CN111656502A

CN111656502A - Actuator and wire bonding device

Info

Publication number: CN111656502A
Application number: CN201980010485.3A
Authority: CN
Inventors: 内田洋平; 平良尚也
Original assignee: Shinkawa Ltd
Current assignee: Shinkawa Ltd
Priority date: 2018-01-30
Filing date: 2019-01-30
Publication date: 2020-09-11
Anticipated expiration: 2039-01-30
Also published as: KR20200103820A; CN111656502B; TW201939627A; WO2019151340A1; JP7002148B2; TWI722376B; KR102420211B1; JPWO2019151340A1

Abstract

The actuator 13 includes: a pair of linear motors 22A, 22B: a control device 27 for controlling the direction and magnitude of the force generated by the pair of linear motors 22A and 22B; and a carriage 26 mounted on the pair of linear motors 22A and 22B. The control device 27 translates the carriage 26 by aligning the direction of the force generated by one of the linear motors 22A with the direction of the force generated by the other linear motor 22B. The control device 27 rotates the carriage 26 by reversing the direction of the force generated by one of the linear motors 22A relative to the direction of the force generated by the other linear motor 22B.

Description

Actuator and wire bonding device

Technical Field

The present disclosure relates to an actuator (activator) and wire bonding apparatus.

Background

Patent document 1 discloses a wire bonding apparatus. The wire bonding apparatus has a bonding pin (capillary) as a bonding tool (bonding tool). The wire bonding apparatus connects a wire to an electrode by applying heat or ultrasonic vibration to the wire using the bonding pin.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2018-6731

Disclosure of Invention

Problems to be solved by the invention

The manufacturing apparatus such as the wire bonding apparatus disclosed in patent document 1 requires a plurality of moving mechanisms. For example, in the operation of the manufacturing apparatus, there are involved the movement of the workpiece to be processed, which is the object of processing, and the movement of the tool relative to the workpiece. Therefore, the manufacturing apparatus requires an actuator for realizing the movement pattern required for each of the part to be processed and the tool.

In the field of manufacturing devices, high functionality is being studied. Due to the high functionality, the required mobility pattern increases. Further, the required mobility pattern is complicated. As a result, since the actuators need to be prepared for each movement pattern, the number of actuators increases as the movement pattern increases.

In view of the above, the present disclosure provides an actuator and a wire bonding apparatus capable of performing a plurality of operations.

Means for solving the problems

An actuator according to an aspect of the present disclosure includes: a first force generating unit that generates a force in a positive direction along the first direction and a force in a negative direction opposite to the positive direction along the first direction; a second force generating unit that is disposed apart from the first force generating unit in a second direction orthogonal to the first direction and generates a force in a positive direction and a force in a negative direction; a control part for controlling the direction and magnitude of the force generated by the first force generating part and the second force generating part; and a moving body that is erected on the first force generating portion and the second force generating portion, wherein the control portion causes the moving body to translate in the first direction by causing the direction of the force generated by the first force generating portion to coincide with the direction of the force generated by the second force generating portion, and causes the moving body to rotate around the center of gravity of the moving body by causing the direction of the force generated by the first force generating portion to be opposite to the direction of the force generated by the second force generating portion.

The actuator includes a first force generating portion and a second force generating portion. The force generated by each force generating unit is controlled by a control unit. According to the above configuration, the movable body can be moved in the first direction by aligning the directions of the forces generated in the first force generating portion and the second force generating portion. Further, the direction of the force generated by the second force generating portion is reversed with respect to the direction of the first force generating portion, so that the moving body generates a torque around the center of gravity. As a result, the movable body can be rotated about its center of gravity. As a result, the actuator can provide the moving body with a plurality of operations such as translation along the first direction and rotation around the center of gravity.

In the actuator, the first force generating portion and the second force generating portion may be disposed along the second direction with a center of gravity of the movable body interposed therebetween. According to the above configuration, the moving body can be rotated efficiently.

In the actuator, the first force generating portion and the second force generating portion may have: an ultrasonic wave generating part connected to the control part and controlled by the control part; and a drive shaft extending in the first direction, having a contact portion contacting the moving body, and fixed to the ultrasonic wave generating portion to receive the ultrasonic wave vibration generated by the ultrasonic wave generating portion. The force generated by the first force generating portion and the second force generating portion may be a frictional force of the contact portion. The frictional force can be controlled by the frequency of the ultrasonic waves. According to the above configuration, the first force generating portion and the second force generating portion can be configured to have a simple configuration.

In the actuator, the platform may have a main face and a back face. One of the major and the rear surfaces may include a contact portion. According to the above configuration, the first force generating portion and the second force generating portion can reliably provide the force to the movable body. As a result, the translation and rotation of the movable body can be reliably performed.

Another aspect of the present invention provides a wire bonding apparatus comprising: a bonding tool for detachably holding the welding pin; and a welding pin replacing part for mounting or dismounting the welding pin to or from the joint tool, wherein the welding pin replacing part is provided with the actuator. The wire bonding apparatus includes a bonding pin exchanging portion including the actuator. The actuator can perform both translational and rotational motions. Therefore, the wire bonding apparatus can be provided with the replacement function of the welding pin, and the enlargement of the welding pin replacement part can be suppressed. Therefore, the wire bonding device can achieve both high functionality and miniaturization.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, an actuator and a wire bonding apparatus capable of performing a plurality of operations are described.

Drawings

Fig. 1 is a perspective view showing a wire bonding apparatus according to an embodiment.

Fig. 2 is an enlarged perspective view of a wire bonding apparatus shown in fig. 1, showing a wire changing portion.

Fig. 3 is a perspective view showing a part of a welding pin holding portion in a cross-sectional view.

Fig. 4 is a view for explaining the operation of the welding pin holding portion.

Fig. 5 is a perspective view showing a part of a welding pin guide in a cross-sectional view.

