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KR-20260064597-A - METHOD FOR FORMING METAL OXIDE COATING

KR20260064597AKR 20260064597 AKR20260064597 AKR 20260064597AKR-20260064597-A

Abstract

It extends the lifespan of the plating solution used for forming metal oxide films, thereby enabling efficient use of the plating solution. A method for forming a metal oxide film comprises a process of forming a metal oxide film on the surface of a plating target using a plating solution containing a compound of a metal that forms a film and a compound of boron that is a reducing agent, and a process of regenerating the plating solution using an adsorption filter that adsorbs boric acid.

Inventors

  • 야마모토 히사미츠
  • 나카야마 토모하루
  • 코메다 타쿠야
  • 요시다 신이치로
  • 마츠모토 칸지

Assignees

  • 우에무라 고교 가부시키가이샤

Dates

Publication Date
20260507
Application Date
20251029
Priority Date
20241031

Claims (8)

  1. A process for forming a metal oxide film on the surface of a plating target by means of a plating solution comprising a metal compound that forms a film and a boron compound that is a reducing agent, and A method for forming a metal oxide film, comprising a process of regenerating the above plating solution using an adsorption filter that adsorbs boric acid.
  2. In paragraph 1, The above adsorption filter is a method for forming a metal oxide film comprising a chelate resin that selectively adsorbs boric acid.
  3. In paragraph 2, A method for forming a metal oxide film, wherein the above chelate resin is a resin having a methylglucamine group as a chelate-forming part.
  4. In paragraph 1, The process of forming the above film is carried out by immersing the plating target in a plating tank containing the above plating solution, and A method for forming a metal oxide film, wherein the above-mentioned regeneration process is carried out by circulating the plating solution in the plating bath through the adsorption filter.
  5. In paragraph 4, A method for forming a metal oxide film, wherein the process of forming the film and the process of regenerating are carried out simultaneously in parallel.
  6. In paragraph 1, A method for forming a metal oxide film, wherein the reducing agent comprises dimethylaminoborane (DMAB).
  7. In paragraph 1, A method for forming a metal oxide film, wherein the above metal is zinc.
  8. A plating tank containing a plating solution comprising a metal compound forming a film and a boron compound acting as a reducing agent, wherein a plating target is immersed to form a metal oxide film on the surface of said plating target; The plating solution regeneration unit for regenerating the plating solution in the plating tank is provided, A plating apparatus having a plating solution regeneration unit comprising an adsorption filter that adsorbs boric acid and a pump that returns the plating solution in the plating tank to the plating tank through the adsorption filter.

Description

Method for Forming Metal Oxide Coating The present disclosure relates to a method for forming a metal oxide film and a plating apparatus thereof. A method for forming a metal film on the surface of a non-conductive plating target, such as a glass substrate, is known, which involves forming a zinc oxide film on the surface of the plating target and then performing electroless plating of a metal film, such as copper or gold. While deposition, sputtering, and the sol-gel method are known as methods for forming a zinc oxide film on the surface of the plating target, the electroless plating method is attracting attention because it can easily form a zinc oxide film on the surface of the plating target. The electroless plating method for a zinc oxide film is carried out using a plating solution containing zinc nitrate and a boron-based reducing agent such as dimethylaminoborane (DMAB). Since the method can be carried out simply by immersing the object to be plated in the plating solution, a zinc oxide film can be easily formed (for example, refer to Patent Document 1). FIG. 1 is a schematic diagram showing an example of a plating apparatus used in the method for forming a metal oxide film of the present disclosure. The method for forming a metal oxide film according to the present embodiment can be carried out using a plating apparatus (100) as shown in FIG. 1. The plating apparatus (100) has a plating tank (101) containing a plating solution (104) and a circulation circuit (102) that circulates the plating solution (104) contained in the plating tank (101). The circulation circuit (102) has a circulation pump (121), a first filter (122), and a second filter (123). The first filter (122) is a conventional filtration filter that removes foreign substances, such as aggregates, from the plating solution (104). The second filter (123) is a column filled with beads of a chelating resin that selectively removes boric acid. The plating solution (104) is an electroless plating solution for a zinc oxide film containing zinc nitrate, which is a metal source, and DMAB, which is a reducing agent. A zinc oxide film can be formed on the surface of a plating target (106), such as a glass substrate, by immersing it in a plating solution (104) in a plating bath (101). In the deposition of the zinc oxide film in the plating solution (104), boric acid and electrons ( e⁻ ) are generated from DMAB, which is a reducing agent (Equation 1). Zinc nitrate dissociates into zinc ions and nitrate ions (Equation 2). Nitrate ions generate nitrite ions and hydroxide ions through water and electrons (Equation 3). Zinc ions combine with hydroxide ions to form zinc hydroxide, and as zinc hydroxide changes into zinc oxide, a zinc oxide film is deposited on the surface of the plating target (106) (Equations 4, 5). (CH 3 ) 2 NHBH 3 +3H 2 O→H 3 BO 3 +(CH 3 ) 2 H 2 N + +5H + +6e - (Equation 1) Zn(NO 3 ) 2 →Zn 2+ +2NO 3 - (Equation 2) NO₃⁻+H₂O + 2e⁻ → NO₂⁻ + 2OH⁻ ( Equation 3) Zn 2+ + 2OH - → Zn(OH) 2 (Equation 4) Zn(OH) ₂ → ZnO + H₂O (Equation 5) Boric acid generated in DMAB has a buffering function, so it inhibits the reaction of Equation (4). Therefore, as the plating reaction progresses, the concentration of boric acid in the plating bath (104) increases, and the film-forming ability decreases rapidly, so it is usually necessary to replace the plating bath (104) every time. However, in this embodiment, boric acid in the plating bath (104) is continuously removed by the second filter (123). Therefore, since the increase in the concentration of boric acid in the plating bath (104) is suppressed, the lifespan of the plating bath (104) is extended, and it can be used efficiently. The generation of boric acid by the decomposition of DMAB proceeds even when the plating target (106) is not immersed in the plating bath (104). Therefore, it is desirable to remove boric acid by operating the circulation pump (121) continuously. However, the circulation pump (121) may be operated intermittently. Additionally, the boric acid concentration in the plating solution (104) may be monitored, and the circulation pump (121) may be operated when the boric acid concentration exceeds a predetermined value. A plating cycle in which the plating target (106) is immersed in the plating solution (104) and a regeneration cycle in which the plating solution (104) is regenerated by operating the circulation pump (121) to remove boric acid from the plating solution (104) may be performed alternately. The configuration of a plating device (100) that removes boric acid by circulating the plating solution (104) in the plating tank (101) by a circulation pump (121) is shown. However, it may also be a batch-type plating device that removes the plating solution (104) from the plating tank (101) to regenerate it, and then returns the plating solution (104) after regeneration back to the plating tank (101). The second filter (123) for removing boric acid is a column filled with chelating