JP3783030B2 - Manufacturing method of mold for fine hole punching - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a fine hole punching mold used for making fine holes in a printed wiring board for IC, LSI, etc., as well as a resin sheet, a thin metal sheet such as gold, silver, aluminum, nickel, etc. About.
[0002]
[Prior art]
Conventionally, as a processing method for making a fine hole in a printed wiring board or a resin sheet, there are a method of irradiating a point with a laser or a method of drilling a point with a drill.
[0003]
[Problems to be solved by the invention]
However, the above-described conventional fine hole drilling method has a drawback that it takes time to punch holes, and the hole punching cost is high.
[0004]
The object of the present invention is to solve such problems, and it is possible to easily produce a fine hole punching mold that can make fine holes in a printed wiring board or a resin sheet at a low processing cost. It is in providing the manufacturing method of the metal mold | die for punching.
[0005]
[Means for Solving the Problems]
In the present invention, when manufacturing a fine hole punching die having a punch portion 2 integrally projecting on one side of a base portion 1, a step of arranging a photoresist 4 on the surface of a mother die 3 as shown in FIG. And a step of placing the pattern film 5 on the surface of the photoresist 4 and exposing it, and then developing it to form a photoresist film 7 having an opening 6 for forming a punch portion, and the surface of the photoresist film 7 and A step of forming a conductive coating 9 on the inner surface of the opening 6; a step of electroforming the surface of the conductive coating 9 to integrally form the base portion 1 and the punch portion 2; and the matrix And the step of peeling the base part 1 together with the punch part 2 from the side 3.
[0006]
In manufacturing the fine hole punching die in which the punch portion 2 is integrally projected on one surface of the base portion 1, the present invention provides a step of arranging a photoresist 4 on the surface of the mother die 3 as shown in FIG. 5. A pattern film 5 placed on the surface of the photoresist 4 and exposed to light, followed by development to form a photoresist film 7 having a convex portion 6 'corresponding to the pattern of the punch portion; A step of forming a primary electrodeposition layer 16 on the surface not covered with the photoresist film 7; and removing the photoresist film 7 to form a concave portion 17 for forming a punch portion on the surface of the primary electrodeposition layer 16 A step of performing a peeling process on the surface of the primary electrodeposition layer 16, and a secondary electroforming on the surface of the primary electrodeposition layer 16 to electrodeposit the base portion 1 and the punch portion 2 together. Forming the base portion 1 from the primary electrodeposition layer 16; Characterized in that comprising the step of each copy 2 stripping.
[0007]
In the present invention, when manufacturing a fine hole punching die in which a punch portion 2 is integrally projected on one side of a base portion 1, a step of arranging a photoresist 4 on the surface of a mother die 3 as shown in FIG. A pattern film 5 placed on the surface of the photoresist 4 and exposed to light, followed by development to form a photoresist film 7 having an opening 6 corresponding to the pattern of the punched portion; A step of etching a surface not covered with the resist film 7 to form a concave portion 17 for forming a punch portion; a step of removing the photoresist film 7; and a step of performing a peeling process on the surface of the mother die 3 And forming the base part 1 and the punch part 2 integrally by electroforming on the surface of the mother die 3 and peeling the base part 1 together with the punch part 2 from the mother die 3. It is characterized by that.
[0008]
[Action]
Since the diameter and pitch of the punch portion 2 are regulated by the photoresist film 7, the precise punch portion 2 having excellent reproducibility can be obtained.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 2 shows a part of a fine hole punching die, in which one or a plurality of punch portions 2 are integrally projected at a predetermined pitch on one side of a flat base portion 1. The punch part 2 is formed in a taper shape, and is rounded on the peripheral edge 2a and the base part 2b of the tip part of the punch part 2 respectively. For example, the length A of the punch portion 2 is 30 to 300 μm, and the diameter B of the base portion 2b of the punch portion 2 is 70 to 500 μm. The cross-sectional shape of the punch portion 2 is not limited to a circular shape, and can be applied to various shapes such as a triangle and a star.
[0010]
FIGS. 1A to 1E show process diagrams for obtaining an electroformed product of such a fine hole punching mold. First, as shown in FIG. 1A, a photoresist 4 is arranged on the surface of the mother die 3. This matrix 3 is rigid, such as a metal body, a synthetic resin body, or glass, regardless of the surface conductivity, and has chemical affinity with the photoresist 4 used in the next step. Anything is acceptable. Next, as shown in FIG. 1B, a desired pattern film 5 is placed on the surface of the photoresist 4 and exposed, and then developed to form a photoresist film 7 having an opening 6 having a trapezoidal cross section for forming a punch portion. It is formed (FIG. 1C). At that time, the opening edge 6a of the opening 6 corresponding to the base portion 2b of the punch portion 2 is bent by applying heat to bend. Further, a low-resolution photoresist 4 is used for the corner 8 where the inner wall of the opening 6 and the matrix 3 intersect, which corresponds to the peripheral edge 2a of the front end portion of the punch portion 2, or overexposure or development capability is achieved. It is possible to put a round by lowering.
[0011]
Next, as shown in FIG. 1D, a conductive film 9 such as a silver thin film is formed on the surface of the photoresist film 7 and the inner surface of the opening 6 by silver mirror reaction or vapor deposition. Next, in a normal nickel sulfamate bath, as shown in FIG. 1E, nickel electroforming is performed to a height exceeding the depth of the opening 6, so that the punch 2 is electroformed in the opening 6. At the same time, the base portion 1 is electrodeposited integrally with the punch portion 2 on the surface of the conductive film 9. Finally, the base part 1 is peeled from the conductive film 9 together with the punch part 2 to obtain a fine hole punching die as shown in FIG.
[0012]
Recent printed wiring boards have a very thin pattern of 3 to 5 lines / mm, and the hole at the end of the pattern is also extremely small in diameter. Such small-diameter drilling, for example, when drilling between the patterns between the front and back surfaces of a sheet-like double-sided printed wiring board in which a double-sided copper foil is stretched on a polyimide sheet, Since it can be mass-produced by punching press using a punching die, the drilling cost can be greatly reduced.
The punch portion 2 is formed in a tapered shape, and when the peripheral edge 2a and the base portion 2b of the front end portion of the punch portion 2 are respectively rounded, the punch portion 2 is copper-clad on both front and back surfaces as shown in FIG. When the double-sided printed wiring board 10 is driven, the communication hole 11 can be formed, and at the same time, a part 12a of the copper 12 at the punching position on the surface of the double-sided printed wiring board 10 breaks through the tip of the punch part 2. As it is extended, it can enter the cylindrical shape into the communication hole 11, and a state in which a part 12 a into which the copper 12 enters is brought into contact with the copper 13 on the back surface side can be obtained. Therefore, after forming the communication hole 11 as in the prior art, it is possible to omit the solder plating work necessary for conducting the copper 12 on the front surface side and the copper 13 on the back surface side.
[0013]
In this case, as shown in FIG. 4, the base portion 1 is attached and set to a press holder 14 of a press die set, but the die 15 that supports the double-sided printed wiring board 10 facing the punch portion 2 is hard ( If it is made of urethane rubber having a Shore hardness of 70 to 80 °, the configuration of the press die set is simplified. Moreover, when it is necessary to surely break through the copper 13 on the back surface side of the double-sided printed wiring board 10, a die plate in which holes corresponding to the punch portions 2 are arranged may be used. For example, when the punch accuracy with the punch portion 2 is to be high, a slightly thicker electroforming along the uneven shape is again applied to the surface of the mother die 3 after the base portion 1 in FIG. Just do it. In the above embodiment, the conductive film 9 after peeling off the punch portion 2 remains on the side of the mother die 3, but this conductive film 9 is coated with a brightening agent such as Co alloy with tungsten or nickel or sulfur. If a conductive metal material having a high hardness such as nickel is used and is made to coexist on the punch portion 2 side at the time of peeling, the surface hardness of the punch portion 2 can be increased and the durability can be improved. it can.
[0014]
(Second embodiment)
A second embodiment of the present invention will be described with reference to FIG. FIGS. 5A to 5G are process diagrams for obtaining an electroformed product of a fine hole punching die. First, as shown in FIG. 5A, a photoresist 4 is arranged on the surface of a SUS matrix 3. Next, as shown in FIG. 5B, a desired pattern film 5 is placed on the surface of the photoresist 4 and exposed to light. Then, development is performed and a photo having a convex portion 6 'having a cross-sectional warhead shape corresponding to the punch pattern. A resist film 7 is formed by patterning (FIG. 5C). At that time, the corner 8 that is in contact with the base 3 of the convex portion 6 ′ corresponding to the peripheral edge 2 a of the front end portion of the punch portion 2 is so deep that it is difficult for the ultraviolet rays to reach the portion and hard to be cured. Can be attached to.
[0015]
Next, in a normal nickel sulfamate bath, a primary electrodeposition layer 16 is formed on the surface not covered with the photoresist film 7 of the matrix 3 as shown in FIG. Next, as shown in FIG. 5E, the photoresist film 7 is removed to form a recess 17 for forming the punch portion 2 in the primary electrodeposition layer 16. Next, the entire surface including the inner surface of the concave portion 17 of the primary electrodeposition layer 16 is subjected to a peeling treatment. Next, secondary nickel electroforming is performed on the primary electrodeposition layer 16 to electrodeposit the punch portion 2 in the recess 17 as shown in FIG. The base portion 1 is electrodeposited integrally with the punch portion 2 on the surface. Finally, the base part 1 is peeled off from the primary electrodeposition layer 16 together with the punch part 2 to obtain a fine hole punching die as shown in FIG. Since the primary electrodeposition layer 16 is peeled off from the mother die 3 and this primary electrodeposition layer 16 has a concave portion 17 corresponding to the punch portion 2, the copper 13 on the back surface side of the double-sided printed wiring board 10 is attached as described above. However, in the case where it is necessary to pierce reliably, it can be used as a die plate in which a concave portion corresponding to the punch portion 2 is arranged.
[0016]
( Reference example)
A reference example of the present invention will be described with reference to FIG. 6 (A) to 6 (G) show process diagrams for obtaining an electroformed product of a fine hole punching mold. First, as shown in FIG. 6A, a photoresist 4 is arranged on the surface of a SUS matrix 3. Next, as shown in FIG. 6B, a desired pattern film 5 is placed on the surface of the photoresist 4 and exposed, and then developed to have a cross-sectional warhead-shaped opening 6 corresponding to the punch pattern. A film 7 is formed. (FIG. 6C). Next, as shown in FIG. 6D, the surface of the matrix 3 that is not covered with the photoresist film 7 is etched to form a recess 17 for forming the punch portion 2. At this time, the radius can be easily attached to the inner bottom corner of the recess 17 by etching.
[0017]
Next, as shown in FIG. 6E, the photoresist film 7 is removed, and the entire surface including the concave portion 17 of the mother die 3 is subjected to a peeling process. Next, in a normal nickel sulfamate bath, nickel electroforming is performed on the surface of the mother die 3 as shown in FIG. 6 (F), and the punch portion 2 is electrodeposited in the concave portion 17. The base portion 1 is electrodeposited integrally with the punch portion 2 on the surface. Finally, by peeling the base portion 1 together with the punch portion 2 from the mother die 3, a die for fine hole punching as shown in FIG. 6G can be obtained. Since the mother die 3 has the concave portion 17 corresponding to the punch portion 2, the punch portion is required when the copper 13 on the back surface side of the double-sided printed wiring board 10 needs to be pierced as in the case of the second embodiment. 2 can be used as a die plate in which concave portions corresponding to 2 are arranged.
[0018]
【The invention's effect】
According to the present invention, it is possible to easily obtain a precise punch portion 2 by electroforming a fine hole punching die that can make fine holes at low processing cost.
[Brief description of the drawings]
FIG. 1 is a manufacturing process diagram of a fine hole punching die according to a first embodiment.
FIG. 2 is an enlarged cross-sectional view of a part of the fine hole punching die according to the first embodiment.
FIG. 3 is a partial cross-sectional view showing an example of use of a fine hole punching die.
FIG. 4 is an overall front view showing a usage example of a fine hole punching die.
FIG. 5 is a manufacturing process diagram of a fine hole punching die according to a second embodiment.
FIG. 6 is a manufacturing process diagram of a fine hole punching die of a reference example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base part 2 Punch part 3 Master mold 4 Photoresist 5 Pattern film 6 Opening part 6 'Convex part 7 Photoresist film 9 Conductive film 16 Primary electrodeposition layer 17 Concave part

Claims (2)

A step of disposing a photoresist 4 on the surface of the mother die 3 in manufacturing a fine hole punching die having a punch portion 2 integrally projecting on one side of the base portion 1;
A step of placing the pattern film 5 on the surface of the photoresist 4 and exposing it, and then developing to form a photoresist film 7 having an opening 6 for punch portion molding;
Forming a conductive film 9 on the surface of the photoresist film 7 and the inner surface of the opening 6;
Electroforming the surface of the conductive film 9 and electrodepositing the base portion 1 and the punch portion 2 together;
A method for producing a fine hole punching mold comprising a step of peeling the base part 1 together with the punch part 2 from the mother die 3 side ,
In the step of forming the photoresist film 7, a low-resolution photoresist 4 is used, or overexposure is performed, or the developing ability is reduced, so that the peripheral edge 2a of the front end portion of the punch portion 2 is rounded. The manufacturing method of the metal mold | die for fine hole punching characterized by attaching | subjecting. A step of disposing a photoresist 4 on the surface of the mother die 3 in manufacturing a fine hole punching die having a punch portion 2 integrally projecting on one side of the base portion 1;
A step of placing the pattern film 5 on the surface of the photoresist 4 and exposing it, and developing to form a photoresist film 7 having a convex portion 6 'corresponding to the pattern of the punch portion;
Forming a primary electrodeposition layer 16 on the surface of the matrix 3 not covered with the photoresist film 7;
Removing the photoresist film 7 to form a concave portion 17 for forming a punch portion on the surface of the primary electrodeposition layer 16;
Performing a peeling treatment on the surface of the primary electrodeposition layer 16;
Secondary electroforming on the surface of the primary electrodeposition layer 16 to integrally form the base portion 1 and the punch portion 2;
A method for producing a fine hole punching mold comprising a step of peeling the base part 1 together with the punch part 2 from the primary electrodeposition layer 16 ;
In the step of forming the photoresist film 7, since ultraviolet rays do not reach the corner 8 in contact with the base 3 of the convex portion 6 ′ sufficiently, an edge is attached to the peripheral edge 2 a of the tip portion of the punch portion 2. The manufacturing method of the metal mold | die for fine hole punching characterized by the above-mentioned.

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