SEMICONDUCTOR DEVICE AND A MANUFACTURING METHOD OF THE SAME
A semiconductor device having a structure in which the structure is laminated in many stages is made thin. A reforming area is formed by irradiating a laser beam, where a condensing point is put together with the inside of the semiconductor substrate of a semiconductor wafer. Then, after applying the binding material of liquid state to the back surface of a semiconductor wafer by a spin coating method, this is dried and a solid-like adhesive layer is formed. Then, a semiconductor wafer is divided into each semiconductor chip by making the above-mentioned reforming area into a division origin. By pasting up this semiconductor chip on the main surface of the other semiconductor chip by the adhesive layer of the back surface, a semiconductor device having a structure in which the semiconductor device is laminated in many stages is manufactured.
1 . A semiconductor device comprising:
a wiring substrate including a main surface, a plurality of wirings formed on the main surface, a plurality of first electrodes formed on the main surface, a back surface opposed to the main surface, and a plurality of second electrodes formed on the back surface;
a first semiconductor chip including a first front surface, a plurality of first bonding pads formed on the first front surface, and a first rear surface opposed to the first front surface, and mounted over the main surface of the wiring substrate via a first adhesive layer such that the first rear surface faces to the main surface;
a second semiconductor chip including a second front surface, a plurality of second bonding pads formed on the second front surface, and a second rear surface opposed to the second front surface, and mounted over the first semiconductor chip via a second adhesive layer such that the second rear surface faces to the first front surface;
a sealing body sealing the first semiconductor chip and the second semiconductor chip; and
a plurality of external terminals formed on the second electrodes, respectively;
wherein a roughness of the first front surface is smaller than a thickness between the second back surface and the first front surface of the second adhesive; and
wherein the thickness between the second back surface and the first front surface of the second adhesive layer is thinner than that between the first rear surface and the main surface of the first adhesive layer.
2 . A semiconductor device according to claim 1 , wherein the main surface has a greater irregularity compare to the irregularity of the first front surface.
3 . A semiconductor device according to claim 1 , wherein the second adhesive layer is formed by using a spin coating method.
4 . A semiconductor device according to claim 1 , wherein the first adhesive layer is a die attach film having a film substrate.