JP2004342273A - Medium bonding method and apparatus - Google Patents

Abstract

An object of the present invention is to correct a warp or a deformation of a medium such as a plastic substrate before bonding with a high-precision glass holding table, interpose an adhesive between a pair of mediums, and keep the medium uniform. By utilizing the capillary phenomenon, the adhesive is uniformly spread, the adhesive does not protrude to the outer peripheral end portion, and a medium manufactured finished product having the above-mentioned quality can be provided.
According to a method of bonding media of the present invention, a position and a posture of each of a pair of media are held and corrected, and an adhesive is applied to at least one of the media. Then, when the adhesive is spread between the pair of media while keeping the distance between the pair of media constant, the spreading speed of the adhesive is controlled by a capillary phenomenon utilizing a temperature difference to control the spread of the adhesive. Paste each other.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and apparatus for bonding media, and more particularly to a method for bonding media when manufacturing optical media such as a microlens array and an optical connector, in addition to an optical disk formed by joining plastics, for example.
[0002]
[Prior art]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2000-76710
[Patent Document 2] Japanese Patent No. 3,096,242
[Patent Document 3] Japanese Patent No. 2,941,196
[Patent Document 4] JP-A-2001-155388
As plastics of optical components have advanced, a technique of joining plastics with higher precision has been desired. As an example, a DVD (Digital Versatile Disk) in which plastic substrates having a thickness of 0.6 mm and a diameter of 120 mm are bonded to each other has already been manufactured and sold. Above all, in a rewritable single-sided dual-layer DVD, the amount of warpage and the uniformity of the thickness of the adhesive layer are important in signal quality. In DVD, adhesives for bonding plastic substrates (thickness: 0.6 mm, diameter: 120 mm) include an ultraviolet curing adhesive, a hot melt adhesive, a double-sided adhesive sheet, and the like. Ultraviolet curing adhesives are often used. A spin coating method is often used as an example of the method. First, as shown in FIG. 14A, which is a joining process diagram according to a conventional medium bonding method, a UV-curable adhesive 93 is applied onto a first substrate 91 placed on a holding table 92 by a syringe. 14B, the second substrate 95 is superimposed next, and as shown in FIG. 14B, the ultraviolet curing adhesive 93 is spread in the outer peripheral direction while rotating the holding table 92. As shown in FIG. 14C, a predetermined thickness of the adhesive 93 is obtained. Next, as shown in FIG. 14D, the adhesive 93 is cured by the ultraviolet rays emitted from the ultraviolet lamp 96 to obtain a finished product as a DVD disk.
[0003]
In the rewritable single-sided dual-layer DVD thus created, it is desired to make the thickness of the adhesive layer more uniform and to minimize the amount of disk warpage. In addition, there was a limit to the uniformity of the thickness of the adhesive layer and the amount of warpage. Specifically, in a rewritable single-sided dual-layer DVD, the thickness of the adhesive layer is X ± 3 μm (X = 30 to 50 μm), and R / T Tilt (α) = 0.3 / 0.15 degree as a warp substitute characteristic. Is desired.
[0004]
Therefore, in order to reduce the amount of warpage of the disk, Japanese Patent Application Laid-Open No. H11-163873 disposes a pair of substrates composed of a pair of optical disk substrates on a mounting table, and on the upper surface of the mounting table, the center side and the outer peripheral side of the substrate pair A bonding method has been proposed in which a difference in height is provided between the two.
[0005]
Further, in Patent Document 2, in order to solve the above-mentioned warpage problem, the warpage is reduced by sandwiching a plastic substrate to be bonded between glass and curing the adhesive layer as it is.
[0006]
Furthermore, in Patent Document 3, the plastic substrate to be bonded is corrected by a pressure plate with a light-transmitting portion, and at the same time, the adhesive is spread to the outer peripheral edge of the plastic substrate, and then only the inner peripheral portion of the substrate is partially cured. Then, the pressure plate is removed and the whole is cured to obtain a finished product.
[0007]
Further, in Patent Document 4 described above, when the ultraviolet curable resin is interposed between the two disks to be bonded and ultraviolet rays are irradiated to cure the ultraviolet curable resin, at least one of the entire surfaces of the disks is suctioned by a suction device. The disk is held on a holding table to correct the warpage and deformation of the disk as much as possible, and to prevent foreign matter from adhering to the disk.
