JP6961306B2 - Inspector, liquid supply device, and protective film coating device - Google Patents

Description

The present invention relates to an inspection device for inspecting a liquid flowing in a pipeline, a liquid supply device including the inspection device, and a protective film coating device including the liquid supply device.

In a processing apparatus provided with a processing unit for processing an workpiece such as a semiconductor wafer or a plate-shaped substrate, various liquids or liquid mixtures are supplied to the workpiece or the processing unit. The processing device includes a liquid supply device (liquid supply unit) including a supply source of the liquid or the like, a discharge port for discharging the liquid or the like, and a pipeline connecting the supply source and the discharge port. In the processing apparatus, in order to operate the processing apparatus appropriately, the liquid or the like having a predetermined temperature and concentration is flowed into the pipeline at a predetermined flow rate and flow velocity.

An ultrasonic flow meter arranged in the pipeline is known as a measuring instrument for measuring the flow rate and the flow velocity of the liquid or the like flowing in the pipeline (see Patent Document 1 and Patent Document 2). The ultrasonic flowmeter propagates ultrasonic waves into the liquid or the like to be measured flowing in the pipeline, and the velocity of the ultrasonic waves propagating from the upstream side to the downstream side and the propagation from the downstream side to the upstream side. The flow velocity of the liquid or the like is measured by comparing with the velocity of the ultrasonic waves to be generated, and the flow velocity is calculated from the flow velocity.

By the way, the liquid or the like used in the processing apparatus is, for example, pure water or a liquid such as an acidic solution, an alkaline solution, or another solution. The liquid also includes a liquid mixture in which solid particles such as a slurry (suspension) are dispersed.

Further, the liquid is, for example, a liquid resin applied to the surface of the work piece in order to prevent the surface of the work piece from being contaminated by debris or the like generated when the work piece is laser-machined. When the liquid resin is applied to the surface of the work piece by the protective film coating device, a protective film made of the liquid resin is formed on the surface of the work piece. Processing devices that use such various liquids are known (see Patent Documents 3 and 4).

Japanese Unexamined Patent Publication No. 2011-7763 Japanese Unexamined Patent Publication No. 2015-206593 Japanese Unexamined Patent Publication No. 2003-257905 JP-A-2010-194672

Bubbles may be mixed in the liquid flowing through the pipeline of the liquid supply device. If air bubbles are mixed in the liquid flowing through the pipeline, the liquid may not be supplied to a predetermined portion of the processing apparatus under predetermined conditions. Further, when air bubbles are mixed in the liquid, the flow velocity, the flow rate, etc. of the liquid cannot be measured correctly by the inspection device, and the flow velocity, the flow rate, etc. of the liquid may not be controlled correctly.

Further, in the protective film coating device in which the liquid resin applied to the surface of the work piece flows through the pipeline, when air bubbles are mixed in the liquid resin, air bubbles are also generated in the protective film formed on the work piece. Remain. When air bubbles are present in the protective film, a laser beam may be applied to the air bubble portion of the protective film, or debris generated by laser processing may reach the air bubble portion. That is, the surface of the work piece is not properly protected.

Therefore, there is a demand for promptly detecting air bubbles when they are mixed in the liquid flowing through the pipeline.

The present invention has been made in view of the above problems, and an object of the present invention is an inspection device capable of inspecting the presence or absence of air bubbles in a liquid flowing through a pipeline, a liquid supply device provided with the inspection device, and the like. The present invention is to provide a protective film coating device including a liquid supply device.

According to one aspect of the present invention, there are two ultrasonic vibrators arranged in a conduit that serves as a flow path for liquids, one on the upstream side and the other on the downstream side of the conduit. And a control unit electrically connected to the two ultrasonic vibrators, the control unit includes an amplitude calculation unit, a determination unit, an amplitude range registration unit, a propagation time calculation unit, and propagation. It has a time range registration unit, and a substance is dissolved or dispersed in the liquid, and the amplitude calculation unit is generated in one of the two ultrasonic vibrators and propagates in the liquid flowing through the conduit. The amplitude of the first ultrasonic wave is calculated from the waveform information obtained by observing the first ultrasonic wave to be generated by the other of the two ultrasonic vibrators, and the propagation time calculation unit calculates the amplitude of the first ultrasonic wave. The first ultrasonic wave generated by the one side of the sound vibrator and propagating in the liquid flowing through the conduit is observed from the other side of the two ultrasonic vibrators, and the first ultrasonic wave is obtained from the waveform information. The propagation time of the ultrasonic waves is calculated, and the second ultrasonic wave generated in the other of the two ultrasonic transducers and propagated in the liquid flowing in the conduit is transferred to the one of the two ultrasonic transducers. The propagation time of the second ultrasonic wave is calculated from the waveform information obtained by observation, and the propagation time of the first ultrasonic wave and the propagation time of the second ultrasonic wave are averaged and averaged. The propagation time is calculated, and the range of the amplitude of the ultrasonic wave propagating in the liquid mixed with bubbles is registered in the amplitude range registration unit, and the concentration is not a predetermined concentration in the propagation time range registration unit. The range of the average propagation time of the ultrasonic waves propagating in the liquid in which the substance is dissolved or dispersed at the concentration is registered, and the determination unit has the amplitude of the first ultrasonic wave calculated by the vibration calculation unit. When it is within the range of the amplitude registered in the amplitude range registration unit, it is determined that air bubbles are mixed in the liquid, and the determination unit is not determined that air bubbles are mixed in the liquid, and the propagation time is calculated. An inspection comprising determining that the concentration of the liquid is not a predetermined concentration when the average propagation time calculated by the unit is within the range of the average propagation time registered in the propagation time range registration unit. A vessel is provided.

