JP2008198267A - Thin laminated board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin laminated board which can be manufactured easily and inexpensively, has small variation in film thickness distribution and is reduced in wobbling. <P>SOLUTION: In the thin laminated board formed by laminating a plurality of thin boards, a base material thinner than the thickness of the thin board is arranged inside an information recording area between a plurality of thin boards, and a thin film containing at least SiO<SB>2</SB>or SiN is laminated at least in one side of the thin board. It is preferred to satisfy 1.02×(t1+t2+to+tn)≤T≤1.10×(t1+t2+to+tn) wherein the thickness of the thin laminated board and the number of thin boards are represented by T and n respectively, and the thicknesses of thin boards are represented by t1, t2 to tn respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical recording medium, for example, a thin bonded substrate for an optical recording medium in which a thin substrate is bonded, and a method for manufacturing the same.

  In recent years, various attempts have been made to increase the capacity of optical disks, and in particular, attention has been focused on increasing the capacity per volume by reducing the thickness of the optical disk substrate. For example, Patent Document 1 proposes a recording / reproducing system in which the recording capacity per volume is increased by combining a thin optical disk and a stabilizer for stably rotating the thin optical disk with less surface shake.

  However, if the thickness of the optical disk substrate is reduced and the optical disk substrate is a single plate, there is a problem that the optical disk substrate is greatly deformed by the bimetal effect. In order to cope with such deformation of the optical disk substrate, it is effective to produce a conventionally known optical disk bonded substrate having a vertically symmetrical structure by bonding two substrates together. As for a thin optical disk, a method of bonding two thin substrates is effective in suppressing substrate deformation, and thus can be applied. For example, Patent Documents 2 and 3 propose a technique in which air is blown and bonded while holding a thin substrate flat.

  As for the bonding method itself, a multilayer film forming method by 2P method (photocuring method) can be applied to the bonding of thin substrates. For example, Patent Document 4 proposes a technique in which a resin used for the 2P method is spread on a substrate in advance, and a thin substrate is rotated to be shaken off and cured.

JP 2003-91970 A JP 2000-048419 A JP 2005-216426 A JP 09-161329 A

  However, in the manufacturing method by bonding optical disk substrates as described in Patent Documents 2 and 3, a conventionally used spin coat apparatus cannot be used, a special apparatus is required, and the cost increases. There was a problem. Further, even if the 2P method as disclosed in Patent Document 4 is applied in the case of bonding thin optical disk substrates having low substrate rigidity, the surface blur characteristic and the surface blur acceleration characteristic are not sufficiently improved. It is clear from their experiments. This is because the dispersion of the film thickness distribution becomes large because the rigidity of the thin substrate itself is low and it is easy to have static electricity.

  The present invention has been made in view of such circumstances, and intends to provide a thin bonded substrate that can be easily and inexpensively manufactured, has a small variation in film thickness distribution, and has reduced surface wobbling. To do.

The thin bonded substrate of the present invention is a thin bonded substrate formed by bonding a plurality of thin substrates, and a base material thinner than the thickness of the thin substrate inside an information recording area between the plurality of thin substrates. And a thin film including at least one of SiN and SiO ₂ is laminated on at least one side of the thin substrate. By laminating a thin film containing at least one of SiN and SiO ₂ , static electricity can be prevented from being generated on the polycarbonate surface, which is a material of the thin substrate, and surface blur characteristics and surface blur acceleration characteristics can be improved. it can.

  Preferably, when the thickness of the thin bonded substrate is T, the number of the plurality of thin substrates is n, and the thickness of each of the plurality of thin substrates is t1, t2,. .02x (t1 + t2 +... + Tn) ≦ T ≦ 1.10x (t1 + t2 +... + Tn). By doing so, a thin laminated substrate with less surface wobbling is realized.

  Another thin laminated substrate of the present invention is a thin laminated substrate formed by bonding a plurality of thin substrates, and is thinner than the thickness of the thin substrate inside the information recording area between the plurality of thin substrates. A substrate is disposed, the thickness of the thin bonded substrate is T, the number of the plurality of thin substrates is n, and the thickness of each of the plurality of thin substrates is t1, t2,. In this case, 1.02x (t1 + t2 +... + Tn) ≦ T ≦ 1.10x (t1 + t2 +... + Tn).

