JP2002144226A - Grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding device capable of efficiently measuring a work by reducing a stroke amount of a measuring instrument. SOLUTION: This grinding device 1 has grinding wheels 17 and 18 for grinding the thin plate shaped work 24 by rotating grinding operating surfaces 17a and 18a and a moving frame 53 which rotatably supports the work 24 and is movable in the direction approaching or detaching to/from the grinding wheels 17 and 18. The measuring instrument 70 for measuring thickness of the work 24 is provided in the moving frame 53. Based on the measuring result of the measuring instrument 70, feed moving amount of the grinding wheels 17 and 18 is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding device provided with a measuring device for measuring the thickness of an object to be ground.

[0002]

2. Description of the Related Art For example, a silicon wafer generally used for a semiconductor chip or the like is obtained by cutting an ingot made of a hard and brittle material with a wire saw, and grinding the cut wafer to a desired thickness with a grinder or a lapping machine. Manufactured. As shown in FIG. 9, a double-headed grinding machine 100 is known which grinds both surfaces of a wafer-like work 24 or the like made of a hard and brittle material cut by a wire saw with a pair of grindstones 17 and 18. The double-headed grinding machine 100 includes a pair of grinding wheels 1.
Two grinding working surfaces 17 which are opposite end surfaces of 7, 18
a, 18a, and the respective grinding action surfaces 17a, 18
“a” is disposed to face each other in a substantially parallel state.

[0003] Then, a plate-like work 24 is arranged between the grindstones 17 and 18 while being supported by the work support mechanism 15,
By moving the two grindstones (17 and 18) or one of the grindstones (17 or 18) toward the work 24 while rotating the two grindstones 17 and 18, the work in contact with the two grinding action surfaces 17a and 18a is moved. 24 are designed to grind both front and back surfaces simultaneously.

When grinding the work 24, the work 2
In order to machine the workpiece 4 into a predetermined thickness, for example, when the grinding is completed, the actual dimensions of the workpiece 24 after the machining are measured, and the cut amounts of the two grindstones 17 and 18 are determined based on the measured dimensions. Then, rough grinding and finish grinding are performed. As schematically shown in FIG. 11, the depth of cut is a grindstone 1 corresponding to a distance between a work surface which is a surface before processing of a workpiece to be ground and a finished surface which is a surface after grinding.
7, 18 are the movement amounts. The greater the cutting depth of the grindstone, the thinner the thickness (width) of the work 24 is processed. Generally, the thickness of the work being processed is controlled by the cutting depth of the grindstone.

[0005] When the grinding operation is not being performed, such as during maintenance of the double-headed grinding machine 100, the grinding stone 17,
Reference numeral 18 is at a retracted position, and is fed and moved from the retracted position to the work surface of the workpiece during grinding. This moving amount is referred to as a feed moving amount of the grindstone. For example, in a vertical double-headed grinding machine, the distance that the upper grindstone 18 descends toward the work surface of the work 24 and the lower grindstone 17 It refers to the distance ascending toward the cut surface.

[0006] However, if a grindstone is used, the grindstone is worn.
The positions of 7a and 18a change. In addition, whetstones 17 and 18
Requires truing (correction of the shape of the grindstone) and dressing (sharpening) of the grinding action surfaces 17a and 18a every time a certain period of use, and the grinding action surfaces 17a and 18a The position of 18a changes. Further, the positions of the grinding surfaces 17a and 18a also change due to thermal displacement.

Therefore, even if the grindstones 17 and 18 are moved from the retracted position to the work surface of the work 24, they can be moved.
8 grinding action surface due to wear, truing, thermal displacement, etc.
Due to the displacement of 7a and 18a, the workpiece 24 may not reach the work surface. Even when cutting is performed by a predetermined cutting amount from that position, the actual cutting amount of the grindstones 17 and 18 is affected by a change in the position of the grinding action surfaces 17a and 18a, and the work 24 is displaced by the displacement amount. The thickness changes.

For this reason, in order to minimize the processing error during the work grinding, the thickness of the workpiece to be ground due to a change in the position of the grinding surfaces 17a, 18a due to wear of the grinding wheels 17, 18 is detected. It is necessary to correct the feed movement amounts of the grindstones 17 and 18 based on the detection results. In particular, when grinding a work 24 such as a semiconductor wafer cut by a wire saw, since the work 24 is a thin plate and requires high-precision grinding, the grinding action surfaces 17a and 17a of the upper and lower grindstones 17 and 18 are required. It is necessary to more accurately detect a change in position due to abrasion or the like of 18a, and to appropriately feed back a feed movement amount of the grindstones 17, 18.

A double-headed grinding machine focusing on the above problems will be described with reference to FIGS.

The double-sided grinding machine 100 has a sizing device 2 for controlling the thickness of the work 24 to a specific size in a grinder for grinding the front and back surfaces of the work 24.

