JP7468943B1 - Ball mounting device and ball mounting method - Google Patents

Abstract

[Problem] To provide a ball mounting device and a ball mounting method capable of mounting conductive balls without ball mounting defects on a substrate having a large ball mounting area and an array pattern of pad electrodes in which minute-diameter conductive balls are densely arranged. [Solution] Flux F is printed on a substrate W using a flux printing mask 26 having a non-opening area 132 in which no flux printing openings 131 exist inside the array pattern of the flux printing openings 131. A ball transfer mask 47 having a ball transfer opening 116 and a non-opening area 117 in the same positions as the flux printing mask 26 is used, and a conductive ball S is transferred from the ball transfer opening 116 onto a pad electrode 107 on which flux F has been printed. The non-opening area 117 of the ball transfer mask 47 has a columnar protrusion 118 on the back surface 47a facing the substrate W. [Selected Figure] FIG. 4

Description

The present invention relates to a ball mounting device and a ball mounting method.

As mobile terminal devices and notebook computers become smaller, lighter, and more powerful, the density of semiconductor chips is increasing. As this trend increases, conductive ball mounting devices capable of mounting micro-diameter conductive balls that become bumps at high density on substrates (e.g., wafers) are being adopted as a means of connecting substrates to other substrates or circuit elements. However, as conductive balls are mounted at high density, there is a demand for ball mounting devices and ball mounting methods that can accommodate the fact that the area of the ball mounting region is larger than before.

Increasing the area of the ball mounting region means that the area of the ball transfer mask used to transfer the conductive balls to the designated positions on the board also increases. This can cause the ball transfer mask to bend toward the board due to the pressure of the brush squeegee when sucking the ball transfer mask onto the board or transferring the conductive balls. If the ball transfer mask bends, the flux that has been printed on the board in advance may adhere to the back surface of the ball transfer mask or get into the ball transfer opening, making it impossible to place the conductive balls in the designated positions.

A ball transfer mask has been disclosed in which a support-like protrusion is provided on the back surface of the ball transfer mask facing the substrate, and this protrusion prevents the ball transfer mask from bending (see, for example, Patent Document 1). In one example of this protrusion, the protrusion is formed in a non-opening region between a large number of ball transfer openings through which conductive balls can be inserted, which are formed according to the arrangement pattern of the pad electrodes. In another example, the protrusion is provided in a non-opening region where the ball transfer openings are not formed, that is, a non-opening region where no conductive balls need to be mounted.

JP 2006-324618 A

In one example of the above-mentioned Patent Document 1, by providing a protrusion, it is possible to prevent the ball transfer mask from bending. However, in the case of a substrate in which the diameter of the conductive balls and the distance between the balls are small, the area of the non-opening region is small, and it is difficult to form a protrusion in this position. In another example, it is only applicable to a ball transfer mask having a non-opening region in which it is not necessary to place conductive balls within the ball array pattern region, and cannot be applied to a ball transfer mask in which there is no non-opening region within the ball array pattern region and the ball transfer openings are densely packed.

The present invention has been made to solve these problems, and aims to realize a ball mounting device and ball mounting method that can mount conductive balls without ball mounting defects on a substrate having a large ball mounting area and an arrangement pattern of pad electrodes in which minute-diameter conductive balls are densely arranged.

[1] The ball mounting device of the present invention is characterized by having a flux printing device that uses a flux printing mask having flux printing openings that are provided in accordance with the arrangement pattern of pad electrodes formed on a substrate and a non-opening area inside the arrangement pattern of the flux printing openings where the flux printing openings are not present, and prints flux on the pad electrodes from the flux printing openings; a ball transfer device that uses a ball transfer mask having a ball transfer opening that is provided in accordance with the arrangement pattern of the pad electrodes, the non-opening area where the ball transfer openings are not present that is provided at a position corresponding to the non-opening area of the flux printing mask, and a columnar protrusion formed on the surface of the non-opening area facing the substrate, and transfers a conductive ball from the ball transfer opening; a flux transfer unit that applies the flux to the pad electrodes in the areas of the substrate where the conductive balls have been transferred, a ball mounting unit that mounts the conductive balls in the non-opening area and the opening area where there is a lack of ball mounting, and an excess ball removal unit that removes excess balls on the substrate.

[2] In the ball mounting device of the present invention, it is preferable that the ball transfer mask has the non-opening regions arranged in a plurality of locations, the ball transfer openings are further arranged between adjacent non-opening regions, and the protrusions are formed in each of the plurality of non-opening regions.

[3] In the ball mounting device of the present invention, it is preferable that the non-opening regions of the flux printing mask are arranged at the same positions as the non-opening regions of the ball transfer mask, and that the flux printing openings are further arranged between adjacent non-opening regions.

[4] In the ball mounting device of the present invention, it is preferable that the height of the protrusion is such that when the conductive ball is transferred into the ball transfer mask, the top of the conductive ball does not protrude from the upper surface of the ball transfer mask.

[5] The ball mounting method of the present invention includes a flux printing process using a flux printing mask having flux printing openings that correspond to the arrangement pattern of the pad electrodes formed on the substrate and a non-opening area inside the arrangement pattern of the flux printing openings where the flux printing openings are not present, and printing flux on the pad electrodes through the flux printing openings; a ball transfer process using a ball transfer mask having a ball transfer opening that corresponds to the arrangement pattern of the pad electrodes, the non-opening area where the ball transfer openings are not present that is provided at a position corresponding to the non-opening area of the flux printing mask, and a columnar protrusion formed on the surface of the non-opening area facing the substrate, and transferring a conductive ball through the ball transfer opening; and a repair process that detects an excess or deficiency of the conductive balls and corrects the excess or deficiency.

[6] In the ball mounting method of the present invention, the repair process preferably includes a process of detecting the position of the flux printing defect on the substrate and the position of the excess or deficiency of the conductive ball mounted on the substrate, a process of transferring the flux to the position of the flux printing defect, a ball mounting process of mounting the conductive ball at the position of the insufficient conductive ball mounting, and an excess ball removal process of removing the excess ball on the substrate.

