TWI736833B - Wire bonding device - Google Patents

Abstract

The present invention provides a wire bonding device that can correct the pressing load of a bonding tool while realizing an increase in productivity. The wire bonding device includes a bonding tool that presses the bonding side to the electrode while bonding in a predetermined bonding area, and includes: a driving source to drive the bonding tool in the vertical direction; a control part connected to the driving source to control the pressing of the bonding tool Load; the elastic part is arranged on the outside of the joint area and generates strain due to the pressing load; the acquisition part acquires the strain of the elastic part; and the correction part, based on the acquisition result of the acquisition part, uses the preset target value of the pressing load and pressing When the load error of the actual measurement value of the load falls within a predetermined range, the correction process of the control unit is performed.

Description

Wire bonding device

The present invention relates to a wire bonding device.

The following wire bonding device is known, which includes a bonding tool (bonding tool) that presses the wire to the electrode while bonding in a predetermined bonding area, a drive source that drives the bonding tool in the vertical direction, and is connected to the drive source And the control part which controls the pressing load of a bonding tool (for example, refer patent document 1).

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 10-284532

Generally speaking, in the wire bonding device, for example, the pressing load of the bonding tool may change with time due to continuous operation for a certain period of time. Therefore, in the wire bonding device, in order to maintain an appropriate pressing load, the pressing load of the bonding tool is periodically corrected.

In the past, for example, in a state where the wire bonding device is stopped, a load cell installed in the bonding area is used, and an operator performs a work of calibrating the pressing load of the bonding tool. In this calibration operation, as the wire bonding While the joining device is stopped, at least the time required for the installation and removal of the load cell and the time required for the operator to calibrate the pressing load are required. As a result, the productivity of the wire bonding device is reduced due to calibration work.

Therefore, an object of the present invention is to provide a wire bonding device that can correct the pressing load of a bonding tool while achieving an improvement in productivity.

The wire bonding device of one aspect of the present invention includes a bonding tool that presses the wire to the electrode while bonding in a predetermined bonding area, and the wire bonding device includes a driving source for driving the bonding tool in the up-down direction; a control part , Connected to the driving source to control the pressing load of the bonding tool; the elastic part is arranged outside the joint area and strain is generated due to the pressing load; the acquisition part acquires the strain of the elastic part; and the correction part, based on the acquisition result of the acquisition part, The correction process of the control unit is performed so that the load error between the preset target value of the pressing load and the actual measured value of the pressing load falls within a predetermined range.

In the wire bonding device of one aspect of the present invention, a bonding tool is used to press the elastic portion to generate strain. Based on the acquisition result of the strain of the elastic portion acquired by the acquisition unit, the correction unit performs the correction processing of the control unit so that the load error between the preset target value of the pressing load and the actual measurement value of the pressing load falls within a predetermined range. According to this wire bonding device, the elastic portion is arranged outside the bonding area. Therefore, compared with the case where a load cell is installed in the bonding area, for example, the stop time of the wire bonding device for performing the calibration process becomes shorter, and the operation of the wire bonding device Time increases. As a result, the pressing load of the bonding tool can be performed while the productivity is improved. Heavy correction.

In the wire bonding device of one aspect of the present invention, the calibration process may also include: actual measurement process, based on the first strain of the elastic part in the non-pressing state where the bonding tool does not press the elastic part, and pressing the load by the control part When the control is performed so that the target value is reached, the bonding tool presses the second strain of the elastic part in the pressed state with the pressing load to calculate the actual measured value of the pressing load; comparison processing is based on the calculated actual measured value of the pressing load And press the target value of the load to calculate the load error, and compare the load error with the preset load threshold; and correction processing, when the load error is greater than the load threshold, change the control so that the load error becomes smaller For the control data of the drive source in the part, the correction part repeatedly performs actual measurement processing, comparison processing and correction processing until the load error becomes less than the load threshold. In this case, the actual measurement value of the pressing load is calculated from the second strain in the pressing state based on the first strain in the non-pressing state, so it is the same as the case where the actual measurement value of the pressing load is calculated based on the displacement of the elastic part, for example. In comparison, the benchmark is not easy to deviate. As a result, the actual measurement value of the pressing load can be calculated with high accuracy. Therefore, the correction processing can be performed accurately.

In the wire bonding device of one aspect of the present invention, the elastic portion may be a leaf spring supported in a single-arm beam shape, and the acquisition portion may include a first strain gauge, And a second strain gauge arranged on the lower surface of the leaf spring. In this case, the space saving of the wire bonding device can be realized with a small and simple structure. In addition, the first strain gauge and the second strain gauge are provided on both surfaces of the leaf spring, so that the expansion and contraction strain of the leaf spring due to temperature changes is offset. Take this, even if not waiting The temperature of the bonding area of the bonding device to be bonded is lowered, and correction processing can also be implemented. Therefore, the continuous operation of the wire bonding device can be realized, and the productivity can be further improved.

