GB2400343A - Laminating device - Google Patents

Abstract

A laminating device 70 includes a vacuum grid 73 for holding a glass substrate 12, a holding surface 86A including a flat region 89 and a curved region 90, for holding a laminated element 16 comprised of a wafer 13 and an adhesive tape 15, and moving means 101;102 for moving the holding surface 86A toward the vacuum grid 73. The flat surface region 89 and the curved surface region 90 are arranged so that the distance to the vacuum grid 73 is gradually increased from one side of the holding surface 86A to the other. By the moving means 101;102, the vacuum grid 73 and the holding surface 86A become close to each other in a substantially vacuum chamber. As a result, the glass substrate 12 and the laminated element 16 are gradually laminated to each other while removing a very small amount of air that may be present therebetween to the outside. The device is of use in semi-conductor wafer production.

Description

LAMINATING DEVICE AND LAMINATING METHOD

The present invention relates to a laminating device and a laminating method capable of preventing the air from being trapped in the resultant lamination when first and second members to be laminated having opposing laminating surfaces are laminated to each other.

Conventionally, a substantially disk-lke semiconductor wafer having a multiplicity of circuit patterns formed on its surface (hereinafter, simply referred to as "wafer) is known. The wafer thickness is commonly adjusted by machining the rear surface of the wafer with a grinder or the like after forming the circuit patterns. Due to the recent demand for ultrathin wafers, the wafer thickness, which is conventionally about 300,um, is reduced to about 100,um to about 50,um. Since the wafer is already thin before the machining process, cracks or the like are likely to occur If the wafems machined withoutany pretreatment. Accordingly, the machining process is sometimes conducted after a glass substrate or the like is laminated to the circuit surface of the wafer for reinforcement by using a double- sided adhesive tape.

Moreover, in the dicing process for dicing the wafer into chips, flaws or cracks are likely to be produced as a result of cutting the ultrathin wafer. Accordingly, as in the machining process, the dicing process is also required to be conducted after a 2 0 glass substrate is laminated to the rear surface of the wafer, the surface opposite to the circuit surface, in order to reinforce the ultrathin wafer.

Since the double-sided adhesive tape is flexible, one surface of the double sided adhesive tape can be laminated to one surface of the wafer by warping one side of the adhesive tape and gradually pressing the adhesive tape from the other side 2 5 thereof while removing the air. However, since the wafer and the glass substrate are less flexible than the adhesive tape, it is difficult to laminate the glass substrate to the other surface of the adhesive tape, the surface opposite to that laminated to the wafer, while removing the air by warping one end of either the wafer or glass substrate to a large degree. Therefore, air is likely to be trapped between the wafer and the glass 3 0 substrate, and thus it is likely to be trapped partially in the resultant lamination Such trapped air would hinder the rear surface of the wafer, the surface to be machined, from being held substantially horizontally in the machining process, thereby degrading accuracy of the machining surface of the wafer. Moreover, chips having a distorted cutting surface or the like are likely to be produced in the dicing process.

The present invention is made in view of the above problems, and it is an object of the present invention to provide a laminating device and a laminating method capable of preventing the air from being trapped in the resultant lamination when a first member to be laminated such as glass substrate and a second member to be laminated such as wafer are laminated to each other.

In order to achieve the above object, according to one aspect of the present invention, there is provided a laminating device for laminating first and second members to be laminated having opposing laminating surfaces, including first and second holding means for holding the first and second members to be laminated, 1 o wherein a holding surface of one holding means has a flat surface region tilted so that a distance between the first and second members to be laminated is gradually increased Inward, and a curved surface region connected to the tilted flat surface region so that the distance between the first and second members to be laminated is gradually increased outward, and the moving means makes the first and second holding means close to each other so as to enable the first and second members to be laminated to be gradually laminated to each other from an outer end of the tilted flat surface region toward an outer end of the curved surface region. In this laminating device, a holding surface 2 o of one of the first and second holding means has a curved surface region curved so that a distance to a holding surface of the other holding means is gradually increased from its center toward outside. The moving means makes the respective holding surface of the first and second holding means close to each other so as to enable the first and second members to be laminated to be gradually laminated to each other from their toward outside. The above object is also achieved by this laminating device According to one aspect of the present invention, in a laminating device for laminating first and second members to be laminated having opposing laminating surfaces, a holding surface of one holding means has a tilted flat surface region titled 3 0 so that a distance between the first and second members to be laminated is gradually increased inward, and a curved surface region connected to the tilted flat surface region and curved so that the distance between the first and second members to be laminated is gradually increased outward. The moving means makes the first and second holding means close to each other so as to enable the first and second members to be laminated to be gradually laminated to each other from an outer end of the tilted flat surface region toward an outer end of the curved surface region. This structure also prevents the air from being trapped in the resultant lamination in the operation of laminating the first and second members to be laminated.