[0008]
[Problems to be solved by the invention]
However, the proposal in Patent Document 1 above assumes that the warpage and deformation of the substrate before bonding are constant, and when the warpage and deformation of the substrate before bonding change, the center of the substrate pair Dx is changed. The height difference between the side and the outer circumference had to be adjusted. In addition, since the spin coating method is used, there is a limit (for example, 50 ± 10 μm) in the uniformity of the adhesive layer. Further, the absolute value X of the adhesive layer in Patent Document 2 depends on the viscosity of the adhesive and the weight of the glass, and it is difficult to make the adhesive layer have an arbitrary thickness. Further, as in the case of the above-mentioned Patent Document 1, since the spin coating method is used, the adhesive protrudes to the outer peripheral end portion, which impairs aesthetic appearance. Furthermore, Patent Document 3 has an advantage that the thickness of the adhesive layer is easily made uniform and the outer peripheral end portion is hardly protruded, but there is a limit on the warpage of the disk. In particular, if the warping and deformation of the substrates before bonding are constant and values within a certain predetermined range are not bonded, the thickness of the adhesive layer X ± 3 μm (X = 30 to 50 μm), and the warpage is R / T Tilt (α) = 0.3 / 0.15 degrees was impossible. Also, in Patent Document 4 described above, warpage after bonding can be prevented, but a spin coating method is also used as a method of applying an ultraviolet curable resin, and a spin coating method is used as in Patent Document 1 described above. In addition, the uniformity of the film thickness of the ultraviolet curable resin was not sufficient, and the adhesive protruded from the outer peripheral end portion, which impaired the appearance.
[0009]
The present invention is intended to solve these problems, and corrects warping and deformation of a medium such as a plastic substrate before bonding with a high-precision glass holding table, and allows an adhesive to be interposed between a pair of mediums. By using the capillary phenomenon while keeping the media uniform, the adhesive is spread evenly, the adhesive does not protrude to the outer peripheral end portion, and a medium manufactured finished product having the above-mentioned quality can be provided. An object of the present invention is to provide a bonding method and a device therefor.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, at least a pair of media such as a plastic substrate or a film, and bonded with an adhesive, according to the medium bonding method of the present invention, each of the pair of media, The position and posture are maintained and corrected, and an adhesive is applied to at least one medium. Then, when the adhesive is spread between the pair of media while keeping the distance between the pair of media constant, the spreading speed of the adhesive is controlled by a capillary phenomenon utilizing a temperature difference to control the spread of the adhesive. Paste each other. Therefore, even if the medium is significantly warped or deformed, the thickness of the adhesive layer can be made uniform by correcting it with a high-precision holding table, and the thickness can be controlled, and the adhesive can also protrude to the outer peripheral end. In addition, it is possible to provide a medium manufactured finished product having the above-mentioned quality.
[0011]
The adhesive is an ultraviolet-curable adhesive, and it is preferable to irradiate ultraviolet rays to the ultraviolet-curable adhesive during bonding.
[0012]
Furthermore, since the viscosity of the ultraviolet curable adhesive is in the range of 1 to 10,000 mPa · s, it can be applied with a general dispenser.
[0013]
Further, a medium bonding apparatus as another invention includes a pair of holding tables for holding and correcting the position and orientation of each of the pair of media, an application unit for applying an adhesive to at least one medium, and a pair of mediums. Distance maintaining means for keeping the distance between the media constant, and when the adhesive is spread between the pair of media, the spreading speed of the adhesive is controlled by a capillary phenomenon utilizing a temperature difference to cause the pair of media to be separated from each other. It is characterized by having a bonding means for bonding. Therefore, even if the medium is significantly warped or deformed, the thickness of the adhesive layer can be made uniform by correcting it with a high-precision holding table, and the thickness can be controlled, and the adhesive can also protrude to the outer peripheral end. In addition, it is possible to provide a medium manufactured finished product having the above-mentioned quality.
[0014]
In addition, since part or all of the distance holding means is made of a component that does not wet the adhesive, it is possible to reliably release the mold after joining with the adhesive.
[0015]
Further, the adhesive is an ultraviolet-curing adhesive, and has an ultraviolet irradiation means for irradiating ultraviolet rays to the ultraviolet-curing adhesive at the time of bonding, and further has a viscosity of 1 to 10,000 mPa · s. Therefore, it can be applied with a general dispenser, and the apparatus can be simplified.
