JP2018076549A - Method for manufacturing substrate with film and etching solution for metal film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a substrate with a film, by which a tapered angle of a metal film patterned by etching can be closer to a right angle.SOLUTION: The method for manufacturing a substrate with a film includes: a step of forming a metal film 3 on a substrate 2; a step of forming a patterned resist film on the metal film 3; and a step of patterning the metal film 3 by using an etching solution. The etching solution contains hydrogen peroxide by 0.5 to 12 mass% and sulfuric acid by 0.05 to 1.0 mass%, with a mass ratio ((mass of hydrogen peroxide)/(mass of sulfuric acid)) of the hydrogen peroxide to the sulfuric acid is 6 or more and 70 or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a film-coated substrate in which a patterned metal film is provided on the substrate, and a metal film etching solution used in the method for manufacturing the film-coated substrate.

  In electrical appliances including displays and the like, higher functionality, lighter weight, or larger screens are being promoted. Along with this, the wiring electrodes are densified. In the capacitive touch panel, as the screen is enlarged, the operation electrode is being replaced by a metal mesh such as silver or copper having a low resistance from a transparent conductive film such as ITO. The metal mesh is printed on the surface of a transparent substrate such as a glass plate or a resin substrate using nano ink, or a pattern is formed on the metal film formed on the surface of the transparent substrate using a photoresist or the like. It is manufactured by etching a film.

  Patent Document 1 below discloses a method of patterning a printed wiring board by etching in a state where a resist is laminated on a metal film provided on a resin substrate. In Patent Document 1, the metal film is etched with an etchant containing hydrogen peroxide and sulfuric acid as main components and further containing amines and azines as additives.

JP 2006-13307 A

  However, when the metal film is patterned with the etching solution of Patent Document 1, the cross-sectional shape of the patterned metal film becomes a trapezoid. In order to obtain the required electrical resistance, the cross-sectional area of the metal film is wired as a predetermined value. Therefore, when the angle (taper angle) between the side of the trapezoid and the base is reduced, Need to be long. Then, the wiring becomes thick. Further, if the wiring interval is not sufficiently provided, the wiring may come into contact (short circuit) when etching is insufficient. For this reason, it has been difficult to achieve finer and higher density circuit patterns.

  The objective of this invention is providing the manufacturing method of the board | substrate with a film | membrane which makes it possible to make the taper angle of the metal film patterned by the etching close to right angle, and the etching liquid for metal films.

  The method for manufacturing a substrate with a film according to the present invention includes a step of forming a metal film on the substrate, a step of forming a patterned resist film on the metal film, and the metal film using an etching solution. And the etching solution contains 0.5 to 12% by mass of hydrogen peroxide and 0.05 to 1.0% by mass of sulfuric acid, and the mass of the hydrogen peroxide with respect to the sulfuric acid. The ratio (mass of hydrogen peroxide / mass of sulfuric acid) is 6 or more and 70 or less.

  In the method for manufacturing a film-coated substrate according to the present invention, the mass ratio of hydrogen peroxide to the sulfuric acid (the mass of hydrogen peroxide / the mass of sulfuric acid) is preferably 9 or more and 60 or less.

  In the method for manufacturing a substrate with a film according to the present invention, the metal film preferably contains copper or a copper alloy.

  In the manufacturing method of the board | substrate with a film | membrane which concerns on this invention, it is preferable that the said copper is electrolytic copper foil or plated copper.

  In the method for manufacturing a film-coated substrate according to the present invention, the substrate is preferably a glass substrate.

  The metal film etching solution according to the present invention is a metal film etching solution for patterning a metal film by etching, and contains 0.5 to 12 mass% hydrogen peroxide and 0.05 to 1.0 mass. % Of sulfuric acid, and a mass ratio of hydrogen peroxide to sulfuric acid (mass of hydrogen peroxide / mass of sulfuric acid) is 6 or more and 70 or less.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a board | substrate with a film | membrane and the etching liquid for metal films which make it possible to make the taper angle of the metal film patterned by the etching close to right angle can be provided.

It is typical sectional drawing for demonstrating the manufacturing method of the board | substrate with a film | membrane which concerns on one Embodiment of this invention. It is typical sectional drawing for demonstrating the manufacturing method of the board | substrate with a film | membrane which concerns on one Embodiment of this invention. It is typical sectional drawing for demonstrating the manufacturing method of the board | substrate with a film | membrane which concerns on one Embodiment of this invention.

  Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Moreover, in each drawing, the member which has the substantially the same function may be referred with the same code | symbol.

(Manufacturing method of substrate with film)
1 to 3 are schematic cross-sectional views for explaining a method for manufacturing a film-coated substrate according to an embodiment of the present invention.

  First, the film-coated substrate 1 shown in FIG. 1 will be described. The substrate with film 1 includes a substrate 2 and a metal film 3 provided on the substrate 2. The metal film 3 is a patterned metal film.

  As the substrate 2, a glass substrate or a resin substrate can be used.

  The material of the glass substrate is not particularly limited, and examples thereof include soda lime glass and alkali-free glass, and may be aluminosilicate glass used as tempered glass.

  The material of the resin substrate is not particularly limited, and examples thereof include polyethylene terephthalate (PET), polyimide (PI), polycarbonate (PC), or epoxy resin (especially a composite reinforced with glass fiber or filler). .

  The thickness of the board | substrate 2 is not specifically limited, For example, 10 micrometers-2000 micrometers, Preferably they are 20 micrometers-1500 micrometers, More preferably, they are 50 micrometers-1000 micrometers. When the thickness of the substrate 2 is less than 10 μm, the substrate 2 may be warped or wrinkled due to the stress of the metal film 3. If the thickness of the substrate 2 exceeds 2000 μm, the density of the circuit per volume including the substrate 2 may be lowered even if the density of the circuit is increased. Moreover, when using it for a flexible substrate etc., since the flexibility is obtained when the thickness of the substrate 2 is 300 μm or less, it is preferable.

  It does not specifically limit as a metal which comprises the metal film 3, For example, although copper, nickel, tin, cobalt, zinc, or an alloy containing these metals can be used, it may be an alloy containing copper or copper. preferable. The copper may be electrolytic copper foil or plated copper. The metal film 3 may be a single layer film or a laminated metal film, but is preferably a single layer film.

  The thickness of the metal film 3 can be set to 0.1 μm to 100 μm, for example. The thickness of the metal film 3 is preferably 0.2 μm to 40 μm, more preferably 0.25 μm to 20 μm. If the thickness of the metal film 3 is too thin, a conduction failure such as a pinhole may be formed, which may cause disconnection. If the thickness of the metal film 3 is too thick, it takes time for etching, and side etching becomes large, so it may be difficult to form a high-density wiring.

  Next, the manufacturing method of the board | substrate 1 with a film | membrane is demonstrated. First, as shown in FIG. 2, a metal film 13 is formed on the substrate 2.

  Examples of the method for forming the metal film 13 on the substrate 2 include wet film formation methods such as electrolytic plating and electroless plating, dry film formation methods such as CVD, vapor deposition, and sputtering, electrolytic copper foil, For example, room temperature bonding, thermocompression bonding, and an adhesion method in which an adhesive is used to attach the rolled copper foil can be used. In the case where the metal film 13 is formed by an electrolytic plating method or an electroless plating method, it is preferable because a large manufacturing facility such as a vapor deposition method or a sputtering method is not required.

  Next, a patterned resist film, that is, a patterned resist film 14 is formed on the metal film 13.

  The pattern resist film 14 is generally formed by applying a liquid resist to a substrate or bonding a sheet-like dry film to the substrate, and then drawing a pattern by a photolithography method or a laser beam, and using a developing solution as a resist material for unnecessary portions. It is formed by dissolving. The pattern resist film 14 has a shape corresponding to a pattern of a metal film (electrode film) formed by etching the metal film 13. After the pattern resist film 14 is formed, the film-coated substrate 11 on which the metal film 13 and the pattern resist film 14 are laminated is immersed in an etching solution described later. Thereby, the metal film 13 is etched to obtain a film-coated substrate 11A having the patterned metal film 3 shown in FIG. Etching may be performed by either a dipping method or a shower method. Specifically, the etching may be performed by swinging the film-coated substrate 11 in which the metal film 13 and the pattern resist film 14 shown in FIG. Etching may be performed by spraying an etchant on the pattern resist film 14 side of the substrate with film 11 on which the pattern resist film 14 is laminated. Moreover, it is preferable to make the temperature of the etching liquid at the time of etching into the range of normal temperature-70 degreeC.

  Finally, the patterned resist film 14 shown in FIG. 3 is removed to obtain the film-coated substrate 1 shown in FIG. As shown in FIG. 1, the obtained substrate 1 with a film includes a substrate 2 and a patterned metal film 3 (electrode film). The pattern resist film 14 can be removed by immersing in an organic solvent or a remover, for example.

(Etching solution for metal film)
Next, the etching solution will be described.

  The etching solution of the present invention is a metal film etching solution for patterning a metal film by etching. The etching solution of the present invention can be used, for example, when the metal film 13 is etched in the manufacturing method of the substrate with film 1 described above.

  In the present invention, the etching solution is an aqueous solution containing 0.5 to 12% by mass of hydrogen peroxide and 0.05 to 1.0% by mass of sulfuric acid. The mass ratio of hydrogen peroxide to sulfuric acid (the mass of hydrogen peroxide / the mass of sulfuric acid) is 6 or more and 70 or less. In the present specification, the contents (concentrations) of hydrogen peroxide and sulfuric acid are contents when the total amount of the etching solution is 100% by mass.

  In the present invention, since the etching solution contains hydrogen peroxide and sulfuric acid in the specific range, the taper angle θ of the patterned metal film 3 shown in FIG. 1 can be made close to a right angle. The taper angle θ is an angle formed between the main surface 2a of the substrate 2 and the side surface 3a of the patterned metal film 3. Further, in the present invention, the reason why the taper angle θ can be made close to a right angle is presumed as follows.

  When the etching solution of the present invention is used, the surface of the metal film 13 shown in FIG. 2 in contact with the etching solution is oxidized by hydrogen peroxide, and the metal film 13 is etched by dissolving the oxide with sulfuric acid. In particular, in the present invention, the rate of oxidation on the surface of the metal film 13 is sufficiently faster than the rate of dissolution by sulfuric acid, so that an oxide film is formed on the surface of the metal film 13. Since the sulfuric acid concentration is low, when the portion of the metal film 13 without the pattern resist film 14 is etched, most of the sulfuric acid becomes a metal sulfate, and the ability of the etching solution to dissolve the oxide film is reduced. Etching (below the pattern resist film 14) is difficult to be performed. That is, as compared with the etching in the thickness direction of the metal film 13, the etching in the width direction of the metal film 13 is less likely to occur, and as a result, the etching can be performed with a large taper angle θ.

  The content of hydrogen peroxide contained in the etching solution of the present invention is preferably 0.7 to 12% by mass, more preferably 1 to 11% by mass. If the hydrogen peroxide content is too small, a sufficient oxide film may not be formed on the surface of the metal film 13 in some cases. Therefore, in this case, the taper angle θ may not be close to a right angle. On the other hand, if the content of hydrogen peroxide is too large, bubbles are likely to be generated in the substrate 2 and the like, and etching may not be performed uniformly. In addition, since the increase in the oxidation rate on the surface is a high-concentration region that saturates, the decomposition of hydrogen peroxide increases the generation of oxygen rather than the oxidation of the metal, so an improvement in the oxidation rate commensurate with the content can be seen. It is not economically preferable.

  The content of sulfuric acid contained in the etching solution according to the present invention is preferably 0.07 to 0.9% by mass, more preferably 0.1 to 0.8% by mass. If the content of sulfuric acid is too small, the rate at which the oxide film is dissolved may become too slow, or the dissolving ability of the etching solution may decrease. On the other hand, if the content of sulfuric acid is too large, the metal film 13 is melted before the oxide film is formed on the surface, so the taper angle θ may not be close to a right angle. In addition, the pattern resist film 14 may be easily peeled off during etching, or the etching rate may become too fast to control the etching amount.

  The mass ratio of hydrogen peroxide to sulfuric acid (mass of hydrogen peroxide / mass of sulfuric acid) is preferably 6.5 or more, more preferably 9 or more, still more preferably 10 or more, preferably 66.7 or less, more preferably 60 or less. If the mass ratio (the mass of hydrogen peroxide / the mass of sulfuric acid) is too small, a sufficient oxide film cannot be formed on the surface of the metal film 13, and the taper angle θ may not be close to a right angle. On the other hand, if the mass ratio (the mass of hydrogen peroxide / the mass of sulfuric acid) is too large, the ability to form an oxide film is sufficient, but the ability to dissolve the oxide film is lowered and the etching rate may be greatly reduced. is there.

  The etching solution of the present invention may contain a surfactant such as ethylene glycol, an amine or an azole compound.

  Since the etching solution of the present invention can bring the taper angle of the patterned metal film close to a right angle as described above, for example, a printed wiring board that requires high-density wiring, a metal mesh such as a touch panel, or regularly It can be suitably used when forming a pillar structure in which cylinders or prisms are arranged.

  Thus, in the present invention, the taper angle θ of the patterned metal film 3 can be made close to a right angle, so that the metal film 3 having a substantially rectangular cross section having a predetermined line width and film thickness can be formed. . Further, since the cross-sectional shape of the patterned metal film is substantially rectangular, the wiring interval can be reduced, so that high-density wiring electrodes can be formed. Therefore, according to the method for manufacturing a film-coated substrate of the present invention, it is possible to reduce the size and density of the circuit pattern.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to these Examples.

(Examples 1-13 and Comparative Examples 1-5)
A glass substrate (manufactured by Nippon Electric Glass Co., Ltd., trade name “OA-10G”, thickness 500 μm) was used as the substrate. After applying an adhesive to one surface of the glass substrate, an electrolytic copper foil having a thickness of 10 μm was bonded. Thereafter, etching was performed until the thickness of the electrolytic copper foil became about 3 μm using an etching solution to form a metal film.

  A resist film patterned using a photolithography method was formed on the metal film formed as described above. The resist film has a plurality of linear shapes extending in one direction, the line width of the resist film is 10 μm, and the interval between the linear resist films is 200 μm.

  The glass substrate on which the metal film and the resist film were formed was cut into a 2 cm × 2 cm square to prepare a sample.

In Examples 1 to 13 and Comparative Examples 1 to 5, the hydrogen peroxide (H ₂ O ₂ ) concentration, the sulfuric acid (H ₂ SO ₄ ) concentration, and the mass ratio (H ₂ O ₂ / H ₂ ) shown in Table 1 below are shown. An etching aqueous solution having SO ₄ ) was prepared and etched under the following conditions.

  200 mL of the etching solution was poured into a 300 mL beaker, the sample was pinched with tweezers and immersed in the etching solution, and the sample was swung 100 times / minute in a direction perpendicular to the surface of the sample. Etching was performed for 10% longer than the etching time when the metal film in the portion without the pattern resist could not be visually confirmed. Then, it washed with water and dried and produced the sample.

  About the obtained sample, taper angle (theta) shown in FIG. 1 was measured. The results are shown in Table 1. The taper angle θ shown in Table 1 is obtained by breaking the sample in a direction perpendicular to the direction in which the linear resist film extends, and observing the fractured surface with an SEM, and the taper angle θ of the side surface 3a of the metal film 3. Was measured with three arbitrary samples, and the average value was taken.

  As shown in Table 1, in Examples 1 to 13 using the etching solution according to the present invention, it can be seen that the taper angle θ is close to a right angle as compared with Comparative Examples 1 to 5.

DESCRIPTION OF SYMBOLS 1,11,11A ... Substrate with film 2 ... Substrate 2a ... Main surface 3, 13 ... Metal film 3a ... Side surface 14 ... Pattern resist film [theta] ... Taper angle

Claims (6)

Forming a metal film on the substrate;
Forming a patterned resist film on the metal film;
Patterning the metal film using an etchant;
With
The etching solution contains 0.5 to 12% by mass of hydrogen peroxide and 0.05 to 1.0% by mass of sulfuric acid,
The manufacturing method of the board | substrate with a film | membrane whose mass ratio (mass of hydrogen peroxide / mass of sulfuric acid) of the said hydrogen peroxide with respect to the said sulfuric acid is 6-70.   The manufacturing method of the board | substrate with a film | membrane of Claim 1 whose mass ratio (mass of hydrogen peroxide / mass of sulfuric acid) of the hydrogen peroxide to the sulfuric acid is 9 or more and 60 or less.   The manufacturing method of the board | substrate with a film | membrane of Claim 1 or 2 with which the said metal film contains copper or a copper alloy.   The manufacturing method of the board | substrate with a film | membrane of Claim 3 whose said copper is electrolytic copper foil or plated copper.   The manufacturing method of the board | substrate with a film | membrane of any one of Claims 1-4 whose said board | substrate is a glass substrate. An etching solution for a metal film for patterning a metal film by etching,
Containing 0.5-12 mass% hydrogen peroxide and 0.05-1.0 mass% sulfuric acid,
The etching solution for metal films whose mass ratio (mass of hydrogen peroxide / mass of sulfuric acid) of the hydrogen peroxide to the sulfuric acid is 6 or more and 70 or less.

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