CN111656502B

CN111656502B - Actuator and wire bonding apparatus

Info

Publication number: CN111656502B
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: 2023-05-26
Anticipated expiration: 2039-01-30
Also published as: KR20200103820A; TW201939627A; WO2019151340A1; JP7002148B2; TWI722376B; KR102420211B1; CN111656502A; JPWO2019151340A1

Abstract

The invention provides an actuator capable of performing a plurality of operations and a wire bonding apparatus. The actuator (13) comprises: 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, 22B); and a carriage (26) mounted on the pair of linear motors (22A, 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 apparatus

Technical Field

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

Background

Patent document 1 discloses a wire bonding apparatus. The wire bonding apparatus has a bonding needle (soldering) as a bonding tool. The wire bonding apparatus applies heat, ultrasonic vibration, or the like to the wire using the bonding needle, thereby connecting the wire to the electrode.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication 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, the operation of the manufacturing apparatus is accompanied by movement of the workpiece to be processed and movement of the tool relative to the workpiece to be processed. Accordingly, the manufacturing apparatus requires actuators for achieving the movement pattern required for each of the processed parts and tools.

In the field of manufacturing devices, high functionality is being studied. The required mobility pattern increases due to the high functionalization. Furthermore, the required movement pattern is complicated. As a result, it is necessary to prepare actuators for each moving pattern, and therefore the number of actuators increases each time the moving pattern increases.

Accordingly, in view of the above, the present disclosure provides an actuator and a wire bonding apparatus that can perform a plurality of actions.

Technical 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 unit for controlling the direction and magnitude of the force generated by the first force generating unit and the second force generating unit; and a moving body which is arranged on the first force generating part and the second force generating part in an erecting way, wherein the control part enables the moving body to translate along the first direction by enabling the direction of the force generated by the first force generating part to be consistent with the direction of the force generated by the second force generating part, and enables the direction of the force generated by the first force generating part to be opposite to the direction of the force generated by the second force generating part, so as to rotate around the gravity center of the moving body.

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 the control unit. According to the above configuration, the moving body can be moved in the first direction by making the orientations of the forces generated in the first force generating portion and the second force generating portion uniform. 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 around its center of gravity. As a result, the actuator can provide a plurality of movements such as translation in the first direction and rotation around the center of gravity to the moving body.

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 moving body interposed therebetween. According to the above structure, the movable body can be rotated with high efficiency.

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 driving shaft extending in the first direction, having a contact portion contacting the moving body, and being fixed to the ultrasonic wave generating portion to receive ultrasonic 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 friction force of the contact portion. The friction force can be controlled by the frequency of the ultrasonic waves. According to the above structure, the first force generating portion and the second force generating portion can be simplified in structure.

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

Another aspect of the present invention provides a wire bonding apparatus comprising: a bonding tool for detachably holding the bonding wire; and a needle replacing part for installing or detaching the needle to or from the bonding tool, the needle replacing part having the actuator. The wire bonding apparatus includes a wire replacement unit including the actuator. The actuator may perform both translational and rotational actions. Therefore, the wire bonding apparatus can be provided with a replacement function for the bonding wire, and the size of the bonding wire replacement part can be prevented from increasing. Therefore, the wire bonding apparatus can be made to have both high functionality and small size.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, an actuator capable of performing a plurality of actions and a wire bonding apparatus 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 showing a wire bonding apparatus of fig. 1 having a wire replacement portion.

Fig. 3 is a perspective view showing a part of the holding portion of the bonding wire in cross section.

Fig. 4 is a diagram illustrating an operation of the pin holder.

Fig. 5 is a perspective view showing a part of the wire guide in cross section.

Fig. 6 is a diagram showing the guiding function of the needle by the needle holding portion and the needle guiding portion.

Fig. 7 is a view showing another guiding function of the needle by the needle holding portion and the needle guiding portion.

