CH718949A2 - Process for manufacturing a drilled microtechnology part in a hard material. - Google Patents

Abstract

The invention relates to a method for manufacturing a drilled part for microtechnology (101) in a hard material having a Vickers hardness equal to or greater than 1,200 HV, the drilled part comprising at least one hole, blind or emerging, characterized in that it comprises the following steps: providing a blank (100) defining a first face (100a), a second face (100b) opposite the first face (100a) and a peripheral face (100c) connecting the first face (100a) to the second face (100b), said peripheral face (100c) having the geometry and dimensions of the drilled part (101), determination, on the first face (100a), of a drilling center location ( C), taking into account the geometry of said peripheral face (100c) and/or the position of said peripheral face (100c) with respect to its final functional environment, machining the blank (100) taking into account said location drilling center (C), said machining comprising the drilled ge by femtosecond laser of a hole (110) from the first face (100a) and/or the second face (100b), whereby a drilled part (101) is obtained.

Description

Technical area

The present invention relates to a method of manufacturing a pierced part of microtechnology in a hard material. In the present text, hard material means a material having a Vickers hardness equal to or greater than 1,200 HV.

[0002] There are many cases in which small parts in hard material must be drilled with great precision. These small parts are microtechnology parts, having dimensions ranging from a few micrometers or a few tens of micrometers to a few millimeters. For example, such parts are parts present in time measurement systems (wristwatches, clocks, sports timing devices), in measuring instruments, telecommunications devices, optical systems (photographic devices and cameras) , industrial production equipment (palletizing devices, industrial robots, manipulators), medical instrumentation devices (analytical devices, pacemakers, endoscopes, prostheses), and for small components (relays, motors, micro -switches, sensors).

[0003] It may be a through hole, in order to form a hole for mounting another moving part, for example a pivoting part in the hole, such as a compass pivot or a watchmaker pivot, or for the mounting of another fixed part relative to the drilled part, such as a pin or a dowel. It can also be a blind hole, for mounting another moving part or another fixed part, or for the presence of a liquid or another function.

State of the art

[0004] With the development of microtechnology and miniaturization, the need to drill small parts with greater precision is increasing. This precision corresponds first of all to the position and to the size of the drilling, namely of the hole, emerging or not emerging, namely of the blind hole. The size of the hole corresponds to the different dimensions of this hole (diameter, or other dimensional parameter if non-circular hole, possibly depth). This precision also corresponds in the micrometric range to the surface condition of the wall of the hole.

[0005] In some cases, the expected precision of the position of the hole must take into account the final functional environment, namely the other part(s) close to the drilled microtechnology part, because the position of the hole and the dimensions of the hole are decisive in the function of the functional assembly into which the drilled part is integrated. For example, the position of the hole and/or the dimensions of the hole is (are) determining with respect to the position of another part or with respect to the position of another functional element such as another hole , a specific surface, a projection, a protrusion, which other functional element can be located on another part, different from the part considered for drilling the hole.

[0006] Moreover, in microtechnology systems and parts, hard materials, or even very hard materials, are commonly used, whether metals, ceramics, sapphire, corundum (in particular polycrystalline), diamond, or one of the following materials: synthetic ruby, synthetic sapphire, SiO2, zirconia, yttria-containing zirconia, Al2O3 such as monocrystalline alumina and alumina-zirconia combination or carbides.

[0007] Small parts made of hard material are traditionally machined by abrasive techniques, in particular with tools filled with diamond, or by chemical or plasma techniques such as DRIE („Deep Reactive Ion Etching“ for deep reactive ion etching). ).

[0008] For example, for the drilling of stones forming ruby or sapphire bearings or swivel bearings for watchmaking, an enlargement of a pre-hole previously made generally by laser drilling is carried out, this enlargement of the diameter internal part of the stone being carried out by machining on a wire covered with diamantine (honing). This manual procedure does not therefore allow sufficient repeatability to systematically respect the specifications and its tolerances.

Brief summary of the invention

An object of the present invention is to provide a method of manufacturing a pierced part of microtechnology in a hard material free from the limitations of known methods.

[0010] Another object of the invention is to provide a method of manufacturing a pierced microtechnology part in a hard material which is simpler and more reliable in terms of compliance with manufacturing dimensions.

[0011] In particular, the invention aims to provide a method of manufacturing a microtechnology pierced part in a hard material which also makes it possible to improve the precision of the position of the hole in the part, and in particular the concentricity between the hole and the peripheral face in the case of a circular part pierced with a concentric circular hole.

[0012] According to the invention, these objects are achieved in particular by means of a process for manufacturing a microtechnology pierced part in a hard material having a Vickers hardness equal to or greater than 1,200 HV, the pierced part comprising at at least one hole, blind or through, characterized in that it comprises the following steps: supply of a blank defining a first face, a second face opposite the first face and a peripheral face connecting the first face to the second face, said peripheral face having the geometry and dimensions of the drilled part, determination, on the first face, of a drilling center location, taking into account the geometry of said peripheral face and/or the position of said peripheral face with respect to its final functional environment, machining of the blank taking into account said drilling center location, said machining comprising the drilling by femtosecond laser of a hole from the first face and/or the second face, whereby a drilled part is obtained.