The ball mounting device and ball mounting method of the present invention use a flux printing device to print flux on a substrate using a flux printing mask having a non-opening area inside the arrangement pattern of the flux printing openings. The ball transfer device uses a ball transfer mask having a ball transfer opening and a non-opening area in the same position as the flux printing mask, and transfers a conductive ball to the substrate from the ball transfer opening. The non-opening area of the ball transfer mask has a columnar protrusion on the back surface facing the substrate. By having such a protrusion, when transferring a conductive ball onto the substrate, even if the area of the ball mounting area and the ball transfer mask becomes large, the ball transfer mask can be prevented from bending toward the substrate. As a result, the flux printed on the substrate in advance does not adhere to the back surface of the ball transfer mask or the ball transfer openings, making it possible to prevent ball mounting defects caused by the adhered flux.

When the conductive balls become smaller and are arranged at a high density, it becomes difficult to provide protrusions, but by providing a non-opening area, it becomes possible to provide protrusions in this non-opening area regardless of the arrangement density of the conductive balls. However, in the non-opening area, the ball transfer device cannot transfer the conductive balls to the substrate. However, the repair device can apply flux and mount the conductive balls on the pad electrodes in the non-opening area. The repair device also has the function of correcting any excess or deficiency of the conductive balls transferred by the ball mounting device.

The ball mounting device and ball mounting method described above make it possible to mount conductive balls on a substrate having a large ball mounting area and an array pattern of pad electrodes in which minute conductive balls are densely arranged, without any ball mounting defects.

1 is a plan view showing a schematic configuration of a ball mounting device 1. FIG. 2 is a front view of the repair device 5 as seen from the direction of the dotted arrow in FIG. 1. 2 is a plan view showing an example of a configuration of a substrate W. FIG. A diagram showing an example of the configuration of a ball transfer mask 47. A diagram showing a modified example of the ball transfer mask 47. 5A and 5B are diagrams illustrating an example of the configuration of a flux printing mask 26. 13A and 13B are diagrams showing modified examples of the flux printing mask 26. FIG. 1 is a process flow diagram showing a ball mounting method. 4A to 4C are explanatory diagrams showing the operation of the flux printing unit 20. A diagram showing the operation of the ball transfer unit 40.

The ball mounting device 1 and ball mounting method according to an embodiment of the present invention will be described below with reference to the drawings. Note that in each of the drawings described below, the size, spacing, and scale of the components are exaggerated to make the description easier to understand.

(Configuration of Ball Mounting Device 1)
1 is a plan view showing a schematic configuration of a ball mounting device 1. The left-right direction on the paper is represented as the X-axis, the direction perpendicular to the X-axis is represented as the Y-axis, and the vertical direction with respect to the X-Y plane (the up-down direction on the paper) is represented as the Z-axis or up-down direction. The ball mounting device 1 is composed of a transport robot device 2 which is a material supply device for a substrate W, a flux printing device 3 which prints flux F on the substrate W, a ball transfer device 4 which transfers conductive balls S (see FIG. 3(b)) onto the substrate W on which the flux F has been printed, and a repair device 5 which corrects the excess or deficiency of the transferred conductive balls S. The transport robot device 2, the flux printing device 3, the ball transfer device 4, and the repair device 5 are arranged and connected in the X-axis direction.

The transport robot device 2 has a robot arm 14 that transports the substrate W housed in a FOUP (Front-Opening-Unified-Pod) 13 arranged on each of the first load port 11 and the second load port 12 to the flux printing device 3. The robot arm 14 picks up the substrate W from either the first load port 11 or the second load port 12, transports it to the pre-aligner 15, corrects the position of the substrate W in the pre-aligner 15, and then transports it to the first substrate stand 16 arranged on the flux printing device 3.

(Configuration of Flux Printing Device 3)
The flux printer 3 has a flux printing unit 20 in the center, a substrate stage 21 that suction-holds the substrate W during flux printing, a first substrate stand 16 disposed on the left side of the substrate stage 21 in the figure, and a second substrate stand 22 disposed on the right side in the figure. A first substrate transport unit 23 is disposed below the substrate stage 21 in the figure. The first substrate transport unit 23 has a first substrate transport arm 24 and a second substrate transport arm 25. A flux printing mask 26 is disposed above the substrate stage 21 in the Z axis direction, and flux F is printed on the substrate W by a flux printing squeegee 140 (see FIG. 9 ).

Next, the transportation of the substrate W by the first substrate transport unit 23 will be described. For the purpose of the description, it is assumed that the substrate W is transported to the first substrate stand 16 as an initial position, and the substrate W on which flux F is printed is on the substrate stage 21. First, the X-axis slider 28 moves the holding block 27 that holds the first substrate transport arm 24 and the second substrate transport arm 25 to a position where the first substrate transport arm axis 29 is on a straight line from the center of the first substrate stand 16 to a line perpendicular to the work transport trajectory L. Next, the first substrate transport unit 23 rotates the second substrate transport arm 25 90 degrees clockwise around the second substrate transport arm axis 30 as the center of rotation, and rotates the first substrate transport arm 24 90 degrees counterclockwise around the first substrate transport arm axis 29 as the center of rotation.

Then, the substrate holding portion 25a of the second substrate transport arm 25 enters between the substrate W and the substrate stage 21 and adsorbs the substrate W. The first substrate transport arm 24 is moved toward the first substrate stage 16 by the Y-axis movement actuator 31 with the open portion of the substrate holding portion 24a facing the center of the first substrate stage 16. The substrate holding portion 24a of the first substrate transport arm 24 then enters between the substrate W and the first substrate stage 16 and adsorbs the substrate W.

The second substrate transport arm 25 picks up the substrate W printed with flux F, and the first substrate transport arm 24 picks up the substrate W before flux printing, and then moves together with the holding block 27 to the position on the right side of the figure (the position shown in FIG. 1) by the X-axis slider 28. The second substrate transport arm 25 transports the substrate W printed with flux F from the substrate stage 21 to the second substrate stand 22. The first substrate transport arm 24 transports the substrate W before flux printing from the first substrate stand 16 to the substrate stage 21. A second substrate transport unit 33 is disposed above the second substrate stand 22 on the Y axis.

The second substrate transport unit 33 is composed of a Y-axis actuator 34, an X-axis slider 35, and a third substrate transport arm 36. A substrate W printed with flux F is placed on the second substrate stand 22. The third substrate transport arm 36 is moved from the position shown in FIG. 1 by the Y-axis actuator 34 until the substrate holding portion 36a enters between the substrate W and the second substrate stand 22, and the substrate holding portion 36a adsorbs the substrate W. The third substrate transport arm 36, which has adsorbed the substrate W printed with flux F, transports it to the third substrate stand 42 of the ball transfer device 4 by the X-axis slider 35.

