JPS61199089A - Electroforming die and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an electroforming die having a complex uneven part in a short period by electrodepositing a thin layer on the surface of a matrix having an uneven part, filling ceramic cement contg. a mixture of a tervalent metallic oxide with metallic powder as the base into the recesses, and forming an electrodeposited layer on the surface of the cement. CONSTITUTION:An electrodeposited thin layer 4 of about 0.2-1mm thickness is formed on the surface of a matrix 1 for an electroforming die such as a toothed matrix having plural projections 2 and recessese 3 on the suface. Ceramic cement 5 is filled into the recesses 3 with the layer 4 in-between to make the surface of the matrix 1 nearly even. A mixture of a tervalent metallic oxide such as Al2O3 with 5-50wt% powder of a metal such as Ni is used as the base of the cement 5. The metallic powder facilitates the activation of the cement 5 and makes the coefft. of thermal expansion of the cement 5 close to that of a plated layer to be formed on the surface of the cement 5. The cement 5 is then cured, and at this time, the surface of the cement is activated with PdCl2 or the like. A plated layer 6 of about 0.01-0.1mm thickness is formed on the activated surface and an electrodeposited layer 7 is formed on the layer 6 in a plating bath through which a high-electric current can be passed.

Description

[Detailed Description of the Invention] "Target Technical Field" This invention relates to an electroforming mold and a method for manufacturing the same. When electrodeposition is carried out at a current density, the electrodeposited layer is formed thick locally, particularly in the convex portions 2, as shown in FIG. 2, and the growth of the electrodeposited layer in the concave portions 3 is thereby inhibited. Therefore, the current density in the electroforming process is set lower than the usual current density, but on the other hand, it has the disadvantage that it takes many days to form the electrodeposited layer. In addition, even if the current density is low (even if the electrodeposited layer on the uneven parts 2 and 3 becomes non-uniform, it is inevitable that the electrodeposited layer will be non-uniform, so it is necessary to perform machining after the electroforming process.
It requires a lot of time and energy.

In addition, for the purpose of correcting non-uniformity of the electrodeposition layer, an auxiliary electrode 8 is used as shown in Fig. 3. Since the electrodeposition is carried out by rotating the electrode, there is a disadvantage that it takes a lot of time to prepare the auxiliary electrode and the mounting device.

"Purpose" The purpose of the present invention is to perform electrodeposition at high speed even in the recesses where the formation of the electrodeposition layer is slow, in the production of electroforming molds having complex irregularities such as tooth patterns.

"Example" An embodiment of the present invention will be described below with reference to the drawings.

That is, in FIG. 1, an electroforming master mold 1 is used for, for example, a tooth mold of a gear, and has a plurality of convex portions 2 and concave portions 3 formed on its surface. First, an electrodeposited thin film layer 4 having a thickness of 0.2 to 1 mm is formed on the surface of the matrix 10, and the thickness varies depending on the shape or size of the matrix 1. 4, if the matrix 1 has a shape that allows electroplating, electroplating is more efficient, but if it is difficult to electroplat If the plating process requires a relatively long time, it can be formed by electroless plating. Next, the recesses 3 on the surface of the electrodeposited thin film layer 4 are filled with ceramic cement 5, so that the surface of the matrix 10 is shaped substantially uniformly. Here, the main ingredient of the ceramic cement 5 is a trivalent metal oxide such as aluminum oxide (AJto3) or nickel oxide (N1zO=
) and metal powder, such as powder of nickel, copper, aluminum, etc., in a weight ratio of 5 to 50%. Since trivalent metal oxides have thermosetting properties, they are particularly suitable when the material of the matrix 1 is made of metal and can be heated at high temperatures.

Furthermore, since the metal powder mixed in the ceramic cement 5 has high thermal conductivity and electrical conductivity, it facilitates activation and brings the thermal expansion of the ceramic cement 5 close to the plating layer applied to the surface. have an effect. Next, the ceramic cement 5 filled in the recess 3 is hardened, but at this time, in order to impart conductivity to the ceramic cement 5,
The surface is activated with palladium chloride A (Pdclt), tin chloride (5nclt), etc., and a plating layer 6 having a thickness of about 0.01 to 0.1 fl is formed on the surface. Note that this plating layer is preferably formed by electroless plating. When this plating layer is formed, the surface of the mother die 10 is free of irregularities, so the surface is then electroplated using a plating bath that can flow a high current, such as a nickel sulfur amino acid bath. An electrodeposition layer 7 is formed thereon. This completes the electroforming mold with a uniform surface.

"Effects" As described above, this invention fills the concave portion of the matrix with ceramic cement which is a mixture of trivalent metal oxide and metal powder in a weight ratio of 5 to 50%.

The σ3 pressure applied to the surface of this ceramic cement provides good electrical conductivity, and the thermal expansion of the ceramic cement and the plating layer applied to this surface can be brought close to each other, and therefore electroforming The time will be shortened quickly. In particular, according to the present invention, the process time can be reduced by one-third to half of the conventional IK. In addition, since there is no need to perform separate machining after electroforming as in the conventional method, the rotatability of electroforming equipment is good, and this has the advantage of significantly improving electroforming efficiency by reducing electricity costs and plating chemicals. There is.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an embodiment of the electroforming method according to the present invention, and FIGS. 2 and 3 are front sectional views showing a conventional processing method. 1... Mother mold, 2... Convex part, 3... Concave part, 4...
Electrodeposited thin film layer, 5...ceramic cement, 6...plating layer. Patent applicant: Yamatake Honeywell Co., Ltd. Figure 1 Figure 2 Figure 3 rM

Claims (2)

[Claims] (1) An electrodeposited thin film layer is formed on the surface of the matrix having uneven parts, and on the surface of the electrodeposited thin film layer, the weight ratio of metal powder to trivalent metal oxide is 5 to 50 in the recessed parts. 1. A method for manufacturing an electroforming mold, which comprises filling the ceramic cement with a mixture of 10% and 20%, activating the surface of the ceramic cement, and further applying an electrodeposited layer on the surface of the ceramic cement. (2) An electrodeposited thin film layer is formed on the surface of the matrix having uneven parts, and on the surface of the electrodeposited thin film layer, the weight ratio of metal powder to trivalent metal oxide is 5 to 50 in the recessed parts. 1. An electroforming mold characterized by being filled with a filler made of ceramic cement mixed with % and an electrodeposited layer on the surface of the filler.