JP7373848B2 - Acoustic foreign object removal device - Google Patents

Description

The present invention relates to the structure of an acoustic foreign object removal device that uses ultrasonic waves to remove foreign objects attached to the surface of an object.

There is a need to remove foreign matter adhering to the surface of semiconductor devices such as image sensors. As a method for removing foreign matter in this manner, a technique is used in which liquid carbon dioxide (CO ₂ ) is used to remove foreign matter from semiconductor devices. In this method, liquid carbon dioxide is injected from an injection nozzle onto the surface of the target object, and dry ice particles that freeze into dry ice due to adiabatic expansion during the injection collide with the target object to remove foreign substances from the surface. (For example, see Patent Document 1).

Japanese Patent Application Publication No. 2000-117201

However, the method described in Patent Document 1 requires a mechanism for freezing high-purity dry ice, making the device large and complicated. Furthermore, when spraying dry ice particles, semiconductor devices may be damaged in some cases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to suppress damage to an object and remove foreign matter with a simple configuration.

The acoustic foreign matter removal device of the present invention is an acoustic foreign matter removal device that removes foreign matter adhering to the surface of an object, and includes a stage that holds the object on a holding surface, and a stage that is placed apart from the stage. The acoustic head includes a plurality of ultrasonic generators having directivity and a plurality of ultrasonic waves generated from the plurality of ultrasonic generators. a casing to which a plurality of ultrasonic generators are attached so as to concentrate sound waves, and the plurality of ultrasonic waves generated from the plurality of ultrasonic generators are concentrated in a gap between the casing and the holding surface of the stage. A low-pressure region with a pressure lower than atmospheric pressure is formed in the gap, and the foreign matter adhering to the surface of the object is sucked into the low-pressure region and removed from the surface, and the moving mechanism is moved away from the object. The present invention is characterized in that the acoustic head is moved relatively to the foreign matter disposal section located therein .

In this way, the foreign matter attached to the surface of the object is removed by suction using the low-pressure area formed in the acoustic head, so the foreign matter can be removed without contacting the surface of the object. damage can be suppressed. Further, a device for freezing dry ice like the conventional technique described in Patent Document 1 is not required, and foreign matter adhering to the surface of the object can be removed with a simple configuration. In addition, the suctioned foreign matter can be disposed of without re-adhering to the object.

In the acoustic foreign object removal device of the present invention, the casing of the acoustic head is annular or dome-shaped with the stage side open, and the plurality of ultrasonic generators are plural ultrasonic speakers, and each axis is concentrated in a gap. It may be attached to the casing as such.

In this way, by arranging the multiple ultrasonic speakers so that each axis is concentrated in the air gap between the casing and the holding surface of the stage, the pressure in the low pressure area can be lowered, resulting in a larger suction force. can be generated.

The acoustic foreign object removal device of the present invention may include a drive circuit that drives a plurality of ultrasonic generators, and the drive circuit may be able to adjust each phase of the ultrasonic waves generated from each ultrasonic generator. Further, the drive circuit may include a plurality of drive units that drive one ultrasonic generator, and the drive unit may be able to adjust the phase of the ultrasonic waves generated from the ultrasonic generator.

In this manner, by adjusting each phase of the ultrasonic waves from the plurality of ultrasonic generators, the shape, size, and position of the formed low-pressure region can be freely adjusted to match the foreign object to be removed.

In the acoustic foreign object removal device of the present invention, the moving mechanism moves the low pressure region formed by the acoustic head to the surface of the object held on the stage at a distance of 1/4 to 1/2 wavelength of the ultrasonic waves. You may move it relatively along.

Due to the ultrasonic waves reflected from the surface of the object, a low-pressure region is located approximately 1/4 wavelength to half a wavelength above the surface of the object. Therefore, by moving the low-pressure region from the surface of the object using a moving mechanism to a distance of 1/4 to 1/2 wavelength of the ultrasonic waves, the low-pressure region is brought close to the surface and foreign matter is effectively sucked into the low-pressure region. can do.