FIG. 8 is a conceptual diagram showing the principle of the sizing device 2. As shown in FIG. 8, the sizing device 2 includes a measuring device 70, an amplifier 3, and a control device 101, and measures the work thickness measured by the measuring device 70 to the grindstone 17 of the double-sided grinding machine 100.
The feed amount is fed back to the work
Is a specific thickness.

Although there are various types of measuring devices 70, a simple example of a differential transformer type is as follows.
Two fingers 82 provided at the tips with contacts 81 sandwiching the work 24, a main body 83 on which both fingers 82 are mounted, and a differential transformer 8 mounted on the main body 83
4 The two fingers 82 are rotatably mounted on the main body 83 at the support shaft 87. A core 85 is rotatably connected to the end of the finger 82 on the main body 83 side with the support shaft 88 as a connection shaft. The differential transformer 84 has a primary coil 89 connected to a power supply, and two secondary coils 8 are provided at positions opposed to the primary coil 89.
6 are arranged. Primary coil 89 and secondary coil 86
A core 85 is arranged between the two coils, and the core 85 can slide between the primary coil 89 and the two secondary coils 86 almost in parallel with both coils.

When measuring the thickness of the work 24, the two fingers 82 are opened and then the work 24 is sandwiched between the contacts 81. At that time, both fingers 82
The position of the core 85 connected to the finger 82 and the position of the secondary coil 86 are relatively displaced from the displacement of the interval or the angle, and the thickness of the work 24 is measured based on the induced voltage generated. The measurement result is displayed on the amplifier 3 in analog or digital form.

In order to keep the thickness of the wafer-like work 24 ground by the double-sided grinding machine 100 at a desired value, the thickness of the work 24 whose both surfaces are ground by the measuring device 70 is measured. To compare the thickness of the work 24 measured by the measuring device 70 with a master wafer serving as a product shipment acceptance standard, a difference ((worked work thickness measured value) − (master wafer thickness)) is calculated. Then, it is detected whether or not the calculated difference value falls within a range of allowable values that can be shipped as a product.

[0015]

The double-sided grinding machine 10 described above.
At 0, the work 24 is rotatably held by a holding frame 53 moving on a support table 52 as shown in FIG. 10, and the grinding is performed by cutting the rotating grindstones 17 and 18 from above and below while rotating the work 24. ing. The movement between the work processing position P2 for grinding the work and the work loading / unloading position P1 for exchanging the work is performed by moving the holding frame 53.

In the conventional double-headed grinding machine 100, FIG.
As shown in FIG.
2 had been installed. Then, the holding frame 53 is attached to the measuring device 7.
The thickness of the work 24 was measured by moving the work 24 to the work thickness measuring position where the work 24 was placed.

However, according to the structure of the double-headed grinding machine 100, when the holding frame 53 is moved, it is necessary to retract the measuring device 70 so that the measuring device 70 does not hinder the movement of the holding frame 53. There is a problem that the amount of stroke for retracting the measuring device 70 is large, and there is a lot of movement when measuring the thickness of the workpiece, so that accuracy is deteriorated, measurement time is long and efficiency is low.

The invention according to the present application has been made in order to solve the above-mentioned problems, and an object of the invention is to reduce the stroke amount of a measuring device to efficiently and efficiently work. An object of the present invention is to provide a grinding device capable of measuring with high accuracy.

It is another object of the present invention to provide a grinding apparatus capable of measuring a work thickness even during a grinding operation.

[0020]

Means for Solving the Problems To achieve the above object, a first invention according to the present application is directed to a grinding wheel for grinding a plate-like workpiece by a rotating grinding surface, and a method for rotating the workpiece. A grinding frame having a supporting frame freely supported and movable in a direction approaching or leaving the grinding wheel, wherein a measuring device for measuring the thickness of the workpiece is provided on the holding frame. This is a grinding device.

Further, the second invention according to the present application is provided with a control unit that measures the thickness of the object to be ground by the measuring device and adjusts the amount of movement of the grindstone based on the measurement result. The grinding device according to the first aspect, characterized in that:

Further, in the third invention according to the present application, the measuring device can measure the thickness of the object to be ground even while the grinding wheel is acting on the object to be ground to perform a grinding process. The grinding device according to the first or second invention, wherein the grinding device is disposed at a position. A fourth invention according to the present application provides the measuring device, wherein the holding frame is located at a position other than a position at which the grindstone acts on the object to be ground to perform a grinding process. The grinding device according to any one of the first to third inventions, wherein the thickness can be measured.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention according to the present application will be described below in detail with reference to FIGS.

FIG. 1 is a schematic view showing a longitudinal section of a grinding apparatus 1 according to the present invention. As shown in FIG. 1, an intermediate frame 12 is fixed on a lower frame 11, and an upper frame 13 is fixed on the intermediate frame 12.
The lower frame 11 is provided with a lower grindstone rotating mechanism 14 and a work supporting mechanism 15, and the upper frame 13 is provided with an upper grindstone rotating mechanism 16.

