JPH10261675A - Method of loading conductive ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method of loading conductive balls, which can surely detect a pickup error and a mis-placing. SOLUTION: A camera 30 is provided for the moving route of a chuck head 11 of conductive balls 1. The lower face of the chuck head 11 is image-picked up. A first search region which is set by surrounding all the chuck holes 11a is set and a second search region in a range except for the first search region, based on the arranging pattern of the chuck holes 11a, which are previously stored in a screen obtained by image-pickup. The presence or absence of the pickup error of the conductive balls is detected according to the first and second search regions. Then, whether or not the conductive balls that are left by means of the placing error exist is detected with the whole range of the lower face of the chuck head 11 as the search regions after the loading of the conductive balls 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a conductive ball on a work by vacuum-suctioning 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 does not always vacuum-suction conductive balls in all the suction holes, and is likely to cause a pick-up error. In addition, the conductive balls picked up by the suction head are not necessarily all mounted on the work, and there are also conductive balls that remain and adhere to the suction holes of the suction head due to a place mistake. The work becomes a defective product in which the conductive balls are missing.

Therefore, conventionally, for example, Japanese Unexamined Patent Publication No.
As described in Japanese Patent Publication No. 18-182, light leakage from the suction hole on the lower surface of the suction head is reflected toward the optical sensor by a mirror provided on the upper portion of the suction head. By detecting this light, it is detected that the conductive ball is not vacuum-sucked in the leaked suction hole. In addition, for a place mistake, light is emitted from the side along the lower surface of the suction head in the middle of the movement path where the suction head returns to the supply unit, and the conductive ball adheres to the lower surface depending on the presence or absence of light shielding. Detecting the presence or absence was performed.

[0005]

However, the conductive balls tend to be miniaturized, and the following problems have been caused by the conventional pickup error and place error detection methods. That is, in the case of detecting a pickup error, the diameter of the suction hole is reduced due to the miniaturization of the conductive ball, and the amount of light leaked from the suction hole is also reduced. For this reason, it has become difficult to reliably detect light leakage with the optical sensor. Also, in the case of detection of a place miss, since the size of the conductive ball is reduced, the light shielding area when detecting and detecting light emitted from the side is reduced, so that it is also difficult to reliably detect the light. I have. As described above, it has been a problem that it is difficult to reliably detect a pick-up miss and a place miss.

Accordingly, an object of the present invention is to provide a method of mounting a conductive ball which can reliably detect a pickup error and a place error.

[0007]

According to the method of mounting a conductive ball of the present invention, a conductive ball provided in a conductive ball supply section is vacuum-sucked into a plurality of suction holes formed on the lower surface of a suction head. And picking up a conductive ball to be mounted on a work, wherein the suction head picks up a conductive ball provided in the supply unit and transfers the conductive ball to the work. Irradiating light from a light source below and imaging the lower surface with a camera; and a first image setting method based on an array pattern of suction holes stored in a screen obtained by the imaging.
Detecting the presence / absence of conductive balls in the search area by image recognition to determine the presence / absence of suction holes in which the conductive balls are not vacuum-sucked; and setting the conductive balls in a range excluding the first search area on the lower surface. Determining the presence or absence of a conductive ball in the second search area, and, if there is a suction hole in which the conductive ball is not vacuum-sucked, repeating the suction operation up to a predetermined number of times; After the suction head mounts the conductive ball on the workpiece, while returning to above the supply unit, irradiates light from a light source below toward the lower surface, and images the lower surface with a camera, Detecting the presence or absence of the conductive ball in the lower surface from the screen obtained by the above.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention having the above-described structure is based on an arrangement pattern of suction holes stored in advance in a screen obtained by imaging the lower surface of a suction head. Setting a first search area and a second search area in a range excluding the first search area;
In accordance with the first and second search areas, a conductive ball pickup error is detected. Further, after the conductive balls are mounted, the entire area of the lower surface of the suction head is used as a search area to detect a place error of the conductive balls.

An embodiment of the present invention will be described below 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, FIG. 2 is a block diagram of a control system of the conductive ball mounting apparatus, and FIG. FIGS. 4 and 5 are flow charts showing the operation of the conductive ball mounting device, and FIGS. 6A, 6B and 6C are suction heads of the conductive ball mounting device. It is an image figure of a lower surface.

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, on the lower surface of which a large number of suction holes 11a are formed. The suction head 11 is held by a block 12. The block 12 is mounted on a guide rail 14 provided on a side surface of the 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 Z-axis motor 17 drives forward and reverse and the feed screw 15 rotates 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 X-axis motor 20 rotates forward and backward, the feed screw 18 rotates forward and reverse, and the suction head 1 held by the bracket 13 is rotated.
1 moves horizontally in the horizontal direction. The suction head 11 is connected to the pneumatic unit 9 via the tube 8.