The method for producing a thin laminated substrate of the present invention is a method for producing a thin laminated substrate by laminating a plurality of thin substrates, wherein a thin film containing at least one of SiN and SiO ₂ is laminated on at least one side. Placing a thin substrate on the turntable, placing a base material thinner than the thin substrate inside the information recording area of the thin substrate on the thin substrate, and applying an adhesive on the thin substrate A step of dropping and rotating the turntable to spread an adhesive on the thin substrate; and a thin film including at least one of SiN and SiO ₂ is laminated on at least one side of the thin substrate. Disposing a thin substrate; rotating the turntable to shake off the adhesive between the thin substrate and the other thin substrate; and the thin substrate. The irradiating ultraviolet radiation, and curing the adhesive, the thin substrate, characterized in that it comprises a laminating n pieces by repeating the above steps.

  Preferably, when the thickness of the thin bonded substrate is T, the number of the plurality of thin substrates is n, and the thickness of each of the plurality of thin substrates is t1, t2,. .02x (t1 + t2 +... + Tn) ≦ T ≦ 1.10x (t1 + t2 +... + Tn).

  Another thin laminated substrate manufacturing method of the present invention is a method of manufacturing a thin bonded substrate by laminating a plurality of thin substrates, the step of placing the thin substrate on a turntable, and the thin substrate on the thin substrate. A step of disposing a base material thinner than the thin substrate inside the information recording area of the thin substrate; dropping an adhesive on the thin substrate; and rotating the turntable to bond the adhesive onto the thin substrate Unfolding, disposing another thin substrate on the thin substrate, rotating the turntable and shaking off the adhesive between the thin substrate and the other thin substrate, A step of irradiating the thin substrate with ultraviolet light to cure the adhesive; and a step of laminating the thin substrate by repeating the above steps, wherein the thickness of the thin bonded substrate is T, Each thickness of the mold substrate t1, t2, when the · · · tn, characterized in that it is a 1.02x (t1 + t2 + ··· + tn) ≦ T ≦ 1.10x (t1 + t2 + ··· + tn).

  According to the present invention, a thin bonded substrate that can be manufactured easily and inexpensively, can be manufactured easily and inexpensively, has a small variation in film thickness distribution, and has reduced surface wobbling is realized.

  In order to realize the present invention, the present inventors have sought a method for inexpensively manufacturing a thin substrate with reduced surface deflection and surface acceleration using a conventional spin coater.

  First, a separate turntable for supporting a thin substrate was prepared in the spin coater that has been used conventionally, and various experiments were repeated by placing the thin substrate on the turntable. However, the thin substrate behaved differently from the conventional thick substrate, and it was difficult to produce a thin bonded substrate having good surface blurring characteristics and surface blur acceleration characteristics. The present inventors have found that this is because the thin substrate itself has low rigidity and easily has static electricity from the following phenomenon, and have attempted to improve it.

First, an ultraviolet curable resin was developed on a thin substrate placed on a turntable using a spin coating method. Next, another thin substrate to be bonded was placed on the thin substrate so that the inner diameters of these thin substrates coincided. Then, the following phenomenon occurred.
(1) There was a place where the thickness of the ultraviolet curable resin near the portion where both thin substrates first contacted decreased depending on the weight of the upper substrate. On the other hand, since the thin substrate is not rigid, the thin substrate is bent during the bonding process, so that portions where the two thin substrates are not in contact with each other are formed.
(2) The appearance frequency is particularly remarkable in the vicinity of the inner periphery, and a place where the resin protrudes from the inner periphery diameter and a place where the thin substrates do not contact each other cause a bonding failure.
(3) When the subsequent resin curing process or the like is advanced in such a state, the variation in the thickness distribution of the finally obtained bonded substrate becomes very large. Furthermore, air is entrained in the bonded substrate, causing local deformation in the vicinity of the location. Further, the resin protruding from the inner diameter severely contaminated the inner periphery of the substrate, thereby increasing the eccentricity of the substrate.

