Wire bonding apparatus, operation method, and control method

Abstract

To provide a wire bonding apparatus, an operation method, and a control method that can suppress the occurrence of bonding defects.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 the load sensor detects a load at a bonding point, and the second position of the bonding tool when the bonding tool is at its lowest position at the bonding point, and bonds the wire based on the calculated height of the bump. The control unit acquires the first positions of the bumps formed on the chip, respectively, and calculates a relative positional relationship between the first positions.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to a wire bonding apparatus, and a method of operation and control. [Background technology]

[0002] A known method involves measuring the surface of the circuit board on which the semiconductor chip is mounted and adjusting the contact height with the terminal by adjusting the size of the conductive ball on the terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3938024 Summary of the Invention [Problem to be solved by the invention]

[0004] When bonding a wire to a bonding target, if the flatness of the material forming the bump is poor, an error will occur between the actual bump height and the calculated bump height, which can lead to bonding defects.

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

[0006] According to an embodiment, a wire bonding apparatus bonds a wire to a bonding point by generating ultrasonic vibrations while the wire is pressed against the bonding point. 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 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 bonding point. The control unit calculates a bump height and bonds the wire based on the calculated bump height. The bump height is calculated 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 bonding point, and a second position of the bonding tool when the bonding tool is at its lowest position at the bonding point. The control unit acquires the first positions of the bumps formed on the chip, and calculates a relative positional relationship between the first positions. [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 diagrams for explaining a process for detecting the shape of a surface on which bumps are formed by a wire bonding apparatus according to a second embodiment. [Figure 9] Top view of the chip. [Figure 10] FIG. 10 is a side view of FIG. 9 seen from the Y direction. [Figure 11] FIG. 10 is a side view of FIG. 9 as seen from the X direction. [Figure 12] FIG. 10 is a diagram showing an example of chip height distribution. [Figure 13] 10 is a flowchart showing an example of a process for adjusting the amount of adhesive. [Figure 14] FIG. 10 is a diagram showing an example of a result of determining an application amount. [Figure 15] FIG. 10 is a diagram showing an example of bumps formed on a chip. [Figure 16] FIG. 10 is a diagram showing an example of adhesive applied to a chip. [Figure 17] FIG. 10 is a diagram showing an example of a state in which a chip and another chip are bonded together. 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 view showing a wire bonding apparatus according to an embodiment, and Fig. 2 is a schematic view showing a part of the wire bonding apparatus according to an 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 is lowest 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 wire 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 wire 3 is executed in order, such as the first chip C1, the second chip C2, ..., the M-th chip Cm (m: natural number). In each chip, for example, in the first chip C1, multiple wires W11, W12, ..., W1n (n: natural number) are joined in order to each of the parts to be joined 2. Next, in the second chip C2, multiple 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 from the second bonding point P2 to the first bonding point P1. At this time, the wire 3 extending from the second bonding point P2 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 description will be given of a process for calculating the bump heights of the first bump B11 and the second and subsequent bumps B12 to B1n in one chip C when the control unit 60 performs wire bonding. 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 In the lowering step R4 shown in FIG. 5, the Z position when the bonding tool 11 is lowered to the lowest position is stored 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 B11.

[0041] Next, the control unit 60 detects the bump height t2 of the second bump B12. The bump B12 is formed at a position (third bonding point) different from the position of the bump B11. 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 B11 and B12. 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 B11. The difference h2 is the Z position h when the bonding tool 11 is at its lowest position in the formation of the bump B11. b1 and the Z position h when the bonding tool 11 is at its lowest position in forming the bump B12. b2 and . Also, the bump height t2 is shown in the lowering step R4 when forming the bump B12. The bump height t2 of the bump B12 is calculated using the bump height t1 and the difference h2.

[0044] In addition, for the third and subsequent bumps B13, for example, up to the bump B1n, 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 B11, 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 B12 and onwards.

[0047] After the bumps B11 to B1n are formed on one chip C, multiple bumps B21 to B2n are formed on, for example, the substrate BA. In other words, in the examples shown in Figures 3, 6, and 7, multiple bump formation steps (shown in Figure 4(a)) are performed on multiple points on one chip C. Then, multiple first bonding steps (shown in Figure 4(b)) are performed on multiple points on the substrate BA. Thereafter, multiple second bonding steps (shown in Figure 4(c)) are performed, whereby the multiple bumps B21 to B2n are connected to the multiple bumps B11 to B1n by wires, respectively.

