Part with 3D decoration and its manufacturing method

Abstract

To provide a method for manufacturing a part made from an electrically non-conductive material.SOLUTION: Provided is a method for manufacturing a part including at least one relief decoration (2a) of a noble metal or its alloy, the method including the steps of: depositing a first adhesion layer (4a) and a second adhesion layer (4b) on the surface of an ebauche (3); depositing by electroforming a layer of the noble metal or of its alloy (5) on the second adhesion layer (4b); laser cutting the layer of noble metal or of its alloy (5) to outline the relief decoration (2a); depositing a protective layer (7) around the relief decoration (2a); removing the layer of noble metal or of its alloy (5) from portions (2c) not covered by the protective layer (7); removing the protective layer (7); and removing the first adhesion layer (4a) and optionally the second adhesion layer (4b) on the portions (2c).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a part made from an electrically non-conductive material, the part having a 3D decoration made from a precious metal or its alloy. [Background technology]

[0002] Decorative features are generally attached, for example by gluing, to components made of hard, non-conductive materials such as ceramics, and decorative features attached in this way have poor adhesion to the substrate, increasing the risk of peeling or separation, especially in components subjected to high stresses such as watch bezels. Summary of the Invention

[0003] The present invention aims to remedy the aforementioned drawbacks by proposing a method for manufacturing parts with raised relief decorative features, in which the risk of the decorative features separating is eliminated.

[0004] More specifically, the present invention relates to a method for manufacturing a component made from an electrically non-conductive material such as ceramic and sapphire, said component including at least one embossed decorative feature made from a precious metal or its alloy, said method comprising: Providing an ébauche (substrate or blank) designed to have a surface; depositing a first adhesive layer and then a second adhesive layer on said surface; depositing a layer of said noble metal or an alloy thereof on said second adhesion layer by electroforming; laser cutting the layer of precious metal or its alloy to define the contours of the relief; depositing a protective layer around the relief decorative portion; removing the layer of the precious metal or its alloy from the parts not covered by the protective layer, and optionally, if the second adhesive layer is made of the same precious metal or the same precious metal alloy as the layer of the precious metal or its alloy, removing the second adhesive layer from said parts; removing the protective layer; removing the first adhesive layer and, optionally, if the second adhesive layer is still present after removing the layer of the noble metal or alloy thereof in the part, removing the second adhesive layer; Includes.

[0005] The method according to the invention ensures that the decorative part does not peel or separate from the substrate.

[0006] The present invention also relates to a component comprising at least one relief decorative feature covering a substrate surface, said relief decorative feature being made of a precious metal or its alloy and having a thickness between 0.02 mm and 0.7 mm, preferably between 0.03 mm and 0.3 mm, said relief decorative feature being bonded to said substrate surface by a first adhesive layer and a second adhesive layer, each having a thickness between 30 nm and 70 nm.

[0007] The layer of precious metal or its alloy in the relief decoration is therefore very thick, reaching several tenths of a millimeter, and the large thickness of the deposited metal or alloy contributes to the "robust" appearance of any decoration that may be attached thereto, such as an appliqué.

[0008] Since the present invention is specifically directed to bezel decoration, there is no risk that friction with clothing could wear off the deposit and expose the substrate.

[0009] Electroformed precious metal alloys, especially gold alloys, have the added advantage of being harder than metallurgical gold alloys that may be bonded to a substrate, which can be exploited to produce a satin finish that is durable over time. [Brief explanation of the drawings]

[0010] [Figure 1] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 2] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 3] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 4] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 5] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 6] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 7] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 8] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 9] 1 to 9 show a schematic diagram of the nine steps of the method according to the invention. [Figure 10] FIG. 10 shows a watch bezel with indexes and numerals forming a 3D ornament made from a precious metal or its alloy according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention relates to a method for making a part with at least one embossed decorative feature made from a precious metal or its alloy. This part 1, shown schematically in Figure 9 and for a bezel in Figure 10, comprises a substrate surface 2b covered with at least one embossed decorative feature 2a formed by indices and numerals made from a precious metal or its alloy.

[0012] The precious metals are more specifically gold and its alloys, silver, platinum, palladium, and rhodium. The part may be, for example, a watch component. More specifically, it may be an exterior part selected from a non-limiting list including a middle section, a case back, a bezel, a crown, buttons, bracelet links, a bracelet, a tongue buckle, a clasp, a dial, and hands. The method is particularly suitable for parts made from electrically non-conductive materials such as ceramic, silicon nitride, YAG, or sapphire. These materials are generally hard, having a hardness of 1,100 HV or more.

[0013] The method is illustrated in nine steps in Figures 1 to 9. In a first step (Figure 1), the ébauche 3 of the part to be manufactured is provided. For example, this part may be a bezel or a dial without indexes. In the case of ceramic, this ébauche can be obtained by conventional powder sintering methods for ceramic, silicon nitride, and YAG, and by the Verneuil method and EFG (Edge-defined, Film-fed Growth) techniques for sapphire. The ébauche 3 is designed with a surface 2, the side intended to contain the relief decoration.

[0014] Then, in an optional second step (FIG. 2), the surface 2 of the ébauche 3 can be provided with micro-holes 6a, engravings 6b and / or intaglios 6c to improve the fixation of future decorative features.

[0015] In a third step (FIG. 3), at least two adhesion layers 4a, 4b are deposited, preferably by PVD (physical vapor deposition), on the surface 2 and in the micropores 6a, engravings 6b and / or intaglios 6c. The first layer 4a is made of Cr or Ti, the second layer 4b is made of Au, Ag or Cu. Each layer has a thickness between 30 nm and 70 nm, typically a layer of the order of about 50 nm.

[0016] In the fourth step (Figure 4), a layer 5 of a precious metal or its alloy is deposited by electroforming on the second adhesive layer 4b. This layer has a thickness between 0.02 mm and 0.7 mm, preferably between 0.03 mm and 0.3 mm. The parameters for growing a gold alloy with a hue ranging from 3N to 5N (according to ISO standard 8654 of February 2018) are as follows: The bath contains 1 to 10 g / l of gold metal in the form of an alkaline gold cyanide complex. The bath contains 30 to 80 g / l of copper metal in alkaline double cyanide form. The bath may contain from 10 mg / l to 5 g / l of indium metal in the form of a complex. The bath contains 15 to 35 g / l of free cyanide. The bath temperature is maintained between 50 and 80°C. The pH of the bath is maintained between 8 and 12. The method is carried out at a current density between 0.05 and 1.5 A / dm2 (amperes per square decimeter).

[0017] In an optional fifth step (FIG. 5), the upper portion 5a of the layer 5 of precious metal or its alloy can be subjected to mechanical manipulation to make it polished, satin-finished and / or matte.

[0018] In a sixth step (FIG. 6), the future indices and patterns that will form the relief decoration 2a are laser cut into a layer 5 of precious metal or its alloy.

[0019] Then, in a seventh step (FIG. 7), a protective layer 7, ie a lacquer, is deposited on the future index and pattern 2a, leaving the layer 5 of precious metal or its alloy not covered by lacquer on the parts 2c.

[0020] In an eighth step (FIG. 8), the layer 5 of precious metal or its alloy is removed from the uncoated portion 2c by immersing the ébauche 3 in a cyanide bath.

[0021] In the ninth and tenth steps (FIG. 9), the lacquer 7 is removed by immersing the ébauche 3 in a Deconex® 196 solvent bath, and the adhesive layers 4a, 4b around the portion 2c are removed by immersing the ébauche 3 in a ChromeEtch No. 1 bath, a commercial product of Technic, for example. The removal of these layers has little effect on the layer of precious metal or its alloy, since the thickness of the adhesive layer differs significantly from that of the layer of precious metal or its alloy. That is, removing any nanometers from the adhesive layer removes proportionally less material from the thicker layer of precious metal or its alloy.

[0022] If the adhesion layer 4b and the layer of noble metal or its alloy 5 are made of the same noble metal, then in this step only the first adhesion layer 4a needs to be removed, since the second layer 4b has already been removed in step 8. Note that steps 9 and 10 are interchangeable.

[0023] In an optional eleventh step (not shown), the ébauche material can be textured to give the surface of the material a matte, satin finish, and / or patterned appearance. Texturing can be done by laser cutting or mechanical means.

[0024] The resulting part 1, shown in FIG. 10 for a bezel, therefore has one or more relief decorative portions 2a covering a substrate surface 2b, the relief decorative portions 2a being made from a precious metal or an alloy 5 thereof.

Claims

1. A method for manufacturing a component (1) made of an electrically non-conductive material such as ceramic and sapphire, said component (1) comprising at least one embossed decorative element (2a) made of a precious metal or its alloy, The method comprises: Providing an ébauche (3) designed with a surface (2); - depositing a first adhesive layer (4a) and then a second adhesive layer (4b) on said surface (2); - depositing a layer (5) of said noble metal or its alloy on said second adhesive layer (4b) by electroforming; - laser cutting the layer of precious metal or its alloy (5) to define the contours of the decorative relief (2a); - depositing a protective layer (7) around said relief decorative portion (2a); removing the layer (5) of precious metal or its alloy from the parts (2c) not covered with the protective layer (7) and, optionally, removing the second adhesive layer (4b) from the parts (2c) if the second adhesive layer (4b) is made of the same precious metal or the same precious metal alloy as the layer (5) of precious metal or its alloy; - removing said protective layer (7); removing said first adhesion layer (4a) and, optionally, removing said second adhesion layer (4b), if it is still present after removing said layer (5) of noble metal or its alloy in said portion (2c); A method comprising:

2. 2. The manufacturing method according to claim 1, wherein the first adhesion layer (4a) is formed from a layer of Cr or Ti, and the second adhesion layer (4b) is formed from a layer of Au, Ag, or Cu, and the first adhesion layer (4a) and the second adhesion layer (4b) are deposited by PVD.

3. 2. The method according to claim 1, wherein the first and second adhesion layers (4a, 4b) each have a thickness between 30 and 70 nm, and the layer of noble metal or its alloy (5) has a thickness between 0.02 mm and 0.7 mm, preferably between 0.03 mm and 0.3 mm.

4. 2. The method according to claim 1, further comprising the step of providing micro-holes (6a), engravings (6b) and / or intaglios (6c) before depositing the first adhesive layer (4a) and the second adhesive layer (4b), said micro-holes (6a), engravings (6b) and / or intaglios (6c) being fixing points for the decorative relief (2a).

5. 2. The method of claim 1, comprising an additional mechanical operation step on the top (5a) of the layer (5) of noble metal or its alloy to polish, satin finish and / or matt finish said layer (5).

6. 2. The method of claim 1, wherein the step of removing the layer (5) of noble metal or its alloy is carried out in a cyanide bath.

7. 2. The method of claim 1, wherein the step of removing the protective layer (7) is performed in a solvent bath.

8. 2. The method of claim 1, wherein the step of removing the first adhesive layer (4a) and optionally the second adhesive layer (4b) is carried out in a commercially available bath.

9. A component (1) comprising at least one embossed decorative portion (2a) covering a substrate surface (2b), said relief decorative part (2a) is made of a precious metal or its alloy and has a thickness between 0.02 mm and 0.7 mm, preferably between 0.03 mm and 0.3 mm; The embossed decorative portion (2a) is bonded to the substrate surface (2b) by a first adhesive layer (4a) and a second adhesive layer (4b), each having a thickness between 30 nm and 70 nm.

10. 10. The component (1) according to claim 9, wherein the relief decorative portion (2a) and the first and second adhesive layers (4a, 4b) open into micropores (6a), engravings (6b) and / or intaglios (6c) made in the substrate surface (2b).

11. 10. The component (1) according to claim 9, wherein the component (1) is a watch component.

12. Component (1) according to claim 11, wherein the component (1) is a bezel or a dial.

13. 10. The component (1) according to claim 9, wherein the component (1) is made from ceramic or sapphire, silicon nitride or YAG.

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