JP2001127026A - Method and device for bonding wafer to mounting board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stick plural sheets of wafers, where fused adhesives are applied on the surfaces, equally to a mounting board regardless of order of sticking. SOLUTION: A wafer 4, where an adhesive is applied, is placed on a mounting board. This mounting board 1 is put on a cooling block 2 having cooling action. Then, the mounting board 1 is surrounded and sealed by a chamber 3. There is an elastic sheet 14 on the topside of the chamber 3, and there is a temperature adjusting jacket 19 on the rear side of that elastic sheet 14. An adhesive is cooled and hardened while pressing the wafer 4 by vacuumizing the air within the chamber 3 with a vacuumizer through an exhaust port 25, thereby pulling the elastic sheet 14 to the wafer face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting plate for bonding a wafer to a mounting plate set in the polishing machine when a wafer such as a semiconductor wafer is polished smoothly by a polishing machine. And a wafer bonding method and apparatus.

[0002]

2. Description of the Related Art In the manufacture of semiconductors, a wafer is adhered to a mount plate of a polishing machine with an adhesive in order to polish the wafer smoothly, and a polishing process is performed. It is required to be applied very uniformly. Therefore, the melted adhesive is thinly applied to the wafer, and the adhesive is applied to the mount plate with its adhesive side down.
A method in which a plurality of wafers are bonded by pressing the wafer from the upper surface is generally employed.

In order to improve the accuracy of attaching a wafer, an adhesive is applied in a very thin and clean, for example, about 0.5 μm, and the adhesive layer is formed without containing dust or bubbles. It is necessary to stick the wafer without breaking. Various methods and apparatuses have been proposed in response to such a current situation. For example, a method is known in which a wafer is pressed with a stamp from the upper surface so as to extrude air bubbles so as not to enclose air bubbles in the adhesive layer, or a method of attaching the wafer to a mount plate in a vacuum. However, in these methods, since the adhesive applied to the wafer is still in a fluid state at a high temperature, and there is time until the adhesive is cured after the application, the peripheral portion is lifted after the application. There is a tendency that the wafer attached to the mounting plate first and the wafer attached last have a slight difference particularly in the attached state of the peripheral portion.

[0004]

The problem to be solved by the present invention is as follows.
When a wafer coated with a thin adhesive is attached to a mounting plate, air bubbles are not sealed in the adhesive layer, and even if a plurality of wafers are attached one after another, all wafers are finally attached. Is to provide a method and an apparatus for bonding a wafer to a mounting plate so that the wafer can be stuck in a uniform state.

[0005]

According to the present invention, there is provided a method for placing a wafer coated with a molten adhesive on a mounting plate, pressing the wafer, and bonding the wafer to the mounting plate.
The mounting plate is placed on a cooling block, the periphery of the mounting plate on which the wafer is placed is sealed with a chamber having an elastic sheet, and the elastic sheet is wafered in the chamber.
Pressing against the c surface to cure the adhesive,
A method of bonding a wafer to a mounting plate, characterized by pressing a wafer, is provided. The pressing of the elastic sheet may be performed by evacuating the chamber or by applying a pressurized fluid from the back side of the elastic sheet. The above-mentioned method is also provided in which the temperature can be controlled by the pressurized fluid, and the above-mentioned problem can be solved.

Further, according to the present invention, there is provided an apparatus for mounting a wafer coated with a molten adhesive on a mounting plate and pressing the wafer to bond the wafer to the mounting plate. A cooling block for cooling the adhesive through the mounting plate, and an elastic shell facing the cooling block.
A chamber that has a housing and seals around the mount plate.
And a pressing means for pressing the elastic sheet in the chamber against a wafer on the mounting plate after sealing the mounting plate in the chamber. Further, there is provided the above wafer bonding apparatus having a vacuum device as a pressing means, a pressurized fluid flowing on the back surface of the elastic sheet, a temperature control jacket using the pressurized fluid as a temperature control fluid, and the like. Is resolved.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate one embodiment of the present invention.
A sectional view of a part of the wafer bonding apparatus is shown. FIG.
FIG. 2 shows a state in which the wafer is pressed, and FIG. 2 shows a state before the wafer is pressed. In the apparatus of the present invention, a cooling block for mounting the mounting plate (1) and cooling the mounting plate is provided. (2) and a chamber (3) provided opposite to the cooling block (2).

The mounting plate (1) is a wafer (4)
The wafer (4), which has been heated to, for example, about 80 to 100 ° C. and is thinly coated with a molten adhesive by spin coating, is placed with the adhesive layer facing the mounting plate. Is placed. As this adhesive, various adhesives can be used.
An adhesive that can be applied at a low temperature of about 80 ° C., preferably about 70 ° C. is suitably used. Each wafer is stamped one by one (not shown) when placed on the mounting plate.
, And a plurality of wafers are successively stuck at predetermined positions on the mounting plate in the same manner.

