Wire bonding apparatus and control method

Abstract

To prevent wire bonding defects from occurring.SOLUTION: According to an embodiment, a control unit of a wire bonding apparatus calculates the height of a bump on the basis of the diameter of a ball-shaped portion detected by a diameter detection unit, the first position of a bonding tool detected by a position detection unit when a load sensor detects a load at a first bonding point, and the second position of the bonding tool when the bonding tool descends at the first bonding point, and then bonds a wire on the basis of the calculated height of the bump.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a wire bonding apparatus and a control method. [Background technology]

[0002] A known technique involves calculating the bump height for each bonding coordinate of an electronic component based on flatness data, forming bumps on the electronic component by wire bonding according to this bump height, and then bonding each bump on the electronic component to a corresponding electrode on a substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3775924 Summary of the Invention [Problem to be solved by the invention]

[0004] In a wire bonding apparatus, it is desirable to suppress the occurrence of poor bonding of the wire.

[0005] The embodiments of the present invention provide a wire bonding apparatus and a control method that can suppress the occurrence of poor bonding of wires. [Means for solving the problem]

[0006] According to an embodiment, a wire bonding apparatus bonds a wire to a first bonding point and a second bonding point by generating ultrasonic vibrations while pressing the wire against the first bonding point and the second bonding point, respectively. The wire bonding apparatus includes a bonding tool, an ultrasonic horn, a load sensor, a position detection unit, a diameter detection unit, and a control unit. The ultrasonic horn generates ultrasonic vibrations. The load sensor detects a load applied from the bonding tool to the first bonding point or the second bonding point. The position detection unit detects the vertical position of the bonding tool. The diameter detection unit detects the diameter of a ball-shaped portion formed at the tip of the bonding tool at the first bonding point. The control unit calculates the height of a bump and bonds the wire based on the calculated bump height. The height of the bump is calculated based on the diameter of the ball-shaped portion detected by the diameter detection unit, the first position of the bonding tool detected by the position detection unit when the load sensor detects a load at the first bonding point, and the second position of the bonding tool when the bonding tool is at its lowest point at the first bonding point. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic view showing an example of a wire bonding apparatus according to a first embodiment. [Figure 2] FIG. 1 is a schematic view showing a part of a wire bonding apparatus according to a first embodiment. [Figure 3] 10A and 10B are diagrams for explaining the process of joining wires. [Figure 4] 10A to 10C are diagrams showing an example of a wire bonding step. [Figure 5] 10A to 10C are diagrams illustrating an example of a process for forming a leading bump. [Figure 6] 10 is a flowchart showing an example of a process for calculating a bump height. [Figure 7] FIG. 10 is a diagram for explaining an example of a method for calculating the bump height of a second bump. [Figure 8] 10A and 10B are a flowchart showing an example of a process for changing the conditions of the second bonding step based on the bump height of the wire bonding apparatus according to the second embodiment, and a diagram showing an example of a correspondence relationship with the bump formation process of the wire bonding apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In this specification and in each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted where appropriate.

[0009] (First embodiment) FIG. 1 is a schematic diagram showing a wire bonding apparatus according to an embodiment. FIG. 2 is a schematic diagram showing a part of the wire bonding apparatus according to the embodiment. As shown in Figures 1 and 2, the wire bonding apparatus 100 according to the embodiment includes a bonding head 10, a position detection unit 10a, an XY stage 20, a bonding stage 30, a load sensor 40, a camera device 50, and a control unit 60.

[0010] The bonding head 10 includes a bonding tool 11, an ultrasonic horn 12, a bonding arm 13, and a drive unit 14.

[0011] The bonding tool 11 pays out a wire 3 that serves as a bonding material. The bonding tool 11 is, for example, a bonding capillary. The wire 3 is, for example, an aluminum wire, a gold wire, a silver wire, or a copper wire. The bonding tool 11 brings the wire 3 into contact with a portion to be joined 2 of the workpiece 1 placed on a bonding stage 30, and applies a load to the portion to be joined 2. In this embodiment, the portion to be joined 2 is a first bonding point P1 and a second bonding point P2, which will be described later.

[0012] The position detection unit 10a detects the position in the Z direction of the bonding tool 11. For example, an origin is defined at a predetermined position, and the position detection unit 10a detects the position of the bonding tool 11 in the vertical direction from this origin. The position detection unit 10a is connected to the control unit 60 so as to be able to communicate with it.

