What Is a Board to Board Connector?
Board-to-board connectors transmit power and signal between PCBs in an accurate, repeatable manner. They have a housing and specific number of terminals that are made from conductive materials and plated for improved conductivity.
Connectors are offered in multiple plating finishes, alloy materials and pitches for both electrical and mechanical requirements. They also come in two gender settings — male connectors (also known as plugs) have protrusions that fit into female connectors, or receptacles.
Pins
Board-to-board connectors attach to printed circuit boards (PCBs) through pins that extend board to board connector from the plastic base. They can make strong vertical connections between a PCB and another or provide more flexible horizontal or side-by-side connectivity, depending on the connector type and application. They can be manufactured using through-hole or surface mount technology. Through-hole connectors have long leads that pass through holes drilled in the PCB and then soldered to pads on the opposite side of the board, while SMT connectors have short, exposed pins. Through-hole connectors are ideal for making connections that need to be durable and strong, while SMT connectors can be used for quick prototyping and testing.
PCB pins are available in different heights, shapes and packaging styles, depending on the specific connector design. Some of the most common are male/female pin headers, also known as plugs and receptacles, which have a protrusion on one end that fits into a notch in its mating connector. These can be configured with straight or right-angle pins and in varying geometry, such as stacked headers or headers with legs that bend over at 90 degrees.
Other board-to-board connectors use pin-clip arrays, which are mechanically encapsulated in a female socket or male plug array and soldered to the mother board or daughter board. These are designed for high current applications and have a rugged construction. They can mate and unmate easily, and have high contact resistance and endurance across wide temperature ranges.
Insulators
A board to board connector connects a printed circuit board (PCB) with wires, and it is available in various packages, mounting styles and pin pitches. Designers need to consider the current that a PCB-to-board connector will conduct and select one with sufficient strength for their application.
Connector housings and contacts are insulated to prevent electrical contact with adjacent components or the environment. Some housings are made of thermoplastic materials, such as polycarbonate, polyvinyl chloride or ABS. These materials have good wear resistance, abrasion resistance, heat resistance and dimensional stability. Others are made of a thermoset material, such as phenolic resin or urinary formaldehyde. These materials have good chemical and solvent resistance, but they are less abrasion-resistant than thermoplastics.
Besides insulation, a connector’s coating or seal protects it from corrosive environments. Some of these devices feature anti-corrosion measures, such as copper or nickel plating. These coatings improve the product’s conductive performance, life cycle and quality.
Other special features include locking and quick connect/disconnect functionality. Locking connectors help prevent unauthorized disconnection, while quick-connect products eliminate the need for soldering by using twist and seat contact methods. They are often used for Board-to-Board Connector Supplier ribbon cables and offer a quick, reliable connection method. Connector pins and terminals are also plated with varying levels of metal, including copper, gold or silver. This enhances the connector’s conductive performance and offers a variety of aesthetic options.
Contacts
Whether it’s a male connector, sometimes called a plug, or a female counterpart, called a receptacle, the pins used in board-to-board connections are often made of gold for reliability. These contacts also come in a variety of shapes and sizes, depending on the intended application.
When selecting the right board-to-board connector for your project, consider factors like the number of contacts needed and the expected maximum voltage handling. A minuscule pitch could offer a greater number of pins in a small space but might be challenging to manufacture. Conversely, a larger pitch might streamline production and mating but could limit the amount of power that can be transmitted.
Other considerations include the board-to-board connection type and termination method. Board-in connectors, for example, establish a direct connection to the PCB without the use of a mating connector. They are available as surface mount or through-hole and can be soldered either by hand or with a re-flow or wave-soldering process.
Through-hole connectors are installed through drilled holes in the circuit board and soldered on both sides of the connection. They are available in a wide range of pitches and pin lengths, with insulator heights to suit different applications. Other features may be included, such as hermetical seals, resistance to chemicals and filters that block EMI. These features make them ideal for harsh environments and high-speed connections.
Special Features
The rapid technological advancements in several industries have fueled the demand for smaller, more efficient board-to-board connectors. These connectors need to be capable of delivering high-quality signal transmission and power transfer, within tight size constraints. They also have to be compatible with different types of PCBs and environmental conditions.
One of the most common variants is the through-hole board-to-board connector. This connector type has contacts that are inserted through drilled holes in the PCB and then soldered to pads on the opposite side to complete an electrical connection. This type of connector is widely used in electronic devices, and it is particularly useful when making strong vertical connections between layered boards.
Through-hole board-to-board connectors come in a wide range of packages, mounting styles and pin pitches. They are available in a variety of heights, allowing designers to match the connector height to the height of the components they plan to use. Connectors with higher heights are best suited for connecting taller components, while those with lower heights can be used to save space.
Other variations include quick-connect products, which are designed to be easily connected and disconnected with a twist, without the need for soldering. The connectors can also be constructed with different plating options to optimize performance, durability and cost. For example, tin plating offers excellent conductivity and resistance to corrosion, while gold plating is the preferred choice for high-speed applications.
