Method for manufacturing an oscillation element

Abstract

One aspect of the invention relates to a method for manufacturing an oscillating element having a predetermined value of a structural property, the method comprising a determining step (31) in which a value of a structural property of an oscillating element (2) formed in a substrate (1a, 1b) is determined by a generating sub-step (39) in which the value is generated on the basis of a prediction algorithm applied by a computer (8) which processes at least one property of an identified resonant frequency of the oscillating element (2) when the oscillating element (2) is subjected to a vibrational excitation in an optical measuring sub-step (38); the method further comprising a modifying step (42) in which a dimension of the oscillating element (2) is modified on the basis of a dimension correction quantity calculated from the determined value of the structural property.

Description

Technical Field

[0001] This invention relates to the field of component manufacturing in the watchmaking industry. More specifically, this invention relates to a method for manufacturing an oscillating element whose structural properties, such as stiffness, have predetermined values. Background Technology

[0002] In the prior art, the manufacturing of oscillating elements from substrates typically employs etching techniques, such as laser etching, plasma etching, deep reactive ion etching (DRIE), or wet etching.

[0003] However, research has found that using this method often results in geometric deviations between multiple oscillating elements formed on the same substrate with the same pattern.

[0004] To overcome these deficiencies, relevant solutions have been proposed in the prior art, especially patents EP 3181938 and EP3181939, which describe methods for manufacturing hairsprings.

[0005] In patent EP 3181938, the manufacturing method includes the following steps: a) forming a hairspring with dimensions larger than those required to obtain a hairspring with a predetermined stiffness; b) determining the stiffness of the hairspring formed in step a) by measuring the frequency of the hairspring connected to a balance wheel having a predetermined inertia; c) calculating the material thickness to be removed in order to obtain the hairspring with the predetermined stiffness; and d) removing the calculated material thickness from the hairspring formed in step a), wherein steps b), c), and d) can be repeated to further improve dimensional accuracy.

[0006] In patent EP 3181939, the manufacturing method includes the following steps: a) forming a hairspring with dimensions smaller than those required to obtain a hairspring with a predetermined stiffness; b) determining the stiffness of the hairspring formed in step a) by measuring the frequency of the hairspring connected to a balance wheel with a predetermined inertia; c) calculating the missing material thickness for obtaining the hairspring with the predetermined stiffness; and d) modifying the hairspring formed in step a) to compensate for the missing material thickness, wherein steps b), c), and d) can be repeated to further improve dimensional accuracy.

[0007] Such methods can be improved, especially to limit substrate contamination that may occur during the measurement steps.

[0008] In this situation, it is clear that a solution is needed that can bring about such an improvement. Summary of the Invention

[0009] The object of the present invention is to provide a method for manufacturing an oscillating element that meets the above requirements.

[0010] This invention relates to a method for manufacturing an oscillating element having predetermined structural characteristics, the method comprising the following steps:

[0011] a) A molding step of forming an oscillating element in a substrate, wherein the size of the formed oscillating element is different from the size required to obtain an oscillating element with predetermined structural characteristics;

[0012] b) A determination step that determines the value of the structural characteristics of the oscillating element in the substrate by a generation sub-step, wherein the value is generated based on a prediction algorithm applied by a computer, the prediction algorithm processing at least one characteristic of the identified resonant frequency of the oscillating element when the oscillating element is subjected to vibration excitation in the optical measurement sub-step.

[0013] d) Based on the determined structural characteristics, calculate the dimensional correction amount to be applied to the formed oscillating element;

[0014] e) Based on the calculated size correction amount, modify the size modification steps of the formed oscillating element in order to obtain an oscillating element with predetermined structural characteristics.

