JPH1116917A - Bump forming method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bump forming method and a bonding apparatus capable of forming a bump efficiently, appropriately and reliably. SOLUTION: Two or more diced semiconductor chips S or printed circuit boards are positioned and arranged at predetermined positions, and bumps using conductive balls are collectively formed. Positioning means for aligning the semiconductor chip S or the electrode portion of the printed circuit board with the conductive balls arranged and held by the ball arranging means is included. The positioning means includes a tray 10 in which a concave groove 11 is formed at a position corresponding to each semiconductor chip S. By using two or more diced semiconductor chips S, a plurality of bumps can be formed at the same time, thereby significantly improving productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming bumps made of minute metal balls on electrodes of a semiconductor chip, printed circuit boards, and the like.

[0002]

2. Description of the Related Art Conventionally, wafer bumps, stud bumps, transfer bumps, and the like have been known as bumps serving as bonding media between electrodes of a semiconductor chip and external circuits. In recent years, as the density of semiconductor devices has increased, the pitch of electrodes has been reduced or the size of bumps has been reduced. A bump forming method in which minute metal balls on which bumps are to be formed are arranged in advance at the same coordinates as electrodes of a semiconductor chip, and the bumps are collectively bonded on the electrodes is being put to practical use.

[0003] For example, the present applicant has already disclosed in
As disclosed in Japanese Patent No. 37675, a metal ball group for one semiconductor chip is collectively picked up from an array substrate on which minute metal balls are arrayed at the same position as the electrode pads of the semiconductor chip. A method of forming a bump, in which the substrate is transported to a joining stage and joined to a portion to be joined, is proposed.

[0004]

In the above-described conventional bump forming method, dicing semiconductor chips are arranged one by one on a bonding stage, and bumps are formed on each semiconductor chip. Therefore, the conventional method has room for improvement in terms of manufacturing efficiency or productivity.

[0005] Conventionally, bumps are formed on one or more semiconductor chips at the wafer stage, that is, before dicing the wafer. However, if a defective semiconductor chip is included in the wafer, bumps are formed not only on good semiconductor chips but also on defective semiconductor chips. Even with this method, it was difficult to achieve high productivity.

The present invention has been made in view of the above circumstances, and has as its object to provide a bump forming method and a bonding apparatus capable of forming a bump efficiently, appropriately, and reliably.

[0007]

According to the bump forming method of the present invention, two or more diced semiconductor chips or printed circuit boards are positioned and arranged at predetermined positions, and bumps are formed at once using conductive balls.

[0008] Further, the bump forming method according to the present invention comprises the steps of:
Arranging and holding conductive balls at positions corresponding to one or more diced semiconductor chips or printed circuit board electrode portions, and aligning the semiconductor chip or printed circuit board electrode portions with the arrayed and held conductive balls. And a step of transferring and joining the conductive balls held in alignment to an electrode portion of a semiconductor chip or a printed circuit board. The method of forming a bump according to the present invention may further include a step of inspecting an arrangement state of the conductive balls held in the arrangement.

Further, the bump forming apparatus according to the present invention has a
Ball arranging means for arranging and holding conductive balls at positions corresponding to one or more diced semiconductor chips or printed circuit board electrode parts; and conductive means arranged and held by the semiconductor chip or printed circuit board electrode parts and the ball arranging means. Positioning means for positioning the ball is provided, and transfer joining means for transferring and joining the conductive balls held in alignment to an electrode portion of a semiconductor chip or a printed circuit board.

Further, in the bump forming apparatus according to the present invention, the positioning means includes a tray having a groove formed at a position corresponding to each semiconductor chip. Further, in the bump forming apparatus according to the present invention, the positioning means includes a stage in which a concave groove is formed at a position corresponding to each semiconductor chip. Further, in the bump forming apparatus according to the present invention,
The positioning means includes two or more stages whose orthogonal and rotational coordinates can be independently controlled. Further, in the bump forming apparatus according to the present invention, the positioning means includes a stage configured to position each semiconductor chip and fix the semiconductor chip at the position by suction.

According to the present invention, two or more diced semiconductor chips are positioned and arranged, and conductive balls are bonded to these semiconductor chips to form bumps. By selecting and using a semiconductor chip after dicing and a good product, the productivity can be remarkably improved. Incidentally, when bumps are formed on two or more semiconductor chips before dicing at the wafer stage, it is difficult to increase production efficiency because defective semiconductor chips are included.

When two or more semiconductor chips after dicing are positioned and arranged on a predetermined stage, the semiconductor chips can be accurately positioned relative to each other by the positioning means. Thus, the alignment between the ball arranging means and the conductive balls can be performed efficiently and accurately.

