JPH0753878Y2 - Blade monitoring device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a blade monitoring device used in a dicing device to determine a damage state of a dicing blade.

[Prior Art] As a conventional blade monitoring device, for example, JP-A-53-88
Some were published in the 285 bulletin. In this conventional example, the rotational speed and power consumption of a motor that rotationally drives a diamond blade (dicing blade) are detected, and the processing state, damage state, and wear state of the diamond blade are detected from the detection results.

Further, other conventional examples include those disclosed in Japanese Utility Model Laid-Open No. Sho 59-122209 or Japanese Patent Laid-Open No. 62-53803. These are intended to detect a damaged portion of the dicing blade in a non-contact manner by a photo sensor or a reflection sensor using light or electromagnetic waves.

[Problems to be solved by the device]

However, in such a conventional blade monitoring device, in the former case, the change in the motor rotation speed and the power consumption due to the damage of the diamond blade is very weak, so the damage detection responsiveness and reliability are high. Is extremely low.

In the latter case, the dicing blade normally rotates in the coolant cover, and since the coolant cover is full of splashes of coolant (cooling water), it is disturbed by the splashes and the responsiveness of damage detection, There is a problem that reliability is extremely low.

Further, the spindle device used in the dicing device is supported by an air bearing and rotates. Therefore, since the spindle shaft is in non-contact with the housing (non-rotating body), the vibration of the spindle shaft is transmitted through air (air acts as a damper), and the housing is a device other than the spindle structure. Since the vibration is picked up from other devices, the vibration sensor cannot be accurately detected even if the vibration sensor is attached to the housing to detect the vibration. There is also a method to detect the vibration of the spindle shaft with a non-contact sensor, but since the air acts as a damper as described above, the detection level is smaller than that of the detection by direct contact, and the abnormality of the spindle shaft becomes considerably large. It cannot be detected unless it comes in.

[Means for Solving the Problems]

Therefore, in order to solve the above problems, the blade monitoring device according to the present invention has a dicing blade attached to one end,
In a dicing device having a spindle shaft that is supported by an air bearing and rotates, a vibration sensor that is provided so as to contact the spindle shaft and detect vibration by direct contact, and that directly detects vibration of the spindle shaft during rotation. ,
A monitoring means for determining the damage state of the dicing blade at the time of actual break is provided by the signal from the vibration sensor.

[Action]

According to the blade monitoring device having such a configuration, the monitoring unit determines the damage state of the dicing blade by the signal from the vibration sensor that directly detects the vibration of the spindle shaft at the time of rotation. Responsiveness and reliability can be significantly improved, changes in the vibration of the spindle shaft due to damage and wear of the dicing blade can be reliably detected, and damage to the dicing blade can be predicted. It is possible to improve the cutting processing yield of each chip (for example, a semiconductor wafer).

Also, even if the dicing blade rotates in the coolant cover and the coolant cover is filled with coolant splash, it is guaranteed that the splash will hinder the response and reliability of damage detection and wear detection. Can be prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of a blade monitoring apparatus according to the present invention.

In FIG. 1, reference numeral 10 is a spindle structure of a dicing device, and a spindle shaft 1 is arranged on an axis portion of the spindle structure 10. At the left end of the spindle shaft 1 in the drawing, a work W placed on the work supporting surface 4a of the chuck table 4, for example, a semiconductor wafer formed by arranging a large number of integrated circuit chips aligned vertically and horizontally, A dicing blade 2 formed of diamond abrasive grains or the like, which is finely cut for each integrated circuit chip, is attached. A main body 3 is formed so as to surround the spindle shaft 1, and air bearings 5 and 6 for bearing-supporting the spindle shaft 1 are provided between the spindle shaft 1 and the main body 3.

At the right end of the spindle shaft 1 in the figure, the spindle shaft 1
A rotary drive unit 8 (motor) for rotating and driving the motor is provided, and the rotary drive unit 8 includes a coil 8a housed in the main body 3,
It is composed of a magnet 8b provided on the spindle shaft 1. The sensor holder 13 is attached to the right end closing member 3b of the main body 3.
Are fixed by bolts 15. The sensor holder 13
In order to cut vibrations from the right end closing member 3b of the main body 3 or a machine main body (not shown) that supports the main body 3, it is preferable to use a vibration absorber such as bakelite as a material. Inside the sensor holder 13, a through hole 13a is formed on the axis line extension of the spindle shaft 1, and a vibration transmission shaft 17 is fitted into the through hole 13a.

A flange portion 17a is formed in the middle of the vibration transmission shaft 17, and a spring 18 is installed in the internal space of the sensor holder 13 on the right side of the flange portion 17a so as to urge the vibration transmission shaft 17 toward the spindle shaft 1 side. Has been done. The left end of the vibration transmission shaft 17 is a spring 18
It is urged to contact the low friction block 7 at the right end of the spindle shaft 1 by being lightly pressed. Since the left end portion of the spindle shaft 1 is restricted from moving in the axial direction via the flange portion 1a, it is not displaced leftward by the urging force of the spring 18. A vibration sensor 12 is housed and held at the right end of the vibration transmission shaft 17, and the vibration sensor 12 outputs a signal to a monitoring circuit 20 (monitoring means).

In such a blade monitoring device, the spindle shaft 1 is supported by air bearings 5 and 6 in a non-contact manner.
Then, the spindle shaft 1 and the dicing blade 2 are rotationally driven by the rotation driving unit 8 and gradually descend, and the work W supported on the work supporting surface 4a of the chuck table 4 is cut by the processing tip 2a.

