Choosing the right board-to-board connectors is a crucial aspect of designing and manufacturing electronic devices. These connectors provide essential links between printed circuit boards (PCBs) and are used in a wide range of applications, from consumer electronics to industrial systems. With the ever-increasing demand for high-speed data transmission and miniaturization, selecting the appropriate connector is more important than ever. This blog post aims to guide you through the various types of board-to-board connectors, their applications, and factors to consider when selecting the right connector for your project.
Key Takeaways
- Understanding Board-to-Board Connectors requires careful consideration of various factors to ensure optimal performance.
- There are a variety of mounting, customization and packaging options available for board-to-board connectors that must be taken into account when selecting the right connector. – Polarized connectors guarantee correct connection between mating headers and sockets for reliable PCB designs.
Understanding Board-to-Board Connectors
Board-to-board connectors are a method of joining two printed circuit boards in a stacked configuration. These connectors can be classified based on their applications as:
- Ruggedized connectors, commonly used in the automotive, aerospace, industrial systems, and power products industries
- High speed connectors
- High frequency connectors
- High current/high power connectors
- Backplane connectors
When selecting the right connector for your project, consider factors such as size, current carrying capacity, physical constraints, and correct connector pitch.
Board-to-board connectors come in various styles, each with their own benefits and drawbacks. For instance, some connectors boast excellent signal integrity for high-speed data transmission applications. When considering a board-to-board connector, factors such as:
- Pitch and pin count
- Power handling
- Governing standard
- Environmental ratings
- Data rate/frequency limit
should be taken into account. Examination of S-parameter data is also crucial while choosing connectors for high-speed signaling standards like high-speed mezzanine connections. Expert advice tailored to your specific application can help guide you in selecting the right connector.
Basic Types of Board-to-Board Connectors
The fundamental types of board-to-board connectors consist of pin headers and sockets, elevated headers and sockets, and shrouded headers. Each type serves a unique purpose and offers its own set of benefits. For instance, the FS series board-to-board connectors are available in a range of 6 to 16.6 mm positions and have a 0.635 mm pitch size, making them suitable for applications requiring right angle connectors. The FR series board-to-board connectors from Phoenix Contact have a 1.27 mm pitch size and provide a maximum data rate of 28 Gbps.
The FQ 1,27 and FQ 2,54 series enable mezzanine connectors for mezzanine, coplanar, and mother-daughter connections. The FS series high-speed connectors can transmit data at a maximum rate of 30 Gbps, providing high speed transmission capabilities. Meanwhile, the FP 0,8 series incorporates ScaleX technology with a double contact for a secure and durable connection, as well as high tolerance compensation when plugging.
Given the multitude of options, a clear understanding of the basic types of board-to-board connectors and their features is fundamental to selecting the best connector for your project.
Pin Headers and Sockets
Pin headers and sockets are simple, cost-effective connectors that provide convenient connection and replacement options. A male pin header is composed of one or more rows of metal pins embedded in a metal-encapsulated plastic base. The cost-effectiveness of male pin headers is attributed to their straightforward design.
Female headers, on the other hand, enable easy connection and replacement of PCBs. Customization options for pin headers and sockets include:
- Voided pins
- Voided contacts
- Post and tail lengths
- Post or pin sizes
- Kinked pins
- Contact types
For PCBs in the 1.27 mm pitch range, parallel and right angle orientation are available, and an elevated stacker header provides additional design choices for stacking polarization. The FR 1,27 series connector offers flexible alignment of the PCB, thanks to its advanced contact design.
Elevated Headers and Sockets
Elevated headers and sockets are employed when an exact distance between PCBs is necessary. These connectors offer additional height and flexibility for PCB stacking and modularization. For example, a 20 mm PCB separation distance can be achieved using a 5.00 mm profile socket with a necessary stacking height of 15 mm. However, bear in mind that 1 mm board-to-board elevated headers are not suitable for applications that require load-bearing capabilities.
The insulator can be employed to facilitate pin alignment when using 1 mm board-to-board elevated headers. This ensures proper alignment and connection of the PCBs while maintaining the desired separation distance.
Elevated headers and sockets are an excellent choice for applications that require precise stacking and modularization of PCBs.