INDUSTRIAL APPLICATION This invention can suppress damage to an object and can remove a foreign object with a simple structure.

FIG. 1 is an elevational view showing the configuration of an acoustic foreign matter removal device according to an embodiment. It is an elevational view showing the composition of the acoustic foreign matter removal device of other embodiments.

Hereinafter, an acoustic foreign object removal device 100 according to an embodiment will be described with reference to the drawings. As shown in FIG. 1, the acoustic foreign matter removal device 100 includes a stage 10, an acoustic head 20, a moving mechanism 30, and a foreign matter disposal section 16. In the following description, the direction perpendicular to the paper surface of FIG. 1 is assumed to be the X direction, the direction perpendicular to the X direction on the horizontal plane is the Y direction, and the vertical direction is the Z direction.

The stage 10 is attached to a base (not shown). The stage 10 attracts and holds an electronic component 13, which is an object, on an upper holding surface 10a. The electronic component 13 may be, for example, an image sensor 12 mounted on the substrate 11. The stage 10 is capable of transporting the electronic component 13 in the X direction. Further, next to the stage 10, a foreign matter disposal section 16 is arranged. The foreign matter disposal section 16 includes, for example, a downward vacuum suction mechanism.

An acoustic head 20 is arranged above the stage 10 and spaced apart from the stage 10. The acoustic head 20 includes a casing 22 and a plurality of ultrasonic speakers 21 attached to the casing 22. The casing 22 of the acoustic head 20 is connected to a moving mechanism 30 that moves the acoustic head 20 relative to the electronic component 13 held by suction on the holding surface 10a of the stage 10.

The moving mechanism 30 includes a guide rail 31 that is attached to a base (not shown) so as to be movable in the X direction, and a slider 33 that moves in the Y direction along the guide rail 31. The guide rail 31 is configured to be movable in the X direction by an X direction movement mechanism 32. The slider 33 includes a Y-direction moving mechanism 34 therein, and is configured to be movable in the Y-direction while being guided by the guide rail 31. The casing 22 of the acoustic head 20 is connected to a slider 33 by an arm 36 extending in the Z direction. The slider 33 is equipped with a Z-direction moving mechanism 35 for driving the arm 36 in the Z-direction, and is configured to be able to move the acoustic head 20 in the Z-direction. Therefore, the moving mechanism 30 is configured to be able to move the acoustic head 20 relative to the electronic component 13 suction-held on the stage 10 in the XYZ directions. Furthermore, the moving mechanism 30 is configured to be able to move the acoustic head 20 to above the foreign matter disposal section 16 .

The casing 22 of the acoustic head 20 has a spherical dome shape and is open on the lower stage side. A spherical center 26 of the spherical surface constituting the casing 22 is located in the gap 14 between the casing 22 and the holding surface 10a of the stage 10 at the lower center of the casing 22 below the lower open surface 25. The ultrasonic speaker 21 is a directional ultrasonic generator, and generates the ultrasonic wave 24 so that the ultrasonic wave 24 propagates in the direction of the axis 21a within a range of directivity angle θ centered on the axis 21a. The plurality of ultrasonic speakers 21 are attached to the casing 22 so that their respective axes 21a intersect at the center 26 of the spherical surface of the casing 22. Therefore, the ultrasonic waves 24 generated from the plurality of ultrasonic speakers 21 intersect at the lower center of the casing 22 where the spherical center 26 is located. Since the spherical center 26 is located in the gap 14 between the spherical center 26 and the holding surface 10a of the stage 10, each ultrasonic wave 24 is concentrated in the gap 14.

Each ultrasonic speaker 21 is connected to a drive unit 23 that drives the ultrasonic speaker 21, respectively. Each drive unit 23 is capable of adjusting the phase of the ultrasonic waves 24 generated by the connected ultrasonic speakers 21. Further, the plurality of drive units 23 constitute a drive circuit that drives an ultrasonic speaker group made up of the plurality of ultrasonic speakers 21.

