Manufacture of watch components

Abstract

The invention relates to the manufacture of watch components, and a method for manufacturing a resin multilayer mold by photolithography, the resin multilayer mold for manufacturing watch components and comprising a cavity provided with an inlet, the method comprising the following sub-steps for producing at least two resin layers of the mold: a sub-step of producing a first resin layer, the first resin layer comprising a first through opening or open opening in the direction of the inlet of the mold to define a first volume of the mold cavity; a sub-step of producing a second resin layer comprising a rigid film, the second layer comprising a second through opening to define a second volume of the mold cavity, the second through opening in the second layer at least partially superimposed on the first through opening or open opening of the first layer, and the second resin layer partially covering the same first through opening or open opening in the first resin layer. The advantage of the above method is that it enables the multi-stage watch components to be formed integrally, completely uniformly and homogeneously.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a timepiece component. It also relates to a method for manufacturing a mould, which is intended to be used in said method for manufacturing a timepiece component. It also relates to such a mould. Background Art

[0002] DGC Mitteilungen No. 104, 2005, mentions the use of LIGA technology (LIthographie Galvanik Abformung: technology invented by W. Ehrfeld of the Karlsruhe Nuclear Research Centre, Germany) for the manufacture of high-precision watch metal parts (e.g. for pallet forks or escape wheels). This method involves the molding of X-ray-sensitive resins irradiated by a high-energy X-ray beam specially generated by a synchrotron, which may be disadvantageous in terms of equipment.

[0003] AB Frazier et al., Journal of Microelectromechanical systems, 2, 2, June 1993, describe the fabrication of metal structures by metal electroplating in a polyimide-based photosensitive resin (photoresist) mold prepared using a technique known as LIGA-UV, which is similar to the LIGA technique mentioned above, but uses ultraviolet radiation to irradiate the resin instead of X-rays.

[0004] Patent applications EP2004881 and EP2405301 describe, for example, solutions for using this technology to manufacture complex metal timepiece components, in particular multilevel timepiece components.

[0005] These prior art solutions allow the manufacture of timepiece components to be well defined. However, these prior art methods generally require more or less cumbersome finishing steps which complicate the manufacturing process, particularly in the case of complex component geometries. Summary of the invention

[0006] The object of the present invention is therefore to propose an improved solution for producing timepiece components.

[0007] More specifically, one object of the invention is to enable the manufacture of timepiece components of complex geometry, such as a pinion shaft, so as to achieve sufficient definition, and in particular sufficient surface conditions, on all functional surfaces, and in particular on the functional surfaces of the pinion, to enable it to perform its function effectively. "Functional surface of the pinion" means in particular a surface that participates in the transmission function of the pinion. It may be the surface of a tooth, for example the lower surface or the upper surface of a tooth. "Pinion" is understood to be any toothed component having a transmission function.

[0008] To this end, the invention relates to a method for manufacturing a resin multilayer mold by photolithography, the resin multilayer mold for manufacturing a watch component and comprising a cavity provided with an inlet, the method comprising the following sub-steps for producing at least two resin layers of the mold:

[0009] a sub-step of producing a first resin layer comprising a first through opening or open opening in the direction of the inlet of the cavity of the mould, so as to define a first volume of the mould cavity;

[0010] A sub-step of producing a second resin layer comprising the rigid film, the second layer comprising a second through-opening to define a second volume of the mould cavity, the second through-opening in the second layer at least partially superimposing on a first through-opening or open opening of the first layer, and the second resin layer partially covering the same first through-opening or open opening in the first resin layer.

[0011] The present invention also relates to a method for manufacturing a watch component, the method comprising: a first step of manufacturing a mold by the above-mentioned manufacturing method; and a second step of at least partially filling the cavity of the mold manufactured in the previous step, in particular a step of filling the first volume and the second volume of the cavity of the mold, thereby manufacturing all or part of the watch component.

[0012] The present invention also relates to a resin multilayer mold, which is manufactured by photolithography, comprises a cavity having an inlet, and is used for manufacturing a watch component, the resin multilayer mold comprising:

[0013] a first resin layer comprising a first through opening or open opening towards the inlet of the cavity of the mold to define a first volume of the mold cavity;

[0014] a second resin layer comprising a rigid film, the second layer comprising a second through-opening to define a second volume of the mold cavity, the second through-opening in the second layer at least partially superimposing on the first through-opening or open opening of the first layer, and the second resin layer partially covering the same first through-opening or open opening in the first resin layer.

[0015] The invention is more particularly defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] These objects, features and advantages of the invention will be disclosed in detail in the following description of specific embodiments given in a non-limiting manner with reference to the accompanying drawings, in which:

[0017] Figures 1 to 7 The different steps of a method for producing a resin multilayer mould for producing a timepiece component by photolithography according to a first embodiment of the invention are schematically represented.

[0018] Figure 8 and Fig. 9 A method according to a first embodiment of the present invention is shown, which is used to use a Figures 1 to 7 Manufactured moulds to produce watch parts.

[0019] Fig.10 A timepiece component manufactured by the manufacturing method according to the first embodiment of the present invention is specifically shown by way of example.

[0020] Figures 11 to 17 The different steps of a method for producing a resin multilayer mould for producing a timepiece component by photolithography according to a second embodiment of the invention are schematically represented.

[0021] Figures 18 to 20 A method according to a second embodiment of the present invention is shown, which is used to use a Figures 11 to 17 Manufactured moulds to produce watch parts.

[0022] Fig.21 A top view showing details of a manufacturing mould according to a variant of the second embodiment of the invention.

[0023] Fig. 22 A timepiece component manufactured using the manufacturing method according to the second embodiment of the present invention will be specifically shown by way of example.

[0024] Fig.23 A cross section of a timepiece component manufactured using a manufacturing method according to a modification of the second embodiment of the present invention is shown by way of example. DETAILED DESCRIPTION

[0025] The invention is firstly based on a first step which comprises a particularly advantageous method for producing a multilayer mould which is subsequently able to produce a timepiece component in a second step.

[0026] The various sub-steps of the first step E1 of manufacturing the mould according to one embodiment will now be described.