In one aspect of the present invention, the liquid temperature measuring device further comprises a liquid temperature measuring device for measuring the temperature of the liquid, and the liquid temperature measuring device measures the temperature of the liquid flowing through the conduit and determines the temperature of the liquid. The determination unit may correct the content of the determination with reference to the temperature of the liquid.

According to another aspect of the present invention, it is an inspection device arranged in a pipeline serving as a flow path of a liquid, and two ultrasonic waves arranged on an upstream side and a downstream side of the pipeline. It further includes a vibrator, a control unit electrically connected to the two ultrasonic vibrators, and a liquid temperature measuring device for measuring the temperature of the liquid, and the control unit includes an amplitude calculating unit. The amplitude calculation unit includes a determination unit and an amplitude range registration unit, and the amplitude calculation unit transmits a first ultrasonic wave generated by one of the two ultrasonic transducers and propagated in the liquid flowing through the conduit. The amplitude of the first ultrasonic wave is calculated from the waveform information obtained by observing the other of the two ultrasonic transducers, and the ultrasonic wave propagating in the liquid mixed with bubbles is stored in the amplitude range registration unit. When the amplitude range of the first ultrasonic wave calculated by the amplitude calculation unit is within the range of the amplitude registered in the amplitude range registration unit, the determination unit is registered. When it is determined that air bubbles are mixed in the liquid, the liquid temperature measuring device measures the temperature of the liquid flowing through the pipeline and transmits the temperature of the liquid to the determination unit, which determines that the liquid is of the liquid. An inspection device is provided that corrects the content of the determination with reference to the temperature.

Further, the pipeline, a supply source of the liquid connected to one end of the pipeline, a pump for supplying the liquid from the supply source of the liquid to the other end of the pipeline, and a pump installed in the pipeline are installed. A liquid supply device including the inspection device according to one aspect of the present invention is also one aspect of the present invention. Further, it is a protective film coating device that coats the surface of a wafer with a liquid resin to form a protective film, and is a rotatable chuck table for holding the wafer and the liquid resin on the surface of the wafer held on the chuck table. A protective film coating device according to an aspect of the present invention is also an aspect of the present invention.

The inspection device according to one aspect of the present invention is arranged in a pipeline through which a liquid to be inspected flows. The inspection device has two ultrasonic vibrators provided on the upstream side and the downstream side of the pipeline, and a control unit electrically connected to the two ultrasonic vibrators. In the inspection device, one ultrasonic vibrator generates ultrasonic waves, and the other ultrasonic vibrator observes the ultrasonic waves propagating in the liquid flowing through the conduit. The amplitude calculation unit calculates the amplitude of the observed ultrasonic wave.

When air bubbles are mixed in the liquid flowing through the pipeline, the transmission path of the ultrasonic waves propagating in the liquid is reduced by that amount, and the amplitude of the observed ultrasonic waves is reduced. In the amplitude range registration unit included in the control unit of the inspection device according to one aspect of the present invention, the amplitude range of the ultrasonic wave propagating in the liquid mixed with bubbles is registered. Then, in the determination unit included in the control unit, when the amplitude of the ultrasonic wave calculated by the amplitude calculation unit is within the range of the amplitude registered in the amplitude range registration unit, air bubbles are mixed in the liquid. Is determined.

Therefore, for example, when the inspection device according to one aspect of the present invention is incorporated in the liquid supply device, it is possible to detect the mixing of air bubbles in the pipeline of the liquid supply device.

Therefore, according to one aspect of the present invention, an inspection device capable of inspecting the presence or absence of air bubbles in a liquid flowing through a pipeline, a liquid supply device including the inspection device, and a protective film coating device including the liquid supply device are provided. Provided.

It is a figure which shows typically the liquid supply device. It is a figure which shows typically the inspection device arranged in a pipeline. FIG. 3 (A) is a chart schematically showing an example of ultrasonic waveforms observed by an ultrasonic vibrator, and FIG. 3 (B) schematically shows two ultrasonic waveforms having different amplitudes. It is a chart which shows. It is a perspective view which shows typically an example of the processing apparatus provided with the liquid supply apparatus. FIG. 5 (A) is a cross-sectional view schematically showing the coating of the liquid resin by the liquid resin coating unit, and FIG. 5 (B) is a cross-sectional view schematically showing the laser processing of the wafer by the laser processing unit. ..

An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. The inspection device according to the present embodiment is incorporated into a processing unit or a liquid supply device that supplies various liquids to the workpiece or the like in a processing apparatus for processing a workpiece such as a semiconductor wafer. The liquid supply device includes a pipeline that serves as a liquid delivery path for the liquid, and the inspection device is arranged in the pipeline. The inspector can inspect the liquid flowing through the pipeline for the presence or absence of air bubbles.

The liquid is, for example, pure water, an acidic solution, an alkaline solution, another solution, or the like. The liquid also includes a liquid mixture in which solid particles such as a slurry (suspension) are dispersed. Alternatively, the liquid is a water-soluble liquid resin described later. The alkaline solution is, for example, a solution in which one or more of potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, potassium carbonate, sodium hydrogencarbonate, or potassium hydrogencarbonate is dissolved.

Next, an example of a liquid supply device provided with a pipeline for supplying a liquid to a predetermined location and the inspection device will be described with reference to FIG. FIG. 1 is a diagram schematically showing a liquid supply device 2. The liquid supply device 2 supplies the liquid from the pipeline 12, the liquid supply source 14 connected to one end of the pipeline 12, and the liquid supply source 14 to the other end of the pipeline 12. The pump 16 is provided. The liquid supply device 2 has, for example, a function of supplying the liquid 8 contained in the liquid supply source 14 to the wafer 10 processed by the processing device.

