| Adhesive jet dispensing has been widely used in many applications such as microelectronic assembly, optoelectronics, and micro-electro-mechanical system packaging. Jet dispensing technology is considered to be the next generation of dispensing technology. Existing jetting dispensing technology is monopolized by ASYMTEK and other few companies. The existing jet dispensers are mainly pneumatic drive. However, the frequency response and the driving force of pneumatic drive have limitations, and fluid dispensing is facing the challenge of advanced and high throughput packaging. In order to break the technological monopoly and to improve the existing jet dispensing technology, an electromagnetic drive dispenser is proposed.In this paper, the backgrounds of dispensing and electromagnetic drive are introduced; and then the principle of the jet dispenser is introduced. Following that a brief description of the design process of the structure of the dispenser is given, and its drive circuit is designed according to the features of the dispenser, the circuit's working principle and the selection of key components is described in detail. The characteristics of a sample electromagnetic drive dispenser including spring stiffness, the electromagnetic force and the displacement of the needle are measured and analyzed. Meanwhile a simulation model is made by using Matlab/Simulink tools in order to analyze how some factors influence on the dispenser. And several improved suggestions are given. The improved results are verified by experiments. Finally> some dispensing experiments are made and the results show that the dispenser can realize a jet dispensing at the speed of 6 drops/second when the viscosity of the glue is about 1.2 Pa.s. So it can do well in microelectronics packaging. |
PDF Full Text Request