[0016]
Further, the holding table transmits ultraviolet light and transmits 70% or more of light of 200 to 500 nm. Therefore, a general one can be used as a reaction initiator in the ultraviolet curable adhesive, and an inexpensive adhesive can be used.
[0017]
Further, since at least one surface of the holding table has a surface roughness Rmax ≦ 3 μm and a flatness ≦ 3 μm, the thickness unevenness of the adhesive layer can be made more uniform.
[0018]
In addition, since at least one of the holding tables is provided with an electrostatic chucking mechanism for electrostatically holding the medium on the surface of the holding table that holds the medium, even if the thickness of the medium is small, it is possible to handle the medium. Becomes easier.
[0019]
Further, since the ultraviolet irradiation means is a flash type ultraviolet lamp, it does not generate heat as compared with a general high-pressure mercury type ultraviolet lamp, so that the spreading speed of the adhesive can be controlled with certainty, and a pair at the time of curing. Is less likely to cause a difference in thermal expansion between the media, and the warpage of the finished product can be reduced.
[0020]
Further, at the time of bonding by the bonding means, by having an air escape mechanism for releasing air existing between the pair of media, it is possible to reliably spread the adhesive to near the center of the medium, It does not impair the aesthetics of the manufactured product.
[0021]
Further, the provision of the core pins for aligning the centers of the pair of media makes it easy to position the pair of media together.
[0022]
In addition, the air escape mechanism has a simple structure with a control mechanism that controls the relative position of the pair of holding tables and a groove that is provided to allow air to escape from the core pin. The agent can be spread.
[0023]
Further, as an air escape mechanism, by having at least one or more intervening means for defining the thickness and the adhesive area of the adhesive layer when the pair of media are bonded by the bonding means, The unevenness of the thickness of the layer can be made more uniform, and the adhesive can be reliably spread to the vicinity of the center of the medium.
[0024]
Further, the intervening means is preferably smaller than the thickness of the adhesive layer and has a spherical shape.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
The medium bonding apparatus of the present invention includes a pair of holding tables for holding and correcting the position and orientation of each of a pair of media, an application unit for applying an adhesive to at least one of the media, Distance holding means for keeping the distance constant, and laminating the pair of media by controlling the spreading speed of the adhesive by capillary action utilizing a temperature difference when the adhesive is spread between the pair of media. Means.
[0026]
【Example】
FIG. 1 is a view showing a bonding step by a medium bonding method according to a first embodiment of the present invention. The final product form in this embodiment is a rewritable single-sided, dual-layer DVD. The manufacturing process of this embodiment will be described. First, as shown in FIG. 1A, a polycarbonate substrate 11 having an outer diameter of 120 mm and a thickness of 0.6 mm is attached to a holding table 12 using an adsorption device (not shown). And fix it by suction. The holding table 12 is provided with a core pin 13 for positioning the substrate. The holding table 12 is made of stainless steel, and the flatness of the holding table 12 is mirror-finished to 5 μm. Although Hitachi Metals' HPM38 is used as the stainless steel material, there is no particular limitation, and a material that easily exhibits flatness in terms of the function of holding the substrate flat, such as glass, may be used. Further, the core pin 13 is formed of a heat pipe made of copper, the temperature can be varied from 0 to 50 ° C., and as can be seen from FIG. The groove 31 is formed with a groove width 32 of about 5 μm. On the other hand, as shown in FIG. 1A, the holding table 12 is connected to a motor (not shown) and is rotatable. The rotation speed is 0.1 to 10000 r. p. m. Can be varied within the range. 60r. p. m. The adhesive 15 is applied in a ring shape by the dispenser 14 on the substrate 11 which is rotating in the above. As the adhesive 15, a modified acrylic ultraviolet curable adhesive having a viscosity of 450 mPa · s (25 ° C.) was used. The type of the adhesive 15 is not particularly limited, but an ultraviolet curable resin is better than a thermosetting resin. Although there is no limitation on the viscosity, if the viscosity is too high (for example, 8000 mPa · s (25 ° C.) or more), there is a problem that the spreading speed of the adhesive 15 becomes slow, and the thickness of the adhesive layer is 40 μm (about 0 0.4 g), preferably 200 to 700 mPa · s (25 ° C.).
