

Some guidelines will be more relevant toward specific types of PCBs than others, such as those pertaining to specific use like flexible PCBs, multilayer boards, and specialized technology including high-density interconnect boards. But there are also a number of guidelines that lend themselves to many disciplines:

General guidelines

Start with a rough plan – a general design that illustrates proposed components and layout will generate a good working plan for proceeding with detailed circuit engineering and PCB layout.

Physical board constraints – determine any factors that influence design

• Size of the board – predetermined dimension requirements
• Materials – need for use of specific board materials will drive component use
• Connectivity – how the board will be mounted or installed will strongly influence layout, as connection points and methods could impact component placement

Estimates – once board components and dimensions are determined, evaluate whether or not the combination of devices and the necessary traces will accommodate the board size.

Layers – determine the need for multiple layers, how connections will be routed among layers, and whether or not the resulting design can be fabricated by the manufacturer.

Planes – along with layer design, consider how power and ground planes will be implemented, with a best practice being to separate the two to minimize electromagnetic interference (EMI) and manage power efficiently. Avoid using partial planes to avoid warping, laminating issues, soldering, and other manufacturing problems. Such construction problems can lead to board reliability issues or total failure.

Trace Guidelines

Traces need to be considered early in the design to avoid a number of PCB issues.

Trace width – traces that are too close and too narrow can result in shorting conditions. Conversely, traces positioned too widely can increase the real estate needed on the board, increasing size, number of layers required, and/or cost.

Trace power capacity – depending on the amount of current to be handled by an individual trace and the board construction, trace width may need to be increased.

Pad and hole size and ratio – by determining the pad/hole ratio and size during initial design, tolerances can be calculated for hole drilling and other considerations. This may vary by manufacturer, making consulting with the intended fabricator early in the process very beneficial. This is even more critical as PCBs continue to shrink in size, and via holes are accordingly critical, as well.

Pad shapes – pad size and shape can vary depending on the components to be incorporated and the manufacturing processes to be utilized. This will impact the PCB layout. Here again, consult with the PCB manufacturer early in the process to ensure the board design adheres to manufacturing standards.

Thermal issues – if board functions will incorporate components that are significant heat generators, allow for dissipation tolerance or heat sink requirements.

EMI/EMC considerations

PCBs are subject to such common problems as electromagnetic interference, electromagnetic compatibility, and other undesirable elements. Avoiding such issues and the resulting board defects requires attention to detail in ground placement and trace angles that tend to increase EMI.

Parallel traces in close proximity can generate crosstalk that generates board performance or failure issues. Where traces actually must cross, a best practice for minimizing capacitance and induction problems is to have them cross at right angles.

Methodology for Solving PCB Layout Problems

Many PCB layout challenges can be avoided by the adherence to basic guidelines, but experience is still an attribute that cannot be over-emphasized. An experienced PCB layout technician, armed with sophisticated and up-to-date design software is the best possible scenario for development of PCBs that will function as designed, and will also be translatable to efficient manufacturing.

Software programs are available today – some at little or no cost – that provide PCB engineers with drag-and-drop simplicity in design and layout functions. Computer aided design and manufacturing (CAD/CAM) systems are today considered essential components in the development of more complex and technical circuit design and fabrication.

Design for manufacturing (DFM) tools are the next step before actual PCB production, validating the design and detecting areas that could potentially generate problems in the manufacturing process.