JP7415181B2 - Mold manufacturing method - Google Patents

Description

Embodiments according to the present invention relate to a method for manufacturing a mold.

Traditionally, molds have been manufactured from metal members. For example, when placing resin on the main surface of a substrate, the mold is placed on the main surface where resin is not provided. , filling with resin and curing it has been carried out (for example, see Patent Document 1).

In Patent Document 1, the space between the substrate and the mold is filled with a thermosetting resin while the mold is pressed against a predetermined position on the substrate. After the resin has hardened, the mold is removed upward from above the substrate. For this reason, the side surface of the mold facing the resin is formed to have a so-called draft angle, which is inclined with respect to the vertical plane so as to move away from the resin as it moves downward.

Japanese Patent Application Publication No. 2020-167366

An object of the embodiments of the present invention is to provide a method for manufacturing a mold that can manufacture a mold that is easy to extract from a cured resin by a process other than cutting.

A method for manufacturing a mold according to one aspect of the present invention includes the steps of: preparing a metal member having one surface and a second surface located on the opposite side of the first surface; arranging a first resist layer on the first surface so as to expose the first resist layer; and spraying a first etching solution onto a part of the first surface exposed from the first resist layer to remove the first resist layer from the first surface. forming a side surface extending to two surfaces and an edge connecting the first surface and the side surface; peeling off the first resist layer from the first surface; and the first surface including the edge. the step of arranging a second resist layer on the first surface so that a portion of the resist layer is exposed; and the step of removing the edge using a second etching solution.

According to one embodiment of the present invention, a mold that is easy to extract from a cured resin during use can be manufactured by a process other than cutting.

FIGS. 1A to 1C are perspective views showing an example of how to use a mold according to an embodiment of the present invention. FIG. 2(A) is a schematic perspective view of a mold according to an embodiment of the present invention. FIG. 2(B) is a schematic side view of a mold according to an embodiment of the present invention. FIG. 3 is a schematic plan view illustrating a state in which a plurality of molds are connected according to an embodiment of the invention. FIG. 4 is a schematic cross-sectional view illustrating a first resist placement step of a mold manufacturing method according to an embodiment of the invention. FIG. 5 is a schematic cross-sectional view illustrating a first etching step of a method for manufacturing a mold according to an embodiment of the invention. FIG. 6 is a schematic cross-sectional view illustrating a first resist stripping step of a mold manufacturing method according to an embodiment of the invention. FIG. 7 is a schematic cross-sectional view illustrating the second resist placement step of the mold manufacturing method according to an embodiment of the invention. FIG. 8 is a schematic cross-sectional view illustrating the second etching step of the method for manufacturing a mold according to an embodiment of the invention. FIG. 9 is a schematic cross-sectional view illustrating the second resist stripping step of the mold manufacturing method according to an embodiment of the invention. FIG. 10(A) is a schematic cross-sectional view illustrating the first resist placement step of the mold manufacturing method according to Modification 1. FIG. 10(B) is a schematic cross-sectional view illustrating the first etching step of the mold manufacturing method according to Modification Example 1. FIG. 11 is a schematic cross-sectional view of the test piece. FIGS. 12A to 12F are schematic diagrams showing the test results.

<Embodiment>
The method for manufacturing the mold 1 according to this embodiment is a method for manufacturing the mold 1 using etching. The mold 1 manufactured by the manufacturing method according to the present embodiment is used, for example, when manufacturing the semiconductor light emitting device 8.

Here, as an example of a method of using the mold 1, a method of manufacturing a semiconductor light emitting device 8 will be described. The semiconductor light emitting device 8 is manufactured, for example, through the steps shown in FIGS. 1(A) to 1(C). As shown in FIG. 1A, first, a plurality of light emitting elements 82 are mounted on a lead frame 81 as a base material. Although not shown here, the lead frame 81 and the light emitting element 82 are actually connected via wires.