In the wire bonding device of one aspect of the present invention, the elastic portion may be a beam material that is supported in a single-arm beam shape and is sandwiched between one end and the other end in the longitudinal direction. In the section, a low-rigidity section with lower rigidity than one end and the other end is provided, and the acquisition section includes a third strain gauge provided on the upper and lower surfaces of one end of the beam, and a third strain gauge provided on the beam The other end of the upper surface and the lower surface of the fourth strain gauge. In this case, a low-rigidity part is provided in the middle part, so the strain of the elastic part increases at the boundary part between the one end part and the middle part and the boundary part between the other end part and the middle part. This situation can be used to obtain the strain of the beam with good sensitivity. In addition, the third strain gauge and the fourth strain gauge are provided on both sides of the beam, so that the expansion and contraction strain of the beam due to temperature changes is offset. Thereby, even if it does not wait for the temperature of the bonding area|region of the wire bonding apparatus to fall, correction processing can be implemented. Therefore, the continuous operation of the wire bonding device can be realized, and the productivity can be further improved.

According to the wire bonding device of the present invention, it is possible to provide a wire bonding device capable of correcting the pressing load of the bonding tool while realizing an increase in productivity.

10: Frame

11: XY platform

12: Joint head

13: Joint arm

13a: recess

14: Ultrasonic welding head

14a: Ultrasonic vibrator

14b, 26: flange

14c, 25: screw

15: Porcelain nozzle (joining tool)

16: rail

17: heating block

17a: heater

18: substrate

19: Electronic parts

20: Leaf spring assembly

20A, 20B: Elastic part assembly

21: Base

22: Support Desk

25a: pressure plate

27: Screw hole

28: Cover

31: Leaf spring (elastic part)

31a: Base end

31b: Front end

31c, 32c: upper surface

31d, 32d: bottom surface

32: beam material (elastic part)

32a: one end

32b: the other end

32e: middle part

32f: Low rigidity part

33: Columnar body (elastic part)

40: Motor (drive source)

41: Stator

42: Rotor

43: Rotation Center

45: Rotation axis

46, 47: a little chain line

48: motor driver

49: power supply

51: current sensor

52: Angle sensor

53: temperature sensor

54: Strain gauge section (first strain gauge)

54a, 54b, 55a, 55b, 56a, 56b, 57a, 57b, 58, 59: strain gauge

55: Strain gauge section (second strain gauge)

56: Strain gauge section (third strain gauge)

57: Strain gauge section (fourth strain gauge)

60: Microcomputer

61: Control Department

62: Correction Department

100: Wire bonding device

BA: Joint area

CA: movable area of porcelain mouth

P: pressing point

S10~S15, S20~S28: steps

Fig. 1 is a plan view of a wire bonding device according to an embodiment of the present invention.

Fig. 2 is a schematic configuration diagram showing a configuration example of the wire bonding device of Fig. 1.

Fig. 3(a) is a perspective view of the leaf spring assembly of Fig. 1. Fig. 3(b) is a plan view of the leaf spring assembly of Fig. 1. Fig. 3(c) is a side view of the leaf spring assembly of Fig. 1.

Fig. 4(a) is a side view illustrating a non-pressing state of the leaf spring assembly of Figs. 3(a) to 3(c). Fig. 4(b) is a side view illustrating a pressed state of the leaf spring assembly of Figs. 3(a) to 3(c).

Fig. 5 is a flowchart of an example of the operation of the wire bonding device of Fig. 1.

Fig. 6 is a flowchart illustrating correction processing.

Fig. 7(a) is a side view of a modified example of the elastic portion. Fig. 7(b) is a side view illustrating a non-pressed state of the elastic portion of Fig. 7(a). Fig. 7(c) is a side view illustrating a pressed state of the elastic portion of Fig. 7(a).

Fig. 8 is a side view of another modification of the leaf spring assembly.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In addition, in the following description, the same or corresponding components are given the same reference numerals, and repeated descriptions are omitted.

[Constitution of wire bonding device]

Fig. 1 is a plan view of a wire bonding device according to an embodiment of the present invention. As shown in FIG. 1, the wire bonding device 100 of the present embodiment is a device including a porcelain nozzle 15 (bonding tool) that presses the wire to the electrode while bonding in a predetermined bonding area BA. The electrode includes an electrode of an electronic component 19 such as a semiconductor wafer, an electrode of a substrate 18 on which the electronic component 19 is mounted, and the like. Furthermore, in the following description, for convenience, The extending direction of the guide rail 16 is defined as the X direction, the horizontal direction orthogonal to the X direction is defined as the Y direction, and the vertical direction orthogonal to the X direction and the Y direction is defined as the Z direction.

The wire bonding device 100 includes: a frame 10; an XY platform 11 provided on the frame 10; a bonding head 12 provided on the XY platform 11; and a bonding arm 13 provided on the bonding head 12 ; Ultrasonic welding head 14 installed at the front end of the joint arm 13; Porcelain nozzle 15 installed at the front end of the ultrasonic welding head 14; a pair of guide rails 16, guiding the substrate 18 along a predetermined horizontal direction; heating block (heat block) 17. Heating the bonding area BA; the leaf spring assembly 20 for correcting the pressing load of the porcelain nozzle 15; and a microcomputer 60 for controlling the overall action of the wire bonding device 100. The pressing load of the porcelain nozzle 15 is a load that acts on the wire bonding when the porcelain nozzle 15 presses the wire to the electrode (so-called bonding load).

As shown in FIG. 2, a motor (drive source) 40 that drives the bonding arm 13 in the Z direction is provided inside the bonding head 12. The motor 40 is composed of a stator 41 fixed to the bonding head 12 and a rotor 42 that rotates around a rotating shaft 45 extending in the X direction.