Further, according to this embodiment, when the spindle shaft 1 is rotated by the rotation drive unit 8, the rotation state at this time, particularly the vibration in the thrust direction thereof, is transmitted through the vibration transmission shaft 17 that is in direct contact with the low friction block 7. Is transmitted to the vibration sensor 12 with extremely small damping property, the vibration sensor 12 detects the vibration of the spindle shaft 1 and inputs a detection signal corresponding to the vibration level to the monitoring circuit 20 (step P1 in FIG. 2). .

Based on the signal, the monitoring circuit 20 compares with the memory value whether the detected vibration level exceeds the first set value as shown in FIG. 3 (step P2 in FIG. 2), and the first When the set value is exceeded (YES in step P2 of the figure), it is determined that the machining tip 2a of the dicing blade 2 attached to the spindle shaft 1 is damaged and worn, and an alarm signal is output or At the same time, the rotation of the spindle shaft 1 is stopped (step P3 in the figure), and then the dicing blade 2 is replaced (step P4 in FIG. 2). In this case, in the overall configuration diagram of this embodiment, the detection embodiment in the thrust direction (axial direction) is shown.
Since the vibration component when the rotation occurs naturally also in the radial direction, the vibration sensor 12 may be detected by setting the mounting direction of the vibration sensor 12 in the radial direction.

Further, the monitoring circuit 20 compares whether or not the vibration level detected based on the signal from the vibration sensor 12 exceeds a second set value as shown in FIG. When the set value is exceeded, it can be predicted that the machining tip 2a of the dicing blade 2 attached to the spindle shaft 1 is about to be damaged soon.

In this way, the vibration sensor 12 and the monitoring circuit 20 can determine that the machining tip 2a of the dicing blade 2 is damaged, or predict that the machining tip 2a of the dicing blade 2 is likely to be damaged. Therefore, it is possible to prevent many processing defects of the work W from occurring and improve the processing yield of the appropriately processed work.

In the above embodiment, the damage of the processing tip 2a of the dicing blade 2 is predicted when the value exceeds the second set value. However, the change state of the detection signal from the vibration sensor 12 (vibration monitor waveform It is also possible to predict breakage of the processing tip portion 2a of the dicing blade 2 by comparing the change state of the dicing blade 2) with the change state in the memory stored in advance.

Further, in the above embodiment, the vibration transmission shaft 17 is formed by the spring 18.
However, other pressing means such as air pressure may be used.

Further, the vibration transmitting shaft 17 or the low friction block 7 of the spindle shaft 1 that contacts the vibration transmitting shaft 17 may be replaceable. In this case, the total amount of wear between the tip of the vibration transmission shaft 17 that contacts the low friction block 7 and the tip of the low friction block 7 that contacts the vibration transmission shaft 17 is detected by a proximity switch or the like, Worn vibration transmission shaft if worn over
By replacing 17 or the low-friction block 7, it is possible to prevent the occurrence of poor contact between the tip of the vibration transmission shaft 17 that contacts the spindle shaft 1 and the tip of the low-friction block 7 that contacts the vibration transmission shaft 17. be able to.

The vibration transmission shaft 17 and the low-friction block 7 are made of a hard material such as high-speed steel, cemented carbide, diamond, or the like with low friction and low wear. Further, the contact surfaces of the both have a flat, low-wear, low-friction surface, and a mirror finish is desirable to reduce friction.

[Effect of device]

As described above, according to the blade monitoring device of the present invention, the damage is detected by the monitoring means determining the damage state of the dicing blade by the signal from the vibration sensor that directly detects the vibration of the spindle shaft during rotation. The responsiveness and reliability of can be significantly improved. Further, since it is possible to reliably detect the change in the vibration of the spindle shaft due to the damage of the dicing blade, it is possible to detect the damage of the dicing blade. Therefore, it is possible to prevent many machining defects of the work W from occurring, and improve the machining yield of the appropriately processed work.

Further, even if the dicing blade rotates in the coolant cover and the coolant cover is filled with the splash of the coolant, the responsiveness and the reliability of the damage detection are not impeded by the splash of the coolant at all.

[Brief description of drawings]

1 to 3 are views showing an embodiment of a rotation abnormality detecting device for a spindle shaft according to the present invention, FIG. 1 is an overall configuration diagram thereof, and FIG. 2 is a flow chart showing an operating procedure,
FIG. 3 is a monitor waveform diagram. 1 …… Spindle shaft, 1a …… Flange part 2 …… Dicing blade, 2a …… Machining tip part 3 …… Main body, 4 …… Chuck table 5,6 …… Air bearing, 7 …… Low friction block 8 …… Rotational drive, 8a ... Coil 8b ... Magnet, 10 ... Spindle structure 12 ... Vibration sensor, 13 ... Sensor holder 13a ... Through hole, 15 ... Bolt 17 ... Vibration transmission shaft, 17a ... Flange Part 18: Spring, 20: Monitoring circuit (monitoring means) W: Work

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A dicing device comprising a spindle shaft which is attached to one end thereof and which is rotated by being supported by an air bearing. A blade monitoring device comprising: a vibration sensor for directly detecting vibration of the spindle shaft at the time; and a monitoring means for determining a damage state of the dicing blade when the dicing blade is actually broken based on a signal from the vibration sensor.