JPH06232241A - Board alignment mechanism for semiconductor manufacturing device - Google Patents

Abstract

PURPOSE:To provide a bump board alignment mechanism which is free of variations in the thickness of a bump transferred. CONSTITUTION:A bump board 4 is loaded on the top of a glass stage where bumps 3 are lined up on the board 4. The board 4 is clamped with a clamping plate 28 for a board clamping device which is movable in every direction and capable of following the movement in the height direction. An electrode 2 of a semiconductor element attracted to the bottom of a pressure chip heated with a heating device 17 is aligned with the bumps 3 by ejecting air from an air blowoff port 23 and slightly floating up the board 4 and supplying a vacuumed air to a vacuum hole 26 after the alignment is over and attracting and fixing the board 4. Then, a bonding tool 16 is lowered and pressure force is added so that the bumps may be thermally contact-bonded with the electrode 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting technique for a semiconductor element having a plurality of electrodes, and more particularly to a semiconductor manufacturing apparatus for collectively bonding bumps to electrodes of a semiconductor element by a transfer method.

[0002]

2. Description of the Related Art There is a technique of forming bumps by transfer as a technique capable of collectively joining a semiconductor element having a multi-terminal, narrow-pitch electrode and a bump arranged on a substrate such as glass. First, a device for this technique will be described with reference to FIG.

A glass bump substrate 4 in which a plurality of bumps 3 corresponding to the arrangement of the electrodes 2 on the lower surface of the semiconductor element 1 are arranged in a grid pattern on a positioning metal fitting 5 is provided on both left and inner end surfaces. They are brought into contact with each other and placed on the stage 6, and are adsorbed and fixed by vacuum. Here, the electrode 2 is made of Al, Au, and the bump 3 is made of Al, Au, Cu or the like and is formed by electrolytic plating. A slider 7 and a nut 9 fitted in a feed screw 8 are connected to the stage 6. When the rotary plate 10 facing the operator is rotated, the feed screw 8 rotates and the nut 9 moves in the axial direction of the feed screw 8. The slider 7 slides smoothly on the rail 11, and the stage 6 can move in the front-back direction (hereinafter referred to as the Y direction) with respect to the operator. Similar to the stage 6, a slider and a nut are attached to the lower portion of the X-axis plate 13 to which the support block 12 of the feed screw 8 and the rail 11 are fixed.
Turn to the left and right with respect to the operator (hereinafter referred to as the X direction)
The stage 6 can be moved to. As described above, above the bump substrate 4 which can be moved in a plane, the semiconductor chip 1 having the electrode 2 can be attracted and pressed, and a bonding device that can move up and down is provided. The bonding apparatus includes a pressure chip 15, a bonding tool 16,
It is composed of a heating device 17, a suction hole 18, and a pressurizing device 19. The pressure tip 15 is made of cemented carbide, ceramic, or the like.

Next, with reference to FIG. 4, a state around the bonding apparatus when forming bumps by transfer will be described. The pressure tip 15 and the bonding tool 16 are preheated by the heating device 17. First, pressure tip 1
The semiconductor element 1 is attracted to the lower part of 5 by vacuum. The electrodes 2 and the bumps 3 of the semiconductor element 1 are displayed on a television monitor, and the stage 6 on which the bump substrate 4 is mounted is moved so that the images of the two overlap, and the alignment is performed. After the alignment, the bonding device is lowered to bring the electrode 2 and the bump 3 into contact with each other, and when pressure is applied by the pressure device 19, heat of the pressure chip is transferred to the electrode 2 via the semiconductor element 1 and the electrode 2 and the bump 3 3 is thermocompression bonded. By raising the bonding apparatus and breaking the vacuum, the semiconductor element 1 having the bumps 3 transferred to the electrodes 2 can be taken out.

