JP7842727B2 - Sheet material application device and sheet material application method - Google Patents

Description

This invention relates to a sheet material application apparatus and a sheet material application method used for applying sheet materials, such as adhesive tape or adhesive film, to a workpiece having a curved surface.

Traditionally, flat wafers or substrates were used as workpieces to which sheet materials, intended for circuit protection and other purposes, were attached. However, in recent years, workpiece shapes have diversified, and sheet materials are sometimes attached to curved surfaces, such as concave surfaces.

When applying a sheet material to a curved surface of a workpiece, wrinkles may form in the sheet material or air bubbles (voids) may be introduced between the workpiece and the sheet material, due to factors such as the sheet material contacting the outer periphery of the curved surface first. For example, if the sheet material contacts the shallower recessed areas on the outer periphery of a concave curved surface before contacting the deeper recessed areas in the center, wrinkles or air bubbles will form when the sheet material is applied to the entire curved surface of the workpiece. To avoid a decrease in the adhesion accuracy of the sheet material to the workpiece due to such wrinkle formation or air bubble incorporation, a sheet material application device that deforms the sheet material using a rod-shaped deformation member has been proposed (see Patent Document 1).

In this type of apparatus, a rod-shaped projection is brought into contact with a portion of the sheet material inside a vacuum chamber, forming a projection that extends toward the curved surface of the workpiece. By bringing the projection closer to the workpiece with the projection formed, the projection is brought into contact with, for example, a deep portion of the workpiece's curved surface. Then, by creating a pressure difference between the upper and lower spaces within the vacuum chamber, which is separated by the sheet material, the sheet material is adhered to the curved surface of the workpiece, spreading outwards from the point of contact with the projection. In this case, since the sheet material is adhered first to the deeper recessed areas of the workpiece, the formation of wrinkles or air bubbles can be more reliably avoided.

Japanese Patent Publication No. 2020-188216

However, the conventional device described above has the following problem: Specifically, when a sheet material is attached to a curved workpiece, it is difficult to ensure uniform properties of the sheet material across the entire workpiece. In other words, it was found that variations in the sheet material's properties occur across the entire workpiece.

The following are possible causes for variations in the properties of such sheet materials. Specifically, in the conventional configuration described in Patent Document 1, when a thin, rod-shaped projection member is applied to form a projection on a portion of the sheet material, the sheet material in the area where the projection is formed is stretched and thinned. In other words, the stretching rate of the sheet material differs significantly between the area where the projection is formed and the area where the projection is not formed. In sheet materials, differences in stretching rate can change the properties of the sheet material. That is, the properties of the attached sheet material will differ significantly between the area of the workpiece to which the sheet material with the projection is attached and the area to which the sheet material without the projection is attached, due to variations in stretching rate. As a result, while the requirement to prevent the occurrence of wrinkles or air bubbles can be met, it becomes difficult to meet the requirement of achieving uniform properties throughout the entire workpiece to which the sheet material is attached.

This invention has been made in view of these circumstances, and its main objective is to provide a sheet material application method and sheet material application apparatus that can apply a sheet material to a curved workpiece with high precision and reduce variations in the properties of the sheet material across the entire surface of the workpiece.

To achieve this objective, this invention has the following configuration.
That is, a sheet material application device for applying a sheet material to a curved surface of a workpiece having a curved surface,
A holding table that holds the workpiece with the side having the curved surface facing upward,
The sheet material is sandwiched between the upper and lower chambers, thereby dividing the space into an upper space and a lower space via the sheet material, with the lower space containing a chamber for housing the holding table,
A supply mechanism for supplying the sheet material,
A deformation member having a contact surface, which deforms the sheet material by bringing the contact surface into contact with the sheet material,
A deformation member moving mechanism moves the deformation member closer to the holding table while the deformation member is in contact with the sheet material, and brings the sheet material, which has been deformed by the deformation member, closer to or in contact with at least a part of the curved surface of the workpiece.
A vacuum mechanism for reducing the pressure of at least the lower space among the upper and lower spaces,
The lower space is depressurized by vacuum, and the sheet material is in close proximity to or in contact with a part of the curved surface of the workpiece. The attachment mechanism attaches the sheet material to the curved surface of the workpiece by the differential pressure formed between the upper space and the lower space within the chamber partitioned by the sheet material.
Equipped with,
The deformable member is characterized in that the curvature of the contact surface is greater than the curvature of the curved surface in the workpiece.

(Function and Effect) This configuration provides a sheet material application device for attaching a sheet material to the curved surface of a workpiece, comprising a chamber and a deformation member. Specifically, the sheet material is sandwiched between the upper and lower chambers while the workpiece with the curved surface is held by a holding table, thereby dividing the internal space of the chamber into an upper and lower space via the sheet material. At this time, the holding table holding the workpiece is housed in the lower space of the chamber. The sheet material sandwiched between the upper and lower chambers is deformed by contact with the contact surface of the deformation member. The sheet material, deformed by the deformation member, approaches or contacts a portion of the curved surface of the workpiece, and is further adhered to the curved surface of the workpiece by the differential pressure formed within the chamber.

In this configuration, the curvature of the contact surface of the deformable member is configured to be greater than the curvature of the curved surface of the workpiece. Therefore, when attaching the sheet material deformed by the deformable member to the curved surface of the workpiece, tension caused by unexpected contact of the sheet material with the workpiece's edges, for example, can be prevented. This tension can cause wrinkles and air bubbles when attaching the sheet material to the curved surface. Consequently, the formation of wrinkles and air bubbles in the sheet material attached to the curved surface of the workpiece can be avoided, allowing for precise and tight adhesion of the sheet material to the workpiece's curved surface.

Furthermore, by making the curvature of the contact surface of the deformable member greater than the curvature of the curved surface of the workpiece, the area of the sheet material that contacts the contact surface and deforms becomes larger. This reduces the degree of stretching of the sheet material per unit area in that region. As a result, the variation in the stretching rate of the sheet material is reduced across the entire sheet material attached to the curved surface of the workpiece, making it possible to achieve uniform characteristics throughout the entire workpiece to which the sheet material is attached.

Furthermore, in the invention described above,
The cross-sectional width a of the contact surface in the deformable member and the cross-sectional width b of the curved surface in the workpiece are
It is preferable that the following conditions be met.

(Effects) With this configuration, the cross-sectional width a of the contact surface in the deformable member and the cross-sectional width b of the curved surface in the workpiece are configured to satisfy the condition a ≥ 0.3 × b. Because the deformable member is configured so that its cross-sectional width satisfies this condition, the area of the sheet material that contacts the contact surface and deforms is further widened, thus reducing the degree of stretching of the sheet material per unit area in that region. As a result, the variation in the stretching rate of the sheet material is reduced across the entire sheet material attached to the curved surface of the workpiece, making it possible to achieve uniform characteristics throughout the entire workpiece to which the sheet material is attached.

Furthermore, in the invention described above, it is preferable to provide a pressure adjustment mechanism that adjusts the air pressure in the lower space to be higher than the air pressure in the upper space, and, while the pressure adjustment mechanism is adjusting the air pressure in the lower space to be higher than the air pressure in the upper space, the deformation member moving mechanism brings the sheet material, which has been deformed by the deformation member, close to or in contact with at least a portion of the curved surface of the workpiece.

(Function/Effect) This configuration allows for more reliable separation of the sheet material from the workpiece by adjusting the air pressure in the lower space to be higher than that in the upper space. Therefore, during the process of deforming the sheet material with the deformation member and the process of bringing the deformed sheet material close to or into contact with the curved surface of the workpiece, the unintended contact of the sheet material with the workpiece's periphery can be more reliably avoided. This ensures that the formation of wrinkles and bubbles caused by unexpected contact between the sheet material and the workpiece is reliably prevented, thereby improving the adhesion accuracy of the sheet material to the curved surface of the workpiece.

Furthermore, in the invention described above, it is preferable that the attachment mechanism adheres the sheet material to the curved surface of the workpiece by the differential pressure formed between the upper and lower spaces within the chamber partitioned by the sheet material, while the sheet material is in contact with a portion of the curved surface of the workpiece.

(Function/Effect) With this configuration, differential pressure is generated after the portion of the sheet material deformed by the deformation member contacts the curved surface of the workpiece. In this case, the timing of the deformation of the entire sheet material within the chamber due to the differential pressure is reliably after the timing of contact between the sheet material deformed by the deformation member and the curved surface of the workpiece. Therefore, it is possible to more reliably avoid situations where the sheet material other than the deformed portion contacts the curved surface of the workpiece before the deformed portion contacts the curved surface of the workpiece. This thus more reliably prevents the occurrence of wrinkles, bubbles, and other defects caused by unexpected contact of the sheet material.

Furthermore, in the invention described above, it is preferable that the deformable member has an elastic body on its contact surface, and that the sheet material is deformed by bringing the elastic body into contact with the sheet material.

(Function and Effect) With this configuration, when the sheet material in the deformed portion of the contact surface comes into contact with the curved surface of the workpiece, the elastic body provided on the contact surface appropriately deforms elastically according to the shape of the curved surface of the workpiece. This elastic deformation prevents excessive pressing force from being applied from the deformed member to the workpiece when the deformed member moves closer to the holding table that holds the workpiece. Therefore, it is possible to more reliably avoid situations in which the workpiece is deformed or damaged due to excessive pressure on the workpiece by the deformed member.

Furthermore, in the invention described above, the workpiece has a concave curved surface, and it is preferable that the deformation member movement mechanism brings the sheet material, deformed by the deformation member, into proximity to or contact with the region including the deepest part of the concave curved surface.

(Effects) In this configuration, the portion of the sheet material deformed by the deformation member approaches or contacts the region containing the deepest part of the concave curved surface of the workpiece. In conventional configurations, the deepest part of the concave curved surface is the last place the sheet material is attached, and it is a part where air bubbles and other defects are likely to occur, and where it is difficult to attach the sheet material accurately. In the configuration according to the present invention, since the deformed portion of the sheet material approaches or contacts the deepest part of the concave curved surface, the sheet material is attached to the curved surface of the workpiece in a way that it radiates outward from the deepest part during the attachment process. Therefore, it is possible to reliably avoid the occurrence of air bubbles and other defects in areas where attachment errors are likely to occur in conventional methods, and the sheet material can be attached to the curved surface of the workpiece with high precision.

Furthermore, in the invention described above, it is preferable that the sheet material comprises a sheet piece having a predetermined shape corresponding to the shape of the workpiece and a long carrier tape for holding the sheet piece.

(Function/Effect) In this configuration, the sheet material comprises a sheet piece having a predetermined shape corresponding to the shape of the workpiece, and a long carrier tape that holds the sheet piece. In this case, during the contact process, a portion of the sheet piece and the carrier tape are deformed by the deformation member, and the deformed portion of the sheet material comes into contact with the curved surface of the workpiece.

In this case, a large force acts only on the deformed portion of the sheet piece, preventing displacement of the sheet piece when bringing the sheet material closer to the workpiece. Therefore, the sheet piece can be precisely brought into contact with the target position on the curved surface of the workpiece, thereby improving the accuracy of the position where the sheet piece is attached to the curved surface of the workpiece.