The stator 41 of the motor 40 is supplied with drive power from the power source 49. The current value supplied to the stator 41 is detected by the current sensor 51, and the current value is adjusted by the motor driver 48.

The rotor 42 is integrated with the rear part of the joint arm 13, and when the rotor 42 is rotated, the front end of the joint arm 13 is driven to swing in the Z direction. An angle sensor 52 that detects the rotation angle Φ of the rotor 42 is mounted on the rotation shaft 45 of the rotor 42.

The rotation center 43 of the rotation shaft 45 of the rotor 42 (the one-point chain line in FIG. 2 The Z-direction position (height) of the intersection of 46 and the one-point chain line 47 is substantially the same as the Z-direction position of the joint surface (the one-point chain line 47 in FIG. 2). The bonding surface is, for example, an imaginary plane along the upper surface of the electrode of the electronic component 19 when the substrate 18 is located on the heating block 17.

At the front end of the joint arm 13, the flange 14b of the ultrasonic welding head 14 is fixed by a screw 14c. On the lower side surface of the tip portion of the joint arm 13, a recess 13 a for accommodating the ultrasonic transducer 14 a of the ultrasonic horn 14 is provided. A porcelain nozzle 15 is installed at the front end of the ultrasonic welding head 14. Therefore, when the rotor 42 is rotated, the ceramic nozzle 15 swings in the vertical direction in a direction substantially perpendicular to the electrode surface of the electronic component 19 and the upper surface of the leaf spring 31. That is, the motor 40 drives the porcelain nozzle 15 as a joining tool in the vertical direction.

The heating block 17 is installed between a pair of guide rails 16 on the frame 10. One or more heaters 17a are installed in the heating block 17. The heater 17a heats the bonding area BA at a temperature suitable for bonding while pressing the bonding surface against the electrode by the porcelain nozzle 15. In the vicinity of the bonding head 12, a temperature sensor 53 for detecting the representative temperature of the wire bonding device 100 is installed.

The bonding area BA is, for example, a virtual area defined along the XY plane, and is an area on the heating block 17 that can obtain temperature conditions suitable for wire bonding by the heat from the heater 17 a of the heating block 17. The bonding area BA is, for example, an area on a substantially rectangular heating block 17 that is line-symmetric with respect to an imaginary line along the extending direction of the bonding arm 13 in the X direction. The X-direction length of the bonding area BA is, for example, when the substrate 18 is located on the heating block 17, the length of the electronic components 19 arranged along the X-direction is included. At least part of the length. The Y-direction length of the bonding area BA is, for example, a length that includes all the electronic components 19 arranged along the Y-direction when the substrate 18 is located on the heating block 17.

The microcomputer 60 is a central processing unit (CPU) that internally performs calculations or signal processing, and a read-only memory (Read Only Memory, ROM) and random access memory (Random Access Memory, RAM) memory. For the microcomputer 60, at least the detection signals of the current sensor 51, the angle sensor 52, and the temperature sensor 53 are input. For the microcomputer 60, imaging information may also be inputted from a not-shown imaging device or the like.

The microcomputer 60 has a control unit 61 that controls the motor 40 and the XY stage 11 to perform bonding processing (processing for performing bonding operations). The control unit 61 acquires position information of the substrate 18, the electronic component 19, and the electrodes based on the input imaging information. The control unit 61 is based on the detection signals of the current sensor 51, the angle sensor 52, and the temperature sensor 53, the acquired position information, and information on the type of electronic component 19 and the distance between electrodes stored in the memory in advance, etc. , Execute the bonding program stored in the memory, thereby causing the motor 40 and the XY stage 11 to operate.

As the engagement process, specifically, the control unit 61 determines the command value of the current supplied to the stator 41 of the motor 40 and outputs the command value of the current to the motor driver 48. The control unit 61 controls the motor driver 48 so that the current value applied to the stator 41 becomes the command value of the current, and adjusts the current value applied to the stator 41. That is, the control unit 61 utilizes a pressing load corresponding to the applied current (for example, as described later) The target value of the pressing load) The pressing load of the porcelain nozzle 15 is controlled by pressing the bonding wire against the electrode. The control unit 61 vibrates the ultrasonic vibrator 14a in a state where the porcelain nozzle 15 presses the bonding wire against the electrode by the pressing load, and the porcelain nozzle 15 joins the pressed bonding wire to the electrode.

The control unit 61 is also connected to the XY stage 11 (refer to FIGS. 1 and 2 ), and outputs the command value of the position of the porcelain nozzle 15 in the XY direction to the XY stage 11. The control unit 61 outputs the command value of the position to the XY stage 11 so that the position of the ceramic nozzle 15 in the XY direction becomes the inside of the ceramic nozzle movable area CA (refer to FIG. 1 ). The control unit 61 drives the XY stage 11 so that the position of the ceramic nozzle 15 in the XY direction becomes the instructed position, and adjusts the position of the ceramic nozzle 15 in the XY direction.

The ceramic nozzle movable area CA is, for example, an imaginary area defined along the joining area BA, which is a wider area than the joining area BA. Compared with the bonding area BA, the movable area CA of the porcelain nozzle extends more widely at least toward the bonding head 12 side of the heating block 17. The movable area CA of the porcelain nozzle may also include a joining area BA.

The microcomputer 60 has a correction unit 62 that performs correction processing of the control unit 61. Regarding the correction processing, the details will be described later.