The cooling block (2) has a circulation channel (7) communicating with an inlet (5) and an outlet (6) so that a temperature control medium such as cooling water can be circulated throughout the block. Is formed, and is configured to move up and down by appropriate lifting means such as a fluid pressure cylinder device not shown. The cooling block (2) may be fixedly provided, and the chamber (3) may be moved up and down, or both may be provided in a movable manner. The cooling temperature of the cooling block (2) is adjusted according to the atmosphere at the place of use, but it is preferable that the surface temperature is about 12 to 15 ° C., which does not cause condensation on the surface.

The movement of the cooling block (2) and the like is performed after it is confirmed by the sensor (8) that the mounting plate (1) is mounted on the upper surface, and the upper surface (9) of the mounting plate is
The mounting plate (1) is formed flat so that the mounting plate (1) can be placed in close contact with it, and a heat-resistant and chemical-resistant packing (10) such as a silicon rubber material is closely attached to the lower surface of the chamber (3). It is provided as follows.

The chamber (3) has an annular chamber main body (11) having a size that surrounds the entire outer periphery of the mounting plate (1) in a closed manner. The packing (10) may be provided on the lower surface of the chamber body (11).

A supporting step (12) is formed on the upper surface of the chamber body (11), and the packing (1) is provided on the supporting step (12).
The peripheral edge of the elastic sheet (14) is held through (3) and (13), and the packing (13) of the upper peripheral edge of the elastic sheet (14) is
It is fixed with the presser piece (15) and also has a waterproof function. The elastic sheet (14) is made of a heat-resistant and chemical-resistant plastic material such as Teflon (trade name) having no air permeability, a stainless steel material coated with these resin materials, and other metal materials. The thickness is about 2 to 7 mm, preferably about 3 to 5 mm. The packing (13) does not deform locally when the elastic sheet is drawn or pressed by a vacuum action or a pressurized fluid as described later. By doing so, the sheet hits the entire surface of the wafer as a whole in a substantially parallel state.

The chamber body (11) is supported by a frame (17) via a mounting shaft (16), and the frame (17) and the chamber body (11) are provided between the frame (17) and the chamber body (11). A spring (18) is provided to provide a buffering action when the chamber body (11) is pressed.

Above the chamber (3), a temperature-controlling fluid is circulated to the back side of the elastic sheet (14) so that
A temperature control jacket (19) is provided to control the temperature of (c) and the adhesive. In the embodiment shown in the figure, as the temperature control jacket, a temperature control fluid such as hot or cold water flows in from the inflow port (20), comes into direct contact with the elastic sheet (19), and flows out from the outflow port (21). Although the temperature is adjusted according to the curing temperature of the adhesive, other appropriate temperature adjusting means can be used. The elastic sheet (14) is formed with a boss (22) at the center so that it does not hang down due to the weight of the temperature control fluid, and the central portion is held by bolts (23) to form the temperature control jacket (19). Is maintained to be about 1 to 3 mm, preferably about 1.5 mm. A water leakage prevention cap (24) is provided on the outer periphery of the bolt (23) to prevent water leakage. Further, the temperature-controlling fluid becomes a pressurized fluid if it flows into the temperature-controlling jacket with the outlet closed, and can be a pressing means for pressing the elastic sheet.

The chamber (3) is provided with an exhaust port (25) opened on the side surface, and the port (25) has a vacuum device (pressing means) for pressing an elastic sheet. (Not shown) is connected. The ports (25) are provided at two places in the annular chamber body (11) in the figure, but may be provided at one place or at three or more places depending on the size of the mount plate (1). An appropriate number can be provided. In the vacuum apparatus, a vacuum pressure controller is provided between the port and the vacuum source to adjust the degree of vacuum, and the speed of the vacuum leak can be varied. Also, in consideration of the case where water enters the vacuum line, a trap or the like is installed in the middle of the pipe to detect the liquid level.

The wafer (4) coated with the molten adhesive on one side is placed on the mounting plate (1) and pressed by a stamp (not shown). This mounting plate (1)
After the required number of wafers are placed, they are transferred onto the cooling block (2) by a suitable transport means such as a robot (FIG. 2). When the robot retreats, the cooling block (2) rises and stores the mounting plate (1) in the chamber (3). The packing (10) of the cooling block (2) is in close contact with the lower surface of the chamber (3).
Sealed by (3).

