The core of electronic devices - revealing the key technologies of PCBA
Publish Time: 2025-03-11
As the core component of electronic devices, the key technologies of PCBA are crucial to ensure the performance, stability and reliability of electronic devices.
1. Circuit design
Circuit design is the soul of PCB design, which determines the function and performance of the circuit system. In circuit design, the layout of components, the direction of wires and the transmission of signals must be carefully considered to ensure the stability and reliability of the system. At the same time, the size, number of layers and material selection of the circuit board must be comprehensively considered to meet the specific needs of the product. Designers will use professional circuit design software (such as Altium Designer, Eagle, etc.) to design circuit diagrams and generate Gerber file format drawings containing all necessary manufacturing information.
2. Material selection
Material selection is the primary consideration in PCB manufacturing. Commonly used PCB materials include FR-4, aluminum substrate, ceramic substrate, etc. The selection of suitable materials depends on the application scenario and performance requirements. For example, FR-4 material is widely used because of its good electrical properties, mechanical properties and heat resistance. At the same time, with the enhancement of environmental awareness, environmental protection and sustainability have gradually become considerations that cannot be ignored when selecting materials.
3. Manufacturing process
The manufacturing process of PCB mainly includes the following steps:
Board preparation: prepare photosensitive film and apply photosensitive paint, import the designed Gerber file into the PCB board software, and automatically generate the graphics of drilling and circuit layout.
Drilling: Use CNC drilling machine to drill accurately according to the preset circuit pattern.
Etching: Through the action of chemical liquid, the unnecessary copper layer or aluminum layer is etched away to expose the pads or other components below.
Filming: Transfer the pads and other component patterns to the other side of the photosensitive film and press them together with copper foil or aluminum foil to form a PCBA with a complete circuit layout and pad structure.
In the manufacturing process, there are several high-end technologies worth noting:
Subtractive method: The earliest traditional PCB process, using photosensitive anti-corrosion materials to complete the pattern transfer, and using this material to protect the areas that do not need to be etched and removed, and then using acidic or alkaline etching solutions to remove the copper layer in the unprotected area.
Full Additive Process (SAP): Using an insulating substrate containing a photosensitive catalyst, after exposure according to the circuit pattern, the conductor pattern is obtained by selective chemical copper deposition.
Semi-additive process (MSAP): Chemical copper is deposited on the substrate and an anti-etching pattern is formed on it. The pattern on the substrate is thickened by electroplating. After removing the anti-etching pattern, the excess chemical copper layer is removed by flash etching to obtain fine copper wire.
In addition, there are some special manufacturing process technologies, such as vias in disks, buried/blind vias, and mSAP, which can greatly improve the wiring density, signal integrity, and thermal management performance of PCBs.
4. Welding technology
The quality of welding is directly related to the performance and reliability of the circuit system. When implementing welding, appropriate welding methods and parameters should be used, and good connection between components and circuit boards should be ensured. At the same time, attention should be paid to controlling thermal stress and mechanical stress during welding to prevent unnecessary damage to the circuit board.
5. Inspection and testing
After production, comprehensive inspection and testing of PCBs are essential steps. These inspections and tests include electrical performance tests, mechanical performance tests, and environmental adaptability tests, etc., to ensure that the quality and performance of the circuit board fully meet the design requirements.
In summary, the key technologies of PCBA cover circuit design, material selection, manufacturing process, welding technology, inspection and testing, etc. The continuous development and innovation of these technologies provide more stable, reliable and efficient circuit system support for electronic equipment.
