Medical electronic PCBA manufacturing needs to strictly follow a series of precautions to ensure product quality, safety and reliability, the following for your detailed introduction:
1、Design stage
Regulations and standards to follow: PCBA design of medical devices need to strictly comply with international and regional regulations and standards, such as ISO13485, IEC60601, FDA’s 21CFR 820, etc., to ensure that the product design is in line with the function of the medical device, the performance requirements and safety standards, in order to pass the relevant certifications to ensure that the product is legally marketed.
PCB materials: Commonly used materials include FR-4, metal substrates (e.g. aluminium substrates) and ceramic substrates, etc. These materials need to have high thermal stability, good mechanical strength and corrosion resistance to adapt to the extreme environments such as high temperature and humidity that medical devices may face.
Components and Solder Paste: Components should meet the quality requirements of medical devices, with accurate information such as model, specification, polarity, etc. Solder paste needs to ensure that it can evenly cover the pads during the soldering process, avoiding the phenomenon of less tin and leakage of brushes, and the amount of solder paste should be moderate to prevent too much or too little from causing soldering defects.
Hierarchical structure and wiring design: Reasonable hierarchical structure and wiring design can effectively reduce signal interference and improve the stability and reliability of the circuit. For complex medical equipment, the use of multi-layer PCB boards, the distribution of different functional modules in different levels is an effective means of improving anti-interference capability. Preparation of design documents: Prepare complete design documents, including circuit schematic, PCB layout and BOM (Bill of Materials), use professional EDA tools for circuit design and PCB layout to ensure the rationality and feasibility of the design.
2、Manufacturing process
PCB manufacturing precision and environmental control:
Manufacturing process: PCB manufacturing process includes cutting, forming, copper plating, drilling, yellow light illumination row, etching, etc., the need to use high-precision equipment and rigorous process control to ensure the quality of PCB, to avoid the slightest deviation from the subsequent patch and welding effect.
Environmental conditions: PCB manufacturing process needs to be carried out in a dust-free, anti-static environment to prevent dust and static electricity on the circuit board to ensure that the PCB board cleanliness and electrical properties.
SMT SMD processing:
SMT precision and speed: the use of high-precision mounter to achieve precise installation of components, error control within 0.01mm, while the pursuit of appropriate high-speed operation to improve production efficiency.
Solder Paste Selection and Printing: Select the appropriate solder paste according to the characteristics of the components, solder paste printing to ensure uniform and accurate coverage of the PCB pad, laying a good foundation for welding.
Reflow Soldering and Temperature Control: By controlling the temperature profile of the exhaust gas furnace, to ensure that the solder paste is fully melted to form a reliable connection, the appropriate temperature profile can ensure the quality of soldering, reduce soldering defects and defective products.AOI Inspection and Quality Control: Automatic Optical Inspection (AOI) technology is adopted to visually inspect the completed PCB boards, to detect soldering defects or errors in a timely manner, and then manually re-inspection is required to ensure that the solder joints and components meet the quality standards. solder joints and components meet quality standards.
DIP plug-in processing: For components that can not be mounted by SMT technology, such as large connectors, electrolytic capacitors, etc., the use of DIP plug-in processing, including plug-ins, wave soldering and manual welding, etc., to strictly control the accuracy of the plug-in and the reliability of welding.
3、Quality control
Component quality control:
Avoid counterfeit components: establish strict procurement process, strict screening and auditing of suppliers to ensure that the components come from regular channels; strengthen the construction of quality inspection departments, strict inspection of incoming components, and establish a random sampling system; implement the outdated management strategy to avoid the use of obsolete and unauthorised components; strengthen staff training to enhance the identification of counterfeit components and preventive awareness.
Testing and Screening: Before PCBA sampling, use professional testing equipment and techniques to conduct electrical performance tests, environmental adaptability tests, etc. on components, and screen qualified components for manufacturing.
Welding quality control: Strictly control the welding quality, automatic welding equipment and technology can be used to ensure the consistency and reliability of welding, welding quality testing and evaluation, timely detection and problem solving. The solder joints should be smooth and burr-free, the solder exceeds 2/3 of the height of the solder end, and there is no tin cracking in the cross-section of the solder joints. Functional testing and debugging:
Functional test: After completing the welding and assembly, carry out strict functional tests, such as ICT test, FCT test and aging test, etc., to find out the potential faults and hidden dangers.
Debugging and programme burning: debug the PCBA according to the requirements of the equipment, check the working status of each component to ensure that the equipment operates as expected; if necessary, burn the corresponding programme to enable the equipment to have intelligent control functions.
Cleaning, coating and packaging:
Cleaning and coating: cleaning after the completion of processing to remove flux and other pollutants left in the welding process; coating on the surface of the PCB to form a protective film to prevent moisture, corrosion and other environmental factors on the circuit.
Packaging and transport: final inspection, including appearance inspection, performance testing and safety inspection to ensure that the product meets the specified standards and requirements, after passing the inspection properly packaged to protect the product from damage during transport and storage.
4、Other aspects
Cleanliness and anti-static control: Strictly control the cleanliness in the production process, remove any through-hole or surface stains that may remain in the welding process; take effective anti-static measures, such as setting up grounding wires, using anti-static coatings, etc., to prevent static electricity from potentially damaging the BGA and IC components.
Environmental adaptability testing: High-end medical electronic equipment needs to operate in a variety of environments, so it is necessary to carry out environmental adaptability testing of circuit boards, including temperature range, humidity range, electromagnetic compatibility, etc., to ensure the stability and reliability of circuit boards in a variety of environments.
Establishment of quality control system and traceability mechanism: Establishment of a comprehensive quality control system, covering raw material inspection, process control, finished product testing and other aspects; establishment of a traceability mechanism, each batch of circuit boards for traceability and management, timely detection and resolution of problems.