Fig. 6 is a view showing a guide function of a bonding wire by a bonding wire holding portion and a bonding wire guide portion.

Fig. 7 is a view showing another guide function of the bonding wire by the bonding wire holding portion and the bonding wire guide portion.

Fig. 8 is a plan view showing a main part of an actuator included in the needle replacing unit shown in fig. 2.

Fig. 9 is a diagram illustrating the operation principle of the actuator.

Fig. 10 is a diagram illustrating specific control of the actuator.

Fig. 11 is a diagram illustrating specific control of the actuator.

FIG. 12 is a view showing a main operation of a welding pin exchanging part.

Fig. 13 is a view showing a main operation of the needle exchanging portion subsequent to fig. 12.

Fig. 14 is a view showing a main operation of the needle replacing unit subsequent to fig. 13.

Fig. 15 is a view showing a main operation of the needle replacing unit subsequent to fig. 14.

Fig. 16 is a perspective view showing a cross section of a probe holding portion according to a modification.

Detailed Description

The actuator and the wire bonding apparatus of the present disclosure will be described in detail below with reference to the accompanying drawings. In the description of the drawings, the same components are denoted by the same reference numerals, and redundant description is omitted.

The wire bonding apparatus 1 shown in fig. 1 electrically connects an electrode provided on a printed board or the like and an electrode of a semiconductor element mounted on the printed board to each other by using a small-diameter metal wire, for example. The wire bonding apparatus 1 applies heat, ultrasonic waves or pressure to the wire to connect the wire to the electrode. The wire bonding apparatus 1 includes a base 2, a bonding section 3, and a conveying section 4. The joint 3 performs the connecting operation. The conveying unit 4 conveys a printed circuit board or the like as a component to be processed to the bonding area.

The bonding portion 3 includes a bonding tool 6, and an ultrasonic horn 7 is provided at the tip of the bonding tool 6. A welding pin 8 is detachably provided at the front end of the ultrasonic welding head 7. The welding pins 8 provide heat, ultrasonic waves or pressure to the bonding wires 8.

In the following description, the direction in which the ultrasonic horn 7 extends is referred to as the X axis, and the direction in which the printed circuit board is conveyed by the conveyor 4 is referred to as the Y axis (second direction). The direction in which the welding pin 8 moves during the joining operation (Z-axis direction, first direction) is defined as the Z-axis.

The welding pins 8 need to be replaced regularly. Therefore, wire bonding apparatus 1 has a probe exchanging portion 9. The welding pin replacing unit 9 automatically replaces the welding pin 8 without the operation of an operator.

The needle changer 9 recovers the welding needle 8 attached to the ultrasonic horn 7. Further, the needle changer 9 attaches the welding needle 8 to the ultrasonic horn 7. The operation of replacing the welding pin 8 includes an operation of collecting the welding pin 8 and an operation of attaching the welding pin 8. The replacement work of the welding pin 8 is automatically performed when a predetermined condition is satisfied. For example, the condition may be the number of times of the joining work. That is, the operation of replacing the welding pin 8 may be performed every time the bonding operation is performed a predetermined number of times.

As shown in fig. 2, the needle replacing portion 9 includes a needle holding portion 11, a needle guide portion 12, and an actuator 13 as main components. The needle replacing unit 9 has an attaching/detaching jig 15 and a jig driving unit 20 for driving the attaching/detaching jig 15 as additional components.

< holding part of welding pin >

The welding pin holding portion 11 holds the welding pin 8. The needle holder 11 is mounted to the actuator 13 via a retainer 14. The shape of the needle holding portion 11 is a cylinder extending in the Z-axis direction. The lower end of the needle holder 11 is held by the holder 14. The welding pin 8 is detachably inserted into the upper end of the welding pin holding portion 11.

As shown in fig. 3, the pin holding portion 11 includes an upper socket 16, a coil spring 17 (elastic portion), a lower socket 18 (pin base portion), and an O-ring 19 (restricting portion) as main components. The upper socket 16, the coil spring 17, and the lower socket 18 are arranged on a common axis. Specifically, the upper socket 16, the coil spring 17, and the lower socket 18 are arranged in this order from the top.

The upper socket 16 is substantially cylindrical in shape. The upper socket 16 has a through hole 16h extending from the upper end face 16a to the lower end face 16 b. The upper socket 16 holds the tapered surface 8a of the welding pin 8. Therefore, the inner diameter of the through hole 16h corresponds to the outer diameter of the tapered surface 8a of the bonding pin 8. For example, the inner diameter of the through hole 16h is smaller than the outer diameter of the pin body 8 b. A countersunk portion 16c for the O-ring 19 is provided on the upper end surface 16a side of the through hole 16 h. The countersunk portion 16c is sized to receive the O-ring 19. The depth of the countersunk portion 16c is the same as the height of the O-ring 19. The inside diameter of the countersunk portion 16c is about the same as the outside diameter of the O-ring 19.

The O-ring 19 is a so-called torus (torus). The O-ring 19 is in direct contact with the tapered surface 8a of the welding pin 8. That is, the O-ring 19 of the needle holder 11 holds the welding needle 8. The retention is achieved by an adhesive layer formed on the surface of the O-ring 19. The inner diameter of the O-ring 19 is substantially the same as the inner diameter of the through hole 16 h. The tapered surface 8a of the welding pin 8 is inserted into the O-ring 19.

The upper socket 16 has a step 16d provided on the outer peripheral surface. Therefore, the outer diameter of the upper socket 16 on the upper end surface 16a side is different from the outer diameter of the upper socket 16 on the lower end surface 16b side. Specifically, the outer diameter on the lower end surface 16b side is slightly smaller than the outer diameter on the upper end surface 16a side. A coil spring 17 is fitted into the small diameter portion 16e on the lower end surface 16b side.

