| With the improvement of IC chip integration and the enhancement of device function,increasing number of I/O integrated circuit, high frequency and high-speed components of continuous increasing of packaging performance requirements, which make solder ball production process attract many scholars research, solder ball made by droplet jetting technology is one of the hot research topic at present. Metal droplet jetting technology driven by Lorentz force was proposed after the study of present situation and tendency of the development of the existing jetting pattern. Metal jetting device is driven by Lorentz force, which has no mechanical moving parts, no impact, no wear, no leakage and can be fast response, quantitative and drop- on-demand, etc.Based on the conditions of the Lorenz force, the solder jetting device is designed, the solder micro jetting experimental platform is built. The solder micro jetting system includes the solder jetting device and five modules which consist of the heating module, the circuit control module, the constant magnetic field module, the solder ball collection module, the electric field module, the design process of the five modules and solder jetting device are introduced in detail.By the high-speed camera recording the solder jetting process, the effect factors on the diameter of the jetting solder which consist of current, voltage, the nozzle diameter, the jetting frequency, the pulse width, the heating temperature of solder, the collection distance,collection media are investigated by experiments. The experimental results show that with the increase of the nozzle diameter and the distance of collection, the formed solder ball diameter is also increasing; with the increase of the current, the solder ball diameter increases like zigzags; with the increase of the jetting frequency, the solder ball diameter is decreasing; the solder temperature between 225 ? to 245 ? has a great influence on the solder ball diameter and affecting solder jetting at the same time, after 265?, the heating temperature is rising, the solder ball diameter has a small change; the solder ball diameterfollowing the voltage variation is like a tub curve; at the beginning of the jetting, because of the mutation of the current and voltage wave, the electric pulse width has a greater influence on the solder ball diameter, later, the current and voltage wave level off, the electric pulse width has no influence on the solder ball diameter.The solder ball consistent experiment and the metal special-shaped parts are done by using the solder jetting device. The 300?m nozzle is adopted, the 50 solder balls average diameter of the jetting forming is 2.61 mm, the standard deviation is 38.89?m, and the diameter fluctuation is ±1.5%. On the basis, making solder metal special-shaped parts and solder metal wires, the feasibility of Lorentz force driving solder jetting technology is preliminarily verified.Through experiments, the flow channel of the inside chamber of solder jetting device is easily blocked; the inside chamber of solder micro jetting device is easy wetting solder,easy corrosion producing solder splash and not enough smooth; the nozzle demounts troublesomely. To solve these problems, the flow channel of the inside chamber of solder jetting device is chamfered cone angle; the inside chamber of the micro solder jetting device is plated titanium; the nozzle is replaced by the screw-type and the inside of the nozzle has a cone angle.The 250?m nozzle is used for the improved solder jetting device in the experiment, the average diameter of the 50 solder balls is 1.55 mm, the standard deviation is 43.02?m, and the diameter fluctuation is ±2.8%.when the nozzle is 150?m, the average diameter of the22 solder balls is 518?m. On the basis, the solder metal special-shaped parts are made, the experimental result is good. |
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