A protrusion may be formed approximately at a center of the holding surface of the one holding means so as to slightly protrude from a surrounding region, and the protrusion may be compressively deformable in a process of laminating the first and second members to be laminated to each other. In this structure, the protrusion is compressively deformed while the first and second members to be laminated are being laminated to each other. This reliably prevents the air from being trapped in a region where the air is likely to be trapped.

Preferably, at least one of the members to be laminated has an adhesive on its laminating surface, and the holding means for holding the member to be laminated having the adhesive has heating means for heating the adhesive. This structure enables the first and second members to be laminated to be laminated to each other with the adhesive melted by the heating means. Since the members to be laminated are laminated to each otherwith a softened adhesive, the air present between the first and second members to be laminated can be more easily removed to the outside In the laminating operation.

The first and second members to be laminated may be capable of being laminated to each other in a substantially vacuum space. This more reliably prevents the air from being trapped between the first and second members to be laminated in the laminating operation.

2 5 Fig. 1 is a conceptual sectional side view of a laminating device according to an embodiment; Fig. 2 is a conceptual plan view of the laminating device according to the same embodiment; Fig. 3 is an enlarged cross sectional view of an essential portion when viewed along a plane different from that of Fig. 1; Fig. 4 Is an enlarged view of an elastic member; Fig. 5(A) is an enlarged side view of a lock mechanism, 3 o showing the unlocked state of second holding means; Fig. 5(B) is an enlarged side view of the lock mechanism, showing the locked state of the second holding means, Fig. 6 is an enlarged cross sectional view of an essential portion of the laminating device, showing the state before laminating operation; Fig. 7 is an enlarged cross sectional view of the essential portion of the laminating device, showing the early stage of the laminating operation; Fig. 8 is an enlarged cross sectional view of the essential portion of the laminating device, showing the state during the laminating operation; and Fig.9 is an enlarged cross sectional view of the essential portion of the laminating device, showing the state after completion of the laminating operation.

Hereinafter an embodiment of the present invention will be described with reference to the drawings.

The laminating device 70 is applied to for laminating the glass substrate 12 as a first member to be laminated and the laminated element 16 as a second member to be laminated to each other.

As shown in Figs. 1 to 3, the laminating device 70 includes a lid 72 having a shape of a substantially rectangular plate and pivotable about the right end in Fig.1, a vacuum grid 73 (second holding means) attached to the inner surface of the lid 72 (the lower surface in Fig.1), for sucking and holding the laminated element 16, a table 74 (first holding means) positioned so as to face the vacuum grid 73 when the lid 72 is closed as shown in Fig. 1, for sucking and holding the glass substrate 12, a table support means 76 for supporting the table 74 so that the table 74 can be moved toward and away from the vacuum grid 73, and a plurality of lock mechanisms 77 provided on the outer periphery of the lid 72, for locking the lid 72 in the closed state.

The lid 72 is rotatably supported by a rotation shaft 79 located at the right end in Fig.1.

2 0 A free end of the lid 72, that is, the left end in the figure, is rotatable within about 180 degrees by a motor 80 (see Fig. 2). The lid 72 is held substantially horizontally both in the opened state (Fig. 2) and closed state (Fig. 1).

