JPS5893884A - Production of metallic mesh - Google Patents

Abstract

PURPOSE:To produce a metallic mesh which is fine and has no deformation by forming a master mesh having a conductive broad part on the outside edge part on an electrically insulating substrate, and depositing a protecting film thereon then forming the metallic mesh by an electroforming method. CONSTITUTION:A projecting master formed of a master mesh 2 of chromium and a broad part 3 of a conductive member in contact with the outside edge part is installed on an electrically insulating substrate 1 made of glass. A protecting film 6 consisting essentially of molybdenum oxide is formed on the mesh wire 5 of the master mesh with an electrodepositing soln. for protection films consisting of a soln. of ammonium molybdate as an electroforming soln. The initial metallic mesh wire 7 in contact with the protecting film are formed by an electroforming method. In succession, the electroforming soln. is infiltrated at the interfaces between the wire 5 and the film 6 and copper is deposited on the rear side of the meshes 7 as well, whereby a metallic mesh 9 consisting of the metallic mesh wire 8 which are held afloat from the wire 5 is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for manufacturing a fine metal mesh by electroforming, which is used in a cathode ray tube with a mesh electrode inside, such as an image pickup tube. .

Technical background of the invention and its problems The metal mesh used in cathode ray tubes such as image pickup tubes is generally composed of 750 to 2000 lattice mesh wires per inch, and the degree of opening for electron beams to pass through is approximately 4
It is 0 to 50%.

Generally, this metal mesh is mainly made of copper, and may also contain palladium, silver, platinum, etc. For example, if a metal mesh is attached to a cylindrical support? = After being attached, it will be recrystallized by heat treatment and will be incorporated into the cathode ray tube under tension.

Conventionally, this metal mesh is generally produced by electroforming. The manufacturing method is to form a master mesh made of a conductive film on an electrically insulating substrate such as glass in the form of a concave groove, or to form it by electroforming on a concave master with grooves, or to form a master mesh pattern on a flat surface. One of the methods of forming a convex master by electroforming is used.

Among these methods, a method of forming a convex master by electroforming is disclosed, for example, in Japanese Patent Publication No. 5'2-3890. A step of forming an electrical connection with a master mesh made of a film of a directly wave-plated conductive material, and a step of forming a metal mesh on the master mesh by electroplating (electroforming).

The publication describes a manufacturing method comprising a step of peeling off a metal mesh from a master mesh. According to this manufacturing method, a master mesh made of one of am, tantalum, tungsten, tin oxide, and indium oxide is used. Since it is possible to peel off the metal mesh so that it remains on the electrically insulating substrate, it is said that 100 metal meshes can be manufactured repeatedly using the same master mesh.

However, the inventors used chromium as the master mesh of the aforementioned convex master to form a metal mesh made of copper in the form of a lattice of 1500 pieces per inch, and as a result of repeated experiments, they selected chromium as the material for the master mesh. It was confirmed that the metal mesh was damaged little by little, causing partial defects in the master mesh, and eventually it became impossible to form a metal mesh.

In addition, the characteristics of the metal mesh made of copper are as follows:
It was also found that there were problems in that it was easy to discolor due to oxidation, and that it was difficult to handle due to its weak mechanical strength.

The biggest cause of the above-mentioned problem is that when the metal mesh is peeled off from the master mesh formed from the beam, the negative part of the master mesh is peeled off along with the metal mesh. This significantly shortens the lifespan of Further, the discoloration prevention treatment of the metal mesh cannot be applied to the entire surface of the metal mesh until after it has been peeled off from the master mesh, and there is also the problem that the metal mesh is significantly deformed after being peeled off.゛Purpose of the Invention This invention was made in view of the conventional problems mentioned above. - When manufacturing a metal mesh using a convex master, the process of peeling off the metal mesh from the master mesh is eliminated. , it is possible to easily perform full-scale treatment such as discoloration prevention treatment on the metal mesh, and it also prevents damage to the master mesh and the effect on the life of the master mesh due to the combination of materials of the master mesh and metal mesh. It is an object of the present invention to provide a method for manufacturing metal mesh that can be made to a minimum.

Summary of the Invention That is, the present invention includes a process of forming a master mesh on an electrically insulating substrate, a wide part contacting the outer edge of the master mesh with a coating made of a conductive material, and a process of forming a protective film on the master mesh. A process of forming a wide metal body and a metal mesh by electroforming on the wide part and the master mesh through a protective film, respectively, by forming a master mesh by forming a wide metal body and a protective film. It is characterized by having at least a few processes.

Embodiments of the Invention Next, embodiments of the invention will be described with reference to FIGS. 1 to 7.

First, a convex master as shown in FIGS. 1 and 2 is created.

That is, an electrically insulating substrate <1> made of 5-inch square glass.
North face t = approx. too wm Angle range 2600- xo
A master mesh made of chrome etc. with a thickness of ooi (
2) Prepare a convex master having a wide part (3) in contact with the outer edge of i. In this case, the master mesh is 15
When creating a grid-like metal mesh with 00 finches, the pitch of the master mesh wires (5) shown in Figure @2 is approximately 17μ, and the thickness of the electroformed metal mesh is the master mesh wire (5) shown in Figure @2. The thicker the wire (5) is, the thicker the wire (5) is, so it is approximately 7oOλ, and in order to increase the degree of opening of the metal mesh, it is rational for the master mesh wire (5) to be thinner, so it is approximately It is said to have two voices.

The master mesh (2) and the master having the wide portion (3) described above are drawn by an electron beam writing IIV device used for forming mask patterns such as general c-L8I, and are photo-transferred optically. Created by etching method. Next, as shown in FIG.
0. The master mesh (
A protective film (6) containing mopden oxide as a main component is formed on the mesh wire (5) of 2) by electroforming for about 1 minute. When forming this protective film (6), remove fine particles on the master made of inorganic and organic materials in advance using concentrated nitric acid, hot concentrated sulfuric acid, or a cleaning solution containing a surfactant. Defects in metal mesh formed from cast C2 can be reduced.

Next, as shown in FIGS. 4 and IIs, a metal mesh is formed by electroforming. First, FIG. 184 shows the initial stage of electroforming with copper, in which a protective film (7) t: An initial metal mesh strand (7) in close contact is formed. Next, as shown in Fig. 5, the current density of the electroforming solution is lowered midway from about 3)y41al to about 0.5 people/dm, thereby changing the precipitation stress and forming the mesh wire (5). By infiltrating electroforming liquid into the interface with the protective film (6), the initial metal mesh (
Copper is also deposited on the back side of the master mesh wire (5).
) It is possible to create a metal mesh (9) consisting of floating metal mesh tension wires (8).

Copper sulfate plating flow is generally suitable as the electroforming solution for creating this metal mesh (9), and basically copper sulfate is used as the electroforming solution.
It has a composition of 150#/7 sulfuric acid 12011/1 and is used at a temperature of about 2-5℃, and if necessary, a stress reducer etc. is added, but the metal mesh wire (8)
By controlling the thickness of the copper deposited on the back surface (8,) of the metal mesh (9), warping of the entire metal mesh (9) can be reduced.

That is, under the above-mentioned conditions, the master mesh (2) and the metal mesh (9) which are not in close contact with each other can be automatically formed, which may cause damage or abnormal precipitation to the protective film (6) and the master mesh wire (5). It can be used repeatedly several tens of times.

In this case, as shown in Fig. 6, the wide metal body (a) of copper deposited on the wide part (3) and the main protective film (2) deposited on the wide part (3) and the main protective film (2) is not formed except for some non-adhered parts (a2). It supports a metal mesh (9) that is in close contact with, but not in close contact with.

That is, since the wide part (3) has a width sufficiently wider than the non-contact part az of 20 to 30 pitches, it can be prevented from falling off from the master together with the metal mesh (9).

Furthermore, metal meshes that are easily oxidized and discolored, such as copper, generally require treatment to prevent discoloration, but in this example, the metal mesh V (9) is held in non-adherent contact with the master mesh (2). Therefore, it is possible to apply chemical treatment or electrolytic treatment such as gold plating or platinum plating to the entire surface of the metal workpiece.

Next, the metal mesh (9) and the wide metal body are separated by cutting a part of the metal mesh (9) with a bottle set, etc., and the metal mesh (9) is made into a piece of metal mesh (9) as shown in No. s@1.
9) is obtained.

Further, this sheet-shaped metal mesh (9) is cut into a circular shape using a press or the like, and as shown in No. 9m, the circular metal mesh (9) is fixed between the supports as A41 by welding or the like, and heated at about 800°C for about 10 minutes. A flat, vibration-resistant mesh electrode is formed using the tension effect caused by recrystallization, and then installed in the imaging tube. In this case, the master mesh (2) shown in FIG. 1 may be formed in a circular shape.

In the above embodiments, molybdenum oxide was used as the main component of the protective film, but it is not limited to this. For example, nickel ammonium sulfate 6011/1 zinc sulfate, which is a plating solution generally used as a black nickel plating solution.
The electrolyte solution consisting of 10 fill sodium thiocyanide 511/1 was applied to about 0. IA/dd,
It may be sulfide of nickel and zinc electrodeposited for about 30 seconds,
It goes without saying that electrically insulating chromium oxide, tantalum oxide, etc. may be used in a thin film of, for example, 50 to 200λ, and metal oxides and sulfides that are difficult to adhere to metal mesh forming materials may be used. If the main protective film is formed, a non-adhesive metal mesh can be automatically obtained, and the life of the protective film is also limited depending on the material used to form the metal mesh, so the protective film may need to be formed every few tens of times. It is necessary to cover it by checking the degree of wear.

Next, regarding the position where the protective film is applied, in the previous example, it was applied so as to surround the master mesh wire and the wide part, but it goes without saying that the protective film may be applied only to the master mesh wire. It is. In addition, as shown in Figure 9, the protective film (2) is partially applied only to the top of the mesh wire (5), or as shown in Figure @10, the protective film (2) is applied to the mesh wire (5) and the electrically insulating substrate. Of course, a protective film ($6.) (36,) may be provided to cover the surface (l,) of (1). Further, in the above embodiments, metal parts such as nickel, nickel,
Or a multi-layer metal mesh with a core made of another metal and coated with copper, or a metal mesh made of other metals, etc.
Of course, the present invention can also be applied directly to the production of fine metal meshes having tensions of about 1,000 wires/inch.

Effects of the Invention As described above, according to the method for manufacturing metal mesh of the present invention, it is possible to significantly extend the life of the expensive master mesh, making it possible to manufacture a large amount of metal mesh at low cost. In the mesh electroforming process, the metal mesh can be kept in a non-adherent state with the master mesh, so the entire surface treatment such as discoloration prevention treatment of the metal mesh can be maintained by the wide part and the wide metal body that is partially in contact with the wide part. It is now possible to completely eliminate the problem of the conventional method where the entire surface treatment cannot be performed unless it is peeled off from the master mesh, and the metal mesh is significantly deformed after being peeled off. Therefore, its industrial value is extremely large.

[Brief explanation of the drawing]

1 to 7 are diagrams showing the method for manufacturing a metal mesh according to the present invention, and FIG. 1 is a perspective view of a master mesh and a wide portion formed on an electrically insulating substrate. @Figure 2 is a partially enlarged perspective view of the master mesh, Figure 3 is an enlarged cross-sectional view showing a state in which a protective film is formed on the master mesh, and Figure 4 is an initial metal layer on the master mesh without a protective film. Enlarged sectional view showing the state in which Metsu V Yu is formed,'@
Figure 5 is an enlarged sectional view showing the completed state of the metal mesh V-yu.
Figure 6 is an explanatory partially enlarged sectional view showing a state in which a metal mesh V-yu and a wide metal body are formed on the master mesh and wide part, respectively, and Figure 7 is a state in which the metal mesh is separated from the wide metal body. FIG. 8 is a perspective view showing a state in which the metal mesh is assembled to a mesh V-shaped electrode for an image pickup tube.
@Figures 9 and 10 are diagrams showing other examples of the relationship between the master mesh and the protective film, and Figure 9 is a partially enlarged cross section showing an example in which the protective film is formed only on the top of the master mesh. 10A and 10B are partially enlarged sectional views showing an example in which a master mesh and a protective film are formed on the surface of the electrically insulating substrate. 1.-Electrically insulating substrate 2...Master mesh 3
...Wide part 5...Master mesh wire 6, 16.26.3!1.3@, -.Protective film...-
Initial metal mesh strand 8...Metal mesh strand 9...Metal mesh 10--Wide metal body #fusanken 12...Non-adhesive portion 13.14...Support body 15--Metal Metsu Sheet Agent Patent Attorney Mr. Inoue Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) A step of forming a master mesh on an electrically insulating substrate and a wide portion in contact with the outer edge of the master mesh with a coating made of a conductive material, and coating at least the master mesh with a protective film. a step of forming a wide metal body and a metal mesh by electroforming on the wide portion and the master mesh via the protective film, and a step of separating the wide metal body and the metal mesh. A method for producing a metal mesh, comprising at least the following. (2) The method for manufacturing a metal mesh according to claim 1, wherein the protective film is made of a member that does not adhere to the metal mesh. t3) The method for producing a metal mesh according to claim 2, wherein the member that does not adhere to the metal mesh is an oxide or sulfide of a metal such as molybdenum, nickel, chromium, or tantalum.