2.54mm PCB Pluggable Terminal Block Male Header

2.54mm PCB Pluggable Terminal Block Male Header

As the name suggests, a straight pin refers to the pin part connected to the PCB board that is straight and perpendicular to the terminal body and the PCB board plane..

1.Type and Pole

Type: Pcb Pluggable Screw Terminal Block

Pole:

1. Design structure and material

Shape: Typically cylindrical or square pins protruding vertically from the bottom of the terminal insulation body.

Material: Formed integrally with the terminal conductor, typically:

Brass: good strength and conductivity, high cost-effectiveness.

Electroplating: To enhance solderability, prevent oxidation, and improve corrosion resistance, the surface of straight pins is typically subjected to electroplating treatment.

Tin plating: the most common choice, low cost, good solderability.

2. Mechanical structural characteristics

Crimp/rivet fixation: A straight pin does not simply insert into the plastic body of the terminal. Its tip usually features a barb, knurling, or riveting structure. During the injection molding or assembly of the terminal, the plastic fills or wraps around this structure, forming an extremely strong mechanical connection that prevents the pin from being pulled out of the body.

Coplanarity: For multi-position terminal blocks, the bottoms of all straight pins must lie on the same absolute plane. This characteristic is known as coplanarity. High coplanarity ensures that all pins can make good contact with PCB pads simultaneously, which is key to achieving high-quality soldering

2.Material  Of  Pluggable Terminal Block

This is the core area where the straight pin terminal forms electrical and mechanical connections with the circuit board.

1. Coordination between pins and pads

PCB pad: PCBs are designed with through-hole pads that correspond one-to-one with terminal pins. The diameter of the through-hole is slightly larger than the pin diameter to allow space for the solder to climb through capillary action.

Matching of pin diameter and through-hole diameter: This is a key design consideration. The through-hole diameter is usually 0.2-0.4mm larger than the pin diameter. For example, a pin with a diameter of 0.64mm will be matched with a PCB through-hole with a diameter of approximately 0.9-1.0mm.

2. Welding process

Straight pin terminals are mainly soldered using through-hole technology.

Wave soldering:

Plugin: Insert the straight pin of the terminal into the corresponding through hole on the PCB.

Fluxing: The bottom of the PCB passes through a flux spray zone to remove oxides and enhance solderability.

Preheating: The PCB enters the preheating zone to prevent thermal shock when it comes into contact with molten solder.

Soldering: The bottom surface of the PCB is subjected to a "wave" of molten solder raised by a pump. The solder is drawn into the through-hole by capillary action, forming a complete solder joint filling between the lead and the pad.

Cooling: Form a firm electrical and mechanical connection.

Manual soldering:

Suitable for small-batch production, repair, or replacement. Use a soldering iron and solder wire to solder each solder joint individually.

3. Solder joint morphology and requirements

A high-quality solder joint should possess the following characteristics:

Full filling: The solder should fill 100% of the through-hole and form a small conical meniscus on the bottom surface of the PCB.

Good contact angle: The contact angle between the solder and the lead and pad should be smooth and rounded, indicating good wetting.

Bright and smooth: The surface of the solder joint should be bright, free of burrs, and without pores.

3.Electrical Of  Pluggable Terminal Block

4.Mechanical  Of  Pluggable Terminal Block

5.Dimensions

6.Advantages 

☑ Adapt to multi-type sockets, device design is highly flexible
☑ Keying requirements can be met
☑ Universal installation method, suitable for various situations

Advantage:

Extremely high mechanical strength: Through-hole soldering provides significantly higher mechanical strength than surface mount technology (SMT). The terminals themselves can withstand greater insertion and extraction forces as well as lateral stress from wires, making them less likely to detach from the PCB.

Reliable connection: The solder forms an all-round connection within the through-hole, with a large contact area, providing a very stable electrical connection and strong resistance to current impact.

Easy to detect and repair: The solder joints are visible to the naked eye, facilitating quality inspection. Tools such as tin suction devices can be used to disassemble and replace them relatively easily.

Cost-effectiveness: Through-hole technology is mature, with a simple production process, and still offers cost advantages in high-volume applications.

Design and application considerations:

Occupied PCB space: Through-holes require the entire thickness of the PCB board, and solder pads occupy space for bottom-layer wiring, making them less space-efficient than SMT devices.

Cannot be used for high-density assembly: In very compact modern electronic devices, the 2.54mm pitch itself is considered relatively large, and the THT process limits the wiring density.

Welding stress: During the wave soldering process, high temperatures may cause thermal stress on the plastic body of the terminals. It is crucial to choose high-temperature resistant materials, such as UL94 V-0 grade PA66.

Pin coplanarity: As mentioned earlier, poor coplanarity can lead to soldering defects or open circuits, making it a critical quality control point in production.

7.Application  Of  Pluggable Terminal Block

1.Motion controller    2.Three-phase power meter   3.Microcomputer protection device  4.Electric equipment

5.Automation equipment  6.Security equipment  7.Internet of things equipment

8.Package  Of  Pluggable Terminal Block

We choose the high quality and safe packaging material to make sure  your order  won't  be damaged during delivery.

These trade terms are acceptable:EXW,FOB,CFR,CIF.