The lower grinding wheel rotating mechanism 14 includes a lower grinding wheel rotating shaft 14a serving as a rotation center axis of the lower grinding wheel 17, and a lower extension line of the lower grinding wheel rotating shaft 14a is connected to a lower grinding wheel driving motor 30 for rotating the lower grinding wheel 17. Of the rotor 31. A flange portion 14b serving as a grindstone holder is provided at the upper end of the lower grindstone rotating shaft 14a.
The rotation of 1 causes the flange portion 14b to rotate at high speed. A lower grindstone 17 is attached and fixed to the flange portion 14b, and the upper surface of the lower grindstone 17 forms a grinding action surface 17a for grinding the work 24. Then, the rotation of the lower grindstone drive motor 30 causes the grinding surface 17a of the lower grindstone 17 to rotate.

Similarly, the upper grinding wheel rotating mechanism 16 has an upper grinding wheel rotating shaft 16a serving as a rotation center axis of the upper grinding wheel 18, and an upper extension line of the upper grinding wheel rotating shaft 16a is
3 of the upper grinding wheel drive motor 32 for rotating the
3 A flange 16b serving as a grindstone holder is provided at the lower end of the upper grindstone rotating shaft 16a, and the rotation of the rotor 33 causes the flange 16b to rotate at high speed. An upper grindstone 18 is mounted and fixed to the flange portion 16b, and the lower surface of the upper grindstone 18 forms a grinding action surface 18a. Therefore, the rotation of the upper grinding wheel drive motor 32 causes the grinding action surface 18a of the upper grinding wheel 18 to rotate.
Has a rotating structure.

The lower wheel driving motor 30 and the upper wheel driving motor 32 are connected to a lower wheel rotation and elevation controller 102 and an upper wheel rotation and elevation controller 103, respectively. Speed is controlled. The center line of the lower grindstone rotating shaft 14a is arranged on an extension of the upper grindstone rotating shaft 16a, and the grinding action surface 17a of the lower grindstone 17 is
8 so as to be substantially parallel to the grinding surface 18a.

The upper frame 13 is provided with a servomotor 19 for raising and lowering, and the servomotor 19 for raising and lowering is connected to an upper grinding wheel rotation raising and lowering control unit 103. The lower frame 11 is provided with a servomotor 20 for raising and lowering, and the servomotor 20 for raising and lowering is connected to a lower grindstone rotation raising and lowering control unit 102.

The upper whetstone rotating mechanism 16 is used to drive the upper frame 1
3 is supported so as to be able to ascend and descend in the direction of the upper grindstone rotating shaft 16a, and moves up and down in accordance with the rotation of an ascending and descending servomotor 19 by a ball screw feed mechanism (not shown). The lower grindstone rotating mechanism 14 is supported by the lower frame 11 so as to be able to move up and down in the direction of the lower grindstone rotating shaft 14a, and is moved up and down by a ball screw feed mechanism (not shown).
Move up and down according to the rotation of.

The upper grinding wheel rotation raising / lowering control unit 103 and the lower grinding wheel rotation raising / lowering control unit 102 are parts for controlling the rotation of the lifting servomotors 19, 20, respectively. Control the amount of movement. In addition, the upper grinding wheel rotation elevating control unit 103 and the lower grinding wheel rotation elevating control unit 102 control the rotation speed of the upper grinding wheel driving motor 32 and the lower grinding wheel driving motor 30, respectively.
The rotation speed of the upper and lower whetstones 18 and 17 is adjusted to a desired rotation speed. The upper grindstone rotation elevating control unit 103 and the lower grindstone rotation elevating control unit 102 are connected to the control device 101 and are managed by the control device 101 as a whole.

Next, the work supporting mechanism 15 will be described. As shown in FIG. 1, the work supporting mechanism 15 is provided between the upper and lower grinding wheel rotating mechanisms 16 and 14 so that the lower frame 11 can rotate.
It is arranged in. FIG. 2 is a simplified plan view showing the work support mechanism 15 as viewed from above. The work support mechanism 15 mainly includes a support table 52, a holding frame 53, a guide rail 54, and a movement motor 55. .

As shown in FIG. 2, a holding frame 53 is supported on a support table 52 via a pair of guide rails 54 so as to be movable left and right.

The moving motor 55 is fixedly disposed on the support base 52, and the ball screw 5 connected to the motor shaft is provided.
6 is screwed into a ball nut 56a fixed to the holding frame 53, so that the holding frame 53 moves. The movement motor 55 is connected to the movement motor control unit 104 shown in FIG. 1, and the rotation is controlled by the control device 101 via the movement motor control unit 104.

As shown in FIG. 2, an annular work holder 57 for holding a work is arranged in a holding frame 53 and is rotatably supported by a hole formed in the holding frame 53. The work holder 57 includes an annular thick outer peripheral frame 5.
7a is provided with a shoe 60 serving as a work support plate. As shown in FIG. 3, a gear 59 is formed on the outer periphery of the lower part of the outer peripheral frame 57a.

