Bonding device

Abstract

In a state in which a first member (7) is placed on the upper surface of a stage (2) and a second member (8) is placed on a ring-shaped jig (4), the ring-shaped jig (4) holds the second member (8) at a position separated from the first member (7). When a pressing jig (6) presses down the second member (8) placed on the ring-shaped jig (4), an elastic body (5) contracts, the ring-shaped jig (4) is lowered, and the second member (8) is pressed against the first member (7) via an adhesive material (9).

Description

Bonding equipment

[0001] The present disclosure relates to a bonding apparatus that bonds two members together.

[0002] Conventionally, a wafer is placed on a glass plate via an adhesive, and the two plates are heated simultaneously and pressed together (see, for example, Patent Document 1). This method can reduce air bubbles that get mixed in the adhesive.

[0003] International Publication No. 2010 / 055730

[0004] However, when the wafer was placed on the glass plate, there was a large error in their positions, and the two would stick together even at room temperature, so it was not possible to adjust their positions after they were placed on the plate.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to obtain a bonding device that can perform high-precision alignment while reducing air bubbles that get mixed into the adhesive.

[0006] The bonding apparatus according to the present disclosure is a bonding apparatus that bonds a first member and a second member together via an adhesive, and includes a base, a stage fixed to the upper surface of the base, a guide fixed to the upper surface of the base and extending upward, a ring-shaped jig arranged on the base so as to surround the stage, whose lateral movement along the upper surface of the base is restricted by the guide and which moves up and down along the guide, an elastic body arranged between the upper surface of the base and the lower surface of the ring-shaped jig, and a pressing jig arranged above the stage, wherein when the first member is placed on the upper surface of the stage and the second member is placed on the ring-shaped jig, the ring-shaped jig holds the second member at a position spaced apart from the first member, and when the pressing jig presses down on the second member placed on the ring-shaped jig, the elastic body contracts, causing the ring-shaped jig to move downward, and the second member is pressed against the first member via the adhesive.

[0007] In the present disclosure, a first member is placed on the upper surface of a stage, and a second member is placed on a ring-shaped jig, which holds the second member at a position spaced apart from the first member. At this point, the first and second members are not attached to each other, so their relative positions can be adjusted. This allows for highly accurate alignment. Furthermore, when the pressing jig presses down on the second member placed on the ring-shaped jig, the elastic body contracts, lowering the ring-shaped jig, and the second member is pressed against the first member with strong force via the adhesive. This reduces air bubbles that may be mixed into the adhesive.

[0008] FIG. 1 is a cross-sectional view showing a bonding apparatus according to embodiment 1. FIG. 2 is a plan view showing a wafer. FIG. 3 is a plan view showing a glass plate. FIG. 4 is a top view showing a bonding apparatus according to embodiment 1. FIG. 5 is a cross-sectional view showing an operation of the bonding apparatus according to embodiment 1. FIG. 6 is a cross-sectional view showing an operation of the bonding apparatus according to embodiment 1. FIG. 7 is a cross-sectional view showing an operation of the bonding apparatus according to embodiment 1. FIG. 8 is a perspective view showing a wafer bonded to a glass plate. FIG. 9 is a cross-sectional view showing a bonding apparatus according to embodiment 2. FIG. 10 is a cross-sectional view showing a modified example of a pressing jig of the bonding apparatus according to embodiment 2. FIG. 11 is a cross-sectional view showing a bonding apparatus according to embodiment 3.

[0009] A bonding apparatus according to an embodiment will be described with reference to the drawings. The same or corresponding components are designated by the same reference numerals, and repeated description may be omitted.

[0010] Embodiment 1. FIG. 1 is a cross-sectional view showing a bonding apparatus according to Embodiment 1. A stage 2 and a guide 3 are fixed to the upper surface of a base 1. The diameter of the upper surface of the stage 2 is 4 inches. The guide 3 is a columnar member extending upward from the upper surface of the base 1. A ring-shaped jig 4 is disposed on the base 1 so as to surround the stage 2. The guide 3 is inserted into a hole in the lower surface of the ring-shaped jig 4. The ring-shaped jig 4 moves up and down along the guide 3, with its lateral movement along the upper surface of the base 1 being restricted by the guide 3. Because there is a gap between the inner wall of the ring-shaped jig 4 and the side wall of the stage 2, the ring-shaped jig 4 does not come into contact with the stage 2 even when it moves up and down. The inner wall of the ring-shaped jig 4 has a mounting portion 4a, a first inclined portion 4b formed below the mounting portion 4a, and a second inclined portion 4c formed above the mounting portion 4a. The mounting portion 4a is a flat surface formed parallel to the upper surface of the stage 2. An elastic body 5 is disposed between the upper surface of the base 1 and the lower surface of the ring-shaped jig 4. The elastic body 5 is, for example, a spring attached to the guide 3. A pressing jig 6 is disposed above the stage 2.

