JP2002208606A - Device and method for arranging and transferring conductive ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for arranging and transferring conductive ball by which conductive balls can be arranged very effectively and precisely on a large-area wafer. SOLUTION: After the conductive balls 101 have been sucked to and arranged on an array board 12, the balls 101 are transferred collectively and jointed to objective electrodes to which the balls 101 are to be jointed. The board 12 has an air-permeable material 13 on its back, and the balls 101 are sucked to and arranged on the board 12 via the material 13. One or more shield plates 14-16 are provided on the rear face of the material 13, and the suction face used for sucking and arranging the balls 101 is divided into two or more suction faces by moving the plates 14-16 upward and downward directions, when the balls 101 are sucked to the board 12. The balls 101 are sucked gradually to the suction face starting from the outer peripheral sections or central parts of the divided suction faces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for collectively holding fine conductive balls on an array substrate and arranging them on electrodes of an electronic component such as a printed circuit board or a chip.

[0002]

2. Description of the Related Art In recent years, ball bumps using fine conductive balls have been used for electrical connection of semiconductor chips. By using the ball bump, various advantages such as miniaturization of the package and increase in the number of pins can be obtained. A bump forming technique using such fine conductive balls is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-15376.
No. 5 publication.

In the bump forming method described in the above publication, a metal ball group for at least one semiconductor chip is sucked and held. Then, in order to suction-hold a plurality of metal ball groups, a ball array substrate having suction holes formed at all positions corresponding to the bump formation positions on the semiconductor chip is used. After adsorbing and holding the minute metal spheres on the ball array substrate, the ball array substrate is transported to a bonding stage and bonded to a portion to be bonded.

According to this method, uniformly formed fine conductive balls can be collectively joined to a bump forming position, so that a crowbar bump having high reliability can be easily and efficiently formed. By the way, recently, the miniaturization of semiconductor devices has been increasingly advanced, and the wiring pitch of the electrodes has become extremely small. For this reason, fine conductive balls used for forming ball bumps on electrodes have become extremely fine as the wiring pitch of the electrodes becomes finer.

In this situation, arranging one semiconductor chip in such a situation involves complicated steps, and has great disadvantages in terms of cost and time. Therefore, before the wafer is cut into individual chips, that is, before the dicing process is performed, ball bumps are arranged on all the electrodes corresponding to a plurality of chips on the wafer.

[0006]

However, when ball bumps are collectively arranged on all the electrodes on a wafer on which a plurality of semiconductor chips are formed, a suction arrangement defect occurs in a ball suction step, There has been a problem that it takes a long time to arrange the suction on the suction head.

There are several factors as a cause of this problem. First, the suction air volume may be extremely large as compared with the case where the conductive balls for one semiconductor chip are sucked. Even if the air volume increases, the jump height of the conductive balls in the ball container is the same as when a single semiconductor chip is sucked, so the speed of the cross wind flowing between the suction head and the container is extremely high. growing. Since the conductive balls placed in the container are concentrated near the center of the container, it is difficult to perform good suction around the suction head, and it takes time to arrange the suction. In particular, since the number of conductive balls placed on the electrode surface reaches hundreds of thousands, when attempting to collectively suck, the jumping balls will concentrate near the center of the container where the balls are stored, Sufficient suction could not be performed in the peripheral portion of the suction head.

[0008] In addition, due to the increase in the air volume, turbulence (vortex) of gas is easily generated between the suction head and the container, and the conductive balls in the container are hardly attracted to the suction head. Was.

Furthermore, since the area of the suction head is large, the suction is insufficient. Further, when a large suction pressure is applied to perform suction on the peripheral portion, a problem has arisen that suction air is increased and the sucked ball is deformed. In addition, since the area of the suction head is increased, the capacity of the suction pump must be increased, and an increase in manufacturing cost cannot be avoided.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. When conductive balls are adsorbed and arranged on a suction head, the conductive balls in a container are provided near the center of the suction head. A conductive ball arrangement transfer apparatus and method capable of suppressing the concentrated suction and shortening the time required for suction, and capable of collectively arranging the conductive balls on a large-area wafer. The purpose is to provide.

[0011]

According to the present invention, there is provided an apparatus for transferring and arranging a conductive ball, comprising: arranging a conductive ball on an array plate by suction; A ball array transfer device that collectively transfers and joins balls, having a permeable material on the back surface of the arranging plate, and performing suction arrangement on the arranging plate through the permeable material, and One or more shielding plates are provided on the rear surface, and by moving the shielding plate up and down, a suction surface for arranging the conductive balls by suction is divided into two or more to suck.

Further, in the conductive ball transfer arrangement apparatus according to the present invention, suction is performed stepwise from an outer peripheral portion or a central portion of the divided suction surface. Further, in the conductive ball transfer arrangement apparatus of the present invention, a pressure sensor and a pressure regulating valve are provided to control a suction pressure. Further, in the conductive ball transfer arrangement device of the present invention, the divided suction surface is divided into a circle or a polygon.

