JPH0225749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grinding machine, and more particularly, to a grinding machine that can freely use two grinding wheels having different grain sizes.

When grinding semiconductor wafers, selecting the grain size of the grindstone is one of the important control points for quality control, but it is generally difficult to achieve both the quality of the finished surface and the grinding efficiency. That is, if a grindstone with fine grain size is used to improve the finished surface, the grinding efficiency will decrease, and if a grindstone with coarse grain size is used to improve the grinding efficiency, the roughness of the finished surface will deteriorate.

In order to resolve this contradiction, we use two grinding wheels with two types of grain size: fine and coarse, and first perform high-efficiency grinding with the coarse-grained whetstone, then perform final grinding with the fine-grained whetstone. However, this method has the following problems. In other words, if two rotating shafts (hereinafter referred to as grindstone shafts) to which the grindstones are attached are provided, and a coarse-grained grindstone or a fine-grained grindstone is attached to each of them so that they can be selectively used, the entire grinding equipment becomes complicated. Not only is it large-sized and expensive to manufacture, but also requires a large amount of man-hours for daily maintenance. In addition, if two types of grindstones, fine and coarse, are prepared for one grindstone shaft, and the worker repeatedly installs and removes them to replace the grindstone, a great deal of effort and time will be wasted. In addition, there is a risk that the set state of the control mechanism attached to the grinding equipment may be disturbed.

The present invention has been made in view of the above circumstances.
The purpose is to provide a glass grinding machine with a simple and inexpensive configuration that allows two types of grindstones attached to one grindstone shaft to be selectively used with a simple operation.

In order to achieve the above object, the present invention concentrically stacks two cup-shaped grindstones with different particle sizes and that fit loosely together and attaches them to a single grindstone shaft.
In addition, by providing a ring-shaped cavity at the joint between two grinding wheels so that the pressure within this cavity can be controlled, elastic deformation is caused in the grinding wheels, and this elastic deformation causes the outer grinding wheel to It is characterized in that the amount of protrusion of the grinding surface of the inner grindstone relative to the grinding surface of the grinding wheel can be freely adjusted.

Next, one embodiment of the present invention will be described with reference to FIG. The grindstone shaft 1 is rotatably supported by bearings 2 and 3, and is driven by a motor 4 (not shown) via a pulley 4 and a belt 5. A cup-shaped rough grinding wheel 6 and a cup-shaped finish grinding wheel 7 are attached to the grindstone shaft 1. The inner diameter D of the cylindrical portion of the rough grinding wheel 6 is sufficiently larger than the outer diameter d of the cylindrical portion of the grindstone 7 for finish grinding, so that the two fit together loosely. Further, the inner height H of the cylindrical portion of the rough grinding wheel 6 is formed to be slightly larger than the outer height H of the cylindrical portion of the finish grinding wheel 7, so that the bottom outer surface 7a of the finish grinding wheel 7 is roughened. When the grinding wheel 6 comes into contact with the inner bottom surface 6a of the grinding wheel 6 and the pressure inside the cavity 10 is maintained at atmospheric pressure as described later, the grinding surface 7b that contacts the end surface of the cylindrical portion of the finish grinding wheel 7 is in contact with the inner surface 6a of the rough grinding wheel 6. It is designed to be retracted more than the grinding surface 6b which corresponds to the end surface of the cylindrical portion. These ground surfaces 6b, 7
Details of the relative position of b will be described later with reference to FIG.

The two grinding wheels 6 and 7 are attached to the grinding wheel shaft 1 in a concentrically fitted position, and are tightened by a grinding wheel mounting bolt 9 via a ring-shaped presser washer 8.

A ring-shaped groove 10 is formed on the bottom outer surface 7a of the finish grinding wheel, which is the joint between the two grinding wheels 6 and 7, and by bringing this surface into contact with the bottom inner surface 6a of the rough grinding wheel. A cavity 10 is formed. Reference numerals 11 and 11' designate O-rings interposed between the two grindstones 6 and 7 in order to keep the cavity airtight.

