Patent ID: 7044355

Claim:
A bonding apparatus which performs bonding with a focal point position varied for an object of bonding that has a plurality of different heights, said bonding being performed using an optical measuring instrument that includes: an image focusing lens, a two-dimensional image sensor that detects an image of each object of bonding created by said image focusing lens, and a light path that passes through a parallel flat plate, said light path being disposed at an intermediate point in a light path that extends from said object of bonding toward said two-dimensional image sensor; wherein said bonding apparatus is characterized in that said light path that passes through a parallel flat plate is a light path which: receives light rays from said object of bonding, conducts light rays from said object of bonding to said two-dimensional image sensor after causing said light rays from said object of bonding to pass twice through a parallel flat plate that has a refractive index and thickness that corresponds to a height of said object of bonding, and varies a focal point position of an optical system while eliminating by mutual cancellation an image deviation generated by a passage of said light rays through said parallel flat plate.