[The composition of the elastic part]

As shown in FIG. 1, the leaf spring assembly 20 is mounted on the frame 10 and installed between the guide rail 16 on the side of the joint arm 13 and the heating block 17. The leaf spring assembly 20 may also be provided with a cover 28 for shielding the heat from the heating block 17.

Fig. 3(a) is a perspective view of the leaf spring assembly of Fig. 1. Fig. 3(b) is a plan view of the leaf spring assembly of Fig. 1. Figure 3(c) is the leaf spring assembly of Figure 1 Side view. As shown in FIG. 3(a), the leaf spring assembly 20 has a base 21 having a quadrangular flat plate shape, a support 22 protruding from the upper end of the base 21 in the Z direction, and a support base 22 protruding from the lower end of the base 21 in the Y direction. The flange 26 is provided, and the leaf spring (elastic part) 31 fixed to the upper end surface of the support base 22 by the screw 25 via the pressure plate 25a. The flange 26 is provided with a screw hole 27 for fixing the leaf spring assembly 20 to the frame 10 with a screw.

The leaf spring 31 is, for example, a metal thin plate, and the base end portion 31 a of the leaf spring 31 is fixed to the upper end surface of the support base 22 to be supported in a cantilever beam shape. The leaf spring 31 extends along the XY plane so that the front end portion 31b protrudes from the upper end surface of the support base 22 toward the joint arm 13 side. The leaf spring 31 is strained by the pressing load of the porcelain nozzle 15.

In the leaf spring assembly 20, at least the leaf spring 31 is arranged outside the bonding area BA. The leaf spring 31 is arranged between the outer edge of the joint area BA and the outer edge of the porcelain mouthpiece movable area CA (that is, more inside than the outer edge of the porcelain mouthpiece movable area CA). The leaf spring 31 is arranged so as to extend along the outer edge of the bonding area BA extending on the bonding head 12 side of the heating block 17. Therefore, the leaf spring 31 is arranged at a position where the porcelain nozzle 15 can be easily reached by the driving of the XY stage 11.

The Z-direction position (height) of the upper surface 31c of the leaf spring 31 is, for example, substantially the same as the Z-direction position of the joint surface (one-point chain line 47 in FIG. 2). The upper surface 31c of the leaf spring 31 is marked with a pressing point P such that, for example, a certain pressing load of the porcelain nozzle 15 generates a certain strain of the leaf spring 31.

A strain gauge 54 (first strain count). A strain gauge portion 55 is provided on the lower surface 31d of the leaf spring 31. The strain gauge part 54 and the strain gauge part 55 are acquisition parts that acquire the strain of the leaf spring 31 due to the pressing load of the porcelain nozzle 15. The detection signals of the strain gauge part 54 and the strain gauge part 55 are input to the microcomputer 60.

The strain gauge portion 54 is provided at a position where the base end portion 31 a side of the upper surface 31 c of the leaf spring 31 does not overlap the upper end surface of the support base 22. The strain gauge portion 54 acquires the strain generated along the upper surface 31 c on the side of the base end portion 31 a of the leaf spring 31. The strain gauge portion 54 includes, for example, two strain gauges 54 a and 54 b arranged side by side in the width direction of the leaf spring 31.

The strain gauge portion 55 is provided at a position where the base end portion 31 a side of the lower surface 31 d of the leaf spring 31 does not overlap the upper end surface of the support base 22. The strain gauge portion 55 (second strain gauge) acquires the strain generated along the lower surface 31d on the base end portion 31a side of the leaf spring 31. The strain gauge unit 55 includes, for example, two strain gauges 55 a and 55 b arranged side by side in the width direction of the leaf spring 31.

The strain gauge 54a and the strain gauge 55a are respectively mounted on the upper surface 31c and the lower surface 31d at positions corresponding to each other with the plate spring 31 interposed therebetween. The strain gauge 54b and the strain gauge 55b are respectively mounted on the upper surface 31c and the lower surface 31d at positions corresponding to each other with the plate spring 31 interposed therebetween. For the strain gauge 54a, the strain gauge 54b, the strain gauge 55a, and the strain gauge 55b, for example, a piezoelectric strain sensor can be used.

[Correction Processing]

Based on the results obtained by the strain gage unit 54 and the strain gage unit 55, the correction unit 62 assumes that the load error between the target value of the pressing load and the actual value of the pressing load is within a predetermined range In the manner described above, the correction process of the control unit 61 is performed. The correction processing of the correction unit 62 will be described in detail. As an example of the correction processing, the correction unit 62 performs actual measurement processing, comparison processing, and correction processing which will be described below. The correction unit 62 repeatedly performs correction processing until the load error becomes smaller than the preset load threshold value.

The load error is the error of the actual measured value of the pressing load with respect to the target value of the pressing load. The target value of the pressing load is an appropriate pressing load for pressing the wire to the electrode while bonding the electrode 15 with the porcelain nozzle 15, and is the pressing load of the porcelain nozzle 15 set in advance. The target value of the pressing load may be a pressing load of a predetermined value, or may be a pressing load of a predetermined range including a certain allowable range based on the predetermined value. The target value of the pressing load may also be stored in the correction unit 62 in advance.