FIG. 3 is a view schematically showing a vertical section of the holding frame 53. As shown in FIG. 3, the shoe 60 is formed to be thinner than the work 24, and in the present embodiment, a set portion 60 a for detachably supporting the work 24, which is a workpiece, is formed by four shoes 60. . The setting portion 60a has a diameter at which the work 24 is loosely fitted so as to be vertically movable.

The work holder drive motor 61 has a holding frame 53
A gear 62 that is disposed on the motor shaft and meshes with the gear 59 of the work holder 57 is fixed to the motor shaft. And
The rotation of the work holder drive motor 61 causes the gear 6 to rotate.
The work holder 57 rotates via the gear 2 and the gear 59.

The work holder drive motor 61 is connected to the rotary motor control unit 105 shown in FIG. 1, and its rotation is controlled by the control unit 101 via the rotary motor control unit 105. The work holder drive motor 61 can rotate in the forward and reverse directions, and rotates in the forward or reverse direction according to a control signal from the control device 101. Therefore, by programming the control device 101 in advance, it is possible to reverse the rotation of the work holder drive motor 61 after a certain time has elapsed.

As shown in FIG. 2, a plurality of air pads 63a and 63b are arranged on the support base 52 along the direction of movement of the holding frame 53. Each air pad 63a, 63
b is a disk-shaped member, and an air ejection hole 64 is formed at the center of the disk-shaped member.

Nozzles (not shown) are connected to the air ejection holes 64 of the air pads 63a and 63b from below, and an air supply source such as an air compressor (not shown) is connected to these nozzles. Then, the air supplied from the air supply source is ejected upward from the air ejection holes 64 of the air pads 63a and 63b, whereby the lower surface of the work 24 is pushed up by the ejection pressure of the air. Then, the work 24 is held in a floating state in the setting section 60a, and is conveyed while floating between the work loading / unloading position P1 and the work processing position P2 with the movement of the holding frame 53. When the holding frame 53 is moved to the work processing position P2 as shown in FIG. 5, the work 24 is placed on the grinding surface 17a of the lower grindstone 17, and the lower grindstone 17 is moved.
The protruding portion faces a plurality of air pads 63b (four in FIG. 5). Then, air is blown from the air pad 63b to the lower surface of the work 24 so that the work 24 is not inclinedly mounted on the grinding operation surface 17a of the lower grindstone 17, and the work 24 is moved to the grinding operation surface of the lower grindstone 17. Maintain parallel to 17a.

As shown in FIG. 5, the work 24, which is an unground wafer cut out of an ingot, is set so as to engage with a notch 24a such as a notch or an orientation flat (orientation flat) serving as a reference for the crystal orientation of a workpiece 24. Part 6
A notch drive 65 having an engagement protrusion 65a protruding toward the inner peripheral side is provided in Oa. This work 24
The shape of the notch portion 24a is a V-groove-shaped notch as in the present embodiment or an edge of an orientation flat that cuts an arc of the outer periphery of the work 24, and the engagement protrusion 65a is
4 has a shape that substantially complements the notch 24a.

When grinding the work 24 having the notch 24a, the work 24 is fitted into the set portion 60a, and the notch 24a is fitted into the engagement protrusion 65a of the notch drive 65 provided in the set portion 60a. The holding frame 53 is moved to the grindstone 1 by the rotation of the moving motor 55.
The lower grinding wheel 1 is transported to the workpiece processing position P2 between
7 on the grinding surface 17a. At this time, work 2
4 is held in a floating state in the setting section 60a, and the notch drive 65 is rotated by rotation of the work holder 57.
The work 24 also rotates together with the work 24 in a floating state via the engagement protrusion 65a.

Then, the upper and lower grindstones 17 and 18 are rotated and the upper grindstone 18 is fed and moved toward the work 24, so that the grinding action surfaces 17a and 18a of the grindstones are formed on the upper and lower surfaces of the work 24 in a rotating state. The upper and lower surfaces of the work 24 are simultaneously ground while rotating. The work holder drive motor 61 controls a rotation direction and a rotation speed of the work 24 via a rotation motor control unit 105 according to a control signal from the control device 101.

(Explanation of the Measuring Apparatus) In the present invention, the above-described differential transformer type measuring apparatus 70 is mounted on the holding frame 53. FIG. 4 is a perspective view showing a state where the measuring device 70 is attached to the holding frame 53. Since the measuring device 70 is attached to the holding frame 53, it moves together with the holding frame 53. Then, the thickness of the work is measured by the contact 81 of the measuring device 70 moving forward or backward toward the work 24 on the holding frame 53. Hereinafter, the attachment structure of the measuring device 70 to the holding frame 53 will be specifically described with reference to FIGS. 6 and 7.

FIGS. 6 and 7 show the measuring device 70 in the holding frame 53.
It is the elements on larger scale which expanded and showed the longitudinal cross section in the state attached. Since the structure of the measuring device 70 itself has been described in [Prior Art], a detailed description thereof will be omitted here.

As shown in FIG. 6, the measuring device 70 has an upper and lower body 83 provided with fingers 82 fixed to a support member 71 and integrated therewith. Finger 8 of main body 83
The side opposite to the side provided with 2 is fixed to the support member 71,
The upper finger 82 and the lower finger 82 are disposed so as to be substantially U-shaped via the support member 71.

