An ultrasonic washing apparatus

Abstract: A sensor chamber is constituted a side portion of a liquid supply inlet of a housing, a sound pressure sensor is mounted on the sensor chamber, ultrasonic waves from an ultrasonic vibrator provided the housing is detected by the sound pressure sensor, and a defect of the ultrasonic vibrator is detected when the output of the sound pressure sensor becomes small.

Description: The present invention according to claim 1 relates to an ultrasonic washing apparatus for washing semiconductor objects having a sound pressure sensor for detecting ultrasonic waves generated by an ultrasonic vibrator. In a prior ultrasonic washing apparatus, a housing has a central hollow portion and an incline hollow portion, a nozzle is formed at the end of the incline portion, and a step portion is formed the central hollow portion. An ultrasonic vibrator is mounted on the step portion, a high frequency oscillator is connected to the ultrasonic vibrator through connected lines, and a liquid flowing inlet is connected to the central hollow portion of the housing and to a liquid supply means. When liquid as washing liquid is supplied to the housing by the liquid supply means and the oscillating output from the high frequency oscillator is applied to the ultrasonic vibrator, liquid with ultrasonic waves is flowed from the nozzle of the housing, and a surface of an object as a semiconductor put in the front of the nozzle is washed by liquid and ultrasonic waves. In this ultrasonic washing apparatus, since a sound pressure sensor is large, the sound pressure sensor must be put on the position of the object for detecting the ultrasonic waves in the liquid flowing from the nozzle of the housing, and the voltage detected by the sound pressure sensor is measured by the voltmeter. Therefore, the ultrasonic waves in the liquid cannot be detected by the sound pressure sensor when the object is washed. The US-A-5,368,054 shows an ultrasonic jet semiconductor wafer cleaning apparatus for removing debris from a surface of a semiconductor wafer as the wafer is rotated about a prescribed axis in a cleaning plane is disclosed. The apparatus comprises a housing having a principal axis, an inlet port, and an outlet port a means for producing focused ultrasonic waves of acoustic energy concentric with and incident the outlet port to form a jet stream of cleaning liquid released through the outlet port. The JP 10 151422 A shows an ultrasonic cleaning nozzle comprises an ultrasonic vibrator, a case body and a nozzle cap. A chemical liquid supplied from a supply port is irradiated with ultrasonic waves by the ultrasonic vibrator, and thereafter sprayed from a spray port. The ultrasonic waves linearly advance in the chemical liquid, strike an inner wall of the nozzle cap, reflect and thereafter spray from the spray port with the chemical liquid. It is the object of the present invention to provide an ultrasonic washing apparatus having a sound pressure sensor for sensing ultrasonic waves when an object is washed. This object is achieved by the ultrasonic vibrator of claim 1, a preferred embodiment being characterized in claim 2. An embodiment of the invention is now described with reference to the drawings, in which: Fig. 1 shows a constitution view of an ultrasonic washing apparatus in the prior art. Fig. 2 shows a constitution view for detecting ultrasonic waves by the ultrasonic washing apparatus of Fig. 1. Fig. 3 shows a constitution view of an ultrasonic washing apparatus in the present invention. Fig. 4 shows a block diagram of an ultrasonic washing apparatus in the other embodiment of the present invention. As shown in Fig, 1, a housing 1 has a central hollow portion 1a and a inclined hollow portion 1b, a nozzle 1c is formed the end of the inclined portion, and a step portion 1d is formed the end of the central follow portion 1a. An ultrasonic vibrator 3 is attached to the step portion 1d of the housing 1 through a packing 2, a high frequency oscillator 5 is connected to the ultrasonic vibrator 3 though electrically connected lines 4, and a liquid supply inlet 6 is attached to the central hollow portion 1a of the housing 1 and is connected to a liquid supply means 7. When liquid as washing liquid from the liquid supply means 7 is supplied to the central hollow portion 1a of the housing 1 through the liquid supply inlet 6 and ultrasonic waves from the ultrasonic vibrator are supplied to the central hollow portion 1a by applying the high frequency power from the high frequency oscillator 5 to the ultrasonic vibrator 3, the liquid and the ultrasonic waves can wash a surface of an object 8 as a semiconductor in the front of the nozzle 1c of the housing 1. In this ultrasonic washing apparatus, since a sound pressure sensor is generally large, for detecting the ultrasonic waves from the nozzle 1c of the housing 1, as shown in Fig. 2, the sound pressure sensor 9 must be set setting portion of the object 8 in the front of the nozzle 1c of the housing 1, the voltage generated by the sound pressure sensor 9 is detected by a voltmeter 10, and thus the ultrasonic waves from the nozzle 1c of the housing 1 is detected by the voltmeter 10. Therefore, when the object 8 is washed, the sound pressure sensor 9 cannot be set the front of the nozzle 1c of the housing 1, and it is impossible to watch whether the ultrasonic waves and liquid are flowed from the nozzle 1c of the housing 1 or not. Referring to Fig. 3, 1 designates a housing, 1a; a central hollow portion, 1b: an inclined hollow portion, 1c; a nozzle, 1d; a step portion, 2; a packing, 3; an ultrasonic vibrator, 4; electrically connected lines, 5; a high frequency oscillator, 6; a liquid supply inlet, and 7; liquid supply means. Since these constitutions are same as that of the above prior art, the explanation of these constitutions is omitted. In the present embodiment, a sensor chamber 11 is formed the central hollow portion 1a, a sound pressure sensor 12 is attached to the sensor chamber 11 and is connected to a receiving means 14 through electrically connected lines 13, and the output of the receiving means 14 is connected to the volt meter 15. In this embodiment of the present invention, when the liquid from the liquid supply means 7 is supplied to the housing 1 through the liquid supply inlet 6, and the high frequency oscillating outputs from the high frequency oscillator 5 are supplied to the ultrasonic vibrator 3 through the electrically connected lines 4, the ultrasonic waves are emitted from the ultrasonic vibrator 3 to the inside of the housing 1 and the ultrasonic waves with liquid are flowed from the nozzle 1c of the housing 1. When the liquid with the ultrasonic waves is flowed, the ultrasonic waves from the ultrasonic vibrator 3 are detected by the sound pressure sensor 12, the sound pressure voltage detected by the sound pressure sensor 12 is amplified by the receiving means 14 and is applied to the voltmeter 15. By watching the sound pressure voltage in the voltmeter 15, it is possible to watching whether the ultrasonic waves of the normal value are generated by the ultrasonic vibrator 3 and the liquid is normally supplied to the housing 1 by movement of the indicator of voltmeter 15 or not. Referring to Fig. 4, when the ultrasonic waves from ultrasonic vibrator 3 are detected by the sound pressure sensor 12 as shown in a dotted line, the sound pressure voltage of the sound pressure sensor 12 is amplified by the receiving means 14 and is applied to a comparing means 16. Also, since a predetermined voltage in a setting means 17 is applied to the comparing means 16, the output voltage of the sound pressure sensor 12 is compared with the predetermined voltage of the setting means 17, the output of the comparing means 16 is applied to a control means 18, and the output of the control means 18 is applied to the high frequency oscillator 6 and a buzzer 19. In this ultrasonic washing apparatus in the present invention, the sound pressure of the ultrasonic waves from the ultrasonic vibrator 3 is detected by the sound pressure sensor 12, the output of the sound pressure sensor 12 is amplified by the receiving means 14, is applied to the comparing means 16 and is compared with the predetermined voltage of the setting means 17. Therefore, when the property of the ultrasonic vibrator 3 becomes wrong and the liquid from the liquid supply means 7 is not applied to the housing 1, it is detected that the output voltage of the sound pressure sensor 12 is lower than the predetermined voltage of the setting means 17, the output of the comparing means 16 is applied to the control means 18, the high frequency output of the high frequency oscillator 6 is stopped by the output of the control means 18 and the buzzer 19 is sounded. Whereby the defect of the ultrasonic vibrator 3 and the stop of the supply of the liquid can be sounded by the buzzer 19.

