• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
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    • 专利摘要:
    The invention relates to a component for a mechanical watch movement, in particular for the exhaust of a mechanical clockwork movement, at least a part of the component being intended to undergo friction during movement, comprising: ) a first silicon layer (Cs1) cut in a first crystalline plane of the silicon; (i) a second silicon layer (Cs2) cut in a second crystalline plane of the silicon; the orientation of the crystal lattice of the first layer being shifted by an angle different from 0 ° or 180 ° with respect to the orientation of the crystalline lattice of the second layer and / or the first crystalline plane being different and not equivalent to the first one; crystalline plane.
    公开号:CH712824A1
    申请号:CH01063/16
    申请日:2016-08-18
    公开日:2018-02-28
    发明作者:Tobenas Susana；Charles Fiaccabrino Jean
    申请人:Richemont Int Sa；
    IPC主号:
    专利说明:

    Description TECHNICAL FIELD [0001] The invention relates to a mechanical silicon component intended to equip a clockwork watch movement and which undergoes friction such as anchors, wheels, jumpers, cams or elastic guide components (such as flexible pivots). ), as well as a method of manufacturing such a component.
    The invention finds a particularly advantageous application for exhaust components made of silicon, for example for escape wheels, anchors, and other mobile bodies undergoing friction in a watch movement. mechanical.
    State of the art [0003] Mechanical watch movements usually comprise a cylinder which drives the display members through a gear train. The speed of rotation of the train is regulated by a regulating organ through an exhaust. The regulating member may comprise a balance and a hairspring.
    [0004] Different types of escapement are known. For example, Swiss anchor escapements are widespread and include an anchor and an escape wheel. These components are usually made of metal and have the problem of a significant loss of energy. A significant part of the energy available in the barrel is thus dissipated in the exhaust, which in particular has the effect of reducing the power reserve. Other types of exhaust have been proposed to improve the yield, without being able to solve this problem entirely.
    [0005] Improvements have also been made through research on the materials used for the exhaust. Silicon has for example been used to replace the metal of the anchor and the escape wheel. It has the advantage of a reduced density, which reduces the inertia of the components and reduce the energy required to move and stop the anchor and the anchor wheel at each oscillation. The photolithography manufacturing processes make it possible to produce very high precision parts, which makes it possible to reduce the losses due to a bad adjustment, for example between the vanes and the teeth of the escape wheel, and to optimize their geometry. to improve performance. Finally, the silicon parts can be made with extremely clean surface conditions, which also helps to reduce friction.
    The methods for producing these mechanical watch components generally use monocrystalline silicon wafers. Monocrystalline silicon indeed belongs to the cubic cubic class m3m whose coefficient of thermal expansion (alpha) is totally isotropic.
    Silicon is, however, a fragile material with bending fracture stress of less than 10 GPa and fatigue of the order of 2 to 3 GPa. The presence of sharp angles in the typical structures of a watch component is at the origin of high stress concentrations, which can quickly produce deformations and accelerate the breakage.
    To mitigate these risks, EP 1 904 901 describes the advantages of a SiO 2 layer on the surface of a watch component made in a wafer (or wafer) of monocrystalline silicon to enhance its mechanical strength. Despite this protection, any crack or defect capable of spreading beyond the oxidized surface of this component will eventually result in its total breakage because it will spread unhindered through the crystalline structure of the component.
    Watchmaking components in silicon coated with an oxide layer have also been described in EP 1 422 436 which suggests a watchmaker spiral made from a monocrystalline silicon core covered by a layer surrounding the core. and made of a different material. The purpose of this layer is above all to compensate for the variation of stiffness of the hairspring depending on the temperature. For this purpose, the outer layer is for example made of amorphous SiO 2, one of the few materials having a positive thermoelastic coefficient (+ 213 ppm / C).