Fig. 8 is a plan view showing a main part of the actuator provided in the needle replacing portion 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 diagram showing main operations of the needle replacing section.

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

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

Fig. 15 is a diagram showing main operations of the needle changing portion subsequent to fig. 14.

Fig. 16 is a perspective view showing a cross section of a modified example of the pin holder.

Description of the reference numerals

1: wire bonding device

2: substrate

3: joint part

4: conveying part

6: bonding tool

7: ultrasonic welding head

7h: hole(s)

8: welding needle

8a: conical surface

8b: welding needle body

9: welding needle replacement part

11: welding needle holding part

12: welding needle guiding part

12h: guide hole

12t: taper hole part

12p: parallel hole part

13: actuator with a spring

14: holder for holding articles

16: upper socket

16c: countersink portion

16d: step difference

16e: small diameter portion

16h: through hole

17: coil spring

18: lower socket

18d: step difference

18e: small diameter portion

18f: large diameter part

19: o-ring

21: actuator base (base part)

22A: linear motor (first force generating part)

22B: linear motor (second force generating part)

24: linear guide

26: sliding frame

27: control device (control part)

28A, 28B: driving 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 needle recovery part

G1, G2: gap of

P1, P2, C1, C2: contact portion

Detailed Description

Hereinafter, the actuator and wire bonding apparatus of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same members are denoted by the same reference numerals, and duplicate description thereof 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, for example, using a metal wire having a small diameter. 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 portion 3, and a conveying portion 4. The joint 3 performs the above-described connection operation. The conveying unit 4 conveys a printed board or the like as a part to be processed to the bonding area.

The joint 3 includes a joint tool 6, and an ultrasonic horn 7 is provided at the tip of the joint tool 6. A needle 8 is detachably provided at the tip of the ultrasonic horn 7. The bonding pins 8 provide heat, ultrasonic or pressure to the wire bond.

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 board is conveyed by the conveying unit 4 is referred to as the Y axis (second direction). The direction in which the bonding needle 8 moves during the bonding operation (Z-axis direction, first direction) is referred to as Z-axis.

The pins 8 need to be replaced regularly. Therefore, the wire bonding apparatus 1 has the wire replacement part 9. The needle replacing unit 9 automatically replaces the needle 8 without an operator's operation.

The needle replacing unit 9 recovers the needle 8 attached to the ultrasonic horn 7. Furthermore, the needle replacing unit 9 mounts the needle 8 to the ultrasonic horn 7. The replacement work of the needle 8 includes work of recovering the needle 8 and work of attaching the needle 8. The replacement operation of the bonding wire 8 is automatically performed when a predetermined condition is satisfied. For example, the condition may be set to the number of joining operations. That is, the work of replacing the needle 8 may be performed every time the bonding work is performed a predetermined number of times.

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

< welding needle holding portion >)

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

As shown in fig. 3, the pin holder 11 has an upper socket 16, a coil spring 17 (elastic portion), a lower socket 18 (pin base portion), and an O-ring 19 (restriction portion) as main structural members. The upper socket 16, the coil spring 17, and the lower socket 18 are disposed on a common axis. Specifically, the upper socket 16, the coil spring 17, and the lower socket 18 are arranged in this order from top to bottom.

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

The O-ring 19 is a so-called circular ring (torus). The O-ring 19 is in direct contact with the tapered surface 8a of the pin 8. Namely, the O-ring 19 of the pin holding portion 11 holds the pin 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 16h. The tapered surface 8a of the needle 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 end face 16a side of the upper socket 16 is different from the outer diameter of the lower end face 16b side of the upper socket 16. Specifically, the outer diameter of the lower end face 16b side is slightly smaller than the outer diameter of the upper end face 16a side. A coil spring 17 is fitted into the small diameter portion 16e on the lower end face 16b side.