[0027] Figure 1The first sub-step E10 shown comprises making a substrate 20 available. The substrate may consist of a metal wafer, in particular of an alloy such as stainless steel, or of silicon, or of glass, or of metal, or of ceramic. The substrate may also comprise structures produced by finishing. It is prepared according to rules known to those skilled in the art, in particular for degreasing, cleaning and, where applicable, passivation and / or activation thereof. The substrate is advantageously planar. Alternatively, it may comprise patterns according to the teachings of the prior art, in particular machined patterns, and / or cavities and / or other structures. The substrate is preferably provided with markings so that it can be positioned very accurately in the various steps. The substrate 20 is made of a conductive material, for example stainless steel. Alternatively, a semiconductor material substrate (for example silicon) or even an electrical insulator (for example ceramic) may also be used.

[0028] like Figure 1 As shown, a conductive layer 21 is deposited on the substrate 20, optionally for example by thermal evaporation. This conductive layer 21 is particularly intended to act as an electrode during the execution of step E2, said electrode being used to start galvanic deposition, electroplating or electroforming. In a known manner, this starting conductive layer 21 may comprise a sublayer of chromium, nickel or titanium covered with a layer of gold or copper, and may therefore take the form of a multilayer structure.

[0029] The aforementioned substrate acts as a support for manufacturing the mold, which will now be described in detail. To simplify the description, we will use the adjective "longitudinal" to specify one of the directions parallel to the plane of the substrate, and the adjective "vertical" to specify one of the directions perpendicular to the plane of the substrate. The mold is constructed by stacking multiple longitudinal layers in the vertical direction. Similarly, we will use the adjective "upper" to specify an area or surface superimposed on the "lower" area or surface on the substrate side relative to the vertical direction.

[0030] exist Figure 2 In the second sub-step E11 shown, the substrate 20, in particular the optional conductive layer 21, is covered by a first layer C10 of a first photosensitive resin 31 to a defined height corresponding to or substantially corresponding to the height of the portion C1 of the timepiece component 1 to be manufactured, as will be described below with reference to Fig.10 The resin is deposited according to rules known to those skilled in the art, for example by spin coating.

[0031] The first resin 31 is a photosensitive resin suitable for photolithography. The resin can be negative or positive. In the first case, it is designed to become insoluble or difficult to dissolve using a developer and irradiation (i.e., the exposed areas resist development), while in the second case, it is designed to become soluble using a developer and irradiation, while the parts not exposed to the irradiation remain insoluble or difficult to dissolve. In an advantageous variant embodiment of the second sub-step E11, the resin 31 used is of the "SU-8" type, which is a negative photosensitive resin polymerized by the action of UV irradiation, such as Microchem SU-8-100 resin.

[0032] Alternatively, the first resin 31 may be in the form of a dry resin film which is applied to the substrate 20, in particular to the optional conductive layer 21, thereby defining a first layer C10 of the first photosensitive resin 31. The dry film is applied in particular by a lamination method. The dry resin film may be, for example, a SUEX or ADEX film from DJ Microlaminates or a TMMF S2000 film from Tokyo Ohka Kogyo. These three films are negative dry resin films.

[0033] Then, the resin layer 31 is subjected to Figure 3 The third photolithography sub-step E12 shown. The latter includes exposing the first layer C10 of the first resin 31 to light irradiation or light through a first mask 41 including an opening and an opaque area. The mask defines the pattern to be produced to produce a portion of the watch component corresponding to the height of the first layer. Here, the luminous irradiation used to irradiate or expose the resin 31 is ultraviolet light. However, it is conceivable to use X-rays, electron beams (then using expression electron beam lithography) or any type of irradiation suitable for the resin used. The irradiation is perpendicular to the plane extended by the mask, so that only the resin area in line with the opening formed in the mask is irradiated. Therefore, these areas are defined by vertical or substantially vertical walls, i.e. walls perpendicular to or substantially perpendicular to the plane of the substrate 20. Alternatively, a transmittance variation mask can be used to form non-vertical or inclined walls of the area.

[0034] This sub-step E12 is optionally followed by a step of thermal cross-linking treatment of the resin 31 .

[0035] Then execute Figure 3The fourth development sub-step E13 shown. Therefore, in the example shown, the first layer C10 of the first resin 31 is locally dissolved to form a first opening 111 in the resin. "Open opening" refers to an opening that is open in the direction of the entrance 110 of the cavity 11 of the mold on the outside, as will be explained below. In addition, this opening has a bottom in the direction opposite to the entrance 110 of the cavity 11 of the mold. Alternatively, the first layer C10 can naturally include a plurality of openings. In the case of this example where the resin 31 is negative, development includes using a method suitable for the resin 31, such as by dissolving it with a chemical product or by a plasma method, to eliminate the unexposed resin area. In the case where a positive photosensitive resin can be used alternatively, the exposed area is eliminated, for example, by a chemical method, during the development process, while the unexposed area remains on the substrate. After dissolution, the substrate 20 or the optional conductive layer 21 will be exposed at the position where the first resin 31 has been removed.

[0036] The remainder of the first resin 31 thus forms a first layer C10 of the mold 10, which, as will be explained below, comprises a first volume formed by the first opening 111. The bottom of this opening is delimited by the substrate 20 or, where appropriate, by the conductive layer 21.

[0037] Figure 4 The fifth sub-step E14 shown consists in covering the first layer C10 of the first resin 31 with a second layer C20 of the second resin 32 .

[0038] This second resin 32 has the particular feature of being in the form of a dry film which is applied to the first layer C10 so as to define a second layer C20 of a second photosensitive resin 32 whose height corresponds or substantially corresponds to the height of the second layer C2 of the timepiece component to be manufactured, as will be seen in reference Fig.10 The dry film is applied in particular by lamination.

[0039] Due to its rigidity, the use of such a film advantageously enables the second resin 32 to be precisely positioned on top of the first opening 111 in the first layer of the first resin, in particular in the vertical direction. Such a film is advantageously self-supporting, that is to say, the integrity of its geometry can be guaranteed solely by its rigidity. In other words, such a film is rigid. According to this embodiment, the elastic modulus of such a film is more particularly 2 to 5 GPa (both inclusive) at 20° C. Therefore, the use of such a film advantageously enables the formation of a second layer C20 of the second resin 32, the longitudinal surface of which is not completely superimposed on the longitudinal surface of the first layer C10 of the first resin 31 during the fifth sub-step E14. Advantageously, such a longitudinal surface that is not completely superimposed on the longitudinal surface of the first layer C10 of the first resin 31 will not be deformed due to the action of gravity in the part thereof that is not supported by the first layer, and can therefore be precisely positioned, in particular in the vertical direction.

