JPS61103774A - Lapping device - Google Patents

Abstract

PURPOSE:To make it possible to accurately control the position of an upper lap plate by providing a programmable controller for controlling the operation of an air cylinder to pressure the upper lap plate according to the operation amount and pressure data of the air cylinder. CONSTITUTION:An air cylinder 6 with solenoid valves 9A and 9B for giving thrust to pressure an upper lap plate 1 to a lower plate 2 and capable of stopping in the middle of stroke is provided. The air pressure of the air chambers 6A and 6B of the air cylinder 6 are detected by pressure sensors 14A and 14B, and in addition, the operation amount of the air cylinder 6 is detected by an operation amount sensor (counter section) 21. In the next step, a programmable controller 23 controls the ratio of the air pressure impressed to the air chambers 6A and 6B of the air cylinder 6 accordingly to the pressure and operation amount data detected by respective sensors (14A and 14B) and 21 based on the objective data previously given for thrust control and controls the thrust of the upper lap plate 1 to the lower lap plate 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lapping device used for surface treatment of semiconductor substrates made of silicon, germanium, etc. [Prior Art] The semiconductor substrate of
From a polycrystalline ingot formed from a crude polycrystalline semiconductor material through chloride distillation, zone refining, etc., a single crystal ingot with a certain crystal alignment is formed by a pulling method, a floating zone melting method, etc. It is manufactured by slicing this single crystal ingot into thin plate shapes and subjecting the obtained semiconductor wafer to surface treatment.

The surface treatment of the semiconductor wafer includes a lapping process to remove the destructive layer, that is, so-called firmness, on the surface of the semiconductor wafer by the slicing, and a polishing process to mirror polish the surface of the semiconductor wafer after the lapping process. This has been commonly done for a long time.

Here, in the lapping process described in L, not only does it remove the firmness caused by slicing, but it also improves the parallelism and smoothness of the semiconductor wafer for the next polygon process, and the cutter in the slicing process. Performs surface treatment to remove defects such as scratches on semiconductor wafers.

Conventionally, the above-mentioned lapping process has been performed by a dedicated lapping device using a hydraulic mechanism designed based on specification data for the semiconductor wafer supplied from a semiconductor material manufacturer.

[Problem that the invention seeks to solve]

In general, with conventional lapping machines that use hydraulic mechanisms, it is difficult to control the position of the lapping plate with high precision. There was a risk that the surface of the semiconductor wafer could be damaged by getting between it and the lapping plate. Furthermore, it has not been possible to efficiently perform surface treatment to improve the parallelism and smoothness of semiconductor wafers in a short period of time.

SUMMARY OF THE INVENTION In view of the above-mentioned problems with conventional lapping apparatuses, the present invention aims to control the position of a lapping plate with high precision and efficiently perform surface treatment to improve the parallelism and smoothness of semiconductor wafers in a short time. It is an object of the present invention to provide a lapping apparatus with a new configuration that can easily perform lapping processing according to specification data of a semiconductor wafer supplied from a semiconductor material manufacturer.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a lapping apparatus for lapping a semiconductor wafer using a lower lapping plate and an upper lapping plate that are rotationally driven to face each other with the semiconductor wafer to be wrapped in between. an air cylinder having an intermediate stop function that applies a thrust to press the lap plate toward the lower lap plate; a pressure sensor that detects the operation air pressure of the air cylinder; and an operation 9 sensor that detects the operation amount of the air cylinder; A programmable controller that controls the operation of the air cylinder according to the operation amount data obtained by the operation position sensor and the pressure data obtained by the pressure sensor, based on thrust control target data arbitrarily given in advance. It is characterized by being equipped with a controller.

[Effect]

In the wrapping device according to the present invention, a programmable controller that operates based on thrust control target data arbitrarily given in advance controls the operation of the air cylinder that provides thrust to press the upper wrap plate toward the lower wrap plate. This is performed according to the operation amount data obtained by the operation amount sensor and the pressure data obtained from the pressure sensor, which indicate the actual operation control state of the controller.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wrapping device according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic front view showing an embodiment of a wrapping apparatus according to the present invention, and FIG. 2 is a block diagram schematically showing the configuration of a control system of this embodiment. moreover,
FIG. 3 is a characteristic diagram for explaining the control operation in the above embodiment.

In the lapping apparatus of this embodiment, the lower lapping plate 1 and the upper lapping plate 2 are arranged on the apparatus main body 4 so as to face each other with the semiconductor wafer 3 to be wrapped in between, and are provided in the apparatus main body 4. They are each rotated by a main motor 5. Further, the upper lap plate 2 is rotatably provided at the lower end portion of the piston rod 7 of the air cylinder 6, so that the air cylinder 6 applies +iI force to press the lower lap plate 1 side. It has become.

The air cylinder 6 operates in accordance with the ratio of air pressure applied to an upper chamber 6A and a lower chamber 6B of the air cylinder () partitioned by a piston 8 provided at the upper end of the piston rod 7. A solenoid valve 9A for intermediate stopping is provided with an intermediate stopping function that can be freely controlled to stop at any position.