A cylindrical hole is formed in the support member 71 to form a cylinder chamber 72c of a cylinder 72 for moving the measuring device 70. A piston 72a is fitted into the cylindrical hole, and a rod 72b is connected to the piston 72a. A supply / discharge pipe (not shown) communicating with the cylindrical hole is connected to the support member 71, and a liquid such as oil or a gas such as air is supplied / discharged along the supply / discharge pipe. The cylinder 72 may be either a hydraulic cylinder or a pneumatic cylinder.

The tip of the rod 72b is fixed to the side surface of the holding frame 53, and the measuring device 70 is movably attached to the holding frame 53 via the cylinder 72. In the present embodiment, the fingers 82 of the measuring device 70 are arranged in a direction orthogonal to the direction in which the holding frame 53 moves. However, the measuring device 70 does not necessarily need to arrange the fingers 82 in a direction orthogonal to the moving direction of the holding frame 53.

Further, as shown in FIG.
The finger 82 is disposed so that the longitudinal extension line does not pass through the rotation center of the work holder 57 and is located on the side away from the grindstones 17 and 18 with respect to the rotation center. By arranging the measuring device 70 in this way, it is possible to prevent the contact 81 from contacting the grindstones 17 and 18 when grinding the work 24.

By operating the cylinder 72 shown in FIG. 6, the measuring device 70 moves in a direction perpendicular to the direction in which the holding frame 53 moves. FIG. 6 shows a state in which the measuring device 70 moves forward and the contact 81 is in contact with the work 24. In this state, the work 2
4 can be measured.

FIG. 7 shows that the finger 82 is opened and the cylinder 7 is opened.
2 shows a state in which the measuring device 70 is retracted from the work 24 by operating the device 2. In this state, the contact 81 is retracted from the work 24 and the contact 81
Does not cover the top and bottom of the work 24. Therefore, in this state, the work 24 can be attached to or detached from the setting section 60a.

Since the contact 81 measures the thickness of the work at a position of about 10 mm from the outer periphery of the work 24, the moving distance of the measuring device 70 by the cylinder 72 may be about 20 mm, and the contact 81 can quickly retreat from the work 24.

(Explanation of Operation of Entire Grinding Apparatus) Next, the operation of the grinding apparatus 1 configured as described above will be described.

When the work 24 is loaded and unloaded to and from the grinding device 1, the holding frame 53 is moved to the workpiece loading and unloading position P1 shown in FIG. 2 by the rotation of the moving motor 55. A set portion 60 of the work holder 57 is moved from an unground work cassette (not shown) containing a plurality of unground works 24 by a robot arm (not shown) or the like.
The work 24 is inserted and set in a, and the notch 24a of the work 24 engages with the engagement protrusion 65a.

When the work 24 is set, air supplied from an air supply source is jetted from the nozzles of the air pads 63a and 63b to the lower surface of the work 24 via the air jet holes 64. Thereby, the work 24
Is held in a floating state in the setting section 60a.

Then, the ball nut 56a fitted to the ball screw 56 is moved by the rotation of the moving motor 55, and the holding frame 53 keeps the work 24 floating.
The workpiece is transported from the workpiece loading / unloading position P1 to the workpiece processing position P2 shown in FIG. At the same time, the work holder 57 is rotated from the work holder drive motor 61 via the gears 62 and 59, and the work 24 is rotated by the notch drive 65.
Also rotate.

At the work processing position P2, the lower grindstone 17 is fed and moved to the lower work surface of the work 24 and rises, so that the work 24 is placed on the lower grindstone 17. Next, the upper grindstone 18 is fed and moved to near the upper work surface of the work 24 and descends. Thereafter, the upper and lower grindstones 17 and 18 and the work 24 are rotated. Then, by cutting the upper grindstone 18 by the cutting amount, the work 2 is formed by the grinding action surfaces 17a, 18a based on the rotation of the upper and lower grindstones 17, 18 and the rotation feed of the work 24.
4 is ground on both upper and lower surfaces.

Further, the work holder 57 rotates in order to evenly grind the upper and lower surfaces of the work 24. At this time,
The work 24 is set in the setting section 6 formed on the work holder 57.
0a, the workpiece 24 is held in a floating state.
Is engaged with the engagement protrusion 65a,
The work 24 does not idle and cannot follow the rotation of the work holder 57. That is, the work 24 is ground flat by rotating the upper and lower grindstones 17 and 18 so as to draw relatively circles on the front and back surfaces of the work 24.

The upper and lower grinding stones 17 and 1 are moved to a predetermined cutting position.
8 is cut and moved, and the work 24 is ground to a desired thickness.
Is returned to the retracted position, and the holding frame 53 is transported to the work loading / unloading position P1 as shown in FIG. At the workpiece loading / unloading position P1, a robot arm or the like (not shown) takes out the workpiece 24 after the grinding processing and stores the workpiece 24 in a grounded work cassette.

