HK1164224A - Ceramic element inlaid with at least one metallic decoration - Google Patents

Description

Ceramic element inlaid with at least one metal decoration

Technical Field

The present invention relates to a ceramic element inlaid with at least one metal decoration, and more particularly to an element of this type intended to be mounted in a timepiece.

Background

It is known to form a bezel made at least partially of synthetic sapphire so as to show, by transparency, the deposits plated in the recesses underneath the bezel, for example forming a scale or a brand name. The advantage of this configuration is that the deposit is protected from any mechanical deterioration by completely covering it with the sapphire part. However, such a configuration may make it difficult to read the decoration not only due to the weakening of the color of the transmitted deposit, but also due to the lack of color differentiation between the sapphire and the deposit.

Disclosure of Invention

It is an object of the present invention to overcome all or some of the above-mentioned drawbacks, while still maintaining the advantages of mechanical strength and increasing the advantages of visual quality improvement.

Accordingly, the present invention relates to a method for manufacturing a mosaic ceramic element, the method comprising the steps of:

a) forming a ceramic body;

b) etching at least one recess in one face of the ceramic body, each of said at least one recess forming a molding/pattern for an ornament;

c) depositing a first layer of about 50nm over the entire face including the at least one recess,

d) depositing a second conductive layer of about 50nm over the entire face including the at least one recess so as to cover the first layer;

e) galvanically depositing a metallic material or an alloy of metallic materials from the second electrically conductive layer so as to completely fill the at least one recess;

f) all deposits are removed from the surface of the ceramic body except for the cavity of the at least one recess.

It is clear that the variation in the colour of the decorations and/or of the ceramic is no longer limited by the transparency of the ceramic, while still ensuring good wear resistance. Thus, as an example, complex visual presentations can be obtained by giving ceramics a shiny appearance and by giving each ornament a satin-like (satin) finish. Advantageously, it is also clear that said ceramic element may form all or part of a timepiece, i.e. a case, a bracelet, a bezel, a dial, a crystal, a push-button and/or a crown, among others. The invention may also be applied to all or part of jewelry, or even to tableware.

According to other advantageous features of the invention:

-step a) is achieved by sintering;

-the ceramic body is based on zirconia;

-step b) is performed by laser;

-each of said at least one recess comprises an inner surface without edges, so as to facilitate the implementation of step e);

-step c) is carried out by autocatalytic plating or by vapour deposition;

the first conductive layer is Cr, Cr₂N, TiN, TiW, Ni, NiP, Cu, Ti or Zr layers;

-step d) is achieved by vapor deposition;

the second conductive layer comprises gold and/or copper and/or silver and/or indium and/or platinum and/or palladium and/or nickel in order to optimize the adhesion and good conductivity of the second conductive layer and to provide a color close to that of the galvanic plating;

-the metallic material deposited during step e) comprises gold and/or copper and/or silver and/or indium and/or platinum and/or palladium and/or nickel;

the method comprises a final step g) for depositing a substantially transparent layer, for example a silicon nitride layer, to protect the decoration from ageing.

Drawings

Further characteristics and advantages will become apparent from the description given below, by way of non-limiting example, with reference to the accompanying drawings, in which:

figure 1 is a diagram of a timepiece according to the invention;

FIG. 2 is a cross-sectional view of a mosaic ceramic element according to the invention;

figures 3 to 8 are successive steps of the manufacturing method according to the invention;

fig. 9 is a flow chart of a method according to the invention.

Detailed Description

As shown in fig. 1, a timepiece, indicated as a whole by 1, is seen, comprising at least one inlaid ceramic element. Each mosaic ceramic element is intended to form a very wear-resistant part comprising at least one metallic decoration whose visual quality is improved, in particular in terms of contrast.

The mosaic ceramic element according to the invention may form all or part of the external part of timepiece 1. It may thus form all or part of case 2, bracelet 3, bezel 4, dial 5, crystal 6, push-button 7 and/or crown 8. In the example described below, the invention will be described with reference to a ceramic ring 10, which ceramic ring 10 comprises an inlaid ornament 13 forming the scale of bezel 4.

As shown in fig. 1, 2 and 8, the inlaid ceramic element 10 comprises a ceramic body 11, which ceramic body 11 contains at least one recess 12 forming a shaping for an ornament 13. Fig. 1 shows that advantageously according to the invention, each ornament 13 can have any shape, for example a geometric figure or an alphanumeric symbol. According to the invention, each recess 12 is completely filled with two electrically conductive layers 14, 15, each having a thickness of about 50nm, and a galvanic deposit 16, which galvanic deposit 16 is formed of a metallic material. This construction protects the individual decorations 13 in the very wear-resistant ceramic body 11.

In order to improve the adhesion of the ornament 13 in the body 11, the recess 12 preferably has a minimum depth P of 100 μm. Furthermore, for the same reason, each recess 12 preferably has a continuous, at least partially rounded surface R, i.e. the inner surface of the recess has no edges. In fact, galvanic deposits can produce filling defects due to the influence of peaks in the region with edges.

The ceramic body 11 can be obtained from a variety of materials. However, zirconia-based ceramics are preferred in view of mechanical properties, polishing ability, and (to a lesser extent) the ability to provide a wide range of shade hues. Of course, other ceramics, such as those based on titanium carbide, are obviously conceivable.

The first layer 14 serves to improve the adhesion of future decorations 13 on the ceramic body 11. In fact, the first layer 14 is preferably deposited, although the micro-roughness of the bottom of the recess 12 facilitates adhesion. Preferably, the first layer 14 has a thickness of about 50nm and is located between the second conductive layer 15 and the ceramic body 11. Depending on the deposition method used for the first layer 14, several types of materials are conceivable, for example Cr, Cr₂N, TiN, TiW, Ni, NiP, Cu, Ti or Zr.

Similarly, for the second electrically conductive layer 15 and the galvanic deposit 16, a variety of materials are also conceivable. Preferably, the second electrically conductive layer 15 is chosen to be as close as possible to the color of the galvanic deposit 16. The second layer 15 is also selected for its adhesion characteristics and the high level of conductivity required for electrodeposition.

Furthermore, according to the invention, the visual presentation effect of each ornament 13 is obtained mainly by the colour of the galvanic deposit 16. Thus, the material used for the galvanic deposit 16 will preferably depend on its color, or more generally on its aesthetic appearance. Thus, the galvanic metallic deposit 16 and, concomitantly, the second layer 15 comprise gold and/or copper and/or silver and/or indium and/or platinum and/or palladium and/or nickel.

As an example, therefore, a complex visual presentation effect can be obtained by giving the ceramic body 11 a shiny appearance and giving the ornament 13 a satin-like appearance. In order to make the color uniform, it is also conceivable that the material forming the ornament 13 is the same as the material surrounding the ceramic body 11. Thus, in the example of fig. 1, the decorations 13 of the bezel 4 are of the same material as the watch case 2, the bracelet 3, the rest of the bezel 4, the dial 5, the push-button 7 and/or the crown 8.

Finally, as shown in fig. 8, the inlaid ceramic element 10 may also be provided with an optional, substantially transparent layer 18 to protect the decorative object 13 from degradation, according to the present invention. This layer 18 may for example comprise silicon nitride in order to prevent the layers 15 and/or 16 from tarnishing, in particular when the layers 15 and/or 16 are mainly based on silver.

A method 21 of manufacturing the damascene ceramic element 10 will now be described with reference to fig. 3 to 9. In a first step 22, shown in fig. 9, the method 21 comprises forming a ceramic body 11, for example made of zirconia. As partially shown by the change from fig. 3 to fig. 4, the final ceramic body 11 of step 22 is preferably obtained by sintering, i.e. from a green or unfired body 17 preformed via an injection process. At the end of step 22, the body 11 visible in fig. 4 has its final dimensions.

As shown in fig. 9, the method 21 comprises a second step 23 for etching at least one recess 12, which may be a blind hole, in one face F of the ceramic body 11, said recess 12 forming a shaping for a future decoration 13, as can be seen in fig. 5. Preferably, each recess 12 has a minimum depth P of 100 μm. Furthermore, each recess 12 preferably has an at least partially rounded surface R, in order to facilitate the implementation of the electrodeposition step 27 described below. Step 23 is preferably achieved by destructive irradiation with a laser in order to obtain a high precision etching.

As shown in fig. 9, method 21 continues to a third step for depositing first conductive layer 14 having a thickness of about 50nm over the entire face F (i.e. including each recess 12 on that face as shown in fig. 6). This step can be implemented according to two preferred embodiments according to the present invention.

In a first embodiment, illustrated by a single line in fig. 9, a third step 24 of the method 21 comprises coating the face F with a wet process, such as chemical autocatalysis or electroless plating. Thus, it is possible to deposit, for example, a nickel-phosphorus chemical layer, which adheres well to the ceramic body 11 and forms a good adhesion layer for the subsequent step 26.

In a second embodiment, shown by double lines in fig. 9, a third step 25 of the method 21 comprises coating the face F using a dry process, for example vapour deposition. Thus, for example, Cr can be deposited₂A layer of N, TiN, TiW, Ni, NiP, Cu, Ti or Zr, which adheres well to the ceramic body 11 and forms a good adhesion layer for the subsequent step 26.

Regardless of which embodiment is chosen, method 21 proceeds to a fourth step 26 for depositing a second conductive layer 15 having a thickness of about 50nm over the entire face F (i.e. including recesses 12) so as to cover first layer 14, thereby providing an optimized surface for electroplating step 27. As mentioned above, the adhesion, good conductivity and color close to that of the galvanic deposit 16 are optimized.

This layer 15 may thus be made of, for example, gold and/or copper and/or silver and/or indium and/or platinum and/or palladium and/or nickel. Furthermore, step 26 is preferably performed using a dry process, such as vapor deposition. In this case, it is clear that when the first embodiment is employed, steps 25 and 26 can be performed in the same capsule.

The method 21 continues to a fifth step 27 for galvanic deposition of the metallic material 16 from the electrically conductive layer 15 so as to completely fill the respective recess 12, as shown in fig. 7. The renewal of the electrolyte in the recesses 12 is preferably forced by stirring, i.e. by effecting a forced displacement of the galvanic bath, in order to prevent any filling problems of the recesses 12.

As mentioned above, the metallic material deposited in step 27 comprises gold and/or copper and/or silver and/or indium and/or platinum and/or palladium and/or nickel, depending on the colour, or more generally on the desired visual presentation.

Finally, the method 21 ends with a sixth step 28, which step 28 comprises removing the deposits 14, 15 and 16 from the surface F of the ceramic body 11, with the exception of the recesses 12, as shown in fig. 2 and 8. The mosaic ceramic element 10 is thus completed and only needs to be assembled into the final part. This step 28 may be accomplished by conventional surface machining methods (e.g., grinding or lapping) for removing any excess material followed by polishing.

The method 21 according to the invention may also have an optional final step 29 for depositing a substantially transparent layer 18 to protect the decoration 13 from ageing. This layer may for example comprise silicon nitride in order to prevent the tarnishing of the layers 15 and/or 16, in particular when the layers 15 and/or 16 are mainly based on silver.

Of course, the invention is not limited to the examples given, but is capable of numerous variations and modifications as will occur to those skilled in the art. In particular, the application of the mosaic ceramic element 10 according to the invention is in no way limited to timepieces 1. Thus, as an example, the inlaid ceramic element 10 may be applied to jewelry or even to tableware.

Furthermore, the recesses 12 made in step 23 can also be made in the blank 17, i.e. before the sintering process is finished. However, at this time, it is necessary to take into account the shrinkage of the final sintered body 11 with respect to the green body 17. Similarly, the recess 12 need not be a blind hole as in the examples shown in fig. 5 to 8, but may be a completely or partially through recess. By corresponding reasoning, the at least one recess may have a depth P that is not flat (not flat) and/or larger than 100 μm.

It is also contemplated that other types of etches may be substituted for the laser etch in step 23 if the accuracy and rejection rate of the other types of etches are acceptable. As mentioned above, alternative etching can also be performed in the blank 17 or in the final body 11 at this time. This etching may be purely mechanical, for example milling.

Finally, it should also be noted that step 24 is not limited to autocatalytic or electroless plating, but can alternatively be achieved, for example, by vapor deposition or ion bombardment.

Claims (14)

1. A method (21) for manufacturing a damascene ceramic element (10), the method comprising the steps of:

a) forming (22) a ceramic body (11);

b) etching (23) at least one recess (12) in one face (F) of the ceramic body (11), each of said at least one recess forming a shaping for the ornament (13);

c) depositing (24, 25) a first layer (14) of about 50nm over the entire face (F) including the at least one recess,

d) -depositing (26) a second conductive layer (15) of about 50nm over the entire face (F) containing said at least one recess, so as to cover the first layer (14);

e) galvanic depositing (27) a metallic material (16) from the second electrically conductive layer (15) so as to completely fill the at least one recess;

f) removing (28) all deposits (14, 15, 16) from the surface of the ceramic body (11) except for the cavity of the at least one recess.

2. The method (21) according to claim 1, characterized in that step a) is carried out by sintering.

3. Method (21) according to claim 1, characterized in that the ceramic body (11) is based on zirconia.

4. Method (21) according to claim 1, characterized in that step b) is performed by means of a laser.

5. Method (21) according to claim 1, wherein each of said at least one recess (12) comprises an inner surface without edges, in order to facilitate the implementation of step e).

6. A method (21) according to claim 1, characterized in that step c) is carried out by electroless plating.

7. A method (21) according to claim 6, characterized in that the first layer (14) comprises nickel-phosphorus.

8. The method (21) according to claim 1, characterized in that step c) is achieved by vapor deposition.

9. A method (21) according to claim 8, characterized in that the first layer (14) is a Cr, Cr2N, TiN, TiW, Ni, NiP, Cu, Ti or Zr layer.

10. The method (21) according to claim 1, characterized in that step d) is achieved by vapor deposition.

11. Method (21) according to claim 1, characterized in that the second conductive layer (15) comprises gold and/or copper and/or silver and/or indium and/or platinum and/or palladium and/or nickel in order to optimize the adhesion and good conductivity of the second conductive layer and to provide a color close to that of the galvanic coating (16).

12. The method (21) according to claim 1, characterized in that the metallic material (16) deposited during step e) comprises gold and/or copper and/or silver and/or indium and/or platinum and/or palladium and/or nickel.

13. Method (21) according to claim 1, characterized in that it comprises a final step g for depositing (29) a substantially transparent layer (18) to protect the decoration (13) from ageing.

14. A method (21) according to claim 13, characterized in that the protective layer (18) comprises silicon nitride.