    [0010] This document EP 1 422 436 suggests a silicon spiral obtained from a wafer cut along the {001} crystalline plane (FIG 5A). Fig. 5A illustrates this plane, and two equivalent planes {010} and {100}, in the case of a cubic-faced crystal. The silicon lattice has a centered cubic face and thus comprises six additional nodes in the center of each of the faces of this cube, which are not shown in FIGS. 5A to 5C for the simplification of the figure; the definition of crystalline planes is however identical.
    The {001} plane has a relatively high planar anisotropy factor. This results in a bending rigidity (Young's modulus) that varies significantly depending on the direction. Due to this anisotropy, a spiral resonator oscillating in breathing mode and manufactured in a wafer engraved in a wafer cut in the {001} plane has a non concentric development, which disturbs chronometry and aesthetics.
    The anisotropy of the planar Young's modulus of a component etched in a wafer cut in the plane {001} is also troublesome if one wants to properly control the equivalent stiffness of a component of complex shape during its conception phase. Indeed, to obtain a good correlation between the calculated values and the values measured for the equivalent stiffness, we must take into account in particular the precise orientation of the elements of the resonator which do not have a perfectly radial symmetry with respect to the different planar directions of the wafer. For example, the different teeth of the escape wheel will have a significantly different flexural Young's modulus and consequently their equivalent stiffness will also be significantly different.
    In order to at least partially overcome these anisotropy problems, EP 2 215 531 suggests a silicon spiral covered with a thermal compensation layer or a layer which compensates for the variations of the Young's modulus in temperature, but of which the soul is obtained from a wafer cut in the {111} plane (Fig. 5C). The Young's modulus in this plane is almost isotropic; its average value is about 169 GPa. The process of shaping silicon {111} orientation is however more delicate than that used on wafers of orientations <001>.
    In all the solutions described above, the presence of a relatively thick oxide layer (about 8% of the total thickness of the component) results in a component with a dark and dull surface, often considered unsightly.
    The growth of an oxide layer on the surface of the spiral of EP 2 215 531 is obtained by a wet oxidation process. Oxidation of components by heating in a dry oxidation chamber has also been suggested. In any case, the growth of the oxide is a slow process, which leads to a significant manufacturing cycle time. For typical mechanical watch component dimensions, relatively thick SiO 2 layers of between 2 and 5 microns must be grown on the silicon surface. It is known that from a certain thickness of thermal SiO 2 (about 3 μm) the physicochemical properties of these layers degrade and their growth becomes too slow. By way of example, the growth of 3 microns of SiO2 thermally lasts more than 50 hours.
    The growth of an oxide layer on the surface of a silicon component takes place at high temperature, typically at 1100 ° C. The original dimensions of the silicon component will expand under the effect of the heat and proportionally to the coefficient of thermal expansion asi. The growth of the oxide will therefore take place on a component with expanded dimensions. The return to ambient temperature at the end of the process takes place on a composite component formed of a silicon core and the newly formed peripheral oxide layer. Since the thermal expansion coefficient of the silicon oxide otsiO 2 is different from that of the silicon aSi (aSi> asiO 2), residual size expansion and compressive stressing of the component ensue. This is particularly true in the case of the spiral in silicon where the elongation of the length of the spiral can reach values of the order of 0.2%, thus modifying the angle of stud, and cause the deformation of the spiral geometry under the effects of the constraint. The presence of an ab initio buried oxide layer, prior to the production of the component and the formation of the peripheral oxide, de facto limits the elongation of the silicon core in the oxidation temperature rise phase, and by way of consequently the residual dilation and the development of stress at the return to ambient temperature. This solution is particularly advantageous in the case of components whose thermal expansion can be catastrophic, as for example in the case of buckling beams embedded at both ends. The oxidation of devices using such elements, such as flexible guides, is very limited.
    CH 699 780 proposes a spiral-type mechanical resonator made from a monocrystalline silicon wafer. The temperature variations of the Young's modulus of the spiral are compensated by two amorphous metal layers or oxide layers disposed inside the silicon bar and whose thermal coefficient of the Young's modulus is opposite to that of the silicon.