The lower socket 18 is generally cylindrical in shape. The upper end face 18a of the lower socket 18 faces the lower end face 16b of the upper socket 16. The outer shape of the lower socket 18 is the same as the outer shape of the upper socket 16. A step 18d is provided on the outer peripheral surface of the lower socket 18. In contrast to the upper socket 16, the upper end surface 18a side of the lower socket 18 is a small diameter portion 18 e. A coil spring 17 is fitted into the small diameter portion 18e on the upper end surface 18a side. The large diameter portion 18f on the lower end surface 18b side of the lower socket 18 is held by the holder 14.

The coil spring 17 is a compression spring. The upper end side of the coil spring 17 is fitted into the small diameter portion 16e of the upper socket 16. The lower end side of the coil spring 17 is inserted into the small diameter portion 18e of the lower socket 18. The upper socket 16 and the coil spring 17 constitute the flexible portion 10. Therefore, the upper socket 16 and the lower socket 18 are coupled by the coil spring 17. The coil spring 17 has elasticity in a direction along the axis 17A and elasticity in a direction intersecting the axis 17A. As a result, the relative position of the upper socket 16 with respect to the lower socket 18 can be changed.

The welding pin holding portion 11 having the above-described structure has a holding form shown in fig. 4. Fig. 4 (a) shows the probe holding portion 11 in an initial state. Fig. 4 (b) shows the probe holding portion 11 according to the first modification. Fig. 4 (c) shows a second modified form of the needle holder 11.

As shown in fig. 4 (a), in the pin holding portion 11 of the first holding state, the axis 16 of the upper socket 16 coincides with the axis 18A of the lower socket 18. Further, the axis 8A of the welding pin 8 is also coincident with the

axes

16A and 18A.

As shown in fig. 4 (b), in the second holding mode of the pin holder 11, the axis 16A of the upper socket 16 does not coincide with the axis 18A of the lower socket 18. Specifically, the lower socket 18 is retained in the retainer 14 to maintain its position. The upper socket 16 moves in the X-axis and Y-axis directions with respect to such a lower socket 18. The axis 16A of the upper socket 16 is parallel with respect to the axis 18A of the lower socket 18.

As shown in part (c) of fig. 4, in the probe holding portion 11 according to the third modification, the axis 16A of the upper socket 16 coincides with the axis 18A of the lower socket 18. That is, their structures are the same as the first retained aspect. On the other hand, the axis 8A of the welding pin 8 is inclined with respect to the axis 16A of the upper socket 16. The O-ring 19 has the shape of a circular ring. Therefore, the inner peripheral surface into which the tapered surface 8a of the welding pin 8 is inserted is a curved surface. For example, the sectional shape of the O-ring 19 in a section parallel to the Z-axis is circular. When the O-ring 19 is cut in a state where the tapered surface 8a is inserted, the O-ring 19 and the tapered surface 8a contact each other at two contact portions C1 and C2. That is, the contact state between the O-ring 19 and the bonding pin 8 is line contact in which they contact each other at an annular contact line CL (see fig. 3). According to such a contact state, the welding pin 8 is allowed to be inclined with respect to the axis 19A of the O-ring 19.

< guide part of welding needle >

As shown again in fig. 2, the needle guide 12 guides the needle 8 when the needle 8 is inserted into the hole 7h (needle holding hole) of the ultrasonic horn 7. The needle guide 12 is provided to the actuator 13. Therefore, the relative positional relationship between the needle guide 12 and the components constituting the actuator 13 is maintained. The needle guide 12 is a single-arm beam extending from the actuator 13 to the ultrasonic horn 7.

Fig. 5 is a perspective view of a main part of the welding pin guide part 12 in section. As shown in fig. 5, a guide hole 12h is provided at a free end portion of the needle guide 12. The guide hole 12h receives the needle body 8b of the welding needle 8. The guide hole 12h guides the welding pin 8 to the hole 7h of the ultrasonic horn 7. The guide hole 12h is a through hole. The guide hole 12h reaches from the upper surface 12a to the lower surface 12b of the needle guide 12. The guide hole 12h is also opened in the tip end surface 12c of the needle guide 12. The guide hole 12h can receive the welding pin 8 from the lower surface 12b and the front end surface 12 c.

The guide hole 12h includes a tapered hole portion 12t and a parallel hole portion 12 p. The lower end of the taper hole portion 12t opens at the lower surface 12 b. The upper ends of the parallel holes 12p are open at the upper surface 12 a. The inner diameter of the taper hole portion 12t in the lower surface 12b is larger than the inner diameter of the parallel hole portion 12p in the upper surface 12 a. The inner diameter is larger than the outer diameter of the upper end of the welding pin 8. That is, the inner diameter of the guide hole 12h gradually decreases from the lower surface 12b to the upper surface 12 a. The inner diameter of the guide hole 12h is smallest at a position connecting the tapered hole 12t and the parallel hole 12 p. The inner diameter is substantially the same as the outer diameter of the upper end of the welding pin 8. The inner diameter of the parallel hole 12p is constant.

Fig. 6 shows a state where the welding pin 8 is guided by the welding pin guide part 12. In the state shown in fig. 6 (a), the axis 7A of the hole 7h of the ultrasonic horn 7 coincides with the axis 12A of the guide hole 12h of the needle guide 12. On the other hand, the axis 8A of the welding pin 8 held by the welding pin holding portion 11 is offset in parallel in the X-axis direction with respect to the

axes

7A and 12A.

The bonding pin holding portion 11 is moved in the Z-axis direction from the state shown in fig. 6 (a). As shown in fig. 6 (b), the upper end of the welding pin 8 contacts the wall surface of the taper hole portion 12 t. When the needle holder 11 is moved upward, the needle 8 moves along the wall surface. The movement includes not only an upward (Z-axis direction) component but also a horizontal (X-axis direction) component. The needle holder 11 can move the upper socket 16 relative to the lower socket 18 by the coil spring 17. That is, when the lower socket 18 is moved upward, the upper socket 16 is moved in the horizontal direction by the coil spring 17 while moving upward.