After the ground work 24 is accommodated in the ground work cassette, the unground work 24 is taken out of the unground work cassette and set in the setting section 60a of the work holder 57. At this time, the work 24 is placed in a direction in which the notch 24a formed in the work 24 and the engagement protrusion 65a are engaged. Then, air is ejected from the air ejection holes 64 of the air pad 63a, and the unground work 24
Is held in a floating state in the setting section 60a, and the holding frame 53 is moved to the work processing position P2. At the workpiece processing position P2, as described above, the upper and lower grinding wheels 17,
The grinding of the work 24 is performed by 18.

(Explanation of the sizing device) In the whole operation of the grinding device, the work thickness is measured at a predetermined timing and fed back to the feed movement amount of the grindstones 17 and 18. In the following description, the sizing device 2 is a whetstone 1
The description will be made assuming that the feed movement amounts of the wheels 7 and 18 are corrected. However, the movement feed amount and the cutting amount of the grindstone are the same as the movement amount of the grindstone, and the same effect can be obtained even if the cutting amount is corrected. Needless to say.

As shown in FIG. 8, in the measuring device 70, the thickness of the workpiece 24 after grinding is measured by a contact 81 provided at the tip of two fingers 82. The output from the differential transformer 84 installed in the measuring device main body 83 is displayed on the amplifier 3 and the information is displayed on the control device 1.
01 (see FIG. 1).

Then, the control device 101 controls the measuring device 70
Then, a correction value of the amount of movement of the grinding wheel is calculated based on the information from the controller, and a control signal is output to the lower grinding wheel rotation elevation controller 102 and the upper grinding wheel rotation elevation controller 103. The upper and lower grindstone raising / lowering control unit rotating mechanisms 103 and 102 control the rotation of the raising / lowering servomotors 20 and 19 based on the control signal, adjust the feed movement amounts of the grindstones 17 and 18, and make the work 24 Grinding is performed to a thickness of

In this embodiment, as a reference adjustment in the initial stage of the grinding operation, a sample wafer presented by the user is sandwiched between the contacts 81 of the measuring device 70 as a master wafer, and the output to the amplifier 3 at that time is used as a reference. Make settings so that the position is reached. Since the measuring device 70 is a differential transformer type, it is possible to detect how much the actual workpiece deviates from a desired thickness.
That is, the measuring device 70 detects how much the contact 81 is open (or closed) from the reference position and outputs the result to the amplifier 3. Based on the output to the amplifier 3, the grindstone 17, The feed amount is fed back to the feed amount of 18.

More specifically, based on the output of the differential transformer 84 when the reference master wafer is sandwiched between the contacts 81, the actual work 24 during or after processing is processed.
Is measured, the difference voltage may be output from the differential transformer 84 in accordance with the difference between the master wafer and the actual work thickness. The output to the amplifier 3 is sent to the control device 101, and the control device 101 adjusts the feed movement amount of the grindstone.

First, the reference of the measuring device 70 is adjusted. When the holding frame 53 is located at the workpiece loading / unloading position P1, the master wafer presented by the user by the robot arm is taken out of the master storage place, and set on the setting section 60a of the holding frame 53. At this time, the measuring device 70
Is in a retracted state (see FIG. 7) so as not to interfere with the set of the master wafer.

After setting the master wafer,
The holding frame 53 is moved to the work processing position P2, where the cylinder 72 is operated to move the measuring device 70 forward. At this time, since the measuring device 70 is attached to the holding frame 53, the distance to advance is smaller than that of the conventional double-headed grinding machine 100. In the present embodiment, the measuring device 70
Stops at about 10 mm from the outer periphery of the master wafer. The master wafer is sandwiched from above and below by the contacts 81 (see FIG. 6), and the state is measured by the measuring device 7.
It is detected as a reference position of 0 and set as a reference of the output of the amplifier 3.

When the reference adjustment is completed, the contact 81 is opened and the cylinder 72 is operated to retract the measuring device 70 (see FIG. 7). With the retreat of the measuring device 70, the obstruction by the contact 81 is eliminated, the upper part of the setting portion 60a of the holding frame 53 is opened, and the work 24 can be replaced. Then, the holding frame 53 is moved to the work loading / unloading position P!
Then, the master wafer is taken out of the setting section 60a by the robot arm, and the master wafer is returned to the original position and stored.

In this embodiment, the reference is adjusted at the work processing position P2. However, the reference can be adjusted at the work loading / unloading position P1. Next, the unground work is taken out of the unground work cassette by the robot arm, and the unground work is set in the setting portion 60 a of the holding frame 53. When the unground work is set in the setting section 60a, the robot arm is retracted, and the holding frame 53 is moved from the work loading / unloading position P1 (see FIG. 2) to the work processing position P2 (see FIG. 5) by the moving motor 55. . At this time, since the measuring device 70 is attached to the holding frame 53, the measuring device 70 moves together with the holding frame 53.