[0015] In other embodiments:

[0016] - The determining step includes an arrangement sub-step in which an oscillating element contained in the substrate is arranged in a determining device, the determining device being used to determine the values ​​of the structural characteristics of the oscillating element;

[0017] - The arrangement sub-step includes a determination phase in which a measurement portion of the oscillating element is determined, which measurement portion is capable of providing a significant vibration response when the oscillating element is subjected to vibration excitation;

[0018] - The arrangement sub-step includes a positioning stage in which the oscillating element is positioned in the optical measurement module, particularly between the laser source and the photodiode photosensor;

[0019] - The arrangement sub-step includes a positioning stage in which the oscillating element is positioned relative to the generator module;

[0020] - The determining step includes a configuration sub-step in which the circular beam is configured by focusing the circular beam emitted by the laser source onto the edge of the oscillating element;

[0021] - The determining step includes an application sub-step in which a time-varying vibration excitation is applied to the oscillating element;

[0022] - In the application sub-step, an excitation signal is applied to the oscillating element, the amplitude of which is sufficient to cause the vibration excitation and can be accurately detected and measured by the optical measurement module;

[0023] - In the optical measurement sub-step, a computer connected to the optical measurement module determines at least one characteristic of the resonant frequency based on the following data: the data includes the amplitude spectrum and phase spectrum of the oscillation displacement of the strip on the oscillating element, the amplitude spectrum and phase spectrum varying according to the excitation frequency;

[0024] The calculation step includes a determination sub-step for determining, based on the determined structural property value, the material thickness to be added or removed for at least one dimension of the oscillating element formed in the molding step, in order to obtain an oscillating element with predetermined structural properties. Attached Figure Description

[0025] Other features and advantages of the invention will become apparent from the following description of specific embodiments of the invention provided only as illustrative and non-limiting examples, along with the accompanying drawings, in which:

[0026] - Figure 1 This is a flowchart relating to a method according to an embodiment of the present invention, which is used to manufacture an oscillating element having predetermined structural characteristics;

[0027] - Figure 2 and Figure 3 This is a schematic diagram of two different substrates according to an embodiment of the present invention. Each substrate includes a set of oscillating elements, all of which are formed simultaneously in these substrates, particularly by etching.

[0028] - Figure 4 and Figure 5 This is a schematic diagram of a first and second variant of a determining device for determining the value of a structural characteristic of an oscillating element according to an embodiment of the present invention. The determining device includes: an element for generating vibration excitation in the body of the oscillating element, the element being in mechanical contact with a portion of an attachment end of a substrate containing the oscillating element; and an optical measurement module for optically measuring at least one characteristic of the identified resonant frequency of the oscillating element.

[0029] - Figure 6 According to an embodiment of the present invention Figure 3 An enlarged schematic diagram of portion A of the substrate shown, which includes an oscillating element;

[0030] - Figure 7This is a schematic diagram of a third variation of a determining device according to an embodiment of the present invention, the determining device comprising: an element for generating vibrational excitation in the body of an oscillating element, the element having no mechanical contact with a portion of a substrate containing an attachment end of the oscillating element; and an optical measurement module for optically measuring at least one characteristic of the identified resonant frequency of the oscillating element; and

[0031] - Figure 8 This is a schematic diagram of an optical measurement module according to an embodiment of the present invention, which is used to optically measure at least one characteristic of an identified resonant frequency of an oscillating element. Detailed Implementation

[0032] Figure 1 This is a schematic diagram of a method for manufacturing an oscillating element 2 with predetermined structural characteristics. The purpose of this method is to ensure that the manufactured oscillating element 2 has extremely high dimensional accuracy, and incidentally, to ensure that these oscillating elements 2 have more precise structural characteristics.

[0033] In this method, the oscillating element 2 is configured to vibrate at a stable frequency, even if certain parameters (particularly those related to setup and manufacturing processes) change. This stable frequency varies according to at least one structural characteristic. Such structural characteristics are defined, in particular, by inherent vibrational characteristics (e.g., resonant frequencies). Each resonant frequency of the oscillating element 2 under an excitation force is such that, at a given frequency, a local maximum displacement amplitude in the plane of the substrates 1a and 1b can be measured within a given portion of the oscillating element 2. In other words, if the oscillating element 2 is excited using an excitation source with a frequency that varies with time, the displacement amplitude tends to increase in that portion before the resonant frequency and then tends to decrease after the resonant frequency. Typically, in such tests, by recording the relationship between the displacement amplitude and the excitation frequency, the peak displacement amplitude or resonant peak value associated with or characterizing the resonant frequency can be displayed.

