Electronic package with a device positioned above a substrate by suction

Abstract

An electronic package including a first circuitized substrate (e.g., printed circuit board) a second, flexible circuitized substrate (e.g., polyimide), an electronic device (semiconductor chip) and a metallic (e.g., aluminum) heat sink member joined to the first substrate to provide a cover for the package's internal components. A predetermined quantity of liquid material (e.g. wax or oil) is located between a defined surface of the chip and a corresponding internal surface of the heat sink member during assembly of the package, this material possessing a surface tension sufficient to create a suction force between the device and heat sink so as to elevate the device in a spaced position from (e.g., above) the first circuitized substrate during said assembly. Should a liquid material such as oil be utilized, this material remains in the liquid state during package operation to continuously provide the defined suction force sufficient to maintain the device at the elevated position. If a material such as wax is used, this material becomes solidified and remains so during package operation to thus maintain the device in elevated position by adhesion. Improved heat dissipation for the package and ease of assembly thereof is thus possible.