JP2004031584A - Method and device for arranging and mounting conductive ball - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for arranging and mounting conductive ball by which conductive balls can be arranged efficiently without causing defective suction. <P>SOLUTION: After the conductive balls B contained in a container 14 are arranged on an array board 19 by suction, the balls B are collectively mounted on an electrode to be mounted with the balls B. The suction and arrangement of the balls B are performed only in the portion of the arranging surface facing the container 14 while the container 14 and the array board 19 are parallelly moved with respect to the arranging surface. The area of the ball supplying area of the container 14 is smaller than the arranging area of the array board 19. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a conductive ball suction mounting method and an array mounting apparatus, in particular, a plurality of ball suction holes are formed on a ball array plate, a plurality of fine balls are collectively held, a wafer or a printed board, The present invention relates to a method and an apparatus for collectively mounting electronic components such as semiconductor chips on electrodes.
[0002]
[Prior art]
Recently, a bump forming technique using minute metal balls has been used for electrical connection of semiconductor chips. By using the bump formation technology, various advantages such as miniaturization of the package and increase in the number of pins can be obtained. A bump forming technique using such a minute metal ball is described in, for example, Japanese Patent Application Laid-Open No. 7-153765.
[0003]
In the bump formation method proposed in the above publication, suction holes are formed at all positions corresponding to the bump formation positions on the semiconductor chip in order to suck and hold at least one metal ball group for a semiconductor chip. Ball arrangement plate is used. Then, after the minute metal balls are sucked and held on the ball array plate, the ball array plate is transported to the joining stage to mount the ball at the bump forming position.
[0004]
Therefore, in this case, minute conductive balls uniformly formed can be collectively mounted at the bump formation positions. This makes it possible to easily and efficiently form bumps having a uniform shape with little variation.
[0005]
However, arranging one semiconductor chip at a time involves a large number of repetitive operations, and is disadvantageous in terms of cost and time. Therefore, before the wafer is cut into individual chips, that is, before the dicing process, balls are arranged on all the electrodes corresponding to a plurality of chips on the wafer.
[0006]
[Problems to be solved by the invention]
However, when the balls are to be collectively arranged on all the electrodes on the wafer on which a plurality of semiconductor chips are formed, the number of electrodes reaches about several hundred thousand. For this reason, during the ball suction arrangement, a large amount of balls are concentrated on the suction holes and surplus balls are likely to be generated, and it is substantially impossible to surely suction the balls to all the suction holes of the ball array plate without a defective arrangement. Was difficult. In particular, the ball arrangement by the collective suction in a large area requires a long suction time and a long bump formation time, which has been a problem in mass production.
[0007]
The present invention has been made in view of the above circumstances, and when a conductive ball is adsorbed and arranged on a ball array plate, poor suction is unlikely to occur, and a conductive ball that enables efficient arrangement of the conductive ball is provided. An object of the present invention is to provide an array mounting method and an array mounting device.
[0008]
[Means for Solving the Problems]
The conductive ball array mounting method according to the present invention is configured such that, after the conductive balls in the container are suction-arranged on the array plate, the conductive balls are collectively mounted on the electrodes of the mounting object on which the balls are to be mounted. The ball array mounting method as described above, wherein the container and the array plate are moved in parallel relative to the array surface, and the suction array is performed only at a portion of the array surface facing the container. .
[0009]
Further, in the conductive ball array mounting method of the present invention, the area of the ball supply area of the container facing the array area of the array plate is smaller than the array area of the array plate.
[0010]
Further, in the conductive ball array mounting method of the present invention, detecting the amount of the conductive balls in the container and supplying the conductive balls to the container such that a predetermined amount of the conductive balls is maintained. Features.
[0011]
Further, the conductive ball array mounting apparatus of the present invention, after the conductive balls in the container are suction-arranged on the array plate, collectively apply the conductive balls to the electrodes of the mounting object on which the balls are to be mounted. A ball array mounting device adapted to be mounted, wherein the container and the array plate move in parallel relative to an array surface, and are suction-arranged only at a portion of the array surface facing the container. And
[0012]
Further, in the conductive ball array mounting device of the present invention, the area of the ball supply area of the container facing the array area of the array plate is smaller than the array area of the array plate.
[0013]
Further, in the conductive ball array mounting device of the present invention, the conductive ball has a sensor for detecting the amount of the conductive balls in the container, the conductive balls in the container so that a predetermined amount of the conductive balls is maintained. It is characterized by having a ball replenishing device for supplying.
[0014]
According to the present invention, when a large number of balls are collectively mounted as in the case of bump formation using balls on a wafer, the arrangement plate and the container are relatively moved in parallel while the arrangement plate and the container are opposed to each other on the arrangement surface. Only the suction arrangement is performed, and as a result, the balls are supplied to the entire arrangement surface. By arranging the suction at the opposed portions of the containers in this manner, a high suction force can be secured.
