Manufacturing method for watch parts

Abstract

A method for manufacturing a die for manufacturing a watch part, comprising the steps of: creating (E1) a recess arising from an upper surface (21) of the substrate (20), forming a recess (30) bounded by at least one surface (31) inclined with respect to a plane (P1) in which the upper surface (21) of the substrate (20) extends; forming (E3) at least one sidewall (41) of the mold, the step comprising depositing (E31) a material on at least a portion of the surface of a substrate (20), optionally coated with a conductive layer and / or an anti-reflective layer (22); Including, forming a mold at least partially bounded by at least one sidewall (41) of the blank, at least one inclined surface (31) of the recess (30), and optionally at least a portion of the top surface (21) of the substrate (20); A method for manufacturing a mold.

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a mold for manufacturing a watch component. The present invention also relates to a method for manufacturing a watch component using said mold. The present invention also relates to the watch component itself obtained using said method. [Background technology]

[0002] Existing manufacturing methods for watch parts are not sufficient or suitable for manufacturing parts with complex shapes, i.e. forming, for example, a "Clou de Paris" type pattern, or including chamfers, bevels, angles, inclined surfaces. They sometimes succeed in achieving certain complex shapes, but only by using laborious steps such as post-machining. In general, existing manufacturing methods for manufacturing watch parts do not allow to manufacture complex shapes with sufficient precision. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] European Patent Application Publication No. 3670441 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention therefore aims to improve known manufacturing methods for producing timepiece parts, in particular to make it possible to produce timepiece parts of complex shape simply and with a high degree of precision. [Means for solving the problem]

[0005] For this reason, the present invention provides a method for manufacturing a die for manufacturing a watch part, comprising the steps of: creating a recess arising from a top surface of a substrate, the recess being bounded by at least one surface inclined with respect to the plane in which the top surface of the substrate extends; a step of forming at least one sidewall of the mold, the step comprising depositing a material on the top surface and / or on at least a portion of the recess of the substrate, the top surface being optionally coated with a conductive layer and / or an anti-reflective layer; Including, The method is based on a method of manufacturing a mold, which forms a mold at least partially bounded by at least one sidewall of the material, the at least one sloping surface of the recess, and optionally at least a portion of the top surface of the substrate.

[0006] The invention is more particularly defined in the claims.

[0007] The objects, features and advantages of the present invention will be explained in detail in the following description of particular embodiments, given as non-limiting examples with reference to the accompanying drawings. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing steps of a method for manufacturing a watch component according to one embodiment of the present invention. [Diagram 2] FIG. 2a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 2b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Diagram 3] FIG. 3a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 3b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Figure 4] FIG. 4a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 4b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Diagram 5]FIG. 5a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 5b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Figure 6] FIG. 6a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 6b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Figure 7] FIG. 7a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 7b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Figure 8] FIG. 8a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 8b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Figure 9] FIG. 9a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 9b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Figure 10] FIG. 10a is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a first embodiment of the present invention, and FIG. 10b is a cross-sectional view of a step of a method for manufacturing a timepiece component according to a second embodiment of the present invention. [Figure 11] FIG. 11 is a top perspective view of a needle according to one embodiment of the present invention. [Figure 12] FIG. 12 is a cross-sectional view of one end of a needle according to an embodiment of the present invention. [Figure 13] FIG. 13 is a cross-sectional view of a mold for manufacturing a needle according to an embodiment of the present invention. [Figure 14] FIG. 14 is a cross-sectional view of a step of manufacturing a needle using a mold according to an embodiment of the present invention. [Figure 15] FIG. 15 is a top perspective view of a modified needle according to an embodiment of the present invention. [Figure 16] FIG. 16 is a cross-sectional view of one end of a modified needle according to an embodiment of the present invention. [Figure 17] FIG. 17 is a cross-sectional view of a step of forming a recess in a substrate to produce a mold for manufacturing a modified needle according to an embodiment of the present invention. [Figure 18] FIG. 18 is a cross-sectional view of a step of forming a recess in a substrate to produce a mold for manufacturing a modified needle according to an embodiment of the present invention. [Figure 19] FIG. 19 is a cross-sectional view of a mold for manufacturing a modified needle according to an embodiment of the present invention. [Figure 20] FIG. 20 is a cross-sectional view of a step of manufacturing a modified needle using a mold according to an embodiment of the present invention. [Figure 21] FIG. 21 is a top perspective view of an inlay according to one embodiment of the present invention. [Figure 22] FIG. 22 is a cross-sectional view of a manufacturing step of a die for making an inlay according to an embodiment of the present invention. [Figure 23] FIG. 23 is a cross-sectional view of a step of manufacturing an inlay using a mold according to an embodiment of the present invention. [Figure 24] FIG. 24 shows cross-sectional views of steps of a method for manufacturing a timepiece component according to the third embodiment of the present invention. [Diagram 25] FIG. 25 shows cross-sectional views of steps of a method for manufacturing a timepiece component according to a third embodiment of the present invention. [Figure 26] FIG. 26 shows cross-sectional views of steps of a method for manufacturing a timepiece component according to a third embodiment of the present invention. [Figure 27] FIG. 27 shows cross-sectional views of steps of a method for manufacturing a timepiece component according to the third embodiment of the present invention. [Figure 28] FIG. 28 shows cross-sectional views of steps of a method for manufacturing a timepiece component according to a third embodiment of the present invention. [Figure 29] FIG. 29 is a cross-sectional view of the entire modified example of FIG. [Diagram 30] FIG. 30 shows cross-sectional views of steps in a method for manufacturing a timepiece component according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The invention achieves the object through the intermediate manufacture of a specific mould having a complex shape, in order to obtain a watch part having a complex shape by simple moulding in said specific mould.

[0010] The present invention comprises, firstly, a method for manufacturing a mold for manufacturing a watch component, and secondly, the method for manufacturing the watch component itself, as shown diagrammatically in Figure 1, a first step Ph1 of which consists in carrying out the method for manufacturing the mold, and a second step Ph2 of which is the use of said mold for manufacturing the watch component itself.

