The Core Classifications of Electronic Connectors

Almost all electronic devices rely on a basic and critical component. This component is the electronic connector. It acts like a joint, connecting various parts to ensure that information and energy can flow smoothly. Complex electronic systems could not function without these small devices.

An electronic device is a system. It transfers electrical current and signals from one point to another. Its main job is to join two circuits so they can communicate safely and reliably. There are many types of these components. They have different designs to fit various application needs.

Understanding the classification of these basic devices is very important for people who design, manufacture, and repair electronic products. The market has thousands of different models. But we can group them into three of the most basic types based on what they connect. This article will provide a detailed introduction to these three core classifications of electronic components. 

The First Type: Wire-to-Wire Connectors

The first basic type is the wire-to-wire connector. Its function is very direct. It connects two or more separate wires or wire harnesses. You can think of it like plugging two extension cords together. The purpose is to extend the length of the wire. Or it is to create a point in a complex harness that can be disconnected.

This type of connection is very common in electronic equipment. For example, a car's electrical system has many wire harnesses. These harnesses need to run from one end of the vehicle to the other. Using wire-to-wire devices makes it easier to install and replace parts during production and repair.

A typical wire-to-wire system usually consists of two parts. One part is a plug and the other is a receptacle. The plug and receptacle contain metal terminals inside. These terminals are the parts that actually make contact and transmit the current. The wires are first secured to their respective terminals. Then the terminals are inserted into a housing made of plastic or metal.

The plug and receptacle are mated together. When this happens, the terminals inside make precise contact. This forms a stable and reliable electrical path. The housing serves a purpose. It protects the internal terminals from damage. It prevents short circuits. And it provides a locking mechanism. This ensures the connection does not accidentally come apart due to vibration or pulling.

Several important factors must be considered when choosing a wire-to-wire device. The current and voltage rating is one of the most important parameters. You must ensure the chosen component can handle the current and voltage in the circuit. If it cannot, it could lead to overheating or even burning out.

Another factor is the wire gauge. Different devices are suitable for wires of different thicknesses. Wire gauge is often expressed in AWG, which stands for American Wire Gauge. A smaller AWG number means a thicker wire. The pin count is also important. This refers to how many individual terminals are in one device. The number can range from a single pin to hundreds of pins.

A locking mechanism is also a key feature for reliability. Many wire-to-wire devices have a latching design to ensure the connection is secure. For example, there are push-to-click latches or threaded screw locks. These mechanisms are especially important in environments with vibration. The ingress protection or IP rating is another consideration. In wet or dusty environments, you need to select components that are waterproof and dustproof. An IP rating, such as IP67, indicates its level of protection.

The applications for wire-to-wire connection methods are extremely broad. They are found in almost every industry. The automotive industry is a big user. A car's engine control unit, lighting systems, sensors, and entertainment systems contain a large number of wire-to-wire connections. These connections must be very reliable. They need to withstand vibration and temperature changes.

Industrial automation is another area. On factory production lines, robots and various automated equipment require a lot of signal and power transmission. Wire-to-wire devices make the installation and maintenance of this equipment more convenient. Consumer electronics also use them. For instance, inside some large home appliances, the power cords or signal lines between different modules are connected this way. The aerospace industry depends on them too. The electrical systems in airplanes and spacecraft are extremely complex. They demand the highest level of connection reliability. The wire-to-wire devices used here are often made of high-performance materials and have very robust locking structures.

In summary, wire-to-wire connectors solve the problem of connecting one wire to another wire. Their design goal is to provide a flexible, reliable, and serviceable connection point in an electrical system.

The Second Type: Wire-to-Board Connectors

The second basic type is the wire-to-board connector. Its job is to connect wires to a Printed Circuit Board, or PCB. The PCB is the heart of modern electronic devices. Almost all electronic components, like chips, resistors, and capacitors, are mounted on the PCB. The power needed by the device and the signals received from the outside usually travel through wires to get to the PCB.

The wire-to-board device is the essential bridge in this process. One end connects to the wire. The other end is fixed onto the PCB.

A wire-to-board system also usually has two parts. One part is the plug or socket that connects to the wires. Its internal structure is similar to a wire-to-wire device, where wires are fixed to terminals by crimping or soldering. The other part is the "board-side" component mounted on the PCB. This is also called a "header" or "base".

The pins of the board-side part are fixed to the pads on the PCB through soldering. The wire-end part is then mated with the board-side part. This action completes the connection from the wire to the PCB circuit.

The board-side parts can be categorized based on their mounting style. There are two main types. The first is through-hole technology. The pins of the component pass through drilled holes in the PCB. Then they are soldered on the opposite side of the board. This method is very strong. It is suitable for applications that need to withstand significant mechanical stress.

The second type is surface-mount technology, or SMT. The component's pins are soldered directly onto pads on the surface of the PCB. They do not pass through the board. This method allows for smaller component sizes. It is well-suited for high-density and automated manufacturing.

When selecting a wire-to-board device, you must consider current, voltage, and pin count. But there are also some unique factors. The pitch is one such factor. Pitch refers to the distance between the centers of adjacent pins. A smaller pitch means a smaller device. This allows for higher connection density. Common pitches include 2.54mm, 2.0mm, 1.27mm, and 1.0mm.

The mounting orientation is another detail. The board-side header can be designed to be perpendicular to the PCB, known as a straight or vertical header. Or it can be parallel to the PCB, known as a right-angle header. The choice depends on the spatial layout inside the device. Keying is also an important feature. To prevent incorrect insertion or mating with the wrong part, many wire-to-board device housings have unique shapes, like ribs or slots. This ensures that they can only be plugged in the correct way. This design is called keying or polarization.

The wire-to-board connection method is one of the most common types of connections in all electronic equipment. You can find them in computers and peripherals. The power interface on a computer motherboard, like the 24-pin ATX connector, SATA data cable interfaces, and internal USB headers are all typical wire-to-board applications. They deliver power and signals from the power supply and external devices to the main board.

Communication equipment also uses them extensively. Inside routers, switches, and other network devices, antenna modules and power supply modules need to connect to the main circuit board via cables. Medical devices are another example. In patient monitors, ultrasound machines, and other medical instruments, various sensor probes and display screens need to send their signals to the internal PCB for processing through cables. Home appliances are full of them. The control panels in washing machines, refrigerators, and air conditioners connect to internal motors and sensors using a large number of wire-to-board devices.

Wire-to-board connectors solve the communication problem between the outside world and the core circuit board. They enable modular design. This greatly simplifies the assembly, testing, and repair processes for electronic products.

The Third Type: Board-to-Board Connectors

The third basic type is the board-to-board connector. Its function is to directly connect two or more Printed Circuit Boards together inside an electronic device. In modern electronic products, it is common to split circuits into multiple functional modules. This is done to save space and achieve complex functionality. Each module is an independent PCB. Then these PCBs are stacked or connected using board-to-board devices, instead of putting all the circuitry on one giant PCB.

This connection method can achieve very high connection density. It also creates very short signal transmission paths. This is very beneficial for high-speed signal transmission.

Board-to-board devices are also typically used in pairs. One part of the pair is soldered onto one PCB. The other part is soldered onto another PCB. When the two PCBs are assembled, these two devices mate precisely. This forms the electrical connection between the boards.

Board-to-board connections can take several different forms, depending on the relative positioning of the two PCBs. The first form is the mezzanine style. This is the most common type. Two PCBs are stacked parallel to each other, like a sandwich. This approach is very space-efficient. It is used extensively in compact devices like smartphones.

Another form is the coplanar style. The two PCBs are on the same plane and connected end-to-end. This method can be used to extend the functionality of a main board. A third form is the motherboard-to-daughterboard style. In this case, one PCB, the daughterboard, is inserted perpendicularly into a slot on another PCB, the motherboard. The memory stick slots and graphics card slots on a computer motherboard are the most classic examples of this.