As shown in Fig. 2, the vacuum grid 73 is shaped approximately like a disk, and is sized to be included within the outer peripheral edge of the lid 72 when viewed 2 5 two-dimensionally. The vacuum grid 73 has substantially the same suction mechanism as that of the vacuum grid 19 of the first embodiment. The vacuum grid 73 has an approximately flat holding surface 73A at the bottom in Fig.3 in order to suck and hold the laminated element 16 thereon. In particular, when the lid 72 is in the closed state as shown in Figs.1 and 3, the laminated element 16 is sucked and held substantially horizontally with the double-sided adhesive tape 15 of the laminated element 16 facing downward. The vacuum grid 73 incorporates heating means 83 (see Fig. 3) such as a heater so that an adhesive of the double-sided adhesive tape 15 on the laminating surface can be heated with the laminated element 16 being sucked and held on the vacuum grid 73. Note that the vacuum grid 73 is slidable in the left-right direction in Fig. 3 along the inner surface of the lid 72. The initial position of the laminated element 16 in the left right direction in the figure is adjustable by an adjust screw 84 capable of advancing toward and retracting from the vacuum grid 73 As shown in fig. 2, the table 74 has an approximately circular shape when viewed from the top. The table 74 has a mechanism capable of sucking and holding the glass substrate 12 on its top surface. As shown in Fig. 3, the table 74 includes a substantially disk-like elastic member 86 formed from silicone rubber, and an elastc member receiving portion 87 formed from stainless steel. The elastic member 86 is located in the upper part of the table 74. The elastic-member receiving portion 87 has a recess 87A for receiving the elastic member 86 approximately without any clearance therebwetween without using an adhesive.

The upper surface of the elastic member 86 serves as a surface 86A for holding the glass substrate 12. As macroscopically shown in Fig. 4, the holding surface 86A has a tilted flat surface region 89 having a substantially linear profile when viewed laterally and a curved surface region 90 having an approximately circular-arc profile when viewed laterally. The tilted flat surface region 89 is titled downward from the outside toward the inside, that is, from left to right in the figure.

The curved surface region 90 is connected to the tilted flat surface region 89 and Is curved downward to the outside, that is, to the right in the figure. Accordingly, before 2 0 lamination, that is, in the state as shown in Fig. 3, the glass substrate 12 held on the table 74 and the laminated element 16 held on the vacuum grid 73 are positioned at a distance gradually Increased from left to right in the figure. The boundary A between the tilted flat surface region 89 and the curved surface region 90 is located on the right hand of the central position M of the elastic member 86 in the left- right direction in 2 5 Fig. 3. In the present embodiment, provided that the elastic member 86 has a diameter of about 250 mm, the boundary A is located about 50 mm to the right of the central position M in Fig. 3. The curved surface region 90 has a radius of curvature of about 1250 mm, and is curved when viewed microscopically. As shown in Figs. 2 and 4, the elastic member 86 has a protrusion 91 approximately at the center C thereof, which 3 o slightly protrudes from the surrounding region of the elastic member 86.

The protrusion 91 is formed by fitting a disk member 93 in a shallow recess 92 formed approximately in the center of the elastic member 86. The disk member 93 has a thickness slightly greater than the depth of the recess 92. Note that the disk-like member 93 may be formed from a film material, paper, rubber or the like As described below, the disk-like member 93 is not particularly limited as long as it is an elastic member that can be compressively deformed while the glass substrate 12 and the laminated element 16 are being laminated to each other. The protrusion 91 may be integral with the elastic member 86.

As shown in Figs. 1 and 2, the table support means 76 includes a platelike table support element 95 for supporting the lower surface of the table 74, a cantilever support member 97 for supporting the table support element 95 in a cantilever manner so that the free end of the table support element 95 is pivotable about the left end thereof in the figure, a plate-like intermediate support element 98 for supporting the cantilever support member 97 with the lower end thereof being fixed thereto, guide members 99 for supporting the intermediate support element 98 so as to allow the intermediate support element 98 to be raised and lowered, a base 100 for supporting the guide members 99, first raising/lowering means 101 for rotating the free end of the table support element 95, and second raising/lowering means 102 for raising and lowering the intermediate support element 98. The first raising/lowering means 101 and the second raising/lowering means 102 form moving means for moving the table 74 toward and away from the vacuum grid 73.

