JPH0753877Y2 - Spindle shaft rotation abnormality detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a rotation abnormality detecting device for a spindle shaft used in a dicing device.

[Conventional technology]

Conventionally, in the dicing device, there has been no particular device for detecting whether the rotation state of the spindle shaft that holds the dicing blade in rotation is proper or abnormal during non-processing. For this reason, first try to machine the work, and discover that the work after machining is not machined cleanly, for example, there are many chips on the work or the chips are large, or the blade wear is abnormally fast. For the first time, I was trying to check the rotation state of the spindle shaft. Possible causes of abnormal rotation of the spindle shaft include clogging of the air discharge hole of the air bearing, imbalance of the spindle shaft, eccentricity of the dicing blade, and tilted mounting.

[Problems to be solved by the device]

After machining the workpiece in this way, a secondary (indirect) abnormality in the spindle shaft rotation state was discovered, and the cause was investigated.
Since it has been removed and corrected, there have been problems that many work defects occur until then, the yield of properly processed works is reduced, and the cost per piece is increased.

In addition, when the vibration of the spindle shaft is detected by the vibration sensor, the spindle shaft (rotating body) supported by the air bearing
Is in non-contact with the housing (non-rotating body), the vibration of the spindle shaft is transmitted to the housing via air (air serves as a damper). Also, the housing is connected to other devices than the spindle structure,
Since vibrations from other devices are also picked up, there is a problem that the vibrations of the spindle shaft cannot be accurately detected even if the vibration sensor is attached to the housing for detection. There is also a method to detect the vibration of the spindle shaft with a non-contact sensor, but since air acts as a damper as described above,
The detection level is smaller than the detection by direct contact, and it cannot be detected unless the abnormality of the spindle axis becomes considerably large.

[Means for Solving the Problems]

Therefore, in order to solve the above problems, the present invention is a dicing device equipped with a dicing blade at one end and having a spindle shaft supported by an air bearing and rotating, and vibration is detected by direct contact with the spindle shaft. A vibration sensor for directly detecting the vibration of the spindle shaft during rotation, and an abnormality determining means for determining whether or not the rotation state of the spindle shaft is abnormal based on a signal from the vibration sensor. It is what

[Action]

According to the spindle shaft rotation abnormality detecting device having such a configuration, the abnormality determining means determines whether the rotation state of the spindle shaft is abnormal or not by the signal from the vibration sensor that directly detects the vibration of the spindle shaft during rotation. By doing so, it is possible to determine the abnormality even during non-machining, prevent the occurrence of many machining defects of the work, and improve the machining yield of the properly machined work.

〔Example〕

Hereinafter, an embodiment of the present invention will be described based on a rotation abnormality detecting device for a spindle shaft shown in FIGS.

In FIG. 1, reference numeral 10 denotes 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 figure, a work W placed on a chuck table, for example, a semiconductor wafer formed by arranging a large number of integrated circuit chips aligned vertically and horizontally is provided for each integrated circuit chip. A dicing blade 2 formed by diamond abrasive grains or the like, which is finely cut, 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.

A rotary drive unit 8 for rotationally driving the spindle shaft 1 is provided at the right end of the spindle shaft 1 in the figure, and the rotary drive unit 8 is provided on the coil 8a housed in the main body 3 and the spindle shaft 1. And a magnet 8b. A sensor holder 13 is fixed to the right end closing member 3b of the main body 3 with a bolt 15. The sensor holder 13 is preferably made of a vibration absorber such as bakelite in order to cut vibrations from the right end closing member 3b of the body 3 or a machine body (not shown) that supports the body 3. 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 4 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 portion of the vibration transmission shaft 17, and the vibration sensor 12 has an abnormality determination circuit 20.
A signal is output to the (abnormality determining means).

In the spindle shaft rotation abnormality detecting device according to such an embodiment, the spindle shaft 1 is supported by air bearings 5 and 6 in a non-contact manner. Then, according to this embodiment, when the spindle shaft 1 is rotated by the rotation drive unit 8,
The rotation state at this time, especially the vibration in the thrust direction,
Through the vibration transmission shaft 17 that is in direct contact with the low friction block 4, the vibration is transmitted to the vibration sensor 12 with extremely small damping,
The vibration sensor 12 detects the vibration of the spindle shaft 1 and inputs a detection signal corresponding to the vibration level to the abnormality determination circuit 20 (step P1 in FIG. 2). Based on the signal, the abnormality determination circuit 20 compares the detected vibration level with a memory value to determine whether it exceeds a predetermined value as shown in FIG. 3 (step P2 in FIG. 2), and exceeds the predetermined value. When (Step P2 in the figure)
YES), it is determined that the rotation state of the spindle shaft 1 is abnormal, and an alarm signal is output, or at the same time, the rotation of the spindle shaft 1 is stopped (step in the same figure).
P3). In this case, the overall configuration diagram of the present embodiment shows the detection embodiment in the thrust direction (axial direction), but as a vibration component when the spindle shaft 1 rotates, of course,
Since the vibration sensor 12 also appears in the radial direction, the vibration sensor 12 may be mounted in the radial direction for detection.

The operator then investigates the cause at this time by inspecting the clogging of the air discharge holes of the air bearings 5 and 6, or inspecting the abnormality of the mounting state of the dicing blade 2 and rotating the spindle shaft 1. The cause of the abnormality is removed (step P4 in FIG. 2). As described above, since the abnormal rotation of the spindle shaft 1 can be detected without machining the work, it is possible to prevent many machining defects of the work and improve the machining yield of the properly machined work.

In the above embodiment, the vibration transmission shaft 17
However, other pressing means such as air pressure may be used.

Further, the vibration transmitting shaft 17 or the low friction block 4 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 4 and the tip of the low friction block 4 that contacts the vibration transmission shaft 17 is detected by a proximity switch or the like, and the predetermined amount is determined. Worn vibration transmission shaft if worn over
By replacing 17 or the low friction block 4, it is possible to prevent occurrence of poor contact between the tip of the vibration transmitting shaft 17 that contacts the spindle shaft 1 and the tip of the low friction block 4 that contacts the vibration transmitting shaft 17. be able to.

The vibration transmission shaft 17 and the low friction block 4 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 present invention, by the signal from the vibration sensor that directly detects the vibration of the spindle shaft at the time of rotation, the abnormality judging means judges whether the rotation state of the spindle shaft is abnormal or not. It is possible to make such a determination even during machining, prevent a large number of machining defects in the work, and improve the machining yield of the appropriately machined work, thereby preventing an increase in cost.

[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, 3 …… Main body 4 …… Low friction block, 5,6 …… Air bearing 8 …… Rotation drive part, 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 ...... Abnormality determination circuit ( Abnormality determination means) W ... Work

Claims (1)

[Scope of utility model registration request] 1. A dicing device having a spindle shaft which is mounted on one end thereof and which is rotated by being supported by an air bearing. The dicing device is provided so as to contact the spindle shaft to detect vibration by direct contact, and to rotate. A vibration sensor for directly detecting the vibration of the spindle shaft at the time, and an abnormality determining means for determining whether or not the rotation state of the spindle shaft is abnormal by a signal from the vibration sensor are provided. Abnormal rotation detection device.