To achieve this objective, this invention may have the following configuration.
In other words, a method for attaching a sheet material to a curved surface of a workpiece having a curved surface, in the internal space of a chamber comprising an upper chamber and a lower chamber,
A workpiece holding process in which the workpiece is held on a holding table with the side having the curved surface facing upwards,
A process of forming upper and lower spaces, wherein the holding table is housed and the sheet material is sandwiched between the upper and lower chambers, thereby dividing the internal space of the chamber into a lower space where the workpiece is placed with the curved side facing upward, and an upper space facing the lower space with the sheet material in between.
The supply process for supplying the aforementioned sheet material,
A deformation process in which a deformable member having a contact surface is brought into contact with the sheet material to deform the sheet material,
A deformation member movement process in which the deformation member is moved closer to the holding table while the deformation member is in contact with the sheet material, and the sheet material deformed by the deformation member is moved closer to or in contact with at least a part of the curved surface of the workpiece,
A depressurization process that reduces the pressure of at least the lower space of the upper space and the lower space to a vacuum,
The lower space is depressurized by vacuum, and the sheet material is in close proximity to or in contact with a part of the curved surface of the workpiece. The application process involves attaching the sheet material to the curved surface of the workpiece by the differential pressure formed between the upper space and the lower space within the chamber partitioned by the sheet material.
Equipped with,
The curvature of the contact surface in the deformable member is configured to be greater than the curvature of the curved surface in the workpiece.Therefore, the cross-sectional width a of the contact surface in the deformable member and the cross-sectional width b of the curved surface in the workpiece are

The conditionsIt is characterized by the following features.

(Function and Effect) According to this configuration, in a sheet material application device for attaching a sheet material to the curved surface of a workpiece, the sheet material is sandwiched between the upper and lower chambers while the workpiece is held on a holding table, thereby dividing the internal space of the chamber into an upper and lower space via the sheet material. At this time, the holding table that holds the workpiece is housed in the lower space of the chamber. The sheet material sandwiched between the upper and lower chambers is deformed by the contact surface of the deformation member. The sheet material, deformed by the deformation member, approaches or contacts a portion of the curved surface of the workpiece, and is further attached to the curved surface of the workpiece by the differential pressure formed within the chamber.

In this configuration, the curvature of the contact surface of the deformable member is configured to be greater than the curvature of the curved surface of the workpiece. Therefore, when attaching the sheet material deformed by the deformable member to the curved surface of the workpiece, tension caused by unexpected contact of the sheet material with the workpiece's edges, for example, can be prevented. This tension can cause wrinkles and air bubbles when attaching the sheet material to the curved surface. Consequently, the formation of wrinkles and air bubbles in the sheet material attached to the curved surface of the workpiece can be avoided, allowing for precise and tight adhesion of the sheet material to the workpiece's curved surface.

Furthermore, by making the curvature of the contact surface of the deformable member greater than the curvature of the curved surface of the workpiece, the area of the sheet material that contacts the contact surface and deforms becomes larger. This reduces the degree of stretching of the sheet material per unit area in that region. As a result, the variation in the stretching rate of the sheet material is reduced across the entire sheet material attached to the curved surface of the workpiece, making it possible to achieve uniform characteristics throughout the entire workpiece to which the sheet material is attached.

According to the sheet material application apparatus and method of the present invention, a sheet material application apparatus for applying a sheet material to the curved surface of a workpiece comprises a chamber and a deformation member. Specifically, while the workpiece with a curved surface is held on a holding table, the sheet material is sandwiched between the upper and lower chambers, thereby dividing the internal space of the chamber into an upper and lower space via the sheet material. At this time, the holding table holding the workpiece is housed in the lower space of the chamber. The sheet material sandwiched between the upper and lower chambers is deformed by contact with the contact surface of the deformation member. The sheet material deformed by the deformation member approaches or contacts a portion of the curved surface of the workpiece, and is further applied to the curved surface of the workpiece by the differential pressure formed within the chamber.

In this configuration, the curvature of the contact surface of the deformable member is configured to be greater than the curvature of the curved surface of the workpiece. Therefore, when attaching the sheet material deformed by the deformable member to the curved surface of the workpiece, tension caused by unexpected contact of the sheet material with the workpiece's edges, for example, can be prevented. This tension can cause wrinkles and air bubbles when attaching the sheet material to the curved surface. Consequently, the formation of wrinkles and air bubbles in the sheet material attached to the curved surface of the workpiece can be avoided, allowing for precise and tight adhesion of the sheet material to the workpiece's curved surface.

Furthermore, by making the curvature of the contact surface of the deformable member greater than the curvature of the curved surface of the workpiece, the area of the sheet material that contacts the contact surface and deforms becomes larger, thus reducing the degree of stretching of the sheet material per unit area in that region. As a result, the variation in the stretching rate of the sheet material is reduced across the entire sheet material attached to the curved surface of the workpiece, making it possible to achieve uniform characteristics across the entire workpiece to which the sheet material is attached. In other words, it is possible to attach the sheet material to a workpiece with a curved surface with high precision while reducing variations in the characteristics of the sheet material across the entire surface of the workpiece.

This is a front view showing the basic configuration of the sheet material application device according to Example 1. This is a perspective view showing a workpiece according to Example 1. (a) is a perspective view showing the shape of a workpiece having a curved surface according to Example 1, (b) is a longitudinal cross-sectional view showing the shape of a workpiece having a curved surface according to Example 1, and (c) is a perspective view showing another example of a workpiece having a curved surface. This is a cross-sectional view showing the structure of the sheet material according to Example 1. This is a side view illustrating the main parts of the sheet material application device according to Example 1. This is a plan view illustrating the main parts of the sheet material application device according to Example 1. This is a side view illustrating the main parts of the sheet material application device according to Example 1. This diagram illustrates the configuration of the chamber according to Example 1. This is a longitudinal cross-sectional view illustrating the relationship between the cross-sectional width of the contact surface in the deformable member according to Example 1 and the cross-sectional width of the curved surface in the workpiece. This is a longitudinal cross-sectional view illustrating the relationship between the curvature of the contact surface in the deformable member according to Example 1 and the curvature of the curved surface in the workpiece. This is a flowchart illustrating the operation of the sheet material application device according to the embodiment. (a) is a flowchart of the operation according to Embodiment 1, and (b) is a flowchart of the operation according to Embodiment 2. This is a diagram illustrating step S1 according to Example 1. This is a diagram illustrating step S2 in Example 1. This is a diagram illustrating step S2 in Example 1. This is a diagram illustrating step S3 in Example 1. This is a diagram illustrating step S3 in Example 1. This is a diagram illustrating step S4 according to Example 1. This is a diagram illustrating step S4 according to Example 1. This is a diagram illustrating step S5 in Example 1. This is a diagram illustrating step S5 in Example 1. This diagram illustrates the problems of conventional methods. (a) is a diagram illustrating the configuration of a sheet material application device in a typical conventional example, (b) is a diagram showing the state in which tension is generated when the sheet material comes into contact with the workpiece, (c) is a diagram showing the problem of air bubbles being generated between the sheet material and the workpiece, (d) is a diagram showing the state in which the sheet material comes into contact with a part other than the intended part, and (e) is a diagram showing the problem of wrinkles being generated in the sheet material. This diagram illustrates the problems of conventional methods. (a) is a diagram illustrating the configuration of a sheet material attachment device according to Patent Document 1, (b) is a diagram illustrating the process of attaching a sheet material using the sheet material attachment device according to Patent Document 1, and (c) is a diagram showing the state of the sheet material attached to a workpiece using the sheet material attachment device according to Patent Document 1. This figure illustrates the elongation ratio of the sheet material in Example 1. (a) is a figure illustrating a first example of a method for calculating the elongation ratio of the sheet material in Example 1, and (b) is a figure illustrating a first example of a method for calculating the elongation ratio of the sheet material in Example 1. This figure illustrates the effects of the configuration in Example 1. (a) is a diagram illustrating the configuration of a comparative example in which the shape of the contact surface of the deformable member matches the shape of the curved surface of the workpiece. (b) is a diagram showing the position where the deformable member and the workpiece come into contact when a misalignment occurs between them in the comparative example. (c) is a diagram showing the position where the deformable member and the workpiece come into contact when a misalignment occurs between them in Example 1. This is a perspective view showing the configuration of the sheet material according to Example 2. This is a diagram illustrating step S2 in Example 2. This is a diagram illustrating step S3 in Example 2. This is a diagram illustrating step S3 in Example 2. This is a diagram illustrating step S4 in Example 2. This is a diagram illustrating step S5 in Example 2. This is a diagram illustrating the configuration of a modified example. This is a diagram illustrating the configuration of a modified example. This diagram illustrates step S3 of the modified configuration. (a) shows the state in which the sheet material deforms so as to move away from the workpiece due to an upward differential pressure, and (b) shows the state in which the sheet material is deformed and the projection is brought into contact with the desired position on the workpiece. This is a diagram illustrating the configuration of a modified example. This is a diagram illustrating the configuration of a modified example. These figures illustrate the shapes of the workpieces in modified forms. (a) is a diagram illustrating a configuration in which the central part of the workpiece has a curved surface and a flat surface, (b) is a diagram illustrating a configuration in which the central part of the workpiece has a curved surface and a recessed portion that is recessed from the curved surface, and (c) is a diagram illustrating a configuration in which the central part of the workpiece has a curved surface and a convex portion that protrudes from the curved surface. This is a diagram illustrating the shape of the workpiece in a modified example.

The following describes Embodiment 1 of the present invention with reference to the drawings. Figure 1 shows the basic configuration of the sheet material application device 1 according to Embodiment 1. Note that in each figure showing the sheet material application device 1, support means for supporting various components and driving means for driving various components are omitted from the illustration as appropriate.

In this embodiment, the sheet material application apparatus 1 uses a dish-shaped workpiece W, as shown in Figures 2(a) and 2(b), as the workpiece to which the sheet material PT is applied. The workpiece W has a flat peripheral edge Wa on its surface W1, while the central part Cp where the circuit is formed has a concave curved surface Wb. Note that the shape of the workpiece W with the curved surface Wb is not limited to a dish shape; other examples include a tile-shaped workpiece as shown in Figure 2(c). The sheet material application apparatus 1 aims to apply the sheet material PT to at least the central part Cp of the workpiece W. Examples of the sheet material PT include adhesive films or adhesive tapes for circuit protection.

As shown in Figure 3, the sheet material PT used in this embodiment has a long, laminated structure consisting of a non-adhesive base material Ta and an adhesive material Tb. A separator S is attached to the adhesive material Tb. That is, the separator S is attached to the adhesive surface of the sheet material PT, and the adhesive surface of the sheet material PT is exposed by peeling off the separator S from the sheet material PT.

Examples of materials constituting the base material Ta include polyolefins, polyethylene, ethylene-vinyl acetate copolymers, polyesters, polyimides, polyurethanes, vinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyethylene terenaphthalate, polyvinylidene chloride, polyethylene methacrylic acid copolymers, polypropylene, methacrylic acid terephthalate, polyamide-imide, and polyurethane elastomers. A combination of multiple of the above materials may also be used as the base material Ta. Furthermore, the base material Ta may be a single layer or a structure consisting of multiple layers laminated together.