[0013] In this way, the hole is made, whether it is blind or open, without an enlargement step, for example, the femtosecond laser drilling making it possible to achieve the desired dimensions for the hole. This solution thus has the particular advantage over the prior art of making it possible to drill the hole with the desired final diameter in a single step, precisely.

[0014] To finalize the manufacture of the hole, all that then remains is to carry out a finishing step on the pierced microtechnology part, such as polishing, brushing and/or bending, possibly with a step additional machining of the hole wall. In the case of the manufacture of a pivot bearing for watchmaking, such an additional step of machining the wall of the hole by femtosecond laser makes it possible, for example, to form a olivage. Such an additional machining step by femtosecond laser makes it possible, if necessary, to produce a progressive transition zone between a hollow located on one of the faces of the pivot bearing and the pivoting zone or surface of the hole, instead of a fish bone.

It is understood that according to the invention, the blank already has an outline corresponding to or substantially that of the pierced part, therefore a peripheral face with a geometry and dimensions falling within the tolerances of the final pierced part. This means that in projection along an axis parallel to the peripheral face of the blank, this peripheral face of the blank also corresponds to the projection of the peripheral face of the pierced part. Thus, taking into consideration the geometry of the peripheral face of the blank, which will remain practically unchanged for the drilled part, or the geometry of this peripheral face of the blank within the parts surrounding it in the case of a drilling the hole with the blank already mounted, it is possible to determine the center of the hole more accurately and therefore to drill in the blank at the correct position of the hole. In this way, assembly play is reduced and compliance with the tolerances of the specifications is improved in relation to the position of the hole of the drilled part in relation to its support (for example the bezel for a watchmaker's shock absorber) and more generally relative to surrounding rooms.

[0016] Advantageously, the determination of the drilling center is carried out by optical means and calculation means, forming a measurement system, present in the machine to be machined by femtosecond laser, which will provide the control information for the control of position and orientation of the laser source. The final delivery of the laser beam is usually achieved by a precessing head. These optical means comprise an optical chain with shooting means such as a camera which will take images of the blank, making it possible to identify the outline of the blank (its peripheral face) and/or images of the blank. blank mounted in its support, which make it possible to identify and determine the position of the outline (of the peripheral face) of the blank in relation to its final functional environment.

[0017] This characterization of the drilling center is carried out individually for each blank, and this while the machining machine which is able to implement the manufacturing method according to the invention, comprises at least one plate on which is fixed a series of blanks, for example a series of at least 500 or at least 1,000 blanks per tray, for example more than 8,000 blanks per tray. The trays are drilled with openings and each blank is secured to the tray with an opening in the tray extending from the center of the blank so that the laser beam does not encounter the tray material when drilling the hole in each blank . This plate is for example a silicon wafer, or another metallic or partially metallic plate, or even a transparent wafer, for example made of glass. This arrangement makes it possible to make profitable the high cost of the machines to be machined by femtosecond laser, by a maximum use of their capacity.

[0018] For even greater processing speed, the machining machine may comprise a system for loading/unloading trays or sets of trays placed in a cassette, with a loader which can bring and place a tray in the zone of treatment (machining field) of the machine to be machined, and also clear the table outside the treatment area.

[0019] The fixing of the blanks on the plate is for example carried out by temporary gluing such as with a film with double-sided sticky or adherent material, for example with a material with low adhesive power in order to be able to easily remove the blanks from the plate after their machining. It is also possible to use a temporary adhesive which is soluble in a solvent, for example in water, or which degrades by heat treatment or treatment with UV rays or treatment with another energy source.

According to certain embodiments of the invention, the blank is an undrilled blank, namely a solid blank.

[0021] According to certain embodiments of the invention, the pierced piece of microtechnology is a pivot bearing, in particular a pivot stone, intended to receive a pivot in the hole.

[0022] According to certain embodiments of the invention, the pierced microtechnology part is made of a material belonging to the following list: ceramics, monocrystalline or polycrystalline corundum, synthetic ruby, synthetic sapphire, SiO2, zirconia, yttria zirconia, Al2O3telle monocrystalline alumina, alumina-zirconia combination, silicon, silicon nitride, tungsten carbide, PZT (lead titanium-zirconate), aluminum nitride, low temperature cofired ceramic (LTCC or „low temperature cofired ceramic) “), high temperature co-fired ceramics (HTCC or „high temperature cofired ceramic“), direct bonded copper (DBC or „direct bonded copper“) and amorphous materials (in particular glasses).

According to certain embodiments of the invention, the material of the blank has a Vickers hardness between 1600 and 2000 HV.

