TW497099B - Manufacturing method for optical discs containing multiple recording layers - Google Patents

Abstract

An automatic manufacturing method for optical discs containing multiple recording layers is disclosed. A resin is spin-coated onto a stamper to replicate the signal pattern on the stamper. Rotating speed is controlled at 200-400 rpm to disperse the resin and then gradually increased to 3200-4500 rpm to spread the resin evenly. A resin recording layer is formed after curing. A substrate containing pre-cast signal is then adhered to the resin recording layer, which is then released easily from the stamper utilizing many gas holes symmetrically placed on the stamper. Repeating the aforementioned process produces an optical disc containing multiple recording layers.

Description

497099 V. Description of the invention (1) [Scope of the invention] The present invention relates to a method for manufacturing an optical disc with multiple recording layers, and particularly relates to a method for manufacturing a thin-film recording layer by spin coating with automatic control, combined with other (2) A method of making a signal emitting substrate or other thin-film recording layer to produce an optical disc with two or more recording layers. [Background of the Invention] The current CD disc is a single-layer recording disc. The storage capacity of a disc with a diameter of 12 cm is only 650 MB, which has gradually become insufficient. If you take a 135-minute movie as an example, Video-CD requires at least two to three, and its compression technology is MPEG-1, which is not good in daylight quality. In contrast, a single-sided single-layer DVD The disc capacity is up to 4.7GB. It adopts MPEG-2 compression technology and AC3 Dolby surround sound. It is not comparable to V ide 〇-CD in terms of day quality or sound enjoyment, and only one DVD disc is required. It can hold 13.5 minutes of high-quality movies. Therefore, for the future development of optical discs, how to increase the recording capacity of optical discs has become the primary focus of research and development. Multi-layer recording discs are an effective way to increase the recording capacity per unit area. The current DV D disc has developed a single-sided double-layer structure with a recording capacity of up to 8.5GB (commonly known as DVD-9). Laser light is incident on one side of the optical disc and can read data from two recording layers. This will double the recording density per unit area, but the current single-sided dual-recording layer disc method is to combine two discs engraved with recording signals and face to face to form two recording layers. This method has not continued to improve Feasibility of recording layers. Therefore, if the disc is to be manufactured without changing the appearance, geometry, and shape of the disc,

497099 5. Description of the invention (2) To make a double-sided double-layer disc with a single-sided three or more recording layers, or a double-layer double-layer disc with a recording capacity of 17GB (known as DVD-18), as specified by the DVD Forum, Also think about other ways to make discs. There are currently no DVD-18 products on the market. There are currently three possible ways to technically overcome the production of double-sided double-layer optical discs (DVD-1 8). The first method is to directly inject a two-layer recording layer π sheet by a mechanical injection molding method.The second method is to use a so-called 2P (P h ◦ t 〇-Ρ ο 1 ymer) method to make a recording layer film. One way is to use a SOAP (spin-on-and-peel) method as the recording layer film. In the first method, two stampers with signal signals are placed on the fixed side and the moving side of the injection mold, respectively, and the molten plastic is directly pressed into the cavity of the mold at high temperature and pressure. Although this method uses today's mature plastic injection molding technology, the manufacturing process requires high temperature and pressure, and the wear of the mold is also a major problem. 'In addition, it is easy to take out the injection product from the mold, and the thickness of the product cannot be too thin.' Otherwise, when the finished plastic product is taken out, due to insufficient mechanical strength or thermal stress or uneven shrinkage of the plastic, it will often cause distortion of the finished product. Therefore, its thickness will exceed the specifications required in the disc specifications, so it is not applicable. Used to produce multi-layered discs. The second method is a method of making _ thin films developed by Pioneer and SONY. This method is to firstly lay a cloth on the stencil that has been engraved with a signal: a layer of easily deformable polymer material. The polymer material is pressed to the stencil, thereby transferring and copying the signal on the stencil, and achieving the purpose of uniform thickness, and then using ultraviolet (UV) irradiation to harden