[0005]

The first problem that occurs when the technique of forming bumps by transfer described above is applied will be described with reference to FIG. If the entire upper surface area of the stage 6 on which the bump substrate 4 is mounted is not configured to be parallel to the semiconductor element adsorption surface of the pressure chip 15, the bump substrate 4
The height of each bump with respect to the semiconductor element adsorbing surface of the pressure chip 15 varies when the semiconductor chip 1 is mounted, and after the semiconductor element 1 is mounted and pressed, the thickness of the crimped bump is not constant. In the conventional method, the bump substrate 4 of the stage 6
The flatness within 0.5 μm must be realized in a wide area of about 125 mm × 125 mm on which the
This is difficult due to problems such as the processing accuracy and assembly accuracy of the stage and the rigidity to withstand pressure.

Next, the second problem will be described with reference to FIG.
As mentioned above, the stage 6 is X for alignment,
It is possible to move in both Y directions, but at the time of this movement, pitching in the longitudinal direction (pitching), shaking in the lateral direction (rolling), etc. occur with respect to the traveling direction. If the movement of the upper surface of the stage 6 is not always performed in parallel with the lower surface of the pressure chip 15, the height of each bump with respect to the semiconductor element suction surface of the pressure chip 15 varies, and the semiconductor element 1 is mounted. After pressurization, the thickness of the bumps that are crimped is not constant.

The present invention solves the above-mentioned problems. Even if the surface of the stage on which the bump substrate is mounted is not flat over a wide area or the stage itself does not move,
The purpose is to keep the height of each bump uniform with respect to the pressure surface of the pressure chip at all times when forming bumps by transfer, while moving the bump substrate for alignment.

[0008]

In order to achieve the above object, the present invention supports a region, in which a bump for one semiconductor element is arranged, from a stage surface on which a bump substrate is mounted with a block of metal or glass. It is possible to move in the XY directions by projecting only a sufficient amount of area and providing a plurality of air blowing holes on the conventional stage surface that is a recess, and ejecting air from the air blowing holes to float the bump substrate. The device is configured to move the substrate with a device capable of gripping the substrate for alignment, and after the alignment is completed, a vacuum hole for sucking and fixing the bump substrate is provided in the block.

[0009]

According to the present invention, with the above-described structure, the block that supports the bump substrate when forming bumps by transfer has a very small area. Even if this area is set parallel to the pressure surface of the pressure chip, the alignment can be adjusted. Is performed by moving the bump substrate itself, so the upper surface of the block, which is parallel to the pressure chip pressure surface, always supports the bonding position of the bump substrate, so it is possible to prevent variations in the bump thickness after transfer. It is a thing.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, the substrate levitation device will be described. Three columns 21 are erected on the mounting plate 20, and on the columns 21, an air supply hole 22 is provided on the side and an air stage 24 having a plurality of air outlets 23 on the upper surface in a lattice shape is placed.
The center of the air stage 24 is hollow,
At the bottom of the hollowed out part, the air stage 2 in the center
The glass holding plate 25 provided with a circular monitoring hole smaller than the central hole 4 is joined. The center hole of the air stage 24 has the same diameter as that of the hole and is 3 mm thicker than the thickness of the air stage 24.
A circular glass stage 27 having a thickness of 0 μm and an upper surface finished to have a flatness of 0.5 μm and further provided with a vacuum hole 26 for adsorbing the bump substrate 4 is attached in parallel to the lower surface of the pressure chip 15 of the bonding apparatus. Here, since the glass stage 27 has a small area of φ40 to φ50 mm, it is possible to easily obtain a flatness of 0.5 μm by performing optical polishing or the like.

Next, the substrate holding device will be described. The grip plate 28 in which the bump substrate 4 is sandwiched by leaf springs provided at the left and right contact portions with the bump substrate 4 has a vertical fulcrum 2 at the front end.
When the bump substrate 4 floats, the grip plate 28 follows the movement and moves up and down with the vertical movement fulcrum 29 as a fulcrum. The vertical motion fulcrum 29 is connected to the moving block 30.

