JP2016119374A - Wire bonding device and wire bonding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform correct determination on the bonding state between a bonding object and a wire.SOLUTION: A wire bonding device 10 includes a bonding head 20 for bonding a wire to a bonding object by crimping followed by ultrasonic vibration. The wire bonding device 10 includes a vibration detection part which irradiates the bonding object with laser beams from three mutually-different directions and detects the state of vibration in the three directions of the bonding object on the basis of a reflection beam LY1 reflected on the bonding object. The three directions include the first direction along the vibration direction of ultrasonic vibration, the second direction intersecting with the first direction and the third direction intersecting with a plane defined by the first direction and the second direction. The wire bonding device 10 includes a determination part 53 which performs determination on the bonding state between the wire and the bonding object on the basis of the state of vibration of the bonding object detected by the vibration detection part.SELECTED DRAWING: Figure 1

Description

  The disclosed technology relates to a wire bonding apparatus and a wire bonding method.

  2. Description of the Related Art A technique for detecting a bonding state between a bonding object such as a semiconductor chip to which a wire is bonded by a wire bonding apparatus and the wire using a laser Doppler vibrometer is known.

  For example, a bonding quality inspection system using a capillary or a horn of a wire bonding apparatus as a measurement object is known. The system irradiates a laser beam following the movement of the capillary or the horn, receives a return light from the capillary or the horn, and receives a laser beam generated by self-mixing in the laser resonator. And a light receiving element. The system includes a beat wave output unit that detects a beat wave from a signal output from the light receiving element, and a signal that determines whether there is an abnormality in the vibration of the measurement object based on the beat wave output by the beat wave output unit And processing means.

  Also known is an ultrasonic bonding apparatus provided with a laser Doppler vibrometer for detecting the relative vibration state of the bonding member and the member to be bonded, means for diagnosing the detection result, and means for feeding back the diagnosis result to the ultrasonic wave generation means. ing.

  There is also known an ultrasonic bonding apparatus including a vibration measuring unit that measures vibration of a bonding tool part using a laser Doppler vibrometer and calculates a position of a vibration node of the bonding tool part.

JP 2000-137026 A JP-A-5-206224 JP 2007-142049 A

  In some cases, an adhesive having a lower elastic modulus than usual is used as an adhesive for bonding a semiconductor chip containing an element requiring high accuracy such as a sensor to a substrate. A highly elastic adhesive has a greater shrinkage after the thermosetting treatment of the adhesive than the shrinkage of the substrate and the semiconductor chip, which may cause the substrate and the semiconductor chip to bend and deteriorate the performance of the semiconductor chip. is there. By using a low-elasticity adhesive, it is possible to suppress bending of the substrate and the semiconductor chip.

  However, when a wire is bonded to a semiconductor chip bonded to a substrate using a low-elasticity adhesive by an ultrasonic bonding type wire bonding apparatus, the bonding quality between the semiconductor chip and the wire is unstable. It is easy to become. That is, in the semiconductor chip bonded on the substrate with the low-elastic adhesive, the vibration due to the ultrasonic wave applied from the bonding head becomes larger than when the high-elastic adhesive is used. That is, there is a case where a loss occurs in the ultrasonic energy output from the bonding head and an appropriate bond cannot be formed. When using low-elasticity adhesives, it is conceivable to set a higher ultrasonic output at the bonding head. However, low-elasticity adhesives tend to change their elastic modulus due to the distribution of contained fillers, and are optimal for bonding conditions. Is difficult. When an adhesive having a low elastic modulus is used, an abnormality is likely to occur in the collapsed shape of the wire, and an unattached wire is likely to occur.

  Further, it is known that when wire bonding is performed at a corner portion of a semiconductor chip, rotational movement occurs in the semiconductor chip (see FIG. 11). That is, since the behavior of the semiconductor chip during wire bonding changes between the corner portion of the semiconductor chip and other portions, there may be a difference in wire bonding quality between the corner portion of the semiconductor chip and other portions. is there. When a low-elasticity adhesive is used for bonding the semiconductor chip and the substrate, the rotational movement of the semiconductor chip increases, so that the difference in bonding quality between the wire bonding sites may become more conspicuous. In this way, even when the bonding quality between the object to be bonded and the wire is not stable, if it is possible to accurately determine the bonding state between the object to be bonded and the wire, it is possible to prevent outflow of defective bonding products. It is.

  An object of the disclosed technique is to accurately perform a determination regarding a bonding state between a bonding target object and a wire as one aspect.

  The wire bonding apparatus according to the disclosed technique includes a bonding head that bonds a wire to a bonding target object by pressure bonding with ultrasonic vibration. The wire bonding apparatus irradiates the joining object with laser light from at least three directions different from each other, and based on the reflected light reflected by the joining object, vibrations in the at least three directions of the joining object are obtained. A vibration detector for detecting the state is included. The at least three directions are a first direction along a vibration direction of the ultrasonic vibration, a second direction intersecting the first direction, and a plane determined by the first direction and the second direction. A third direction intersecting with. The wire bonding apparatus includes: a determination unit configured to perform a determination regarding a bonding state between the wire and the bonding target based on vibration states of the bonding target in the at least three directions detected by the vibration detection unit. Including.

  According to the technique of an indication, there exists an effect that the determination regarding the joining state of a joining target object and a wire can be performed exactly as one side.

