Most PCB designers have designed their boards in mostly rectangular or square shapes. However, when the enclosure is in an irregular shape, they have two choices—to continue with a rectangular/square shape that is considerably smaller than the enclosure or to design irregularly shaped PCBs that closely match the enclosure shape. In the first case, the total real estate available to the designer may reduce considerably, and this may or may not be adequate for the circuit. In the second case, although more real estate is available on the board, the PCB manufacturer and assembler may add a surcharge and additional turnaround time to their PCB quotations for the irregular shape of the PCB. However, eminent manufacturers and assemblers like PCB Trace Technologies Inc. show no such preferential treatment for the PCB shape.
Circuit boards being the backbone of electronic devices, provide a platform for mounting electronic components, allowing them to electrically connect and function seamlessly.
PCB designers, manufacturers, and assemblers are more used to standard shapes such as squares, rectangles, and circles. However, the advancement of technology and the increasing demand for innovative and compact devices are increasing the popularity of irregularly shaped PCBs. Non-standard shapes follow a separate path from the constraints of traditional designs while offering new and more exciting possibilities for designers and engineers.
Circuit Board Shapes
Circuit boards are always evolving to meet the changing demands of the electronic industry. Initially, electronic equipment was mostly large and capable of accommodating simple and rectangular circuit boards. With the progress of technology, more complex but smaller electronic devices prevailed, leading to the introduction of other form factors like oval, circular, square, and triangular circuit boards. More recently, irregular circuit boards have gained popularity, pushing the boundaries of functionality and design.
Why Irregular Circuit Boards?
Specific design requirements demand irregularly shaped circuit boards. Among these requirements are conforming to specific spatial constraints, fitting into non-standard enclosures, or complimenting the aesthetic appeal of a product. Deviating from the standard and traditional shapes allows designers and engineers to overcome limitations and create innovative solutions for various applications.
Benefits of Irregular Shapes
Designing circuit boards in irregular shapes has many advantages:
Improved Design Flexibility
With irregularly shaped boards, designers gain increased flexibility not only in terms of fitting them into unique shapes but also in aesthetics. They can customize the shape to match the contours of the product enclosure, making the maximum use of the available space. This allows designers to create visually appealing products with elegant and ergonomic designs, taking advantage of the irregularly shaped circuit board.
Optimum Use of Space
The main advantage of an irregularly shaped circuit board is its ability to make optimum utilization of space. The designer can utilize every nook and cranny within the device, maximizing the functionality of the product without compromising on its performance. They can tailor the irregular shape to fit around other components, allowing effective use of available space, while reducing the overall size of the device.
Improved Functionality
With irregularly shaped circuit boards, designers can integrate additional components and features, improving functionality. Designers often face limitations with traditional rectangular boards when they have to add extra elements. On the other hand, irregularly shaped boards provide more surface area, accommodating connectors, specialized sensors, or batteries, improving device capabilities.
Improved Signal Integrity
Wireless connectivity and other high-frequency applications of electronic equipment require signal integrity. With irregularly shaped circuit boards, designers have better control over signal paths, thereby reducing the risk of noise interference. Designers can ensure optimal performance and minimize signal loss by carefully designing the shape of the circuit board.
Reduced Electromagnetic Interference
Irregularly shaped circuit boards can also help mitigate EMI or electromagnetic interference. Designers often incorporate unique shapes and place components strategically to minimize the impact of EMI on the circuit board. This is specifically necessary in sensitive applications like automotive electronics or medical devices, where EMI can compromise safety by disrupting performance.
Irregularly Shaped PCB Applications
Wearable Electronics
With the proliferation of wearable devices like fitness trackers and smartwatches, there is an increasing need for flexible and compact circuit boards that allow the device to fit comfortably on the wearer’s body. It is easy to seamlessly integrate an irregularly shaped circuit board into a wearable product, thereby offering a sleek and ergonomic product while enhancing functionality.
Internet of Things
IoT or the Internet of Things makes use of interconnected devices that communicate with each other. Irregular board shapes allow engineers to seamlessly embed IoT devices within various objects like industrial equipment or home appliances. Irregularly shaped circuit boards are flexible enough to allow their integration into everyday objects, transforming them into becoming smart and connected.