The liquid discharge portion 6 provided at the other end of the pipeline 12 is arranged above the chuck table 4 that holds the workpiece such as the wafer 10. The liquid discharge unit 6 has a function of discharging the liquid 8 supplied from the liquid supply source 14 through the pipeline 12 to the wafer 10 or the like held on the chuck table 4. The liquid discharge unit 6 supplies, for example, a water-soluble liquid resin as the liquid 8 to the surface of the wafer 10 or the like.

When a wafer 10 having a plurality of devices formed on its surface is divided into each device, a plurality of device chips can be formed. When the wafer 10 is divided, a laser beam having a wavelength at which the wafer 10 has absorbency is irradiated to a predetermined processing scheduled position of the wafer 10, and a processing groove is formed in the wafer 10 by ablation processing. When the wafer 10 is ablated, processing debris called debris is generated and scattered on the surface of the wafer 10, but if debris adheres to the surface of the wafer 10, it is not easy to remove it.

Therefore, before the ablation process is performed, the water-soluble liquid resin is supplied to the surface of the wafer 10 in advance, and a protective film is formed on the surface of the wafer 10. Then, since the debris generated by the ablation process adheres to the protective film, the debris does not directly adhere to the wafer 10. After that, when the surface of the wafer 10 is washed with a cleaning liquid containing water, the debris is washed away together with the protective film, so that the debris is less likely to remain on the surface of the wafer 10. That is, the surface of the wafer 10 is protected from debris by the protective film.

In the pipeline 12 through which the liquid 8 such as the liquid resin flows, air bubbles may be mixed in the liquid 8. When the liquid 8 mixed with air bubbles is supplied to the wafer 10 to form a protective film, air bubbles remain in the protective film as well. When the bubble portion of the protective film is irradiated with a laser beam or the debris generated by laser processing reaches the bubble portion, the debris adheres to the surface of the wafer 10. That is, if air bubbles are mixed in the liquid 8 flowing through the pipeline 12, the protective film cannot appropriately protect the surface of the wafer 10.

Further, when a liquid other than the liquid resin is flowed through the pipeline 12, air bubbles may be mixed in the liquid 8 flowing through the pipeline 12. If air bubbles are mixed in the liquid 8, the flow velocity, flow rate, etc. of the liquid 8 cannot be measured correctly with a flow meter or the like, and the flow velocity, flow rate, etc. of the liquid 8 may not be controlled correctly. Further, if air bubbles are mixed in the liquid 8 in which the substance is dissolved or dispersed, the concentration of the liquid 8 flowing through the pipeline 12 may not be measured with high accuracy.

Therefore, the inspection device 18 according to the present embodiment is arranged in the pipeline 12. The inspection device 18 has a function of inspecting the liquid 8 flowing in the pipeline 12 and detecting the inclusion of air bubbles when the liquid 8 is mixed with air bubbles. Hereinafter, the inspection device 18 will be described in detail.

The inspection device 18 is attached to two ultrasonic vibrators 22a and 22b and two ultrasonic vibrators 22a and 22b arranged on the upstream side and the downstream side of the pipeline 12 through which the liquid 8 flows. It includes an electrically connected control unit 24. FIG. 2 is a cross-sectional view schematically showing an inspection device 18 arranged in the pipeline 12. FIG. 2 schematically shows a configuration example of the control unit 24.

The two ultrasonic vibrators 22a and 22b can generate ultrasonic waves and propagate the ultrasonic waves into the liquid 8 flowing through the conduit 12. Further, the ultrasonic vibrators 22a and 22b can observe the ultrasonic waves propagated to the ultrasonic vibrators 22a and 22b.

For example, when ultrasonic waves are generated in one of the two ultrasonic vibrators 22a and 22b, the ultrasonic waves propagate to the liquid 8 flowing through the pipeline 12. The ultrasonic waves propagating in the liquid can be observed by the other of the two ultrasonic vibrators 22a and 22b. Similarly, when an ultrasonic wave is generated in the other of the two ultrasonic vibrators 22a and 22b, the ultrasonic wave can be observed in the one of the two ultrasonic vibrators 22a and 22b.

The inspection device 18 further has a control unit 24 electrically connected to the two ultrasonic vibrators 22a and 22b. The control unit 24 controls the measurement of ultrasonic waves by the inspection device 18. The control unit 24 has a switching unit 26 electrically connected to the two ultrasonic vibrators 22a and 22b. The switching unit 26 has a function of switching between ultrasonic vibrators 22a and 22b for generating ultrasonic waves and ultrasonic vibrators 22a and 22b for observing the ultrasonic waves.

The switching unit 26 is electrically connected to the power supply 28, and the power supply 28 is connected to one of the two ultrasonic vibrators 22a and 22b to generate ultrasonic waves in the ultrasonic vibrator. Further, the switching unit 26 is electrically connected to the amplifier 30, and the other of the two ultrasonic vibrators 22a and 22b is connected to the amplifier 30. The ultrasonic wave reaching the other side of the ultrasonic vibrator is converted into an electric signal including waveform information, and the electric signal is sent to the amplifier 30. The electric signal includes, for example, waveform information obtained by converting the ultrasonic wave into a voltage value.

The amplifier 30 is electrically connected to the calculation unit 32 of the inspection device 18, and amplifies an electric signal including the waveform information and sends it to the calculation unit 32. The calculation unit 32 includes an amplitude calculation unit 34, a determination unit 36, an amplitude range registration unit 38, a propagation time calculation unit 40, a propagation time range registration unit 42, and a liquid temperature measurement for measuring the temperature of the liquid 8. A liquid temperature calculation unit 46 connected to the vessel 44 is provided. The electric signal including the waveform information amplified by the amplifier 30 is transmitted to the amplitude calculation unit 34 of the calculation unit 32 and the propagation time calculation unit 40.

