JP2000269253A - Device and method for conductive ball mounting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the conductive ball mounting device and mounting method with which conductive balls can be efficiently and stably mounted on the electrodes of a plurality of electronic parts formed on a substrate. SOLUTION: In this conducive ball mounting method wherein conductive balls are mounted on the electrodes of a plurality of electronic parts formed on a substrate using a chucking tool, the conductive balls 10 are chucked and picked up in the predetermined limited range in accordance with each division divided by a mask member 12 when the conducive balls are picked up by the chucking tool where a chucking part 14, which is the aggregate or chucking holes 8b formed correspondng to the electrode arrangement of the electronic part on the chucking surface covering the split division of the substrate, and the conductive balls are collectively mounted on each split division. Accordingly, the conductive balls can be mounted in a highly efficient and stable manner using a single chucking tool.

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 (semiconductor elements) formed on a substrate.

[0002]

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

[0003]

However, when conductive balls are directly mounted on a wafer, there have been the following problems in the prior art. Since the wafer has a circular shape and rectangular individual electronic components are cut out from the circular wafer, the cutout line does not coincide with the outer periphery of the wafer. Therefore, the cutting line has an irregular step shape near the outer periphery of the wafer. As a result, when the conductive balls are mounted on each electronic component of the wafer, a plurality of electronic components cannot be bundled as a well-formed rectangular block, and may be mounted individually or as a whole. I had no choice but to choose either. For this reason, when mounting in individual pieces, it is necessary to perform mounting many times, reducing productivity,
Conventionally, it was difficult to efficiently and stably mount conductive balls directly on a wafer. .

Accordingly, an object of the present invention is to provide a conductive ball mounting apparatus and a mounting method capable of efficiently and stably mounting conductive balls on electrodes of a plurality of electronic components formed on a substrate. I 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. A suction tool having a substantially rectangular suction surface covering each of the divided sections obtained by dividing the substrate into a plurality of sections; and a suction tool formed on the suction surface of the suction tool in correspondence with the arrangement pitch of the electronic components. A suction unit for sucking the conductive ball at a position corresponding to the electrode; and a suction limiting unit for sucking the conductive ball only to the suction unit corresponding to the electronic component in the divided section.

A conductive ball mounting apparatus according to a second aspect is the conductive ball mounting apparatus according to the first aspect,
The suction unit includes a plurality of suction holes for sucking the conductive ball by vacuum suction, and the suction limiting unit includes suction holes of suction units other than the suction unit corresponding to the electronic component in the divided section among the suction units. This is a suction hole closing means for closing the suction hole.

A conductive ball mounting apparatus according to claim 3 is the conductive ball mounting apparatus according to claim 1,
The suction unit includes a plurality of charging units that suction the conductive ball by electrostatic suction, and the suction limiting unit controls the charging unit to perform suction that corresponds to an electronic component in the divided section of the suction unit. Charging control means for releasing the charging of the charging unit of the suction unit other than the charging unit.

A method of mounting a conductive ball according to claim 4, wherein the conductive ball is mounted on electrodes of a plurality of electronic components formed on a substrate by a suction tool. Has a substantially rectangular suction surface that covers a divided section obtained by dividing the substrate into a plurality of sections, and has conductive balls formed at positions corresponding to the arrangement pitch of the electronic components on the suction surface and at positions corresponding to the electrodes. Is formed. When a conductive ball is picked up by the suction tool, the conductive ball is limited to only the suction part corresponding to the electronic component in the divided section by the suction limiting means. Then, the conductive balls sucked by the suction tool are collectively mounted for each divided section.

According to a fifth aspect of the present invention, there is provided a method for mounting a conductive ball, comprising the steps of:
The suction unit includes a plurality of suction holes for sucking the conductive ball by vacuum suction, and the suction limiting unit includes suction holes of suction units other than the suction unit corresponding to the electronic component in the divided section among the suction units. This is a suction hole closing means for closing the suction hole.

According to a sixth aspect of the present invention, there is provided a method for mounting a conductive ball, comprising the steps of:
The suction unit includes a plurality of charging units that suction the conductive ball by electrostatic suction, and the suction limiting unit controls the charging unit to perform suction that corresponds to an electronic component in the divided section of the suction unit. Charging control means for releasing the charging of the charging unit of the suction unit other than the charging unit.

According to the present invention, when the conductive ball is sucked, the conductive ball is sucked and picked up by the suction limiting means only in a predetermined range of sucking portions determined according to each divided section. By mounting conductive balls collectively in each divided section, the conductive balls can be efficiently and stably mounted on a substrate having a specific portion where the conductive balls are not mounted using a single suction tool. be able to.

