Processing method for wafer

Abstract

A processing method for a wafer includes: preparing a wafer which has a device region having plural devices formed on a surface of the wafer; and a peripheral reinforcing portion which is integrally formed around the device region and has a projection projecting outwardly on a rear surface of the wafer. The processing method further includes: holding the wafer on a holding surface of a rotatable holding table such that the rear surface of the wafer is exposed and the surface of the wafer closely contacts the holding table. The processing method further includes: thinning the peripheral reinforcing portion by cutting and removing at least the projection of the peripheral reinforcing portion of the wafer by using a cutting tool having a rotational shaft parallel to the holding surface, while rotating the wafer by rotating the holding table after the holding of the wafer. The peripheral reinforcing portion is thinned so as to have a thickness equal to or thinner than that of the device region by the thinning.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are a surface side perspective view, a rear surface side perspective view, and a cross sectional view which show a wafer processed in an embodiment according to the present invention.

FIG. 2 is an overall perspective view of a wafer processing apparatus of the embodiment according to the present invention.

FIG. 3 is a plan view of the wafer processing apparatus shown in FIG. 2.

FIG. 4 is a plan view which shows a wafer hand of wafer supply section of the wafer processing apparatus.

FIGS. 5A to 5D are side views which show actions of the wafer hand in turn.

FIGS. 6A and 6B are a plan view and a cross sectional view which show a dicing tape and a dicing frame.

FIGS. 7A to 7H are side views which show an action example of the cutting blade in turn, the cutting blade cutting a peripheral reinforcing portion of the wafer.

FIGS. 8A to 8C are side views which show a process in turn, in which the dicing tape is applied to the rear surface of the wafer by a pressing roller.

FIG. 9 is one example of conventional method for removing a peripheral reinforcing portion.

FIG. 10 is a cross sectional view of the method shown in FIG. 9.

FIG. 11 is another example of conventional method for removing a peripheral reinforcing portion.

FIG. 12 is an enlarged view of the method shown in FIG. 11.

Claims

1. A processing method for a wafer, comprising: preparing a wafer which has a device region having plural devices formed on a surface of the wafer; and a peripheral reinforcing portion which is integrally formed around the device region and has a projection projecting outwardly on a rear surface of the wafer;holding the wafer on a holding surface of a rotatable holding table such that the rear surface of the wafer is exposed and the surface of the wafer closely contacts the holding table; andthinning the peripheral reinforcing portion by cutting and removing at least the projection of the peripheral reinforcing portion of the wafer by using a cutting tool having a rotational shaft parallel to the holding surface, while rotating the wafer by rotating the holding table after the holding of the wafer;wherein the peripheral reinforcing portion is thinned so as to have a thickness equal to or thinner than that of the device region by the thinning.

2. A processing method for a wafer according to claim 1, wherein the cutting tool has a width equal to or wider than that of the projection, and the cutting tool cuts from a top end surface of the projection in a thickness direction of the wafer, so that the cutting tool cuts and removes at least the projection.

3. A processing method for a wafer according to claim 1, wherein entry amount of the cutting tool with respect to the wafer in a thickness direction of the wafer is set such that an edge of the cutting tool corresponds to the rear surface of the device region, andthe cutting tool faces the projection and moves parallel to the holding surface, so that the cutting tool cuts and removes at least the projection.

4. A processing method for a wafer according to claim 1, wherein while the cutting tool moves relatively to the wafer parallel to the holding surface, the cutting tool cuts and removes at least the projection.

5. A processing method for a wafer according to claim 4, wherein the cutting tool moves parallel to an axial direction of the rotational shaft.

6. A processing method for a wafer according to claim 1, wherein a metal film is provided on a region of the rear surface which corresponds to the device region.