The calibration unit 62 executes a calibration process program stored in the memory before the actual measurement process, thereby operating the motor 40 and the XY stage 11. Thereby, the porcelain nozzle 15 moves outside the joining area BA and moves above the pressing point P of the leaf spring 31. Then, in the actual measurement process, the motor 40 is controlled by the control unit 61 to be driven so that the porcelain nozzle 15 presses the pressing point P of the leaf spring 31.

As actual measurement processing, the correction unit 62 calculates the actual measurement value of the pressing load based on the detection signals of the strain gauge unit 54 and the strain gauge unit 55. Specifically, the correction unit 62 uses a well-known method (for example, using the strain gauge unit 54 and the strain gauge unit 54 , Method of bridge circuit composed of strain gauge section 55) Calculate the actual measured value of the pressing load. That is, the correction unit 62 has a detection signal for detecting the strain of the leaf spring 31 based on the detection signals of the strain gauge 54a, the strain gauge 54b, the strain gauge 55a, and the strain gauge 55b. The function of the circuit (amplifier). The actual measurement value of the pressing load is the pressing load of the porcelain nozzle 15 calculated based on the strain of the leaf spring 31 acquired by the strain gauge section 54 and the strain gauge section 55.

Fig. 4(a) is a side view illustrating a non-pressing state of the leaf spring assembly of Figs. 3(a) to 3(c). As shown in FIG. 4(a), the correcting part 62 acquires the first strain of the leaf spring 31 in the non-pressed state. The non-pressing state is, for example, a state in which the porcelain nozzle 15 does not press the leaf spring 31. The non-pressing state can also be said to be a state where the porcelain nozzle 15 and the leaf spring 31 are separated. The first strain is, for example, a strain generated in the leaf spring 31 when the dead weight of the leaf spring 31 acts on the pressing point P as a point load. The correction unit 62 calculates the first actual measured load based on the first strain. The first actual measured load is an actual measured load used as a reference in the calculation of the actual measured value of the pressing load.

Fig. 4(b) is a side view illustrating a pressed state of the leaf spring assembly of Figs. 3(a) to 3(c). As shown in FIG. 4(b), the correction part 62 acquires the second strain of the leaf spring 31 in the pressed state. The pressing state is, for example, a state in which the porcelain nozzle 15 presses the pressing point P of the leaf spring 31 with the pressing load when the control unit 61 controls the porcelain mouthpiece 15 so that the pressing load becomes a target value. The porcelain nozzle 15 whose pressing load is controlled by the control unit 61 so that the pressing load becomes the target value is in the state of the pressing point P of the pressing plate spring 31. The second strain is a strain generated in the leaf spring 31 due to the dead weight of the leaf spring 31 and the pressing load of the porcelain nozzle 15 acting as a point load on the pressing point P. The correction unit 62 calculates the second actual measured load based on the second strain. The second actual measured load is an actual measured load including the pressing load of the porcelain nozzle 15 and the self-weight component of the leaf spring 31.

The correction unit 62 calculates the third actual measured load by subtracting the first actual measured load from the second actual measured load. The third actual measured load is a substantially actual measured value of the pressing load of the porcelain nozzle 15 after removing the self-weight component of the leaf spring 31.

Furthermore, when the first measured load corresponding to the self-weight component of the leaf spring 31 is sufficiently small and negligible relative to the second measured load, the first measured load may also be set to 0. In this case, the calculation process of the first measured load may be omitted, and the second measured load may be used as the third measured load.

As a comparison process, the correction unit 62 calculates a load error based on the third actual measured load and the target value of the pressing load, and compares the calculated load error (for example, an absolute value) with a preset load threshold. The load threshold value is a threshold value that specifies the allowable range of the load error, and is used to determine the completion of the correction process of the control unit 61. The load threshold value may also be stored in the correction part 62 in advance.

As a correction process, when the load error is equal to or greater than the load threshold, the correction unit 62 changes the command value (control data) of the current of the motor 40 in the control unit 61 so that the load error becomes smaller. Specifically, when the load error is greater than or equal to the load threshold and the third actual measured load is greater than the target value of the pressing load, the correction unit 62 reduces the power of the motor 40 in the control unit 61 in such a way that the third actual measured load becomes smaller. The mode of the current command value is changed. In this case, the correction unit 62 can also gradually reduce the command value of the current of the motor 40 by a predetermined value in such a manner that the correction process can be repeated multiple times until the load error becomes smaller than the load threshold value.

In addition, when the load error is greater than or equal to the load threshold and the third actual measured load is less than the target value of the pressing load, the correction unit 62 uses the third actual measured load to be larger. The formula is changed to increase the command value of the current of the motor 40 in the control unit 61. In this case, the correction unit 62 can also gradually increase the command value of the current of the motor 40 by a predetermined value in such a manner that the correction process can be repeated multiple times until the load error becomes smaller than the load threshold value.

On the one hand, referring to Figs. 5 and 6, on the other hand, an operation example of the wire bonding device 100 will be described. Fig. 5 is a flowchart of an example of the operation of the wire bonding device of Fig. 1. Fig. 6 is a flowchart illustrating correction processing.

As shown in FIG. 5, the wire bonding apparatus 100 is activated by the microcomputer 60 (step S10). In step S10, the wire bonding apparatus 100 turns on the heater 17a of the heating block 17. Then, it waits until the temperature of the heating block 17 rises to a predetermined temperature, and preheats the wire bonding apparatus 100 (step S11).

