JPH07249601A - Grinding equipment - Google Patents

Abstract

PURPOSE:To decrease the frequency of dressing work for the clogging of a grindstone, by washing the grindstone periodically and automatically. CONSTITUTION:A washing nozzle 3 is situated at a waiting position outside the circumference of a grindstone 1 when a semiconductor wafer 6 is ground. When grinding reaches the set specified number of sheets, grinding is ended. A control circuit 5 drives a motor 4, and moves the washing nozzle 3 to a position vertical to the grinding surface of the grindstone 1 and on its circumference. The washing position and the waiting position are detected by a photosensor or the like, and the control circuit 5 drives the motor 4. At the time of washing, the control circuit 5 rotates a spindle 2 at a low speed, and the washing nozzle 3 injects high pressure cleaning fluid for a specified period. After washing, the washing nozzle 3 is moved to the waiting position by the motor 4. The number of rotation of the spindle 2 is increased up to the set value for grinding, and the griding is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding machine for grinding and cutting semiconductor wafers and the like, and more particularly to a technique effectively applied to cleaning a grindstone of the grinding machine.

[0002]

2. Description of the Related Art According to a study made by the present inventor, grinding of a semiconductor wafer to a predetermined thickness is performed by rotating a grindstone provided in a grinding machine at a high speed to bring the grinding wafer into contact with the semiconductor wafer. There is.

In order to deal with the clogging of the grindstone, a dressing board for dressing is provided at a predetermined position when the finished state of the ground surface of the semiconductor wafer changes, and the grindstone is clogged with the dressing board. The so-called dressing work is performed by scraping off the part and exposing the new grindstone surface.

As an example of grinding a semiconductor wafer, "LSI Handbook" published by Ohmsha, Ltd.
Published on January 30, published by The Institute of Electronics and Communication Engineers, P237.

[0005]

However, in the above grinding apparatus, an operator must manually set the dressing board when performing the dressing work, and the time of one dressing work is 3 to 10. The work time is increased because the work time is extended to about 4 hours.

The dressing work often depends on the skill of the worker, and the life of the grindstone until the dressing work must be performed once for every 500 semiconductor wafers. Is becoming a heavy burden.

Further, between grinding with a grindstone immediately before the dressing work and grinding with the grindstone immediately after the dressing work, the finish of the ground surface such as surface roughness of the treated surface and reduction of bending strength changes, resulting in variations. Will end up.

An object of the present invention is to provide a grinding apparatus which reduces the frequency of dressing work due to clogging of the grindstone by regularly and automatically cleaning the grindstone.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0010]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, the grinding apparatus of the present invention includes a grinding apparatus for grinding a semiconductor wafer, a cleaning means for cleaning a grindstone, a moving means for moving the cleaning means, and a control means for controlling the cleaning operation and the grinding operation. Is provided.

In the grinding apparatus of the present invention, the cleaning means is
It is composed of an injection means for injecting a high-pressure fluid.

Further, in the grinding apparatus of the present invention, the fluid jetted from the jetting means is a cleaning liquid, an inert gas or air.

Further, in the grinding apparatus of the present invention, the cleaning means is
It is composed of a cylindrical brush and a rotating means for rotating the brush.

[0015]

According to the grinding apparatus of the present invention described above, the grindstone can be automatically cleaned periodically by the cleaning mechanism.

As a result, the frequency of dressing work is reduced, and the work man-hour and the burden on the worker can be reduced.

Further, it is possible to reduce variations in the finish of the ground surface, such as surface roughness of the treated surface and reduction of the transverse strength.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a side view of a main part of a grinding apparatus for grinding a semiconductor wafer according to a first embodiment of the present invention,
FIG. 2 is a configuration diagram of a cleaning mechanism portion of a grinding device that grinds a semiconductor wafer according to the first embodiment of the present invention.

In the first embodiment, the grinding mechanism portion of the grinding device for grinding a semiconductor wafer includes a grindstone 1 for grinding,
A spindle 2 for rotating the attached grindstone 1 at a high speed, a cleaning nozzle (cleaning means) 3 for cleaning the grindstone 1, a moving motor (moving means) 4 for moving the cleaning nozzle 3, and a cleaning operation and a grinding operation are controlled. Control circuit (control means)
5 and 5. Also, at the bottom of the grindstone 1,
A semiconductor wafer 6 to be ground is attached.