[0013] The ultrasonic horn 12 generates ultrasonic vibrations. The ultrasonic horn 12 has an ultrasonic vibrator that generates the ultrasonic vibrations. The ultrasonic horn 12 supports the bonding tool 11. The ultrasonic vibrations generated from the ultrasonic horn 12 are transmitted to the wire 3 via the bonding tool 11. When the wire 3 is in contact with the part to be bonded 2, the ultrasonic vibrations are transmitted to the wire 3, thereby bonding the wire 3 to the part to be bonded 2. The ultrasonic horn 12 is electrically connected to the control unit 60.

[0014] Bonding arm 13 supports ultrasonic horn 12. That is, bonding arm 13 supports bonding tool 11 via ultrasonic horn 12. Bonding arm 13 is provided rotatable about shaft 13a.

[0015] The driving unit 14 drives the bonding arm 13 in the Z direction around the shaft 13a. The driving unit 14 is, for example, a linear motor. As the bonding arm 13 moves in the Z direction, the bonding tool 11 and the ultrasonic horn 12 supported by the bonding arm 13 move in the Z direction. As the bonding tool 11 moves in the Z direction, the wire 3 can be brought into contact with the bonding tool 11 at a first bonding point P1 and a second bonding point P2, which will be described later, and a load can be applied from the bonding tool 11. The driving unit 14 is connected to the control unit 60 so as to be able to communicate with the control unit 60.

[0016] In this specification, the direction connecting the bonding tool 11 and the workpiece 1 is defined as the Z direction, the direction perpendicular to the Z direction is defined as the X direction, and the direction perpendicular to the Z and X directions is defined as the Y direction.

[0017] The bonding head 10 is mounted on an XY stage 20. The XY stage 20 is movable in the X and Y directions. When the XY stage 20 moves in the X and Y directions, the bonding head 10 moves in the X and Y directions. In other words, the XY stage 20 functions as a positioning means for positioning the bonding tool 11 and other components provided on the bonding head 10 in the X and Y directions. The XY stage 20 is connected to a control unit 60 so as to be able to communicate with the control unit 60.

[0018] The bonding stage 30 supports the workpiece 1, which is the target of wire bonding. The bonding stage 30 supports the workpiece 1, for example, by suction. The workpiece 1 is, for example, a semiconductor chip such as an IC chip or a substrate.

[0019] The load sensor 40 continuously detects the load applied from the bonding tool 11 to the portion to be bonded 2 of the workpiece 1. The load sensor 40 has, for example, a strain gauge. The load sensor 40 may also detect the load applied to the tip of the bonding tool 11 on the workpiece 1 side. In this example, the load sensor 40 is attached to the bonding arm 13. The load sensor 40 is connected to the control unit 60 so as to be able to communicate with the control unit 60. The load sensor 40 outputs data of the detected load to the control unit 60.

[0020] For example, the camera device 50 photographs a ball-shaped portion (described later) formed at the tip of the bonding tool 11 at a first bonding point P1 (described later) based on an instruction from the control unit 60. The camera device 50 is connected to the control unit 60 so as to be able to communicate with the control unit 60. Image data representing the image photographed by the camera device 50 is transmitted to the control unit 60.

[0021] The control unit 60 controls the operations of the ultrasonic horn 12, the drive unit 14, and the XY stage 20. The control unit 60 controls the ultrasonic horn 12, thereby controlling the output of ultrasonic vibrations generated from the ultrasonic horn 12.

[0022] The control unit 60 can control the operation of the bonding tool 11 by controlling the operation of the drive unit 14. More specifically, the control unit 60 can control the position of the bonding tool 11 in the Z direction by controlling the drive unit 14 to drive the bonding arm 13 in the Z direction. In this way, the control unit 60 can control the magnitude of the load applied from the bonding tool 11 to the part to be bonded 2.

[0023] The position detection unit 10a acquires the position in the Z direction of the bonding tool 11 driven by the drive unit 14. The position detection unit 10a may be included in the control unit 60. For example, the position detection unit 10a includes an encoder. When the motor of the drive unit 14 operates, the position detection unit 10a detects the rotation direction and rotation position of the motor. The position detection unit 10a calculates the position of the bonding tool 11 in the Z direction from the detected rotation direction and position.

[0024] The control unit 60 can control the operation of the bonding tool 11 by controlling the operation of the XY stage 20. More specifically, the control unit 60 can control the positions of the bonding tool 11 in the X and Y directions by controlling the XY stage 20 to drive the bonding head 10 in the X and Y directions.