The first raisng/lowering means 101 includes a cam 105 having a top surface 104 tilted upward to the right in Fig.1, a feed screw shaft mechanism 107 for moving 2 o the cam 105 in the horizontal direction, the left-right direction in Fig. 1, by rotation of a motor 106, and a cam roller 108 fixed approximately to the center of the lower surface of the table support element 95 and having its outer peripheral surface in contact with the tilted surface 104. The first raising/lowering means 101 operates as follows: as the cam 105 moves to the left in Fig. 1 by rotation of the motor 106, the 2 5 cam roller 108 moves upward while rolling along the tilted surface 104 As a result, the free end of the table support element 95 is moved toward the vacuum grid 73.

The second raising/lowering means 102 has substantially the same structure as that of the first raising/lowering means 101. The second raising/lowering means 102 includes a cam 111 having a top surface 110 tilted upward to the right in Fig. 1, 3 0 a feed screw shaft mechanism 113 for moving the cam 111 in the horizontal direction by rotation of a motor 112, and a cam roller 114 fixed approximately to the center of the lower surface of the intermediate support element 98 and having its outer peripheral surface in contact with the tilted surface 110. The second raising/lowering means 102 operates as follows: as the cam 111 moves to the left from the position in Fig. 1 by rotation of the motor 112, the cam roller 114 moves upward while rolling along the tilted surface 110, thereby raising the intermediate support element 98. The first raising/lowering means 101 and the table 74 are raised and lowered in this way.

As shown in Figs.1 and 2, the lock mechanisms 77 are provided approximately at regular intervals at three brackets 78, respectively, in order to lock three sides of the lid 72 except the side about which the lid 72 is pivoted (i.e., the right end in Fig. 1).

Each lock mechanism 77 includes a fixed cam 117 having a bottom surface 116 tilted upward to the left in Fig.1, a base block 119 movable in the horizontal direction by a cylinder 118, a pressing plate 120 supported on the base block 119 and capable of being raised and lowered, and capable of pressing the edge region of the lid 72 with its tip, a cam roller 121 rotatably supported by the pressing plate 120 and having its outer peripheral surface in contact with the tilted surface 116, and a spring member 122 for biassing the cam roller 121 against the tilted surface 116.

More specifically, the lock mechanisms 77 operate as follows: when the cylinder 118 moves the pressing plate 120 horizontally to the right in the figure in the unlocked state in Fig. 5(A), the cam roller 121 rolls on the tilted surface 116 by the biassing force of the spring member 122, whereby the pressing plate 120 is lowered toward the base block 119. In the locked state in Fig. 5(B), the tip portion of the pressing plate 120 is pressed against the outer surface of the lid 72.

2 o Hereinafter, effects of the laminating device 70 will be described.

First, with the lid 72 being opened (see Fig. 2), the rear surface of the wafer 13 is sucked and held at a prescribed position on the top surface of the vacuum grid 73 in the figure so that the double-sided adhesive tape 15 of the laminated element 16 faces upward. The glass substrate 12 is sucked and held on the table 74. The lid 72 is then rotated to the closed state in Fig. 1 by the motor 80, and the lock mechanisms 77 lock the lid 72. In this state, as shown in enlarged view in Fig. 6, the glass substrate 12 approximately faces the double- sided adhesive tape 15 of the laminated element 16 at a prescribed distance.

Dnving of the motor 112 of the second raising/lowering means 102 (see Fig. 1) then moves the lower cam 111 in the direction shown by arrow A in Fig. 6, whereby the intermediate support element 98 is raised and thus the first raising/lowering means 101 and the table 74 are raised. As shown in Fig. 7, the left end of 28 the glass substrate 12 located closest to the laminated element 16 first contacts the laminated element 16. The second raising/lowering means 102 continuously raises the table 74, and the motor 106 of the first raising/lowering means 101 (see Fig.1) starts driving the cam 105. The cam 105 thus moves in the direction shown by arrow B in Fig. 7, and the free end of the table 74, the right end in the figure, is rotated upward accordingly.

