Method for manufacturing a clock component

Abstract

The present invention provides a method for manufacturing a master mold for a mold of a clock component, wherein the method at least comprises the following steps: manufacturing (E1) a first structure including at least one layer of photosensitive resin from a first photosensitive resin, the first structure including a first pattern obtained by polymerizing the first photosensitive resin by irradiation with the aid of at least one mask and then developing the first photosensitive resin; transforming (E2) the first structure into a second structure by structuring at least one surface of the first structure by adding a second photosensitive resin to at least one surface of the first structure.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a master mold for a mold for a watch component and a method for manufacturing a watch component. In other words, the present invention relates to a method for manufacturing a master mold for a mold for a watch component and a method for manufacturing a watch component. Background Art

[0002] Lithography is a technique commonly used in the manufacture of watch components, and in particular, it can form a resin mold for manufacturing watch components.

[0003] For example, Patent EP2405300 describes the implementation of a method for manufacturing at least two-layer metal parts using lithography technology.

[0004] Document EP3035125 proposes an improved method for manufacturing multi-layer watch components using lithography technology.

[0005] Document EP3260932 describes a method for manufacturing a watch component made of polycrystalline ceramics, in which a mold formed by lithography is used.

[0006] However, these methods of the prior art based on so-called conventional lithography have the following disadvantages: They cannot produce absolutely arbitrary three-dimensional shapes, such as complex shapes at the micron or even nanometer scale.

[0007] In addition, the term "soft lithography" is used to describe a method for obtaining a mold made of a soft material from a master mold that can be manufactured by, for example, using a conventional lithography method.

[0008] However, this method of the prior art has the following disadvantages: It cannot produce absolutely arbitrary three-dimensional shapes, such as complex shapes at the micron or even nanometer scale.

[0009] Therefore, an object of the present invention is to improve the methods known in the prior art and propose a solution for manufacturing three-dimensional watch components that may have complex shapes at the micron or even nanometer scale. Another object of the present invention is to allow the manufacture of watch components with a high degree of reliability, high reproducibility, and high precision. Summary of the Invention

[0010] To this end, the present invention relates to a method for manufacturing a master mold for a mold for a watch component and a method for manufacturing a watch component.

[0011] The method for manufacturing a master mold for a mold for a watch component at least includes the following steps:

[0012] - Fabricate a first structure including at least one layer of photosensitive resin from a first photosensitive resin, the first structure including a first pattern obtained by polymerizing the first photosensitive resin by irradiation through at least one mask and then developing the first photosensitive resin;

[0013] - Transform the first structure into a second structure by structuring at least one surface of the first structure by adding a second photosensitive resin to at least one surface of the first structure. This step advantageously employs two - photon polymerization technology.

[0014] The present invention is more particularly defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above - mentioned objects, features and advantages of the present invention will be described in detail in the following description of specific embodiments given by way of non - limiting examples with reference to the accompanying drawings, in which:

[0016] Figure 1 A perspective view of an automatic pawl prepared by a manufacturing method according to an embodiment of the present invention is depicted.

[0017] Figure 2 Depicts an enlarged perspective view of an opening in a pawl prepared by a manufacturing method according to an embodiment of the present invention Figure 1 of.

[0018] Figures 3 to 9 Shows successive steps in a method for manufacturing a master mold of a mold designed to allow the manufacture of Figure 1 and Figure 2 the depicted automatic pawl according to a first embodiment of the present invention.

[0019] Figure 10 Based on the master mold obtained from the steps shown by Figures 3 to 9 shows the manufacturing steps of a mold for an automatic pawl.

[0020] Figure 11 Based on the mold obtained especially at the end of the steps shown in Figure 10 shows the manufacturing steps of an automatic pawl.

[0021] Figures 12 to 16 Shows successive steps in a method for manufacturing a master mold of a mold designed to allow the manufacture of Figure 1 and Figure 2 the depicted automatic pawl according to a second embodiment of the present invention.

[0022] Figure 17 Based on the master mold produced from the steps shown by Figures 12 to 16 shows the manufacturing steps of a mold for an automatic pawl.

[0023] Figure 18 Based on especially inFigure 17 The mold obtained at the end of the steps shown illustrates the manufacturing steps of the automatic pawl.

[0024] Figure 19 A flowchart is shown, which schematically depicts the steps and sub-steps of the first alternative form and the second alternative form of the first embodiment.