In the flux printing device 3, the first substrate transport arm 24 and the second substrate transport arm 25 return to the initial state shown in FIG. 1 and wait while the flux printing unit 20 prints flux F on the substrate W. The method of printing flux F will be described with reference to FIG. 9.

(Configuration of the ball transfer device 4)
The ball transfer device 4 has a ball transfer unit 40 in the center, a substrate stage 41 that suction-holds the substrate W during ball transfer, a third substrate stand 42 arranged on the left side of the substrate stage 41 in the figure, and a fourth substrate stand 43 arranged on the right side in the figure. A third substrate transport unit 44 is arranged below the substrate stage 41 in the figure. The third substrate transport unit 44 has a fourth substrate transport arm 45 and a fifth substrate transport arm 46. A ball transfer mask 47 is arranged above the substrate stage 41 in the Z axis direction, and conductive balls S are transferred to the substrate W by a brush squeegee 141 (see FIG. 9).

Next, the transportation of the substrate W by the third substrate transport unit 44 will be described. For the purpose of the description, it is assumed that the substrate W on which the flux F is printed is transported to the third substrate stand 42 as an initial position, and the substrate W on which the conductive balls S are mounted is on the substrate stage 41. First, the X-axis slider 48 moves the holding block 57 to a position where the fourth substrate transport arm shaft 50 is on a straight line from the center of the third substrate stand 42 perpendicular to the work transport trajectory L. Next, the third substrate transport unit 44 rotates the fifth substrate transport arm 46 90 degrees clockwise around the third substrate transport arm shaft 49 as the center of rotation, and rotates the fourth substrate transport arm 45 90 degrees counterclockwise around the fourth substrate transport arm shaft 50 as the center of rotation.

Then, the substrate holding portion 46a of the fifth substrate transport arm 46 enters between the substrate W and the substrate stage 41 and adsorbs the substrate W. The fourth substrate transport arm 45 is moved toward the third substrate stage 42 by the Y-axis movement actuator 51 with the open portion of the substrate holding portion 45a facing the center of the third substrate stage 42. The substrate holding portion 45a of the fourth substrate transport arm 45 then enters between the substrate W and the third substrate stage 42 and adsorbs the substrate W.

The fifth substrate transport arm 46 adsorbs the substrate W on which the conductive balls S are mounted, and the fourth substrate transport arm 45 adsorbs the substrate W on which the flux F is printed, and is then moved together with the holding block 57 by the X-axis slider 48 to a position on the right side of the figure (the position shown in FIG. 1). The fifth substrate transport arm 46 transports the substrate W on which the conductive balls S are mounted from the substrate stage 41 to the fourth substrate stand 52. The fourth substrate transport arm 45 transports the substrate W before the balls are mounted from the third substrate stand 42 to the substrate stage 41. A fourth substrate transport unit 53 is disposed above the fourth substrate stand 52 on the Y-axis.

The fourth substrate transport unit 53 is composed of a Y-axis actuator 54, an X-axis slider 55, and a sixth substrate transport arm 56. A substrate W with conductive balls S mounted thereon is placed on the fourth substrate stage 52. The sixth substrate transport arm 56 is moved from the position shown in FIG. 1 by the Y-axis actuator 54 until the substrate holder 54a enters between the substrate W and the fourth substrate stage 52, and the substrate holder 54a adsorbs the substrate W. The sixth substrate transport arm 56, which has adsorbed the substrate W with conductive balls S mounted thereon, transports it to the substrate stage 70 of the repair device 5 by the X-axis slider 55.

In the ball transfer device 4, the fourth substrate transport arm 45 and the fifth substrate transport arm 46 return to the initial state shown in FIG. 1 and wait while the ball transfer unit 40 prints the conductive balls S on the substrate W. The method of transferring the conductive balls S will be described with reference to FIG. 10.

(Configuration of Repair Device 5)
Next, the configuration of the repair device 5 will be described with reference to Figures 1 and 2. The repair device 5 is a device that inspects whether or not the conductive balls S are properly mounted on the predetermined pad electrodes 107 (see Figure 3) of the substrate W, and corrects the case where the conductive balls S are not mounted on the predetermined pad electrodes 107.

Figure 2 is a front view of the repair device 5 as seen from the direction of the dotted arrow in Figure 1. Note that Figure 2 is an enlarged view of Figure 1. The repair device 5 has an inspection unit 60, a flux transfer unit 61, a ball mounting unit 62, and an excess ball removal unit 63. The repair device 5 further has a substrate stage 70 that receives and holds the substrate W on which the conductive balls S are mounted from the ball transfer device 4, and a stage transport mechanism 64 that transports the substrate stage 70 in the X-axis and Y-axis directions. The stage transport mechanism 64, the inspection unit 60, the flux transfer unit 61, the ball mounting unit 62, and the excess ball removal unit 63 are arranged in series on a stand 65. In addition, the inspection unit 60, the flux transfer unit 61, the ball mounting unit 62, and the excess ball removal unit 63 are supported by a frame 68 that is approximately U-shaped in plan view, and both ends of the frame 68 are fixed to the stand 65 by supports 69.

The stage transport mechanism 64 has a Y-axis drive unit 72 that moves the substrate stage 70 holding the substrate W transported from the ball transfer device 4 in the Y-axis direction along the Y-axis guide 71, an X-axis drive unit 74 that moves the substrate stage 70 in the X-axis direction along the X-axis guide 73, and a calibration unit 75 fixed to the substrate stage 70. The calibration unit 75 acquires position information in the X-axis direction, the Y-axis direction, and the Z-axis direction of the flux transfer unit 61, the ball mounting unit 62, and the surplus ball removal unit 63. These position information are information on the positions of the tips of the flux transfer pins 76 of the flux transfer unit 61, the tips of the ball mounting nozzles 77 of the ball mounting unit 62, and the tips of the ball removal nozzles 78 of the surplus ball removal unit 63 in the X-, Y-, and Z-axis directions. The position information acquired by the calibration unit 75 is then used to calibrate the position of the substrate W.

