Position Force Switching on Flip Chip Machine Bonding Axis

Compared with the traditional die bonding machine, the flip chip machine combines die bonding and wire bonding interconnection process together. This advanced packaging method can greatly reduce the electrical signal interconnection length. So, the integrated circuits can be much smaller, denser, and have better electrical performance. Because of this advantage, flip chip technology benefits the miniaturization of electronic products. The flip chip machine has become a hot topic. Voice coil motor is widely used in microelectronic packaging equipment like the bonding head of the die bonder because it's characterized with fast response and high acceleration. To ensure the bonding quality, which is good for the integrity and quality of IC chips, the contact force and speed need to be accurately controlled when the bonding head touches the IC surface. It is better that the bonding head control is switched from position control to force control when necessary. This is called position-force switching. Practice proves that too large contact force will damage the chip. And of course, too small force is not enough to fix the chip to substrate. This paper introduces the working process, control structure of the flip chip machine bonding process, and analyze the performance of position force switching according to speed change. By studying various parameters, including Start_Dac, search speed tolerance, switching lost count, etc., the influence of various conditions is analyzed with the help of sensors. Based on the experimental data, there is no excessive bonding force overshoot in bonding process, and the force during switching is controlled stable and fast, which can be used in flip chip bonding mass production.