In the method of transferring and arranging conductive balls according to the present invention, after arranging the conductive balls by suction on an array plate, the conductive balls are collectively transferred and bonded to an electrode of an object to be bonded. A ball array transfer method, through a gas-permeable material provided on the back surface of the array plate, while suction arrangement with the array plate, having one or more shielding plate on the rear surface of the gas-permeable material, By moving the shielding plate up and down, a suction surface for arranging the conductive balls by suction is divided into two or more portions and sucked.

Further, in the method for transferring and arranging conductive balls according to the present invention, suction is performed stepwise from an outer peripheral portion or a central portion of the divided suction surface.

According to the present invention, the suction surface of the array substrate is divided into a plurality of regions, and the suction of each suction surface can be controlled independently. The conductive balls can be suctioned toward the center or sequentially from the center to the periphery. Therefore, even if the conductive balls arranged on the electrodes of the large-diameter wafer are sucked at once, they can be arranged properly and reliably.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a conductive ball transfer arrangement apparatus and method according to the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration example of a main part of the apparatus of the present invention. The ball transfer arrangement device of this embodiment has a transfer arrangement head 10 (hereinafter, simply referred to as a head) for conductive balls and a ball container 100. Ball container 10
A plurality of conductive balls 101 are placed in the ball 1, and the ball 1 is sucked using the head 10.
01 (hereinafter, simply referred to as a ball) is collectively adsorbed to the lower portion of the head 10.

In FIG. 1, reference numeral 11 denotes a head body, 12 denotes an array substrate having a large number of suction holes 12a, 13 denotes a permeable material disposed on the back of the array substrate 12, and 14 to 16 denote rear surfaces of the permeable material 13. It is an arranged shielding plate. The array substrate 12 is held on the head body 11 of the head 10 by being vacuum-sucked by a suction system different from the system for sucking the conductive balls 101. The array substrate 12 may be formed integrally with the head main body 11 by a method such as bonding.

A vacuum chamber is formed in the head body 11 inside the array substrate 12. In this example, three shielding plates 1
4 to 16, ie, a circular shielding plate 14 in the center, and a ring or donut-shaped shielding plate 15 and 16 on the outer side thereof
(See FIG. 3). Each of the shielding plates 14 to 16 is vertically movably supported by lifting devices 17 to 19, respectively. The vacuum chamber is evacuated by a vacuum device 20, and a leak valve 21 is connected to an appropriate position. In addition to the pressure regulating valve, a pressure sensor 22 for detecting the pressure in the head body 11 is provided, so that the suction pressure can be appropriately controlled.

By providing the shielding plates 14 to 16 as described above, the suction surface of the array substrate 12 is divided into _three regions, namely, the suction surfaces S _{1 to} S ₃ , and the vacuum chamber is correspondingly formed. It is divided into substantially three vacuum chambers a ₁ to a _3. In each of the vacuum chambers A _{1 to} A ₃ , each of the shielding plates 14 to 16 is moved up and down by the elevating devices 17 to 19 so that the suction surfaces S _{1 to} S ₃ can be suctioned separately and independently.
The ball 101 can be sucked sequentially from the periphery to the center or from the center to the periphery.

When the conductive balls 101 are collectively arranged on the electrodes of a plurality of semiconductor chips formed on a large diameter wafer such as a 200 mm radius wafer, for example, 2,000 l / l
It is necessary to perform suction at a flow rate of about min. Array board 1
The amount of air between the container 2 and the container 100 becomes extremely large, and in particular, the suction in the peripheral region of the arrayed substrate 12 becomes insufficient. However, by performing divided suction, the amount of air when suctioning with one suction surface is reduced. It is possible to prevent the conductive balls 101 from being concentrated near the center of the container 100 and improve the adsorption efficiency on the array substrate 12.

The rear surface (upper side) of the array substrate 12 is covered with a permeable material 13. And the shielding plates 14 to 16
Is not in direct contact with the arrangement substrate 12, and a permeable material 13 is interposed between the shielding plates 14 to 16 and the arrangement substrate 12. The gas permeable material 13 is made of, for example, a porous material, and is a material having a predetermined gas permeability.

For example, as shown in FIG. 2, when one of the adjacent shielding plates 15 and 16 is brought into contact with the permeable material 13 and the other shielding plate 15 is lifted and released from the permeable material 13, the suction surface S with ₃ is substantially closed, the suction surface S ₂ becomes possible suction. In this case, the upper side of the suction surface S ₂ because it is located breathable material 13, it is possible to equalize the suction force in the region of the suction surface S _2.