Next, the feed positioning device will be described. On the right side of the upper surface of the mounting plate 20, a support rail 33 in which a rail on which the nut 31 slides and a block supporting the end portion of the feed screw 32 are integrated is attached. The feed screw 32 in which the nut 31 is fitted has both ends supported, and when the rotating plate 34 facing the worker is rotated, the feed screw 32 rotates, and the nut 31 is linearly moved in the Y direction while being supported by the support rail. Move. An L-shaped connection block 35 is attached to the upper surface of the nut 31, and the support rail 3
3, a so-called uniaxial moving device including the feed screw 32, the rotating plate 34, and the nut 31 is arranged in the X direction. The nut that moves in the X direction is connected to the moving block 30, so that the substrate holding device can move in both the X and Y directions.

A bump forming method by transfer using the above apparatus and a bonding apparatus will be described. Pressure chip 15 of bonding apparatus, bonding tool 16
Has been preheated by the heating device 17. Positioning camera 36 installed below the glass stage 27
Thus, the bumps on the bump substrate 4 are projected through the transparent glass stage 27 and the transparent glass bump substrate 4, and the electrode 2 of the semiconductor element 1 adsorbed to the lower surface of the pressure chip 15 of the bonding apparatus is projected on the television monitor. In order to align the two, air is first supplied from the air supply hole 22 and ejected from the air blowing hole 23 to float the bump substrate 4. While watching the television monitor, the rotating plate 34 is rotated to move the bump substrate 4 held by the holding plate 28. When the bumps 3 and the electrodes 2 are aligned with each other on the television monitor, a vacuum is supplied to the vacuum holes 26 to adsorb and fix the bump substrate 4. Then, the bonding device is lowered to bring the electrode 2 and the bump 3 into contact with each other, and when pressure is applied by the pressure device 19, the heat of the pressure chip is transferred to the electrode 2 via the semiconductor element 1 and the electrode 2 and the bump 3 are separated from each other. It is crimped. If you raise the bonding equipment and turn off the vacuum,
The semiconductor element 1 having the bumps 3 transferred to the electrodes 2 can be taken out.

[0015]

As is apparent from the above description, according to the present invention, the plane parallel to the lower surface of the pressure chip always supports the pressure position of the bump substrate, and the moving device for moving the substrate moves. The accuracy does not affect the parallelism between the pressure chip bottom surface and the stage. In addition, it is possible to provide a semiconductor element in which the transferred bumps have uniform thickness.

[Brief description of drawings]

FIG. 1 is a perspective view showing a substrate positioning mechanism of a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a perspective view showing a substrate positioning mechanism of a conventional semiconductor manufacturing apparatus.

FIG. 4 is a side view showing a state around a bonding device during bump transfer.

FIG. 5 is a side view showing a problem of the conventional technique.

FIG. 6 is a side view showing a problem of the conventional technique.

[Explanation of symbols]

 1 semiconductor element 2 electrode 3 bump 4 bump substrate 5 positioning bracket 6 stage 7 slider 8 feed screw 9 nut 10 rotating plate 11 rail 12 support block 13 X-axis plate 14 rotating plate 15 pressure chip 16 bonding tool 17 heating device 18 suction hole 19 Pressurizing device 20 Mounting plate 21 Strut 22 Air supply hole 23 Air blowing hole 24 Air stage 25 Glass holding plate 26 Vacuum hole 27 Glass stage 28 Grip plate 29 Vertical movement fulcrum 30 Moving block 31 Nut 32 Feed screw 33 Support rail 34 Rotation Plate 35 Connection block 36 Camera

Front page continued (72) Inventor Hiroaki Fujimoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Kenzo Hatada, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Koichi Nagao 1006, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. An air supply hole is regularly arranged on an end surface of a plate material such as metal or glass, and a plurality of air blowing holes are regularly arranged on an upper surface,
Substrate levitation device in which a block of metal or glass, in which vacuum holes are regularly arranged on a rectangular or circular upper surface, is fixed to the central portion of the plate material by protruding from the upper surface of the plate material, and adjacent to the substrate levitation device A substrate positioning mechanism for a semiconductor manufacturing apparatus, which comprises a feed positioning device arranged as described above and a substrate gripping device in which a vertical movement fulcrum is provided in a block connected to the feed positioning device and the other end is arranged on the substrate floating device.