As an example of the positioning means, a semiconductor chip or a printed board is placed in a groove larger than a semiconductor chip or a printed board formed on the tray or the stage, and the tray or the stage is appropriately inclined. Thus, the positioning of the semiconductor chip or the like can be performed at the corners of the concave groove.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a bump forming method and apparatus according to the present invention will be described below with reference to the drawings. In this embodiment, two or more diced semiconductor chips are positioned and arranged at predetermined positions, and bumps using conductive balls are collectively formed. The wafer W is diced as shown in FIG. The diced semiconductor chip S is positioned and arranged at a predetermined position on the stage 1 by the transfer head 100 as shown in FIG. The transfer head 100 arranges only the good semiconductor chips S selected from the diced wafers W on the stage 1. At this time, if two or more transport heads 100 are used, two or more semiconductor chips S can be quickly arranged.

Further, as shown in FIG. 3, a ball array head 200 is provided as a ball array means for arraying and holding conductive balls B on which bumps are to be formed. Array head 200
Is provided with an array substrate 201 having a large number of ball array holes 201a corresponding to the electrode portions of two or more semiconductor chips S, and is evacuated via a suction chamber 202. A vacuum pump 203 as a vacuum suction source is connected to the suction chamber 202, and the ball arrangement head 200 arranges and holds the conductive balls B in the ball arrangement holes 201a as shown in the drawing.

The ball array head 200 is supported by a moving transport mechanism (not shown) so as to be movable in the horizontal and vertical directions as shown in FIG. Ball arrangement head 200 in which conductive balls B are arranged and held in a supply section of conductive balls B
Is transported to the stage 1 by this moving transport mechanism. The ball array head 200 is configured to join the conductive balls B to the corresponding semiconductor chips S while being aligned with the semiconductor chips S positioned and arranged at predetermined positions on the stage 1.

The semiconductor chip S is transported by the transport head 100.
Is arranged on the stage 1, a tray 10 having a concave groove 11 formed at a position corresponding to each semiconductor chip S as shown in FIG. 5 is used. The tray 10 functions as a positioning unit for positioning the electrode portions of the semiconductor chip S and the conductive balls B arranged and held by the ball arrangement head 200. The concave groove 11 is formed with high dimensional accuracy between itself and each other, so that the semiconductor chip S can be accurately positioned.

The concave groove 11 formed in the tray 10 preferably has a guide portion 12 formed in an appropriate tapered shape as shown in FIG. By providing such a guide portion 12, the semiconductor chip S can be set smoothly in the concave groove 11. Note that these concave grooves 11 and guide portions 12 may be formed in advance without using the separate tray 10, that is, in the stage 1 itself.

As described above, two or more diced semiconductor chips S are arranged on the stage 1. FIG. 7 shows an example of the arrangement of the semiconductor chips S in that case. The four semiconductor chips S1 to S4 are squared (FIG. 7).
(A)) or four semiconductor chips S1 to S4 are arranged in a row (FIG. 7B). The arrangement is not limited to the illustrated arrangement example, and two or more diced semiconductor chips S may be positioned and arranged at predetermined positions.

Alternatively, when arranging two or more semiconductor chips or printed boards on the tray 10 or the stage 1, for example, as shown in FIG. 8, a concave groove larger than the size of the target semiconductor chip S or printed board or the like. 11 is formed. First, as shown in FIG.
The semiconductor chips S1 to S4 or the printed circuit board are placed as described above, and the tray 10 or the stage 1 is appropriately inclined to align the semiconductor chips S1 to S4 at the corners of the concave groove 11 (FIG. 8B )).

When aligning the semiconductor chips S1 to S4 and the like in the concave groove 11, as shown in FIG.
1 to S4 are suction-fixed from the back side by suction holes 13.
Then, while maintaining this positioning state, the tray 10 or the stage 1 is returned to the original state position as shown in FIG.

On the other hand, the ball arrangement head 200 descends at a predetermined timing into the container 20 from above the container 20 for accommodating the conductive balls B for forming bumps in the conductive ball B supply section (FIG. 9). (A)). further,
As shown in FIG. 9B, the conductive balls B are arranged and held in the ball arrangement holes 201a of the arrangement substrate 201 by evacuating through the suction chamber 202. The array substrate 20
When the conductive balls B are adsorbed to the one ball arrangement hole 201a, a measure is taken such that the conductive balls B are floated in the container 20 by vibrating the container 20 to facilitate the adsorption.

As shown in FIG. 9C, one conductive ball B is sucked into each ball array hole 201a of the array substrate 201. Here, when adsorbing the conductive balls B, the arrangement substrate 2
01 to remove the extra balls from each ball arrangement hole 201a.
Further includes a surplus ball removing means for adsorbing one conductive ball B. The surplus ball removing means can be configured, for example, to apply a minute vibration to the array substrate 201 so that the extra conductive balls B are separated from the array substrate 201.