[0011] FIG. 2 is a plan view showing a wafer. Wafer 7 has an orientation flat formed on part of its outer periphery. The diameter of wafer 7 is 4 inches. FIG. 3 is a plan view showing a glass plate. Glass plate 8 also has an orientation flat and its outer shape corresponds to the outer shape of wafer 7, but is larger than wafer 7. The diameter of glass plate 8 is 5 inches.

[0012] 4 is a top view showing the bonding apparatus according to embodiment 1. The upper surface of stage 2 and the inner wall of ring-shaped jig 4 form a cone-shaped pocket. The outer shape of the upper surface of stage 2 corresponds to the outer shape of wafer 7 having an orientation flat. The outer shape of mounting portion 4a of ring-shaped jig 4 corresponds to the outer shape of glass plate 8 having an orientation flat.

[0013] 5 to 7 are cross-sectional views illustrating the operation of the bonding apparatus according to the first embodiment. First, as shown in FIG. 5, the wafer 7 is placed on the upper surface of the stage 2 with the surface coated with the adhesive 9 facing up. The adhesive 9 is, for example, a wax material. The wafer 7 placed on the stage 2 is located within the opening of the ring-shaped jig 4 and does not shift position, eliminating the need for vacuum suction on the stage 2. For example, accurate alignment can be achieved by aligning the upper left corner of the orientation flat of the wafer 7 with the corresponding point on the upper surface of the stage 2. The wafer 7 slides down the first inclined portion 4b of the inner wall of the ring-shaped jig 4 due to its own weight, allowing the wafer 7 to be easily placed on the upper surface of the stage 2.

[0014] The glass plate 8 is placed on a heat plate (not shown) at 110°C and left there for at least one minute, after which the temperature of the heat plate is increased to 150°C and further heated. The glass plate 8 thus preheated is then placed on the mounting portion 4a of the ring-shaped jig 4. For example, accurate alignment can be achieved by aligning the upper left corner of the orientation flat of the glass plate 8 with the corresponding position on the mounting portion 4a of the ring-shaped jig 4. The glass plate 8 slides down the second inclined portion 4c on the inner wall of the ring-shaped jig 4 due to its own weight, allowing the glass plate 8 to be easily placed on the mounting portion 4a.

[0015] In this state, the ring-shaped jig 4 is supported by the elastic body 5 and holds the glass plate 8 at a position spaced apart from the wafer 7. At this point, the wafer 7 and the glass plate 8 are not attached to each other, so the relative positions of the wafer 7 and the glass plate 8 can be adjusted.

[0016] Next, as shown in Figure 6, when the pressing jig 6 presses down on the glass plate 8 placed on the ring-shaped jig 4, the pressing force is transmitted from the glass plate 8 to the ring-shaped jig 4. The elastic body 5 then contracts, causing the ring-shaped jig 4 to lower. As a result, the glass plate 8 is pressed against the wafer 7 via the adhesive 9. Note that if the pressing jig 6 is configured to be pressed down manually, a power source is not required, simplifying the structure of the bonding device. The heat from the glass plate 8 warms and softens the adhesive 9. When the adhesive 9 cools and hardens, the wafer 7 and glass plate 8 are bonded together.

[0017] 7, when the pressing jig 6 stops pressing the glass plate 8 and rises, the ring-shaped jig 4 is lifted by the elastic body 5 and returns to its original position. As a result, the glass plate 8 with the wafer 7 attached also returns to its original position. As a result, the wafer 7 separates from the stage 2.

[0018] 8 is a perspective view showing a wafer 7 attached to a glass plate. The wafer 7 and the glass plate 8 are attached so that the orientation flat of the wafer 7 and the orientation flat of the glass plate 8 are parallel to each other.

[0019] As described above, in this embodiment, with the wafer 7 placed on the upper surface of the stage 2 and the glass plate 8 placed on the ring-shaped jig 4, the ring-shaped jig 4 holds the glass plate 8 at a position spaced apart from the wafer 7. At this point, the wafer 7 and the glass plate 8 are not attached to each other, so the relative positions of the wafer 7 and the glass plate 8 can be adjusted. Therefore, high-precision alignment can be achieved. As a result, misalignment of the backside exposure of the wafer 7 can be reduced.

[0020] When the amount of misalignment between the wafer and the glass plate was measured using a camera in an actual exposure device, the 3σ of the misalignment was 2928 μm when the jig according to this embodiment was not used, whereas when the jig according to this embodiment was used, 3σ was improved to 384 μm. As a result, it was confirmed that 3σ could be kept within the target value (≦500 μm).

