JPS60259360A - Dicing - Google Patents

Abstract

PURPOSE:To detect the breakdown of a rotary edge instantaneously thus to reduce the loss time by monitoring the cutting noise through a microphone provided on a table and automatically stopping feed of wafer upon breakdown of blade. CONSTITUTION:Upon breakdown of a rotary edge 1, said edge 1 and a wafer 3 will never contact or contact insufficiently even if the rotary edge 1 is brought near to the end of wafer 3, to produce low output voltage from a high frequency microphone 7 thereby the output from a comparator 11 is low during the interval when the output signal from a diconnecting range setting circuit 14 is high thus to detect breakdown of the rotary edge. The output voltage from said microphone 7 will also drop upon breakdown of the rotary edge under dicing, thereby the circuit 13 will perform stoppage of lateral feed motor 6, lowering of an up/down motion motor 5 and stoppage of the apparatus. It will be more effective if predetermined alarm is produced upon droppage of the output voltage of the microphone 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blade damage detection device for a processing device using a rotary blade.

For example, a sound wave monitoring method for machine tools is disclosed in Japanese Patent Laid-Open No. 50-8182.

A semiconductor wafer that has undergone characteristic testing must be cut into individual circuits (chips). As methods for this division, a diamond scribe method and a dicing method are known. In this case, the dicing method is superior because it provides accurate pellet dimensions and a flat cut surface, as well as high mechanical positioning accuracy in the next step.

When dividing the wafer using this dicing method,
It is necessary to deeply cut the wafer, leaving about 100 μm, without completely cutting the wafer for handling in subsequent steps. A rotary blade made of a hard material is used to perform such cutting, but the problem of damage to this rotary blade is that it cannot be ignited. By the way,
A metal bond grindstone or a resin bond grindstone is used as the rotary blade, but it is said that neither of them can prevent the above-mentioned damage.

Conventionally, damage to rotary blades has been detected visually by an operator. However, even if the rotary blade is damaged, cutting water and the cover are in the way, making it impossible for the operator to immediately determine whether or not there is damage, and the device continues to "feed." That is,
Abnormalities were often noticed when the ``dry feed'' had progressed considerably or after the work on the work was completed, resulting in a significant reduction in work efficiency.

The present invention has been made to solve the above problems, and its purpose is to provide a device that can instantly detect the damaged state of a rotary blade, and another purpose is to reduce loss time. It is an object of the present invention to provide a processing device that can reduce the amount of damage and improve workability.

An embodiment of the present invention to achieve the above object monitors the cutting sound with a microphone installed on the table, and automatically stops wafer feeding etc. when the blade is damaged. This reduces wasted time due to blade damage during work.

The present invention will be specifically described below using Examples.

FIG. 1 is a principle diagram showing an example of a processing device using a rotary blade according to the present invention.

In the figure, 1 is a rotating blade (for example, a resin bonded grindstone)
2 is a table which is moved up and down by a pulse motor 5 for vertical movement, and moved laterally by a pulse motor 6 for lateral movement to control the relative positional relationship with the rotary blade. The wafer 3 placed thereon is diced (cut). In addition, 4 is
A mechanism for closely fixing the wafer 3 to the upper surface of the table 2 by vacuum suction is shown.

In the present invention, in order to detect damage to the rotary blade in a processing device using the rotary blade configured as described above, four parts are formed on the lower surface of the tape/I/2, and a high frequency microphone 7 is attached thereto. The output signal of the microphone 7 is amplified by an amplifier 8, rectified by a full-wave rectifier 9, smoothed by an integrating circuit 1o, and then input to a comparator circuit 11.

The comparison circuit 11 receives the comparison voltage V from the comparison voltage setting circuit 12.
If the level of the output of the integrating circuit is lower than this VT, a low level signal is output, and if it is higher than VT, a high level signal is output.

The output of the comparison circuit 11 is sent to the pulse motor drive control circuit 13.
Enter.

Said circuit 13, on the other hand, receives an output signal from a cutting range setting circuit 14.

The cutting range setting circuit 14 outputs a high level signal during the period when the ueno 3 on the table is in contact with the rotary blade.

For this purpose, this circuit 14 includes a detection device (not shown) such as a microswitch that detects the lateral position of the table 2.
It receives a detection signal DT from and outputs the above-mentioned signal based on this detection signal.

