JP7298887B2 - Ball loading device and ball loading method - Google Patents

Description

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

2. Description of the Related Art In recent years, as the density of semiconductor chips increases, a method of mounting conductive balls on electrodes (electrode pads) of a substrate or the like at high density has been adopted as a means for connecting semiconductor chips. A method of mounting conductive balls on a substrate uses a ball array mask placed on the substrate, and the conductive balls are placed by swinging (dropping) the balls into the ball array holes provided in the ball array mask. are placed on predetermined electrodes. Furthermore, with the increase in density, it is required to change the height of solder bumps and to mount conductive balls of different sizes on the same substrate.

As a method of forming solder bumps having different heights on electrodes of a substrate, a conductive ball is used as a solder ball, and a single through hole into which one solder ball of the same size can be thrown and a solder ball of the same size are used. There is a method of mounting solder balls one by one or two by two on electrodes (electrode pads) on a substrate using a ball array mask having continuous through holes into which two solder balls can be applied. Then, the solder balls mounted on the substrate are heated and melted, and the height of the solder bump obtained by melting and uniting the two solder balls thrown into the continuous through hole is measured by one solder ball blown into the single through hole. There is known a method of making the height higher than that (see, for example, Patent Document 1).

As a method for mounting conductive balls having different diameters on a substrate, first, small diameter balls are placed at predetermined positions on the substrate using a ball arrangement mask having ball transfer holes for conductive balls with a small diameter (referred to as small diameter balls). and then, using a ball array mask having ball transfer holes for large-diameter conductive balls, a large-diameter conductive ball (referred to as a large-diameter ball) is mounted at a predetermined position on the substrate. There is (for example, see Patent Document 2).

Also, as a method of mounting conductive balls having different diameters on a substrate, a single ball array mask having ball array holes corresponding to both large and small balls is used. There is a ball mounting device and a ball mounting method in which a ball is thrown upward and then a small-diameter ball is thrown onto the substrate (see, for example, Patent Document 3).

JP 2013-201284 A JP 2007-281369 A JP 2019-67991 A

In the method of mounting solder balls on a substrate described in Patent Document 1, the height of a solder bump formed by two solder balls blown into continuous through holes is equal to the height of one solder ball blown into a single through hole. can be higher than the solder bumps formed by However, since the height of the two solder bumps depends on the size and shape of the electrode pads on the substrate, the shape and size of the continuous through holes, and the heating temperature, the height and shape of the solder bumps can be freely controlled. It is extremely difficult to do. Therefore, it is desirable to mount solder balls having different diameters corresponding to the required solder bumps on the board.

In the method of mounting conductive balls on a substrate described in Patent Document 2, small-diameter balls are mounted on a substrate using a ball array mask for small-diameter balls, and then large-diameter balls are mounted on the substrate. It is mounted on the substrate using a mask. Therefore, a ball mounting device for mounting small-diameter balls, a ball mounting device for mounting large-diameter balls, and a board transporting device and a substrate removing device are required for each ball mounting device. There is a problem of putting away. It is also possible to mount small-diameter balls and large-diameter balls with a single ball mounting device, but it takes time to switch the ball array mask, etc., and the processing time increases, resulting in a decrease in productivity. There is a problem of getting lower.

In addition, in the ball mounting apparatus and ball mounting method for mounting conductive balls on a substrate described in Patent Document 3, two types of diameters are obtained using one ball array mask for both large-diameter balls and small-diameter balls. A conductive ball is mounted on the substrate. In this ball mounting device, since it is possible to simultaneously mount small-diameter balls and large-diameter balls, productivity is improved. However, it is conceivable that the small-diameter ball remains between the large-diameter ball that has been swept in and the ball transfer hole.

Therefore, the present invention has been made to solve at least one of these problems, and it is possible to mount two or more types of conductive balls having different diameters on a single unit, so that there is no excess or deficiency of conductive balls. It is an object of the present invention to realize a ball mounting device and a ball mounting method capable of improving productivity.

[1] A ball mounting device according to the present invention is a ball mounting device for mounting two or more types of conductive balls having different diameters on predetermined electrodes provided on a substrate, wherein the balls are mounted on the electrodes using a flux printing mask. Using a flux printing apparatus for printing flux and two or more types of ball transfer masks having ball transfer holes with opening diameters corresponding to different diameters of the conductive balls, a ball transfer device for transferring the conductive balls onto the electrodes, wherein the flux printing device and each of the ball transfer devices have a substrate transfer unit that transfers the substrate, and each of the ball transfer devices includes: It is characterized in that the conductive balls are connected in the order in which the small-diameter conductive balls and the large-diameter conductive balls next to the small-diameter conductive balls are thrown from the flux printing device side.

According to the ball loading device of the present invention, the ball feeding device has a ball feeding mask corresponding to each conductive ball having a different diameter, and uses this ball feeding mask to feed the conductive balls having different diameters onto the electrode. It has As a result, two or more types of conductive balls having different diameters can be mounted on a single substrate. In this manner, since the conductive balls to be transferred are transferred by the ball array mask corresponding to each diameter of the conductive balls, it is possible to mount the conductive balls on the substrate just enough.

Also, if the diameter of the conductive balls is of two types, two ball moving devices are connected, and if the diameter of the conductive balls are of three types, three ball moving devices are connected. By connecting the ball swinging devices, it becomes possible to mount many types of conductive balls on predetermined electrodes. Since the ball-throwing device can simultaneously and concurrently mount multiple types of conductive balls onto the substrate, the same takt time is required even when there are multiple types of conductive balls as when there is only one type. It is possible to mount the ball at 1000 rpm, and it is possible to improve productivity. Furthermore, since the ball swinging devices each have a substrate transfer unit for transferring a substrate, they can be easily connected according to the type of conductive balls.

As described above, according to the ball mounting device of the present invention, two or more types of conductive balls having different diameters can be mounted in one device, and there is no excess or deficiency in the number of conductive balls, and productivity can be improved. Become.

[2] In the ball mounting device of the present invention, each of the ball transfer devices supplies the conductive balls to be transferred onto the ball transfer mask for each diameter of the conductive balls, and It is preferable to further have a ball transfer head for transferring the conductive balls into the transfer holes.

