摘要 |
A flexible polyimide film is used to support an array of precisely located contact bumps which are used to probe die on a wafer of semiconductor circuits, or an unmounted integrated circuit die, several integrated circuits, or hybrid devices. By utilizing a standard I/O contact pattern for the flexible film and fabricating the membrane assembly of interconnects on an aluminum substrate, it is possible to produce a more reliable probe card, while reducing the fabrication time and costs for the probe card. The polyimide film must be selected to have a CTE of 3 to 5, which is only about 1/5 to 1/7 as great as the CTE of the aluminum substrate on which the film is formed. This produces a critical degree of compressive stress in the polyimide film, and a resulting "bow" of the film when the central area of the aluminum is etched away.
|