JPH0740335A - Dicing method - Google Patents

Abstract

PURPOSE:To provide a dicing method for reducing a variation of a knotching amount based on a thickness error of an Si wafer and a tape and preventing an occurrence of chipping and cracking caused by a variation of a knotching amount. CONSTITUTION:A distance (c) to a top surface of an Si wafer 10 is measured by a camera 40. A distance (d) from the lower end of a blade 30 to the top surface of the Si wafer 10 is calculated. The blade 30 is lowered by a distance obtained by adding a predetermined knotching amount to the calculated distance (d).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of dicing a product base such as a semiconductor wafer in a semiconductor maker, a glass maker, a ceramic maker, etc. The present invention relates to a method of forming a notch.

[0002]

2. Description of the Related Art Conventionally, a semiconductor maker or the like performs a dicing process of cutting and separating chips inspected in a wafer state in an assembly process of electronic parts such as transistors. Also, although different from the step of cutting and separating,
For example, in the case of manufacturing a laser submount diode element, as shown in FIG. 4, a crystal is formed by making a notch at a predetermined depth from the surface of a Si wafer and cracking the half-cut portion by making the notch. Separated in direction, the cracking surface is used as the reflecting surface of the laser.

In this case, when the cutting depth is deeper than a predetermined value as shown by the dotted line in FIG. 4, the reflection area becomes small and it becomes impossible to reflect light, so that the electrical characteristics change, and conversely. However, if the depth of cut is small, the half-cut portion cannot be cracked, and if it is forcibly cracked, it breaks into pieces, and the depth of cut is very important.

Here, conventionally, when making a cut in a Si wafer, the cut amount was set as follows. That is, as shown in FIG. 5, S is placed on the suction cutting table (hereinafter referred to as “table”) T.
Dicing tapes (hereinafter referred to as “tape”) 20 for holding an i-wafer are arranged and the tape 2
The Si wafer 10 is arranged on the wafer 0, and a dicing blade (hereinafter referred to as “blade”) 30 is provided above the Si wafer 10. For example, a cut of 0.04 mm is made in this Si wafer 10.

Here, the blade 30 is held at an initial position at a distance of height h1 from the upper surface of the table T.
The thickness a of the tape 20 is 0.12 mm, and
The thickness b of the wafer 10 is 0.23 mm, and the tape 2
0 and the Si wafer 10 have a thickness of 0.35 mm. Therefore, in order to make a cut of 0.04 mm in the Si wafer 10, it is sufficient to lower the lower end of the blade 30 to a height of 0.31 mm from the upper surface of the table T. Then, the lower end of the blade 30 was controlled to descend to a height of 0.31 mm from the upper surface of the table T, and a cut of 0.04 mm was made in the Si wafer 10. The microscope 40 is for performing alignment, that is, alignment of the Si wafer 10.

[0006]

However, according to the above conventional method, the thickness a of the tape 20 is 0.015 m.
Since there is an error of m, and the thickness b of the Si wafer 10 also has an error of 0.015 mm, a =
0.12 ± 0.015 mm, b = 0.23 ± 0.015
mm, and a + b = 0.35 ± 0.03 mm,
The tape 20 and the Si wafer 10 have a thickness error of 0.03 mm. Furthermore, as an error,
In addition to the error in the thickness of the Si wafer 10 and the tape 20, there is an error due to the abrasion of the blade. Then, when the cut amount into the Si wafer 10 is set to 0.04 ± 0.02 mm, this standard value is deviated. Further, the standard is not satisfied, and the product (pallet) or the like is greatly varied.

Further, since the area of the dressing portion for cutting is limited at the tip portion of the blade, if the cutting depth varies, the non-smooth portion other than the dressing portion of the blade comes into contact with the Si wafer. , Chipping and cracks may occur.

Therefore, it is an object of the present invention to provide a dicing method capable of reducing the variation in the depth of cut and preventing the occurrence of chipping and cracks due to the variation in the depth of cut.

[0009]

DISCLOSURE OF THE INVENTION The present invention is a dicing method for making a cut of a predetermined depth from the upper surface of a product base by a rotating blade, or cutting the product base, wherein the lower end of the blade and the product base are A step of calculating the distance between the upper surfaces, and the blade is lowered by a distance obtained by adding a predetermined cut amount to the calculated distance between the lower end of the blade and the upper surface of the product base to form a cut of a predetermined depth in the product base. And a step of performing.

