Patent ID: 7514294

Claim:
A manufacturing method of a semiconductor device, comprising the steps of: (a) preparing a wiring substrate which has a main surface and a back surface which become an opposite side mutually along a thickness direction; (b) mounting a first chip over the main surface of the wiring substrate; and (c) piling up a second chip over the first chip, and adheres the second chip over the first chip by an adhesive layer of solid state of the back surface; wherein a formation step of the second chip comprises the steps of: preparing a wafer which has a main surface and a back surface which become an opposite side mutually along a thickness direction; forming an element in the main surface of the wafer; forming a wiring layer over the main surface of the wafer; making the wafer thin; forming a reforming area used as a division origin of the wafer in a later wafer cutting step by irradiating a laser along a chip separating region of the wafer, putting together a condensing point with an inside of the wafer; applying a binding material of liquid state to the back surface of the wafer by a spin coating method, and forming the adhesive layer of the solid state over the back surface of the wafer; and cutting the wafer with the reforming area as a starting point, and obtaining the second chip which has the adhesive layer of the solid state over the back surface.