[0011] A method for manufacturing a mould for the production of a watch part according to a particular embodiment, chosen as an illustrative example to facilitate understanding, will first be described with reference to figures 2a to 10a, 2b to 10b and also to figures 24 to 30.

[0012] The method includes, according to two first embodiments, a preliminary step consisting of obtaining a substrate 20, potentially including substantially parallel upper and lower surfaces 21 and 23, with a thickness of a few hundred microns to a few millimeters, and with a thin, substantially flat shape. The upper surface 21 is usually flat. As a variant, the upper surface may not be flat, for example it may be dome-shaped and / or have one or more recesses. In any case, for the sake of simplicity, a plane P1 is described in which the upper surface 21 extends, but in the case of a surface that is not perfectly flat, as will be explained in more detail below, said plane P1 is a tangent plane. The lower surface 23 extends in a plane P3 as well. The thickness of the substrate 20 is the distance between the two planes P1 and P3.

[0013] Furthermore, the substrate 20 may be made of a conductive material, such as a metal or metal alloy, such as stainless steel, or may be made of a non-conductive material, such as silicon, glass, or ceramic, or a polymer, or a composite material, for example in the form of a wafer or block. The substrate preferably has a low roughness. The substrate may advantageously undergo conventional preparation steps, including degreasing, cleaning, and optionally its passivation and / or activation. In addition, the substrate may be provided with markers to allow precise orientation.

[0014] The method comprises a first step E1 of creating a recess 30 originating from the upper surface 21 of the substrate 20 to form a recess 30 bounded by at least one surface 31 inclined relative to a plane P1 in which the upper surface of the substrate extends. Said plane P1 is considered to be at the interface 4 between the recess 30 and the upper surface 21 of the substrate 20, being considered as the continuous upper surface except for the recess, i.e. at the interface 4. Said interface forms an edge. As mentioned above, said plane is a plane tangential to the upper surface 21 of the substrate when the entire upper surface 21 of the substrate is not flat. Similarly, the inclined surface 31 of the recess 30 is considered relative to a plane Pi tangential to the inclined surface when the inclined surface is not flat. In general, the recess 30 comprises at least one inclined surface if it comprises at least one tangent plane Pi that is non-perpendicular or non-parallel to the plane P1 of the upper surface 21 of the substrate 20.

[0015] Advantageously, the inclined surface 31 has a slope, at the interface 4 between the upper surface 21 and the recess 30, which forms an angle with the upper surface 21 (ie with the plane P1) of between 10 and 80 degrees.

[0016] 2a shows a first embodiment of a recess 30 having a curved, rounded, continuous and concave surface. The recess has a curved cross section, i.e. a cross section in a plane perpendicular to the plane P1, which forms a generally rounded U-shape. In this example, the recess 30 has an inclined surface 31 on substantially the entire surface.

[0017] 2b shows a second embodiment of a recess 30 having the shape of a conical surface forming a V-shaped cross section. As a variant, the recess may be triangular in shape and have the same V-shaped cross section. Each arm of the V forms a straight portion of the inclined surface 31 of the recess 30.

[0018] Of course, the invention does not relate to the shape of the recess 30 itself and is not limited to the two embodiments shown. The recess 30 may include an inclined surface only on a subsection of its entire surface. The inclined surface may be formed by a number of flat and / or curved small planes, each of which is potentially finally an inclined surface as defined above. The recess may also have a concave or convex shape. In general, an inclined surface is defined as a surface that makes an angle other than 0° or other than 90° with the plane P1 of the upper surface 21 of the substrate 20. The inclined surface 31 may be continuous or discontinuous. The angle that the inclined surface makes with the plane P1 may be constant or not. The inclined surface may be flat or curved. In the case of a curved surface, the aforementioned angle may be characterized, for example, by the angle that the tangent at a given point on the inclined surface makes with the plane P1, which angle varies depending on the contour of the inclined surface. The angle that the inclined surface makes with the plane P1 can be seen more specifically in the view of a section passing through a plane perpendicular to the plane P1, i.e. the cross-section defined above. It is noted that in the case of a non-flat top surface 21, the angle is measured relative to a plane tangent to the top surface 21 at interface 4. In addition, one or more recesses 30 may be formed in the substrate 20. The recesses 30 may include one or more sloping surfaces 31.

[0019] In addition, the recess 30 may be formed by any means known to the person skilled in the art, such as conventional mechanical machining, laser machining, laser etching, chemical etching or electrochemical dissolution. As a variant, the recess may not be formed by a specific machining step, but may result directly from the manufacture of the substrate 20, whose top surface 21 is locally non-flat. In all cases, the recess 30 takes the form of a surface recessed with respect to the top surface 21 of the substrate 20, the recess extending into the thickness of the substrate 20 to a predetermined depth d.

[0020] According to a third embodiment illustrated in figures 24 to 28, the substrate 20 at least partially exhibits the shape of a layer or block, in which at least one recess 30 is formed in the shape of a recessed area, in particular by means of the two-photon polymerization technique known under the acronym TPP, said substrate 20 being made of resin or of any material that can be constructed by means of two-photon polymerization (for example certain ormocers, photosensitive composite materials and certain glass-ceramics). Said substrate 20 is placed on a support 70, as shown in figure 24. In a variant not shown, the substrate 20 subjected to two-photon polymerization may take the shape of a plate, with a shape similar to that of the substrates of the first two embodiments described above.

[0021] It is noted that the two-photon polymerization technique used in the third embodiment offers many advantages, including many possible complex shapes, such as protruding overlapping areas, or non-continuous structures, or corrugated shapes. The technique also allows to achieve a very high level of precision, with a fineness of less than 100 nm and a roughness Ra of less than 10 nm. The technique also allows to perform over a large irradiation volume. The technique allows to create, for example, locally curved and also angled sloping sidewalls.

[0022] Alternatively, a substrate 20 made of resin or other compatible material can be formed with the recesses using stereolithography or grayscale photolithography techniques, which have less precision and more limited geometry.