Since each ball transfer device has a dedicated ball transfer head corresponding to the diameter of the conductive balls, it is possible to transfer multiple types of conductive balls to the electrodes at the same time. It is possible to improve the quality.

[3] In the ball mounting device of the present invention, the substrate-side surface of the ball transfer mask to which balls are to be transferred is provided with a concave portion for accommodating the conductive balls that have already been transferred onto the electrode. preferably.

Since the ball transfer mask to be transferred is configured so that the small-diameter conductive balls mounted in front of it are covered with the bottom of the recess, conductive balls having different diameters are mixed on the substrate. It is possible to prevent transfer.

[4] In the ball mounting device of the present invention, it is preferable that the gap between the bottom of the recess and the small-diameter conductive ball is 10 μm or more, and the remaining thickness of the bottom is 10 μm or more.

With this configuration, there is always a gap between the conductive balls that have already been deposited and the bottom, so that the conductive balls can be deposited onto the electrodes while the ball transfer mask is brought into close contact with the substrate. Become. Further, by setting the remaining thickness of the bottom portion to 10 μm or more, the ball transfer mask is not warped or deformed in the concave portion, and the conductive balls can be transferred smoothly.

[5] In the ball mounting device of the present invention, it is preferable that the diameter difference between the conductive balls is at least 20 μm.

Although the details will be described later in the embodiment, the diameter of the ball transfer hole should be set to the diameter of the conductive ball considering smooth transfer of the conductive balls and workability including the precision of the ball transfer mask. By setting the difference to 20 μm or more, it becomes possible to reliably mount the conductive ball to be transferred on the predetermined electrode.

[6] A ball mounting method of the present invention is a ball mounting method using the ball mounting device according to any one of [1] to [5] above, wherein the flux is printed on the electrodes of the substrate. a flux printing step; a carrying step of carrying the substrate on which the flux is printed to the ball transfer device corresponding to the conductive ball having the smallest diameter; a ball transfer step of transferring balls to the substrate; a transfer step of transferring the substrate to the ball transfer device corresponding to the conductive balls having the next largest diameter compared to the conductive balls transferred in the ball transfer step; a ball transfer step of mounting a conductive ball having a diameter to be the next ball transfer target on the substrate, each of the conveying steps is executed at the same timing, and the flux printing step and each of the ball transfer steps are performed, It is characterized by executing at the same timing.

According to the ball mounting method of the present invention, the conductive balls to be transferred are transferred onto the electrodes by the ball transfer device corresponding to each diameter of the conductive balls, so that the conductive balls can be properly mounted on the substrate. It becomes possible. In addition, the transport process of transporting the substrate from the flux printer to the small-diameter ball feeding device and the transporting process of transporting the substrate from the small-diameter ball feeding device to the next large-diameter ball feeding device are executed at the same timing. Furthermore, since it is possible to execute the flux printing process, the ball transfer process for transferring small-diameter conductive balls, and the ball transfer process for transferring large-diameter conductive balls at the same timing, the diameter of the conductive balls Even if there are two or more types, the tact time does not increase compared to the case of one type, so productivity can be improved. It should be noted that the "same timing" does not necessarily mean that the timings are completely the same, and the timings may be shifted within a range in which the transporting process and the ball mounting process do not affect each other.

According to the ball mounting method described above, two or more types of conductive balls having different diameters can be mounted by one ball mounting device, and there is no excess or deficiency in the number of conductive balls, making it possible to improve productivity. Become.

1 is a plan view showing the overall configuration of a ball mounting device 1; FIG. FIG. 4 is a plan view showing an example when the substrate W is a rewired wafer-like plate-like object; 4 is an explanatory view schematically showing the operation of the flux printing unit 25 that prints the flux F on the substrate W; FIG. It is sectional drawing which expands and shows a part of board|substrate W with which the flux F was printed, and the mask 22 for flux printing separated from the plate typically. 4A and 4B are diagrams showing the operation of the ball transfer unit 44 for transferring the conductive balls B1 to the substrate W. FIG. FIG. 10 is a diagram showing the operation of a ball transfer unit 47 that transfers a conductive ball B2 having a diameter larger than that of a conductive ball B1 to a substrate W; FIG. 4 is a cross-sectional view showing a portion of a substrate W on which conductive balls B1 and B2 are mounted; 4 is a process flow chart showing main steps of a ball mounting method using the ball mounting device 1. FIG.

A ball mounting device 1 and a ball mounting method according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 8. FIG. In the ball mounting device 1 of the present invention, a plurality of types of conductive balls B having different diameters can be mounted on the substrate W. In the following description, two types of conductive balls B1, An example of mounting B2 on the substrate W will be described. Among the conductive balls B, a conductive ball B1 has a smaller diameter, and a conductive ball B2 has a larger diameter than the conductive ball B1.

[Configuration of Ball Mounting Device 1]
The substrate W is a plate-like or film-like member for fixing and wiring electronic components, and is, for example, a printed wiring board, a silicon wafer, or the like. including. The conductive balls B1 and B2 are, for example, conductive spheres having a diameter of 20 μm to 300 μm, such as solder balls, metal balls, conductive plastic balls, and conductive ceramic balls.

FIG. 1 is a plan view showing the overall configuration of the ball mounting device 1. FIG. In FIG. 1, the horizontal direction is the X axis, the right side is the X(+) direction, and the left side is the X(-) direction. The direction orthogonal to the X-axis is the Y-axis, the upper side in the drawing is Y(+), and the lower side in the drawing is Y(-). Also, the direction perpendicular to the XY plane is referred to as the Z axis or the vertical direction. The ball mounting device 1 includes a transfer robot device 5 which is a feeding device for the substrate W, a flux printing device 6 which prints the flux F (see FIG. 3) on the substrate W, and a conductive ball on the substrate W on which the flux F is printed. A first ball transfer device 7 for transfer of B1, a second ball transfer device 8 for transfer of conductive balls B2, and a transfer robot device 9 as a removal device for the substrate W to which the conductive balls B1 and B2 have been transferred are provided. . The transfer robot device 5, the flux printing device 6, the first ball transfer device 7, the second ball transfer device 8, and the transfer robot device 9 are linearly connected in this order.