[0048] According to the wire bonding apparatus 100 described above, the bump heights t1 to t ncan 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 operation method of the wire bonding apparatus 100 described above, the occurrence of bonding defects of the wire 3 can also be suppressed.

[0049] Furthermore, the wire bonding apparatus 100 can calculate the bump height t1 in the bump bonding process (see FIG. 4(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. 4(c)). Even if the first and second bonding processes are performed consecutively immediately after the bump bonding process, there is a time period 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.

[0050] (Second embodiment) The second embodiment differs from the first embodiment in that it adds a process of bonding another chip to a chip on which bumps are formed. It also adds a process of calculating the Z position when each bump is formed and correcting the bump height according to the relative positional relationship of multiple Z positions. Components similar to those in the first embodiment are given the same reference numerals, and detailed descriptions of these components will be omitted.

[0051] FIG. 8 is a diagram for explaining the process of acquiring the bump height. 8 shows a search step R1, a bonding step R2, a reversing step R3, and a lowering step R4, and also shows the Z position of the bonding tool 11 and the detection state of the load sensor 40 in each of the steps R1 to R4.

[0052] In this embodiment, the control unit 60 determines the Z position Z at the timing X when the ball-shaped portion BO comes into contact with the upper surface of the chip C11 (first chip) in the search step R1. x The timing X is the timing of the rise of the load signal detected by the load sensor 40. When forming a plurality of bumps on the chip C11, the control unit 60 obtains the Z position Z at the timing X when forming all the bumps B. x Get.

[0053] 9 to 11 are diagrams showing an example of bumps formed on a chip C11. FIG. 9 is a top view of the chip C11, FIG. 10 is a side view of FIG. 9 as seen from the Y direction, and FIG. 11 is a side view of FIG. 9 as seen from the X direction. As shown in FIGS. 9 to 11, a plurality of bumps B are formed on the chip C11. In this embodiment, a plurality of bumps B are formed on the chip C11 at equal intervals along two directions perpendicular to each other. Arrows A1 in the figure indicate the flow of forming the bumps B. When a plurality of bumps B are formed on the chip C11 in this way, the Z position Z x is obtained.

[0054] 12 is a diagram showing an example of the height distribution of the chip C11. In FIG. 12, the Z position Z obtained when each bump B is formed is x In the example shown in FIG. 12, the relative positional relationship between the multiple Z positions Z x From the relative positional relationship of the two, it can be seen that the shape of the surface on which the bump B is formed is tilted at an angle α with respect to the X direction in the XZ plane. This surface shape is just an example, and for example, the surface shape may be uneven or distorted. Even in such cases, the control unit 60 can determine the position of the bump B at multiple Z positions Z x From the relative positional relationship of these, it is possible to obtain the shape of the surface according to the density of the bumps B.

[0055] As shown in FIGS. 9 to 11, another chip C12 (second chip) is bonded to a chip C11 on which bumps B are formed. For bonding, for example, adhesive is applied to positions on the chip C12 corresponding to each bump B. That is, the bumps B are bonded to the adhesive, thereby bonding the chip C11 and the chip C12. Note that an apparatus for applying adhesive to the chip C12 and bonding the chip C12 to the chip C11 is a general apparatus, and therefore illustration and description thereof are omitted. This apparatus is communicably connected to the wire bonding apparatus 100, and receives the bump height t1 and the amount of adhesive applied calculated by the control unit 60. Then, this apparatus applies adhesive to the chip C12 and bonds the chip C11 to the chip C12. The wire bonding apparatus 100 may be configured to include this apparatus.

[0056] The following describes a process for adjusting the amount of adhesive to be applied to the chip C12. Fig. 13 is a flowchart showing an example of the process for adjusting the amount of adhesive.

[0057] As shown in FIG. 13, first, the control unit 60 forms a plurality of bumps B on the chip C11 (ST201). At this time, as described above, the plurality of Z positions Z x As a result, the height distribution shown in Fig. 12, in other words, the shape of the surface of the chip C11 on which the plurality of bumps B are formed, is obtained.

[0058] Next, the control unit 60 determines the maximum height point (Po max For example, from the distribution of chip heights shown in FIG. 12, the highest Z position Z x Po max is stored as

[0059] Next, the control unit 60 outputs all the connection points Po i And, Po max The difference between (HD i The connection point Po is calculated (ST203). The connection point Po is the point where the bump B is formed. i and Pomax The difference (hd i ) is obtained for each bump B formed on chip C11.

