JP2001262080A - Method for manufacturing composite substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a composite substrate by a method wherein unevenness is eliminated from the surface of a thin covering plate as much as possible in the installation of the thin covering plate on the surface of a substrate with a functional film stuck thereon. SOLUTION: In the composite substrate manufacturing method, a level block having an excellently flattened surface is fixed immovable with its flattened surface facing upward to the workpiece fixing chuck of a rotary applicator, a thin covering plate is installed on the level block to be in close contact therewith, a liquid bonding agent is dropped on the thin covering plate or on the level block, a substrate with a functional film stuck thereon is placed on the applied bonding agent with the functional film facing downward, and then the workpiece fixing chuck is rotated for the removal of the excess from the bonding agent. The substrate should be a substrate 5 wherein a functional film 6 is surrounded by dummy films 7 having practically the same thickness as that of the functional film 6 or another substrate wherein the dummy films 7 are replaced by functional films.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of manufacturing a composite substrate having a structure in which a surface of a substrate to which a functional film such as an optical film is adhered is covered with a thin plate for a cover via an adhesive. Belong to.

[0002]

2. Description of the Related Art Conventionally, as one of electronic parts and optical parts, a composite substrate having a structure in which the surface of a substrate on which various functional films are adhered is covered with a thin plate for a cover such as a glass plate or a film. There is. In order to manufacture such a composite substrate, for example, a substrate and a thin plate are stacked with an adhesive therebetween, sandwiched between a pair of plates having high flatness, and the thickness of the adhesive layer is increased until a predetermined thickness is obtained. A method of pressing and curing the adhesive in that state has been adopted. However, with this method,
The adhesive protrudes from between the stacked substrate and the thin plate and goes around to a surface that is not related to the bonding of the substrate and the thin plate, which not only causes a problem in reusing the highly flat plate used for pressing but also In addition, the accuracy of controlling the thickness of the adhesive layer was insufficient, and it was also difficult to pressurize each part with a constant pressure. further,
Since the pressure is applied by the pressure plate, there is a problem that the degree of adhesion is increased and peeling is not easy.

[0003] Therefore, the substrate is mounted on a vacuum chuck of a spinner, a liquid adhesive is dropped on the substrate, a thin plate of glass or the like is superimposed on the substrate, and the adhesive is spread over the entire surface by air blowing. Then, a method has been proposed in which a spinner is rotated so that excess adhesive is scattered to bring the two into close contact, and then the composite substrate is removed from the vacuum chuck (see, for example, Japanese Patent Application Laid-Open No. 55-68040). ).

[0004]

Although the above-mentioned method can considerably eliminate the drawbacks of the prior art, the composite substrate produced by this method has a defect that the surface covered with a thin plate has poor smoothness. Have been found to have
The reason is that unless the substrate is polished, there is unevenness in the wall thickness and the flatness is insufficient, and glass or film or the like is formed on this substrate or on another layer formed thereon. This is because, when a thin plate is attached, the unevenness of the thickness of the lower substrate becomes the surface of the thin plate which is the outermost surface as it is.

The present invention has been made in view of the above problems, and an object of the present invention is to cover the surface of a substrate to which a functional film is attached with a thin plate for a cover. An object of the present invention is to provide a method for manufacturing a composite substrate in which surface irregularities are eliminated as much as possible.

[0006]

In order to achieve the above object, a method of manufacturing a composite substrate according to the present invention comprises bonding a substrate provided with a functional film and a thin plate for a cover via an adhesive. This is a method for manufacturing a composite substrate, characterized by using a substrate provided with a dummy film having substantially the same thickness around a functional film.

Specifically, a step of fixing a platen having a flat surface with improved flatness on a chuck for fixing an object to be coated of a rotary coating machine, with the flat surface side facing upward, and fixing the platen on the platen. A step of placing a thin plate for a cover and bringing it into close contact, a step of dropping an adhesive liquid onto the thin plate or platen adhered to a surface plate, and attaching a functional film on the dropped adhesive. A method of manufacturing a composite substrate by performing in this order a step of placing the substrate on which the functional film is placed on its lower side and a step of rotating a chuck for fixing an object to be coated and removing an excess portion of the adhesive. The present invention is characterized in that a substrate formed by surrounding a functional film and attaching a dummy film having substantially the same thickness to the periphery thereof is used as the substrate.

