Ultrasonic bonding machine

Abstract

Two aluminum alloy plates are sandwiched between an anvil and a chip of a horn which is being vibrated by a vibration unit, to perform ultrasonic bonding. A deposit removing unit is provided above the horn. When the horn is vibrated by the vibration unit and raised by an elevator, the chip positioned on the top of the horn comes into contact with a removal section, with the chip being vibrated, to allow the removal section to remove a deposit adhering to the chip.

Claims

1. An ultrasonic bonding machine comprising: a horn provided with a chip for bonding located at a bottom of the horn; a vibrator which horizontally vibrates the horn; an elevator which raises and lowers the horn; an anvil arranged below the horn and allowing two bonding targets to be placed thereon, with the two bonding targets overlapping each other; and a chip position changer configured, via rotation of the horn, for changing a position of the chip to a position at a top of the horn, wherein: the vibrator vibrates the horn and the elevator lowers the horn, so that the anvil and the vibrating chip sandwich, and ultrasonically bond, the bonding targets, a deposit remover is provided above the horn, when the horn is vibrated by the vibrator and raised by the elevator, the chip, positioned at the top of the horn by the chip position changer, comes into contact with the deposit remover, with the chip being vibrated to allow the deposit remover to remove a deposit adhering to the chip, the horn is configured to move to: a contact position at which the horn comes into contact with the bonding targets, a switching position at which a position of the chip is switched, and a deposit removal position at which the horn comes into contact with the deposit remover, the horn is located in the switching position when raised from the contact position, and the horn is located in the deposit removal position when raised from the switching position.

2. The ultrasonic bonding machine of claim 1, wherein: the chip position changer is a rotary motor, which rotates the horn about a center line of the horn extending horizontally.

3. The ultrasonic bonding machine of claim 2, wherein: the chip comprises a plurality of chips arranged at regular intervals around the center line of the horn.

4. The ultrasonic bonding machine of claim 3, wherein: an even number of the chips are provided around the center line of the horn.

5. The ultrasonic bonding machine of claim 1, further comprising: a deposit removing member including a removal section which removes the deposit adhering to the chip; a slide member which is placed above the removal section so as to be in contact with the removal section and which is vertically slidable; and a biasing member which biases the slide member downward.

6. The ultrasonic bonding machine of claim 5, wherein: a drive roller having a horizontally extending rotation axis is provided above the biasing member; and the deposit removing member is an endless belt wound around the drive roller and the slide member so as to be circularly movable.

7. The ultrasonic bonding machine of claim 6, wherein: when the deposit remover removes the deposit on the chip, the drive roller is stopped, and after removing the deposit on the chip and positioning the horn at the switching position, the drive roller is actuated to move the deposit remover.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a diagram illustrating a perspective view of an ultrasonic bonding machine according to an embodiment of the present disclosure.

(2) FIG. 2 is a diagram illustrating a view along the arrow II of FIG. 1.

(3) FIG. 3 a diagram illustrating a state during ultrasonic bonding after the state of FIG. 2.

(4) FIG. 4 a diagram illustrating a state in which a horn is rotated about its center line after the state of FIG. 3.

(5) FIG. 5 a diagram illustrating a state in which a deposit adhering to a surface of a chip is removed after the state of FIG. 4.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

(6) An embodiment of the present disclosure will now be described in detail with reference to the drawings. Note that the following description of an embodiment is merely illustrative in nature.

(7) FIG. 1 shows an ultrasonic bonding machine 1 according to an embodiment of the present disclosure. The ultrasonic bonding machine 1 integrates two aluminum alloy plates W1 (i.e., bonding targets), which are overlapped with each other, by ultrasonic bonding. The ultrasonic bonding machine 1 includes a machine body 2 installed on a floor, and an anvil 3 which is arranged on a side of the machine body 2. The two aluminum alloy plates W1 can be placed on the anvil 3, while overlapping each other.

(8) The machine body 2 includes a processing unit 4 extending horizontally toward a position above the anvil 3, and an elevator 5 for raising and lowering the processing unit 4. The anvil 3 is located below the protruding end of the processing unit 4.

(9) The processing unit 4 includes an elongated substantially rectangular parallelepiped housing case 6 having a housing space 6a inside. The housing space 6a houses a substantially cylindrical vibration unit (i.e., vibrator) 7, and a rotary motor (i.e., chip position changer) 8.

(10) The vibration unit 7 has a cylinder center line C1 extending along the length of the processing unit 4. One end of the vibration unit 7 faces outside the housing case 6.

(11) The rotary motor 8 is placed near the other end of the vibration unit 7, and has a rotary shaft 8a that is located on the cylinder center line C1 of the vibration unit 7 and protrudes toward the inside of the vibration unit 7.

(12) A horn 9 is provided at the one end of the vibration unit 7. The horn 9 has a center line C2 that coincides with the cylinder center line C1 of the vibration unit 7.

