JP3246342B2 - 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 a work by vacuum-sucking the conductive ball with a suction head.

[0002]

2. Description of the Related Art It is known to manufacture a work with bumps by mounting conductive balls on the surface of a work such as a chip or a substrate. As a method for mounting the conductive balls on the work, a method using a suction head is known.
This method is a method in which conductive balls provided in a container or the like are vacuum-sucked to suction holes formed in a large number on the lower surface of a suction head, picked up, and transferred and mounted on a work.

[0003] However, such a suction head cannot always pick up the conductive ball by vacuum suction in all the suction holes, and is likely to cause a pick-up error. Therefore, the present applicant has previously proposed a method for easily detecting a pickup error (Japanese Patent Laid-Open No. 8-97218). In this method, as shown in FIG. 2 in particular, light leaking from a suction hole on the lower surface of a pickup head (suction head) is reflected by a mirror provided above the pickup head toward an optical sensor. By detecting this light, it is detected that the conductive ball is not vacuum-sucked in the leaked suction hole.

[0004]

In recent years, conductive balls have tended to be reduced in size, and accordingly, the diameter of suction holes has been gradually reduced. For this reason, the amount of light leaked from the suction hole is reduced, and the above-described conventional configuration has a problem that it is difficult to reliably detect the light leak by the optical sensor.

Accordingly, it is an object of the present invention to provide a conductive ball mounting apparatus and a mounting method capable of reliably detecting light leakage from a suction hole of a suction head and detecting a pickup error of the conductive ball.

[0006]

According to a first aspect of the present invention, there is provided a method for picking up a workpiece by vacuum-suctioning a plurality of conductive balls provided in a conductive ball supply section into suction holes formed in a lower surface of a suction head. A mounting device for a conductive ball mounted on the suction head, wherein an optical sensor and a light-collecting element for condensing light on the optical sensor are provided above the suction head, and an inner surface of an inner wall of the suction head is disposed inside the suction head. The light reflecting portion reflects light leaked from the suction hole near the wall toward the light collecting element. The invention according to claim 2 is characterized in that the suction head is divided into a plurality of chambers by the inner wall, and the inner surface of the inner wall is used as the light reflecting portion , and the suction head is
Are divided into a plurality of chambers by the inner wall,
The inner surface of the inner wall was used as the light reflecting portion .

[0007] According to a second aspect of the present invention, there is provided the conductive material according to the first aspect.
A method of mounting a conductive ball Ru using the mounting device of the ball, while the suction head is transferred mounting the into the conductive balls provided in the supply unit to pick up the work, towards the bottom surface light source irradiating light from the is reflected toward the light leakage from the suction holes into the condensing element by the light reflecting portion, is further incident on condensed by the condenser element to the optical sensor, detects the pickup mistakes I did it.

[0008]

According to the first and second aspects of the present invention, a pick-up error can be detected by causing light leaked from a suction hole to enter an optical sensor. In particular, light leaking from the suction hole near the inner wall, which is difficult to sufficiently enter the optical sensor, is reflected toward the light collecting element by the light reflecting portion, so that the light can be effectively incident on the optical sensor.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a conductive ball mounting apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view of the suction head.

First, the overall structure of the conductive ball mounting device will be described with reference to FIG. In FIG. 1, reference numeral 11 denotes a suction head. The suction head 11 is held by a block 12. The block 12 is mounted on a guide rail 14 provided on a front surface of a bracket 13 so as to be vertically movable. A nut 15 is provided integrally with the block 12, and a vertical feed screw 16 is screwed to the nut 15. Therefore, when the motor 17 is driven forward and reverse to rotate the feed screw 15 forward and backward, the suction head 11 is guided by the guide rail 14 and moves up and down.

A nut (not shown) provided on the back surface of the bracket 13 is screwed to a horizontal feed screw 18.
19 is a holding table for the feed screw 18. Therefore, when the motor 20 is driven forward and backward, the feed screw 18 rotates forward and backward, and the suction head 11 held by the bracket 13 moves horizontally in the horizontal direction. The suction head 11 is connected to the pneumatic unit 9 via the tube 8.

A supply section 21 for the conductive balls 1 is provided below the moving path of the suction head 11. The supply unit 21 is formed of a container, and is supported by a box 22.
A large number of holes 23 are formed at the bottom of the supply unit 21.
The box 22 is mounted on a base 24, and a gas blower 25 is installed inside the base 24. Gas such as air blown from the gas blower 25 is supplied from the hole 23 to the supply unit 21 (see a broken arrow), and the gas pressure causes the conductive balls 1 to fluidize. By performing the up / down operation, the suction head 11 vacuum-adsorbs and picks up the conductive ball 1 on its lower surface.

A positioning section 26 for the substrate 5 as a work is provided on the side of the supply section 21. The positioning section 26 is configured by stacking an X table section 27 and a Y table section 28, and further installing a clamper 29 for clamping the substrate 5 above the X table section 27 and the Y table section 28. When the motor Mx of the X table 27 is driven, the substrate 5 moves in the X direction, and when the motor My of the Y table 28 is driven, the substrate 5 moves in the Y direction. Thus, the position of the substrate 5 is adjusted by moving the substrate 5 horizontally.