    BRIEF SUMMARY OF THE INVENTION [0018] An object of the present invention is to propose a mechanical watch movement component, especially for the exhaust of a mechanical clockwork movement, which makes it possible to avoid the above disadvantages. , or in any case to offer a better compromise between these disadvantages.
    In particular, an object of the present invention is to provide a new component for mechanical clockwork.
    Another object is to provide a mechanical component with more precise dimensions and having fewer residual stresses.
    Another object is to provide a less brittle mechanical component than the components made of silicon or silicon oxide surface.
    Another object is to provide a component for mechanical watch movement faster to produce.
    An object is also to overcome the disadvantages mentioned above and therefore to provide a single-crystal silicon mechanical component, simple to manufacture, whose mechanical characteristics are similar in all directions of a plane.
    The component may advantageously be thermocompensated.
    According to one aspect, these objects are achieved by means of a component for mechanical watch movement, in particular for the exhaust of a mechanical clockwork movement, at least a part of the component being intended to undergo friction during movement step, characterized in that the component comprises: (i) a first silicon layer cut in a first crystalline plane of the silicon; (i) a second silicon layer cut in a second crystalline plane of the silicon; and in that the orientation of the crystal lattice of the first layer is shifted by an angle different from 0 ° or 180 ° with respect to the orientation of the crystalline lattice of the second layer and / or in that the first crystalline plane is different and not equivalent to the first crystalline plane.
    The "crystalline directions" (or nodal directions) of the layers correspond to the directions of the vectors [xyz] joining the nodes n of the crystal. Silicon having a crystal structure with cubic symmetry, the four diagonals are equivalent, the three faces of the cube are equivalent, and so on. For example, the directions [100], [1 "00], [010], [01" 0], [001], [001] and [001 "] are equivalent to each other and form a family of directions designated by 100> (the operator "designating the opposition).
    [0027] Plans are said to be equivalent if they can be obtained by permutations and / or oppositions of the indices. The plane (xyz) is perpendicular to the direction [xyz]. For example, the planes (100), (100), (010), (010), (001), (001) and (001 ") are equivalent and form a family of planes denoted by {100} (the operator "designating the opposition).
    The mechanical strength is enhanced by the fact that the component does not consist of a monocrystalline and monolithic structure but of several monocrystalline layers of crystalline lattices cut into different sectional planes, and / or oriented differently. Failure to break through one of the silicon layers can not propagate easily into the other silicon layer because the crystallographic planes are oriented differently and the cleavage lines are therefore discontinuous or non-rectilinear.
    According to the first alternative claimed, the mechanical strength is enhanced by the different directions or orientations of the crystal lattices in the different silicon layers. Thus, a crack generated in a crystalline silicon layer and which would have passed through the separation layer or layers has less risk of propagating in the other crystalline silicon layer, because of the phase shifts between the crystallographic planes.
    According to the second alternative, the mechanical strength is also enhanced by cutting the various silicon layers of the component in different crystalline planes and not equivalent. For example, the first silicon layer may be cut in the {001} plane and the second silicon layer may be cut in the {011} plane or the {111} plane. Alternatively, the first silicon layer may be cut in the {011} plane and the second silicon layer cut in the {111} plane. According to these embodiments, the orientations of the crystal lattices are different since each layer is cut in a different crystalline plane, which further favors the robustness of the structure of the component.
    The robustness can also be improved by separating the different silicon layers by one or more separation layers. Thus, a crack generated in a crystalline silicon layer can be stopped by the separation layer, and avoid spreading to the other crystalline layer.
    At least one separation layer may consist of an amorphous material. An amorphous material further reduces the risk of crack propagation.
    At least one separation layer may consist of a material having a thermal coefficient of Young's modulus of sign opposite to that of silicon for thermocompensation. Thus the thermocompensation of the mechanical component is not done, or not only, through an outer SiO 2 layer but also through at least one buried separation layer.
    At least one separation layer preferably has a first thermal coefficient of the isotropic Young's modulus in the plane of the layer.
    At least one separating layer may consist of SiO 2.
    The component may comprise more than two silicon layers separated from each other.
    The component may comprise several separation layers between two silicon layers.
    The component may also include an outer layer which further limits the risk of breakage. This outer layer may consist of an amorphous material, for example SiO 2.
    The outer layer may be made of a material having a thermal coefficient of Young's modulus of sign opposite to that of silicon. The use of the separation layer performing thermal compensation between the first and second silicon layers limits the thickness of this outer layer. The thickness of this outer layer is greater than the thickness of the native silicon oxide resulting from the natural oxidation of silicon at room temperature.
    According to the embodiments of the invention, at least some of the following advantages can be obtained:
    Buried layer [0041] A) Less oxide required at the surface of the component. B) Shorter manufacturing cycle times. D) Better dimensional control of the components E) Reduction of residual stresses in the component F) Amorphous layer limiting the propagation of cracks on the height of the component. Offset of crystal lattices with or without a buried layer A) Better mechanical robustness of the system. B) Delay crack propagation and premature breakage of the component.
    Planar homogeneity of the elastic and thermoelastic properties A) Free orientation of the component with respect to the plane of the wafer.
    The invention also relates to a method of manufacturing such a mechanical component.
    According to one embodiment, the method of manufacturing a mechanical component comprises the superposition of two different or differently oriented silicon wafers, and the etching structure of several mechanical components.
    A separation layer may be provided between the two wafers, for example a thermal compensation layer, for example an SiO 2 layer.
    Within the meaning of the invention, the term "depositing a layer of material" means the processes consisting in adding material by deposit, adding material by growth and transformation of the existing material or the postponement of a supplemental layer by sealing the auxiliary layer.
    BRIEF DESCRIPTION OF THE DRAWINGS [0048] Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: FIG. 1 illustrates by way of example a cross section of a portion of a mechanical component for a watch movement, made here with two monocrystalline silicon layers of similar sections but whose orientations of the crystal lattices are shifted by 30 °; fig. 2 illustrates a cross section of a portion of a mechanical component for clockwork, made here with three layers of silicon cut in different planes ({001} or {111}) and separated from each other by layers of buried Si02. In this example, there is no angular offset networks in the two layers cut according to the plane {001}; fig. 3 schematically illustrates two silicon wafers {001} whose orientations of the crystal lattices are shifted by 30 °, as well as the planar Young's modulus EA, EB of the two wafers; fig. 4 schematically illustrates, in 2D, three silicon wafers {001} whose crystal lattices are shifted by 30 °, as well as the planar Young's modulus EA, EB, Ec of the three wafers; fig. Figure 5 illustrates schematically the crystalline directions in a cubic crystal. The crystalline directions are defined in the same way in a face-centered cubic crystal, such as silicon; fig. 6 is a schematic representation of the method of producing a mechanical component according to a first embodiment; fig. 7 is a schematic representation of the method of producing a mechanical component according to a second embodiment;
    Fig. 8 is a schematic representation of the method of producing a mechanical component according to a third embodiment; fig. 9 is a schematic representation of the method of producing a mechanical component according to a fourth embodiment; fig. 10 is a schematic representation of the method of making a mechanical component according to a fifth embodiment; and FIG. 11 is a schematic representation of the method of producing a mechanical component according to a sixth embodiment.
    Example (s) of Embodiment of the Invention [0049] FIG. 1 illustrates a cross-sectional view of a mechanical component portion, for example of an anchor or an escape wheel. This figure shows a stack of three layers: a first monocrystalline Cs1 silicon layer directly in contact with a separation layer Co1 directly in contact with a second monocrystalline Cs2 silicon layer. The separation layer Co1 is optional. It is advantageously carried out in an amorphous material, for example SiO 2.
    The first silicon layer Cs1 extends over a height hs1 and over the entire width L of the component 1. The second silicon layer Cs2 extends over a height hs2 substantially equal to the height hs1 and over the entire width L. The separation layer Co1 extends over a height h1 much lower than the two heights hs1, hs2 and over the entire width L.
    It is also possible to provide several separation layers between the two silicon layers Cs1, Cs2.
    In this example, the first silicon layer Cs1 and the second silicon layer are cut along the same crystalline plane, preferably the plane {001}, or the plane {011}. It is also possible to provide a stack of layers cut in different crystalline planes; for example a layer cut in the plane {001} and another layer cut in the plane {011}.
    The orientation of the crystal lattice Ds1 of the first silicon layer Cs1 is shifted by an angle α with respect to the orientation of the crystalline lattice Ds2 of the second silicon layer Cs2. These directions Ds1, Ds2 are defined from any corresponding crystalline vector in the layers Cs1, Cs2.
    The hatching of FIGS. 1 and 2 show schematically the offsets between the directions Ds1 and Ds2. However, the offsets between the directions Ds1 and Ds2 are performed in the plane of the silicon layers.
    The separation layer Co1 may advantageously consist of a material having a thermal coefficient of Young's modulus of sign opposite that of silicon so that the variation of the mechanical strength of the silicon layers Cs1, Cs2 depends on the temperature is at least partially compensated by the separation layer Co1. Preferably, the separation layer Co1 is formed of silicon oxide. The thermal coefficient of Young's modulus for silicon is -64.10-¾-1 and the thermal coefficient of the Young's modulus for silicon oxide is 187.5 × 10 -1 at room temperature, about 20 ° C. vs. Thus, to compensate, at least partially, the variation of the stiffness of the silicon layers Cs1, Cs2 as a function of temperature, the volume ratio between the thermal separation and compensation layer Co1 and the silicon layers Cs1, Cs2 is advantageously at least 5%, preferably at least 10%, for example more than 20%, at an ambient temperature of 20 ° C. In fig. 1, the area of the section hol.L is therefore at least 20% of the area of sections L.hsl and L.hs2. In one example, the thickness of the separation layer Co1 is between 1 and 4 microns, for example 2 microns.
    FIG. 3 illustrates a stack of two wafers cut in the plane {001}, the orientation of the crystal lattice of the upper wafer 2B being angularly offset by an angle α in this example with respect to the orientation of the crystal lattice of the lower wafer 2A. The figure also shows the value of Young's modulus EA respectively EB, according to the direction, for each of the two wafers 2A respectively 2B. As can be seen schematically in this figure, the maxima and minima of the Young's modulus do not correspond on the two wafers, so that the value of the Young's modulus of the two superimposed wafers (or of an engraved or structured component in these two superimposed wafers) is less dependent on the direction. In the example illustrated, the phase shift a is 30 °. Other angular phase shift values are however possible, in particular all angles other than 0 ° or 180 °.
    Most silicon wafers have a flat, represented by references 20A and 20B respectively in FIG. 3. The phase shift of the superimposed wafers can be achieved by controlling the angle between these two flats, then sealing the two wafers to one another before the components are etched.
    FIG. 2 illustrates a variant of the invention in which the component 1, shown in cross section, comprises three layers of silicon Cs1, Cs2, Cs3 intersected by two separation layers Co1, Co2 optional. The orientation of the crystal lattice Ds1 of the first silicon layer Cs1 is the same as the orientation of the crystalline lattice Ds3 of the third silicon layer Cs3. The second silicon layer Cs2 disposed between the first and the third silicon layers Cs1, Cs3 comprises a crystal lattice whose orientation or direction Ds2 is shifted by an angle different from 0 ° and 180 ° relative to the orientations of the networks. corresponding crystalline layers Ds1, Ds3.
    In this example, the first silicon layer Cs1 and the third silicon layer Cs3 are cut in the same crystal plane or equivalent crystal planes, preferably the plane {001}, or the plane {011}. The second silicon layer is in turn cut along the {111} crystalline plane.
    The layers Cs1 to Cs3 may, however, correspond to any section or combination of sections in the {110}, {111} and {001} planes. In another embodiment, the layers correspond to a combination of sections in the {110} and {001} planes. In a preferred embodiment, all the layers correspond to sections in the {001} plane, the orientations of their crystal lattices being angularly offset from each other so as to limit the risk of crack propagation and to homogenize the properties. thermoelastic. In a preferred example, this offset angle between the orientations of the corresponding crystal lattices may be 30 (FIG 4), but other angular offsets are of course possible.
    The height hs2 of the second silicon layer Cs2 may be equal to or different from the sum of the heights hs1 and hs3 of the two other silicon layers Cs1, Cs3. In order to compensate, at least partially, the temperature drift, the sum of the heights of the separation layers Co1 and Co2 is advantageously at least 5%, preferably at least 10%, for example more than 20%, of the sum heights of the silicon layers Cs1, Cs2, Cs3.
    In all the embodiments described above, the thickness h01, ho2 of the separation layers Co1, Co2 may advantageously be between 1 and 4 microns, for example 2 microns. Different separation layers may be made of the same material, or different materials. The thickness of different separation layers may be the same or variable. Two silicon layers can be separated by different separation layers into different materials.
    In all embodiments, the component 1 may comprise an outer layer not shown. This outer layer may be made of an amorphous material, and limit the risk of cleavage initiation during an impact on the surface of the component. The outer layer may be made of a material having a thermal coefficient of Young's modulus of sign opposite to that of silicon. The use of a separation layer performing thermal compensation between the first and second silicon layers limits the thickness of this outer layer, and therefore the manufacturing time of each component. The thickness of this outer layer may be greater than the thickness of the native silicon oxide resulting from the natural oxidation of silicon at room temperature. The sum of the surfaces of the separating layers and of the outer layer is determined so as to compensate as precisely as possible the variation of the Young's modulus according to the temperature. The outer layer may be disposed on all sides of the component, or only on the upper and lower faces. It can be obtained by oxidation of silicon in an oxidation chamber.
    FIG. 4 illustrates a stack of three cutting wafers in the plane {001} 2A, 2B and 2C. The orientation of the crystal lattice of the three wafers is shifted relative to each other. In the preferred example illustrated, the offset is 30 °. Other offset values are possible. The figure also shows the value of Young's modulus EA respectively EB and Ec, according to the direction, for each of the three wafers 2A, 2B and respectively 2C. As can be seen schematically in this figure, the value of the Young's modulus of the stack is homogenized according to the direction.
    Several multi-core components 1 are preferably structured by etching in a stack of wafers sealed to each other before cutting. The different wafers are oriented relative to each other before burning the components.
    Figs. 6 to 11 illustrate methods of making a component 1. The method of FIG. 6 uses two silicon wafers silicon on insulator SOI. Each silicon-on-insulator wafer SOI comprises a substrate Su1, Su2 surmounted by a layer of insulator CH, Ci2 and then a layer of monocrystalline silicon Cs1, Cs2. The substrate Su1, Su2, may be made of silicon. In a first optional step 21, an optional separation layer Co1, for example an amorphous Si02 layer, is deposited on the silicon layer Cs1 of the first wafer. In a second step 22, one or more mechanical component patterns is etched on the separation layer Co1 and on the silicon layer Cs1. In a third step 23, the silicon layer Cs2 of the second wafer is sealed on the separation layer Co1. The second wafer is shifted by an angle α relative to the first wafer before this sealing step 23 so that the orientations or the directions Ds1, Ds2 of the crystal lattices are also shifted by an angle α. In a step 24, the assembly is turned over and the substrate Su1 and the insulating layer Ci1 of the first wafer are removed. In a step 25, the silicon layer Cs2 of the second wafer is etched in the pattern of the desired component using an etching mask. The etching can be performed by a deep reactive ion etching technique (also known by the acronym DRIE for "Deep Reactive Ion Etching"). The substrate Su2 and the insulating layer Ci2 of the second silicon wafer are then removed in a step 26 to release the mechanical component (s) 1.
    FIG. 7 illustrates a production method also using two SOI wafers. In the optional steps 32 and 33, two parts Copi, Cop2 of the separation layer Co1 are respectively deposited on each silicon layer Cs1, Cs2 of the two wafers SOI. In the steps 34, 35, the patterns of the component or components are then etched on the two parts Copi and Cop2 of the separation layer Co1 as well as on the two silicon layers Cs1, Cs2 of the two wafers. In a step 36, the two parts Copi, Cop2 are then sealed with an offset a between the wafers so as to form the complete separation layer Co1. Steps 37, 38 consist in eliminating the two substrates Su1, Su2 and the two insulating layers Ci1, Ci2 in order to release the mechanical component or components.
    FIG. 8 illustrates a production method using a single wafer of the double-SOI type. A wafer of the double-SOI type consists of a substrate Su1 surmounted by a first layer of insulator Cil, a first layer of silicon
    权利要求:
    Claims (13)
    [1]
    Cs1 monocrystalline, a second layer of insulator C12 and a second layer of single crystal silicon Cs2. The second insulating layer Ci2 is optional and performs the function of the separation and thermal compensation layer Col of the component 1. The first silicon layer Cs1 and the second silicon layer Cs2 comprise crystal lattices whose orientations are shifted by an angle a. A first step 41 consists of etching the mechanical component pattern in the first silicon layer Cs1, the second optional insulating layer Ci2 and the second silicon layer Cs2. A second step 42 consists of removing the substrate Su1 and the first insulating layer Ci1 to release the mechanical component (s). FIG. 9 illustrates a variant of the method of FIG. 8 using a wafer of the double-SOI type. A first step 51 consists of etching the pattern of mechanical components in the second silicon layer Cs2 and the second insulating layer Ci2. In a second step 52, a silicon wafer Si2 is sealed on the second silicon layer Cs2. This silicon wafer Si2 is a sacrificial layer which serves only as support for the structure and will be removed in a subsequent step. In a step 53, the assembly is turned over and the substrate Su1 and the first insulating layer Ci1 of the first wafer are removed. The mechanical component pattern is etched on the first silicon layer Cs1 in a step 54 and, in a step 55, the silicon wafer Si2 is removed to release the mechanical component (s).
    1. This variant of the method of FIG. 8 can be implemented when the components 1 are too thick and that the etching step 41 does not correctly etch the first layer of silicon Cs1. FIG. 10 illustrates a production method using an SOI type wafer and an Si2 silicon wafer. In a first optional step 61, a separation layer Co1 is deposited on the silicon layer Cs1 of the first wafer of the SOI type. In a second step 62, a mechanical component pattern is etched on the separation layer Co1 and on the silicon layer Cs1. The silicon wafer Si2 is then sealed with an offset α on the separation layer Co1 (or directly on the silicon layer Cs1) in a step 63. The step 64 consists of thinning the silicon wafer Si2 until it reaches the desired height hs2 for the second silicon layer Cs2 of the component 1. In a step 65, the mechanical component (s) pattern (s) 1 is etched on the second silicon layer Cs2 formed by the silicon wafer Si2 and, in a step 66, the substrate Su1 and the insulating layer Ci1 are removed to release the mechanical component (s). FIG. 11 illustrates a production method using a single wafer of the SOI type in which the substrate Su1 is made of silicon and forms the second silicon layer Cs2. The optional separation layer Co1 is formed by an insulating layer Ci1 preferentially made of silicon oxide. A first step 71 consists of thinning the substrate Su1 until reaching the desired height hs2 for the second silicon layer Cs2. In a step 72, the pattern of one or more mechanical components is etched on the silicon layer Cs1. A structuring layer Cst is then deposited on the thinned substrate Su1 in a step 73 in order to stiffen the structure and the mechanical component pattern is etched in the insulating layers Ci1 and substrate Su1 in a step 74. In a step 75 , the structuring layer Cst is removed to release the mechanical components 1. As a variant, an external heat-compensation layer may be produced in a silicon oxidation chamber, thus forming a layer of silicon oxide around the component. 1. The realization of a third layer of silicon Cs3 can be achieved, for example, by the sealing of a third wafer silicon-on-insulator type and corresponding additional etching steps. claims
    1. A component for a mechanical watch movement, in particular for the exhaust of a mechanical clockwork movement, at least a part of the component being intended to undergo friction during movement, characterized in that the component comprises: (i) a first silicon layer (Cs1) cut in a first crystalline plane of the silicon; (i) a second silicon layer (Cs1) cut in a second crystalline plane of the silicon; and in that the orientation of the crystal lattice of the first layer is shifted by an angle different from 0 ° or 180 ° with respect to the orientation of the crystalline lattice of the second layer and / or in that the first crystalline plane is different and not equivalent to the first crystalline plane.
    [2]
    2. Component according to claim 1, comprising at least one separation layer between the first and second silicon layers (Cs1, Cs2).
    [3]
    3. Component according to claim 2, at least one said separation layer consisting of an amorphous material.
    [4]
    4. Component according to one of claims 2 or 3, at least one said separation layer consisting of a material having a thermal coefficient Young's modulus of opposite sign to that of silicon.
    [5]
    5. Component according to claim 4, at least one said separation layer consisting of SiO 2.
    [6]
    6. Component according to one of claims 2 to 5, the thickness of at least one said separation layer being between 1 and 4 microns.
    [7]
    7. Component according to one of claims 1 to 6, the second crystalline plane being different and not equivalent to the first crystalline plane.
    [8]
    8. Component according to one of claims 1 to 6, the second crystalline plane being identical or equivalent to the first crystalline plane, and the orientation of the crystal lattice of the first layer being shifted by an angle other than 0 ° or 180 ° relative to the crystalline lattice orientation of the second layer the crystalline direction.
    [9]
    9. Component according to one of claims 1 to 8, comprising more than two silicon layers separated from each other.
    [10]
    10. Component according to one of claims 1 to 9, comprising several said layers of separation between silicon layers.
    [11]
    11. Component according to one of claims 1 to 9, comprising an outer layer consisting of a material having a thermal coefficient of Young's modulus of opposite sign to that of silicon.
    [12]
    12. Component according to one of claims 1 to 10, consisting of an escape wheel, an anchor or an elastic guide component.
    [13]
    13. A method of manufacturing a mechanical watch movement component, for example a component according to one of claims 1 to 11, comprising the superposition of two silicon wafers of different crystalline cut and / or crystalline orientation different, and the structuring by etching of at least one component after the superposition.
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    同族专利:
    公开号 | 公开日
    CH712824B1|2020-11-30|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CH699780A2|2008-10-22|2010-04-30|Richemont Int Sa|Self-compensating balance spring for mechanical spiral balance-wheel oscillator of e.g. timepiece, has silicon bar with exterior surface, and material in form of cover, where cover partially covers exterior surface|
    CH708067B1|2008-10-22|2014-11-28|Richemont Int Sa|of self-compensating balance spring watch.|
    WO2016128694A1|2015-02-13|2016-08-18|Tronic's Microsystems|Mechanical oscillator and associated production method|
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    优先权:
    申请号 | 申请日 | 专利标题
    CH01063/16A|CH712824B1|2016-08-18|2016-08-18|Component for a mechanical watch movement as well as a method of manufacturing such a component.|CH01063/16A| CH712824B1|2016-08-18|2016-08-18|Component for a mechanical watch movement as well as a method of manufacturing such a component.|
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