In addition to the phenomenon described above, when static electricity was generated in the thin substrate, the following phenomenon occurred.
(A) A part of the thin substrate charged by static electricity and a part of the turntable adhered to each other.
(B) The thin substrate was partially distorted by (a), and an island-like portion (air biting portion) left without being in close contact with the turntable and entrained with air remained around the thin substrate.
(C) If the substrate bonding and the subsequent curing process are performed without removing the air-engaged portion, the air-engaged displacement state is transferred as it is and remains semi-permanently on the laminated thin substrate. It became impossible to remove in the subsequent process.

  In order to solve the above-mentioned problems, in the thin bonded substrate of the present invention, when the thin substrate is bonded, firstly, in the region inside the information region between the thin substrates to be bonded, the thickness is thinner than the thin substrate. Lamination is performed with the base material sandwiched. Thereby, mixing of air in the bonding process can be reduced, and local deformation is reduced. Further, since the resin can be prevented from leaking from the inner peripheral diameter, the substrate is not soiled.

Second, make sure that the thin substrate has as little static electricity as possible. That is, a thin film containing at least one of SiN and SiO ₂ is laminated on at least one side of the thin substrate, thereby preventing static electricity on the polycarbonate surface, which is the material of the thin substrate.

  Here, when laminating the thin substrate, an ultraviolet curable resin serving as an adhesive is applied onto the first thin substrate material, and the second thin substrate material is applied onto the first thin substrate material. And the turntable is rotated, and the adhesive is spread on the entire surface of the disk and then cured. In the thin bonded substrate of the present invention, when forming a thin bonded substrate by bonding n thin substrates, the thickness of the completed thin bonded substrate is T, and the thickness of the original n thin substrates is When the thicknesses are t1, t2,... Tn, the viscosity of the resin and the rotation of the turntable so that 1.02x (t1 + t2 +... + Tn) ≦ T ≦ 1.10x (t1 + t2 +. When a thin bonded substrate is manufactured by adjusting the number, variation in thickness distribution on the information recording surface can be reduced most. This is because if the thickness of the thin bonded substrate to be manufactured is less than 2% of the total thickness of the original bonded substrate, sufficient space cannot be secured to prevent the inner peripheral curing failure, and if the thickness becomes 10% or more, the space This is because the thickness becomes too large to the information recording area.

  Hereinafter, a method for producing a thin bonded substrate according to the present invention and a best mode for carrying out the method will be described in detail with reference to the accompanying drawings. 1 to 6 are diagrams illustrating embodiments of the present invention. In these drawings, the same reference numerals denote the same components, and the basic configuration and operation are the same. To do.

  FIG. 1 is a diagram showing an example of the configuration of a spin coater for producing a thin bonded substrate of the present invention. The thin substrate 101 is placed on the turntable 102, fixed by the clamp 103, and the turntable 102 is rotated to spread the adhesive, cut it off, and bond the thin substrates together. A spacer 104 for lifting the inner peripheral portion of the thin substrate 101 from below is disposed on the inner peripheral portion of the turntable 102. The thin substrate 101 is held between the upper clamp 103 and the lower spacer 104. The spacer 104 secures a gap between the thin substrate 101 and the turntable 102.

  When the turntable 102 is rotated in this state, the air in the gap between the thin substrate 101 and the turntable 102 moves from the inner periphery to the outer periphery due to centrifugal force starting from the vicinity of the outer peripheral end of the spacer 104, and further the through hole 105. A steady air flow from the inner periphery to the outer periphery is generated by the air flowing in from the inner periphery. As a result, the local air biting phenomenon caused by static electricity when stationary is completely removed. The distance between the thin substrate 101 formed by the spacer 104 and the turntable 102 is preferably 0.01 to 0.5 mm.