[0027]
Next, as shown in FIG. 1B, the outer peripheral ring 16 having a function of keeping the distance between the pair of plastic substrates constant is operated. The thickness of the adhesive 15 is determined by the thickness of the claw portion 17 of the outer ring 16. The outer peripheral ring 16 has a structure in which the ring is divided into four parts as shown in FIG. 3A shows a state in which the ring is closed, and FIG. 3B shows a state in which the ring is opened. A spring 22 is inserted between the four parts. In addition, portions that come into contact with the substrate 11 and the adhesive 15 are coated with Teflon (registered trademark) to prevent the adhesion of the adhesive 15. There is no problem even if the outer peripheral ring 16 itself is made of Teflon (registered trademark) resin.
[0028]
Next, as shown in FIG. 1C, a polycarbonate substrate 18 having an outer diameter of 120 mm and a thickness of 0.6 mm adsorbed on the holding table 19 is fitted to the substrate 11 with an adhesive layer of an adhesive 15 interposed therebetween. . At this time, the thickness of the adhesive 15, which is 40 μm in this embodiment, is defined by the contact between the claw portion 17 of the outer peripheral ring 16 and the substrate 18. Here, when a temperature distribution as shown in FIG. 1C is generated by the heat pipe, as shown in FIGS. 4A and 4B, the adhesive 15 is moved in the direction of arrow a by capillary action. Start spreading to. The spreading speed depends on the temperature and the viscosity of the adhesive as shown in FIG. The horizontal axis in FIG. 5 indicates the temperature difference between the core pin and the outer peripheral ring, and the vertical axis indicates the time until the adhesive reaches a predetermined position. Eventually, the adhesive 15 reaches the core pin 13, but in this embodiment, as shown in the enlarged view of the portion A in FIG. The adhesive 15 stops at a portion where the convex portions 20 have a shape and the convex portions 20 are joined together with a clearance of about 5 to 10 μm. This state will be described in detail with reference to FIG. 2. As shown in FIG. 2B, when the adhesive 15 spreads in the direction of the core pin 13, the air between the substrate 11 and the substrate 18 is released from the core pin 13. Escape through the groove 31. Thereby, as shown in FIG. 2C, the adhesive 15 can be surely spread to the vicinity of the center hole of the substrate. Although the number of the grooves 31 is set to four, the number is not limited to this, and may be any number and may be changed as appropriate according to the viscosity of the adhesive 15, the thickness of the layer of the adhesive 15, and the like. As a method for escaping air, the same effect can be obtained even if the cross-sectional shape of the core pin 13 is triangular as shown in FIG. As described above, the protrusions 20 of the substrate 11 and the substrate 18 do not completely match each other, and have a clearance of about 5 to 10 μm. However, if the viscosity of the adhesive 15 in this embodiment is used, the adhesive 15 does not enter the gap. Therefore, since the adhesive 15 does not reach the groove 31 of the core pin 13, the groove 31 reliably functions as an escape path for air. Further, as another structure of the core pin, as shown in FIG. 7, there is a structure provided with an air chuck mechanism 41 for determining the center position of the substrate 11 and the substrate 18. Glass beads 42 are interposed between the substrate 11 and the substrate 18 in addition to the adhesive 15. The size of the glass beads 42 is 15 μm. The size is not specified, and may be appropriately changed depending on the thickness and viscosity of the adhesive layer. There is no problem with steel balls, plastics, etc. other than glass beads. However, regarding the shape, a spherical shape is best. Then, when the substrate 11 and the substrate 18 are overlapped with each other, as shown in FIG. 7A, the center position of the substrate 11 and the substrate 18 is aligned by the air chuck mechanism 41, and the adhesive 15 is formed by a capillary phenomenon due to a temperature difference. Begins to spread. Next, as shown in FIG. 7B, at the same time as the claw portion of the air chuck mechanism 41 is retracted, the holding table 12 sucks and fixes the substrate 11, and the holding table 19 descends to a predetermined position. Then, the pressure of the adhesive 15 and the air causes the glass beads 42 to move to the minute recesses 43 at predetermined positions where the glass beads 42 fit. Since there is a clearance between the core pin 13 and the center holes of the substrates 11 and 18, air can be reliably expelled as shown by the arrow b. Therefore, it is possible to spread the adhesive 15 uniformly to the vicinity of the center hole. Further, as shown in FIG. 7 (c), the adhesive 15 is dammed by the glass beads 42 and the substrate 18, and it is possible to reliably prevent the adhesive 15 from protruding into the center hole. In this example, the minute recess 43 is formed at a predetermined position where the glass bead 42 fits into the substrate 11. However, even without the recess 43, the convex portion of the substrate 11 or the substrate 18 may be appropriately adjusted. The same effect can be obtained by adjusting. Further, the shape of the projection is not particularly limited. Further, the air chuck mechanism 41 includes a rotary drive type and a slide guide type, but the type is not limited. Any mechanism may be used as long as the center positions of both substrates can be simply adjusted. The adhesive used in this example had a viscosity of 450 mPa · s (25 ° C.), but there is no problem as long as the viscosity is in the range of 10 to 10,000 mPa · s (25 ° C.). What is necessary is just to change suitably according to a desired film thickness, a spreading speed, etc.
[0029]
On the other hand, the holding table 19 is made of quartz glass. The surface accuracy of the quartz glass is finished with Rmax ≦ 0.3 μm and surface accuracy ≦ 7λ (JIS B0601). In addition, since the parallelism between the holding table 12 and the holding table 19 is 3 μm or less, the layer thickness of the adhesive 15 can be suppressed to within ± 2 μm.
[0030]
Finally, as shown in FIG. 1D, the ultraviolet curing adhesive 15 is cured by an ultraviolet lamp 21. As the ultraviolet lamp 21, a flash type ultraviolet lamp was used. The lamp has a spiral shape. Specifically, a flash lamp RC-742 manufactured by XENON was used, but the invention is not limited to this. A high-pressure mercury lamp may be used, but in that case, a cooling mechanism that does not cause a temperature difference between the holding table 12 and the holding table 19 is required. This is because if a difference in thermal expansion between the substrate 11 and the substrate 18 occurs, even if the substrate 11 is flat immediately after bonding, warpage occurs with time. Further, the lamp may have a linear shape, but in this case, it is necessary to devise a method of uniformly irradiating ultraviolet rays on the front surface of the optical disk.
[0031]
FIG. 8 is a view showing a bonding step by a medium bonding method according to the second embodiment of the present invention. Similarly to the first embodiment, the final product form in this embodiment is a rewritable single-sided, two-layer DVD, but three plastic substrates having an outer diameter of 120 mm and a thickness of 0.4 mm are provided via two adhesive layers. It is stuck. The manufacturing process is basically the same as that of the first embodiment. After applying the adhesive 52 to the substrate 51 and bonding the substrate 52 to the substrate 53, the adhesive 52 is applied to the substrate 51, which is turned upside down, and bonded to the substrate 54 to obtain a finished product. The recording layer 55 includes a guide groove and a reflection film as shown in an enlarged view of a portion B in the drawing.
[0032]
FIG. 9 is a view showing a bonding step by a medium bonding method according to the third embodiment of the present invention. The final product form in the present embodiment is such that a plastic film 62 having an outer diameter of 120 mm and a thickness of 0.95 mm and a plastic substrate 61 having an outer diameter of 120 mm and a thickness of 1.1 mm form an adhesive layer having a thickness of 0.05 mm. It is a structure that is bonded together. Polycarbonate was used as the material of the plastic substrate 61 and the plastic film 62, but the material is not limited to this, and there is no problem even if acrylic resin, olefin resin or the like is used. The manufacturing process of the present embodiment is the same as that of the first embodiment, but differs from the first embodiment in the configuration of the holding table 19 as shown in FIG. The holding table 63 includes a base 64, an insulating layer 65, an extraction electrode 66, an internal electrode 67, and a dielectric layer 68. The base 64 and the insulating layer 65 are made of SiO ₂ The extraction electrode 66 and the internal electrode 67 are made of Cu, and the dielectric layer 68 is made of ZnS-SiO. ₂ Consists of Although there is no particular limitation on the thickness of the material, it is desirable that 70% or more of light of 200 to 500 nm is transmitted. The material of the insulating layer 65 and the dielectric layer 68 is Al ₂ O ₃ , Al ₂ O ₃ —SiC, polycrystalline Si, AlN and the like. On the other hand, examples of the electrode material include Ag, Pt, and Au. When a voltage is applied to the extraction electrode 66, the dielectric layer 68 is charged. By this charging, the plastic film 62 having a thickness of 0.95 mm is electrostatically attracted. As a result, even a relatively thin (thickness ≦ 0.1 mm) plastic film can be easily handled, and can be easily detached by cutting off the voltage after the lamination, and the thickness of the adhesive layer can be made uniform. This electrostatic attraction method may use a method using discharge or frictional charging in addition to the method of applying a voltage as in this embodiment, and there is no problem as long as the holding table and the plastic film can be uniformly attracted.
[0033]
FIG. 11 is a perspective view showing a state of bonding by a method for bonding media according to a fourth embodiment of the present invention. FIG. 12 is a schematic cross-sectional view showing a bonding step of this embodiment. The finished product in this embodiment is a unit component of a reading device of a copying machine. The unit components of the reading device of the copying machine mainly include a three-line (RGB) CCD sensor 71, a structure 72, and a polyimide film 73. In addition, a contact for an electrode is formed on an end of the CCD sensor 71. Further, the contact and the polyimide film 73 on which the electric wire is patterned are attached via an adhesive. The thickness of the polyimide film 73 is 50 μm. The CCD sensor 71 is made of silicon, and the structure 72 is made of polycarbonate containing glass fiber. The manufacturing process of this embodiment will be described. As shown in FIG. 12A, first, an adhesive 74 is applied to a part of the structure 72. As the adhesive 74, an epoxy-based ultraviolet ray + thermosetting resin was used. The viscosity is 8,000 mPa · s. Next, the polyimide film 73 is fixed to the holding base 76 by electrostatic attraction. As shown in FIG. 12B, which is a cross-sectional view taken along line AA ′ in FIG. 12A, a part of the holding base 76 is formed with a tapered portion 77 having a tapered shape. The tapered portion 77 is fitted with the tapered portion 78 of the structure 72 and the position is fixed. When the temperature of a holding table (not shown) that fixes the structure 72 is controlled to a temperature distribution as shown in FIG. 12C, the adhesive 74 spreads in the direction of arrow c due to capillary action. Extend. Next, an ultraviolet curing adhesive 74 is cured by an ultraviolet lamp (not shown), and the contact of the CCD sensor 71 and the polyimide film 73 are bonded. In the present embodiment, the structure 72 and the CCD sensor 71 can be simultaneously bonded by controlling the amount of the adhesive 74, so that the number of assembling steps and the number of assembling mechanisms can be reduced.
[0034]
Next, FIG. 13 is a schematic cross-sectional view showing a state of bonding by a medium bonding method according to a fifth embodiment of the present invention. This figure shows a schematic cross-section when the microlens array sheets 81 are adhered to each other. The microlens array sheet 81 is made by using special extrusion and hot press molding, and is an acrylic resin having a size of 5 cm and a thickness of 0.8 mm. The manufacturing process according to the present embodiment will be described. As shown in FIG. 13A, similarly to the third embodiment and the fourth embodiment, the holding tables 82 and 83 having the electrostatic suction mechanism are provided with: The micro lens array sheet 81 is fixed by suction. Further, the holding tables 82 and 83 are formed with tapered portions 84 and 85 having a tapered shape, respectively. The holding tables 82 and 83 are combined to define the thickness of the adhesive layer, which is 10 ± 1 μm in this embodiment. ing. Next, as shown in FIG. 13B, a temperature difference is made by a temperature control mechanism (not shown) of the holding tables 82 and 83, and the ultraviolet curable adhesive 86 is applied in the direction of arrow d by capillary action. It is spread and cured by an ultraviolet lamp (not shown) to obtain a finished product. The size and thickness of the microlens array sheet 81 and the thickness of the layer of the adhesive 86 are not limited. There is no particular limitation on the size of the microlens.
[0035]
It should be noted that the present invention is not limited to the above embodiment, and it goes without saying that various modifications and substitutions can be made within the scope of the claims.
