In the field of electronic and electromechanical components, electrical contacts are fundamental in facilitating interconnections between individual points. The schematic diagram of an electronic device maps out the necessary interconnection pattern that is required to achieve the intended functionality.
While the printed circuit board (PCB) is a key component in electronic products, it alone cannot constitute a finished product. Consequently, there is a need for external connections, including those between PCBs, PCBs and components, or PCBs and product panels. As a result, selecting an optimal interconnection method that amalgamates reliability, manufacturability, and cost-effectiveness factor is a critical aspect of PCB design. Given that various interconnections possess distinct characteristics, it is imperative to carefully choose the appropriate method that aligns with the specific requirements of each design.
What is interconnect PCB ?
Interconnect PCB (Printed Circuit Board) is a type of PCB that facilitates the connection between multiple electronic components or devices on a single board. It comprises a conductive pattern of tracks, pads, and vias that connect different components to each other and to other circuits or power sources. Interconnect PCBs are widely used in a variety of electronic applications, from basic consumer electronics to complex industrial equipment, where a reliable and efficient interconnection between components is crucial for the overall performance and functionality of the device or system.
What Benefits Do Interconnect PCB ?
The reliable interconnect PCB is critical for the functioning of electronic devices as it directly affects the electrical performance, mechanical stability, and long-term durability of the entire system. Here are some reasons why a reliable interconnect PCB is important:
● Improved Electrical Performance: A well-designed and reliable interconnect PCB ensures that the electrical signals are transmitted accurately and reliably between the components, resulting in improved performance and reduced signal loss or distortion.
● Enhanced Mechanical Stability: A reliable interconnect PCB helps to maintain the mechanical stability of the components, preventing them from getting dislodged or damaged during thermal cycling, vibration, or shock. This, in turn, reduces the risk of component failures and improves the overall product reliability.
● Reduced Manufacturing Costs: A reliable interconnect PCB design ensures that the manufacturing process is efficient and streamlined, resulting in reduced costs and improved production yields.
● Easy Troubleshooting and Maintenance: A well-designed interconnect PCB makes it easier to troubleshoot and diagnose faults in the system, enabling faster and more efficient maintenance and repairs.
● Better Product Quality and Customer Satisfaction: A reliable interconnect PCB ensures that the final product meets the desired quality standards, resulting in higher customer satisfaction and improved brand reputation.
Guidelines for Interconnect PCB Design and Manufacture
Design and manufacturing guidelines are essential to ensure that interconnect PCBs are reliable, efficient, and meet the desired performance specifications. Here are some guidelines for interconnect PCB design and manufacture:
● PCB Stackup and Layer Count: The PCB stackup should be designed to minimize signal interference and maintain signal integrity. The layer count should be optimized to provide sufficient routing capacity while avoiding excessive complexity and cost.
● Routing and Trace Width Considerations: The routing of traces should be designed to minimize the length of signal paths and avoid crosstalk or interference from other signals, such as power and ground. Appropriate trace widths must be selected to ensure the necessary current-carrying capacity, while also considering the space constraints and manufacturability.
● Component Placement and Orientation: The placement of components should be optimized to minimize the routing distance and avoid signal interference. The orientation of components should be selected to match the preferred manufacturing process and ensure that the components are easily accessible for inspection and maintenance.
● Manufacturing Tolerances and Process Capability: The design tolerances should be selected to match the manufacturing process capability and ensure efficient, reliable, and repeatable manufacture. An appropriate PCB design for manufacturability (DFM) methodology should be employed to minimize fabrication issues and reduce costs.
● Testing and Reliability Considerations: The PCB design should be tested thoroughly for electrical and mechanical integrity, and a well-designed testing strategy should be employed to ensure reliability. The design and layout should also incorporate reliability enhancing techniques such as proper ESD protection, thermal management, and mechanical strain relief.
By following these guidelines, interconnect PCBs can be designed and manufactured to meet the desired electrical and mechanical performance specifications while ensuring efficient and reliable operation of the electronic system
Printed Circuit Board Interconnection Method
Welding Method
The connection method boasts simplicity, low-cost implementation, high reliability, and circumvents failures that may result from poor contact. However, it also presents certain drawbacks, including limited convenience for interchangeability or maintenance. This method is commonly adopted when there are fewer external leads associated with the component under consideration.
