引线成形中劈刀与引线拐点运动学关系研究

Study on Kinematic Relations for Capillary and Wire Kink Points in Wirebonding Loops

基于引线键合视频分解得到的图像序列,分别采用相位相关法和点到弦距离累积曲率估计算法获得了劈刀和引线拐点的运动轨迹。根据运动轨迹计算了劈刀和拐点对第一键合点的旋转角及速度变化分布,通过分析两者的旋转角和速度变化,得出了在键合过程中,劈刀和引线运动的相关性规律。由于劈刀下降段的运动是圆周运动,利用圆拟合法拟合得到了下降段劈刀和拐点轨迹圆的圆心位置,结果表明,各圆心的相对位置与引线线形存在对应关系。该方法为研究引线成形中劈刀与引线结构动态特性提供了有价值的参考。

The video of wire bonding was divided into continuous image sequences.The trajectories of capillary and wire＇s kink points were obtained by phase correlation algorithm and chord-to-point distance accumulation technique respectively.The velocity distributions and rotation angles of capillary and kink points to the first bonding were calculated according to the trajectories.The correlation rules of capillary and wire movement were obtained by analyzing their rotation angles and velocity distributions in wire bonding.For the capillary falling stage is circular motion,the circle center positions of locus circles were obtained by fitting the falling stage trajectories.The corresponding relation between circle center positions and wire profiles was found.The proposed method provides valuable reference for further studying the dynamics characteristics of the capillary and wire in the wire bonding looping formation.