[0060] Next, the control unit 60 determines the application amount of the adhesive to be applied to the connection point Po of chip C12 (ST204). For example, the control unit 60 has a criterion for determining the application amount. This criterion is defined such that 0 ≦ hd i <a is the application amount AA, a ≦ hd i <b is the application amount BB, b ≦ is the application amount CC. Here, 0, a, and b represent differences. The values of a, b, AA, BB, and CC can be arbitrarily set. The application amounts have the relationship of application amount AA < application amount BB < application amount CC. That is, the larger the difference, the larger the application amount. i <b is the application amount BB, b ≦ is the application amount CC. Here, 0, a, and b represent differences. The values of a, b, AA, BB, and CC can be arbitrarily set. The application amounts have the relationship of application amount AA < application amount BB < application amount CC. That is, the larger the difference, the larger the application amount.

[0061] For example, the case where there are five connection points Po1 to Po5 will be described. For the sake of simplicity, the case where there are five connection points in a straight line will be described, but even in the plane shown in FIG. 9, the control unit 60 can similarly adjust the application amount of the adhesive applied to the position corresponding to each bump B.

[0062] As an example, the plurality of bumps B formed on chip C11 include a first bump and a second bump. The plurality of adhesives formed on chip C12 include a first adhesive and a second adhesive. The first adhesive is adhered to the first bump. The second adhesive is adhered to the second bump. When the difference between the first position at the time of forming the first bump and the maximum height in the first chip is larger than the difference between the first position at the time of forming the second bump and the maximum height, the amount of the first adhesive is larger than the amount of the second adhesive. <l [[ID=2 l]]

[0063] FIG. 14 is a diagram showing an example of the determination result of the application amount in the case where there are five connection points Po1 to Po5. As shown in FIG. 14, in the determination result 70, according to the five connection points Po1 to Po5, Po maxThe differences from these are the differences hd1 to hd5, and the coating amounts are shown to be coating amount CC, coating amount BB, coating amount AA, coating amount BB, and coating amount CC, respectively.

[0064] Next, a case where the chip C11 and the chip C12 are bonded together will be described. Fig. 15 is a diagram showing an example of bumps B formed on the chip C11. Fig. 16 is a diagram showing an example of adhesive applied to the chip C12. Fig. 17 is a diagram showing an example of the state where the chip C11 and the chip C12 are bonded together.

[0065] As shown in FIG. 15, connection points (bumps B) Po1 to Po5 are formed on a chip C11. The shape of the top surface of the chip C11 is such that the center is highest. Therefore, Po3 is the highest. The differences between the height of Po3 and those of Po2 and Po4 are differences hd2 and hd4, and the differences between the height of Po3 and those of Po1 and Po5 are differences hd1 and hd5. In this case, the amount of adhesive to be applied is determined as shown in FIG. 14.

[0066] As shown in FIG. 16, adhesive is applied onto the chip C12 according to the positions of the connection points (bumps) Po1 to Po5. The amounts of adhesive applied onto the chip C12 are application amount CC, application amount BB, application amount AA, application amount BB, and application amount CC according to the positions of Po1 to Po5. As mentioned above, the application amounts have the relationship application amount AA<application amount BB<application amount CC. In other words, application amount AA has the least amount of adhesive, and application amount CC has the most amount of adhesive. In other words, on the top surface of the chip C12, the amount of adhesive is less in the center and more at the edges.

[0067] 17, the positions of the connection points Po1 to Po5 of the chip C11 are the same as the positions on the chip C12 where the adhesive is applied. Furthermore, the amount of adhesive on the chip C12 is adjusted according to the relative positional relationship of the multiple bumps B on the chip C11. Therefore, the wire bonding apparatus 100 can accurately bond the chip C11 and the chip C12.

[0068] As described above, the wire bonding apparatus 100 determines the Z position Z at the time X when the ball-shaped portion BO comes into contact with the upper surface of the chip C11. x Each time bump B is formed, the Z position Z x By obtaining multiple Z positions Z x The relative positional relationship can be obtained.

