Chemical and mechanical processing methods are used to manufacture substrates, and the commonly used material is fiberglass reinforced plastic (FR-4).
● Opening: Before production, PCB design needs to be carried out by drawing circuit diagrams and determining component parameters. In the process of wiring, copper laying, embossing, and cutting, factors such as reliability, cost, and complexity need to be considered.
● Forming: Cover glass fiber and epoxy resin on copper foil and press it into a unit board. Multi layer PCBs require combination of unit boards. The pressing plate needs to maintain uniform depth and pressure to ensure flatness and quality.
● Opening: requires drilling holes for connection. Each hole must maintain its standard size and position, without any residue.
● Copper coating: Cover the copper foil to form the core plate and inner wall of the through-hole. Copper foil must maintain good adhesion and smoothness.
Assemble the mounting components one by one onto the substrate, and use SMT equipment to perform automated mounting operations.
● Component bonding: All SMT components need to be assembled using automated equipment. During the bonding process, the position and direction of each component need to be precise, and a reliable bonding structure can prevent the risk of detachment or drift during assembly.
● Hot melt welding: When small SMT devices require high-temperature fusion, the temperature should be suitable for the type of component and the manufacturer's requirements. The heat should be moderate, do not damage the components, and avoid brittle fracture.
For components that cannot be automated through SMT, manual or semi-automatic plugin insertion and removal is required.
● Hand inserted components: For DIP plugins, manual insertion and removal are required according to layout requirements. Each component should be accurately positioned and inserted, paying attention to the installation and stability of the socket.
● Wave soldering: By using a different wave heating method from most SMT devices, small DIP components are fused together. Wave fusion welding is different from hot fusion welding, which requires the addition of appropriate melting agents to ensure connectivity.
By drilling through holes, it is used to maintain connectivity between the surface of the component and the underlying circuit board.
● Drilling: The drill bit should be qualified and able to maintain radial accuracy and verticality. The position and size of the drilling template must not be wrong.
● Copper coating: It is necessary to ensure the integrity and connectivity of the copper coating so that both the components and the bottom layer wires can pass through.
The metalization method varies for different components, including chemical impregnation, electrodeposition, etc.
● Chemical immersion coating: Cover a certain thickness of metalized material on the surface of the component and the inner wall of the through-hole for welding or wiring. Chemical copper plating, silver plating, gold plating, etc. require the use of standardized processes in the chemical industry.
● Electrochemical deposition: Similar to chemical immersion coating, but more suitable for complex circuit designs with high capacity requirements or broadband transmission.
Welding on PCBA, overall inspection, repeated testing to ensure it meets quality standards.
● Welding: divided into ferrite, high-temperature torch welding, and horizontal wave welding. During the welding process, attention should be paid to size and accuracy. Moderate increase in welding temperature and time can improve heating uniformity and reduce thermal stress between components.
● Placement: It is necessary to first use a bonding quality monitoring machine to determine the bonding quality of each component in the entire PCBA. Insufficient precision and stability of SMT will lead to assembly failure and deviation.
Appearance inspection: Check the surface paint, solder pads, and curved parts of the appearance to ensure that there are no cracks, wrinkles, or defects.
Through functional and automated testing, ensure that the PCBA can function properly and meet quality standards.
● Functional testing: conducted through the application of an automated testing platform to verify the short circuit or poor electrical behavior and output signals of the circuit board, in order to avoid design errors.
● Automated testing: Use joint testing methods such as shell shooting and black box testing to verify limits or reliability aspects. Attention should be paid to the quality and accuracy of the testing equipment.
● During the packaging process, each PCBA needs to undergo a visual inspection to ensure that there are no defects and undergo appropriate protective measures to ensure safety during transportation
● Consider using moisture-proof, anti-static, and corrosion-resistant materials for protective packaging. Container, airplane, road, or railway container transportation methods can be used to ensure the safety of the transportation route and maintain the same quality upon arrival at the destination.
The above content is the entire production process of PCBA. New Chip Co., Ltd. has been engaged in the PCBA manufacturing industry for more than 10 years. It has a senior R&D engineering team, a flat control team, a professional technical team, and a professional material procurement team. Please feel free to contact us for any questions about PCBA, and we will provide you with 24-hour professional answers
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