Choosing the Right Board to Board Connector
Board to board connectors connect power and signals between circuit boards without the use of wires. They are essential in most electronic equipment and devices to make them work properly.
Choosing the right board to board connector can improve your design process, especially when working with form factor constraints and signal integrity issues. Several factors should be considered when selecting the best BTB connector for your application:
Types
Board-to-board connectors come in many variations, based on their design and application. They’re available in different pin-pitches, plating options, and package styles. Choosing the right connectors is important for creating a successful PCB layout.
One of the most common types of connectors are through-hole pins, which are installed in drilled holes on the PCB. They’re able to withstand high currents and provide a robust physical board to board connector connection. They also have a variety of locking mechanisms, such as snap-on clips, screws, latches, and bayonet-style locks.
Another type of board to board connector is a surface mount connector. These are used to connect directly onto the top of the PCB. They’re typically smaller than through-hole connectors and don’t require soldering to install. They also have a floating structure that allows them to absorb vibrations and minor misalignment of the PCB. This makes them ideal for applications that need high contact reliability. This includes devices such as smartphones and wearables that are constantly evolving with new features. They’re also suitable for high-speed transmission of data. This requires premium signal integrity that reduces power loss, reflections, and crosstalk.
Insulators
Board-to-board connectors transfer power and signals between PCBs without the use of wires. They can be mounted using through-hole or surface-mount methods. Through-hole connectors are installed through drilled holes in a PCB and soldered on both ends to complete the connection. Surface-mount board-to-board connectors are placed on the PCB through a hole in the insulating material.
The insulators in board to board connectors protect the conductors (pins) from one another. Different insulators offer different levels of performance in terms of strength, weatherability and chemical resistance. In addition, they also differ in their ability to absorb vibration and shock.
Some board-to-board connectors, such as the JAE AX01 floating connector series, use a spring action that flexes to withstand horizontal vibrations. This technology reduces contact insertion force to prevent plating abrasion and improves contact reliability.
When choosing a board-to-board connector, consider its mounting method, pin pitch, row number and contact density. Also take into account the PCB’s operating environment and manufacturing requirements when designing its layout. It is important to leave enough space around the headers so that technicians can work on the circuit board without obstructions.
Pins
Using a male-to-female system of pins and sockets, board to board connectors transfer signals, power, and data between PCBs. They’re used for a wide variety of applications in consumer electronics, industrial, and computer systems.
The connections made by these connectors can be either through-hole or surface mount. Through-hole connectors make a connection by inserting their leads into holes drilled on both sides of the circuit board, while surface mount connectors plug into PCB-mounted pin strips.
Both types of connectors can be found in a range of different sizes, pin pitch, and contact plating options. Copper, gold, and silver plated contacts offer higher electrical conductivity and lower contact resistance than unplated options.
Traditional board-to-board connectors work adequately as long as they’re free from structural stresses. These stresses are often caused by misalignments during the manufacturing process or a skew in the relative position of mated boards. These stressors can cause the solder joints to fail and lead to other problems, such as oxidation on the contact surfaces. This problem led to the creation of floating board-to-board connectors, which allow for movement in the X and Y axes and absorb these stresses to prevent damage.
Stack Height
The stack height used in board-to-board connectors depends on the needs of your application. High-speed applications such as smart factories and 5G communication need higher data transmission rates, packing density and signal integrity. In these applications, you need a reliable solution that can compensate for manufacturing and assembly tolerances as well as board movement caused by shocks and vibration.
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In PCB design, the stack height determines how much space is available for other components on the same layer. Many component suppliers have library tools and plugins that can check your stack height, ensuring your component layout complies with your circuit board design rules. Phoenix Contact’s FINEPITCH family of board-to-board connectors allows designers to choose from a range of mating stack heights and pitch options. They also feature a hermaphroditic design that enables TwinMezz connectors to mate to each other without an additional header.
Signal Integrity
In digital circuits, the integrity of signal transmission is vital for ensuring accurate data transfer. However, signals can be degraded by a number of internal and external sources. Fortunately, certain straightforward design rules can mitigate these issues.
One of the most common causes of poor signal integrity is inadequate impedance control. This can occur due to a variety of factors, including:
Other contributing factors to poor signal integrity include:
Poor signal quality can also be caused by using too many vias, which increases the inductance of the trace and can cause a reduction in the overall circuit efficiency.
It is also important to minimize the use of through-holes on the board and to make sure that they are Board-to-Board Connector Supplier as short as possible. This will reduce their inductance and minimize the effects of signal discontinuities.
Another important factor in achieving good signal integrity is to develop a clean power distribution network (PDN) for the board. This will ensure that the signals on all of the interconnects are properly terminated and have a clear path back to their source. Additionally, it is critical to avoid routing high-speed transmission lines through blocked areas on the standard planes. This can lead to increased EMI generated by the board.