(13) The horn 9 includes a horn body 9a that is an elongated round bar, and a processing head 9b that is a thick square plate attached to one end of the horn body 9a. The other end of the horn body 9a is inserted and fitted in the vibration unit 7.

(14) The other end of the horn body 9a is coupled to the rotary shaft 8a of the rotary motor 8. The horn 9 is rotatable about the center line C2 in accordance with the rotation of the rotary shaft 8a of the rotary motor 8.

(15) Further, the other end of the horn body 9a is connected to a vibration mechanism (not shown) provided inside the vibration unit 7. The horn 9 is capable of being vibrated by the vibration unit 7 in the horizontal directions orthogonal to the center line C2 (i.e., in the directions of arrows X1 shown in FIGS. 3 and 5).

(16) The processing head 9b is provided with four rectangular plate-shaped chips 9c intended for bonding at regular intervals around the center line C2. As shown in FIG. 4, the rotation of the horn 9, caused by the rotary motor 8, causes one of the chips 9c to be located at the top of the horn 9, and another chip 9c to be located at the bottom of the horn 9, one after another.

(17) As shown in FIGS. 2 and 3, the ultrasonic bonding machine 1 is configured to cause the horn 9 to vibrate by the vibration unit 7 and lower the horn 9 by the elevator 5 so that the two aluminum alloy plates W1, overlapping each other on the anvil 3, are sandwiched between the anvil 3 and the vibrating chip 9c located at the bottom of the horn 9, thereby achieving ultrasonic bonding.

(18) A deposit removing unit (i.e., deposit remover) 10 is provided above the protruding end of the processing unit 4. The deposit removing unit 10 is capable of removing deposits adhering to the chips 9c.

(19) As shown in FIG. 2, the deposit removing unit 10 includes a slide member 10a, a coil spring (i.e., biasing member) 10b, a drive roller 10c arranged above the coil spring 10b, and a copper belt (i.e., deposit removing member) 10d. The slide member 10a has a rectangular plate-like shape in plan view, and is vertically slidable. The coil spring 10b biases the slide member 10a downward. The drive roller 10c has a rotation axis R1 extending in the same direction as the cylinder center line C1. The copper belt 10d is an endless belt wound around the slide member 10a and the drive roller 10c so as to be circularly movable. A region of the copper belt 10d, which is in contact with the lower surface of the slide member 10a, serves as a removal section 10e of the present disclosure.

(20) As shown in FIG. 5, the ultrasonic bonding machine 1 is configured such that when the horn 9 is vibrated by the vibration unit 7 and the horn 9 is raised by the elevator 5, one of the vibrating chips 9c which is located at the top of the horn 9 comes into contact with the removal section 10e of the copper belt 10d, causing the slide member 10a to slide upward against the biasing force of the coil spring 10b.

(21) Since the vibrating chip 9c, which is located at the top of the horn 9, comes into contact with the removal section 10e of the copper belt 10d, deposits adhering to the vibrating chip 9c are removed by the removal section 10e.

(22) Now, an ultrasonic bonding operation using the ultrasonic bonding machine 1 according to the embodiment of the present disclosure will be described in detail.

(23) First, as shown in FIG. 2, two unbonded aluminum alloy plates W1 are placed on the anvil 3 so as to overlap with each other by an industrial robot (not shown).

(24) The ultrasonic bonding machine 1 is actuated after the placement of the aluminum alloy plates W1 on the anvil 3 by the industrial robot. The vibration unit 7 starts vibrating the horn 9, and the elevator 5 starts lowering the horn 9.

(25) Meanwhile, as shown in FIG. 3, one of the vibrating chips 9c which is located at the bottom of the processing head 9b of the horn 9 comes into contact with the upper surface of the upper aluminum alloy plate W1 placed on the anvil 3, so that the aluminum alloy plates W1 are sandwiched and pressed between the anvil 3 and the vibrating chip 9c. A solid-phase bonding portion (not shown) is therefore formed between the aluminum alloy plates W1, which are integrated together as a result.

(26) After the completion of the ultrasonic bonding of the aluminum alloy plates W1, the elevator 5 raises the horn 9 until the horn 9 is located in between the deposit removing unit 10 and the anvil 3, where the horn 9 is stopped.

(27) After that, as shown in FIG. 4, the horn 9 is rotated about the center line C2 by the rotational movement of the rotary shaft 8a of the rotary motor 8, so that the chip 9c located at the top of the horn 9 is changed to the next chip 9c in the circumferential direction about the center line C2, and that the chip 9c located at the bottom of the horn 9 is changed to the next chip 9c in the circumferential direction about the center line C2.

(28) This means that the ultrasonic bonding machine 1 is ready for another ultrasonic bonding, that is, ready for the industrial robot to place two unbonded aluminum alloy plates W1 on the anvil 3, after the industrial robot removes the bonded aluminum alloy plates W1 from the anvil 3.

