Mounting method for electronic device elements

A method for mounting an electronic device element on a mounting substrate comprising:

• providing a bonding tool having a pressing surface to contact a reverse surface of the electronic device element having metal bumps located on a surface thereof, in which a vacuum opening to apply a suction force to the electronic device element is provided on the pressing surface of the bonding tool;
• positioning the vacuum opening on the reverse surface of the electronic device element at a location where no metal bumps of the electronic device element are provided when the vacuum opening applies the suction force to the electronic device element;
• placing the electronic device element on the mounting substrate;
• and
• applying an ultrasonic wave to the bonding tool thereby mounting said electronic device element on said mounting substrate;
• wherein
• a maximum length of the pressing surface of the bonding tool in the ultrasonic-wave-oscillation direction is at least about 0.5 times a maximum length of the reverse surface of the electronic device element in the ultrasonic-wave-oscillation direction.

A method of manufacturing a surface acoustic wave unit comprising the steps of:

• providing a surface acoustic wave unit having metal bumps located on a surface thereof;
• providing a bonding tool having a pressing surface;
• providing a mounting substrate;
• providing a package having side walls;
• installing the surface acoustic wave unit and the mounting substrate in the package;
• keeping the pressing surface of the bonding tool in contact with a reverse surface of the surface acoustic wave unit;
• applying an ultrasonic wave to the bonding tool such that the bonding tool does not interfere with the side wells of the package, thereby mounting the surface acoustic wave unit on the mounting substrate;
• and
• closing the package using a cap;
• wherein
• a maximum length of the pressing surface of the bonding tool in the ultrasonic-wave-oscillation direction is at least approximately 0.5 times a maximum length of the reverse surface of the surface acoustic wave unit in the ultrasonic-wave-oscillation direction.