The lower socket 18 is generally cylindrical in shape. The upper end surface 18a of the lower receptacle 18 faces upward toward the lower end surface 16b of the receptacle 16. The shape of the lower socket 18 is the same as the shape of the upper socket 16. A step 18d is provided on the outer peripheral surface of the lower socket 18. The upper end surface 18a side of the lower receptacle 18 is a small diameter portion 18e opposite to the upper receptacle 16. A coil spring 17 is fitted into the small diameter portion 18e on the upper end surface 18a side. The large diameter portion 18f of the lower socket 18 on the lower end surface 18b side 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 connected 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 upper receptacle 16 can change the relative position with respect to the lower receptacle 18.

The pin holder 11 having the above-described structure has the holding pattern shown in fig. 4. Part (a) of fig. 4 shows the initial-stage needle holding part 11. Part (b) of fig. 4 shows the first modified form of the pin holder 11. Part (c) of fig. 4 shows a second modified form of the needle holding part 11.

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

axes

16A and 18A.

As shown in fig. 4 (b), in the pin holding portion 11 of the second holding pattern, the axis 16A of the upper socket 16 is not overlapped with the axis 18A of the lower socket 18. Specifically, the lower receptacle 18 is held in place by the holder 14. 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 fig. 4 (c), in the third modified pin holder 11, the axis 16A of the upper socket 16 overlaps the axis 18A of the lower socket 18. I.e. their structure is identical to the first holding pattern. On the other hand, the axis 8A of the 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 needle 8 is inserted is curved. For example, the cross-sectional shape of the O-ring 19 in a cross-section parallel to the Z-axis is a circle. When the tapered surface 8a is inserted into the O-ring 19 in cross section, the O-ring 19 contacts the tapered surface 8a at two contact portions C1 and C2. That is, the contact pattern between the O-ring 19 and the needle 8 is a line contact that contacts on an annular contact line CL (see fig. 3). According to this contact state, the welding needle 8 is allowed to tilt with respect to the axis 19A of the O-ring 19.

< welding needle guide >)

As shown in fig. 2 again, 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 pin guide 12 is provided in the actuator 13. Therefore, the relative positional relationship between the pin guide 12 and the component constituting the actuator 13 is maintained. The needle guide 12 is a single-arm beam extending from the actuator 13 toward the ultrasonic horn 7.

Fig. 5 is a perspective view showing a main portion of the needle guide 12 in cross section. As shown in fig. 5, a guide hole 12h is provided at the free end of the needle guide 12. The guide hole 12h receives the pin body 8b of the pin 8. The guide hole 12h guides the needle 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 wire guide 12. The guide hole 12h is also opened at the distal end face 12c of the pin guide 12. The guide hole 12h receives the bonding wire 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 12p. The lower end of the taper hole portion 12t opens at the lower surface 12b. The upper end of the parallel hole portion 12p opens on the upper surface 12 a. The inner diameter of the tapered 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 taper hole 12t and the parallel hole 12p. The inner diameter is approximately the same as the outer diameter of the upper end of the pin 8. The parallel hole 12p has a constant inner diameter.

Fig. 6 shows a state in which the needle 8 is guided by the needle guide 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 needle 8 held by the needle holding portion 11 is offset in parallel in the X-axis direction with respect to the

axes

7A and 12A.

The needle holder 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 pin 8 contacts the wall surface of the taper hole 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 pin holder 11 is movable relative to the upper socket 16 by a coil spring 17. That is, when the lower receptacle 18 is moved upward, the upper receptacle 16 is moved upward and also moved in the horizontal direction by the coil spring 17.

According to this movement, the axis 8A of the welding needle 8 gradually approaches the axis 7A of the hole 7h. When the upper end of the needle 8 reaches the parallel hole 12p, the axis 8A of the needle 8 overlaps the axis 7A of the hole 7h. Thus, the needle 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 needle 8 in the state shown in fig. 7 (b) will be described. As shown in fig. 7 (b), the axis 8A of the needle 8 is inclined with respect to the axis 7A of the hole 7h. In this state, the upper end of the bonding wire 8 is in contact with the wall surface of the hole 7h. Therefore, the bonding wire 8 cannot be inserted into the hole 7h more. In order to insert the pin 8 into the hole 7h, it is necessary to make the axis 8A of the pin 8 parallel with respect to the axis 7A of the hole 7h. Further, the axis 8A is superimposed on the axis 7A.

