CH712650A2 - A method of manufacturing a watch, jewelery or jewelery piece with a multi-level trim element. - Google Patents

Abstract

The invention relates to a method (Pr1) for manufacturing a part, comprising the following steps: Superposer (Pr1_sup) an electrically insulating layer (CL) comprising a first orifice (OL1), an additional layer (CS) having a first opening (OS1), an intermediate layer (CT) comprising a first hole (OT1), and a base layer (CB) surmounted by a base pattern (MB1) depositing a metal layer, so that after the this step, the metal layer forms a shell covering the electrically conductive walls of the base pattern (MB1), the first orifice (OL1), the first opening (OS1) and the first hole (OT1), and comprises a lateral zone resting on the insulating layer (CL) Dissolve the insulating layer (CL) Cover the metal or alloy layer with a volume made up of a base material of the part, so that the volume matches the shapes of the metal layer. The invention relates to the field of watchmaking, jewelery and jewelery.

Description

Description

FIELD OF THE INVENTION [0001] The invention relates to a method for manufacturing a part such as a timepiece, jewelery or jewelery piece, for example a watch face, a bezel, a crown, a bracelet link, a clasp, etc., or a piece of tooling such as a striking tool, a mold, etc. The method more particularly makes it possible to produce a part comprising a workpiece body and a multi-level dressing element embossed on the body of the workpiece, the cladding element being such that an hour indicator, a decorative element , a letter, etc. Multilevel means that the element comprises at least two visible planar faces which extend parallel to each other and parallel to the body of the part.

BACKGROUND OF THE INVENTION [0002] In the field of watchmaking, jewelery or jewelery, it is conventional to produce multi-level trim elements by photolithography and galvanic deposition techniques. EP 2316 056 B1 describes in particular a method of manufacturing a metal element or multi-level metal alloy, using the LIGA-UV technique. This method comprises the following steps: - providing a substrate comprising a conductive surface - covering the conductive surface of the substrate with a first layer of photoresist - irradiating the first photoresist layer through a mask corresponding to a desired imprint developing the first layer of photosensitive resin so as to dig openings therein and thereby obtain a first level of a resin mold, the openings in the first resin layer revealing the conductive surface of the substrate; a new layer of photoresist on the developed resin layer, so as to cover the latter and, preferably, to fill the openings therein - to irradiate the new layer of photoresist through a mask corresponding to the desired imprint - develop the new layer of photosensitive resin so as to dig into ns it openings and to obtain a multi-level resin mold, the openings in the multi-level mold revealing the conductive surface of the substrate - filling the openings of the multi-level resin mold of a metal or of an alloy, by galvanic deposition - remove the resin layers so as to reveal a metal element or multi-level alloy consisting of said metal or alloy deposited in the openings.

The multi-level elements thus manufactured are then separated from the substrate and implanted on a timepiece, jewelery or jewelery body.

This method of manufacturing parts with multi-level trim elements has the disadvantage of being long to implement, especially because of the need to completely fill the openings of the mold during the galvanic deposition. A second disadvantage is the need for an assembly of the cladding elements on the body of the room, hence the risk of disengagement in case of shocks, for example. SUMMARY OF THE INVENTION [0005] The present invention aims to overcome all or part of the disadvantages mentioned above.

For this purpose, according to a first embodiment, the invention relates to a method of manufacturing a part provided with a cladding element, comprising the following steps: - Superimpose an electrically insulating layer comprising a first through hole, an additional layer having a first through opening of dimensions similar to the first port, an intermediate layer comprising a first through hole, and a base layer surmounted by a base pattern, so as to place the base pattern in the first hole, cover the first hole by the first opening, and superimpose the first opening and the first hole. - Galvanically deposit a metal or metal alloy layer, so that at the end of this step, the metal or metal alloy layer forms a shell covering electrically conductive walls of the base pattern, the first orifice, the first opening and the first hole, and has a lateral zone resting on the insulating layer. - Dissolve the insulating layer. - Cover the metal or metal alloy layer of a volume consisting at least in part of a base material of the part, so that the volume matches the shapes of the metal layer or metal alloy. - Extract the volume and the metal layer or metal alloy.

