JPH10277699A - Metal mold and production of metal mold as well as formation of matrix and production of electroformed parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the productivity of metal molds having intricate shapes by forming recessed parts on a base material for constituting a matrix and forming resist patterns in these recessed parts in a first step, electroforming a metal in the matrix and peeling electroforming layers from the matrix, thereby obtaining the metal molds in a second step. SOLUTION: The recessed parts 750 of prescribed shapes are formed on the surface of the base material 7 by using a rotating grinder 8. The resist 10 is applied on the base material 7 in such a manner that the recessed parts 750 are embedded. The resist is so applied that the surface of the resist 10 and the original surface 710 of the base material 7 are made flush with each other. A mask 9 previously subjected to pattern is brought into tight contact with the surface of the base material 7 after baking and exposure is executed by applying light 11 thereto. The resist is then developed and the unexposed resist is removed to form the resist patterns 15 on the base material 7. The metal is electroformed on the surface of the base material 7 and the electroforming layers are grown to the prescribed thickness. The base material 7 is removed by a processing liquid after the electroformed parts 12 are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold and a method for manufacturing a mold, and a method for forming a master mold and a method for manufacturing an electroformed product, and more particularly to a mold suitable for manufacturing a mold having a complicated shape. The present invention relates to a method for manufacturing and a method for forming a master mold, and a method for manufacturing a mold and an electroformed product with improved durability and productivity.

[0002]

2. Description of the Related Art A resin component is formed using a mold (molding mold) by an injection molding method, a compression molding method, or the like.

[0003] In recent years, the requirements for the shape of molded articles have been diversified. As such a shape, for example, there is a shape having a concave portion, and the bottom surface of the concave portion is undulating. In order to perform molding into such a shape, it is necessary to manufacture a mold having an inverted shape of the shape.

[0004] As a molded product having a concave portion with a raised and recessed bottom as described above, for example, there is a recording head part for an ink jet recording system. This component has a plurality of concave portions arranged in parallel, and each concave portion has a groove shape whose bottom surface is undulated. That is, a groove-shaped concave portion having both a shallow portion and a deep portion is formed. In this component, a shallow portion of the concave portion is used as an ink flow channel, and a deep portion of the concave portion is used as an ink reservoir communicating with the ink flow channel. That is, the integrated ink flow channel and ink pool are used as a plurality of parallel components. Here, the volume of the ink reservoir is secured because the depth is deeper than the ink flow channel groove.

[0005] In recent years, as the definition of recording has been advanced, it has been required for such an ink jet recording head that ink flow grooves are arranged in parallel at a fine pitch. For example, if the ink ejection density (recording detail) is 40
In order to make 0 dpi, the pitch at which the ink flow grooves are arranged in parallel is 63.5 μm. Therefore, if the width of the ink flow channel is 50.0 μm, the wall thickness between the ink flow channels is 13.5 μm.

[0006] Accordingly, it is required that a mold used for molding is also formed into a fine structure with an accuracy of the order of submicron.

[0007] Photolithography is generally applied to the processing of such a fine structure.
When molding a molding die, the resist pattern itself is not suitable for molding a resin in terms of strength, heat resistance, and the like. However, if a resist pattern having a shape to be formed is formed on a substrate, it can be used as a matrix for manufacturing a mold. Then, a mold having an inverted shape of the matrix can be manufactured, and resin molding can be realized.

[0008]

In photolithography, unexposed portions are removed while leaving the exposed portions of the resist to form a resist pattern. However, it is difficult to control the exposure of the resist in the thickness direction.
It is also difficult to make the surface shape of the applied resist a predetermined shape other than a plane. Therefore, it is difficult to form a resist pattern having a different thickness at each portion by a single photographic process.

As a countermeasure for this, for example, it is conceivable to perform a plurality of photolithography processes while changing the mask pattern. However, it takes a lot of time to form a resist pattern having a matrix shape to be formed.

For this reason, it has been difficult to improve the productivity of the matrix.

Further, when an inverted shape is obtained from a matrix by electroforming, it takes a long time to grow the electroformed layer to a thickness usable as a mold. For example, when electroforming nickel at a current density of 4 A / dm ² , 3 mm
It takes 3 to 4 days to obtain an electroformed layer. For this reason, it has been difficult to improve productivity in the manufacture of a mold by electroforming.

In order to further improve the molding productivity, the present inventors have studied to improve the life of the mold.

A first object of the present invention is to provide a method for manufacturing a mold and a method for forming a master mold, which can improve the productivity of a mold having a complicated shape for forming a molded article having a complicated shape. To provide.

A second object of the present invention is to provide a method and a mold for manufacturing an electroformed product which can reduce the time required for manufacturing the mold.

A third object of the present invention is to provide a method for manufacturing an electroformed product and a mold capable of improving the life of the mold.

[0016]

In order to achieve the first object, according to a first aspect of the present invention, in a mold manufacturing method for manufacturing a mold, a mold is to be formed by the mold. A first step of forming a matrix having at least a portion of a surface shape equivalent to a molded product, and a second step of obtaining a mold having an inverted shape of the formed matrix, The first step includes a step of forming a concave portion by machining on a base material for forming a matrix, and a step of forming a resist pattern in the concave portion by using a photolithography process. A step of electroforming a metal on the matrix, and a step of peeling and obtaining an electroformed layer in which the metal is electroformed from the matrix, Is provided.

According to a second aspect of the present invention, there is provided a method for forming a matrix for producing a mold having the inverted shape, wherein the surface of the substrate for forming the matrix is provided. Forming a concave portion, filling the concave portion with a filling material, removing a part of the filling material, and patterning the filling material into a predetermined shape. .

According to a third aspect of the present invention, in order to achieve the second object, when a metal is electroformed to grow an electroformed layer, a shape is previously determined during the growth of the electroformed layer. The intermediate material thus formed is held in contact with the surface of the electroformed layer grown so far, and a metal is electroformed on the intermediate material together with the electroformed layer grown so far. A method for manufacturing a casting is provided.

According to a fourth aspect of the present invention, there is provided a mold having a preformed intermediate material inside a metal layer grown by electroforming.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

The first embodiment of the present invention will be described with reference to FIGS. 1 (a) to 1 (d), FIGS. 2, 5 and 8 to 11.

Prior to description of a mold manufacturing method to which the present embodiment is applied, a structure of a mold to be manufactured will be described.

First, with reference to FIG. 2, the shape of the molded product, the shape of the matrix, and the relationship between them will be described. FIG. 2 shows a part of a molded product (mother). In FIG.
Reference numeral 4 denotes a molded product, and reference numeral 3 written in parentheses following the reference numeral 4 denotes a matrix. Also, as for other symbols, the symbols before the parentheses are the symbols indicating the respective parts of the molded article 4, and the symbols written in the parentheses are the symbols indicating the respective parts of the mold.

In FIG. 2, the molded product 4 is formed in a shape having a plurality of grooves 420 having undulations at the bottom. That is, each groove 420 has a stepped structure in which the bottom portions 461 to 463 are sequentially deepened. This groove 420 is
Are configured to be separated by a partition wall 410.
For example, when the molded article 4 is used as a component of an ink jet recording head, the groove 420 is used as a shape in which an ink flow path groove and an ink reservoir are integrated.

The mother die 3 for manufacturing such a molded product 4 is formed into a shape having the surface shape of the molded product 4 in at least a part thereof. In the present embodiment, the matrix 3
In the present embodiment, a filling material (for example, a pattern in a resist) 5 is formed in a concave portion 750 formed in the base material 7 to realize a groove structure. Hereinafter, a method of manufacturing such a mother die and a method of forming a mold (stamper) for actual molding will be described.

The mold manufacturing method to which this embodiment is applied is as follows.
The method includes a first step for forming a matrix and a second step for obtaining a mold having an inverted shape of the formed matrix. The matrix has at least a part of a surface shape equivalent to a molded product to be molded by a mold.
(A) to (c) of FIG. 1 each show a shape corresponding to the XX ′ cross section of FIG. FIG. 1D shows a shape corresponding to the inverted shape in the XX ′ section of FIG.

First, the first step will be described with reference to FIGS. 1 (a) and 1 (b). This step is for forming a matrix having a shape equivalent to the shape shown in FIG.

First, with reference to FIG. 1A, the step of machining the substrate 7 will be described. As the base material 7,
For example, a silicon substrate can be used. In FIG. 1A, a concave portion 750 having a predetermined shape is formed on the surface of the base material 7 using the rotating grindstone 8. Thereby, the base material 7 is formed in a shape as shown in FIG. The concave portion 750 has, for example, a plurality of bottom surfaces 761 to 763 having different depths from each other, and these bottom surfaces, and the bottom surface and the surface of the base material 7 can be connected by an inclined surface. . Specifically, the bottom surface 76
In the order of 1, 762, 763, the depth (the height difference with respect to the original surface 710 left on the substrate 7) becomes shallower, and in this order, the width of the bottom surface can be increased. For example, the shallow bottom surface 763 can have a depth of 50 μm or more, and the narrowest bottom surface 761 can have a width of 70 μm or less.

The grinding wheel 8 is formed in advance into a shape determined according to the shape of the concave portion 750 to be formed. For example, a shape having a flat portion 810 and inclined portions 821 and 822 provided on both sides of the flat portion 810 can be used. For example, the inclined part 821 and the inclined part 822
Can be used. For example, the width of the flat portion 810 can be 70 μm, and the angle between the two inclined portions 821 and 822 can be 30 degrees (that is, the inclined angle of each inclined portion is 15 degrees). A method for forming the grindstone 8 will be described later.

The width of the step portions 761 to 763 can be made larger than the width of the flat portion 810 by changing the position where the grinding stone 8 contacts, and repeating the processing.

Referring to FIG. 11, an example of a procedure for forming the concave portion 750 will be described.

First, the grindstone 8 is positioned at a predetermined position above the substrate 7. Then, the grindstone 8 is brought close to the substrate 7 while rotating, and the upper surface 710 of the substrate 7 is rotated.
Adjust the height so that it touches.

Then, a cut is made by a depth D, and a groove is formed in the bottom surface 761 having a width A.

Next, the grindstone 8 is moved upward to the depth E. In this state, the grindstone 8 is moved horizontally to perform groove processing on the bottom surface 762 having a width B. The width of the slope connecting the bottom surface 761 and the bottom surface 762 is, for example, (B / A). At this time, the amount of horizontal movement of the grinding wheel 8 is (B + B /
A).

Further, the groove processing of the bottom surface 763 is performed in the same manner as the groove processing of the bottom surface 762. That is, the depth F
The whetstone 8 is moved upward until it moves horizontally in this state. This horizontal movement amount can be, for example, (C + C / B).

After the recess 750 is formed in this way, the grindstone 8 is moved to a position sufficiently above the base material 7. Thereby, the groove processing of another position in the base material 7, or
It can be prepared for removal of the processed base material 7.

Next, a process for forming a resist pattern will be described with reference to FIG.

A resist 10 is formed on the substrate 7 in which the concave portions are formed.
Is applied. The application of the resist 10 is performed so that the concave portion 750 is filled with the resist 10. Resist 10
It is preferable to use a thick film resist having high viscosity. The application of the resist 10 is performed so that the surface of the applied resist 10 and the original surface 710 of the base material 7 coincide. By applying the resist 10 in this manner, the upper surface of the resist pattern formed by performing a process described later can be made to coincide with the original surface 710 of the base material 7.

As described above, the original surface 710 and the resist 1
For the purpose of applying so that the surfaces of the zeros coincide with each other, for example, after the resist 10 is applied to the concave portion so as to be higher than the original surface 710, the excess resist 10 is removed. The removal of the resist 10 is performed by an amount corresponding to the expected shrinkage in post-baking described later.
This is performed so that the resist 10 rises from 10. In post-baking, the amount by which the resist 10 shrinks depends on the baking temperature and time. As a result, the surface of the post-baked resist 10 and the original surface 710 have a uniform height over the substrate 7. At this time, if a step occurs, the height on the resist side is increased by about 1 μm.

The removal of the resist 10 so as to swell is performed, for example, by using the restoring force due to the viscosity of the resist 10. That is, after the resist 10 is spin-coated on the substrate 7, the resist 10 is wiped off with a spatula while the substrate 7 is spinning. For example, when the post-baking of the resist 10 is expected to be 5%, the resist 10 is removed so as to rise from the original surface 710 to a height of 5% of the depth of the concave portion.

With the resist 10 applied, baking is performed for several minutes. Thereafter, a mask 9 in which a pattern having a shape as shown in FIG. 4 is patterned in advance is brought into close contact with the surface of the base material 7 and light 11 is applied to perform a predetermined exposure process. Thereafter, a developing process is performed to remove the unexposed resist. In this manner, the resist pattern 15 left in the surface shape corresponding to the transmission portion 90 (see FIG. 4) of the pattern of the mask 9 can be formed on the base material 7.

In this way, it is possible to obtain a matrix formed into a shape having the same shape as the shape of the molded product shown in FIG.

Next, the second step will be described with reference to FIGS. 1C and 1D and FIG.

First, with reference to FIG. 1 (c), a process of electroforming a metal on a matrix will be described.

A metal is electroformed on the surface of the base material 7 on which the resist pattern 15 is formed, and an electroformed layer is grown to a predetermined thickness. As the metal to be electroformed, for example, nickel can be used. By using nickel electroforming, the stress remaining in the electroformed product can be reduced, the transferability of the shape of the master mold can be improved, and the durability as a mold can be improved.

Prior to electroforming, a conductive film may be formed on the entire surface of the matrix (base material 7 and resist pattern 15). By performing electroforming after forming the conductive film, electroforming can be performed smoothly even if the base material 7 and the resist pattern 15 are non-conductive. Especially,
Even when the conductivity on the surface of the matrix is not uniform, such as when the conductivity between the base material 7 and the resist pattern 15 is different,
Electroforming can be performed while avoiding uneven electroforming. For the conductive film, for example, a highly conductive metal such as gold, silver, or copper can be used. The formation of the conductive film can be performed by, for example, evaporation, sputtering, or the like.

Next, a process for obtaining the electroformed product 12 grown on the surface of the matrix will be described with reference to FIG.

After the electroformed product 12 is formed, the substrate 7 is removed with a processing liquid. When the substrate 7 is a silicon substrate, the resist pattern 15 is removed together with the substrate 7.

In this manner, the electroformed product 12 having the inverted shape of the matrix can be obtained.

Next, with reference to FIG. 5, a process of machining the electroformed product 12 to form a mold 20 suitable for use as a molding core will be described.

The outer shape of the electroformed product 12 is formed or a mounting hole is formed in order to mount the core on a predetermined mounting portion (for example, a template) of the molding apparatus. This processing can be omitted depending on the structure of the molding apparatus.

The processing of the electroformed product 12 includes, for example,
As shown in FIG. 5, an unnecessary portion 1 of the peripheral portion of the electroformed product 12 is formed.
9 is removed, and a mounting hole 21 is formed. The unnecessary portion 19 can be removed by, for example, milling, wire electric discharge machining, grinding, or the like. If necessary, the end of the mounting hole 19 can be counterbored, or the inner peripheral surface can be tapped.

Next, a method for forming the grindstone 8 into the shape used in FIG. 1A will be described with reference to FIGS.

For example, the following first method, and
By the second method, it is possible to form the grindstone 8 into the above-described shape, respectively. Here, two inclined portions 82
The angle between 1,822 is described as G, and the width of the flat portion as A.

First, a first method for forming a grindstone will be described with reference to FIG. This method is a method of forming using an electrodeposited diamond tool.

In FIG. 8, the grinding stone 8 is formed by a diamond tool 500 having a processing groove 530 in which an abrasive layer 510 is formed. The processing groove 530 is formed in a shape corresponding to the shape of the concave portion to be formed by the grindstone 8.

Then, the grindstone 8 is rotated so that the portion to be formed moves in the circumferential direction. For example, when the grindstone 8 is formed in a plate shape, it is rotated within the plate surface. That is, the grindstone 8 can be rotated as shown by the arrow O in FIG. 8 or in the opposite direction.

Further, the grindstone 8 is scanned in the groove direction of the processing groove 530. This is a direction perpendicular to the paper surface in FIG. In this scanning, it is sufficient that these relative positional relationships change in the groove direction.
00 may move, or the grinding wheel 8 and the electrodeposited diamond tool 500 may move together.

As described above, the interval between the grindstone 8 and the electrodeposited diamond truer 500 is reduced while the grindstone 8 is being rotated and scanned. Then, these are brought close to each other until the circumferential portion 810 of the grindstone 8 is ground, and the grindstone 8 is formed in a shape having an inverted shape of the cross section of the processing groove 530.

The processing groove 530 is formed in a shape having, for example, a depth D ′, a width A at the bottom, and an angle G between the inclined portions on both sides, and is used to form the concave portion 750 in FIG. It is possible to cope with the formation of the grindstone 8.

Here, the depth D 'is at least twice the depth D of the deepest part of the concave portion to be formed. This depth D corresponds to the depth of the bottom 761 of the concave portion 750 in FIG.

The width A ′ is a width corresponding to the thickness T of the electrodeposited layer 510 with respect to the width A of the narrowest bottom portion 761 (see FIG. 1A) of the concave portion to be formed. Wide width. The thickness T of the electrodeposition layer 510 corresponds to a thickness obtained by adding a plating thickness to twice the particle diameter of the diamond abrasive grains.

Such an electrodeposited diamond truer 5
00 can be created as follows.

First, a base metal 520 having a groove 530 having a depth D ′, a width A ′ and a sandwich angle G degrees is formed. Next, the base metal 520 is immersed in a plating solution, and an abrasive layer 510 is
To form the electrodeposited diamond truer 500. As the plating solution, for example, a nickel electrolytic solution or the like can be used.

Next, a second method of forming a grindstone will be described with reference to FIGS. 9 and 10. This method
This is a method of forming a grindstone using a discharge truing device.

First, as shown in FIG.
As shown by the arrow K, the machining surface (discharge electrode surface) 6
Scan in the direction along 11. Then, the whetstone 8 is moved to the arrow O
Rotate as shown. In other words, each is moved such that the direction of the rotation axis of the grindstone 8 and the scanning direction of the processing surface 611 become parallel.

In this state, the distance between the grindstone 8 and the discharge electrode 610 is reduced, and the outer peripheral side surface of the grindstone 8 is trued.

Here, the deformation of the processing surface 610 and the transfer of the shape of the processing surface 610 to the outer peripheral side surface of the grindstone 8 can be avoided by scanning the discharge electrode surface 610. Thus, the outer peripheral portion side surface 810 of the grindstone 8 can be formed into a flat shape in the direction indicated by the arrow K.

After the outer peripheral side surface is formed as described above, the grinding wheel 8 and the discharge electrode 610 are crossed so that the rotation axis direction o of the grinding wheel 8 and the scanning direction k of the discharge electrode 610 intersect at a predetermined intersection angle. The electrode 610 is arranged. That is, FIG.
At 0, the discharge electrode 610 is scanned in a state where the scanning direction k forms an intersection angle g with the rotation axis direction o.
In this state, the distance between the grindstone 8 and the discharge electrode 610 is reduced,
The inclined surface 821 of the grindstone 8 is formed with a predetermined width h. Then, the discharge electrode 610 is arranged on the opposite side (the left side of the grindstone 8 in FIG. 10), and the inclined surface 822 is formed.

Thus, on both sides of the flat portion 810,
The grindstone 8 can be formed into a shape in which the inclined portions 821 and 822 are formed.

For example, if the intersection angle g is g = ｇ90 degrees−
(G / 2)} and the width h of the inclined portion = {(HA) / 2}.
By doing so, it is possible to form the flat portion 810 having the width A and the inclined portions 821, 821 having the sandwiching angle G on both sides thereof. Here, H is the width of the grindstone 8.

Next, a second embodiment of the present invention will be described with reference to FIGS. 1 (a) to 1 (d) and FIG. The basic procedure of the mold manufacturing method according to the present embodiment is the same as that of the mold manufacturing method according to the above-described first embodiment. Therefore, the description here will focus on the differences.

In the present embodiment, a plurality of concave portions 750 are formed in parallel in the step shown in FIG.

Then, in the step shown in FIG. 1B, a resist 1 is placed in each of the plurality of recesses 750 formed.
5 is applied. Then, as shown in FIG.
Exposure is performed a plurality of times by changing the position of the mask 9 so that the exposures 91 to 91d are respectively exposed. When the exposure is performed for all the regions, a developing process is performed, and an etching process is performed. Here, a case has been described in which two concave portions 750 are formed and each concave portion is divided into two exposure regions. However, the number of concave portions formed and the number of exposure regions into which the concave portions are divided are different from this. Not exclusively.

In the case of the above example, as shown in FIG.
Four resist patterns 15 are formed for the entire substrate 7, two for each recess 750.

Then, in FIG. 7, each area 91a-9
The substrate element 720 containing 1d is divided. When the base material 7 is divided, an unnecessary portion 730 can be removed according to the shape in which the electroformed product is to be grown.

In this manner, a plurality of mother dies 720 can be collectively formed.

In this description, the case where a plurality of resist patterns 15 having a common pattern are formed using the same mask 9 has been described. Different resist patterns may be formed on the same base material 7. At this time, it is needless to say that the plurality of concave portions 750 can be formed in different cross-sectional shapes.

Electroforming is performed on each of the plurality of formed master dies 720 to obtain a plurality of electroformed products having inverted shapes of the master dies 720. Of course, the electroforming can be performed in parallel.

According to the present embodiment, it is possible to obtain a plurality of electroformed products having a common shape easily and in a short time. Further, it is possible to obtain various types of electroformed products.

In the first and second embodiments described above, the steps for manufacturing the electroformed product are not limited to the above-described embodiments. For example, an electroformed product can be manufactured in a manner described below with reference to an example.

First, a first example of another embodiment of a process for manufacturing an electroformed product will be described. This example is an example in which the surface of a grown electroformed product is subjected to electroless plating. Thereby, the durability when the electroformed product is used as a mold can be improved.

In the step of forming a base material described above with reference to FIG. 1A, a base die is formed in a shape offset with respect to a molded product corresponding to a predetermined thickness.

Then, electroforming is performed on the formed matrix. The grown electroformed product is separated from the matrix.

Next, on the surface of the separated electroformed product, metal electroless plating is grown to a thickness corresponding to the offset. As the metal to be electrolessly plated, for example, nickel can be used.

The thickness for growing the electroless plating is as follows:
For example, it can be selected to be 2 μm. That is, in this case, the shape of the matrix is offset with respect to the shape of the molded product so that the surface of the matrix retreats by 2 μm.

Next, a second example of another embodiment for manufacturing an electroformed product will be described with reference to FIG. This example is an example in which electroless plating is grown on a matrix and an electroformed layer is grown thereon.

Prior to the electroforming in FIG. 1C, electroless plating was performed, and as shown in FIG. 12, the entire surface of the matrix, that is, the surface of the base material 7 and the surface of the resist pattern 15 were formed. Next, the electroless plating layer 30 is formed. In FIG. 12, reference numeral 31 denotes the surface of the electroless plating layer formed on the side surface of the resist pattern. Electroless plating layer 3
0 grows to a thickness of about several μm to about 50 μm, and then electroforming the metal, until the electroless plated layer 30 and the electroformed layer 12 as a whole have a predetermined thickness. Grow.

Then, the electroformed layer 12 is
Along with 0, it is peeled from the matrix.

By manufacturing the electroformed product in this manner, the electroformed layer 1 having the electroless plated layer 30 on the forming surface is formed.
2 can be obtained.

In the case of this example, the durability as a mold can be improved as in the first example described above. Further, unlike the first example, there is no need to offset the shape of the matrix with respect to the molded product. In addition, since the surface of the obtained electroformed product used for molding, that is, the surface of the electroless plating is directly transferred from the mother die, the accuracy of the surface used for molding can be further improved.

By manufacturing an electroformed product as in the first example and the second example, the surface used as the cavity of the mold (the surface in contact with the molded product) is subjected to electroless plating. Can be a layer grown. Thereby, the hardness of the surface used as the cavity can be improved. Therefore, it is possible to improve the durability against the injection pressure in the injection molding, and to prevent the mold from being damaged due to poor peeling of the molded product. Therefore, it is expected that the number of shots that can be formed by one mold increases.

For example, when the metal to be electroformed is nickel, the hardness of the electroplated layer is about Hv250, but the hardness of the electrolessly plated layer is about Hv500. This is probably because the electroplated layer is crystalline and the electrolessly plated layer is amorphous. In the case of this nickel electroformed mold, the number of shots per mold was about several thousand by counting the number of molded products, but the number of shots by using an electroless plating layer on the cavity surface Increased to about ten thousand.

Next, a third example of another embodiment for manufacturing an electroformed product will be described with reference to FIG. This example is an example in which an intermediate material formed in advance is included in an electroformed layer. This example may be applied to a process for manufacturing a normal electroformed product, or may be applied to any of the first example and the second example.

In order to use the electroformed product as a mold, a certain thickness is required. It takes a long time to grow the electroformed layer to such a thickness. For example, under the condition of 4 A / dm ² , in order to grow nickel electroformed to a thickness of 3 mm, in the electroforming tank,
It takes about 3 to 4 days (72 to 96 hours).

Therefore, in this example, at the stage when the electroformed layer has grown to a thickness having no problem in strength as a mold, FIG.
As shown in FIG. 3, the preformed intermediate material 100 is kept in contact with the electroformed layer 12a that has been grown so far.

Then, the electroformed layer 12 grown so far
a, and an electroformed layer 12b is grown on the intermediate material 100 to form the electroformed layer 12 including the intermediate material 100.

For example, a plate on a mesh is pressed as a core during the growth of an electroformed product grown to about 0.5 to 1 mm, and the mesh-shaped plate is wrapped together with the electroformed product that has been grown up to that time. The nickel electroforming is grown so that Thereby, to the thickness required as a mold core,
It can be formed in a short time.

In the above description, the substrate 7 is
Although the description has been made mainly on the case where the silicon substrate is used, the material of the base material 7 is not limited to this. For example, a metal can be used as the base material. For example, free cutting steel, brass, or the like can be used. When metal is used as the base material 7, the mold 7 is formed by machining the inverted shape of the mold. Examples of the machining include cutting, grinding, and electric discharge machining. At this time, the processing surface can be made a mirror surface by using a diamond tool as a processing tool. The brass is a material suitable for processing with the diamond bite.

Further, prior to machining, the base material 7 can be pre-treated to improve the workability. When brass is used as the base material 7 as such a pretreatment, the brass can be subjected to cold rolling and low-temperature annealing. Thereby, the hardness of brass can be improved and the crystal grains can be refined. Improvement of hardness and refinement of crystal grains are suitable for fine processing by diamond cutting. For example, by performing a pretreatment on brass, the Vickers hardness can be 170 or more and the size of crystal grains can be 30 μm.

After the above-described mechanical processing, the surface can be subjected to chemical polishing. By performing chemical polishing,
It is possible to eliminate the return generated by performing the machining.

The mold parts obtained as described above can be used for molding by a casting method, a compression molding method, an injection molding method or the like.

[0103]

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, a case where four master molds are obtained from one substrate will be described. However, the number of master molds obtained from one substrate is not limited to this.

As the substrate 7, a silicon substrate was used.

A plurality of grooves 750 were formed on the silicon substrate 7 with a grindstone 8 using a dicing machine manufactured by Disco Corporation. As shown in FIG. 4, a predetermined truing and dressing was performed on the outer peripheral portion of the grindstone 8 used for cutting, and a shape corresponding to a required inverted shape of the molded product was previously formed.

The shape of the grindstone 8 was as shown in FIG. 11 corresponding to the shape of the molded product. That is, the whetstone 8
The width of the tip 810 of the bottom shape is set to a width corresponding to the width A of the bottom 761, and the inclined surfaces 821 and 822 are formed in a V-shape having a sandwich angle G degrees corresponding to the inclined portion of the concave portion 750. I put it. Here, in FIG.
m, B = 90 μm, C = 150 μm, D = 50 μm
, E = 35 μm, F = 20 μm, and G = 30 degrees.

Using the grinding stone 8 thus formed, the bottom portion 761 was formed by passing through at the position of the depth D.

The bottom portion 762 was formed at the position of the depth E, and the bottom portion 763 was formed at the position of the depth F by performing through processing. These threading processes are:
Depending on the width relationship with the width B of the bottom portion 762 or the width C of the bottom portion 763, the pitch was shifted several times. Also,
A slope connecting the bottom 761 and the bottom 762, and
In consideration of the formation of the inclined surface connecting the bottom 762 and the bottom 763, B / A and C / B were processed so as to overlap each other.

The movement of the pitch for working through the grindstone 8 was carried out by stepping the numerical control. In the above-mentioned overlap processing, the number of steps of the pitch movement was determined by rounding up the decimals.

In this embodiment, this processing is performed by using the silicon substrate 7.
I went to the above two places. The shape accuracy obtained by this processing method is 1 μm
Was within. Further, the surface roughness of the processed surface was set to about 0.2 μm at the maximum height by adjusting the particle size of the grinding wheel 8 for processing.

After the completion of the shape processing, the silicon substrate 7 was subjected to predetermined cleaning and pretreatment.

Then, the pre-processed silicon substrate 7
Was coated with a resist. The resist used was JSR THB resist manufactured by Japan Synthetic Rubber Co., Ltd. The resist was dropped at the center, and after being spread by gravity, the resist was uniformly applied on the substrate by spin coating. In this state, the recess 7
A swell was generated between the resist that entered the processed portion 50 (see FIG. 11) and the upper surface of the original substrate. For this reason, the excess resist was removed using a spatula over substantially the entire surface of the silicon substrate 7.

After the application of the resist, post-baking was performed using a hot plate at a temperature of 90 ° C. for a time of 5 minutes. Thereafter, as shown in FIG. 1B, exposure was performed by irradiating light 11 with the mask 9 kept in close contact. Thereafter, development was performed to remove unexposed resist. In this embodiment, a mask having a transmission pattern with a pitch of 70 μm and a pattern width of 20 μm was used as the mask 9.

After that, a conductive film was formed on the entire surface of the silicon substrate on which the resist pattern was formed. The formation of the conductive film
Au was deposited by an evaporation apparatus.

The silicon substrate on which the conductive film was formed was divided. For this purpose, the above dicing machine was used and divided into four parts by a dedicated grindstone so that each part had one resist pattern. At this time, as shown in FIG. 7, a portion 730 that is no longer required as a matrix was removed.

Then, a predetermined stripping process was performed to remove the silicon substrate and the resist pattern.
That is, the silicon substrate was removed using a KOH (potassium hydroxide) solution. At this time, the resist pattern was also removed at the same time.

Next, nickel electroforming was performed to obtain an inverted shape. The temperature of the electroforming liquid is 50 degrees and the condition is 4A
/ Dm ^2, and nickel was grown to a thickness predetermined as a mold thickness. Then, it was taken out of the electroforming tank.

Electroforming was performed smoothly until the pattern was fine. This is considered to have a great effect of forming the above Au on the matrix.

Next, milling, finishing, grinding, and the like were performed so as to obtain a suitable shape as a mold part.

[0121]

According to the present invention, it is possible to form a matrix having a concave portion having undulations on the bottom surface. Then, using the matrix, the shape of the matrix is reversed and
A mold having a surface shape having convex portions having undulations at the top can be obtained.

Further, the time required for forming an electroformed product can be reduced, and the productivity of manufacturing a mold can be improved.

Further, the durability of the electroformed product can be improved, and the number of shots that can be formed by one mold can be increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a mold manufacturing method to which the present invention is applied, in which (a) a cross-sectional view showing a step of forming a concave portion in a substrate, and (b) a cross-sectional view showing a step of forming a resist pattern. (C) a cross-sectional view showing a step of electroforming a metal, (d)
It is sectional drawing which shows the process of acquiring an electroformed product.

FIG. 2 is a perspective view showing a part of a plastic molded product to be molded.

FIG. 3 is a perspective view showing a part of a concave portion formed in a base material.

FIG. 4 is a perspective view showing a pattern of a mask used for a photolithography process.

FIG. 5 is a perspective view showing a relationship between a shape suitable for use as a mold core for molding and a shape of an electroformed product.

FIG. 6 is a perspective view showing a position where a mask is placed in a photolithography process.

FIG. 7 shows a case where four matrixes are obtained from one base material.
It is a perspective view which shows the relationship between a base material and each matrix.

FIG. 8 is a cross-sectional view showing the formation of a grindstone by an electrodeposited diamond truer.

FIG. 9 is a cross-sectional view showing a step of forming a circumferential end face in the processing of the grindstone by the electric discharge truing device.

FIG. 10 is a cross-sectional view showing a step of forming an inclined surface in processing of a grindstone by an electric discharge truing device.

FIG. 11 is a cross-sectional view showing the relationship between the shape of a concave portion to be formed in a matrix and the shape of a grindstone.

FIG. 12 is a cross-sectional view showing an electroless plating layer formed on a matrix.

FIG. 13 is a cross-sectional view showing a step of forming an electroformed product including an intermediate material.

FIG. 14 is a perspective view showing a state in which a plurality of concave portions are formed in a base material.

[Explanation of symbols]

3 ... Matrix, 4 ... Molded product, 5 ... Fine pattern, 7 ... Base material,
8 ... whetstone, 9 ... mask, 10 ... resist, 11 ... light, 1
2: electroformed product, 15: resist pattern, 19: unnecessary part, 20: mold, 21: mounting hole, 90: transparent part,
91a, 91b, 91c, 91d ... exposure area, 100 ...
Intermediate material, 410: partition wall, 420: groove structure, 500: electrodeposited diamond tool, 510: electrodeposited layer, 520: base metal, 610: discharge electrode, 710: original surface, 720: divided base element, 730: unnecessary part, 750: concave part,
761, 762, 763...

Claims (14)

[Claims] 1. A mold manufacturing method for manufacturing a mold, comprising: a first step of forming a matrix having at least a part of a surface shape equivalent to a molded product to be molded by the mold; And a second step of obtaining a mold having an inverted shape of the formed matrix. The first step is a step of forming a concave portion by machining in a base material for forming the matrix. And a step of forming a resist pattern in the concave portion using a photolithography process. The second step is a step of electroforming a metal on the matrix, and an electroforming step in which the metal is electroformed. Removing the layer from the matrix to obtain the layer. 2. The mold manufacturing method according to claim 1, further comprising a third step of machining the electroformed product obtained in the second step. 3. The mold manufacturing method according to claim 1, wherein the first step is a step of forming the resist pattern in a concave portion, wherein the resist pattern is formed on the base material. And a step of dividing the substrate on which the resist pattern is formed in each of the plurality of regions into substrate elements each including the above-described region. 4. The method of manufacturing a mold according to claim 1, wherein the first step includes a step of forming a concave portion in the base material and a step of forming the resist pattern. A method for manufacturing a mold, comprising a step of chemically polishing a base material between them. 5. The method according to claim 1, wherein, in the second step, prior to the step of electroforming, a surface of the mother die on which metal is to be electroformed. Forming a conductive film on the mold. 6. The method for manufacturing a metal mold according to claim 1, wherein the metal is electrolessly plated on the matrix when the metal is electroformed on the matrix in the second step. A metal mold is formed by electroforming a metal on the electroless-plated matrix, and separating the electroformed metal layer together with the electroless-plated metal layer from the matrix. Production method. 7. The metal mold manufacturing method according to claim 1, wherein the metal is electroformed on the mother die in the second step when the metal is electroformed on the mother die. Mold production characterized in that an electroformed metal layer is peeled off from the matrix, and a metal is electrolessly plated on at least a surface used as a molding surface of the mold, of the peeled metal layer. Method. 8. The metal mold manufacturing method according to claim 1, wherein the metal layer is grown by electroforming when the metal is electroformed on the matrix in the second step. In the middle of the process, a preformed intermediate material is brought into contact with the surface of the metal layer grown so far, and the metal is electroformed on the intermediate material together with the metal layer grown so far. A mold manufacturing method. 9. A method for forming a matrix for manufacturing a mold having the inverted shape, wherein a recess is formed on a surface of a base material for forming the matrix, and the recess is formed in the recess. A method for forming a matrix, comprising filling a filling material, removing a part of the filling material, and patterning the filling material into a predetermined shape. 10. A method for manufacturing an electroformed product for manufacturing a mold having an inverted shape of a matrix, comprising: electrolessly plating a metal on the matrix; and electroforming the metal on the electrolessly plated matrix. An electroformed product manufacturing method, comprising separating the electroformed metal layer together with the electrolessly plated metal layer from the matrix. 11. A method for producing an electroformed product for producing a mold having an inverted shape of a matrix, comprising: electroforming a metal on the matrix; and peeling the electroformed metal layer from the matrix. An electroformed product manufacturing method, comprising: electroless plating a metal on at least a surface used as a molding surface of a mold in the separated metal layer. 12. A state in which a preformed intermediate material is brought into contact with the surface of an electroformed layer grown so far during the growth of the electroformed layer when the metal is electroformed to grow the electroformed layer. And electroforming a metal on the intermediate material together with the electroformed layer grown so far. 13. A mold comprising a metal layer grown by electroforming and a metal layer grown by electroless plating. 14. A mold having a preformed intermediate material inside a metal layer grown by electroforming.