The propagation time calculation unit 40 transmits ultrasonic waves (first ultrasonic waves) generated in one of the two ultrasonic vibrators and propagating in the liquid 8 flowing in the conduit 12 of the two ultrasonic vibrators. On the other hand, the propagation time of the ultrasonic wave is calculated as the first propagation time from the waveform information obtained by observing. Further, the propagation time calculation unit 40 uses the two ultrasonic waves (second ultrasonic waves) generated in the other of the two ultrasonic vibrators and propagated in the liquid 8 flowing in the conduit 12. From the waveform information obtained by observing one of the vibrators, the propagation time of the ultrasonic wave is calculated as the second propagation time.

FIG. 3A is a chart schematically showing an example of ultrasonic waveforms observed by the two ultrasonic vibrators 22a and 22b. FIG. 3A schematically shows an example of the ultrasonic waveform 48 generated by the ultrasonic vibrator on the upstream side and observed by the ultrasonic vibrator on the downstream side. Further, FIG. 3A schematically shows an example of the ultrasonic waveform 50 generated by the ultrasonic vibrator on the downstream side and observed by the ultrasonic vibrator on the upstream side.

The two ultrasonic vibrators 22a and 22b include a piezoelectric element, and the ultrasonic waves reaching the ultrasonic vibrators 22a and 22b are converted into an electric signal having a voltage reflecting the amplitude of the ultrasonic waves by the piezoelectric element. For example, the horizontal axis of the chart represents the propagation time of ultrasonic waves, and the vertical axis of the chart is the observed voltage value representing the amplitude (intensity) of ultrasonic waves.

Since the liquid 8 flowing in the pipeline 12 flows from the upstream side to the downstream side at a predetermined flow velocity, the velocity of the ultrasonic waves propagating in the liquid 8 flowing in the pipeline 12 is affected by the flow of the liquid 8. For example, the propagation speed of ultrasonic waves propagating from the upstream side to the downstream side is faster than the propagation speed of ultrasonic waves propagating in the stationary liquid 8, and the propagation speed of ultrasonic waves propagating from the downstream side to the upstream side is. It is slower than the propagation speed of ultrasonic waves propagating in the stationary liquid 8.

Therefore, the first propagation time 52 is smaller than the second propagation time 54. The faster the flow velocity of the liquid 8 flowing through the pipeline 12, the larger the difference in the propagation time of the ultrasonic waves propagating in the liquid 8. The propagation time calculation unit 40 calculates the average of the calculated first propagation time 52 and the second propagation time 54 as the average propagation time 56. The propagation time calculation unit 40 is connected to the determination unit 36, and transmits the calculated average propagation time 56 to the determination unit 36.

When a liquid 8 in which a substance is dissolved or dispersed flows through a pipeline 12, the propagation speed of ultrasonic waves propagating in the liquid 8 changes depending on the concentration of the liquid 8, so that the ultrasonic waves propagating in the liquid 8 propagate. By monitoring the time, the occurrence of an abnormality in the concentration of the liquid 8 can be detected. In the propagation time range registration unit 42, a range of propagation time of ultrasonic waves propagating in the liquid 8 in which a substance is dissolved or dispersed at a concentration other than a predetermined concentration, for example, a range of the average propagation time 56 is registered. There is.

The propagation time range registration unit 42 transmits the registered propagation time range of the ultrasonic wave propagating in the liquid 8 in which the substance is dissolved or dispersed at a concentration other than a predetermined concentration to the determination unit 36. When the average propagation time 56 is within the range of the propagation time registered in the propagation time range registration unit 42, the determination unit 36 has an abnormality in the concentration of the liquid 8 instead of the predetermined concentration. Can be determined to have occurred.

The range of the propagation time of the ultrasonic wave registered in the propagation time range registration unit 42 is not limited to the range of the propagation time of the ultrasonic wave when the concentration of the liquid 8 is abnormal. For example, the propagation time range of ultrasonic waves when the concentration of the liquid 8 is normal is registered in the propagation time range registration unit 42, and the propagation time range registration unit 42 registers the ultrasonic waves in the determination unit 36. The range of propagation time of may be transmitted. In this case, the determination unit 36 determines that the concentration of the liquid 8 is not a predetermined concentration and an abnormality has occurred in the liquid 8 when the average propagation time 56 deviates from the range of the propagation time.

Further, the range of the propagation time of the ultrasonic waves registered in the propagation time range registration unit 42 is not the average propagation time 56, but the normal or abnormal time of the first propagation time 52 or the second propagation time 54. The range may be registered. Since the flow rate of the liquid 8 is determined by the pump 16 that flows the liquid 8 through the pipeline 12, when the flow rate of the liquid 8 is determined by the operating status of the pump 16, the flow rate of the liquid 8 is taken into consideration. The occurrence of an abnormality in the liquid 8 can be detected.

Since the propagation speed of the ultrasonic wave propagating in the liquid 8 also changes depending on the temperature of the liquid 8, if the temperature of the liquid 8 is taken into consideration at the time of determination, the abnormality of the liquid can be detected with high accuracy. The temperature of the liquid 8 is measured by the liquid temperature measuring device 44. The liquid temperature measuring device 44 is, for example, a thermometer. The liquid temperature calculation unit 46 causes the liquid temperature measuring device 44 to measure the temperature of the liquid 8 flowing through the conduit 12, and transmits the obtained temperature of the liquid 8 to the determination unit 36.

The liquid temperature measuring device 44 is arranged, for example, on the outer surface of the pipeline 12. In that case, it is preferable to cover the liquid temperature measuring instrument 44 with a heat insulating material or the like in order to suppress the influence of the external environment. Further, the liquid temperature measuring device 44 may not be arranged in the pipeline 12, and may be arranged in, for example, a liquid supply source 14 or a liquid discharge unit 6.