Further, the cleaning nozzle 3 is driven by the movement motor 4 under the control of the control circuit 5 so that the cleaning nozzle 3 becomes perpendicular to the grindstone surface of the grindstone 1 and on the circumference, and when cleaning is not performed. It can be moved to the standby position.

In order to detect the positions of the cleaning position and the standby position, for example, a waterproof photo sensor (not shown) is provided, and the control circuit 5 drives the moving motor 4 based on a signal from the photo sensor. Let

Further, as shown in FIG. 2, from the cleaning jet portion 3a of the cleaning nozzle 3, as cleaning liquid at the time of cleaning,
For example, pure water is jetted at high pressure.

Next, the operation of this embodiment will be described.

First, at the time of grinding the semiconductor wafer 6 which is a regular work, the cleaning nozzle 3 is located at a predetermined standby position outside the circumference of the grindstone 1.

Then, when the number of semiconductor wafers 6 to be ground reaches a preset number, the grinding is automatically terminated,
The control circuit 5 drives the moving motor 4 to move the grindstone 1
The cleaning nozzle 3 is moved to a position that is perpendicular to the whetstone surface of and is on the circumference.

Next, the control circuit 5 rotates the spindle 2 at a low speed (for example, about 50 revolutions / minute or less) so that the grindstone 1 is likely to receive the pressure of the cleaning liquid sprayed from the cleaning nozzle 3. After that, a high-pressure (for example, about 5 kg / cm ² or more) cleaning liquid is sprayed from the cleaning nozzle 3 for a predetermined time.

When the cleaning operation is completed, the cleaning nozzle 3 is again moved to a predetermined standby position by the moving motor 4 controlled by the control circuit 5.

Further, the spindle 2 is rotated under the control of the control circuit 5 to a set rotational speed at which grinding can be performed, and the grinding of the semiconductor wafer 6 is started.

Therefore, by repeatedly grinding a predetermined number of semiconductor wafers 6 and cleaning the grindstone 1,
Clogging of the grindstone is reduced, and the frequency of manual dressing work can be reduced.

(Embodiment 2) FIG. 3 is a schematic view of a main part of a grinding apparatus for grinding a semiconductor wafer according to a second embodiment of the present invention.

In the second embodiment, the grindstone 1 for grinding is used.
In order to wash the, the cleaning brush 7 which is a nylon brush, for example, is provided at a predetermined position.

Further, the cleaning brush 7 is provided with a moving motor 4 for moving the cleaning brush 7 and a rotating motor (rotating means) 4a for rotating the cleaning brush at the time of cleaning. The operation is the control circuit 5
Is controlled by. Further, a semiconductor wafer 6 to be ground is attached below the grindstone 1.

Further, the control circuit 5 drives the moving motor 4 to move the cleaning brush 7 between the cleaning position on the circumference of the grindstone 1 and the standby position when cleaning is not performed.

Further, the positions of the cleaning position and the standby position are detected by, for example, a waterproof photo sensor (not shown).
Etc. are provided, and the control circuit 5 drives the moving motor 4 based on the signal from the photo sensor.

Further, in the cleaning brush 7, the brush portion is rotated at a high speed by driving the rotation motor 4a during cleaning.

Next, the operation of this embodiment will be described.

First, at the time of grinding the semiconductor wafer 6 which is a regular work, the cleaning brush 7 is located at a predetermined standby position outside the circumference of the grindstone 1.

When the number of semiconductor wafers 6 to be ground reaches a preset number of wafers, the grinding is automatically terminated,
The control circuit 5 drives the moving motor 4 to move the grindstone 1
The cleaning brush 7 is moved to a position which is perpendicular to the grindstone surface and is on the circumference.

Next, the cleaning brush 7 is rotated at a high speed by the rotation motor 4a to clean the grinding surface of the grindstone 1 for a predetermined time.

