PCB Plated Through-Hole Description
A PCB plated through-hole, often abbreviated as PTH, is a type of hole that passes through a printed circuit board and is plated with a conductive material to create an electrical connection between different layers or sides of the board. Plated through holes are a fundamental feature of many multilayer PCBs and provide a means to connect various circuit components, traces, and layers.
The process of creating plated through holes involves several steps:
- Drilling: Holes are drilled through the PCB at specific locations where interconnections are needed. Depending on the PCB design, these holes can be small, ranging from a fraction of a millimeter to a few millimeters in diameter.
- Plating: After drilling holes, they are typically coated with a thin layer of conductive material, such as copper. This plating can be done using various methods, including electroplating or chemical deposition. The conductive material lines the walls of the hole and covers its surface.
- Copper Etching: The outer layers of the PCB are typically made by etching away excess copper from a copper-clad laminate sheet. The plated through-holes are not etched, so the copper plating remains intact.
- Component Mounting: Components (such as resistors, capacitors, integrated circuits, etc.) are placed on the PCB’s surface and soldered to the copper traces. The plated-through holes allow these components to be electrically connected to other layers of the PCB, enabling complex circuit configurations.
- Soldering: Soldering creates a solid mechanical and electrical connection between the components and the PCB. The solder flows through the plated through-holes, making contact with the copper plating inside.
A PCB Plated Through-Hole is critical in enabling the interconnection between different layers of a multilayer PCB, which is commonly used in modern electronic devices. They provide a reliable means of transmitting signals and power between various parts of the circuit, facilitating the functionality of the device as a whole.