In this case, by making the ball supply area of the container smaller than the arrangement area of the arrangement plate, the balls can be supplied uniformly and properly over the entire arrangement surface. As a result, errors such as surplus balls during the ball suction arrangement can be significantly reduced. Moreover, since the adsorption time can be shortened, the productivity can be greatly improved.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a method and an apparatus for arranging and mounting conductive balls according to the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of the device of the present invention. In this embodiment, the semiconductor substrate or the wafer W moves while being fixed on the wafer stage 10 along a wafer transfer path in a direction (X direction) perpendicular to the paper surface, and waits at a predetermined position.
[0016]
Here, in the embodiment of the present invention, for example, particularly, a wafer having a size of 3 inches or more is targeted. According to the wafer W, a plurality of semiconductor chips C (individual square portions) to be formed as shown in FIG. 3 can be obtained, and the electrode portion of each semiconductor chip C has the device of the present invention as described later. , A plurality of conductive balls are mounted. Although the conductive balls are simplified in FIG. 3, the number of conductive balls used in the entire semiconductor chip C is several hundred thousand. According to the present invention, an extremely large number of conductive balls are mounted on the wafer W at a time.
[0017]
As shown in FIG. 1, a guide or guide rail 11 is provided along a direction (Y direction) orthogonal to the wafer transfer path, and the guide rail 11 has a ball mounting head 12 movable in the YZ directions. Is supported. The ball mounting head 12 arranges the conductive balls B by suction on a ball array plate, as described later. Then, the conductive balls B are collectively mounted on the electrode portions of the semiconductor chips C formed on the wafer W.
[0018]
A ball supply device 13 is disposed at one end of the guide rail 11 below the ball mounting head 12. The ball supply device 13 includes a ball storage container (ball tray) 14 that stores a considerable amount of conductive balls B, and a vibrator that vibrates the ball tray 14 and causes the conductive balls B to jump in the ball tray 14. I have. The ball supply method may be a method of jumping the conductive ball B as in the present embodiment, or a method of blowing up or blowing by a gas flow.
[0019]
Although the ball replenishing device is simplified in FIG. 1, an optical sensor 21 is provided so that the conductive balls B in the ball tray 14 do not decrease beyond a certain level (see FIG. 2). According to this optical sensor 21, if the jumping conductive ball B is a considerable amount or more, the light is blocked. However, if the density of the conductive ball decreases and light is transmitted, the light sensor 21 transmits the transmitted light. Is received. Thus, the conductive ball replenishing device 22 always automatically replenishes a considerable amount of the conductive balls B.
[0020]
Between the ball supply device 13 and the ball mounting stage 10, an arrangement failure ball removing mechanism 16 and an arrangement inspection camera 17 are arranged. The ball removing mechanism 16 removes the misaligned balls in the ball mounting head 12 by suction or gas blowing. When vibration is applied to the mounting head 12 during the removal, the removal can be performed more effectively. In this case, the vibration frequency is preferably about several Hz to 1 GHz. The arrangement inspection camera 17 inspects the ball mounting head 12 for a defective ball arrangement.
[0021]
The ball mounting head 12 reciprocates between the ball supply device 13 and the ball mounting stage 10, but has a suction mechanism 18 connected to a negative pressure or a vacuum source as shown in FIG. Thus, a large number of conductive balls B are arranged by suction. The ball array plate 19 has suction holes 19a corresponding to the electrode portions of the plurality of semiconductor chips C on the wafer W. Then, the conductive balls B jumping in the ball tray 14 can be sucked one by one into the suction holes 19a by the suction mechanism 18.
[0022]
Here, as can be seen from FIGS. 2A and 2B, the area (opening 14a) of the ball supply area portion 20 of the ball tray 14 facing the ball arrangement plate 19 is determined by the arrangement of the ball arrangement plate 19. It is set smaller than the area. In this case, as shown in FIG. 4, the width of the ball tray 14 (in the illustrated example, in the X direction) may be substantially the same as or wider than the arrangement area of the ball arrangement plate 19.
[0023]
In the above configuration, an arrangement operation from when the ball mounting head 12 starts sucking the ball to when the conductive ball B is mounted on the mounting target will be described.
In the ball supply device 13, the conductive balls B in the ball tray 14 are jumping by a vibrator. As shown by the dotted line in FIG. 1, the ball mounting head 12 is lowered to a predetermined height of the ball tray 14, and the jumping conductive balls B are sucked. At this time, as shown in FIG. 4, while keeping the Z-axis direction constant, the head is moved in the Y direction from one side of the array area to the other to supply the ball to the entire array surface. In this case, by making the ball supply area of the ball tray 14 facing the arrangement area smaller than the arrangement area of the ball arrangement plate 19, the balls can be supplied uniformly and properly over the entire arrangement surface.
[0024]
Here, when the ball arrangement plate 19 and the ball tray 14 are relatively moved in parallel as described above, the suction arrangement is performed only at the opposing portion of the ball tray 14 on the arrangement surface of the ball arrangement plate 19, thereby achieving a high suction force. Can be secured. That is, the unsucked portion of the arrangement surface that is not opposed to the ball tray 14 (the area of the arrangement surface to be absorbed from now on) is substantially closed, and only the opposed portion of the ball tray 14 is opened. Good. In this case, for example, a plate member that can be raised and lowered separately is mounted in the ball mounting head 12, and the plate member is configured to be linked with the movement (Y direction) of the ball tray 14 to be moved up and down. By performing suction while opening only the opposing portion of the ball tray 14, high suction efficiency can be obtained.