[0024] According to certain embodiments of the invention, the blank and the pierced part have rotational symmetry. In particular, the peripheral face of the pierced part is of revolution. According to one possibility, the hole, emerging or not, has a cylindrical geometry of circular section.

[0025] In the present text, the "hole" corresponds to the initial recess resulting from the drilling of the blank by femtosecond laser, whether it is a through hole resulting from the complete drilling from one side to the other of the roughing by femtosecond laser, or a blind hole resulting from drilling from one of the faces of the roughing. This hole is then optionally enlarged in one or the other or, where appropriate, the two portions adjacent to the two faces of the blank. For a pivot bearing comprising a hole and a recess or an engagement cone, the hole remains only in its shape and its dimension resulting from the initial drilling, in the part of the stone in contact with which the pivot will pivot in normal operation . The diameter of the hole thus corresponds substantially to the diameter of the drilled part, in particular for a pivot, within tolerances and clearances.

[0026] In certain embodiments, the step of machining the blank further comprises, after the drilling of the hole, the production by femtosecond laser of an additional step of machining the wall of the hole, in all its depth or only over a portion of its depth. The realization of an olive grove is a possibility. According to other possibilities, it can be the machining of a chamfer, the machining of a groove, the machining of a conical cylindrical surface, micro-machining, texturing or surface structuring .

[0027] In certain embodiments, the step of machining the blank further comprises, before or after the drilling of the hole, the production on at least one of the first face and the second face, of a functional element centered on said drilling center, by removal of material. For example, it may involve machining a functional element by femtosecond laser, such as a hollow.

[0028] In some embodiments, the step of machining the blank further comprises producing on each of the first face and the second face, a functional element centered on said drilling center, by removal of material. For example, it may involve machining a functional element, such as a hollow on each face, to form a stone with two hollows, by femtosecond laser or by another material ablation technique.

[0029] In certain embodiments, the step of machining the blank further comprises the removal of material on the peripheral face of the blank, which connects the first face to the second face, on at least least one of the surfaces of the peripheral face. It is thus possible, for example, to form a chamfer.

[0030] In either of the above situations, material ablation can be performed by femtosecond laser machining.

[0031] In certain embodiments, the hole is of revolution around a central axis passing through the center of the hole.

It is understood that in certain configurations of the invention for which the drilling of the blank is carried out in a blank not mounted in a support, the formation of the hole is carried out by reference to the peripheral face of the blank, which is generally circular in shape, but can have any other shape. This solution has the particular advantage over the prior art of allowing, by this construction of the hole around the peripheral face, therefore for example of the outer diameter, to take into account any deviations in shape and/or geometry of this outer face with respect to the ideal theoretical shape of this outer face, these deviations then not being added to any dimensional deviation of the hole with respect to its ideal model.

In the same way, in the other implementation configurations of the invention, in which the blank is already mounted in its support which belongs to the final functional environment of the pierced part, this support possibly being mounted in another part, the position of the blank in the support and/or in this other part can be taken into account, to determine the drilling center and then to drill the hole by femtosecond laser.

[0034] More generally, when determining said drilling center location, the geometry of the support and/or the position of the blank in said support and/or the position of the support in the final functional environment of the drilled part , may also be taken into account.

[0035] Such a support or such other part is for example a bridge or a plate or a bezel. A final pierced part is therefore obtained forming a pivot bearing which is less likely to come out of tolerance deviations to fulfill its pivoting function in the functional assembly to which the pivot bearing belongs, than in the case of a traditional manufacturing process. . Such a support or such another part is, for example, a body surrounding an optical fiber connection ferrule, a pass-hole for insulated connectors, a bearing of an axial micro-actuator.

According to certain embodiments, said support is metallic. According to other embodiments, said ceramic support.

According to certain embodiments, said support and the blank (therefore the pierced part) are made of different materials, for example the support is metallic and the blank (therefore the pierced part) is ceramic.

[0038] According to certain embodiments, said support forms a watch component belonging to the following list: bezel, part of a watch shock absorber, part of a set of gears, bridge, plate, cog, part of the winding mechanism and time-setting device, part of a horological movement or of a horological blank, a bearing, a ball-bearing cage, a jewelery component and a component for a writing instrument or the said support forms a component of a fuel injection device, vertical sample card or vertical micro-pocket, metered dose inhaler, scientific instrumentation device, ink jet printer nozzle, a detector, or a sensor, of a high resolution circuit, of a fuel cell, or of an interconnection system of optical fibers, for example a ferrule, or of an electronic interconnection system , for example a micro screw.

When the hole is intended to receive a component, this component is in many cases formed from a set of parts. Thus, for example, the component is for example a timepiece component formed of a balance assembled with an oscillator of the balance-spring type. By "assembled balance", we mean an assembly consisting of a balance and a shaft, the balance being mounted, in particular driven on the shaft which is inserted into the hole of the pivot bearing formed by the drilled part. According to other situations, the component intended to be housed in the hole belongs to a set of parts: for example, the set of parts can comprise a watchmaker damper. Such a damper may comprise a kitten, the bearing, a counter-pivot stone and a spring. The pierced part is then a bearing of the pivot stone or pivot stone type which is housed in the bezel.

