Duan Ji'an

Bump Thermal Management Analysis of LED with Flipchip Package

LED solid state lighting (SSL) has a good prospects, but there are some bottlenecks, the one is that efficiency of light emitting is not enough for general lighting, the other is too much heat generated by higher power which affect the efficiency and life of LED. Flipchips applying is good for improvement of efficiency of light emitting of LED and especially for thermal management. The effect of the layout and the number of bumps of LED flipchip to thermal management of LED light was analyzed by using FEM simulation. The results show that better effect of thermal management can get after optimizing layout of bumps, and also show that the more bump number used the better thermal management can get, but there is a best optimal number as there are some other limiting factors such as structure and cost

Optimization of a zoom mechanism with flexible hinge for dispenser valve

In order to improve the life span of the jet valve, a novel structure of zoom mechanism is proposed. A hinge of the new zoom mechanism is set vertically in the new structure, compared with the horizontally hinge arranged way of the traditional zoom mechanism. Mechanical simulation models of traditional and new zoom mechanisms are established to calculate the stress of the flexible hinge. It is found that the stress of the hinge is 0.5 times smaller than the traditional hinge, and the life span is more than 10 times longer than the traditional one. Experimental results confirmed that the life span of the new jet valve exceeds 10 million times, and will provide a new structure for high frequency and heavy load zoom mechanism.