Next, the structure of the suction head 11 will be described with reference to FIG. The suction head 11 has a dark box structure including an upper case 30 and a lower case 31. The lower case 31 is partitioned by an inner wall 31a into a plurality of chambers 32, and a plurality of suction holes 33 are formed on the lower surface thereof. A light-collecting element 34 is provided above each chamber 32, and an optical sensor 35 is provided above the light-collecting element 34. The optical sensor 35 is connected to the light leakage detection unit 37. The light condensing element 34 condenses the light incident from below toward the optical sensor 35. Each side wall 31
The inner surface of a is mirror-finished to form a light reflecting portion a.
A linear light source 40 is provided below the moving path of the suction head 11 (see also FIG. 1). The light source 40
The longitudinal direction is the Y direction orthogonal to the moving direction (X direction) of the suction head 11, and therefore the suction head 11
By moving in the direction, the entire lower surface is irradiated with light.

The conductive ball mounting apparatus is constructed as described above, and the operation will be described below. In FIG. 1, when the suction head 11 is located above the supply unit 21 and the motor 17 is driven forward and backward, the suction head 11 performs a lowering / upward operation, and the supply unit 21 is inserted into the suction hole 33 on the lower surface thereof. The conductive ball 1 provided in the above is picked up by vacuum suction. At this time, gas is blown out from the gas blower 25 so that the suction head 11 easily sucks the conductive ball 1 into all the suction holes 33 in vacuum, and the supply unit 21.
The conductive balls 1 inside are flowing.

Next, the suction head 11 moves toward the substrate 5, and in the middle thereof, as shown in FIG.
Pass over the. At this time, light is emitted from the light source 40 toward the suction head 11. Here, in FIG.
If there is a suction hole 33 in which the conductive ball 1 is not vacuum-sucked, light leaks from the suction hole 33 into the lower case 31, and the light is collected by the light-collecting element 34 and enters the optical sensor 35. The output signal of the optical sensor 35 is input to the light leakage detection unit 37, and it is found that the suction hole 33 that does not vacuum-suck the conductive ball 1 exists, that is, that the pick-up of the conductive ball 1 has occurred.

In this case, the suction head 11 is
Then, the pick-up operation is performed again by lowering / upward movement. Then, the suction head 11 moves again above the light source 40 and determines again whether or not there is light leakage. If no light leakage is detected, it is determined that the conductive balls 1 are correctly vacuum-sucked in all the suction holes 33 (that is, there is no pickup error), and
It moves above the substrate 5 as it is. So suction head 1
1 performs the lowering and raising operations again, and releases the vacuum suction state, thereby mounting the conductive balls 1 on the substrate 5. Note that a flux is applied to the substrate 5 in advance. The suction head 11 having the conductive balls 1 mounted on the substrate 5 as described above returns to the supply unit 21 and the above operation is repeated.

In FIG. 2, the light L1 that has passed through the suction hole 33 near the center of the chamber 32 proceeds straight to the upper light-collecting element 34 as it is, is collected by the light-collecting element 34, and It can be sufficiently incident. On the other hand, a part of the light L2 that has passed through the suction hole 33 near the side wall 31a hits the inner wall 31a, but the inner surface of the inner wall 31a is mirror-finished and the light reflecting portion a
Therefore, the light L2 hitting the light condensing element 34
The light is reflected to the side and can enter the optical sensor 35 sufficiently. Therefore, by forming such an inner wall 31a,
Light passing through all the suction holes 33 can be reliably detected by the optical sensor 35. If the inner surface of the inner wall 31a is not a light reflecting portion a, the light incident thereon will be absorbed,
Therefore, sufficient light does not enter the optical sensor 35, and a pickup error cannot be reliably detected.

[0019]

According to the present invention, the light leakage from the suction holes near the inner side wall of the suction head can be reliably detected by the light sensor, it can detect the pickup errors of the conductive ball.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of the suction head of the conductive ball mounting apparatus according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive ball 5 Substrate (work) 11 Suction head 21 Supply part 31a Inner wall 33 Suction hole 34 Light-collecting element 35 Optical sensor a Light reflection part

Claims (2)

(57) [Claims] An apparatus for mounting a conductive ball, wherein a conductive ball provided in a conductive ball supply section is vacuum-sucked into a plurality of suction holes formed in a lower surface of a suction head, picked up, and mounted on a work. A light sensor and a light-collecting element for condensing light on the optical sensor are provided above the suction head, and light leaking from the suction hole near the inner wall of the suction head near the inner wall is provided. A light reflecting portion for reflecting light toward the light-collecting element ; and
It is divided into several chambers by the inner wall,
An apparatus for mounting a conductive ball, wherein an inner surface of a wall is the light reflecting portion . 2. The conductive ball mounting device according to claim 1,
A conductive mounting method of balls Ru used, while the suction head is transferred mounting the into the conductive balls provided in the supply unit to pick up the work, light is irradiated from the light source toward the lower surface The light leakage from the suction hole
Wherein toward the condensing element is reflected, further this is incident is condensed by the condensing element to the optical sensor, method of mounting a conductive ball and detecting a pickup mistake reflecting portion.