It is a block diagram which shows the structure of the wire bonding apparatus which concerns on embodiment of the technique of an indication. It is a side view showing the composition of the bonding head concerning the embodiment of the art of an indication. It is a figure which shows an example of the joining target object which concerns on embodiment of the technique of an indication. It is a figure which shows operation | movement of the wire bonding apparatus which concerns on embodiment of the technique of an indication. It is a figure which shows operation | movement of the wire bonding apparatus which concerns on embodiment of the technique of an indication. It is a figure which shows operation | movement of the wire bonding apparatus which concerns on embodiment of the technique of an indication. It is a figure which shows operation | movement of the wire bonding apparatus which concerns on embodiment of the technique of an indication. It is a figure which shows an example of a structure of the optical head which concerns on embodiment of the technique of an indication. It is a figure which shows an example of the irradiation direction of the measurement light with respect to the joining target object which concerns on embodiment of the technique of an indication. It is a figure which shows the irradiation method of the measurement light with respect to the joining object surface which concerns on embodiment of the technique of an indication. It is a figure which shows the irradiation method of the measurement light with respect to the joining object surface which concerns on embodiment of the technique of an indication. It is a figure which shows the irradiation method of the measurement light with respect to the joining object surface which concerns on embodiment of the technique of an indication. It is a figure which shows the relationship between the wire bonding position which concerns on embodiment of the technique of an indication, and the irradiation position of measurement light. It is a figure which shows the relationship between the wire bonding position which concerns on embodiment of the technique of an indication, and the irradiation position of measurement light. It is a figure which shows the relationship between the wire bonding position which concerns on embodiment of the technique of an indication, and the irradiation position of measurement light. 6 is a flowchart showing an operation of a wire bonding apparatus according to an embodiment of the disclosed technology. It is a figure which shows an example of the time transition of the vibration detection signal which concerns on embodiment of the technique of an indication. It is a figure which shows the rotational motion of the semiconductor chip which arises at the time of the wire joint to a corner part. It is a figure which shows the time transition of the vibration detection signal when the joining state of a wire and a semiconductor chip is favorable. It is a figure which shows the time transition of the vibration detection signal when the joining state of a wire and a semiconductor chip is not favorable. It is a block diagram which shows the structure of the wire bonding apparatus which concerns on other embodiment of the technique of an indication. It is a flowchart which shows operation | movement of the wire bonding apparatus which concerns on other embodiment of the technique of an indication.

  Hereinafter, an exemplary embodiment of the disclosed technology will be described with reference to the drawings. In the drawings, the same or corresponding components and parts are denoted by the same reference numerals.

[First Embodiment]
FIG. 1 is a block diagram illustrating a configuration of a wire bonding apparatus 10 according to an embodiment of the disclosed technology. The wire bonding apparatus 10 includes a bonding head 20. FIG. 2 is a diagram illustrating the configuration of the bonding head 20. The bonding head 20 includes a piezoelectric element 21, a horn 22 and a capillary 23. The piezoelectric element 21 is an ultrasonic transducer which converts an ultrasonic drive signal S _U, which is the electrical signal supplied from the ultrasonic control unit 55 (see FIG. 1) to the ultrasonic vibration, attached to one end of the horn 22 Yes. The horn 22 increases the ultrasonic vibration generated by the piezoelectric element 21 and transmits it to the capillary 23 attached to the tip portion thereof. The capillary 23 has a through hole (not shown) through which a wire is inserted, and is a crimper that joins the wire to a joining target such as a semiconductor chip by crimping with ultrasonic vibration.

  In the present embodiment, the vibration direction of the ultrasonic wave output from the bonding head 20 is a direction along the extension direction of the horn 22, and this direction is defined as the Y direction. In addition, a direction orthogonal to the Y direction is defined as an X direction in a plane parallel to a bonding target surface to which a wire is bonded in a bonding target such as a semiconductor chip. A direction orthogonal to the XY plane determined by the X direction and the Y direction is defined as a Z direction.

  As shown in FIG. 1, the wire bonding apparatus 10 includes an XY stage 33 that moves the bonding head 20 along the X direction and the Y direction. The wire bonding apparatus 10 further swings the bonding head 20 around the axis of a support shaft (not shown) that rotatably supports the end of the bonding head 20 on the piezoelectric element 21 side so that the capillary 23 moves in the Z direction. It has a bonding head drive mechanism 32 that is moved along. The bonding head 20 is mounted on the XY stage 33 while being connected to the bonding head drive mechanism 32.

The position control unit 56 performs position control by supplying position control signals _SP1 and _SP2 to the XY stage 33 and the bonding head drive mechanism 32, respectively. The position controller 56 allows the bonding head driving mechanism 32 and the XY stage 33 to interlock with each other, so that a wire can be bonded to an arbitrary portion of a bonding target such as a semiconductor chip.

  The wire bonding apparatus 10 includes a fixed stage 31 on which a bonding target for wire bonding is placed. FIG. 3 is a side view showing an example of the joining object placed on the fixed stage 31. As shown in FIG. 3, for example, the semiconductor chip 200 bonded to the wiring board 210 with the adhesive 220 can be placed on the fixed stage 31 as a bonding target. The adhesive 220 may be a low elastic adhesive having a lower elastic modulus (for example, about 1 MPa) than an adhesive having a relatively high elastic modulus (for example, 700 MPa) that has been conventionally used. The wire bonding apparatus 10 connects the electrode pads provided on the surface of the semiconductor chip 200 and the electrode pads provided on the surface of the wiring substrate 210 with a wire 300. Below, the case where the semiconductor chip 200 is used as an object to be bonded by the wire bonding apparatus 10 will be described as an example.

Figure 4A~ Figure 4D is a diagram illustrating the operation of the wire bonding apparatus 10 in the case of bonding the wire 300 to the electrode pads 201 provided on the bonding target surface _{S 1} of the semiconductor chip 200.

  First, the tip of the wire 300 inserted into the capillary 23 is melted to form an FAB (Free Air Ball) 301 at the tip of the capillary 23 (FIG. 4A). Next, the capillary 23 descends toward the electrode pad 201 of the semiconductor chip 200 (FIG. 4B). Next, the capillary 23 deforms the FAB 301 by applying an impact load when the FAB 301 is brought into contact with the electrode pad 201. Thereafter, the capillary 23 further deforms the FAB 301 by applying heat and a load together with ultrasonic vibration over a predetermined period, and joins the wire 300 to the electrode pad 201 (FIG. 4C). Thereafter, the capillary 23 moves upward while feeding the wire 300, and moves to the second bond position while forming a loop (FIG. 4D).

  The wire bonding apparatus 10 includes a laser Doppler vibrometer that detects a vibration state of a bonding target object placed on the fixed stage 31 while ultrasonic waves are output from the bonding head 20. The laser Doppler vibrometer includes optical heads 41, 42, and 43 and an arithmetic processing unit 51 (see FIG. 1).

  FIG. 5 is a diagram illustrating an example of the configuration of the optical head 41. The configuration of the optical heads 42 and 43 is the same as that of the optical head 41. The optical head 41 includes a laser light source 401, beam splitters 402, 403, 404, an acousto-optic conversion element (Bragg cell) 405, a reflection mirror 406, and a light receiving element 407.