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

Actuator

The actuator 13 moves the needle 8 to be replaced or the new needle 8. The actuator 13 holds the needle 8 at a predetermined position and posture. The actuator 13 is reciprocally movable along a predetermined translation axis (Z axis) direction. In the present embodiment, the translation axis is along the vertical direction (Z axis). Accordingly, the actuator 13 moves the bonding needle 8 upward and downward in the vertical direction. Further, the actuator 13 rotates the bonding needle 8 about the rotation axis (X axis). In the present embodiment, the rotation axis is orthogonal to the vertical direction (Z axis). That is, the rotation axis is along the horizontal direction (X axis). Thus, the actuator 13 rotates the welding pin 8 around the horizontal direction.

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

linear motors

22A, 22B (first force generating portion, second force generating portion), 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 in the shape of a flat plate. The actuator base 21 has a main face 21a. The normal direction of the main surface 21a is along the horizontal direction (X-axis direction). The linear motor 22A, the linear motor 22B, the linear guide 24, and the carriage 26 are disposed on the main surface 21a.

The linear motor 22A moves the carriage 26. The linear motor 22A is an ultrasonic motor based on the so-called impact drive (impact drive) principle. The linear motor 22A has a drive shaft 28A and an ultrasonic element 29A (ultrasonic wave generating unit). The drive shaft 28A is a metal round bar. The axis of the drive shaft 28A is parallel 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 base 21. The upper end of the drive shaft 28A may be fixed with respect 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 slightly vibrates along the Z-axis. The ultrasonic element 29A may be a piezoelectric (piezo) element as the piezoelectric element, for example. The piezoelectric element deforms according to the applied voltage. Therefore, when a high-frequency voltage is applied to the piezoelectric element, the piezoelectric element repeatedly deforms 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 element 29A is electrically connected to a control device 27. The ultrasonic element 29A receives 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 element 29A.

The linear motor 22B has the same single structure as 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 motor 22A and the linear motor 22B. The carriage 26 is in the shape of a disk. The carriage 26 is installed 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 a driving force in the Z-axis direction to the carriage 26.

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

The rear disk 36 is coupled to the platform 24a of the linear guide 24. The platform 24a is located on a bracket 24b of the linear guide 24. The rear disk 36 is rotatably coupled with respect to the platform 24a. 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 relative to the rear disk 36. Thus, the carriage 26, including the front disk 33, the pressing disk 34, and the rear disk 36, is generally rotatable relative to the platform 24a of the linear guide 24.

As shown in fig. 8, the

drive shafts

28A, 28B are sandwiched in the gap G1 between the pressing disk 34 and the rear disk 36. A pair of

drive shafts

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

drive shafts

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

drive shafts

28A, 28B do not contact the outer peripheral surface 38A of the shaft body 38. The gap G1 has an outer diameter smaller than the outer diameters of the pressing disk 34 and the rear disk 36. The outer diameter of the gap G1 is larger than the outer diameter of the shaft 38. The difference between the outer diameter of the shaft 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. Likewise, 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 slightly smaller than the outer diameter of the drive shaft 28A and the outer diameter of the drive shaft 28B. A gap G2 is formed between the front disk 33 and the pressing disk 34. As a result, when the

drive shafts

28A, 28B are arranged between the pressing disk 34 and the rear disk 36, the pressing disk 34 is slightly deflected toward the front disk 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. Fig. 9 (a), fig. 9 (b) and fig. 9 (c) 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 the other linear motor 22B and the like are omitted.