Next, as shown in FIG. 1B, the mold 1 obtained by the manufacturing method of this embodiment is placed on the lead frame 81 so as to cover the plurality of light emitting elements 82. Hereinafter, the portion of the base material covered by the mold 1 will be referred to as a "covering target area."

Next, mold resin 83 before hardening is placed so as to cover lead frame 81 and mold 1 . Next, the mold resin 83 is cured. Thereafter, as shown in FIG. 1C, the mold 1 is extracted from the cured mold resin 83.

In this way, the mold 1 according to the present embodiment is used to cover a part of the main surface of the base material when the resin is provided on the main surface. As shown in FIG. 2, the mold 1 includes a top plate part 2, a plurality of side plate parts 3, and a plurality of connection parts 4, which are integrally formed.

When the mold 1 is placed on a base material, the top plate part 2 has a shape when the base material is viewed along a direction perpendicular to the main surface of the base material (hereinafter referred to as "planar view"). , is a portion of the base material that overlaps with the area to be coated. The top plate portion 2 has a polygonal shape in plan view. In this embodiment, the top plate portion 2 has an octagonal shape in plan view. The upper surface of the top plate portion 2 may be referred to as the "top surface 21." The top surface 21 is a surface located on the opposite side to one surface of the top plate portion 2 that faces the base material when the mold 1 is placed on the base material.

The plurality of side plates 3 extend from the outer edge of the top plate 2 in a direction perpendicular to the top plate 2 and toward the base material side. A portion surrounded by a plurality of side plates 3 forms a recess 11, and a tip surface of the side plate 3 forms an opening surface. The distal end surfaces of the plurality of side plates 3 face the main surface of the base material when placed on the base material.

One surface of the side plate portion 3 located on the outside may be referred to as an outer surface 31. As shown in FIG. 2(B), the outer surface 31 is inclined with respect to the vertical plane so that the closer the outer surface 31 is to the distal end surface of the side plate portion 3, the closer to the center of the mold 1 it is. That is, the plurality of side plate parts 3 have a so-called draft angle. Thereby, after the resin around the area to be covered has hardened, the mold 1 can be easily removed. In this specification, "outside" means the outside when focusing on one mold 1, and means the direction from the center of the mold 1 toward the side plate part 3 in plan view. Moreover, in this specification, "inside" means the direction opposite to the outside, and means the direction from the side plate part 3 toward the center of the mold 1 in plan view.

A through hole 32 is formed in the side plate portion 3 . The through hole 32 is formed to pass a wire that electrically connects the base material and the light emitting element 82. The through hole 32 passes through the outer surface 31 and the inner surface of the side plate portion 3 and is open at the distal end surface. The through holes 32 are formed in the plurality of side plate parts 3 as necessary.

The plurality of connecting portions 4 are connected to connecting portions 4 of other adjacent molds 1. One surface of the connecting portion 4 is flush with the top surface 21 of the top plate portion 2 in this embodiment. Although FIGS. 2A and 2B show one mold 1, in reality, as shown in FIG. , a plurality of molds 1 are connected. The method for manufacturing the mold 1 according to the present embodiment will be described with reference to FIGS. 5 to 11, focusing on the portion shown in the sectional view taken along the line AA in FIG. 3.

The manufacturing method of the mold 1 includes a preparation process, a first resist placement process, a first etching process, a first resist peeling process, a second resist placement process, a second etching process, and a second resist peeling process. and a surface treatment step. These steps are performed in this order.

(1) Preparation process The preparation process is a process of preparing the metal member 5 that will become the base material of the mold 1. Examples of the material of the metal member 5 include pure metals such as copper, iron, nickel, molybdenum, titanium, aluminum, and tungsten, composite materials thereof, and alloys of these with additives. The metal member 5 is formed into a plate shape. The thickness of the metal member 5 is approximately the same as the thickness of the mold 1, and is, for example, 0.1 mm or more and 1.0 mm or less.

