JP3430933B2 - 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 a conductive ball on an electrode of a work.

[0002]

2. Description of the Related Art As a method for forming bumps on a bumped electronic component such as a flip chip, a method using conductive balls such as solder balls is known. In this method, a conductive ball is mounted on an electrode of an electronic component and joined to the electrode. A suction tool is used as a means for mounting the conductive balls. In the method using this suction tool, a large number of suction holes simultaneously hold the conductive balls by vacuum suction. Generally, the suction hole is formed by processing a suction hole with a drill and then performing taper processing for forming a tapered surface as a ball introduction portion on the surface of the suction tool.

[0003]

By the way, with the progress of miniaturization of electronic parts, the pitch of bumps formed on the electronic parts has become smaller, and in recent years, it has been required to cope with a minute pitch of 200 μm or less. Has become. However, the suction holes are often processed by drilling, which is cheap in terms of cost. However, when the pitch becomes about 200 μm as described above, the degree of difficulty increases drastically. It is almost impossible to process correctly.

On the other hand, as a method suitable for fine processing rather than drilling, etching processing, electric discharge processing and the like are known. By using these processing techniques, it is possible to form the suction holes at a pitch of 200 μm or less. However, when the suction holes are formed with a pitch smaller than 200 μm, a large number of suction holes exist in a narrow area of the suction tool, which causes a problem of frequent pick-up mistakes for sucking extra conductive balls. With such a fine pitch, problems due to the processing technology of the suction tool and problems with suction mistakes become prominent, making it difficult to mount the conductive balls.

Therefore, it is an object of the present invention to provide a conductive ball mounting apparatus and mounting method capable of mounting conductive balls corresponding to a fine pitch.

[0006]

According to a first aspect of the present invention, there is provided a conductive ball mounting apparatus, wherein conductive balls are sequentially mounted on a plurality of electrodes arranged on the same surface by a plurality of suction tools. A mounting apparatus, which is provided with n suction tools from 1 to n in which a plurality of suction holes are arranged differently for each suction tool, and the i-th suction tool of the n suction tools. The suction holes of the tool correspond to the arrangement of the electrodes of the i-th group of the first to n-th groups of the plurality of electrodes divided according to the mounting order, and each suction tool Are arranged so that the distances between the adjacent suction holes are not less than the minimum distance of the arrangement of the electrodes. Furthermore, the lower surface of the second and subsequent suction tools has already been mounted when the conductive balls are mounted on the electrodes. Escape to prevent interference with the mounted conductive balls. Parts are formed corresponding to the position of the already mounted conductive balls.

According to a second aspect of the present invention, there is provided a method of mounting a conductive ball, wherein a conductive ball is mounted on a plurality of electrodes arranged on the same surface by a suction tool. The electrodes are divided into n groups from the 1st to nth groups according to the mounting order, and the intervals of the adsorbing holes adjacent to each other corresponding to the electrode arrangement of these n groups are The conductive balls are mounted in n times by n suction tools having suction holes arranged so as not to be less than the minimum interval of the arrangement.

According to the invention described in each claim, the electrodes on which the conductive balls are mounted are divided into n groups, and the electrodes are arranged adjacent to each other in correspondence with the respective electrode arrangements of these n groups. The distance between the suction holes is widened by mounting the conductive balls in n times by n suction tools having suction holes arranged so that the distance between the suction holes does not become smaller than a predetermined size. Therefore, it is possible to facilitate the processing and realize the formation of bumps with a fine pitch.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a conductive ball mounting device according to an embodiment of the present invention, and FIG. 2 is a plan view of the same substrate.
3A and 3B are layout diagrams of suction holes on the lower surface of the suction tool, and FIG. 4 is a partial sectional view of the suction tool.

First, the structure of a conductive ball mounting device will be described with reference to FIG. In FIG. 1, a conductive ball supply unit 2 is disposed on a base 1. The supply unit 2 comprises a container 3 in which a large number of conductive balls 4 are stored. A work positioning unit 5 is provided on the side of the supply unit 2.
A substrate 7, which is a work, is held by a holder 7 on the movable table 6 of the positioning unit 5. By driving the movable table 6, the substrate 8 moves in the horizontal direction,
Positioned.

