JP2005249855A - Alignment bonding method, alignment bonding device, optical device, and optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an alignment bonding method and an alignment bonding device realizing the improvement of bonding quality by using a mask holder having good flatness. <P>SOLUTION: The bonding method uses a device 30 equipped with an alignment detection means 32, a substrate chuck 38 fixing a lower substrate, moving means 39 and 41 capable of moving the substrate chuck in directions X, Y, Z, and θ, the mask holder 33 composed of an optically transparent plane member, and a light irradiation part 31, and includes a process for setting the lower substrate 20 equipped with an alignment mark 24 on the substrate chuck 38, a process for setting an upper substrate 10 equipped with an alignment mark 12 on the mask holder 33, a process for aligning the alignment marks of the upper and the lower substrates, a process for applying an adhesive, a process for introducing inert gas to the periphery of a bonding part and covering an atmosphere on the periphery of the adhesive with the inert gas, a process for spreading the adhesive, and a process for radiating light so that the adhesive is cured to obtain a bonding result. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an alignment bonding method and an alignment bonding apparatus used for manufacturing an optical element, an optical element manufactured using the alignment bonding method and the alignment bonding apparatus, and an optical pickup device using the optical element.

  Conventionally, as a conventional technique related to an alignment bonding apparatus used for manufacturing an optical element, for example, there is a structure as shown in FIG. In FIG. 14, reference numeral 101 denotes a light irradiation device, 102 denotes an alignment mark detection optical system that emits alignment light, 103 denotes a mask holder, 104 denotes a mask (upper substrate), 105 denotes a vacuum exhaust port, and 106 denotes a mask (upper substrate). An adsorption groove, 107 is a substrate chuck having X, Y, and θ direction moving devices 115, 108 is a wafer adsorption groove, 109 is a wafer (lower substrate), 110 is an alignment mark, 111 is a resist, and 112 is above and below the substrate chuck (Z Direction) moving mechanism, 113 is a device pattern, and 114 is a base.

In the alignment bonding apparatus 100 shown in FIG. 14, a wafer (lower substrate) 109 having an alignment mark 110 provided on a device formation surface is fixed on a substrate chuck 107, and this alignment mark detection optical system 102 is used to align the alignment mark. 110 is detected and aligned with one alignment mark 110 provided on one mask (upper substrate) 104. After the alignment is completed, the device pattern 113 is exposed to this alignment position.
Usually, alignment is performed by forming a film structure for forming the device pattern 113 of the next layer on the alignment mark 110 and a resist film 111 for forming a resist pattern used for patterning by etching the device pattern 113. Further, for example, the alignment mark detection optical system 102 detects and executes the alignment mark 110 through these film configurations and the resist film.

Alignment is performed by detecting a deviation amount between a preset alignment mark position and an exposure position for forming a device pattern by detecting an alignment mark, and then exposing a wafer (lower substrate) to correct the deviation amount. ) The stage (substrate chuck) 107 is moved to the position 109, and exposure is executed.
As a method for defining the parallelism of the wafer (lower substrate) 109 and the mask (upper substrate) 104, there is a method in which the substrates are brought into close contact with each other and pressed in parallel. In this method, the mask (upper substrate) 104 and the wafer (lower substrate) 109 are brought into surface contact, and the pressure is controlled by interference fringes generated on the contact surface, or an air spring (so-called air damper) is used. There is a method of making the force applied between the wafer and the mask constant. In general, the medium between the mask and the wafer is air.
However, when alignment adhesion is performed with a viscous medium such as an adhesive (adhesive) sandwiched between the mask and the wafer, the adhesive repulsive force becomes larger than the pressure of the air spring due to the viscosity of the adhesive. In addition to thickness control, there are problems such as no parallelism. There is a method of controlling the gap between the substrate chuck 107 and the mask holder 103 using a hall sensor as a countermeasure for the air gap, but there is a problem that the cost of the apparatus becomes high. Further, the mask holder 103 has a shape in which an exposure part (light irradiation range) is opened, and there is a problem that the mask is warped.

  Furthermore, since the adhesive that protrudes to the periphery of the substrate reacts with the surrounding air and moisture and does not cure in a predetermined curing process, it adheres to the substrate chuck or the mask holder, so that a cleaning process is required. Further, there are problems such as a conveyance trouble caused by an uncured adhesive around the substrate in the subsequent process and a deterioration in device quality due to the adhesive. In order to avoid such a problem, there is a method of making the bonding range smaller than the substrate size. However, in this case, since the number of devices that can be taken from one substrate is reduced, there is a problem that the cost of the device is increased.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an alignment bonding method and an alignment bonding apparatus capable of improving the bonding quality by using a mask holder having good flatness. Another object of the present invention is to provide an alignment adhesion method and an alignment adhesion apparatus that can shorten the process. Furthermore, an object of the present invention is to provide an alignment bonding method and an alignment bonding apparatus capable of stably curing an adhesive and improving the bonding quality. Furthermore, an object of the present invention is to provide an optical element produced by using the alignment bonding method or alignment bonding apparatus, particularly an optical element (polarization separation element) having a polarization separation function and a small wavefront aberration. Another object of the present invention is to provide an optical pickup device that uses the optical element and is suitable for miniaturization.

As means for achieving the above object, the present invention has the following features.
[1]. The alignment bonding method of the present invention includes a means for detecting alignment, a substrate chuck for fixing the substrate, a moving means for moving the substrate chuck in each of X, Y, Z, and θ directions, and an optically transparent Using an apparatus including a mask holder made of a planar member and a light irradiating unit that irradiates light, and setting a lower substrate having an alignment mark having irregularities formed by etching on the substrate chuck; Adhering to the mask holder portion, a step of setting an upper substrate provided with alignment marks having irregularities formed by etching, a step of aligning the alignment marks of the upper and lower substrates, and a step of applying an adhesive Introducing gas into the periphery and covering the atmosphere around the adhesive with gas, expanding the adhesive, and irradiating light to cure and bond the adhesive And having a degree (claim 1).

[2]. In the alignment bonding method according to [1], the introduced gas is an inert gas (claim 2).
[3]. In the alignment bonding method according to [2], the inert gas is nitrogen gas or argon gas (claim 3).
[4]. In the alignment adhesion method according to any one of [1] to [3], the inert gas introduction step and the light irradiation step are interlocked (claim 4).
[5]. In the alignment bonding method according to any one of [1] to [4], the inert gas is introduced between a mask holder and a substrate chuck (Claim 5).
[6]. In the alignment adhesion method according to any one of [1] to [5], the inert gas is introduced so as to cover the entire apparatus (Claim 6).

[7]. In the alignment bonding method according to any one of [1] to [6], the adhesive is a photo-curing acrylic resin-based or epoxy resin-based material (Claim 7).
[8]. In the alignment bonding method according to any one of [1] to [7], the inert gas is ejected from a mask holder (claim 8).
[9]. In the alignment adhesion method according to any one of [1] to [8], the mask holder includes a gas ejection port in which micro holes are processed around the outer periphery of the substrate. ).
[10]. [9] The alignment bonding method according to [9], wherein a flexible sheet is provided outside a gas ejection port of the mask holder.
[11]. In the alignment bonding method according to any one of [1] to [10], a gas suction port is provided in the substrate chuck (claim 11).