According to said movement, the axis 8A of the welding pin 8 is progressively closer to the axis 7A of the hole 7 h. When the upper end of the bonding pin 8 reaches the parallel hole portion 12p, the axis 8A of the bonding pin 8 coincides with the axis 7A of the hole 7 h. Thus, the welding pin 8 is inserted into the hole 7h of the ultrasonic horn 7.

In the example shown in fig. 6 (a), the positional relationship between the ultrasonic horn 7 and the needle guide 12 is ideal. On the other hand, in the example shown in fig. 7 (a), the axis 7A of the hole 7h of the ultrasonic horn 7 is inclined with respect to the axis 12A of the needle guide 12.

The operation of inserting the welding pin 8 in the state shown in part (b) of fig. 7 will be described. As shown in fig. 7 (b), the axis 8A of the welding pin 8 is inclined with respect to the axis 7A of the hole 7 h. In this state, the upper end of the welding pin 8 is in contact with the wall surface of the hole 7 h. Therefore, the welding pin 8 cannot be inserted into the hole 7h more. In order to insert the welding pin 8 into the hole 7h, it is necessary to make the axis 8A of the welding pin 8 parallel with respect to the axis 7A of the hole 7 h. Further, the axis 8A and the axis 7A are made to coincide.

In the pin holder 11, the upper socket 16 can be offset with respect to the lower socket 18. Further, the welding pins 8 may be inclined with respect to the axis 16A of the upper socket 16. By these actions, as shown in part (c) of fig. 7, as the needle holding portion 11 is raised, the axis 8A of the needle 8 gradually approaches the axis 7A of the hole 7 h. Then, the welding pin 8 is finally inserted into the hole 7 h. That is, the bonding pin holding portion 11 flexibly holds the bonding pin 8. As a result, the displacement of the bonding wire 8 from the bonding wire guide 12 can be absorbed. Further, the offset of the welding pin 8 from the hole 7h of the ultrasonic horn 7 can be absorbed. Therefore, the needle holder 11 and the needle guide 12 can reliably attach the needle 8 to the ultrasonic horn 7.

< actuator >

The actuator 13 moves the welding pin 8 to be replaced or a new welding pin 8. The actuator 13 holds the welding pin 8 at a predetermined position and posture. The actuator 13 is movable back and forth along a prescribed translation axis (Z axis). In the present embodiment, the translation axis is along the vertical direction (Z axis). Therefore, the actuator 13 moves the bonding pin 8 upward and downward in the vertical direction. Further, the actuator 13 rotates the welding pin 8 about a rotation axis (X axis). In the present embodiment, the rotation axis is orthogonal to the vertical direction (Z axis). I.e. the axis of rotation is along the horizontal direction (X-axis). Thus, the actuator 13 rotates the welding pin 8 about the horizontal direction.

The actuator 13 includes an actuator base 21 (base portion), a pair of

linear motors

22A and 22B (first and second force generating portions), a linear guide 24, a carriage 26 (moving body), and a control device 27 (control portion, see fig. 1 and the like).

The actuator base 21 is shaped as a flat plate. The actuator substrate 21 has a principal surface 21 a. The normal direction of the main surface 21a is along the horizontal direction (X-axis direction). On the main surface 21a, a linear motor 22B, a linear guide 24, and a carriage 26 are arranged.

The linear motor 22A moves the carriage 26. The linear motor 22A is an ultrasonic motor based on a so-called impact drive (impact drive) method. The linear motor 22A has a drive shaft 28A and an ultrasonic element 29A (ultrasonic wave generating section). The drive shaft 28A is a metal round rod. The axis of the drive shaft 28A is disposed in parallel with respect to the main surface 21a of the actuator base 21. The carriage 26 moves along the drive shaft 28A. Therefore, the length of the drive shaft 28A determines the movement range of the carriage 26. The lower end of the drive shaft 28A is fixed to the ultrasonic element 29A. The upper end of the drive shaft 28A is supported by a guide 31. The guide 31 protrudes from the main surface 21a of the actuator substrate 21. The upper end of the drive shaft 28A may be fixed relative to the guide 31. In addition, the upper end of the drive shaft 28A may also be in contact with the guide 31. That is, the lower end of the drive shaft 28A is a fixed end, and the upper end of the drive shaft 28A is a fixed end or a free end.

The ultrasonic element 29A provides ultrasonic vibration to the drive shaft 28A. The drive shaft 28A provided with ultrasonic vibration vibrates slightly along the Z-axis. The ultrasonic element 29A may be a piezoelectric (piezo) element as a piezoelectric element, for example. The piezoelectric element deforms in accordance with the applied voltage. Therefore, when a high-frequency voltage is applied to the piezoelectric element, the piezoelectric element is repeatedly deformed according to the frequency and the magnitude of the voltage. That is, the piezoelectric element generates ultrasonic vibration. The ultrasonic element 29A is fixed to a guide 32 protruding from the actuator base 21.

The ultrasonic device 29A is electrically connected to the control device 27. The ultrasonic device 29A is connected in parallel with a driving voltage generated by the control device 27. The control device 27 controls the frequency and amplitude of the ac voltage supplied to the ultrasonic device 29A.

The single body structure of the linear motor 22B is the same as that of the linear motor 22A. The linear motor 22B is disposed apart from the linear motor 22A in the Y-axis direction intersecting the Z-axis. The drive shaft 28B of the linear motor 22B is parallel with respect to the drive shaft 28A of the linear motor 22A. The height of the upper end of the linear motor 22B is the same as the height of the upper end of the linear motor 22A. Likewise, the height of the lower end of the linear motor 22B is the same as the height of the lower end of the linear motor 22A.