[0023] The depth d of the recess 30 corresponds to the distance measured between a plane P1 of the upper surface 21 of the substrate 20 and a plane P2 that is parallel to the plane P1 and passes through a point on the recess 30 that is furthest from the plane P1. The depth d is measured in a direction perpendicular to the planes P1 and P2, i.e. perpendicular to the upper surface 21 of the substrate 20. Preferably, the depth d of the recess is 1000 μm or less, or 500 μm or less, or 400 μm or less. The depth d is also preferably 10 μm or more, or 50 μm or more, or 80 μm or more, or 100 μm or more.

[0024] As will become clear hereinafter, the recess 30 acts at least partially as a mould for the production of the watch component. It is more particularly used to define the complex shape of the watch component, so that said component can be advantageously produced by simple moulding, without the need for additional machining steps. It is noted that the recess has a shape suitable for the future de-moulding of the part of the watch component moulded in it. To this end, according to one exemplary embodiment, the area of ​​the cross-section of the recess along a plane parallel to the plane P1 in which the upper surface 21 of the substrate extends is smaller at every depth than the cross-section of the opening of the recess, i.e. at the interface 4 between the recess 30 and the upper surface 21 of the substrate 20. According to another exemplary embodiment, the area of ​​the cross-section of the recess 30 parallel to the plane P1 in which the upper surface 21 of the substrate extends decreases with increasing distance from said plane P1. It is noted that the substrate 20 has the single function of forming part of a mould for the production of the watch component, and that the substrate does not belong to the future watch component. It is noted that the third embodiment shown in Figures 24 to 29 uses a support 70 which does not form part of the surface of the mould or of the future watch part.

[0025] Optionally, but not shown, a conductive layer may be deposited on all or part of the upper surface 21 of the substrate 20 and at least partly in the recess 30, in particular on its inclined surface. Such a conductive layer is necessary if the substrate is not made of a conductive material and if the second stage of the manufacturing requires a conductive mold, as will be explained in more detail below. The conductive layer is particularly suitable to act as an electrode for starting an electroforming, electrodeposition or electroplating step intended to grow a future metal layer on the watch part. As is known, the starting conductive layer may comprise a sub-layer of chromium, nickel or titanium covered with a layer of gold or copper, thus presenting a multilayer structure. The conductive layer may be deposited by the methods of physical vapor deposition (PVD), or chemical vapor deposition (CVD), or atomic layer deposition (ALD), or pulsed laser deposition (PLD), by thermal evaporation or by any other means known to the person skilled in the art.

[0026] The method according to the embodiment then comprises an optional step E2 consisting of applying an anti-reflection treatment to the substrate, the function of which is explained below. According to the embodiment, said step is carried out in the form of a step consisting of depositing an anti-reflection layer 25 over at least a part of the upper surface 21 of the substrate 20 and / or of the recess 30, which is not perpendicular to the incident irradiation radiation suitable for the irradiation of the resin, which is carried out in a subsequent step described below. The application of the anti-reflection layer 25 is particularly relevant for the inclined surface 31 of the recess 30, given that it is generally preferred to apply the irradiation radiation perpendicular to the plane P1 in which the upper surface 21 of the substrate 20 extends. The anti-reflection layer 25 may extend over all or part of the upper surface 21 of the substrate 20 and / or of the recess 30, as shown in Figures 3a and 3b, or additionally over a part of the support 70, as shown in Figure 25.

[0027] Preferably, the antireflection layer makes it possible to attenuate the reflection of radiation, in particular UV radiation, by more than 98%, or more than 99%, or more than 99.9%. The antireflection layer may be of any chemical nature known to the person skilled in the art. The antireflection layer may comprise an organic material. In particular, the antireflection layer may be a layer of material known under the trade name AZ®-BARLi® II.

[0028] The anti-reflection treatment may comprise depositing an anti-reflection layer 25 by spin-coating or spray-coating or dip-coating or by chemical vapor deposition (CVD) or physical vapor deposition (PVD) or by atomic layer deposition (ALD) or pulsed laser deposition (PLD) or using any technique known to the person skilled in the art. As a variant, the step E2 consisting of applying an anti-reflection treatment to the substrate may comprise a special structuring of the upper surface 21 of the substrate 20 and or of the recess 30 or of the surface of the support 70. Such a physical structuring of the upper surface 21 of the substrate may be achieved, inter alia, by sandblasting, for example by means of a laser.

[0029] The method according to the embodiment then comprises a step E3 consisting of depositing E31 a material, in particular a resin, on the top surface and / or on the recess 30 of the substrate, to complete the mold formed by the combination of the resin and the part of the substrate, thereby forming at least one side wall of the mold. Advantageously, the sub-step consisting of E31 depositing material is such as to form a side wall of the production mold, which side wall complements the substrate forming all or part of the bottom of the mold, in particular all or part of the recess of the substrate. Alternatively, materials other than resin may be used to form the mold, for example polymers such as silicon polymers (PDMS), or any material that can be structured by nanoimprint lithography, or any laser structured polymer, or alternatively other materials such as silicon, which are held by gluing (including bonding).

[0030] According to this embodiment, the resin is deposited using photolithographic techniques during the step, which includes several sub-steps, as will be explained in detail below.

[0031] First, the step includes a substep E31 consisting of depositing a layer of photosensitive resin 40 on all or part of the upper surface 21 of the substrate 20 and / or on the recess 30 and optionally on the support 70 (optionally coated with a conductive layer and / or an anti-reflective layer 25 as described above), in particular on at least part of the recess 30, in particular on the inclined surface 31 of the recess 30, as shown in Figures 4a and 4b and 26.

[0032] The photopolymer may be negative or positive: if negative, the photopolymer is designed to become insoluble or sparingly soluble in a developer under the action of the irradiating radiation (i.e. the exposed areas resist development), whereas if positive, the photopolymer is designed to become soluble in a developer under the action of the irradiating radiation, while the parts not exposed to radiation remain insoluble or sparingly soluble.

