Thermal stress absorbing interface structure and wafer level package using the same and method for manufacturing the same

摘要

PURPOSE: A thermal stress absorption structure, a wafer level package using the same, and a method for fabricating the same are provided to enhance reliability of connection between a chip and a substrate by improving a design of a wafer level package. CONSTITUTION: A thermal stress absorption interface structure(20) is arranged between a semiconductor IC(Integrated Circuit) chip and a surface mounted structure. The thermal stress absorption interface structure(20) has a structure of a flat multi-layer. The thermal stress absorption interface structure(20) includes the first polymer layer(26) and the second polymer layer(28). The second polymer layer(28) is formed on a whole surface of the first polymer layer(26) in order to absorb thermal stress. The first polymer layer(26) has an elliptical shape. The first and second polymer layers(26,28) have different moduli of elasticity. The thermal stress absorption interface structure(20) has a conductive bump pad(30) and a side portion. The conductive bump pad(30) has the first end portion(32) and the second end portion(34). A conductive bump(21) is formed on the conductive bump pad(30).