[12]. The alignment bonding apparatus of the present invention includes a means for detecting alignment, a substrate chuck for fixing the substrate, a moving means for moving the substrate chuck in each of X, Y, Z, and θ directions, and an optically transparent device. A mask holder comprising a planar member; and a light irradiating unit for irradiating light, and means for setting a lower substrate having an alignment mark having irregularities formed by etching on the substrate chuck; and the mask holder unit In addition, means for setting an upper substrate provided with alignment marks having irregularities formed by etching, means for aligning the alignment marks on the upper and lower substrates, means for applying an adhesive, and gas around the area to be bonded A means for introducing and covering the atmosphere around the adhesive with a gas; a means for spreading the adhesive; and a means for irradiating light to cure and bond the adhesive. , Characterized by using the alignment method of bonding according to any one of [1] to [11] (claim 12).

[13]. An optical element having a structure in which a substrate is bonded with an adhesive is manufactured by using the alignment bonding method according to any one of [1] to [11] (claim 13).
[14]. An optical element having a structure in which a substrate is bonded with an adhesive is manufactured by the alignment bonding apparatus according to [12] (claim 14).
[15]. The optical element according to [13] or [14] is characterized by having a diffraction grating or a hologram on or between substrates and having a polarization separation function.

[16]. An optical pickup apparatus for recording, reproducing, or erasing information on an optical recording medium uses the optical element according to [15] (Claim 16).

  In the alignment bonding method according to [1] of the solving means, a means for detecting alignment, a substrate chuck for fixing the substrate, and a moving means capable of moving the substrate chuck in each of X, Y, Z, and θ directions. And an alignment mark having unevenness formed by etching on the substrate chuck, using a device including a mask holder made of an optically transparent flat member and a light irradiation unit for irradiating light. A step of setting a substrate, a step of setting an upper substrate having alignment marks formed by etching on the mask holder portion, a step of aligning the alignment marks of the upper and lower substrates, and an adhesive A step of applying, a step of introducing a gas around the adhesive and covering the atmosphere around the adhesive with a gas, a step of spreading the adhesive, and irradiating light The process of curing and bonding the adhesive can prevent warping of the upper substrate, alignment accuracy, controllability of the adhesive layer thickness, uniformity of the adhesive layer thickness, and control of the total thickness of the upper and lower substrates after bonding. , The quality of parallelism and the uniformity of the adhesive layer thickness can be improved, and stickiness around the adhesive after curing can be prevented, and a high quality and stable adhesion method can be provided.

  In the alignment adhesion method according to [2] to [6] of the solving means, in addition to the effect of [1], a process of irradiating light using an inert gas (particularly nitrogen gas or argon gas) as an introduction gas atmosphere The inert gas atmosphere is formed by introducing an inert gas around the adhesive in conjunction with the above, thereby enabling a low-cost bonding with a shortened process.

  In the alignment bonding method according to [7] of the above solution, in addition to the effect of any one of [1] to [6], a photo-curing acrylic resin or epoxy resin material is used for the adhesive. Thus, a low-cost bonding method can be provided.

  In the alignment adhesion method according to [8] to [11] of the above solution, a fine hole is processed in the mask holder along the periphery of the outer shape of the substrate, an inert gas is ejected from the hole, and the gas is supplied to the substrate chuck side. By forming the discharge port, it is possible to provide an adhesion method for stably curing the adhesive and to improve the adhesion quality.

  In the alignment bonding apparatus according to [12], the means for detecting alignment, the substrate chuck for fixing the substrate, and the moving means for moving the substrate chuck in the X, Y, Z, and θ directions. And a mask holder made of an optically transparent flat member, and a light irradiation unit for irradiating light, and setting a lower substrate having alignment marks having irregularities formed by etching on the substrate chuck Means, means for setting an upper substrate provided with alignment marks having irregularities formed by etching on the mask holder portion, means for aligning the alignment marks of the upper and lower substrates, and means for applying an adhesive A means for introducing a gas around the adhesive and covering the atmosphere around the adhesive with a gas; a means for spreading the adhesive; and a means for hardening the adhesive by irradiating light. By using the alignment adhesion method according to any one of [1] to [11], the same effect as any one of [1] to [11] can be obtained, A bonding apparatus capable of performing high-quality and stable bonding can be provided.

In the optical element according to [13] and [14] of the solving means, the alignment bonding method according to any one of [1] to [11] or the alignment bonding apparatus according to [12] is used. As a result, a high-quality optical element with good adhesion quality can be obtained.
Further, in the case of a configuration having a diffraction grating or a hologram on or between substrates and having a polarization separation function as in the optical element described in [15], polarized light capable of improving wavefront aberration and miniaturization. A separation element can be obtained.

  In the optical pickup device described in [16] of the solving means, by using the optical element described in [15], an optical pickup device capable of improving the wavefront aberration and reducing the size can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described in detail based on the embodiments shown in the drawings.

[Example 1]
First, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1A is a view showing a top surface and a cross section of an upper substrate (mask) 10 in which a grating 13 and an alignment mark 12 are formed on an optical glass substrate 11 made of BK7 having a diameter of 100 mm and a thickness of 1.00 mm. 1 (b) shows an organic birefringent film 23 having a diameter of 80 mm and a thickness of 0.10 mm on an optical glass substrate 21 made of BK7 having a diameter of 100 mm and a thickness of 1.00 mm, having the same refractive index as that of the organic birefringent film. FIG. 2 is a view showing an upper surface and a cross-section of a lower substrate (wafer) 20 on which a diffraction grating 25 and an alignment mark 24 are formed after bonding with a UV curable adhesive 22 centered.

The substrate was manufactured by first placing the lower substrate 21 made of shot optical glass BK7 having a diameter of 100 mm and a thickness of 1.00 mm on a substrate fixing table of a spin coater (not shown), and vacuum-adsorbing and fixing. Then, while rotating the substrate fixing table at 10 to 50 rpm, EX1500-4 epoxy resin UV curing made by Otex Co., Ltd. having a refractive index of 1.52 and a viscosity of 500 cps (25 ° C.) using a dispenser at the center of the lower substrate 21. About 10 g of mold adhesive 22 was dropped. Thereafter, the substrate fixing table was rotated at 300 to 500 rpm, the adhesive 22 was spread over the entire surface of the lower substrate 21, and the rotation of the substrate fixing table was stopped.
Thereafter, the center of the organic birefringent film 23 having a diameter of 80 mm and a thickness of 100 μm was aligned with the center of the substrate and placed on the adhesive surface on the lower substrate using a mounting device.
Thereafter, the substrate fixing table was rotated at 1000 to 2000 rpm, the ultraviolet curable adhesive 22 was shaken off, and the surface of the organic birefringent film was flattened with the adhesive layer thickness kept constant within the substrate surface.
Thereafter, the rotation of the substrate fixing table was stopped, and ultraviolet rays having a wavelength of 356 nm and an intensity of 50 mW / cm ² were irradiated for 200 seconds from the organic birefringent film side using a high-pressure mercury lamp to cure the ultraviolet curable adhesive 22. The adhesive layer thickness after curing at this time was 20 μm.

Next, the lower substrate 21 to which the organic birefringent film 23 was bonded was removed from the substrate fixing table, a positive resist was applied to the organic birefringent film to a thickness of 1.1 μm, and prebaked at 90 ° C. for 30 minutes. . Thereafter, the lower substrate 21 is mounted on a reduction projection exposure apparatus (NA = 0.45, σ = 0.6, wavelength; i-line), and a 2.0 μm line-and-space device pattern having 1000 cycles and a line width of 30 μm. Then, exposure was performed using a reticle having a cross-shaped alignment pattern having a length of 130 μm, development was performed using a developer NMD-3, and post-baking was performed at 100 ° C. for 30 minutes to complete a periodic resist pattern. . Thereafter, aluminum (Al) was vapor-deposited on the resist pattern by sputtering, and subsequently the resist was dissolved using acetone to perform Al lift-off to complete an Al pattern in which the resist pattern was inverted.
Thereafter, using an NLD-800 etching apparatus manufactured by Nippon Vacuum Technology Co., Ltd., an organic birefringent film 23 using the Al pattern as a metal mask under etching conditions of substrate bias 200 W, antenna power 1 KW, oxygen gas 40 SCCM, substrate temperature −30 ° C. Was etched 4 μm deep.
Thereafter, the Al pattern is removed using a phosphoric acid-based Al etching solution, and a lower substrate (wafer) 20 having an uneven grating 25 (hereinafter referred to as a diffraction grating) 25 having 1000 cycles and an uneven alignment mark 24 is formed. Completed.