The carriage 26 is a moving body. The movable body is translated and rotated by the

linear motors

22A and 22B. The carriage 26 is shaped as a disc. The carriage 26 is mounted between the

linear motors

22A and 22B. Between the actuator base 21 and the carriage 26, a linear guide 24 that guides the carriage 26 in the Z-axis direction is provided. The carriage 26 is guided in the Z-axis direction by the linear guide 24. The linear guide 24 restricts the moving direction of the carriage 26. The linear guide 24 does not provide the carriage 26 with a driving force in the Z-axis direction.

The carriage 26 has a front disc 33, a pressing disc 34, and a rear disc 36. The outer diameters of these disks are identical to each other. In addition, the disks are stacked along a common axis. A shaft body 37 is interposed between the front disc 33 and the pressing disc 34. The shaft body 37 has an outer diameter smaller than the outer diameters of the front disk 33 and the pressing disk 34. Therefore, a gap is formed between the outer peripheral portion of the front disk 33 and the outer peripheral portion of the pressure disk 34. Similarly, a shaft body 38 is also interposed between the rear disk 36 and the pressure disk 34. The shaft body 37 also has an outer diameter smaller than the outer diameters of the rear disk 36 and the pressure disk 34. Therefore, a gap is also formed between the outer peripheral portion of the rear disk 36 and the outer peripheral portion of the pressure disk 34.

The rear disc 36 is attached to the platform 24a of the linear guide 24. The rear disc 36 is rotatably coupled with respect to the platform 24 a. On the other hand, the pressing disk 34 and the front disk 33 are mechanically fixed to the rear disk 36. Therefore, the pressing disk 34 and the front disk 33 do not rotate with respect to the rear disk 36. Thus, the carriage 26 including the front disc 33, the pressing disc 34, and the rear disc 36 is rotatable generally with respect to the platform 24a of the linear guide 24.

As shown in fig. 8, the

drive shafts

28A and 28B are sandwiched in the gap G1 between the pressure disc 34 and the rear disc 36. The pair of

drive shafts

28A, 28B sandwich the center of gravity of the carriage 26. The

drive shafts

28A and 28B are in contact with the back surface 34B of the pressure disk 34 and the main surface 36a of the rear disk 36. The

drive shafts

28A and 28B do not contact the outer peripheral surface 38A of the shaft body 38. The outer diameter of the gap G1 is smaller than the outer diameters of the pressure disc 34 and the rear disc 36. The outer diameter of the gap G1 is larger than the outer diameter of the shaft body 38. The difference between the outer diameter of the axle body 38 and the outer diameter of the rear disk 36 is greater than the difference between the outer diameter of the drive shaft 28A and the outer diameter of the drive shaft 28B. Similarly, the difference between the outer diameter of the shaft body 37 and the outer diameter of the pressing disk 34 is larger than the difference between the outer diameter of the drive shaft 28A and the outer diameter of the drive shaft 28B.

The gap G1 is spaced slightly less than the outer diameter of drive shaft 28A and the outer diameter of drive shaft 28B. A gap G2 is formed between the front disk 33 and the pressing disk 34. As a result, when the drive shaft 28A and the drive shaft 28B are disposed between the pressure disc 34 and the rear disc 36, the pressure disc 34 slightly bends toward the front disc 33. The deflection generates a force that presses the

drive shafts

28A, 28B against the rear disk 36.

The operation principle of the actuator 13 will be described below with reference to fig. 9. The part (a) of fig. 9, the part (b) of fig. 9, and the part (c) of fig. 9 show the operation principle of the actuator 13. For convenience of explanation, fig. 9 shows one of the linear motors 22A and the carriage 26, and illustration of the other linear motor 22B and the like is omitted.

Fig. 9 (a) shows a state where the position of the carriage 26 is held. The drive shaft 28A of the carriage 26 is sandwiched between the pressing disk 34 and the rear disk 36. The position of the carriage 26 is maintained by pressurization due to the sandwiching. More specifically, the position of the carriage 26 is maintained by frictional resistance with pressurization as a vertical biasing force. The control device 27 does not apply a voltage to the ultrasonic device 29A. That is, as indicated by the voltage E1, the voltage value is zero. Further, the control device 27 may supply a dc current having a predetermined voltage value to the ultrasonic device 29A.

The position of the carriage 26 is maintained by frictional resistance with the drive shaft 28A. Here, as a mode of moving the drive shaft 28A, there are a first mode in which the carriage 26 moves along with the drive shaft 28A and a second mode in which the carriage 26 continues to maintain the position by its inertia without accompanying the drive shaft 28A. The mode of moving the drive shaft 28A is to select the first mode or the second mode according to the speed of moving the drive shaft 28A. The speed at which the drive shaft 28A moves is related to the frequency of the ultrasonic vibration. Therefore, the mode of moving the drive shaft 28A is to select the first mode or the second mode according to the frequency of the ultrasonic vibration. For example, when the frequency of the ultrasonic vibration is relatively low (15kHz to 30kHz), the carriage 26 moves along with the drive shaft 28A. For example, when the frequency of the ultrasonic vibration is relatively high (100kHz to 150kHz), the carriage 26 does not maintain the position along with the drive shaft 28A.

For example, as shown in fig. 9 (b), when the drive shaft 28A is moved upward (forward direction), the carriage 26 is moved in accordance with the movement of the drive shaft 28A. In this case, the relative positional relationship of the drive shaft 28A and the carriage 26 does not change. When the drive shaft 28A is moved downward (negative direction), the carriage 26 is moved without corresponding to the movement of the drive shaft 28A. In this case, the relative positional relationship of the drive shaft 28A and the carriage 26 changes. When these operations are repeated, the carriage 26 gradually moves upward. That is, the period of the voltage (symbol E2a in the voltage E2) that moves the drive shaft 28A upward is longer than the period of the voltage (symbol E2b in the voltage E2) that moves the drive shaft 28A downward. As a result, the carriage 26 moves upward.

