Types of Board to Board Connectors
Board to board connectors connect printed circuit boards together without a cable. They are available in different sizes and configurations with various insulator heights, pin lengths, and pitch options.
They can be either through-hole or surface mount. Thru-hole connectors make connections using leads that are installed through holes drilled on the PCB and soldered to pads on the opposite side.
Types
There are many different types of board-to-board connectors. Some are simple and easy to use, while others require special engineering skills or tools to mount. Different types also have varying pitches and pin-counts. Choosing the right type for your application will help ensure that it fits in the space available on the PCB and provides reliable electrical and mechanical performance.
The basic type of board-to-board connector is a plug or receptacle with a plastic base that contains contact pins. These can be arranged in either a horizontal or vertical orientation. Those with a vertical orientation allow two PCBs to be stacked on top of each other, minimizing space requirements. They are sometimes referred to as board to board connector mezzanine or vertical connectors. Others have a perpendicular connection with the motherboard, known as motherboard-daughterboard connections. This type of connection is used in hard drive applications to efficiently stack multiple “daughterboards” on one motherboard.
There are many other types of board-to-board connectors, including terminal block connectors and polarized header connectors. The insulators of these connectors are molded into various shapes to fit in the space on the PCB and provide different levels of strength, weatherability, and chemical resistance. In addition, there are a variety of different termination options, such as soldering or surface mount. Choosing the right termination method will help reduce assembly time and cost.
Gender
Board-to-board connectors allow two circuit boards to join each other without the use of a wire. They are available in a variety of configurations, including through-hole, surface mount and mezzanine. The type of connector that best suits a project will depend on the header type and gender. The header is the plastic base to which the contacts are attached. A box header completely encloses its contacts, while a pin header exposes them. Board-to-board connectors have two gender settings, with male connectors known as plugs and female connectors called receptacles.
The pins of a male plug are inserted into the socket holes of a female receptacle to connect the two devices. The pins are often colored to help identify the gender of the connector and the corresponding wire. They are then crimped using a specialized tool, which can be a ratchet or manual crimper with color-coded jaws that match the gauge of the wire being inserted. Once crimped, the terminal between the wire and the connector needs to be sealed. This can be done by applying heat that melts the connector’s plastic material.
Another important consideration when selecting a connector is the pitch, which is the distance between the center of one contact and the center of the next. A mismatch between the pitch of a female and male connector can lead to shorts, arcing or other problems. To prevent this from happening, many manufacturers provide strain relief, which transfers any forces acting on a connector to a more mechanically sound object than the fragile electrical connections it supports.
Material
Board-to-board connectors are miniature coupling plugs and sockets that directly connect power and signal between printed circuit boards (PCB) without the need for wires. Their conductors, or pins, are typically made of copper alloy that is plated to improve conductivity and resist oxidation over time. Various connectors are designed to mate with different PCB pad layouts, signal frequencies, and physical constraints.
The miniaturization megatrend has limited PCB real estate, driving the need for finer pitch connections and other special features. Rosenberger offers a variety of board-to-board solutions to address these challenges.
Some of the most common board-to-board connector types are card edge connectors, crimp-style connectors, and IDC (Insulation Displacement Connector) connectors. Card edge connectors are a quick and easy way to attach expansion cards to PCBs, while crimp-style connectors involve crimping a contact onto a wire and inserting it into a housing that mates with a PCB-mounted connector. IDC connectors are used with ribbon cables and provide a simple, reliable connection method.
Board-to-board connectors also come in a range of stack heights to accommodate differing PCB designs. Typically, a board that needs to be connected vertically will use a mezzanine connector, while a board that requires a perpendicular connection to a motherboard will require a backplane connector.
Plating
Board-to-board connectors come in both thru-hole and surface mount pin configurations. Thru-hole pins are more durable, making them an ideal choice for board-to-board connections that will be plugged and unplugged frequently. Surface mount pins, on the other hand, are more affordable and compact. But they don’t offer the same level of mechanical stability as a thru-hole connector.
Choosing the right plating for board to board connectors is crucial. The type of electrodeposit chosen will have a significant impact on Board-to-Board Connector Supplier the product’s performance, quality, life cycle, and cost. The best option is a metal alloy that’s both conductive and non-corrosive. A good example is white bronze, which consists of copper and tin. It has a higher melting point than nickel and provides better resistance to corrosion and wear.
The type of plating used for the connectors’ pins should also be taken into consideration. Some are plated with silver, which is excellent for power connectors because it’s a natural lubricant that lowers mating friction and contact resistance. Other options include gold and palladium. The latter offers the benefits of gold with a lower cost and greater resistance to wear.
