JPH04185308A - Manufacturing device of stamper - Google Patents

Abstract

PURPOSE:To manufacture accurately and at a favorable yield a mold having high plane properties, by a method wherein confronting parallel surfaces are constituted of an upper part and lower part plane plates, pressure is applied to a base, plated layer, adhesive agent and plated reinforcing plate placed between the confronting parallel surfaces and a space and parallelism between the confronting surfaces are controlled so that a space between interference patterns of rays to be generated between the lower part plane plate and base becomes widest. CONSTITUTION:The surfaces 1, 2 which are confronted vertically are provided, between those of which a base 3 only one surface of which is plated 4 and a reinforcement material 6 arranged on the surface 4 through an adhesive agent 5 are arranged and a space between the confronting surfaces 1, 2 is narrowed, through which adhesion between the plated surface 4 and reinforcing material 6 is made firm. Then one surface 2 is constituted of a transparent base having high flatness, with which nonplated surface of the base 3 is pressure-contacted and the space and parallelism between the confronting surfaces 1, 2 are adjusted so that a space between interference patterns of rays generated between the base 3 and the surface 2 becomes widest, through which a mold having favorable flatness is manufactured. Then one surface is made into a metal, into which a heater 7 is arranged, the other surface 2 is constituted of a heat insulation material and simultaneously with application of pressure to the surface 2 a space between the plated metallic surface 4 and base 3 surface is let to have a heat gradient, through which the favorable flatness is manufactured.

Description

[Detailed Description of the Invention] Industrial Fields of Application The present invention can be effectively used in fields where it is necessary to manufacture microscopic optical components at low cost and with high precision by resin molding. Lens mirrors, etc. are made by polishing with stone moxibustion glass, etc., so productivity does not increase, and the specific gravity is 2.7, so there is a problem of weight.
In particular, it is important that the optical components for optical pickup required for optical discs, which have been attracting attention recently, and compact discs, which are widely popular, are lightweight and inexpensive. Resin molded products are inexpensive and have a specific gravity of about 1.7, so they have the advantage of being lightweight, so research on making optical parts from resin is being conducted in various fields.
However, in order to construct optical components, particularly reflective mirrors, by molding resin, it is necessary to manufacture the entire surface with high precision.

