The Reseach Of The Key Technology For Detecting PCB Solder

As the electronic and large-scaled integrated circuit technology develops,Automated Optical Inspection is becoming more and more widespread in surface mount technology(SMT). The quality determination of the PCB solder joints, which is one of the most critical factor for quality of products, particularly is important so that this article is about analysis and design of key technologies on the quality determination of the PCB solder joints.The research proposed several common characteristics of defective solder joints and analysis about the incident forms and common structures in the existing light source based on RGB ring hierarchy theory of reflection of light and high brightness color tilt diagram theory, according to Solder joint basic features and surface description method.Otherwise, the RGB ring level positive direct light source structure conformed to the need to detect welding spots was showed and the design of RGB ring level positive direct light source was finished. According to the need of practical determination,dimensions and distinguishability of FOV, LED light source which had best sensitivity to RGB tricolor for suited CCD sensors, by choosing the functions of industrial CCD camera and lens. Tests were finished to determine relevant parts of light source and imaging system. The number of phase method was assumed, that divide each ring of LED into several phases or a phase including eight or twelve rings of LED, whose fixed voltage was 24 V, to reduce circuit heating and improve the luminescence homogeneity and stability of the whole LED ring. The simplified double screw model and mathematical model were completed to improve the stability and positiona I accuracy of objective table drive system, based on simulated analysis by software and verification by experiments testing.In the proposed design, an idle channel was obligated to be convenient for maintaining and increase the light path. the method was completed, that decide the quality of welding spot and locate the components by extracting tricolor RGB and detecting the color proportion in sensor filed, according to RGB tilted high brightness diagram theory and Color of trichromatic theory.