JP2004106341A - Mold for microcomponent and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for a microcomponent, which reduces manufacturing costs and has high accuracy and wherein a hardness of a surface layer is high, and a manufacturing method therefor. <P>SOLUTION: This mold 10 for the microcomponent is composed of plated metal in which a hard coating 11 is formed at least as the surface layer. The hard coating 11 has a skewed distribution composition. The hard coating 11 is composed of a titanium film including titanium nitride, and the concentration of the titanium nitride is gradually decreased inward from the surface layer of the coating 11. In this manufacturing method for the mold 10, a surface of a silicon substrate 20 is worked; an original mold for the mold 10 is prepared; the coating 11 is formed on the surface of the original mold; an electroless-plating metallic layer 13 and/or an electrolytic-plating metallic layer 14 are/is formed on the surface of the coating 11 by electroless plating and/or electrolytic plating; the metallic layer 13 and/or the metallic layer 14 and the coating 11 are brought into close contact with one another; and the original mold for the mold 10 is transferred to the metallic layer 13 and/or the metallic layer 14. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a metal mold for a micro component and a method for manufacturing the same, and more particularly to a metal mold for a micro component having a low manufacturing cost, high accuracy, and high surface hardness, and a method for manufacturing the same.
[0002]
[Prior art]
Examples of the micro component include a spectral device having a diffraction grating, a scale for an encoder, a Fresnel lens, and a micro lens.
For example, as shown in FIG. 6, a spectral device having a diffraction grating has a diffraction grating formed at a fine pitch on the surface 1a of a flat plate 1 made of metal or glass. By irradiating light to the spectral device, the device is a device that splits a light wavelength satisfying a predetermined diffraction condition.
[0003]
The encoder scale is, for example, a flat scale having fine irregularities formed on the surface of the flat plate 2 as shown in FIG.
The Fresnel lens is a lens in which grooves formed at regular intervals on the surface of a flat plate are formed in a lens shape, and extracts light from a plane direction in a direction perpendicular to the plane.
The microlenses are formed by forming an aggregate of fine lenses on a flat substrate, enabling collective optical alignment, and also enabling manufacture of a compound eye lens.
[0004]
Conventionally, the above-mentioned micro component has been manufactured by directly cutting the product itself by machining, or by patterning the product on a glass or silicon by a photolithography method and then etching the product.
For example, when manufacturing the above-mentioned spectral device, in order to machine a diffraction grating on the surface of a flat plate, a very high-precision processing machine and processing control technology are required, and processing takes a long time. Therefore, the manufacturing cost was high. This was the same for the other micro components described above.
[0005]
In addition to machining, as a method of manufacturing a micro component, there is a method of using a micro component mold. As a method of manufacturing the micro component mold, there is the following method.
(1) A method of directly cutting a product die itself by machining (2) LIGA process (Lithographie Galvanoformung Abformung) (for example, see Non-Patent Document 1).
(3) Electric discharge machining method
[Non-patent document 1]
“Surface Technology” Vol. 52, no. 11, 2001, p. 734-736
[0007]
[Problems to be solved by the invention]
However, each of the above manufacturing methods has the following problems.
The method of (1) by machining has a problem in machining accuracy, and a large-sized, high-rigidity machine is required in order to obtain sufficient machining accuracy. Therefore, the mold manufacturing cost was high.
The LIGA process (2) is a process in which a thick resist film is formed on a substrate made of silicon or the like, patterned using radiation light, and the resist pattern is copied by electroplating (electroforming). However, this method requires special and expensive equipment for irradiating the emitted light. In addition, since a mold manufactured by electroplating is limited to a relatively soft material such as gold or nickel, a highly accurate mold cannot be manufactured.
The electric discharge machining method (3) is, for example, a method of machining a metal mold using an electrode prepared by a method called a WEDG method. Since the electrodes must be replaced frequently, it has been difficult to increase the processing accuracy. In addition, since the electrodes are exchanged, the cost of mold production is enormous. Furthermore, since the electrical discharge machining was performed by thermal machining, the obtained mold had a rough surface roughness.
[0008]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a micropart mold having a low manufacturing cost and high accuracy, and a high hardness of a surface layer, and a method of manufacturing the same. .
[0009]
[Means for Solving the Problems]
The present invention provides a metal mold for a micro component comprising a plated metal having a hard film formed on at least a surface layer.
The present invention provides a mold for microparts, wherein the hard coating has a gradient distribution composition.
The present invention provides a micro component mold in which the hard coating is formed of a titanium film containing titanium nitride, and the concentration of the titanium nitride is gradually reduced from the surface layer of the hard coating toward the inside.
In the present invention, a surface of a substrate is processed to prepare a mold for a micro component mold, and then a hard film is formed on the surface of the mold for the micro component mold, and a hard film is formed on the surface of the hard film. By forming a plating metal by electrolytic plating and electrolytic plating, or electroless plating, and bringing the plating metal into close contact with the hard film, a prototype of the micro component mold is formed on the plating metal via the hard film. And a method for manufacturing a mold for a micro component to obtain a mold for a micro component by removing the original mold of the mold for the micro component.
According to the present invention, a resist pattern of a prototype of the mold for micro parts is formed on a surface of a substrate by a photolithography method, a hard film is formed on the surface of the resist pattern, and a hard film is formed on a surface of the hard film. By forming a plating metal by electrolytic plating and electrolytic plating, or by electroless plating, and bringing the plating metal into close contact with the hard film, a prototype of the micro component mold is formed on the plating metal via the hard film. And a method for manufacturing a mold for a micro component to obtain a mold for a micro component by removing the original mold of the mold for the micro component.
The present invention provides the method for manufacturing a mold for a micro component, wherein, after forming the hard coating, a plating catalyst layer is formed on the surface of the hard coating, and the surface of the plating catalyst layer is plated by at least electroless plating. Provided is a method for manufacturing a metal mold for forming a metal layer.
The present invention provides a method for manufacturing a mold for a micro component, in which the concentration of a hard forming substance forming the hard film is reduced from the surface of the substrate toward the plating metal side.
The present invention provides a method for manufacturing a micro component mold, wherein the substrate is made of silicon and the hard forming material is made of titanium nitride.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
1 and 2 are sectional views showing a first embodiment of a mold for a micro component of the present invention.
The micropart mold 10 of this embodiment is formed on the hard film 11 via the hard film 11 serving as a surface layer, the plating catalyst layer 12 formed on the hard film 11, and the plating catalyst layer 12. It has a laminated structure including the electroless plating metal layer 13 and the electrolytic plating metal layer 14 formed on the electroless plating metal layer 13. Here, a micro component mold 10 formed on a silicon substrate 20 is shown in order to explain a method of manufacturing the micro component mold.
[0011]
The hard coating 11 is made of a titanium film containing titanium nitride (TiN) having high hardness. The hard coating 11 has a TiN concentration that gradually decreases toward the surface where the hard coating 11 and the plating catalyst layer 12 are in contact with each other. It has a gradient distribution composition in which only Ti exists.
The thickness of the hard coating 11 is appropriately set according to the thickness of the intended micropart mold 10, and is preferably 1 μm or more. When the thickness of the hard coating 11 is 1 μm or more, the strength (rigidity) of the micro component mold 10 is increased, and a desired mold shape is maintained.
[0012]
The plating catalyst layer 12 is provided to cause an initial reaction for depositing the electroless plating layer 13 on the hard film 11.
Examples of the material for forming the plating catalyst layer 12 include iron, nickel, and palladium. Of these, palladium is preferably used because of the high reactivity of the initial reaction of electroless plating.
Note that the plating catalyst layer 12 is formed to serve as a catalyst for causing an initial reaction for depositing the electroless plating layer 13 on the hard film 11, and therefore, it is sufficient that the plating catalyst layer 12 slightly exists. , The thickness may be 0.02 μm or more.
[0013]
The electroless plating metal layer 13 is formed by electroless nickel plating, electroless cobalt plating, electroless copper plating, electroless gold plating, electroless tin plating, or the like. Among these, it is preferable that the electroless plating metal layer 13 is formed by electroless nickel plating because of its high corrosion resistance and extremely high hardness. Electroless plating can provide a plating layer having a uniform film thickness, and is suitable for applications requiring high dimensional accuracy, such as molds for micro components.
The thickness of the electroless plating metal layer 13 is appropriately set according to the thickness of the intended micropart mold 10 or the thickness of the hard coating 11, but is preferably 30 μm or more. If the thickness of the electroless plating metal layer 13 is 30 μm or more, the strength (rigidity) of the micro component mold 10 is increased, and a desired mold shape is maintained.
[0014]
Examples of the electroless nickel plating for forming the electroless plating metal layer 13 include electroless nickel-phosphorous plating (medium phosphorus), electroless nickel-phosphorous plating (low phosphorus), and electroless nickel-phosphorous plating (high phosphorus). , Electroless nickel-boron plating, electroless nickel-tungsten plating, and the like. In particular, in the electroless nickel-phosphorus plating, the hardness of the plating can be adjusted according to the amount of phosphorus to be used. When the amount of phosphorus is small, the plating is soft, and when the amount of phosphorus is large, the plating becomes hard. It should be noted that, when the amount of phosphorus is large, the layer becomes hard, but becomes brittle. In addition, it is preferable to form the electroless plated metal layer 13 by electroless nickel-phosphorus plating (medium phosphorus).
[0015]
To form electroless nickel-phosphorus plating (medium phosphorus), the composition of the plating solution is, for example, nickel sulfate 21 g / L, complexing agent, sodium hypophosphite 21 g / L, pH buffer, stabilizer, etc. Shall consist of
Acetic acid, citric acid, organic acids and the like are used as complexing agents.
Acetic acid, propionic acid and the like are used as the pH buffer.
As a stabilizer, a trace amount of lead or the like is used.
[0016]
The electrolytic plating metal layer 14 is formed by electrolytic copper plating, electrolytic nickel plating, electrolytic chromium plating, electrolytic zinc plating, electrolytic tin plating, electrolytic gold plating, electrolytic silver plating, or the like. Among these, the electrolytic plating metal layer 14 is preferably formed by electrolytic nickel plating because the formation time is short and the cost is low.
The thickness of the electroplated metal layer 14 is appropriately set according to the thickness of the intended micro component mold 10, and is particularly limited as long as the thickness is such that the desired micro component mold 10 can be obtained. Not something.
[0017]
The composition of the electrolytic nickel plating solution for forming the electrolytic plating metal layer 14 is, for example, composed of 200 to 400 g / L of nickel sulfate, 30 to 60 g / L of nickel chloride, 30 to 40 g / L of boric acid, additives, and the like. .
[0018]
In the mold 10 for a micro component of this embodiment, since the hard film 11 made of a titanium film containing TiN is formed as a surface layer, the shape of the mold is maintained for a long time, and the life of the mold is extended. become longer.
Further, since the hard electroless plating metal layer 13 is formed, the life of the mold is longer than when only the hard film 11 is formed.
[0019]
Next, a method of manufacturing the micro component mold according to this embodiment will be described.
In order to manufacture the micro component mold 10 of this embodiment, first, a photoresist is applied to a surface of a silicon substrate to a predetermined thickness. Next, a mask is arranged on the silicon substrate, and the surface of the silicon substrate is irradiated with light through the mask to transfer the mask pattern to the photoresist. Next, the portion of the photoresist exposed to the light is removed by a solvent. Next, the surface of the silicon substrate is etched to a predetermined depth by dry etching such as ion irradiation to form a groove corresponding to the resist pattern on the surface of the silicon substrate. Next, the remaining photoresist is removed to obtain a silicon substrate 20 having a desired micro component mold shape on the surface.
[0020]
Next, TiN is vapor-deposited on the surface of the silicon substrate 20 to a predetermined thickness by reactive sputtering to form a hard coating 11, thereby preparing a surface layer portion of a micro component mold. The hard film 11 has a gradient distribution composition in which the TiN concentration decreases toward the surface layer on the side in contact with the plating catalyst layer 12 by adjusting the sputtering conditions, and the surface in contact with the plating catalyst layer 12 becomes substantially pure Ti. It forms so that it may become.
[0021]
Next, palladium or the like is vapor-deposited to a predetermined thickness on the surface of the hard film 11 by sputtering to form a plating catalyst layer 12.
[0022]
Next, the silicon substrate 20 on which the hard coating 11 and the plating catalyst layer 12 are formed is immersed in an electroless plating bath, the temperature of the plating bath is set to 90 ° C., and the plating is grown while stirring the plating bath. The electroless plating metal layer 13 is formed.
[0023]
Next, the silicon substrate 20 on which the hard coating 11, the plating catalyst layer 12, and the electroless plating metal layer 13 are formed is immersed in an electrolytic plating bath adjusted to pH 3.0 to 4.5, and the temperature of the plating bath is set to 40 to The plating is grown at a current density of 1 to 10 A / dm ² while the temperature of the plating bath is set to 60 ° C. and the air is stirred in the plating bath to form an electroplating metal layer 14 having a predetermined thickness.
[0024]
Next, the silicon substrate 20 is removed by wet etching, mechanical shaving, or the like, to obtain the micro component mold 10.
[0025]
In the manufacturing method of the micro component mold of this embodiment, the hard coating 11 made of the titanium film containing TiN is formed on the surface of the silicon substrate 20 by reactive sputtering. The shape can be transferred, and as a result, the uneven shape of the silicon substrate 20 can be transferred with high accuracy.
In addition, the presence of the plating catalyst layer 12 made of palladium or the like which serves as a catalyst for electroless plating on the surface on which the electroless plating metal layer 13 is formed increases the reactivity of the initial reaction of electroless plating, thereby facilitating easier electroless plating. The electroless plating metal layer 13 can be formed on the substrate.
Further, since the electroless plating metal layer 13 functions as an electric conductive film at the time of electrolytic plating, electric conductivity can be secured on the surface on which the electrolytic plating metal layer 14 is formed. Therefore, the electroplating metal layer 14 can be formed more easily.
[0026]
In the method of manufacturing the micro component mold, the silicon substrate 20 having a desired micro component mold shape on the surface is used, but the manufacturing method of the micro component mold of the present invention is not limited to this. As shown in FIG. 3, a relatively thick photoresist is applied to the surface of the silicon substrate 21, and the photoresist is patterned to form a shape on the resist itself, thereby forming a desired micro component mold shape. May be formed.
Further, instead of the silicon substrate 21, a glass substrate may be used.
[0027]
FIG. 4 is a cross-sectional view showing a second embodiment of the mold for a micro component of the present invention. This embodiment is different from the first embodiment in that the electroless plating metal layer 13 forms a surface layer. 4, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
[0028]
In the micro component mold 10 of this embodiment, only the electroless plating layer 13 is formed without forming a hard film made of a titanium film containing TiN as a surface layer. Since the plating catalyst layer 12 does not have enough strength to maintain the shape of the micro component mold, the thickness of the electroless plating layer 13 must be reduced in order to maintain the desired shape of the micro component mold. It is preferably 30 μm or more.
[0029]
In the micro component mold 10 of this embodiment, a hard film made of a titanium film containing TiN is not formed, but the thickness of the electroless plating metal layer 13 is required to be slightly larger than that of the first embodiment. Thereby, the shape of the mold is maintained for a long time, and the life of the mold is prolonged.
[0030]
In order to manufacture the micro component mold 10 of this embodiment, it is manufactured by the same manufacturing method as that of the above-described first embodiment, but it is not necessary to form a hard film made of a titanium film containing TiN. The process is simplified, and the micro component mold 10 can be manufactured at lower cost.
[0031]
FIG. 5 is a sectional view showing a third embodiment of the mold for a micro component of the present invention. This embodiment is different from the first embodiment in that the electroplating metal layer 14 is not formed. In FIG. 5, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
[0032]
In the mold 10 for a micro component of this embodiment, only the electroless plating layer 13 is formed on the hard coating 11 and the plating catalyst layer 12. Therefore, it is preferable that the thickness of the electroless plating layer 13 be 100 μm or more in order to maintain a desired shape of the micro component mold.
[0033]
In the mold 10 for a micro component of this embodiment, a relatively soft electrolytic plating layer is not formed, and a hard coating 11 and an electroless plating layer 13 are formed. The mold 10 is obtained, the shape of the mold is maintained for a long time, and the life of the mold is prolonged. Therefore, the micropart mold 10 of this embodiment is suitable for applications requiring higher precision and higher durability.
[0034]
The micro component mold 10 of this embodiment is also manufactured by the same manufacturing method as in the first embodiment.
[0035]
【The invention's effect】
As described above, the mold for a micro component of the present invention has, as a surface layer, a hard coating or a hard electroless plating metal layer made of a titanium film containing TiN, or a hard coating and a hard electroless plating metal layer. Is formed, the shape of the mold is maintained for a long time, and the life of the mold is prolonged.
According to the method of manufacturing a mold for a micro component of the present invention, a hard film made of a titanium film containing TiN is formed on the surface of a silicon substrate or the like having a desired mold shape. Can be transferred, and as a result, a desired mold shape can be transferred with high accuracy. Further, since a plating catalyst layer made of palladium or the like serving as a catalyst for electroless plating is present on the surface on which the electroless plating metal layer is formed, the reactivity of the initial reaction of electroless plating is increased. Furthermore, since the electroless plating metal layer functions as an electric conductive film at the time of electrolytic plating, electric conductivity can be secured on the surface on which the electrolytic plating metal layer is formed.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a first embodiment of a mold for a micro component of the present invention.
FIG. 2 is a cross-sectional view showing a first embodiment of a mold for a micro component of the present invention.
FIG. 3 is a cross-sectional view showing the method for manufacturing the micro component mold according to the first embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a second embodiment of the mold for a micro component of the present invention.
FIG. 5 is a cross-sectional view showing a third embodiment of the mold for a micro component of the present invention.
FIG. 6 is a partial cross-sectional view showing a spectral device on which a diffraction grating is formed.
FIG. 7 is a partial cross-sectional view showing an encoder scale.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Die for micro parts, 11 ... Hard film, 12 ... Plating catalyst layer, 13 ... Electroless plating metal layer, 14 ... Electroplating metal layer, 20 ... Silicon substrate , 21 ... glass substrate, 22 ... resist film

Claims (8)

A mold for a micro component, comprising a plated metal having a hard film formed on at least a surface layer. The mold according to claim 1, wherein the hard coating has a gradient distribution composition. 3. The micro component according to claim 1, wherein the hard coating is made of a titanium film containing titanium nitride, and a concentration of the titanium nitride is gradually reduced from a surface layer of the hard coating toward the inside. Mold. The surface of the substrate is processed to prepare a mold for a micro component mold, then a hard film is formed on the surface of the mold for the micro component mold, and electroless plating and electrolytic plating are performed on the surface of the hard film. By plating, or by electroless plating, a plating metal is formed, and the plating metal and the hard coating are brought into close contact with each other, thereby transferring the prototype of the micro component mold to the plating metal via the hard coating, A method for manufacturing a micro component mold, comprising removing a prototype of the micro component mold to obtain a micro component mold. A resist pattern of the prototype of the micro component mold is formed on the surface of the substrate by a photolithography method, then a hard film is formed on the surface of the resist pattern, and electroless plating and electrolysis are performed on the surface of the hard film. By plating, or by electroless plating, a plating metal is formed, and the plating metal and the hard coating are brought into close contact with each other, thereby transferring the prototype of the micro component mold to the plating metal via the hard coating, A method for manufacturing a micro component mold, comprising removing a prototype of the micro component mold to obtain a micro component mold. The method for manufacturing a mold for a micro component according to claim 4 or 5,
After forming the hard coating, a plating catalyst layer is formed on the surface of the hard coating, and a plating metal layer is formed on the surface of the plating catalyst layer by at least electroless plating. Manufacturing method. The method according to claim 4 or 5, wherein the concentration of the hard forming substance forming the hard coating is reduced from the surface of the substrate toward the plating metal. 7. The method according to claim 6, wherein the substrate is made of silicon, and the hard forming material is made of titanium nitride.

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