Robotics plays an essential role in automation and robotics systems rely on printed circuit boards (PCBs) to control their electronic operations. Robotics manufacturers strive to find PCBs that meet their specifications without negatively impacting the structure or design of the robot. The PCB connects the components electrically while controlling electronic functions such as control system sensors, motors, user input/output devices, power distribution, and other critical robot components.
There are a variety of considerations when choosing a PCB for a robot. We will guide you through how PCBs fit into robotics, how robot circuit boards work, and what to consider when designing a PCB for robotics.
PCB Components for Robotics
The PCB is critical in controlling and operating electrical components of robotics systems. It controls the primary components in a robot, along with the power supply, body, feedback, actions, and sensors. Automated land, sea, and air vehicles; drones; and other robots rely on PCBs that meet their unique specifications. PCBs make up components including control system sensors of robots and the power distribution board.
How Circuit Boards Work in PCBs
The robotics industry relies on rigid PCBs, flex PCBs, and rigid-flex PCBs to meet specific design requirements.
Rigid printed circuit boards are stiff, and made from a substrate that allows for no twisting or folding of the board. They can be designed with a single layer of circuitry, or two, or many layers, sometimes 50 or more. They include fiberglass substrate layers, copper layers, and then usually solder mask and nomenclature layers which are the printed letters on the PCB. The circuits are etched into the copper layers on the fiberglass substrates, and then the layers are bonded together with a heat-activated adhesive. Rigid PCBs provide several advantages, including their affordability, compact and lightweight design, vibration absorption, and ease of maintenance and repair.
Flexible or flex PCBs can be made of PEEK, polyimide, or polyester films, allowing them to fold and twist. They can be fit to the form required for the application, and perform a similar function as rigid PCBs. Flex PCBs have various benefits, including reliability, repeatability, elimination of connectors, space-saving designs, and thermal management. PEEK and polyester flexible PCBs are very economical but are not used in multilayered applications. Polyimide flexible PCBs can be built into multilayer PCBs and are often very reliable for mission-critical applications.
Rigid-flex PCBs combine the properties of rigid and flex PCBs, allowing the board to be folded on the flex section and electronic interconnection is accomplished in the rigid sections, similar to hard boards. The flex layers are integrated into the multilayer PCB, eliminating connectors and freeing up valuable real estate on the PCB. Also, because they eliminate connectors, rigid flex PCBs are unsurpassed in high reliability and never fail electronic packaging. They excel in high vibration or high shock environments, where traditional connectors with flex cables will fail.
Rigid flex designs tend to be more complex than either rigid or flex PCBs and allow for 3D designs. Rigid-flex PCBs provide various advantages, including high reliability, 360° bendability, lightweight design features, simple assembly, and increased shock resistance. They can also reduce costs when four or more rigid boards are connected with flexible cables.
When selecting a rigid, flex, or rigid-flex PCB, it is critical to consider the design and application of the robot. The shape and size of the robot where the PCB will be affixed, thermal properties, and bendability are all factors to consider when choosing a PCB.
Design Considerations for Robot PCB Components
Implementing the following considerations into the robotics design will help manufacturers avoid delays and production issues:
- Trace Width: The trace defines the capacity for power and ground line currents. It is crucial to have enough trace width capacity and not design traces with a 90° turn. Trace widths that are too narrow can cause heat issues, but excessively wide traces can interfere with adjacent components.
- Thermal Issues: A critical consideration during PCB design is thermal issues. Heat can cause problems for large and complex boards with higher density. Avoid heat problems by allowing heat to dissipate with adequate space between components that heat up or include heat sinks, fans, and thermally conductive planes.
- Lead Times: Design elements can significantly impact lead times. Pouches to protect the PCB during manufacturing increase fabrication steps and drying time. Filled vias, laser vias, and buried vias can also increase lead times and cause yield losses.
- Shape: PCB shape is a primary consideration when creating a board with a suitable size for the components within the constraints of the robot. Rectangular PCBs are popular, but unique shapes are necessary for specialty designs. Rigid-flex PCBs fold at the flex section allowing for design optimization.
- Material: Rare and costly materials can increase lead times and the overall manufacturing cost. Find a balance between cost-effective and high-performance materials.
- Manufacturing Documentation: Good documentation is crucial to an effective design. Dimensional drawings of the hardware and assembly drawings assist in PCB design and assembly. A bill of material (BOM) identifies the components within the PCB. The component placement file is crucial documentation, along with the Gerber file, which generates the layout file and includes the silkscreen, solder mask, drill file, and other necessary documentation.
- Environment: Robots operate in various conditions, including land, air, and sea. The PCB should perform in the intended operating conditions.
- Risk Reduction: Certain factors increase the risk to your PCB. Refining PCB placement can reduce risk and ensure proper space for other components. Protecting circuitry with noise-reducing capacitors, fuses, and Zener diodes will prevent the failure of critical components. Consider system requirements and power ratings along with LED indicators for troubleshooting.
Contact us to learn more about PCB design for robots, or request a quote today.