[0040] The resin film may be, for example, a SUEX or ADEX film from DJ Microlaminates or a TMMF S2000 film from Tokyo Ohka Kogyo. The film may have a thickness of 100 μm to 1 mm both inclusive.

[0041] Then execute by Figure 5 The sixth sub-step E15 of photolithographically treating the second layer of the second resin 32 is shown. The latter consists in exposing the second layer of the second resin 32 to light radiation or light through a second mask 42 comprising openings and opaque areas. This mask defines a pattern to be replicated to produce another part C2 of the timepiece component, as will be described below with reference to Fig.10 Described in detail.

[0042] This sub-step E15 is optionally followed by a step of thermal cross-linking treatment of the second resin 32 .

[0043] Then execute Figure 5 A seventh development sub-step E16 is shown. In the example shown where the second resin 32 is negative, the development consists in eliminating the unexposed second resin areas using a method suitable for the resin 32, for example by dissolving it with chemical products or by a plasma method.

[0044] According to the example shown in this embodiment, after dissolution, in the second layer C20 of the mold, a second through opening 112 is formed at the location where the resin has been removed. This second through opening 112 is at least partially superimposed on the first opening 111. "Through opening" refers to an opening that completely passes through the layer formed in the vertical direction. In other words, this opening is open in particular in the direction of the inlet 110 of the cavity 11 of the mold 10, as will be described in detail below, towards the first opening 111. This opening has no bottom.

[0045] The remaining part of the resin thus forms a second layer C20 forming a second volume of the cavity 11 of the mold 10 in the second opening 112 , complementary to the first volume formed by the first opening 111 .

[0046] The resulting geometry has specific characteristics, on the one hand, the second opening 112 through the second layer C20 is superimposed on the first opening 111 opening outwardly from the first layer C10, forming a cavity of the future mold of continuous volume, and on the other hand, the second resin layer C20 partially covers the same first opening 111 opening outwardly from the first resin layer. In other words, the contour of the second layer C20 at the height of the second opening 112 is projected within the vertical height of the contour formed by the first opening 111. The dry film of the second resin 32 has sufficient rigidity to support the portion positioned above the gap at the height of the first opening 111.

[0047] In the described embodiment, the two superposed openings 111, 112 are centered, in particular coaxial. The surface section of the second opening 112 is smaller than the section of the first opening 111. Of course, according to alternative embodiments, the two openings 111, 112 may at least partially be superposed and not centered.

[0048] The method for manufacturing a mold according to the first embodiment includes Figure 6 An eighth sub-step E17 is shown, which consists in covering the second layer C20 of the second resin 32 with a top layer C30 of the third resin 33 .

[0049] This third resin 33 may take the form of a dry film applied, in particular by lamination, to the second layer C20 so as to define a third layer C30 of a photosensitive third resin 33 whose height corresponds or substantially corresponds to the height of the portion C3 of the timepiece component to be manufactured, as will be seen in reference Fig.10 Alternatively, the third resin 33 may be deposited to a desired height according to rules known to those skilled in the art, for example by spin coating.

[0050] Then, the third layer of the third resin 33 is subjected to photolithography. Figure 7 The ninth sub-step E18 shown consists in exposing the resin layer 33 to light radiation or light through a third mask 43 having openings and opaque areas. In the example chosen, the mask defines a pattern to be replicated to produce a portion of the timepiece component corresponding to the height of the third layer.

[0051] This sub-step E18 is optionally followed by a step of thermal cross-linking treatment of the third resin 33 .

[0052] Then execute as Figure 7A tenth development sub-step E19 is shown. In the case of this example of embodiment in which the resin 33 is negative, the development consists in eliminating the unexposed resin areas using a method suitable for the resin 33, for example by dissolving it with chemical products or by a plasma method.

[0053] The remainder of the resin thus forms a third layer C30 of the mould which, according to the example chosen, comprises a third through-opening 113 at least partially superimposed on the first two openings 111, 112. This third opening forms a third volume of the cavity of the mould.

[0054] Thus, the three openings 111, 112, 113 are at least partially superimposed to form a cavity 11. Steps E10 to E19 result in the multilayer resin mold 10 comprising a cavity 11 having an inlet 110. The volume of this cavity 11 corresponds to the three volumes of the three openings 111, 112, 113 corresponding to the three layers C10, C20, C30, respectively. All or part of this cavity 11 is intended to be filled during a second step E2 described below.

[0055] The invention also relates to a method for manufacturing a timepiece component using a mould preformed according to a method for manufacturing a mould, which method for manufacturing a mould forms a first step E1 of the method for manufacturing a timepiece component according to the invention.

[0056] The method for manufacturing a timepiece component then comprises a second step E2 , the sub-steps of which will be described in detail hereinafter.

[0057] A first sub-step E20 consists in filling all or part of the cavity of the mold 10 with metal 12 by electroplating, electroforming or galvanic deposition.

[0058] The conductive layer 21 or substrate 20 directly acts as a cathode for starting sub-step E20. This sub-step uses, for example, a LIGA method and a metal or metal alloy 12, such as nickel (Ni) or nickel-phosphorus (NiP). An alloy such as that described in patent application WO2017102661 can be advantageously used. The metal or metal alloy 12 is deposited in all or part of the cavity 11 of the mold 10 through the inlet 110 of the cavity 11 formed on the upper surface of the third opening 113 of the third layer C30.

[0059] like Figure 8As shown, this sub-step E20 preferably extends until the entire height of the cavity 11 of the mold 10 is filled, said mold 10 having the advantage of enabling a metal or metal alloy to grow integrally in the three volumes formed by the openings 111, 112, 113 of the cavity 11 of the mold 10. Thus, unlike the parts produced by the manufacturing methods of patent applications EP2004881 and EP2405301, the watch component formed using the mold 10 results from a single and unique step of growing the metal or metal alloy. Furthermore, the watch component has a controlled definition on its functional surfaces, in particular a surface state corresponding to that of all or some of the surfaces of the cavity 11 of the mold 10.

[0060] Furthermore, the height of the resulting timepiece component is preferably the same as the height of the stack of three layers C10 , C20 , C30 corresponding to the mold 10 .

[0061] This sub-step E20 may optionally include finishing to a certain thickness by mechanically polishing the metal layer and the mold 10 simultaneously to obtain a desired flat and level upper surface with a satisfactory surface state.