As shown in FIG. 4, the metal member 5 includes a first surface 51 and a second surface 52 located on the opposite side to the first surface. In this specification, a direction that is parallel to at least a portion of the first surface in a cross-sectional view is defined as a "first direction." Further, in a cross-sectional view, a direction perpendicular to the first direction is defined as a "second direction." In the second direction, the direction from the first surface 51 side to the second surface 52 side is defined as a "second + direction." In the second direction, the direction from the second surface 52 side to the first surface 51 side is defined as a "second direction." In Figure 4, the first direction is the horizontal direction, the second direction is the vertical direction, the second + direction is the upward direction, and the second - direction is the downward direction. That's true.

In the second direction, the second surface 52 is located on the opposite side to the first surface 51. In cross-sectional view, at least a portion of the second surface 52 is parallel to the first direction. The first surface 51 includes the tip surface of the side plate portion 3 in the mold 1. The second surface 52 includes the top surface 21 of the mold 1 and one surface of the connecting portion 4 that is flush with the top surface 21 .

(2) First resist arrangement step The first resist arrangement step is a step of arranging the first resist layer 6 on the first surface 51 so that a part of the first surface 51 is exposed, as shown in FIG. It is. In the manufacturing method according to this embodiment, the first resist layer 6 is arranged not only on the first surface 51 but also on the second surface 52 .

In the manufacturing method according to the present embodiment, as shown in FIG. 4 , the portion of the first surface 51 covered by the first resist layer 6 corresponds to the tip surface of the side plate portion 3 . The "portion corresponding to the tip surface" herein refers to the portion of the first surface 51 that is the sum of the portion that will become the tip surface and a certain area outside of the portion that will become the tip surface. In FIG. 4, the side plate portion 3 of the mold 1 after manufacture is indicated by a chain double-dashed line. It is placed so as to cover the combined area. In a cross-sectional view, the dimension M1 between the outer edge of the first resist layer 6 and the virtual line of the outer edge of the tip surface is, for example, 50 μm or more and 600 μm or less.

The first resist layer 6 is a protective film that is resistant to etching (wet etching) performed in the first etching step. The material of the first resist layer 6 is appropriately selected depending on the etching solution used in the first etching step, and includes, for example, organic materials, inorganic materials, metals, and the like. The method for providing the first resist layer 6 is not particularly limited, and examples thereof include a photoresist method, a screen printing method, a screen offset printing method, and the like. In the first resist placement step according to the present embodiment, a dry film resist formed by a photoresist method is used as the first resist layer 6.

In the first resist placement step according to the present embodiment, the first resist layer 6 is placed over the entire second surface 52 . However, in one embodiment according to the present invention, the etching solution may also be sprayed onto the second surface 52 in the first etching step described below. In this case, the first resist layer 6 may be placed on the second surface 52 so that a portion of the second surface 52 is exposed.

(3) First etching step As shown in FIG. 5, in the first etching step, a first etching solution is sprayed onto a part of the first surface 51 exposed from the first resist layer 6 to remove the first surface. This is a step of forming a side surface 53 extending from the second surface 51 to the second surface 52 and an edge 54 connecting the first surface 51 and the side surface 53. Moreover, in this embodiment, the recessed part 11 surrounded by the side plate part 3 of the mold 1 is also formed by the first etching process.

The edge 54 connecting the first surface 51 and the side surface 53 is defined as the "first edge 54", and the edge connecting the second surface 52 and the side surface 53 is defined as the "second edge 55". When simply referred to as "edge 54", the first edge 54 is meant.

In the first etching step, at least the first surface 51 is spray etched. For example, a spray etching device can be used for the spray etching. The first etching solution used in the spray etching includes, for example, a ferric chloride solution, a cupric chloride solution, a hydrogen peroxide-sulfuric acid etchant, an alkali etchant, and the like.

When using a ferric chloride solution as the first etching solution, the concentration of the first etching solution is preferably 2.7 mol/L or more and 4.3 mol/L or less, more preferably 3 It is .0 mol/L or more and 4.0 mol/L or less. Further, the specific gravity of the first etching solution is preferably 35 degrees Baume or more and 50 degrees Baume or less, more preferably 38 degrees Baume or more and 48 degrees Baume or less.

For example, the spray pressure for spraying the first etching solution during spray etching may be set to 0.3 kg/cm ² or more and 5.0 kg/cm ² . When the spray pressure is 0.3 kg/cm ² or more, the processing time in the first etching step is shortened, and production efficiency is improved. When the spray pressure is 5.0 kg/cm ² or less, the metal member 5 that is removed by the first etching solution can be easily controlled.

When the first etching solution is sprayed onto the metal member 5 from the first surface 51 side, corrosion progresses from the portion exposed from the first resist layer 6. At this time, the side surface 53 has a portion that slopes inward as it progresses from the first edge 54 toward the second + direction. That is, the side surface 53 is formed such that the edge 54 on the first surface 51 is located outside a part of the side surface 53 in cross-sectional view. Further, the side surface 53 has a portion that slopes inward as it progresses from the second edge 55 toward the second direction. That is, the side surface 53 is formed such that the second edge 55 is located outside a part of the side surface 53 in cross-sectional view.

In this embodiment, the second edge 55 is located outside the first edge 54 in the first direction. In one embodiment of the present invention, the second edge 55 may be located closer to the center than the first edge 54 .

(4) First resist peeling process The first resist peeling process is a process of peeling the first resist layer 6 from the first surface 51, as shown in FIG. In the first resist stripping step, the first resist layer 6 is dissolved and stripped from the first surface 51 and the second surface 52 using, for example, a wet station, an ashing device, or the like.

In this embodiment, since the first resist layer 6 is arranged on the first surface 51 and the second surface 52 in the first resist arrangement step, the first resist layer 6 is disposed not only from the first surface 51 but also from the second surface 52. The resist layer 6 is peeled off.

(5) Second resist arrangement step The second resist arrangement step is a step of arranging the second resist layer 7 on the first surface 51 so that a part of the first surface 51 is exposed, as shown in FIG. It is. In the manufacturing method according to this embodiment, the second resist layer 7 is arranged not only on the first surface 51 but also on the second surface 52.

In the second resist placement step, as shown in FIG. 7, the portion of the first surface 51 exposed from the second resist layer 7 includes at least the first edge 54. In this embodiment, the portion exposed from the second resist layer 7 includes a portion including an edge 54 on the first surface 51, which will be described next, and a side surface 53 formed in the first etching step.

Here, in a cross-sectional view, the length from the second resist layer 7 to the first edge 54 in the first direction is defined as "first length dimension L1", and the length from the first edge 54 to the first edge 54 is The maximum length up to a part of the side surface 53 located on the inside is defined as a "second length dimension L2." Further, the point on the side surface 53 when taking the second length dimension L2 is defined as the "apex P".

It is preferable that the second resist layer 7 is arranged such that the first length dimension L1 is longer than the second length dimension L2. More preferably, the first length dimension L1 is set to be 1.3 times or more the second length dimension L2. By doing so, the convex portion including the first edge portion 54 can be easily removed. However, even if the first length dimension L1 is less than or equal to the second length dimension L2, at least a portion of the convex portion including the first edge 54 will be removed after the second etching step described below. A mold 1 having a desired draft angle can be obtained.

On the other hand, the upper limit of the first length dimension L1 is preferably 3.3 times or less the second length dimension L2. By doing so, it becomes easy to control the metal member 5 to be removed by etching. It is more preferable that the upper limit of the first length dimension L1 is twice the second length dimension L2 or less. By doing so, it becomes easier to control the metal member 5 to be removed by etching.

The second resist layer 7 is a protective film that is resistant to etching (wet etching) performed in the second etching step. The material of the second resist layer 7 is appropriately selected depending on the etching solution used in the second etching step, and examples thereof include organic materials, inorganic materials, metals, and the like. The second resist layer 7 may be made of the same material as the first resist layer 6, or may be made of a different material.

As with the first resist layer 6, the method for providing the second resist layer 7 is not particularly limited, and includes, for example, a photoresist method, a screen printing method, a screen offset printing method, and the like. In the second resist placement step according to the present embodiment, an electrodeposited resist formed by a photoresist method is used as the second resist layer 7.

Further, in the second resist placement step according to the present embodiment, the second resist layer 7 is also placed at a position corresponding to the recess 11 of the mold 1, and is also placed over the entire second surface 52. Then, the second resist layer 7 is placed.

(6) Second Etching Step The second etching step is a step of removing the edge portion 54 exposed from the second resist layer 7 using a second etching solution. As shown in FIG. 8, in the second etching step, by removing the edge 54, the outer surface 31 of the mold 1 can be formed into a surface having a desired draft angle.

That is, as shown in FIG. 8, the side surface (outer surface 31 of the mold 1) formed by the second etching step is located on the outer side in the first direction as it goes from the first surface 51 to the second surface 52. As such, it is inclined with respect to the vertical plane. Here, the outer surface 31 is not a flat surface but a curved surface, but a portion of the outer surface 31 may include a flat surface.

The second etching step may be spray etching as in the first etching step as long as the edge portion 54 can be removed with the second etching solution, but in this embodiment, the metal member 5 on which the second resist layer 7 is disposed is etched. is immersed in a second etching solution to remove the edge 54. By performing the second etching step by immersion etching, it becomes easier to adjust the etching rate to a lower value than by spray etching. This facilitates control of the metal member 5 to be removed by etching.

The bath used for immersion etching is preferably a static bath. The term "static bath" as used herein refers to an etching solution used in immersion etching in which the second etching solution is not stirred or circulated. By employing a static bath, the etching rate can be kept close to a constant value, making it easier to control the metal member 5 to be removed by etching.

In order to keep the etching rate close to constant, it is preferable to keep the second etching solution at a constant temperature as much as possible. Specifically, the difference in bath temperature is preferably within 4°C, more preferably within 3°C.

The bath temperature for immersion etching is not particularly limited. The bath temperature for immersion etching is preferably, for example, 20° C. or higher and 40° C. or lower. When the bath temperature for immersion etching is 20° C. or higher, the etching rate becomes faster and production efficiency improves. When the bath temperature of the immersion etching is 40° C. or less, the etching rate is slowed down, so that it becomes easy to control the metal member 5 to be removed by etching. The bath temperature for immersion etching is preferably 25°C or more and 35°C or less. By doing so, it becomes easier to control the shape of the metal member 5 removed by etching while further improving production efficiency.

The second etching solution includes, for example, a ferric chloride solution, a cupric chloride solution, a hydrogen peroxide-sulfuric acid-based etchant, a chlorine sulfate-based etchant, and the like. Among these, when a ferric chloride solution is included as the second etching solution, the specific gravity is preferably 35 degrees Baume or more and 50 degrees Baume or less, and more preferably the specific gravity is 38 degrees Baume or more and 48 degrees Baume or less. In this case, the concentration of the ferric chloride solution is preferably 2.7 mol/L or more and 4.3 mol/L or less, more preferably 3.0 mol/L or more and 4.0 mol/L or less. be.

On the other hand, when the second etching solution contains a cupric chloride solution, the specific gravity is preferably 1.09 or more and 1.42 or less, more preferably 1.19 or more and 1.33 or less. In this case, the concentration of the cupric chloride solution is preferably 0.5 mol/L or more and 3.5 mol/L or less, more preferably 1.5 mol/L or more and 2.5 mol/L. It is as follows.

(7) Second resist peeling process The second resist peeling process is a process of peeling the second resist layer 7 from the metal member 5, as shown in FIG. In the second resist stripping step, as in the first resist stripping step, the second resist layer 7 is dissolved and stripped from the first surface 51 and the second surface 52 using, for example, a wet station, an ashing device, or the like.

(8) Surface Treatment Step The surface treatment step is a step of forming a plating layer on the surface of the metal member 5. This makes it easier for the outer surface 31 of the mold 1 and the hardened resin to separate at the interface. Therefore, when the mold 1 is used and the mold 1 is extracted from the cured resin, the mold 1 can be easily extracted.

In the surface treatment step, it is preferable that a base plating layer is formed on the metal member 5, and then a surface plating layer is formed on the base plating layer. Examples of the base plating layer include a nickel plating layer, a nickel alloy plating layer, or a composite layer thereof. Examples of the surface plating layer include a gold plating layer, a gold alloy plating layer, a chromium plating layer, a nickel plating layer, a nickel alloy plating layer, or a composite layer thereof. Note that the base plating layer may not be provided depending on the hardness of the metal member 5. Further, the surface plating layer may also serve as the base plating layer.

The plating method performed in the surface treatment step is not particularly limited, and may be either a dry plating method or a wet plating method. Examples of the dry plating method include hot-dip plating, vacuum plating, and the like. Examples of the wet plating method include electrolytic plating, electroless plating, and the like.

According to the method for manufacturing the mold 1 according to the present embodiment described above, the edge 54 connecting the first surface 51 and the side surface 53 can be removed. Thereby, the mold 1 having a desired draft angle can be formed. As a result, it is possible to manufacture a mold 1 that is easy to extract from the cured resin. Furthermore, since a plurality of molds 1 can be manufactured simultaneously by etching, the production efficiency of molds 1 can be improved.

<Modified example>
The above embodiment is only one of various embodiments of the present invention. One embodiment of the present invention can be modified in various ways. Modifications of the present invention will be described below. The modified examples described below can be applied in combination as appropriate.

In the method for manufacturing the mold 1 according to the above embodiment, the first etching liquid is sprayed only on the first surface 51 in the first etching step, but for example, in addition to the first surface 51, the second surface The etching solution may also be sprayed onto 52.

In this modification, in the first resist placement step, the first resist layer 6 is placed so that a portion is also exposed on the second surface 52, as shown in FIG. 10(A).

In the first etching step according to this modification, as shown in FIG. 10(B), the first etching liquid is sprayed onto the first surface 51 and the second surface 52. However, in this case as well, the shape of the side surface 53 after the first etching step is such that it is positioned outward from the vertex P toward the second surface 52. For example, the following method can be used to give the side surface 53 a desired shape by the first etching step.

The time for spraying the first etching solution onto the second surface 52 is made shorter than the time for spraying the first etching solution on the first surface 51. For example, the time for spraying the first etching solution on the second surface 52 may be set to 20% or more and 30% or less, more specifically, 25% of the time for spraying the first etching solution on the first surface 51. Can be mentioned.

Further, as another example, the first etching liquid sprayed onto the first surface 51 and the first etching liquid sprayed onto the second surface 52 may have different concentrations, or may have different spray pressures. You can also let Specifically, the concentration of the first etching liquid sprayed onto the second surface 52 may be made lower than that of the first etching liquid sprayed onto the first surface 51, and/or the spray pressure may be reduced. In addition, also in this case, the time for spraying the first etching liquid on the second surface 52 may be shorter than the time for spraying the first etching liquid on the first surface 51.

With these methods, in the first etching step, the first etching liquid can be sprayed onto both the first surface 51 and the second surface 52 to obtain the desired shape.

Other modifications of the embodiment will be listed below.

In the above embodiment, the lead frame 81 is used as the base material, but the base material may be, for example, an electronic board, a metal plate, etc. in addition to the lead frame 81. Furthermore, examples of the light emitting element 82 include an LED light emitting element, a semiconductor laser element, a VCSEL element, and the like. The area to be coated is not limited to the area where the light emitting element 82 is provided, but may be an area where other electronic components are provided, or may be an area on the base material where there is no object such as a component. .

Although the mold 1 according to the above embodiment had the recess 11, the recess 11 may not be provided as long as the mold 1 has the outer surface 31 that contacts the resin during use. Further, although the top plate portion 2 has a substantially rectangular shape in plan view, the present invention is not limited to this, and may have a circular shape, a substantially triangular shape, etc., for example.

In the method for manufacturing the mold 1 according to the embodiment described above, a plurality of molds 1 are manufactured at the same time, but only one mold 1 may be manufactured.

Although the method for manufacturing the mold 1 according to the embodiment described above includes a surface treatment step, the method for manufacturing a mold according to one embodiment of the present invention may not include the surface treatment step.

In this specification, expressions accompanied by "approximately" such as "approximately parallel" or "approximately perpendicular" may be used. For example, "substantially parallel" means that they are substantially "parallel," and not just "parallel," which is a state in which two straight lines, sides, planes, etc. do not intersect even if they are extended, but also several This is a meaning that includes an error of about 1 degree. The same applies to other expressions accompanied by "abbreviation".

Further, in this specification, expressions such as "end" and "end" are used that are distinguished by the presence or absence of "...part". For example, "edge" means the end part of an object, while "edge" means an area having a certain range that includes the "edge." Any point within a certain range that includes the edge is considered to be an "edge." The same applies to other expressions accompanied by "...part".

Hereinafter, the present invention will be explained in more detail through tests using Examples. However, the method for manufacturing the mold 1 according to the present invention is not limited to the following examples.

A test was conducted using the metal member 5 (hereinafter referred to as a test piece) obtained through the first etching process. As shown in FIG. 11, the test piece has a first surface 51, a second surface 52, and a side surface 53 connecting the first surface 51 and the second surface 52. The side surface 53 is concave inward in the first direction from the edge 54 connecting the first surface 51 and the side surface 53 toward the second surface 52, and the closer the side surface 53 is from the apex P to the second surface 52, the more the side surface 53 is concave in the first direction. It is inclined with respect to the vertical plane so that it is located outside of the vertical plane. The length dimension in the first direction between the vertex P and the edge 54 was L2=30 μm.

A second resist layer 7 was placed on the first surface 51 of this test piece. The length dimension L1 in the first direction between the second resist layer 7 and the edge 54 at this time is L1=0 μm, L1=20 μm, L1=40 μm, L1=60 μm, L1=80 μm, L1=100 μm. The second etching process was performed under the following conditions. Note that L1=0 μm is a comparative example, and L1=20 μm, L1=40 μm, L1=60 μm, L1=80 μm, and L1=100 μm are examples.

The conditions for the second etching step are as follows. Etching method: immersion etching, second etching solution: ferric chloride solution, specific gravity: 40 degrees Baume, solution temperature: 30 degrees C., processing time: 8 minutes, static bath.

The cross-sectional shape of the test piece after the second etching step was observed, and the state of the convex portion including 54 edges was evaluated. The results are shown in FIGS. 12(A) to 12(F). FIG. 12(A) shows the cross-sectional shape of the test piece when L1=0 μm. FIG. 12(B) shows the cross-sectional shape of the test piece when L1=20 μm. FIG. 12C shows the cross-sectional shape when L1=40 μm. FIG. 12(D) shows the cross-sectional shape when L1=60 μm. FIG. 12(E) shows the cross-sectional shape when L1=80 μm. FIG. 12(F) shows the cross-sectional shape when L1=100 μm.

As can be seen from FIG. 12A, when the length L1 between the second resist layer 7 and the edge 54 is L1=0 μm, that is, the second resist layer 7 is formed on the entire first surface 51. When , a large convex portion remained. In this case, the convex portion largely protrudes from the outer surface of the mold, making it difficult to remove.

As can be seen from FIG. 12(B), when the length L1 between the second resist layer 7 and the edge 54 is L1=20 μm, that is, 0.7 times the length L2 of the convex portion. In some cases, most of the convex portion including the edge 54 could be removed. This made it possible to easily remove the mold 1 after the resin around the area to be covered had hardened.

As can be seen from FIGS. 12C to 12F, when the length L1 between the second resist layer 7 and the edge 54 is 40 μm or more, that is, with respect to the dimension L2 of the convex portion, , 1.3 times or more, all the convex parts could be removed. On the other hand, as can be seen from FIG. 12(F), when the length L1 between the second resist layer 7 and the edge 54 is L1 = 100 μm, all the convex portions can be removed, but corrosion may occur. It went too far and a slight dent was formed on the side surface 53. When the dimension L1 is equal to or less than 100 μm, that is, when it is equal to or less than 3.3 times the dimension L2 of the convex portion, it becomes easy to control the metal member 5 to be removed by etching.

As can be seen from FIGS. 12(C) and (D), when the length dimension L1 between the second resist layer 7 and the edge 54 is L1=40 μm and L1=60 μm, that is, when the length dimension L2 of the convex portion On the other hand, in the case of 1.3 times or more and 2 times or less, all the convex portions could be removed without creating a dent in the side surface 53.

1 Mold 5 Metal member 51 First surface 52 Second surface 6 First resist layer 7 Second resist layer 53 Side surface 54 First edge (edge)

Claims (12)

A mold manufacturing method for manufacturing a mold from a metal member, the method comprising:
preparing a metal member having a first surface and a second surface located on the opposite side of the first surface;
arranging a first resist layer inside a portion of the first surface so that a portion of the first surface that is a portion located outside the mold is exposed;
A first etching solution is sprayed onto a portion of the first surface exposed from the first resist layer to form a side surface extending from the first surface to the second surface and an edge connecting the first surface and the side surface. a step of forming the side surface such that the edge portion is located outside the innermost portion of the side surface in cross-sectional view ;
Peeling the first resist layer from the first surface;
arranging a second resist layer on the first surface so that a portion of the first surface including the edge is exposed;
removing a portion outside the second resist layer using a second etching solution;
in order,
The step of removing the portion outside the second resist layer includes removing the portion outside the second resist layer using the second etching solution, thereby making the side surface after the removal the same as the side surface. Formed so as to be located outward from the edge connecting the first surface toward the second surface;
Mold manufacturing method. In the step of arranging the second resist layer, a first length dimension from the edge to the second resist layer in a first direction parallel to the first surface in a cross-sectional view is equal to the first length dimension in the first direction. longer than a second length dimension, which is the maximum length from the edge to a part of the side surface located inside the edge;
A method for manufacturing a mold according to claim 1 . The first length dimension is 1.3 times or more and 3.3 times or less of the second length dimension,
A method for manufacturing a mold according to claim 2 . the first length dimension is not more than twice the second length dimension;
A method for manufacturing a mold according to claim 3 . In the step of removing a portion outside the second resist layer , the metal member is immersed in the second etching solution to remove the edge.
A method for manufacturing a mold according to any one of claims 1 to 4 . The mold manufacturing method according to claim 5 , wherein in the step of removing the portion outside the second resist layer , a temperature difference of the second etching solution is within 4°C. In the step of removing a portion outside the second resist layer , the second etching solution is a static bath;
The method for manufacturing a mold according to claim 5 or 6 . In the step of removing the portion outside the second resist layer , the second etching solution contains a ferric chloride solution with a specific gravity of 35 degrees Baume or more and 55 degrees Baume or less.
A method for manufacturing a mold according to any one of claims 5 to 7 . In the step of removing a portion outside the second resist layer , the second etching solution has a cupric chloride solution with a concentration of 1 mol/L or more and 4 mol/L or less.
A method for manufacturing a mold according to any one of claims 5 to 7 . In the step of removing the portion outside the second resist layer , the temperature of the second etching solution is 20° C. or more and 40° C. or less,
A method for manufacturing a mold according to any one of claims 5 to 9 . After the step of removing the portion outside the second resist layer , the method further includes the steps of peeling off the second resist layer, and forming a plating layer on the surface of the metal member.
A method for manufacturing a mold according to any one of claims 1 to 10 . The plating layer includes any one of a gold plating layer, a gold alloy plating layer, a nickel plating layer, a nickel alloy plating layer, and a chromium plating layer.
The method for manufacturing a mold according to claim 11 .

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