In the conventional method of manufacturing mirror-finished molds by polishing the metal surface, etc., since metal is originally a crystalline substance, the surface roughness is restricted by the final metal microcrystals, and it is impossible to finish the surface to a surface roughness of less than 300 angstroms. In addition, if the reflective surface is simply a flat surface, polishing as described above is also possible.Recently, research is being conducted in various places, such as gratings, which require not just a mirror surface but a relief-like uneven shape. In this case, it is impossible to make a mold using this method.Therefore, in this case, it is necessary to make a mold using the mold manufacturing process shown in Figure 6. (This process is the same as the manufacturing process of disc stampers for optical discs, etc., so the mold manufactured by this process will be referred to as a stamper below.) To explain the stamper manufacturing process, first, a A photoresist 18 is thinly coated on a substrate (glass, stone, silicon single crystal, etc.) that can provide good flatness (a). Thereafter, the photoresist is exposed to light using various exposure methods and then developed. Since a positive type resist is usually used, the photoresist irradiated with light is dissolved by a developer, resulting in the relief pattern shown in (b). 11
Even if it is made with photoresist, this relief pattern 1
A plated layer 4 is applied on the metal plated layer 4, and a pattern 11 is transferred onto the metal plated layer 4.A plated layer 4 is applied on the base material 3 thus produced, as shown in FIG. Usually, Cu, Ni, etc. are used as the plating metal, and the thickness is usually 250-300 μm.The resulting state is that it warps as if being pulled by the metal plating surface, as shown in Figure 3. The cause of this warping is mainly due to the following two reasons.
During metal plating on the surface of the plated metal, it is necessary to heat the plating solution, and warping occurs due to the difference in thermal expansion coefficient. Normally, the temperature of the plating solution during plating is set between 40-50℃ to minimize this generated stress, but if the solution temperature is not set within this range, the ion concentration of the plating solution will decrease, making it difficult for current to flow. The plating time is extremely long.However, as mentioned earlier, since the plating solution temperature is set within this range and the plating is performed, when the temperature is returned to room temperature after plating is completed, the thermal expansion coefficient between the Ni metal and the base glass will change. There is a difference, and the metal side shrinks better, so the metal side will warp as shown in Figure 3. However, this warpage is a big problem when making molds for optical elements. This is because the surface accuracy that can be used as optical parts, especially mirror surfaces, is 1/4λ.
In other words, although a flatness of within 0°2 μm is required within a plane of approximately 5 mmφ, if there is such a warp, it cannot be used as a mold for molding optical components (- Conventionally, molds with this warp As shown in Table 6, a method of forcing the above-mentioned parallel 2 is to simply place a metal-plated base material 4 and a metal reinforcing material for reinforcing the plated surfaces on the inside of two well-parallel surfaces.
However, with this method, each part, base material,
Plating trap If the reinforcing material is not parallel in the thickness direction, the pressure will be uneven and good results will not be obtained. Problems to be Solved by the Invention Since it was impossible to manufacture molds for optical reflective surfaces with high accuracy and high yield, the present invention has solved the problem of manufacturing molds for optical reflective surfaces with high precision and high yield. The aim is to solve the problems that were difficult to achieve, and thereby create a mold that ensures the mold surface precision required for optical parts through resin molding, and makes it easier to form optical surfaces with resin molding. The present invention has two opposing surfaces, and between these two surfaces (the two surfaces are plated and the other surface is not plated). After arranging a reinforcing material on the plating surface of the base material via an adhesive, the adhesion between the plating surface and the reinforcing material is strengthened by narrowing the distance between the two opposing surfaces. At least one of these surfaces is constituted by a transparent base material having a high degree of flatness, and the unplated surface of the base material is pressure-bonded to the transparent base material, and the transparent base material and the base material are bonded together. A device for producing a stamper (mold) having good flatness by adjusting the distance and parallelism between the two opposing surfaces so that the interference pattern has the widest distance between the surfaces. Furthermore, the present invention provides nine of the two opposing surfaces; one surface is made of metal and a heater is disposed in the metal, while the other surface is made of a heat insulating material; The purpose of the present invention is to provide a means for producing good flatness by applying pressure and at the same time creating a thermal gradient between the plated metal surface and the base material surface. Although the explanation is given based on this principle diagram as shown in Fig. 4, the base material 3 and plating layer 4 plated on the substrate obtained from the plating process may be distorted as shown in this figure, as shown in No. 3FgJ. When the lower plane plate 2, which is a transparent body having a surface, is brought into contact with the contact point 16 and the reference light 9 is incident as shown in the figure, the third Dark area 14 and bright area 15 shown at the bottom of the figure
The Newton rings 4 and 17 are spaced at intervals of 1/4λ.The amount of strain on the base material 3 due to the provision of the plating layer 4 can be determined from the spacing 17 of the Newton rings. If the thickness condition is accurately controlled, the interference pattern between the base material surface and the optically transparent body will conclusively indicate the flatness of the plated surface and the optically transparent body. It is possible to control the surface precision of the plated surface by controlling the interference pattern between the body and the base material.Although FIG. 4 shows the second invention of this patent, The strain generated during plating was simply forced by applying pressure to the plated base material. However, with this method, when pressure is applied, the plated metal does not necessarily spread uniformly (t) This is because the plated metal is stretched. Due to irregularities and minute bumps on the back side of the plating, there are parts that can be stretched well and parts that are not smooth and cannot be fully extended, and while flatness is restored in some parts, complex surface distortion occurs in others. However, it was not always possible to obtain a uniformly strain-free plated surface simply by applying pressure.Therefore, in the present invention, pressure is simply applied to the plated surface to remove the strain that would otherwise occur at this point, rather than stretching the plated metal. The idea was to focus on the fact that most of the distortion caused by the bimetallic distortion is caused by the difference between the liquid temperature and the air temperature during plating. Therefore, the flatness of the surface of the plating layer 4 For best results, it is desirable to apply the same temperature to the plated surface and the base material as during plating. Therefore, in the present invention, the inner surfaces of the opposing surfaces effectively apply heat to the reinforcing material and the plated metal when heated. Since it is necessary to transmit heat, it is desirable to use metal.And it is desirable that as much heat as possible does not escape from the opposite surface.If, unlike the present invention, the opposing plane is made of metal, it will be made from this metal. Because of the intense heat dissipation, it is not possible to obtain a -like temperature distribution within the contact surface between the base material and the plated surface.Therefore, in this case, a good surface cannot be obtained due to temperature unevenness.Therefore, the temperature is as uniform as possible within the surface. In order to achieve this distribution, it is preferable to use a heat insulating material; however, in the present invention, since the plated metal is heated while applying much weaker pressure than in the past, the plated metal extends very smoothly. EMBODIMENT OF THE INVENTION An embodiment of the present invention in which a smooth surface can be obtained over the entire plated surface is shown in FIG. 2, and the present invention will be described in detail based on this figure.