[0062] The method then comprises a sub-step E21 of separating the metallic material 12 and its mould 10 from the substrate 20 , for example by delaminating the layers 21 of the substrate.

[0063] The last sub-step E22 finally enables the separation of the timepiece component 1 formed by depositing metal in the cavity 11 of the mold 10 from the resin or resins forming the mold 10, for example by chemical etching or with the aid of a plasma. This thus frees the timepiece component 1, such as Fig. 9 shown.

[0064] Fig.10 , a watch component 1 obtained according to an example of the above-described first embodiment is shown in more detail. The watch component 1 is a pinion shaft and comprises three parts C1, C2, C3 respectively molded in three openings 111, 112, 113 of the cavity 11 of the mold 10 described above. The two ends C1, C3 are similar cylinders of the same diameter and height arranged coaxially. The middle area C2 forms a pinion, which is integrated into the shaft formed by the cylinders of the parts C1, C3. The middle area C2 is inscribed in the cylinder defined by the extension parts C1, C3. The middle area C2 forms the pinion of the watch component 1 and is defined by a second volume formed by a second opening 112 in the second layer C20 of the mold 10 during the manufacturing stage, so that the second volume has a geometry corresponding to the pinion to be manufactured, in particular the teeth to be formed. Moreover, the cross-sectional area of ​​the middle part C2 is smaller than the cross-sectional area of ​​the parts C1, C3.

[0065] A first advantage of the method for manufacturing a timepiece component 1 described above is that it enables a multi-stage timepiece component 1 to be formed integrally, completely uniformly and homogeneously. In this way, it is formed in a single electroforming step, contrary to the prior art methods based on different current deposits or on successive electroforming steps carried out layer by layer, which generate an inhomogeneous multilayer structure comprising weak zones at the junctions between the layers of the finished timepiece component. On the other hand, it should be noted that the functional portion of the timepiece component 1 formed by the intermediate portion C2 has a profile perfectly defined on the resin side walls by one or more surfaces of the cavity 11 of the mold 10 and also on its upper and lower longitudinal surfaces, since they are precisely defined by the portions C1, C3 of the component themselves, which themselves are precisely defined by one or more surfaces of the cavity 11 of the mold 10. Therefore, there is no need to carry out a final reworking of the timepiece component 1 after leaving the mold to improve the definition of the functional portion of the portion C2, in particular the surface condition. Therefore, the method makes it possible to obtain a reliable timepiece component in a simplified manner.

[0066] Note that the watch component has been described based on galvanic deposition in the cavity 11 of the mold 10. Alternatively, the watch component may be made of some other material, such as a metal matrix or polymer matrix composite. Furthermore, the watch component may be formed by any method of filling the cavity of the mold other than galvanic deposition.

[0067] The invention is naturally not limited to the first embodiment described above. According to a second embodiment, the method may comprise a step of adding an insert in at least a portion of the cavity of a mould produced by a method similar to that described above, followed by a step of manufacturing a portion of a watch component by filling a portion of the cavity of the mould in a manner similar to that of the first embodiment, making it possible not only to manufacture a portion of said watch component 1 but also to fix it to the insert, thereby forming a final watch component consisting of the insert and of a portion fixed to the insert, which portion clasps the insert. Such an insert is advantageously made of a material different from that of the portion of the watch component produced by filling a portion of the cavity of the mould.

[0068] This second embodiment will now be described in more detail.

[0069] According to this second embodiment, the invention is also based firstly on a method for producing a resin multilayer mould by photolithography, which method constitutes a first step E1 ′ of the method for producing a timepiece component according to the second embodiment.

[0070] Fig.11The two first sub-steps shown comprise, on the one hand, a sub-step E100' of pre-fixing the substrate and, on the other hand, a sub-step E101' of producing a lower layer C10' of resin 31'. These two sub-steps are similar to the two first sub-steps E10, E11 of the first embodiment and will not be described again. Note that in the manner shown, the substrate 20' does not include the optional intermediate layer 21.

[0071] The method then includes Fig.12 The two sub-steps E102', E103' shown also correspond to the two sub-steps E12, E13 of the first embodiment and will not be described again. After the above sub-steps, an open-bottomed opening 114' is formed in the inner layer C10', which will form the cavity of the future mold of smaller volume.

[0072] The method comprises a fifth sub-step E104' of metallizing the upper surface of the lower layer C10' of the resin 31', such as Fig.13 As shown. This sub-step consists more specifically in depositing a conductive layer 21 ', which is intended in particular to act as an electrode for starting galvanic deposition, electroplating or electroforming, while carrying out a second step E2' that will be described later. In a known manner, this starting conductive layer 21 'can comprise a sub-layer of chromium, nickel or titanium covered with a layer of gold or copper, and can therefore take the form of a multilayer structure. This conductive layer 21 'covers not only the surface of the lower layer C10', but can also cover the bottom of the opening 114', that is to say, the surface of the substrate 20' in the example shown, or even the side of the opening 114'.

[0073] The method includes Fig.14 The sixth sub-step E105 ′ shown includes forming a first layer C20 ′ of a first photosensitive resin 32 ′ to a desired height on the conductive layer 21 ′.

[0074] The first resin 32' can take the form of a dry film, which is applied to the conductive layer 21' in particular by lamination. The resin film can be, for example, a SUEX or ADEX film from DJ Microlaminates or a TMMF S2000 film from Tokyo OhkaKogyo. These three films are negative resin films. Alternatively, the first resin 32' is deposited to the desired height according to rules known to those skilled in the art, for example by spin coating. Alternatively, the first resin 32' is of the "SU-8" type, which is a negative photosensitive resin that polymerizes by the action of UV radiation, for example Microchem SU-8-100 resin.

[0075] Then, the method includes Fig.15The two sub-steps E106', E107' shown correspond substantially to the two sub-steps E18, E19 of the first embodiment. This makes it possible to form a first through opening 111' in the first layer C20', which will form a first volume of the cavity 11' of the mold 10', complementary to the volume formed by the lower opening 114'.

[0076] The method then comprises a ninth sub-step E108' consisting in covering the first layer C20' of the first resin 32' with a second layer C30' of the second resin 33', such as Fig.16 shown.

[0077] The second resin 33' is characterized by taking the form of a dry film, which is applied to the second layer C20', in particular by lamination, so as to define a second layer C30' of a second photosensitive resin 33' of a predefined height. Due to its rigidity, the use of such a film advantageously enables the second resin 33' to be accurately positioned on the first opening 111' formed in the first layer C20', in particular in the vertical direction, as will be explained in detail below. Such a film is advantageously self-supporting, that is to say, the integrity of its geometric shape can be guaranteed only by its rigidity. In other words, such a film is rigid. The elastic modulus of such a film is advantageously and more particularly 2 to 5 GPa (including both ends) at 20°C. The thickness of the film can be 100 μm to 1 mm (including both ends).

[0078] Then, the method includes Fig.17 The two sub-steps E109 ′, E110 ′ shown enable the formation of a second through-opening 112 ′ in the second layer C30 ′ in a manner similar to the two sub-steps E15 , E16 of the first embodiment. It forms the second volume of the cavity 11 ′ of the mold 10 ′.

[0079] Finally, the three openings 114', 111', 112' respectively form three volumes corresponding to the volumes of the cavity 11' of the mold 10'. In other words, they at least partially overlap to form the cavity 11'.

[0080] As in the first embodiment, the resulting geometry has the particular feature that, on the one hand, the second through-opening 112' in the second layer C30' is superimposed on the first through-opening 111' in the first layer C20' and, on the other hand, the second layer C30' of resin partially covers the same first through-opening 111' in the first layer of resin. In other words, the profile of the second layer C30' at the height of the second opening 112' is projected within the vertical height of the profile formed by the first opening 111'. The second resin 33' has sufficient rigidity to support the portion positioned above the gap at the height of the first opening 111'.

[0081] In the described embodiment, the two overlapping openings 111', 112' are centered, in particular coaxial. The cross-sectional area of ​​the second opening 112' is smaller than the cross-sectional area of ​​the first opening 111'. Of course, in alternative embodiments, the two openings 111', 112' may at least partially overlap and not be centered.

[0082] The result of steps E100' to E110' is a multilayer resin mold 10' comprising a cavity 11' with an inlet 110'. The volume of this cavity 11' corresponds to three volumes corresponding to the three openings 114', 111', 112' in the three layers C10', C20', C30' respectively.

[0083] The invention also relates to a method for manufacturing a timepiece component using a mould formed as above according to a method for manufacturing a mould, which method for manufacturing a mould forms a first step E1 ′ of a method according to a second embodiment of a method for manufacturing a timepiece component according to the invention.

[0084] According to this second embodiment, the method for manufacturing a timepiece component comprises an intermediate step E3' of inserting an element or insert into a portion of the cavity of the mould, followed by a second step E2' of filling the portion of the cavity of the mould similar to the second step E2 of the first embodiment. The sub-steps of these manufacturing steps will now be described in detail hereinafter.

[0085] like Fig.18 As shown, according to the second embodiment shown, a portion of an element 1b', in this example a shaft, is inserted through three openings 112', 111', 114' of a mold 10'. In view of this, the form of the section of the lower opening 114' of the lower layer C10' of the mold 10' is preferably substantially equivalent to the form of the section of the inserted portion of the element 1b', in particular having a diameter substantially equal to the diameter of the section of the inserted portion of the element 1b'. The inserted shaft portion is preferably driven into this lower opening 114' so as to fit the shaft in the cavity 11' of the mold 10' with a small clearance, while the axis A1b' of the shaft is perpendicular to the plane of the substrate 20' according to the prescribed fitting tolerance. This insertion of the shaft, driven into the lower layer of the "SU-8" type resin 31', advantageously allows the shaft to be firmly held during the rest of the process.

[0086] In this embodiment, the diameter of the insertion portion of the shaft 1b' is also equal to the diameter of the receiving portion 10b' of the shaft 1b', which is intended to receive the part 1a' to be manufactured subsequently, as will be described in detail later. Of course, the two parts of the shaft may have different diameters and / or shapes.

[0087] Moreover, in this embodiment, the shaft is driven until it abuts against the substrate 20', in particular against the metal layer 21' on the substrate 20' created during step E104'. Alternatively, the substrate 20' may have an opening below the lower opening 114', which is arranged to allow the passage of a shaft portion, in particular to guide the passage of a shaft portion, in particular the pivot of the shaft.

[0088] In this embodiment, the element 1 b ' that forms the insert in the method is previously machined in its entirety before the intermediate step E3'. In other words, it has a finished state when it is assembled in the mold 10' during the intermediate step E3'. Alternatively, it may have an intermediate state when it is assembled in a portion of the cavity 11 ' of the mold 10' during the intermediate step E3' and is finished after the second step E2'.

[0089] In addition, the second opening 112' in the second layer C30' also has a shape that substantially corresponds to the diameter of the element 1b'. Once the element 1b' has been disposed in a portion of the cavity 11' of the mold 10', the first opening 111' disposed between the lower opening 114' and the upper opening 112' (i.e., the second opening) is in fact closed, ignoring the corresponding gap defined between the element 1b' and the two openings 114', 112'. More specifically, the first opening 111' is closed on its vertical side walls by the first layer C20', on its central vertical wall by the element 1b', on its longitudinal lower surface by the longitudinal upper surface of the lower layer C10' (more specifically, the metallization layer 21' deposited on the lower layer C10'), and on its longitudinal upper surface by the longitudinal lower surface of the second layer C30'.

[0090] The second step E2' of the method aims at forming, using the mould 10', a portion 1a' of a timepiece component 1', which is formed at Fig. 22 To this end, part of the volume of the cavity 11' of the mold 10', in particular part of the first volume delimited by the first opening 111', that is to say the volume of the cavity 11' not occupied by the element 1b', is filled with material in a manner similar to the second step E2 of the first embodiment.

[0091] A portion 1a' of the timepiece component may be made of metal or a metal alloy. Alternatively, the portion 1a' may be made of a composite material, for example a composite material having a metal or polymer matrix.

[0092] According to this embodiment, the second filling step E2 ′ comprises the following sub-steps.

[0093] Fig.19The first sub-step E20' shown consists in depositing a metallic material in a portion of the cavity of the mould 10', and thus around the element 1b', by electrodeposition, electroforming or galvanic deposition. The resulting metallic portion, electrodeposited or electroformed, and in particular isotropically electroformed or electroformed, has internal stresses such that it perfectly supports and grips the element 1b', thus being able to retain the future portion 1a' of the timepiece component 1' on the element 1b'. Note that in this example, the portion of the volume of the cavity 11' of the mould 10' to be filled is limited to that delimited by the first opening 111', the remaining volume being occupied by the inserted element 1b'.

[0094] In this sub-step, the conductive layer 21 ' acts as a cathode for starting the deposition. This step uses, for example, the LIGA process and a metal or metal alloy, such as nickel (Ni) or nickel-phosphorus (NiP). An alloy such as that described in patent application WO2017102661 can be advantageously employed.

[0095] As mentioned in the case of the first embodiment, this sub-step E20' has the advantage of enabling a portion 1a' of the watch component 1' to be grown integrally from a metal or a metal alloy. Moreover, the metal is formed at a height perfectly defined by the first layer C20'. Since a portion of the cavity of the mold formed by the first opening 111' is perfectly defined on all its surfaces, including the lower surface and the upper surface, the portion 1a' forms an excellent final surface state, including on its longitudinal surface. In particular, it is interesting to emphasize that the growth of the second layer C30' of the metal or metal alloy relative to the second resin enables the excellent surface state of the upper surface of the portion 1a' to be obtained. Therefore, the presence of the second layer C30' on the portion of the first opening 111' produces a portion 1a' of the watch component 1' whose functional surface is perfectly controlled and processed, regardless of any mechanical rework.

[0096] However, sub-step E20' may optionally comprise a finishing step of the junction between element 1b' and the metal forming portion 1a'. This finishing step may be performed, for example, with the aid of a laser, in particular a femtosecond laser.

[0097] Finally, in order to obtain Fig. 20 As a result shown, the method comprises the separation of timepiece component 1 ′ in sub-steps E21 ′, E22 ′, similar to steps E21 , E22 of the first embodiment, for example by chemical etching or with the aid of plasma.

[0098] exist Fig.21The pattern 330' of the second layer C30' at the level of the second opening 112' shown may advantageously have an elastic structure 331'. This configuration advantageously enables the element 1b' to be centered and perpendicular to the substrate 20', in particular to the underlying layer C10' of the resin 31' in which the portion 1a' is intended to be placed.

[0099] Additionally or alternatively, the selected pattern 330' is advantageously designed to define a sufficient gap between the element 1b' and the second layer C30' of the second resin 33' so that the electrolyte can pass through the first opening 111' during the second step E2'. This gap represents the gap of the entrance 110' of the cavity 11' of the mold thus constituted. Alternatively or additionally, the pattern 330' may include one or more holes 332' to enable the electrolyte to pass. Therefore, each hole is part of the entrance 110' of the cavity 11' of the mold. Alternatively or additionally, the mold 10' may include one or more holes, which are arranged in a plane different from the plane of the pattern 330'. Each of these holes is also part of the entrance 110' of the cavity 11' of the mold.

[0100] The pattern 330' of the second layer C30' is formed during the above-mentioned sub-steps E109', E110', which consist in exposing the second layer of resin 33' to light radiation or light through a third mask 43' comprising openings and opaque areas. This mask thus defines the pattern 330' to be replicated, allowing the electrolyte to pass through the first openings 111' during the second step E2'.

[0101] Of course, if Fig.23 As shown, the element 1b' can be particularly suitable for optimizing the retention of the portion 1a' on the element 1b'. For example, the shaft portion 10b' can include grooves 101b' designed to optimize the torque retention of the pinion on the shaft. During step E2', metal is, for example, accommodated in these grooves 101b'. Alternatively or additionally, the shaft portion 10b' can include a bearing surface 102b' designed to maximize the axial retention of the pinion on the shaft. Alternatively or additionally, the shaft portion 10b' can include a structured surface, the purpose of which is to locally increase the roughness in order to optimize the retention of the pinion on the shaft.

[0102] Fig. 221 shows in more detail a timepiece component 1' obtained according to an example of an implementation of the second embodiment described above. This timepiece component 1' is a pinion shaft. The shaft is formed by the above-mentioned insert and the pinion corresponds to the portion 1a' produced around the portion of the inserted shaft. Thus, the timepiece component 1' advantageously comprises a first portion 1a', here the pinion, advantageously made of a first metallic material, and a second portion, corresponding to an element 1b', here the shaft, made of a second material, which is preferably non-conductive and different from the first material.

[0103] Here, the shaft of the watch component 1 ' passes completely through the pinion. The shaft can be made of a non-conductive material, such as a ceramic, in particular zirconium oxide, in particular 3% yttria-stabilized zirconium oxide, or single-crystal aluminum oxide, or a combination of aluminum oxide-zirconia. Alternatively, the shaft of the watch component can be made of a composite material.

[0104] The shaft comprises a portion 10b' for receiving a pinion, a portion of which has a first diameter D10b'. Advantageously, the shaft also comprises at least one portion 11b' for guiding the pinion shaft 1', preferably two guiding portions 11b', in particular two pivots 11b', the cross section of which has a second diameter D11b'. The second diameter D11b' is preferably smaller or even much smaller than the first diameter D10b'.

[0105] Due to the intrinsic properties of the aforementioned ceramics, which are very hard, the pivots of the shafts will not mark in the event of a collision. In the event of a strong impact, these pivots will advantageously not deform, unlike steel pivots, which would bend and thus reduce the chronograph function and / or the function of the watch movement. Furthermore, ceramics have the additional advantage that they are particularly insensitive to magnetic fields, in particular magnetic fields greater than 80 kA / m (1000 G), and do not affect their operation when they are subjected to magnetic fields.

[0106] The first diameter D10b' is preferably smaller than 2 mm, or even smaller than 1 mm, or even smaller than 0.5 mm, or even smaller than 0.3 mm, and the diameter D10b' is preferably larger than 0.1 mm, or even larger than 0.2 mm.

[0107] The second diameter D11b' is preferably less than 0.5 mm, or even less than 0.4 mm, or even less than 0.2 mm, or even less than 0.1 mm, or even less than 0.08 mm, and the second diameter D11b' is preferably greater than 0.03 mm, or even greater than 0.05 mm.

[0108] More preferably, the ratio D10b′ / D11b′ is from 2 to 8, including from 3 to 6.

[0109] Alternatively, the shaft may take the form of a cylinder comprising a portion 10b' to receive the pinion and be machined after the second step E2'. In particular, the guide portion 11b' may be subsequently machined.

[0110] Of course, the invention is not limited to the described embodiments. For example, as with component 1, the first part 1a' of component 1' may comprise a plurality of parts arranged at different heights. Alternatively, the second part 1b' of component 1' may take the form of an insert whose height is less than or equal to the total height of part 1a' and may therefore be inscribed within the volume defined by the first part 1a'. As another alternative, part 1a' may constitute the entirety of component 1'. In the latter two cases, the use of the lower layer C10' is not mandatory. In all these cases, at least one functional surface of all or part of component 1' is perfectly defined by the second layer C30', in particular with regard to its surface state.

[0111] It may advantageously enable the manufacture of timepiece components of any geometry and therefore of the associated moulds.

[0112] Finally, the invention is based on a method for manufacturing a timepiece component by photolithography of a resin multilayer mould, comprising the following sub-steps for manufacturing at least two resin layers of the mould:

[0113] o a sub-step of producing a first resin layer, the first resin layer comprising a first through opening or open opening in the direction of the inlet of the cavity of the mold, so as to define a first volume of the mold cavity;

[0114] ○ A sub-step of producing a second resin layer comprising a rigid film, wherein the second layer comprises a second through opening to define a second volume of the mold cavity, the second through opening in the second layer at least partially superimposed on the first through opening or open opening of the first layer, and the second resin layer partially covers the same first through opening or open opening in the first resin layer.

[0115] This method makes it possible to obtain a mold comprising:

[0116] a first resin layer comprising a first through opening or an open opening towards the inlet direction of the cavity of the mold to define a first volume of the mold cavity;

[0117] ○ A second resin layer, comprising a rigid film, wherein the second layer comprises a second through opening to define a second volume of the mold cavity, the second through opening in the second layer at least partially overlapping the first through opening or open opening of the first layer, and the second resin layer partially covering the same first through opening or open opening in the first resin layer.

[0118] As mentioned above, the second layer therefore includes a portion above the portion of the opening in the first lower layer. To this end, it includes a resin including a rigid film that allows it to maintain a continuous and stable shape despite this special configuration, thereby applying force on the free end of the second layer suspended above the first opening in the first layer. To this end, the second resin layer may include a resin coated with a dry film, in particular a SUEX or ADEX film from DJ Microlaminates or a TMMF S2000 film from TokyoOhka Kogyo. Naturally, any other resin film that can achieve satisfactory rigidity may be suitable. For example, this resin film advantageously has a stiffness characterized by an elastic modulus of 2 to 5Gpa (including both ends) at 20°C. Therefore, this film is advantageously self-supporting or rigid, that is, its geometric integrity can be ensured only by its rigidity. In addition, the second layer advantageously has a thickness greater than or equal to 100μm, advantageously 100μm to 1mm (including both ends).

[0119] As described above, the various other resins of the other layers may be the same as or different from the resin of the second layer.

[0120] Naturally, the invention does not specifically concern a design formed by one or more openings. The latter may thus be cylindrical or of any other shape. Moreover, each layer may have one or more openings. Thus, the mould may comprise a plurality of cavities. The geometry of the openings is determined by the watch component to be manufactured. Finally, as mentioned above, the mould comprises at least two superimposed layers and may have three or more layers. Thus, it may comprise a plurality of sets of two layers as described above, wherein a plurality of resin layers comprise a rigid film similar to the second layer described above.

[0121] The present invention also relates to a method for manufacturing a watch component, the method comprising: a first step of manufacturing a mold according to the above-mentioned manufacturing method; and a second step of at least partially filling the cavity of the mold manufactured in the previous step with an insert and / or a filling material, in particular filling the first volume and the second volume of the cavity of the mold, so as to manufacture all or part of the watch component.

[0122] The second filling step may comprise inserting the electrolyte through the inlet of the cavity of the mould and filling at least two openings of at least two corresponding layers of the mould, so that all or part of the electroformed watch component is in this way in a one-piece, integrated form (monolithic) in the cavity of the mould without superposition of different layers.

[0123] In all cases, the second opening of the mold at least partially overlaps the first through-opening or open opening in the first layer to form a continuous volume corresponding to the volume of the mold cavity, and the second resin layer partially covers the same first through-opening or opening in the first layer.

[0124] By means of this particular construction of the mould according to the invention, in which the first step of manufacturing the mould consists of manufacturing a layer of the mould with a through opening or an open opening in the direction of the inlet of the mould and covered by another layer, the lower and / or upper longitudinal functional surface of all or part of the timepiece component obtained by the second filling step has a shape and in particular a surface condition perfectly defined by the boundaries of the corresponding surface of the cavity of the mould. Thus, the timepiece component advantageously has a very good surface condition immediately when leaving the mould cavity.

[0125] Furthermore, the method of the invention advantageously enables the manufacture of a clock axle comprising teeth. More advantageously, the axle comprises a non-metallic part clamped by a pinion, whose upper and lower functional surfaces are perfectly defined by the resin surface of the cavity of the mould and whose surface state is perfectly controlled by the surface state of the resin surface of the cavity of the mould.

[0126] Naturally, the above-described method for manufacturing timepiece parts is not limited to the manufacture of pinion shafts and can be used to manufacture timepiece parts, such as, as non-limiting illustrative examples, a shaft with a cam, a pivot anchor (i.e. an anchor and its pivot pin), a pivot balance (i.e. a balance and its pivot).

Claims

1. A method for manufacturing a watch component, characterized in that The method comprises: a first step for manufacturing a resin mold for manufacturing a watch component and comprising a cavity provided with an inlet; and a second step for at least partially filling a first volume and a second volume of the cavity of the mold manufactured in the first step, thereby manufacturing all or part of the watch component, The first step comprises the following sub-steps for producing at least two resin layers of the mould: o a sub-step of producing a first resin layer, the first resin layer comprising a first through opening or open opening towards the inlet direction of the cavity of the mold, so as to define a first volume of the cavity of the mold; o a sub-step of producing a second resin layer forming a rigid film, the second resin layer comprising a second through opening to define a second volume of the cavity of the mould, the second through opening in the second resin layer at least partially superimposing on a first through opening or open opening of the first resin layer, and the second resin layer partially covering the same first through opening or open opening in the first resin layer, so that the second resin layer comprises a profile projected within the vertical height of the profile formed by the first through opening according to the partial positioning above the gap at the height of the first through opening, the rigid film having sufficient rigidity to support the partial positioning above the gap, It is also characterized in that: the watch component includes an opening in at least one layer of the mold and has a form corresponding to the element to be inserted, and the method includes an intermediate step of inserting the element in the opening so as to retain the element during the second step, so that the second step is able to produce a part of the watch component in a part of the cavity of the mold, which surrounds the element inserted into the part of the cavity of the mold.

2. The method for manufacturing a timepiece component according to claim 1, wherein: The sub-step of producing the second resin layer comprises applying a dry film-forming resin, and / or the second resin layer comprising a rigid film has an elastic modulus of 2 to 5 GPa and / or a thickness greater than or equal to 100 μm, and / or is self-supporting.

3. The method for manufacturing a watch component according to claim 1 or 2, comprising: ○ The sub-step of producing the first resin layer comprises: - depositing a first photosensitive resin; - exposing the first photosensitive resin through a mask and developing the first photosensitive resin to form a mold, the mold comprising a first through opening or an open opening toward an entrance direction of the cavity of the mold to define a first volume of the cavity of the mold; ○ The sub-step of producing the second resin layer comprises: - depositing a second photosensitive resin forming a dry film, said dry film being applied onto the first resin; - exposing the second photosensitive resin through a mask and developing the second photosensitive resin to form a cavity of the mold including the second through opening.

4. The method for manufacturing a timepiece component according to claim 3, wherein: The dry film is laminated to the first resin.

5. The method for manufacturing a watch component according to claim 1 or 2, wherein: The second through-opening in the second resin layer is centered over the first through-opening or open opening in the first resin layer.

6. The method for manufacturing a timepiece component according to claim 1, wherein: The second step comprises filling all or part of the cavity of the mould by electrolysis, including circulating an electrolyte through an inlet of the cavity of the mould.

7. The method for manufacturing a timepiece component according to claim 1, wherein: The second step comprises filling all or part of the cavity of the mold by electroforming.

8. The method for manufacturing a timepiece component according to claim 1 or 7, wherein: The second step consists in inserting an electrolyte through the inlet of the cavity of the mould and filling at least two openings of two corresponding layers of the mould, so that all or part of the electroformed timepiece component is integrally formed in the cavity of the mould in this way without superposition of different layers.

9. The method for manufacturing a watch component according to claim 1 or 6, wherein: A first step in manufacturing the mold comprises producing a mold comprising a through opening or an open opening in the direction of the entrance of a cavity of the mold and a layer partially covered by another layer, the through opening or the open opening of the layer in the direction of the entrance of the cavity of the mold forming a first volume of the cavity of the mold to define all or part of the watch component to be manufactured, so that all or part of the lower functional surface and / or the upper functional surface of the watch component produced by the second step has a shape perfectly defined by the limits of the surface of the cavity of the mold.

10. The method for manufacturing a timepiece component according to claim 1, wherein: The method comprises an intermediate step of inserting an element into a second through-opening of the second resin layer and into a first through-opening or open opening of the first resin layer of the mould.

11. The method for manufacturing a timepiece component according to claim 10, wherein: The element is a shaft.

12. The method for manufacturing a timepiece component according to claim 1 or 6, wherein: The first step for manufacturing the mold includes: producing a lower layer including a lower opening; a second upper layer including a second upper opening centered on the lower opening of the lower layer; and a first intermediate layer between the lower layer and the second upper layer, the first intermediate layer including a first intermediate through opening centered on the openings in the lower layer and the second upper layer, the cross-sectional area of ​​the first intermediate through opening of the first intermediate layer being larger than the cross-sectional area of ​​the openings in the lower layer and the second upper layer, the first intermediate through opening forming a cavity portion of the mold of a portion of the watch component, and wherein the second step enables the manufacture of the watch component in a portion of the cavity of the mold, the watch component including a portion of the watch component surrounding an element inserted into the mold.

13. The method of manufacturing a timepiece component according to claim 1 or 6, comprising the step of coating the lower layer of the mold with a metal layer, and wherein the second step comprises filling a portion of the cavity in the mold by electroforming.

14. Method for manufacturing a timepiece component according to claim 12, comprising an opening in the upper layer of the mould having a form substantially corresponding to the element to be inserted, in order to guide and / or retain the element to be inserted, the upper layer being adapted to: - elastically retaining said element during said second step, said opening comprising a pattern forming an elastic structure; and / or - by patterning a structure comprising at least one hole in the upper layer of the mould as part of the entrance to the cavity of the mould and / or by a structure defining gaps at the level of the inserted elements enabling material to pass to fill the cavity of the mould.

15. The method for manufacturing a timepiece component according to claim 14, wherein: When the second step includes an electroforming step, an electrolyte can be passed through.

16. The method for manufacturing a timepiece component according to claim 12, wherein: The inserted element is a cylindrical shaft so that the second step enables the pinion to surround the shaft and the upper and lower functional surfaces of the shaft are perfectly defined by the resin surface of the mold during the second step, thereby forming a timepiece component as a timepiece shaft including teeth.

17. The method for manufacturing a timepiece component according to claim 1 or 6, wherein: The inserted element is a cylindrical ceramic shaft and the pinion is made of metal, the shaft comprising: at least one bearing surface at the height of the pinion to maximize the axial retention force of the pinion on the shaft; and / or at least one groove to maximize the torque retention force and / or roughness difference of the pinion on the shaft to facilitate the connection of the pinion to the shaft.

18. A resin multilayer mold, manufactured by photolithography, comprising a cavity having an inlet and used for manufacturing a watch component, the resin multilayer mold comprising: a first resin layer comprising a first through opening or an open opening towards the inlet direction of the cavity of the mold to define a first volume of the cavity of the mold; a second resin layer forming a rigid membrane, the second resin layer comprising a second through opening to define a second volume of the cavity of the mold, the second through opening in the second resin layer at least partially superimposing on a first through opening or open opening of the first resin layer, and the second resin layer partially covering the same first through opening or open opening in the first resin layer, so that the second resin layer comprises a profile projected within the vertical height of the profile formed by the first through opening according to the partial positioning above the gap at the height of the first through opening, the rigid membrane having sufficient rigidity to support the partial positioning above the gap, The timepiece component comprises, in at least one layer of the mould, an opening having a form corresponding to the element to be inserted, the inserted element being a cylindrical shaft around which a pinion surrounds, and the pinion being made of metal.

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