On the contrary, as shown in part (c) of fig. 9, when the drive shaft 28A is moved downward, the carriage 26 is moved in accordance with the movement of the drive shaft 28A. In this case, the relative positional relationship of the drive shaft 28A and the carriage 26 does not change. When the drive shaft 28A is moved upward, the carriage 26 is moved without responding to the movement of the drive shaft 28A. In this case, the relative positional relationship of the drive shaft 28A and the carriage 26 changes. When these operations are repeated, the carriage 26 gradually moves downward. That is, the period of the voltage (symbol E3a in the voltage E3) that moves the drive shaft 28A upward is shorter than the period of the voltage (symbol E3b in the voltage E3) that moves the drive shaft 28A downward. As a result, the carriage 26 can be moved downward.

Further, in the case of moving the carriage 26 downward, it is also possible to make the carriage 26 not correspond to both the upward movement and the downward movement of the drive shaft 28A in addition to the control. That is, the frictional resistance acting between the carriage 26 and the drive shaft 28A is apparently smaller than the gravitational force acting on the carriage 26. As a result, the carriage 26 appears to fall. In this aspect, the gravitational force acting on the carriage 26 is utilized as the force to move the carriage 26 downward.

Next, a specific operation of the actuator 13 will be described with reference to fig. 10 and 11.

Part (a) of fig. 10 shows an operation of maintaining the position of the carriage 26. When the position of the carriage 26 is maintained, the controller 27 supplies a constant voltage to each of the

ultrasonic elements

29A and 29B (see voltages E4 and E5 in part (a) of fig. 10).

Fig. 10 (b) shows an operation of moving the carriage 26 upward. At this time, the controller 27 supplies an ac voltage indicated by a voltage E6 in fig. 10 (b) to one of the ultrasonic elements 29A. The period of the voltage for moving the drive shaft 28A upward is longer than the period of the voltage for moving the drive shaft 28A downward. Similarly, the controller 27 also supplies an ac voltage indicated by the voltage E7 in fig. 10 (B) to the other ultrasonic device 29B. The period of the voltage that moves the drive shaft 28B upward is longer than the period of the voltage that moves the drive shaft 28B downward. That is, the controller 27 supplies the same ac voltage to the two ultrasonic devices 29A and 26B. The control device 27 makes the timing to move one of the drive shafts 28A upward coincide with the timing to move the other drive shaft 28B upward. That is, the controller 27 sets the phase of the voltage supplied to one of the ultrasonic elements 29A and the phase of the voltage supplied to the other ultrasonic element 29A to have the same phase relationship with each other. Therefore, contact portion P1 gradually moves upward at the same distance as contact portion P2. Here, the contact portion P1 is a portion that presses the pressure disc 34 and the rear disc 36 in one of the drive shafts 28A. The contact portion P2 is a portion that is pressed against the pressure disc 34 and the rear disc 36 in the other drive shaft 28B. As a result, contact portions P1 and P2 move upward while maintaining the parallel state. That is, the carriage 26 does not rotate about the center of gravity, but translates upward.

Part (c) of fig. 10 shows an operation of moving the carriage 26 downward. At this time, the controller 27 supplies an ac voltage indicated by a voltage E8 in fig. 10 (c) to one of the ultrasonic elements 29A. The cycle of the voltage that moves the drive shaft 28A upward is shorter than the voltage that moves the drive shaft 28A downward. Similarly, the controller 27 also supplies an ac voltage indicated by the voltage E9 in fig. 10 (c) to the other ultrasonic device 29B. The cycle of the voltage that moves the drive shaft 28B upward is shorter than the cycle of the voltage that moves the drive shaft 28B downward. As a result, the contact portion P1 of one of the drive shafts 28A and the contact portion P2 of the other drive shaft 28B gradually move downward at the same distance. As a result, contact portions P1 and P2 move downward while maintaining the parallel state. That is, the carriage 26 does not rotate about the center of gravity, but translates downward.

According to the above control, when the carriage 26 is moved downward, frictional resistance acts between the carriage 26 and the

drive shafts

28A and 28B. That is, the relative positions of the carriage 26 and the

drive shafts

28A and 28B do not change. Thus, the carriage 26 does not rotate about the center of gravity. For example, torque may be generated to rotate the carriage 26 depending on the posture of the welding pin 8 held by the carriage 26. Even in this case, the actuator 13 can move the carriage 26 downward while suppressing the rotation of the carriage 26.

Translation to move carriage 26 up and down may also be accomplished using a linear motor 22A. The actuator 13 of the embodiment has two

linear motors

22A and 22B, and thus can improve the propulsive force as compared with the configuration having one linear motor 22A.

Fig. 11 (a) shows an operation of rotating the carriage 26 in the clockwise direction. At this time, the controller 27 supplies an ac voltage indicated by a voltage E10 in fig. 11 (a) to one of the ultrasonic elements 29A. The cycle of the voltage that moves the drive shaft 28A upward is shorter than the cycle of the voltage that moves the drive shaft 28A downward. On the other hand, the controller 27 supplies an ac voltage indicated by a voltage E11 in fig. 11 (a) to the other ultrasonic device 29B. The period of the voltage that moves the drive shaft 28B upward is longer than the period of the voltage that moves the drive shaft 28B downward. That is, the voltage applied to the ultrasonic wave element 29A is the same as the voltage applied to the ultrasonic wave element 29B. Then, the controller 27 makes the timing to move one of the drive shafts 28A upward and the timing to move the other drive shaft 28B downward coincide with each other. That is, the phase of the voltage supplied to one of the ultrasonic elements 29A is opposite to the phase of the voltage supplied to the other ultrasonic element 29B. Then, the contact portion P1 of one of the drive shafts 28A moves downward, and the contact portion P2 of the other drive shaft 28B moves upward. Contact portions P1 and P2 move in opposite directions to each other. When the movement amounts of these contact portions match, the carriage 26 rotates clockwise while maintaining the position in the Z-axis direction.