Above the supply unit 2 and the positioning unit 5,
A moving table 11 having a motor 12 is arranged. A lifting drive unit 13 is mounted on the moving table 11, and a first suction head 14A and a second suction head 14B are coupled to the two lifting mechanisms built in the lifting drive unit 13, respectively. First suction head 14A, second
The suction head 14B includes suction tools 15A and 15B each having a large number of suction holes. By suctioning the inside of the first suction head 14A and the second suction head 14B by vacuum suction means (not shown), the suction holes 1
The conductive balls 4 are vacuum-adsorbed on the electrodes 6. Therefore, a plurality of first suction heads 14A and second suction heads 14B
Thus, the conductive balls 4 can be vacuum-adsorbed and picked up from the supply unit 2 in a plurality of times, and can be transferred and mounted on the substrate 8 of the positioning unit 5.

Next, the substrate 8 on which the conductive balls 4 are mounted will be described with reference to FIG. In FIG. 2, on the surface of the substrate 8, a plurality of electrodes 9 are arranged in a grid pattern on the same surface at a predetermined pitch interval P. The minimum interval of the arrangement of the electrodes 9 is also the pitch interval P. In the present embodiment, the above-mentioned pitch interval P is set to about 150 μm, which is an extremely narrow pitch.

These electrodes 9 are divided into two groups as shown in FIG. That is, it is divided into an electrode 91 (hatched) forming a diagonal grid and another electrode 92, and the conductive ball 4 is first mounted on the electrode 91. Therefore, the group composed of the electrodes 91 is the first group, and the group composed of the electrodes 92 is the second group.
It is the second group. The minimum interval of the array of the electrodes 91 (92) divided into each group is larger than the above-mentioned pitch interval P.

Next, the suction tools 15A and 15B for vacuum-suctioning the conductive balls 4 will be described with reference to FIG.
FIG. 3A shows the arrangement of the suction holes 16 of the suction tool 15A mounted on the first suction head 14A. This arrangement is the first one where the conductive balls 4 are mounted first. This corresponds to the arrangement of the electrodes 91 of the group (see FIG. 2). Similarly, FIG. 3B shows the second suction head 1
4B shows the arrangement of the suction holes 16 of the suction tool 15B mounted on the 4B, and this arrangement shows the second conductive ball 4 at the second position.
Corresponds to the arrangement of the electrodes 92 of the second group on which is mounted.

As shown in FIGS. 3A and 3B, the distance between adjacent suction holes 16 of the suction tools 15A and 15B is as shown in FIG.
If expressed by P, it is √2P, which is about 212 in this embodiment.
μm. That is, this interval is a predetermined dimension (about 200 μm) that indicates the limit that is possible with the current drilling technology.
Not the following: Therefore, the suction tools 15A, 1
5B can be manufactured by the current processing technology without any particular problem. Further, as shown in FIG. 4, in the suction tool 15 </ b> B for mounting the conductive balls 4 secondly, a concave portion (a relief portion) for preventing interference with the mounted conductive balls 4 already mounted on the electrodes 91. ) 17 are formed corresponding to the positions of the already mounted conductive balls 4.

The device for mounting the conductive balls is constructed as described above, and its operation will be described below. First, in FIG. 1, the motor 12 is driven to move the elevating / lowering drive unit 13 to position the first suction head 14 </ b> A on the container 3 of the supply unit 2. Then, the first suction head 14A is lowered with respect to the container 3 by the elevating mechanism, the suction tool 15A is settled on the layer of the conductive balls 4, and vacuum suction is performed from the suction holes 16. Thereby, each suction hole 1 of the suction tool 15A
The conductive balls 4 are vacuum-adsorbed on the electrodes 6.