[0036]
【The invention's effect】
As described above, according to the medium bonding method of the present invention, in which at least a pair of media such as plastic substrates or films are bonded with an adhesive therebetween, the position and orientation of each of the pair of media are Is held and corrected, and an adhesive is applied to at least one medium. Then, when the adhesive is spread between the pair of media while keeping the distance between the pair of media constant, the spreading speed of the adhesive is controlled by a capillary phenomenon utilizing a temperature difference to control the spread of the adhesive. Paste each other. Therefore, even if the medium is significantly warped or deformed, the thickness of the adhesive layer can be made uniform by correcting it with a high-precision holding table, and the thickness can be controlled, and the adhesive can also protrude to the outer peripheral end. In addition, it is possible to provide a medium manufactured finished product having the above-mentioned quality.
[0037]
The adhesive is an ultraviolet-curable adhesive, and it is preferable to irradiate the ultraviolet-curable adhesive with ultraviolet light during bonding.
[0038]
Furthermore, since the viscosity of the ultraviolet curable adhesive is in the range of 1 to 10,000 mPa · s, it can be applied with a general dispenser.
[0039]
Further, a medium bonding apparatus as another invention includes a pair of holding tables for holding and correcting the position and orientation of each of the pair of media, an application unit for applying an adhesive to at least one medium, and a pair of mediums. Distance maintaining means for keeping the distance between the media constant, and when the adhesive is spread between the pair of media, the spreading speed of the adhesive is controlled by a capillary phenomenon utilizing a temperature difference to cause the pair of media to be separated from each other. It is characterized by having a bonding means for bonding. Therefore, even if the medium is significantly warped or deformed, the thickness of the adhesive layer can be made uniform by correcting it with a high-precision holding table, and the thickness can be controlled, and the adhesive can also protrude to the outer peripheral end. In addition, it is possible to provide a medium manufactured finished product having the above-mentioned quality.
[0040]
In addition, since part or all of the distance holding means is made of a component that does not wet the adhesive, it is possible to reliably release the mold after joining with the adhesive.
[0041]
Further, the adhesive is an ultraviolet-curable adhesive, and has an ultraviolet irradiation means for irradiating ultraviolet rays to the ultraviolet-curable adhesive at the time of bonding, and further has a viscosity of 1 to 10,000 mPa · s. Therefore, it can be applied with a general dispenser, and the apparatus can be simplified.
[0042]
Further, the holding table transmits ultraviolet light and transmits 70% or more of light of 200 to 500 nm. Therefore, a general one can be used as a reaction initiator in the ultraviolet curable adhesive, and an inexpensive adhesive can be used.
[0043]
Further, since at least one surface of the holding table has a surface roughness Rmax ≦ 3 μm and a flatness ≦ 3 μm, the thickness unevenness of the adhesive layer can be made more uniform.
[0044]
In addition, since at least one of the holding tables is provided with an electrostatic chucking mechanism for electrostatically holding the medium on the surface of the holding table that holds the medium, even if the thickness of the medium is small, it is possible to handle the medium. Becomes easier.
[0045]
Further, since the ultraviolet irradiation means is a flash type ultraviolet lamp, it does not generate heat as compared with a general high-pressure mercury type ultraviolet lamp, so that the spreading speed of the adhesive can be controlled with certainty, and a pair at the time of curing. Is less likely to cause a difference in thermal expansion between the media, and the warpage of the finished product can be reduced.
[0046]
Further, at the time of bonding by the bonding means, by having an air escape mechanism for releasing air existing between the pair of media, it is possible to reliably spread the adhesive to near the center of the medium, It does not impair the aesthetics of the manufactured product.
[0047]
Further, the provision of the core pins for aligning the centers of the pair of media makes it easy to position the pair of media together.
[0048]
The air escape mechanism has a simple structure with a control mechanism for controlling the relative position of the pair of holding tables and a groove provided to allow air to escape from the core pin, and ensures a secure adhesion to the vicinity of the center of the medium. The agent can be spread.
[0049]
Further, as an air escape mechanism, by having at least one or more intervening means for defining the thickness and the adhesive area of the adhesive layer when the pair of media are bonded by the bonding means, The unevenness of the thickness of the layer can be made more uniform, and the adhesive can be reliably spread to the vicinity of the center of the medium.
[Brief description of the drawings]
FIG. 1 is a view showing a bonding step by a medium bonding method according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a structure of a core pin.
FIG. 3 is a diagram showing a structure of an outer peripheral ring.
FIG. 4 is a diagram showing a state in which an adhesive spreads.
FIG. 5 is a characteristic diagram showing the relationship between the temperature and viscosity of the adhesive and the spreading speed.