In particular and without limitation, the present invention relates to the manufacture of such a drilled part from a blank, whether or not this blank is already mounted in a support which belongs to the final functional environment of said pierced part. This final functional environment corresponds to the part forming the support (of the blank then of the pivot bearing) or the set of parts which is located in the vicinity of the drilled part, which includes the support, and which is is (are) attached to the pierced part, such as its support, or either which is (are) mounted, mobile(s) or fixed, with one of these parts attached to the pierced part. For example, the final functional environment and the part assembly may comprise a bridge such as a plate or a balance bridge forming the support on which the pierced part is driven forming a pivot bearing resulting from the manufacturing method according to the invention. . In the present text, the final functional environment does not include the parts which could hinder or prevent the machining of the blank and in particular the drilling of the blank to form the pivot bearing. Thus, for example, the pin or the shaft intended to come to pivot in the hole of the pivot bearing, must be absent during the drilling of the blank to form the hole of the pivot bearing, so that this pin or this shaft is not part of the final functional environment when drilling.

The present invention also relates to a pierced microtechnology part in a hard material having a Vickers hardness equal to or greater than 1,200 HV, obtained by the manufacturing method as described in this text.

Brief description of figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: Figure 1 illustrates the steps of the manufacturing method according to the invention for a pierced part forming a first type of pivot bearing, Figure 2 illustrates the steps of the manufacturing method according to the invention for a pierced part forming a second type of pivot bearing, FIG. 3 represents a projected view of a first face of a plate in which are mounted pivot bearings obtained by the manufacturing method according to the invention, the plate also forming a pierced part according to the present invention, Figure 4 shows a perspective view of the plate of Figure 3 according to the second face of the plate, FIG. 5 shows in longitudinal section a nozzle whose outlet from the liquid passage is equipped with a blank intended to form a pierced part obtained by the manufacturing method according to the invention, FIG. 6 shows in longitudinal section the nozzle of FIG. 5 whose outlet from the liquid passage is equipped with the pierced part obtained by the manufacturing method according to the invention, FIG. 7 represents in perspective and in section a tool used for artificial insemination of a queen bee, equipped with a blank intended to form a pierced part obtained by the manufacturing method according to the invention, Figure 8 is the same view as that of Figure 7 after drilling the blank according to the manufacturing method according to the invention, forming the openings for the introduction of the stinger of a queen bee during a artificial insemination, FIG. 9 shows in perspective and in longitudinal section a separator element allowing the passage of wires, such as electrical wires, while maintaining a seal, this separator element being equipped with blanks intended to form pierced parts obtained by the manufacturing process according to the invention, and FIG. 10 is the same view as that of FIG. 9 after drilling the blanks according to the manufacturing method according to the invention, forming the openings for the individual passage of the wires.

Example(s) of embodiment of the invention

In Figure 1, is shown the method of manufacturing a pierced piece of microtechnology which is a pivot bearing 101 forming a flat stone. The blank 100 visible in Figure 1.a has a first flat face 100a, a second flat face 100b, parallel to the first face 100a and a peripheral face 100c connecting the first face 100a to the second face 100b. The peripheral face 100c is essentially cylindrical with a circular section. The blank 100 therefore essentially forms a cylinder section of circular section with an axis of revolution X-X'. This blank 100 possibly has tolerance deviations from the theoretical dimensions, but according to the present invention, a blank is used with very small deviations from the theoretical dimensions, which remain in the specifications. Typically, these deviations are at most + or - 3 micrometers with respect to the theoretical value, for the diameter D measured at the level of the peripheral face 100c, in particular for a diameter comprised between 700 and 1000 micrometers.

This blank 100 is for example obtained by machining (by removal or ablation of material) by means of a machining machine such as a 5-axis CNC (computer numerical control) turning machine, by a technique not not resorting to the determination of a material center, to having a "centerless" technique.

This blank 100 is then placed in the femtosecond laser machining machine (not shown), on a plate and shooting means such as a camera take images of the blank from its first face 100a and make it possible to identify the contour of the blank 100 delimiting its peripheral face 100c and to determine, by image recognition and by calculation, a location of the drilling center C. the knowledge of this drilling center C makes it possible to determine the position of the hole to be drilled, centered on this drilling center C through which passes the axis of revolution X-X' of the pivot bearing 101 after drilling the hole 110. The blank 100 is subjected to femtosecond laser drilling according to a beam 200, as schematically illustrated in Figure 1.b, in order to drill the circular hole 110, forming a through hole between the first face 100a and the second face 100b, according to a cylindrical geometry of circular section, centered on the axis X-X'. A high dimensional precision is obtained to the micron of this hole 110, with a maximum dimensional difference of the order of 1 to 2 micrometer(s) with respect to the theoretical diameter. In this way, it is understood that the external diameter D (peripheral face 100c) is concentric with the internal diameter d (hole 110). The hole generally has a diameter of the order of 50 micrometers to 100 micrometers.

