In the process of PCBA surface mount processing, although we strive for perfection, it is inevitable to encounter some processing defects. Understanding these common defects is crucial for improving production quality and efficiency.
1、 Poor welding
Virtual soldering: Incomplete or unstable solder joints may cause circuit breakage or instability. Cold welding: Insufficient welding temperature, incomplete melting of solder, resulting in poor welding points. Continuous soldering: An unexpected connection between two or more solder joints, causing a short circuit.
2、 Component mounting issues
Component offset: Components are not accurately mounted in the predetermined position, which may result in poor electrical connections. Component missing: Due to nozzle issues or feeder malfunctions, some components were not properly mounted. Component polarity error: For example, polarity components such as diodes and transistors are reverse mounted.
3、 Substrate issue
Substrate warpage: Deformation of the substrate caused by improper heat treatment or substrate material issues. Pad detachment: The separation of substrate pads from the substrate is usually caused by thermal stress during the soldering process.
4、 Printing issues
Uneven solder paste printing: Excessive or insufficient solder paste can affect the quality of soldering. Printing offset: The solder paste is not accurately printed on the solder pad, which may result in poor soldering.
5、 Testing and Inspection Issues
Functional test failed: The PCBA failed the functional test, possibly due to component damage, soldering issues, or design errors. Visual inspection omission: Manual visual inspection may overlook certain defects, especially minor or concealed defects.
6、 Other common questions
Electrostatic damage: Electrostatic discharge may cause component damage, especially in dry environments. Pollution: Dust, impurities, and other pollutants may cause poor welding or short circuits in circuits.