[0021] If air bubbles are trapped between the wafer 7 and the glass plate 8, a strong force will be applied to the bulged surface of the wafer 7 during the subsequent surface grinding process, causing cracks and breakage. Furthermore, when the wafer 7 is peeled off from the glass plate 8, the wafer 7 is over-ground, reducing its flatness and preventing it from achieving its original characteristics. In contrast, in this embodiment, when the pressing jig 6 presses down on the glass plate 8 placed on the ring-shaped jig 4, the elastic body 5 contracts, causing the ring-shaped jig 4 to descend, and the glass plate 8 is pressed against the wafer 7 with strong force via the adhesive 9. This reduces air bubbles trapped in the adhesive 9, enabling high-quality bonding. Since the surface of the wafer 7 is smooth and free of surface bulges due to air bubbles, cracks and breakage do not occur during grinding and polishing. Furthermore, uniform grinding and polishing ensure consistent device quality.

[0022] Embodiment 2. Figure 9 is a cross-sectional view showing a bonding apparatus according to embodiment 2. In this embodiment, the width of the contact surface of the pressing jig 6 that contacts the glass plate 8 is smaller than the width of the wafer 7. In addition, the elastic body 5 that holds up the ring-shaped jig 4 is made solid. As a result, when the pressing jig 6 is pressed against the glass plate 8, the glass plate 8 warps. For this reason, the center of the glass plate 8 contacts the wafer 7 first, and the glass plate 8 and the wafer 7 are bonded together while the air between them escapes to the sides. As a result, the amount of air bubbles mixed into the adhesive 9 can be further reduced.

[0023] 10 is a cross-sectional view showing a modified example of the pressing jig of the bonding apparatus according to embodiment 2. The contact surface of the pressing jig 6 that comes into contact with the glass plate 8 has a convex shape that is curved so that the center portion protrudes downward. This makes it even more likely that the glass plate 8 will warp when the pressing jig 6 is pressed against the glass plate 8.

[0024] 11 is a cross-sectional view showing a bonding apparatus according to embodiment 3. In this embodiment, a heating device 10 is provided on the stage 2, and a heating device 11 is provided on the pressing jig 6. The other configurations are the same as those in embodiment 1.

[0025] In the first embodiment, the glass plate 8 is heated in advance by a heat plate, and the residual heat melts the adhesive 9 applied to the wafer 7, bonding the wafer 7 and the glass plate 8 together. In contrast, in the present embodiment, the heating device 10 heats the wafer 7 placed on the stage 2. Furthermore, the heating device 11 heats the glass plate 8 against which the pressing jig 6 is pressed. Therefore, the preliminary step of heating the glass plate 8 in advance can be omitted. Other effects are the same as those of the first embodiment. Note that, since it is sufficient to heat at least one of the wafer 7 and the glass plate 8, only one of the heating devices 10 and 11 may be provided. Furthermore, the heating devices 10 and 11 may be combined with the configuration of the second embodiment.

[0026] REFERENCE SIGNS LIST 1 base, 2 stage, 3 guide, 4 ring-shaped jig, 4a placement portion, 4b first inclined portion, 4c second inclined portion, 5 elastic body, 6 pressing jig, 7 wafer (first member), 8 glass plate (second member), 9 adhesive material, 10, 11 heating device

Claims

1. A bonding apparatus that bonds a first member and a second member together via an adhesive, The foundation and a stage fixed to the upper surface of the base; a guide fixed to an upper surface of the base and extending upward; a ring-shaped jig that is disposed on the base so as to surround the stage, whose lateral movement along the upper surface of the base is restricted by the guide, and that moves up and down along the guide; an elastic body disposed between the upper surface of the base and the lower surface of the ring-shaped jig; a pressing jig disposed above the stage, the first member is placed on an upper surface of the stage, and the second member is placed on the ring-shaped jig, and the ring-shaped jig holds the second member at a position spaced apart from the first member; When the pressing jig presses down on the second member placed on the ring-shaped jig, the elastic body contracts, causing the ring-shaped jig to move down, and the second member is pressed against the first member via the adhesive.

2. an inner wall of the ring-shaped jig has a mounting portion, a first inclined portion formed below the mounting portion, and a second inclined portion formed above the mounting portion; 2. The bonding apparatus according to claim 1, wherein the second member is placed on the placement portion of the ring-shaped jig.

3. the first member is a wafer having an orientation flat, the second member is a glass plate having an orientation flat, the outer shape of the upper surface of the stage corresponds to the outer shape of the wafer; 3. The bonding apparatus according to claim 2, wherein the outer shape of the mounting portion corresponds to the outer shape of the glass plate.

4. 4. The bonding apparatus according to claim 1, wherein a width of a contact surface of the pressing jig that contacts the second member is smaller than a width of the first member.

5. 4. The bonding apparatus according to claim 1, wherein a contact surface of the pressing jig that contacts the second member has a convex shape.

6. 4. The bonding apparatus according to claim 1, further comprising a heating device for heating at least one of the first member and the second member.