FIG. 6 is a diagram showing another structure of the core pin.
FIG. 7 is a view showing still another structure of the core pin.
FIG. 8 is a view showing a bonding step by a medium bonding method according to a second embodiment of the present invention.
FIG. 9 is a view showing a bonding step by a medium bonding method according to a third embodiment of the present invention.
FIG. 10 is a view showing a structure of a different holding table.
FIG. 11 is a transparent perspective view showing a state of bonding by a medium bonding method according to a fourth embodiment of the present invention.
FIG. 12 is a schematic cross-sectional view showing a bonding step of the fourth embodiment.
FIG. 13 is a schematic cross-sectional view showing a state of bonding by a medium bonding method according to a fifth embodiment of the present invention.
FIG. 14 is a schematic cross-sectional view showing a bonding step according to a conventional medium bonding method.
[Explanation of symbols]
11, 18; substrate, 12, 19; holding table, 13; core pin,
14; dispenser, 15; adhesive, 16; outer peripheral ring,
17; claw portion, 20; convex portion, 21; ultraviolet lamp, 22; spring,
31; groove; 41; chuck mechanism; 42; glass bead; 43;

Claims (18)

At least one or more media such as a plastic substrate or a film, in a method of bonding a medium to be bonded via an adhesive,
The position and orientation of each of the pair of media are held and corrected, the adhesive is applied to at least one of the media, and the distance between the pair of media is kept constant. A method of bonding a pair of media by controlling a spreading speed of the adhesive by a capillary phenomenon utilizing a temperature difference when the two media are spread. 2. The method according to claim 1, wherein the adhesive is an ultraviolet-curable adhesive, and ultraviolet rays are applied to the ultraviolet-curable adhesive during bonding. 3. 3. The method according to claim 2, wherein the viscosity of the ultraviolet curable adhesive is in the range of 1 to 10,000 mPa · s. At least a pair of media such as plastic substrates or films, in a medium bonding apparatus for bonding with an adhesive interposed,
A pair of holding tables for holding and correcting the position and posture of each of the pair of media,
Application means for applying the adhesive to at least one medium,
Distance holding means for keeping the distance between the pair of media constant,
When the adhesive is spread between a pair of media, a laminating means for controlling a spreading speed of the adhesive by a capillary phenomenon using a temperature difference to bond the pair of media to each other is provided. Bonding device for media. 5. The medium bonding apparatus according to claim 4, wherein a part or all of the distance holding unit is formed of a component that does not wet the adhesive. The medium bonding apparatus according to claim 4, wherein the adhesive is an ultraviolet-curable adhesive. 5. The medium bonding apparatus according to claim 4, further comprising an ultraviolet irradiation means for irradiating the ultraviolet curable adhesive with ultraviolet light at the time of bonding. 8. The medium bonding apparatus according to claim 6, wherein the viscosity of the ultraviolet curable adhesive is in a range of 1 to 10,000 mPa · s. The apparatus according to claim 4, wherein the holding table transmits ultraviolet light. The apparatus according to claim 4, wherein the holding table transmits 70% or more of light having a wavelength of 200 to 500 nm. 5. The apparatus according to claim 4, wherein at least one surface of the holding table has a surface roughness Rmax ≦ 3 μm and a flatness ≦ 3 μm. 5. The medium bonding apparatus according to claim 4, wherein at least one of the holding tables is provided with an electrostatic suction mechanism for electrostatically holding the medium on a surface of the holding table that holds the medium. The medium bonding apparatus according to claim 7, wherein the ultraviolet irradiation means is a flash ultraviolet lamp. 5. The medium bonding apparatus according to claim 4, further comprising an air escape mechanism for releasing air existing between the pair of media when the bonding is performed by the bonding unit. The medium bonding apparatus according to claim 4, further comprising a core pin for aligning each center of the pair of media. 16. The medium bonding apparatus according to claim 14, wherein the air release mechanism has a control mechanism for controlling a relative position of the pair of holding tables, and a groove provided in the core pin for releasing air. 15. The medium according to claim 14, wherein the air escape mechanism has at least one or more intervening means for defining the thickness of the adhesive layer and the bonding area when the pair of media are bonded by the bonding means. Bonding equipment. 18. The medium bonding apparatus according to claim 17, wherein the intervening means has a spherical shape smaller than the thickness of the adhesive layer.

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