Fig. 11 (b) shows an operation of rotating the carriage 26 counterclockwise. At this time, the controller 27 supplies an ac voltage indicated by a voltage E12 in fig. 11 (b) to one of the ultrasonic elements 29A. The period of the voltage for moving the drive shaft 28A upward is longer than the period of the voltage for moving the drive shaft 28A downward. On the other hand, the controller 27 supplies an ac voltage indicated by a voltage E13 in fig. 11 (B) to the other ultrasonic device 29B. The cycle of the voltage that moves the drive shaft 28B upward is shorter than the cycle of the voltage that moves the drive shaft 28B downward. Then, the contact portion P1 of one of the drive shafts 28A moves upward, and the contact portion P2 of the other drive shaft 28B moves downward. That is, the contact portions P1 and P2 move in opposite directions to each other. When the movement amounts of these contact portions match, the carriage 26 rotates counterclockwise while maintaining the position in the Z-axis direction.

< Change action >

Next, a welding pin replacing operation by the welding pin replacing part 9 will be described.

Fig. 12 (a) shows a state immediately before the replacement of the welding pin 8U attached to the ultrasonic horn 7. The wire replacement unit 9 includes, as additional components, not only the wire holding unit 11, the wire guide unit 12, and the actuator 13, but also a wire storage unit (caliper) 39 and a wire collection unit 41. The wire storage portion 39 stores a plurality of replacement wires 8N. The pin collecting unit 41 receives a used welding pin 8U.

Part (a) of fig. 12 shows a state in which wire bonding work is performed by, for example, the welding pin 8U attached to the ultrasonic horn 7. The probe exchanging portion 9 may be retracted to a position not interfering with the wire bonding operation.

Part (b) of fig. 12 shows a state of the first step in the replacement operation. The needle replacing unit 9 rotates the carriage 26 in the clockwise direction by the control device 27. The rotation corresponds to the operation shown in part (a) of fig. 11. By the rotation, the pin holding portion 11 which has been retracted to a position not interfering with the wire bonding operation is positioned below the pin 8U.

Part (a) of fig. 13 shows a state of the second step in the replacement operation. The needle replacing unit 9 moves the carriage 26 upward by the control device 27. The movement corresponds to the operation shown in part (b) of fig. 10. By the movement, the needle holder 11 holds the needle 8U attached to the ultrasonic horn 7.

Part (b) of fig. 13 shows a state of the third step in the replacement operation. The needle replacing unit 9 moves the carriage 26 downward by the control device 27. The movement corresponds to the operation shown in part (c) of fig. 10. By this movement, the welding pin 8U held by the welding pin holder 11 is removed from the ultrasonic welding head 7.

Part (a) of fig. 14 shows a state of the fourth step in the replacement operation. The needle replacing unit 9 rotates the carriage 26 in the clockwise direction by the control device 27. The movement corresponds to the operation shown in part (a) of fig. 11. By the movement, the welding wire 8U held by the welding wire holding part 11 is conveyed to the welding wire collecting part 41. As a result, the bonding wire 8U is collected as a used bonding wire 8U.

Part (b) of fig. 14 shows a state of the fifth step in the replacement operation. The needle replacing unit 9 rotates the carriage 26 counterclockwise by the control device 27. The movement corresponds to the operation shown in part (b) of fig. 11. By the movement, the needle holding portion 11 holds the new needle 8N for replacement.

Part (a) of fig. 15 shows a state of the sixth step in the replacement operation. The needle replacing unit 9 rotates the carriage 26 in the clockwise direction by the control device 27. The movement corresponds to the operation shown in part (a) of fig. 11. By this movement, the new welding pin 8N held by the welding pin holder 11 is positioned below the hole 7h of the ultrasonic horn 7.

Part (b) of fig. 15 shows a state of the seventh step in the replacement operation. The needle replacing unit 9 moves the carriage 26 upward by the control device 27. The movement corresponds to the operation shown in part (b) of fig. 10. By this movement, the new welding pin 8N held by the welding pin holder 11 is inserted into the hole 7h of the ultrasonic horn 7. During the insertion, the displacement of the needle 8N from the needle guide 12 and the displacement of the needle 8N from the hole 7h of the ultrasonic horn 7 are eliminated by the actions of the needle holder 11 and the needle guide 12 shown in fig. 6 and 7. As a result, the bonding pin 8N can be reliably attached to the hole 7 h.

The operation and effects of the actuator 13 and the wire bonding apparatus 1 according to the embodiment will be described below.

The actuator 13 includes a pair of

linear motors

22A, 22B. The forces generated by the

linear motors

22A and 22B are controlled by a control device 27. According to the above configuration, the carriage 26 can be translated by aligning the directions of the forces generated by the pair of

linear motors

22A, 22B. Further, by reversing the directions of the forces generated by the

linear motors

22A and 22B, a torque around the center of gravity can be applied to the carriage 26. As a result, the carriage 26 can be rotated about its center of gravity. Therefore, the actuator 13 can provide a plurality of motions such as translation and rotation to the carriage 26.

The actuator 13 of the present disclosure can perform both translation and rotation. Further, it is not necessary to separately prepare a drive mechanism for only translation and a drive mechanism for only rotation. Therefore, the size of the actuator 13 can be reduced as compared with a configuration in which the translation drive mechanism and the rotation drive mechanism are separately prepared.

Wire bonding apparatus 1 includes a probe exchanging portion 9 having an actuator 13. The actuator 13 may provide both translational and rotational motion to the carriage 26. Therefore, the replacement function of the welding pin 8 can be provided to the wire bonding apparatus 1, and the increase in size of the welding pin replacement portion 9 can be suppressed. Therefore, the wire bonding apparatus 1 can achieve both high functionality and miniaturization.