The transfer robot device 5 supplies the flux printer 6 with the substrates W accommodated in FOUPs (Front-Opening-Unified-Pods) 13 arranged at the first load port 11 and the second load port 12 respectively. It has a robot arm 14 that The robot arm 14 picks up the substrate W from 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 is provided in the flux printing device 6. The substrate is transported to the first substrate table 16 .

In the flux printing device 6, a substrate stage 17 for sucking and holding the substrate W when printing the flux F is arranged in the central portion in the plane direction. , the second substrate table 18 is arranged on the right side of the drawing. A first substrate transfer unit 19 is arranged below the substrate stage 17 in the figure. The first substrate transfer unit 19 has a first substrate transfer arm 20 and a second substrate transfer arm 21 . A flux printing mask 22 is arranged above the Z-axis of the substrate stage 17 , and flux F is printed on the substrate W by a printing squeegee 23 . The printing squeegee 23 prints the flux F on the substrate W while moving the upper surface of the flux printing mask 22 in the Y-axis direction by the squeegee drive mechanism 24 . A unit composed of the substrate stage 17 , the flux printing mask 22 , the printing squeegee 23 and the squeegee drive mechanism 24 is referred to as a flux printing unit 25 . A second substrate transfer unit 26 is arranged on the Y(+) direction side of the second substrate table 18 . The details of the method of printing the flux F will be described later with reference to FIG.

The first substrate table 16 and the second substrate table 18 are provided with suction holes (not shown) for vacuum-sucking the substrate W. As shown in FIG. The first substrate transfer arm 20 and the second substrate transfer arm 21 are also provided with suction holes (not shown) for vacuum suction of the substrate W, so that the substrate W can be held by suction. On the other hand, the third substrate transfer arm 27 is also provided with suction holes (not shown).

Next, a method of transporting the substrate W in the flux printer 6 will be described with reference to FIG. It is assumed that the substrate W transported by the robot arm 14 is held on the first substrate table 16 . A flux F is printed on the substrate W on the substrate stage 17 . First, after the first substrate transfer unit 19 is moved to the X(−) side by the X-axis slider 30 , the first substrate transfer arm 20 is rotated by the rotary actuator 31 to a position perpendicular to the first substrate table 16 . Then, the first substrate transfer arm 20 is moved in the Y(+) direction by the Y-axis movement actuator 32 to hold the back surface of the substrate W by suction. The second substrate transfer arm 21 moves in the X(−) direction together with the first substrate transfer arm 20 and is rotated clockwise by the rotary actuator 33 to hold the substrate W on the substrate stage 17 by suction.

The first substrate transport unit 19 is moved in the X(+) direction while the first substrate transport arm 20 and the second substrate transport arm 21 are respectively sucking the substrate W. As shown in FIG. The first substrate transfer arm 20 transfers the substrate W from the first substrate table 16 to the substrate stage 17 . The second substrate transport arm 21 transports the substrate W on which the flux F is printed to the second substrate table 18 . After the substrate stage 17 and the second substrate table 18 suck and hold the substrate W, the first substrate transfer arm 20 and the second substrate transfer arm 21 return to the state shown in FIG. 1 and wait. On the substrate stage 17 , the flux F is printed on the substrate by driving the printing squeegee 24 using the flux printing mask 22 .

The substrate W on which the flux F is printed, which is adsorbed and supported by the second substrate table 18 , is transported to the first ball transfer device 7 by the second substrate transport unit 26 . The second substrate transfer unit 26 has a third substrate transfer arm 27 , an X-axis slider 34 and a Y-axis movement actuator 35 . The third substrate transfer arm 27 is moved by the Y-axis movement actuator 35 toward the second substrate table 18 to suck the substrate W on which the flux F is printed, and is moved by the X-axis slider 34 to the first ball transfer device 7 . The substrate W is transported to the first substrate table 16 and is attracted to the first substrate table 16, and the state shown in FIG. 1 is restored. The centers of the first substrate stage 16, the substrate stage 17, and the second substrate stage 18 are arranged on a straight line. 18 are the same.

After transporting the substrate W to the substrate stage 17 and the second substrate table 18, the first substrate transport unit 19 returns to the state of the flux printing apparatus 6 shown in FIG. That is, the first substrate transport unit 19 transports the substrate W from the first substrate stage 16 to the substrate stage 17 and transports the substrate W on which the flux F is printed on the substrate stage 17 to the second substrate stage 18 . The second substrate transport unit 16 transports the substrate W on which the flux F is printed to the first ball feeding device 7 for small diameter. The first ball transfer device 7 mounts small-diameter conductive balls B1 on the substrate W on which the flux F is printed.

The first ball rolling device 7 is a device that rolls small-diameter conductive balls B1 onto the substrate W. As shown in FIG. The first ball transfer device 7 has the same structure as the flux printing device 6 and is arranged at the same position as the first substrate stage 16, the substrate stage 17, the second substrate stage 18, the first substrate transfer unit 19, and the second substrate transfer unit. 26. Since the operations of the first substrate transfer unit 19 and the second substrate transfer unit 26 are the same as those of the first substrate transfer unit 19 and the second substrate transfer unit 26 in the flux printing apparatus 6, detailed description thereof will be omitted.

A ball transfer mask 40 for a small-diameter conductive ball B1 is arranged above the Z-axis of the substrate stage 17 , and the conductive ball B1 is transferred to the substrate W by a ball transfer head 41 . The ball transfer head 41 transfers the conductive balls B1 from the ball transfer holes 71 (see FIG. 5) to the substrate W while moving on the upper surface of the ball transfer mask 40 by the X-axis slider 42 and the Y-axis slider 43. Mount. A unit composed of the substrate stage 17 , the ball transfer mask 40 , the ball transfer head 41 , the X-axis slider 42 and the Y-axis slider 43 is called a ball transfer unit 44 . A method of mounting the conductive balls B1 will be described later with reference to FIG.

