JP3525856B2 - Apparatus and method for mounting conductive ball - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive ball mounting apparatus and method for mounting conductive balls on electrodes of a plurality of electronic components formed on a substrate.

[0002]

2. Description of the Related Art In the process of forming bumps, which are protruding electrodes, on electronic parts, conductive balls such as solder balls are mounted on the electrodes of the electronic parts. In recent years, as a mounting form of the conductive balls, a method of mounting the conductive balls in a state of a wafer before the electronic components are cut into individual pieces, that is, in a state where a large number of semiconductor elements which are the electronic components are formed in a grid-like arrangement Is being used.

[0003]

However, when the conductive balls are directly mounted on the wafer, there have conventionally been the following problems. Since the wafer has a circular shape and rectangular individual electronic components are cut out from the circular wafer, the cut line does not match the outer circumference of the wafer. Therefore, the cutting line has an irregular step shape near the outer periphery of the wafer. As a result, when mounting the conductive balls on each electronic component of the wafer, it is not possible to bundle multiple electronic components into a well-coordinated rectangular block. I had no choice but to choose one. For this reason, when mounting with individual pieces, it is necessary to mount many times, which reduces productivity,
In addition, when mounting the whole as a batch, there is a difficulty in ensuring normal mounting. In the past, when mounting the conductive balls directly on the wafer, efficient and stable mounting was difficult. .

Therefore, an object of the present invention is to provide a conductive ball mounting apparatus and mounting method capable of efficiently and stably mounting conductive balls on electrodes of a plurality of electronic components formed on a substrate. To do.

[0005]

According to a first aspect of the present invention, there is provided a conductive ball mounting apparatus for mounting a conductive ball on electrodes of a plurality of electronic components formed on a substrate by a suction tool. There is a suction tool having a suction portion that is formed corresponding to the arrangement pitch of the electronic components and that holds a conductive ball at a position corresponding to the electrode, and the substrate among the conductive balls held by the suction tool. The viscous material supply unit that adheres the viscous material only to the conductive balls in the range corresponding to the predetermined mounting area of the, and the conductive balls held by the suction tool on the substrate by moving the suction tool relative to the substrate. The moving means for mounting and the ball removing means for removing the conductive balls located outside the predetermined mounting area among the conductive balls mounted on the substrate are provided.

A conductive ball mounting apparatus according to a second aspect is the conductive ball mounting apparatus according to the first aspect,
The suction unit suctions the conductive balls by vacuum suction.

According to a third aspect of the present invention, there is provided a method for mounting a conductive ball, wherein the conductive ball is mounted on electrodes of a plurality of electronic parts formed on a substrate by a suction tool. A step of holding the conductive balls by a suction tool having a suction portion which is formed corresponding to the arrangement pitch of and which adsorbs the conductive balls at positions corresponding to the electrodes, and among the conductive balls held by the suction tool. The step of attaching the viscous material only to the conductive balls in a range corresponding to the predetermined mounting area of the substrate, and the conductive balls held by the suction tool by moving the suction tool relative to the substrate are mounted on the substrate. And a step of removing the conductive balls located outside the predetermined mounting area among the conductive balls mounted on the substrate.

A conductive ball mounting method according to claim 4 is the conductive ball mounting method according to claim 3,
The suction unit suctions the conductive balls by vacuum suction.

According to the present invention, of the conductive balls held by the suction tool, the viscous material is adhered only to the conductive balls in a range corresponding to the predetermined mounting area of the substrate, and the conductive balls held by the suction tool are attached. By mounting the conductive balls on the substrate and then removing the conductive balls located outside the specified mounting range, it is possible to mount the conductive balls only on the mounting area, and use a single suction tool to improve efficiency. It is possible to mount a conductive ball having good conductivity.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 is a front view of a conductive ball mounting apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of a semiconductor wafer according to an embodiment of the present invention, and FIG. 3A is an embodiment of the present invention. FIG. 3B is a cross-sectional view of the pickup head of the conductive ball mounting apparatus according to the first embodiment, and FIG. 3B is a bottom view of the pickup head of the conductive ball mounting apparatus according to the embodiment of the present invention.
FIG. 4 is a plan view of a flux supply unit of a conductive ball mounting apparatus according to an embodiment of the present invention, and FIG. 5 is a sectional view of a flux supply unit of a conductive ball mounting apparatus according to an embodiment of the present invention. 6, FIG. 7, FIG. 8, FIG. 9, and FIG. 10 are process explanatory views of the method of mounting the conductive balls according to the embodiment of the present invention.

First, the structure of the conductive ball mounting device will be described with reference to FIG. In FIG. 1, a ball supply unit 2, a flux supply unit 3, and a substrate holding unit 4 are arranged on a base 1. The ball supply unit 2 includes a ball tank 5, and a large number of conductive balls 6 are stored in the ball tank 5. The flux supply unit 3 includes a transfer unit 3 a having a horizontal flat surface, and the squeegee 8 of the squeegee unit 9 is provided.
The flux 7, which is a viscous material, is spread and supplied onto the transfer portion 3a.