Similarly, for the upper substrate 11 made of shot optical glass BK7 having a diameter of φ100 mm and a thickness of 1.00 mm, a positive resist is applied to the substrate 11 to a thickness of 1.1 μm and prebaked at 90 ° C. for 30 minutes. went. After that, the substrate 11 is mounted on a reduction projection exposure apparatus (NA = 0.45, σ = 0.6, wavelength; i-line), and a 5-μm line-and-space device pattern having 1000 cycles, a line width of 20 μm, and a length. Exposure was performed using a 110 μm cross-shaped alignment pattern reticle, development was performed using a developer NMD-3, and post-baking was performed at 100 ° C. for 30 minutes to complete a periodic resist pattern.
Then, using a NLD-800 etching apparatus manufactured by Nippon Vacuum Engineering Co., Ltd., with a substrate bias of 400 W, antenna power of 1 kW, oxygen gas of 60 SCCM, and substrate temperature of −30 ° C., using the resist pattern as a mask to a depth of 0.5 μm Etched.
Thereafter, the resist was removed using acetone to complete an upper substrate (mask) 10 having an uneven grating 13 having 1000 cycles and an alignment mark 12 having an uneven shape.

  2A and 2B are configuration explanatory views of the alignment bonding apparatus according to the first embodiment of the present invention. FIG. 2A is a cross-sectional view showing a schematic configuration of the alignment bonding apparatus 30, and FIG. It is the top view which looked at the quartz glass mask holder from the lower surface side. This alignment bonding apparatus 30 includes a light irradiation device 31, an alignment mark detection optical system 32 that detects alignment marks by irradiating alignment light, a quartz glass mask holder 33, a vacuum exhaust port 34, an upper substrate suction groove 35, and gas introduction. A port 36, a gas ejection port 37, a substrate chuck 38 on the lower substrate side, a moving device 39 for moving the substrate chuck 38 in the X, Y, and θ directions, and a base 40 of the substrate chuck 38 are moved up and down by a Z-axis control stage (not shown). The moving mechanism 41 moves in the Z direction), the substrate chuck side vacuum exhaust port 42, the lower substrate suction groove 43, and an adhesive dropping device (not shown).

In the quartz glass mask holder 33, as shown in FIG. 2 (b), a suction groove 35 for fixing the upper substrate on a quartz glass having a thickness of 10 mm and a diameter of φ180 mm by vacuum suction, and for evacuating the groove. The vacuum exhaust port 34 is processed.
The shape of the upper substrate suction groove 35 is such that the diameter of the upper substrate 10 used this time is φ100 mm and with an orientation flat with a length of 35 mm, so the outer diameter is φ90 mm, the inner diameter is φ87 mm, and the groove depth is 0.5 mm. did. Furthermore, 24 holes with a diameter of 0.5 mm were formed at intervals of 15 ° on the circumference of the same plane with a diameter of 120 mm so as to surround the outer periphery of the upper substrate, thereby forming a gas ejection port 37.
The substrate chuck 38 for fixing the lower substrate 20 is made of aluminum with a diameter of φ180 mm, and after processing the groove 43 for vacuum-adsorbing the substrate and the vacuum exhaust port 42, the whole surface is anodized and the surface is covered with a fluoride. did. Below the substrate chuck 38, a moving mechanism of an X, Y, θ direction moving device 39 (not shown in detail) is installed, and the substrate chuck 38 is moved relative to the base 40 in the X direction, Y direction, θ direction ( It can be moved in each direction. The base 40 of the substrate chuck 38 is fixed on a Z-axis control stage (not shown) of a substrate chuck vertical movement mechanism 41 (not shown in detail) so that it can move up and down (Z direction).

First, the upper substrate 10 made by the above-described method was fixed to the quartz glass mask holder 33 by vacuum suction, and the lower substrate 20 was fixed to the substrate chuck 38 by vacuum suction. Thereafter, an alumina cylinder 44 having a diameter of 6 mm, a height of 2.000 mm, a parallelism of 0.001 mm, and a surface roughness Ra <10 nm is not shown between the upper substrate 10 and the organic birefringent film 23 on the lower substrate 20. After the three support arms are inserted at 120 ° equal positions by the movement of the support arm, the substrate chuck 38 is raised by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, and the alumina cylinder 44 is moved to the organic substrate of the upper substrate 10 and the lower substrate. The substrate chuck 38 was fixed between the refractive films 23, pressed at 1N / piece, and the stopped point as a parallel plane, and stored as a gap of 2.000 mm. FIG. 3 shows a state in which an alumina cylinder 44 is sandwiched between the organic birefringent films 23 on the upper substrate 10 and the lower substrate 20, and parallel alignment and gap reference alignment are performed.
Thereafter, a gap of 10.000 mm was designated, the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, and the alumina cylinder 44 was moved out of the substrate.

Next, the substrate chuck 38 to which the lower substrate 20 is fixed is moved to the left in the figure by the moving device 39, and a UV curable epoxy resin adhesive manufactured by Otex Co., Ltd. is used at the center of the lower substrate 20 using a dispenser (not shown). 0.5 mL of an agent (model number EX-1500-4) was dropped.
Next, the substrate chuck 38 to which the lower substrate 20 is fixed is returned to the right in the drawing by the moving device 39, and the substrate is moved by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 up to a gap of 2.300 mm to ensure an adhesive layer thickness of 100 μm. After raising the chuck 38, the alignment detection optical system (microscope with image storage device) 32 detected the alignment mark positions of the upper and lower substrates through the quartz glass mask holder 33, and the alignment was performed.

Here, the detailed method of alignment is described. First, the alignment mark 12 on the upper substrate 10 is detected by the alignment detection optical system (microscope with image storage device) 32, the image sandwiched between the cross lines is stored, and then the focus position of the microscope is aligned with the lower substrate 20. Then, the alignment mark 24 of the lower substrate 20 is detected, and the detected alignment error (deviation from the cross line storing the image) is moved by the moving device 39 of the substrate chuck 38, and the substrate chuck 38 is moved in each of the X, Y, and θ directions. It was corrected by moving to. This was aligned at at least two points 50 mm apart on the same line within the substrate surface. After the alignment correction, the substrate chuck 38 of the lower substrate is fixed to the X, Y, θ direction moving device 39 and the base 40 of the substrate chuck by vacuum suction or the like. FIG. 4 shows the state of pre-alignment.
Thereafter, in order to secure a final adhesive thickness of 50 μm, the substrate chuck 38 is raised again by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 to spread the adhesive 45 over the entire substrate, and at a gap of 2.200 mm. Fixed (total thickness of upper and lower substrates is 2.000 mm, organic birefringent film 23 is 0.100 mm thick, adhesive thickness of lower substrate 21 and organic birefringent film is 0.050 mm, organic birefringent film 23 and upper substrate 10 are (Because the adhesive layer thickness is 0.050 mm). This state was maintained for 2 minutes while the adhesive 45 was sufficiently spread.

Next, as shown in FIG. 5, ultraviolet light (UV) having a wavelength of 365 nm and a light intensity of 40 mW / cm ² is irradiated on the entire surface of the adhesive through the quartz glass mask holder 33 by the light irradiation device 31 for 200 seconds. Cured. In this ultraviolet irradiation process, an inert gas (for example, nitrogen gas) of 0.5 L / min is introduced into the gas inlet 36 of the quartz glass mask holder 33 from a gas cylinder (not shown) at a pressure of 0.2 kgf / cm ² , The adhesive 45 was cured with the space in a nitrogen gas atmosphere.
Thereafter, UV irradiation and introduction of nitrogen gas are stopped, the quartz glass mask holder 33 is evacuated, and the upper substrate 10 is released from vacuum suction and fixation. Next, after the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, the vacuum chucking of the substrate chuck 38 was turned off, and the alignment bonded upper and lower substrates were taken out.

  The aligned upper and lower substrates 50 were cut into 5 mm squares by a dicing device 51 as shown in FIG. 6A to cut out a large number of optical elements 52. As shown in FIG. 6B, the optical element 52 has a diffraction grating 25 composed of an organic birefringent film 23 between upper and lower substrates, and transmits outgoing light according to the polarization state of incident light. And an optical element (polarized light separating element) having a polarization separating function for separating the light into diffracted light.

  In this embodiment, when the optical element having such a configuration is manufactured, the upper substrate 10 and the lower substrate 20 are bonded by the bonding method using the alignment bonding apparatus 30 described above, so that warpage of the upper substrate is prevented. Alignment accuracy, controllability of adhesive layer thickness, uniformity of adhesive layer thickness, controllability of total thickness of upper and lower substrates after bonding, improved parallelism quality and uniformity of adhesive layer thickness, high quality and stability Bonding can be performed. In addition, since the atmosphere in which the bonding process is performed is an inert gas (for example, nitrogen gas) atmosphere, it was possible to bond the adhesive without sticking out around the substrate.

  Table 1 below shows the results of a comparative evaluation of the adhesive stickiness and the occurrence of substrate transport troubles in the subsequent steps for the substrates bonded by the bonding apparatus of this example and the conventional bonding apparatus. In the evaluation, a case where there was no stickiness in the adhesive sticking out around the substrate was indicated as “◯”, and a case where there was stickiness was indicated as “X”. Further, in the subsequent process apparatus, the presence or absence of a conveyance trouble such as the substrate being adhered (adhered) to the conveyance mechanism and being unable to be normally conveyed was examined. As shown in Table 1, in the bonding method using the conventional bonding apparatus, the adhesive sticking out to the periphery of the substrate has a stickiness, and there is a problem of conveyance, but in the bonding method using the bonding apparatus of this embodiment, The adhesive sticking out from the periphery of the substrate is not sticky, and the subsequent process equipment adheres (adheres) the substrate to the transport mechanism and cannot be transported normally, or the adhesive adheres to the device surface. Alignment adhesion without quality problems such as degradation of optical properties was achieved.

  In the present embodiment, a method of alternately detecting a plurality of alignment marks arranged with high accuracy using one alignment detection optical system has been shown. However, a plurality of alignment detection optical systems are installed to detect a plurality of alignment marks simultaneously. It is also possible to do this. Moreover, although the example which moves the focus of a microscope was shown in order to detect the alignment mark of an up-and-down board | substrate, the method of fixing a microscope and moving each board | substrate to a predetermined focus position and aligning may be used.

  In this embodiment, an example in which borate crown glass (BK7) is used for the upper and lower substrates 11 and 21 is shown. However, the substrate is not limited to BK7, and quartz glass, borosilicate glass, and fluoric crown can be used. A transparent glass substrate such as glass, barium crown glass, or crown glass, a polymer film such as polyester or acrylic, a sheet, a plate, or the like may be used. Further, although an ultraviolet curable epoxy resin adhesive is used as the adhesive, an acrylic resin adhesive may be used. In this embodiment, nitrogen gas is introduced in the ultraviolet irradiation process, but it is desirable to introduce nitrogen gas from the step of dropping the adhesive. The pressure of the nitrogen gas is preferably changed according to the thickness of the substrate after bonding so that the pressure in this space does not increase. Further, nitrogen gas is used as the introduction gas because of process cost, but an inert gas such as argon gas may be used, or the introduction gas may be introduced by controlling the temperature of the introduction gas. In this example, the temperature of the introduced gas was set to 28 ° C. in order to slightly lower the viscosity of the adhesive.

In this embodiment, the alumina cylinder 44 is used in the step shown in FIG. 3, but an alumina ball may be used. The material may be zirconia, alumina nitride, silicon carbide, silicon nitride, boron nitride ( C-BN), titanium nitride (TiN), ZrSiO _{4 and} other ceramics, tungsten carbide (WC), WC—Co alloy, WC—TiC—Co alloy, and so-called cemented carbide may be used. In this embodiment, the diameter is 6 mm and the thickness is 2 mm. However, the present invention is not limited to these dimensions, and the diameter may be changed depending on the substrate thickness to be used, the target adhesive layer thickness, or the like. Similarly, although the upper and lower substrate shapes are circular, the shape is not limited to this, and may be a polygonal shape, an elliptical shape, or the like. In consideration of contact with the apparatus, it is desirable to chamfer the corners of the substrate (for example, 0.3R or 0.3C).

[Example 2]
Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 7 is a schematic sectional view of an alignment bonding apparatus showing a second embodiment of the present invention. The basic configuration of the alignment bonding apparatus is the same as that of the alignment bonding apparatus 30 described in the first embodiment. In this embodiment, the alignment bonding apparatus 30 is covered with conductive vinyl 61 to form a sealed space. The gas confining device 60 is provided with a gas inlet 62 and a gas outlet 63 on the side surface.
The configurations of the upper substrate 10 and the lower substrate 20 are the same as those in FIG. 1, and the manufacturing method is the same as that described in the first embodiment.

First, the upper substrate 10 manufactured by the same method as in the first embodiment is fixed to the quartz glass mask holder 33 by vacuum suction, and the lower substrate 20 is fixed to the substrate chuck 38 by vacuum suction. 1 L / min of nitrogen gas was introduced from the introduction port 62 through the gas introduction port 36 of the quartz glass mask holder 33 at a pressure of 0.2 kgf / cm ² , and the inside was replaced with nitrogen gas. Next, a zirconia cylinder having a diameter of 6 mm, a height of 2.000 mm, a parallelism of 0.001 mm, and a surface roughness Ra <10 nm is moved between the organic birefringent films on the upper substrate 10 and the lower substrate 20 by a support arm (not shown). 3 are inserted at positions equal to 120 ° (steps similar to FIG. 3), the substrate chuck 38 is raised by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, and the zirconia cylinders are moved to the upper substrate 10 and the lower substrate. The substrate chuck 38 was fixed with the point of stopping between the organic birefringent films being pressed at 1 N / piece, and the stopped point as a parallel plane, and stored as a gap of 2.000 mm.
Thereafter, a gap of 10.000 mm was designated, the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, and the zirconia cylinder was moved out of the substrate.

Next, the substrate chuck 38 to which the lower substrate 20 is fixed is moved to the left in the figure by the moving device 39, and a UV curable epoxy resin adhesive manufactured by Otex Co., Ltd. is used at the center of the lower substrate 20 using a dispenser (not shown). 0.5 mL of an agent (model number EX-1500-4) was dropped.
Next, the substrate chuck 38 to which the lower substrate 20 is fixed is returned to the right in the drawing by the moving device 39, and the substrate is moved by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 up to a gap of 2.300 mm to ensure an adhesive layer thickness of 100 μm. The chuck 38 was raised, and the alignment mark positions of the upper and lower substrates were detected through the quartz glass mask holder 33 by an alignment detection optical system (microscope with an image storage device) to perform alignment. The details of the alignment method are the same as those in the first embodiment, and the description is omitted here.

After the alignment correction, the substrate chuck 38 of the lower substrate is fixed to the moving device 39 and the base 40 in the X, Y, and θ directions by vacuum suction or the like.
Thereafter, in order to secure a final adhesive thickness of 50 μm, the substrate chuck 38 is raised again by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 to spread the adhesive 45 over the entire substrate, and at a gap of 2.200 mm. Fixed. Further, this state was maintained for 2 minutes while the adhesive 45 was sufficiently spread.

Next, as shown in FIG. 7, the entire surface of the adhesive is irradiated with ultraviolet light (UV) having a wavelength of 365 nm and a light intensity of 40 mW / cm ² through the quartz glass mask holder 33 by the light irradiation device 31 for 200 seconds. Cured.
Thereafter, UV irradiation and nitrogen gas introduction are stopped, dry air is introduced into the gas confining device 60 from a dry air inlet (not shown), the vacuum exhaust of the quartz glass mask holder 33 is turned off, and the vacuum suction fixing of the upper substrate 10 is performed. Is released. Next, after the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, the vacuum chucking of the substrate chuck 38 was turned off, and the alignment bonded upper and lower substrates were taken out.

  The aligned upper and lower substrates 50 were cut into 5 mm squares by a dicing apparatus 51 as shown in FIG. As shown in FIG. 6B, the optical element 52 has a diffraction grating 25 composed of an organic birefringent film 23 between upper and lower substrates, and transmits outgoing light according to the polarization state of incident light. And an optical element (polarized light separating element) having a polarization separating function for separating the light into diffracted light.

  In this embodiment, when the optical element having such a configuration is manufactured, the upper substrate 10 and the lower substrate 20 are bonded by the bonding method using the alignment bonding apparatus 30 described above, so that warpage of the upper substrate is prevented. Alignment accuracy, controllability of adhesive layer thickness, uniformity of adhesive layer thickness, controllability of total thickness of upper and lower substrates after bonding, improved parallelism quality and uniformity of adhesive layer thickness, high quality and stability Bonding can be performed. Further, in this embodiment, as shown in FIG. 7, the alignment adhesive device 30 is disposed in the gas confinement device 60, and the atmosphere in which the bonding process is performed is a nitrogen gas atmosphere. It was possible to bond without causing stickiness.

[Example 3]
Next, a third embodiment of the present invention will be described with reference to FIG.
FIG. 8 is a schematic sectional view of an alignment bonding apparatus showing a third embodiment of the present invention. The basic configuration of the alignment bonding apparatus 70 is substantially the same as that of the alignment bonding apparatus 30 described in the first embodiment. However, the alignment bonding apparatus 70 has the same apparatus configuration as that of the first embodiment and the quartz glass mask holder 33. Sixteen holes with a diameter of 0.5 mm are formed at 22.5 ° intervals on the same plane with a diameter of 120 mm in diameter so as to surround the outer periphery of the upper substrate. On the holder 33 side, a Si rubber seal 47 having a thickness of 0.2 mm and a length of 2.1 mm and having a rectangular cross-sectional shape is fixed so as to surround the gas ejection port 36. The substrate chuck 38 is provided with a gas suction port 46.
The configurations of the upper substrate 10 and the lower substrate 20 are the same as those in FIG. 1, and the manufacturing method is the same as that described in the first embodiment.

  First, the upper substrate 10 produced by the same method as in Example 1 was fixed on the quartz glass mask holder 33 by vacuum suction, and similarly the lower substrate 20 was fixed to the substrate chuck 38 by vacuum suction. Thereafter, between the substrate chuck 38 and the quartz glass mask holder 33, a zirconia cylinder having a diameter of 5 mm, a height of 5.000 mm, a parallelism of 0.001 mm, and a surface roughness Ra <10 nm is equally divided by 120 ° by movement of a support arm (not shown). Three of them were inserted at the positions (similar steps as in FIG. 3). Next, the substrate chuck 38 is lifted by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, a zirconia cylinder is sandwiched between the substrate chuck 38 and the quartz glass mask holder 33, the pressure is applied at 1N / piece, and the stopped point is bonded. The substrate chuck 38 was fixed as a parallel plane, and the gap was memorized as 5.000 mm. Thereafter, the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, and the zirconia cylinder was moved out of the substrate.

Next, the substrate chuck 38 to which the lower substrate 20 is fixed is moved to the left in the figure by the moving device 39, and a UV curable epoxy resin adhesive manufactured by Otex Co., Ltd. is used at the center of the lower substrate 20 using a dispenser (not shown). 0.5 mL of an agent (model number EX-1500-4) was dropped. At the same time, 0.5 L / min of nitrogen gas is introduced into the gas introduction port 36 of the quartz glass mask holder 33 from a gas cylinder (not shown) at a pressure of 0.2 kgf / cm ² and the space partitioned by the Si rubber seal 47 is filled with nitrogen gas. The space around the substrate was replaced with a nitrogen gas atmosphere. In this embodiment, the space around the substrate is partitioned by the Si rubber seal 47, so that a nitrogen gas atmosphere can be formed more reliably. Hereinafter, nitrogen gas was introduced until the curing of the adhesive was completed.

Next, the substrate chuck 38 to which the lower substrate 20 is fixed is returned to the right in the drawing by the moving device 39, and the substrate is moved by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 to a gap of 0.500 mm to secure the adhesive layer thickness of 500 μm. The chuck 38 is raised. Thereafter, alignment was performed in the same manner as in Example 1. After the alignment correction, the substrate chuck 38 of the lower substrate was fixed to the moving device 39 and the base 40 in the X, Y, and θ directions by vacuum suction or the like.
Thereafter, in order to obtain a final adhesive thickness of 50 μm, the substrate chuck 38 is raised again by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 to spread the adhesive 45 over the entire substrate as shown in FIG. Fixing was performed at a position of 0.050 mm, and an alignment shift was confirmed. After the alignment, this state was maintained for 2 minutes while the adhesive 45 was sufficiently spread.

Next, the adhesive 45 was cured by irradiating the entire surface of the adhesive with ultraviolet light (UV) having a wavelength of 365 nm and a light intensity of 40 mW / cm ² through the quartz glass mask holder 33 by the light irradiation device 31 for 250 seconds. Thereafter, the vacuum suction of the quartz glass mask holder 33 is turned off, and the vacuum suction fixation of the upper substrate 10 is released. Next, after the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, the vacuum chucking of the substrate chuck 38 was turned off and the upper and lower substrates bonded and aligned were taken out.

  The aligned upper and lower substrates 50 were cut into 5 mm squares by a dicing apparatus 51 as shown in FIG. As shown in FIG. 6B, the optical element 52 has a diffraction grating 25 composed of an organic birefringent film 23 between upper and lower substrates, and transmits outgoing light according to the polarization state of incident light. And an optical element (polarized light separating element) having a polarization separating function for separating the light into diffracted light.

  In this embodiment, when the optical element having such a configuration is manufactured, the upper substrate 10 and the lower substrate 20 are bonded by the bonding method using the alignment bonding apparatus 70, and thus warpage of the upper substrate is prevented. Alignment accuracy, controllability of adhesive layer thickness, uniformity of adhesive layer thickness, controllability of total thickness of upper and lower substrates after bonding, improved parallelism quality and uniformity of adhesive layer thickness, high quality and stability Bonding can be performed. Further, in this embodiment, as shown in FIG. 8, the nitrogen gas atmosphere space is limited by surrounding the substrate with a Si rubber seal 47, so that the nitrogen concentration can be increased even with a small amount of gas. It was possible to bond without causing stickiness of the protruding adhesive.