[0025] The control unit 60, as will be described in detail later, calculates the bump height t1 based on the diameter of the ball-shaped portion BO detected by the camera device 50, the Z position (first position) in the Z direction of the bonding tool detected by the position detection unit 10a when the load sensor 40 detects a load at the first bonding point P1, and the Z position (second position) in the Z direction of the bonding tool 11 when the bonding tool 11 descends at the first bonding point P1, and joins the wire 3 based on this calculated bump height t1.

[0026] A bump 2a is formed on a portion to be bonded 2 of a workpiece 1 placed on a bonding stage 30. A wire 3 is bonded to the bump 2a. A wire bonding apparatus 100 performs the formation of the bump 2a and bonding of the wire 3 to the bump 2a. For example, as shown in FIG. 2 , the wire bonding apparatus 100 bonds the wire 3 to the portion to be bonded 2 by generating ultrasonic vibrations from an ultrasonic horn 12 while pressing the wire 3, which is fed from a bonding tool 11, against the portion to be bonded 2.

[0027] FIG. 3 is a diagram for explaining the flow of joining the wires 3. In the following, the case where the workpiece 1 is an IC chip (hereinafter referred to as "chip") will be explained. The joining process of the wires 3 is executed in order, such as the first chip C1, the second chip C2, ..., the Nth chip Cn (n: natural number). In each chip, for example, the first chip C1, a plurality of wires W11, W12, ..., W1m (m: natural number) are joined in order to each of the parts to be joined 2. Next, in the second chip C2, a plurality of wires 3 are joined in order to each of the parts to be joined 2. In this way, the wires in the chip are joined in order for each chip.

[0028] Next, a description will be given of the step of joining the wire 3. Figure 4 shows an example of the wire joining step. As shown in Figure 4, the wire bonding process includes three steps: a bump bonding process (Figure 4(a)), a first bonding process (Figure 4(b)), and a second bonding process (Figure 4(c)). A chip C is placed on a substrate BA. A first bonding point P1 is located on the chip C, and a second bonding point P2 is located on the substrate BA. A wire 3 is bonded to the bumps formed at the first bonding point P1 and the second bonding point P2.

[0029] First, as shown in FIG. 4(a), a bump bonding process is performed. A bump B1 is formed at a first bonding point P1. A bonding tool 11 is positioned above the first bonding point P1 on the chip C. A wire 3 passes through the bonding tool 11. The tip of the wire 3 is positioned at the first bonding point P1 on the chip C, and a load is applied to the wire 3. The tip of the wire 3 becomes a bump on the chip C, and the wire is cut by ultrasonic waves, forming a bump B1 on the chip C. Then, the bonding tool 11 is moved from above the first bonding point P1 to above the second bonding point P2.

[0030] Next, as shown in Fig. 4(b), the first bonding step is performed. With the bump B1 formed on the chip C, the bonding tool 11 operates on the second bonding point P2 to press the tip of the wire 3 onto the substrate BA, forming a bump B2.

[0031] Next, as shown in FIG. 4(c), a second bonding step is performed. With the bump B2 formed, the bonding tool 11 moves a predetermined distance in the Z direction, and then the bonding tool 11 bends the wire 3 and moves it from the second bonding point P2 to the first bonding point P1. At this time, the wire 3 is bonded to the bump B1 on the chip C. Then, the wire 3 is cut by ultrasonic vibration, and the wire 3 is bonded to the chip C and the substrate BA. Wire bonding is performed in this manner. Therefore, by accurately calculating the height of the bump B1 and controlling bonding conditions such as the load and ultrasonic output when connecting the wire 3 according to the calculated height, it is possible to prevent poor wire bonding. .

[0032] Next, a more detailed description will be given of the step of forming the leading bump B1 on the chip C. Figure 5 is a diagram for explaining an example of the step of forming the bump B1. As shown in FIG. 5, in this embodiment, the process of forming a bump includes a search process R1, a bonding process R2, a reversing process R3, a lowering process R4, a tail forming process R5, a tail cutting process R6, and a sparking process R7.

[0033] The search process R1 is a process of bringing the ball-shaped portion BO formed at the tip of the wire 3 inserted into the bonding tool 11 into contact with the surface of the chip C. The bonding process R2 is a process of applying load and ultrasonic vibration to the ball-shaped portion BO to crush and bond it to the surface of the chip C. The reverse process R3 is a process of raising the bonding tool 11 a predetermined distance. The lowering process R4 is a process of determining the bump height by shifting the bonding tool 11 in the X direction and then lowering it. The tail forming process R5 is a process of raising the bonding tool 11 to a predetermined position to form a tail. The tail cutting process R6 is a process of applying ultrasonic vibration while raising the bonding tool 11 to separate the tail from the bump B1. In this way, the bump B1 is formed on the chip C. The subsequent spark process R7 is a process of generating a spark at the tip of the wire 3 to melt the wire 3 and form the ball-shaped portion BO.

