Thin Optical Head With Flip-chip Bonded Module For CD-ROM Drives

The use of CD-ROMs has grown enormously in recent years as they have become a favored media for electronic books and software applications, and this has created a great demand for more compact optical heads for CD-ROM drives. In an attempt to improve upon previous efforts at greater compactness), authors developed a compact optical module which integrated a laser diode chip, a photodiode chip, and a holographic optical element, and which could be combined with an objective lens and an actuator to produce a compact optical head). This paper describes a further improvement in compactness achieved using a new flip-chip bonded module design. Optical module size is 6mm(W)x6mm(D)x1.64mm (H), its weight is 0.25g, and head thickness is less than 7mm, including the objective lens working distance.