[0025] Figure 20 A flowchart is shown, which schematically depicts the steps and sub-steps of the first alternative form, the second alternative form, and the third alternative form of the second embodiment. Detailed Description of the Invention

[0026] The present invention particularly implements a manufacturing method for a master mold designed to allow the manufacture of a mold for a horological component, which advantageously combines at least one step based on traditional lithography with at least one step based on two-photon polymerization technology (abbreviated as TPP). For example, this method is used in the method described in document US9302430 in a field far from horology. Ultimately, it can be compared to a specific form of three-dimensional lithography that is very different from traditional lithography.

[0027]

[0028] More specifically, the present invention implements a manufacturing method that at least includes a first step and a second step. The first step consists of manufacturing a first structure E1 on a substrate using traditional lithography techniques, and the second step advantageously consists of transforming the first structure E2 into a second structure by structuring at least one surface of the first structure using two-photon polymerization technology.

[0028] In a first embodiment of the present invention, in addition to the first step E1 and the second step E2, the manufacturing method further includes:

[0029] - A third step, which consists of manufacturing E3, E3' designed to allow the manufacture of a master mold 2 for a mold 3 for a horological component 6;

[0030] - A fourth step, which consists of manufacturing E4 the mold 3;

[0031] - And a step of manufacturing E5 the horological component 6.

[0032] Regarding Figure 1 And Figure 2The manufacture of the depicted automatic pawl 6 will be used to illustrate a manufacturing method according to a first alternative form of a first embodiment of the present invention. The automatic pawl 6 is made of, for example, industrial ceramics, preferably ceramics such as yttria-stabilized zirconia, and includes an opening 62, the wall of the opening 62 including a microstructure 63 that is designed to, for example, reduce the contact area between the wall of the opening 62 of the pawl and the guiding device with which it cooperates. The pawl, in particular the microstructured wall of the opening 62, has a very complex geometry, which can advantageously be obtained by the manufacturing method according to the first embodiment.

[0033] Now refer to Figures 3 to 11 A first embodiment of a manufacturing method for manufacturing a master mold for a mold for a horological component and a method for manufacturing a horological component using the mold obtained from the master mold are described. The mold obtained from the master mold is particularly suitable for manufacturing the automatic pawl as described above and, more generally, for manufacturing any horological component.

[0034] The method includes a first step E1 of manufacturing a first structure 10 on a substrate 20 using conventional lithography techniques.

[0035] By convention, the horizontal direction is defined as the direction parallel to the plane of the substrate 20. The vertical direction is defined as the direction perpendicular to the horizontal direction and thus perpendicular to the plane of the substrate.

[0036] The substrate 20 can take the form of a wafer made of a metal such as stainless steel, or a silicon wafer, a glass wafer, or a ceramic wafer. Advantageously, it is planar. Optionally, it can include structures prepared, for example, by laser machining. These structures can include, for example, patterns, in particular machining patterns and / or cavities. The substrate is prepared according to rules known to those skilled in the art, in particular with regard to degreasing, cleaning, possible passivation, and / or activation. Preferably, the substrate 20 has reference marks that enable it to be positioned with high precision. The substrate 20 can be made of a conductive material (e.g., stainless steel). As an alternative, a substrate made of a non-conductive material such as silicon can also be used, for example. In this case, in a preparatory step that can be carried out before the first step E1, a conductive layer 21 can be applied to the upper surface of the substrate 20, for example, using thermal evaporation. In a known manner, the conductive initiation layer 21 can include an underlying layer of chromium, nickel, or titanium covered with a gold layer or a copper layer and can thus take the form of a multilayer structure.

[0037] The first step includes sub-steps which consist in applying (E11) a first photosensitive resin 31 such that it covers, according to rules known to those skilled in the art, all or part of the upper surface of the conductive layer 21 of the substrate 20 with a layer of the first photosensitive resin 31 of a desired height (or, in the absence of the conductive layer 21, directly covers the upper surface of the substrate 20). This first photosensitive resin 31 is suitable for conventional photolithography. It can be negative or positive. In the case where it is negative, it is designed to become insoluble or hardly soluble in the developer under the action of irradiation (i.e., the exposed areas resist development), while in the case where it is positive, it is designed to become soluble in the developer under the action of irradiation, and the parts not exposed to irradiation remain insoluble or hardly soluble. The photosensitive resin 31 can be of the SU-8 type (a negative photosensitive resin that polymerizes under the action of UV irradiation), for example, the resin of the model SU-8-100 from Microchem.

[0038] Then, the first step includes a sub-step which consists in: exposing E12 the first photosensitive resin 31, particularly using UV irradiation, X-ray irradiation or electron beam, in a direction substantially perpendicular to the mask, so as to polymerize it according to a first pattern defined by the mask 4, as Figure 3 shown. This exposure consists in exposing the layer of the photosensitive resin 31 to light irradiation by means of a mask 4 including openings and opaque areas. Thus, this mask defines a first pattern to be reproduced in order to produce a structure or a part of a structure. The irradiation used extends perpendicular or substantially perpendicular to the plane in which the mask extends, and perpendicular or substantially perpendicular to the substrate 20, such that only the resin areas arranged directly in alignment with the openings formed in the mask are irradiated. Thus, these areas are delimited by vertical or substantially vertical walls (i.e., walls perpendicular or substantially perpendicular to the plane of the substrate 20). Alternatively, a mask with variable transmittance can be used to form non-vertical or inclined walls.

[0039] Next, the first step includes a sub-step which consists in developing E13 the first photosensitive resin 31. In an embodiment where the resin 31 is a negative resin, the development consists in eliminating, according to a method suitable for the photosensitive resin 31, for example, by using chemicals to dissolve the photosensitive resin 31 or using a plasma process, the unexposed (i.e., non-irradiated) areas of the resin. As an alternative, in the case of a positive photosensitive resin, the irradiated areas are eliminated, for example, by chemical means during development, while the non-irradiated areas are retained on the substrate. After development, the upper surface of the substrate 20 or, optionally, the conductive layer 21 is exposed at the locations where the resin has been removed. Thus, the remaining resin parts form Figure 4The first structure 10 shown. This structure remains on the upper surface of the substrate 20 or on the conductive layer 21 of the substrate 20 if present. Thus, the first structure 10 extends between two horizontal surfaces (an upper horizontal surface (defined as the interface between the polymeric resin and air) and a lower horizontal surface (defined as the interface between the polymeric resin and the upper surface of the substrate 20 or optionally the conductive layer 21)), and includes side surfaces 11 that extend between these two horizontal surfaces. The side surfaces 11 are generally substantially vertical, but alternatively may be inclined. These side surfaces are the result of forming openings in the first photosensitive resin 31 by removing the unpolymerized photosensitive resin using conventional lithography. Preferably, the first structure 10 has a constant height (measured between the two surfaces of the upper and lower surfaces).

[0040] To produce a multi-layer structure, the first step E1 may involve repeating the above sub-steps using different masks having different first sub-patterns, the result being a first structure having a first pattern corresponding to the combination of the different first sub-patterns.

[0041] Then, the method includes a second step, which consists of transforming the first structure 10 into a second structure 1 by structuring at least one surface of the first structure 10, in particular at least one side surface 11 of the first structure 10. This step involves adding a second three-dimensional pattern 12 of polymeric resin on the at least one surface.

[0042] Thus, the second step includes a sub-step, which consists of: applying a layer of a second photosensitive resin 32 in liquid or semi-liquid form on at least a part of at least one of the above surfaces of the first structure 10, in particular on at least one side surface 11, as Figure 5 shown. For example, this step can be carried out by drop casting or any other means that allows the application of a liquid or semi-liquid resin (spraying, spin coating, etc.). The second photosensitive resin 32 is particularly suitable for the aforementioned two-photon polymerization technique. It can be negative or positive. In a particular embodiment, the photosensitive resin 32 used is a semi-liquid resin, such as Nanoscribe's IP-Dip TM resin, which is a negative resin. The embodiments are not limited to the above description. The aforementioned surfaces of the first structure can alternatively or additionally be horizontal, not just the side surfaces, especially in the case of manufacturing multi-layer watch components.

[0043] Advantageously, the first photosensitive resin 31 and the second photosensitive resin 32 can be the same. Thus, the resins used for the two steps E1, E2 are suitable for both conventional lithography and two-photon polymerization.

[0044] Then, the second step includes sub-steps which consist in: performing two-photon polymerization E22 (as Figure 6 shown) on at least a part of the layer of the second photosensitive resin 32 so as to achieve three-dimensional polymerization according to a predetermined second three-dimensional pattern. To this end, the method can employ a photon device 5 which is designed to emit electromagnetic waves onto or into the photosensitive resin 32 so as to polymerize it according to the spatial coordinates corresponding to the second pattern. The advantage of such a method lies in the defined precision and the complexity of the patterns that can be achieved, for example especially patterns that are discontinuous in the vertical direction.

[0045] According to an advantageous embodiment, the photon device 5 includes an objective lens 51 which is at least partially immersed in the second photosensitive resin 32 so as to polymerize it according to the spatial coordinates defining the shape or three-dimensional geometry 12 of the second pattern. This alternative form advantageously allows optimizing the resolution of the second three-dimensional pattern. More specifically, the objective lens 51 is designed to direct and focus the laser beam 52 such that the focal point passes through the respective spatial coordinates defining the shape or geometry 12 of the second pattern. For each coordinate, two photons can be simultaneously absorbed by the resin 32 at the focal point of the laser 52 in a very small volume called a "voxel". A chemical reaction is triggered and the liquid or semi-liquid resin polymerizes and becomes solid within the voxel. Thus, the voxels generated by the path of the focal point of the laser beam 52 define the shape or geometry 12 of the second pattern. When the focusing optics of the laser and the material of the photosensitive resin 32 act together advantageously, the diameter of the voxel can be less than 0.1 μm, so that very high-resolution microstructures or even nanostructures can be defined on at least one surface of the first structure 10, especially on at least one side surface 11. Thus, this step can define a second pattern with a three-dimensional resolution of 0.001 μm 3 or better and a lateral resolution equal to the diameter of the voxel (i.e., 0.1 μm) or better.

[0046] In addition, at least a part or all of the objective lens 51 being immersed in the second photosensitive resin 32 prevents the laser beam 52 from passing through the interface between the objective lens and the air and the interface between the air and the second photosensitive resin, and avoids the deflection of the laser beam at these interfaces. The laser beam (photon beam) only interacts with the second photosensitive resin: it is processed in a continuous medium, avoiding any parasitic reflection or refraction or power loss. As a result, the path of the laser beam is minimized and the detection of the already polymerized part is made easier. The result is that the three-dimensional resolution of the second pattern is optimized and the processing speed is maximized.

[0047] Furthermore, as Figure 6As depicted, by applying a second photosensitive resin 32 on the side surface 11 of the first structure 10, particularly on a surface perpendicular or substantially perpendicular to the substrate 20, the second pattern can extend at least partially in the horizontal direction or in a direction having a significant horizontal component.

[0048] Thus, this step can form microstructures or even nanostructures. For example, as Figure 7 shown, these structures can take the shape of a square wave or a step 12 on the surface 11. These shapes do not cut into the surface 11 but are applied to the surface 11 in the form of a relief.

[0049] Then, the second step includes a sub-step which consists in: developing (E23) the second photosensitive resin 32 to eliminate the unpolymerized second photosensitive resin 32 and obtain a second structure 1 having a shape defined by the first pattern and the second pattern. Specifically, once the second photosensitive resin 32 has been polymerized according to a predetermined three-dimensional geometry, in the case of a negative photosensitive resin, for example, by dissolving the unexposed areas of the photosensitive resin 32 in a chemical or using a plasma process to eliminate these unexposed areas. Preferably, the chemical used is the same as the chemical used in the first step. For example, it can be a solvent based on PGMEA.

[0050] At the end of this second step, the combination of the two photosensitive resins 31, 32 shaped into the above two patterns finally forms the second structure 1 attached to the substrate 20.

[0051] According to the first embodiment, the second structure 1 is intended to form, together with the substrate 20, a first mold for manufacturing a master mold, which is intended for manufacturing a second mold for manufacturing watch components. In the first embodiment, the second structure 1 can include at least one cavity 13.

[0052] Due to the steps E1, E2 of the above method, a second structure 1 having an absolutely arbitrary complex three-dimensional shape can be formed, and thus it is possible to prepare an absolutely arbitrary master mold for a mold for watch components having a corresponding complex three-dimensional shape.

[0053] Then, the method implements a third step, which consists in using E3, E3' the second structure 1 to manufacture a master mold, which is intended for manufacturing a manufacturing mold for watch components.

[0054] More specifically, the third step E3, E3' consists in using the second structure 1 together with the substrate 20 as a manufacturing mold for a master mold 2, which is intended for manufacturing a third mold 3, and the third mold 3 is intended for directly manufacturing watch components 6.

[0055] The master mold 2 may in particular comprise a metal or a metal alloy or a ceramic or a composite material. Preferably, the master mold 2 comprises a substrate 20.

[0056] According to a first alternative form of the first embodiment described below, the master mold 2 is the result of growing a metal or metal alloy layer 22 on the substrate 20. Thus, the master mold preferably consists of the substrate 20, the layer 21 (if any), and the layer 22 of metal or metal alloy grown on said substrate. Alternatively, the master mold 2 does not comprise the substrate 20 and takes the form of a layer 22 of metal or metal alloy that has been grown on a substrate and that has been previously separated from the substrate.

[0057] In this first alternative form of the embodiment, the third step comprises a sub-step which consists in applying E31 the metal layer 22 which at least partially forms the master mold 2 into one or more cavities 13 of the second structure 1 by electrodeposition or electroplating, as Figure 8 shown. In this sub-step, the above-mentioned conductive layer 21 or the substrate 20 itself (if it is made of a conductive material) is used as the cathode to initiate the deposition reaction. This step uses, for example, the LIGA process and a metal or a metal alloy, such as nickel (Ni) or nickel-phosphorus (NiP) or any nickel-based alloy. Advantageously, the alloys described in document WO2017102661 can be used. The height H of the obtained metal layer 22 is preferably the same as the height of the mold formed by the second structure 1. The height of the metal layer 22 can also be less than the height of the mold, or even greater than the height of the mold. Optionally, this sub-step may include adjusting the height by mechanically polishing the metal layer and the mold simultaneously in order to obtain a completely flat upper surface.

[0058] Furthermore, the height H of the obtained metal layer 22 is preferably significantly greater than the height of the layer 21. It is preferably more than five times the height of the layer 21, or even more than ten times the height of the layer 21.

[0059] In this first alternative form of the embodiment, the third step may include an optional sub-step which consists in separating E32 the assembly formed by the metal layer 22 and the second structure 1 from the substrate 20, for example by peeling the conductive layer 21 from the substrate.

[0060] In this first alternative form of the embodiment, the third step comprises a sub-step which consists in separating E33 the master mold 2, formed in particular by the metal layer 22, from the second structure 1, for example by chemical etching or using a plasma, in order to achieve Figure 9 the result depicted.

[0061] The possible sub-step E32 and the sub-step E33 can be carried out in any order.

[0062] According to a second alternative form of the first embodiment described below, the master mold 2 results from the formation of a ceramic layer on a substrate 20. Thus, the master mold preferably consists of the substrate 20, the layer 21 (if any), and the ceramic layer formed on the substrate. Alternatively, the master mold 2 does not include the substrate 20 and takes the form of a ceramic layer on a substrate, which layer is pre-separated from the substrate.

[0063] In this second alternative form of the embodiment, the third step E3’ includes a sub-step which consists of filling the second structure E31’ with a product containing ceramic powder using a liquid path. For example, this step can involve pouring a slurry or pouring a gel or pouring a coagulum. Alternatively, in the case where the substrate is made of a conductive material or where the upper surface of the substrate is covered with a conductive layer 21, electrophoresis can be used to implement this step. In the case of a slurry, it can contain a liquid substance, ceramic powder, and at least one additive. The liquid substance can include water, alcohol, or other organic solvents. The ceramic powder can include, for example, zirconia or alumina or oxides or carbides or nitrides. This step can be carried out under vacuum to ensure perfect filling without entrapment of air.

[0064] This sub-step E31’ can be preceded by an optional sub-step which consists of preparing at least one surface portion of the substrate 20 facing at least one cavity 13 of the second structure 1, or of applying a coating on at least one surface portion of the substrate 20 facing at least one cavity 13 of the second structure 1 to make it easier to release the blank of the master mold 2 from the substrate 20 in the future. Note that the blank can take the form of a green body, for example, which is a precursor of the master mold 2.

[0065] In this second alternative form of the embodiment, the first step includes a sub-step which consists of consolidating the product located in the second structure E32’. This sub-step can in particular include drying the slurry to obtain a blank of the master mold 2.

[0066] An optional intermediate sub-step can consist of adjusting the height of the blank of the master mold 2 before demolding. The blank can take the form of a green body, for example, which is a precursor of the master mold 2.

[0067] In this second alternative form of the embodiment, the third step includes a sub-step which consists of separating the blank of the master mold from the manufacturing mold formed by the second structure 1 E33’. This separation can be achieved, for example, by chemical erosion or by treatment using plasma.

[0068] In this second alternative form of the embodiment, the third step finally comprises sub-steps consisting in degreasing the blank obtained in the foregoing step and then densifying it by sintering E34'. Preferably, the substrate 20 is made of a material intended to be able to withstand the temperature of the sub-steps of the third step E3'. For example, the substrate may be made of silicon or alumina. Alternatively, the master mold 2 does not include the substrate 20 and takes the form of a ceramic layer pre-separated from said substrate.

[0069] According to an alternative form of the first embodiment, the master mold 2 may be at least partially made of a soft material such as an elastomer. By way of example but not exhaustively, mention may be made of silicone, PDMS (polydimethylsiloxane), rubber, polybutadiene, fluororubber, etc.

[0070] Regardless of the alternative implementation forms of the first embodiment, the method for manufacturing a watch component comprises a fourth step consisting in manufacturing a second mold 3 using the master mold obtained in the method steps above E4. The second mold 3 is advantageously prepared from a soft material such that it can be easily removed from the master mold 2. The second mold 3 may for example be made of a polymer, in particular an elastomer such as PDMS (polydimethylsiloxane) or silicone.

[0071] This step E4 comprises a first step consisting in using the master mold 2 which at least partially defines the imprint cavity of the mold and an auxiliary device such as an annular element 7 to delimit E41 the volume intended to receive a quantity of elastomer 33 which is the precursor of the second mold 3.

[0072] Then, this step E4 comprises a second sub-step consisting in pouring E42 the above-mentioned quantity of elastomer 33 into the imprint cavity defined by the master mold 2 and the annular element 7, as Figure 10 shown.

[0073] Then, this step E4 comprises a third sub-step consisting in polymerizing E43 the above-mentioned quantity of elastomer 33 to cure it in the previously defined imprint cavity.

[0074] Then, this step E4 comprises a fourth sub-step consisting in separating E44 the elastomer mold 3 from the master mold 2 and the annular element 7.

[0075] Regardless of the alternative implementation forms of the first embodiment, the method for manufacturing a watch component comprises a fifth step consisting in manufacturing E5 a watch component 6 using the second mold 3.

[0076] For example, this step E5 comprises sub-steps E51, E52, E53, E54 which are similar to the sub-steps E31', E32', E33', E34' of the step E3' of the second alternative form of the first embodiment of the present invention.

[0077] This step E5 may in particular include the sub-step of filling the die 3 of E51 with a product containing ceramic powder using a liquid route. For example, this step may involve pouring a slurry or pouring a gel or pouring a condensate. In the case of a slurry, it may contain a liquid substance, ceramic powder, and at least one additive. The liquid substance may include water, alcohol, or other organic solvents. The ceramic powder may include, for example, zirconia or alumina or oxides or carbides or nitrides. This step may be carried out under vacuum to ensure perfect filling without entrapment of air.

[0078] Before this sub-step E51, there may be an optional sub-step which consists of preparing at least one surface portion of the die 3, or of applying a coating on at least one surface portion of the die 3, to make it easier to release the green body of the member 6 from the die 3 in the future. Note that the green body may, for example, take the form of a green compact, which is a precursor of the member 6.

[0079] Then, step E5 may in particular include the sub-step of consolidating the product located in the die 3, E52. This sub-step may in particular involve drying the slurry to obtain the green body of the member 6.

[0080] An optional intermediate sub-step may consist of adjusting the height of the green body of the member 6 before demolding.

[0081] Then, step E5 may in particular include the sub-step of separating the green body of the member 6 and the die 3, E53. For example, this separation may be achieved by chemical erosion or by treatment using plasma.

[0082] Then, step E5 may in particular include the sub-step of degreasing the green body of the member 6 obtained in the foregoing step and densifying it by sintering, E54.

[0083] The clock component is preferably made of ceramic or composite material. Such a ceramic component is preferably made of a ceramic known as industrial ceramic. "Industrial ceramic" is the name of a dense material based on alumina; and / or based on zirconia; and / or based on zirconia stabilized especially with yttrium oxide and / or cerium oxide and / or magnesium oxide; and / or made of strontium aluminate, especially doped strontium aluminate; and / or made of nitrides; and / or made of carbides; and optionally colored especially using metal oxides and / or mixed metal oxides and / or spinel phases. For the sake of simplicity of description, the term "ceramic" can be used to refer to the "industrial ceramic" that can be used to manufacture component 6. A material is considered "dense" if its density is between 95% and 100% of the theoretical density of the material under discussion. Note that the idea of "based on" here means that the mentioned chemical composition accounts for at least 50% by weight of the total chemical composition of the ceramic involved. Note that the industrial ceramic used to form the component is theoretically different from the ceramic that can be used to form the mold.

[0084] In the second embodiment of the present invention, the second structure 1 is intended to at least partially form the master mold 2' of the mold 3' for manufacturing the clock component 6. At the end of the second step E2, the combination of the two photosensitive resins 31, 32 respectively formed into the above two patterns forms the second structure 1 attached to the substrate 20.

[0085] Figures 12 to 16 Shows the successive steps in the manufacturing method of the master mold 2' of the mold 3' for the automatic pawl depicted and Figure 1 and Figure 2 aiming to allow the manufacture of the clock component 6 according to the second embodiment of the present invention. Here, the second structure 1 is intended to form, together with the substrate 20, the master mold 2' of the mold 3' for manufacturing the clock component 6. Alternatively, the master mold 2' does not include any substrate 20 and takes the form of the second structure 1, which is pre-separated from the substrate. Thus, different from the first embodiment, the second structure 1 directly forms the master mold 2' here, rather than the mold for manufacturing the master mold.

[0086] In this second embodiment, the second structure 1 may include at least one cavity 13.

[0087] In this second embodiment, the manufacturing method of the clock component includes a third step of manufacturing the mold 3' using the master mold 2' of E4', E4", E4*, as Figure 17 shown.

[0088] According to the first alternative form of the second embodiment, the mold 3' is advantageously made of a soft material so that it can be easily removed from the master mold 2'. The mold 3' can be made, for example, of a polymer, especially an elastomer such as PDMS (polydimethylsiloxane) or silicone.

[0089] According to this first alternative form of the second embodiment, the method for manufacturing a clockwork member comprises a third step of manufacturing a mold 3' by using a master mold 2' of E4', as Figure 17 shown. The step E4' may include, for example, sub-steps E41', E42', E43', E44' similar to the sub-steps E41, E42, E43, E44 of the step E4 described previously.

[0090] In the second and third alternative forms of the second embodiment, the mold 3' may be rigid. In this case, the master mold 2' may be a sacrificial master mold.

[0091] According to the second alternative form of the second embodiment, the mold 3' is the result of growing a layer of metal or metal alloy on a substrate 20. Thus, the mold 3' preferably consists of the substrate 20, the layer 21 (if any), and the layer of metal or metal alloy that has been grown on said substrate. Alternatively, the mold 3' does not include the substrate 20 and takes the form of a layer of metal or metal alloy that has been grown on a substrate and has been previously separated from the substrate. The mold 3' includes at least one cavity herein.

[0092] According to this second alternative form of the second embodiment, the third step of manufacturing the mold 3' by using a master mold 2' of E4'' includes sub-steps E41'', E42'', E43'' similar to E31, E32, E33 of the sub-step E3 of the first alternative form of the first embodiment of the present invention.

[0093] According to the third alternative form of the second embodiment, the mold 3' is the result of forming a ceramic layer on a substrate 20. Thus, the mold 3' preferably consists of the substrate 20, the layer 21 (if any), and the ceramic layer formed on the substrate. As an alternative, the mold 3' does not include the substrate 20 and takes the form of a ceramic layer on the substrate that has been previously separated from the substrate. The mold 3' includes at least one cavity herein.

[0094] According to the third alternative form of the second embodiment, the third step of manufacturing the mold 3' by using a master mold 2' of E4* includes sub-steps E41*, E42*, E43*, E44* similar to the sub-steps E31', E32', E33', E34' of the step E3' of the second alternative form of the first embodiment of the present invention.

[0095] Regardless of the alternative implementation forms of the second embodiment, the method for manufacturing a clockwork member includes a fourth step of manufacturing an E5' clockwork member 6 by using the mold 3'.

[0096] The step E5' may particularly include sub-steps E51', E52', E53', E54' similar to the sub-steps E51, E52, E53, E54 of the step E5 described previously.

[0097] In the case of the rigid mold 3', the member 6 or the blank of the member 6 can be removed from the mold 3' by taking advantage of the shrinkage of the material used to manufacture the member or the blank of the member 6.

[0098] The method for manufacturing a timepiece member described above can be used to manufacture all timepiece members. For example, by way of illustrative and non-limiting examples, there are balance wheels, pallet forks, detents, pinions, wheels, levers, springs, cams or even blanks. Of course, it can in particular be used to manufacture any element including a microstructure.

[0099] Thus, it is clear that the present invention achieves the sought-after objective by advantageously combining two different techniques. Conventional lithography can simply, quickly and reliably form the bulk of the master mold of the mold intended to allow the manufacture of timepiece members in a first step, while two-photon polymerization technology can add complex shapes to this bulk in a second step that is more complex, less fast but more precise and more flexible, thereby allowing the definition of absolutely arbitrary three-dimensional patterns. This results in a master mold of the mold for a timepiece member having a complex shape and being manufactured in a simple and powerful manner.

Claims

1. A method for manufacturing a master mold of a mold for a clock component, wherein, The method at least comprises the following steps: - Manufacturing (E1) a first structure comprising at least one layer of photosensitive resin from a first photosensitive resin, the first structure comprising a first pattern obtained by polymerizing the first photosensitive resin by irradiation through at least one mask and then developing the first photosensitive resin; - Transforming (E2) the first structure into a second structure by structuring at least one surface of the first structure by adding a second photosensitive resin to at least one surface of the first structure, the step of transforming (E2) the first structure comprising the following steps: o Applying (E21) a layer of the second photosensitive resin on at least a part of at least one surface of the first structure; o Performing two-photon polymerization (E22) on the second photosensitive resin according to a second pattern using a photon device, to obtain a three-dimensional polymerization, the photon device comprising an objective lens at least partially immersed in the second photosensitive resin to direct and focus a light beam on a voxel, the voxel defining the shape and / or geometry of the second pattern; o Developing (E23) so as to eliminate the unpolymerized second photosensitive resin and obtain the second structure having a form defined by the first pattern and the second pattern, wherein the second structure directly forms a master mold for a clockwork member, or wherein the second structure forms a mold for a master mold for manufacturing a clockwork member.

2. The manufacturing method of the master mold for the mold of the clock component according to claim 1, wherein, The step of transforming (E2) the first structure comprises adding the second photosensitive resin on at least one side surface of the first structure.

3. The manufacturing method of the master mold of the mold for watch components according to claim 1 or 2, wherein The step of performing two-photon polymerization (E22) can define a second pattern having a three-dimensional resolution of better than or equal to 0.001 μm 3 and / or a lateral resolution of better than or equal to 0.1 μm.

4. The manufacturing method of the master die of the mold for watch components according to claim 3, wherein The step of exposing (E12) the first photosensitive resin produces a first structure comprising side surfaces perpendicular or substantially perpendicular to the substrate and / or a constant cross-section parallel or substantially parallel to the substrate.

5. The method for manufacturing a master mold for a clockwork member according to claim 1 or 2, wherein: - The two resins are the same or different; and / or - The two resins are positive or negative; and / or - The first photosensitive resin is of the SU-8 type or the SU-8-100 type; and / or - The second photosensitive resin is a liquid or semi-liquid resin.

6. The manufacturing method of the master mold of the mold for a clock component according to claim 5, wherein, The second photosensitive resin is IP-Dip TM .

7. A method for manufacturing a master mold of a mold for a clock component according to claim 1 or 2, wherein The method comprises the following steps: - Applying (E31) a metal layer on the second structure using electrodeposition or electroplating, the metal layer at least partially forming a master mold for a clockwork member; - Separating (E33) the master mold for a clockwork member formed by the metal layer from the second structure.

8. The manufacturing method of the master mold of the mold for watch components according to claim 7, wherein, The metal is nickel-based.

9. A method for manufacturing a master mold of a mold for a clock component according to claim 1 or 2, wherein, The method comprises the following steps: - Filling (E31’) the second structure with a product containing ceramic powder using a liquid route; - Consolidating (E32’) the product; - Separating (E33’) the blank formed by the product from the second structure; - Debinding the blank obtained in the previous step and then densifying it by sintering (E34’).

10. A manufacturing method of a clock component, wherein, The method comprises the steps of using the method according to any one of claims 1 - 9 to manufacture a master mold (2; 2'), using the master mold to manufacture a mold (3; 3') for manufacturing a clockwork component, and then comprising the step of using the mold (3; 3') as a manufacturing mold to manufacture (E5; E5') the clockwork component, which can be made of ceramic.

11. The method for manufacturing a clockwork component according to the preceding claims, wherein the clockwork component can be made of industrial ceramic.

12. The manufacturing method of the clock component according to claim 10, wherein, The mold (3; 3') is made of a polymer.

13. The manufacturing method of the clock component according to claim 10, wherein, The mold (3; 3') is made of an elastomer.

14. The manufacturing method of the clock component according to claim 13, wherein, The elastomer is polydimethylsiloxane or silicone.

15. The manufacturing method of the clock component according to any one of claims 12 - 14, wherein, The step of using the master mold to manufacture (E4; E4') the mold (3; 3') comprises the following sub - steps: - supplementing the master mold (2; 2') with an annular element (7) to delimit (E41; E41') a volume intended to receive a quantity of polymer; - pouring (E42; E42') a quantity of elastomer into the impression cavity formed by the master mold (2; 2') completed by the annular element (7); - polymerizing (E43; E43') the quantity of elastomer to cure it; - separating (E44; E44') the elastomer mold (3; 3') from the master mold (2; 2') and the annular element (7).

16. The manufacturing method of the clock component according to claim 10, wherein, The mold (3; 3') is made of metal or ceramic.

17. A method for manufacturing a clock component according to any one of claims 10 to 14, wherein The step of manufacturing (E5; E5') the clockwork component comprises manufacturing the clockwork component from industrial ceramic using the following sub - steps: - filling (E51; E51') the mold (3; 3') with a product containing ceramic powder using a liquid path; - consolidating the product (E52; E52'); - separating (E53; E53') the blank formed by the product from the manufacturing mold (3; 3'); - degreasing the blank obtained in the preceding sub - steps and then densifying it by sintering (E54; E54').

Images