Shrouded Headers
Shrouded headers offer guided mating and enhanced protection against connection mistakes. These connectors are employed in applications that necessitate reliable and secure connections, such as automotive, industrial, and medical applications. Box header connectors are an example of shrouded headers, featuring a plastic shroud surrounding the header, which facilitates proper mating and prevents any potential errors.
The use of shrouded headers provides an efficient and dependable connector assembly, ensuring correct connection and minimizing the risk of errors in various applications. By incorporating shrouded headers in your PCB design, you can enhance the overall reliability and performance of your electronic device.
Mounting Options for Board-to-Board Connectors
Mounting options for board-to-board connectors include:
- Through-hole (TH)
- Surface mount (SMT)
- Vertical orientation
- Right-angle orientation
- Mixed technology
- Press-fit
- Pass-through terminations
Through-hole technology involves inserting the connector pins into the board and soldering them in place, whereas surface mount technology involves soldering the connector pins directly to the board.
Locating pegs are employed to guarantee that the board-to-board connectors are suitably aligned when mounted. They are generally utilized in combination with through-hole and surface mount technologies. Choosing the appropriate mounting option for your board-to-board connector can guarantee a secure and reliable connection between your PCBs.
Connector Pitch Considerations
The connector pitch is the distance between the centers of adjacent contacts, and it plays a crucial role in the overall performance of the connector. In the case of multi-row connectors, the pitch in each row and the pitch between rows may differ. When selecting a connector pitch, factors such as size, current carrying capacity, and physical constraints should be taken into account.
Various options are available to suit different applications, such as the FS series board-to-board data connectors with a 0.635 mm pitch size, which are suitable for right angle connectors. The FR series board-to-board connectors from Phoenix Contact have a 1.27 mm pitch size and provide a maximum data rate of 28 Gbps.
Taking into account the connector pitch and the specific requirements of your application can ensure optimal performance and compatibility between your PCBs.
Row Configurations and PCB Orientations
Row configurations and PCB orientations play a vital role in the design and assembly of board-to-board connectors. Single, dual, triple, and quad row configurations are available, offering design flexibility and accommodating various application requirements. Parallel, horizontal, perpendicular, and U-shaped orientations are also available for different PCB arrangements.
Choosing the appropriate row configuration and PCB orientation for your board-to-board connector can enhance the overall performance and reliability of your electronic device. Understanding the various row configurations and PCB orientations is essential for designing a successful PCB assembly that meets the specific needs of your application.
Connector Orientation Variations
Connector orientation variations are essential to accommodate different PCB orientations and applications, including vertical connectors. Straight, right angle, and U-shaped connector orientation options are available. U-shaped pin headers, for example, enable the establishment of a connection between two perpendicular PCBs without requiring multiple mating cycles.
Taking into account the specific requirements of your application and selecting the appropriate connector orientation variation can ensure a proper connection between your PCBs and enhance the overall performance of your electronic device. Understanding the various connector orientation options is crucial for creating a successful PCB assembly that meets the unique needs of your project.
Pin and Contact Customization Options
Customization options for board-to-board connectors include:
- Voided pins: create larger pitches through selective loading by leaving out every second pin in a pin header
- Voided contacts
- Post and tail lengths: post length is the length of the pin below the insulator used for soldering to the PCB, while the tail length is the length of the pin above the plastic insulator used to mate with the socket
- Post or pin sizes
- Kinked pins
- Contact types
Kinked pins are an effective fastening solution. They can be used to easily affix a through-hole pin header or socket to a PCB before soldering. Taking into account the specific requirements of your application and selecting the appropriate pin and contact customization options can enhance the overall performance and reliability of your board-to-board connector assembly.
Material Selection: Plastic Insulators and Contact Plating
Material selection for board-to-board connectors is an important factor to consider for optimal performance and durability. Plastic insulators made of Nylon 6T or LCP are used for insulation purposes and to secure the contacts. High-quality copper alloy is employed in the production of core header pins and receptacle contacts for board-to-board connectors from GCT.
Contact plating options include high-quality copper alloy, gold, or RoHS compliant tin plating. Finish plating is the second step of the plating process, which serves to enhance electrical conductivity, while underplating improves performance and inhibits pollutants from reacting with the base metal.