The adhesive Tb is preferably composed of a material that can ensure both the function of protecting the workpiece W and the function of maintaining the sheet material PT's adhesion to the workpiece W. Examples of materials constituting the adhesive Tb include acrylic ester copolymers, silicones, olefins, natural rubber, butadiene rubber, and cellulose. Furthermore, it is preferable to appropriately select an adhesive Tb that hardens by energy ray irradiation or thermal energy. In this case, applying energy rays or thermal energy makes it easier to peel the sheet material PT from the workpiece W. Examples of separators S include long sheets of paper or plastic.

<Explanation of the overall structure>
The sheet material application device 1 comprises a sheet supply unit 2, a separator recovery unit 3, a sheet application unit 4, and a sheet recovery unit 5. The sheet supply unit 2 includes a supply bobbin 6, a tensioning mechanism 7, and a peeling roller 8, etc. A roll of raw material with sheet material PT wound around it is loaded into the supply bobbin 6.

The supply bobbin 6 is linked to the electromagnetic brake 9, applying appropriate rotational resistance. This prevents excessive dispensing of the sheet material PT from the supply bobbin 6. The tensioning mechanism 7 includes a cylinder 11 that oscillates the swing arm 10. The swing arm 10 has a free-rotating roller 12 pivotally supported on a pivot shaft at its fixed end, and a dancer roller 13 at its free end.

Therefore, the free-end side of the swinging arm 10, which swings in conjunction with the operation of the cylinder 11, is configured to descend, pushing the sheet material PT downward and applying tension. The sheet material PT, fed out from the raw material roll 6, is tensioned in the feeding direction by the guide roller 14 and the like, and is adjusted to prevent wrinkles from forming.

The peeling roller 8 is configured to peel the separator S from the sheet material PT and guide it to the separator recovery unit 3. The separator recovery unit 3 is equipped with a recovery bobbin 15 for winding the separator S peeled from the sheet material PT. The recovery bobbin 15 is rotated in both forward and reverse directions by a motor (not shown).

The sheet application unit 4 comprises a chamber 17, a sheet application mechanism 18, a nip roller 19, and a sheet cutting mechanism 21. The chamber 17 is composed of a pair of upper and lower housings, namely an upper housing 20 and a lower housing 22, each having an inner diameter smaller than the width of the sheet material PT. The sheet application device 1 according to this embodiment comprises one upper housing 20 and two lower housings 22. Of the two lower housings 22, one is distinguished as lower housing 22A and the other as lower housing 22B.

As shown in Figure 4, the lower housings 22A and 22B are provided at both ends of the swivel arm 23. The swivel arm 23 is connected and fixed to the rotation shaft 27 of the rotary drive device 25. That is, for example, when one lower housing 22A moves to the adhesive area P1 to form a chamber 17 with the upper housing 20, the other lower housing 22B is configured to move to the retraction area P2. As shown in Figures 1 and 4, the sheet material PT is fed out between the upper housing 20 and the lower housing 22 in the adhesive area P1.

Furthermore, joint portions 29 are formed on the upper surfaces of the lower housings 22A and 22B, and joint portion 30 is formed on the lower surface of the upper housing 20. The chamber 17 is formed by joining the upper housing 20 and the lower housing 22 via joint portions 29 and 30. The joining surfaces of joint portions 29 and 30 are subjected to a release treatment, such as fluorine coating.

As shown in Figures 4 to 6, a holding table 31 is housed in each of the lower housings 22A and 22B. The holding table 31 is configured to be vertically movable and includes a workpiece holding section 33 for holding the workpiece W. A workpiece mounting surface 35 is formed in the center of the workpiece holding section 33. The workpiece mounting surface 35 is shaped to conform to the lower surface of the workpiece W. In this embodiment, the workpiece mounting surface 35 is circular in plan view and concave in cross-sectional view. By placing the workpiece W on the workpiece mounting surface 35, the workpiece W can be held more stably.

Furthermore, it is preferable that the shape of the workpiece mounting surface 35 is predetermined such that, when the workpiece W is placed on the workpiece mounting surface 35, the height of the peripheral edge Wa of the workpiece W is higher than the height of the upper surface of the holding table 31 (see Figure 7). By making the height of the peripheral edge Wa of the workpiece W higher than the upper surface of the holding table 31, it becomes easier to separate the workpiece W from the holding table 31 after the sheet material PT has been attached.

The holding table 31 is connected to a rod 37 that passes through the lower housing 22. The other end of the rod 37 is driven by an actuator 39 equipped with a motor or similar device. Therefore, the holding table 31 can move up and down within the lower housing 22.

The holding table 31 has multiple support pins 41 built into it. The support pins 41 are configured to move vertically, allowing their tips to protrude higher than the holding surface of the workpiece holding section 33. A heater 43 is also embedded in the holding table 31.

As shown in Figure 6, the upper housing 20 is mounted on the drive mechanism 44. The drive mechanism 44 includes a movable platform 47 that can move up and down along a rail 46 vertically positioned on the back of the vertical wall 45, a movable frame 48 supported on the movable platform 47 so as to be height-adjustable, and an arm 49 extending forward from the movable frame 48. The upper housing 20 is mounted on a support shaft 50 extending downward from the tip of the arm 49.

The movable base 47 is configured to be raised and lowered by rotating the screw shaft 51 in forward and reverse directions using a motor 52. Furthermore, the upper housing 20 is configured to retract from the attachment area P1 at appropriate timings, for example, by the rotation of the movable base 47 or the extension and retraction of the arm 49.

As shown in Figure 7, the upper housing 20 and the lower housing 22 are connected to the vacuum device 55 via a passage 53. A solenoid valve 56 is provided in the passage 53 on the vacuum device 55 side. Furthermore, passages 59 equipped with solenoid valves 57 and 58 for venting to the atmosphere are connected to both the upper housing 20 and the lower housing 22, respectively. Additionally, the upper housing 20 is connected to a passage 61 equipped with a solenoid valve 60 for adjusting the internal pressure, which has been reduced, through leakage.

The opening and closing operations of the electromagnetic valves 56, 57, 58, and 60, and the operation of the vacuum device 55, are performed by the control unit 62. The control unit 62 is equipped with a CPU (Central Processing Unit) and is configured to provide comprehensive control over various operations of each component of the sheet material application device 1.

As shown in Figure 4 and other figures, the sheet application mechanism 18 includes a deformation member 63 inside the upper housing 20. A cylinder 65 is connected to the upper part of the deformation member 63, and the deformation member 63 can be raised and lowered inside the chamber 17 by the operation of the cylinder 65. By lowering the deformation member 63 while the sheet material PT is sandwiched between the upper housing 20 and the lower housing 22, the deformation member 63 deforms the sheet material PT. A preferred material for the deformation member 63 is an elastic body, and examples of elastic bodies include rubber, urethane, and elastomer. When the deformation member 63 is an elastic body, when the deformation member 63 contacts the workpiece W via the sheet material PT, the deformation member 63 elastically deforms according to the shape of the curved surface Wb of the workpiece W. This allows the sheet material PT to adhere well to the workpiece W and prevents damage to the sheet material PT or the workpiece W.

The nip roller 19 comprises a feed roller 67 driven by a motor and a pinch roller 68 that moves up and down by a cylinder. The nip roller 19 is configured to move left and right along a guide rail 69. The guide rail 69 is mounted on a pair of support frames 71 erected on the device base 70, flanking the chamber 17.

The sheet cutting mechanism 21 is positioned above the application area P1 and, as shown in Figure 1, includes a cutter unit 75 located at the tip of a support arm 73. The support arm 73 extends radially from the lower end of an arm cantilevered from a movable base 77. The movable base 77 is configured to be vertically movable along a frame 79.

The cutter unit 75 is equipped with a cutter 81 with its cutting edge facing downwards, mounted via a cutter holder. The cutter unit 75's rotation radius can be adjusted via a support arm 73. The sheet cutting mechanism 21 cuts the sheet material PT attached to the workpiece W so that it is approximately the same shape and size as the peripheral edge Wa of the workpiece W.

As shown in Figure 1, the sheet recovery unit 5 is equipped with a recovery bobbin 83 for winding and recovering the unwanted sheet material PT that has been peeled off after cutting. The recovery bobbin 83 is configured to be rotated in both forward and reverse directions by a motor (not shown).

As shown in Figures 7 and 8, the deformable member 63 comprises a base portion 91 and a tip portion 93. In Embodiment 1, the base portion 91 is a substantially cylindrical member, and the tip portion 93 is a member with a spherical lower surface. In other words, the tip portion 93 is a member with a shape resembling a part of a sphere. The tip portion 93 is connected to the lower part of the base portion 91, and a contact surface 95 is formed on the lower surface side of the tip portion 93. The contact surface 95 has a curved surface, and as the deformable member 63 descends, the contact surface 95 comes into contact with the sheet material PT. In Embodiment 1, the contact surface 95 has a curved surface that constitutes a part of a sphere.

Figures 8 and 9 show the relationship between the shape of the contact surface 95 on the deformable member 63 and the shape of the curved surface Wb on the workpiece W. As shown in Figure 8, the width of the contact surface 95 in the longitudinal section is defined as the cross-sectional width a of the contact surface 95, and the width of the curved surface Wb in the longitudinal section of the workpiece W is defined as the cross-sectional width b of the curved surface Wb. In other words, in this embodiment, the cross-sectional width a of the contact surface 95 corresponds to the length of the contact surface 95 in the x direction. Similarly, the cross-sectional width b of the curved surface Wb corresponds to the length of the curved surface Wb in the x direction. In the sheet material application device 1 according to Embodiment 1, the cross-sectional width a of the contact surface 95 and the cross-sectional width b of the curved surface Wb are configured to satisfy the following condition (1).
a ≥ 0.3 × b ……(1)

In other words, the cross-sectional width a of the contact surface 95 is configured to be at least 0.3 times the width b of the curved surface Wb. By configuring the deformation member 63 such that the ratio of cross-sectional width a to cross-sectional width b is 0.3 or more, as described later, when the sheet material PT is deformed using the deformation member 63, the ratio of the elongation rate of the sheet material PT in the portion deformed by contact with the contact surface 95 to the elongation rate of the sheet material PT in the portion not in contact with the contact surface 95 can be reduced. In other words, when the sheet material PT is deformed by the deformation member 63, variations in the overall elongation rate of the sheet material PT can be suppressed.

Furthermore, in the sheet material application apparatus 1 according to Embodiment 1, the curvature of the contact surface 95 of the deformation member 63 is configured to be greater than the curvature of the curved surface Wb of the workpiece W. Here, the curvature of the contact surface 95 and the curvature of the curved surface Wb will be explained using Figure 9. Figure 9, like Figure 8, shows a longitudinal cross-section of the deformation member 63 and the workpiece W.

In Figure 9, a predetermined point on the contact surface 95 of the deformable member 63 is indicated by the symbol NP, and the normal to the contact surface 95 at point NP is indicated by the symbol T1. Furthermore, one end of the contact surface 95 in the width direction (here, the x-direction) of the deformable member 63 is indicated by the symbol NL, and the other end of the contact surface 95 is indicated by the symbol NR. The curvature of the curved contact surface 95 corresponds to the change in the slope of the normal T1 as point NP moves along the arc-shaped contact surface 95 from one end NL to the other end NR.

In Figure 9, a predetermined point on the curved surface Wb of the workpiece W is indicated by the symbol WP, and the normal to the curved surface Wb at point WP is indicated by the symbol T2. Furthermore, one end of the curved surface Wb in the width direction (here, the x-direction) is indicated by the symbol WL, and the other end of the curved surface Wb is indicated by the symbol WR. The curvature of the curved surface Wb in the workpiece W corresponds to the change in the slope of the normal T2 as point WP moves along the arc-shaped curved surface Wb from one end WL to the other end WR.

<Princess Overview>
Here, the basic operation of the sheet material application device 1 according to Embodiment 1 will be explained. Figure 10(a) is a flowchart illustrating the process of applying sheet material PT to workpiece W using the sheet material application device 1. In the initial state, the lower housing 22A of the lower housing 22 is positioned in the retraction area P2, and the lower housing 22B is positioned in the application area P1 together with the upper housing 20.

Step S1 (Workpiece supply)
When an attachment command is issued, the workpiece W is transported to the holding table 31 by a transport device (not shown). At this time, the workpiece W is transported to the holding table 31 located inside the lower housing 22 (lower housing 22A in this embodiment) which is positioned in the retracted position P2. An example of a transport device is a vacuum suction type robot arm.

Furthermore, heating by the heater 43 is started at an appropriate timing. The heater 43 heats the holding table 31, which in turn heats the sheet material PT along with the workpiece W in subsequent processes. As a result, the material constituting the sheet material PT becomes softer, making it easier to deform.

When the workpiece W is transported, the holding table 31 rises appropriately, and the support pin 41 built into the holding table 31 protrudes from the workpiece holding section 33 and rises to the receiving position. Then, as shown in Figure 11, the workpiece W is handed over to the tip of the support pin 41, which is pushed up to a position higher than the upper surface of the lower housing 22A.

When the workpiece W is handed over, the support pin 41 descends and returns to its initial position, and the workpiece W is placed on the workpiece mounting surface 35 of the workpiece holding section 33. At this time, the height of the holding table 31 is adjusted so that the height of the peripheral edge Wa of the workpiece W held by the holding table 31 via the workpiece mounting surface 35 is lower than the height of the upper surface of the lower housing 22A. Furthermore, to hold the workpiece W more stably, the holding table 31 may use a vacuum device (not shown) to vacuum-suction the back surface of the workpiece W via the workpiece mounting surface 35. As a result of step S1, the workpiece W is held by the holding table 31 with the back surface W2 facing downwards and the curved surface W1 facing upwards.

At this time, the pinch roller 68 is raised and, in cooperation with the feed roller 67, nip the sheet material PT, while the dancer roller 13 is swung down to a predetermined height, applying a predetermined tension to the sheet material PT in the longitudinal direction.

Step S2 (Cambodia formation)
When the workpiece W is held by the holding table 31, the rotary drive device 25 is activated to rotate the swivel arm 23, as shown in Figure 12. The rotation of the swivel arm 23 moves the lower housing 22A from the retraction area P2 to the attachment area P1. In conjunction with the movement of the lower housing 22A, the lower housing 22B moves from the attachment area P1 to the retraction area P2. When the lower housing 22A has moved to the attachment area P1, the workpiece W held by the holding table 31 has a predetermined clearance from the sheet material PT.

After moving the lower housing 22A to the attachment area P1, the upper housing 20 is lowered as shown in Figure 13. As it lowers, the upper housing 20 and the lower housing 22A sandwich the sheet material PT, forming a chamber 17.

The internal space of the formed chamber 17 is divided into two spaces by the sheet material PT. Specifically, it is divided into a lower space H1 surrounded by the sheet material PT and the lower housing 22A, and an upper space H2 surrounded by the sheet material PT and the upper housing 20. The workpiece W and the holding table 31 are placed in the lower space H1, and the upper space H2 faces the lower space H1 with the sheet material PT in between.

Step S3 (Deformation of the sheet material)
After forming the chamber 17, the leak-proof electromagnetic valve 60 is closed, and electromagnetic valves 56, 57, and 58 are opened to activate the vacuum device 53 and reduce the pressure in the lower space H1 and the upper space H2. At this time, the openings of electromagnetic valves 57 and 58 are adjusted so that the pressure in the lower space H1 and the upper space H2 is reduced at the same rate. When the pressure in the lower space H1 and the upper space H2 is reduced to a predetermined pressure (for example, a vacuum), the control unit 62 closes electromagnetic valves 56-58 and stops the operation of the vacuum device 53.

After reducing the pressure in the lower space H1 and the upper space H2 to a predetermined level, the control unit 62 activates the sheet application mechanism 18. That is, the control unit 62 lowers the deformation member 63. As the deformation member 63 descends, as shown in Figure 14, the tip 93 of the deformation member 63 contacts and presses against the sheet material PT. This pressing causes a portion of the sheet material PT to deform according to the shape of the contact surface 95 provided on the tip 93, forming a protruding portion V on the sheet material PT that faces the workpiece W. In this embodiment, since the workpiece W is housed in the lower space H1, the protruding portion V faces the lower space H1.

The control unit 62 further lowers the deformation member 63. As the deformation member 63 continues to descend, the sheet material PT is pushed down by the tip portion 93. As a result, as shown in Figure 15, the portion of the sheet material PT that has been deformed into a protruding portion V comes into contact with a part of the curved surface Wb of the workpiece W. In Figure 15 and other figures, the area of the curved surface Wb that the protruding portion V contacts is shown as the contact area M1. In this embodiment, the position of the deformation member 63 is adjusted so that the contact area M1 includes the deepest part Wc of the curved surface Wb. When the deformation member 63 comes into contact with the curved surface Wb via the protruding portion V, the control unit 62 stops the descent of the deformation member 63.

Step S4 (Attaching the sheet material)
After bringing the protruding portion V into contact with a part of the curved surface Wb of the workpiece W, the process of attaching the sheet material to the workpiece is started. That is, while the protruding portion V is in contact with the curved surface Wb, the control unit 62 adjusts the opening of the electromagnetic valve 60 to allow leakage and gradually increases the air pressure in the upper space H2 to a preset target value.

By adjusting the electromagnetic valve 60, the air pressure in the upper space H2 becomes higher than the air pressure in the lower space H1, creating a differential pressure F between the two spaces. This differential pressure F then gradually draws the seat material PT into the lower housing 22A.

At the point when the differential pressure F is formed, the protruding portion V, which is part of the sheet material PT, is already in contact with the contact region M1 on the curved surface Wb. Therefore, as shown in Figure 16, the sheet material PT is attached radially to the curved surface Wb of the workpiece W, from the contact region M1 toward the outer circumference. Then, as shown in Figure 17, the sheet material PT is attached and adheres tightly to the entire surface of the curved surface Wb. That is, the sheet material PT is attached to the entire central portion Cp of the surface W1 of the workpiece W. In this embodiment, after the sheet material PT is attached to the central portion Cp, the differential pressure F is maintained, and the sheet material PT is also attached to the peripheral portion Wa of the surface W1.

The control unit 62 opens the electromagnetic valves 57 and 58 after a predetermined time has elapsed, adjusting them so that the atmospheric pressure in the lower space H1 and the upper space H2 are equal. Once the atmospheric pressures in the lower space H1 and the upper space H2 are equal, the control unit 62 adjusts the opening of the electromagnetic valve 60 to return the atmospheric pressures in the lower space H1 and the upper space H2 to atmospheric pressure. Afterward, the upper housing 20 is raised to release the space into the atmosphere.

Furthermore, while the sheet material PT is being attached to the workpiece W within the chamber 17, the process of step S1 can be performed in the lower housing 22B, which has moved to the retraction area P2. By providing multiple lower housings 22 and performing the process of attaching the sheet material PT to the workpiece W alternately, the efficiency of attaching the sheet material PT to the workpiece W can be improved.

Step S5 (Cutting the sheet material)
Once the sheet material PT is attached to the workpiece W, the cutting process of the sheet material PT is started. That is, the upper housing 20 is moved away from the attachment area P1 to an appropriate position. At this time, the holding table 31 may be raised as appropriate. In this embodiment, the holding table 31 is raised to a height where the surface of the peripheral edge Wa of the workpiece W and the upper surface of the lower housing 22A are flush.

Furthermore, the cutter unit 75 of the sheet cutting mechanism 21 is lowered to a predetermined height. Due to the vertical movement of the holding table 31 and the sheet cutting mechanism 21, as shown in Figure 18, the cutter 81 penetrates the sheet material PT at a point slightly away from the peripheral edge Wa of the workpiece W.

When the cutter 81 is inserted into the sheet material PT, the support arm 73 rotates around the vertical axis P as its pivot point. In this embodiment, the vertical axis P is assumed to be an axis passing through the center of the holding table 31 and the center of the workpiece W. As the support arm 73 rotates, the cutter 81 moves along the outer circumference of the peripheral edge Wa of the workpiece W, and the sheet material PT is cut to approximately the same shape and size as the peripheral edge Wa. Once the cutting of the sheet material PT is complete, the cutter unit 75 rises and returns to its standby position.

Furthermore, the pinch roller 68 provided on the nip roller 19 is lowered to release the nip of the sheet material PT. Then, as shown in Figure 19, the nip roller 19 is moved along the guide rail 69 toward the tape supply unit 2, thereby separating the sheet material PTw, which is the portion of the sheet material PT cut out along the outer shape of the peripheral edge Wa, from the sheet material PTTa, which is the portion of the sheet material PT other than PTw.

Step S6 (Workpiece retrieval)
Once the cutting and separation of the sheet material PT is complete, the rotary drive device 25 is activated to rotate the swivel arm 23. The rotation of the swivel arm 23 moves the lower housing 22A from the attachment area P1 to the retraction area P2. In conjunction with the movement of the lower housing 22A, the lower housing 22B moves back to the attachment area P1. The workpiece W, with the sheet material PTw attached to the curved surface Wb, is then transported out by a transport mechanism (not shown) and collected in a workpiece storage section (not shown).

The sheet material PTa, separated from the sheet material PTw, is wound up and recovered by the recovery bobbin 83 of the sheet recovery unit 5. As the sheet material PTa is recovered, a predetermined amount of sheet material PT is dispensed from the sheet supply unit 2.

This completes one cycle of operations. From here on, the operations from step S1 to step S6 are repeated sequentially.

<Effects of the configuration in Example 1>
According to the apparatus of the above-described embodiment 1, a sheet material PT can be accurately attached to a workpiece W having a curved surface Wb. The effects of the configuration of embodiment 1 will now be explained in comparison with the conventional configuration.