497099 5. Description of the invention

(cure) This polymer film layer is simultaneously bonded to another layer of polycarbonate substrate with a recording signal, and then continues to perform subsequent actions such as flying keys (sPuMering). Double-layer structure. Continuing this action will make a true single-sided multilayer structure. However, the disadvantage of this method is that high pressure is required to obtain a good signal transfer and reproduction effect, which will cause considerable wear on the surface of the stencil. Due to the wear of the stencil surface, the error rate of discs produced in the later stage is higher than that produced in the previous stage. Discs. The third method of thin film is to harden and form the rotating mold after the transfer agent is volatilized. Basically, it is on a plate. By spin-printing the recorded signal on the stencil, it can produce a true film. The advantages of using the S 0 AP process, and the mechanical strength of the film obtained by the 2 P method, the relative viscosity of the carbonic acid substrate is π, the same as the thin finished product: a multi-recording layer disc and another layer have subsequent actions such as f. This action will Although the injection molding degree of Lewin and South Pressure is thinner, the chance of poly damage of thin recording signals is also (wrinkle: This method is used to make a SOAP produced by coMedia company. A polymer resin solution is dropped in a forward rotation coating. The resin solution covers the function of the entire stencil signal. When the polymer resin is dissolved in the South molecular film of the film layer, the polycarbonate substrates are bonded together, and then continue to form a true single-sided double-layer structure. The multi-layered structure of the recording film is produced without the need to use a high film thickness produced by this method is thinner than the film thickness, but when the film layer thickness becomes worse, the After the bonding layer has in mind, is generated from the template in the subsequent one of the reasons is not easy to obtain a flat without wrinkles' This is why the industry has not been adopted sheet. Further, on side SOAP

V. Description of Invention (4) Among the patents published in the law, ^ T is as the national patent Nos. 5, 468 324, 5, 6 6 9, Θ9 5 and 5, 7 0 〇5 3 9 patent households Jinjiejie # 土牌 恩 # + "The corpse juice revealer only has a conceptual description of how to make multiple feasible solutions, and this does not propose actual and Shiben μ & $ for each step. One of the important reasons for the popular production of film products. [Objective and Summary of the Invention] The purpose of the present invention is to apply the above-mentioned SOAP process. It can be applied to the automated production of multi-recording layer optical discs. In the aspect of fa, the present invention further provides a method for making the recording film easy to release when applying the above-mentioned SOAP technology. The finished product is separated without causing wrinkling or damage to the recording film. ^ ^ ^ The purpose of the present invention described above, the proposed method of fabricating a multi-recording layer optical disc can be summarized as follows: Take ^ first ^ using traditional injection molding technology to produce the first layer of recording film Grease substrate (L1 layer). After this, repeat the following process disclosed in the present invention to form a second recording film, a third recording film, etc. on the L 1 layer to obtain a single-sided two I recording layer. CD. If there are two single-sided multi-recording layer discs, The combination of surface and surface methods can be obtained-a double-sided multi-layer recording layer of the disc gluer = taken from a stamper with & already recorded, and a large amount of δ on the flat substrate, this template records Required for a second recording film

Page 8 497099 5. The signal pattern of the description of the invention (5) (or the third layer of the recording film ... etc., it depends on the recording layer to be formed), and the diameter of the stencil is about 2 during the manufacturing process. The center part of the stencil at 2 ~ 3 5 mm is used as the clamping area to form symmetrical air holes to facilitate the release of the second recording film formed in the subsequent process. Next, the recording pattern on the stencil was copied by spin coating, including spraying the resin at a speed of 2000-400 rpm, and then gradually increasing the speed to 3200-4500 rpm to spread the resin to form A recording film having a thickness of about 1 -1 5 // m. Then, the substrate carrying the stencil and this recording layer is turned over, and a reflective layer film is formed on the recording layer formed on the previous L 1 layer, for example, a metal such as Au, A1, Ag, A1N, Si3N4, or SiC, or a dielectric material. The thickness is about 10 ~ 30 nm (the thickness varies according to the material being sputtered, and then a layer of adhesive is coated on the reflective layer to make it adhere to the side with the recording layer. After curing, Control the shrinkage of the selected adhesive to be less than 3% to avoid excessive deformation. Finally, separate the bottom plate from the stencil and the resin recording film, and blow air into the air hole from the above to separate the film layer in the center. Separate, and then continue to expand from the inner to the outer circumference, so that the demolding process is easy and does not cause harm. After repeating the above process, the desired recording layer is adhered to the L 1 layer, and then placed in the sputtering machine. Reflective layer sputtering is performed, and the finished product after sputtering is a single-sided multilayer recording layer structure. Finally, as long as two single-sided multi-recording sheets are bonded to each other with the recording side and the recording surface, it becomes a double-sided Optical disc recording layer. In order to make the aforementioned and other objects of the present invention, features, and advantages of significantly comprehensible, a preferred embodiment hereinafter, and with the accompanying drawings, for details

497099 5. Description of the invention (6) The detailed description is as follows. Description of the drawings: Fig. 1 shows a block flow chart of a method for manufacturing a multi-layer recording layer optical disc according to the present invention; Figs. 2 a to 2 g show a schematic flowchart of a process for producing an optical disc with two recording layers by the method of the present invention; Figures 3a, 3b show the formation of a number of symmetrical pores on the template of the process of the present invention; Figures 4a, 4b show the template of the present invention glued to the base plate to facilitate the clamping process; Figure 5a illustrates a method of bonding a recording layer to a reflective layer in the process of the present invention, and Figure 5b illustrates another method of bonding a recording layer to a reflective layer in the process of the present invention; Figures 6a, 6b illustrate Comparison of the signal pattern recorded on the template in the process of the present invention with the pattern obtained after the recording layer is copied. [Explanation of the embodiment] Please refer to "Fig. 1", which is a method for manufacturing a multi-recording layer optical disc according to the present invention. The process steps used to form a CD-disc multi-recording layer structure are as follows. First, a polycarbonate substrate with a first recording signal is made (step 1a), and then a half reflective layer is deposited on the polycarbonate substrate (step 1). b) standby; another template (stamper) is provided (step 2

Page 497099 V. Description of the invention (7) a), which has a signal pattern of a subsequent recording layer to be formed thereon, and glues it to a base plate (step 2b); and then uses a spin coating method ( Step 3) forming a thin film layer of polymer material on the stencil, and after curing (step 4) so as to form a recording layer that reproduces the recording signal of the stencil; and then apply an adhesive on it (step 5) , Flip the entire bottom plate and template, and adhere the bottom plate and the template to the recording layer (step 6), and cure the adhesive with a curing process so that the recording layer can be firmly bonded to the polycarbonate substrate; The stencil is separated from the recording film, that is, the demolding process (step 7); finally, the new surface exposed by the demolding is sputtered with a reflective layer (step 8) to complete the single-sided double-layer structure; the above steps are repeated by repeating 1 b ~ 5 procedures, can successively form a second, third, ... recording layer on a polycarbonate substrate; finally, a protective coating is formed on the outside of the completed single-sided multi-recording layer structure (step 9 a) 〇 Follow the same As long as the above-mentioned CD series optical discs or two single-sided multi-layered layers are laminated, they are bonded face to face to form a complete disc. The present invention can be applied to various CD and DVD read-only and recordable optical discs In the following, a DVD double-sided double-layer optical disc with a diameter of 120mm and a thickness of 1.2mm will be taken as an example of expression. The true DVD double-sided double-layer disc method is to make two single-sided double-layer recording sheets with a diameter of 120mm (thickness about 0 · 6mm), and the recording faces are bonded to each other to form a disc with a thickness of 1.2mm. . Therefore, it is necessary to first produce a recording sheet having a thickness of 0.6 mm on one side but having a double recording layer.

497099 V. Description of the invention (8) Please refer to Figures 2a to 2g ", which is a schematic diagram of the process steps of the present invention. As shown in "Figure 2a", first create a template 12. The signal recorded on this template is the signal to be recorded on the single-sided second layer (for easy identification, the recorded signal on this layer is called b). Subsequent delamination, symmetrical air-bl0Wn holes 122 are opened in the discontinuity area (diameter 22-3 5mm) in the central part of the stencil. Please refer to the embodiment of "Figures 3a and 3b" , Can be made with three-hole symmetry or four-hole symmetry. Next, this template 12 will be glued to a flat bottom plate 10. This step has two purposes. The first is to facilitate the subsequent automatic clamping. The second is to improve the mechanical strength of the Southern Edition. The thickness of the stencil obtained after forming) is only about 0. 3-0. 5 mm, which is quite soft and easy to be damaged. Therefore, combining the stencil 12 with the bottom plate 10 can avoid direct manipulation of the stencil and reduce damage to the stencil 12. Please refer to "Figures 4a and 4b", the bottom plate 10 can be used with different fixtures to make a design suitable for clamping. As shown in "Figure 2b", the method of copying the recorded signal on the template 12 using the spin coating method is to first glue the template 1 2 and the bottom plate 10, which are flat and flawless after inspection, by a robotic arm, and place Once a specially designed spin coater is applied, and resin is dripped onto the surface in an amount of 5-10 ml. The type of resin used may be, for example, Aery 1 ic polymer, Poly-Ether-Imide (PEI ), Photo Imide (PI), etc. In order to make the thickness of the film uniform, spin coating needs to go through at least two processes: (1) whistle, disperse and (2) spread uniformly.

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V. Description of Invention (9)

During the process of Shuyue Yue, first spray at a speed of 2 0-4 0 0 r pm. The nozzles are pushed outward from the inner radial direction or from the outer diameter of the two-way inner diameter, or sprayed back and forth multiple times. The nozzle moving speed is not greater than 5m / sec, the nozzle diameter used must be less than 100 / zm. Over $$ off. Gradually increase the rotation speed to 32 0 0 — 4 5 () () rpm, and finally match the resin rotation speed to obtain a uniform film 14, at this time the thickness of this layer is about 1-15, ° W 14 Transfer and copy the surface shape opposite to the stencil. For the sake of convenience, we will call the finished product of this part A 2 (that is, it includes the bottom plate 〇0, 12 and the resin recording layer! 4). As shown in "Figure 2c", Wu uses traditional injection molding techniques to make a carbonate substrate (called the L1 layer) 20, which has this single-sided ^ one layer on the L1 layer 20 and the required recording signal (one layer) For easy identification, the layer recording signal is called a) music. If it is the D series of discs to be produced, the thickness of the L 丨 disc is about 2mm. If it is a DVD series, the thickness of the L1 disc is 0.6mm. As shown in "the second d picture", the li Layer 20 is sputtered with a semi-reflective film 2 2 'The material of this semi-reflective layer and the thickness of the sputtering have a close relationship with the wavelength used in future readings' Generally, for example, a metal or a dielectric material such as Gold (Au), aluminum (A1), silver (Ag), silicon (Si), nitride = (A1N), silicon carbide (S! 3N4), or silicon carbide (SiC), etc. The 10-3 0 nm semi-reflective layer 22, for the convenience of subsequent description, we call the finished product of this part as A1 (that is, it includes the li layer 20 and the semi-reflective layer 22). As shown in "Fig. 2e", the semi-reflective layer 22 of the finished A 丨 finished product is placed on a bonding machine facing upwards, and at the same time, a glue 24 is applied to the A1 semi-finished product. Reflective layer 22, this adhesive 24 can be, for example, UV-curable

Page 13 / uy9 V. Description of the invention (10) But its knowledge: The shrinkage rate during curing must be reduced or less than 3%. Then turn the above-mentioned A2 finished product, so that the resin recording film layer 14 of A2 contacts the adhesive 24 of A1, and at the same time, adhere to μ and A2 by spin coating and pressure. Another feasible method to avoid air bubble inclusion is to refer to "No.

f: The figure "No" is using an injection tube 50, and a long needle 52 is used to inject the adhesive 24 between A1 and A2. During the injection, the needle 52 moves to the outside of the disc at the same time. Relationship with the surface tension of resin 丨 'Adhesive 24 will be filled in the narrow space of a 1 and A2, and finally excess adhesive will be thrown away by rotation. There is also a feasible way to avoid the inclusion of bubbles. As shown in "Figure 5b", it is opposite to the positions of a 1 and A2 in the above illustration, that is, ... under the person, using the needle above. The method of filling the adhesive glue 24, or firstly apply a group of adhesive glue 24 to the A2 resin 4 and then test Al. Because A1 is a layer of polycarbonate plastic material, it is easy to deform into a prominent shallow disk shape. First, let A2 contact the central area of the person, then slowly rotate and press A1, while increasing the area contact surface 'until the adhesive tape fills the entire disc Q. Then the adhesive glue 24 is cured. It is a UV curing adhesive. The UV light source 26 is injected from the polycarbonate plastic surface of A1 to allow the UV curing adhesive to absorb light energy and cure. If it is a heat curing curing adhesive, put the entire clamp. Baking in a hot air oven, regardless of the type of adhesive used, its shrinkage should be less than 3% to avoid excessive deformation. As shown in Figure 2f, “the bottom plate 10 and the stencil plate 12 of the A 1 portion are separated from the resin recording film 14. In order to facilitate separation,

The description of the invention on page 14 (11) The central part of the template 14 is about 2 2-3 5mm. There is an air hole in the 5-20 mm misalignment area. 22,: 1, just blow in the air during separation, and let the film layer in the center part separate. After the performance is expanded from the inner to the outer circumference, it can be easily demolded. Since there is no signal recorded on the CD or HDD discs in the region of miscarriage, a slight k-shape 'during separation will not affect the quality of the film. "/ As shown in Figure 2g", finally put the entire article into the coin plating machine = line reflective film 2 6 sputtering, the finished product after sputtering is a single-sided double recording layer structure. In addition, in order to prevent dust or small particles from sticking to the surface of the dish during the entire production process, which will cause signal distortion, all processes must work in a clean room at a level of 1,000 or more, and there must be a Powered by neutral air. "Figures 6a and 6" are copies of the surface shape of the signal using the method of the present invention. "Figure 6a" is the result of using the atomic force microscope (AFM) to scan = the surface shape of the template; and "Figure 6 “b” is the result of using “Bei Ming Zhi private” to copy the recorded signals on the stencil by spin coating. The stencil was originally a raised part, and after the transfer, it became a depressed part. Otherwise, it was a depressed part. After being transferred, it becomes a protruding part. From the result of Αρμ, it can be understood that the method of the present invention will transfer the signal pattern on the original template with great accuracy and efficiency.

Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit this rabbit to anyone who is familiar with the art, without departing from the spirit and scope of the present invention, should make some modifications and retouching. Therefore, the protection scope of the present invention shall be determined by the scope of the appended patent application. [Illustration of Symbols in the Schematic]

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Claims (1)