[0034] 5 shows the vibration state of the ultrasonic vibration (US) in accordance with each of the steps R1 to R7, the Z position of the bonding tool 11, and the detection state of the load sensor 40. a1 indicates the Z position when the load signal detected by the load sensor 40 rises. b1 indicates the Z position when the bonding tool 11 is lowered to the lowest position by the lowering operation. The ball crushing amount h, which indicates the amount by which the ball-shaped portion BO is crushed, is expressed as h a1 -h b1 The Z position h a1 , and Z position h b1 The bump height t1 can be calculated using

[0035] Next, a process for calculating the bump heights of the first bump B1 and the second and subsequent bumps B2 when the control unit 60 performs wire bonding will be described. Fig. 6 is a flowchart showing an example of the process for calculating the bump heights.

[0036] The control unit 60 first detects the bump height of the bump for joining the leading wire W11 on the first chip C1. More specifically, as shown in FIG. 6, the control unit 60 calculates the diameter D of the ball-shaped portion BO from image data captured by the camera device 50 (ST101). For example, the control unit 60 includes an image analysis unit (not shown), which analyzes the image data and calculates the diameter D of the ball-shaped portion BO. For example, the dimension of the ball-shaped portion BO in the vertical direction is used as the diameter D. The dimension of the ball-shaped portion BO in the horizontal direction or in a direction inclined relative to the vertical direction may also be used as the diameter D.

[0037] The position at which the ball-shaped portion BO is photographed may be the position at which the ball-shaped portion BO is formed, as shown in search step R1 in Figure 5, or it may be the position just before the ball-shaped portion BO comes into contact with the chip C after it has been formed.

[0038] Next, the control unit 60 determines the Z position h of the bonding tool 11 in the Z direction. a1 In this embodiment, in the search step R1 described above, the Z position h of the bonding tool 11 when the ball-shaped portion BO comes into contact with the upper surface of the chip C is stored. a1 The control unit 60 may determine whether or not there is contact based on the detection state of the load sensor 40.

[0039] Next, the control unit 60 determines the Z position h b1 The control unit 60 stores the Z position when the bonding tool 11 is lowered to the lowest position in the lowering step R4 shown in FIG. 4 as the Z position h b1 Remember it as.

[0040] Next, the control unit 60 calculates the bump height t1 (ST104). The bump height t1 is calculated by the following equation, where D is the diameter of the ball-shaped portion BO and h is the amount of squashing of the ball. t1=(Dh) Furthermore, the amount of ball squashing h is calculated as h a1 -h b1 Therefore, this formula becomes t1=(D-(h a1 -h b1 )) This allows the control unit 60 to determine the bump height t1 of the leading bump B1.

[0041] Next, the control unit 60 detects the bump height t2 of the second bump B2. More specifically, as shown in FIG. 6, the control unit 60 detects the Z position h b2 (ST1111) and store the Z position h for the first downward movement. b1 and Z position h b2 The difference h2 is calculated, and the bump height t2 is calculated (ST1112). t2=t1-h2 t2=t1-(h b1 -h b2 ) The method for calculating the bump height t2 will be described in more detail with reference to Fig. 7. The difference h2 will be described in Fig. 7.

[0042] FIG. 7 is a diagram for explaining a method for calculating the bump height t2 of the second bump. 7 shows the search process R1, bonding process R2, reversing process R3, and lowering process R4 for each of the bumps B1 and B2. Also shown are the vibration state of the ultrasonic vibration (US), the Z position of the bonding tool 11, and the detection state of the load sensor 40 corresponding to each of the processes R1 to R4.

[0043] The bump height t1 is shown in the descending step R4 when forming the bump B1. The difference h2 is the Z position h when the bonding tool 11 is at its lowest position in the formation of the bump B1. b1 and the Z position h when the bonding tool 11 is at its lowest position in forming the bump B2. b2 and . Also, bump height t2 is shown in the lowering step R4 when forming bump B2. The bump height t2 of bump B2 is calculated using bump height t1 and difference h2.

[0044] In addition, for the third and subsequent bumps B3, for example, up to bump Bn, the control unit 60 controls the Z position h bn (ST111n), t n =(t n-1 -(h b(n-1) -h bn )) the bump height t n can be calculated (ST112n).

[0045] In this way, for the second and subsequent wires, the control unit 60 can calculate the bump height by using the Z position at the time of forming the previous bump. This allows the wire bonding apparatus 100 to limit the process of photographing the ball-shaped portion BO by the camera device 50 and calculating the diameter D to only the first bump B1, thereby suppressing an increase in tact time.

[0046] It is also possible to calculate the amount of ball crushing and the diameter of the ball-shaped portion for bumps B2 and onward.

[0047] According to the wire bonding apparatus 100 described above, the bump heights t1 to t n can be accurately calculated. Therefore, the wire bonding apparatus 100 can accurately connect the wire 3 to the bonded portion 2. Therefore, the wire bonding apparatus 100 can suppress the occurrence of bonding defects of the wire 3. Furthermore, according to the control method of the wire bonding apparatus 100 described above, the occurrence of bonding defects of the wire 3 can also be suppressed.

[0048] Furthermore, the wire bonding apparatus 100 can calculate the bump height t1 in the bump bonding process (see FIG. 3(a)). Based on this calculated bump height t1, the wire bonding apparatus 100 can execute a process of bonding the wire 3 to the bonded portion 2 in the second bonding process (see FIG. 3(c)). There is a processing time of, for example, about 50 ms between the bump bonding process and the second bonding process. Therefore, in the second bonding process, it is possible to ensure time for bonding the wire 3 based on the calculated bump height t1. Furthermore, it becomes possible to quantify the bump height t1.

[0049] (Second embodiment) The second embodiment differs from the first embodiment in that a process for changing the conditions of the second bonding step based on the calculated bump height is added. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions of these components will be omitted.

[0050] FIG. 8 is a flowchart showing an example of processing for changing the conditions of the second bonding step based on the calculated bump height t1, and a diagram showing an example of the correspondence with the bump formation process of the wire bonding apparatus 100.

[0051] 8, the control unit 60 first calculates the bump height t1 (ST201). The method for calculating the bump height t1 of the leading bump B1 is the same as in the first embodiment, and therefore the explanation will be omitted.

[0052] Next, the control unit 60 determines whether the bump height t1 is within a first reference range (ST202). If it is determined that the bump height t1 is within the first reference range (ST202: YES), the control unit 60 performs the second bonding under a first condition (ST203). The first condition may be, for example, at least one of the load applied to the bonding tool 11 and the output of the ultrasonic horn 12.

[0053] On the other hand, if it is determined that the bump height is not within the first reference range (ST202: NO), the control unit 60 determines whether the bump height is within a second reference range (ST204). If it is determined that the bump height is within the second reference range (ST204: YES), the control unit 60 performs a second bonding under a second condition (ST205). The second condition may be, for example, at least one of the load applied to the bonding tool 11 and the output of the ultrasonic horn 12.

[0054] Moreover, when it is determined that the result is not within the second reference range (ST204; NO), the control unit 60 stops the operation of the wire bonding apparatus 100 (ST206). When stopping the operation, the control unit 60 may output information indicating the occurrence of an abnormality to, for example, a preset terminal device.

[0055] The bump height t1 is calculated in the bump bonding process. Then, for example, 25 ms later, the first bonding process is performed. Then, for example, 25 ms later, the second bonding process is performed. Therefore, the control unit 60 can secure a processing time for performing the second bonding process under the first condition or the second condition after calculating the bump height t1 in the bump bonding process.

[0056] According to the wire bonding apparatus 100 and its control method, the conditions of the second bonding step can be changed according to the bump height t1. Furthermore, the control unit 60 of the wire bonding apparatus 100 can stop the operation of the wire bonding apparatus 100 when the bump height t1 is within a second reference range, for example, a range in which an abnormality is detected. At this time, by reporting the occurrence of an abnormality, it is possible to alert, for example, a manager of the wire bonding apparatus 100.