The inspection unit 60 inspects whether the conductive ball S is properly mounted on the pad electrode 107 (see FIG. 3) of the substrate W. The inspection unit 60 is composed of a main inspection unit 66 and a verify inspection unit 67. The main inspection unit 66 has a camera 80 that captures an image of the substrate W that has been transported, a Z-axis drive unit 81 that drives the camera 80 in the Z-axis direction, and a lighting device 82. The verify inspection unit 67 has a camera 85 that captures an image of the substrate W that has been transported, a Z-axis drive unit 86 that moves the camera 85 in the Z-axis direction, and a lighting device 87. The main inspection unit 66 acquires information on whether the conductive ball S is properly mounted on the pad electrode 107 of the substrate W. The verify inspection unit 67 acquires information on whether the conductive ball S is properly mounted on the pad electrode 107 of the substrate W based on the information of the main inspection unit 66 by using the camera 85 to capture the ball mounting areas 105A to 105D (see FIG. 3) and acquires position information that requires repair (correction). The information acquired by the verify inspection unit 67 is displayed as an image on the display device D. By visually checking the image displayed on the display device D, the operator can determine whether or not correction by the repair device 5 is necessary.

The flux transfer unit 61 has a flux transfer pin 76 that applies flux F to the pad electrode 107 in the non-opening region 132, a flux tray 90 that supplies flux F to the flux transfer pin 76, a Y-direction drive unit 91 that moves the flux tray 90 in the Y-axis direction, a camera 92 that captures the transfer target position of the flux F, and a lighting device 93. The flux transfer unit 61 has a Z-direction drive unit 94 that moves the flux transfer pin 76, the flux tray 90, and the camera 92 in the Z-axis direction. The flux transfer pin 76 attaches flux F to the flux tray 90, and while the flux tray 90 retreats in the Y-axis direction from the position of the flux transfer pin 76, it descends to transfer the flux F to the transfer target position of the substrate W (pad electrode 107) one by one. The transfer target position of the flux F is the position of the pad electrode 107 located in the non-opening region 117 (see FIG. 4) of the ball transfer mask 47.

The ball mounting unit 62 has a ball mounting nozzle 77 that mounts conductive balls S on the non-opening region 117 of the ball transfer mask 47 and on the pad electrode 107 where the ball transfer device 4 has insufficient ball transfer, a ball supply tray 96 that supplies conductive balls S to the ball mounting nozzle 77, a Y-axis drive unit 97 that moves the ball supply tray 96 in the Y-axis direction, and a Z-axis drive unit 98 that moves the ball mounting nozzle 77 in the Z-axis direction. The ball mounting nozzle 77 adsorbs the conductive ball S from the ball supply tray 96 and mounts the conductive ball S at the ball mounting target position. After adsorbing the conductive ball S, the ball mounting nozzle 77 descends while the ball supply tray 96 is retracted from the ball mounting nozzle 77 in the Y-axis direction to mount the conductive ball S at the ball mounting target position. The mounting target position of the conductive ball S is the position of the pad electrode 107 in the non-opening region 117 of the ball transfer mask 47, or the position of the pad electrode 107 where a ball mounting defect is found in the ball transfer opening region 115.

The surplus ball removal unit 63 has a ball removal nozzle 78 that removes conductive balls S (referred to as surplus balls) that are mounted on the substrate W in excess of the conductive balls S or that are misaligned from the designated pad electrode 107, a surplus ball receiving tray 100 that collects the surplus balls, a Y-axis drive unit 101 that moves the surplus ball receiving tray 100 in the Y-axis direction, and a Z-axis drive unit 102 that moves the ball removal nozzle 78 in the Z-axis direction. The ball removal nozzle 78 picks up the surplus balls remaining on the substrate W and discharges them into the surplus ball receiving tray 100. The ball removal nozzle 78 descends to pick up the surplus balls while the surplus ball receiving tray 100 is retracted in the Y-axis direction, and then rises, and the surplus ball receiving tray 100 moves below the ball removal nozzle 78 to discharge the surplus balls.

Next, we will explain the substrate W on which the conductive balls S are mounted in the ball mounting device 1, and the flux printing mask 26 and ball transfer mask 47 used. First, we will explain the substrate W when the conductive balls S are mounted in the ball mounting device 1.

(Configuration of the Substrate W)
FIG. 3 is a plan view showing one configuration example of the substrate W. FIG. 3(a) is a plan view, and FIG. 3(b) is a cross-sectional view showing an enlarged portion of the substrate W. The area surrounded by a dotted line in FIG. 3(a) is the ball mounting area 105, and in this example, four ball mounting areas 105A to 105D are provided. Pad electrodes 107 are formed in the ball mounting areas 105A to 105D. The substrate W is a silicon wafer or the like, and has a circular or rectangular outer shape. The pad electrodes 107 are rewired electrodes. After the conductive balls S are mounted on the substrate W, the substrate W is cut along scribe lines 106 between the ball mounting areas 105A to 105D to be divided into substrates WA to WD, each of which becomes a semiconductor integrated circuit chip.

The cutting of the substrate W is performed after the substrate W carrying the conductive balls S is reflowed to form bumps of the conductive balls S, or after the circuit elements are mounted. In the substrate W shown in FIG. 3(a), the pad electrodes 107 provided on the substrate W and the numerous pad electrodes 107 on which the conductive balls S are mounted are aligned. However, for convenience of illustration, the pad electrodes 107 are arranged in 10 horizontal rows and 8 vertical rows in each pad electrode formation region, but in reality, many more are provided. The pitch of the pad electrodes 107 in this example is approximately 50 μm to 400 μm. As shown in FIG. 3(b), the pad electrodes 107 are provided at the bottom of the recesses 108 provided on the substrate W. After the pad electrodes 107 are formed and the flux F is printed, the conductive balls S are dumped into the recesses 108. The diameter of the conductive balls S in this example is 10 μm to 30 μm.

When the conductive balls S are transferred onto the substrate W through the ball transfer mask 47, the center of the ball transfer mask 47 may bend toward the substrate W due to the pressing force of the brush squeegee 141 (see FIG. 10). Before the ball transfer, flux F is printed on the substrate W. Therefore, flux F may adhere to the surface of the ball transfer mask 47 facing the substrate W (hereinafter referred to as the back surface 47a) and the ball transfer opening 116 (see FIG. 4) through which the conductive balls S are transferred, which may cause ball mounting defects. Therefore, the ball transfer mask 47 is designed to prevent bending. The flux printing mask 26 is designed to prevent flux F from adhering to the ball transfer mask 47. The configurations of the ball transfer mask 47 and the flux printing mask 26 are described below.