[0012]

(Embodiment 1) FIG. 1 is a perspective view of a conductive ball mounting apparatus according to Embodiment 1 of the present invention, and FIG.
2A is a cross-sectional view of a pickup head of the conductive ball mounting apparatus, FIG. 2B is a plan view of a lower surface of the pickup head of the conductive ball mounting apparatus, and FIG. 3A is a plan view of the wafer. FIG. 3B is a partial plan view of the wafer, and FIG.
6A and 6B are plan views of the same wafer, FIG. 5 is a plan view of a mask mounting portion of the conductive ball mounting apparatus, and FIGS.
(B), (c), (d), and (e) are process explanatory views of the mounting method of the conductive ball, and FIG. 7 is a cross-sectional view of the mounting head.

First, the structure of the conductive ball mounting device will be described with reference to FIG. In FIG. 1, a transport path 2 is provided at the center of a base 1. The transfer path 2 transfers and positions the plate 3 holding the wafer 4. The wafer 4 is a substantially circular substrate, and a plurality of semiconductor elements are formed in a lattice shape as described later. Two Y-axis tables 5 are arranged at both ends of the upper surface of the base 1. An X-axis table 6 is installed on the two Y-axis tables 5,
A mounting head 7 is mounted on the X-axis table 6.

The mounting head 7 has a pickup head 8 at the lower part. X axis table 6 and Y axis table 5
, The mounting head 7 moves horizontally. A ball supply unit 9 is provided in front of the transport path 2, and a large number of conductive balls 10 are stored in the ball supply unit 9. The pickup head 8 picks up the conductive balls 10 by moving the pickup head 8 up and down with the mounting head 7 positioned above the ball supply unit 9. Then, by positioning the mounting head 7 on the positioned wafer 4 and moving the pickup head 8 up and down again, the conductive balls 10 held by the pickup head 8 are mounted on the wafer 4.

A mask mounting portion 11 for mounting a mask member 12 mounted on the pickup head 8 is provided on a side of the ball supply portion 9. By moving the pickup head 8 up and down with respect to the mask placement section 11, the mask member 11 can be attached to and detached from the pickup head 8 and replaced.

Here, the wafer 4 will be described with reference to FIG. As shown in FIG. 3A, the wafer 4 is a substantially circular substrate, and a large number of semiconductor elements 4a, which are rectangular electronic components, are formed in a lattice at an arrangement pitch Px, Py on the wafer 4. As shown in FIG. 3B, each semiconductor element 4
On a, a large number of electrodes 4b on which the conductive balls 10 are mounted are formed in a predetermined electrode arrangement pattern, and these electrodes 4b form an electrode group 4c. That is, in the wafer 4, the area where these electrode groups 4c are formed is the ball mounting area (the area surrounded by the thick line in FIG. 3A).
The outer shape of the ball mounting area is stepped.

Next, the pickup head 8 provided on the mounting head 7 and the suction tool 8a on the lower surface of the pickup head 8 will be described with reference to FIG. FIG.
As shown in FIG. 3A, the lower surface of the pickup head 8 is a protrusion-shaped suction tool 8a, and a plurality of suction holes 8b are provided on the suction surface of the lower surface of the suction tool 8a. The conductive ball 10 is suction-held in the suction hole 8b by vacuum suction from the suction hole 8c.

Here, the arrangement of the suction holes 8b will be described. On the suction surface of the suction tool 8a, suction portions 14, which are collections of suction holes 8b, are arranged in a grid pattern over the entire suction surface. Here, the arrangement pitch of the suction portions 14 is equal to the arrangement pitches Px and Py of the semiconductor elements 4a on the wafer 4. That is, the suction portions 14 are formed corresponding to the arrangement pitch of the semiconductor elements 4a. In each suction portion 14, a plurality of suction holes 8b are formed at positions corresponding to the electrode arrangement patterns of the electrodes 4b constituting the electrode group 4c. That is, the suction hole 8b of each suction portion 14
The arrangement of the conductive balls 10 sucked and held on the wafer 4
Corresponds to the arrangement of the electrodes 4b of the semiconductor element 4a.

Next, the division of the above-mentioned ball mounting area when the conductive balls are mounted on the wafer 4 using the suction tool 8a will be described with reference to FIG. Wafer 4
In most cases, the size of the wafer 4 exceeds the size in which the conductive balls can be collectively mounted in a single mounting operation with a single suction tool. In such a case, the ball mounting area of the wafer 4 is divided into a plurality of divided sections. The conductive balls are mounted on each of the divided sections.