The laser beam emitted from the laser light source 401 is split by the beam splitter 402 into two systems, one is the measuring light L _Y irradiated (semiconductor chip 200 in this embodiment) the measurement object X, the other It is the reference light _{L R.} The reflected light L _Y1 from the measurement object X enters the beam splitter 404 via the beam splitter 403 and the reflection mirror 406. The frequency of the reflected light _LY1 is shifted according to the vibration velocity V of the measurement object X (semiconductor chip 200) (Doppler shift). The reference light _LR is incident on the beam splitter 404 after the frequency is shifted by the acousto-optic conversion element 405. The reflected light _LY1 and the reference light _LR are superimposed on the beam splitter 404 and interfere with each other. The beat frequency obtained by the interference light L _i. The interference light Li is converted into a beat signal S _BY that is an electric signal by the light receiving element 407 and supplied to the arithmetic processing unit 51.

The measurement lights L _Y , L _X and L _Z emitted from the optical heads 41, 42 and 43 are applied to the semiconductor chip 200 from different directions. FIG. 6 is a diagram illustrating an example of the irradiation direction of the measurement lights L _Y , L _X and L _Z irradiated on the semiconductor chip 200.

Measuring light L _Y emitted from the optical head 41 is irradiated from the ultrasonic vibration direction parallel to the Y direction to the semiconductor chip 200. The measurement light L _X emitted from the optical head 42 is applied to the semiconductor chip 200 from the X direction. Measuring light L _Z emitted from the optical head 43 is irradiated from the Z direction to the semiconductor chip 200. Note that the irradiation directions of the measurement lights L _Y , L _X, and L _{Z to} the semiconductor chip 200 are preferably coincident with the Y direction, the X direction, and the Z direction, respectively, but must be completely coincident with each other. do not do.

In the example shown in FIG. 6, the semiconductor chip 200 has a rectangular parallelepiped outer shape, two sides of the outer edge of the bonding target surface S ₁ is along the Y direction, are arranged remaining two sides along the X direction Yes. Therefore, the measurement light _{L Y} is irradiated substantially perpendicular to the side surface _{S 2} of the semiconductor chip 200 which intersects the bonding target surface _{S 1,} the measurement light _{L X} side surface _{S 3} which is adjacent to the side surface _{S 2} of the semiconductor chip 200 On the other hand, it is irradiated substantially perpendicularly. Further, the measurement light L _Z is irradiated substantially perpendicularly to the bonding target surface S ₁ of the semiconductor chip 200.

In the present embodiment, the measurement lights L _Y and L _X are directly irradiated onto the semiconductor chip 200 from the optical heads 41 and 42, respectively. On the other hand, the measurement light L _Z is Figure 7A, as shown in FIGS. 7B and 7C, it is changed the traveling direction by the reflection mirror 60 provided in the vicinity of the mounting position of the capillary 23 of the bonding head 20 to the semiconductor chip 200 Irradiated. In the present embodiment, the measurement light _LZ is emitted from the optical head 43 in the Y direction and is applied to the reflection mirror 60. The reflection mirror 60 has a reflection surface inclined by 45 ° with respect to the Y direction. The measurement light _{LZ that} has entered the reflection mirror 60 travels in the Z direction with the traveling direction being bent at 90 ° on the reflection surface of the reflection mirror 60, and is irradiated onto the bonding target surface S ₁ of the semiconductor chip 200.

In the present embodiment, as shown in FIGS. 7B and 7C, the two reflection mirrors 60 are juxtaposed in the X direction with the capillary 23 interposed therebetween. The two reflecting mirrors 60 are connected to the XY stage 33 by a support (not shown), and can move in the X direction and the Y direction together with the bonding head 20. That is, the relative positions of the two reflection mirrors 60 and the bonding head 20 in the X direction and the Y direction are fixed. As shown in FIGS. 7B and 7C, when a wire is bonded to the end portion in the X direction of the semiconductor chip 200, the reflection mirror 60 positioned inside the semiconductor chip 200 is used out of the two reflection mirrors 60. . Thus, it is possible to irradiate the measurement light L _Z on the semiconductor chip 200 bonding target surface S _1.

In the present embodiment, the optical heads 41, 42, and 43 move with the movement of the wire bonding position in the semiconductor chip 200. That is, the irradiation position of the measurement light L _Y , L _X and L _{Z to} the semiconductor chip 200 moves as the wire bonding position moves.

As shown in FIG. 1, the optical head 41 can be moved in the X direction by an optical head moving mechanism 44 including a guide provided along the X direction. In other words, the irradiation position of the measurement light L _Y which definitive semiconductor chip 200 is movable in the X direction. The optical head moving mechanism 44 moves the optical head 41 based on the position control signal _SP3 supplied from the position controller 56.

The optical head 42 can be moved in the Y direction by an optical head moving mechanism 45 including a guide provided along the Y direction. In other words, the irradiation position of the measurement light L _X of the semiconductor chip 200 is movable in the Y direction. The optical head moving mechanism 45 moves the optical head 42 based on the position control signal _SP4 supplied from the position control unit 56.

The optical head 43 is mounted on the XY stage 33 and can move in the X direction and the Y direction together with the bonding head 20. Further, as described above, the reflection mirror 60 is connected to the XY stage 33 by a support body (not shown), and can move in the X direction and the Y direction together with the bonding head 20. In other words, the irradiation position of the measurement light L _Z for the semiconductor chip 200 is movable in X and Y directions. Measurement light L _Z is near the capillary 23 in a bonding target surface S ₁ of the semiconductor chip 200, i.e., is irradiated to the vicinity of the joint position of the wire.

The position control unit 56 performs position control of the bonding head 20 in the X direction and Y direction by performing position control of the XY stage 33 in the X direction and Y direction. The position control unit 56, the irradiation position of the measurement light L _Y and L _X is, control the position of the optical head 41 and 42 so as to correspond to the bonding position of the wire of the semiconductor chip 200.

8A, 8B, and 8C are diagrams illustrating a relationship between the bonding position of the wire in the semiconductor chip 200 and the irradiation position of the measurement light L _X , L _Y, and L _Z to the semiconductor chip 200. FIG. For example, as shown in FIG. 8A, in the case of joining a wire to an electrode pad 201a provided on the bonding target surface S ₁ of the semiconductor chip 200, the measurement light L _Y in the coordinate position in the X direction of the electrode pads 201a The position of the optical head 41 is controlled so as to be irradiated. Further, the position control of the optical head 42 is performed so that the measurement light L _X is irradiated to the coordinate position in the Y direction of the electrode pad 201a. On the other hand, the relative positions of the optical head 43 and the reflecting mirror 60 in the X direction and the Y direction with respect to the bonding head 20 are fixed, and the measurement light _LZ is always at the wire bonding position on the bonding target surface S ₁ of the semiconductor chip 200. Irradiate nearby. That is, when bonding the wire to the electrode pad 201a, the measurement light _{L Z} is irradiated to the vicinity of the electrode pad 201a.

FIG. 8B shows a case where a wire is bonded to the electrode pad 201b, and FIG. 8C shows a case where a wire is bonded to the electrode pad 201c. Also in these cases, the measurement lights L _X , L _Y and L _Z are irradiated to the positions corresponding to the bonding positions of the wires as described above.

The arithmetic processing unit 51 (see FIG. 1) extracts Doppler shift frequency components from the beat signals S _BY , S _BX, and S _BZ supplied from the optical heads 41, 42, and 43, respectively, and performs predetermined arithmetic processing. Accordingly, the arithmetic processing unit 51 outputs vibration detection signals S _DY , S _DX and S _DZ indicating the displacement of the semiconductor chip 200 in the Y direction, X direction and Z direction. That is, the vibration detection signal S _DY indicates the vibration amplitude A _Y in the Y direction of the semiconductor chip 200, the vibration detection signal S _DX indicates the vibration amplitude A _X in the X direction of the semiconductor chip 200, and the vibration detection signal S _DZ indicates the semiconductor chip 200. It shows the vibration amplitude _{a Z} in the Z direction 200.

The storage unit 52 stores the vibration detection signals S _DY , S _DX and S _DZ output from the arithmetic processing unit 51.

The determination unit 53 determines whether the semiconductor chip 200 is bonded to the wire based on the vibration detection signals S _DY , S _DX and S _DZ stored in the storage unit 52. The determination unit 53 includes, for example, vibration amplitudes A _Y , A _X , A _Z that are peak values of displacement in the Y direction, X direction, and Z direction of the semiconductor chip 200 indicated by the vibration detection signals S _DY , S _DX , S _DZ . It is determined whether the joining state is good or not by determining whether or not the relative ratio is within a predetermined range. For example, the determination unit 53, the vibration amplitude _{A X} and the ratio _{R 1 (= A X / A} Z) of the _{A Z,} the vibration amplitude _{A Y} and the ratio _{R 2 (= A Y / A} Z) of the _{A Z} and the vibration amplitude A The ratio R ₃ (= A _X / A _Y ) between _X and A _Y is calculated. The determination unit 53 compares the calculated amplitude ratios R ₁ , R _2, and R ₃ with upper and lower limit values determined in advance, and any of the amplitude ratios R ₁ , R _2, and R ₃ is the upper / lower limit value. If it is not within the range, it is determined that the bonding state between the semiconductor chip 200 and the wire is not good. On the other hand, the determination unit 53 determines that the bonding state between the semiconductor chip 200 and the wire is good when all of the amplitude ratios R ₁ , R _2, and R ₃ are within the upper and lower limit values. The upper and lower limit values for the amplitude ratios R ₁ , R ₂ and R ₃ are preferably determined for each wire bonding position (for each electrode pad).

The adjustment unit 54 derives a correction value N for adjusting the amplitude of the ultrasonic vibration output from the bonding head 20 when the determination result by the determination unit 53 is not good. For example, the adjustment unit 54 derives the correction value N so that the amplitude ratios R ₁ , R _2, and R ₃ supplied from the determination unit 53 are within the range of the upper and lower limit values. The correction value N may be a value that is uniquely determined from the amount of deviation from the upper and lower limits of each of the amplitude ratios R ₁ , R _2, and R ₃ . For example, adjusting unit 54 functions _{N = f (e 1, e} 2 of the deviation amount _{e 1,} e 2, _{e 3} from the upper and lower limits of each of the amplitude ratio _R 1, _{R 2} and _{R 3} variables, The correction value N may be derived from e ₃ ).

Ultrasonic control unit 55 supplies to the piezoelectric element 21 to generate an ultrasonic driving signal S _U which is the electrical signal. The amplitude of the ultrasonic vibration piezoelectric element 21 to generate is controlled by the voltage of the ultrasonic drive signal S _U (amplitude). Ultrasonic control unit 55, when the correction value N from the adjusting unit 54 is supplied, supplies ultrasonic drive signal S _U corrected in accordance with the correction value N to the piezoelectric element 21.

  That is, when the result of determination by the determination unit 53 is not a good determination, the magnitude of ultrasonic vibration in the bonding head 20 is adjusted by the adjustment unit 54. Thus, according to the wire bonding apparatus 10 according to the present embodiment, the ultrasonic output from the bonding head 20 is feedback-controlled. The wire bonding apparatus 10 performs the above feedback control for all the bonding sites (electrode pads) of the semiconductor chip 200. The wire bonding apparatus 10 stops the operation of one bonding site (electrode pad) when the determination result in the determination unit 53 does not become a good determination within a predetermined time from the start of outputting ultrasonic waves.

  Below, operation | movement of the wire bonding apparatus 10 is demonstrated. FIG. 9 is a flowchart showing an operation flow of the wire bonding apparatus 10.

In step S1, the position control unit 56 supplies position control signals S _{P1 to} S _P4 to the XY stage 33, the bonding head driving mechanism 32, and the optical head moving mechanisms 44 and 45, respectively, and the bonding head 20 and the optical heads 41 to 41 are supplied. 43 is positioned. As a result, the capillary 23 moves to the wire bonding position of the semiconductor chip 200 and the optical heads 41 to 43 move to positions corresponding to the wire bonding position.

In step S2, the optical heads 41, 42, and 43 emit measurement light L _X , L _Y, and L _Z , respectively. Measuring light _{L Y} emitted from the optical head 41 is irradiated on the side surface _{S 2} of the semiconductor chip 200, the measurement light _{L X} emitted from the optical head 42 is irradiated to the side surface _{S 3} of the semiconductor chip 200 (FIG. 6 reference). Measuring light L _Z emitted from the optical head 43 is reflected by the reflecting mirror 60 and is irradiated to the bonding target surface S ₁ of the semiconductor chip 200 (see FIG. 7).

In step S <b> 3, the ultrasonic control unit 55 supplies the ultrasonic drive signal _SU to the piezoelectric element 21. As a result, the bonding head 20 outputs ultrasonic waves in a state where the FAB 301 formed at the tip of the capillary 23 is pressed against the semiconductor chip 200 as shown in FIG. The semiconductor chip 200 vibrates with the ultrasonic wave output from the bonding head 20. The optical heads 41, 42, and 43 output beat signals S _BY , S _BX, and S _BZ corresponding to the vibration state of the semiconductor chip 200, respectively. The optical heads 41, 42, and 43 continue to emit the measurement lights L _X , L _Y, and L _Z while the ultrasonic waves are being output from the bonding head 20, and output beat signals S _BY , S _BX, and S _BZ . To continue.

In step S4, the arithmetic processing unit 51 extracts a Doppler shift frequency component from the beat signals S _BY , S _BX, and S _BZ supplied from the optical heads 41, 42, and 43, respectively, and performs predetermined arithmetic processing. The arithmetic processing unit 51 outputs vibration detection signals S _DY , S _DX, and S _DZ indicating vibration amplitudes of the semiconductor chip 200 in the Y direction, X direction, and Z direction (that is, displacement amounts due to ultrasonic vibration). The arithmetic processing unit 51 continues outputting the vibration detection signals S _DY , S _DX, and S _DZ while the ultrasonic wave is output from the bonding head 20. The vibration detection signals S _DY , S _DX and S _DZ output from the arithmetic processing unit 51 are stored in the storage unit 52.

Here, FIG. 10 is a diagram illustrating an example of a time transition of the vibration detection signals S _DY , S _DX, and S _DZ output from the arithmetic processing unit 51. In FIG. 10, a period from time t ₁ to t ₂ is an ultrasonic wave output period in the bonding head 20. Incidentally, in FIG. 10 is shown also to the time course of the ultrasonic drive signal S _U.

In step S <b> 5, the determination unit 53 determines the quality of the bonding state between the semiconductor chip 200 and the wire based on the vibration detection signals S _DY , S _DX, and S _DZ stored in the storage unit 52. Determining unit 53, for example, the vibration amplitude _{A X} and _A ratio of _{Z R 1 (= A X /} A Z), the vibration amplitude _{A Y} and the ratio _{R 2 (= A Y / A} Z) of the _{A Z} and the vibration amplitude A The ratio R ₃ (= A _X / A _Y ) between _X and A _Y is calculated. The determination unit 53 compares the calculated amplitude ratios R ₁ , R _2, and R ₃ with upper and lower limit values determined in advance, and any of the amplitude ratios R ₁ , R _2, and R ₃ is the upper / lower limit value. If it is not within the range, it is determined that the bonding state between the semiconductor chip 200 and the wire is not good. On the other hand, the determination unit 53 determines that the bonding state between the semiconductor chip 200 and the wire is good when all of the amplitude ratios R ₁ , R _2, and R ₃ are within the upper and lower limit values. The upper and lower limit values for the amplitude ratios R ₁ , R _2, and R ₃ are preferably determined for each wire bonding position (for each electrode pad) in the semiconductor chip 200. If the determination unit 53 determines that the bonding state between the semiconductor chip 200 and the wire is good, the process proceeds to step S <b> 6, and if it is determined that the bonding state is not good, the process proceeds to step S <b> 6. Proceed to S8.

In step S <b> 6, the ultrasonic control unit 55 stops outputting ultrasonic waves from the bonding head 20. Further, the optical heads 41, 42, and 43 stop the output of the measurement lights L _Y , L _X, and L _Z , respectively.

  In step S7, it is determined whether or not the bonding of the wires to all the electrode pads of the semiconductor chip 200 has been completed. If the bonding of the wires to all the electrode pads has not been completed, the process returns to step S1. As a result, the bonding of the wire to the next electrode pad is started. When the bonding of the wires to all the electrode pads has been completed, this routine ends.

  On the other hand, if it is determined in step S5 that the bonding state between the semiconductor chip 200 and the wire is not good, whether or not a predetermined time has elapsed since the output of ultrasonic waves from the bonding head 20 was started in step S8. Is determined. If it is determined in step S8 that the predetermined time has not elapsed, the process proceeds to step S9.

In step S <b> 9, the adjustment unit 54 derives a correction value N for adjusting the amplitude of ultrasonic vibration in the bonding head 20 and supplies this to the ultrasonic control unit 55. For example, the adjustment unit 54 derives the correction value N so that the amplitude ratios R ₁ , R _2, and R ₃ supplied from the determination unit 53 are within the range of the upper and lower limit values. The correction value N may be a value that is uniquely determined according to the amount of deviation from the upper and lower limit values of the amplitude ratios R ₁ , R _2, and R ₃ . For example, adjusting unit 54 functions _{N = f (e 1, e} 2 of the deviation amount _{e 1,} e 2, _{e 3} from the upper and lower limits of each of the amplitude ratio _R 1, _{R 2} and _{R 3} variables, The correction value N may be derived from e ₃ ). Ultrasonic control unit 55 supplies the ultrasonic drive signal S _U corrected according to the correction value N supplied from the adjustment unit 54 to the piezoelectric element 21. Thereby, the amplitude of the ultrasonic vibration output from the bonding head 20 changes in a direction in which the amount of deviation from the upper and lower limit values of the amplitude ratios R ₁ , R ₂ and R ₃ is reduced.

Thereafter, the process returns to step S4. The processes in steps S4, S5, S8, and S9 are repeated until it is determined in step S5 that the bonding state between the semiconductor chip 200 and the wire is good. However, when a predetermined time has elapsed after the ultrasonic wave output from the bonding head 20 is started, the process proceeds to step S10, and the operation of the wire bonding apparatus 10 is stopped. That is, if the amplitude ratios R ₁ , R _2, and R ₃ do not converge within the upper and lower limit values even after adjusting the ultrasonic output in the bonding head 20, the wire bonding apparatus 10 stops its operation.

  As is apparent from the above description, the wire bonding apparatus 10 according to the present embodiment has a laser Doppler vibrometer that detects the vibration state of the bonding target object during wire bonding. The laser Doppler vibrometer is an optical head 41, 42 that irradiates a laser beam to an object to be joined from the Y direction along the vibration direction of ultrasonic vibration, the X direction orthogonal to the Y direction, and the Z direction orthogonal to the XY plane. 43. That is, the laser Doppler vibrometer detects the state of vibration in the Y direction, the X direction, and the Z direction of the objects to be joined. Thus, it is possible to accurately grasp the behavior of the object to be joined at the time of wire bonding by detecting the vibration state of the object to be welded in the above three directions determined based on the ultrasonic vibration direction. is there.

  In addition, the wire bonding apparatus 10 according to the present embodiment determines whether or not the bonding state between the wire and the bonding target object is good based on the vibration states of the bonding target objects in the three directions. Since the behavior of the bonding target object during wire bonding is closely related to the bonding quality of the wire, according to the wire bonding apparatus 10 according to the present embodiment, the quality determination of the bonding state between the wire and the bonding target object is performed. Can be performed accurately.

  Further, it is known that when wire bonding is performed at a corner portion of a semiconductor chip, a rotational motion as shown in FIG. 11 occurs in the semiconductor chip. That is, since the behavior of the semiconductor chip during wire bonding changes between the corner portion of the semiconductor chip and other portions, there may be a difference in wire bonding quality between the corner portion of the semiconductor chip and other portions. is there. When the semiconductor chip is bonded to the substrate using a low-elasticity adhesive, the rotational movement of the semiconductor chip increases, so the difference in bonding quality between the corner of the semiconductor chip and other parts Becomes more prominent. According to the wire bonding apparatus 10 according to the present embodiment, since vibrations in the above three directions of the bonding target are detected, the rotational motion generated in the bonding target can be captured and reflected in the determination of the quality of the bonded state. Can do.

Further, in the wire bonding apparatus 10 according to the present embodiment, the measurement light L _Z is irradiated to the bonding target surface S ₁ in the traveling direction is changed by the reflection mirror 60. Thus, it is possible to reduce the scale of comparison to devices with the case of directly irradiating the measurement light L _Z on the bonding target surface S _1. That is, when irradiating the direct measurement light L _Z on the bonding target surface S _1, it is necessary to install an optical head and an optical head moving mechanism above the stationary stage 31. On the other hand, as in the present embodiment, by controlling the traveling direction of the measurement light L _Z by using a reflection mirror 60, it is possible to increase the freedom of arrangement of the optical head 43 for emitting the measurement light L _Z. In the present embodiment, the optical head 43 for emitting the measurement light L _Z is because it is arranged on the XY stage 33, the moving mechanism of the optical head 43 is not required.

Further, in the wire bonding apparatus 10 according to the present embodiment, the measurement light L _Y, L _X and L _Z is irradiated to a position corresponding to the wire bonding positions of the bonding object. Thereby, it becomes possible to suppress the variation in the quality determination accuracy of the bonding state between the bonding object and the wire due to the change in the wire bonding position.

  Further, the wire bonding apparatus 10 according to the present embodiment is based on the detected vibration state of the bonding target object when the result of the quality determination of the bonding state between the wire and the bonding target object is not a good determination. The ultrasonic output in the bonding head 20 is changed. In this way, by performing feedback control of the ultrasonic output from the bonding head 20, it is possible to improve the bonding quality between the wire and the object to be bonded.

In addition, the wire bonding apparatus 10 according to the present embodiment is configured so that the wire and the bonding object are based on the relative ratio of the vibration amplitude in the Y direction, the X direction, and the Z direction of the bonding object detected by the laser Doppler vibrometer. The quality of the bonding state between the two is determined. Here, FIG. 12A is a diagram illustrating a time transition of the vibration detection signals S _DY , S _DX, and S _DZ at the time of wire bonding (when ultrasonic waves are applied) when the bonding state between the wire and the semiconductor chip is good. . On the other hand, FIG. 12B is a diagram showing a time transition of the vibration detection signals S _DY , S _DX and S _{DZ at} the time of wire bonding (at the time of applying ultrasonic waves) when the bonding state between the wire and the semiconductor chip is not good. 12A and 12B, the bonding state between the wire and the semiconductor chip is reflected in the relative ratio of the vibration amplitude in the Y direction, the X direction, and the Z direction of the semiconductor chip. In the wire bonding apparatus 10 according to the present embodiment, the quality determination of the bonding state between the wire and the bonding target is performed based on the relative ratio of the amplitude of vibration in the Y direction, the X direction, and the Z direction of the bonding target. Therefore, an accurate determination result can be obtained.

[Second Embodiment]
FIG. 13 is a block diagram illustrating a configuration of a wire bonding apparatus 10A according to the second embodiment of the disclosed technique. 10 A of wire bonding apparatuses are not provided with the adjustment part 54 (refer FIG. 1) with which the wire bonding apparatus 10 which concerns on 1st Embodiment is provided. Further, in the wire bonding apparatus 10A according to the second embodiment, the determination unit 53 includes a non-volatile memory 53a that stores the determination result of the bonding state derived by itself. The memory 53a may be provided outside the determination unit 53.

  FIG. 14 is a flowchart showing an operation flow of the wire bonding apparatus 10A. Steps S1 to A4, S6 and S7 in this flowchart are the same as steps S1 to A4, S6 and S7 in the flowchart according to the first embodiment shown in FIG. Hereinafter, parts different from the operation of the wire bonding apparatus 10 according to the first embodiment will be described.

In step S <b> 5 </ b> A, the determination unit 53 determines the quality of the bonding state between the semiconductor chip 200 and the wire based on the vibration detection signals S _DY , S _DX, and S _DZ stored in the storage unit 52. The determination method in the determination unit 53 is the same as that of the wire bonding apparatus 10 according to the first embodiment.

  In step S5B, the determination unit 53 stores the determination result derived in step S5A in the memory 53a together with the identification code of the wire bonding position. The identification code of the wire bonding position may be an identification number assigned to each electrode pad of the semiconductor chip 200, for example.

  The processes from step S1 to S7 are repeated until the bonding of the wires to all the electrode pads is completed. That is, the quality determination result of the bonding state with the wire for all the electrode pads is stored in the memory 53a.

  As described above, the wire bonding apparatus 10 </ b> A according to the second embodiment does not include the adjustment unit 54 (see FIG. 1) included in the wire bonding apparatus 10 according to the first embodiment. Feed control for sound wave output is not performed. In the wire bonding apparatus 10A, the quality determination result of the bonded state is stored in the memory 53a for all the electrode pads subjected to wire bonding. In this way, by leaving a history of determination results, it is possible to take a countermeasure such as performing a follow-up survey or performing wire bonding again for electrode pads that have not been determined to be good. In addition, you may provide the adjustment part 54 in 10 A of wire bonding apparatuses which concern on 2nd Embodiment.

In each of the above embodiments, the determination unit 53 determines whether or not the relative ratios of the vibration amplitudes A _Y , A _X , and A _Z in the Y direction, X direction, and Z direction of the objects to be joined are within predetermined ranges. The case where the quality determination of the joining state is performed by determining whether or not is performed is illustrated. However, it is not limited to this aspect. For example, the determination unit 53, the vibration detection signal _{S DY,} S _DX, the vibration waveform _W DY showing a temporal transition of _{S DZ,} W _DX, the _{W DZ,} compared corresponding reference waveform _{W SY,} W _SX, and _{W SZ} You may determine the quality of a joining state based on a result. The reference waveforms W _SY , W _SX , and W _SZ can be acquired based on, for example, vibration detection signals S _DY , S _DX , and S _DZ when the bonding state between the wire and the bonding target is good. For example, the determination unit 53 uses index values M _Y , M _X , and M _Z that indicate the similarity between the vibration waveforms W _DY , W _DX , and W _DZ and the corresponding reference waveforms W _SY , W _SX , and W _SZ. It may be determined that the joined state is good when all of the derived index values M _Y , M _X , and M _Z are equal to or greater than the threshold value (that is, when the similarity is high). On the other hand, when any of the derived index values M _Y , M _X , and M _Z is smaller than the threshold value (that is, when the similarity is low), it may be determined that the joining state is not good.

Further, in each of the above-described embodiments, the case where the arithmetic processing unit 51 outputs the vibration detection signals S _DY , S _DX and S _DZ indicating the displacement in the Y direction, the X direction, and the Z direction of the objects to be joined has been illustrated. However, it is not limited to this embodiment. The arithmetic processing unit 51 may output vibration detection signals S _DY , S _DX, and S _DZ that indicate vibration speeds in the Y direction, X direction, and Z direction of the objects to be joined. In this case, the determination unit 53 determines whether or not the joining state is good by determining whether or not the relative ratio of the peak values of the vibration speeds in the Y direction, the X direction, and the Z direction of the objects to be joined is within a predetermined range. You may go. Moreover, you may judge the quality of a joining state by comparing the vibration waveform which shows the time transition of the vibration speed of the Y direction of a joining target object, a X direction, and a Z direction with a reference | standard waveform.

  Further, in each of the above embodiments, the case where the adjustment unit 54 adjusts the ultrasonic output in the bonding head 20 is exemplified, but other parameters such as the load, the bonding time, and the ultrasonic frequency at the time of wire bonding are output as ultrasonic waves. In addition, it may be adjusted instead of the ultrasonic output.

Further, in the above embodiments, the measurement light L _Z a through reflecting mirror 60 has been illustrated a structure for irradiating the bonding target surface S ₁ of the bonding target, the measurement light L _Z direct bonding target surface S ₁ May be irradiated.

  In each of the above-described embodiments, the case where the state of vibration in the three directions of the bonding target object is detected by irradiating the bonding target object with the laser beam from the three directions is illustrated, but the present invention is not limited thereto. is not. The state of vibrations in the four or more directions of the bonding target may be detected by irradiating the bonding target with laser light from four or more directions.

  The wire bonding apparatus 10 is an example of a bonding apparatus in the disclosed technology. The bonding head 20 is an example of a bonding head in the disclosed technology. The optical heads 41, 42, and 43 and the calculation unit processing unit 51 constituting the Doppler vibrometer are an example of a vibration detection unit in the disclosed technology. The determination unit 53 is an example of a determination unit in the disclosed technology. The XY stage 33 and the optical head moving mechanisms 44 and 45 are examples of moving mechanisms in the disclosed technology. The adjustment unit 54 is an example of an adjustment unit in the disclosed technology. The memory 53a is an example of a storage unit of the disclosed technology. The reflection mirror 60 is an example of a mirror according to the disclosed technology.

  Regarding the above first and second embodiments, the following additional notes are disclosed.

(Appendix 1)
A bonding head for bonding a wire to an object to be bonded by pressure bonding with ultrasonic vibration;
A first direction along a vibration direction of the ultrasonic vibration, a second direction intersecting with the first direction, and a third direction intersecting with a plane determined by the first direction and the second direction. A vibration detection unit that irradiates the object to be joined from at least three directions including the laser beam and detects a state of vibration of the object to be joined in the at least three directions based on reflected light reflected by the object to be joined. When,
A determination unit configured to perform a determination on a bonding state between the wire and the bonding target object based on a vibration state in the at least three directions of the bonding target object detected by the vibration detection unit;
A wire bonding apparatus including:

(Appendix 2)
The joining object has a rectangular parallelepiped outer shape,
2. The wire bonding apparatus according to claim 1, wherein the vibration detection unit irradiates the laser beam to a bonding target surface to which the wire of the bonding target object is bonded and two adjacent surfaces that intersect the bonding target surface. .

(Appendix 3)
The wire bonding apparatus according to claim 2, further comprising a reflection unit that reflects incident laser light toward the bonding target surface.

(Appendix 4)
The wire bonding apparatus according to any one of appendix 1 to appendix 3, further including a moving mechanism that moves the irradiation position of the laser beam in accordance with the movement of the bonding position of the wire in the bonding object.

(Appendix 5)
The storage unit for storing, for each bonding position of the wire, a determination result regarding the bonding state between the wire and the bonding target derived by the determination unit. The wire bonding apparatus as described in.

(Appendix 6)
The vibration detection unit detects a displacement or speed in the at least three directions of the joining objects,
The determination unit performs a determination on a bonding state between the wire and the bonding target based on a relative ratio of displacements or velocities in the at least three directions of the bonding target detected by the vibration detection unit. The wire bonding apparatus according to any one of appendix 1 to appendix 5.

(Appendix 7)
The vibration detection unit detects a displacement or speed in the at least three directions of the joining objects,
The determination unit is configured to determine whether a vibration waveform indicating a time transition of displacement or a time transition of speed in the at least three directions of the bonding target object is between the wire and the bonding target object based on a result of comparison with a reference waveform. The wire bonding apparatus according to any one of Supplementary Note 1 to Supplementary Note 5, wherein a determination relating to a bonding state is performed.

(Appendix 8)
The state of vibration in the at least three directions of the joining object detected by the vibration detecting unit when the result of the judgment on the joining state between the wire and the joining object by the judging unit is not good The wire bonding apparatus according to any one of appendix 1 to appendix 7, further including an adjustment unit that changes a magnitude of the ultrasonic vibration based on the above.

(Appendix 9)
9. The wire bonding apparatus according to claim 8, wherein the operation is stopped when a result of a determination regarding a state of bonding between the wire and the bonding target by the determination unit is not a good determination within a predetermined time.

(Appendix 10)
The wire bonding apparatus according to claim 3, wherein the reflection unit includes two mirrors juxtaposed with the bonding head interposed therebetween.

(Appendix 11)
The wire bonding apparatus according to any one of Supplementary Note 1 to Supplementary Note 10, wherein the vibration detection unit irradiates the laser light at a position corresponding to a joining position of the wire of the joining object.

(Appendix 12)
A wire bonding method for bonding a wire to an object to be bonded by pressure bonding with ultrasonic vibration,
A first direction along a vibration direction of the ultrasonic vibration, a second direction intersecting with the first direction, and a third direction intersecting with a plane determined by the first direction and the second direction. Irradiating the joining object with laser light from at least three directions including:
Based on the reflected light reflected by the joining object, the state of vibration of the joining object in the at least three directions is detected,
A wire bonding method that performs a determination on a bonding state between the wire and the bonding object based on the detected vibration state of the bonding object.

(Appendix 13)
The wire bonding method according to claim 12, wherein the laser beam is irradiated to a bonding target surface to which the wire of the bonding target object having a rectangular parallelepiped shape is bonded and to two adjacent surfaces intersecting the bonding target surface.

(Appendix 14)
The wire bonding method according to claim 13, wherein one of the laser beams is reflected and irradiated to the bonding target surface.

(Appendix 15)
The wire bonding method according to any one of appendix 12 to appendix 14, wherein the laser beam irradiation position is moved in accordance with the movement of the bonding position of the wire in the bonding object.

(Appendix 16)
The wire bonding method according to any one of Supplementary Note 12 to Supplementary Note 15, wherein a determination result related to a joint state between the wire and the joint target is stored for each joint position of the wire.

(Appendix 17)
Detecting displacements or velocities in the at least three directions of the joining objects,
The determination as to the bonding state between the wire and the bonding object is performed based on a relative ratio of displacement or velocity in the at least three directions of the bonding object. Wire bonding method.

(Appendix 18)
Detecting displacements or velocities in the at least three directions of the joining objects,
Judgment regarding the joining state between the wire and the joining object based on the result of comparing the vibration waveform indicating the time transition of displacement or the time transition of the speed in the at least three directions of the joining object with a reference waveform. The wire bonding method according to any one of appendix 12 to appendix 16.

(Appendix 19)
When the result of the determination regarding the bonding state between the wire and the bonding object is not a good determination, the magnitude of the ultrasonic vibration is determined based on the vibration state in the at least three directions of the bonding object. The wire bonding method according to any one of appendix 12 to appendix 18, wherein the wire bonding method is changed.

(Appendix 20)
The wire bonding method according to claim 19, wherein the operation is stopped when a result of the determination regarding the bonding state between the wire and the bonding target object does not become a good determination within a predetermined time.

(Appendix 21)
The wire bonding method according to any one of appendix 12 to appendix 20, wherein the laser beam is irradiated to a position corresponding to a bonding position of the wire of the bonding target object.

DESCRIPTION OF SYMBOLS 10 Wire bonding apparatus 20 Bonding head 33 XY stage 41, 42, 43 Optical head 44, 45 Optical head moving mechanism 51 Operation processing part 53 Determination part 53a Memory 54 Adjustment part 55 Ultrasonic control part 56 Position control part

Claims (10)

A bonding head for bonding a wire to an object to be bonded by pressure bonding with ultrasonic vibration;
A first direction along a vibration direction of the ultrasonic vibration, a second direction intersecting with the first direction, and a third direction intersecting with a plane determined by the first direction and the second direction. A vibration detection unit that irradiates the object to be joined from at least three directions including the laser beam and detects a state of vibration of the object to be joined in the at least three directions based on reflected light reflected by the object to be joined. When,
A determination unit configured to perform a determination on a bonding state between the wire and the bonding target object based on a vibration state in the at least three directions of the bonding target object detected by the vibration detection unit;
A wire bonding apparatus including: The joining object has a rectangular parallelepiped outer shape,
2. The wire bonding according to claim 1, wherein the vibration detection unit irradiates the laser beam to each of a bonding target surface to which the wire of the bonding target object is bonded and two adjacent surfaces intersecting the bonding target surface. apparatus. The wire bonding apparatus according to claim 2, further comprising a reflection unit that reflects incident laser light toward the bonding target surface. The wire bonding apparatus according to any one of claims 1 to 3, further comprising a moving mechanism that moves the irradiation position of the laser light in accordance with the movement of the bonding position of the wire in the bonding target object. The memory | storage part which memorize | stores the result of the determination regarding the joining state between the said wire and the said joining object derived | led-out by the said determination part for every joining position of the said wire. Item 1. A wire bonding apparatus according to item 1. The vibration detection unit detects a displacement or speed in the at least three directions of the joining objects,
The determination unit performs a determination on a bonding state between the wire and the bonding target based on a relative ratio of displacements or velocities in the at least three directions of the bonding target detected by the vibration detection unit. The wire bonding apparatus of any one of Claims 1-5. The vibration detection unit detects a displacement or speed in the at least three directions of the joining objects,
The determination unit is configured to determine whether a vibration waveform indicating a time transition of displacement or a time transition of speed in the at least three directions of the bonding target object is between the wire and the bonding target object based on a result of comparison with a reference waveform. The wire bonding apparatus according to any one of claims 1 to 5, wherein a determination relating to a bonding state is performed. The state of vibration in the at least three directions of the joining object detected by the vibration detecting unit when the result of the judgment on the joining state between the wire and the joining object by the judging unit is not good The wire bonding apparatus according to claim 1, further comprising: an adjustment unit that changes a magnitude of the ultrasonic vibration based on the frequency. The wire bonding apparatus according to claim 8, wherein the operation is stopped when a result of determination regarding a bonding state between the wire and the bonding target by the determination unit is not good determination within a predetermined time. A wire bonding method for bonding a wire to an object to be bonded by pressure bonding with ultrasonic vibration,
A first direction along a vibration direction of the ultrasonic vibration, a second direction intersecting with the first direction, and a third direction intersecting with a plane determined by the first direction and the second direction. Irradiating the joining object with laser light from at least three directions including:
Based on the reflected light reflected by the joining object, the state of vibration of the joining object in the at least three directions is detected,
A wire bonding method that performs a determination on a bonding state between the wire and the bonding object based on the detected vibration state of the bonding object.