In the ball mounting device 7 , the first substrate transport arm 20 transports the substrate W on which the flux F is printed from the first substrate table 16 to the substrate stage 17 , and the second substrate transport arm 21 is held by the substrate stage 17 by suction. The substrate W on which the conductive balls B1 are mounted is transported to the second substrate table 18 . On the substrate stage 17, the conductive balls B1 are transferred onto the substrate W through the ball transfer holes 71 (see FIG. 5) of the ball transfer mask 40 by the brush squeegee 68 (see FIG. 5) of the ball transfer head 41. FIG. The substrate W mounted with the conductive balls B1 sucked and held by the second substrate table 18 is transferred to the first substrate table 16 of the second ball transfer device 8 by the second substrate transfer unit 26 .

The large-diameter second ball rolling device 8 is a device that rolls onto the substrate W conductive balls B2 having a larger diameter than the conductive balls B1 mounted on the first ball rolling device 7 . The second ball transfer device 8 has the same structure as the flux printing device 6 and the first ball transfer device 7, and is arranged at the same position. 19 and a second substrate transfer unit 26 . Since the operations of the first substrate transfer unit 19 and the second substrate transfer unit 26 are the same as those of the flux printing device 6 and the ball mounting device 7, detailed description thereof will be omitted.

Above the Z-axis of the substrate stage 17, a ball transfer mask 45 having a ball transfer hole 72 (see FIG. 5) with an opening diameter corresponding to the diameter of the conductive ball B2 is arranged. A conductive ball B2 is mounted on the substrate W by the ball transfer head 46 corresponding to the diameter of the ball B2. The ball transfer head 46 transfers the conductive balls B2 from the ball transfer holes 72 while moving on the upper surface of the ball transfer mask 45 by the X-axis slider 42 and the Y-axis slider 43, and mounts them on the substrate W. FIG. A unit composed of the substrate stage 17 , the ball transfer mask 45 , the ball transfer head 46 , the X-axis slider 42 and the Y-axis slider 43 is called a ball transfer unit 47 . A method of transferring the conductive balls B2 will be described later with reference to FIG.

In the second ball transfer device 8, the first substrate transfer arm 20 transfers the substrate W on which the conductive balls B1 are mounted from the first substrate table 16 to the substrate stage 17, and the second substrate transfer arm 21 transfers the substrate W to the substrate stage 17. The substrate W on which the large-diameter conductive balls B<b>2 that are held by suction on the substrate W are carried to the second substrate table 18 . The substrate W mounted with the conductive balls B1 and B2 adsorbed and held by the second substrate table 18 is transported by the second substrate transport unit 26 to the inspection section 48 of the transport robot device 9 for material removal. .

The transfer robot device 9 as a material removal device includes an inspection unit 48 that inspects the excess or deficiency of the conductive balls B1 and B2 on the substrate W to which the conductive balls B1 and B2 have been transferred, and an inspection unit 48 that checks whether the conductive balls B1 and B2 have been transferred. and a robot arm 51 for transporting the substrate W picked up from the inspection unit 48 to the third load port 49 or the fourth load port 50 . The third load port 69 and the second load port 70 are provided with FOPUs 52 that accommodate substrates W removed from the inspection section 68 by the robot arm 51 . Although illustration is omitted, the inspection unit 48 includes conductive B1. It has an inspection camera for inspecting excess or deficiency of B2. The inspection unit 48 is arranged at the same position as the first work table 16 in the second ball moving device 8 . That is, the center distance between the second substrate table 18 of the second ball moving device 8 and the inspection unit 48 is is the same as the center distance of The excess or deficiency of the conductive balls B1 and B2 on the substrate W is inspected while scanning the inspection camera in the X and Y directions. The inspection camera may be fixed and the substrate W may be moved.

The robot arm 14 and the robot arm 51 have a common configuration, and are driven and controlled by a program for material supply and material removal. Also, although not shown, a repair device can be connected to the inspection unit 48 .

In the ball mounting device 1 described above, the flux printing device 6, the first ball transfer device 7, and the second ball transfer device 8 each have a flux printing unit 25, a ball transfer unit 44, and a ball transfer unit 47. FIG. Further, each unit has a first substrate transfer unit 19 and a second substrate transfer unit 26, respectively. In other words, when the ball mounting apparatus 1 includes the first board transfer unit 19 and the second board transfer unit 26 as a board transfer unit, the flux printing apparatus 6 is configured by combining the board transfer unit and the flux printing unit 25 . By combining the substrate transfer unit and the ball transfer unit 44, the first ball transfer device 7 can be configured, and by combining the substrate transfer unit and the ball transfer unit 47, the second ball transfer device 8 can be configured. For example, even when a plurality of types of conductive balls are mounted on the substrate W, it is possible to successively connect ball transfer devices corresponding to the diameters of the conductive balls to be transferred. Next, the configuration of the substrate W to which the balls are transferred will be described with reference to FIG.

[Structure of Substrate W]
FIG. 2 is a plan view showing an example when the substrate W is a rewired wafer-like plate-like object. FIG. 2(a) is a plan view showing the entire substrate W, and FIG. 2(b) is an enlarged view showing an electrode formation region 55 surrounded by a dotted line A shown in FIG. 2(a). A large number of electrode groups 56 are arranged in the electrode formation region 55 . The electrode group 56 is surrounded on four sides by scribe lines 57, and by cutting the scribe lines 57, individual semiconductor integrated circuit chips are obtained. This cutting is performed after the substrate W on which the conductive balls B1 and B2 are mounted is reflowed in a reflow furnace or at the end of the mounting process. The electrode group 56 is composed of a set of electrodes 58 on which the small-diameter balls B1 are arranged and mounted, and a set of electrodes 59 on which the large-diameter balls B2 are arranged and mounted. Electrodes 58 and 59 shown in FIG. 2(b) are rewired electrodes. The pitch of the electrodes 58 is approximately 50 μm to 400 μm. FIG. 2 is for explaining the arrangement of the electrodes 58 and 59 formed on the substrate W and the electrode forming region 55 where the electrodes 58 and 59 are formed. The shape of the area 55 is different from the real thing. Next, a method of printing the flux F on the electrodes 58 and 59 of the substrate W will be described with reference to FIG.