Thereafter, the first suction head 14A is raised, and the elevating and lowering drive unit 13 is moved again by the moving table 11 to move the first suction head 14A to the substrate 8 of the positioning unit 5.
Position it on top. Then, the first suction head 14A is moved down with respect to the substrate 8 to release the vacuum suction, so that the conductive balls 4 are moved to the electrodes 91 of the first group of the substrate 8.
Mount on top.

After that, if the first suction head 14A is lifted, then the second suction head 14B causes the same pickup operation / mounting operation to be performed, and the conductive ball 4
Are mounted on the second group of electrodes 92 of the substrate 8. At this time, since the recess 17 is formed at the position corresponding to the conductive ball 4 already mounted, the mounting of a new conductive ball 4 is not hindered. First suction head 14A
And the distribution density of the suction holes 16 of the second suction head 14B is
Since the distribution density is lower than that when one suction head is formed with suction holes corresponding to all the electrodes 9, the conductive balls 4
It is possible to reduce pick-up mistakes in which the conductive balls are accidentally sucked excessively when sucking.

As described above, in the present embodiment, the plurality of electrodes 9 on the substrate 8 are divided into the above-mentioned two groups, and the electrodes are provided corresponding to the respective electrode arrangements of these two groups. By using two suction tools having suction holes, the conductive balls are mounted in two steps. As a result, the distance between the adjacent suction holes of each suction tool can be set to a dimension that can be manufactured by the current processing technology, and it is possible to reduce the conductivity of electrodes with a minute pitch, which was difficult to achieve due to restrictions on the processing of suction holes. It is possible to mount a conductive ball and form a solder bump. Although the electrodes are divided into two groups in the present embodiment, the present invention is not limited to this and may be divided into three or more groups.

[0020]

According to the present invention, the electrodes on which the conductive balls are mounted are divided into n groups, and the suction holes which are adjacent to each other and correspond to the respective electrode arrangements of these n groups. The conductive balls are mounted in n times by n suction tools having suction holes arranged so as not to be less than a predetermined size, so that the electrodes arranged at a fine pitch are electrically conductive. A sex ball can be mounted.

[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 substrate according to an embodiment of the present invention.

FIG. 3A is a layout view of suction holes on a lower surface of a suction tool according to an embodiment of the present invention. FIG. 3B is a layout view of suction holes on a lower surface of a suction tool according to an embodiment of the present invention.

FIG. 4 is a partial sectional view of a suction tool according to an embodiment of the present invention.

[Explanation of symbols]

2 supply section 4 conductive balls 8 substrates 9 electrodes 14A, 14B suction head 15A, 15B suction tool 16 adsorption holes 17 Recess (Escape)

Claims (2)

(57) [Claims] 1. A conductive ball mounting apparatus for sequentially mounting conductive balls on a plurality of electrodes arranged on the same surface by a plurality of suction tools, wherein a plurality of suction holes are arranged on each suction tool. The first to n-th different suction tools are provided for each of the n suction tools.
The suction holes of the th suction tool correspond to the array of the electrodes of the i-th group of the first to n-th groups of the plurality of electrodes divided according to the mounting order, and Adjacent suction holes of each suction tool are arranged so that the distance between adjacent suction holes does not become less than the minimum distance of the arrangement of the electrodes. Further, on the lower surface of the second and subsequent suction tools, conductive balls to the electrodes A conductive ball mounting apparatus, characterized in that a relief portion for preventing interference with an already mounted conductive ball at the time of mounting is formed corresponding to the position of the already mounted conductive ball. 2. A method of mounting a conductive ball on a plurality of electrodes arranged on the same surface by a suction tool, the method comprising: mounting the plurality of electrodes on a first to n-th order according to a mounting order. It is divided into n groups up to the n-th group and arranged so as to correspond to the electrode arrangement of each of these n groups and the distance between adjacent adsorption holes is not less than the minimum distance of the arrangement of the electrodes. A method of mounting a conductive ball, characterized in that the conductive balls are mounted in n times by n suction tools each having a suction hole provided therein.