The elastic sheet is pressed against the wafer surface by operating the pressing means. When using a vacuum device as the pressing means, the upper surface (9) of the cooling block (2)
The air between the and the elastic sheet (14) is sucked. At this time, the presence or absence of the mount plate (1) is confirmed by the sensor (26) similar to the sensor (8) provided in the chamber body (11). The sensor (26) is provided so as to make the inside of the chamber main body airtight. Due to the suction, the elastic sheet (14) is attracted to the upper surface of the wafer (4) while being maintained in a substantially flat state, since the peripheral edge is held by the packing (13), and a plurality of wafers are pulled. C) Press the entire surface of (4) uniformly. At this time, the temperature control jacket (1
According to 9), the adhesive layer is also cooled from the elastic sheet side, and at the same time, cooled by the cooling block (2), and the adhesive layer is hardened so as not to flow. Since the curing temperature differs depending on the type of the adhesive, the temperature is adjusted to an optimum temperature with hot and cold water according to the type of the adhesive. At this time, the outlet of the temperature control jacket may be closed so that the temperature control fluid functions as a pressurized fluid, and the elastic sheet may be pressed together with the vacuum device. Further, the elastic sheet may be pressed only by the pressurized fluid without operating the vacuum device.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The elastic sheet (14) is pressed from above a mounting plate (1) on which a wafer (4) coated with a molten adhesive is placed using a vacuum device as a pressing means. Was drawn toward the wafer, and at the same time, the wafer was cooled. Vacuum arrival time is about 30 seconds, leak time is about 10 seconds,
When the total cooling time (pressing time) is set to about 100 seconds, the wafer is pressed by an elastic sheet so that the outer peripheral portion is reliably and uniformly pressed, and the wafer can be stuck uniformly. Was. At this time, the surface temperature of the wafer (4) can be cooled down to about 60 ° C. by the action of the cooling block (2) and the temperature control jacket (19), and the adhesive is cured while the adhesive is cured. I could attach it.

[0019]

The present invention is constructed as described above,
The mount plate on which the c is placed is placed on the cooling block, the periphery of the mount plate is sealed with a chamber having an elastic sheet, and the elastic sheet is pressed against the wafer surface in the chamber. Since the wafer is pressed while the adhesive is being hardened, the adhesive is hardened to such an extent that the adhesive does not flow by mounting and cooling without enclosing bubbles or the like in the adhesive, and mounting. Multiple wafers can be pressed evenly without breaking the thin adhesive layer at a predetermined position on the board, and can be stuck uniformly. Ideal for adhesives by adjusting the temperature from the back side of the elastic sheet In this state, the adhesive can be efficiently bonded, and a highly accurate wafer can be obtained by polishing.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a partial sectional view of a state where a wafer is being pressed.

FIG. 2 is a partial cross-sectional view showing a state before a wafer is pressed.

[Explanation of symbols]

 1 Mounting plate 2 Cooling block 3 Chamber 4 Wafer 14 Elastic sheet 19 Temperature control jacket 25 Exhaust port

Claims (9)

[Claims] In a method of placing a wafer coated with a molten adhesive on a mounting plate and pressing the wafer to bond the wafer to the mounting plate, the mounting plate is placed on a cooling block, and -The periphery of the mount plate on which the c is mounted is sealed with a chamber having an elastic sheet, and the elastic sheet is pressed against the wafer surface in the chamber to cure the adhesive while the adhesive is being cured. A method for bonding a wafer to a mounting plate, which comprises pressing the wafer. 2. The method for bonding a wafer to a mounting plate according to claim 1, wherein the pressing of the elastic sheet is performed by evacuating the chamber and drawing the elastic sheet. 3. The elastic sheet is pressed against the elastic sheet.
3. The method for bonding a wafer to a mount plate according to claim 1 or 2, wherein the method is performed by flowing a pressurized fluid through the back surface of the wafer. 4. The pressurized fluid is a temperature-controlled fluid.
3. The method for bonding a wafer to a mounting plate according to 1. 5. An apparatus for placing a wafer coated with a molten adhesive on a mounting plate and pressing the wafer to bond the wafer to the mounting plate, wherein the mounting plate is placed and placed through the mounting plate. A cooling block for cooling the adhesive by cooling, a chamber having an elastic sheet opposed to the cooling block, and sealing the periphery of the mounting plate; A device for bonding a wafer to a mounting plate, comprising a pressing means for pressing the elastic sheet against a wafer on the mounting plate. 6. A wafer mounted on a mounting plate according to claim 5, wherein the peripheral edge of the elastic sheet is held by packing so as to be pressed substantially over the entire surface of the wafer while maintaining a substantially flat state.
C bonding equipment. 7. The apparatus for bonding a wafer to a mounting plate according to claim 5, wherein said pressing means is a vacuum apparatus for sucking air in the chamber. 8. An apparatus for bonding a wafer to a mounting plate according to claim 5, wherein said pressing means is a pressurized fluid flowing on a back surface of said elastic sheet. 9. The apparatus for bonding a wafer to a mounting plate according to claim 8, wherein the pressurized fluid is a temperature-controlling fluid, and the device has a temperature-controlling jacket through which the temperature-controlling fluid flows.