In this embodiment, the upper plane plate 1 and the lower plane plate 2 constitute opposing parallel surfaces. In order to apply pressure 8 to the base material 3, the plating layer 4, the adhesive resin layer 5, and the plating reinforcing plate 6, the upper flat plate 1 must be forcibly moved. It is made up of a 10mm thick quartz plate4
In this diagram, the surfaces of the base material 3 and plating layer 4 are shown as straight lines for simplicity, but in reality, as shown in Figure 3, the temperature at the time of plating production was around 45°C, so this should be returned to atmospheric temperature. In this case, the contraction of the metal surface is faster, so it recurs as shown in Figure 3.If this is installed as shown in the figure on the lower flat plate 2, which has an optically polished surface, this lower flat plate 2 Every time 1/4λ (optical wavelength) separates from the upper surface 2a, the chamber 1
4. Interference fringes consisting of bright areas 15 are generated. Therefore, based on this principle, in order to eliminate warpage of the base material as much as possible and ensure flatness, the number of dark areas 14 of the interference fringes generated in this way should be reduced. It would be a good idea to move the upper plane plate 1 and press it against the lower plane by applying pressure 8, but originally the plane parallelism of the plated reinforcing plate 6 was not controlled (
In such a case, it is not possible to reduce the interference pattern by applying pressure all at once.
2, as shown in FIG.
For this reason, in this embodiment, a heating heater 7 is embedded in the upper flat plate 2. Even if heating is possible by passing current through this heater 7, the temperature difference can be increased by heating the base material to the same temperature as the temperature generated or applied during plating to the base material that has been strained during bonding. This was done to alleviate the distortion caused by the plating when there is a difference between the temperature at the time of plating and the atmospheric temperature, which causes warping. After the resin 5 hardens by pasting a plated reinforcing plate 6 thick enough to overcome this stress on the back side,
Even if this heating temperature is removed and the temperature is returned to room temperature, the plated reinforcing plate 6
FIG. 5 shows the temperature distribution in the longitudinal direction in an embodiment of the present invention. As is clear from this figure, the heating heater 7
is incorporated inside the upper flat plate 1 made of a metal block, and this upper flat plate 1 is in close contact with the plated reinforcing plate 6 also made of metal, so there is no thermal resistance between them, so no heat is generated between them. There is no gradient (t), and the heat is applied to the plating layer 4 through the very thin resin layer 5. However, the subsequent base material 3 and lower flat plate 2 are made of a heat insulating material such as glass. As shown in the figure, the temperature does not rise and no heat escapes from this direction. This heat also makes it possible to eliminate warpage in the resin layer 5.
After that, the adhesive constituting the stamper is removed from the stamper making machine, the photoresist 8 is washed away by the solvent, and the glass base material is also peeled off.
Even if a mold with good flatness as shown in the figure is manufactured, by applying the present invention, it is possible to manufacture molds with high flatness with extremely high precision and high yield, as shown by the effects of the invention. It has become possible to easily produce replicas of mirror surfaces with excellent flatness inscribed with holograms using techniques such as photocuring resin or injection, which was previously impossible.

[Brief explanation of the drawing]

Fig. 1 shows a cross-sectional view of the main parts of a stamper production apparatus according to an embodiment of the present invention. Fig. 2 shows the status on the screen. Fig. 4 shows how an interference pattern is generated. Fig. 5 shows an embodiment of the present invention. Fig. 6 @ Fig. 7 is a process cross-sectional view showing the mold manufacturing method using the stamper manufacturing method.
・Base material, 4... Plating 5... Resin clothing 6...
Plated reinforcing plate, 7... Heating heater, 8... Pressure, 9... Reference light, 10... Reflected light, 11... Shadow i, 12... Screen, 13... Support stand,
14...Dark vein 15...Light! 1.6...Contact, arc 17...1/4λ interval [1,8--Photoresist. Name of agent: Patent attorney Akira Okaji and 2 others r--1
4-Mesomisakis -1fI N & 4 6=-Menoya, wI Hosaka 7-10 Book heater No. 2 Ro/4--11 units Translation ts--tr Month House P 7/4 Figure ζ'14 Figure 5

Claims (3)

[Claims] (1) A base material having two opposing surfaces, and between these two surfaces, one surface is plated and the other surface is not plated, and the base material is plated. After arranging the reinforcing material on the surface with an adhesive, the distance between the two opposing surfaces is narrowed to strengthen the adhesion between the plated surface and the reinforcing material, and at least one of the surfaces has a high flatness. The non-plated surface of the base material is pressed onto the transparent body to cause optical interference between the transparent body and the base material, and this interference pattern is formed with a maximum spacing. A stamper manufacturing device characterized in that the distance and parallelism between the two opposing surfaces can be adjusted so that the two opposing surfaces become wider. (2) A base material that has two opposing surfaces, and between these two surfaces, one of the two surfaces is plated, and a reinforcing material is placed on this plated surface via an adhesive. In a machine that strengthens the adhesion between the plated surface and the reinforcing material by narrowing the distance between the two opposing surfaces, at least one of these surfaces is metal, and a heater is disposed in the metal, and at the same time the other surface is is a stamper manufacturing device characterized by being made of a heat insulating material. (3) A stamper manufacturing apparatus according to claim 1, wherein at least one surface is made of metal and a heater is disposed in the metal, and the other surface is made of a heat insulating material.