Then, the grinding of the work 24 is started by cutting the upper and lower grindstones 17 and 18, and when the processing surface of the work 24 is almost uniformly ground, the cylinder 72 is operated to move the measuring device 70 to the work 24. Advance towards. Note that the measuring device 70 may operate the cylinder 72 and move it forward when the holding frame 53 moves to the work processing position P2, not when the processing surface of the work 24 is uniformly ground.

When the work 24 has been ground to some extent and the unevenness of the work 24 is eliminated, the contact 81 is closed and the work 2 is closed.
The work thickness measurement is started while the work 24 is being ground with the front and back surfaces of No. 4 interposed therebetween. The measurement is continued while the work 24 is being ground, and when the work 24 being processed has the same thickness as the master wafer, the cutting of the grindstones 17 and 18 is stopped by a control signal from the control device 101, and the spark is stopped for a while. Do out. After the spark out, the upper and lower whetstones 17 and 18 are retracted.

After the grinding is completed and the rotation of the work 24 is stopped, the work thickness can be measured again by the measuring device 70. The measurement of the workpiece 24 can be more accurately performed when the workpiece 24 is not rotating. When measuring when not rotating, follow the procedure below. The work thickness after grinding is measured by the measuring device 70, and when the output of the amplifier 3 is within a desired range, the measuring device 70 is retracted and the holding frame 53 is moved to the work loading / unloading position P.
1 and ground by the robot arm 2
4 is housed in a ground work cassette. The work thickness after grinding is measured by the measuring device 70. If the output of the amplifier 3 does not fall within the desired thickness range and indicates (-), the work 24 has been thinly ground. The work 24 is treated as an NG product. When the output of the amplifier 3 does not fall within the desired thickness range and indicates (+), the work 24 has been ground thick, and the grinding wheels 17 and 18 are controlled based on the output of the amplifier 3. Correct the feed movement amount, and again,
The grinding by No. 18 is performed. That is, when the output of the amplifier 3 is larger than the desired value by α μm,
When the cutting is performed by increasing the feed movement amount by α μm, the workpiece 24 can be ground so as to be thin by α μm. Then, the work thickness after grinding is measured again by the measuring device 70, and when the output of the amplifier 3 is within a desired range, the measuring device 70 is retracted and the holding frame 5 is removed.
3 is moved to the work loading / unloading position P1, and the ground work 24 is stored in the ground work cassette by the robot arm.

After the above operation or the above operation is completed, the robot arm takes out the next unground work 24 from the unground work cassette and sets it in the setting section 60 a of the holding frame 53. Then, the holding frame 53 is moved to the work processing position P2, and grinding is performed by the grindstones 17 and 18.

When the measurement device 70 repeatedly measures the thickness of the workpiece, a measurement error occurs due to a mechanical error, thermal deformation, or the like of the measurement device 70 itself. Therefore, after the predetermined number of workpieces 24 have been ground, the reference of the measuring device 70 is adjusted again.

According to the present invention, by attaching the measuring device 70 to the holding frame 53, the stroke of the forward or backward movement of the measuring device 70 can be reduced, and the working time can be shortened. In addition, since the measurement of the work thickness after the actual grinding and the reference adjustment by the master wafer are performed at the same position (work processing position P2) and under the same conditions, the work dimensions can be measured accurately, and the processing can be performed with high precision. can do.

As described above, according to the present invention, the measuring device 70
Can measure the work thickness at the work processing position P2. That is, the work 24 is composed of the upper and lower whetstones 17 and 18.
However, as shown in FIG. 4, the measuring device 70 is located away from the grindstones 17 and 18 so that the grindstones 17 and 1 can be ground even during the grinding operation.
The workpiece thickness can be measured without touching the workpiece 8. Then, the measured values are fed back to the feed movement amounts of the grindstones 17 and 18 to perform the grinding while controlling the thickness of the work. When the measurement is performed during the grinding operation, the work thickness can be measured in real time, and the measured value can be directly fed back to the feed movement amount of the grinding wheel. Therefore, it is not necessary to perform the work thickness measurement again, so that the operation time can be significantly reduced.

In the above embodiment, the master wafer and the ground work are measured at the work processing position P2.
Needless to say, the work thickness can be measured even when the position is other than 2. For example, holding frame 5
When the workpiece 3 is moved to the work loading / unloading position P1 and is located at the work loading / unloading position P1, the measuring device 70 is advanced by operating the cylinder 72, and the measurement may be performed with the contact 81 sandwiching the workpiece 24. .

Further, according to the present invention, the measurement of the work thickness is performed during and after the grinding, but according to the present invention, the measurement of the work thickness is not limited to during and after the grinding. For example, when the unground work 24 is set at the work loading / unloading position P1, the work thickness can be measured. As described above, when the work thickness is measured before grinding, the grindstones 17 and 18 are respectively determined based on the measured values.
Can be determined, and the work can be suitably ground without being affected by the variation in the thickness of the unground work.

