Understanding the Basics of Rigid PCBs

Insulating materials play a vital role in Rigid PCBS, not only providing physical support for circuit components, but also preventing the unintended flow of current. The insulating material of rigid PCBS is usually made of materials such as fiberglass board (FR4) or paper-based phenolic resin board (FR2), which have good insulation properties and thermal stability and can maintain their performance under various environmental conditions. The choice of insulation material has a direct impact on the performance of rigid PCB, with excellent mechanical strength and thermal stability, suitable for applications requiring high frequency and high temperature environments. Paper-based phenolic resin boards have lower cost and good insulation properties, and are suitable for low cost and low power applications.

Electroless Nickel/Immersion Gold (ENIG) is a common surface treatment technique used in the manufacture of Rigid PCB. ENIG surface treatment involves electroplating a layer of nickel on the PCB surface and then plating a thin layer of gold. The nickel layer is mainly used to protect the PCB surface and prevent oxidation, while the gold layer provides good conductivity and weldability. The advantages of ENIG surface treatment include good weldability, long-term storage stability, and environmental resistance. Due to the presence of the gold layer, the ENIG treated PCB can provide stable welding performance, so that the components can be reliably welded to the PCB. The gold layer can also prevent the oxidation of the PCB during storage and improve the storage stability of the PCB. Finally, since both gold and nickel have good corrosion resistance, ENIG treated PCBS can maintain their performance under various environmental conditions.

Some of the main steps of the rigid PCB manufacturing process:

Design: Use computer aided design (CAD) software to design circuit diagrams. The function, size, layout and other factors of the circuit to create an effective and workable design.

Plate making: After the design is complete, the design needs to be converted into the actual circuit board. Through lithography technology, ultraviolet light is irradiated on a copper plate covered with a photosensitive material, and then the part that is not irradiated by ultraviolet light is etched through an acidic solution to form a circuit pattern.

Drilling: Drilling holes in the circuit board to install electronic components. This is done using a CNC drilling machine, which allows drilling to be done precisely at the specified location.

Coating: After drilling, a thin layer of copper needs to be plated on the wall of the hole to ensure the conductivity in the hole, which is achieved by electrochemical deposition.

Patch: Mount electronic components to a circuit board. This is done with an automatic mounter, which can quickly and accurately attach components to the specified position.

Welding: The components are welded together with the circuit board to ensure electrical connections. Use wave soldering or reflow welding method to achieve.

Each step requires precise control and rigorous quality checks to ensure the performance and reliability of the final product.

In the manufacturing process of Rigid PCB, surface treatment is a key step. Organic Solderability Preservative (OSP) is a common surface treatment technique. OSP surface treatment involves coating the PCB surface with a thin layer of organotin protective film. This treatment method provides good welding performance, but also provides a certain amount of environmental protection. The advantages of OSP surface treatment include good weldability, lower cost and environmental protection. Due to the presence of organotin protective film, OSP-treated PCBS can provide stable welding performance, so that components can be reliably welded to the PCB. In addition, the cost of OSP treatment is relatively low, which can reduce the total cost of PCBS. The materials used in the OSP treatment are environmentally friendly and meet the green manufacturing requirements of modern electronic devices.