After the preheating of the wire bonding device 100 is completed, the bonding process (bonding) is performed by the microcomputer 60 (step S12). For example, the control unit 61 controls the pressing load of the porcelain nozzle 15 so that the wire bonding is pressed against the electrode with the target value of the pressing load. The control unit 61 vibrates the ultrasonic vibrator 14a in a state where the porcelain nozzle 15 presses the wire to the electrode, and the porcelain nozzle 15 joins the pressed wire to the electrode. In step S12, the wire bonding device 100 operates continuously by repeatedly performing the bonding process.

Then, it is judged by the correction part 62 of the microcomputer 60 whether the correction implementation condition which is a condition for implementing the correction process of the control part 61 is satisfied (step S13). In step S13, it is determined by the correction part 62 whether the wire bonding apparatus 100 continuously performed the bonding process for a predetermined period, such as 1000 hours.

In step S13, when it is determined by the calibration unit 62 that the calibration implementation conditions are not satisfied, the process jumps to step S15, and the microcomputer 60 determines whether to stop the operation of the wire bonding device 100 (step S15). In step S15, when it is determined that the operation of the wire bonding device 100 is not to be stopped, the process returns to step S12, and the microcomputer 60 continues to perform the bonding process.

In step S15, when it is determined that the operation of the wire bonding device 100 is stopped, the microcomputer 60 stops the wire bonding device 100, and the operation of the program is stopped.

On the other hand, in step S13, when it is determined by the correction unit 62 that the correction implementation conditions are satisfied, the correction unit 62 performs correction processing (step S14). Specifically, the correction processing of step S14 is implemented as in the example of FIG. 6.

As shown in FIG. 6, the XY stage 11 is operated while the heater 17a is kept turned on by the correction unit 62, and the position of the porcelain nozzle 15 is moved out of the bonding area BA (step S20). In step S20, the position of the porcelain nozzle 15 is moved to above the pressing point P of the leaf spring 31. In this non-pressed state, the leaf spring 31 generates a first strain. The first strain of the leaf spring 31 is acquired by the correcting part 62 in the non-pressed state (step S21).

The correction unit 62 applies a current corresponding to the target value of the pressing load at the current time to the motor 40, and the plate spring 31 is pressed with the pressing load by the porcelain nozzle 15 (step S22). In this pressed state, the leaf spring 31 generates a second strain. The second strain of the leaf spring 31 is acquired by the correcting part 62 in the pressed state (step S23). The correction part 62 reduces the current applied to the motor 40, and the pressing of the plate spring 31 by the porcelain nozzle 15 is released (step S24).

The correcting unit 62 calculates the actual measurement value of the pressing load based on the first strain and the second strain (step S25). In step S25, the first measured load and the second measured load are calculated, and the third measured load is calculated based on the first measured load and the second measured load. Furthermore, the steps S21 to S25 are equivalent to actual measurement processing.

The correction unit 62 calculates the load error based on the target value of the third actual measured load and the pressing load, and compares the calculated absolute value of the load error with a preset load threshold to determine whether the absolute value of the load error is less than the load threshold Value (step S26). In addition, this step S26 corresponds to a comparison process.

In step S26, when it is determined that the absolute value of the load error is greater than or equal to the load threshold (step S26: NO), the actual measured value of the pressing load deviates from the target value of the pressing load, and it is considered that the pressing load needs to be corrected. Therefore, the correction unit 62 changes the command value of the current of the motor 40 in the control unit 61 so that the load error becomes smaller (step S27). In addition, this step S27 corresponds to a correction process. After step S27, return to step S21 to implement actual measurement processing.

In step S26, when it is determined that the absolute value of the load error is smaller than the load threshold value (step S26: YES), it is considered that it is not necessary to correct the pressing load. Therefore, the XY stage 11 is operated by the correction part 62, and the position of the ceramic nozzle 15 moves into the joining area BA (step S28). Then, returning to step S15 in FIG. 5, the microcomputer 60 determines whether to stop the operation of the wire bonding device 100, restart the bonding operation, or stop the operation of the wire bonding device 100.

As described above, the wire bonding device 100 uses the porcelain nozzle 15 to press the plate spring 31 to generate strain. Based on the leaf spring obtained by the strain gauge part 54 and the strain gauge part 55 As a result of the strain acquisition of 31, the correction process of the control unit 61 is performed by the correction unit 62 so that the load error between the preset target value of the pressing load and the actual measured value of the pressing load falls within a predetermined range. According to the wire bonding device 100, the leaf spring 31 is arranged outside the bonding area BA. Therefore, the stop time of the wire bonding device 100 for performing the calibration process is shortened compared with the case where, for example, a load cell is installed in the bonding area BA. The operating time of the wire bonding device 100 increases. Thereby, it is possible to correct the pressing load of the porcelain nozzle 15 while realizing an improvement in productivity.

