| With the development of science and technology,such as mobile phones and computers,and are becoming more and more compact and lightweight.people have more requirement in the functions of electronic devices,This requires a high degree of integration of chips.The chip flip-chip is different from the traditional wire bond packaging method.It is an advanced packaging technology that interconnects chip to substrate,with high integration.In the flip-chip positioning process,not only the precise positioning in the XY direction,but also the θ direction around the Z axis is required,which requires XYθ three axis to cooperate precisely.Considering the difficulty in realizing the offset of the wafer level chip alignment,and aiming at the demand of large stroke and high precision in the process of wafer level chip detection,a new type of XYθ nano-displacement compensator based on flexible hinges is designed in this paper.It is integrated and assembled on macro motion stage by macro-micro compounding,which is used to compensate for the motion accuracy of the existing macro positioning stage in the three directions of XYθ in real time.This system uses a heterogeneous RELM intelligent position deviation algorithm as a visual detection device,and combines the PID motion control algorithm as a feedback to further improve the positioning accuracy.Finally,the XY direction of the whole positioning platform is 300 mm,the compensation range of the XY direction is 100μm,the positioning accuracy is ±0.5μm,and the angular displacement positioning accuracy is ± 20μrad.The display of these data can meet the requirement of flip chip positioning for chips with large and fine spacing.The main contents of the paper are summarized as follows:1.The research background of the macro-micro composite positioning stage is expounded,in-depth study of domestic and foreign research status and development trends,analyze the key technologies of macro-micro composite precision positioning stage with angular displacement compensation,and determine the research objectives of this paper.2.The stroke and accuracy of the existing macro-position stage are verified by laser interferometer to determine the stroke of the micro motion platform.In-depth study of the relevant theoretical knowledge of flexible hinges,combined with the lever principle design flexible hinge lever displacement amplification mechanism.3.Based on the design requirements of the stage about three degrees of freedom,the micro-motion stage is optimized in size and shape,and get the final micro positioning platform.Compliance matrix method is applied to analyze the output flexibility,input flexibility and amplification displacement ratio of 3-RRR micro-position stage.4.Using ANSYS analysis software simulation and verification,the 3-RRR micro-position stage was analyzed statically and modally,and the motion simulation diagram of the mechanism was obtained.The pseudo-rigid body model was established on the micro-position stage,the Jacobian matrix was calculated,and the input-output relation formula was obtained,but the effect was general.Therefore,a heterogeneous RELM neural network was used to simulate the input and output relations of the black box model by training a large amount of data,and the effect is improved obviously.5.A macro and micro positioning stage experimental system was set up.The open loop control experiment and closed loop control experiment of the micro positioning platform are carried out.Sub-pixel vision was used to detect positioning errors,and the accuracy of RELM neural network and PID closed-loop control was verified. |
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