Automotive Electronics
Modern vehicles incorporate an astonishing number of electronic systems for enhancing safety, navigation, and entertainment. Irregularly shaped circuit boards allow efficient use of the limited space within the interior of a vehicle. By customizing the board to fit into limited spaces, automotive engineers enhance the overall performance and functionality of the electronic systems in vehicles.
Medical Electronics
Medical electronic devices must often be compact. They use specialized circuit boards to meet stringent design requirements. Irregularly shaped circuit boards allow designers to precisely integrate microcontrollers, sensors, and other components, thereby allowing the creation of cutting-edge medical devices with improved reliability and accuracy.
Design Considerations for Irregularly Shaped PCBs
Every design of an irregularly shaped circuit board has its own set of challenges and considerations. Some key aspects that designers must focus on are:
Component Placement
Designers must carefully consider component placement on irregularly shaped PCBs. They must ensure the strategic positioning of components to optimize functionality while aiming to minimize signal interference and simplify the manufacturing process.
Routing Challenges
Designers can find it more complex to route traces on irregularly shaped boards, as compared to that on regular boards. They must plan the routing paths to avoid signal degradation, excessive signal loss, or crosstalk. They can make use of CAD software for effectively routing traces on such boards.
Mechanical Constraints
The device’s form factor or enclosure often dictates the mechanical constraints leading to the irregular shape of the circuit board. Designers must make sure the board will fit precisely while taking into account the connectors, fastening mechanisms, and other mechanical considerations.
Manufacturing Challenges of Irregularly Shaped PCBs
Although offering numerous benefits, irregularly shaped circuit boards pose certain challenges for manufacturing. These can include:
Custom Tooling
Custom tooling and specialized equipment are necessary to obtain the irregular shape of the board when manufacturing it. Manufacturers need to invest in developing these new tools and processes to create boards with non-standard shapes. Prototyping is necessary for testing the feasibility of the irregular shape before large-scale production can begin.
Assembly and Soldering
Assembling and soldering components on irregularly shaped boards can be more complex than they are for standard shapes. Operators need to pay special attention to ensure proper alignment of components during assembly. The irregular shape of the board may also need adaptations in the soldering technique.
Inspection and Testing
Non-standard board shapes may not allow the use of standard inspection and testing processes. This is mainly due to the inability of standard fixtures to hold the irregularly shaped board reliably during the inspection and testing procedures. Manufacturers may have to develop specialized fixtures and processes to ensure the reliability and performance of these boards.
Manufacturing Irregularly Shaped PCBs
Although manufacturing irregularly shaped PCBs is almost similar to that of regular boards, additional considerations are involved:
Design Software
For designing irregularly shaped circuit boards, designers must use specialized PCB design software that allows the handling of complex shapes and has advanced routing capabilities. With such software, engineers can effectively create and optimize the layout on irregularly shaped boards.
Prototyping and Production
Prototyping an irregularly shaped board is crucial to validate its performance and functionality, both mechanically and electrically. On successful verification, production can commence. To ensure high-quality fabrication and assembly of irregularly shaped boards, manufacturers must have considerable experience.
Cost Considerations
Most importantly, manufacturing and assembly of irregularly shaped circuit boards may incur additional costs, as compared to regular boards. The complexity of the design may require specialized manufacturing processes, unique tooling requirements, and newer inspection and testing methods. All this can contribute to higher production costs. Designers must evaluate the trade-offs between cost and design requirements.
Innovations and Future Trends
With the arena of irregularly shaped circuit boards evolving continuously, research and innovation are also ongoing in parallel. Innovative flexible and bendable circuit boards are already in the market, soon to be followed by 3-D printed circuit boards, and the use of advanced materials for miniaturization and improved performance.
Conclusion
For electronic devices, especially with reduced form factors, irregularly shaped PCBs offer a new realm of possibilities. These benefits come in the form of increased design flexibility, enhanced functionality, space utilization, and improved signal integrity. Such boards are now becoming a compelling choice for designers and engineers. PCB Trace Technologies Inc. proposes addressing the new challenges carefully to allow irregularly shaped circuit boards to realize their full potential in the electronic industry.