The above-mentioned cavity 10 communicates with an air pressure supply hole 12 formed in the grinding wheel shaft 1, and is connected to a compressed air tank (not shown) via a rotary joint 13. 14 is a stop valve provided in the connecting pipe, 15 is a regulator, and 16 is a pressure gauge. When the stop valve 14 is opened, air pressure is supplied to the cavity 10, and the pressure is applied to the regulator 15.
It has come to be freely controlled by the

FIG. 2 is an enlarged view of the periphery of the cavity 10 shown in FIG. 1. Next, the operation of the device according to the present invention will be explained with reference to this figure.

The pressure inside the cavity 10 is designed to be freely controlled, but for convenience of explanation, two pressures are used: high pressure and atmospheric pressure.
The case where switching control is performed in stages will be described.

(i) When the inside of the cavity 10 is made high pressure When the inside of the cavity 10 is made high pressure, the cavity 10
Due to the internal pressure, the outer periphery of the finish grinding wheel 7 is elastically deformed downward as shown by imaginary lines A and B, with the outer periphery pressing part of the presser foot 8 as a base point.
The grinding surface 7b protrudes below the grinding surface 6b of the rough grinding wheel 6 by a dimension δ (for example, 5/100 mm). Therefore, if grinding is carried out in this state, finish grinding can be performed on the grinding surface 7b of the finish grinding wheel 7.

(ii) When the inside of the cavity 10 is brought to atmospheric pressure, when the inside of the cavity 10 is lowered to atmospheric pressure, the elastic deformation of the outer circumference of the finish grinding wheel 7 disappears, and the grinding surface 7b of the finish grinding wheel 7 disappears. is the rough grinding wheel 6
6b above the grinding surface 6b. Therefore, by grinding in this state, rough grinding can be performed on the grinding surface 6b of the rough grinding wheel 6.

In this way, in the grinding machine of the above embodiment,
By adjusting the pressure inside the cavity in two ways, the grinding surface 7b of the finishing grinding wheel 7 is controlled to protrude, retract, and be on the same plane as the grinding surface 6b of the rough grinding wheel 6. Can perform finish grinding and rough grinding.

In the above embodiment, compressed air was communicated as the pressure control means in the cavity 10, but when carrying out the present invention, the pressure is not limited to pneumatic pressure, and hydraulic pressure,
Any fluid pressure can be used, such as water pressure.
It is also recommended to use cutting oil for grinding equipment.

As explained above, in the present invention, two types of grindstones, one with fine grain and one with coarse grain, are attached to one grindstone shaft, and a ring-shaped cavity is provided at the joint between the two, and the pressure inside this cavity can be controlled. By using a simple configuration such as this, and causing elastic deformation of the grindstone by adjusting the pressure within the cavity, any grindstone can be selected and used.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention with pneumatic piping added thereto, and FIG. 2 is a detailed sectional view enlarging a part of FIG. 1. 1... Grinding wheel shaft, 6... Grinding wheel for rough grinding, 7... Grinding wheel for finishing grinding, 8... Presser washer, 9... Grinding wheel mounting bolt, 1
0...Cavity, 11, 11'...O-ring, 12...Air pressure supply hole, 13...Rotary joint, 14...Stop valve, 15...Regulator, 16...Pressure gauge.

Claims (1)

[Scope of Claims] 1. Two cup-shaped grindstones having different particle sizes and loosely fitting are concentrically stacked and attached to one rotary grindstone shaft, and each of the two cup-shaped grindstones is A ring-shaped cavity is provided at a location where the portions corresponding to the bottoms of the wheels face each other, and a means for controlling the pressure within the ring-shaped cavity is provided, and a cup-shaped grindstone is adjusted according to the pressure change within the cavity. A grinding machine capable of selectively performing rough grinding and finish grinding, characterized by having a structure in which the amount of protrusion of an inner grindstone relative to an outer grindstone changes by causing elastic deformation.