JP2005256065A - Electrically conductive film with through hole formed and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electrically conductive films in which fine through holes are formed with high controllability, and to provide a method for producing the same. <P>SOLUTION: The method for producing electrically conductive films in which through holes are formed comprises: a stage wherein a plurality of masks 11 are formed on a main face 10a of a substrate 10 at intervals; a stage wherein films each composed of an electrically conductive material are grown from the parts in which the masks 11 are not formed in the main face 10a of the substrate 10 by a plating method, thus electrically conductive films 12 in which through holes 12a with a size of ≤20 μm are formed at the parts located in the upper direction of the center in each mask 11 are formed; and a stage wherein the substrate 10, the masks 11 and the electrically conductive films 12 are separated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a conductive film in which a through hole is formed and a method for manufacturing the conductive film.

  As a method for producing a porous metal film or metal plate having fine through holes in a predetermined pattern, a method using electrolytic plating has been reported. For example, in Japanese Patent Application Laid-Open No. 9-136422 (Patent Document 1), after forming a pattern with a photoresist on a matrix, electrolytic plating is performed in two stages, thereby obtaining a hole diameter of the same size (40 μm) as the photoresist. A through-hole metal plate is manufactured. Further, in the literature (Science, Vol. 268, pp. 1466-1468, 9 June 1995), a through-hole metal film is manufactured by a two-step mold process including electrolytic plating using anodized alumina as a matrix. .

  However, in these manufacturing methods, the pore diameter of the through hole is not controlled by the electrolytic plating process.

  In particular, in the latter case, only a through-hole metal film having a limited pore size size possessed by anodized alumina can be produced. Furthermore, there are drawbacks that the manufacturing process is complicated and that the manufacturing process consists of multiple stages.

As a method of manufacturing a porous fine through-hole metal film or metal plate using a method other than plating, a manufacturing method has been proposed in which holes are formed in a metal foil by etching or punching. For example, in JP-A-6-52794 (Patent Document 2), holes are formed by etching, and in JP-A-10-202594 (Patent Document 3), holes are formed by punching. It was as large as several tens of μm (for example, 30 μm in Patent Document 3), and the pore diameter was not controlled.
JP-A-9-136422 JP-A-6-52794 Japanese Patent Laid-Open No. 10-202594 Science, Vol. 268, pp. 1466-1468,9 June 1995

  In view of the above situation, an object of the present invention is to provide a conductive film in which fine through holes are formed with good controllability by a simple method using plating, and a method for manufacturing the conductive film.

  In order to achieve the above object, the present invention provides a conductive film made of a conductive material and having a plurality of through holes formed at desired intervals, wherein the through holes are formed with a size of 20 μm or less. A conductive film.

  In one embodiment, the conductive material is nickel.

  In one embodiment, the size of the through hole is 3 to 8 μm.

  Further, in the manufacturing method of the present invention, (i) a step of forming a plurality of masks on one main surface of the substrate at intervals, and (ii) the mask is not formed on the one main surface of the substrate. Forming a conductive film in which a through hole having a size of 20 μm or less is formed in a portion located above the center of the mask by growing a film made of a conductive material from the portion by plating; iii) A method for producing a conductive film in which a through hole is formed, comprising the step of separating the substrate and the mask from the conductive film.

  In one embodiment, the planar shape of the mask is a rectangular shape with one side of 150 μm or more.

  In one embodiment, a plurality of the masks are arranged at intervals of 50 μm or less.

  In one embodiment, in the step (i), the mask is formed on one main surface of the substrate using a lithography method.

  In one embodiment, the substrate is a conductive substrate, and the plating method is an electrolytic plating method.

  In one embodiment, the conductive material is nickel.

  In one embodiment, in the step (ii), plating is performed while increasing the current value of electrolytic plating.

  In one embodiment, in the step (iii), the substrate, the mask, and the conductive film are separated by immersing them in an alkaline solution.

According to the present invention, a conductive film in which fine through holes having a size of 20 μm or less are formed with good controllability can be easily obtained. In the present specification, the size of the through hole means the maximum diameter of the circle when the through hole is substantially circular, and the maximum size of the rectangle when the through hole is substantially rectangular. Means the length of the side of
The material of the conductive film is applicable as long as it can be plated. That is, the degree of freedom in selecting the pore structure and the material is high, and this makes it possible to improve the function as a porous material including a diaphragm, a filter, and an electrode, and to increase the usefulness thereof. In addition, the manufacturing process is small and simple, and the manufacturing cost can be reduced.

  Embodiments of the present invention will be specifically described below.

  The conductive film of the present invention and the manufacturing method thereof will be described.

  The conductive film of the present invention is a conductive film made of a conductive material and having a plurality of through holes formed at desired intervals, and the size of the through holes is 20 μm or less (for example, 1 μm to 20 μm). Preferably, the size of the through hole is 10 μm or less, more preferably 3 to 8 μm.

  As the conductive material, for example, various metals and semiconductors including nickel, gold, and copper can be used. Among these, nickel is preferable because it can be easily formed by plating.

  Since the growth of plating proceeds at a constant speed in all directions (substrate plane direction and film thickness direction), the thickness of the conductive film of the present invention is a maximum of the mask thickness plus half the length of the side of the mask plane. It will be. Therefore, when the side length of the mask plane is 150 μm or more, a conductive film having a thickness of about 100 μm or more can be obtained.

  As will be described later, the process of separating the conductive film is facilitated by increasing the length of the side of the mask plane.

  Further, by setting the thickness of the conductive film to 100 μm or more, the conductive film can be handled as a free-standing film at the same time.

  A through hole having a size of 20 μm or less is formed in the conductive film of the present invention. The size of the through hole is preferably 10 μm or less, and more preferably 3 to 8 μm.

  Usually, the through holes are formed in a desired size and a desired arrangement. For example, the through holes have a size error of 10% or less, and are arranged at intervals of 200 μm to 1000 μm. Although there is no limitation on the arrangement of the through holes, for example, they are arranged in a matrix (lattice).

  Hereinafter, the manufacturing method of the electrically conductive film of this invention is demonstrated based on FIG.

  In the manufacturing method of the present invention, first, as shown in FIG. 1B, a plurality of masks 11 are formed on one main surface 10a of the substrate 10 (step (i)).

  As the substrate 10, various substrates 10 can be used. When the conductive film 12 is formed by an electrolytic plating method, a conductive substrate 10 such as stainless steel is used.

  The mask 11 can be formed by, for example, photolithography. Although the material according to the formation method can be used for the material of the mask 11, it does not raise | generate peeling etc. in the plating process (ii) mentioned later, and also the isolation | separation process of the electrically conductive film 12 from the board | substrate 10 mentioned later. In (step (iii)), it is necessary to use a material that can be easily separated by dissolution or the like. Specifically, for example, those using cresol nomorac resin as a base material can be used.

  The mask 11 is formed in a predetermined shape and arrangement according to the desired thickness of the conductive film 12 to be formed, the size of the through hole 12a, and the like. For example, rectangular masks 11 such as squares are arranged on the matrix at regular intervals.

  In an example of the method of the present invention, the planar shape of the mask 11 is a rectangular shape having a side of 150 μm or more (for example, 214 μm). In an example of the method of the present invention, the plurality of masks 11 are arranged at intervals of 50 μm or less (for example, 40 μm).

  Of the one main surface 10a, the area where the mask 11 is formed is larger than the area where the mask 11 is not formed. The ratio of “area where mask is formed” / “area where mask is not formed” is preferably set to 1.5 or more. By setting the ratio to this value, the conductive film 12 formed in the step (iii) can be easily peeled from the substrate 10 and the mask 11. That is, since the connection surface of the conductive film 12 formed on the substrate 10 is less likely to be peeled off from the surface of the substrate 10 than the mask 11, the substrate 10 of the conductive film 12 is set by setting the area ratio of the connection surface small. The releasability from the surface can be improved.

  Next, as shown in FIG. 1C, a film made of a conductive material is grown by plating from a portion of the main surface 10a of the substrate 10 where the mask 11 is not formed. As a result, as shown in FIG. 1D, the conductive film 12 is formed in which the through hole 12 a having a size of 20 μm or less is formed in a portion located above the central portion of the mask 11.

  As the conductive material, the above-described materials can be used. Plating may be performed by either electrolytic plating or electroless plating.

  In the case of electrolytic plating, it is preferable to perform plating while increasing the current value of electrolytic plating. This is because the surface area of the conductive film 12 increases as the plating grows, so that the current density during plating is substantially constant.

  The conductive film 12 grows from a portion where the mask 11 is not formed, and grows so as to cover the mask 11. Plating is performed until the through hole 12a has a desired size.

  The method of the present invention is characterized in that the size of the through hole 12a is controlled by controlling the plating. The size of the through hole 12a can be controlled, for example, by controlling the plating bath and the plating time. Further, the size of the through hole 12a may be controlled by plating while monitoring the size of the through hole 12a with a microscope.

  Next, the substrate 10 and the mask 11 are separated from the conductive film 12 (step (iii)). The separation method is not particularly limited, and can be performed, for example, by immersing the substrate 10, the mask 11, and the conductive film 12 in an alkaline solution. With such a method, there is an advantage that the mask 11 is dissolved and the conductive film 12 is peeled off from the surface of the substrate 10 to easily obtain the conductive film 12.

  In this manner, as shown in FIG. 2, a conductive film 22 having a through hole 22a having a size of 20 μm or less is obtained. In FIG. 2, a dashed line indicates a portion where the mask is present. In the method of the present invention, the arrangement and size of the through holes 12a can be easily controlled by the arrangement of the mask 11 and the plating method. Further, in the method of the present invention, since the conductive film 12 can be formed by one-step plating and can be easily peeled off, the conductive film 12 in which the through holes 12a are formed can be formed at low cost.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to the following Example.
Example 1
On a stainless steel (SUS304) substrate, a photoresist (XP-20602, Zipley) was applied with a thickness of 5 μm by a spin coater. After drying at 90 ° C. for 25 minutes, a square lattice pattern was exposed at a cycle of 254 μm. Development was performed to leave a 214 μm square photoresist pattern, and the other portions were removed. This was subjected to nickel electroplating in a plating bath (nickel sulfamate 450 g / liter, boric acid 35 g / liter) at 50 ° C. for 11.5 hours. At this time, the current value was increased stepwise from 500 mA (1 hour) to 600 mA (0.5 hours), 800 mA (2 hours), 1000 mA (4 hours), and 1200 mA (4 hours).

  Thereafter, the stainless steel substrate and the photoresist were removed from the nickel plating layer by dipping in 5% NaOH at 40 ° C. for 2 minutes.

  As a result, a porous fine through-hole nickel film having a pore interval of 254 μm and a pore diameter of 5 μm arranged in a square lattice at equal intervals was obtained.

  Each through hole had an ideal regular arrangement, and the uniformity of the pore diameter was also good.

  The present invention relates to filters, printing screens, various jet nozzles such as inkjet nozzles, cathode ray tube shadow masks, aperture grills, IC leads, fluorescent display meshes, electromagnetic wave shielding sheets, diaphragms (for example, diaphragms for solar hydrogen production equipment) ), And can be applied to electrodes.

It is process sectional drawing which shows an example of the manufacturing method of this invention typically. It is a top view which shows the state of FIG.1 (d).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate 10a One main surface 11 Mask 12, 22 Conductive film 12a, 22a Through hole

Claims (11)

A conductive film made of a conductive material and having a plurality of through holes formed at desired intervals,
A conductive film in which a through hole is formed, wherein the size of the through hole is 20 μm or less. The conductive film according to claim 1, wherein the conductive material is nickel. The conductive film according to claim 1, wherein a thickness of the conductive film is 100 μm or more, and a size of the through hole is 3 to 8 μm. (i) forming a plurality of masks at intervals on one main surface of the substrate;
(ii) A through hole having a size of 20 μm or less is formed at the center of the mask by growing a film made of a conductive material from a portion of the main surface of the substrate where the mask is not formed by plating. Forming a conductive film formed in a portion located above;
(iii) separating the substrate and the mask from the conductive film;
The manufacturing method of the electrically conductive film in which the through hole was formed including this. The method for producing a conductive film having a through hole according to claim 4, wherein the planar shape of the mask is a rectangular shape having a side of 150 μm or more. The method for producing a conductive film in which through holes are formed according to claim 4, wherein the plurality of masks are arranged at intervals of 50 μm or less. The method for manufacturing a conductive film having a through hole according to any one of claims 4 to 6, wherein, in the step (i), the mask is formed on one main surface of the substrate using a lithography method. The method for producing a conductive film having a through hole according to any one of claims 4 to 7, wherein the substrate is a conductive substrate, and the plating method is an electrolytic plating method. The method for producing a conductive film having a through hole according to claim 8, wherein the conductive material is nickel. The method for producing a conductive film having a through hole according to claim 8 or 9, wherein in the step (ii), plating is performed while increasing a current value of electrolytic plating. 11. The conductive film having a through hole according to claim 4, wherein in the step (iii), the substrate, the mask, and the conductive film are separated by being immersed in an alkaline solution. Production method.

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