The substrate holding portion 4 has a holding member 4a, and a large number of suction holes 4b (FIG. 8) provided in the holding member 4a.
The semiconductor wafer 10, which is a substrate, is adsorbed and held according to (a). A removal nozzle 30 for air blow is arranged above the holding member 4a. Removal nozzle 30
As will be described later, the excess conductive balls 6 on the semiconductor wafer 10 are removed by air blow and dropped into the recovery container 11 provided around the holding member 4a.

Above the ball supply unit 2, the flux supply unit 3, and the substrate holding unit 4, a ball mounting unit 12 is arranged. The ball mounting portion 12 includes a moving table 13 having an X-axis motor 13a, and an elevating portion 14 is mounted on the moving table 13. The elevating unit 14 includes a mounting head 15, and by driving the moving table 13 and the elevating unit 14, it is possible to perform each operation required for mounting the conductive balls described below.

First, the suction tool 1 on the lower surface of the mounting head 15
6, the conductive balls 6 are picked up from the ball supply unit 2 and held. Then, the mounting head 15 is moved up and down with respect to the flux supply unit 3, so that the flux 7 is attached to the lower surface of the conductive ball 6 suction-held by the suction tool 16. After that, the mounting head 15 is moved onto the substrate holding part 4 and moved up and down with respect to the semiconductor wafer 10, so that the conductive balls 6 are mounted on the semiconductor wafer 10 due to the viscosity of the flux 7. That is, the moving table 13 and the lifting / lowering unit 14 are mounted on the mounting head 15.
Has become a means of transportation.

The semiconductor wafer 10 will now be described with reference to FIG. As shown in FIG. 2, the semiconductor wafer 10
Is a substantially circular substrate, and a large number of semiconductor elements 10a, which are rectangular electronic components, are formed in a grid pattern. Electrodes 10b are formed in a predetermined electrode arrangement pattern on each semiconductor element 10a to form an electrode portion 10c.
A conductive ball 6 is mounted on each of 0b. That is, a portion of the semiconductor wafer 10 where the semiconductor element 10a is formed is a mounting area of the conductive ball 6.

Next, the mounting head 15 will be described with reference to FIG. As shown in FIG. 3A, a suction tool 16 is mounted on the lower surface of the mounting head 15, and a suction portion 16a, which is a set of a plurality of suction holes 16b, is provided on the lower surface of the suction tool 16 over the entire range of the suction surface. It is formed in a lattice shape over. The arrangement pitch of the suction portions 16a is the semiconductor wafer 10
Corresponding to the arrangement of the semiconductor elements 10a in FIG.
By suctioning the inside of 5 by vacuum, the adsorption portion 16a adsorbs and holds the conductive ball 6 at a position corresponding to the electrode arrangement pattern of the semiconductor element 10a.

The shape of the suction tool 16 is the semiconductor wafer 1
0 is divided into four unit sections (section [1] shown in FIG. 2,
[2], [3], and [4]), the semiconductor wafer 1 can be formed by using the same suction tool 16 a plurality of times (four times in this embodiment).
It is designed to cover the entire mounting area of 0.

Next, the flux supply section 3 will be described with reference to FIGS. As shown in FIG. 5A, the flux supply unit 3 has a structure in which a table 22 is arranged on a base member 21 installed on the frame 20.
A recess 22a is provided in the center of the table 22, and a transfer unit 3a is provided in the recess 22a so as to be vertically movable by a cylinder 23.

The transfer portion 3a will be described. Cylinder 2
The block 24 is coupled to the rod 23a of No. 3,
The block 24 is fixed to the lower surface of the plate 26.
A transfer plate 27 is mounted on the upper surface of the plate 26. As shown in FIG. 4, the transfer plate 27 has a shape corresponding to the conductive ball mounting area of the semiconductor wafer 10 (see also FIG. 7). That is, the transfer plate 27
Is equivalent to the shape of the area of the semiconductor wafer 10 in which the semiconductor element 10a having the electrode 10b is formed. The sections [1 ′], [2 ′], [3 ′], and [4 ′] obtained by dividing the transfer plate 27 into four have sizes corresponding to the lower surface of the suction tool 16.

FIG. 5 shows the ABCD cross section of FIG.
As shown in FIG. 5, a flexible film member 25 such as a rubber film is flexibly mounted between the end surface of the plate 26 and the inner surface of the recess 22a. The membrane member 25 is mounted in a state in which the inside of the concave portion 22a is liquid-tightly divided into two upper and lower spaces, and the flux 7 is stored in the space above the membrane member 25.
As shown in FIG. 5 (a), the rod 23 a of the cylinder 23
The upper surface of the transfer plate 27 is flush with the upper surface of the table 22 in a state where the table 22 is immersed.