In FIG. 1c, an additional machining step is illustrated: this is a turning step to reduce the friction surface with the shaft which will be housed in the hole 110. The wall of the hole 110 is made convex to form an olive-shaped hole 110'. In this case, the step of machining the blank further comprises, after the drilling of the hole 110, the production by femtosecond laser (beam 200) of a olivage of at least a section of the wall of said hole 110 In the case of FIG. 1.c, the truing is carried out over the entire height of the hole 110' which has the shape of a diabolo. This olivage can be done from the first face 100a (the one on which the center of the hole is determined) as in figure 1.c, or from the second face 100b, or even from each of the two faces 100a and 100b successively if this is more suitable for reasons of accessibility of the entire extent of the area to be rounded off. At the end of this binding, the hole 110' still has a diameter d, in its zone of smallest diameter, centered on the axis X-X'.

After machining the blank 100, one can proceed to a finishing step on the pivot bearing 100 (or more generally on the pierced part), comprising at least one of the following operations: polishing, brushing , produced using a conventional technique. It can be a finishing process by mechanical means or chemical means or by plasma such as DRIE („Deep Reactive Ion Etching“). In this way, it is possible, for example, to minimize the roughness of the operational surfaces of the hole in the bearing (or more generally of the drilled part) and/or to confer convexity on one or the other of the faces of the bearing (or more generally on the drilled part), such as a domed face.

Referring now to Figure 2 showing the method of manufacturing a pivot bearing 102 forming an olive stone. The starting point is a blank similar to the blank 100 of FIG. 1a, and the center of the hole C is determined from the peripheral face 100c which here is essentially cylindrical with a circular section. One could have a blank with another shape for the peripheral face 100c, or for example a cylindrical shape of non-circular section. In this case, the step of machining the blank 100 further comprises, before drilling the hole, making a recess 112 centered on said drilling center C. According to a variant not shown, the recess 112 is machined after drilling the hole 110. In FIG. 2.a, the recess is machined from the second face 100b of the blank 100, which has a chamfer 100b1 along its edge. According to a variant not shown, the hollow is machined from the first face 100a of the blank 100. According to a variant not shown, a hollow is machined from the first face 100a of the blank 100 and another hollow 112 is machined from the second face 100b of the blank 100. The machining of this hollow 112 or of these hollows is for example carried out by a machining machine such as a CNC digital machine. More generally, the realization of the recess 112 is carried out before the drilling of the hole on a machine to be machined by removal of material by means of a tool. The case of the machining of this hollow 112 after the drilling of the hole 110, by a femto laser machine, is not excluded within the scope of the invention.

As in the case of Figure 2, if the recess is machined before drilling the hole 110, the center of the hole C is determined (through which the axis of revolution X-X' of the pivot bearing 102 passes) before machine the hollow. Then the blank is transferred to the femtosecond laser machining machine (not shown), and the image pickup means take images of the blank from its second face 100b and make it possible to identify the outline of the blank 100 delimiting its peripheral face 100c and to determine, by image recognition and by calculation, a drilling center location C′ at the bottom of the recess 112. The blank 100 is subjected to femtosecond laser drilling according to a beam 200, as illustrated schematically in Figure 2.b, in order to drill the hole 110 opening onto the first face 100a. This drilling of the hole is carried out on the blank 100 already provided with the recess 112, therefore between a second face 100b which is not planar and the first face 100a.

[0050] In Figure 2.c, an additional machining step is illustrated: this is a step of binding by the laser beam 200 to reduce the friction surface with the shaft which will be housed in the hole 110. The wall of hole 110 is made convex to form a keyhole 110'.

[0051] For these possible steps which follow the drilling of the hole, therefore for example the olive-turning, or another type of machining of the hole or of one or the other of the faces of the blank, such as the formation of the hollow, the position of the center of the hole C can therefore be used as a reference. drilling the hole. Thus, we understand that for these machining steps by material ablation, with the femtolaser or by another machining technology, we can take into account the position of the drilling center which has been determined beforehand so that these other shapes machined are also positioned accurately relative to the peripheral face of the blank. Thus, in the case of a drilled part, in particular a bearing or a revolution stone, all the shapes and machined zones have been machined in relation to the outer diameter of the blank, or more exactly by relative to the outline of the blank.

The femtosecond pulsed laser machining operations are carried out with a laser with a wavelength comprised for example between 200 nm and 2000 nm, preferably between 400 nm and 1000 nm, limits included. The parameters of the laser can be for example: average power between 1 W and 100 W, energy per pulse between 10 µJ and 4000 µJ, frequency between 100 kHz and 1000 kHz, pulse duration between 100 fs and 2 ps. It is possible to achieve high machining accuracies, of the order of 1 micrometer, or even less, and surface roughness Ra of the order of 50 nanometers, or even less.