The temperature of the liquid 8 may be measured by the two ultrasonic vibrators 22a and 22b and the control unit 24 using ultrasonic waves. For example, the control unit 24 calculates the propagation speed of the ultrasonic waves by measuring the ultrasonic waves propagating in the liquid 8 flowing through the pipeline 12, and calculates the temperature of the liquid 8 from the propagation speed.

The amplitude calculation unit 34 transfers the ultrasonic waves generated in one of the two ultrasonic vibrators 22a and 22b and propagated in the liquid 8 flowing in the conduit 12 to the two ultrasonic vibrators 22a and 22b. On the other hand, the amplitude of the ultrasonic wave is calculated from the waveform information obtained by observing. The amplitude calculation unit 34 is connected to the determination unit 36, and transmits the calculated amplitude of the ultrasonic wave to the determination unit 36.

The amplitude calculation unit 34 transmits the ultrasonic waves generated at the other of the two ultrasonic vibrators 22a and 22b and propagating in the liquid 8 flowing through the conduit 12 to the two ultrasonic vibrators 22a and 22b. On the other hand, the amplitude of the ultrasonic wave may be calculated from the waveform information obtained by observing. Further, the amplitude calculation unit 34 may calculate the average of the observed amplitudes of the two ultrasonic waves as the amplitude of the ultrasonic waves.

FIG. 3B is a chart schematically showing the waveforms of two ultrasonic waves having different amplitudes. Here, the amplitude of the ultrasonic wave is the maximum value of the absolute value of the observed intensity (voltage value) of the ultrasonic wave. For example, in FIG. 3B, the amplitude 62a in the ultrasonic waveform 58 shown on the upper side is larger than the amplitude 62b in the ultrasonic waveform 60 shown on the lower side.

When the bubbles 20 are mixed in the liquid 8 flowing through the conduit 12, the propagation path of the ultrasonic waves propagating in the liquid 8 is reduced, so that the case where the bubbles 20 are not generated in the liquid 8 is compared with the case where the bubbles 20 are not generated. The amplitude of the ultrasonic wave calculated by the amplitude calculation unit 34 becomes smaller. Therefore, by monitoring the amplitude of the ultrasonic wave calculated by the amplitude calculation unit 34, it is possible to detect the mixing of bubbles 20 in the liquid 8.

The amplitude range registration unit 38 registers the amplitude range of the ultrasonic wave propagating in the liquid 8 mixed with the bubbles 20, and transmits the amplitude range of the ultrasonic wave to the determination unit 36. Then, when bubbles are mixed in the liquid 8, the determination unit 36 can detect the mixing of the bubbles.

The range of the amplitude of the ultrasonic wave registered in the amplitude range registration unit 38 is not limited to the range of the amplitude of the ultrasonic wave propagating in the liquid 8 mixed with the bubbles 20. For example, the amplitude range of the ultrasonic wave propagating in the liquid 8 in which the bubble 20 is not mixed is registered in the amplitude range registration unit 38, and the amplitude range registration unit 38 registers the ultrasonic wave in the determination unit 36. The range of amplitude of may be transmitted. In this case, the determination unit 36 detects that bubbles of the liquid 8 are mixed when the amplitude of the ultrasonic wave propagating in the liquid 8 flowing through the conduit 12 deviates from the range of the amplitude of the ultrasonic wave.

The determination unit 36 is connected to the amplitude calculation unit 34, the amplitude range registration unit 38, the propagation time calculation unit 40, the propagation time range registration unit 46, and the liquid temperature calculation unit 46. There is.

The amplitude of the ultrasonic wave propagating in the liquid 8 flowing through the conduit 12 is transmitted to the determination unit 36 from the amplitude calculation unit 34, and the amplitude of the ultrasonic wave propagating in the liquid 8 in which the bubbles 20 are mixed. The range of is transmitted from the amplitude range registration unit 38. The determination unit 36 determines whether or not the amplitude transmitted from the amplitude calculation unit 34 is within the range transmitted from the amplitude range registration unit 38, and when the amplitude is within the range. It is determined that air bubbles are mixed in the liquid 8. The inspection device 18 according to the present embodiment can detect the generation of air bubbles in the liquid 8 flowing through the pipeline 12 in this way.

The determination unit 36 is connected to, for example, a control unit, a display unit, or the like of the processing device in which the liquid supply device 2 is incorporated, and when the mixing of air bubbles in the liquid 8 is detected, the operator of the processing device Is notified of the inclusion of the air bubbles, or the operation of the processing apparatus is stopped. Therefore, it is possible to prevent the liquid 8 from being supplied from the liquid discharge unit 6 or the like while air bubbles are mixed in the liquid 8.

Further, the average propagation time of the ultrasonic waves propagating in the liquid 8 flowing through the conduit 12 is transmitted from the propagation time calculation unit 40 to the determination unit 36, and the concentration is not a predetermined concentration from the propagation time range registration unit 46. The range of propagation time of ultrasonic waves propagating in the liquid 8 in which the substance is dissolved or dispersed at a concentration is transmitted. The determination unit 36 determines whether or not the average propagation time 56 of the ultrasonic wave transmitted from the propagation time calculation unit 40 is within the range transmitted from the propagation time range registration unit 46. Then, when the average propagation time 56 is within the range, it is determined that the concentration of the liquid 8 is abnormal.

The temperature of the liquid 8 is transmitted to the determination unit 36 from the liquid temperature calculation unit 46. Since the propagation velocity of the ultrasonic wave propagating in the liquid 8 changes not only with the concentration of the liquid 8 but also with the temperature, the determination unit 36 takes into consideration the temperature of the liquid 8 and makes an abnormality in the concentration of the liquid 8. Judge the presence or absence of.