Next, the process of manufacturing the thin bonded substrate of the present invention using the spin coater shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a flowchart showing a process for manufacturing the thin bonded substrate of the present invention, and FIG. 3 is a table showing coating conditions. In this example, two thin substrates are bonded together to form a bonded substrate. First, a disk-shaped thin substrate A on which a thin film of SiN or SiO ₂ is laminated and has a central hole is set on the turntable 102 (step S21). Next, a disk-shaped base material having a central hole similar to that of the thin substrate, which is thinner than the thin substrate A, is formed on the turntable 102 on the inner side of the information recording area of the thin bonded substrate to be manufactured. It arrange | positions, aligning the board | substrate A and a central axis (step S22). Next, an adhesive is applied on the thin substrate A, and the turntable 102 is rotated to spread the adhesive under a predetermined coating condition (for example, the coating condition A shown in FIG. 3) (step S23). Subsequently, while aligning the central axis with the thin substrate A on the turntable 102, a disk-shaped thin substrate B in which a thin film of SiN or SiO ₂ is similarly stacked and a central hole is formed is overlaid thereon (step S24). The turntable 102 is rotated and the adhesive between the thin substrates A and B is shaken off under a predetermined coating condition (for example, the coating condition B shown in FIG. 3) (step S25). Thereafter, the thin substrates A and B are irradiated with ultraviolet rays using an ultraviolet irradiation device, the adhesive is solidified, and the rotation of the turntable 102 is stopped (step S26).

  Through the above steps, a thin bonded substrate with improved surface blur characteristics and surface blur acceleration characteristics according to the present invention can be manufactured. Hereinafter, more specific examples will be described.

A thin substrate made of a disc-shaped polycarbonate film having a thickness of 92 μm and an outer diameter of 120 mmφ and having a central hole with an inner diameter of 15 mmφ is prepared. Grooves and pits were formed. Next, a dye recording layer was formed by spin coating on the surface of the thin substrate where the grooves and pits were formed, and a metal alloy reflective layer mainly composed of silver was laminated thereon by 50 nm using an Anelva sputtering apparatus. . Next, 5 nm of silicon nitride (SiN) or silicon oxide (SiO ₂ ) was laminated on the side opposite to the surface on which the dye recording layer and the reflective layer of the thin substrate were laminated.

  The turntable consists of a disk-shaped glass plate with a surface roughness of # 1000, a thickness of 1 mm and an outer diameter of 118 mmφ. A center hole with an inner diameter of 15 mmφ is formed, and a 6 mmφ inflow through hole is located at a position 18 mm from the center. A total of 8 pieces arranged at regular intervals were prepared. Also, a spacer made of SUS304, having a disk shape with a thickness of 0.2 mm and an outer diameter of 30 mmφ, and a center hole having an inner diameter of 15 mmφ was prepared.

  FIG. 4 is a diagram schematically showing the configuration of a spin coater used for manufacturing the thin bonded substrate of the present invention used in this example. The rotating table 200, the turntable 201, the syringe 203, the syringe movement support mechanism 204, the ultraviolet irradiator 205, the ultraviolet irradiator movement support mechanism 206, the vacuum chuck 207, and the vacuum chuck support movement mechanism 208 are configured. The center bar of the turntable 200 is used to align the eccentricity of the thin substrates to be overlapped, and has a diameter of 15.1 mm (± 0.02) so as to penetrate the center hole φ15.05 mm (± 0.02) of the thin substrates. ), And the tip is tapered cone shape to facilitate penetration. The vacuum chuck 207 is made of a porous ceramic manufactured by Nippon Tungsten Co., Ltd., and can be switched between the suction side and the ejector side by switching the valve. The syringe 203 is a device for dropping the ultraviolet curable adhesive onto the thin substrate while adjusting the dropping amount.

  Hereinafter, a procedure for laminating a thin substrate by the spin coater will be described. First, one thin substrate 202 was held by the vacuum chuck 207 and placed on the turntable 201 from above the spin coater. Hereinafter, this thin substrate 202 is referred to as a thin substrate A. Next, a disk-shaped base material having a center hole of φ15.05 mm, which is thinner than the thickness of the thin substrate A, is disposed inside the information recording area. Next, an ultraviolet curable resin was dropped onto the inner peripheral position (r = 18 to 23 mm) of the thin substrate A by the syringe 203, and the ultraviolet curable resin was spread to approximately r = 35 mm according to the coating condition A shown in FIG. . That is, UV curable resin was dropped for 4 s at a rotation speed of 30 rpm, then spread on the substrate for 6 s at 50 rpm, and finally the rotation was stopped for 2 s. In addition, as the ultraviolet curable resin, a resin having a good curability with a viscosity of 30 to 200 mPa · s (about 100 mJ / cm 2 or less) was used. Note that the thickness (T) of the bonded substrate can be changed not only by changing the thickness of the substrate to be used, but also by changing the thickness of the adhesive layer. The thickness can be reduced by increasing the number of rotations when the adhesive is shaken off as shown in FIG.

  Next, another thin substrate 209 (hereinafter referred to as a thin substrate B) was placed on the thin substrate A on the turntable 201 by the vacuum chuck 207. Magnet clamps (not shown) are arranged on the thin substrates A and B, and the adhesive between the thin substrates A and B is shaken off according to the coating condition B shown in FIG. The thickness of the adhesive was not uneven at the inner and outer peripheries. That is, the rotational speed was increased to 3000 rpm in 6 s, held at 3000 rpm for 4 s, and finally stopped for 4 s.

  Next, the thin substrates A and B bonded together by the ultraviolet irradiator 205 were irradiated with ultraviolet rays to cure the ultraviolet curable resin. When the ultraviolet curable resin was cured, the rotation of the turntable 201 was stopped and the clamp was removed. In order to make the both surfaces of the bonded thin substrates A and B uniform, the ultraviolet curable resin is first irradiated with an ultraviolet irradiation intensity that cures about 30 to 70% of one surface, and then applied to the other surface. Therefore, it is preferable to irradiate the insufficient amount of ultraviolet rays. Thereby, since the deformation | transformation of the board | substrate originating in a heat ray and the bias | inclination of a hardening grade reduce, the bonded thin board | substrate with smaller surface blurring is obtained.

  In the above process, an adhesive layer is formed between the thin substrates A and B. In particular, the inner peripheral portion between the thin substrates A and B is thinner than the thickness of the thin substrates A and B as described above. Material was placed. In addition, the effect of this invention was able to be acquired if the base material put between thin board | substrates A and B is 15 micrometers or more. For this reason, when a large number of thin substrates are stacked, it is preferable to use a base material that is as thin as possible. Even when the base material was not coated with the ultraviolet curable resin, the thin film substrates A and B could be bonded because the ultraviolet curable resin wraps around between the thin substrate and the base material at the time of bonding. If the base material is not inserted, adhesion failure occurs particularly at the inner periphery of the substrate, or air is caught between the adhesive layers, which causes errors in recording and reproduction. Alternatively, the variation in the thickness distribution of the adhesive layer becomes large, which similarly causes an error. Therefore, in this embodiment, a double-sided adhesive base material having an inner diameter of 15 mmφ, an outer diameter of 24 mmφ, and a thickness of 25 μm is prepared, and the center hole of the base material is aligned with the center holes of the thin substrates A and B to be bonded. Placed on top. As a result, the ultraviolet curable resin spreads on the thin substrate starting from the outer peripheral edge of the base material, so that the air is not trapped. Furthermore, since the development of the UV curable resin became smooth, the substrate thickness could be made uniform. FIG. 5 (a) shows a schematic cross-sectional view of the inner peripheral portion of a thin bonded substrate by a conventional manufacturing method in which a base material is not inserted, and FIG. 5 (b) is a thin shape of the present invention in which the base material is inserted. The typical sectional view of the substrate inner circumference part of a bonded substrate is shown. FIG. 6 is a graph showing the measured values of the respective substrate thickness distributions. The horizontal axis indicates the distance r from the center in mm, and the vertical axis indicates the thickness in μm. A bonded substrate without a substrate had a substrate thickness distribution of about 5 μm in the information recording area. On the other hand, in the bonded substrate containing the base material, the thickness of the substrate becomes thick at the position where the base material is present, but the thickness is almost uniform in the information recording area (radius r is 24 mm or more).

  The various conditions described above are merely examples, and the type of the ultraviolet curable resin and the conditions for forming the adhesive layer are not limited thereto. However, regarding the thickness (T) in the information area of the completed thin substrate, when the thickness of the original n thin substrates is t1, t2,... Tn, at least 1.02x (t1 + t2 + ... + Tn) .ltoreq.T.ltoreq.1.10x (t1 + t2 +... + Tn), a thin bonded substrate with small surface blurring could be produced.