(Configuration of the ball transfer mask 47)
4 is a diagram showing an example of the configuration of the ball transfer mask 47. FIG. 4(a) is an overall plan view, and FIG. 4(b) is an enlarged cross-sectional view showing a part of the ball transfer mask 47 (the ball transfer opening area 115A part). The ball transfer mask 47 shown in FIG. 4 is an example corresponding to the substrate W shown in FIG. 3. The ball transfer mask 47 has ball transfer opening areas 115A to 115D at positions corresponding to the respective solidified substrates WA to WD (see FIG. 3) (within the dotted frame in the figure). The ball transfer opening areas 115A to 115D have ball transfer openings 116 at positions corresponding to the pad electrodes 107. However, in the center of the inner side of the arrangement pattern of the ball transfer openings 116, a non-opening area 117 where the ball transfer openings 116 are not formed is provided. The ball transfer opening areas 115A to 115D may be collectively referred to as the ball transfer opening areas 115.

In the non-opening region 117 of the ball transfer mask 47, a columnar protrusion 118 is provided on the back surface 47a side facing the substrate W. The protrusion 118 can be of any shape, such as a cylinder, a truncated cone, a rectangular column, or a truncated pyramid, and can be made of the same material as the ball transfer mask 47, a different material, or integral with the ball transfer mask 47. The ball transfer mask 47 in this example is a metal mask, and the protrusion 118 can be made of resin. The ball transfer mask 47 is very thin and may bend when handled as is, so both sides of the outer periphery of the four sides are reinforced with a frame 119. In FIG. 4(a), the frame 119 is represented by a two-dot chain line.

The frame 119 arranged on the back surface 47a side of the ball transfer mask 47 comes into contact with the substrate W during ball transfer, and serves as a spacer 120 that regulates the position of the gap between the back surface 47a of the ball transfer mask 47 and the substrate W. The protrusion 118 has a size that is strong enough not to deform (e.g., buckle) during ball transfer within the non-opening region 117, and has a height that does not contact the flux F printed on the pad electrode 107 during ball transfer. The height of the protrusion 118 is a height that can appropriately press the conductive ball S into the flux F when the conductive ball S is transferred into the ball transfer mask 47 with the brush squeegee 141, and prevent the conductive ball S transferred by the brush squeegee 141 from being scraped out. The spacer 120 also optimally manages the gap between the back surface 47a of the ball transfer mask 47 and the substrate W. Therefore, it is preferable that the height of the protrusion 118 is approximately the same as the thickness of the spacer 120.

However, the configuration of the ball transfer mask 47 is not limited to the configuration shown in FIG. 4. Therefore, a modified example of the ball transfer mask 47 will be described with reference to FIG. 5.

Figure 5 shows a modified example of the ball transfer mask 47. Figure 5 (a) is an overall plan view, and Figure 5 (b) is a cross-sectional view showing an enlarged portion of the ball transfer mask 47 (the ball transfer opening area 115A portion). The ball transfer mask 47 has four ball transfer opening areas 115A to 115D. The example shown in Figure 5 is an example in which each ball transfer opening area is larger in the horizontal direction shown in the configuration example of the ball transfer mask 47 shown in Figure 4. In other words, the ball transfer mask 47 is larger in the horizontal direction. Each ball transfer opening area is provided with multiple non-opening areas 117 (in this example, non-opening areas 117A and 117B). Each of these two non-opening areas 117A and 117B is provided with a protrusion 118 (referred to as protrusions 118A and 118B). Parts that can be explained in common with the explanation of Figure 4 will be explained using the same symbols as in Figure 4. Frame 119 is not shown in the illustration.

Each of the non-opening regions 117A and 117B of the ball transfer mask 47 has a columnar protrusion 118A, 118B on the back surface 47a side facing the substrate W. The protrusions 118A and 118B have the same height. The protrusions 118A and 118B can have any shape, such as a cylinder, a truncated cone, a rectangular column, or a truncated pyramid, as with the ball transfer mask 47 shown in FIG. 4, and can be made of the same material as the ball transfer mask 47, a different material, or integral with the ball transfer mask 47. The protrusions 118A and 118B have a size that is strong enough not to deform (e.g., buckle) during ball transfer within the non-opening regions 117A and 117B, and have a height that does not come into contact with the flux F printed on the pad electrode 107 during ball transfer.

As shown in FIG. 5(a), a ball transfer opening 116 is arranged between the non-opening region 117A and the non-opening region 117B. The non-opening regions 117A and 117B may be arranged in a continuous configuration. However, the conductive balls S cannot be transferred into the non-opening regions 117A and 117B by the ball transfer device 4 using the ball transfer mask 47. Therefore, in order to realize the arrangement pattern of the conductive balls S as shown in FIG. 3, the additional mounting process of the conductive balls S by the repair device 5 takes time, so it is preferable to reduce the number of additional mounting of the conductive balls S. Therefore, the range of the non-opening regions 117A and 117B is narrowed, and the ball transfer opening 116 is arranged between the non-opening region 117A and the non-opening region 117B.

If the ball transfer mask 47 is made even larger, that is, if the ball transfer opening areas 115A-115D are wider, it is possible to increase the number of non-opening areas 117 or, for example, to add protrusions 118 between adjacent ball transfer opening areas 115 among the ball transfer opening areas 115A-115D.

(Configuration of Flux Printing Mask 26)
6 is a diagram showing an example of the configuration of the flux printing mask 26. The flux printing mask 26 shown in FIG. 6 is an example corresponding to the ball transfer mask 47 shown in FIG. 4. The flux printing mask 26 has flux printing opening areas 130A-130D at positions corresponding to the ball transfer opening areas 115A-115D, respectively (within the dotted line frame in the figure). The flux printing opening areas 130A-130D have flux printing openings 131 at positions corresponding to the ball transfer openings 116. However, a non-opening area 132 where the flux printing openings 131 are not formed is provided in the center of the inner side of the array pattern of the flux printing openings 131.

That is, the flux printing mask 26 is configured to have flux printing opening regions 130A-130D, flux printing openings 131, and non-opening regions 132 at the same positions as the ball transfer opening regions 115A-115D, ball transfer openings 116, and non-opening regions 117 of the ball transfer mask 47. By providing the non-opening region 132, the flux printing mask 26 prevents ball mounting defects caused by flux F adhering to the tip portions of the protrusions 118 provided in the non-opening regions 117, 117A, and 117B of the ball transfer mask 47.

The flux printing mask 26 is configured to correspond to the ball transfer mask 47, and can therefore also correspond to a configuration in which the non-opening regions 132 are provided in two locations. A modified example of the flux printing mask 26 will be described with reference to FIG. 7.

