Development of 0.45-mm thick ultra-thin small outline package

The authors developed an ultra-thin small outline package (UTSOP) with a package thickness of 0.45 mm. In spite of its significant reduction relative to conventional TSOP's (1.0-mm thick), the inner leads of the lead frame can be bonded to the electrodes on the chip with gold wire as with conventional plastic package. It is feasible since the lead that supports the chip (support lead) through insulating tape is placed on the top side of the chip. Establishing molding technology and overcoming problems such as warping of package or chip during assembly were key points in the development of the UTSOP. The UTSOP retains the same level of reliability as a TSOP.<
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