Developing And Studying On Bonding Head Of Die Bonder

In this article, according to the process of chip placing in LED packaging, intents to develop an LED die bonder key components:welding head、 thimble institutions、 wafer transfer mechanism, combined with the virtual prototype technology and finite element analysis simulation of the dynamic design agency analysis, simulation results focus butt head comparison and evaluation mechanism. The design has a certain theoretical significance and practical application value.The main researches in this dissertation are as follows:(1)The design of die bonding mechanismDie bonding mechanism adopt the way of parallel mechanism (theta direction and Z direction), the crank rocker organization coordination with the eccentric shaft to complete from taking chips to the movement of the chip with belt drive. Use of dead point position and by crank rocker mechanism transmission chips, it can improve the die bonding’s end resolution, high accuracy; Use of belt transmission can reduce the motor vibration on the impact of the crank rocker; Using eccentric shaft drive slider-crank mechanism to complete the movement of Z direction can reduce the vibration of the Z direction. Adopt a rigid connection with the crank bearings can improve the response speed Z movement, to avoid delays and vibration generated by the traditional spring return.(2) The design of the Ejector and wafer transfer mechanismThe ejector institutions with small eccentricity of the eccentric institutions cooperate with a pair of bearing thimble rigid connection fittings, improve the response speed thimble agencies, and driven by motor directly, rotary screw can adjust the ejector is located in the right position of the chip by hand. Structure simple, practical, and can realize high speed and high precision finished short prickles chip movements.Wafer transmission mechanism adopts the series XY worktable drag cantilever bracket which is fixed on multi-chip rings, replace the wafer ring can reduce time, increase the diversity of chip solid crystal; belt driven multi-wafer rotating ring is completed by positioning precision positioning cylinder, making it more efficient and accurate completed single chip was learned.(3) The optimization of the welding head to calculate the size of crank rockerThe key welding head mechanism adopts crank rocker mechanism, the performance impact of solid crystal quality. Transmission angle is the criterion crank and rocker mechanism’s transmitting performance. Vibration is easy created because of small transmission angle. This chapter through to rocker swing angle90°and the average transmission angle as the largest design goals, the length of the crank rocker mechanism as the design variables for optimization. Experimental results show that when the average transmission Angle is73.9975°, can achieve the best transmission results, l1=0.6062l3, l2=0.9945l3, l3=l3and l4=0.9205l3, l1,l2, l3and l4, respectively the crank, connecting rod, rocker and the length of the scaffold pole.(4) Key results of the bonding process are obtained by simulating the mechanical bonding motion with the dynamics analysis software ADAMS and ANSYS flexible body, in order to estimate whether to meet the design requirements, which include the comparison analysis of crank rocker mechanism and the force of contact and vibration displacement in chip position. Experiment results show that the two kinds of contact force are meet the requirements within the scope of the75gf-85gf; Before optimization theta direction of vibration displacement is1.07um, balance time to be12.8ms, the optimized theta direction vibration displacement is0.43um, balance time to be4.96ms, transmission effect optimization is obviously better than before.In this paper, three-dimensional design software SolidWorks to design and virtual prototype assembly and crank rocker mechanism butt heads agencies do optimization, simulation comparative evaluation using ADAMS butt heads, and ultimately concluded that the maximum design based on the average transmission angle weld head mechanism significantly better performance.