The drive unit 23 that drives the X-direction movement mechanism 32, the Y-direction movement mechanism 34, the Z-direction movement mechanism 35, and each ultrasonic speaker 21 of the movement mechanism 30 is connected to the control section 50 and Driven by command. The control unit 50 is a computer that includes a CPU 51, which is a processor that processes information, and a storage unit 52 that stores control programs and control data.

The operation of the acoustic foreign matter removal device 100 configured as above will be explained. The control unit 50 drives each ultrasonic speaker 21 using each drive unit 23 to generate ultrasonic waves 24 of a predetermined frequency from each ultrasonic speaker. Each ultrasonic speaker 21 has directivity, and propagates in the direction of each axis 21a within a range of directivity angle θ centered on the axis 21a. Each ultrasonic speaker 21 is attached to the casing 22 so that each axis 21a intersects at the spherical center 26 located at the lower center of the casing 22, so the ultrasonic wave 24 generated from each ultrasonic speaker 21 is transmitted to the casing 22. 22 or in the gap 14, and are concentrated and overlapped. Due to the superposition of the ultrasonic waves 24, a low pressure region 40 having a pressure lower than atmospheric pressure is formed in the lower center of the casing 22. The low pressure region 40 has a diameter that is approximately half the wavelength of the ultrasonic wave 24 .

The control unit 50 causes the moving mechanism 30 to move the low-pressure region 40 so as to scan in the X and Y directions so that it is above the image sensor 12, for example, several mm above. Due to the ultrasonic wave 24 reflected from the surface 15 of the image sensor 12, the low-pressure region 40 is located above the surface 15 of the image sensor 12 at a distance of 1/4 to half a wavelength of the ultrasonic wave 24. The acoustic head 20 may be moved to scan in the XY directions so that the region 40 is spaced apart from the surface 15 of the image sensor 12 by a quarter wavelength to a half wavelength of the ultrasonic wave 24. When the frequency of the ultrasonic wave 24 is 40 kHz, the half wavelength is 4.25 mm and the quarter wavelength is 2.125 mm. Move the acoustic head 20.

As a result, the low pressure region 40 formed at the lower center of the casing 22 moves in the XY directions above the surface 15 of the image sensor 12 held on the stage 10 and along the surface 15. Further, ultrasonic waves 24 generated from each ultrasonic speaker 21 hit the surface 15 of the image sensor 12 . Then, when the low pressure region 40 comes over the foreign object 90 attached to the surface 15 of the image sensor 12, the foreign object 90 is separated from the surface 15 of the image sensor 12 due to the vibration caused by the ultrasonic wave 24. The foreign matter 90 is then attracted to the nearby low pressure region 40 as indicated by the white arrow 91 in FIG. 1 and removed from the surface 15 of the image sensor 12. The attracted foreign matter 90 is trapped in the low pressure region 40 and moves together with the acoustic head 20 in a floating state.

After scanning the acoustic head 20 in the X and Y directions above the image sensor 12, the control section 50 moves the acoustic head 20 above the foreign matter disposal section 16. The foreign matter disposal section 16 includes, for example, a downward vacuum suction mechanism. When the acoustic head 20 comes above the foreign matter disposal section 16, the control section 50 stops the driving of each ultrasonic speaker 21 by each drive unit 23. As a result, the low pressure region 40 disappears, and the foreign matter 90 trapped in the low pressure region 40 is vacuum-suctioned to the lower foreign matter disposal section 16 and disposed of outside. Thereby, the foreign matter 90 sucked by the low pressure region 40 can be disposed of without being attached to the image sensor 12 again.