Conventional adhesive application devices, such as those disclosed in Patent Document 1 or Patent Document 2, are designed for the process of applying sheet material PT to flat workpieces. Therefore, it has been newly discovered that when a workpiece has a curved surface, it is difficult to accurately apply the sheet material PT to the workpiece using conventional adhesive application devices.

The following are possible reasons why precise adhesion becomes difficult. Specifically, in a typical conventional configuration where differential pressure is used to adhere the sheet material to the workpiece, as shown in Figure 20(a), a differential pressure F is generated inside the chamber Ty while the sheet material PT is flat, and this differential pressure F is used to adhere the sheet material PT to the workpiece W. In this typical conventional configuration, the entire sheet material PT inside the chamber Ty deforms uniformly due to the differential pressure F. Therefore, parts of the workpiece W that are closer to the sheet material PT will come into contact with the sheet material PT before parts that are further away.

Therefore, when using a workpiece W with a curved surface Wb, as shown in Figure 20(b), the sheet material PT is concave and contacts the flat peripheral edge Wa of the workpiece W, which is higher in the z-direction, before the curved surface Wb of the workpiece W, which is lower in the z-direction. This contact between the sheet material PT and the peripheral edge Wa generates tension Tx in the sheet material PT.

In this case, the sheet material PT, after contacting the peripheral edge Wa, deforms further as the central part of the sheet material PT attempts to follow the curved surface Wb. However, tension Tx is generated in the sheet material PT, and this tension Tx gradually increases as the deformation progresses. As a result, the sheet material PT can no longer deform completely, and a portion of the sheet material PT fails to follow the curved surface Wb.

When this situation occurs, the sheet material PT in the portion that cannot deform to follow the curved surface Wb cannot adhere to the curved surface Wb, resulting in the formation of air bubbles Vo between the sheet material PT and the curved surface Wb of the workpiece W, as shown in Figure 20(c). In particular, the deepest part Wc of the curved surface Wb is the last part that the sheet material PT, deformed by differential pressure, contacts, so air bubbles Vo occur frequently there. Therefore, the adhesion accuracy of the sheet material PT becomes low, especially in the deepest part of the curved surface Wb.

The tension Tx generated when the sheet material PT first contacts the peripheral edge Wa is thought to cause another problem. Specifically, when the sheet material PT deforms to follow the curved surface Wb while tension Tx is present, it deforms unevenly. As a result, as shown in Figure 20(d), a portion of the sheet material PT adheres prematurely to an unexpected region Wbx within the curved surface Wb. When this occurs, the sheet material PT cannot adhere tightly to the curved surface Wb, and as shown in Figure 20(e), the portion of the sheet material PT in contact with region Wbx becomes wrinkled Sw.

Furthermore, even if the sheet material PT is attached to a curved surface Wb while tension Tx is present, strong tensile stress will accumulate in the sheet material PT due to the tension Tx. Therefore, over time, the sheet material PT may peel off the curved surface Wb due to the tensile stress, potentially causing air bubbles Vo and wrinkles Sw to form.

To avoid the sheet material PT contacting the peripheral edge Wa before the curved surface Wb when attaching it to the curved surface Wb, the configuration in Patent Document 1, as shown in Figure 21(a), involves arranging a thin rod-shaped projection member 101 inside the chamber Ty. Then, as shown in Figure 21(b), the projection member 101 is lowered, and the central portion Q1 of the sheet material PT is pressed with the pressing member K to attach it to the workpiece W. Afterward, a differential pressure is generated to ensure the sheet material PT adheres tightly to the entire surface of the workpiece W, spreading radially from the central portion.

However, it was found that the configuration described in Patent Document 1 presents the following new problems. Specifically, as shown in Figure 21(b), the projection member 101 is a thin, rod-shaped member, and therefore contacts and presses against a very narrow region Q1 of the sheet material PT. As a result, a very large pressing force acts on this narrow region Q1, causing the portion of the sheet material PT in region Q1 to stretch significantly due to this force. In other words, the stretching rate of the sheet material PT in region Q1 becomes very high. Furthermore, the sheet material PT becomes thinner when stretched. That is, the thickness of the portion of the sheet material PT in region Q1 decreases.

On the other hand, in region Q2 of the sheet material PT where the projection member 101 does not come into contact, the pressing force applied by the projection member 101 is very weak, resulting in a lower elongation rate of the sheet material PT in region Q2. Furthermore, the sheet material PT in region Q2 is thicker than that in region Q1. In other words, in the configuration of Patent Document 1, variations in elongation rate and thickness occur depending on the position of the sheet material PT due to the projection member 101.

When sheet material PT is attached to the curved surface Wb of workpiece W with such variations in stretch ratio and thickness, the sheet material PT attached to the curved surface Wb will be in the state shown in Figure 21(c). That is, region Q1 of the sheet material PT is attached to the central part of the curved surface Wb, and region Q2 is attached to the peripheral part of the curved surface Wb. Therefore, the thickness of the sheet material PT attached to the curved surface Wb is relatively thin in the central part, and relatively thick in the peripheral part of the curved surface Wb.

The properties of sheet material PT, such as light transmittance, vary significantly depending on the thickness of the sheet material PT. As a result, the properties of sheet material PT attached to the center of a curved surface Wb differ greatly from those attached to the periphery of the curved surface Wb. Therefore, it is considered difficult to uniformly exhibit the properties of sheet material PT across the entire curved surface Wb using the conventional sheet material application device described in Patent Document 1.

On the other hand, in the sheet material application device 1 according to Embodiment 1, the sheet material PT is deformed using the contact surface 95 of the deformation member 63, and the deformed portion of the sheet material PT is brought into contact with the curved surface Wb of the workpiece W. While the deformed portion of the sheet material PT is in contact with the curved surface Wb of the workpiece W, a differential pressure F is generated to apply the sheet material PT to the entire curved surface Wb. The contact surface 95 of the deformation member 63 is configured such that its curvature is greater than the curvature of the curved surface Wb of the workpiece W. Furthermore, the configuration of the contact surface 95 relative to the curved surface Wb of the workpiece W is determined such that the cross-sectional width a of the contact surface 95 and the cross-sectional width b of the curved surface Wb satisfy the condition a ≥ 0.3 × b.

By configuring the deformation member 63 so that the cross-sectional width or curvature of the contact surface 95 satisfies the condition, the area of the sheet material PT that the contact surface 95 contacts can be made larger when the deformation member 63 is brought into contact with the sheet material PT. As a result, the pressing force acting per unit area of the sheet material PT can be reduced during the process of the deformation member 63 deforming the sheet material PT, thereby suppressing an excessive increase in the elongation rate of the sheet material PT in the area where the contact surface 95 contacts. Therefore, the difference in elongation rate between the area of the sheet material PT that the contact surface 95 contacts and the area that the contact surface 95 does not contact becomes smaller, thus reducing the variation in elongation rate of the sheet material PT as a whole attached to the curved surface Wb of the workpiece W. In other words, the variation in the thickness of the sheet material PT on the curved surface Wb can be reduced, allowing the sheet material's properties to be exhibited more uniformly throughout the entire sheet material PT attached to the curved surface Wb.

In this embodiment, the elongation ratio of the sheet material PT is calculated as follows, as an example. Figure 22(a) shows a first example of calculating the elongation ratio. The left diagram in Figure 22(a) shows the deformation member 63 and the sheet material PT when the contact surface 95 of the deformation member 63 is not in contact with the sheet material PT. In this state, the length of the portion J of the sheet material PT facing the contact surface 95 is denoted as F1. In the left diagram of Figure 22(a), since the contact surface 95 is not in contact with the sheet material PT, the length F1 is equal to the cross-sectional width a of the contact surface 95.

Next, the right-hand diagram of Figure 22(a) shows the deformation member 63 and the sheet material PT in a state where the contact surface 95 of the deformation member 63 is in contact with the sheet material PT. In this state, let F2 be the length of the portion of the sheet material PT that faces the contact surface 95 (the portion in contact with the contact surface 95). In the right-hand diagram of Figure 22(a), the sheet material PT is deformed along the contact surface 95, so the length F2 is the length along the surface of the contact surface 95. In this first example, the elongation ratio Ex of the sheet material PT due to contact with the deformation member 63 is calculated using the formula shown in (3) below, with respect to the length F1 of the sheet material PT before deformation and the length F2 of the sheet material PT after deformation.
Ex=(F2-F1)/F1...(3)

In equation (3) above, F1 corresponds to the initial length of the opposing portion J, and (F2 - F1) corresponds to the length of the opposing portion J stretched by the deformation member 63. Therefore, the elongation ratio Ex of the sheet material PT can be calculated using equation (3).

Next, Figure 22(b) shows a second example of calculating the elongation ratio. The left side of Figure 22(b) shows a plan view of the sheet material PT before the deformation member 63 is brought into contact with it. The right side of Figure 22(b) shows a plan view of the sheet material PT after the deformation member 63 is brought into contact with it. That is, by bringing the contact surface 95 of the deformation member 63 into contact with the sheet material PT, the length of the sheet material PT in the x direction changes from X1 to X2, and the length of the sheet material PT in the y direction changes from Y1 to Y2. In this second example, the elongation ratio Ex of the sheet material PT due to contact with the deformation member 63 can also be calculated using the formula shown in (4) below, with respect to lengths X1, X2, Y1, and Y2. The term (X1・Y1) corresponds to the product of length X1 and length Y1.

Furthermore, in the configuration according to Embodiment 1, the curvature of the contact surface 95 of the deformation member 63 is configured to be greater than the curvature of the curved surface Wb of the workpiece W. Therefore, by bringing the sheet material PT, deformed by the contact surface 95, closer to the curved surface Wb of the workpiece W together with the deformation member 63, it becomes easy to bring the sheet material PT into contact with the deepest part Wc of the curved surface Wb first. Therefore, in the process of attaching the sheet material PT to the curved surface Wb using differential pressure, the sheet material PT is attached radially from the deepest part Wc outwards. Thus, it is possible to reliably avoid the trapping of air bubbles in the deepest part Wc, which is considered to be a particularly prone area for air bubble formation in conventional methods, and further improve the adhesion of the sheet material PT to the curved surface Wb.

Furthermore, it was found that by making the curvature of the contact surface 95 greater than the curvature of the curved surface Wb on the workpiece W, a new effect can be obtained: even if a misalignment occurs between the position of the deformable member 63 and the position of the workpiece W, the sheet material PT can be attached with high precision. This effect will be explained using the figures in Figure 23.

Figure 23(a) shows a configuration in which the shape of the contact surface 95 matches the shape of the curved surface Wb of the workpiece W. In this case, the curvature and cross-sectional width of the contact surface 95 are equal to the curvature and cross-sectional width of the curved surface Wb on the workpiece W. In such a configuration in which the shape of the contact surface 95 matches the shape of the curved surface Wb of the workpiece W, if the position of the deformation member 63 and the position of the workpiece W are accurately matched in the x and y directions, the sheet material PT can be accurately attached to the entire curved surface Wb. That is, when the center line Kn of the contact surface 95 and the center line Kw of the curved surface Wb are at the same position, the contact surface 95 will come into contact with the entire curved surface Wb of the workpiece W by lowering the deformation member 63, so that the sheet material PT can be accurately attached to the entire curved surface Wb.

However, in a configuration where the shape of the contact surface 95 matches the shape of the curved surface Wb of the workpiece W, the adhesion accuracy of the sheet material PT is significantly reduced due to a slight misalignment between the center line Kn of the contact surface 95 and the center line Kw of the curved surface Wb. Figure 23(a) shows a configuration where the shape of the contact surface 95 matches the shape of the curved surface Wb of the workpiece W, and the center line Kn of the contact surface 95 and the center line Kw of the curved surface Wb are slightly misaligned in the x-direction.

When the deformation member 63 is lowered in the state shown in Figure 23(a), the positional relationship between the deformation member 63 and the workpiece W becomes as shown in Figure 23(b). If the center line Kn of the contact surface 95 and the center line Kw of the curved surface Wb are misaligned, even if the misalignment is slight, the contact surface 95 will no longer be able to contact the curved surface Wb. That is, the contact surface 95 will contact the flat peripheral edge Wa, or the boundary between the peripheral edge Wa and the curved surface Wb (for example, one end WL or the other end WR), via the sheet material PT.

In the state shown in Figure 23(b), the contact surface 95 is not fitted to the curved surface Wb. Therefore, even if the deformation member 63 is further lowered, the sheet material PT cannot be accurately attached to the curved surface Wb. Furthermore, even when a differential pressure F is generated in the state shown in Figure 23(b), the sheet material PT is attached to the peripheral portion Wa of the workpiece W before the curved surface Wb. This frequently results in the formation of air bubbles Vo between the sheet material PT and the workpiece W, or the formation of wrinkles Wbx on the sheet material PT attached to the workpiece W (see Figures 20(b) to (d)).

Therefore, in a configuration where the shape of the contact surface 95 matches the shape of the curved surface Wb of the workpiece W, it is necessary to match the position of the deformation member 63 and the position of the workpiece W with very high precision in the horizontal direction (x and y directions). Even a slight misalignment will significantly reduce the adhesion accuracy of the sheet material PT.

On the other hand, if the curvature of the contact surface 95 of the deformable member 63 is greater than the curvature of the curved surface Wb of the workpiece W, the sheet material PT can be accurately attached even if a misalignment occurs between the deformable member 63 and the workpiece W. Figure 23(c) shows the state in which the deformable member 63 is lowered and in contact with the workpiece W when the positions of the center line Kn of the contact surface 95 and the center line Kw of the curved surface Wb are misaligned in the x direction.

If the curvature of the contact surface 95 is greater than the curvature of the curved surface Wb, the distance between the center of the contact surface 95 and the curved surface Wb of the workpiece W will be significantly greater than the distance between the periphery of the contact surface 95 and the curved surface Wb of the workpiece W. Therefore, even if the positions of the center line Kn of the contact surface 95 and the center line Kw of the curved surface Wb are misaligned horizontally, as shown in Figure 23(c), the curved portion of the contact surface 95 will reliably come into contact with the curved surface Wb of the workpiece W.

Furthermore, when misalignment occurs, the location of the contact region M2 between the contact surface 95 and the curved surface Wb is close to the location of the contact region M1 when no misalignment occurs (for example, the location of the deepest part Wc). Therefore, when a differential pressure F is generated while the contact surface 95 is in contact with the contact region M2 on the curved surface Wb via the sheet material PT, the sheet material PT is attached to the entire curved surface Wb, starting from the contact region M2 closest to the contact region M1 (deepest part Wc) and spreading radially.

As a result, the occurrence of air bubbles Vo or wrinkles Wbx can be reliably prevented. In other words, unlike a configuration where the shape of the contact surface 95 matches the shape of the curved surface Wb of the workpiece W, a configuration where the curvature of the contact surface 95 is greater than the curvature of the curved surface Wb allows for a much larger tolerance for positional misalignment between the deformation member 63 and the workpiece W in the horizontal direction. In other words, in a configuration where the curvature of the contact surface 95 is greater than the curvature of the curved surface Wb, the sheet material PT can be accurately attached to the curved surface Wb of the workpiece W even if the positions of the center line Kn of the contact surface 95 and the center line Kw of the curved surface Wb are misaligned in the horizontal direction.

Next, we will describe Embodiment 2 of the present invention. Embodiment 1 described an example of a configuration in which a long sheet material PT is attached to a workpiece W having a curved surface Wb. Embodiment 2 describes an example of a configuration in which sheet material PT, which is in the form of a predetermined shape according to the shape of the workpiece W, is attached to a predetermined area including the curved surface Wb. That is, Embodiment 2 describes an example of a configuration in which pre-cut adhesive tape is attached to a workpiece. Note that components identical to those in the sheet material attachment device 1 of Embodiment 1 are denoted by the same reference numerals, and different components will be described in detail.

As shown in Figure 24, the sheet material PT in Embodiment 2 is pre-cut into a predetermined shape, and each sheet material PT is held by a long carrier tape CT. That is, in the sheet material application device 1A according to Embodiment 2, the sheet material PT fragments of a predetermined shape are arranged on the carrier tape CT at predetermined distances, and the carrier tape CT is fed from the sheet supply unit 2 together with the sheet material PT. The sheet application unit 4 applies the fragmented sheet material PT to the circuit-forming surface of the workpiece W having a curved surface Wb. The sheet recovery unit 5 winds up and recovers the carrier tape CT peeled off from the sheet material PT.

In this embodiment, the sheet material PT is assumed to be circular in shape. Furthermore, since the sheet material PT already conforms to the outer shape of the workpiece W, the sheet cutting mechanism 21 can be omitted in the sheet material application device 1A.

The operation of the sheet material application device 1A according to Example 2 will be explained with illustrations showing the differences from Example 1. The flowchart of the operation of the sheet material application device 1A is shown in Figure 10(b). The outline of the sheet material application process according to Example 2 is the same as that according to Example 1, so details will be omitted as appropriate.

Step S1 (Workpiece supply)
In step S1, the workpiece W having a curved surface Wb is transported to the lower housing 22A located in the retraction area P2. The workpiece W is then placed on the holding table 31 housed in the lower housing 22A, and the workpiece W is held via the workpiece placement surface 35 of the holding table 31. The workpiece W is held with the side of the surface W1 having the curved surface Wb facing upward.

Step S2 (Cambodia formation)
Next, in step S2, the lower housing 22A is moved to the adhesive area P1. At this time, the position of the unwound sheet material PT is adjusted in advance so that it is above the curved surface Wb of the workpiece W. After moving the lower housing 22A, the upper housing 20 is lowered. As shown in Figure 25, the upper housing 20 and the lower housing 22A are joined together, sandwiching the carrier tape CT, to form the chamber 17.

The internal space of the formed chamber 17 is divided into two spaces by the carrier tape CT. Specifically, it is divided into a lower space H1 surrounded by the carrier tape CT and the lower housing 22A, and an upper space H2 surrounded by the carrier tape CT and the upper housing 20.

Step S3 (Deformation of the sheet material)
After forming the chamber 17, the vacuum device 53 is activated to reduce the pressure in the lower space H1 and the upper space H2 at the same rate. When the air pressure in the lower space H1 and the upper space H2 is reduced to a predetermined pressure, the sheet application mechanism 18 is activated to lower the deformation member 63. As the deformation member 63 is lowered, as shown in Figure 26, the contact surface 95 provided at the tip 93 of the deformation member 63 comes into contact with the sheet material PT via the carrier tape CT, pressing down on the sheet material PT. Due to this pressing, a part of the sheet material PT is deformed according to the shape of the contact surface 95, and a protrusion V is formed.

After the sheet material PT is deformed by the contact surface 95, the control unit 62 further lowers the deformation member 63. As the deformation member 63 continues to descend, the protruding portion V contacts a part of the curved surface Wb of the workpiece W, as shown in Figure 27. Similar to Embodiment 1, it is preferable that the position of the deformation member 63 is adjusted so that the contact region M1 on the curved surface Wb, where the protruding portion V contacts, includes the deepest part Wc of the curved surface Wb. When the deformation member 63 contacts the curved surface Wb via the protruding portion V, the control unit 62 stops the descent of the deformation member 63.

Step S4 (Attaching the sheet material)
After bringing the protruding portion V into contact with a part of the curved surface Wb of the workpiece W, a differential pressure is formed between the upper space H2 and the lower space H1 while the protruding portion V is in contact with the curved surface Wb. Due to the differential pressure between the upper space H2 and the lower space H1, the sheet material PT is gradually drawn into the lower housing 22A. The sheet material PT is then attached to the curved surface Wb of the workpiece W so as to spread radially from the contact area M1 toward the periphery. As a result, the sheet material PT is attached to the entire surface of the curved surface Wb, as shown in Figure 28.

After a predetermined time has elapsed, the control unit 62 raises the deformation member 63 to return it to its initial position and adjusts the air pressure in the lower space H1 and the upper space H2 to be the same. Then, it returns the air pressure in both the lower space H1 and the upper space H2 to atmospheric pressure and raises the upper housing 20 to open it to the atmosphere.

Step S5 (Removal of carrier tape)
Since the sheet material PT in Example 2 is already in the form of a fragment shaped to match the outer shape of the workpiece W, the step of cutting the sheet material PT can be omitted. Therefore, in Example 2, after attaching the sheet material PT to the workpiece W, the carrier tape CT is peeled off from the sheet material PT. That is, the upper housing 20 is moved away from the attachment area P1 to an appropriate position. In Example 2, at this time, the holding table 31 is raised in the same manner as in Example 1.

Next, the pinch roller 68 on the nip roller 19 is lowered to release the nip on the sheet material PT. Then, as shown in Figure 29, the nip roller 19 is moved along the guide rail 69 toward the tape supply unit 2, causing the carrier tape CT to be wound up and peeled away from the sheet material PT attached to the workpiece W.

Step S6 (Workpiece retrieval)
Once the peeling of the carrier tape CT is complete, the swivel arm 23 is rotated to move the lower housing 22A from the application area P1 to the retraction area P2. The workpiece W, with the sheet material PT attached to the curved surface Wb, is then transported away by a transport mechanism (not shown) and collected in a workpiece storage section (not shown). The carrier tape CT separated from the sheet material PT is wound up and collected by the collection bobbin 83 in the sheet collection section 5.

This completes one cycle of operations. From here on, the operations from step S1 to step S6 are repeated sequentially.

<Effects of the configuration in Example 2>
According to the apparatus of Embodiment 2, when a pre-cut adhesive tape-like sheet material PT is attached to a workpiece W having a curved surface Wb, the sheet material PT can be attached to the curved surface Wb with high precision. That is, similar to Embodiment 1, a part of the sheet material PT is deformed to form a protrusion V, and this protrusion V is first brought into contact with a part of the curved surface Wb. After the protrusion V is brought into contact with the curved surface Wb, the sheet material PT is attached to the entire curved surface Wb by the differential pressure between the lower space H1 and the upper space H2 inside the chamber 17.

Therefore, even in the configuration of Example 2, the generation of tension Tx caused by the sheet material PT contacting the peripheral edge Wa first can be avoided. Consequently, even when attaching the sheet material PT to a workpiece W having a curved surface Wb, situations such as wrinkles forming in the sheet material PT or air bubbles forming between the sheet material PT and the curved surface Wb can be avoided. Thus, the sheet material PT can be attached with high precision to adhere closely to the entire surface of the curved surface Wb.

Furthermore, in Example 2, similar to Example 1, the contact surface 95 of the deformable member 63 is configured such that its curvature is greater than the curvature of the curved surface Wb of the workpiece W. The configuration of the contact surface 95 with respect to the curved surface Wb of the workpiece W is determined such that the cross-sectional width a of the contact surface 95 and the cross-sectional width b of the curved surface Wb satisfy the condition a ≥ 0.3 × b.

By configuring the deformation member 63 so that the cross-sectional width and curvature of the contact surface 95 satisfy the conditions, the area of the sheet material PT that the contact surface 95 contacts can be made larger when the deformation member 63 is brought into contact with the sheet material PT. As a result, the pressing force acting per unit area of the sheet material PT can be reduced during the process of the deformation member 63 deforming the sheet material PT, thereby suppressing an excessive increase in the elongation rate of the sheet material PT in the area where the contact surface 95 contacts. Therefore, the difference in elongation rate between the area of the sheet material PT that the contact surface 95 contacts and the area that the contact surface 95 does not contact becomes smaller, thus reducing the variation in elongation rate of the sheet material PT as a whole attached to the curved surface Wb of the workpiece W. In other words, the variation in the thickness of the sheet material PT on the curved surface Wb can be reduced, allowing the sheet material's properties to be exhibited more uniformly throughout the entire sheet material PT attached to the curved surface Wb.

Furthermore, by making the curvature of the contact surface 95 greater than the curvature of the curved surface Wb on the workpiece W, the sheet material PT can be accurately attached even if a misalignment occurs between the position of the deformation member 63 and the position of the workpiece W. In other words, unlike a configuration where the shape of the contact surface 95 matches the shape of the curved surface Wb on the workpiece W, a configuration where the curvature of the contact surface 95 is greater than the curvature of the curved surface Wb allows for a much larger tolerance for positional misalignment between the deformation member 63 and the workpiece W in the horizontal direction.

Furthermore, in the configuration according to Embodiment 2, the deformation member 63 presses against a portion of the pre-cut sheet material PT, deforming that portion into a shape that protrudes toward the workpiece W, thereby forming a protruding portion V. When this protruding portion V is formed, horizontal displacement of the sheet material PT is suppressed. Therefore, in step S3, the protruding portion V of the sheet material PT can be accurately brought into contact with the desired position (contact area M1) on the curved surface Wb of the workpiece W. As a result, the accuracy of the position where the sheet material PT is attached in the attachment process in step S4 can be greatly improved compared to the conventional method, allowing the sheet material PT to be attached to the workpiece W with greater precision using differential pressure.

The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above-described embodiments, and includes all modifications (exceptions) within the meaning and scope of the claims. For example, the present invention can be modified as follows:

(1) In each embodiment, sheet material PT was used as an example of a sheet material to be attached to the workpiece W, but the sheet material is not limited to this. In addition to adhesive tape for protecting the circuit surface, adhesive tapes used for other purposes, such as support adhesive tape (dicing tape), may also be used. In this invention, the sheet material can be a sheet, tape, or film, etc., equipped with an adhesive or bonding material having adhesive properties.

Furthermore, the structure of the sheet material is not limited to the structure shown in Figure 3, in which an adhesive material Tb is laminated on one side of the base material Ta; a laminated structure of adhesive and base material is also acceptable. In addition, a single-layer structure of adhesive or bonding material without a base material, or a structure with adhesive or bonding material on both sides of the base material Ta, are also suitable examples. Moreover, a sheet material consisting only of the base material Ta may be used, as long as the sheet material can adhere closely to the workpiece W.

In this embodiment, a configuration in which a separator S is attached to a sheet-like adhesive material T is illustrated. However, depending on the structure of the sheet material application device 1 or the sheet material, the separator S may be omitted.

(2) In each embodiment, a workpiece W having a concave curved surface Wb was exemplified as the workpiece to which the sheet material is to be attached, but the shape and material of the workpiece are not limited thereto. The configuration according to this embodiment can be applied to workpiece materials such as materials used in various semiconductor components, such as substrates, panels, and wafers, as well as ceramics, such as porcelain, resins, metals, glass, wood, stone, paper, or mixtures of the above materials. Furthermore, the shape of the workpiece may be circular, rectangular, polygonal, or substantially circular.

(3) In each embodiment, the workpiece W is shown as having a concave curved surface Wb, but the curved surface is not limited to concave; for example, it may be convex. When attaching the sheet material PT to a convex curved surface Wd provided on the workpiece W, as shown in Figure 30, a part of the sheet material PT is deformed to form a protrusion V, and the attachment process using differential pressure is started after the protrusion V is brought into contact with a part of the convex curved surface Wd.

In this case, the contact area M1 to which the protrusion V makes contact is preferably the area including the highest point, the apex We, of the convex curved surface Wd. By starting the adhesive bonding process using differential pressure with the protrusion V in contact with the apex We, it is possible to more reliably avoid situations where air bubbles are trapped between the sheet material PT and the workpiece W, and where wrinkles occur in the sheet material PT.

(4) In each embodiment, the differential pressure bonding process, i.e., the process related to step S4, is started with the deformable member 63 in contact with the curved surface Wb via the protruding portion V, but this is not limited to this. That is, if the protruding portion V of the sheet material PT is stably attached to the curved surface Wb, the differential pressure bonding process may be started after raising the deformable member 63, as shown in Figure 31. Even in the configuration according to this modified example, the differential pressure bonding is started with the sheet material PT in contact with a part of the curved surface Wb. Therefore, the sheet material PT can be attached radially from the contact area M1 to the curved surface Wb of the workpiece W without generating tension Tx in the sheet material PT. Thus, the sheet material PT can be precisely adhered to the entire surface of the curved surface Wb.

(5) In each embodiment, the shape of the deformable member 63 may be changed as appropriate. Examples of the base end portion 91 of the deformable member 63 include, in addition to a cylindrical shape, a cone shape, a pyramidal shape, a rectangular parallelepiped shape, a frustocone shape, and a frustocone shape. Furthermore, examples of the tip portion 93 of the deformable member 63 include a shape obtained by cutting off a part of a sphere (perfect sphere), as well as a shape obtained by cutting off a part of an ellipsoid.

(6) In each embodiment, control is initiated to generate a differential pressure F between the lower space H1 and the upper space H2 after the deformation member 63 has contacted the curved surface Wb via the protrusion V. However, the timing of contacting the protrusion V with the curved surface Wb is not limited to this. That is, the differential pressure F may be generated when the protrusion V of the sheet material PT formed by the contact surface 95 of the deformation member 63 is close to the curved surface Wb of the workpiece W (in a non-contact state).

In this case, after reducing the pressure in the lower space H1 and the upper space H2 to a vacuum state, the contact surface 95 of the deformable member 63 is brought into contact with the sheet material PT and deformed to form a protrusion V. Then, the deformable member 63 is lowered and moved closer to the curved surface Wb of the workpiece W. At this point, when the tip 93 has moved to a position where a small gap is formed between the protrusion V and the curved surface Wb, the control unit 62 stops the lowering of the deformable member 63. Then, with the protrusion V in close proximity to the curved surface Wb, the control unit 62 starts control to generate a differential pressure F between the lower space H1 and the upper space H2.

When a differential pressure F is generated, the sheet material PT constituting the protruding portion V is adhered to the contact area M1 by the differential pressure F. Then, starting from this contact area M1, the sheet material PT is adhered to the entire curved surface Wb in a radial manner. By generating a differential pressure F while the protruding portion V is in close proximity to the curved surface Wb, and adhering the sheet material PT to the curved surface Wb of the workpiece W, it is possible to more reliably prevent air bubbles Vo from being trapped between the workpiece W and the sheet material PT.

(7) In each embodiment, before lowering the deformation member 63 in step S3 to form the protrusion V, control may be performed to make the air pressure in the lower space H1 higher than the air pressure in the upper space H2. That is, after starting step S3 and reducing the pressure in the lower space H1 and the upper space H2 to a predetermined air pressure at a constant rate, the control unit 62 adjusts the opening degree of each electromagnetic valve so that the air pressure in the lower space H1 is higher than the air pressure in the upper space H2.

As the atmospheric pressure in the lower space H1 is higher than that in the upper space H2, a differential pressure Fb is generated between the two spaces, as shown in Figure 32(a). This differential pressure Fb causes the sheet material PT to deform, moving away from the workpiece W. After the sheet material PT is deformed by the differential pressure Fb, the deformation member 63 is lowered to form the protruding portion V.

In this modified example, the protrusion V is formed while a differential pressure Fb is generated. Therefore, in the process of forming the protrusion V and bringing it into contact with the curved surface Wb, the sheet material PT in the portion other than the protrusion V deforms to move away from the workpiece W (Figure 32(b)). Consequently, in the process of bringing the protrusion V into contact with the curved surface Wb, the situation where the sheet material PT in the portion other than the protrusion V comes into contact with the workpiece W before the protrusion V is avoided.

In other words, when bringing the protruding portion V into contact with the contact area M1 of the curved surface Wb, it is possible to prevent the sheet material PT other than the protruding portion V from coming into contact with unintended parts of the curved surface Wb or the peripheral portion Wa. As a result, it is possible to prevent wrinkles or air bubbles from forming when attaching the sheet material PT to the curved surface Wb.

After the protrusion V is brought into contact with the curved surface Wb, the control unit 62 adjusts the opening of each electromagnetic valve so that the air pressure in the upper space H2 is higher than the air pressure in the lower space H1. This adjustment generates a differential pressure F, which causes the sheet material PT to adhere to the curved surface Wb radially from the contact area M1 outward. In this modified example, where a differential pressure Fb is generated, the protrusion V may be formed by pressing the sheet material PT against the deformation member 63 using the differential pressure Fb.

(8) In each embodiment, one workpiece W is housed inside the chamber 17 and the sheet material PT is attached to it, but this is not limited to this. That is, the sheet material PT may be attached with multiple workpieces W housed inside the chamber 17. In this modified example, multiple holding tables 31 are arranged inside the lower housing 22 according to the number of workpieces W, and multiple deformation members 63 are arranged inside the upper housing 20 according to the number of workpieces W. In this modified example, as shown in Figure 33, two holding tables 31A and 31B are arranged in the lower housing 22, and two deformation members 63A and 63B are arranged in the upper housing 20.

In this modified example, when the chamber 17 is formed, the positions of the holding tables 31 and the deformation members 63 are pre-adjusted so that each deformation member 63 is positioned above each of the holding tables 31. Specifically, it is preferable that the positions of the deformation members 63A contact the deepest part Wc of the workpiece W held by the holding table 31A, and the deformation member 63B contacts the deepest part Wc of the workpiece W held by the holding table 31B. In this modified example, sheet material PT can be attached to multiple workpieces W simultaneously, thus improving attachment efficiency.