[0025]
Note that the ball tray 14 may move in the Y direction so that the ball mounting head 12 and the ball tray 14 move relatively in parallel. If the entire suction area cannot be completely absorbed by only one suction operation in one direction in the Y direction, the ball may be reciprocated several times, or two ball trays may be prepared and set at intervals. To form a double structure. Alternatively, as shown in FIG. 5, a ball mounting head 12 may be provided at the center of the arrangement area, and the ball tray may be rotated to cover the entire arrangement area.
[0026]
Next, after attracting the conductive ball B, the ball mounting head 12 moves up and moves to the ball mounting stage 10 along the guide rail 11. At this time, defective balls are removed. Thereafter, the array inspection camera 17 moves in the X direction, and inspects the ball suction state on the entire array surface of the ball array plate 19. If the inspection result is good, the stage moves to the ball mounting stage 10. If an alignment defect is found during this inspection, the defect is returned to the position of the ball removing mechanism 16 and removed.
[0027]
At the time of this defect removal, the removed position is stored by a removal position storage device (not shown), and the ball tray 14 is fed back to the defect removal position on the ball array plate 19 so as to perform re-adsorption. You can also
[0028]
Next, the ball mounting head 12 is aligned with the wafer W waiting on the ball mounting stage 10. Then, by lowering the ball mounting head 12, the conductive balls B adsorbed on the ball array plate 19 are mounted on the electrode portions of the wafer W coated with the flux.
[0029]
Note that the ball mounting head 12 is configured so that the mounting load when coming into contact with the wafer W can be controlled in accordance with the type of the conductive balls and the like. Thus, the conductive balls B are brought into contact with the wafer W with an optimum load, and the conductive balls B can always be appropriately and smoothly mounted.
[0030]
After the balls are mounted on the wafer W, a suction removing operation is performed by the ball removing mechanism 16 in consideration of the balls remaining on the ball array plate 19.
[0031]
The specific shape and the like of the ball tray 14 in the above embodiment are not limited to those in the illustrated example, and various forms such as a polygon or an arc can be adopted.
[0032]
【The invention's effect】
As described above, according to the present invention, in this type of ball mounting apparatus or method, typically, when a large number of balls are collectively mounted such as bump formation using balls on a wafer, a ball suction arrangement is used. At times, errors such as extra balls can be significantly reduced. Moreover, since the adsorption time can be shortened, there is an advantage that productivity can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a device of the present invention.
FIG. 2 is a side view and a plan view showing a configuration around a ball mounting head in the device of the present invention.
FIG. 3 is a plan view illustrating an example of a wafer on which conductive balls are mounted according to the embodiment of the present invention.
FIG. 4 is a perspective view showing an operation in the embodiment of the present invention.
FIG. 5 is a view showing a modification of the ball tray according to the embodiment of the present invention.
[Explanation of symbols]
10 Ball mounting stage 11 Guide rail 12 Ball mounting head 13 Ball supply device 14 Ball storage container (ball tray)
Reference Signs List 15 Vibrator 16 Ball removal mechanism 17 Camera for array inspection 18 Suction mechanism 19 Array plate 19a Suction hole 21 Optical sensor 22 Conductive ball refilling device W Wafer

Claims (6)

A ball array mounting method in which the conductive balls in the container are arranged by suction on an array plate, and the conductive balls are mounted collectively on an electrode of a mounting object on which the balls are to be mounted,
A method for arranging and mounting conductive balls, wherein the container and the arrangement plate are moved in parallel relative to the arrangement surface, and the suction arrangement is performed only at a portion of the arrangement surface facing the container. 2. The method of claim 1, wherein an area of a ball supply area of the container that faces the arrangement area of the arrangement plate is smaller than an arrangement area of the arrangement plate. 3. 3. The conductive ball according to claim 1, wherein the amount of the conductive ball in the container is detected, and the conductive ball is supplied to the container such that a predetermined amount of the conductive ball is maintained. Array mounting method. A ball array mounting device, in which the conductive balls in the container are arranged by suction on the array plate, and then the conductive balls are collectively mounted on an electrode of a mounting object on which the balls are to be mounted,
The conductive ball arrangement mounting apparatus, wherein the container and the arrangement plate are moved relatively in parallel with respect to the arrangement surface, and the suction arrangement is performed only at a portion of the arrangement surface facing the container. 5. The conductive ball arrangement mounting device according to claim 4, wherein an area of the ball supply area of the container facing the arrangement area of the arrangement plate is smaller than an arrangement area of the arrangement plate. 6. A ball refilling device having a sensor for detecting an amount of the conductive balls in the container and supplying the conductive balls to the container so that a predetermined amount of the conductive balls is maintained. Item 6. A conductive ball array mounting device according to Item 4 or 5.

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