Further, a substrate having a functional film disposed thereon may be used instead of the dummy film.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a spin coater, commonly called a spinner, is used for applying an adhesive. The spinner has an air chuck capable of vacuum suction at one end of a rotating shaft, and fixes an object to be applied to the air chuck. Then, the application liquid is stored in another pressure tank for liquid supply, and a certain amount of the application liquid is discharged by adjusting the opening / closing time of the solenoid valve and dropped on the object to be coated. By spreading the dropped coating liquid on the surface of the object to be coated by centrifugal force, it is suitable for coating on a relatively small plate-like object. It is often used for example. In the present invention, such a spinner is used not only for merely applying the adhesive, but also for bonding thin plates and controlling the thickness of the adhesive.

FIG. 1 is a process chart showing a procedure for manufacturing a composite substrate according to the present invention. Hereinafter, an embodiment of the present invention will be described with reference to FIG.

First, as shown in FIG. 1A, a surface plate 2 is fixed on an air chuck 1 which is a chuck for fixing an object to be coated, which is installed in a rotary coating machine. The fixing of the surface plate 2 may be performed by means other than vacuum suction, such as mechanically. The surface on the front side of the surface plate 2, that is, the air chuck 1
The surface on the side opposite to the one fixed with is processed into a flat surface with improved flatness. Specifically, the flatness is 0.5μ
m or less, and the material is preferably quartz glass, for example. The high flatness of the platen 2 in this way means that the flatness of the surface of the product after bonding is created, and by fixing the thin plate by close contact, the thin plate comes into contact with anything other than the platen. Therefore, no extra stress is applied to the thin plate at the time of rotation, and two roles, that is, stable rotation can be obtained.

Although the conventional air chuck does not necessarily consider the flatness, there is an opening for vacuum suction, so that the object to be coated is sucked into the opening at that portion, and the entire surface is placed on the lower side. There may be convex deformation. On the other hand, in the present invention, a highly rigid surface plate is fixed by an air chuck, and a surface of the surface plate having no opening for vacuum suction is used.

The size of the surface plate 2 is comparable to the size of a thin plate to be coated. However, as for the surface plate 2, the one that is slightly smaller than the thin plate, the dropped adhesive is shaken off by the rotation of the rotary coating machine and scatters, and wraps around the thin plate toward the surface plate and adheres. This is preferable because it does not cause complication such as necessity of washing. On the other hand, if the surface plate 2 is too small, the ability to adhere the thin plate as the object to be coated is reduced, and there is no restriction on the portion protruding from the surface plate 2, so the flatness of the thin plate may be reduced. . Therefore, the size of the platen 2 is 60 to
About 90% is preferable. Further, it is preferable that the surface plate 2 is sufficiently thick so as not to bend by a fixing means such as an air chuck.

Next, as shown in FIG. 1 (b), a thin plate 3 for covering is placed on the fixed surface plate 2 and brought into close contact therewith. To bring the thin plate 3 into close contact with the surface plate 2, it is only necessary to place the thin plate 3 on the flat surface of the surface plate 2 without any intervention. The size of the thin plate 3 is preferably equal to or slightly larger than the area of the platen 2 so that the adhesive does not flow around the platen 2. In addition, surface plate 2
When a repair agent or the like is used, the size may be smaller than the surface plate. When the thin plate 3 is positioned and a part of the end comes into contact, vacuum contact is performed between the thin plate 3 and the surface plate 2. Alternatively, an air blow or the like may be used in combination. If sticking is poor, a suitable amount of a volatile organic solvent may be used.
It is to be noted that both the platen 2 and the thin plate 3 have been cleaned and used in a clean bench having a high degree of cleanliness in a clean room in order to prevent entry of foreign matter or the like during bonding.

When the thin plate 3 is placed on the surface plate 2 and brought into close contact therewith, the surface of the surface plate 2 has a high flatness. Even if there is a deflection, it is corrected by the surface plate 2, and the lower surface of the thin plate 3,
That is, the surface in contact with the surface plate 2 has the flatness of the surface plate 2. Here, if the thin plate 3 is charged, the adhesion is improved, and thus it is preferable to increase the reliability of the chuck. However, in the case of dust suction or electronic components, there is a possibility that the charging may have an adverse effect. If there is such a concern, remove electricity in advance.

Next, on the thin plate 3 adhered to the surface plate 2,
Alternatively, an appropriate amount of adhesive is dropped on the surface plate 2 where the thin plate 3 is not provided. The adhesive is in a liquid feed tank whose temperature is controlled,
The discharge amount is controlled by opening and closing the solenoid valve. When the liquid adhesive is dropped by a dispenser or the like, discharge conditions are set so that the amount is sufficient and not excessive for bonding, and care is taken so that air bubbles are not mixed. After the adhesive is dropped, a functional substrate 5 is placed on the adhesive 4 as shown in FIG.

The substrate 5 used here is as shown in FIG. 2. A functional film 6 is laminated on the substrate 5 as shown in FIG. A dummy film 7 having the same thickness is laminated. When the substrate 5 is placed on the dropped adhesive 4 with its functional film 6 facing down, the thin plate 3
The adhesive 4 between the substrate 5 and the substrate 5 gradually spreads around the substrate 5 by its own weight.

When the adhesive 4 has spread to the surroundings, the surface plate 2, the thin plate 3, the adhesive 4, and the substrate 5 on the air chuck 1
Are rotated integrally with a spinner. Due to the rotation of the spinner, the adhesive 4 spreads to the periphery between the thin plate 3 and the substrate 5, and accordingly the thickness of the adhesive 4 decreases, and the excess adhesive 4 protruding from the periphery is removed by the centrifugal force.
Can be shaken to the periphery without soiling the back surface of the table and the surface plate 2. At this time, the thickness of the adhesive 4 can be controlled by adjusting the number of rotations, the rotation time, the viscosity of the adhesive, the standing time after mounting the substrate, and the like. Since the spinner rotates at a high speed, it is desirable to attach a slope to the spinner at a high speed, and it is better to attach a slope and gradually reduce the rotation even after a desired film thickness is obtained.

After the rotation of the spinner, as shown in FIG. 1D, the thin plate 3 and the substrate 5 are laminated with a uniform layer of the adhesive 4 interposed therebetween. If the adhesive 4 is curable with ionizing radiation, the adhesive is cured by irradiating with ionizing radiation (for example, ultraviolet rays, electron beams, etc.) in this state.

After the adhesive is cured, the substrate 5 is peeled from the surface plate 2. When peeling, use an air blow,
A reinforced plastic separator (peeling jig) or the like may be used so as not to damage the glass. At this time, since the interface between the platen 2 and the thin plate 3 is only in vacuum contact, it can be easily peeled off.

The composite substrate manufactured by the above steps is
Since the dummy film 7 is arranged around the functional film 6, the influence of the step at the peripheral portion of the functional film 6 is reduced. Further, the difference in the thickness of the adhesive layer between the portion where the functional film 6 is provided and the portion where the functional film 6 is not provided reduces the influence of the shrinkage rate after curing. Therefore, the bending of the thin plate 3 is reduced, and a composite substrate having high flatness and parallelism can be obtained.
Then, a final product is obtained by cutting out the portion of the substrate on which the functional film 6 is attached by dicing.

In the above-described example, the case where a substrate is used in which a functional film is surrounded and a dummy film is attached around the functional film has been described. It is also possible to adopt an embodiment in which a substrate having multiple sheets of a conductive film is used.

[0023]

EXAMPLE First, as a surface plate, AL glass manufactured by Asahi Glass Co., Ltd. (thermal expansion coefficient: 37 × 10 ⁻⁷ / ° C., thickness: 6.35 mm, 150 mm)
mm □, flatness of 5 μm or less) were prepared and fixed to an air chuck of a spinner.

Next, as a thin plate for the cover, a glass plate (“AF45” manufactured by Schott Co., Ltd .: thermal expansion coefficient: 45 × 10 ⁻⁷ /
C., a thickness of 50 μm, and a thickness of 150 mm) were prepared, and the thin glass sheet was placed on a surface plate and brought into close contact therewith.

Next, 2 g of an ionizing radiation-curable adhesive ("Norland 65" manufactured by Norland) is applied on the thin glass.
It was dropped, and the substrate was overlaid on the dropped adhesive. The substrate used was of the type shown in FIG. 2 and had a thickness of 1.1 m.
m with a size of 150 × 150 mm, and a functional film (thickness: 20 μm, 30 × 40 mm)
□), and a dummy film of the same thickness was laminated around the four sides of the functional film at an interval of 2 mm. Then, the functional film was placed on the adhesive with the functional film facing down.

Subsequently, the spinner was rotated at a high speed. The rotation speed was 3000 rpm and the rotation time was 60 seconds.
As a result, the adhesive spread to the periphery between the thin plate and the substrate, and the thickness of the adhesive decreased accordingly, and the excess adhesive protruding from the periphery was shaken off by the centrifugal force.

After the rotation of the spinner, the adhesive was cured by irradiating ultraviolet rays. The curing was performed using a UV irradiation device (handy UV800) manufactured by Oak Co., Ltd. for 60 seconds with uniform irradiation from the substrate surface opposite to the adhesive, that is, the back surface of the substrate.

After the adhesive was cured, the substrate was peeled off from the surface plate using an air blow. Then, the flatness and the parallelism of the peeled substrate were measured by a surface measuring device called a Fizeau interferometer. In addition, the thickness of the adhesive layer was measured using a reflection film on a substrate provided at four points around the functional film using a film thickness measuring device ("LT-8100" manufactured by Keyence Corporation). .

On the other hand, for comparison with the above embodiment, FIG.
The same composite substrate was prepared using a substrate having no dummy film as shown in (1), and the flatness and parallelism were measured in the same manner, and the thickness of the adhesive layer was measured.

Table 1 shows the results. As can be seen from Table 1, the substrate 1 with the dummy film has better flatness, parallelism, and film thickness uniformity than the substrate 2 without the dummy film, and the characteristics are particularly improved in the parallelism. Was.

[0031]

[Table 1]

[0032]

As described above, according to the present invention,
A composite substrate is manufactured by laminating a substrate provided with a functional film and a thin plate for a cover via an adhesive, and a dummy film having substantially the same thickness is provided around the functional film as the substrate. By using the substrate provided, specifically, a platen having a flat surface with increased flatness on the chuck for fixing the object to be coated of the rotary coating machine with the flat surface side up. Fixing, placing a cover thin plate on the surface plate and making it adhere, and dropping an adhesive liquid on the thin plate or surface plate that is brought into close contact with the surface plate, and dropping the adhesive. A step of stacking the substrate on which the functional film is attached on top of the agent with the functional film facing down, and a step of rotating the chuck for fixing the object to be coated and removing an excess portion of the adhesive. Go in this order and combine A board is manufactured, and as the above-mentioned substrate, a functional film is used as a substrate surrounding a functional film and a dummy film of approximately the same thickness is pasted around the functional film, or a functional film is disposed in place of the dummy film. The effect of the step at the periphery of the functional film and the difference in the thickness of the adhesive layer between the part without the functional film and the shrinkage after curing due to the use of a substrate made of Since the thickness is reduced, the bending of the thin plate is reduced, so that a composite substrate having good flatness and parallelism can be manufactured.

[Brief description of the drawings]

FIG. 1 is a process chart showing a procedure for manufacturing a composite substrate according to the present invention.

FIG. 2 is a perspective view of a substrate formed by surrounding a functional film and attaching a dummy film around the functional film.

FIG. 3 is a perspective view of a substrate on which a dummy film is not provided.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air chuck 2 Surface plate 3 Thin plate 4 Adhesive 5 Substrate 6 Functional film 7 Dummy film

Claims (3)

[Claims] 1. A method of manufacturing a composite substrate by laminating a substrate provided with a functional film and a thin plate for a cover via an adhesive, wherein a dummy having substantially the same thickness is provided around the functional film. A method for producing a composite substrate, comprising using a substrate provided with a film. 2. A step of fixing a platen having a flat surface with improved flatness on a chuck for fixing an object to be coated of a rotary coating machine with the flat surface side up, and a step for fixing a cover on the platen. A step of placing a thin plate and bringing it into close contact, a step of dropping an adhesive liquid onto the thin plate or the platen adhered to the platen, and a step of attaching a functional film to the dropped adhesive on a substrate. A method of manufacturing a composite substrate by performing in this order a step of placing the functional film on the lower side and placing the same, and a step of rotating a chuck for fixing the coated object to remove an excess portion of the adhesive. A method of manufacturing a composite substrate, comprising using a substrate surrounding a functional film and attaching a dummy film having substantially the same thickness to the periphery thereof as the substrate. 3. The method for manufacturing a composite substrate according to claim 1, wherein a substrate on which a functional film is arranged is used instead of the dummy film.