[0033] The method then comprises a substep E32 consisting of irradiating the photosensitive resin 40 with incident irradiating radiation 45 through a mask 5, as shown in Figures 5a and 5b and 27. The irradiating radiation 45 may be UV radiation, in order to irradiate the photosensitive resin 40 according to a pattern defined by the mask 5, which has openings and opaque areas corresponding to the pattern. Alternatively, the irradiation may be performed by direct writing of the predetermined pattern (thus not requiring a mask) using a laser or an electron beam. The irradiating radiation 45 may be X-ray, UV, visible light, IR (infrared) radiation or an electron beam.

[0034] According to an advantageous embodiment, the illumination radiation 45 used is perpendicular or substantially perpendicular to the plane in which the mask 5 extends, the mask itself being parallel to the plane P1 of the upper surface 21 of the substrate 20, so that only those areas of the photosensitive resin 40 positioned in coincidence with the openings formed in the mask 5 are illuminated. The illuminated areas are defined by sidewalls that are perpendicular or substantially perpendicular to the plane P1; these sidewalls are by definition called "upright sidewalls". As a variant, the illumination radiation 45 may be inclined with respect to the plane P1 of the substrate 20, such incident radiation defining inclined sidewalls of the resin.

[0035] The step consisting of depositing the resin then includes a sub-step E33 consisting of developing the resin, according to a variant embodiment, as shown in figures 6a, 6b, 7a, 7b, 8a, 8b, 28, 29. Figure 29 illustrates a general variant of figure 28 of the third embodiment, noting that the variant is the result obtained by developing, following the aforementioned step E32, tilted and rotated with respect to the incident radiation, during which the resin 40 of the substrate 20 is polymerized. If the resin is a negative resin, the development consists of removing the areas of the resin that are not irradiated, for example by dissolving in a chemical or by plasma treatment. If a positive photosensitive resin is used, the irradiated areas are removed during development, while the non-irradiated areas remain on the substrate. After development, the substrate 20 is exposed where the resin has been removed. The remaining parts of the resin define the side walls of the mould, and the parts of the substrate circumscribed by the side walls of the mould define the bottom of the mould. Thus, the combination of the part of the substrate and the part made of resin forms the mould.

[0036] As mentioned above, the mask 5 allows to define the areas of the resin that should or should not be irradiated and ultimately to define the resin walls of the mold and the shape of the mold. In order to achieve a sufficient mold precision, it is important to limit or prevent any stray irradiation, i.e. any unwanted irradiation radiation that may reach the resin. Such stray irradiation radiation 46 may arise in figures 5a and 5b in the absence of an anti-reflection treatment of the substrate 20. Stray irradiation radiation 46 may also result from irradiation radiation 45 reflecting from the surface of the substrate 20, which may lead to the reflected irradiation reaching the resin in undesired areas. In particular, stray irradiation radiation may be able to reach areas of the resin that are intended to form the future side walls of the mold, which may result in the formation of a mold with irregularities in the resin side walls, which is undesirable since it may lead to the presence of small cavities (or small protrusions, depending on the type of resin) in the side walls of the watch parts that will ultimately be produced with said mold.

[0037] The phenomenon of stray radiation may result in particular from the inclined surface 31 of the recess 30. As a variant, such stray reflection configurations may also arise in the case of non-perpendicular incident radiation 45 on the substrate 20, in particular on its upper surface 21 if it is not flat. The presence of stray radiation is relatively foreseeable, since it depends on the shape of the selected structure. In case of risk of stray radiation, the optional step E2 consisting of applying an anti-reflection treatment to the substrate, preferably carried out as described above, completely or partially eliminates the appearance of such stray radiation, thus ensuring the correct formation of the mould defined by the mask 5.

[0038] In summary, if the direction of the incident radiation is not perpendicular to the surface on which the resin to be irradiated is deposited and / or if the substrate contains inclined surfaces that are not perpendicular to the direction of the incident radiation, this can lead to a risk of stray irradiation of the resin outside the areas directly irradiated by the incident radiation. Such stray irradiation impairs the definition of the mold by lateral irradiation of areas of the resin that should not be irradiated. For example, in the case of a substrate 20 having a flat and polished top surface 21, as shown in Figures 5a and 5b, the radiation 45 incident on the positive resin 40 in a direction perpendicular to the plane P1 is reflected from the inclined surface 31 of the recess 30 created in the substrate 20, generating a stray reflection that forms a stray radiation 46 that is not perpendicular to the plane P1.

[0039] According to a variant embodiment, the resin side walls forming part of the mold may be produced by the method described in US Pat. No. 5,999,333, which combines at least one step based on conventional photolithography as described above and at least one step based on two-photon polymerization technology, thus the same technology used to form recesses in the resin of the substrate 20 in the third embodiment of the invention.

[0040] The above steps, as shown diagrammatically in Figures 25 to 28, are equally applicable to the embodiment depicted in Figure 24 and will not be described in further detail.

[0041] Furthermore, the resin mold portion may be multi-layered with a first resin layer including a first opening and a second resin layer made of a hard film including a second opening, involving at least one step based on conventional photolithography.

[0042] Alternatively, steps E1 and E3 may be performed in reverse order.

[0043] As a result of the steps E1 of creating the recess and E3 of forming at least one side wall of the mold, the mold is formed by the combination of substrate and material (resin 40) as described above. The substrate 20, in particular the recess 30 with at least one inclined surface 31 defined thereon, allows the definition of the complex shape of the watch part to be produced. The material, such as resin 40, in particular the fully defined side wall 41 formed from the substrate 20, defines the wall of the watch part to be produced.

[0044] It is noted that several configurations are foreseeable for the placement of the sidewalls 41 of the resin 40 on the substrate 20 .

[0045] According to a first configuration, shown in figures 6a and 6b, a sidewall 41 of the resin may be formed coincident with the interface 4 between the recess 30 and the upper surface 21 of the substrate. In this case, the sidewall extends at the end of the recess 30, i.e. at an edge formed on the outer edge of the recess 30, perpendicular to the plane in which the upper surface of the substrate extends.

[0046] The quality of the production of the mould has a direct influence on the watch part produced in said mould. It is evident that it is not easy to position the resin side wall 41 exactly in line with the edge defining the outer periphery of the recess 30 described above. Any deviation in the contact point with the resin side wall 41 can result in defects in the mould and thus in the watch part produced, such as, for example, protrusions.

[0047] To reduce this risk, a second configuration, shown in figures 7a, 7b, 28 and 29, consists in generating at least one side wall 41 in the recess 30, in order to eliminate the need for precise positioning at the interface 4. With such an approach, the recess 30 is formed in a shape larger than the watch part to be produced, before being bounded by the side wall 41 which is positioned within the recess.

[0048] According to a third configuration shown in Figures 8a and 8b, the photosensitive resin forms at least one sidewall 41 outside the recess, i.e. the resin sidewall extends from the upper surface 21 of the substrate outside the interface 4 with the recess 30.

[0049] The present invention is not limited to the above-mentioned embodiments. As an example, Fig. 30 illustrates the manufacture of a mold according to a fourth embodiment, which combines one of the first two embodiments with the third embodiment. In particular, the mold first includes at least one recess 30 formed in a first substrate 20 by applying a method similar to that described with reference to the first two embodiments, and at least one recess 30' formed in a second substrate 20' positioned on the first substrate 20 by applying the third embodiment of the present invention. In the fourth embodiment, the first substrate 20 also serves to support the second substrate 20'.

[0050] Of course, other embodiments are foreseeable, particularly using an approach similar to that of FIG. 30, where the recesses may be formed using different techniques.

[0051] Finally, the method for producing a mold may comprise, after a sub-step not shown, consisting for example of developing the photosensitive resin with exposure radiation, an optional step E4 of partial or complete removal of the antireflection layer 25, if of course a step consisting of E2 of applying an antireflection treatment has been carried out. Such removal of the antireflection layer 25 is not mandatory in all cases. When carried out, such removal is applied to the substrate 20 belonging to the mold for producing the watch part, i.e. between the resin side walls 41. Said removal may be carried out mechanically or chemically, for example by stripping or plasma treatment.

[0052] Finally, as mentioned above, the method makes it possible to form a mould whose bottom is formed by all or part of the at least one recess 30 of the substrate 20 and optionally by part of the top surface 21 of the substrate, and whose sides are at least partially defined by the resin side walls 41. The substrate 20 and the at least one recess 30 form part of the mould and do not in any way belong to the watch part to be produced in the future.

[0053] In certain mould variants, the mould may also consist of the entire recess 30 of the substrate without the resin sidewall 41, in which case step E3 is not performed.

[0054] According to one embodiment, the at least one recess is formed by a material removal technique, in particular by machining, whereas according to another embodiment, the at least one recess or the side wall of the mold is obtained, completely or partly, by two-photon polymerization or grayscale photolithography or stereolithography techniques.

[0055] The invention also relates to a method for the manufacture of a watch component per se, in which a first method stage Ph1 consists in carrying out the method for the manufacture of a mould as described above. A second method stage Ph2 is based on the manufacture of the watch component per se, using said mould. An example of said second stage is described below.

[0056] The second stage of the manufacturing method first comprises a step E5 consisting of filling all or part of the mould obtained from the first stage with the material of the watch part, called part blank 10, as shown in figures 9a and 9b. The step E5 consisting of filling the mould may comprise a step of electro-deposition, electro-forming, electro-plating, casting or thermoforming, or a step of filling the part blank by casting.

[0057] Thus, according to an advantageous embodiment, the filling step may be carried out by electroforming of a metallic material, in which case the mould must be manufactured at least partially from a conductive material so that it can act as a starting electrode in view of the future growth of the metallic material of the watch part in the mould, so that, if the substrate is not made of a conductive material, a conductive layer is added to the substrate in a first stage of the manufacture of the mould, as described above.

[0058] In a variant, the mould may be used for slip casting to obtain ceramic watch parts. According to another variant, composite materials or glassy alloys can be poured or moulded into the mould.

[0059] The method then comprises a step E6 consisting of removing (in other words demoulding) the watch part 1 obtained in the preceding step from the mould, as shown in figures 10a and 10b. In the demoulding step, the substrate 20 and the at least one recess 30 exhibit properties that make them suitable for demoulding the watch part 1. In addition, the resin that forms part of the mould is dissolved. Said dissolution may be achieved using any means known to the person skilled in the art, such as chemical dissolution, deep reactive ion etching (DRIE) or laser ablation. In addition, optionally, the part may be removed from the substrate.

[0060] As a result of the above-mentioned method, all surfaces 2 of the watch part 1 formed directly in contact with the mould according to the invention have a perfect final shape after demolding, without the need for additional operations. The invention therefore makes it possible in a very simple way to produce watch parts 1 with complex shapes, in particular corresponding to the recess 30 and its inclined surface(s) 31. The watch part 1 comprises, at least locally, at least one inclined surface which is not perpendicular and not parallel to the other surfaces of the watch part, in particular to the two mutually parallel main planes, or which is inclined with respect to the surface of the part formed by the specific mould bottom.

[0061] Optionally, a finishing step may be performed on the face 3 facing the bottom of the mould, which face is not directly formed by the mould obtained by the method according to the invention. Said finishing step may consist of polishing or grinding the facing face 3 of the watch part, for example to ensure its flatness. Additionally or alternatively, said finishing step may consist of modifying the colour or the tribological properties of at least part of the surface of the watch part by deposition of a coating formed by physical vapour deposition (PVD), chemical vapour deposition (CVD), atomic layer deposition (ALD) or pulsed laser deposition (PLD). It is noted that said finishing step is applied to the facing face 3 of the watch part, which is not in direct contact with the mould. For this reason, the finishing step may be carried out before or after the step E6 consisting of removing the watch part from the mould. As a variant, the finishing step, in particular the colouring step, may be applied to the whole of the watch part.

[0062] According to another embodiment, the material of the watch component is a metal or a metal alloy, in particular based on nickel or gold or copper. According to another embodiment, the material of the component may be based on ceramic or on a composite material, i.e. completely or partially composed of ceramic or composite material, advantageously at least 50% by weight of ceramic or composite material. Thus, the resulting watch component is mainly made of a metal or a metal alloy, for example based on nickel or gold or copper, or mainly made of a ceramic or composite material.

[0063] The method for manufacturing a watch part described above is suitable for the manufacture of many different watch parts. By way of example, the watch parts may be external watch parts such as inlays or hands, or parts of the movement such as escape wheels, levers, springs, etc.

[0064] The invention also relates to the timepiece component itself. In particular, a major advantage of the invention is that it allows the production of timepiece components of complex shapes that could not be produced before.

[0065] In particular, the invention allows the manufacture of a watch part, preferably one that is manufactured in one piece, being mainly a one-piece part. The watch part may comprise a surface formed by the mould of the invention, comprising a first surface extending to the first face and a second surface inclined relative to the first surface, corresponding to one or more inclined faces of one or more recesses of the mould defined above, in particular domed and / or concave and / or convex and / or chamfered and / or comprising at least one sharp edge. Said inclined face may comprise at least one sharp edge, for example in the formation of a pattern of the "Clou de Paris" type, optionally with a polished or structured surface. The inclined face may take the form of a surface comprising a plurality of inclined portions, in particular including a profile exhibiting the shape of a ripple. The inclined face may also comprise sharp edges and / or chamfers and / or bevels and / or angles. Such an inclined face may exhibit a certain roughness.

[0066] According to a variant embodiment, the watch part may include one or more aesthetic or functional inserts. For this purpose, the manufacturing method may include an intermediate step consisting of placing at least one insert in the manufacturing mould, before the step of filling the mould with the part's material, followed by fixing the part's material to the at least one insert. Such an insert may be a decorative jewel or stone.

[0067] Moreover, advantageously, the watch part is manufactured as a single piece or as one piece, with the exception of any inserts. Alternatively, the watch part or watch may consist of at least two related separate parts, at least one of which results from the manufacturing method according to the invention.

[0068] The invention also relates to a timepiece comprising at least one timepiece part according to the invention.

[0069] The invention also relates to a mould for the manufacture of a watch part, the mould comprising a substrate, at least the upper surface of which and / or a part of a recess 30 forms the bottom of the mould, at least one inclined surface of the recess arising from the upper surface of the substrate at the same height as the bottom of the mould, the mould being at least partially delimited by a resin, in particular a photosensitive resin, deposited on the substrate, which forms at least part of the side walls of the mould.

[0070] The resin can form at least one sidewall of the mold that coincides with the outer edge of the recess in the substrate, and / or the resin can form at least one sidewall of the mold that arises from the top surface of the substrate within and / or outside the recess. The resin can form all or part of the sidewall of the mold.

[0071] At least one sloping surface of a recess in the substrate may have a slope that forms an angle between 10 and 80 degrees with the upper surface of the substrate, considered at the interface between the upper surface and the recess, said sloping surface may be rounded or may be formed by a number of planar facets, may have one or more sharp edges and may be concave or convex, among others.

[0072] Thus, the invention achieves its desired objects and more generally provides the following advantages: The manufacturing method is simple to implement and low cost. - The manufacturing method makes it possible to obtain watch parts of complex shape.

[0073] The invention will be described below in terms of the actual manufacture of some particular watch components selected as non-limiting examples.

[0074] As a first example, the timepiece part is a hand 50, shown in figure 11, which includes an end with a complex visible surface, in particular a dome-shaped inclined portion 52 with respect to a surrounding flat upper surface 51. Said inclined portion 52 can be seen more specifically in the cross-section along line II in figure 12. The inclined portion forms a protruding spherical cap with a rotation axis A perpendicular to the plane P1 of the hand 50.

[0075] The method for manufacturing the needle 50 includes the steps according to the above-mentioned embodiment, which are briefly described below.

[0076] In a first step E1, the method consists in making a recess 30 on a silicon substrate 20 with the aid of grey photolithography, using a deep reactive ion etching (DRIE) method, the shape of the recess now corresponding to a dome-shaped surface in the shape of a spherical cap. The depth d of the recess is 50 μm. Once the recess 30 has been produced, a conductive layer 22 is deposited on the substrate 20.

[0077] The side wall 41 of the mold made of resin 40 is then formed in a third step E3. For this, the following sub-steps are carried out:

[0078] On the surface of the conductive layer 22, a photosensitive resin 40 is deposited, suitable for conventional photolithography, for example SU-8, an epoxy-based negative resin which crosslinks under the action of UV radiation. - the photosensitive resin 40 is then exposed to UV radiation through a mask in order to cross-link the resin in the pattern defined by the mask, the pattern here corresponding to the circumference of the needles 50. The radiation used is perpendicular to the plane in which the substrate 20 extends, and only those areas of the resin 40 which lie in coincidence with the openings formed in the mask and which correspond to the resin parts to be retained to form the mould are irradiated. These areas are thus defined by vertical side walls 41, i.e. perpendicular to the plane P1 of the substrate 20. These upright resin side walls correspond to the faces of the needles, which form their lateral sides. It is noted that the presence of an anti-reflection layer 25 on the substrate 20 is not necessary here, since due to the shape of the needles and the use of a negative resin, the areas present at the boundaries of the recesses 30 cannot be irradiated due to stray reflections of the incident radiation. - The photosensitive resin 40 is then developed. As the resin 40 is negative, the development consists of removing the non-irradiated areas of the resin. These areas of the resin 40 are removed by dissolving them with a PGMEA based chemical (Polypropylene glycol methyl ether acetate).

[0079] After development, conductive layer 22 is visible where the resin has been removed. The remaining portions of resin 40 and the visible base of the substrate (covered with conductive layer 22) define the shape of the mold, as shown in Figure 13. Here, substrate 20, and in particular recess 30, defines the sloping visible surface of the complex shaped needle 50.

[0080] A fifth step E5 of the method consists in producing the needles by electrolytic deposition of the blank 10 of the part in order to fill the mould. Here, the mould is filled with electroformed 24 carat gold. Figure 14 illustrates the mould of figure 13 filled via step E5.

[0081] The sixth step E6 of the method consists of removing the needle 50 from the mould. The visible inclined surface 52 of the complex shaped needle 50 obtained now corresponds exactly to the bottom of the mould and to the required shape. The needle can be used directly following step E6 without any post-processing, i.e. without reworking or tribo-finishing the inclined surface 52 and the surrounding flat top surface 51 defined by the substrate 20 of the mould. The opposite surface 53 of the needle 50, which has not come into contact with the mould, is polished to ensure flatness.

[0082] According to a second embodiment, forming a variant of the first embodiment, the timepiece part is a hand 50, comprising an end portion with a complex visible surface comprising a plurality of distinct inclined portions 52 in the form of three domed caps projecting from the visible upper surface of the hand relative to a surrounding domed upper surface 51, as shown in Figures 15 and 16. The three substantially spherical caps have respective axes of rotation A1, A2, A3 substantially perpendicular to the upper surface 51 of the hand 50.

[0083] The method for manufacturing the needle 50 includes the steps according to the above embodiment, which will be briefly described below.

[0084] Figures 17 and 18 show more specifically the first step E1 of the method, consisting of creating a recess 30 in a substrate 20 consisting of a flat stainless steel wafer. The recess 30 is formed in two stages of electrochemical dissolution. The first dissolution stage first forms the dome-shaped surface of the needle 50 by forming a temporary recess 30t, as shown in Figure 17. Then, as shown in Figure 18, three recesses 30a, 30b, 30c in the shape of recess cap parts are formed at the bottom of the previously obtained temporary recess 30t to complete the final shape of the recess 30. Said recess 30 corresponds to the complex shape of the end of the needle 50, which can be seen in particular in Figure 16. It is noted that said recess 30 defines a number of inclined surfaces 31. The depth d of the recess is 50 μm.

[0085] A second step E2 of the method consists of depositing an anti-reflective layer 25 on the substrate 20. The anti-reflective layer 25 is formed of a layer of material known under the trade name AZ®-BARLi® II. The layer is deposited by means of a spin-coating method.

[0086] The third step E3 of the method is the formation of the side walls 41 of the mold from the resin 40. This step includes several sub-steps similar to those described above. Note that in this embodiment, the side walls 41 are located inside the recess 30. Once the resin has been irradiated and developed, the remaining part of the resin 40 and the visible substrate 20, in particular at least the recess portion 30, define the mold.

[0087] The fourth step of the method consists of removing E4 the anti-reflective layer 25 in the openings in the resin, i.e. at the bottom of the mold, to expose the substrate 20 as shown in Figure 19. The anti-reflective layer is now removed by an oxygen plasma treatment.

[0088] A fifth step E5 of the method consists in producing the component by filling the previously obtained mould by electroforming, as shown in Figure 20. As the substrate 20 is made of a conductive material, the electroforming method is able to start and continue growing in the conductive areas along the side walls 41 made of photosensitive resin. The needles 50 are, for example, made of nickel or gold.

[0089] A sixth step E6 of the method consists in removing the complex-shaped needle from the mould. The bevel of the needle has a polished surface corresponding to the recess 30 (and the recesses 30a, 30b, 30c it contains) manufactured in the substrate 20, with dimensions and bevels that correspond closely to the required shape. The visible surface defined by the cavity of the recess 30 on the substrate is used directly following this step E6 without any post-treatment, i.e. without reworking or tribo-finishing. No modifications are made to the shape of this surface from the mould.

[0090] The facing surface 53 of the needle is the result of the growth of electroplated material terminating. The facing surface 53 may be polished and conditioned before or after demolding.

[0091] The needle may, for example, have straight walls or may have chamfered side walls.

[0092] The watch part may then be colored using techniques known to those skilled in the art (ALD, PVD, PLD, pad printing, etc.).

[0093] According to a third embodiment, the watch part is an inlay 60 including a bevelled complex visible surface formed by two flat inclined surfaces 62 forming an inverted V-shaped cross section, as shown in FIG. 21.

[0094] The first step E1 of the method consists of creating a recess 30 in a substrate 20 consisting of a flat stainless steel wafer. Before machining, the upper surface 21 of the substrate 20 is flat and corresponds to the plane P1 defined above. Conventional machining is used to create the recess 30 in the form of two inclined surfaces that meet along the midline of the inlay, thus forming a V-shaped cross-section. The recess depth d measured at the midline of the inlay is 250 μm.

[0095] A second step E2 of the method consists of depositing an anti-reflective layer 25 on the substrate 20. The anti-reflective layer 25 has a thickness of 200 nanometers and is made of a commercial product known under the name AZ®-BARLi®. The anti-reflective layer 25 formed makes it possible to completely attenuate the UV reflections on the substrate. The anti-reflective layer is also an electrical insulator.

[0096] The third step E3 is the formation of the plastic mold side wall 41. This step comprises several photolithography sub-steps similar to those described above.

[0097] In the exemplary embodiment, the sidewall is positioned coincident with the boundary surface 4 of the recess 30, as shown in Fig. 22. Due to the positioning of the sidewall close to the inclined surface 31, the presence of an anti-reflection layer 25 is highly recommended for sufficient definition of the cross-linking of the photosensitive resin 40. Incident radiation 45 reaching the boundary surface 4 of the recess 30 may generate stray reflections, as mentioned above.

[0098] The fifth step E5 of the method consists in producing the part by casting a blank, in particular known under the trade name HyCeram®, to fill the mould and then heat treating it to give it its final configuration. The result of step E5 is shown in FIG. 23.

[0099] The sixth step E6 of the method consists in removing the part of complex shape from the mould. The resulting one-piece, one-piece fitting, has a mirror-like surface finish directly resulting from the manufacturing process and includes chamfered inclined surfaces with dimensions and inclinations that correspond closely to the required shape. The part is directly usable following the demoulding step E6 without subsequent treatment, i.e. without reworking or tribo-finishing, of the surfaces obtained in contact with the substrate forming the bottom of the mould.

[0100] The opposing surface 63 of the fitting, which is not in contact with the die, is polished to ensure its flatness.

Claims

1. A method for manufacturing a mold for manufacturing timepiece parts, a step of forming a recess (E1) that occurs from the upper surface (21) of at least one substrate (20, 20'), the step of forming a recess (30, 30') delimited by at least one surface (31) inclined with respect to a plane (P1) in which the upper surface (21) of the substrate (20, 20') extends, a step of forming at least one side wall (41) of the mold (E3), the step including a sub-step of depositing a material (E31) on at least a part of the upper surface (21) and / or the recess (30, 30') of the substrate (20, 20'), optionally covered by a conductive layer (22) and / or an antireflection layer (22), including, forming a mold at least partially delimited by at least one side wall (41) of the material, the at least one inclined surface (31) of the recess (30, 30'), and optionally at least a part of the upper surface (21) of the substrate (20, 20'), A method for manufacturing a mold.

2. The step of forming at least one side wall of the mold (E3), which includes depositing a resin (40) on at least a part of the upper surface (21) and / or the recess (30, 30') of the substrate (20, 20'), a sub-step of depositing a layer of photosensitive resin (40) on at least a part of the upper surface (21) and / or the recess (30, 30') of the substrate (20, 20') (E31), a sub-step of irradiating the photosensitive resin (40) with irradiation radiation (45) according to a predetermined pattern (E32), and then a sub-step of developing the resin (40) (E33), including, The method for manufacturing a mold according to Claim 1.

3. The material or the resin (40) forms at least one side wall (41) of the mold in coincidence with an interface (4) between the surface (21) of the substrate (20, 20') and the recess (30), and / or the material or the resin (40) forms at least one side wall (41) of the mold within the recess (30, 30'), and / or the material or the resin (40) forms at least one side wall (41) of the mold on the upper surface (21) of the substrate, outside the recess (30, 30'), The method for manufacturing a mold according to Claim 1.

4. The step of creating the recesses (30, 30') (E1) forms at least one inclined surface (31) having an inclination that forms an angle in the range of 10 to 80 degrees with respect to the upper surface (21) of the substrate (20, 20'). The method for manufacturing a mold according to claim 1.

5. The step of creating the recesses (30, 30') (E1) uses two-photon polymerization or grayscale photolithography or stereolithography technology. The method for manufacturing a mold according to claim 1.

6. Before the step of depositing the layer of photosensitive resin (E31), in order to prevent reflection of the irradiation radiation (45) used to irradiate the photosensitive resin, an antireflection treatment is applied (E2) to at least a part of the surface of the substrate (20, 20') that is not perpendicular to the incident irradiation radiation (45) intended to irradiate at least the resin. The method includes this intermediate step. The method for manufacturing a mold according to claim 2.

7. The intermediate step of applying the antireflection treatment (E2) includes depositing an antireflection layer (25) by spin coating, or spray coating, or dip coating, or chemical vapor deposition (CVD), or physical vapor deposition (PVD), or atomic layer deposition (ALD), or pulsed laser deposition (PLD). The method for manufacturing a mold according to claim 6.

8. After the step of developing the photosensitive resin with irradiation radiation (E33), the method includes the step of partially or completely removing the antireflection layer (25) (E4). The method for manufacturing a mold according to claim 7.

9. The substrate (20, 20') is made of a material selected from the group consisting of a metal wafer, a silicon wafer, a glass wafer, a ceramic wafer, a polymer, and a composite material. The method for manufacturing a mold according to claim 1.

10. Forming a timepiece part (1) includes manufacturing by the method according to claim 1 and filling all or part of the mold with a material (10) of the part (E5). The method for manufacturing a timepiece part (1).

11. The step of filling the mold (E5) includes electroplating, electroforming, electroplating, casting, thermoforming steps, or filling the material (10) of the part by casting (E5). The method for manufacturing a timepiece part according to claim 10.

12. The method includes the step of removing (E6) the clock part (1) obtained by the step of filling (E5) the mold from the mold. The method for manufacturing a clock part according to claim 10.

13. The material (10) of the part is selected from the group consisting of metals, metal alloys, and composite materials. The method for manufacturing a clock part according to claim 10.

14. The clock part (1) is an external clock part or a part of a movement. The method for manufacturing a clock part according to claim 10.

15. A mold for manufacturing a clock part, including a substrate (20, 20') including an upper surface (21) and at least one recess (30, 30') formed extending from the upper surface (21), the recess (30, 30') having at least one surface (31) that is inclined with respect to a plane (P1) in which the upper surface (21) of the substrate (20, 20') extends, including a material deposited on at least a part of the upper surface (21) of the substrate (20, 20') and / or at least a part of the recess (30, 30'), and forming at least a part of at least one side wall (41) of the substrate. The inclined surface (31) of the recess (30, 30') of the substrate (20, 20') forms at least a part of the bottom of the mold. A mold for manufacturing a clock part.

16. The material forms at least one side wall (41) of the mold in coincidence with an interface (4) between the recess (30, 30') and the upper surface (21) of the substrate (20, 20'), and / or The material forms at least one side wall (41) of the mold within the recess (30, 30'), and / or The material forms at least one side wall (41) of the mold on the upper surface (21) of the substrate (20, 20') outside the recess (30, 30'), and / or The at least one inclined surface (31) of the recess (30, 30') of the substrate (20, 20') has an inclination forming an angle in the range of 10 to 80 degrees, which is an angle measured with respect to the upper surface (21) of the substrate (20, 20') taking the upper surface (21) at the interface (4) between the upper surface (21) and the recess (30, 30') as a reference. The mold for manufacturing a clock part according to claim 15.

17. A timepiece component obtained by the manufacturing method according to claim 10, wherein the timepiece component is mainly integrally formed and includes a first surface and a second surface inclined with respect to the first surface. Timepiece component.

18. The timepiece component is mainly made of a material selected from the group consisting of metal, nickel-based metal alloy, gold-based metal alloy, copper-based metal alloy, ceramic, and composite material. The timepiece component according to claim 17.

19. An external timepiece component or a component of a movement. The timepiece component according to claim 17.

20. The timepiece component includes an aesthetic or functional insert. The timepiece component according to claim 17.

21. The timepiece component includes at least one sharp edge. The timepiece component according to claim 17.

Images