As shown in FIG. 4, the ball mounting area of the wafer 4 is divided into a plurality of sections. FIG. 4A shows an example in which the ball mounting area of the wafer 4 is divided into four sections. At this time, the suction surface (size WX, W
Y) covers each of the divided sections [1], [2], [3], and [4]. That is, when dividing the ball mounting area, the divided sections of the ball mounting area of the wafer 4 are set so that each divided section is equal to or smaller than the size of the suction surface of the suction tool 8a.

In FIG. 4A, the ball mounting area of the wafer is divided into four sections [1], [2],
Although an example of dividing into [3] and [4] is shown, the shape and size of the divided sections are not limited to the same shape and the same size.
For example, as in the example of FIG. 4B, when dividing the ball mounting area of the wafer 4 ′ having a size larger than the wafer 4, nine sections [ 1] to [9]. That is, if the arrangement pitch of the semiconductor elements 4a and the electrode arrangement pattern in the semiconductor elements 4a are the same, the setting of the division section is changed even for wafers having different sizes, so that the same suction tool can be used. The ball can be mounted.

Next, a description will be given of a mask member used for mounting conductive balls on different divided sections using the same suction tool 8a. As shown in FIG. 2A, a mask member 12 is mounted on the lower surface of the suction tool 8a. The mask member 12 corresponds to the shape of the protrusion of the suction tool 8a, and the plate portion 12a that comes into contact with the suction surface of the suction tool 8a partially removes the suction portion 14 as shown in FIG. It is shaped to be closed. As shown in FIG. 2A, the conductive ball 10 is sucked only in the area B of the suction section 14 of the suction tool 8a, and the suction hole 8b of the suction section 14 is in the area A in the plate section 12a. The conductive ball 10 is not adsorbed because it is closed by.

That is, the mask member 12 is a suction hole closing means, and the conductive ball 10 is limited to only a predetermined range of the suction portion 14 in the divided section by closing the suction hole 8b in the area A. This is an adsorption limiting means for performing the adsorption. The mask member 12 is aligned with the pickup head 8 by the positioning pin 13, and is detachably held on the pickup head 8 by vacuum suction from the suction hole 8d through the suction opening 8e.

The mask member 12 is prepared in a different shape according to each of the four divided sections [1], [2], [3] and [4] shown in FIG. That is, the mask member 12A used for mounting the conductive ball in the divided section [1] includes a plate portion 12a having a shape as shown in FIG. The conductive balls 10 are adsorbed only in a predetermined range that targets only the adsorbing portions 14 corresponding to the semiconductor elements 4a therein. Mask member 12 used for mounting conductive ball 10 in divided sections [2], [3], [4]
The same applies to B, 12C, and 12D.

The four types of mask members 12A, 12A
B, 12C, and 12D are mask mounting portions 1 as shown in FIG.
The mask member 12 is mounted on the mask mounting portion 11 and moved up and down with respect to the mask mounting portion 11, so that the already mounted mask member 12 can be detached and another arbitrary mask member 12 can be newly mounted. .

The conductive ball mounting apparatus is configured as described above, and a ball mounting method will be described below with reference to FIG. In FIG. 6A, the pickup head 8 has a mask member 12A corresponding to the divided section [1].
The pickup head 8 is lowered with respect to the conductive balls 10 in the ball supply section 9, and the conductive balls 10 are vacuum-sucked by the suction tool 8a.

At this time, the mask member 12A closes the suction hole 8b in a portion other than the predetermined range C of the suction tool 8a, and the conductive ball 10 is provided only in the suction portion 14 corresponding to the semiconductor element 4a in the divided section [1]. Is adsorbed. Next, the pickup head 8 is raised and moved onto the wafer 4, and is positioned with respect to a predetermined portion of the wafer 4, and the pickup head 8 is lowered, as shown in FIGS. 6B and 6C. The conductive ball 10 is mounted on each electrode 4b (see FIG. 3) of each semiconductor element 4a belonging to the divided section [1].

Thereafter, the pickup head 8 is raised and moved onto the mask mounting portion 11. Then, the pickup head 8 is lowered, the suction holding of the mask member 12A is released, and the pickup head 8 is placed at a predetermined position on the mask placement section 11 as shown in FIG. Next, the pickup head 8 is moved onto the mask member 12B to be used next time and lowered, whereby the mask member 12B corresponding to the divided section [2] is mounted on the lower surface of the suction tool 8a.