● PCB Wire Welding: This method omits the need for any connectors, as external connection points on the PCB printed board are directly soldered to the components or other components outside the board via wires. Examples of scenarios where this method applies include a speaker in a radio or a battery case.
During the soldering process, it is important to pay attention to the interconnection of the board. The pads of the soldered wires should be positioned as close as possible to the PCB printed board’s edge and uniformly sized to facilitate soldering and maintenance.
Holes should be drilled near the solder joint on the PCB printed board to improve the wire connection’s mechanical strength and prevent the wire or printed wire from becoming detached due to pulling. Through these via holes, the wire should be passed from the surface of the component through the pad hole for soldering.
Neatly arrange or bundle the wires and secure them with wire cards or other fasteners to prevent movement-induced wire breakage.
● PCB Cable Welding: When two PCB printed boards require a connection, a cable junction is often used due to its reliability, but it can be challenging to establish a connection. This method does not limit the relative positions of the two PCB boards.
Another alternative is direct soldering between the PCB printed boards, which is frequently implemented when the boards are oriented at a 90-degree angle. Once joined, the resulting product comprises a single, unified PCB printed board component.
Connector Connection Method
In the case of more complex instruments and equipment, connector-based interconnection is a prevalent method. This “building block” structure ensures the quality of the products manufactured en masse, reduces system costs, and fosters convenience when debugging and conducting maintenance.
When equipment malfunctions, maintenance staff does not need to conduct component-level inspections to trace the source of the issue, ascertaining the failed board is enough to replace it promptly. This approach allows for rapid troubleshooting, reducing downtime and bolstering equipment utilization. The replaced circuit board can be repaired at leisure and used as a spare part once it has been fixed.
● Printed Circuit Board Socket: In complex instruments, an interconnection type that is often used is the printed plug connection. In this method, the plug is produced from the edge of the printed circuit board (PCB) and is designed based on the socket’s size, number of contacts, contact distance, positioning hole location, and other specific requirements necessary to match the customized PCB socket.
During plug fabrication, the plug part undergoes gold plating to enhance wear resistance and reduce contact resistance. This approach is simple to assemble, easily interchangeable, has good maintenance performance, and is suitable for standardized mass production. The disadvantage is that the PCB’s manufacturing cost is elevated, and there are high precision and process requirements associated with printed board manufacturing. This method’s reliability is slightly compromised since the plug portion can oxidize or the socket spring can deteriorate, leading to poor contact. To bolster external connection reliability, cords with equal lead wire taken in parallel pass through same-side or two-side circuit board contacts.
A PCB printed circuit board socket connection method is often chosen for multi-board structure products, featuring two types of reed and pin-type sockets for integration with a socket or the PCB or base plate.
● Standard Pin Connection: This approach is applicable for external connections in printed boards, particularly in small instruments. The method involves integrating the two printed boards through standard pins, which can be either perpendicular or parallel, thereby simplifying mass production.
Considerations for Selecting Interconnect PCB Method
Selecting the right interconnect PCB method is critical for achieving the desired electrical and mechanical performance, as well as managing the cost and lead times. Here are some considerations that can help in the selection of the appropriate interconnect PCB method:
● Electrical Performance: The interconnect PCB method should be selected based on the required electrical performance specifications, such as signal integrity, power distribution, thermal management, etc. This includes selecting the appropriate material, trace width, spacing, impedance control, and other electrical parameters.
● Mechanical Stability: The interconnect PCB method should provide the necessary mechanical stability to support the components and withstand the stresses of temperature variations, vibration, shock, and other environmental factors. This includes selecting the appropriate thickness, layer count, and stacking configuration, as well as the use of stiffeners, adhesives, and other support structures.
● Manufacturing Tolerance and Cost: The interconnect PCB method should be selected based on the required manufacturing tolerances and capability, as well as the overall cost and lead time requirements. This includes selecting the appropriate manufacturing process, material availability, and panel utilization.
● Design Complexity: The interconnect PCB method should be selected based on the required design complexity, such as the number of layers, the density of components, the type of interconnect, and the overall circuit complexity. This includes selecting the appropriate manufacturing capabilities and equipment, as well as the design for manufacturability.
● Volume and Lead Time: The interconnect PCB method should be selected based on the required production volume and lead time requirements, including the availability of raw materials, equipment capacity, and production efficiency.