7 is a plan view showing a modified example of the flux printing mask 26. The modified example of the flux printing mask 26 corresponds to the modified example of the ball transfer mask 47 shown in FIG. 5, and the flux printing opening areas 130A, 130B, 130C, and 130D are arranged at the same positions as the ball transfer opening areas 115A, 115B, 115C, and 115D (within the dotted frame in the figure). The flux printing opening 131 is arranged at the same position as the ball transfer opening 116, and the non-opening areas 132A and 132B in which the flux printing opening 131 is not formed are arranged at the same positions as the non-opening areas 117A and 117B of the ball transfer mask 47. The modified flux printing mask 26 has non-opening areas 132A and 132B, which prevents ball mounting defects caused by flux F adhering to the tips of the protrusions 118A and 118B provided in the non-opening areas 117A and 117B of the ball transfer mask 47.

Next, the ball mounting method using the ball mounting device 1 will be explained in accordance with the process flow diagram shown in Figure 8, with reference to Figures 9 and 10 and the previously described Figures 1 to 7.

(Ball mounting method)
8 is a process flow diagram showing a ball mounting method. First, the transport robot device 2 transports the substrate W to the flux printer 3 (step S1). Next, the flux printer 3 prints flux F on the pad electrodes 107 of the substrate W (flux printing step, step S2). The flux printing method will be described with reference to FIG. 9.

(Flux printing method)
9 is an explanatory diagram showing the operation of the flux printing unit 20. FIG. 9(a) is a cross-sectional view showing the flux printing operation in a schematic manner, and FIG. 9(b) is an enlarged view showing the area surrounded by the dotted line A in FIG. 9(a). Flux printing is performed using a flux printing mask 26 and a flux printing squeegee 140 in a state where the substrate W is vacuum-adsorbed to the substrate stage 21. The substrate stage 21 has a vacuum suction hole 21a. The flux printing squeegee 140 is made of a flexible resin so as not to damage the flux printing mask 26. The substrate W is adjusted by a stage up-down driving actuator (not shown) so as to have a predetermined gap with respect to the flux printing mask 26.

The flux printing squeegee 140 prints flux F on the pad electrodes 107 of the substrate W while moving in the direction of the arrow in the figure while pressing the flux printing mask 26 to a position where it contacts the substrate W. In FIG. 9(b), the position of the left flux printing opening 131 is position (1), the position of the middle flux printing opening 131 is position (2), and the position of the right flux printing opening 131 is position (3). A recess 108 is formed in the substrate W at a position where the conductive ball S is to be inserted, and a pad electrode 107 is formed at the bottom of the recess 108.

Position (1) represents the flux F immediately after the flux printing squeegee 140 passes through the flux printing opening 131, and the flux F does not overflow from the surface of the flux printing mask 26. The flux F fits within the recess 108 so as to contact the pad electrode 107. Position (2) represents the state immediately before the flux printing squeegee 140 prints the flux F from the flux printing opening 131 onto the substrate W. Position (3) represents the flux printing opening 131 that will be printed next. When the flux printing mask 26 is released after the squeegee operation is completed, the flux F is applied to the pad electrode 107, and the flux printing is completed.

As shown in FIG. 6, the flux printing mask 26 has flux printing openings 131 corresponding to the arrangement pattern of the pad electrodes 107 formed on the substrate W, and non-opening areas 132 inside the arrangement pattern of the flux printing openings 131 where no flux printing openings 131 exist. Naturally, in the non-opening areas 132, flux F is not printed on the pad electrodes 107.

The substrate W on which the flux F is printed is transported by the second substrate transport unit 33 to the ball transfer device 4 (step S3), and the ball transfer device 4 transfers the conductive balls S onto the substrate W (ball transfer process, step S4). The ball transfer method will be described with reference to FIG. 9.

(How to transfer balls)
FIG. 10 is a diagram showing the operation of the ball transfer unit 40. FIG. 10(a) is a cross-sectional view showing a schematic diagram of the ball transfer operation, and FIG. 10(b) is an enlarged view showing the area surrounded by the dotted line A in FIG. 10(a). In the ball transfer unit 40, ball transfer is performed using the ball transfer mask 47 and the brush squeegee 141 in a state where the substrate W on which the flux F is printed is attracted to the substrate stage 41. The substrate W is attracted by magnetic attraction by a magnet (not shown) arranged on the lower side of the substrate stage 41 because the substrate W has a protrusion 118. The brush squeegee 141 is composed of a binding wire member whose end is embedded in the brush attachment portion 143 on the lower side of the ball transfer portion 142. The ball transfer mask 47 is attracted to the substrate stage 41, but the gap between the back surface 47a and the substrate W is kept constant by the protrusion 118 and the spacer 120 without bending.

The brush squeegee 141 moves in the X and Y directions while rotating, and transfers the conductive ball S supplied from the ball transfer section 142 into the rotational trajectory of the brush squeegee 141 into the ball transfer opening 116 of the ball transfer mask 47.

As shown in FIG. 10(b), the conductive balls S supplied onto the ball transfer mask 47 are transferred one by one into the ball transfer opening 116 by the brush squeegee 141. Flux F is printed on the pad electrodes 107 of the substrate W. The conductive balls S are lightly pressed against the flux F by the brush squeegee 141, and are temporarily fixed by the adhesiveness of the flux F, and this temporarily fixed state is maintained during subsequent substrate transport.

As shown in FIG. 4, the ball transfer mask 47 has ball transfer openings 116 that correspond to the arrangement pattern of the pad electrodes 107 formed on the substrate W, and non-opening regions 117 inside the arrangement pattern of the ball transfer openings 116 where no ball transfer openings 116 exist. Naturally, in the non-opening regions 117, the conductive balls S are not transferred to the pad electrodes 107.

(Repair method)
The substrate W onto which the conductive balls S have been transferred by the ball transfer device 4 is transferred to the repair device 5 by the third substrate transfer unit 44 (step S5). The substrate W transferred from the ball transfer device 4 is held by suction on the substrate stage 70 and transferred to a position below the inspection section 60 by the stage transfer mechanism 64. The inspection section 60 detects a no-flux-printed position (flux-printing defect position) and an excess or shortage position of the conductive balls S (ball mounting defect position) by the main inspection section 66 and the verify inspection section 67 (step S6). The no-flux-printed position is the position of the pad electrode 107 where the flux should be printed in the non-opening region 132 of the flux printing mask 26.