[Flux printing method]
3A and 3B are explanatory diagrams schematically showing the operation of the flux printing unit 25 for printing the flux F on the substrate W. FIG. FIG. 3(a) is a cross-sectional view schematically showing the flux printing operation, and FIG. 3(b) is an enlarged view of the area surrounded by the dotted line A in FIG. 3(a). The flux F is printed using the flux printing mask 22 and the printing squeegee 23 while the substrate W is vacuum-sucked to the substrate stage 17 by the suction holes 60 . The printing squeegee 23 is preferably made of flexible resin so as not to damage the flux printing mask 22 . The substrate W is adjusted by a stage vertical drive actuator (not shown) so as to have a predetermined gap with respect to the flux printing mask 22 .

The printing squeegee 23 prints the flux F on the electrodes 58 and 59 of the substrate W while pressing the flux printing mask 22 to a position where it contacts the substrate W and moving in the direction of the arrow shown. In this example, the flux F is simultaneously printed on the electrodes 58 and 59 on which the conductive balls B1 and B2 are respectively mounted. In FIG. 3B, the left mask opening 62 is at position (1), the middle mask opening 62 is at position (2), and the right mask opening 62 is at position (3). . Position ( 1 ) represents the state immediately after the printing squeegee 23 passes through the mask opening 62 , and the flux F does not protrude from the upper surface of the flux printing mask 22 . Then, the flux F comes into contact with the electrodes 58 and 59 and settles. Position ( 2 ) represents a state immediately before the printing squeegee 23 prints the flux F onto the substrate W through the mask opening 62 . Position (3) represents the mask opening 62 to be printed next. By separating the flux printing mask 22 after the squeegee operation is finished, the flux F is transferred to the electrodes 58 and 59 and the flux printing is completed.

FIG. 4 is a cross-sectional view schematically showing an enlarged part of the substrate W on which the flux F is printed and a part of the flux printing mask 22 that is separated from the plate. The flux F printed on the substrate W has a cross-sectional shape in which the central portion rises on the electrodes 58 and 59 due to the viscosity and surface tension of the flux F. As shown in FIG. In the flux printing mask 22, the flux F stays in the mask openings 62 (62A for the small diameter and 62B for the large diameter), and the next flux printing is performed in that state. The flux F in the mask openings 62A and 62B has a cross-sectional shape in which the central portion is reduced by surface tension, but excessive flux may adhere to the reference surface 22a due to repeated flux printing. At that time, excess flux is removed by a cleaning device (not shown). Excess flux may be removed each time flux printing is performed, periodically, or as needed. Next, a ball mounting method using the ball mounting device 1 described above will be described with reference to FIGS. 5 to 7. FIG.

[Ball transfer method]
In the ball transfer method of the present embodiment, first, the first ball transfer device 7 (ball transfer unit 44) transfers the small-diameter conductive ball B1 to the substrate W, and then the second ball transfer device 8 (ball transfer unit 47). 2, two types of conductive balls B1 and B2 having different diameters are mounted on the substrate W by one ball mounting device 1 by throwing the large-diameter conductive ball B2 onto the substrate W. FIG.

5A and 5B are diagrams showing the operation of the ball transfer unit 44 for transferring the conductive balls B1 to the substrate W. FIG. FIG. 5(a) is a cross-sectional view schematically showing a ball swing operation, and FIG. 5(b) is a cross-sectional view showing an enlarged area surrounded by a dotted line A in FIG. 5(a). In the ball transfer unit 44, the conductive balls B1 are transferred onto the electrodes 58 of the substrate W by the ball transfer mask 40 and the ball transfer head 41 while the substrate W on which the flux F is printed is vacuum-sucked to the substrate stage 17. The ball transfer head 41 is composed of a ball transfer portion 66 that supplies the conductive balls B1 to the ball transfer mask 40, and a binding wire-like member whose end is embedded in a brush mounting portion 67 below the ball transfer portion 66. and a brush squeegee 68 . The ball transfer mask 40 is vacuum-sucked by suction holes 60 provided in the substrate stage 17 and suction holes 70 provided in the mask support 69 . As a result, the ball transfer mask 40 is in close contact with both upper surfaces of the substrate W and the mask support 69, and ball transfer is possible even near the outer periphery of the substrate W. FIG.

The brush squeegee 68 moves in the X and Y directions while rotating, and pushes the conductive balls B1 supplied from the ball transfer section 66 into the rotational trajectory of the brush squeegee 68 into the ball transfer holes 71 ( (See FIG. 5(b)).

As shown in FIG. 5B, the conductive balls B1 supplied onto the ball transfer mask 40 are transferred one by one into the ball transfer holes 71 by the brush squeegee 68 . A flux F is printed on the electrodes 58 of the substrate W. As shown in FIG. The conductive balls B1 are lightly pressed against the flux F by the brush squeegee 68, temporarily fixed by the adhesiveness of the flux F, and positional deviation does not occur in the subsequent board transfer. Since the ball transfer mask 40 is not provided with the ball transfer holes 72 (see FIG. 6) for transferring the large-diameter conductive balls B2, only the conductive balls B1 can be transferred to the substrate W. is possible. A post 40b protrudes from the rear surface 40a of the ball transfer mask 40 on the substrate W side. A plurality of pillars 40b are arranged at positions avoiding the electrodes 58 and 59 so that the back surface 40a of the ball array mask 40 does not come into contact with the printed flux F. FIG. Next, a method of throwing the conductive balls B2 onto the substrate W will be described with reference to FIG.

6A and 6B are diagrams showing the operation of the ball transfer unit 47 that transfers the conductive ball B2 having a diameter larger than that of the conductive ball B1 to the substrate W. FIG. FIG. 6(a) is a cross-sectional view schematically showing the ball swinging operation, and FIG. 6(b) is a cross-sectional view showing an enlarged state of swinging the conductive ball B2. The transfer of the conductive balls B2 to the substrate W is performed in the second ball transfer device 8 after the transfer of the conductive balls B1. In the ball transfer unit 47, the conductive balls B2 are transferred to the substrate W by the ball transfer mask 45 and the ball transfer head 46 while the substrate W on which the flux F is printed and the conductive balls B1 are transferred is vacuum-adsorbed to the substrate stage 17. is applied onto the electrode 59 of . The ball transfer head 46 is composed of a ball transfer portion 73 that supplies the conductive balls B2 to the ball transfer mask 45, and a binding wire-like member whose end is embedded in a brush mounting portion 74 below the ball transfer portion 73. and a brush squeegee 75 . The ball transfer mask 45 is vacuum-sucked by suction holes 60 provided on the substrate stage 17 and suction holes 70 provided on the mask support 69 . As a result, the ball transfer mask 45 is in close contact with both upper surfaces of the substrate W and the mask support 69, and ball transfer is possible even near the outer periphery of the substrate W. FIG.