The design of board-to-board devices is very precise. Selecting them requires consideration of some special parameters. Stacking height is a key parameter for mezzanine connectors. It refers to the distance between the two parallel PCBs when they are stacked. Designers need to choose the appropriate stacking height based on the internal space of the product.

Connection reliability is also critical. Board-to-board devices often have a large number of pins that must make contact simultaneously. So the alignment accuracy and contact stability are very important. Some high-end products feature floating designs. These designs allow for a certain amount of misalignment tolerance. This improves the success rate of assembly.

High-speed performance is another major factor. When transmitting high-speed digital signals, like PCIe or USB 3.0, the signal integrity of the device is crucial. It is necessary to select models specifically designed for high-speed applications. These models offer good impedance control and low signal loss. The number of mating cycles is also relevant. Some board-to-board devices are designed for a one-time assembly. But others, like memory slots, must withstand being plugged and unplugged many times.

The board-to-board connection method is essential in modern electronic products that pursue miniaturization and high performance. Mobile devices are a prime example. The internal space of smartphones, tablets, and laptops is extremely limited. The mainboard, camera module, display module, and battery management board are all connected using miniature board-to-board devices.

Servers and data centers rely heavily on this technology. The backplane system in a server is a large motherboard with many slots. CPU boards, memory boards, and hard drive interface boards can be plugged into these slots. This modular design facilitates upgrades and maintenance. Embedded systems also use this approach. Many industrial control and Internet of Things devices use a "core board + carrier board" architecture. The core board integrates core components like the CPU and memory. It plugs into a feature-rich carrier board via a board-to-board device. This allows for flexible product customization for different applications. High-speed switches and routers in communication and networking equipment also depend on them. The signal processing boards and interface boards inside these devices need to transmit massive amounts of data. High-performance board-to-board devices are fundamental to achieving this high-speed interconnection.

Board-to-board connectors solve the problem of direct connection between PCBs. They are a key technology for achieving the miniaturization, modularization, and high performance of electronic products.

Conclusion

We have now looked at the three basic types of electronic connectors in detail. These are wire-to-wire, wire-to-board, and board-to-board. They form the backbone of connections within an electronic system.

Wire-to-wire connectors join wires. They are used to extend lines or create separable harness connection points. Wire-to-board connectors join wires and PCBs. They are the gateway for external signals and power to enter the core circuitry. Board-to-board connectors join two PCBs. They are key to achieving compact and modular designs.

In a real electronic design, these three connection methods often exist together in a single device. A signal might come from an external sensor through a wire. It first connects to an input/output board via a wire-to-board device. Then this board might use a board-to-board device to transmit the signal to the main processing board. During this process, wire-to-wire devices might also be needed to connect different parts of the wiring harness.

Understanding these three basic connection types and their characteristics is the first step in making the right design decisions. Engineers need to carefully select the most suitable electronic component based on the specific needs of the application. These needs include factors like current rating, signal speed, space constraints, cost, and environmental conditions. It is these seemingly small and simple parts that work together to ensure that the vast and complex world of electronics can operate precisely and reliably.

FAQ

What is the main function of electronic connectors?

Electronic connectors establish electrical pathways, transmitting current and signals from one part to another. They act as "bridges" in electronic systems, ensuring stable and reliable operation.

What are the common types of electronic connectors?

The three most common categories are: wire-to-wire connectors (connecting wires to wires), wire-to-board connectors (connecting wires to printed circuit boards), and board-to-board connectors (directly connecting different circuit boards).

What factors should be considered when selecting the right connector?

Common considerations include current and voltage specifications, wire size, number of pins, mounting method (through-hole or surface mount), and operating environment (whether waterproof, dustproof, or high-temperature resistant).

What industries are electronic connectors commonly used in?

Almost all electronic products require connectors. Typical applications include automotive, industrial automation, consumer electronics, communications equipment, medical devices, and aerospace.