In the wire bonding device 100, the calibration processing includes: actual measurement processing, based on the first strain of the leaf spring 31 in the non-pressed state where the leaf spring 31 is not pressed by the porcelain nozzle 15, and the pressing of the porcelain nozzle 15 by the control unit 61 When the load is controlled so that the load becomes the target value, when the porcelain nozzle 15 presses the second strain of the leaf spring 31 in the pressing state of the pressing point P of the leaf spring 31 with the pressing load, the actual measured value of the pressing load (the first actual measured load) is calculated. ~The third actual measured load); comparison processing, which compares the preset load threshold with the load error; and correction processing, when the load error is greater than the load threshold, the control unit 61 is changed so that the load error becomes smaller The current in the motor 40. The correction unit 62 repeatedly performs actual measurement processing, comparison processing, and correction processing until the load error becomes smaller than the load threshold. In this way, the actual measurement value of the pressing load is calculated from the second strain in the pressing state based on the first strain in the non-pressing state, which is comparable to the case where the actual measurement value of the pressing load is calculated based on the displacement of the leaf spring 31, for example. Compared with the standard, it is not easy to deviate, so the actual measurement value of the pressing load can be calculated with high accuracy. Therefore, the correction processing can be performed accurately.

Especially in the wire bonding device 100, it is based on the first The first measured load of a strain is used as a reference. Here, in the actual measurement process, for example, a method of calculating the actual measurement value of the pressing load based on the displacement of the leaf spring 31 caused by the pressing of the porcelain nozzle 15 is also conceivable. However, in this case, it may be difficult to determine the displacement of the leaf spring 31. Benchmark. In the case where the first actual measured load based on the first strain in the non-pressed state is used as the reference, for example, the non-pressed state can be easily realized by separating the porcelain nozzle 15 from the leaf spring 31, so that the first measured load can be suppressed from becoming the reference. The actual measured load has a deviation, and the actual measured value of the pressing load can be calculated with high accuracy. Therefore, the correction processing can be performed accurately.

In the wire bonding device 100, as the elastic portion, a leaf spring 31 supported in a single-arm beam shape is used. The strain gauge portion 54 and the strain gauge portion 55 include a strain gauge 54a and a strain gauge provided on the upper surface 31c of the leaf spring 31 54b and strain gauges 55a and 55b provided on the lower surface 31d of the leaf spring 31. Thereby, the space saving of the wire bonding device 100 can be realized with a small and simple structure. In addition, the strain gauge 54a, the strain gauge 54b, the strain gauge 55a, and the strain gauge 55b are provided on both surfaces of the leaf spring 31, so that the expansion and contraction strain of the leaf spring 31 accompanying the temperature change is offset. Thereby, even if it does not wait for the temperature of the bonding area BA of the wire bonding apparatus 100 to fall, correction processing can be performed. Therefore, the continuous operation of the wire bonding device 100 can be realized, and the productivity can be further improved.

Incidentally, according to the wire bonding device 100, it can also be said that the following is achieved in the same way as the previous calibration work performed by the operator using the load cell installed in the bonding area in the state where the wire bonding device is stopped, for example. In the case of high calibration accuracy, the calibration of the pressing load can also be implemented fully automatically. In addition, it can also be achieved The reliability and life of the wire bonding device 100 are improved. Furthermore, it is also possible to save operators who perform calibration work (so-called unmanned operation). Since the continuous operation of the wire bonding device 100 can be realized, the maintenance time for the calibration work of the wire bonding device 100 itself may be said to be unnecessary.

[Modifications]

As mentioned above, although the embodiment of this invention was described, this invention is not limited to the said embodiment.

For example, as correction processing, the correction unit 62 repeatedly performs actual measurement processing, comparison processing, and correction processing until the load error becomes smaller than the load threshold. However, the actual measurement processing, comparison processing, and correction processing may be completed at one time.

For example, the correction unit 62 calculates the first measured load based on the first strain, calculates the second measured load based on the second strain, and calculates the third measured load based on the first measured load and the second measured load, but how to calculate the actual measured value of the pressing load Not limited to this. For example, the difference in strain may be calculated based on the first strain and the second strain, and the third actual measured load may be calculated based on the difference in the calculated strain.

The leaf spring 31 is supported in the shape of a single-arm beam, but it can also be in other support forms.

As the control data of the drive source in the control unit 61, the current value applied to the stator 41 of the motor 40 is exemplified, but it may be, for example, the electric power supplied to the motor 40 or the like. The point is, as long as the pressing load of the porcelain mouth 15 can be changed in such a way that the load error becomes smaller.

As the strain gauge part 54 and the strain gauge part 55, four strain gauges 54a, 54b, 55a, and 55b are exemplified, but the number of strain gauges is not limited to this.

In addition, the elastic portion is not limited to the leaf spring 31. As the elastic part, it can be used as long as it is a mechanism that generates strain such as a Roberval mechanism. The elastic portion may be deformed into an elastic portion assembly 20A having a beam 32 shown in FIGS. 7(a) to 7(c), for example.

Fig. 7(a) is a side view of a modified example of the elastic portion. Fig. 7(b) is a side view illustrating a non-pressed state of the elastic portion of Fig. 7(a). Fig. 7(c) is a side view illustrating a pressed state of the elastic portion of Fig. 7(a). As shown in FIGS. 7( a) to 7 (c ), the elastic portion assembly 20A is different from the leaf spring assembly 20 in that the beam 32 is used instead of the leaf spring 31.

The beam 32 is a long plate-shaped or prismatic member extending in the same direction as the longitudinal direction of the leaf spring 31. One end 32a of the beam 32 is supported in a single-arm beam shape. In the beam 32, a low-rigidity portion 32f having a rigidity lower than that of the one end 32a and the other end 32b is provided in an intermediate portion 32e sandwiched by one end 32a and the other end 32b in the longitudinal direction. The low rigidity portion 32f may be a space formed inside the beam 32, for example.