When air bubbles are mixed in the liquid 8, it may not be possible to correctly detect an abnormality in the concentration of the liquid 8 even by observing ultrasonic waves propagating in the liquid 8. In the inspection device 18 according to the present embodiment, it is possible to determine the presence or absence of an abnormality in the concentration after confirming that no air bubbles are mixed in the liquid 8, so that the accuracy of detecting the abnormality in the concentration can be further improved. ..

When an abnormality in the concentration of the liquid 8 is detected, the determination unit 36 transmits the fact to the control unit or the display unit of the processing device in which the liquid supply device 2 is incorporated, and informs the operator of the processing device to that effect. Notifies the abnormality of the concentration and stops the operation of the processing apparatus.

Even if an abnormality other than the concentration occurs in the liquid 8, such as when the type of the liquid 8 flowing through the pipeline 12 is incorrect or the liquid 8 is deteriorated, the liquid 8 propagates in the liquid 8. The effect may appear on the propagation speed of ultrasonic waves. Similarly, the determination unit 36 may detect the occurrence of an abnormality other than the concentration. Further, even in the case of a pure liquid 8 in which a substance or the like is not dissolved or dispersed, an abnormality in the propagation speed of ultrasonic waves may be detected to detect foreign matter contamination or an error in the type of liquid.

Next, an example of a processing device in which the liquid supply device 2 in which the inspection device 18 according to the present embodiment is arranged is incorporated will be described. The processing device is, for example, a laser processing device that processes a wafer made of a semiconductor or the like with a laser beam. FIG. 4 is a perspective view schematically showing a laser processing device 64 as an example of a processing device including the liquid supply device 2.

A cassette mounting table 68 is provided at a corner of the device base 66 that supports each component of the laser processing device 64. A cassette 70 for accommodating the wafer 10 before laser machining is placed on the cassette mounting table 68. The laser processing device 64 includes a guide rail 72 and a loading / unloading device (not shown), and the loading / unloading device carries out the wafer 10 from the cassette 70 along the guide rail 72.

The upper surface of the apparatus base 66 includes a chuck table 88 for holding the wafer 10, a moving mechanism for moving the chuck table 88, and a laser processing unit 94 arranged above the chuck table 88. ..

A pair of Y-axis guide rails 74 parallel to the Y-axis direction, a Y-axis ball screw 78, and a Y-axis pulse motor 80 are provided on the upper surface of the device base 66, and the Y-axis guide rail 74 is provided. The Y-axis moving plate 76 is slidably attached.

A nut portion (not shown) is provided on the lower surface side of the Y-axis moving plate 76, and the Y-axis ball screw 78 parallel to the Y-axis guide rail 74 is screwed into the nut portion. .. The Y-axis pulse motor 80 is connected to one end of the Y-axis ball screw 78. When the Y-axis ball screw 78 is rotated by the Y-axis pulse motor 80, the Y-axis moving plate 76 moves in the Y-axis direction along the Y-axis guide rail 74.

The upper surface of the Y-axis moving plate 76 is provided with a pair of X-axis guide rails 82 parallel to the X-axis direction, an X-axis ball screw 86, and an X-axis pulse motor (not shown). An X-axis moving plate 84 is slidably attached to the rail 82.

A nut portion (not shown) is provided on the lower surface side of the X-axis moving plate 84, and the X-axis ball screw 86 parallel to the X-axis guide rail 82 is screwed into the nut portion. .. The X-axis pulse motor is connected to one end of the X-axis ball screw 86. When the X-axis ball screw 86 is rotated by the X-axis pulse motor, the X-axis moving plate 84 supporting the chuck table 88 moves in the X-axis direction along the X-axis guide rail 82.

The upper surface of the chuck table 88 supported by the X-axis moving plate 84 serves as a holding surface for holding the wafer 10. The chuck table 88 is internally provided with a suction path (not shown) having one end connected to the holding surface of the chuck table 88 and the other end connected to a suction source (not shown). A clamp 90 for gripping the wafer 10 is provided on the outer peripheral side of the holding surface. When the wafer 10 is placed on the holding surface and the suction source is operated, a negative pressure acts on the wafer 10 and the wafer 10 is sucked and held on the chuck table 88.

The chuck table 88 is machined and fed in the X-axis direction, and indexed and fed in the Y-axis direction, for example. Further, the chuck table 88 can rotate about an axis perpendicular to the holding surface, and the moving direction of the wafer 10 held by the chuck table 88 with respect to the laser processing unit 94 can be switched.

A support portion 92 is erected at the rear portion of the device base 66, and the laser processing unit 94 is arranged on the front surface of the support portion 92. The laser processing unit 94 includes a processing head 96, oscillates a laser beam having a wavelength at which the wafer 10 has absorbency, and irradiates the wafer 10 held on the chuck table 88 from the processing head 96 with the laser beam. Has the function of

When the wafer 10 is moved in the X-axis direction while irradiating the wafer 10 with a laser beam, the wafer 10 is ablated and a processing groove along the X-axis is formed on the surface of the wafer 10.

A cleaning unit 100 for cleaning the surface of the wafer 10 after laser machining is provided in the vicinity of the cassette mounting table 68 of the device base 66. The cleaning unit 100 supplies a cleaning liquid to the surface of the wafer 10 subjected to laser processing, and removes processing debris called debris generated by the laser processing together with a protective film formed of a water-soluble liquid resin described below. do.

A liquid resin coating unit 98 is provided in the vicinity of the cleaning unit 100. The liquid resin coating unit 98 is a protective film coating device that coats a water-soluble liquid resin on the surface of a wafer 10 before laser machining to form a protective film on the surface of the wafer 10. The protective film covers the surface of the wafer 10 and prevents debris generated by laser processing from directly adhering to the surface of the wafer 10.

The liquid resin coating unit 98 includes a chuck table 4 that holds the wafer 10 and a liquid supply device 2 that supplies the water-soluble liquid resin to the surface of the wafer held by the chuck table 4. The chuck table 4 is configured in the same manner as the chuck table 88 described above.