Choosing the appropriate materials for your board-to-board connector can ensure optimal performance and longevity of your electronic device.
Stacking and PCB Mating Techniques
Stacking and PCB mating techniques involve using pin headers, sockets, and elevated connectors to achieve precise distances and orientations between PCBs. These techniques are essential for maintaining accurate distances and orientations between PCBs, ensuring proper connection and performance of your electronic device.
For example, bottom entry socket mating enables mating with a pin header from the underside of the PCB rather than the top side. Implementing appropriate stacking and PCB mating techniques, in consideration of the specific requirements of your application, can enhance the overall performance and reliability of your board-to-board connector assembly.
Packaging Options for Board-to-Board Connectors
Packaging options for board-to-board connectors include:
- Standard and custom options
- Bulk (PE bag or small box)
- Trays
- Tubes
- Tubes with pick and place (P&P) cap or Kapton tape
- Tape and reel (T&R) with pick and place (P&P)
These options cater to various assembly requirements and preferences, ensuring efficient handling and protection of your connectors.
Custom trays, tubes, and tape and reel packaging are also available for board-to-board connectors. The advantages of each packaging option vary depending on the application.
- Bulk packaging is generally the most cost-efficient option
- Trays and tubes offer improved protection for the components
- Tape and reel packaging is advantageous for automated assembly processes.
Choosing the appropriate packaging option for your board-to-board connectors can guarantee proper handling and protection during assembly and transport.
Polarized Connectors: Ensuring Correct Connection
Polarized connectors ensure correct connection between mating headers and sockets by using shrouding and keying features in various pitch sizes. These features help prevent connection errors and ensure proper alignment between mating connectors. Polarized connectors are particularly useful in applications where reliable and secure connections are essential.
For example, in the 2.54 mm pitch board-to-board connector, the central bump system is utilized to prevent header and socket mismating. The headers are keyed while the receptacle features a sidewall bump, ensuring correct connection and minimizing the risk of errors in various applications, such as connecting parallel boards.
Incorporating polarized connectors in your printed circuit board (PCB) design can boost the overall reliability and performance of your electronic device.
Summary
Throughout this blog post, we have discussed various aspects of board-to-board connectors, including their types, applications, factors to consider when selecting the right connector, and customization options. Understanding the importance of connector pitch, row configurations, PCB orientations, and material selection is crucial for designing a successful PCB assembly that meets the specific needs of your application.
By gaining a comprehensive understanding of board-to-board connectors and their features, you can optimize the overall performance and reliability of your electronic device, ensuring that it meets the unique requirements of your project. With the ever-increasing demand for high-speed data transmission and miniaturization, selecting the appropriate board-to-board connector is more important than ever.
Frequently Asked Questions
How do you connect two circuit boards together?
Flat flexible cables and board-to-board connectors (“headers”) are the most common methods used to connect two circuit boards together. The former can be soldered at each end directly onto the printed circuit board, while the latter involves one board with a connector and pins and another board with a mating receptacle. Headers are often used when the boards need to be connected in a specific orientation, or when the boards need to be easily disconnected and reconnected. They are also used when the boards need to be connected in a way that is not easily
What is a floating board to board connector?
A floating board to board connector is an electro-mechanical interconnect that absorbs misalignments in both “x” and “y” directions, usually when mounted on a PCB. It features a suspended mechanism on the mating interface, allowing a range of space to accommodate for misalignment errors and is composed of a floating side and a fixed side. The floating side is designed to move in the “x” and “y” directions, while the fixed side is designed to remain stationary. This allows for a wide range of misalignment errors to be absorbed, while still providing a secure connection. The floating board to board connector
What are the different types of connectors for circuit boards?
The most common types of circuit board connectors include one-piece card edge, two-piece board-to-board, FFC/FPC, stacking connectors, wire-to-board, DIN41612, PCMCIA, M55302, memory/adapter card sockets, backplane and mezzanine connectors, and square/round post headers.
How can I ensure correct connection between mating headers and sockets?
Ensure correct connection between mating headers and sockets by using polarized connectors, which feature shrouding and keying features in various pitch sizes.
What factors should I consider when selecting a connector pitch?
When selecting a connector pitch, it’s important to consider size, current carrying capacity, and any physical constraints of your setup.