The elastic portion assembly 20A includes a strain gauge portion 56 (third strain gauge) provided on the upper surface 32c and the lower surface 32d of one end portion 32a of the beam material 32, and an upper surface 32c provided on the other end portion 32b of the beam material 32 And the strain gauge part 57 (fourth strain gauge) on the lower surface 32d serves as an acquiring part for acquiring the strain of the beam 32. The strain gauge part 56 may also include a strain gauge 56 a provided on the upper surface 32 c of the beam 32 and a strain gauge 56 b provided on the lower surface 32 d of the beam 32. The strain gauge part 57 may also include the upper table provided on the beam 32 The strain gauge 57a on the surface 32c and the strain gauge 57b provided on the lower surface 32d of the beam 32.

In such a beam 32, a low-rigidity portion 32f is provided in the middle portion 32e. Therefore, the strain of the beam 32 is increased at the boundary portion between one end portion 32a and the middle portion 32e, and the boundary portion between the other end portion 32b and the middle portion 32e. Big. This situation can be used to acquire the strain of the beam 32 with good sensitivity. In addition, the strain gauge part 56 and the strain gauge part 57 are provided on both surfaces of the beam member 32, so that the expansion and contraction strain of the beam member 32 accompanying the temperature change is offset. Thereby, even if it does not wait for the temperature of the bonding area BA of the wire bonding apparatus 100 to fall, correction processing can be performed. Therefore, in this case, the continuous operation of the wire bonding device 100 can also be realized, and the productivity can be further improved.

In addition, the elastic portion can be deformed into the elastic portion assembly 20B shown in FIG. 8. Fig. 8 is a side view of another modification of the elastic portion. As shown in FIG. 8, in the elastic portion assembly 20B, a strain gauge 58 and a strain gauge 59 are attached to a columnar body 33 constituting a part of the block body. In this way, the elastic part and the acquisition part can also be configured in such a way that the strain gauge 58 and the strain gauge 59 are used to acquire the strain of the columnar body 33 pressed by the porcelain nozzle 15 from above.

10: Frame

11: XY platform

12: Joint head

13: Joint arm

13a: recess

14: Ultrasonic welding head

14a: Ultrasonic vibrator

14b: flange

14c: Screw

15: Porcelain nozzle (joining tool)

16: rail

17: heating block

17a: heater

18: substrate

19: Electronic parts

20: Leaf spring assembly

28: Cover

31: Leaf spring (elastic part)

40: Motor (drive source)

41: Stator

42: Rotor

43: Rotation Center

45: Rotation axis

46, 47: a little chain line

48: motor driver

49: power supply

51: current sensor

52: Angle sensor

53: temperature sensor

60: Microcomputer

61: Control Department

62: Correction Department

Claims (4)

A wire bonding device includes a porcelain nozzle that presses the wire bonding side against the electrode while bonding in a predetermined bonding area, the porcelain nozzle is installed at the front end of the welding head, and the wire bonding device includes: a driving source for connecting the porcelain The nozzle is driven in the up and down direction; the control part is connected to the drive source to control the pressing load of the porcelain nozzle; the elastic part is supported on the outside of the joint area in a single-arm beam shape, the elastic part There is a pressing point to be pressed at the front end of the porcelain mouth, and strain is generated due to the pressing load; an acquiring part, which acquires the pressing load toward the pressing point through a strain gauge provided on the elastic part; and correction Section, based on the acquisition result of the acquisition section, performing the correction processing of the control section so that the load error between the preset target value of the pressing load and the actual measurement value of the pressing load falls within a predetermined range, wherein The so-called pressing load is a load that causes the elastic portion to be strained by driving the porcelain nozzle with the tip of the porcelain nozzle in contact with the pressing point. The wire bonding device according to claim 1, wherein the correction processing includes actual measurement processing, based on the first strain of the elastic part in a non-pressing state where the porcelain nozzle does not press the elastic part, And when the control unit is controlled so that the pressing load becomes the target value, the porcelain mouthpiece presses the second elastic part in the pressing state of the elastic part with the pressing load Second strain, calculate The actual measured value of the pressing load; comparison processing, calculating a load error based on the calculated actual measured value of the pressing load and a target value of the pressing load, and calculating the load error with a preset load threshold Performing comparison; and correction processing, when the load error is greater than or equal to the load threshold value, the control data of the drive source in the control unit is changed in such a way that the load error becomes smaller, and the correction The part repeatedly performs the actual measurement process, the comparison process, and the correction process until the load error is less than the load threshold. The wire bonding device described in item 1 or item 2 of the scope of patent application, wherein the elastic portion is a leaf spring, and the strain gauge includes a first strain gauge provided on the upper surface of the leaf spring, and The second strain gauge on the lower surface of the leaf spring. According to the wire bonding device described in item 1 or item 2 of the scope of patent application, the elastic part is a beam material, and the beam material is in the middle part sandwiched by one end and the other end in the longitudinal direction, A low-rigidity portion having lower rigidity than the one end portion and the other end portion is provided, and the strain gauge includes a third strain gauge provided on the upper surface and the lower surface of the one end portion of the beam And fourth strain gauges provided on the upper surface and the lower surface of the other end of the beam.

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