A squeegee unit 9 having two squeegees 8 is arranged above the table 22.
As shown in FIG. 4, a feed screw 18 rotationally driven by a motor 19 is screwed into a nut member 17 fixed to the squeegee unit 9. By driving the motor 19, the squeegee unit 9 horizontally moves on the table 22 in the X direction.

With the upper surface of the transfer plate 27 aligned with the upper surface of the table 22, the squeegee 8 is lowered to set the squeegee unit 9 horizontally while the gap between the lower end of the squeegee 8 and the upper surface of the transfer plate 27 is set to a predetermined value. By moving, the lower end of the squeegee 8 spreads the flux 7 in the recess 22a. As a result, the flux film 7a having a predetermined film thickness t is formed on the upper surface of the transfer plate 27. When the rod 23a of the cylinder 23 is projected in this state, the transfer plate 27 having the flux film 7a formed on the upper surface thereof projects above the upper surface of the table 22 as shown in FIG. 5B.

As a result, in the flux supply section 3, the flux film 7a having a predetermined thickness is formed on the upper surface of the transfer plate 27 having a shape corresponding to the shape of the lower surface of the suction tool 16. Then, the suction tool 16 holding the conductive balls 6 is lowered onto the transfer plate 27, so that the semiconductor wafer 1 among the held conductive balls 6 is held.
The flux 7 adheres only to the lower ends of the conductive balls 6 in the range corresponding to the mounting area of 0.

The conductive ball mounting device is configured as described above, and a method of mounting the conductive balls will be described below with reference to FIGS. 6 to 10. First, as shown in FIG. 6A, the mounting head 15 is lowered into the ball tank 5 of the ball supply unit 2, and the conductive balls 6 are vacuum-sucked on the lower surface of the suction tool 16. Next, the mounting head 15 is raised,
The flux supply unit 3 is moved above the transfer unit 3a.
Then, as shown in FIG. 6B, the mounting head 15 is lowered to bring the lower surface of the conductive ball 6 held by the suction tool 16 into contact with the flux film 7a.

At this time, as shown in FIG. 7, the suction tool 1
6 is aligned with one of the four unit divisions of the transfer plate 27. As a result, of the conductive balls 6 held by the suction tool 16, the flux 7 adheres only to the conductive balls 6a that are in contact with the flux film 7a on the upper surface of the transfer plate 27, and to the other conductive balls 6b. No flux adheres. By this flux transfer operation, the flux 7 is transferred only to the conductive balls 6 in a range corresponding to the mounting area of the semiconductor wafer 10.

Next, the mounting head 15 holding the conductive balls 6a to which the flux 7 has been transferred and the conductive balls 6b to which the flux has not been transferred moves onto the substrate holding portion 4 as shown in FIG. 8 (a). To do. The semiconductor wafer 10 is held on the holding member 4 a of the substrate holding unit 4. Note that FIG. 8A shows a state in which the conductive balls 6 a are already partially mounted on the semiconductor wafer 10. By aligning the mounting head 15 with an unmounted unit section of the semiconductor wafer 10 and lowering it to release the vacuum suction, the conductive balls 6a and 6b held by the mounting head 15 land on the upper surface of the semiconductor wafer 10.

Thereafter, the mounting head 15 is raised as shown in FIG. 8 (b). Then, the conductive balls 6 a to which the flux 7 is attached by transfer are held by the electrodes 10 b of the semiconductor wafer 10 by the adhesive force of the flux 7. On the other hand, the conductive balls 6b to which the flux 7 does not adhere are simply left on the upper surface of the semiconductor wafer 10, and the conductive balls 6b located outside the range of the semiconductor wafer 10 have the outer periphery of the holding member 4a. It falls into the recovery container 11 provided in the.

After landing of the conductive balls, as shown in FIG.
As shown in, air is ejected from the removal nozzle 30 disposed above the holding member 4a toward the outer edge. As a result, as shown in FIG. 9B, the conductive balls 6b to which the flux 7 is not attached do not have a holding force due to the adhesive force of the flux 7 and are blown away by the air blow, and are dropped and collected in the collection container 11. .

Therefore, the removing nozzle 30 serves as a removing means for removing the conductive balls 6 mounted on the semiconductor wafer 10 and located outside the predetermined mounting area. As the removing means, in addition to the method using air blow, by tilting the holding member 4a,
A method of dropping the conductive balls 6 on the semiconductor wafer 10 by its own weight may be used.