When drilling the hole 110 in the blank 100 of the drilled part, the femtosecond laser machining machine is able to make holes having a diameter between 200 micrometers and 500 micrometers and a depth between 500 micrometers and 1000 micrometers , each hole 110 being made in a machining time of less than 1 second. In the field of watchmaking, stones typically have an outside diameter comprised between 50 micrometers and 2000 micrometers, and often comprised between 700 micrometers and 1000 micrometers, limits included. In the field of watchmaking, stones typically have a thickness of between 50 micrometers and 1000 micrometers, limits included. Typically, the machining machine makes it possible to perform the drilling of the holes, and possibly one or two additional machining operations, in less than 10,000 seconds for at least 5,000 blanks or parts.

Referring now to Figures 3 and 4 illustrating a plate 120 forming a pierced part provided with three holes 122 for receiving a pivot bearing 102 in the form of olive stone. In this case, these three holes 122 are emerging and positioned in a zone of the plate of reduced thickness, this zone being formed of a non-emerging cavity 126 visible in FIG. 4 showing the second face of the plate 120. This blind cavity 126 can be machined in plate 120 by femtosecond laser according to the method of the present invention, plate 120 then forming the drilled part and cavity 126 forming the hole, or machined by another material ablation technique, for example on a 5-axis CNC (computer numerical control) turning machine. This blind cavity 126 has a complex shape with three circles which intersect in pairs, and each circle has a bore 122 placed substantially in the center of the circle.

According to a possible arrangement of the method according to the present invention, the drilling of the hole 110 of each pivot bearing 102 is carried out by femtosecond laser while the blank of this pivot bearing 102 is already mounted (driven out) in the hole 122 of the plate 120. In this case, the location of the drilling center C′ of the blanks of these pivot bearings 102 is determined by taking into account the position of the peripheral face of the blank relative to the plate 120. In FIGS. 3 and 4, only the bearings 102 are mounted on the plate 120, but one may find oneself in the situation in which other elements of the watch movement are mounted on the plate during the implementation of the method according to the invention, which comprises the determination of the center of the drilling and the production by femtosecond laser machining of the drilling of the hole 110.

For example, one can consider the case of a bridge forming a pivot bearing support, in which are mounted recessed, one by one, in corresponding openings, blanks intended to form pivot bearings. This bridge with blanks is processed by a vision system with image capture during the implementation of a measurement step, which makes it possible to determine the "true" drilling center of each bearing, then to drill femto laser each blank on the „real“ drilling center before placing the bridge on another processing station. It is understood that the „true“ drilling center is the functional center, and not the geometric center of the blank/stone. This functional center is the location on the bridge which is functionally correct for the pivoting of the journal with a view to the proper kinematic running of the watch movement.

[0057] Also, the plate 120 has two holes 124 and 125 which are through holes not equipped with a pivot bearing or stone, which serve respectively to mount an element (part or set of parts) of the watch movement mounted on the plate. (mounting hole 124), and to identify the position of the plate 120 (indexing hole 125). Such an indexing hole 125 is circular in FIGS. 3 and 4, but it could have another shape, for example an oblong shape to facilitate, by its orientation, the mounting angle of the plate 120 in the watch movement. Each of these two holes 124 and 125 can be made by femtosecond laser according to the method of the present invention, the plate 120 then forming the drilled part and the hole 124 (125) then forming the hole. These two holes 124 and 125 or one of these two holes 124 and 125 can be used as a reference point when determining the center of the hole C for the holes 110' of the pivot bearings 102.

According to another example of implementation of the method according to the invention, not illustrated, the manufacture of a pivot bearing is carried out from its blank already mounted in a kitten, with a view to constituting a shock-absorbing member or anti-shock to retain the balance shaft or pivot mounted in the pivot bearing in the event of an impact. In this case, the pivot bearing support is the kitten and the final functional environment of said pivot bearing is the shock absorber member.

The invention also relates to a series of drilled microtechnology parts which have a through hole (or a blind hole) whose dimensions meet the specifications for at least 90% of the drilled parts, and preferably for at least 95% of parts pierced.

[0060] Among the dimensions measured for checking compliance with the specifications, there is at least one of the following parameters: the diameter of the hole, in particular in the zone where the diameter is minimal in the case of olive stone. According to one arrangement, this diameter of the hole respects the theoretical dimension of the diameter of the hole with a maximum difference of 2 micrometers, or even with a maximum difference of 1 micrometer. According to one provision, this diameter of the hole respects the theoretical dimension of the diameter of the hole with a maximum deviation of 1% compared to the theoretical diameter, even with a maximum deviation of 0.5% compared to the theoretical diameter, even with a maximum deviation of 0.1 % compared to the theoretical diameter.

Mention may also be made, among the dimensions and parameters measured for checking compliance with the specifications, the concentricity between the peripheral face and the hole of the pierced part (for example a stone or a pivot bearing). According to one arrangement, this concentricity has a maximum deviation of 8 micrometers, or even a maximum deviation of 5 micrometers, or even a maximum deviation of 3 micrometers between the center of the hole and the center of the peripheral face.

For example, such a series of pierced parts comprises at least 100 pierced parts, preferably at least 1000 pierced parts and advantageously at least 10,000 pierced parts.

Thanks to the method according to the invention, it is in fact possible to obtain series of drilled parts having a rate of compliance with the dimensional tolerances of the specifications which is higher than in the prior art.

[0064] In some of the examples described above in relation to the figures, the pierced piece of microtechnology is a pivot stone for a watch movement. In other examples, the pierced microtechnology part is a connection ferrule for an optical fiber, a ball seat or a bearing for a valve of an implantable device, in particular an electro-medical device, an implantable defibrillator, a heart pump , a pacemaker, an implant, a medical device, or a drilled part for a vertical sampling pocket, a sensor, an actuator, an isolator, a connector, a filter, an inkjet printer nozzle, a metered dose inhaler, or a drilled part for scientific instrumentation having an orifice or slot, or a drilled part for a fuel cell, or a high resolution circuit.

Figures 5 and 6 show a nozzle 210 in longitudinal section, respectively before and after drilling the blank 100 located at the end of the fluid passage (liquid or gas). Thus, in Figure 6, the pierced stone 103 with the hole 110 is visible. The hole 110 has a high dimensional precision, which guarantees the properties expected for the jet of liquid or gas emerging from the nozzle 210.

In Figures 7 and 8, a tool 220 is shown in perspective and in axial section of the functional end, respectively before and after drilling the blank 100 located at the functional end. Thus, in FIG. 8, the pierced stone 103 is visible with the hole 110 at the functional end of the tool 220. This tool 220 notably makes it possible to insert the stinger of a queen into the hole 110, then to spread during instrumental fertilization of queen bees.

In Figures 9 and 10, a separator element 230 is shown in perspective and in longitudinal section of the zone with the blanks 100/pierced stone 103, respectively before and after drilling of the blanks 100. This separator element 230 forms a pass insulated partition used in environments requiring tightness to liquids and gases at the location of the separator element 230. Thus, in Figure 9, the separator element 230 is visible forming a support for a series of blanks 100 placed each in line in an opening passing through the thickness of the separating element 230. The blanks 100 are surmounted by a plate forming a layer of impermeable material 234 (for example glass). In FIG. 10, after drilling the blanks 100, pierced stones 103 are obtained with the hole 110 through which passes a wire 234 such as an electric wire or an optical fiber. After passage of the wire 234, the separator element 230 is raised in temperature so that the melting of the layer of waterproof material 234 and its diffusion by capillarity around the wire 234 seals the pierced stone. This separator element tool 230 is for example used in the space domain where there is a relative vacuum, or in the biomedical domain in particular for a pace maker.

In these three examples of Figures 5 to 10, the drilling of holes 110 can be performed either with a blank 100 not mounted in its support, or with a blank 100 mounted in its support. It is possible to obtain great precision on the position, and on the shape and dimensions of the hole 110 of the pierced stone 103 obtained.

Reference signs used in the figures

[0069] 100 Blank 100a First face 100b Second face 100b1 Chamfer 100c Peripheral face 101 Pivot bearing (flat stone) 102 Pivot bearing (olive stone) 103 Pierced stone 110 Hole 110' Olive hole 112 Hollow 120 Plate 122 Hole for receiving the bearing 124 Mounting hole 125 Indexing hole 126 Non-emerging cavity 200 Laser beam C Drilling center C' Center of drilling in case of recess X-X' Axis of revolution or pivot axis D External bearing diameter d Internal bearing diameter 210 Nozzle 220 Artificial insemination tool 230 Separator element or insulated bulkhead 232 Electric wire or optical fiber 234 Layer of waterproof material

Claims (19)

1. Method for manufacturing a drilled microtechnology part (101; 102, 103; 120) in a hard material having a Vickers hardness equal to or greater than 1,200 HV, the drilled part comprising at least one hole, blind or emerging , characterized in that it comprises the following steps: – supply of a blank (100) defining a first face (100a), a second face (100b) opposite the first face (100a) and a peripheral face (100c) connecting the first face (100a) to the second face ( 100b), said peripheral face (100c) having the geometry and dimensions of the pierced part (101; 102; 120), - determination, on the first face (100a), of a drilling center location (C; C'), taking into account the geometry of said peripheral face (100c) and/or the position of said peripheral face (100c ) in relation to its final functional environment, – machining of the blank (100) taking into account said drilling center location (C; C'), said machining comprising the drilling by femtosecond laser of a hole (110; 126; 124; 125) from the first face (100a) and/or the second face (100b), whereby a pierced piece (101; 102, 103; 120) is obtained. 2. The manufacturing method according to claim 1, wherein the step of machining the blank (100) further comprises, after drilling the hole (110; 126; 124; 125) producing by femtosecond laser d an additional step of machining the wall of the hole (110; 126; 124; 125). 3. Manufacturing process according to one of claims 1 to 3, wherein the material has a Vickers hardness between 1600 and 2000 HV. 4. Manufacturing method according to one of claims 1 to 3, wherein the step of machining the blank (100) further comprises, before or after drilling the hole (110; 126; 124; 125 ), the production on at least one of the first face (100a) and the second face (100b), of a functional element centered on said drilling center (C; C'), by removal of material. 5. Manufacturing process according to the preceding claim, in which the step of machining the blank (100) further comprises producing on each of the first face (100a) and the second face (100b), d 'a functional element centered on said drilling center (C; C'), by removal of material. 6. Manufacturing method according to one of claims 1 to 5, wherein the step of machining the blank (100) further comprises the removal of material on the peripheral face (100c) of the draft (100). 7. Manufacturing process according to one of claims 4 to 6, in which the ablation of material is carried out by femtosecond laser machining. 8. Manufacturing method according to one of claims 1 to 7, wherein the hole (110; 126; 124; 125) is a through hole (110; 124; 125). 9. Manufacturing process according to the preceding claim, in which the hole (110; 126; 124; 125) is of revolution around a central axis (X-X') passing through the center of the hole (C; C') . 10. Manufacturing process according to the preceding claim, in which the hole (110) is capable of receiving a watch component pivoting about the central axis (X-X') of the hole (110). 11. Manufacturing process according to one of claims 1 to 10, in which, after machining the blank (100), a finishing step is carried out on the pierced microtechnology part (101; 102, 103; 120), comprising at least one of the following operations: polishing, brushing. 12. Manufacturing process according to one of claims 1 to 11, in which the pierced microtechnology part (101; 102, 103; 120) is a pivot stone (101; 102) for a watch movement, a plate (120 ), a bridge, or a connection ferrule for an optical fiber, a ball seat or a bearing for a valve of an implantable device, in particular an electro-medical device, an implantable defibrillator, a heart pump, a pacemaker, an implant , a medical or veterinary instrument, an artificial insemination tool, or a drilled part for a vertical sampling pocket, sensor, actuator, isolator, connector, filter, jet printer nozzle ink, a metered dose inhaler, or a drilled part for scientific instrumentation having an orifice or slot, or a drilled part for a fuel cell, or for a high resolution circuit. 13. Manufacturing method according to one of claims 1 to 12, wherein the pierced microtechnology part (101; 102, 103; 120) has rotational symmetry. 14. Manufacturing process according to one of claims 1 to 13, wherein during the step of providing the blank (100), said blank (100) is mounted in a support (120) which belongs to the final functional environment of the pierced microtechnology part (101; 102, 103; 120). 15. Manufacturing process according to the preceding claim, in which, when determining the said drilling center location (C; C′), the geometry of the support (120) and/or the position of the blank (100) in said support (120) and/or the position of said support in the final functional environment of the pierced microtechnology part (101; 102, 103; 120), is also taken into account. 16. Manufacturing method according to claim 14 or 15, wherein said support (120) is metallic. 17. Manufacturing process according to one of claims 14 to 16, in which said support (120) forms a horological component belonging to the following list: chaton, part of a horological shock absorber, part of a set of racks, bridge , mainplate (120), gear train, part of the winding and time-setting mechanism, part of a watch movement or of a watchmaking blank (100), a bearing, a ball bearing cage, a jewelery component and a component for a writing instrument or a part forming a component of a fuel injection device, a vertical sample card or vertical micro-pocket, a metered dose inhaler, an instrumentation device scientist, an implantable device, in particular an electro-medical device, an implantable defibrillator, a heart pump, a pacemaker, an implant, a medical or veterinary instrument, an artificial insemination tool, an inhaler -doser, an inkjet printer nozzle, of a detector, or of a sensor, of a high-resolution circuit, of a fuel cell, or of an interconnection system of optical fibers, for example a ferrule, or of a system of electronic interconnection, for example a micro screw, a fuel cell, or a high resolution circuit. 18. Manufacturing process according to one of claims 1 to 17, in which the pierced microtechnology part (101; 102, 103; 120) is made of a material belonging to the following list: ceramics, Al2O3, monocrystalline or polycrystalline corundum , synthetic ruby, synthetic sapphire, SiO2, zirconia, yttria zirconia, monocrystalline alumina, alumina-zirconia combination, metallic material, silicon, silicon nitride, tungsten carbide, PZT (lead titano-zirconate), aluminum nitride, ceramic low temperature co-fired ceramic (LTCC or „low temperature cofired ceramic“), high temperature co-fired ceramic (HTCC (or „high temperature cofired ceramic“), direct bonded copper (DBC or „direct bonded copper“), amorphous materials and glasses. 19. Pierced microtechnology part (101; 102, 103; 120) in a hard material having a Vickers hardness equal to or greater than 1,200 HV, obtained by the method according to one of claims 1 to 18.