In this way, with elastic deformation of the holding surface 86A, the glass substrate 12 and the laminated element 16 are gradually laminated from the outer end of the tilted flat surface region 89 toward the outer end of the curved surface region 90 while removing a very small amount of air present therebetween, as shown in Fig. 8. The glass substrate 12 and the laminated element 16 are thus laminated each other approximately completely as shown in Fig. 9. Note that, in the above laminating operation, the adhesive of the double-sided adhesive tape 15 is melted by the heating means 83 (Fig. 3) in order to facilitate removal of the air present between the glass substrate 12 and the laminated element 16 to the outside.

According this embodiment, the air can be reliably prevented from being trapped between the glass substrate 12 and the laminated element 16 in the resultant lamination even when the operation of laminating the glass substrate 12 and the laminated element 16 is not conducted in a vacuum chamber.

Since the glass substrate 12 is held by the elastic member 86, the elastic member 86 is compressively deformed while the glass substrate 12 and the laminated element 16 are being laminated to each other. The elastic member 86 thus absorbs 2 o the load that is intensively applied to a prescribed part of the glass substrate 12 and the wafer 13. As a result, the glass substrate 12 and the wafer 13 can be prevented from being damaged in the laminating operation.

Moreover, the elastic protrusion 91 provided approximately in the centre of the elastic member 86 slightly protrudes therefrom. Since the protrusion 91 is compressively deformed in the laminating operation, the air can be effectively prevented from being trapped in the region around about the centre of the glass substrate 12 where the air is most likely to be trapped.

Moreover, the holding means for holding the member to be laminated having an adhesive has heating means for heating the adhesive. This facilitates removal of the air present between the first and second members to be laminated to the outside in the laminating operation.

Moreover, since the first and second members to be laminated can be laminated in a substantially vacuum space, the air can be more reliably prevented from being trapped between the first second members to be laminated in the laminating operation.

For example, the present invention can be utilized as an apparatus and method for laminating a semiconductor wafer and a glass substrate by using an adhesive tape.

Note that the glass substrate 12 and the laminated element 16 may be laminated to each other with the laminated element 16 being held on the table 74 and the glass substrate 12 being held on the vacuum grid 73.

The elastic member 86 may be formed from a material other than silicone rubber as long as it is compressively deformable in the laminating operation.

The laminating device 70 may have a structure capable of laminating the glass substrate 12 and the laminated element 16 in a substantially vacuum space.

In the above embodiment, the glass substrate 12 and the laminated element 16 are laminated to each other. However, the present invention is not limited to this, and other members having opposing laminating surfaces may be laminated to each other.

The structure of each part of the laminating device of the present invention is not limited to the illustrated example, and various modifications can be made as long as substantially the same effects are obtained.

Claims (4)

1. A laminating device for laminating first and second members to be laminated having opposing laminating surfaces, including first and second holding means for holding the first and second members to be laminated, wherein a holding surface of one holding means has a flat surface region tilted so that a distance between the first and second members to be laminated is gradually increased inward, and a curved surface region connected to the tiled flat surface region so that the distance between the first and second members to be laminated is gradually increased outward and the moving means makes the first and second holding means close to each other so as to enable the first and second members to be laminated to be gradually laminated to each other from an outer end of the tilted flat surface region toward an outer end of the curved surface region.

2. The laminating device according to claim 1, wherein a protrusion is formed approximately at a centre of the holding surface of the one holding means so as to slightly protrude from a surrounding region, and the protrusion is compressively deformable in a process of laminating the first and second members to be laminated i 2 o to each other.

3. The laminating device according to any one of claims 1 or 2, wherein at least one of the members to be laminated has an adhesive on its laminated surface, and the holding means for holding the member to be laminated having the adhesive has 2 5 heating means for heating the adhesive.

4. The laminating device according to any one of claims 1 to 3, wherein the first and second members to be laminated are capable of being laminated to each other in a substantially vacuum space.