497099 6. Application Patent Scope 1. A method for manufacturing an optical disc with multiple recording layers, including the following steps: making a substrate with a first recording signal layer; forming a semi-reflective layer on the substrate; providing a pattern with recording signals The template is placed on a flat base plate; a polymer solution is spin-coated on the template to form a second recording layer that reproduces the signal recorded by the template, and further includes: a speed control of about 2 0 0- Spray the polymer solution on the stencil at 400 rpm; shake the polymer solution under a speed control of about 3 2 0-4 500 rpm; and solidify the polymer solution to form The second recording layer; bonding the second recording layer and the semi-reflective layer; peeling off the stencil and the flat substrate; and forming a protective coating on the recording layer. 2. The method for manufacturing an optical disc with a multi-layer recording layer as described in item 1 of the scope of patent application, wherein the forming of the pre-coating method further includes combining two substrates having the first and second recording layers face to face. Form a complete disc. 3. The method for manufacturing an optical disc with multiple recording layers as described in item 1 of the scope of patent application, further comprising repeating the following steps: forming a reflective layer on the substrate; providing a template with a recording signal pattern, and Placed in Yiping Page 17 497099 VI. Patent application surface baseplate; spin-coating a polymer solution on the stencil to form a recording film with the stencil recording signal copied; bonding the recording film and the reflective layer; and peeling off the stencil and The planar base plate successively forms a plurality of recording layers on the substrate. 4. The method for manufacturing an optical disc with a multi-layer recording layer as described in item 3 of the scope of the patent application, wherein the forming of the pre-coating method further includes combining two substrates with the multi-layer recording layer to form a complete one. CD. 5. The method for manufacturing an optical disc with multiple recording layers as described in item 1 of the scope of patent application, wherein the reflective layer is a metal or a dielectric material. 6. The method for manufacturing an optical disc with multiple recording layers as described in item 5 of the scope of patent application, wherein the reflective layer is one selected from gold, aluminum, silver, silicon, aluminum nitride, silicon nitride, or silicon carbide . 7. The method for manufacturing an optical disc with multiple recording layers as described in item 1 of the scope of the patent application, wherein the thickness of the reflective layer is about 10 to 30 nm. 8. The method for manufacturing an optical disc with multiple recording layers as described in item 1 of the scope of the patent application, wherein the template is formed with a plurality of symmetrical air holes, so that the template can be borrowed when it is separated from the second recording layer. Air is blown into the air holes to make the stencil easy to peel off. 9. The method for manufacturing an optical disc with a multi-layer recording layer as described in item 8 of the scope of the patent application, wherein the air holes are formed at a diameter of about 22 to 35 mm in the central portion of the stencil. The first layer of the tree layer is recorded in the high-level item of the 1-I branch of the subordinate branch of the liquid and solvent-solving branch with many layers. 497099 vi 11. The method for manufacturing an optical disc with multiple recording layers as described in item 10 of the scope of patent application, wherein the resin is selected from Aery 1 i C polymer, Po1y—Ether—I mide (PEI) ^ Photo Imide ( PI) and so on. 12. The method for manufacturing an optical disc with multiple recording layers as described in item 10 of the scope of patent application, wherein the resin is used in an amount of about 5 to 10 m1. 13. The method for manufacturing an optical disc with multiple recording layers as described in item 1 of the scope of the patent application, wherein the thickness of the second recording layer is about 1 to 15 m. 14. The method for manufacturing an optical disc with multiple recording layers as described in item 1 of the scope of the patent application, wherein the moving speed of the nozzle used when spraying the polymer solution must be less than 5 cm / sec, and the aperture must be less than 1 0 0 // m 〇1 5. The method for manufacturing an optical disc with multiple recording layers as described in item 1 of the scope of patent application, wherein the step of bonding the recording film and the reflective layer further includes: placing the reflective layer The substrate is applied to a laminator; an adhesive is applied to the reflective layer; the base plate is clamped to turn over the stencil having the second recording layer; the second recording layer is brought into contact with the adhesive to perform spin coating Adheres both to pressure; and Page 19 497099, patent application scope The adhesive is cured. 16. The method for manufacturing an optical disc with multiple recording layers as described in item 15 of the scope of the patent application, wherein the adhesive is a curing type or a heat treatment curing type. 17. The method for manufacturing an optical disc with multiple recording layers as described in item 15 of the scope of patent application, wherein the shrinkage of the adhesive when cured should be less than 3%. 18. The method for manufacturing an optical disc with multiple recording layers as described in item 1 of the scope of patent application, wherein the step of bonding the recording film and the reflective layer further includes: placing the substrate with the reflective layer on a sticker Turning on the machine; clamping the base plate to turn over the stencil with the second recording layer; bringing the second recording layer into contact with the reflective layer, and injecting an adhesive glue from inside to outside with an injection tube; using rotation Shake off the excess adhesive; and cure the adhesive. 19. The method for manufacturing an optical disc with multiple recording layers as described in item 18 of the scope of patent application, wherein the adhesive is a curing type or a heat treatment curing type. 20. The method for manufacturing an optical disc with multiple recording layers as described in item 18 of the scope of the patent application, wherein the shrinkage of the adhesive when cured should be less than 3%. 497099 6. The steps of applying for a patent range further include: placing the stencil with the second recording layer on a laminator; turning over the substrate with the reflective layer; coating an adhesive on the center of the second recording layer; bending The reflective layer and the polycarbonate substrate are first brought into contact with the second recording layer at the center of the reflective layer, and then the reflective layer is gradually rotated until the adhesive blanket is filled between the two; and the adhesive is cured. 2 2. The method for manufacturing an optical disc with multiple recording layers as described in item 21 of the scope of patent application, wherein the adhesive is a curing type or a heat-processed curing type. 2 3. The method for manufacturing an optical disc with multiple recording layers as described in item 21 of the scope of the patent application, wherein the shrinkage of the adhesive when cured must be less than 3%. Page 21