Research For Laser Soldering Technique Of Ceramic Capacitor

Ceramic capacitor is one of extensive use of electronic components in electronic equipment.It is widely used in the circuits such as isolation,coupling,bypass,filter,tuning circuit,energy conversion and control.However,the traditional ceramic capacitor soldering methods such as infrared,hot air soldering method has shortcomings of high energy consumption,complex and bulky control system.The laser soldering is suitable for the "lead-free" assembly of micro and small electronic components due to its local heating,rapid heating and rapid cooling.However,it cannot realize the reflow profile needed for the ceramic capacitor soldering.In this paper,the design of laser gradient energy band and the design of laser uniform energy band are used to realize the ceramic capacitor reflow profile,which can finish the double-side soldering of ceramic capacitor with high efficiency and low consumption.The main contents of this paper are as follows:(1)Analysis the main factors affecting the ceramic laser soldering,establish the Ceramic laser heat conduction model.(2)Design of laser gradient energy band and laser uniform energy band.The energy distribution characteristics of the laser gradient energy band and the temperature rise characteristic of the ceramic capacitor are analyzed.Uniform energy with different laser power density corresponding to different temperature characteristics is analyzed.(3)Different schemes of laser soldering splicing are designed to realize the reflow profile: two symmetrical laser gradient energy band splicing,three different laser power density of laser uniform energy band splicing,Laser gradient energy band and laser uniform energy band hybrid splicing.The advantages and disadvantages of different splicing schemes are compared and analyzed.(4)Based on two symmetrical laser gradient energy band splicing experiments,the soldering effect and efficiency of splicing of two laser energy gradient distribution soldering devices in different transmittance are analyzed.The results show that the design of laser gradient energy band and the design of laser uniform energy band can achieve the ceramic capacitor reflow profile and high efficiency and low consumption of soldering ceramic capacitors,in which three different laser power density of laser uniform energy band splicing is the best Splicing scheme.