Impact of high frequency transducer on capillary design

Higher transducer frequency on the wire bonder is developed and introduced into the market. One of the key driving forces is to reduce the bonding time for higher uph especially for Cu wire bonding. On the other hand, there are few capillary outline designs are deployed newly to reduce displacement in order to achieve efficient energy transmission. The special capillary outline design is necessary to minimize any pre-damage on the active metal line structure underneath of the bond pad. The selection of capillary outline design becomes more crucial and cautious when wire bonder with high transducer frequency is being deployed. This paper will study the interaction of two transducer frequencies (>130KHz and <;130kHz) and two different capillary outline designs bonding on sensitive bond pad metal structure design. The sensitive bond pad metal structure design required some capillary outline design changes as compared to the traditional standard capillary outline design. Initial study compares the process window range during the initial process optimization cycle with different capillary outline design with high frequency transducer of >130Khz. The results shown there is significant difference of parameter window range between different capillary outline design. Capillary vibration check also carried out by using laser vibrometer. The vibration amplitude is being measured on the capillary tip as well as on the transducer with US fix setting. This paper also studies and compares the amplication ratio.