(9) In each embodiment, the workpiece W is shown to have one curved surface Wb, but the present invention is not limited to this configuration. That is, the configuration of the present invention can also be applied to workpiece W having multiple curved surfaces Wb. In this modified example, as shown in Figure 34, the workpiece W has three curved surfaces Wb. Each of the curved surfaces Wb is distinguished from left to right as curved surface Wb1, Wb2, and Wb3.

In a workpiece W having multiple curved surfaces Wb, the portions connecting the curved surfaces Wb are defined as curved surface connection portions G. In this modified example, the curved surface connection portion G connecting curved surface Wb1 and curved surface Wb2 is denoted with reference numeral G1, and the curved surface connection portion G connecting curved surface Wb2 and curved surface Wb3 is denoted with reference numeral G2 to distinguish between the two.

In this modified example, the shape of the workpiece mounting surface 35 is adjusted according to the shape of the workpiece W, which has three curved surfaces Wb. Furthermore, multiple deformation members 63, namely deformation members 63A, 63B, and 63C, corresponding to the number of curved surfaces Wb, are arranged on the upper housing 20.

In this modified example, when the chamber 17 is formed, the position of the workpiece mounting surface 35 and the position where the deformation members 63 are arranged are pre-adjusted so that each deformation member 63 is positioned above each of the curved surfaces Wb. Specifically, deformation member 63A is positioned to contact curved surface Wb1, deformation member 63B is positioned to contact curved surface Wb2, and deformation member 63C is positioned to contact curved surface Wb3.

Specifically, it is preferable that the placement positions of the deformation members 63A contact the deepest part Wc1 of the curved surface Wb1, the deformation member 63B contacts the deepest part Wc2 of the curved surface Wb2, and the deformation member 63C contacts the deepest part Wc3 of the curved surface Wb3. With this configuration, the protrusions V formed by each of the deformation members 63 contact the respective deepest parts Wc. By performing the bonding process using differential pressure F while this contact is occurring, it is possible to more reliably prevent air from being trapped between the sheet material PT and the workpiece W. As a result, wrinkles and air bubbles in the sheet material PT can be avoided, and the sheet material PT can be adhered to the curved surface Wb with high precision.

Furthermore, in this modified example, when the workpiece W is held by the holding table 31, it is preferable that the height of each of the curved surface connection portions G is lower than the height of the peripheral edge Wa. This configuration makes it possible to more reliably avoid the situation where, when each of the protrusions V is brought into contact with each of the curved surfaces Wb, the sheet material PT other than the protrusions V comes into contact with the curved surface connection portion G, resulting in tension being generated in the sheet material PT due to such contact.

In this modified example, it is preferable to make each of the protrusions V contact each of the curved surfaces Wb while generating a differential pressure Fb by making the atmospheric pressure in the lower space H1 higher than the atmospheric pressure in the upper space H2, as described above in the modified example related to (7). Since the generation of the differential pressure Fb deforms the sheet material PT so as to move it away from the workpiece W, it is possible to more reliably avoid contact between the sheet material PT and the peripheral edge Wa or the curved surface connection G during the process of bringing the protrusions V into contact with the curved surface Wb.

(10) In each embodiment, the configuration is not limited to bringing the protruding portion V into contact with the curved surface Wb by lowering the deformation member 63. That is, the protruding portion V may be brought into contact with the curved surface Wb by raising the holding table 31 while it is holding the workpiece W.

(11) In each embodiment, the position where the heater 43 is installed is not limited to the inside of the workpiece holding section 33, but can be changed as appropriate as long as it heats the workpiece W or sheet material PT. The timing of heating by the heater 43 can also be changed as appropriate.

Furthermore, it is preferable to perform heating with a heater in at least one of the contact process in step S3 and the bonding process in step S4. During this process, the sheet material PT is deformed. Heating the sheet material PT softens the base material Ta and adhesive Tb, making them easier to deform. Therefore, the contact process or the bonding process can be performed more effectively.

(12) In each embodiment, the configuration is illustrated in which the entire central portion Cp of the surface W1 of the workpiece W is a curved surface Wb, but the invention is not limited to this. Another example of the shape of the central portion Cp is a configuration in which a part of the central portion Cp is a curved surface. That is, as shown in Figure 35(a), the configuration according to the present invention can be applied even to a workpiece W in which the central portion Cp of the surface W1 has both a curved surface Wb and a flat surface St. In this modified example, the process of attaching the sheet material PT in step S4 is started with the protruding portion V in contact with at least a part of the central portion Cp of the surface W1. That is, in step S3, the protruding portion V may be in contact with a part of the curved surface Wb, or with a part of the flat surface St. Alternatively, the protruding portion V may be in contact with a part of the curved surface Wb and a part of the flat surface St.

Furthermore, the shape of the central portion Cp is not limited to a configuration having only a single curved surface Wb. That is, as shown in Figure 33(b), the central portion Cp may have a concave curved surface Wb and a recessed portion Ht. The shape of the recessed portion Ht is not limited to a substantially hemispherical curved surface with a different curvature from the curved surface Wb, as shown in Figure 35(b), but can be any shape. Examples of the shape of the recessed portion Ht include a conical recess, a pyramidal recess, a cylindrical recess, and a prismatic recess.

The shape of the central portion Cp may include a concave curved surface Wb and a convex portion Gt, as shown in Figure 35(c). The shape of the convex portion Gt may be any shape. Examples of the shape of the convex portion Gt include a roughly hemispherical, conical, pyramidal, cylindrical, and prismatic shapes. Furthermore, the central portion Cp may also have a curved surface Wb, a concave portion Ht, and a convex portion Gt.

(13) In each embodiment, the configuration is illustrated in which both the front surface W1 and the back surface W2 of the workpiece W have curved surfaces, but the invention is not limited to this. That is, as shown in Figure 36, the back surface W2 may have a flat shape. When the back surface W2 is flat, the workpiece W can be held more stably on the holding table 31. Therefore, the sheet material PT can be more suitably attached to the side of the front surface W1 which has a curved surface Wb.

1… Sheet material application device 2… Sheet supply unit 3… Separator recovery unit 4… Sheet application unit 5… Sheet recovery unit 6… Supply bobbin 7… Tension mechanism 13… Dancer roller 14… Guide roller 15… Recovery bobbin 17… Chamber 18… Sheet application mechanism 19… Nip roller 20… Upper housing 21… Sheet cutting mechanism 22… Lower housing 29… Joint 30… Joint 31… Holding table 33… Workpiece holding unit 35… Workpiece mounting surface 41… Support pin 43… Heater 55… Vacuum device 62… Control unit 63… Deformable member 65… Cylinder 67… Feed roller 68… Pinch roller 69… Guide rail 75… Cutter unit 81… Cutter 83… Recovery bobbin 91… Base end part 93... Tip part 95... Contact surface

Claims (7)

A sheet material application device for applying a sheet material to a curved surface of a workpiece having a curved surface,
A holding table that holds the workpiece with the side having the curved surface facing upward,
The sheet material is sandwiched between the upper and lower chambers, thereby dividing the space into an upper and lower space via the sheet material, with the lower space containing the chamber that houses the holding table,
A supply mechanism for supplying the aforementioned sheet material,
A deformation member having a contact surface, which deforms the sheet material by bringing the contact surface into contact with the sheet material,
A deformation member moving mechanism moves the deformation member closer to the holding table while the deformation member is in contact with the sheet material, and brings the sheet material, which has been deformed by the deformation member, closer to or in contact with at least a part of the curved surface of the workpiece.
A vacuum mechanism for reducing the pressure of at least the lower space of the upper and lower spaces,
A bonding mechanism that, with the lower space being reduced by vacuum and the sheet material in close proximity to or in contact with a part of the curved surface of the workpiece, attaches the sheet material to the curved surface of the workpiece by the differential pressure formed between the upper space and the lower space within the chamber partitioned by the sheet material,
Equipped with,
The curvature of the contact surface in the deformable member is configured to be greater than the curvature of the curved surface in the workpiece.Occasionally,
The cross-sectional width a of the contact surface in the deformable member and the cross-sectional width b of the curved surface in the workpiece are

The conditions
A sheet material application device characterized by the following: In the sheet material application device according to claim 1 ,
The system includes a pressure adjustment mechanism that adjusts the pressure in the lower space to be higher than the pressure in the upper space.
A sheet material application device characterized in that, while the pressure adjustment mechanism adjusts the pressure in the lower space to be higher than the pressure in the upper space, the deformation member moving mechanism brings the sheet material deformed by the deformation member close to or in contact with at least a part of the curved surface of the workpiece. In the sheet material application device according to claim 1 ,
The aforementioned attachment mechanism is a sheet material attachment device characterized in that, with the sheet material in contact with a part of the curved surface of the workpiece, the sheet material is attached to the curved surface of the workpiece by differential pressure formed between the upper space and the lower space within the chamber partitioned by the sheet material. In the sheet material application device according to claim 1 ,
The deformable member is provided with an elastic body on the contact surface, and the sheet material is deformed by bringing the elastic body into contact with the sheet material, characterized in that the sheet material is attached to the deformable member. In the sheet material application device according to claim 1 ,
The workpiece has a concave curved surface,
The aforementioned deformation member movement mechanism is
A sheet material application device characterized by bringing the sheet material, deformed by the deformation member, into proximity to or in contact with the region including the deepest part of the concave curved surface. In the sheet material application device according to claim 1 ,
The sheet material application device is characterized in that the sheet material comprises a sheet piece having a predetermined shape according to the shape of the workpiece and a long carrier tape that holds the sheet piece. A method for attaching a sheet material to a curved surface of a workpiece, comprising an upper chamber and a lower chamber, in the internal space of the chamber,
A workpiece holding process in which the workpiece is held on a holding table with the side having the curved surface facing upwards,
A process of forming upper and lower spaces, wherein the holding table is housed and the sheet material is sandwiched between the upper and lower chambers, thereby dividing the internal space of the chamber into a lower space where the workpiece is placed with the curved side facing upward, and an upper space facing the lower space with the sheet material in between.
The supply process for supplying the aforementioned sheet material,
A deformation process in which a deformable member having a contact surface is brought into contact with the sheet material to deform the sheet material,
A deformation member movement process in which the deformation member is moved closer to the holding table while the deformation member is in contact with the sheet material, and the sheet material deformed by the deformation member is moved closer to or in contact with at least a part of the curved surface of the workpiece,
A depressurization process that reduces the pressure of at least the lower space of the upper space and the lower space to a vacuum,
The lower space is depressurized by vacuum, and the sheet material is in close proximity to or in contact with a part of the curved surface of the workpiece. The application process involves attaching the sheet material to the curved surface of the workpiece by the differential pressure formed between the upper space and the lower space within the chamber partitioned by the sheet material.
Equipped with,
The curvature of the contact surface in the deformable member is configured to be greater than the curvature of the curved surface in the workpiece.Occasionally,
The cross-sectional width a of the contact surface in the deformable member and the cross-sectional width b of the curved surface in the workpiece are

The conditions
A method for attaching sheet material characterized by the following: