Method of ultrasonic mounting and ultrasonic mounting apparatus using the same

Abstract

A method of ultrasonic mounting can increase mounting efficiency by using high-frequency ultrasound and can also mount large semiconductor chips. The method ultrasonically bonds a semiconductor chip 52 to a substrate 50 using an ultrasonic mounting apparatus including a horn 15 that propagates ultrasonic vibration of an ultrasonic vibrator, the horn 15 being made of a ceramic that has a higher vibration propagation speed than metal. The method includes steps of disposing the substrate 50 on a stage 13 , disposing the semiconductor chip 52 on the substrate 50 , and placing the semiconductor chip 52 in contact with a convex part 15 a provided on the horn 15 and applying ultrasonic vibration to bond the semiconductor chip 52 to the substrate 50.

1 . An ultrasonic mounting apparatus that includes a horn for propagating ultrasonic vibration of an ultrasonic vibrator and that bonds a semiconductor chip to a substrate by placing the semiconductor chip in contact with a convex part of the horn and applying ultrasound,
 wherein the horn is formed of a ceramic that has a higher vibration propagation speed than metal.   
   
   
       2 . An ultrasonic mounting apparatus according to  claim 1 ,
 wherein stepped parts are provided in walls of the convex part.   
   
   
       3 . An ultrasonic mounting apparatus according to  claim 1 ,
 wherein a spacer, which is composed of a material that has a vibration propagation speed of an intermediate magnitude in between a vibration propagation speed of the ultrasonic vibrator which is made of metal and a vibration propagation speed of the horn which is made of ceramic, is interposed at a joint between the ultrasonic vibrator and the horn.   
   
   
       4 . An ultrasonic mounting apparatus according to  claim 1 ,
 wherein a male screw for joining to the horn is formed on the ultrasonic vibrator and a coating layer composed of a soft metal material such as copper or solder is formed on the male screw.