Various materials can be used as the gas permeable material 13 as long as it is a gas permeable material and has a material strength with respect to suction and transfer. Particularly, a porous porous metal, a honeycomb or a porous material can be used. A material in which a mesh (wire mesh) is attached to the surface of a porous plate, or a material such as a woven fabric such as a cloth or a sponge can be used. In particular,
When a mesh is used on the surface of the porous plate as the air permeable material 13, there is an advantage that the interval between the shield plates 14 to 16 and the array substrate 12 can be accurately maintained. Mesh is a shielding plate 14-1
6 and the array substrate 12 are in point contact with each other, so that good air permeability can be maintained.

Here, in the present invention, the divided suction surface S _{1 is used.}
To S ₃ and the area ratio of the set inlet peripherally thereof downward, to avoid variations over a predetermined amount among the respective divided suction surface,
When suction is performed on each of the suction surfaces S _{1 to} S ₃ , the array substrate 12 and the container 1
The conductive balls 101 are prevented from concentrating near the center of the container 100 due to the crosswind generated between the conductive balls 101 and 00.

In this embodiment, the array substrate 1
Although the example in which the suction surface 2 is divided into three concentric circles as shown in FIG. 3 has been described, the suction surface may be divided into four or more. Also, the shape may be divided into a polygonal shape or a block shape.

As described above, according to the present embodiment,
The suction surface of the array substrate 12 is divided into three regions, and the suction surface S
_Since the suction of S _{1 to} S ₃ can be controlled independently, by sequentially performing suction on the suction surfaces S _{1 to} S ₃ , the array substrate 1
The conductive balls 101 can be sequentially sucked from the periphery to the center or from the center to the periphery. Therefore, even when the conductive balls 101 arranged on the electrode of a large diameter wafer such as a 200 mm radius wafer are sucked at a time, the conductive balls 101 concentrate on the vicinity of the center of the container 100 due to the air volume of the suction. Alternatively, it is possible to prevent a vortex from being generated between the arrangement substrate 12 and the container 100 and insufficient suction to the arrangement substrate 12.

Further, since the air-permeable material 13 is interposed between the array substrate 12 and the shielding plates 14 to 16, the conductive balls 101 are uniformly and reliably formed in the suction holes 12a of the suction surfaces S _{1 to} S _3. Can be arranged by suction. Moreover, setting the area of the suction surface S ₁ to S ₃ in a substantially uniform flow velocity for each suction surface S ₁ to S ₃ between the array substrate 12 and the container 100, to each area of the array substrate 12 The conductive balls 101 can be evenly sucked.

[0028]

According to the present invention, it is possible to prevent the conductive balls in the container from being concentrated near the center of the arrangement plate when the conductive balls are arranged on the arrangement plate. Therefore, it is possible to improve the efficiency of the suction, shorten the time required for the suction, and arrange the conductive ball suction array device capable of collectively arranging the conductive balls on a large-area wafer. It is possible to provide a suction arrangement method.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a main part surface of a ball transfer arrangement device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a part P in FIG.

FIG. 3 is a plan view showing the periphery of a shielding plate according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 transfer arrangement head 11 head main body 12 arrangement substrate 13 air-permeable material 14 to 16 shielding plate 17 to 19 elevating device 20 vacuum device 21 leak valve 100 container 101 conductive ball

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kohei Tatsumi 20-1 Shintomi, Futtsu-shi Nippon Steel Corporation Technology Development Division (72) Inventor Hideji Hashino 20-1 Shintomi, Futtsu-shi Nippon Steel Corporation Technology Development Headquarters (72) Inventor Kazuo Niizuma 58 Shizuya Kogyo Co., Ltd.

Claims (6)

[Claims] 1. A ball array transfer device which, after suction-arranging conductive balls on an array plate, collectively transfers and joins the conductive balls to an electrode of an object to be joined to which the balls are to be joined, A breathable material is provided on the back surface of the arranging plate, and suction arrangement is performed by the arranging plate through the permeable material. At least one shielding plate is provided on a rear surface of the permeable material, and the shielding plate is vertically moved. The conductive ball arrangement transfer device, wherein the suction surface for arranging the conductive balls by suction is divided into two or more and sucked. 2. The conductive ball array transfer device according to claim 1, wherein suction is performed stepwise from an outer peripheral portion or a central portion of the divided suction surface. 3. The conductive ball array transfer device according to claim 1, wherein a pressure sensor and a pressure regulating valve are provided to control a suction pressure. 4. The conductive ball array transfer device according to claim 1, wherein the divided suction surface is divided into a circular shape or a polygonal shape. 5. A ball array transfer method, comprising: after electrically arranging a conductive ball on an array plate, transferring and bonding the conductive ball to an electrode of an object to be bonded to the ball at a time. Through the air-permeable material provided on the rear surface of the array plate, the array is suction-arranged by the array plate, and the air-permeable material has one or more shielding plates on the rear surface, and the shielding plate is moved up and down, 7. The method according to claim 6, wherein a suction surface for arranging the conductive balls by suction is divided into two or more and sucked. 6. The conductive ball array transfer method according to claim 5, wherein suction is performed stepwise from an outer peripheral portion or a central portion of the divided suction surface.