JP4716023B2 - Manufacturing method of transparent shield case - Google Patents

Description

  The present invention relates to a method for manufacturing a transparent shield case having a function of shielding electromagnetic waves, and in particular, to cover at least a part of an electronic circuit board so as to prevent malfunction of the electronic circuit caused by electrostatic discharge or unnecessary electromagnetic waves. The present invention relates to a method for manufacturing a transparent shield case.

  In gaming machines with a display device such as a pachinko machine, a display device and an electronic circuit board on which an electronic circuit for controlling the display device is mounted are accommodated in a transparent case. This is because the visibility of the electronic circuit board is also visible (transparency) for the purpose of enabling confirmation from the outside whether or not illegal ROM is used in the electronic circuit board without opening the case. ) Is required. In addition, the transparent case is required to have an electromagnetic wave shielding property in order to protect the electronic circuit board and the display device from electromagnetic waves generated by fraud.

  For the above reasons, a transparent shield case is used in gaming machines and the like. However, it is difficult to manufacture a transparent shield case having a complicated shape by a conventional transparent shield case manufacturing method. It was difficult to achieve both shielding performance and transparency. For example, a conductive thin film made of metal oxide, metal nitride or metal is formed on the inner or outer surface of the transparent case by sputtering, vapor deposition or ion plating as shown in Patent Document 1 below. In this manufacturing method, it is difficult to form a conductive thin film in a concave portion that is a shadow of a convex portion in a case having a concave and convex portion partially.

JP 2004-313465 A

  In addition, for example, there is a method of manufacturing a transparent shield case by applying a conductive paint mixed with a needle-like conductive material made of metal oxide, metal nitride or metal to the transparent case, but the shield performance is improved. In order to achieve this, it is necessary to increase the mixing amount of the acicular conductive material, and the transparency is lowered. Therefore, it is difficult to achieve both sufficient shielding performance and transparency.

  An object of this invention is to provide the manufacturing method of the transparent shield case which can respond to a complicated case shape in view of said point, and can make sufficient shield performance and transparency compatible.

  Other objects and novel features of the present invention will be clarified in embodiments described later.

To achieve the above object, a manufacturing method of the transparent shield case according to the present invention, the solution containing conductive fine particles after application to the transparent casing, the conductive fine particles are arranged in a mesh shape on the surface of the transparent casing ,
After the arrangement of the conductive fine particles, the surfaces and portions that require a transparent shield are coated to maintain the adhesion of the conductive fine particles, and the surfaces and portions that do not require a transparent shield are washed to It is characterized by removing fine particles .

  In the method for producing the transparent shield case, the application may be performed by dipping or by spray application.

  According to the method for manufacturing a transparent shield case according to the present invention, after the solution containing conductive fine particles is applied to the transparent case, the conductive fine particles are arranged in a mesh shape on the surface of the transparent case. Can achieve both electromagnetic shielding performance and transparency. In addition, since it is the application of a solution containing conductive fine particles, it does not interfere with film formation in the case of complicated case shapes such as sputtering, vapor deposition, and ion plating, and the complicated case shape Even so, electromagnetic wave shielding is possible.

  Hereinafter, as a best mode for carrying out the present invention, an embodiment according to a method for producing a transparent shield case will be described with reference to the drawings.

  Embodiment 1 of the method for manufacturing a transparent shield case according to the present invention will be described with reference to FIG. First, as shown in FIG. 1A, a box-shaped transparent case 1 having an opening on one side is prepared. The transparent case 1 is preferably made of resin, and is formed of, for example, acrylic, polypropylene, polycarbonate, ABS resin, or the like.

  A solution 2 containing conductive fine particles is applied to the transparent case 1 as shown in FIG. As the conductive fine particles, fine conductive metal particles such as copper (Cu), silver (Ag), gold (Au), and nickel (Ni) can be used, and the particle size is set to a size that cannot be visually recognized. The solution 2 contains at least a volatile organic solvent as a liquid in which conductive fine particles are mixed. As a method for applying the solution 2, dipping (spraying) or spray coating can be employed.

  As shown in FIGS. 1C to 1E, which are enlarged views of the transparent case 1, the transparent case 1 is in a transparent and clear state shown in FIG. Immediately after 2 is applied to the surface of the transparent case 1, the conductive fine particles are uniformly dispersed and clouded as shown in FIG. 1 (D), but the figure is shown with time (several seconds to several tens of seconds). Transparency can be ensured by arranging the conductive fine particles in a mesh pattern on the surface of the transparent case 1 as in 1 (E). In order to secure the electromagnetic wave shield, it is necessary that the entire inner surface or the entire outer surface of the transparent case 1 is within the application range of the solution 2 containing at least conductive fine particles. Here, it is assumed that the solution 2 is applied to the entire surface of the transparent case 1.

  In the case of dipping, the time from when the solution 2 is applied until the conductive fine particles are arranged in a network may be about 1 to 5 seconds. In the case of spray coating, the conductive fine particles are arranged in a network. It is preferable that the time to do is long. In the case of spray coating, it is preferably 10 seconds or longer, and particularly preferably about 30 to 60 seconds (adjustable by the volatilization rate of the solvent). This is because, when a solution containing conductive fine particles is applied again to the portion where conductive fine particles have been arranged in a network shape, the arrangement of the conductive fine particles applied again cannot be performed well, and transparency is impaired. It is. Therefore, in the case of spray application, continuous application is preferable, and application with a programmed robot or the like is conceivable.

  When the solution 2 containing the conductive fine particles is applied to the surface of the transparent case 1 and then dried, conductive fine particles arranged in a mesh form remain. As shown in FIG. 1F, a coating 3 is provided to protect the conductive fine particle adhering portion 2a. The coating agent used for the coating 3 is preferably made of the same material as the transparent case 1. For example, it includes acrylic, polypropylene, polycarbonate, ABS resin and the like. The coating can be applied by spray application or dipping. In the case of FIG. 1 (F), the coating 3 is applied to the entire inner surface of the transparent case 1, and the coating 3 is cured to maintain the adhesion of conductive fine particles on the entire inner surface. Thus, when apply | coating a coating agent partially, spray application is used suitably.

  Finally, the transparent case 1 as a whole is immersed in a cleaning solution and cleaned, so that the conductive fine particles on the outer surface of the transparent case without coating can be removed as shown in FIG. As the cleaning liquid, for example, the organic solvent used in the solution 2 can be used. After this cleaning treatment, it is possible to form a transparent shield in which the conductive fine particle adhering portions 2a in a mesh arrangement are protected and fixed by the coating 3 only on the inner surface of the transparent case 1. As a result, a transparent shield case 10 in which a transparent electromagnetic wave shield is provided on the entire inner surface of the transparent case 1 is completed.

  FIG. 2 is an application example in which one surface of the electronic circuit board 20 of a gaming machine such as a pachinko machine is covered with the transparent shield case 10 obtained in the above-described embodiment. Thus, for example, a ROM or the like mounted on the electronic circuit board 20 These electronic components and display devices can be visually observed through the transparent shield case 10 from the outside. In this case, the entire surface of the electronic circuit board 20 may be covered, or only a necessary part may be covered.

  Moreover, even if it is uses other than gaming machines, such as a pachinko machine, the visibility from the outside is requested | required and the transparent shield case 10 can be used suitably for the required location of an electromagnetic wave shield.

  According to the first embodiment, the following effects can be obtained.

(1) The conventional sputtering method, vapor deposition method, ion plating method, or transparent shield case manufacturing method by applying a conductive paint makes it difficult to manufacture a transparent shield case with a complicated shape. Although it was difficult to achieve both sufficient shielding performance and transparency, in the case of the present embodiment, after applying the solution 2 containing the conductive fine particles to the transparent case 1, the conductive property is applied on the surface of the transparent case 1. Since the electromagnetic particles are shielded by arranging the fine particles in a mesh shape, sufficient shielding performance and transparency can be achieved at the same time, and a complicated case shape can be dealt with.

(2) Visible light transmittance is 50 to 90% by adjusting the width of the line composed of conductive fine particles arranged in a network and the diameter of the opening surrounded by the line composed of the conductive fine particles. It can be adjusted within a range.

(3) The network-like arrangement of the conductive fine particles remaining after the solution 2 containing the conductive fine particles is dried can easily remove portions where the coating 3 is not applied, and the coating 3 is selectively applied only to necessary portions. By providing in, unnecessary conductive fine particles can be removed by washing with a washing liquid. As a result, a transparent shield can be selectively formed on the surface of the transparent case 1.

  Embodiment 2 of the method for producing a transparent shield case according to the present invention will be described with reference to FIG. In this case, first, as shown in FIG. 3A, masking 4 is provided (applied) on a portion of the box-shaped transparent case 1 having an opening on one surface where the transparent shield is not required, for example, on the front surface outside the case. Here, when the masking 4 is provided on the front surface, considering that the transparent shield is formed on the entire inner surface of the transparent case 1, the transparent shield is omitted in the sense that the front surface outside the case does not deteriorate the transparency. This is because it may be preferable.

  For the masking 4, a masking mold or a release agent made of masking tape, silicon or the like can be used.

  Next, as shown in FIG. 3B, the solution 2 containing conductive fine particles is entirely applied to the transparent case 1 subjected to masking 4 by dipping or spraying. Since it is covered with the masking 4, the solution 2 does not adhere to the front surface of the transparent case 1 (attaches on the masking 4).

  When the solution 2 containing the conductive fine particles is applied to the surface of the transparent case 1 and then dried, conductive fine particles arranged in a mesh form remain. When the solution 2 is thus dried, the masking 4 is peeled off as shown in FIG. The front surface of the transparent case 1 is a surface to which no conductive fine particles are attached, and the other portion is a conductive fine particle attached portion 2a.

  Thereafter, as shown in FIG. 3D, in order to protect the conductive fine particle attached portion 2a, a coating 3 is provided so as to cover at least the conductive fine particle attached portion 2a (it can be provided on the entire surface of the transparent case 1). ). The coating agent used for the coating 3 can be applied by spray application or dipping. As a result, a transparent shield case 10 </ b> A in which a transparent electromagnetic wave shield is applied to the other surface (in other words, the region including the entire inner surface of the case and the entire side surface of the outer case) other than the outer front surface of the transparent case 1 is completed.

  Also in the case of the second embodiment, the masking 4 can provide a portion where the conductive fine particles do not adhere to the surface of the transparent case 1, and as a result, a transparent shield is selectively formed on the surface of the transparent case 1. Is possible.

  The transparent shield case 10A can also be used as in the application example of FIG.

  Although the embodiments of the present invention have been described above, it will be obvious to those skilled in the art that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims.

It is explanatory drawing which shows Embodiment 1 of the manufacturing method of the transparent shield case which concerns on this invention. It is a perspective view which shows the application example of the transparent shield case obtained in Embodiment 1 of this invention. It is explanatory drawing which shows Embodiment 1 of the manufacturing method of the transparent shield case which concerns on this invention.

Explanation of symbols

1 Transparent case 2 Conductive fine particle solution 3 Coating 4 Masking

Claims (3)

After applying a solution containing conductive fine particles to the transparent case, the conductive fine particles are arranged in a mesh on the surface of the transparent case ,
After the arrangement of the conductive fine particles, the surfaces and portions that require a transparent shield are coated to maintain the adhesion of the conductive fine particles, and the surfaces and portions that do not require a transparent shield are washed to A method for producing a transparent shield case, wherein fine particles are removed .   The method for producing a transparent shield case according to claim 1, wherein the coating method is dipping.   The method of manufacturing a transparent shield case according to claim 1, wherein the coating method is spray coating.

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