If the output signal of the comparison circuit 11 is at a high level during the period when the output signal of the cutting range setting circuit 14 is at a high level, the pulse motor drive control circuit 13 normally controls the pulse motors 5 and 6. outputs a drive signal. The circuit 13 stops the output pulse signal to the horizontal feed Tanabata 6 when the output signal of the comparison circuit 11 becomes low level during the period when the output signal of the cutting range setting circuit 14 shows a high level; The motors 5 and 6 are controlled so that the table is lowered by the vertical movement motor 5 and the device is stopped.

The rotary blade damage detection operation in the processing apparatus having the above configuration is as follows.

First, with the rotary blade l rotating, the table ,,2
The rotary blade l is brought closer to the edge of the wafer 3 by raising and moving it laterally. At this time, if the rotary blade 1 is not damaged, the rotary blade 1 and the wafer 3 will be in sufficient contact with each other, and vibrations caused by this contact will be detected by the high frequency microphone 7 via the tape 2. As a result, the output signal of the amplifier 8 is at time t1 as shown in FIG. 2B.
It will get bigger after that. This signal is rectified by the full-wave rectifier 9 as shown in FIG. 2C, and smoothed by the integrating circuit 10 as shown in the same figure. The comparison circuit 11 outputs the signal shown in FIG. 2EK.

Since the output of the comparison circuit 11 indicates a high level, the pulse motor drive control circuit 13 performs normal control. However, if the rotary blade 1 is damaged, even if the rotary blade is rotated and brought close to the edge of the wafer 3, the rotary blade 1 and the wafer 3 will not come into contact at all or the contact will be insufficient. The output voltage from the high-frequency microphone 7 is extremely small, so that the output voltage from the comparison circuit 1 is extremely low during the period in which the output signal from the cutting range setting circuit 14 is at a high level as shown in FIG.
The output signal of 1 becomes low level. From this K, it can be detected that the rotary blade is damaged. If the rotary blade is damaged during dicing, the output voltage of the high frequency micro follower will also drop. Therefore, in such a case, the circuit 13
The horizontal feed motor 0 is stopped, the vertical movement motor 5 is lowered, and the device is stopped. Note that it will be more effective if a predetermined alarm is generated when the output voltage of the high frequency microphone 7 decreases.

As explained above, in the present invention, if the rotary blade is damaged at the beginning of machining or if the rotary blade is damaged during machining, each pulse motor is returned to its initial state and the device is stopped. Therefore, damage to the rotary blade can be detected quickly and reliably. In addition, by stopping the device, "idle feeding" can be prevented and loss time can be reduced. Therefore, workability can be improved.

The present invention is not limited to the above embodiments, and various modifications can be made. For example, any means for converting vibrations into electrical signals may be used, but when using a microphone for audio, a low frequency removal filter must be provided to remove surrounding low frequency sounds. In this sense, the high frequency 74 micro 7 on as shown in the above embodiment would be most suitable.

In addition, in the above embodiment, the high frequency microphone is formed in a recessed part on the back surface of the table, and is installed in this recessed part.
The present invention is not limited to this, and it may be directly attached to the back or side surface of the table using an adhesive or the like.

In this case, care must be taken to ensure that the adhesive does not become too thick and vibrations are sufficiently transmitted.

The present invention can be widely used in processing devices using rotary blades.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram showing an example of the present invention, and FIG. 2 is an output waveform diagram of each circuit in FIG. 1. 1...Rotary blade, 2...Table, 3...Wafer,
4...Adsorption mechanism, 5, 6...Afiy motor, 7
...High frequency microphone, 8...Amplifier, 9...
- Full wave rectifier, 10... Integrating circuit, 11... Comparator, 12... Comparison voltage setting circuit, 13... Pulse motor drive control circuit, 14... Cutting range setting circuit. Agent Patent Attorney 'J'Jll Hat -. 1, , - Figure 1C Figure 2

Claims (1)

[Claims] 1. In a dicing device for cutting semiconductor wafers or integrated circuit wafers into individual pellets by cutting them with a rotating blade and separating them into individual pellets, the state of the blade is determined based on the cutting sound monitored on the workpiece mounting table. detect,
A dicing device for plate-shaped materials, characterized in that the cutting operation can be automatically stopped when the blade is damaged.