FIG. 10 shows the unit block [1] in this way.
It shows a state after mounting the conductive balls 6 on the. Then, after this, other unloaded unit sections [2],
The conductive balls 6 are mounted on [3] and [4]. During the operation of mounting each of these unit compartments, when the flux is transferred to the conductive balls, the suction tools are attached to the compartments [2 ′], [3 ′], [4 ′] (see FIG. 7) of the transfer plate 27 corresponding to the unit compartments. Align 16 Then, by repeating the above operation four times, the conductive balls 6 are mounted on the entire mounting area of the semiconductor wafer 10, and the mounting efficiency of the conductive balls is remarkably increased as compared with the conventional method of mounting individual balls. Can be improved.

In the present embodiment, an example is shown in which vacuum suction is used as the suction portion for sucking the conductive balls, but the present invention is not limited to this, and for example, only a required portion is charged and electrostatically charged. A method of attracting and holding the conductive balls by attraction may be used.

As described above, according to the present invention, when the conductive balls are mounted on a substrate such as a semiconductor wafer in which the mounting areas of the conductive balls are arranged irregularly, the conductive balls corresponding to the mounting areas are previously prepared. By attaching a viscous material such as flux to only the conductive balls, it is possible to selectively mount the conductive balls only in the mounting area using a single suction tool.

In this embodiment, an example is shown in which the conductive balls are mounted on the semiconductor elements provided on the semiconductor wafer, but the conductive balls are mounted on the substrate on which a plurality of electronic parts are formed. The present invention can be applied to the case of mounting.

[0034]

According to the present invention, the viscous material is adhered only to the conductive balls held by the suction tool in a range corresponding to the predetermined mounting area of the substrate, and the viscous body is held by the suction tool. After mounting the conductive balls on the substrate, the conductive balls located outside the predetermined mounting range are removed, so that the conductive balls can be attached and mounted only in the mounting area. It is possible to efficiently mount the conductive balls by using.

[Brief description of drawings]

FIG. 1 is a front view of a conductive ball mounting device according to an embodiment of the present invention.

FIG. 2 is a plan view of a semiconductor wafer according to an embodiment of the present invention.

3A is a cross-sectional view of a pickup head of a conductive ball mounting apparatus according to an embodiment of the present invention. FIG. 3B is a bottom view of a pickup head of a conductive ball mounting apparatus according to an embodiment of the present invention.

FIG. 4 is a plan view of a flux supply unit of a conductive ball mounting device according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of a flux supply unit of a conductive ball mounting device according to an embodiment of the present invention.

FIG. 6 is a process explanatory diagram of a conductive ball mounting method according to an embodiment of the present invention.

FIG. 7 is a process explanatory diagram of a method of mounting a conductive ball according to an embodiment of the present invention.

FIG. 8 is a process explanatory diagram of a conductive ball mounting method according to an embodiment of the present invention.

FIG. 9 is a process explanatory view of a method of mounting a conductive ball according to an embodiment of the present invention.

FIG. 10 is an explanatory process diagram of a method of mounting a conductive ball according to an embodiment of the present invention.

[Explanation of symbols]

2 ball supply section 3 Flux supply section 4 Substrate holder 6 conductive balls 7 Flux 10 Semiconductor wafer 10a Semiconductor element 10b electrode 12-ball mount 13 Moving table 14 Lifting part 15 mounting head 16 Suction tool 16a adsorption part 16b Adsorption hole 30 removal nozzle

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Claims (4)

(57) [Claims] 1. A conductive ball mounting apparatus for mounting conductive balls on electrodes of a plurality of electronic components formed on a substrate by a suction tool, wherein the electrodes are formed in correspondence with an arrangement pitch of the electronic components. A suction tool having a suction portion for sucking the conductive balls at a position corresponding to the above, and a viscous body is attached only to the conductive balls in a range corresponding to the predetermined mounting area of the substrate among the conductive balls held by the suction tool. The viscous material supply unit to be attached, moving means for moving the suction tool relative to the substrate to mount the conductive ball held on the suction tool on the substrate, and the conductive ball mounted on the substrate A device for mounting a conductive ball, comprising: a ball removing means for removing a conductive ball located outside a predetermined mounting area. 2. The mounting device for a conductive ball according to claim 1, wherein the suction part sucks the conductive ball by vacuum suction. 3. A conductive ball mounting method for mounting conductive balls on electrodes of a plurality of electronic components formed on a substrate by a suction tool, the electrodes being formed corresponding to an arrangement pitch of the electronic components. A step of holding the conductive ball by a suction tool having a suction portion for sucking the conductive ball at a position corresponding to, and a range of the conductive balls held by the suction tool corresponding to a predetermined mounting area of the substrate. A step of attaching a viscous material only to the conductive balls,
A step of moving the suction tool relative to the substrate to mount the conductive balls held by the suction tool on the substrate; and a conductive ball mounted on the substrate outside the predetermined mounting area. And a step of removing the ball. 4. The method of mounting a conductive ball according to claim 3, wherein the suction part sucks the conductive ball by vacuum suction.