Wafer dicing method

The present invention relates to wafer dicing; more particularity, relates to dicing a wafer with an effective control to prevent a crack of chip on being removed from a mounting tape; reducing an amount of the mounting tape used; and lowering a production cost.

As shown in FIG. 5 , a wafer 3 is usually pasted with a mounting tape 31 on a surface to be diced to obtain chips 32 . The chip 32 cut out is then removed from the mounting tape 31 , where the mounting tape 31 is used to protect the chip 32 .

Although the mounting tape 31 is used to protect the chip 32 on dicing the wafer 3 , the stickiness between the chip 32 and the mounting tape 31 is usually too strong. It is because the chip 32 has a small thickness and a smooth surface. As a result, the chip 32 cut out has a difficulty on being removed from the mounting tape 31 and thus has a problem in being apt to be broken on the removing. Hence, the prior art does not fulfill all users' requests on actual use.

The main purpose of the present invention is to dice a wafer with an effective control on the cutting depth through partially corresponding a plurality of holes to a plurality of chips on the wafer, where a crack of the chip is prevented on removing the chip from amounting tape; an amount of the mounting tape used is reduced; and a production cost is lowered.

To achieve the above purpose, the present invention is a wafer dicing method, where a wafer is stacked on a mounting layer; a plurality of chips to be cut out is located on the wafer; the mounting layer has a plurality of holes; the holes are partially corresponding to the chips; and then the wafer is diced with a cutting device to obtain the chips. Accordingly, a novel wafer dicing method is obtained.

The present invention will be better understood from the following detailed description of the preferred embodiment according to the present invention, taken in conjunction with the accompanying drawings, in which

FIG. 1 is the sectional view showing the wafer used in the preferred embodiment according to the present invention;

FIG. 2A and FIG. 2B are the views showing the holes arranged into circles and dense circles on the first preferred embodiment of the mounting layer;

FIG. 3 is the view showing the second preferred embodiment of the mounting layer;

FIG. 4 is the view showing the second preferred embodiment of the mounting layer;

FIG. 5 is the sectional view of the wafer of the prior art.

The following description of the preferred embodiment is provided to understand the features and the structures of the present invention.

Please refer to FIG. 1 , which is a sectional view showing a wafer used in a preferred embodiment according to the present invention. As shown in the figure, the present invention is a wafer dicing method, comprising the following steps:

(a) A wafer 2 having a plurality of chips 21 on a surface to be diced is stacked on a mounting layer 1 , where the mounting layer 1 has a thickness between 10 and 200 micrometers; the mounting layer has a plurality of holes 11 ; the holes 11 are partially corresponding to the chips 21 ; and the chips 21 and the holes 11 have a partial contact whose ratio is between 1 and 50 percents.

(b) Then the chips 21 on the wafer 2 are diced by a dicing device (not shown in the figure).

With the holes 11 partially corresponding to the chips 21 on the mounting layer 1 , the mounting layer 1 is easily removed after the dicing, where a crack of the chip 21 is prevented; an amount of a mounting tape used is reduced; and thus a production cost is reduced as well. Thus, a novel wafer dicing method is obtained.

Please refer to FIG. 2A and FIG. 2B , which are views showing holes arranged into circles and dense circles on a first preferred embodiment of a mounting layer. As shown in the figures, holes 11 of a mounting layer 1 is arranged into a few orderly circles, as shown in FIG. 2A . And the circles can also be densely arranged, as shown in FIG. 2B .

Please refer to FIG. 3 , which is a view showing a second preferred embodiment of the mounting layer. As shown in the figure, holes 11 a of a mounting layer 1 is arranged into a few orderly rectangles according to an actual need.

Please refer to FIG. 4 , which is a view showing a third preferred embodiment of the mounting layer. As shown in the figure, holes 11 b of a mounting layer 1 is arranged into a few orderly arcs according to an actual need.

To sum up, the present invention is a wafer dicing method, where a crack of a chip on being removed from a mounting tape after the dicing is prevented with holes partially corresponding to the chips to be diced; an amount of the mounting tape used is reduced; and thus a production cost is lowered as well.

The preferred embodiment herein disclosed is not intended to unnecessarily limit the scope of the invention. Therefore, simple modifications or variations belonging to the equivalent of the scope of the claims and the instructions disclosed herein for a patent are all within the scope of the present invention.