JP3004437B2 - Ultrasonic cleaning device and injection volume control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic cleaning apparatus ,
Ultrasonic cleaning equipment with improved cleaning effect
It is.

[0002]

2. Description of the Related Art A conventional ultrasonic cleaning apparatus, such as a semiconductor wafer or a liquid crystal glass, which requires precise cleaning, has an ultrasonic vibration 2 fixed to a bottom outer wall of a cleaning tank 1 as shown in FIG. A trough 3 for receiving the overflow of the cleaning liquid is provided on the upper part, and liquid injection pipes 4 and 4 are provided on both lower inner surfaces of the cleaning tank 1.
, And a cleaning liquid is supplied from a large number of injection ports 5 and 5, and ultrasonic energy is applied from the ultrasonic vibrator 2.
I was doing it .

[0003]

[SUMMARY OF THE INVENTION In a conventional ultrasonic cleaning apparatus, according to the simulation as shown in FIG. 4
If, in the portion where the liquid injection tube 4 is installed, the flow vector
Is not going straight. That is, Rukoto have hindered the flow caused by applying ultrasonic waves. Therefore ,
Vortex occurs in a portion opposite the ultrasonic transducer 2 of the liquid injection pipe 4, linearity of the flow by ultrasound has been disturbed. There is a close relationship between the cleaning effect and flow by ultrasound cleaning power and that by the ultrasonic flow is disturbed is reduced considerably.
Further, the vortex portion of the flow tends to occur accumulation of dust, were tied to low under more <br/> cleaning effect.

[0004] Further, the speed of the flow by the ultrasonic wave and the sound pressure are closely related, and the speed varies depending on the type of cleaning liquid, the temperature, the frequency of the ultrasonic wave, the output, and the like. In the conventional apparatus, since the interaction between the flow velocity from the inlet and the flow velocity by the ultrasonic wave was not taken into consideration, the flow balance was lost near the inlet, causing a vortex. Therefore, in the present invention, the injection pipe is installed outside and the sound pressure sensor measures the flow velocity of the ultrasonic wave to set the optimal flow rate of the liquid supply , preventing the flow from being unbalanced,
It is an object of the present invention to provide an ultrasonic cleaning apparatus capable of performing ultrasonic cleaning under appropriate conditions .

[0005]

According to the present invention, there is provided a liquid injection pipe having an ultrasonic vibrator fixed to a lower surface of a cleaning tank and having a plurality of injection ports opened outside a lower end of the cleaning tank. An ultrasonic cleaning device is provided, and a sound pressure sensor is installed inside the cleaning tank and connected to a control device that adjusts the flow rate. And an injection amount control device for controlling the flow rate adjusting valve.

[0006]

SUMMARY OF THE INVENTION The present invention has the structure described above, the flow of the cleaning liquid by an ultrasonic vibrator is inhibited in the vicinity of the liquid injection pipe
It not, the total power is uniformly distributed into the cleaning tank the entire unattenuated. Moreover, the sound pressure measured by the sound pressure sensor, so that the feed to the control device, Runode feed optimum flow in result of calculation by controlling the flow rate adjusting valve by computer or the like to the washing tank from the inlet, the flow balance Will not collapse
Efficient ultrasonic cleaning under optimal conditions
Can be.

[0007]

An example of the embodiment of the present invention when had not a group is described in Figure 1, the liquid injection tube 4,4 is fixed on both sides of the lower end of the cleaning tank 1,
A number of injection ports 5, 5,... Are opened at the positions of the liquid injection pipes 4, 4 of the cleaning tank 1 to supply the cleaning liquid. Then, a liquid injection pipe 4 is communicated with a conduit 3 through a filter 6 to an overflow gutter 3 provided outside and above the cleaning tank 1 so that the overflowing cleaning liquid is returned to the cleaning tank 1. In FIG. 1, 2 are identical with those of the ultrasonic vibrator. Furthermore, the sound pressure is
The sensor 8 is provided outside the cleaning tank 1 with a signal from the sound pressure sensor 8.
Of the flow control valve 10 provided in the conduit 7 based on the
A control device 9 for adjusting the opening is provided.

[0008] The examples are constructed as described above, performing the applied length <br/> et washed ultrasound more cleaning solution to the ultrasonic transducer 2. The cleaning liquid is washed from the injection port 5 of the liquid injection pipe 4.
Flows into Tank 1, the overflowed cleaning liquid received in the trough 3, and is so that to the circulation through the filter 6. Vector flow by simulation in the vicinity of inlet 5 As apparent from FIG. 3 is hardly disturbed, no vortex attenuation and ultrasonic power, problems such retention of dust is gone.

Further , the sound pressure is measured by a sound pressure sensor 8 installed in the washing tank 1, and the result is sent to a control device 9, which detects an optimum flow rate and , based on this, detects a conduit flow. 7
The opening degree of the flow control valve 10 provided in is adjusted.

The relationship between the flow velocity and the sound pressure generated by the ultrasonic wave can be obtained by the following approximate expression.

(Equation 1) P = ρ₀[(V ▽) v + v ▽ · v] ρ₀: Density of medium v: Flow velocity p: Sound pressure-: Time averaging operation Ultrasonic flowSpeedIs the higher the sound pressurebigBecome.
In addition, the control device 9By the above approximationNumber determined by
Values are modified and stored experimentally
You.

[0011]

The present invention has the above-described structure and operation. By providing a liquid injection pipe outside, the flow of the cleaning liquid by the ultrasonic waves becomes smooth, and the power of the ultrasonic waves is not attenuated. It can be distributed throughout the tank, further
, The injection volume of optimum cleaning liquid by measuring the flow velocity
Decision, so the flow balance will not be lost
As a result, a reduction in cleaning power is prevented, and uneven cleaning of a work such as a semiconductor wafer or liquid crystal glass can be reduced, and the yield can be improved.

[0012]

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of an ultrasonic cleaning apparatus according to the present invention.

FIG. 2 is a sectional view of an embodiment of an injection amount control device according to the present invention.

FIG. 3 is a diagram showing a simulation according to FIG. 1;

FIG. 4 is a sectional view of a conventional device.

FIG. 5 shows a simulation according to FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning tank 2 Ultrasonic vibrator 3 Gutter 4 Liquid inflow pipe 5 Inlet 6 Filter 7 Conduit 8 Sound pressure sensor 9 Control device 10 Flow control valve

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B08B 3/12

Claims (1)

(57) [Claims] An ultrasonic vibrator is fixed to a lower surface of a cleaning tank,
<br/> was opened a number of inlets at the lower end outside of the cleaning tank liquid injection tube provided Rutotomoni, inside the cleaning tank by installing a sound pressure sensor connected to a control device for regulating the flow rate, the control device in the flow rate adjusting valve provided in a conduit for sending the cleaning liquid to the <br/> injection tube
Ultrasonic cleaning equipment characterized by controlling the opening
Place .