Flat Package Using Three-Layer Film
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-27
A flat package using a three-layer film is disclosed, which is effective to improve heat dissipation and increase I/O density. As shown in the figure, the three-layer film consists of an upper heat dissipative layer, such as copper, an intermediate insulating base layer, such as polyimide, and a lower conductive layer, such as copper. The conductive layer is patterned to provide leads. The IC chip is mounted on the lower surface of the heat dissipative layer through openings in the conductive layer and the base layer and wire-bonded to the leads. The chip is encapsulated by a plastic material. The base layer extends to the end of the leads to provide mechanical reinforcement and protection for the leads. This enables use of a thinner conductive layer for the leads and facilitates increasing the lead or I/O density.