The liquid supply device 2 is housed inside the device base 66, and is a liquid supply source 14 containing the water-soluble liquid resin supplied to the liquid resin coating unit 98, and a liquid supply source 14 A pipeline 12 connected to the liquid resin coating unit 98 and a pump 16 (see FIG. 1) are provided.

The liquid supply device 2 further includes a liquid discharge unit 6 arranged above the chuck table 4. The water-soluble liquid resin is supplied from the liquid supply source 14 to the liquid discharge unit 6 through the pipeline 12 by the function of the pump 16, and the wafer 10 is held by the liquid discharge unit 6 on the chuck table 4. Is supplied to the surface of.

Since the inspection device 18 according to the present embodiment is provided in the pipeline 12 of the liquid supply device 2, the contamination can be detected even when air bubbles are mixed in the water-soluble liquid resin flowing through the pipeline 12. .. Therefore, it is possible to prevent the water-soluble liquid resin in which air bubbles are mixed from being supplied to the surface of the wafer 10.

Further, the device base 66 may include another liquid supply device that supplies a cleaning liquid such as pure water to the cleaning unit 100. The other liquid supply device may include, for example, the inspection device 18 according to the present embodiment in the same manner as the liquid supply device 2 connected to the liquid resin coating unit 98.

Here, the application of the liquid resin carried out by the liquid resin application unit 98 will be described with reference to FIG. 5 (A). FIG. 5A is a cross-sectional view schematically showing the coating of the liquid resin by the liquid resin coating unit 98.

As shown in FIG. 5A, a tape 10c stretched on the opening of the annular frame 10d made of metal or the like is attached to the back surface 10b of the wafer 10. The wafer 10 is housed in the cassette 70 in the state of a frame unit integrated with the annular frame 10d and the tape 10c, and is carried out from the cassette 70 and processed.

After the wafer 10 is carried out from the cassette 70, the wafer 10 is placed on the chuck table 4 of the liquid coating unit 98 via the tape 10c with the back surface 10b side of the wafer 10 facing downward. By operating the suction source of the chuck table 4 to suck the wafer 10 and causing the clamp of the chuck table 4 to grip the frame 10d, the chuck table 4 holds the wafer. Then, the surface 10a of the wafer 10 is exposed upward.

Next, a liquid discharge unit 6 is arranged above the wafer 10, the chuck table 4 is rotated around an axis perpendicular to the surface 10a of the wafer 10, and the liquid discharge unit 6 is water-soluble as a liquid 8. Liquid resin is discharged. Then, the water-soluble liquid resin is applied to the surface of the wafer 10a to form a protective film.

Next, the laser processing in the laser processing unit 94 of the laser processing apparatus 64 will be described with reference to FIG. 5 (B). FIG. 5B is a cross-sectional view schematically showing laser machining of the wafer 10 by the laser machining unit 94. The wafer 10 on which the protective film is formed is conveyed onto a chuck table 88 (see FIG. 4) below the laser processing unit 94 and held by the chuck table 88.

As shown in FIG. 5B, a plurality of devices 10e are provided on the surface of the wafer 10, and the surface 10a of the wafer 10 including the upper surface of the device 10e is formed of the water-soluble liquid resin. It is covered with a protective film 102. The region between the two adjacent devices 10e is called a street, and the wafer 10 is irradiated with a laser beam from the processing head 96 along the street. Then, the wafer 10 is ablated along the street, and the processing groove 104 along the street is formed on the wafer 10.

When the liquid 8 is applied to the surface 10a by the liquid supply device 2 and the protective film 102 is formed on the surface 10a, even if the wafer 10 is ablated and the processing debris called debris 10f is scattered. , The debris 10f does not directly adhere to the surface 10a. In particular, since the liquid supply device 2 provided with the inspection device 18 according to the present embodiment can supply the liquid resin containing no air bubbles to the surface 10a, the air bubbles do not remain on the formed protective film 102. Therefore, the surface 10a is appropriately protected from the debris 10f by the protective film 102.

After the laser processing of the wafer 10 is completed, when the wafer 10 is carried into the cleaning unit 100 and the wafer 10 is cleaned, the debris 10f is washed away together with the protective film 102, so that the surface 10a of the wafer 10 is washed away. The debris 10f does not remain.

The pipeline 12 provided in the processing apparatus or the like may be provided with an ultrasonic flow meter for measuring the flow rate or the like of the liquid 8 flowing through the pipeline 12. Since the inspection device 18 according to the present embodiment is composed of two ultrasonic vibrators 22a and 22b and a control unit 24, it can also have the function of the ultrasonic flow meter. Therefore, by arranging the inspection device 18 according to the present embodiment in the pipeline 12 instead of the ultrasonic flow meter, the space for attaching the inspection device 18 can be saved, and the inspection device 18 can be installed. The introduction cost can be suppressed.

The present invention is not limited to the description of the above embodiment, and can be implemented with various modifications. One aspect of the present invention is an inspection device provided in the pipeline of a liquid supply device provided in the processing device, but the liquid supply device in which the inspection device is provided and the processing provided with the liquid supply device. The device is also an aspect of the present invention. Furthermore, a protective film coating device that supplies a water-soluble liquid resin to form a protective film is also an aspect of the present invention.

In the above embodiment, the case where the inspection device 18 is arranged in the pipeline 12 of the liquid supply device 2 provided in the laser processing device 64 has been described, but the processing device in which the inspection device 18 is arranged is laser-machined. Not limited to equipment. For example, a grinding device for grinding a workpiece such as a wafer 10 and a cutting apparatus for cutting a workpiece are also provided with a pipeline through which various liquids supplied to the workpiece and the machining unit flow. Therefore, the inspection device can also be arranged in a pipeline provided in a grinding device or a cutting device.