A conductive ball supply unit 21 is provided below the moving path of the suction head 11. This supply unit 2
1 comprises a container, which 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 out from the gas blower 25 is supplied from the hole 23 to the supply unit 21 (see the broken arrow), and the pressure difference causes the conductive balls 1 to fluidize. By performing the up / down operation, the suction head 11
Picks up a conductive ball on its lower surface by vacuum suction.

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 mounting a clamper 29 for clamping the substrate 5 above the table section. 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.

A camera 30 is provided below a moving path from the supply section 21 to the positioning section 26. Camera 3
“0” captures an image of the lower surface of the suction head 11 and sends image data to the conductive ball detection unit 32. A light source 31 for irradiating the lower surface of the suction head 11 from below is provided on a side of the camera 30. The lower surface of the suction head 11 is dark-colored on the surface, and the contrast between the glossy conductive ball 1 irradiated with the light source 31 and the image on the image is clear. Is possible.

Next, the configuration of a control system of the conductive ball mounting apparatus will be described with reference to FIG. In FIG. 2, the camera 3
The image data from 0 is sent to the conductive ball detection unit 32. The arrangement of the suction holes on the lower surface of the suction head 11 is stored in the suction hole array pattern storage unit 33, and the position data is sent to the conductive ball detection unit 32. The conductive ball detection unit 32 detects a pick-up error in which the conductive ball 1 does not exist in the suction hole, or the conductive ball 1 exists in a portion other than the suction hole, and a play in which the conductive ball 1 remains after mounting. Detect Smith.

Here, a search area set when detecting a pickup error and a place error will be described. In FIG. 3, a large number of suction holes 11a are provided on the lower surface of the suction head 11. First, a first search area S1 (see a range surrounded by a chain line in FIG. 3) surrounding each of the suction holes 11a is set. The first search area S1 is for detecting whether or not there is a suction hole 11a on which the conductive ball 1 is not sucked.

Next, as shown in FIG. 3, the search area is inverted, and the second search area is shifted to a range excluding the first search area S1.
(See the hatched area) is set. The second search area S2 is for detecting whether or not the conductive ball 1 exists in a portion other than the suction hole 11a. When detecting a place mistake, the suction hole 11a
The search area is the entire lower surface of the suction head 11 irrespective of whether the position is the position or not. However, if the position where the place mistake occurs is specified by the tendency of the place mistake during the actual operation, the detection time is shortened. For this purpose, a search area may be set only at that specific position.

The pick-up miss counter 35 counts the number of re-suction operations performed after a pick-up error is detected. The input means 36 is a keyboard or the like, and is used for inputting a numerical value for setting the number of times of the pickup error counter 35 and the like. The valve driving unit 38 controls the vacuum suction valve 37 of the suction head 11. The motor drive unit 39 includes an X-axis motor 20 that drives the suction head 11,
Z-axis motor 17, motor Mx of positioning unit, motor M
Control the driving of y. The control unit 40 receives the position data of the conductive ball 1 from the conductive ball detection unit 32, and controls the valve driving unit 38 and the motor driving unit 39.
The notification unit 41 notifies the operator of a pickup error or the like in response to a command from the control unit 40.

The conductive ball mounting apparatus has the above-described configuration, and its operation will be described below with reference to the drawings according to the flow charts of FIGS. First, before starting the operation, S
At T1, the pickup miss counter is set to zero. Next, the suction head 11 is connected to the conductive ball supply unit 21.
(ST2). Next, the suction head 11
Is lowered (ST3), the valve for vacuum suction 37 is opened (ST4), and the conductive ball 1 is sucked into the suction hole 11a. Thereafter, the suction head 11 is raised (ST5), and then the suction head 11 is moved above the camera 30 (ST6). At this time, the lower surface of the suction head 11 is
The height of the suction head 11 is set so as to fall within the focal length of 0.

Next, the suction head 11 is stopped and the camera 3 is stopped.
0, the lower surface of the suction head is imaged (ST7). Based on this image data, the first search area S1 is searched to detect whether or not the conductive ball 1 exists at all the positions of the suction holes 11a (ST8). FIG. 6A shows a state where the conductive ball 1 is not sucked in one of the suction holes 11a (indicated by a black circle).

When the conductive balls 1 are present in all the suction holes 11a, the search range is changed to the second search area S2.
To detect whether or not the conductive ball exists at a position other than the suction hole 11a (ST9). FIG. 6 (b)
Shows an example in which the conductive ball 1a exists in one place other than the suction hole 11a.

Next, if there is no pick-up error, the operation proceeds to the following mounting operation. First, the suction head 11 is moved above the work (ST10), then the suction head 11 is lowered (ST11), the valve 37 is closed, and the conductive ball 1 is mounted on the work (ST12).

