In PCB (printed circuit board) assembly, plug-in machining is a key step that involves inserting electronic components into designated holes on the PCB board and securing them to the board through a welding process. The following are some important tips in PCB assembly plug-in processing:
First, plug-in preparation skills
Material check and pretreatment
Carefully check the BOM (Bill of Materials) to ensure that the model, specification, and quantity of all electronic components are correct.
Pretreat components, such as pin bending and cutting, to ensure that they meet the hole position requirements on the PCB board.
Check the surface of components for contaminants such as oil stains and dust, and clean them if necessary.
PCB board inspection
Ensure that the quality and specifications of the PCB board meet the requirements, check whether the board surface is smooth, whether the hole position is accurate, and whether there is a scratch or short circuit phenomenon.
For multi-layer PCB boards, check whether the inner line is connected correctly and whether there are open or short circuit problems.
Second, plug-in skills
Manual plug-in
When manually inserting, the operator needs to have rich experience and good eyesight in order to accurately insert the component into the hole on the PCB board.
Follow the principle of first small and then large, first inside and then outside, to avoid large components blocking the insertion position of small components.
When inserting components, the force should be moderate to avoid damaging the component pins or holes on the PCB board.
Pay attention to the direction and polarity of the components to ensure that they are inserted correctly. Note For components with directional markings, such as diodes and electrolytic capacitors, insert them in the direction marked.
Automatic plug-in
When using automatic inserts, it is necessary to perform regular maintenance and calibration of the equipment to ensure stable operation and accurate plug-in.
Select the appropriate feeder and plug-in head according to the packaging and shape requirements of the components.
Monitor the operating status of the automatic insertion machine, detect and deal with abnormal conditions, such as card material, plug-in offset, etc.
Third, welding skills
Crest welding
Adjust the temperature of the wave welding furnace, the speed of the conveyor belt, the height of the wave peak and other parameters to ensure the welding quality.
Before welding, ensure that the flux on the PCB board is evenly coated to avoid problems such as virtual welding and short circuit during welding.
During the welding process, observe the shape and stability of the soldering wave peak, adjust the welding parameters in time to ensure the welding quality.
After the welding is completed, check the quality of the solder joints, including the fullness of the solder joints, smoothness, whether there are defects such as virtual welding and short circuit.
Hand welding
For special components or solder joints that cannot be handled by wave soldering, manual welding is used for repair welding.
Manual welding, select the appropriate electric soldering iron and solder wire, control the welding temperature and welding time.
Before welding, the solder joint is preheated to avoid cold welding in the welding process.
After the welding is complete, check the quality of the solder joints to ensure that the welding is solid, free of virtual welding, short circuit and other problems.
Fourth, quality control skills
Process control
During the processing of plug-in, key control points are set to monitor and adjust key steps such as plug-in and welding in real time.
AOI (Automatic Optical Inspection) equipment is used for online inspection of PCB board to find and deal with welding defects in time.
Inspection of finished product
Carry out comprehensive functional and performance testing of the PCB board completed by the plug-in processing to ensure that the product quality meets the standard requirements.
Using ICT (online testing), FCT (functional testing) and other test methods, PCB board electrical performance testing, functional testing, reliability testing, etc.
Fifth, other tips
Antistatic measures
During plug-in processing, take ESD measures, such as wearing an ESD bracelet or using an ESD floor mat, to prevent electrostatic damage to components.
Environmental cleanliness
Keep the plug-in processing area clean to prevent debris and foreign matter from contaminating components and PCB board.
Regular cleaning and maintenance of the plug-in processing equipment to ensure its normal operation.
Personnel training
Regular training and assessment of plug-in processing operators to improve their operational skills and quality control awareness.
Operators are encouraged to share experience and skills to jointly improve the quality and efficiency of plug-in processing.