When the cleaning operation is completed, the control circuit 5 stops the rotation motor 4a and restarts the cleaning brush 7
Is moved to a predetermined standby position by the moving motor 4, the rotation speed of the spindle 2 is increased to a set rotation speed at which grinding can be performed, and grinding of the semiconductor wafer 6 is started.

Therefore, by repeatedly grinding a predetermined number of semiconductor wafers 6 and cleaning the grindstone 1,
It is possible to reduce manual dressing work.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the cleaning liquid sprayed from the cleaning nozzle 3 may be other than the pure water of the first embodiment, and a liquid that does not adversely affect the semiconductor wafer, air, or a gas of an inert gas such as nitrogen is sprayed at a high pressure. However, the effect is the same.

The position of the cleaning nozzle 3 and the cleaning brush 7 in the first and second embodiments may be detected by a sensor such as a photo sensor, and the position may be detected by a pulse signal from a pulse motor or the like.

Further, as shown in FIG. 4, a grindstone 8 which is a blade for a kerf of a dicing device which is a processing device for forming a kerf-shaped kerf for dividing the semiconductor wafer 6 into individual dies. It is also possible to clean the grindstone 8 by disposing a cleaning nozzle 3 on the upper part of the wafer, dicing a predetermined number of semiconductor wafers 6 and then periodically spraying a high-pressure cleaning liquid onto the grindstone 8 from the cleaning spraying unit 3a. it can.

[0047]

The effects obtained by the typical ones of the inventions disclosed by the present application will be briefly described as follows.
It is as follows.

(1) According to the present invention, since the grindstone can be regularly and automatically cleaned, the frequency of manual dressing work can be reduced.

(2) Further, in the present invention, the number of working steps can be reduced and the life of the grindstone can be extended by the above (1).

(3) Further, according to the present invention, there is no variation in the finish of the ground surface such as the surface roughness of the processed surface of the semiconductor wafer due to the clogging of the grindstone and the reduction of the bending strength, so that a highly reliable product can be obtained. Can be supplied.

[Brief description of drawings]

FIG. 1 is a side view of essential parts of a grinding device for grinding a semiconductor wafer according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a cleaning mechanism portion of a grinding device that grinds a semiconductor wafer according to a first embodiment of the present invention.

FIG. 3 is a configuration diagram of a main part of a grinding device for grinding a semiconductor wafer according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a main part of a dicing device for dicing a semiconductor wafer according to another embodiment of the present invention.

[Explanation of symbols]

 1 Grindstone 2 Spindle 3 Cleaning Nozzle (Cleaning Means) 3a Cleaning Jet 4 Motor for Moving (Moving Means) 4a Motor for Rotating (Rotating Means) 5 Control Circuit (Control Means) 6 Semiconductor Wafer 7 Cleaning Brush 8 Grinding Stones

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Uchida 3-3, Fujibashi, Ome, Tokyo 2-3 Hitachi Hitachi Electronics Co., Ltd. (72) Inventor Koichi Koyanagi 3-3, Fujibashi, Ome, Tokyo 2 Within Tokyo Electronics Co., Ltd. (72) Inventor Jiro Sakaguchi 3-3 Fujitabashi, Ome, Tokyo 2-3 Hitachi inside Tokyo Electronics Co., Ltd. (72) Tadao Sakamoto 3-3 Fujibashi, Ome-shi, Tokyo 2 Hitachi Tokyo Electronics Co., Ltd.

Claims (4)

[Claims] 1. A grinding apparatus for grinding a semiconductor wafer, comprising: cleaning means for cleaning a grindstone; moving means for moving the cleaning means with respect to the grindstone; cleaning operation for cleaning the grindstone; and the semiconductor. A grinding device, comprising: a control means for controlling a grinding operation for grinding a wafer. 2. The grinding apparatus according to claim 1, wherein the cleaning unit is an injection unit that injects a high-pressure fluid. 3. The grinding apparatus according to claim 1, wherein the fluid jetted from the jetting means is a cleaning liquid, an inert gas or air. 4. The grinding apparatus according to claim 1, wherein the cleaning unit includes a cylindrical brush and a rotating unit that rotates the brush.