In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention.

2 Liquid supply device 4,88 Chuck table 6 Liquid discharge part 8 Liquid 10 Wafer 10a Front surface 10b Back surface 10c Tape 10d Frame 10e Device 10f Debris 12 Pipeline 14 Liquid source 16 Pump 18 Inspector 20 Bubbles 22a, 22b Ultrasonic vibration Child 24 Control unit 26 Switching unit 28 Power supply 30 Amplifier 32 Calculation unit 34 Amplitude calculation unit 36 Judgment unit 38 Amplitude range registration unit 40 Propagation time calculation unit 42 Propagation time range registration unit 44 Liquid temperature measuring instrument 46 Liquid temperature calculation unit 48, 50 , 58,60 Ultrasonic waveform 52 First propagation time 54 Second propagation time 56 Average propagation time 62a, 62b Ultrasonic amplitude 64 Laser processing equipment 66 Equipment base 68 Cassette mount 70 Cassette 72 Guide rail 74 Y Axis Guide Rail 76 Y Axis Moving Plate 78 Y Axis Ball Screw 80 Y Axis Pulse Motor 82 X Axis Guide Rail 84 X Axis Moving Plate 86 X Axis Ball Screw 90 Clamp 92 Support 94 Laser Machining Unit 96 Machining Head 98 Liquid Resin Coating Unit 100 Cleaning unit 102 Protective film 104 Machining groove

Claims (5)

An inspection device that is placed in a pipeline that serves as a flow path for liquids.
It is provided with two ultrasonic vibrators arranged on the upstream side and the downstream side of the pipeline, and a control unit electrically connected to the two ultrasonic vibrators.
The control unit includes an amplitude calculation unit, a determination unit, an amplitude range registration unit, a propagation time calculation unit, and a propagation time range registration unit .
A substance is dissolved or dispersed in the liquid, and the substance is dissolved or dispersed in the liquid.
The amplitude calculation unit was obtained by observing the first ultrasonic wave generated in one of the two ultrasonic transducers and propagating in the liquid flowing through the conduit in the other of the two ultrasonic transducers. The amplitude of the first ultrasonic wave is calculated from the waveform information,
The propagation time calculation unit
Waveform information obtained by observing the first ultrasonic wave generated in one of the two ultrasonic transducers and propagating in the liquid flowing through the conduit on the other of the two ultrasonic transducers. The propagation time of the first ultrasonic wave is calculated from
From the waveform information obtained by observing the second ultrasonic wave generated in the other of the two ultrasonic transducers and propagating in the liquid flowing through the conduit by observing the second ultrasonic wave generated in the other of the two ultrasonic transducers. The propagation time of the second ultrasonic wave was calculated and
The average propagation time was calculated by averaging the propagation time of the first ultrasonic wave and the propagation time of the second ultrasonic wave.
The amplitude range of the ultrasonic wave propagating in the liquid mixed with bubbles is registered in the amplitude range registration unit.
In the propagation time range registration unit, the range of the average propagation time of ultrasonic waves propagating in the liquid in which the substance is dissolved or dispersed at a concentration other than a predetermined concentration is registered.
The determination unit, when the ultrasonic amplitude of the first of amplitude calculation unit is calculated in the range of amplitude registered in the amplitude range registering unit determines that air bubbles in the liquid ,
When the determination unit does not determine that air bubbles are mixed in the liquid and the average propagation time calculated by the propagation time calculation unit is within the range of the average propagation time registered in the propagation time range registration unit. In addition, an inspection device for determining that the concentration of the liquid is not a predetermined concentration. Further having a liquid temperature measuring device for measuring the temperature of the liquid,
The liquid temperature measuring device measures the temperature of the liquid flowing through the pipeline, transmits the temperature of the liquid to the determination unit, and transmits the temperature of the liquid to the determination unit.
The inspection device according to claim 1, wherein the determination unit corrects the content of the determination with reference to the temperature of the liquid. An inspection device that is placed in a pipeline that serves as a flow path for liquids.
It is provided with two ultrasonic vibrators arranged on the upstream side and the downstream side of the pipeline, and a control unit electrically connected to the two ultrasonic vibrators.
Further having a liquid temperature measuring device for measuring the temperature of the liquid,
The control unit includes an amplitude calculation unit, a determination unit, and an amplitude range registration unit.
The amplitude calculation unit was obtained by observing the first ultrasonic wave generated in one of the two ultrasonic transducers and propagating in the liquid flowing through the conduit in the other of the two ultrasonic transducers. The amplitude of the first ultrasonic wave is calculated from the waveform information,
The amplitude range of the ultrasonic wave propagating in the liquid mixed with bubbles is registered in the amplitude range registration unit.
The determination unit determines that air bubbles are mixed in the liquid when the amplitude of the first ultrasonic wave calculated by the amplitude calculation unit is within the range of the amplitude registered in the amplitude range registration unit. ,
The liquid temperature measuring device measures the temperature of the liquid flowing through the pipeline, transmits the temperature of the liquid to the determination unit, and transmits the temperature of the liquid to the determination unit.
The determination unit is an inspection device characterized in that the content of the determination is corrected with reference to the temperature of the liquid. The pipeline, a supply source of the liquid connected to one end of the pipeline, a pump for supplying the liquid from the supply source of the liquid to the other end of the pipeline, and a pump installed in the pipeline. A liquid supply device comprising the inspection device according to any one of claims 1 to 3, wherein the liquid supply device comprises. A protective film coating device that coats the surface of a wafer with a liquid resin to form a protective film.
The protective film coating device according to claim 4, further comprising a rotatable chuck table for holding the wafer and the liquid supply device for supplying the liquid resin to the surface of the wafer held on the chuck table. ..

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