  In this embodiment, the Si rubber seal 47 having a rectangular cross-sectional shape is used. However, the shape is not limited to this, and the Si rubber seal 48 having a triangular cross-sectional shape as shown in FIG. Alternatively, the gas ejection port 37 may be surrounded by a Si rubber seal having a polygonal shape such as a square or a pentagon. The material is not limited to Si rubber, and other rubber such as fluorine-based rubber, or polymer film such as polyethylene, polypropylene, and fluorine-based resin may be used. The length of the seal is preferably the same as the thickness of the adhesive-cured substrate or shorter than the thickness of the adhesive-cured substrate.

[Example 4]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
10A and 10B are configuration explanatory views of an alignment bonding apparatus according to a fourth embodiment of the present invention. FIG. 10A is a schematic cross-sectional view of the alignment bonding apparatus, and FIG. 10B is a schematic view parallel to the ring surface of the gas ejection apparatus. It is sectional drawing. This alignment bonding apparatus 80 is an example in which a gas blowing device is formed in a ring shape, and an inert gas (for example, nitrogen gas) is blown and bonded to the side surface of the adhesive, and the gas is disposed at the outer peripheral portion of the substrate chuck 38. The basic configuration of the alignment bonding apparatus is substantially the same as that of the alignment bonding apparatus 30 described in the first embodiment except that a jetting apparatus is provided.

The gas jetting device is formed in a ring-like shape having an inner diameter of φ180 mm after forming holes with a diameter of φ0.3 mm serving as gas ejection ports 83 at a pitch of 10 mm in a SUS pipe 82 having an outer diameter of φ3 mm and an inner diameter of φ2 mm. The gas introduction SUS pipe used as the gas introduction port 81 is connected to one end thereof. A device 84 that moves up and down is attached to the gas ejection device, and the gas ejection device is configured to eject gas after moving to the same position as the adhesive layer 45 to which the upper and lower substrates 10 and 20 are bonded.
The configurations of the upper substrate 10 and the lower substrate 20 are the same as those in FIG. 1, and the manufacturing method is the same as that described in the first embodiment.

  First, the upper substrate 10 made by the above-described method was fixed on the quartz glass mask holder 33 by vacuum suction, and similarly, the lower substrate 20 was fixed on the substrate chuck 38 by vacuum suction. Thereafter, between the substrate chuck 38 and the quartz glass mask holder 33, a zirconia cylinder having a diameter of 5 mm, a height of 5.000 mm, a parallelism of 0.001 mm, and a surface roughness Ra <10 nm is equally divided by 120 ° by movement of a support arm (not shown). Three of them were inserted at the positions (similar steps as in FIG. 3). Next, the substrate chuck 38 is lifted by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, a zirconia cylinder is sandwiched between the substrate chuck 38 and the quartz glass mask holder 33, the pressure is applied at 1N / piece, and the stopped point is bonded. The substrate chuck 38 was fixed as a parallel plane, and the gap was memorized as 5.000 mm. Thereafter, the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, and the zirconia cylinder was moved out of the substrate.

Next, the substrate chuck 38 to which the lower substrate 20 is fixed is moved to the left in the figure by the moving device 39, and a UV curable epoxy resin adhesive manufactured by Otex Co., Ltd. is used at the center of the lower substrate 20 using a dispenser (not shown). 0.5 mL of an agent (model number EX-1500-4) was dropped. At the same time, after moving the ring-shaped gas ejection device to the same position as the adhesive 45 by the vertical movement device 84, nitrogen gas of 0.5 L / min at a pressure of 0.2 kgf / cm ² is supplied from a gas cylinder (not shown) to the gas inlet 81. Was introduced, and nitrogen gas was ejected from the gas ejection port 83 to make the space around the adhesive end face a nitrogen gas atmosphere. Thereafter, nitrogen gas was blown out until the curing of the adhesive was completed.

Next, the substrate chuck 38 to which the lower substrate 20 is fixed is returned to the right in the drawing by the moving device 39, and the substrate is moved by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 to a gap of 0.500 mm to secure the adhesive layer thickness of 500 μm. The chuck 38 is raised. Thereafter, alignment was performed in the same manner as in Example 1. After the alignment correction, the substrate chuck 38 of the lower substrate was fixed to the moving device 39 and the base 40 in the X, Y, and θ directions by vacuum suction or the like.
Thereafter, in order to obtain a final adhesive thickness of 50 μm, the substrate chuck 38 is raised again by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 to spread the adhesive 45 over the entire substrate as shown in FIG. Fixing was performed at a position of 0.050 mm, and an alignment shift was confirmed. After the alignment, this state was maintained for 2 minutes while the adhesive 45 was sufficiently spread.

Next, the adhesive 45 was cured by irradiating the entire surface of the adhesive with ultraviolet light (UV) having a wavelength of 365 nm and a light intensity of 40 mW / cm ² through the quartz glass mask holder 33 by the light irradiation device 31 for 250 seconds. Thereafter, the vacuum suction of the quartz glass mask holder 33 is turned off, and the vacuum suction fixation of the upper substrate 10 is released. Next, after the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, the vacuum chucking of the substrate chuck 38 was turned off and the upper and lower substrates bonded and aligned were taken out.

  The aligned upper and lower substrates 50 were cut into 5 mm squares by a dicing apparatus 51 as shown in FIG. As shown in FIG. 6B, the optical element 52 has a diffraction grating 25 composed of an organic birefringent film 23 between upper and lower substrates, and transmits outgoing light according to the polarization state of incident light. And an optical element (polarized light separating element) having a polarization separating function for separating the light into diffracted light.

  In this embodiment, when the optical element having such a configuration is manufactured, the upper substrate 10 and the lower substrate 20 are bonded by the bonding method using the alignment bonding apparatus 80, so that warpage of the upper substrate is prevented. Alignment accuracy, controllability of adhesive layer thickness, uniformity of adhesive layer thickness, controllability of total thickness of upper and lower substrates after bonding, improved parallelism quality and uniformity of adhesive layer thickness, high quality and stability Bonding can be performed. Further, in this embodiment, as shown in FIG. 10, the gas jetting device has a ring shape, and the nitrogen gas atmosphere space is limited, so that the nitrogen concentration can be increased, and the adhesive that protrudes to the periphery of the substrate. It was possible to bond without causing stickiness.

  In the present embodiment, the gas blowing device uses the SUS pipe 82 having a circular cross section, but the shape is not limited to this, and the cross section may be a polygon such as a triangle or a quadrangle. The diameter of the ejection port 83 is not limited to the diameter φ0.3 mm of the present embodiment, and the diameter is more preferably φ0.1 mm to φ2 mm, and φ0.1 mm to φ0.3 mm is preferable in consideration of the manufacturing cost. . Although it is desirable that the number of the gas ejection ports 83 is large, similarly, it is desirable that the number is 100 or less in consideration of the manufacturing cost.

[Example 5]
Next, a fifth embodiment of the present invention will be described with reference to FIG.
FIG. 11 is a schematic cross-sectional view of an alignment bonding apparatus showing a fifth embodiment of the present invention. This alignment bonding apparatus 80 'is a ring-shaped gas ejection device similar to the alignment bonding apparatus of the fourth embodiment (FIG. 10), and further includes a conductive plastic sheet 85 formed on the outside thereof. is there. That is, the basic configuration of the alignment bonding apparatus 80 ′ is the same as that of the fourth embodiment except that the conductive plastic sheet 85 is formed on the outer periphery of the mask holder.

