JPS63134174A - Grinding wheel - Google Patents

Abstract

PURPOSE:To stabilize a blade to a grinding surface as well as to improve the extent of dischargeability for dust and sludge, by reducing each thickness of many blades tightly attached to the perimeter of a wheel lower surface, and setting up these blades obliquely in the rotational direction of a wheel. CONSTITUTION:A numerous blade 2a is a thin, square small piece of less than 2mm each, and a perpendicular of each small piece is tightly attached to the perimeter of a lower surface of a grinding wheel 1 in the diagonal direction to a rotational direction 4 of the wheel 1. Thus, a lot of blades 2a are attached whereby dischargeability for dust and sludge comes better, and these blades 2a can be made contact with a wafer 5 in a three-dimensional manner, so that these blades 2a are not largely varied up and down to a grinding surface, and stability is improved, thus the wafer 5 is polishable to a flat surface.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention grinds the back side of a semiconductor wafer during the semiconductor device manufacturing process to enable electrical connection on the back side and to process it so that it does not interfere with the assembly process. The present invention relates to a grinding wheel used in the back grinding process.

[Conventional technology]

Conventional grinding used in the back grinding process of semiconductor wafers8
1" wheel, as shown in the bottom view in FIG. 4 tal and the partial sectional view in FIG. As shown in Figure (b), the wafer 5 is scraped thinly from the side at the outer corner of each blade 3a.

Fig. 5 (al is the same) A partial bottom view of another example of the conventional grinding wheel, Fig. 5 (b) is a partial sectional view showing wafer grinding. 3b is a thin strip with a thickness of 1 mm or less, forming a wide ring, and its outer periphery is uneven like the teeth of a gear. Next, the wafer 5 is ground from the side along the surface using the corners of the outer peripheral convex portion.

[Problem that the invention seeks to solve]

The example shown in FIG. 4 described above has the disadvantage that since the blades and the wafer are in contact with each other on a plane, grinding debris and dirt may be inserted between the blade and the wafer and may damage the wafer.

In addition, in the example shown in Figure 5, since the tip of the thin blade is in linear contact with the wafer, the deflection of the blade and mechanical parts (K) causes large vertical fluctuations, making it impossible to obtain a flat surface. There is a drawback.

[Means for solving problems]

The wheel of the present invention improves the ability to discharge dust and sludge by making the blades as thin as 2 mm or less, and also enables two-dimensional contact with the wafer by arranging the blades diagonally. , ensuring the stability of the grinding surface.

〔Example〕

Next, the present invention will be explained by examples.

Figure 1 (ta) is a partial bottom view of one embodiment of the present invention;
b) is a sectional view for explaining grinding of a semiconductor wafer. In FIG. 1, a large number of blades 2a are
The blade is a thin rectangular piece that is smaller than the blade, and is fixed around the lower surface of the wheel 1 with the vertical surface of the piece obliquely with respect to the rotational direction 4 of the wheel 1. In this embodiment, a sufficient radial distance (referred to as depth) D between the tip and rear end of the blade 2a in the rotating direction 4 is provided, so even if the thickness of the blade 2a is thin, the grinding surface sufficient stability against Note that this oblique mounting greatly improves the strength of the blade and the ability to discharge dust and sludge.

2 and 3 are bottom views of a second embodiment and a third embodiment of the present invention, respectively. In FIG. 2, the blade 2b is bent into a dogleg shape, which has the effect of providing good vertical stability when attached to the wheel 1.

Also, in FIG. 3, the blade 2C is bent inwardly so that it can be attached to the wheel with good vertical stability as in the example of FIG.

〔Effect of the invention〕

As explained above, the present invention makes the blade sufficiently thin,
Moreover, by arranging them diagonally in the direction of rotation of the wheel, it is possible to achieve both stability of the grinding surface and discharge of dust and sludge.

[Brief explanation of the drawing]

FIG. 1(a) is a partial bottom view of one embodiment of the present invention;
b) is a sectional view for explaining the grinding of a wafer by the grinding wheel of ta+ in the same figure, FIGS. 2 and 3 are partial bottom views of the second and third embodiments of the present invention, respectively, and FIG. 4 t
al is a bottom view of a conventional grinding wheel, FIG. 5(b) is a partial cross-sectional view for explaining wafer grinding, and FIG. 5(a)
is a partial bottom view of the second conventional example (bl is a partial cross-sectional view for explaining wafer grinding. 1...wheels, 2a, 2b, 2c)
, 3a, 3b・---Blade, 4・・・・
...Wheel rotation direction, 5...Wafer.

Claims (1)

[Claims] A grinding wheel used in the process of grinding the back surface of a semiconductor wafer, in which a number of blades fixed around the bottom surface of the wheel have a thickness of 2 mm or less and are fixed diagonally to the rotation direction of the wheel. A grinding wheel characterized by: