JP4414847B2 - Electroforming mold and manufacturing method thereof - Google Patents

Description

  The present invention relates to an electroforming mold used in an electroforming method and a manufacturing method thereof, and more particularly, to a die used for manufacturing a part having a high aspect ratio and a minute shape and a manufacturing method thereof.

  The electroforming method is suitable for mass production and is used for manufacturing various parts. For example, a watch is manufactured by depositing a conductive film on the resin surface to which the original shape is transferred (see, for example, Patent Document 1).

  A heat press molding method is known as a transfer method to the original resin (see, for example, Non-Patent Document 1).

  The hot press molding method is a method in which the resin is heated to a temperature equal to or higher than the glass transition point and softened, and the original shape is transferred to the resin by pressing the original. In the hot press molding method, the original shape can be transferred to a resin with dimensional accuracy on the order of nanometers.

  In recent years, a mold using a silicon process has been used as a mold for manufacturing a component or mold having a minute shape. A LIGA method (Lithographie Galvanoformung Abformung) is well known as a method for producing an electroforming mold using a silicon process. In the LIGA method, PMMA (polymethyl methacrylate), which is a resist material, is applied on an electrode, and the resist material is exposed to synchrotron radiation within a desired shape range, developed, and then developed. This is a method of producing a microstructure having a desired fine shape by casting (see, for example, Non-Patent Document 2).

  Further, instead of the expensive synchrotron radiation used in the LIGA method, a UV-LIGA method for forming a resist pattern with ultraviolet light used in a general semiconductor exposure apparatus is also used. The electroforming mold produced by the LIGA method or the UV-LIGA method has no electrode on the side wall of the mold, and the electroformed product is deposited from the bottom surface of the mold. Therefore, a high aspect ratio structure is produced by the electroforming method. However, it is possible to form a good part free from bubbles and defects inside the electroformed product.

In addition, there is a method in which a replica mold is formed and an electroformed product is formed using a shape manufactured by the LIGA method or the UV-LIGA method as a prototype. For example, a method of forming a replica mold by embedding a silicon resin in an original mold patterned with a photosensitive resin on a glass substrate is known (see, for example, Patent Document 2).
JP-A-52-60241 JP-A-10-168591 “Current Status of Nanoimprint” Journal of Abrasive Technology, Vol. 46, No. 6, p282 IEEE, MicroElectroMechanicalSystemProceedingsPP86, W.Ehrfeld, 1994

  However, conventionally, an electrode is formed by forming electrodes on all surfaces (hereinafter referred to as electroformed surfaces) on which electroforming of a resin whose shape is transferred (hereinafter referred to as a transfer resin mold) is performed. Therefore, when electroforming is performed, the electroformed product is deposited on the entire surface on which the electrode of the electroforming mold is formed. Therefore, in order to take out the timepiece hand, it is necessary to remove unnecessary portions. In addition, when producing electroformed parts with a high aspect ratio, if electroforming is performed simultaneously from the mold side and the mold bottom, the electric field concentrates on the opposite side of the mold side to the mold bottom, that is, the mold top surface. It is easy to increase the electroforming speed on the mold upper surface side of the mold side surface. Therefore, the electroformed product deposited from the side surface of the die is connected to the upper surface portion of the die, and a gap is formed inside the electroformed product. Therefore, there is a problem that the strength and mold transferability of the electroformed part are lowered.

  In addition, when an electroforming mold is obtained by forming an electrode only on the bottom surface of the recessed portion of the transfer resin mold while forming the electrode, it is necessary to align the mask shape with the shape of the transfer resin mold. However, there are problems that it takes time for alignment, and a desired electrode pattern cannot be formed due to misalignment between the mask shape and the shape of the transfer resin mold. The finer the shape of the transfer resin mold is, the more difficult it is to form an electrode pattern only on the bottom surface of the mold.

  In addition, it is necessary to deposit, expose, and develop a resist material in order to produce an electroforming mold, and there is a problem that many steps must be performed before obtaining the electroforming mold.

  Conventionally, a transfer resin mold was produced using a hot press molding method, and the original shape could be easily transferred in a short time. However, a residual film is formed by the hot press molding method. Even if a conductive material is used for the substrate, it is difficult to obtain an electroforming mold having electrodes only on the bottom surface because the substrate and the electroformed surface cannot be electrically connected. In addition, it is considered that an electroforming mold having an electrode only on the bottom surface can be obtained by removing the residual film by etching using oxygen plasma. However, etching using oxygen plasma is isotropic etching, so There was a problem that the dimensional accuracy of the mold deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electroforming mold that can be easily manufactured by a hot press molding method and in which an electroformed product is deposited only from the bottom surface of the mold.

  In the present invention, in an electroforming mold used in an electroforming method, a conductive conductor, a resin formed on the conductor and having a component shape transferred thereon, dispersed in the resin, and at least the surface has conductivity. The electroforming mold is characterized in that at least one of the particles has an electrode portion that is in contact with the conductor and whose surface is exposed from the resin. In addition, an electrode mold is characterized in that the electrode portion is formed in a portion where the thickness of the resin is smaller than the particle size of the particles. Further, an electroforming mold characterized in that particles are dispersed throughout the resin. In addition, an electroforming mold is characterized in that the resin includes an anisotropic conductive layer in which particles are dispersed and a non-particle-containing resin layer that does not contain particles. Further, the electroforming mold is characterized in that the particles are composed of a spherical core portion and a conductor layer formed so as to cover the core portion. Further, the material of the core part is a resin, and the glass transition point of the resin of the core part is higher than the glass transition point of the resin layer or the anisotropic conductive layer and the non-particle-containing resin layer. A mold was used. Further, the electroforming mold is characterized in that the material of the core portion is a metal. Further, the electroforming mold is characterized in that the core part and the conductor layer are made of the same material. In addition, an electroforming mold characterized in that a plurality of component shapes are transferred. Also, a step of forming a conductive conductor on the substrate, a resin forming step of forming a resin layer on the conductor, and a shape transfer step of transferring the original shape to the resin using a hot press molding method And the resin contains at least one conductive particle on the surface. Further, in the resin forming step, a method of manufacturing an electroforming mold is characterized in that a resin in which particles are dispersed throughout the resin is formed. In addition, the resin forming step includes a step of forming an anisotropic conductive layer in which particles are dispersed and a step of forming a non-particle-containing resin layer that does not contain particles. It was a method. Further, the electroforming method is characterized in that the particles comprise a spherical core portion and a conductor layer formed so as to cover the core portion. Further, the material of the core part is a resin, and the glass transition point of the resin of the core part is higher than the glass transition point of the resin layer or the anisotropic conductive layer and the non-particle-containing resin layer. A mold manufacturing method was adopted. The method for producing an electroforming mold is characterized in that the material of the core portion is a metal. The method for producing an electroforming mold is characterized in that the core part and the conductor layer are made of the same metal material. In the shape transfer step, the shape of a plurality of parts is transferred.

  Therefore, the shape of the original pattern can be transferred to the resin by the heat press molding process, and the particles can be crushed by the original pattern, so that the conductive layer and the bottom surface of the electroforming mold can be connected via the particles 5. Further, when the particle core material is a resin and has a glass transition point at a temperature higher than the glass transition point of the resin, since the hardness of the particles is large, the anisotropic conductive particles 5 are different from those of the resin 4 and the resin. It becomes easy to break through the remaining film of the anisotropic conductive layer 3. Further, when the particles are dispersed throughout the resin, the resin forming step can be omitted by one step. Moreover, a plurality of electroformed parts can be obtained by a single electroforming by transferring a plurality of part shapes. At this time, since the component shapes are independent of each other, each electroformed component can be taken out independently.

  Therefore, the present invention can provide an electroforming mold that can be easily manufactured by a hot press molding method and in which an electroformed product is deposited only from the bottom surface of the mold, and a manufacturing method thereof.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram for explaining a method for manufacturing an electroforming mold 101 according to Embodiment 1 of the present invention. First, as shown in FIG. 1A, a transfer resin mold precursor 102 and a master 6 are prepared. The transfer resin type precursor 102 includes a conductive layer 2 formed on the substrate 1, an anisotropic conductive layer 3 formed on the conductive layer 2, and a resin formed on the anisotropic conductive layer 3. It consists of four. In the anisotropic conductive layer 3, anisotropic conductive particles 5 are dispersed. As shown in FIG. 3, the anisotropic conductive particles 5 are obtained by forming a conductive film 52 on the surface of a resin ball 51. The prototype 6 is made of a machining method such as machining, electric discharge machining, LIGA method, UV-LIGA method, RIE (Reactive Ion Etching) method or DRIE (Deep Reactive Ion Etching) method. The thickness of the substrate 1 is several tens of μm to several mm, and may be any thickness that can maintain the strength of the electroforming mold 101 in the electroforming process described later. The thickness of the conductive layer 2 is from several tens of nm to several μm, and may be any thickness as long as conduction can be obtained in an electroforming process described later. The thickness T3 of the anisotropic conductive layer 3 is several μm to several hundred μm, and may be larger than the diameter D5 of the anisotropic conductive particle 5. The average diameter D5 of the anisotropic conductive particles 5 is several μm to several tens of μm. The thickness T4 of the resin 4 may be approximately the same as the thickness of the electroformed part to be produced, and is several μm to several mm. The height H6 of the prototype 6 may be equal to or greater than the thickness of the electroformed part to be produced, and is several μm to several mm. However, in order to sufficiently crush the anisotropic conductive particles 5 in the hot press molding process described later, the following formula H6> T4 + T3-D5
It is desirable that

  The material of the substrate 1 is a material generally used in a silicon process such as glass or silicon, or a metal material such as stainless steel or aluminum. The material of the conductive layer 2 is gold (Au), silver (Ag), nickel (Ni), etc., and an anchor metal (for enhancing the adhesion of the conductive layer 2 between the conductive layer 2 and the substrate 1) Chrome (Cr), titanium (Ti), or the like may be formed as not shown. In addition, when the material of the board | substrate 1 is a metal, the conductive layer 2 is not necessarily required. The resin 4 and the anisotropic conductive layer 3 are made of thermoplastic resin such as vinyl chloride (PVC), polymethyl methacrylate (PMMA), polystyrene (PS), polycarbonate (PC), polyethylene terephthalate (PET), etc. A thermosetting resin such as epoxy is used. The material of the resin 4 and the anisotropic conductive layer 3 may be the same material or different materials. The material of the ball 51 is a thermoplastic resin such as PMMA, PVC, PS, PC, or PET, a thermosetting resin such as epoxy, a material used in a silicon process such as glass or silicon, or a metal such as gold or aluminum. Use. The conductive film 52 is made of a metal such as gold or silver. Alternatively, a layer in which chromium, titanium, or the like is deposited as an adhesion reinforcing layer (not shown) between the ball 51 and the conductive film 52 may be used. Further, the ball 51 may be made of the same metal material as that of the conductive film 52. The material of the prototype 6 is a material used in a silicon process such as Ni, an alloy of Ni and cobalt (Co) (Ni—Co alloy), a metal such as stainless steel (SUS), or glass or silicon. The formation method of the conductive layer 2 is a sputtering method, a vacuum evaporation method, or the like. The method for forming the anisotropic conductive layer 3 is a method such as spin coating or roll coating of an anisotropic conductive paste (ACP: Anisotropic Conductive Paste). Further, the anisotropic conductive layer 3 may be formed by attaching a film-like anisotropic conductive film (ACF: Anisotropic Conductive Film). The resin 4 may be formed by spin coating a liquid resin, adhering a plate-like resin, or simply placing the resin 4 on the anisotropic conductive layer 3.

 Next, FIG. 1B is a diagram showing a state in which the mold 6 is pressed against the transfer resin mold precursor 102 by the heat press molding process. FIG. 5 is a diagram for explaining the hot press molding process. The hot embossing device includes a resin side heater 34, a mold side heater 32, a movable stage 33, a resin side heater temperature control unit 35, a mold side heater temperature control unit 36, and a movable stage controller 37. And the transfer resin mold precursor 102 is fixed to the resin side heater 34. The method of fixing the mold 6 to the mold side heater is performed using a method such as mechanically fixing with a screw or a pin, fixing with an adhesive, welding or joining. The temperatures of the mold side heater 32 and the resin side heater 34 are controlled by temperature control units 35 and 36. The movable stage 33 is controlled by a movable stage controller 37 and can change the relative distance between the mold 101 and the resin 31. The heaters 32 and 34 are heated by the temperature control units 35 and 36 above the higher glass transition point of the glass transition point of the resin 4 and the anisotropic conductive layer 3 constituting the transfer resin type precursor 102 to be movable. The stage 33 is moved and the mold 6 is pressed against the transfer resin mold precursor 102. Since the resin of the transfer resin mold precursor 102 having a glass transition point or higher has fluidity, the shape of the mold 6 can be accurately transferred. The mold 6, the transfer resin mold precursor 102, the heater 32, the heater 34, and the stage 33 are placed in a vacuum chamber (not shown), and the vacuum chamber is placed in a reduced pressure atmosphere by a vacuum exhaust unit (not shown). The transfer accuracy of the resin mold precursor 102 to the mold 6 can be improved. At this time, as shown in FIG. 1B, the anisotropic conductive particles 5 are crushed into anisotropic conductive particles 5a. The portion where the anisotropic conductive particles 5a are formed is a portion where the space between the mold 6 and the conductive layer 2 is equal to or less than the diameter D5 of the anisotropic conductive particles 5. In order to make it easy to separate the mold 6 and the transfer resin mold precursor 102 in the mold release step described later, before the hot press molding process, the mold 6, using a fluorocarbon resin or a silicone resin as a mold release agent, You may apply to. In addition, when the material of the ball 51 of the anisotropic conductive particle 5 is a resin, the material of the ball 51 is, in order for the anisotropic conductive particle 5 to easily break through the remaining film of the resin 4 and the anisotropic conductive layer 3. It is desirable to use a material having a glass transition point higher than that of the material of the resin 4 and the anisotropic conductive layer 3.

  Next, after the heat press molding step, the resin 4 and the anisotropic conductive particles 5 are heated or cooled until they are cured, and the mold 6 is separated from the resin as shown in FIG. An electroforming mold 101 is obtained. FIG. 2 is an enlarged view of a portion indicated by a broken line A in FIG. Since the contact area between the spherical anisotropic conductive particles 5 and the conductive layer 2 and the mold 6 becomes very small, no conduction film is formed between the anisotropic conductive particles 5 a and the conductive layer 2. And the surface of the anisotropic conductive particle 5 a is exposed from the anisotropic conductive layer 3. That is, it is possible to form a transfer resin mold necessary for forming the electroforming mold 101 and to form electrodes only on the bottom surface of the electroforming mold 101 by a single hot press molding process.

  FIG. 6 is a diagram for explaining an electroforming process using the electroforming mold 101. The electrocasting iron 21 is filled with the electroforming liquid 22, and the electroforming mold 101 and the electrode 23 are immersed in the electroforming liquid 22. The electroforming liquid 22 varies depending on the metal to be deposited. For example, when nickel is deposited, an aqueous solution containing nickel sulfamate hydrate is used. The material of the electrode 23 is substantially the same material as the metal to be deposited. When nickel is deposited, nickel is used, and a nickel plate or a nickel basket with a nickel ball is used as the electrode 23. The material deposited by the production method of the present invention is not limited to nickel. The present invention is applicable to all materials that can be electroformed, such as copper (Cu), cobalt (Co), and tin (Sn). The conductive layer 2 of the electroforming mold 101 is connected to the power source V. When electrons are supplied from the anisotropic conductive particles 5a through the conductive layer 2 by the voltage of the power source V, a metal is gradually deposited from the anisotropic conductive particles 5a. The deposited metal grows in the thickness direction of the substrate 1 and also grows in a direction orthogonal to the thickness direction of the substrate 1.

  FIG. 4 is a diagram for explaining a process for producing the electroformed component 100 using the electroforming mold 101. By the electroforming process described with reference to FIG. 6, as shown in FIG. 4A, the electroformed product 100a is deposited from the anisotropic conductive particles 5a. Thereafter, electroforming is performed so as to obtain a desired thickness or more.

  Next, as shown in FIG. 4B, the thickness of the electroformed product 100a is made uniform by a polishing process. In the electroforming process, when the thickness of the electroformed product 100a can be controlled, the polishing process may not be performed.

  Next, as shown in FIG. 4C, the electroformed product 100 a is taken out from the electroforming mold 101 to obtain the electroformed component 100. For example, the electroformed product 100a can be taken out by dissolving the resin 4 and the anisotropic conductive layer 3 with an organic solvent, or heating and softening the resin 4 and the anisotropic conductive layer 3 with the electroformed product 101a. This is done by applying a force to separate

  As described above, according to the first embodiment of the present invention, the shape of the prototype 6 can be transferred to the resin 4 and the anisotropic conductive layer 3 by the hot press molding process. At the same time, the anisotropic conductive particles 5 dispersed in the anisotropic conductive layer 3 are crushed by the prototype 6, and conduction between the conductive layer 2 and the bottom surface of the electroforming mold 101 is established via the anisotropic conductive particles 5. be able to. Therefore, it is possible to provide an electroforming mold that can be easily manufactured by a hot press molding method and in which an electroformed product is deposited only from the bottom surface of the mold. Further, by making the relationship among the height T3 of the anisotropic conductive layer 3, the thickness T4 of the resin 4, the average diameter D5 of the anisotropic conductive particles, and the height H6 of the mold 6 as shown in Equation 1, Since the B surface of the mold 6 and the resin 4 do not contact, the anisotropic conductive particles 5 can be reliably crushed. Therefore, the electroforming mold 101 with good conductivity can be obtained. Further, when the material of the balls 51 of the anisotropic conductive particles 5 is a resin and has a glass transition point higher than the glass transition points of the resin 4 and the anisotropic conductive layer 3, the anisotropic conductive particles 5 Since the particle 5 has a high hardness, the anisotropic conductive particle 5 easily breaks through the remaining film of the resin 4 and the anisotropic conductive layer 3, and the electroforming mold 101 having stable conductivity can be manufactured.

  Note that, as shown in FIG. 7, even if the resin transfer type precursor 103 in which the resin layer is formed only by the anisotropic conductive layer 3 instead of the resin 4 is used, the electroforming process is performed in the same manner as the resin transfer type precursor 102. Can be obtained. The thickness T3b of the anisotropic conductive layer 3 of the resin transfer type precursor 103 may be equal to or greater than the thickness of the electroformed component 100 to be produced. In this case, since the resin forming step can be omitted, the electroforming mold 101 can be obtained in a short time.

  In the above description, the method for producing one electroformed component 100 from the electroforming mold 101 has been described. However, by forming the shape of the plurality of electroformed components 100 on the master 6, a plurality of electroformed components 100 as shown in FIG. Can be formed, and a plurality of electroformed parts 100 can be obtained by one electroforming. At this time, since the cavities 103 are separated from each other, each electroformed component 100 can be taken out independently. Therefore, the process of separating parts can be omitted.

It is a figure explaining the manufacturing method of the electroforming mold concerning Embodiment 1 of the present invention. It is an enlarged view of the electroforming mold concerning Embodiment 1 of the present invention. It is a figure which shows the structure of an anisotropic conductive particle. It is a figure explaining the manufacturing method of the electroformed component using the electroforming mold which concerns on Embodiment 1 of this invention. It is a figure explaining the hot press molding method for producing the electroforming mold concerning Embodiment 1 of this invention. It is a figure explaining the electroforming method using the electroforming mold concerning Embodiment 1 of this invention. It is a figure explaining the resin transfer type precursor which concerns on Embodiment 1 of this invention. It is a figure showing the electroforming mold which has a plurality of cavities.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Conductive layer 3 Anisotropic conductive layer 4 Resin 5, 5a Anisotropic conductive particle 6 Prototype 100 Electroformed component 101 Electroforming mold

Claims (17)

In electroforming molds used in electroforming,
A conductor having conductivity; and
A resin formed on the conductor and having a transferred part shape;
Consisting of particles dispersed in the resin and having conductivity on at least the surface,
One or more of the particles have an electrode part that is in contact with the conductor and whose surface is exposed from the resin.   2. The electroforming mold according to claim 1, wherein the electrode portion is formed in a portion where the thickness of the resin is equal to or smaller than the particle diameter of the particles.   The electroforming mold according to claim 1, wherein the particles are dispersed throughout the resin.   The electroforming mold according to claim 1 or 2, wherein the resin includes an anisotropic conductive layer in which the particles are dispersed and a non-particle-containing resin layer that does not include the particles.   5. The electroforming mold according to claim 1, wherein the particle includes a spherical core portion and a conductor layer formed so as to cover the core portion. 6.   The material of the core part is resin, and the glass transition point of the resin of the core part is higher than the glass transition point of the resin layer or the anisotropic conductive layer and the non-particle-containing resin layer. The electroforming mold according to claim 5.   The electroforming mold according to claim 5, wherein a material of the core portion is a metal.   The electroforming mold according to claim 7, wherein the core part and the conductor layer are made of the same material.   The electroforming mold according to any one of claims 1 to 8, wherein a plurality of component shapes are transferred. Forming a conductive conductor on the substrate;
A resin forming step of forming a resin layer on the conductor;
Including a shape transfer step of transferring the original shape to the resin using a hot press molding method,
The method for producing an electroforming mold characterized in that the resin contains one or more particles having conductivity on the surface.   The method for producing an electroforming mold according to claim 10, wherein in the resin forming step, a resin in which the particles are dispersed throughout the resin is formed.   The said resin formation process consists of the process of forming the anisotropic conductive layer in which the said particle | grains are disperse | distributed, and the process of forming the non-particle containing resin layer which does not contain the said particle | grain. The manufacturing method of the electroforming mold as described in 2.   The method for producing an electroforming mold according to any one of claims 10 to 12, wherein the particles include a spherical core portion and a conductor layer formed so as to cover the core portion.   The material of the core part is resin, and the glass transition point of the resin of the core part is higher than the glass transition point of the resin layer or the anisotropic conductive layer and the non-particle-containing resin layer. The method for producing an electroforming mold according to claim 13.   The method of manufacturing an electroforming mold according to claim 13, wherein a material of the core portion is a metal.   The method of manufacturing an electroforming mold according to claim 15, wherein the core part and the conductor layer are made of the same metal material.   The method of manufacturing an electroforming mold according to any one of claims 10 to 16, wherein in the shape transfer step, the shapes of a plurality of the parts are transferred.

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