Similarly to FIG. 10 (b), the gas jetting apparatus opens holes of φ0.3 mm that become gas jetting ports 83 at a pitch of 10 mm in a SUS pipe 82 having an outer diameter of φ3 mm and an inner diameter of φ2 mm. The inside is processed into a ring shape with an inner diameter of 180 mm, and a gas introduction SUS pipe serving as a gas introduction port 81 is connected to one end thereof. A device 39 that moves up and down is attached to the gas ejection device, and the gas ejection device is configured to eject gas after moving to the same position as the adhesive layer 45 to which the upper and lower substrates 10 and 20 are bonded. A conductive plastic sheet 85 having a thickness of 0.2 mm is provided on the outer periphery of the mask holder located outside the gas ejection device.
The configurations of the upper substrate 10 and the lower substrate 20 are the same as those in FIG. 1, and the manufacturing method is the same as that described in the first embodiment.

  First, the upper substrate 10 made by the above-described method was fixed on the quartz glass mask holder 33 by vacuum suction, and similarly, the lower substrate 20 was fixed on the substrate chuck 38 by vacuum suction. Thereafter, between the substrate chuck 38 and the quartz glass mask holder 33, a zirconia cylinder having a diameter of 5 mm, a height of 5.000 mm, a parallelism of 0.001 mm, and a surface roughness Ra <10 nm is equally divided by 120 ° by movement of a support arm (not shown). Three of them were inserted at the positions (similar steps as in FIG. 3). Next, the substrate chuck 38 is lifted by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, a zirconia cylinder is sandwiched between the substrate chuck 38 and the quartz glass mask holder 33, the pressure is applied at 1N / piece, and the stopped point is bonded. The substrate chuck 38 was fixed as a parallel plane, and the gap was memorized as 5.000 mm. Thereafter, the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, and the zirconia cylinder was moved out of the substrate.

Next, the substrate chuck 38 to which the lower substrate 20 is fixed is moved to the left in the figure by the moving device 39, and a UV curable epoxy resin adhesive manufactured by Otex Co., Ltd. is used at the center of the lower substrate 20 using a dispenser (not shown). 0.5 mL of an agent (model number EX-1500-4) was dropped. At the same time, after moving the ring-shaped gas ejection device to the same position as the adhesive 45 by the vertical movement device 84, nitrogen gas of 0.5 L / min at a pressure of 0.2 kgf / cm ² is supplied from a gas cylinder (not shown) to the gas inlet 81. Was introduced, and nitrogen gas was ejected from the gas ejection port 83 to make the space around the adhesive end face a nitrogen gas atmosphere. Thereafter, nitrogen gas was blown out until the curing of the adhesive was completed.

Next, the substrate chuck 38 to which the lower substrate 20 is fixed is returned to the right in the drawing by the moving device 39, and the substrate is moved by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 to a gap of 0.500 mm to secure the adhesive layer thickness of 500 μm. The chuck 38 is raised. Thereafter, alignment was performed in the same manner as in Example 1. After the alignment correction, the substrate chuck 38 of the lower substrate was fixed to the moving device 39 and the base 40 in the X, Y, and θ directions by vacuum suction or the like.
Thereafter, in order to obtain a final adhesive thickness of 50 μm, the substrate chuck 38 is raised again by the Z-axis control stage of the substrate chuck vertical movement mechanism 41 to spread the adhesive 45 over the entire substrate as shown in FIG. Fixing was performed at a position of 0.050 mm, and an alignment shift was confirmed. After the alignment, this state was maintained for 2 minutes while the adhesive 45 was sufficiently spread.

Next, the adhesive 45 was cured by irradiating the entire surface of the adhesive with ultraviolet light (UV) having a wavelength of 365 nm and a light intensity of 40 mW / cm ² through the quartz glass mask holder 33 by the light irradiation device 31 for 250 seconds. Thereafter, the vacuum suction of the quartz glass mask holder 33 is turned off, and the vacuum suction fixation of the upper substrate 10 is released. Next, after the substrate chuck 38 was lowered by the Z-axis control stage of the substrate chuck vertical movement mechanism 41, the vacuum chucking of the substrate chuck 38 was turned off and the upper and lower substrates bonded and aligned were taken out.

  The aligned upper and lower substrates 50 were cut into 5 mm squares by a dicing apparatus 51 as shown in FIG. As shown in FIG. 6B, the optical element 52 has a diffraction grating 25 composed of an organic birefringent film 23 between upper and lower substrates, and transmits outgoing light according to the polarization state of incident light. And an optical element (polarized light separating element) having a polarization separating function for separating the light into diffracted light.

  In this embodiment, when the optical element having such a configuration is manufactured, the upper substrate 10 and the lower substrate 20 are bonded by the bonding method using the alignment bonding apparatus 80, so that warpage of the upper substrate is prevented. Alignment accuracy, controllability of adhesive layer thickness, uniformity of adhesive layer thickness, controllability of total thickness of upper and lower substrates after bonding, improved parallelism quality and uniformity of adhesive layer thickness, high quality and stability Bonding can be performed. Further, in this embodiment, as shown in FIG. 11, the gas blowing device is formed in a ring shape, and a conductive plastic sheet 85 is formed on the outside thereof to limit the nitrogen gas atmosphere space, thereby increasing the nitrogen concentration. It was possible to bond without causing stickiness of the adhesive that protruded around the substrate.

  In the present embodiment, the gas blowing device uses the SUS pipe 82 having a circular cross section, but the shape is not limited to this, and the cross section may be a polygon such as a triangle or a quadrangle. The diameter of the ejection port 83 is not limited to the diameter φ0.3 mm of the present embodiment, and the diameter is more preferably φ0.1 mm to φ2 mm, and φ0.1 mm to φ0.3 mm is preferable in consideration of the manufacturing cost. . Although it is desirable that the number of the gas ejection ports 83 is large, similarly, it is desirable that the number is 100 or less in consideration of the manufacturing cost.

[Example 6]
Next, a sixth embodiment of the present invention will be described with reference to FIG.
FIG. 12 is a schematic configuration diagram of an optical pickup device showing a sixth embodiment of the present invention. Light using a CD (compact disc) optical disc (CD, CD-R, CD-RW, etc.) as an optical recording medium. It is a structural example of a pickup apparatus.
In the optical pickup device for CD, light having a wavelength of 780 nm emitted from the laser diode 91 irradiates the CD optical disk 95 through the polarization separation element 92, the collimator lens 93, and the objective lens 94. The reflected light from the recording pit passes through the objective lens 94 and is diffracted by the polarization separation element 92 and guided to the photodiode 96, and focus detection, track detection, and signal detection are performed.
In the optical pickup apparatus of the present embodiment, the polarization separation element 52 manufactured by any of the apparatuses and methods of Examples 1 to 5 and having the configuration shown in FIG. 6B is used as the polarization separation element 92. ing.

A signal was recorded on a CD-RW using the optical pickup device of this example, and then the signal was reproduced by the same optical pickup device. As a result, a beam splitter and a quarter-wave plate (λ Can be obtained, and it can be confirmed that the optical pickup device of this embodiment has recording / reproduction characteristics equivalent to those of the conventional optical pickup device. It was.
Further, in the optical pickup device of the present embodiment, the polarization separation element 92 is smaller than the conventional beam splitter to which the prism is bonded, and the grating 13 is formed on the upper substrate 10 of the polarization separation element so that λ / 4 Since the function of the plate is also incorporated, the miniaturization can be realized as compared with the conventional optical pickup device.

