PCB (printed circuit board) is an indispensable component in electronic equipment, which connects electronic components through conductive lines and connecting points. In the PCB design and manufacturing process, metallized holes and through holes are two common types of holes, and they each have unique functions and characteristics. The following is a detailed analysis of the difference between PCB metallized holes and through holes.

Metallized Holes

Metallized holes are holes in the PCB manufacturing process that form a metal layer on the hole wall by electroplating or chemical plating. This layer of metal, usually made of copper, allows the hole to conduct electricity.
Characteristics of metallized holes:
1.Electrical conductivity: There is a conductive metal layer on the wall of the metalized hole, allowing the current to flow from one layer to another through the hole.
2.Reliability: Metalized holes provide a good electrical connection and enhance the reliability of the PCB.
3.Cost: Due to the additional plating process required, the cost of metalized holes is usually higher than that of nonmetalized holes.
4.Manufacturing process: The manufacture of metallized holes involves a complex electroplating or electroless plating process.
5.Application: Metallized holes are often used in multi-layer PCBS to achieve electrical connections between internal layers
Advantages of metallized holes:
1.Multi-layer connection: Metallized holes allow electrical connections between multi-layer PCBS, helping to achieve complex circuit designs.
2.Signal integrity: Since the metallized hole provides a good conductive path, it helps to maintain the integrity of the signal.
3.Current carrying capacity: Metallized holes can carry large currents and are suitable for high power applications.
Disadvantages of metallized holes:
1.Cost: The manufacturing cost of metallized holes is higher, which may increase the total cost of PCB.
2.Manufacturing complexity: The manufacturing process of metallized holes is complex and requires precise control of the plating process.
3.Hole wall thickness: Metal plating may increase the diameter of the hole, affecting the layout and design of the PCB.

Through Holes

A through-hole is a vertical hole in the PCB that penetrates the entire PCB board, but does not form a metal layer on the hole wall. The holes are mainly used for the physical installation and fixing of the components, not for electrical connections.
Characteristics of the hole:
1.Non-conductive: the hole itself does not provide an electrical connection, and there is no metal layer on the hole wall.
2.Physical connection: Through holes are used to fix components, such as plug-in components, to the PCB by welding.
3.Cost: The manufacturing cost of through holes is usually lower than that of metallized holes.
4.Manufacturing process: Through the hole manufacturing process is relatively simple, no plating process is required.
5.Application: Through holes are often used for single – or double-layer PCBS, or for component installation in multi-layer PCBS.
Advantages of the hole:
1.Cost effectiveness: The manufacturing cost of the hole is low, which helps to reduce the cost of PCB.
2.Simplified design: Through holes simplifies the PCB design and manufacturing process because it does not require plating.
3.Component mounting: Through holes provides a simple and effective way to install and secure plug-in components.
Disadvantages of passing holes:
1.Electrical connection limitation: The hole itself does not provide electrical connection, and additional wiring or pad is required to achieve connection.
2.Signal transmission limitations: Pass holes are not suitable for applications that require multiple layers of electrical connections.
3.Component type limitation: The through hole is mainly used for the installation of plug-in components and is not suitable for surface mount components.
Conclusion:
Metallized holes and through-holes play different roles in PCB design and manufacture. The metallized holes provide the electrical connection between the layers, while the through-holes are primarily used for the physical installation of the components. The type of hole chosen depends on the specific application requirements, cost considerations, and design complexity.