Common pin types in PCB design

In PCB design that needs to interface with external mechanisms, you need to consider pins and sockets. PCB design directly or indirectly involves a variety of pins.

After browsing the numerous catalogs of manufacturers, you will find that the types of pins are usually divided into the following categories:

1. Single/double row needle

2. Turret slotted pin

3. Soldering PCB pins

4. Winding terminal pins

5. Soldering cup terminal pin

6. Slotted terminal pins

7. Terminal pin

Most of these pins are paired with their sockets and are made of different materials. Common materials used to produce these pins are beryllium copper, beryllium nickel, brass alloys, phosphor bronze, and copper tellurium. The pins are plated with different surface treatment materials, such as copper, lead, tin, silver, gold and nickel.

Some pins are soldered or crimped to the wires, but the pins (such as plugs, solder mounts, press fits, and turret samples) are mounted on the PCB.

How to choose the correct pin type for PCB design?

Choosing PCB pins requires far fewer considerations than other electronic components. Supervision of mechanical or electrical details can lead to functional problems in prototype or production PCBs.

When choosing PCB pins, you need to consider the following aspects.

1. Type

Obviously, you need to determine the PCB pin type that suits your design. If you are looking for terminal pins for board-to-board connections, the headers are the right choice. Pin headers are usually installed through holes, but there are also surface-mounted versions, which are very suitable for automatic assembly.

In recent years, solderless technology has provided more options for PCB pins. Press fit pins are ideal for eliminating welding. They are designed to fit padded PCB holes and provide safe mechanical and electrical continuity. Single-row pin headers are used for board-to-board and wire-to-board.

2. Pitch

Some PCB pins provide various sizes of pitch. For example, double-row pin headers are usually 2.54mm, 2mm and 1.27mm. In addition to the pitch size, the size and rated current of each pin are also different.

3. Material

The materials used to plate the pins may cause differences in cost and conductivity. Gold-plated pins are generally more expensive than tin-plated pins, but they are more conductive.

PCB design with various types of pins

Like any other PCB assembly, there are some tricks that can save you from worry when using terminal pins and connector designs. One of the most important rules is to set the size of the filling hole correctly. Please always refer to the correct size footprint recommended by the manufacturer. Filling holes that are too small or too large can cause assembly problems.

The electrical characteristics of the terminal pins are also very important, especially when there is a large current flowing through it. You need to allocate a sufficient number of pins to ensure the required current throughput without causing heat problems.

Mechanical clearance and placement are important for the PCB header pins of the package.

Using plug pins for board-to-board connections can be tricky. In addition to proper alignment, it must also be ensured that no high profile parts such as electrolytic covers block the gap between the two PCBs. The same is true for package pins that extend beyond the edge of the PCB.

If you use through-hole or surface mount pins, you need to ensure that thermal relief is applied to the ground polygon connected to that pin. This ensures that the heat applied during the soldering process will not quickly dissipate and subsequently affect the solder joints.