[Example 7]
Next, a seventh embodiment of the present invention will be described with reference to FIG.
FIG. 13 is a schematic block diagram of an optical pickup device showing a seventh embodiment of the present invention. As an optical recording medium, a DVD (digital versatile disk) type optical disk (DVD, DVD-R, DVD-RW, DVD-ROM) is shown. , DVD-RAM, etc.).
In a DVD optical pickup device, light having a wavelength of 680 nm emitted from a laser diode 91 passes through a polarization separation element 92, a collimator lens 93, a λ / 4 plate 97, and an objective lens 94, and then irradiates a DVD optical disk 98. The reflected light from the recording pits of the DVD optical disk 98 is linearly polarized by the λ / 4 plate 97 and then diffracted by the polarization separation element 92 and guided to the photodiode 96 for focus detection, track detection, and signal detection. Is done.
In the optical pickup apparatus of the present embodiment, the polarization separation element 52 manufactured by any of the apparatuses and methods of Examples 1 to 5 and having the configuration shown in FIG. 6B is used as the polarization separation element 92. ing.

When the information signal was reproduced from the DVD-ROM using the optical pickup device of this example, a signal output equivalent to that of a conventional DVD optical pickup device combining a beam splitter with a bonded prism and a λ / 4 plate was obtained. Thus, it was confirmed that the optical pickup device of this example had reproduction characteristics equivalent to those of the conventional optical pickup.
Further, in the optical pickup device of the present embodiment, the polarization separation element 92 is smaller than the conventional beam splitter to which the prism is bonded, so that it is smaller than the conventional optical pickup device.

  As described above, the alignment bonding method and apparatus of the present invention has an optical element having a structure in which substrates are bonded with an adhesive, particularly a diffraction grating or hologram on or between substrates, and has a polarization separation function. It can be suitably used for producing an optical element (polarized light separating element). The optical element (polarization separation element) according to the present invention can be suitably used for an optical pickup device, and the optical pickup device can be miniaturized. The optical pickup device according to the present invention can be suitably used as an optical pickup mounted on a CD-type optical disc drive device, a DVD-type optical disc drive device, or the like.

It is structure explanatory drawing of the upper board | substrate and lower board | substrate which comprise an optical element. 1 is a configuration explanatory view of an alignment bonding apparatus showing a first embodiment of the present invention. FIG. It is explanatory drawing of the adhesion process by the alignment adhesion apparatus of the structure shown in FIG. It is explanatory drawing of the adhesion process by the alignment adhesion apparatus of the structure shown in FIG. It is explanatory drawing of the adhesion process by the alignment adhesion apparatus of the structure shown in FIG. It is a figure which shows the structural example of the process of cutting out an optical element from the adhere | attached upper and lower board | substrate, and the cut-out optical element. It is a schematic sectional drawing of the alignment bonding apparatus which shows the 2nd Example of this invention. It is a schematic sectional drawing of the alignment bonding apparatus which shows the 3rd Example of this invention. It is a schematic principal part sectional drawing of the alignment bonding apparatus which shows another structural example of the 3rd Example of this invention. It is a schematic sectional drawing of the alignment bonding apparatus which shows the 4th Example of this invention. It is a schematic sectional drawing of the alignment bonding apparatus which shows the 5th Example of this invention. It is a schematic block diagram of the optical pick-up apparatus which shows the 6th Example of this invention. It is a schematic block diagram of the optical pick-up apparatus which shows the 7th Example of this invention. It is a schematic sectional drawing of the alignment bonding apparatus which shows an example of a prior art.

Explanation of symbols

10: Upper substrate 11: Optical glass substrate 12: Alignment mark 13: Grating 20: Lower substrate 21: Optical glass substrate 22: Adhesive 23: Organic birefringent film 24: Alignment mark 25: Diffraction grating 30, 70, 80, 80 ': Alignment bonding device 31: Light irradiation device 32: Alignment detection optical system 33: Quartz glass mask holder 34: Vacuum exhaust port 35: Upper substrate suction groove 36: Gas introduction port 37: Gas ejection port 38: Substrate chuck 39: Moving device in X, Y, and θ directions 40: Base 41: Substrate chuck vertical movement mechanism 42: Vacuum exhaust port 43: Lower substrate suction groove 44: Alumina cylinder 45: Adhesive 46: Gas suction port 47, 48: Si rubber seal 50 : Upper and lower substrates 51: Dicing saw 52: Optical element 60: Gas confinement device 91: Laser diode De 92: polarization separating element 93: collimating lens 94: objective lens 95: CD-based optical disc (optical recording medium)
96: Photo diode 97: λ / 4 plate 98: DVD optical disk (optical recording medium)

Claims (16)

  A means for detecting alignment; a substrate chuck for fixing the substrate; a moving means for moving the substrate chuck in each direction of X, Y, Z, and θ; a mask holder made of an optically transparent planar member; A step of setting a lower substrate provided with an alignment mark having unevenness formed by etching on the substrate chuck using an apparatus provided with a light irradiation portion for irradiating light; and etching the mask holder portion by etching. A step of setting an upper substrate having alignment marks having irregularities to be formed, a step of aligning the alignment marks of the upper and lower substrates, a step of applying an adhesive, and an adhesive by introducing a gas into the periphery to be bonded And a step of covering the surrounding atmosphere with a gas, a step of spreading the adhesive, and a step of irradiating light to cure and bond the adhesive. Imento bonding method. The alignment bonding method according to claim 1,
The alignment bonding method, wherein the introduced gas is an inert gas. In the alignment adhesion method according to claim 2,
The alignment bonding method, wherein the inert gas is nitrogen gas or argon gas. In the alignment adhesion method according to any one of claims 1 to 3,
An alignment adhesion method, wherein the inert gas introduction step and the light irradiation step are linked. In the alignment adhesion method according to any one of claims 1 to 4,
An alignment bonding method, wherein the inert gas is introduced between a mask holder and a substrate chuck. In the alignment adhesion method according to any one of claims 1 to 5,
An alignment bonding method, wherein the inert gas is introduced so as to cover the entire apparatus. In the alignment adhesion method according to any one of claims 1 to 6,
An alignment adhesion method, wherein the adhesive is a photo-curing acrylic resin or epoxy resin material. In the alignment adhesion method according to any one of claims 1 to 7,
An alignment adhesion method, wherein the inert gas is ejected from a mask holder. In the alignment adhesion method according to any one of claims 1 to 8,
The mask bonding method includes an alignment bonding method characterized in that the mask holder has a gas ejection port in which fine holes are processed around the outside of the substrate. In the alignment adhesion method according to claim 9,
An alignment adhesion method comprising a structure in which a flexible sheet is provided outside a gas ejection port of the mask holder. In the alignment adhesion method according to any one of claims 1 to 10,
An alignment bonding method, wherein a gas suction port is provided in the substrate chuck.   A means for detecting alignment; a substrate chuck for fixing the substrate; a moving means for moving the substrate chuck in each direction of X, Y, Z, and θ; a mask holder made of an optically transparent planar member; A light irradiating portion for irradiating light, means for setting a lower substrate having an alignment mark having unevenness formed by etching on the substrate chuck, and unevenness formed by etching on the mask holder portion Means for setting the upper substrate having alignment marks, means for aligning the alignment marks on the upper and lower substrates, means for applying an adhesive, and introducing an atmosphere around the adhesive to create an atmosphere around the adhesive A means for covering with gas, a means for spreading the adhesive, and a means for irradiating light to cure and bond the adhesive, Alignment bonding apparatus characterized by using the alignment method of bonding according. In an optical element having a structure in which a substrate is bonded with an adhesive,
An optical element manufactured using the alignment adhesion method according to claim 1. In an optical element having a structure in which a substrate is bonded with an adhesive,
An optical element manufactured by the alignment bonding apparatus according to claim 12. The optical element according to claim 13 or 14,
An optical element comprising a diffraction grating or a hologram on or between substrates and having a polarization separation function. In an optical pickup device for recording or reproducing or erasing information on an optical recording medium,
An optical pickup device using the optical element according to claim 15.

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