Part (a) of fig. 9 shows a state in which 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 the pressurization caused by the sandwiching. More specifically, the position of the carriage 26 is maintained by frictional resistance with pressurization as a vertical abutment force. The control device 27 does not supply a voltage to the ultrasonic element 29A. That is, as shown by voltage E1, the voltage value is zero. The control device 27 may supply a dc current having a predetermined voltage value to the ultrasonic element 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 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 pattern of moving the drive shaft 28A is selected to be either the first pattern or the second pattern depending on the speed at which the drive shaft 28A is moved. The speed at which the drive shaft 28A is moved is related to the frequency of the ultrasonic vibrations. Thus, the pattern of moving the drive shaft 28A is selected to be either the first pattern or the second pattern depending on the frequency of the ultrasonic vibration. For example, when the frequency of the ultrasonic vibration is a relatively low frequency (15 kHz to 30 kHz), the carriage 26 moves along with the drive shaft 28A. For example, when the frequency of the ultrasonic vibration is a relatively high frequency (100 kHz to 150 kHz), the carriage 26 maintains its position without accompanying 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 not to correspond 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.

Conversely, as shown in fig. 9 (c), when the drive shaft 28A is moved downward, the carriage 26 is moved in response to 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 so as not to correspond 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, the carriage 26 may not correspond to both the upward movement and the downward movement of the drive shaft 28A, in addition to the control. That is, on the surface, the frictional resistance acting between the carriage 26 and the drive shaft 28A is smaller than the gravitational force acting on the carriage 26. As a result, it appears that the carriage 26 falls. In this aspect, gravity 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 control device 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).

Part (b) of fig. 10 shows an operation of moving the carriage 26 upward. At this time, the control device 27 supplies an ac voltage indicated by a voltage E6 in part (b) of fig. 10 to one of the ultrasonic elements 29A. The period of the voltage that moves the drive shaft 28A upward is longer than the period of the voltage that moves the drive shaft 28A downward. Similarly, the control device 27 supplies an ac voltage indicated by a voltage E7 in part (B) of fig. 10 to the other ultrasonic element 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 control device 27 supplies the same ac voltage to the two

ultrasonic elements

29A and 29B. The control device 27 matches the timing of moving one of the drive shafts 28A upward with the timing of moving the other drive shaft 28B upward. That is, the control device 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 29B to have the same phase relationship with each other. Therefore, the contact portion P1 and the contact portion P2 gradually move upward at the same distance. Here, the contact portion P1 is a portion pressed against the pressing disk 34 and the rear disk 36 in one of the drive shafts 28A. The contact portion P2 is a portion pressed against the pressing disk 34 and the rear disk 36 in the other drive shaft 28B. As a result, the 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 control device 27 supplies an ac voltage indicated by a voltage E8 in part (c) of fig. 10 to one of the ultrasonic elements 29A. The period of the voltage that moves the drive shaft 28A upward is shorter than the voltage that moves the drive shaft 28A downward. Similarly, the control device 27 supplies an ac voltage indicated by a voltage E9 in the section (c) of fig. 10 to the other ultrasonic element 29B. The period of the voltage that moves the drive shaft 28B upward is shorter than the period of the voltage that moves the drive shaft 28B downward. As a result, the contact portion P1 in one of the drive shafts 28A gradually moves downward at the same distance from the contact portion P2 in the other drive shaft 28B. As a result, the 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 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, 28B are not changed. Thus, the carriage 26 does not rotate about the center of gravity. For example, a torque may be generated to rotate the carriage 26 due to the posture of the needle 8 held by the carriage 26. Even in this case, the actuator 13 can move the carriage 26 downward in a state in which the rotation of the carriage 26 is suppressed.

Translation of the 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, 22B, and thus can improve the propulsive force as compared with a structure having one linear motor 22A.