  This is due to the following two reasons. First of all, when it becomes thinner than 2% of the total thickness of the original bonded substrate, it is not possible to secure a sufficient space for the resin to enter the inner periphery to prevent defective curing. On the other hand, when the thickness is 10% or more, the space becomes too large, and the thickness of the information recording area is increased beyond the point where a space for the resin to enter can be secured only in the information recording area.

  Second, in order to prevent local deformation caused by entrainment of sub-micron or less dust exceeding the cleanliness of the process when the adhesive layer made of UV resin is formed by the spin coat method like the thin laminated substrate of the present invention. To some extent, the adhesive layer must be thick. If the substrate used for bonding is too thin, the substrate rigidity (proportional to the cube of the disk thickness) becomes too small, and unevenness occurs in the substrate with minute dust as the core, which tends to create a large defect. On the other hand, if the adhesive layer becomes too thick, the disc rigidity after being bonded will become extremely high, so that the surface blur control by the rotation stabilizing plate as used in the present invention has become ineffective.

  Hereinafter, the thin bonded substrate of the present invention according to the above example and the thin bonded substrate manufactured by the conventional method were prepared, and the performance was compared.

  First, there is a clear visual difference between these two types of thin bonded substrates, and the thin bonded substrates obtained by the conventional manufacturing method have several large displacement changes due to air being mixed. Whereas ten places were seen, the thin laminated substrate of the present invention had almost no air entrainment, and the whole substrate looked flat.

Next, with respect to the thin bonded substrate by the conventional manufacturing method and the thin bonded substrate of the present invention, the surface blur acceleration at the time of rotating the substrate was measured using a laser Doppler meter made by SONY. FIGS. 7 and 8 are graphs showing the results of measuring the surface blur acceleration at each radial position of 40 mm. The horizontal axis indicates the rotation speed in rpm, and the vertical axis indicates the surface blur acceleration in m / s ² . As is apparent from FIGS. 7 and 8, the thin bonded substrate of the present invention has a significantly lower surface acceleration than the thin bonded substrate obtained by the conventional manufacturing method at any rotational speed. I understand that. For example, the surface blur acceleration at 5000 rpm is 120 m / s ² in the conventional thin substrate, and is significantly improved to 50 m / s ^{2 in the} thin substrate according to the present embodiment. This indicates that the specification of the DVD-R has been cleared, and it has been shown that the structure of the thin bonded substrate of the present invention is effective in reducing the surface shake.

Next, in addition to the 92 μm-thick PC substrate, 67 μm, 40 μm, and 20 μm-thick PC substrates are separately prepared by extrusion molding. Similarly, formation of pits and grooves by nanoimprinting, recording film formation by dyes, sputtering reflection of Ag alloy Film formation was performed. Using the PC substrates having various thicknesses after the above process, five kinds of thin bonded substrates from disk 1 to disk 5 as shown in the table of FIG. 9 were produced by the bonding method described in the above example. FIG. 10 is a table in which the surface blur acceleration with a radius of 30 mm at the rotational speed of 5000 rpm is summarized from disk1 to disk5. As is clear from FIG. 10, regarding the thickness (T) in the information area of the resulting thin bonded substrate, when the thickness of the original n thin substrates is t1, t2,. At least, if such is in the range of 1.02x (t1 + t2 + ··· + tn) ≦ T ≦ 1.10x (t1 + t2 + ··· + tn), good characteristics than the runout acceleration and an object (70m / ^{s 2)} A thin bonded substrate was produced.

  As described above, the thin bonded substrate of the present invention has been described with reference to specific embodiments, but the present invention is not limited thereto. A person skilled in the art can make various changes and improvements to the configurations and functions of the invention according to the above-described embodiments or other embodiments without departing from the gist of the present invention.

