An interconnect structure of an integrated circuit and manufacturing method therefor are provided, relating to an interconnect structure of flexible packaging. The interconnect structure includes a first and a second conductive pads. A plurality of tiny and conductive first pillars is respectively formed on the first and second pads. With different densities and thicknesses of the first and second pillars, a contact strength can be generated when the pillars interconnecting with each other, such that the pillars are connected closely. Furthermore, the interconnect structure can also be used to connect with fibers made of conductive materials. Moreover, the higher the density of the pillars, the stronger the contact strength. And, electronic substrates and active or passive electronic elements can be stuck on the other side of each pad. Therefore, the interconnect structure can maintain flexibility and have high reliability without being enhanced by any thermosetting polymer.