Part (a) of fig. 11 shows an operation of rotating the carriage 26 in the clockwise direction. At this time, the control device 27 supplies an ac voltage indicated by a voltage E10 in part (a) of fig. 11 to one of the ultrasonic elements 29A. The period of the voltage that moves the drive shaft 28A upward is shorter than the period of the voltage that moves the drive shaft 28A downward. On the other hand, the control device 27 supplies the other ultrasonic element 29B with an ac voltage indicated by the voltage E11 in the section (a) of fig. 11. 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 supplied to the ultrasonic element 29A is the same as the voltage supplied to the ultrasonic element 29B. The control device 27 sets the timing of moving one of the drive shafts 28A upward to the timing of moving the other drive shaft 28B downward. 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. The contact portions P1 and P2 move in opposite directions to each other. When the movement amounts of the contact portions are equal, the carriage 26 rotates clockwise while maintaining the position in the Z-axis direction.

Part (b) of fig. 11 shows an operation of rotating the carriage 26 in the counterclockwise direction. At this time, the control device 27 supplies an ac voltage indicated by a voltage E12 in part (b) of fig. 11 to one of the ultrasonic elements 29A. The period of the voltage that moves the drive shaft 28A upward is longer than the period of the voltage that moves the drive shaft 28A downward. On the other hand, the control device 27 supplies the other ultrasonic element 29B with an ac voltage indicated by the voltage E13 in the section (B) of fig. 11. The period of the voltage that moves the drive shaft 28B upward is shorter than the period 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 the contact portions are equal, the carriage 26 rotates counterclockwise while maintaining the position in the Z-axis direction.

< exchange action >

Next, the needle replacement operation by the needle replacement unit 9 will be described.

Fig. 12 (a) shows a state immediately before the replacement of the needle 8U attached to the ultrasonic horn 7. The needle replacing portion 9 includes not only the needle holding portion 11, the needle guiding portion 12, and the actuator 13, but also a needle storing portion (capillary stocker) 39 and a needle recovering portion 41 as additional structural members. The pin storage unit 39 stores a plurality of replacement pins 8N. The needle recovery unit 41 accommodates the used needle 8U.

Fig. 12 (a) shows a state in which wire bonding is performed by, for example, a wire 8U attached to the ultrasonic horn 7. The wire replacement part 9 may be retracted to a position where it does not interfere with the wire bonding operation.

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

Part (a) of fig. 13 shows a state of the second step in the replacement operation. The needle changing unit 9 moves the carriage 26 upward by the control device 27. The movement corresponds to the operation shown in fig. 10 (b). By this 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 changing unit 9 moves the carriage 26 downward by the control device 27. The movement corresponds to the operation shown in fig. 10 (c). By this movement, the needle 8U held by the needle holding portion 11 is removed from the ultrasonic horn 7.

Part (a) of fig. 14 shows a state of the fourth step in the replacement operation. The needle changing unit 9 rotates the carriage 26 clockwise by the control device 27. The movement corresponds to the operation shown in fig. 11 (a). By this movement, the needle 8U held by the needle holding portion 11 is transported to the needle recovery portion 41. As a result, the pins 8U are recovered as used pins 8U.

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

Part (a) of fig. 15 shows a state of the sixth step in the replacement operation. The needle changing unit 9 rotates the carriage 26 clockwise by the control device 27. The movement corresponds to the operation shown in fig. 11 (a). By this movement, the new needle 8N held by the needle holding portion 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 changing unit 9 moves the carriage 26 upward by the control device 27. The movement corresponds to the operation shown in fig. 10 (b). By this movement, the new needle 8N held by the needle holding portion 11 is inserted into the hole 7h of the ultrasonic horn 7. During the insertion, the pin 8N and the pin guide 12 are offset and the pin 8N and the hole 7h of the ultrasonic horn 7 are offset by the pin holding portion 11 and the pin guide 12 shown in fig. 6 and 7. As a result, the bonding wire 8N can be reliably attached to the hole 7h.