The brush squeegee 75 moves in the X direction and the Y direction while rotating, and the conductive balls B2 supplied from the ball transfer section 73 into the rotation locus of the brush squeegee 75 are applied to the ball transfer holes 72 of the ball transfer mask 45. Transfer.

As shown in FIG. 6B, the conductive balls B2 supplied onto the ball transfer mask 45 are transferred one by one into the ball transfer holes 72 by the brush squeegee 75 . A flux F is printed on the electrodes 59 of the substrate W. FIG. The conductive balls B2 are lightly pressed against the flux F by the brush squeegee 75, temporarily fixed by the adhesiveness of the flux F, and no positional deviation occurs during the subsequent board transfer. The back surface 45a of the ball transfer mask 45 is provided with a recess 76 for accommodating the small-diameter conductive ball B1 already transferred to the substrate W. As shown in FIG. The area into which the conductive balls B1 are thrown is covered with a ball transfer mask, and only the ball transfer holes 72 through which the large-diameter conductive balls B2 are transferred are opened.

Here, the relationship between the recess 76 and the conductive ball B1 will be described. In this example, the gap H between the bottom portion 76a of the recess 76 and the conductive ball B1 is set to 10 μm or more, and the remaining thickness T of the bottom portion 76a of the recess 76 is set to 10 μm or more. By setting the gap H and the remaining thickness T as described above, the total thickness of the ball transfer mask 45 is specified to an optimum value, the conductive balls B1 and the ball transfer mask 45 do not contact each other, and the concave portions 76 are formed. is formed, the ball transfer mask 45 can be prevented from being warped or deformed.

A support 45b is protruded from the rear surface 45a of the ball transfer mask 45 on the substrate W side. A plurality of columns 45b are arranged at positions avoiding the electrodes 58 and 59 so that the back surface 45a of the ball array mask 45 does not come into contact with the printed flux F. FIG.

FIG. 7 is a cross-sectional view showing a portion of the substrate W on which the conductive balls B1 and B2 are mounted. Conductive balls B1 and B2 are mounted on flux F printed on electrodes 58 and 59 provided on the same plane of substrate W. FIG. The conductive balls B1 and B2 are maintained in the mounted position and state due to the viscosity of the flux F. FIG.

In this example, the minimum diameter of the conductive balls having different diameters is 20 μm, and the difference in diameter between the small-diameter conductive ball and the next conductive ball to be mounted is at least 20 μm. The minimum diameter of the conductive balls is set in consideration of the processability of the flux printing mask 22, the limit of flux printing using the flux printing mask 22, the processability of the ball transfer mask, and the ball transferability. Further, if the diameter D1 of the ball transfer hole 71 is 1.1 times the diameter d1 of the conductive ball, the diameter difference between the conductive balls is set to 20 μm or more, so that after mounting the small-diameter conductive ball It is possible to prevent a mistake in mounting a large-diameter conductive ball to be mounted next. Similarly, if the diameter D2 of the ball transfer hole 72 is set to 1.1 times the diameter d2 of the conductive ball, the diameter difference between the conductive balls is set to 20 μm or more, so that after mounting the small-diameter conductive ball It is possible to prevent mounting errors of the large-diameter conductive balls to be mounted next.

[Ball mounting method]
Next, the ball mounting method using the ball mounting device 1 and the ball transfer method described above will be described along the process flow chart shown in FIG. 8 with reference to FIGS. 1 to 7. FIG.

FIG. 8 is a process flow diagram showing main steps of a ball mounting method using the ball mounting apparatus 1. FIG. The robot arm 14 transports the substrate W from the first load port 11 or the second load port 12 for material supply to the pre-aligner 15 (step S1). The position of the substrate W is corrected in the pre-aligner 15 (step S2). After the position correction, the robot arm 14 transports the substrate W to the first substrate table 16 of the flux printer 6 (step S3). The substrate W transported to the first substrate platform 16 is transported to the substrate stage 17 of the flux printing device 6 by the first substrate transport arm 20, and the flux F is printed on the substrate W by the flux printing unit 25 (step S4). The substrate W on which the flux F has been printed is temporarily transported to the second substrate platform 18 by the second substrate transport arm 21, and further transferred via the first substrate platform 16 of the first ball transfer device 7 by the third substrate transport arm 27. Then, it is transported to the substrate stage 17 (step S5). The substrate W is transferred from the first substrate table 16 of the first ball transfer device 7 to the substrate stage 17 by the first substrate transfer arm 20 .

In the first ball transfer device 7, the ball transfer unit 44 transfers the small-diameter conductive balls B1 to the substrate W printed with the flux F on the substrate stage 17 (step S6). Then, the substrate W on which the conductive balls B1 are mounted is transferred to the second ball transfer device 8 (step S7). The substrate W on which the conductive balls B1 are mounted is once transferred to the second substrate table 18 of the first ball transfer device 7 by the second substrate transfer arm 21, and then transferred to the second ball transfer device 8 by the third substrate transfer arm 27. , and further transferred to the substrate stage 17 of the second ball transfer device 8 by the first substrate transfer arm 20 . Subsequently, a large-diameter conductive ball B2 is sprinkled onto the substrate W (step S8).

Subsequently, the substrate W on which the conductive balls B1 and B2 have been deposited is transferred to the transfer robot device 9 (step S9). The substrate W on which the conductive balls B1 and B2 are mounted is temporarily transferred to the second substrate table 18 of the second ball transfer device 8 by the second substrate transfer arm 21, and then transferred to the transfer robot device by the third substrate transfer arm 27. 9 inspection section 48. The inspection unit 48 inspects whether the conductive balls B1 and B2 are excessive or insufficient (step S10). Subsequently, the substrate W that has been inspected by the inspection unit 48 is transported to the third load port 49 or the fourth low port by the robot arm 51 for material removal (step S11). For example, substrates W determined to be non-defective by the inspection unit 48 may be transported to the third load port 49 , and substrates W determined to be defective may be transported to the fourth load port 50 .