[0069] The positional relationship can be, for example, multiple Z positions Z x The maximum Z position Z x and each Z position Z x Alternatively, the positional relationship is expressed as the difference between the Z position Z between adjacent bumps B in the X or Y direction. x It may be expressed as the difference between

[0070] Furthermore, the wire bonding apparatus 100 detects a plurality of Z positions Z11 on the chip C11. x The amount of adhesive to be applied to the chip C12 can be adjusted according to the relative positional relationship between the chips C11 and C12. This allows the wire bonding apparatus 100 to accurately bond the chip C11 and C12, thereby preventing bonding defects from occurring.

[0071] Furthermore, the wire bonding apparatus 100 can perform the following operations at a plurality of Z positions Z x Based on the relative positional relationship of the bumps, the bump height t n For example, the formula for calculating the bump height t n =(t n-1 -(h b(n-1) -h bn )) and add the correction amount H based on the relative positional relationship. n =(t n-1 -(h b(n-1) -h bn ))+H, the control unit 60 calculates the bump height t n at multiple Z positions Z x Here, the correction amount H can be calculated based on the relative positional relationship of the Z-position Z x The highest Z position Z xand each Z position Z x Thus, the wire bonding apparatus 100 can determine the bump height t n can be calculated.

[0072] The embodiments include the following aspects. (Appendix 1) A wire bonding apparatus that bonds a wire to a bonding point by generating ultrasonic vibrations while the wire is pressed against the 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 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 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 bonding point, and a second position of the bonding tool when the bonding tool is at its lowest position at the bonding point, and bonds the wire based on the calculated height of the bump; Equipped with the control unit acquires the first positions of the bumps formed on the chip, and calculates a relative positional relationship between the first positions. Wire bonding equipment. (Appendix 2) 2. The wire bonding apparatus according to claim 1, wherein the control unit acquires information about the surface of the chip on which the bumps are formed based on the relative positional relationship. (Appendix 3) 3. The wire bonding apparatus according to claim 1, wherein the control unit adjusts the amount of adhesive to be applied to another chip to be bonded to the chip based on the relative positional relationship. (Appendix 4) 4. The wire bonding apparatus according to claim 1, wherein the control unit corrects the calculated height of the bump based on the relative positional relationship. (Appendix 5) 1. A method for operating a wire bonding apparatus that bonds a wire to a bonding point by generating ultrasonic vibrations while the wire is pressed against the bonding point, the method comprising: Detecting the diameter of a ball-shaped portion formed at the tip of the bonding tool at the bonding point; detecting a first position of the bonding tool in a vertical direction when a load applied from the bonding tool to the bonding point is detected; detecting a second position of the bonding tool in the vertical direction when the bonding tool is at its lowest position at the bonding point; calculating a height of the bump based on the diameter of the ball-shaped portion, the first position, and the second position; bonding the wire based on the calculated height of the bump; An operating method comprising acquiring a plurality of first positions of a plurality of the bumps formed on a chip, and calculating a relative positional relationship between the plurality of first positions. (Appendix 6) The operating method of claim 5, further comprising obtaining information about the surface of the chip on which the bumps are formed based on the relative positional relationship. (Appendix 7) The operating method described in Appendix 5 or 6, further comprising adjusting the amount of adhesive to be applied to another chip to be bonded to the chip based on the relative positional relationship. (Appendix 8) The operating method according to any one of appendices 5 to 7, further comprising correcting the calculated bump height based on the relative positional relationship. (Appendix 9) moving a bonding tool of a wire bonding device toward a predetermined bonding point on the first chip; detecting a first position of the bonding tool in a vertical direction when a load applied from the bonding tool to the bonding point is detected; A control method for forming a bump at the bonding point after detecting the first position, comprising: A control method comprising: acquiring a plurality of first positions of a plurality of the bumps formed on the first chip; and calculating a relative positional relationship between the plurality of first positions. (Appendix 10) 10. The control method according to claim 9, wherein after forming the plurality of bumps on the first chip, a plurality of adhesives are provided on a second chip at positions corresponding to the plurality of bumps. (Appendix 11) 11. The control method of claim 10, wherein the amount of each of the plurality of adhesives is adjusted depending on the relative positional relationship of the plurality of first positions. (Appendix 12) the plurality of bumps include a first bump and a second bump; the plurality of adhesives include a first adhesive bonded to the first bump and a second adhesive bonded to the second bump; a difference between the first position and the maximum height of the first chip when the first bump is formed is greater than a difference between the first position and the maximum height of the second bump when the second bump is formed; 12. The control method of claim 10, wherein the amount of the first adhesive is greater than the amount of the second adhesive.