By considering these factors, and working with a trusted interconnect PCB provider, it is possible to select the most appropriate method to achieve the desired electrical.
Designing for Effective High-Speed Interconnection
For high-speed design interconnectivity, especially for clock signals and triggers in communication interfaces, specific considerations are necessary to ensure optimal system performance, particularly in low-power environments. It is vital to minimize cross talk and excess noise generation among other factors.
Impedance matching is a necessary aspect of high-speed design since it maximizes power transfer and minimizes signal reflection. At high speeds, a signal from a low-impedance source transferring to a high-impedance destination will flip its phase 180 degrees back and forth without proper termination at each end.
For high-speed SPI communication, designers should consider adding in-line resistors or buffers before connecting to an external board. The resistance used should be related to the PCB trace impedance, as using too little resistance will consume a lot of current, while using too much will have little impact on improving signal transfer.
In high-speed signal design, it is recommended to integrate a ground between every other pin on the connector, such that the pins dedicate to the ground continually surround the pins that handle power and signals (for example, pin 1 = power, pin 3 = trigger 1, pin 5 = trigger 2, pin 7 = trigger 3, and pins 2, 4, 6, and 8 are all ground). This method helps reduce inductive coupling and cross talk.
These tried-and-true tips and considerations contribute to effective interconnectivity of PCBs. From the outset, designers should consider the product goals and market and use excellent design software to work through a workflow which takes into consideration the critical aspects of design, test, manufacturing, and servicing, before creating the first board.
Why It’s Important to Define the Appropriate Components ?
There are numerous options available when researching components needed for circuit board assembly, as defined by the design. Although the internet is an excellent source of information, trying to sift through marketing jargon can be challenging.
Meeting with manufacturer representatives is an alternative approach to learn about the latest technologies; however, there is the potential for this interaction to be purely sales-driven. Nonetheless, certain manufacturers may be willing to share their expertise, offer insight into industry standards, share past experiences, and provide samples, resulting in them serving as a valuable resource.
Future Outlook for Interconnect PCB Technology
The future of interconnect PCB technology is driven by the increasing demand for higher performance, functionality, and miniaturization in electronic devices. Here are some trends and developments that are expected to shape the future of interconnect PCB technology:
● High-Speed and Low-Loss Interconnects: The demand for faster data rates and lower signal losses is driving the development of advanced interconnect technologies such as low-loss dielectric materials, signal integrity optimized routing, and embedded passive components.
● Advanced Manufacturing Processes: The use of advanced manufacturing processes such as 3D printing, additive manufacturing, and laser direct imaging is enabling the production of more complex and miniaturized interconnect PCBs, while also reducing the cost and lead times.
● Flexible and Stretchable Circuits: The development of flexible and stretchable interconnect PCBs is enabling the creation of novel applications such as wearable and implantable electronics, soft robotics, and biomedical devices.
● High-Density Integration: The demand for miniaturization and higher component densities is driving the development of advanced stacking and interposer technologies, enabling the integration of multiple layers of components in a single interconnect PCB.
● Material Developments: The use of new materials such as graphene, nanotubes, and other nanomaterials is expected to lead to the development of novel interconnect PCB technologies with improved electrical performance, thermal dissipation, and reliability.
Conclusion
Interconnect PCB technology plays a vital role in the functioning and performance of electronic devices. Designing and manufacturing reliable interconnect PCBs involves considering several factors, such as the electrical and mechanical performance, manufacturing tolerances and process capability, testing, and reliability considerations. Selecting the appropriate interconnect PCB method depends on a range of factors, including the required electrical and mechanical performance specifications, design complexity, manufacturing tolerance and cost, volume, and lead time requirements.
Commonly used interconnect PCB methods, such as surface mount technology, through-hole technology, multi-chip modules, and flexible and rigid-flex PCBs, have their respective advantages and disadvantages. By carefully considering these factors and working with a trusted interconnect PCB provider, it is possible to select the most appropriate method that achieves the desired electrical and mechanical performance while managing the cost and lead times effectively.
In China, JarnisTech is a PCB manufacturing and assembly factory that offers comprehensive Turnkey PCB assembly services ranging from component procurement to PCB assembly. If you Next one PCB project requiring our services, we encourage you to contact us without hesitation.