Next, the pickup head 8 is moved to the ball supply section 9 again, and is moved up and down so that the conductive balls 10 are sucked only in the predetermined range D on the lower surface of the suction tool 8a. Then, similarly, the conductive balls 10 are mounted on the electrodes of the semiconductor elements 4a belonging to the divided section [2] of the wafer 4. The above operation is repeated four times while exchanging the mask member 12, whereby the wafer 4
Conductive balls 10 for each electrode of all the semiconductor elements 4a.
Can be mounted.

In the above mounting operation, the number of reciprocations of the mounting head 7 only needs to be four times, and the number of reciprocations is much smaller than that of the conventional method of mounting each individual piece. Can be improved. In this embodiment, the same expensive suction tool 8a is used, and only the mask member 12, which can be manufactured simply and inexpensively, is replaced, so that the equipment cost can be reduced. In addition, since the size of the divided section is set within an appropriate range that does not become excessive in view of the conventional results, stable mounting of the conductive ball with less mounting failure is ensured. In other words, it is possible to achieve both good mounting efficiency and stable mounting quality, which were difficult to achieve with the conventional method.

In this embodiment, the mask member 12 attached to the lower surface of the suction tool 8a is used as a suction hole closing means.
However, a pickup tool 18 as shown in FIG. 7 may be used. In this example, by mounting a mask plate 19 as suction hole closing means on the upper surface of the suction tool 18a, a portion of the suction hole 18b provided in the plate-shaped suction tool 18a except for a predetermined range E is closed. Is what you do. Suction hole 1 for vacuum suction
The suction tool 18a and the mask plate 19 are held by vacuum suction from the suction holes 18d, and the positioning of the suction tool 18a is performed by positioning pins 18e. By using the pickup tool 18 having such a configuration, the suction tool 18
a is always in a flat state, and the conductive ball 1
When 0 is mounted, interference with the already mounted conductive balls can be avoided.

(Embodiment 2) FIG. 8A is a sectional view of a pickup head of a conductive ball mounting apparatus according to Embodiment 2 of the present invention, and FIG. 8B is a sectional view of the conductive ball mounting apparatus. FIG. 3 is a plan view of the lower surface of the pickup head. In the first embodiment, a method using vacuum suction is used as the suction unit for sucking and holding the conductive ball. In the second embodiment, a position corresponding to each suction hole 8b of the suction tool 8a in the first embodiment is used. That is, a charging unit that attracts the conductive ball by electrostatic attraction is provided at a position corresponding to the electrode of the semiconductor element. Hereinafter, FIG.
This will be described with reference to FIG.

In FIG. 8A, a suction substrate 21 is mounted on the lower surface of the pickup head 20. The suction substrate 21 is made of an insulating material such as glass or resin, and a plurality of charging units 22 are provided on the lower surface (front surface) of the suction substrate 21. The charging portion 22 forms a conductor 22a of a good conductor such as aluminum on the inner surface of the concave portion provided on the suction substrate,
The surface is coated with an insulating film 22 such as silicon oxide or polyimide resin.
b. The recess is formed in order to securely hold one conductive ball 10 in one charging unit 22.

As shown in FIG. 2B, the charging section 22 is provided in each of the suction holes 8b in the suction section 14 of the first embodiment (see FIG. 3).
Are formed at positions corresponding to the
The other surface of the suction substrate 12 is covered with a conductor 23 similar to the conductor 21a. The conductor 23 is electrically insulated from the conductor 22 a on the adsorption substrate 21. The conductor 22 a of each charging unit 22 is electrically connected to the charging control unit 24. The charging control unit 24 controls charging / discharging of each charging unit 22 by disconnecting and connecting a power supply unit (not shown) to the conductor 22a of each charging unit 22. When the charging section 22 is charged, the conductive ball 10 is held in the recess by electrostatic attraction. When the charging of the charging unit is released, the held conductive balls 10 are separated from the concave portions. Therefore, the charging unit 2 provided on the lower surface of the pickup head 20 by the charging control unit 24
2 is controlled to release the charging of the charging units other than the suction unit 14 corresponding to the semiconductor element 4a in the divided section of the wafer 4 in the suction unit 14 so that the suction unit 14 corresponding to the semiconductor element 4a is released. The conductive ball 10 can be adsorbed only by limiting to only. That is, the charging control unit 24 is a suction limiting unit.

In the first and second embodiments, the wafer on which the semiconductor elements are formed is shown as an example of the substrate on which the conductive balls are mounted. However, the present invention is not limited to this. A substrate in which components are formed in a lattice shape may be used. In this case, conductive balls are mounted on the electrodes of the electronic component.