The process flow shown in FIG. 8 shows the flow at the start of operation of the ball mounting device 1 . Assuming that steps S1 to S11 constitute one cycle of the ball loading operation, after completing one cycle, each of the substrate stages 17 of the flux printing device 6, the first ball transfer device 7, and the second ball transfer device 8 and the inspection unit 48 A substrate W is being transported to . Therefore, the flux printing device 6 prints the flux, the first ball transfer device 7 transfers the conductive balls B1, the second ball transfer device 8 transfers the conductive balls B2, and the inspection unit 48 transfers the conductive balls B1 and B2. It is possible to perform the processing operations such as the excess/deficiency inspection almost at the same time even if there is some deviation. However, each tact time may be set within the scope of the process that requires the most time.

Regarding the transport of the substrate W, it is performed at the same timing outside the time of the processing operation. That is, in each device of the flux printing device 6, the first ball transfer device 7, and the second ball transfer device 8, the first substrate platform 16--substrate stage 17--second substrate platform 18--substrate W on first substrate platform 16 By making the transfer strokes the same, it is possible to transfer the substrates W at the same timing. The transfer of the substrate W from the second ball swinging device 8 to the inspection unit 48 can be performed at the same timing as the transfer between the devices. In addition, since the robot arm 14 for material supply and the robot arm 51 for material removal have a high degree of freedom of movement, they are operated so as not to affect the operations of the first substrate transfer unit 19 and the second substrate transfer unit 26 . Timing can be set.

The ball mounting device 1 described above includes the flux printing device 6 that prints the flux F on the electrodes 58 and 59 using the flux printing mask 22, and the ball feeding holes having opening diameters corresponding to different diameters of the conductive balls. A first ball-swinging device 7 and a second ball-swinging device 8 which use two or more types of ball-swiping masks 40 and 45 and swing conductive balls B1 and B2 having different diameters onto electrodes 58 and 59 respectively. ing. The flux printing device 6 and each of the ball transfer devices 7 and 8 have substrate transfer units (first substrate transfer unit 19 and second substrate transfer unit 26) for transferring the substrate W. As shown in FIG. The ball mounting device 1 is connected in the order in which the small-diameter conductive balls 58, the conductive balls B1, and then the large-diameter conductive balls B2 are transferred from the flux printing device 6. As shown in FIG.

According to the ball mounting device 1, the conductive balls 58 and 59 having different diameters have the corresponding ball transfer masks 40 and 45, and the ball transfer masks 40 and 45 are used to transfer the conductive balls 58 having different diameters. , 59 onto the electrodes. This makes it possible to mount two types of conductive balls having different diameters on the substrate W with one ball mounting device 1 . In this manner, since the conductive balls to be transferred are transferred by the ball array mask corresponding to each diameter of the conductive balls, it is possible to mount the conductive balls on the substrate just enough.

Also, if the diameter of the conductive balls is of two types, two ball moving devices are connected, and if the diameter of the conductive balls are of three types, three ball moving devices are connected. By connecting the ball swinging devices, it becomes possible to mount many types of conductive balls on predetermined electrodes. Since the ball swinging device 1 can simultaneously and concurrently mount a plurality of types of conductive balls onto the substrate W, even when there are a plurality of types of conductive balls, it is the same as when there is only one type of conductive balls. Balls can be mounted in takt time, and productivity can be improved. Furthermore, since the ball feeding device 1 has substrate transport units (the first substrate transport unit 19 and the second substrate transport unit 26) for transporting the substrates W, respectively, it is easy to handle the types of conductive balls. It is possible to connect a plurality of ball swinging devices to each other.

As described above, according to the ball mounting device of the present invention, two or more types of conductive balls having different diameters can be mounted in one device, and there is no excess or deficiency of conductive balls, and productivity can be improved. It becomes possible.

In the ball mounting device 1, each of the ball transfer devices 7 and 8 supplies the conductive balls to be transferred onto the ball transfer masks 40 and 45 for each diameter of the conductive balls B1 and B2, and fills the ball transfer holes. Ball transfer heads 44 and 47 for transferring conductive balls 58 and 59 to 71 and 72 are provided.

Since the ball swinging devices 7, 8 have dedicated ball swinging heads 41, 46 corresponding to the diameters of the conductive balls 58, 59, the ball swinging devices 7, 8 are not limited to two types, but can be used for conductive balls having a plurality of types of diameters. Since the transfer to the electrodes can be performed concurrently, productivity can be improved.

In the ball mounting device 1, a concave portion 76 for accommodating the conductive ball B1 that has already been deposited onto the electrode 58 is provided on the back surface 45a on the substrate W side of the ball transfer mask 45 to which the ball is to be transferred. Since the ball transfer mask 45 to be transferred is configured so that the small-diameter conductive balls B1 mounted in front thereof are covered with the bottoms 76a of the recesses 76, the conductive balls 58 and 58 having different diameters are formed. 59 can be prevented from being transferred to the substrate W in a mixed manner.

Further, in the ball mounting device 1, the gap H between the bottom of the concave portion 76 provided in the ball transfer mask 45 to which the ball is to be transferred and the conductive ball B1 that has already been transferred is set to 10 μm or more, and the remaining thickness of the bottom portion 76a is is 10 μm or more. With this configuration, there is always a gap between the conductive ball B1 that has already been deposited and the bottom portion 76a. It becomes possible to inject B2 onto the electrode 59 . Further, by setting the remaining thickness of the bottom portion 76a to 10 μm or more, the ball transfer mask 45 is not warped or deformed in the concave portion, and the conductive balls B2 can be transferred smoothly.

Further, in the ball mounting device 1, the difference in diameter of the conductive balls is set to at least 20 μm. The minimum diameter of the conductive balls is set in consideration of the processability of the flux printing mask 22, the limit of flux printing using the flux printing mask 22, the processability of the ball transfer masks 40 and 45, and the ball transferability. be. Further, if the diameter D1 of the ball transfer hole 71 is 1.1 times the diameter d1 of the conductive ball, the diameter difference between the conductive balls is set to 20 μm or more, so that after mounting the small-diameter conductive ball It is possible to prevent a mistake in mounting a large-diameter conductive ball to be mounted next. Similarly, if the diameter D2 of the ball transfer hole 72 is set to 1.1 times the diameter d2 of the conductive ball, the diameter difference between the conductive balls is set to 20 μm or more, so that after mounting the small-diameter conductive ball It is possible to prevent mounting errors of the large-diameter conductive balls to be mounted next.