(29) After the ultrasonic bonding described above has repeated predetermined times, the ultrasonic bonding machine 1 turns to a chip polishing mode to polish the chips 9c. Specifically, the elevator 5 raises the horn 9, which is being vibrated by the vibration unit 7, until the chip 9c located at the top of the horn 9 comes into contact with the removal section 10e of the copper belt 10d as shown in FIG. 5. The slide member 10a slides upward against the biasing force of the coil spring 10b, so that the removal section 10e polishes the chip 9c located at the top of the horn 9 to remove deposits adhering to the surface of the chip 9c.

(30) After the completion of the deposit removal by the removal section 10e, the horn 9 is lowered by the elevator 5 until the horn 9 is located in between the deposit removing unit 10 and the anvil 3, where the horn 9 is stopped. At this moment, the slide member 10a is slid downward by the biasing force of the coil spring 10b, and returns to the original position.

(31) After that, the drive roller 10c is rotated to move the copper belt 10d in an M1 direction by a predetermined amount, as shown in FIG. 2, so that the region of the copper belt 10d serving as the removal section 10e is replaced with a new region which has not yet undergone the polishing process.

(32) As described above, according to the embodiment of the present disclosure, surfaces of the chips 9c used for ultrasonic bonding can be periodically polished by the deposit removing unit 10 capable of removing deposits, which reliably prevents or reduces the fixture of the aluminum alloy plates W1 to the chips 9c in the ultrasonic bonding. Since the deposit removing unit 10 is positioned above the horn 9, the entire ultrasonic bonding machine 1 has a smaller horizontal size, thereby requiring no large site for installation. Further, the chip 9c can be moved to a polishing position, where the surface of the chip 9c is polished, by utilizing the upward movement of the elevator 5 used during ultrasonic bonding; and the surface of the chip 9c can be polished by utilizing the vibrations of the vibrating unit 7 used during ultrasonic bonding. It is therefore not necessary to provide additional mechanisms intended for movement and polishing of the chips 9c in polishing the surfaces of the chips 9c. That is, no additional cost is required to polish the surfaces of the chips 9c.

(33) The positions of the chips 9c are changed by simply rotating the horn 9 about the center line C2 by the rotary motor 8, without vertically changing the position of horn 9. Thus, the ultrasonic bonding machine 1 requires only a small vertical size.

(34) In replacing the chip 9c having deposits on its surface with another chip 9c not yet having deposits on its surface, no complicated operation is needed, such as attachment/detachment of the chips 9c to/from the horn 9 by an operator. That is, the chips 9c are easily replaced.

(35) When the elevator 5 raises the horn 9, and the chip 9c located at the top of the horn 9 comes into contact with the copper belt 10d, the slide member 10a slides upward against the biasing force of the coil spring 10b, with the copper belt 10d kept in contact with the surface of the chip 9c due to the biasing force of the coil spring 10b. This configuration can reduce an impact when the chip 9c comes into contact with the copper belt 10d, and hence can reduce malfunctions of the ultrasonic bonding machine 1.

(36) After polishing the surface of the chip 9c, the drive roller 10c is actuated to move the copper belt 10d by a predetermined amount between the drive roller 10c and the slide member 10a. As a result, a new region of the copper belt 10d which has not yet undergone the polishing process is positioned below the slide member 10a. This configuration allow each chip 9c to be polished with the copper belt 10d in a region having a good surface condition, which makes it possible to reliably remove deposits adhering to the surface of the chip 9c.

(37) Although in the embodiment of the present disclosure, four chips 9c are provided at regular intervals around the center line C2 of the horn 9, two or three chips 9c may be provided at regular intervals around the center line C2 of the horn 9. Alternatively, five or more chips may be provided. If an even number of the chips 9c are provided at regular intervals around the center line C2 of the horn 9, one of the chips 9c is located at the bottom of the horn 9, and one of the rest of the chips 9c is located at the top of the horn 9. Ultrasonic bonding is carried out using the chip 9c located at the bottom of the horn 9 lowered by the elevator 5 while being vibrated by the vibration unit 7. Polishing is carried out thereafter with respect to the chip 9c located at the top of the horn 9 raised by the elevator 5 while being vibrated by the vibration unit 7. This configuration allows efficient bonding and polishing.

(38) In the embodiment of the present disclosure, deposits adhering to the chips 9c are removed by the endless copper belt 10d, but the configuration is not limited thereto. The deposits may be removed with an endless sandpaper belt, for example.

(39) In the embodiment of the present disclosure, the copper belt 10d for removing deposits are moved in a circumferential direction, but it is not essential to move the belt in the circumferential direction.

(40) The present disclosure is suitable for an ultrasonic bonding machine configured to bond two bonding targets, which are overlapped with each other, by ultrasonic vibrations.