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 force generated by each of the

linear motors

22A and 22B is controlled by the control device 27. According to the above configuration, the carriage 26 can be translated by aligning the orientations 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 provided to the carriage 26. As a result, the carriage 26 can be rotated about its center of gravity. Thus, the actuator 13 can provide a plurality of movements, such as translation and rotation, to the carriage 26.

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

The wire bonding apparatus 1 includes a wire replacement part 9 including an actuator 13. The actuator 13 may provide both translational and rotational motion to the carriage 26. Therefore, the wire bonding apparatus 1 can be provided with the replacement function of the bonding wire 8, and the bonding wire replacement part 9 can be prevented from being enlarged. Therefore, the wire bonding apparatus 1 can be made both highly functional and compact.

In the wire bonding apparatus 1, the wire 8 held by the wire holding portion 11 is inserted into the hole 7h while being guided by the wire guiding portion 12. Therefore, even if the pin 8 is offset with respect to the hole 7h, the offset is corrected by the pin guide 12. The position of the needle 8 is held in a relatively displaceable manner with respect to the lower socket 18 fixed to the actuator 13, the needle holding portion 11 including the upper socket 16 and the flexible portion 10 of the coil spring 17. As a result, even when the needle guide 12 is offset from the hole 7h in addition to the offset of the needle 8 from the hole 7h, the needle 8 can be inserted while changing the posture of the needle 8 so that the needle guide 12 and the hole 7h are followed by the needle 8. Therefore, the new bonding wire 8 can be automatically mounted on 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 above embodiments and can be implemented in various forms.

Modification 1 >

In the embodiment, an ultrasonic drive motor based on the impact drive system using the principle of inertia is exemplified as the first force generating unit and the second force generating unit. However, the first force generating portion and the second force generating portion are not limited to the above-described structure, and a structure that may generate 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 force generating portion and the second force generating portion.

Modification 2 >

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

The needle holder 11A has a metal pipe (pipe) 42, a silicone resin hose (tube) 43, and a cap (cap) 44 as main structural members. The duct 42 is cylindrical in shape. A hose 43 is housed inside the duct 42. One end of the conduit 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 holder 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 retains the tapered surface 8a of the welding pin 8.

The hose 43 of the needle holder 11A has a predetermined flexibility. Therefore, the needle holding portion 11A can allow the posture of the needle 8 to be changed to the extent of the gap formed between the outer peripheral surface of the hose 43 and the inner peripheral surface of the pipe 42. Specifically, the pin holder 11A can accommodate decentration and tilting in a direction intersecting the axis 42A of the pipe 42.

When the needle holding portion 11A includes only the hose 43, the rigidity of the hose 43 is insufficient, and thus the needle 8 may not be held depending on the posture of the needle 8. However, on the outside of the hose 43, there is a pipe 42 that is stiffer than the hose 43. Therefore, even in the case where the rigidity of the hose 43 is insufficient, the displacement of the welding needle 8 can be limited to the allowable range through the pipe 42.

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

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 configured to control the direction and magnitude of the force generated by the first force generating unit and the second force generating unit; and

a moving body which is arranged on the first force generating part and the second force generating part,

the control section translates the moving body in the first direction by making the direction of the force generated by the first force generating section coincide with the direction of the force generated by the second force generating section,

rotating around the center of gravity of the moving body by reversing the direction of the force generated by the first force generating part relative to the direction of the force generated by the second force generating part, and

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

A driving shaft extending in the first direction, having a contact portion that contacts the moving body, and being fixed to the ultrasonic wave generating portion to receive ultrasonic vibration generated by the ultrasonic wave generating portion.

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

3. The actuator according to claim 1, wherein the moving body has a main surface and a rear surface,

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

4. A wire bonding apparatus, comprising:

a bonding tool for detachably holding the bonding wire; and

A welding needle replacing part for installing or detaching the welding needle relative to the jointing tool,

the welding needle replacing portion has the actuator as defined in any one of claims 1 to 3.