[0010]

In the cutting device according to the present invention, first, the distance between the blade for cutting or cutting the product base and the upper surface of the product base is calculated. Then, the blade is lowered by a distance obtained by adding a predetermined cut amount to the calculated distance to cut the product base to a predetermined depth.

In the present invention, since the distance from the lower end of the blade to the upper surface of the product base is calculated, the blade is lowered by the distance obtained by adding the depth of cut to that value.
When a predetermined amount of cut is made, the tape thickness error and the product base thickness error do not affect the cut amount, and the cut amount can be controlled to a predetermined amount. Further, if the dressing portion at the tip of the dicing is formed to have a predetermined width, the amount of cut does not vary, so that the portion other than the dressing portion is not hit and chipping and cracking can be prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the dicing apparatus A according to the present embodiment has an autofocus function and cuts a camera 40 as a distance measuring unit for measuring a distance to an object and a Si wafer 10 as a product base. Blade 30
Is connected to the camera 40 and the blade 30, and calculates the distance from the lower end of the blade 30 to the surface of the object based on the distance to the object measured by the camera 40, and lowers the blade 30 by a predetermined amount. It has a control unit 50. Further, the Si wafer 10, which is a target to be cut, is fixed on the table T via the tape 20 for fixing. The thickness a of this tape 20,
The thickness b of the Si wafer 10 is a = 0.
12 ± 0.015 mm, b = 0.23 ± 0.015 mm
Is.

The state of use of the cutting device A based on the above configuration will be described. The Si wafer 1 is connected via the tape 20.
The table T on which 0 is placed is sent below the camera 40 and alignment adjustment is performed. At that time, the camera 40
Measures the distance c from the upper surface of the Si wafer 10. The controller 50 calculates the distance d from the lower edge of the blade to the upper surface of the Si wafer 10 from the distance c measured by the camera 40. The controller 50 controls the Si wafer 10 to a depth of 0.
When making a 04 mm cut, add 0.0 to d above.
The blade 30 is lowered by d + 0.04 mm to which 4 mm is added to form a cut in the Si wafer 10 as shown in FIGS.

In this embodiment, the distance d from the lower end of the blade 30 to the upper surface of the Si wafer 10 is calculated to obtain S
Since the notch is made in the i-wafer 10, the tape 20 and S
The depth of cut can be suppressed to a predetermined standard value without being affected by an error in the thickness of the i-wafer 10. Even when the standard value of the cut amount is 0.04 mm + 0.02 mm, the standard value can be suppressed.

Further, in the above embodiment, the case where a predetermined amount of incision is made in the product base such as the Si wafer has been described, but the above embodiment is also effective in cutting the product base. That is, the tip portion of the blade has a dressing portion as a portion which actually comes into contact with the product mother body and is cut. The dressing portion is determined according to the cutting depth. Therefore, by making the cutting depth constant according to the present embodiment, the product mother ensures the cutting, and the blade portion other than the dressing portion comes into contact by chipping too deeply, so that chipping and cracking may occur. To be prevented.

[0016]

As described above, in the present invention, by calculating the distance from the lower end of the blade to the upper surface of the product matrix, the blade is lowered by the distance obtained by adding the cut amount to the predetermined value. When making the cut, the tape thickness error and the product base are not affected by the cut amount, and the cut amount can be controlled to a predetermined amount. In addition, chipping and cracking can be prevented.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a dicing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a usage state of a dicing apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram showing a usage state of a dicing apparatus according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a problem of a conventional example.

FIG. 5 is an explanatory diagram illustrating a conventional dicing method.

[Explanation of symbols]

 10 Si wafer 20 Tape 30 Blade 40 Camera 50 Control unit T table

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/301

Claims (1)

[Claims] 1. A dicing method in which a rotating blade makes a cut to a predetermined depth from the upper surface of a product base or cuts the product base, and a step of calculating a distance between a lower end of the blade and an upper surface of the product base. And a step of lowering the blade by a distance obtained by adding a predetermined cut amount to the calculated distance between the lower end of the blade and the upper surface of the product base to form a cut having a predetermined depth in the product base. Characteristic dicing method.