Image pickup apparatus for endoscope

An image pickup apparatus for an endoscope, the image pickup apparatus comprising:

• an image pickup device including a row of external electrodes provided on an end portion of an image sensor, the image pickup device having a bottom area of no less than 0.25 mm2 and no more than 4 mm2;
• and
• a wiring board including end portion electrodes ultrasonically bonded to the external electrodes,
• wherein a saw mark is formed by grinding in a back face of the image pickup device, the back face opposing a surface on which the image sensor is disposed, the saw mark is inclined at an angle of no less than 80 degrees and no more than 100 degrees relative to a direction of the row of the external electrodes in the entire back face, and a surface roughness Rz, in a direction orthogonal to the direction of the row of the external electrodes, of the back face is no less than 0.5 μm and no more than 10 μm.

A method for manufacturing an image pickup apparatus for an endoscope, the image pickup apparatus including an image pickup device including a row of external electrodes provided on an end portion of an image sensor, and a wiring board including end portion electrodes ultrasonically bonded to the respective external electrodes, the method comprising:

• forming a plurality of image sensors on a first principal surface of a semiconductor substrate;
• cutting the semiconductor substrate to produce a plurality of image pickup devices;
• re-arranging the plurality of image pickup devices in a grinding machine in such a manner that a direction of saw marks to be formed is inclined relative to a short axis direction of the image pickup device;
• grinding back faces of the plurality of image pickup devices, the back faces opposing the respective surfaces upon which the image sensors are disposed, to form saw marks inclined relative to a vibration direction of ultrasonic vibration during ultrasonic bonding;
• and
• ultrasonically bonding the external electrodes of the image pickup devices, mounted on an anvil of an ultrasonic bonding apparatus, and the end portion electrodes of the wiring board to each other.