As explained above, the acoustic foreign matter removal device 100 removes the foreign matter 90 by suctioning the foreign matter 90 attached to the surface 15 of the electronic component 13 with the low pressure region 40 formed by the acoustic head 20. The foreign matter 90 can be removed without contacting the surface 15 of the electronic component 13, and damage to the electronic component 13 can be suppressed. Moreover, a device for freezing dry ice like the conventional technique described in Patent Document 1 is not required, and the foreign matter 90 attached to the surface 15 of the electronic component 13 can be removed with a simple configuration.

Further, each drive unit 23 of the acoustic foreign object removal device 100 is capable of adjusting the phase of the ultrasonic waves 24 generated by the connected ultrasonic speaker 21, and by adjusting each phase, the ultrasonic waves 24 are formed. The shape, size, and position of the low pressure region 40 can be freely adjusted according to the foreign object 90 to be removed.

Further, in the acoustic foreign object removal device 100, the casing 22 has a spherical dome shape, and each ultrasonic speaker 21 is attached so that each axis 21a intersects at the center 26 of the sphere. In this way, by overlapping each ultrasonic wave 24 at one point, it is possible to stably form a low pressure region 40 with lower pressure. Therefore, the position of the low pressure region 40 does not fluctuate, and the foreign matter 90 can be reliably sucked.

However, the shape of the casing 22 is not limited to such a spherical shape. For example, the casing 22 may have an elliptical dome shape. Furthermore, even if the axes 21a of each ultrasonic speaker 21 do not intersect at the lower center of the casing 22, the axes 21a are concentrated at the lower center of the casing 22, and each ultrasonic wave generated from each ultrasonic speaker 21 24 may be attached to the casing 22 so as to be concentrated at the lower center of the casing 22. For example, the ultrasonic speakers 21 may be arranged such that the ranges of the directivity angles θ centered on the respective axes 21a of the ultrasonic speakers 21 intersect with each other.

Further, although the drive unit 23 that drives the ultrasonic speakers 21 has been described as being connected to each ultrasonic speaker 21, the present invention is not limited to this, and several ultrasonic speakers 21 can be connected to one drive unit 23. It may be configured to be driven.

Furthermore, although the moving mechanism 30 has been described as being composed of the guide rail 31 that moves in the X direction, the slider 33 that moves in the Y direction, and the Z direction moving mechanism 35 attached to the slider 33, the present invention is not limited to this. do not have. For example, the acoustic head 20 may be attached to the tip of a robot arm that is freely movable in the XYZ directions. In this case, the robot arm constitutes the moving mechanism 30. Furthermore, the stage 10 may be configured to move in the XYZ directions, or the electronic component 13 placed on the stage 10 may be configured to be moved in the XY directions.

Next, an acoustic foreign object removal device 200 according to another embodiment will be described with reference to FIG. Components similar to those of the acoustic foreign object removal device 100 previously described with reference to FIG. As shown in FIG. 2, the acoustic head 60 of the acoustic foreign matter removal device 200 has a plurality of ultrasonic speakers 21 attached to an annular casing 62.

As shown in FIG. 2, the casing 62 is a spherical annular member with a small-diameter open surface 64 on the upper side and a large-diameter open surface 65 on the lower side, and a plurality of ultrasonic speakers 21 are attached to the spherical belt surface 63. ing. A spherical center 66 of the spherical belt surface 63 is located in the gap 14 between the acoustic head 60 and the holding surface 10a of the stage 10 at the lower center of the casing 62 below the lower open surface 65. The plurality of ultrasonic speakers 21 are attached to the casing 62 so that their respective axes 21a intersect at a spherical center 66 of the spherical surface of the casing 62. Similar to the acoustic foreign object removal device 100 previously described with reference to FIG. 1, the ultrasonic waves 24 generated from each ultrasonic speaker 21 intersect at the lower center of the casing 22 and are concentrated and overlapped. Due to the superposition of the ultrasonic waves 24, a low pressure region 40 having a pressure lower than atmospheric pressure is formed in the lower center of the casing 22.