Claims: An ultrasonic washing apparatus comprising: a housing (1) comprising a central hollow portion (1a) providing a liquid supplying inlet (6); a sensor chamber (11) and an inclined hollow portion (1b), one end of which is connected to the central hollow portion (1a) and the other end of which forms a nozzle (1c); a high frequency oscillator (5) connected to an ultrasonic vibrator (3), a receiving means (14) connected to a sound pressure sensor (12), and a voltmeter (15) connected to the receiving means (14), characterized in that : the ultrasonic vibrator (3) is fixed on a step portion (2) of the end of the central hollow portion (1a); the sound pressure sensor (12) is arranged within the sensor chamber (11): the receiving means (14) is designed to amplify the sound pressure voltage detected by the sound pressure sensor (12); a comparing means (16) is designed to compare the amplified voltage of the receiving means with a predetermined voltage from a setting means (17); and a control means (18) is designed to receive the output of the comparing means (16) and to apply an output to the high frequency oscillator (5) to stop high frequency oscillation when the sound pressure voltage of the ultrasonic waves from the ultrasonic vibrator (3) becomes lower than the predetermined voltage of the setting means (17). The apparatus of claim 1 comprising a buzzer is designed to be sounded by the output of the control means (18) owing to the output of the comparing means (16) when the sound pressure voltage of the ultrasonic waves from the ultrasonic vibrator (3) becomes lower than the predetermined voltage of the setting means.

Inventors: SHUICHI SANO, TOSHIAKI MIYAMOTO, SHUICHI, SANO, TOSHIAKI, MIYAMOTO, Shuichi, Sano, c/o Honda Electronics Co., Ltd, Toshiaki, Miyamoto, c/o Honda Electronics Co., Ltd
Applicants: HONDA ELECTRONIC, HONDA ELECTRONICS CO., LTD.
Application year: 1999
Main classification: H01L21
IPC codes: H01L21