It is a figure which shows an example of a structure of the spin coater which manufactures the thin bonded substrate of this invention. It is a flowchart which shows the process of manufacturing the thin bonded substrate of this invention. It is a table | surface which shows coating conditions. It is a figure which shows roughly the structure of the spin coat apparatus used for manufacture of the thin bonded substrate of this invention. (A) is typical sectional drawing of the board | substrate inner peripheral part of the thin bonding substrate by the conventional manufacturing method, (b) is typical sectional drawing of the board | substrate inner peripheral part of the thin bonding substrate of this invention. Show. It is the graph which showed the actual value of substrate thickness distribution. It is a graph which shows the result of having measured the surface blur acceleration of the radial position 40mm of the thin bonded substrate by the conventional manufacturing method. It is a graph which shows the result of having measured the surface blur acceleration of the radial position 40mm of the thin laminated substrate of this invention. It is a table | surface which shows the number of layers and thickness of five types of thin laminated substrates. It is the table | surface which put together the surface blur acceleration with a radius of 30 mm in the rotation speed of 5000 rpm of five types of thin bonded substrates.

Explanation of symbols

101, 202, 209 Thin substrate 102, 201 Turntable 103 Clamp 104 Spacer 105 Through hole 200 Rotary table 203 Syringe 204 Syringe movement support mechanism 205 Ultraviolet irradiation machine 206 Ultraviolet irradiation machine movement support mechanism 207 Vacuum chuck 208 Vacuum chuck support movement mechanism

Claims (8)

  A thin bonded substrate formed by bonding a plurality of thin substrates, wherein a base material thinner than the thickness of the thin substrate is disposed inside an information recording region between the plurality of thin substrates. A thin bonded substrate.   When the thickness of the thin bonded substrate is T, the number of the plurality of thin substrates is n, and the thickness of each of the plurality of thin substrates is t1, t2,... Tn, 1.02 × (t1 + t2 + ... + Tn) ≦ T ≦ 1.10x (t1 + t2 +... + Tn)   A thin bonded substrate formed by bonding a plurality of thin substrates, wherein a base material thinner than the thickness of the thin substrate is disposed inside an information recording area between the plurality of thin substrates, the thin substrate When the thickness of the bonded substrate is T, the number of the plurality of thin substrates is n, and the thickness of each of the plurality of thin substrates is t1, t2,... Tn, 1.02x (t1 + t2 + ... A thin bonded substrate characterized in that + tn) ≦ T ≦ 1.10x (t1 + t2 +... + Tn). The thin bonded substrate according to any one of claims 1 to 3, wherein a thin film including at least one of SiN and SiO ₂ is laminated on at least one side of the thin substrate. A method of manufacturing a thin bonded substrate by bonding a plurality of thin substrates,
Placing a thin substrate on a turntable;
Placing a base material thinner than the thin substrate inside the information recording area of the thin substrate on the thin substrate;
Dropping an adhesive on the thin substrate, rotating the turntable to spread the adhesive on the thin substrate; and
Placing another thin substrate on the thin substrate;
Rotating the turntable to swing off the adhesive between the thin substrate and the other thin substrate;
Irradiating the thin substrate with ultraviolet light to cure the adhesive;
And a step of laminating n thin substrates by repeating the above steps.   When the thickness of the thin bonded substrate is T, the number of the plurality of thin substrates is n, and the thickness of each of the plurality of thin substrates is t1, t2,... Tn, 1.02 × (t1 + t2 + ... + Tn) ≦ T ≦ 1.10x (t1 + t2 +... + Tn), The method for producing a thin bonded substrate according to claim 5. A method of manufacturing a thin bonded substrate by bonding a plurality of thin substrates,
Placing a thin substrate on a turntable;
Placing a base material thinner than the thin substrate inside the information recording area of the thin substrate on the thin substrate;
Dropping an adhesive on the thin substrate, rotating the turntable to spread the adhesive on the thin substrate; and
Placing another thin substrate on the thin substrate;
Rotating the turntable to swing off the adhesive between the thin substrate and the other thin substrate;
Irradiating the thin substrate with ultraviolet light to cure the adhesive;
Laminating the thin substrate by repeating the above steps, and
When the thickness of the thin bonded substrate is T and the thickness of each of the n thin substrates is t1, t2,... Tn, 1.02x (t1 + t2 + ... + tn) ≦ T ≦ 1.10x ( (t1 + t2 +... + tn) A method for manufacturing a thin bonded substrate. The method for manufacturing a thin bonded substrate according to claim 5, wherein a thin film including at least one of SiN and SiO ₂ is laminated on at least one side of the thin substrate.

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