In wire bonding apparatus 1, bonding pin 8 held by bonding pin holder 11 is inserted into hole 7h while being guided by bonding pin guide 12. Therefore, even if the bonding pin 8 is displaced from the hole 7h, the displacement is corrected by the bonding pin guide portion 12. The pin holding portion 11 includes an upper socket 16 and a flexible portion 10 of a coil spring 17, and holds the position of the welding pin 8 in a relatively displaceable manner with respect to a lower socket 18 fixed to the actuator 13. As a result, even when the pin guide 12 is offset with respect to the hole 7h in addition to the offset of the pin 8 with respect to the hole 7h, the pin 8 can be inserted while changing the posture thereof so as to follow the pin guide 12 and the hole 7 h. Therefore, the new bonding pin 8 can be automatically attached to the wire bonding apparatus 1 without depending on the hand of the operator.

The embodiments of the present invention have been described above, but the present invention is not limited to the embodiments and can be implemented in various forms.

< modification 1 >

In the embodiment, as the first force generating portion and the second force generating portion, an ultrasonic drive motor based on an impact drive method using an inertia rule is exemplified. However, the first force generating portion and the second force generating portion are not limited to the above-described configuration, and a structure capable of generating a force in a predetermined direction may be employed as the first force generating portion and the second force generating portion. For example, linear guides using ball screws (ball screws) may be used as the first and second force generating portions.

< modification 2 >

The bonding pin holding portion may hold the bonding pin 8 in a manner that the posture of the bonding pin 8 can be flexibly changed. Therefore, the structure of the welding pin holding part is not limited. Fig. 16 shows a modified example of the welding pin holding portion 11A.

The needle holder 11A includes a metal pipe (pipe)42, a silicone resin hose (tube)43, and a cap (cap)44 as main components. The duct 42 is cylindrical in shape. The hose 43 is housed inside the duct 42. One end of the duct 42 is closed by a cap 44. One end of the hose 43 is closed by a cap 44. The cover 44 is held by the retainer 14. The upper end 43a (upper end opening edge) of the hose 43 substantially coincides with the upper end 42a of the duct 42. The outer diameter of the hose 43 is smaller than the inner diameter of the pipe 42. That is, a slight gap is formed between the outer peripheral surface of the hose 43 and the inner peripheral surface of the pipe 42. The upper end 43a of the hose 43 holds the tapered surface 8a of the welding pin 8.

The hose 43 of the needle holder 11A has predetermined flexibility. Therefore, the needle holder 11A can allow the posture of the needle 8 to be changed to such an extent as to form a gap between the outer peripheral surface of the tube 43 and the inner peripheral surface of the tube 42. Specifically, the needle holder 11A can tolerate eccentricity and inclination in a direction intersecting the axis 42A of the tube 42.

When the wire holder 11A includes only the tube 43, the tube 43 has insufficient rigidity, and therefore the wire 8 may not be held depending on the posture of the wire 8. On the outside of the hose 43, however, there is a tube 42 which is more rigid than the hose 43. Therefore, even in the case where the rigidity of the hose 43 is insufficient, the displacement of the welding pin 8 can be limited to the allowable range by the tube 42.

In a state where the welding pin 8 is inserted into the tube 43, the contact state between the inner peripheral edge of the upper end 43a and the tapered surface 8a is line contact. Therefore, the welding pin 8 can also be held obliquely, as in the welding pin holding portion 11A of the present disclosure.

Description of the symbols

1: wire bonding device

2: substrate

3: joint part

4: conveying part

6: joining tool

7: ultrasonic welding head

7 h: hole(s)

8: welding pin

8 a: conical surface

8 b: welding needle body

9: welding needle replacing part

11: welding needle holding part

12: welding needle guide part

12 h: guide hole

12 t: taper hole part

12 p: parallel hole part

13: actuator

14: holding device

16: upper socket

16 c: countersunk hole part

16 d: step difference

16 e: small diameter part

16 h: through hole

17: coil spring

18: lower socket

18 d: step difference

18 e: small diameter part

18 f: large diameter part

19: o-shaped ring

21: actuator substrate (base)

22A: linear motor (first force generating part)

22B: linear motor (second force generating part)

24: linear guide

26: sliding rack

27: control device (control part)

28A, 28B: drive shaft

29A, 29B: ultrasonic device

31. 32: guide piece

33: front disc

34: pressurizing disc

36: rear disc

37. 38: shaft body

39: welding needle storage part

41: welding pin recovery part

G1, G2: gap

P1, P2, C1, C2: contact part

Claims

1. An actuator, comprising:

a first force generating unit that generates a force in a positive direction along a first direction and a force in a negative direction opposite to the positive direction along the first direction;

a second force generating unit that is disposed apart from the first force generating unit in a second direction orthogonal to the first direction and generates a force in the positive direction and a force in the negative direction;

a control unit for controlling the direction and magnitude of the forces generated by the first force generating unit and the second force generating unit; and

a movable body which is erected on the first force generating portion and the second force generating portion,

the control portion makes the moving body translate in the first direction by making a direction of the force generated by the first force generating portion coincide with a direction of the force generated by the second force generating portion,

the first force generating portion generates a force in a direction opposite to a direction of the force generated by the second force generating portion, and the first force generating portion rotates around the center of gravity of the movable body.

2. The actuator according to claim 1, wherein the first force generating portion and the second force generating portion are arranged along the second direction with a center of gravity of the moving body interposed therebetween.

3. The actuator according to claim 1 or 2, wherein the first force generating portion and the second force generating portion have:

an ultrasonic wave generating unit connected to the control unit and controlled by the control unit; and

and a drive shaft extending in the first direction, having a contact portion that contacts the moving body, and fixed to the ultrasonic wave generating portion to be subjected to ultrasonic vibration generated by the ultrasonic wave generating portion.

4. The actuator according to claim 3, wherein the moving body has a main surface and a back surface,

one of the main surface and the back surface includes the contact portion.

5. A wire bonding apparatus comprising:

a bonding tool configured to detachably hold a welding pin; and

a welding pin replacing portion for mounting or dismounting the welding pin relative to the jointing tool,

the welding pin replacing portion has the actuator according to any one of claims 1 to 4.