[0057] The embodiments include the following aspects. (Appendix 1) A wire bonding apparatus that bonds a wire to a first bonding point and a second bonding point by generating ultrasonic vibrations while pressing the wire against the first bonding point and a second bonding point, A bonding tool; an ultrasonic horn that generates ultrasonic vibrations; a load sensor that detects a load applied from the bonding tool to the first bonding point or the second bonding point; a position detection unit that detects the vertical position of the bonding tool; a diameter detection unit that detects the diameter of a ball-shaped portion formed at the tip of the bonding tool at the first bonding point; a control unit that calculates a height of a bump based on the diameter of the ball-shaped portion detected by the diameter detection unit, a first position of the bonding tool detected by the position detection unit when the load sensor detects a load at the first bonding point, and a second position of the bonding tool when the bonding tool is at its lowest position at the first bonding point, and bonds the wire based on the calculated height of the bump; A wire bonding apparatus comprising: (Appendix 2) 2. The wire bonding apparatus according to claim 1, wherein the control unit stops bonding of the wire in accordance with the calculated height of the bump. (Appendix 3) The wire bonding apparatus according to claim 1 or 2, wherein the control unit changes at least one of the load and ultrasonic output applied to the bonding tool when bonding the wire, depending on the calculated height of the bump. (Appendix 4) A method for controlling a wire bonding apparatus, which bonds a wire to a first bonding point and a second bonding point by generating ultrasonic vibrations while pressing the wire against the first bonding point and a second bonding point, Detecting a diameter of a ball-shaped portion formed at a tip of a bonding tool at the first bonding point; acquiring a first position of the bonding tool in a vertical direction when a load applied to the first bonding point from the bonding tool is detected at the first bonding point; acquiring a second position of the bonding tool at the first bonding point when the bonding tool is at its lowest position; A control method that calculates a bump height based on the diameter of the ball-shaped portion, the first position, and the second position, and joins the wire based on the calculated bump height.

[0058] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Furthermore, the above-described embodiments can be implemented in combination with each other. [Explanation of symbols]

[0059] 1: Workpiece, 2: Part to be bonded, 3: Wire, 10: Bonding head, 10a: Position detection unit, 11: Bonding tool, 12: Ultrasonic horn, 13: Bonding arm, 13a: Shaft, 14: Drive unit, 20: XY stage, 30: Bonding stage, 40: Load sensor, 50: Camera device, 60: Control unit, 100: Wire bonding device, B1: Bump, B2: Bump, BA: Substrate, BO: Ball-shaped part, Bn: Bump, C: Chip, C1: First chip, C2: Second chip, Cn: Nth chip, D: Diameter, P1: First bonding point, P2: Second bonding point, R1: Search process, R2: Bonding process, R3: Reverse process, R4: Lowering process, R5: Tail formation process, R6: Tail cut process, R7: Spark process, W11: Wire, W12: Wire, h: Ball squash amount, h2: Difference in Z position, h a1 :Z position, h b1 :Z position, h bn : Z position, t1: bump height, t2: bump height, t n: Bump height

Claims

1. A wire bonding apparatus that bonds a wire to a first bonding point and a second bonding point by generating ultrasonic vibrations while pressing the wire against the first bonding point and a second bonding point, A bonding tool; an ultrasonic horn that generates ultrasonic vibrations; a load sensor that detects a load applied from the bonding tool to the first bonding point or the second bonding point; a position detection unit that detects the vertical position of the bonding tool; a diameter detection unit that detects a diameter of a ball-shaped portion formed at a tip of the bonding tool at the first bonding point; a control unit that calculates a height of a bump based on the diameter of the ball-shaped portion detected by the diameter detection unit, a first position of the bonding tool detected by the position detection unit when the load sensor detects a load at the first bonding point, and a second position of the bonding tool when the bonding tool is at its lowest position at the first bonding point, and bonds the wire based on the calculated height of the bump; A wire bonding apparatus comprising:

2. the control unit stops bonding the wire in accordance with the calculated height of the bump.

2. The wire bonding apparatus according to claim 1.

3. the control unit changes at least one of a load applied to the bonding tool and an ultrasonic output when bonding the wire, depending on the calculated height of the bump.

2. The wire bonding apparatus according to claim 1.

4. A method for controlling a wire bonding apparatus, the method comprising: generating ultrasonic vibrations while pressing a wire against a first bonding point and a second bonding point, thereby bonding the wire to the first bonding point and the second bonding point, Detecting a diameter of a ball-shaped portion formed at a tip of a bonding tool at the first bonding point; acquiring a first position of the bonding tool in a vertical direction when a load applied to the first bonding point from the bonding tool is detected at the first bonding point; acquiring a second position of the bonding tool at the first bonding point when the bonding tool is at its lowest position; A control method comprising: calculating a height of a bump based on the diameter of the ball-shaped portion, the first position, and the second position; and bonding the wire based on the calculated height of the bump.

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