Fumax

Process specification for PCB assembly and design is a broad topic that covers all aspects from design to manufacturing. Here are some of the key points.

PCB design specifications

1. Circuit board size: Select the appropriate circuit board size according to actual needs. A board that is too large or too small can cause manufacturing issues or limit component placement.
2. Number of layers: Choose the appropriate number of circuit board layers based on the complexity of the signal and the requirements for the circuit board. Multilayer circuit boards provide better signal integrity and routing flexibility.
3. Layout: When laying out, the performance, manufacturability, maintainability and reliability of the circuit should be considered. Try to place critical and high-frequency components as close to the center as possible for better grounding and heat dissipation.
4. Wiring: Wiring should be as simple and regular as possible, avoiding sharp and right angles. Using a 45° angle for cornering can reduce signal reflection and radiation.
5. Spacing: The spacing between components and between pads should comply with IPC standards (IPC-2221A). For tiny or high-density circuit boards, the spacing should be appropriately reduced to maintain manufacturability.
6. Pads and Holes: Pad size and hole diameter should comply with IPC standards (IPC-2221A). The edge of the pad should be large enough to support soldering, and the diameter of the hole should match the component pin.
7. Component Identification: Ensure each component is appropriately labeled for identification during manufacturing and assembly.

PCB Manufacturing Specifications

1. Substrate selection: According to the performance requirements of the circuit board, select the appropriate substrate (such as FR4, CEM-1, etc.). The thickness of the substrate should meet the requirements to ensure the mechanical strength and electrical performance of the circuit board.
2. Surface treatment: Choose the appropriate surface treatment method (such as gold plating, nickel plating, etc.) as needed to improve welding performance and corrosion resistance.
3. Manufacturing accuracy: Ensure that the manufacturing accuracy of the circuit board meets the requirements, including size, shape, hole location and spacing, etc. This can be achieved through the use of high-precision manufacturing equipment and processes.
4. Weldability: Ensure that the welding quality between the pad and component pins meets the requirements. This can be achieved by selecting appropriate welding materials and processes.
5. Testing: Testing is performed during the manufacturing process to ensure that the electrical performance of the circuit board meets requirements. Testing includes functional testing, impedance testing, etc.
6. Quality assurance: Establish a strict quality assurance system to ensure that every manufacturing link meets the requirements. This can be achieved through the use of statistical process control (SPC) and other quality tools.

PCB assembly specifications

1. Component selection: Select appropriate components according to the functional requirements of the circuit board. Ensure that the component specifications and parameters meet the requirements of the circuit design.
2. Component identification: Ensure that each component is clearly identified for identification during the assembly process. Labeling should be clear, accurate, and easy to read.
3. Component layout: When laying out components, the arrangement, direction and spacing of components should be considered. Components should be arranged neatly, in the same direction, and the spacing should comply with IPC standards (IPC-7351).
4. Soldering materials: Select appropriate soldering materials, including solder paste, solder balls, and solder films. Ensure that the quality and specifications of welding materials meet requirements.
5. Welding process: Choose the appropriate welding process, including temperature curve, welding time and welding method. Ensure that the soldering process achieves good soldering quality and does not cause damage to components and circuit boards.
6. Quality inspection: Quality inspection is performed during the assembly process to ensure that the quality of the assembly meets the requirements. Quality inspection includes appearance inspection, electrical performance inspection, etc.
7. Environmental control: Ensure that the assembly environment meets the requirements, including temperature, humidity, cleanliness, etc. Environmental control can ensure the stability of the assembly process and the consistency of product quality.
8. Safety regulations: Comply with relevant safety regulations to ensure safe operation during assembly. This includes anti-static measures, fire prevention measures, etc.
9. Document management: Establish complete assembly documents, including component list, welding material list, process flow chart, etc. Documentation management can help trace issues and optimize future assembly processes.
10. Training and technology updates: Regular employee training and technology updates are conducted to maintain their technical level and continuously improve the process. This ensures the stability of the assembly process and product reliability.
11. Environmental friendliness: Try to choose environmentally friendly components, materials and processes to reduce the impact on the environment. At the same time, rationally plan the production process to reduce energy consumption and waste generation.
12. Reliability testing: Conduct reliability testing after assembly is completed, including vibration testing, temperature cycle testing, humidity testing, etc., to ensure the reliability and stability of the product.
13. Quality control: Establish a strict quality control system to ensure that each assembly link meets the requirements. This can be achieved through the use of statistical process control (SPC) and other quality tools. At the same time, we strictly control and handle substandard products to prevent problematic products from entering the market.
14. Continuous improvement: Continuously collect and analyze production data, discover and solve problems in the assembly process, continuously improve processes and processes, and improve production efficiency and product quality.