Although the above embodiment has been described using a double-headed grinding device having a pair of grinding wheels 17 and 18 on both the upper and lower sides, the present invention is not limited to this, and the single-side grinding device having a grinding wheel only on one side is used. It goes without saying that the present invention can be applied to an apparatus.

As described above, according to the present invention, the grindstones 17 and 18 for grinding the plate-shaped work 24 by the grinding action surfaces 17a and 18a, and the work 24 are rotatably supported and approached or separated from the grindstones 17 and 18. And a holding frame 53 that is movable in the direction in which the workpiece 24 is to be moved.

Further, the thickness of the work 24 is measured by the measuring device 70, and based on the measurement result, the grindstones 17 and 1 are measured.
8 is a grinding device 1 including a control device 101 for adjusting the amount of movement of the grinding device 8.

Further, the measuring device 70 is arranged at a position where the thickness of the work 24 can be measured even while the grindstones 17 and 18 act on the work 24 to perform grinding.

Further, the measuring device 70 sets the workpiece processing position P at which the grindstones 17 and 18 act on the workpiece 24 to perform grinding.
When the holding frame 53 is located at a position other than
Can be measured.

[0083]

According to the present invention, by attaching the measuring device to the holding frame, the stroke amount of the measuring device can be reduced, and the working time can be reduced and the efficiency can be improved.

According to the present invention, the object to be ground can be measured regardless of the position of the holding frame.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a grinding device of the present invention.

FIG. 2 is an enlarged plan view showing a work supporting mechanism.

FIG. 3 is a longitudinal sectional view schematically showing a section of a holding frame.

FIG. 4 is a perspective view showing a positional relationship between a measuring device and a holding frame.

FIG. 5 is a plan view showing a state where a holding frame is at a work processing position P2.

FIG. 6 is a longitudinal sectional view showing a positional relationship between a holding frame and a measuring device in a state where a work thickness is being measured.

FIG. 7 is a longitudinal sectional view showing a positional relationship between the holding frame and the measuring device in a state where the holding frame is retracted from the work.

FIG. 8 is a conceptual diagram showing a configuration of a sizing device.

FIG. 9 is a front view showing a conventional double-headed grinding machine.

FIG. 10 is an enlarged plan view showing a work supporting mechanism of a conventional double-headed grinding machine.

FIG. 11 is an explanatory diagram for explaining a feed movement amount and a cutting amount of a grindstone.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Grinding device 2 ... Sizing device 3 ... Amplifier 11 ... Lower frame 12 ... Intermediate frame 13 ... Upper frame 14 ... Lower grindstone rotating mechanism 14a ... Lower grindstone rotating shaft 1
4b: Flange 15: Work support mechanism 16: Upper grindstone rotating mechanism 16a: Upper grindstone rotating shaft 1
6b: Flange 17: Grinding stone 17a: Grinding working surface 18: Grinding stone 18a: Grinding working surface 19, 20: Servo motor for lifting / lowering 24: Work 24a: Notch 30: Lower grindstone drive motor 31: Rotor 32: Upper grindstone drive motor 33 ... rotor 52 ... support stand 53 ... holding frame 54 ... guide rail 55 ... moving motor 56 ... ball screw 56a ... ball nut 57 ... work holder 57a ... outer peripheral frame 59 ... gear 60 ... shoe 60a ... set part 61 ... work holder Drive motor 62 ... Gear 63a, 63b ... Air pad 64 ... Air ejection hole 65 ... Notch drive 65a ... Engagement projection 70 ... Measuring device 71 ... Support member 72 ... Cylinder 72a ... Piston 72b ... Rod
72c ... Cylinder chamber 81 ... Contact 82 ... Finger 83 ... Measuring device main body 84 ... Differential transformer 85 ... Core 86 ... Secondary coil 87,88 ... Support shaft 89 ... Primary coil 100 ... Double head grinding machine 101 ... Control device 102 ... Lower Grinding wheel rotation raising / lowering control unit 103: Upper grinding wheel rotation raising / lowering control unit 104: Moving motor control unit 105: Rotary motor control unit P1: Work loading / unloading position P2: Work processing position.

Claims (4)

[Claims] A grinding wheel for grinding a plate-like workpiece by a rotating grinding surface; a holding frame rotatably supporting the workpiece and movable in a direction to approach or leave the grinding wheel; The grinding device according to claim 1, further comprising a measuring device for measuring a thickness of the object to be ground, provided on the holding frame. 2. The apparatus according to claim 1, further comprising a controller configured to measure a thickness of the object to be ground by the measuring device, and to adjust a moving amount of the grindstone based on a result of the measurement.
A grinding device according to claim 1. 3. The apparatus according to claim 1, wherein the measuring device is arranged at a position where the thickness of the object to be ground can be measured even while the grinding wheel acts on the object to be ground to perform a grinding process. The grinding device according to claim 1 or 2, wherein 4. The apparatus according to claim 1, wherein the measuring device is capable of measuring the thickness of the object to be ground when the holding frame is located at a position other than the position at which the grinding wheel acts on the object to perform grinding. The grinding device according to any one of claims 1 to 3, wherein