A stay 67 is attached to the upper open surface 64 of the casing 62, and the arm 36 is connected to the stay 67. The acoustic head 60, like the acoustic head 20 of the acoustic foreign object removal device 100 described above with reference to FIG. It is relatively movable.

The operation of the acoustic foreign object removal device 200 is similar to the operation of the acoustic foreign object removal device 100 described above with reference to FIG. 1, and can remove the foreign object 90 while suppressing damage to the electronic components 13. .

Since the casing 62 of the acoustic foreign matter removal device 200 is made of a spherical annular member, the thickness in the Z direction can be reduced, and it can be incorporated into a small bonding device or the like.

In the above description, the casing 62 of the acoustic head 60 has been described as a spherical annular member having a small-diameter open surface 64 on the upper side and a large-diameter open surface 65 on the lower side, but the present invention is not limited to this. It is also possible to attach a lid to the In this case, the ultrasonic waves 24 generated from the ultrasonic speaker 21 are less affected by the outside air, so the position and size of the low pressure region 40 can be more stabilized. Further, an ultrasonic speaker 21 may be attached to the lid. Thereby, the pressure in the low pressure region 40 can be lowered to make it possible to suction the large foreign object 90.

10 stage, 10a holding surface, 11 substrate, 12 image sensor, 13 electronic component, 14 gap, 15 surface, 16 foreign matter disposal section, 20, 60 acoustic head, 21 ultrasonic speaker, 21a shaft, 22, 62 casing, 23 Drive unit, 24 Ultrasonic wave, 25, 64, 65 Open surface, 26 Sphere center, 30 Movement mechanism, 31 Guide rail, 32 X direction movement mechanism, 33 Slider, 34 Y direction movement mechanism, 35 Z direction movement mechanism, 40 Low pressure area, 50 control section, 51 CPU, 52 storage section, 63 spherical zone surface, 66 spherical center, 67 stay, 90 foreign object, 100,200 acoustic foreign object removal device.

Claims (5)

An acoustic foreign object removal device that removes foreign objects attached to the surface of an object,
a stage that holds the object on a holding surface;
an acoustic head disposed apart from the stage ;
a moving mechanism that moves the acoustic head relative to the stage,
The acoustic head includes a plurality of ultrasonic generators having directivity, and a casing to which the plurality of ultrasonic generators are attached so that the plurality of ultrasonic waves generated from the plurality of ultrasonic generators are concentrated. have,
A plurality of ultrasonic waves generated from the plurality of ultrasonic generators are concentrated in a gap between the casing and the holding surface of the stage to form a low pressure area in the gap that is lower than atmospheric pressure, and the The foreign matter adhering to the surface of the object is removed from the surface by being sucked into the low pressure region;
The moving mechanism relatively moves the acoustic head to a foreign matter disposal section located apart from the target object;
An acoustic foreign object removal device featuring: The acoustic foreign matter removal device according to claim 1,
The casing of the acoustic head has an annular shape or a dome shape with the stage side open,
the plurality of ultrasonic generators are a plurality of ultrasonic speakers, each of which is attached to the casing so that each axis is concentrated in the gap;
An acoustic foreign object removal device featuring: The acoustic foreign matter removal device according to claim 1 or 2,
comprising a drive circuit that drives a plurality of the ultrasonic generators,
The drive circuit is capable of adjusting each phase of the ultrasonic waves generated from each ultrasonic generator;
An acoustic foreign object removal device featuring: The acoustic foreign matter removal device according to claim 3,
The drive circuit includes a plurality of drive units that drive one of the ultrasonic generators,
The drive unit is capable of adjusting the phase of the ultrasonic waves generated from the ultrasonic generator;
An acoustic foreign object removal device featuring: The acoustic foreign matter removal device according to any one of claims 1 to 4 ,
The moving mechanism moves the low pressure region formed by the acoustic head along the surface so as to be spaced from the surface of the object held on the stage by a quarter wavelength to a half wavelength of the ultrasonic waves. to move relatively;
An acoustic foreign object removal device featuring:

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