[0073] 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]

[0074] 1: Workpiece, 2: Bonded part, 3: Wire, 10: Bonding head, 10a: Position detection part, 11: Bonding tool, 12: Ultrasonic horn, 13: Bonding arm, 13a: Shaft part, 14: Drive part, 20: XY stage, 30: Bonding stage, 40: Load sensor, 50: Camera device, 60: Control part, 70: Decision result, 100: Wire bonding device, A1: Arrow, B, B1, B2, Bn: Bump, BA: Substrate, BO: Ball-shaped part, C: Chip, C1, C11: First chip, C2, C12: Second chip, Cm: Mth chip, D: Diameter, H: Correction amount, P1: First bonding point, P2: Second bonding point, R1: Search process, R2: Bonding process, R3: Reverse process, R4: Lowering process, R5: Tail forming process, R6: Tail cutting process, R7: Spark process, W11, W12: Wire, X: Timing, Zx: Z position, a: Application amount, b: Application amount, h: Ball crushing amount, h2: Difference in Z position, h a1 ,h b1 ,h bn :Z position, t1,t2,t n : bump height, α: angle

Claims

1. A wire bonding apparatus that bonds a wire to a bonding point by generating ultrasonic vibrations while the wire is pressed against the 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 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 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 bonding point, and a second position of the bonding tool when the bonding tool is at its lowest position at the bonding point, and bonds the wire based on the calculated height of the bump; Equipped with the control unit acquires the first positions of the bumps formed on the chip, and calculates a relative positional relationship between the first positions; Wire bonding equipment.

2. 2. The wire bonding apparatus according to claim 1, wherein the control unit acquires information about the surface of the chip on which the bumps are formed based on the relative positional relationship.

3. 2. The wire bonding apparatus according to claim 1, wherein the control unit adjusts the amount of adhesive to be applied to another chip to be bonded to the chip based on the relative positional relationship.

4. 2. The wire bonding apparatus according to claim 1, wherein the control unit corrects the calculated height of the bump based on the relative positional relationship.

5. 1. A method for operating a wire bonding apparatus that bonds a wire to a bonding point by generating ultrasonic vibrations while the wire is pressed against the bonding point, the method comprising: Detecting the diameter of a ball-shaped portion formed at the tip of the bonding tool at the bonding point; detecting a first position of the bonding tool in a vertical direction when a load applied from the bonding tool to the bonding point is detected; detecting a second position of the bonding tool in the vertical direction when the bonding tool is at its lowest position at the bonding point; calculating a height of the bump based on the diameter of the ball-shaped portion, the first position, and the second position; bonding the wire based on the calculated height of the bump; An operating method comprising: acquiring a plurality of first positions of a plurality of the bumps formed on a chip; and calculating a relative positional relationship between the plurality of first positions.

6. The operating method according to claim 5 , further comprising: acquiring information about the surface of the chip on which the bumps are formed based on the relative positional relationship.

7. The operating method according to claim 5 , further comprising adjusting an amount of adhesive to be applied to another chip to be bonded to the chip based on the relative positional relationship.

8. The operating method according to claim 5 , further comprising correcting the calculated bump height based on the relative positional relationship.

9. moving a bonding tool of a wire bonding apparatus toward a predetermined bonding point on the first chip; detecting a first position of the bonding tool in a vertical direction when a load applied from the bonding tool to the bonding point is detected; A control method for forming a bump at the bonding point after detecting the first position, comprising: A control method comprising: acquiring a plurality of first positions of a plurality of the bumps formed on the first chip; and calculating a relative positional relationship between the plurality of first positions.

10. 10. The control method according to claim 9, further comprising the steps of: forming the plurality of bumps on the first chip; and then providing a plurality of adhesives on the second chip at positions corresponding to the plurality of bumps.

11. The control method according to claim 10 , wherein the amount of each of the plurality of adhesives is adjusted according to a relative positional relationship between the plurality of first positions.

12. the plurality of bumps include a first bump and a second bump; the plurality of adhesives include a first adhesive bonded to the first bump and a second adhesive bonded to the second bump; a difference between the first position at the time of forming the first bump and a maximum height on the first chip is larger than a difference between the first position at the time of forming the second bump and the maximum height, The method of claim 10 , wherein the amount of the first adhesive is greater than the amount of the second adhesive.

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