Further, the arrangement state of the conductive balls B arranged and held on the arrangement substrate 201 as described above is inspected.
In this case, as shown in FIG. 9C, the arrangement state of the conductive balls B can be photographed from below the arrangement substrate 201 by the image recognition means (TV camera) 30, and the quality of the arrangement state can be confirmed.

The ball array head 200 in which the conductive balls B are properly arranged and held is mounted on the semiconductor chip S on the stage 1.
, And the conductive balls B can be joined to the electrodes of the corresponding semiconductor chips S.

The two or more diced semiconductor chips S are positioned and arranged on the stage 1, and conductive balls B are bonded to these semiconductor chips S to form bumps. By using non-defective semiconductor chips S after dicing, defective products can be removed from the manufacturing process, and productivity can be significantly improved.

Another aspect of the positioning means in the above embodiment includes two or more stages whose orthogonal (xy) and rotational coordinates (θ) can be independently controlled. In this case, one semiconductor chip is positioned and arranged on one stage to join the conductive balls B, and the next semiconductor chip is positioned and arranged on the next stage to form the conductive balls B.
And this operation is repeated as many times as necessary. As still another aspect of the positioning means, the positioning means includes a stage configured to position each semiconductor chip and fix the semiconductor chip at the position.

In the above embodiment, the example in which the bumps are formed on the electrodes of the semiconductor chip has been described. According to the invention, the two or more semiconductor chips need not be of the same type, but may include different types of semiconductor chips. The present invention is not limited to the case of the semiconductor chip, but can be applied to, for example, a printed circuit board or the like, and the same operational effects as those of the above embodiment can be obtained.

[0029]

As described above, according to the present invention, when this kind of bump is formed, by using two or more diced semiconductor chips, a plurality of bumps are simultaneously formed to improve productivity. It can be significantly improved. In this case, since a non-defective semiconductor chip can be selected, the non-defective product rate can be increased to nearly 100%, and the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a wafer dicing step in the present invention.

FIG. 2 is a perspective view showing a step of positioning and arranging a semiconductor chip after dicing in the present invention.

FIG. 3 is a diagram showing a configuration example of a ball array head according to the present invention.

FIG. 4 is a diagram showing a state of moving and transporting a ball array head according to the present invention.

FIG. 5 is a diagram showing a configuration example of a tray for a semiconductor chip according to the present invention.

FIG. 6 is a view showing a configuration example of a concave groove of the tray according to the present invention.

FIG. 7 is a plan view showing an example of the arrangement of semiconductor chips on a stage according to the present invention.

FIG. 8 is a perspective view showing an example of positioning means for a semiconductor chip or the like on a stage or the like in the present invention.

FIG. 9 is a view sequentially showing a ball arrangement step of the ball arrangement head according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 stage 10 tray 11 concave groove 12 guide section 20 ball container 100 transfer head 200 ball array head 201 array substrate 201a ball array hole 202 suction chamber 203 vacuum pump B conductive ball S semiconductor chip

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Toshiharu Kikuchi 3-35-1 Ida, Nakahara-ku, Kawasaki-shi Nippon Steel Corporation Technology Development Division

Claims (8)

[Claims] 1. A bump forming method comprising: positioning at least two diced semiconductor chips or printed boards at predetermined positions; and forming bumps using conductive balls at a time. 2. A step of arranging and holding conductive balls at positions corresponding to two or more diced semiconductor chips or electrode parts of a printed board; and an electrode part of the semiconductor chip or printed board; A step of aligning conductive balls with each other, and a step of transferring and bonding the conductive balls held in alignment to an electrode portion of a semiconductor chip or a printed circuit board. 3. The bump forming method according to claim 2, further comprising a step of inspecting an arrangement state of the conductive balls held in the arrangement. 4. A ball arranging means for arranging and holding conductive balls at positions corresponding to two or more diced semiconductor chips or electrode parts of a printed circuit board; and an electrode part of the semiconductor chip or printed circuit board and the ball arranging means. Positioning means for aligning the aligned and held conductive balls, Transfer joining means for transferring and joining the aligned and held conductive balls to an electrode portion of a semiconductor chip or a printed circuit board,
A bump forming apparatus comprising: 5. The bump forming apparatus according to claim 4, wherein said positioning means includes a tray having a groove formed at a position corresponding to each semiconductor chip. . 6. The bump forming apparatus according to claim 4, wherein said positioning means includes a stage in which a concave groove is formed at a position corresponding to each semiconductor chip. 7. The bump forming apparatus according to claim 4, wherein said positioning means includes two or more stages whose orthogonal and rotational coordinates can be independently controlled. 8. The bump forming apparatus according to claim 4, wherein said positioning means includes a stage configured to position each semiconductor chip and to fix said semiconductor chip by suction. Bump forming equipment.