Compressed air is supplied to the upper chamber 6A and the royal chamber 6B via 9B. The air cylinder 6 also outputs a detection output pulse obtained by detecting the scale of an optical scale 11 connected to the piston rod 7 via an arm 10 to a counter section 21. By supplying the air, the amount of movement of the piston rod 7, that is, the amount of operation of the air cylinder 6 is read by the counter section 21. moreover,
The air cylinder 6 includes the intermediate stop solenoid valve 9A,
The air pressure in the upper chamber 6A and the lower chamber 6B, to which compressed air is supplied through the pressure sensor 14A and 1
4B. The air cylinder 6 obtained by the pressure sensors 14A and 14B
The detected output signals of the air pressures of the upper chamber 6A and the royal chamber 6B are supplied to an analog-to-digital (A/D) converter 22.

Further, the apparatus main body 4 is provided with a control box 20 having a central processing unit (CPU) 23 for controlling the operation of the wrapping apparatus of this embodiment. The control box 20 includes a storage section 2 for storing various data used for controlling the operation.
4. A real-time control unit 25 that generates time information for real-time control, a keyboard interface unit 26 for inputting data, an input/output interface unit 27 for sequence control, and rotation control of the main motor 5. An inverter interface section 28 for an inverter (not shown) that performs the above-mentioned counter section 13 and A/
l) provided with the converter 15;

In this embodiment, the control box 20
The CPU 23 installed at each point A, B, C, D, E, F shown in the characteristic diagram shown in FIG.
Each control target data of the target intelligence production amount, target thrust, and time is given in advance by key operations on a keyboard (not shown) via the keyboard interface unit 26, and the entire device is controlled in a predetermined sequence based on the control target data. The operation amount data read by the counter unit 21 and the pressure sensor 14A while controlling the
.

14B of the air cylinder 6 obtained by
j The intermediate stop supplying compressed air to the air cylinder 6 according to pressure data obtained by digitizing the detection output signal of each air pressure in the upper chamber 6A and the T chamber 6B with the A/D converter 22. Solenoid valve 9A, 9B for
by controlling the upper chamber 6A of the air cylinder 6 and the royal room 6.
Control the ratio of air pressure applied to B. The air cylinder 6 is controlled in real time by the PU 23 in accordance with the operation amount data and pressure data indicating the actual operation control state, so that the ratio of the air pressure applied to the upper chamber 6A and the royal chamber 6B is controlled in real time. The operation is controlled so that the thrust that presses the upper lap plate 2 toward the lower lap plate I is applied in accordance with the characteristic diagram shown in FIG. 3 above.

Note that the control target data given in advance via the keyboard interface unit 26 can be arbitrarily used, such as semiconductor wafer specification data supplied from a semiconductor material manufacturer or data obtained as actual experimental results.

In this embodiment, the operation of the air cylinder 6 is controlled according to the characteristic diagram shown in FIG. By gradually increasing the weak thrust up to the first target point A at which the process starts, and performing the firming process up to the next target point B, the firming process can be performed well and the yield can be improved. I can do it. Then, once the above-mentioned firming process is completed,
The thrust of the air cylinder 6 is maximized to each target point C, D.
During the finishing stage, that is, between each target point E and F, the air cylinder 6 is again used.
The parallelism of the surface of the semiconductor wafer 3 by weakening the thrust of
By performing surface treatment to increase smoothness, lapping can be efficiently performed in a short time with high dimensional accuracy.

〔Effect of the invention〕

As is clear from the description of the above-mentioned embodiments, the present invention provides a lapping apparatus for lapping a semiconductor wafer using a lower lapping plate and an upper lapping plate that are driven to rotate opposite to each other with the semiconductor wafer to be wrapped sandwiched therebetween. an air cylinder having an intermediate stop function that provides a thrust to press the upper lap plate toward the lower lap plate; a pressure sensor that detects the operating air pressure of the air cylinder; and an operation amount sensor that detects the operating amount of the air cylinder. , a programmable controller that controls the operation of the air cylinder according to operation amount data obtained from the operation amount sensor and pressure data obtained from the pressure sensor, based on thrust control target data arbitrarily given in advance. By setting it up, uh.

By controlling the position of the pin plate with high precision, it is possible to efficiently perform surface treatment to improve the parallelism and smoothness of semiconductor chips in a short time, and to apply the specification data of semiconductor wafers supplied by semiconductor material manufacturers. The desired wrapping process can be easily performed and the intended purpose can be fully achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing an embodiment of a wrapping apparatus according to the present invention, and FIG. 2 is a block diagram schematically showing the configuration of a control system of this embodiment. moreover,
FIG. 3 is a characteristic diagram for explaining the control operation in the above embodiment. ■...Upper wrap plate 2...Upper wrap plate 3...Semiconductor wafer 4...Equipment body 5...Main motor 6...Air cylinders 9A, 9B...Intermediate stop solenoid valve 11 ...Optical scale 12...Detection heads 14A, 14B...Pressure sensor 20...Control box 21...Counter section 22...A/D converter 23...CPU 24... storage section

Claims (1)

[Claims] In a lapping device that wraps a semiconductor wafer using a lower wrap plate and an upper wrap plate that are rotationally driven to face each other with a semiconductor wafer to be wrapped in between, a thrust force is applied to press the upper wrap plate toward the lower wrap plate. An air cylinder having an intermediate stop function, a pressure sensor that detects the operation air pressure of the air cylinder, an operation amount sensor that detects the operation amount of the air cylinder, and the above-mentioned operation based on thrust control target data arbitrarily given in advance. A wrapping device comprising a programmable controller that controls the operation of the air cylinder in accordance with operation amount data obtained by the operation amount sensor and pressure data obtained by the pressure sensor.