Next, the suction head 11 is raised (ST1).
3) The suction head 11 is moved above the camera 30 (ST14), and the suction head 11 is stopped. At this time, the height of the suction head 11 is adjusted so that the lower surface of the suction head 11 is within the focal length of 30 of the camera. Next, the lower surface of the suction head 11 is imaged by the camera 30 (ST15), and it is detected whether or not the conductive balls 1 of all the suction holes 11a are mounted and no longer exist on the lower surface (ST16). If the conductive ball 1 does not exist, there is no place error and the mounting operation is completed. If the conductive ball 1 exists, a place miss is notified (ST17). FIG.
(C) shows an example in which one conductive ball 1 exists on the lower surface of the suction head 11.

If the suction hole 11a in which the conductive ball 1 does not exist is detected in ST8, an operation of adding one value to the pickup miss counter 35 is performed (ST18). It is determined whether or not the value exceeds the set value (ST19). If it is equal to or smaller than the set value, the process returns to ST2 to perform the suction operation again, and repeats the suction operation until the pickup miss counter 35 reaches the set value. Then, when the value of the pickup error counter 35 reaches a predetermined value, a pickup error is notified (ST20).

As described above, in the present embodiment, all the suction holes 11a are individually surrounded based on the arrangement pattern of the suction holes 11a stored in advance in the screen obtained by imaging the lower surface of the suction head 11. It is detected whether or not there is a suction hole 11a in which the conductive ball 1 is not sucked in the first search area S1 set as follows, and then the second search area is set in a range excluding the first search area S1. In the search area S2, it is detected whether or not extra conductive balls 1 are attached to portions other than the suction holes 11a. After the conductive balls are mounted, the entire area of the lower surface of the suction head 11 or a place error during actual operation is detected. The search area is a specific range determined from the tendency to occur, and it is detected whether or not there is a conductive ball 1 remaining without being mounted.

[0026]

According to the present invention, all the suction holes are set so as to surround each of the suction holes based on the arrangement pattern of the suction holes stored in advance in the screen obtained by imaging the lower surface of the suction head. A first search area and a second search area are set in a range excluding the first search area, and the presence or absence of a conductive ball pickup error is detected according to the first and second search areas. After the conductive balls are mounted, the entire area of the lower surface of the suction head is used as a search area to detect whether or not there are conductive balls remaining without being mounted. It is possible to accurately detect a pickup error at the time of suction and a place error at the time of mounting.

[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 block diagram of a control system of the conductive ball mounting apparatus according to one embodiment of the present invention;

FIG. 3 is a plan view of the lower surface of the suction head of the conductive ball mounting apparatus according to one embodiment of the present invention;

FIG. 4 is a flowchart showing the operation of the conductive ball mounting apparatus according to one embodiment of the present invention;

FIG. 5 is a flowchart showing the operation of the conductive ball mounting apparatus according to one embodiment of the present invention;

FIG. 6A is an image diagram of the lower surface of the suction head of the conductive ball mounting apparatus according to one embodiment of the present invention; FIG. 6B is the lower surface of the suction head of the conductive ball mounting apparatus of one embodiment of the present invention; Image view (c) Image view of lower surface of suction head of conductive ball mounting apparatus according to one embodiment of the present invention

[Explanation of symbols]

 Reference Signs List 1 conductive ball 5 substrate 11 suction head 12 block 21 supply unit 24 base 30 camera 31 light source 32 conductive ball detection unit 33 suction hole array pattern storage unit 40 control unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Teruaki Kasai 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Koichi Takahashi 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A method for mounting a conductive ball mounted on a workpiece by vacuum-sucking a plurality of conductive balls provided in a supply section of the conductive ball to suction holes formed in a lower surface of a suction head and picking up the same. While the suction head picks up a conductive ball provided in the supply unit and transfers and loads the conductive ball to the work, light is emitted from a light source below toward the lower surface, and a camera is used to illuminate the lower surface. A step of imaging, and a first set based on an arrangement pattern of suction holes stored in advance in a screen obtained by the imaging.
Detecting the presence / absence of conductive balls in the search area by image recognition to determine the presence / absence of suction holes in which the conductive balls are not vacuum-sucked; and setting the conductive balls in a range excluding the first search area on the lower surface. Determining the presence or absence of a conductive ball in the second search area, and, if there is a suction hole in which the conductive ball is not vacuum-sucked, repeating the suction operation up to a predetermined number of times; After the suction head mounts the conductive ball on the workpiece, while returning to above the supply unit, irradiates light from a light source below toward the lower surface, and images the lower surface with a camera, Detecting the presence or absence of the conductive ball in the lower surface from the screen obtained by the above method.