[0036]

According to the present invention, when the conductive ball is sucked, the conductive ball is sucked and picked up by the suction limiting means only in a predetermined range of the sucking portion determined according to each divided section. Since the conductive balls are collectively mounted in each of the divided sections, it is possible to efficiently mount the conductive balls on a substrate having a specific portion where the conductive balls are not mounted using a single suction tool. It can be performed stably.

[Brief description of the drawings]

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

FIG. 2A is a cross-sectional view of a pickup head of the conductive ball mounting apparatus according to the first embodiment of the present invention. FIG. 2B is a plan view of a lower surface of the pickup head of the conductive ball mounting apparatus according to the first embodiment of the present invention. Figure

3A is a plan view of a wafer according to the first embodiment of the present invention. FIG. 3B is a partial plan view of the wafer according to the first embodiment of the present invention.

4A is a plan view of a wafer according to the first embodiment of the present invention. FIG. 4B is a plan view of a wafer according to the first embodiment of the present invention.

FIG. 5 is a plan view of a mask mounting portion of the conductive ball mounting device according to the first embodiment of the present invention.

FIG. 6A is a process explanatory view of a conductive ball mounting method according to the first embodiment of the present invention. FIG. 6B is a process explanatory view of a conductive ball mounting method according to the first embodiment of the present invention. Process explanatory diagram of the conductive ball mounting method of Embodiment 1 of the present invention (d) Process explanatory diagram of the conductive ball mounting method of Embodiment 1 of the present invention (e) Conductivity of Embodiment 1 of the present invention Explanatory drawing of the process of mounting the conductive ball

FIG. 7 is a sectional view of the mounting head according to the embodiment of the present invention;

8A is a sectional view of a pickup head of a conductive ball mounting apparatus according to a second embodiment of the present invention. FIG. 8B is a plan view of a lower surface of the pickup head of the conductive ball mounting apparatus according to the second embodiment of the present invention. Figure

[Explanation of symbols]

 Reference Signs List 4 wafer 4a semiconductor element 4b electrode 8 pickup head 8a suction tool 8b suction hole 10 conductive ball 12, 12A, 12B, 12C, 12D mask member 12a plate portion 14 suction portion 21 suction substrate 22 charging portion 24 charging control portion

Claims (6)

[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 each of the divided sections obtained by dividing the substrate into a plurality of sections is covered. A suction tool having a substantially rectangular suction surface, and a suction portion formed on the suction surface of the suction tool corresponding to the arrangement pitch of the electronic components, and suctioning a conductive ball at a position corresponding to the electrode; A conductive ball suction device, comprising: suction limiting means for sucking the conductive ball only in the suction portion corresponding to the electronic component in the divided section. 2. The suction section has a plurality of suction holes for sucking the conductive balls by vacuum suction, and the suction limiting means includes a suction section other than the suction section corresponding to the electronic component in the divided section. 2. The conductive ball mounting device according to claim 1, wherein the mounting means is a suction hole closing means for closing the suction hole of the suction portion. 3. The attraction unit includes a plurality of charging units for attracting the conductive ball by electrostatic attraction, and the attraction limiting unit controls the charging unit to control an electron in the divided section of the attraction unit. 2. The conductive ball mounting device according to claim 1, wherein the charging unit is a charging control unit that releases charging of a charging unit other than the suction unit corresponding to the component. 4. A method for mounting a conductive ball on an electrode of a plurality of electronic components formed on a substrate by means of a suction tool using a suction tool, wherein the suction tool divides the substrate into a plurality of sections. A suction portion that has a substantially rectangular suction surface and covers the suction surface and that is formed in accordance with the arrangement pitch of the electronic components and that sucks a conductive ball at a position corresponding to the electrode; When picking up the conductive ball by the suction tool, the suction limiting means restricts only the suction portion corresponding to the electronic component in the divided section to the conductive ball by picking up and picking up the conductive ball. A method for mounting a conductive ball, wherein the conductive balls adsorbed on a suction tool are collectively mounted. 5. The suction section has a plurality of suction holes for sucking the conductive balls by vacuum suction, and the suction limiting means includes a suction section other than the suction section corresponding to the electronic component in the divided section. 4. The method for mounting a conductive ball according to claim 3, wherein said means is a suction hole closing means for closing a suction hole of said suction portion. 6. The attraction unit includes a plurality of charging units for attracting the conductive balls by electrostatic attraction, and the attraction limiting unit controls the charging unit to control an electron in the divided section of the attraction unit. 5. The method for mounting a conductive ball according to claim 4, wherein the charging means is a charging control unit for releasing charging of a charging unit other than the suction unit corresponding to the component.