The ball mounting method described above is a ball mounting method using the ball surveying device 1 described above. First, the flux F is printed on the electrodes 58 and 59 of the substrate W. As shown in FIG. Next, the substrate W on which the flux F is printed is conveyed to the ball transfer device 7 corresponding to the conductive ball B1 having the smallest diameter, and among the conductive balls to be mounted, the conductive ball B1 having the smallest diameter is transferred to the substrate W. . Next, the substrate W onto which the conductive balls B1 have been deposited is conveyed to the ball transfer device 8 corresponding to the conductive balls B2 having the next largest diameter, and the conductive balls B2 are deposited onto the substrate W. In the flux printing device 6, the ball transfer device 7, and the ball transfer device 8, the substrate W is transported at the same timing, and the flux printing and the conductive balls B1 and B2 are transferred at the same timing.

In the above-described ball mounting method, the conductive balls to be transferred are transferred onto the electrodes 58 and 59 by the ball transfer devices 7 and 8 corresponding to the diameters of the conductive balls B1 and B2. It becomes possible to mount them on the substrate W without being too much or too little. In addition, there is a transfer step of transferring the substrate W from the flux printing device 6 to the ball transfer device 7 for small diameter, and a transfer step of transferring the substrate W from the ball transfer device 7 for small diameter to the next ball transfer device 8 for large diameter. are executed at the same timing, and furthermore, the flux printing process, the ball transfer process for transferring the conductive balls B1, and the ball transfer process for transferring the conductive balls B2 are executed at the same timing, so that the diameter of the conductive balls is Even if there are two or more types, the tact time does not increase compared to the case of one type, so productivity can be improved. According to the ball mounting method described above, two or more types of conductive balls having different diameters can be mounted in one ball mounting device 1, and there is no excess, deficiency, or mixture of conductive balls, thereby improving productivity. becomes possible.

DESCRIPTION OF SYMBOLS 1... Ball mounting apparatus, 5, 9... Transfer robot apparatus, 6... Flux printing apparatus, 7... 1st ball transfer apparatus, 8... 2nd ball transfer apparatus, 16... 1st substrate stand, 17... Substrate stage, 18 2nd substrate table 19 1st substrate transfer unit 20 1st substrate transfer arm 21 2nd substrate transfer arm 22 Flux printing mask 23 Printing squeegee 25 Flux printing unit 26 2nd substrate transfer unit 27 3rd substrate transfer arm 40, 45 ball transfer mask 45a back surface 41, 46 ball transfer head 44, 47 ball transfer unit 48 inspection section 58 , 59... electrodes, 60, 70... suction holes, 62, 62A, 62B... mask openings, 66, 73... ball transfer parts, 68, 75... brush squeegees, 71, 72... ball transfer holes, 76... concave parts, 76a...bottom, B1, B2...conductive balls, d1, d2...diameters of conductive balls, D1, D2...diameters of ball transfer holes, F...flux, H...gap between conductive balls and bottom, T... Remaining thickness of the bottom part, W ... substrate

Claims (6)

A ball mounting device for mounting two or more types of conductive balls having different diameters on predetermined electrodes provided on a substrate,
a flux printing device that prints flux on the electrodes using a flux printing mask;
Two or more types of ball transfer masks having ball transfer holes with opening diameters corresponding to different diameters of the conductive balls are used, and the conductive balls having different diameters are transferred onto the electrodes. a ball transfer device;
with
The flux printing device and each of the ball transfer devices each have a first substrate platform, a substrate stage for printing flux or transferring balls, a second substrate platform, and a substrate transport unit for transporting the substrate. death,
Each of the ball throwing devices is connected in the order of throwing a small-diameter conductive ball and then a large-diameter conductive ball after the small-diameter conductive ball from the flux printing device side ,
Each of the substrate transport units includes a first substrate transport arm that transports a substrate from the first substrate stage to the substrate stage, and a second substrate transport arm that transports the substrate from the substrate stage to the second substrate stage. have
The first substrate transfer arm and the second substrate transfer arm are mounted on one slider and transfer substrates at the same timing,
A ball loading device, wherein the flux printing device and each of the ball transfer devices are configured to execute flux printing and ball transfer at the same timing. The ball mounting device according to claim 1,
Each of the ball transfer devices supplies the conductive balls to be transferred onto the ball transfer mask for each diameter of the conductive balls, and transfers the conductive balls into the ball transfer holes. further having a head;
A ball mounting device characterized by: In the ball mounting device according to claim 1 or claim 2,
The substrate-side surface of the ball transfer mask to which balls are transferred is provided with a concave portion for accommodating the conductive balls that have already been transferred onto the electrode.
A ball mounting device characterized by: In the ball mounting device according to claim 3,
The gap between the bottom of the recess and the small-diameter conductive ball is set to 10 μm or more, and the remaining thickness of the bottom of the recess is set to 10 μm or more.
A ball mounting device characterized by: The ball mounting device according to claim 1,
the diameter difference of the conductive balls is at least 20 μm;
A ball-mounted device characterized by: A ball mounting method using the ball mounting device according to any one of claims 1 to 5,
a flux printing step of printing the flux on the electrodes of the substrate;
a conveying step of conveying the substrate on which the flux is printed to the ball transfer device corresponding to the conductive balls having the smallest diameter;
A ball transfer step of transferring the conductive balls having the smallest diameter among the conductive balls to be mounted to the substrate;
a transfer step of transferring the substrate to the ball transfer device corresponding to the conductive ball having the next largest diameter with respect to the conductive balls transferred in the ball transfer step;
a ball transfer step of mounting a conductive ball having a diameter to be next ball transferred onto the substrate;
including
executing each of the conveying processes at the same timing, and executing the flux printing process and each of the ball transfer processes at the same timing;
A ball loading method characterized by:

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