A shortage of conductive balls S is detected by the position of the pad electrode 107 that is located in the non-opening area 117 of the ball transfer mask 47, where no conductive balls S are transferred by the ball transfer device 4, and the position of the pad electrode 107 where no conductive balls S are present in the position where they should be transferred by the ball transfer device 4. An excess of conductive balls S is detected when more than a predetermined number of conductive balls S are transferred to the substrate W, or when conductive balls S are mounted offset from the predetermined position, which are called surplus balls.

The flux transfer unit 61 adheres the flux F in the flux tray 90 to the flux transfer pin 76 based on the no-flux-printing position information detected by the inspection unit 60, and transfers the flux F to the pad electrode 107 on which the flux F is not printed (step S7). The flux transfer is performed after the stage transport mechanism 64 aligns the flux transfer pin 76 with the position to be transferred to. The flux transfer process is repeated as many times as necessary.

Then, the flux transfer unit 61 mounts a conductive ball S on the pad electrode 107 to which the flux F has been transferred and on the ball transfer device 4 at a position where there is a lack of ball mounting. Specifically, the ball mounting unit 62 causes the ball mounting nozzle 77 to adsorb a conductive ball S from the ball supply tray 96 based on the ball mounting shortage position information detected by the inspection unit 60, and mounts the conductive ball S on the pad electrode 107 where there is a lack of ball mounting (step S8). The ball mounting is performed after the stage transport mechanism 64 aligns the ball mounting nozzle 77 with the ball mounting target position. The ball mounting process is repeated as many times as necessary.

Next, the surplus balls are removed (step S9). Based on the position information of the surplus balls detected by the inspection unit 60, the surplus ball removal unit 63 sucks up the surplus balls with the ball removal nozzle 78 and discharges them into the surplus ball receiving tray 100. The surplus ball removal is performed after the stage transport mechanism 64 aligns the surplus ball target position with the ball removal nozzle 78. The surplus ball removal process is repeated as many times as necessary.

The substrate W, in which the mounting defects of the conductive balls S have been corrected by the repair device 5, is transported to a device for the next process, for example, a reflow device (not shown) (step S10). The conductive balls S that have passed through the reflow device melt and become what are known as bumps. Although not shown, the substrate W can also be discharged from the repair device 5 to a material removal load port by a robot arm.

The ball mounting device 1 uses the flux printing device 3 to print flux F on the pad electrode 107 of the substrate W using a flux printing mask 26 having a non-opening area 132 where no flux printing openings 131 exist inside the arrangement pattern of the flux printing openings 131. The ball transfer device 4 uses a ball transfer mask 47 having a ball transfer opening 116 and a non-opening area 117 in the same position as the flux printing mask 26, and transfers a conductive ball S from the ball transfer opening 116 onto the pad electrode 107 on which the flux F has been printed.

The non-opening region 117 of the ball transfer mask 47 has a columnar protrusion 118 on the back surface 47a facing the substrate W. By having such a protrusion 118, when the conductive ball S is transferred onto the substrate W using the brush squeegee 141, the ball transfer mask 47 can be prevented from bending toward the substrate due to the pressing force of the brush squeegee 141. As a result, the flux F printed on the pad electrode 107 does not adhere to the back surface 47a of the ball transfer mask 47 or the ball transfer opening 116, making it possible to prevent ball mounting defects caused by the adhered flux F.

However, in the conventional ball transfer mask 47, when the conductive balls S are miniaturized and arranged at a high density, it is difficult to provide the protrusions 118 at positions that avoid the ball transfer openings 116. However, by providing a non-opening region 117 in the ball transfer mask 47, it is possible to provide the protrusions 118 in this non-opening region 117 regardless of the arrangement density of the conductive balls S. However, the ball transfer device 4 cannot transfer balls to the non-opening region 117, but the repair device 5 can transfer the flux F to the pad electrode 107 arranged in the non-opening region 117 of the ball transfer mask 47 and mount the conductive balls S.

The ball mounting device 1 described above makes it possible to mount conductive balls S on a substrate W having a large ball mounting area 105 and an array pattern of pad electrodes 107 in which minute-diameter conductive balls S are densely arranged, without any ball mounting defects.

The ball transfer mask 47 has non-opening regions 117A and 117B, and a ball transfer opening 116 is arranged between the adjacent non-opening regions 117A and 117B. Protrusions 118A and 118B are formed in the non-opening regions 117A and 117B, respectively. The area of the ball mounting region 105 may become even larger, and the ball transfer mask 47 may become larger accordingly. However, by providing non-opening regions 117 corresponding to the size of the ball transfer mask 47 and providing protrusions 118 at appropriate positions, it is possible to prevent the ball transfer mask 47 from bending even if the ball transfer mask 47 becomes larger and the area of the ball mounting region 105 becomes even larger. In addition, the ball transfer device 4 cannot transfer the conductive ball S into the non-opening regions 117A and 117B, which results in a ball mounting defect, but the repair device 5 corrects the ball mounting defect. Therefore, by arranging the ball transfer opening 116 between adjacent non-opening regions 117, it is possible to reduce the number of flux transfers and ball mountings at the defective ball mounting positions during the repair process.

The flux printing mask 26 has a non-opening region 132 that is located at the same position as the non-opening region 117 of the ball transfer mask 47. And between adjacent non-opening regions 132, a flux printing opening 131 is located. Since the flux printing device 3 does not print flux F on the substrate W in the non-opening region 132, the flux F does not adhere to the protrusion 118 of the ball transfer mask 47 in the subsequent process, and it is possible to suppress the occurrence of ball mounting defects. Since flux F cannot be printed in the non-opening region 132, a flux printing defect occurs, but the flux printing defect is corrected by the repair device 5. Therefore, by arranging the flux printing opening 131 between adjacent non-opening regions 132, it is possible to reduce the number of flux transfers in the repair process.

The height of the protrusion 118 is set so that when the conductive ball S is transferred into the ball transfer mask 47, the top of the conductive ball S does not protrude from the upper surface of the ball transfer mask 47. This makes it possible to press the conductive ball S into the flux F appropriately when transferring the conductive ball S into the ball transfer mask 47 with the brush squeegee 141, and to prevent the transferred conductive ball S from being scraped out by the brush squeegee 141.