According to a second embodiment, the invention relates to a method for manufacturing a part provided with a covering element, comprising the following steps: - superimposing an electrically insulating layer comprising a second through hole, an additional layer having a second through opening of similar dimensions to the second port, and an intermediate layer surmounted by an intermediate pattern, so as to place the intermediate pattern in the second opening, and superimpose the second opening and the second port. - Galvanically deposit a metal or metal alloy layer, so that at the end of this step, the metal or metal alloy layer forms a shell covering electrically conductive walls of the intermediate pattern, the second orifice and the second opening, and has a lateral zone resting on the insulating layer. - Dissolve the insulating layer. - Cover the metal or metal alloy layer of a volume consisting at least in part of a base material of the part, so that the volume matches the shapes of the metal layer or metal alloy. - Extract the volume and the metal layer or metal alloy.

The method according to the first and the second embodiment makes it possible simultaneously to manufacture the body of the part (constituted by the volume of base material of the part) and the covering element (constituted by the metal layer or alloy). The cladding element is directly attached to the workpiece body, without the need for an assembly step. Indeed, the lateral zone of the metal layer or alloy resting on the insulating layer at the end of the deposition phase, is found sealed in the volume at the end of the recovery phase.

In addition, the method according to the first or second embodiment is faster to implement than the method of the prior art described above. Indeed, the duration of the galvanic deposition is shorter, because the metal or alloy layer does not have to fill the holes, openings and holes (forming a mold), but must simply cover their walls and the pattern. In other words, the metal structure or metal alloy is not massive, it instead forms a hollow shell. The thickness to be deposited by electroplating is therefore lower.

The interfaces between the workpiece body and the trim element are sharp, without burrs. Moreover, by choosing appropriate shapes and dimensions for the various patterns, openings, or holes or holes involved in the manufacturing processes, it is possible to produce trim elements of various shapes and sizes. In addition, a texture on the additional layer is imprinted on the workpiece (the volume of base material of the workpiece).

In addition, the manufacturing method according to the first embodiment (first method) may comprise one or more of the characteristics below, taken independently or in any technically possible combination.

According to a non-limiting embodiment, the first method comprises a step of forming electrically conductive surfaces on the walls of the base pattern, the first orifice, the first opening and / or the first hole, for example by a physical vapor deposition technique.

According to a non-limiting embodiment, the first method comprises a step of forming an electrically conductive surface on a portion of an upper face of the insulating layer located at the periphery of the first orifice.

According to a non-limiting embodiment, the first method comprises a step of forming the base pattern on the base layer, comprising an application, an irradiation and a development of a photosensitive resin, for example an SU8 resin.

According to a non-limiting embodiment, the first method comprises a step of forming the base layer from a silicon wafer, comprising a coating of said wafer with a conductive film.

In addition, the method according to the first embodiment and / or the second embodiment may / may comprise one or more of the characteristics below, according to all the technically possible combinations.

According to a non-limiting embodiment, the method comprises a step of forming electrically conductive surfaces on the walls of the intermediate pattern, the second orifice and / or the second opening.

According to a non-limiting embodiment, the method comprises a step of forming an electrically conductive surface on a portion of an upper face of the insulating layer located at the periphery of the second orifice.

According to a non-limiting embodiment, the method comprises a step of forming the intermediate pattern on the intermediate layer, comprising an application, an irradiation and a development of a photosensitive resin, for example an SU8 resin.

According to a non-limiting embodiment, the method comprises a step of deformation of the intermediate layer comprising a cut, for example by laser, a plate, for example brass.

According to a non-limiting embodiment, the method comprises a step of forming the additional layer comprising a cut, for example by laser, a plate, for example brass.

According to a nonlimiting embodiment, the step of forming the additional layer comprises a stamping of the additional layer so as to form an additional pattern, the electrically insulating layer comprising a third orifice, the third orifice. being placed opposite the additional pattern when the insulating layer and the additional layer are superimposed.

According to a non-limiting embodiment, the step of forming the additional layer comprises an etching of the additional layer so as to locally reduce its thickness, the insulating layer having areas of extra thickness so that the assembly comprising the additional layer and the superposed insulating layer are of constant thickness.

According to a non-limiting embodiment, the method comprises a step of forming the insulating layer comprising an application, an irradiation and a development of a photosensitive resin, for example an SU8 resin, on the additional layer, so forming a third orifice, the third orifice being placed opposite the additional pattern when the insulating layer and the additional layer are superimposed.

According to a non-limiting embodiment, the volume is formed in part of a second material, other than the base material, such that the second material fills the internal space to the shell metal or metal alloy.

According to a non-limiting embodiment, the method comprises a step of cutting the lateral zone, performed before the recovery step.

BRIEF DESCRIPTION OF THE DRAWINGS [0027] Other particularities and advantages will become clear from the description which is given hereinafter, by way of indication and in no way limitative, with reference to the appended drawings, in which: FIG. 1 is a schematic representation of a base layer used in a method according to a non-limiting embodiment of the invention, the method for producing a part provided with at least one multi-level dressing element fig. 2 is a schematic representation of an intermediate layer used in the process of FIG. 3 is a diagrammatic representation of an additional layer and an electrically insulating layer, said layers being used in the process of FIG. 4 represents a superposition step of the layers of FIGS. 1,2 and 3, according to the method of FIG. 5 represents a step of galvanic deposition of a metal layer or alloy according to the method FIG. 6 represents a step of covering or incrustation of the metal or alloy layer by a volume of a base material of the part according to the method FIG. 7 represents the final piece obtained by the method, the piece being provided with two elements of multi-level dressing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present description relates to two manufacturing processes Pr1, Pr2, the combined implementation of which makes it possible to manufacture a PC timepiece with two EH1, EH2 multi-level skin elements. such as that shown in FIG. 7. More particularly, the first cladding element EH1 is obtained by the first method Pr1, while the second cladding element EH2 is obtained by the second method Pr2. The two methods Pr1, Pr2 comprising common steps and using common elements, their combined implementation makes it possible to manufacture a part equipped with these two elements of dressing. However, the methods Pr1, Pr2 could be made independently of each other, to form not a room with two trim elements, but two parts each with a trim element. In addition, the methods Pr1, Pr2 could be applied to all kinds of parts, for example a piece of jewelry or jewelery, or a piece of tooling, and all kinds of elements of multi-level clothing. Finally, the piece could naturally have more than one dressing element of each type.

Figs. 1 to 3 show four layers CB, CT, CS and CL, which are then superimposed on each other during a superposition step of the manufacturing process. Each of the layers CB, CT, CS and CL is metallic, or metal alloy, or mineral. However, if a layer is mineral, some of its zones must be made electrically conductive, for example by a physical vapor deposition technique (or PVD for the English "Physical Vapor Deposition"), as explained in the following of the description.

FIG. 1 shows a CB base layer surmounted by a basic pattern MB1. The set CB / MB1 was obtained by a formation step Pr1_fCB of the base layer CB followed by a formation step Pr1 JMB1 of the basic pattern MB1 according to the first method Pr1. In a non-limiting embodiment of step Pr1_fCB, the base layer CB is formed of a substrate, for example a silicon wafer. In a non-limiting embodiment, said substrate is coated with an electrically conductive film by PVD. This step is not mandatory, as explained in the following text, some parts of the base layer CB can be made conductive in a subsequent step of the process, by a method such as PVD or by contact with a layer conductive. In a non-limiting embodiment of step Pr1_fMB1, the basic pattern MB1 is formed by: - applying a photoresist to the base layer CB, for example a SU-8 type resin; irradiating the resin through a photomask corresponding to the desired shape of the base unit MB1, by ultraviolet rays in the case of a SU-8 resin, to polymerize a zone of the resin corresponding to the base unit MB1; - Development of the resin, to dissolve the uncured areas and show the basic pattern MB1.

In another non-limiting embodiment of step Pr1_fMB1, the basic pattern MB1 is formed by depositing a uniform layer (varnish or other) which is then selectively ablated by laser [0032] FIG. 2 shows an intermediate layer CT comprising a first hole OT1 through and surmounted by an intermediate pattern MT2. The CT / MT2 assembly was obtained by a formation step Pr12_fCT of the intermediate layer CT followed by a formation step Pr12JMT2 of the intermediate unit MT2 according to the first and second methods Pr1, Pr2. In a non-limiting embodiment of the Pr12_fCT step, the intermediate layer CT is formed of a metal alloy plate, for example brass, which is cut, for example by laser, to obtain the first hole OT1. Note that the first hole OT1 is smaller than the first opening OS1 of FIG. 3. In a non-limiting embodiment of step Pr12_fMT2, the intermediate unit MT2 is formed by: applying a photosensitive resin to the intermediate layer CT, for example a resin of SU-8 type - irradiation of the resin through a photomask corresponding to the desired shape of the intermediate unit MT2, by ultraviolet rays in the case of a resin SU-8, to polymerize a zone of the resin corresponding to the intermediate unit MT2 - development of the resin, to dissolve the uncured areas and to reveal the MT2 intermediate pattern.

FIG. 3 shows an additional layer CS comprising a first through aperture OS1, a second aperture OS2 through, an additional pattern MS3, and areas of reduced thickness ZS. The additional layer CS is superimposed on an electrically insulating layer CL comprising a first orifice OL1, a second orifice OL2, a third orifice OL3 and zones of excess thickness ZL. It is noted that the areas of reduced thickness ZS of the additional layer CS could alternatively be zones of excess thickness. In this case, the areas of extra thickness ZL would be areas of reduced thickness.

The additional layer CS was obtained by a deformation step Pr12_fCS of said layer according to the first and the second method Pr1, Pr2. In a non-limiting embodiment of step Pr12_fCS, the additional layer CS is formed of a metal alloy plate, for example brass, which is cut, for example by laser, to obtain the first opening OS1 and the second opening OS2. Note that in a non-limiting embodiment of step PM2JCS, the plate is previously textured, for example guilloche or brushed. In addition, in a non-limiting embodiment of step Pr12_fCS, the additional layer CS is stamped so as to create a footprint forming a third pattern MS3 such as that shown in FIG. 3. Furthermore, in a non-limiting embodiment of step PM2JCS, ZS zones of the additional layer CS are etched, so as to reduce their thickness, as shown in FIG. 3. Naturally, all these substeps of step Pr12_fCS are not mandatory, only some of them can be realized.

The insulating layer CL was obtained by a Pr12_fCL forming step of said layer according to the first and the second method Pr1, Pr2. In a non-limiting embodiment of step Pr12_fCL, the insulating layer CL is obtained by: - applying a photoresist to the additional layer CS, for example a resin of SU-8 type. It is noted that the resin then has areas of excess thickness ZL at the reduced thickness areas of the additional layer CS, or conversely if the additional layer CS has areas of extra thickness; irradiation of the resin through a photomask, by ultraviolet rays in the case of a resin SU-8, to polymerize the resin with the exception of the zones opposite the first opening OS1, the second opening OS2 and the pattern additional MS3; - Development of the resin, to dissolve the uncured areas and reveal a first port OL1 superimposed on the first opening OS1, a second port OL2 superimposed on the second opening OS2, and a third port OL3 next to the additional pattern MS3.

FIG. 4 shows the four superimposed layers at the end of an overlay step Pr1_sup, Pr2_sup of the first method Pr1 and the second method Pr2. More specifically, the insulating layer CL is superimposed on the additional layer CS, itself superimposed on the intermediate layer CT, itself superimposed on the base layer CB. The various orifices, openings, holes and patterns are such that: the basic pattern MB1 is positioned in the first hole OT1, the first hole OT1 is covered by the first opening OS1, and the first hole OL1 is superimposed on the first opening OS1 - the intermediate pattern MT2 is positioned in the second opening OS2, and the second port OL2 is superimposed on the second opening OS2 - the additional pattern MS3 is positioned opposite the third port OL3.

Then, in a step not shown, SC walls (visible in Figure 5) of the base pattern MB1, the first orifice OL1, the first opening OS1, the first hole OT1, and the walls exposed of the base layer CB are made conductive, for example by PVD deposition of a conductive film. Naturally, the PVD deposition of the conductive film is only necessary on non-initially conducting faces. Thus, in an alternative embodiment, only some of the aforementioned walls undergo PVD deposition or any other equivalent treatment in order to make them conductive. During this step, an SCL portion of the upper face of the insulating layer CL (that is to say the non-contacting surface with the upper layer CS) at the periphery of the first orifice OL1 can also be made conductive.

Similarly, walls of the intermediate pattern MT2, the second orifice OL2, the second opening OS2, and exposed walls of the intermediate layer CT are optionally made conductive. It is the same for walls of the additional pattern MS3, the third orifice OL3, and exposed walls of the additional layer CS. Similarly, a portion of the upper face of the insulating layer CL at the periphery of the second orifice OL2 and / or the third orifice OL3 can also be made conductive.

FIG. 5 schematically represents a step of galvanic deposition PR1_gal of a metal layer or CM alloy on the internal faces of the first orifice OL1, the first opening OS1, the first hole OT1, on the faces of the base pattern MB and on the exposed faces of the base layer CB, according to the first method Pr1. Thus, the four layers CB, CT, CS and CL superimposed are immersed in a galvanic bath suitable for the deposition of a metal such as gold, silver, nickel, or any other metal or metal alloy that can be deposited in relatively thick layer, to undergo electroforming. The electroforming is completed when the aforementioned walls are completely covered with the metal layer or alloy CM and that the thickness of the shell obtained is considered sufficient. The metal or alloy layer CM then comprises a lateral zone EL which rests on the insulating layer CL. In the case where the portion SCL of the upper face of the insulating layer CL at the periphery of the first orifice OL1 has been made conductive, the lateral zone EL extends at least in part on said portion SCL.

Although this is not shown, a metal or alloy layer is deposited in a similar way on the walls of the second orifice OL2, the second opening OS2, the intermediate unit MT2 and on the exposed walls of the intermediate layer. CT. Similarly, a metal or alloy layer is similarly deposited on the walls of the third orifice OL3, the additional pattern MS3 and on the exposed walls of the additional layer CS. In the case where a portion of the upper face of the insulating layer CL at the periphery of the second orifice OL2 and / or the third orifice OL3 has been made conductive, the lateral zone EL extends at least in part over said portion.

The metal layer or alloy CM forms a shell of a certain thickness. Then, in a step not shown, the insulating layer CL is dissolved by passing through suitable baths. The lateral zone EL is then optionally cut, depending on the type of part to be produced. Cutting the lateral zone EL is interesting if the part to be manufactured is a punch-type tool, for example.

FIG. 6 schematically represents a step of recovery or incrustation Pr1_rec of the additional layer CS and the metal layer or alloy CM, by a volume VL of a base material of the part to be manufactured, according to the first method Pr1. In one embodiment, the base material is amorphous or partially amorphous metal, interesting for its mechanical properties. In another embodiment, the base material is a polymer or a composite (polymer ceramic, carbon fiber composite, etc.). In these two cases, a block of metal or metal alloy or of amorphous or partially amorphous alloy, or of polymer or composite, is pressed on the additional layer CS and against the metal or alloy layer CM at a temperature of which has a pasty consistency. This allows it to deform to marry the shapes of the metal layer or alloy CM, and in particular the shapes of the lateral zone EL of the metal layer or alloy CM if they have not been previously cut. Alternatively, the base material can be cast. In another embodiment, the base material is any other metal or metal alloy, for example nickel, gold, etc., and the coating is made by galvanic growth of said metal. It should be noted, in the case where the lateral zone EL has not been cut beforehand, that at the end of the step Pr1_rec, the metal or alloy CM layer is secured to the volume VL of the base material, because the lateral zone EL is sealed in the volume VL of base material. Although not shown, the metal or alloy layers (at intermediate pattern MT2 and additional pattern MS3) are covered and sealed in volume VL in a similar manner.

In an alternative embodiment of the recovery step / incrustation Pr1_rec, the volume VL is not entirely made of the base material of the part. In this case, only part of the volume is made of the base material of the part, while the other part is made of a second material, advantageously less expensive than the base material. The part of the volume VL made of the second material thus advantageously fills the space inside the alloy metal shell, while the volume parts VL made of the base material are located at the visible, external locations of the part.

FIG. 7 schematically represents an extraction step Pr1_ext, Pr2_ext volume VL and metal layers or alloys CM, according to the first method Pr1 and the second method Pr2. In other words, the volume VL and the metal or alloy layers CM are separated from the additional layer CS, the intermediate layer CT and the base layer CB. To do this, the assembly is for example immersed in a selective acid bath in which the additional layer CS, the intermediate layer CT and the base layer CB are dissolved. Alternatively, the

Claims (15)

separation is achieved by force release. It is noted that having previously carried out a surface treatment of the additional layer CS facilitates demolding. This treatment is for example the application of a release agent or a passivation treatment. The volume VL then forms the body of the workpiece PC, and the metal layers or CM alloys form the elements EH1 dressing, EH2 (the third cladding element, resulting from the duplication of the third pattern MS3, is not shown in Fig. 7). It is therefore understood that the shapes and dimensions of the cladding elements are directly dependent on the shapes and dimensions of the patterns, as well as the shapes and dimensions of the various orifices, openings and holes involved during the processes. With the methods described, the disengagement of the cladding elements of the volume of base material is impossible without destroying the room. In addition, it is noted that the interfaces between the workpiece body and the cladding elements are clear. On the other hand, by imprinting the texture of the additional layer on the volume occurring during the covering step, the workpiece body is texture. Of course, the present invention is not limited to the illustrated example but is capable of various variations and modifications that will occur to those skilled in the art, in particular with regard to the number of superposed layers, the shapes and sizes of the various holes, openings, holes, patterns, etc. claims 1. Process (Pr1) for manufacturing a part (PC) equipped with a covering element (EH1), comprising the following steps: - Superimposing (Pr1_sup) an electrically insulating layer (CL) comprising a first orifice (OL1) ), an additional layer (CS) having a first opening (OS1) of similar dimensions to the first orifice (OL1), an intermediate layer (CT) comprising a first hole (OT1) through, and a base layer (CB) surmounted by a base pattern (MB1), so as to place the base pattern (MB1) in the first hole (OT1), cover the first hole (OT1) with the first opening (OS1), and superimpose the first opening (OS1) and the first port (OL1). - Remove (Pr1_gal) galvanically a metal layer or metal alloy (CM), so that at the end of this step, the metal layer or metal alloy (CM) forms a shell covering electrically conductive walls of the basic pattern (MB1), the first orifice (OL1), the first opening (OS1) and the first hole (OT1), and has a lateral zone (EL) resting on the insulating layer (CL). - Dissolve the insulating layer (CL). - Cover (Pr1_rec) the metallic layer or metal alloy (CM) of a volume (VL) formed at least in part by a base material of the piece (PC), so that the volume (VL) matches the shapes of the metal layer or metal alloy (CM). - Extract (Pr1_ext) the volume (VL) and the metal or metal alloy layer (CM). 2. Method (Pr1) according to the preceding claim, comprising a step of forming electrically conductive surfaces (SC) on the walls of the base pattern (MB1), the first orifice (OL1), the first opening (OS1) and / or the first hole (OT1), for example by a physical vapor deposition technique. 3. Method (Pr1) according to the preceding claim, comprising a step of forming an electrically conductive surface (SCL) on a portion of an upper face of the insulating layer (CL) located at the periphery of the first orifice (OL1). 4. Method (Pr1) according to one of the preceding claims, comprising a step of forming (Pr1_fMB1) of the base pattern (MB1) on the base layer (CB), comprising an application, an irradiation and a development of a photosensitive resin, for example an SU8 resin. 5. Process (Pr1) according to one of the preceding claims, comprising a step of forming (Pr1_fCB) of the base layer (CB) from a silicon wafer, comprising a coating of said wafer with a conductive film. 6. Process (Pr2) for manufacturing a part (PC) equipped with a covering element (EH2), comprising the following steps: - Superimposing (Pr2_sup) an electrically insulating layer (CL) comprising a second orifice (OL2) ) through, an additional layer (CS) having a second opening (OS2) through similar dimensions to the second orifice (OL2), and an intermediate layer (CT) surmounted by an intermediate pattern (MT2), so as to place the pattern intermediate (MT2) in the second aperture (OS2), and superimpose the second aperture (OS2) and the second aperture (OL2). - Galvanically deposit a metal or metal alloy layer, so that at the end of this step, the metal or metal alloy layer forms a shell covering the electrically conductive walls of the intermediate pattern (MT2), the second orifice (OL2) and the second opening (OS2), and has a lateral zone resting on the insulating layer (CL). - Dissolve the insulating layer (CL). - Cover the metal or metal alloy layer of a volume consisting at least in part of a base material of the piece (PC), so that the volume matches the shapes of the metal layer or metal alloy. - Extract (Pr2_ext) the volume and the metal layer or metal alloy. 7. Method (Pr2) according to the preceding claim, comprising a step of forming electrically conductive surfaces on the walls of the intermediate pattern (MT2), the second orifice (OL2) and / or the second opening (OS2). 8. Process (Pr2) according to the preceding claim, comprising a step of forming an electrically conductive surface on a portion of an upper face of the insulating layer (CL) located at the periphery of the second orifice (OL2). 9. Process (Pr2) according to one of claims 6 to 8, comprising a step of formation (Pr2_fMT2) of the intermediate unit (MT2) on the intermediate layer (CT), comprising an application, an irradiation and a development of a photosensitive resin, for example an SU8 resin. 10. Process (Pr1, Pr2) according to one of the preceding claims, comprising a forming step (Pr12_fCT) of the intermediate layer (CT) comprising a cutting, for example laser, a plate, for example brass. 11. Method (Pr1, Pr2) according to one of the preceding claims, comprising a forming step (Pr12_fCS) of the additional layer (CS) comprising a cut, for example laser, a plate, for example brass. 12. Method (Pr1, Pr2) according to the preceding claim, the forming step (Pr12_fCS) of the additional layer (CS) comprising a stamping of the additional layer (CS) so as to form therein an additional pattern (MS3), the electrically insulating layer (CL) comprising a third orifice (OL3), the third orifice (OL3) being placed opposite the supplementary pattern (MS3) when the insulating layer (CL) and the additional layer (CS) are superimposed. 13. The method (Pr1, Pr2) according to one of claims 11 or 12, the forming step (Pr12_fCS) of the additional layer (CS) comprising an etching of the additional layer (CS) so as to reduce locally its thickness. , the insulating layer (CL) having areas of extra thickness so that the assembly comprising the additional layer (CS) and the insulating layer (CL) superimposed is of constant thickness. 14. Process (Pr1, Pr2) according to one of claims 12 or 13, comprising a step of forming (Pr12_fCL) the insulating layer (CL) comprising an application, an irradiation and a development of a photoresist, for example a resin SU8, on the additional layer (CS), so as to form a third orifice (OL3), the third orifice (OL3) being placed opposite the additional pattern (MS3) when the insulating layer (CL) and the additional layer (CS) are superimposed. 15. Method (Pr1, Pr2) according to one of the preceding claims, characterized in that the volume (VL) consists in part of a second material, other than the base material, such that the second material fills the space internal to the hull made of metal or metal alloy.