In the ball mounting method using the ball mounting device 1, first, flux F is printed on the pad electrodes 107 using a flux printing mask 26 having flux printing openings 131 corresponding to the arrangement pattern of the pad electrodes 107 formed on the substrate W and non-opening areas 132 arranged inside the arrangement pattern of the flux printing openings 131. Next, a ball transfer mask 47 having a ball transfer opening 116 and a non-opening area 117 arranged in the same position as the non-opening area 132 of the flux printing mask 26, and a columnar protrusion 118 formed on the back surface 47a of the non-opening area 117 facing the substrate W, is used to transfer the conductive balls S from the ball transfer opening 116. Then, the flux printing defect and the excess or shortage of the conductive balls S are detected, and the flux printing defect and the excess or shortage of the conductive balls S are corrected.

The non-opening region 117 of the ball transfer mask 47 has a columnar protrusion 118 on the back surface 47a facing the substrate W, which prevents the ball transfer mask 47 from bending toward the substrate W due to the pressing force applied by the brush squeegee 141 when transferring the balls. As a result, the flux F that has been printed on the substrate W in advance does not adhere to the back surface 47a of the ball transfer mask 47 or the ball transfer opening 116, making it possible to prevent ball mounting defects caused by the adhered flux F.

The ball transfer device 4 cannot transfer conductive balls S to the non-opening region 117. However, the repair process can transfer flux F and mount conductive balls S on the pad electrodes 107 in the non-opening region 117. In addition, the repair device 5 can correct any excess or deficiency of conductive balls S transferred by the ball mounting device 1.

The ball mounting method described above makes it possible to mount conductive balls S on a substrate W having a large ball mounting area 105 and an array pattern of pad electrodes 107 in which minute-diameter conductive balls S are densely arranged, without any ball mounting defects.

In the repair process, the inspection unit 60 first detects the position of the flux printing defect on the substrate W, and the excess or shortage of conductive balls S mounted by the ball mounting device 1. Next, the flux transfer unit 61 transfers flux F to the position of the flux printing defect, and the ball mounting unit 62 mounts conductive balls S at the positions where there is an insufficient number of conductive balls S mounted. Then, the excess ball removal unit 63 removes the excess balls on the substrate W. Through such a process, it is possible to manufacture a substrate W without ball mounting defects.

1...ball mounting device, 3...flux printing device, 4...ball transfer device, 5...repair device, 20...flux printing unit, 21, 41, 70...substrate stage, 23...first substrate transport unit, 26...flux printing mask, 40...ball transfer unit, 47...ball transfer mask, 47a...rear surface, 60...inspection section, 61...flux transfer section, 62...ball mounting section, 63...excess ball removal section, 64...stage transport mechanism, 66...main inspection section, 67...verify inspection section, 76...flux transfer pin, 77...ball mounting nozzle, 78...ball removal removal nozzle, 105, 105A to 105D...ball mounting area, 107...pad electrode, 115, 115A to 115D...ball transfer opening area, 116...ball transfer opening, 117, 117A, 117B...non-opening area, 118, 118A, 118B...projection, 130A to 130D...flux printing opening area, 131...flux printing opening, 132, 132A, 132B...non-opening area, 140...flux printing squeegee, 141...brush squeegee, F...flux, S...conductive ball, W...substrate, WA, WB...solidified substrate

Claims (6)

a flux printing device that uses a flux printing mask having flux printing openings provided in correspondence with an arrangement pattern of pad electrodes formed on a substrate and a non-opening area inside the arrangement pattern of the flux printing openings where the flux printing openings are not present, and prints flux on the pad electrodes from the flux printing openings;
a ball transfer mask having ball transfer openings arranged in correspondence with the arrangement pattern of the pad electrodes, non-opening regions in which the ball transfer openings are not present and arranged at positions corresponding to the non-opening regions of the flux printing mask, and columnar protrusions formed on a surface of the non-opening regions facing the substrate, the ball transfer mask transferring a conductive ball through the ball transfer openings;
a repair device having a flux transfer unit that applies the flux to the pad electrodes in the areas of the substrate where the conductive balls have been transferred, a ball mounting unit that mounts the conductive balls in the non-opening areas and in the ball mounting shortage positions of the ball transfer opening, and an excess ball removal unit that removes excess balls on the substrate;
It has
the pad electrodes are disposed in areas of the substrate corresponding to the non-opening areas of the flux printing mask;
the repair device mounts the conductive ball on the pad electrode in an area corresponding to the non-opening area into which the conductive ball has not been transferred by the ball transfer device;
A ball mounting device. 2. The ball mounting device according to claim 1,
The ball transfer mask has a plurality of non-opening regions arranged therein, and the ball transfer opening is further arranged between adjacent non-opening regions;
The protrusions are formed in each of the non-opening regions.
A ball mounting device. 2. The ball mounting device according to claim 1,
The flux printing mask has non-opening regions arranged at the same positions as the non-opening regions of the ball transfer mask, and the flux printing openings are further arranged between adjacent non-opening regions.
A ball mounting device. 2. The ball mounting device according to claim 1,
The height of the protrusion is such that, when the conductive ball is transferred into the ball transfer mask, the top of the conductive ball does not protrude from the upper surface of the ball transfer mask.
A ball mounting device. a flux printing process using a flux printing mask having flux printing openings provided in correspondence with an arrangement pattern of pad electrodes formed on a substrate and a non-opening region inside the arrangement pattern of the flux printing openings where the flux printing openings are not present, and printing flux on the pad electrodes through the flux printing openings;
a ball transfer process in which a conductive ball is transferred from the ball transfer opening using a ball transfer mask having a ball transfer opening provided in accordance with the arrangement pattern of the pad electrodes, a non-opening region in which the ball transfer opening is not present and provided at a position corresponding to the non-opening region of the flux printing mask, and a columnar protrusion formed on a surface of the non-opening region facing the substrate;
a repair process for detecting an excess or deficiency of the conductive balls and correcting the excess or deficiency;
Including,
the pad electrodes are disposed in areas of the substrate corresponding to the non-opening areas of the flux printing mask;
the repair step includes mounting the conductive ball on the pad electrode in a region corresponding to the non-opening region into which the conductive ball has not been transferred in the ball transferring step ;
A ball mounting method comprising the steps of: 6. The ball mounting method according to claim 5,
The repair process includes:
detecting a position of a flux printing defect on the board and a position of an excess or shortage of the conductive balls mounted on the board;
transferring the flux to the flux printing defect location;
a ball mounting step of mounting the conductive ball at a position where the conductive ball is not mounted;
a surplus ball removing step of removing surplus balls on the substrate;
including,
A ball mounting method comprising the steps of:

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