[0034] In this respect, such structural characteristics can be stiffness, strip thickness, or even elastic moment.

[0035] It should be noted that, in one embodiment, the oscillating element 2 may be a beam, a measuring structure, a sample, or even a mechanical resonator specifically designed to equip a regulating mechanism in a watch, and in the form of a silicon hairspring designed to equip a balance wheel in a mechanical watch movement.

[0036] exist Figure 2 and Figure 3The diagram shows a set of oscillating elements 2 contained in substrates 1a and 1b, each oscillating element 2 generally shaped like a beam. Each oscillating element 2 in this set includes a flexible section. As previously mentioned, this oscillating element can be a clockwork hairspring, in which case it includes a flexible band connected at one end to an inner stud and wound into a spiral to form several consecutive turns, the last turn extending into an attachment section intended for attachment, for example, to a fixed balance wheel bridge via an outer stud of the hairspring.

[0037] Reference Figure 1 The method includes a forming step 30 for forming a set of oscillating elements on substrates 1a and 1b. In this set of oscillating elements, each oscillating element 2 has a different size than the oscillating element 2 to be manufactured and has predetermined structural characteristics. Now refer to... Figure 3 The substrate 1b includes a through hole 20 formed in a portion 16 of the substrate 1b, the portion 16 including an attachment end 5a for attaching the oscillating element 2 to the substrate 1b.

[0038] In this forming step 30, these oscillating elements 2 are preferably formed simultaneously in substrates 1a and 1b. Each oscillating element 2 can be formed in substrates 1a and 1b by an etching method, such as deep reactive ion etching, laser etching, chemical etching, or focused ion beam etching. It should be noted that, in substrates 1a and 1b, the oscillating elements 2 in this group of oscillating elements preferably have similar geometries.

[0039] The oscillating element 2 formed in the substrates 1a and 1b includes at least one strip 3. Now refer to Figure 8 When the strip 3 is polygonal, the dimensions of the cross section 4 of the strip 3 are E and H, that is, characterized by the height H and thickness E of the cross section 4—these dimensions are different from the corresponding dimensions of the oscillating element 2 whose structural characteristics are to be obtained. In other words, the strip 3 on the oscillating element 2 can have a cross section 4, wherein the dimensions E and H are greater than or less than the corresponding dimensions of the cross section 4 of the strip 3 on the oscillating element 2 whose structural characteristics are to be obtained.

[0040] The oscillating element 2 includes an attachment end 5a and at least one free end 5b. Each oscillating element 2 is contained within a through hole 6 formed in the substrates 1a and 1b. The through hole 6 forms a space in which the oscillating element 2 can freely perform controlled mechanical oscillation motion within the plane of the substrates 1a and 1b.

[0041] In the context of this method, substrates 1a and 1b are preferably made of doped or undoped silicon. The silicon can be monocrystalline silicon, polycrystalline silicon, or amorphous silicon. Furthermore, the crystal orientation of the silicon can be {1,1,1}, {-1,1,1}, {1,-1,1}, or {-1,-1,1}. Alternatively, substrates 1a and 1b can be made of glass, ceramics, carbon nanotubes, quartz, metal, or alloys.

[0042] The method then includes a determination step 31 for determining values ​​of structural characteristics of the oscillating element 2 formed in the substrates 1a and 1b. In determination step 31, the method uses a determination device 7 to determine the values.

[0043] The determining device 7 includes (but is not limited to):

[0044] - Computer 8;

[0045] - Generator modules 9a, 9b, and 9c generate time-varying vibration excitation within the body of oscillating element 2;

[0046] - Optical measurement module 10, which is used to measure at least one characteristic of the identified resonant frequency of the oscillating element 2, and includes a laser source 12 and a photodiode photosensor 13.

[0047] The computer 8 in the determining device 7 is connected to the generator modules 9a, 9b, 9c and the optical measurement module. The computer 8 includes at least one processor and a storage element. The computer 8 is capable of executing instructions to execute a computer program (e.g., designed to drive / test the drive module and the measurement module) and performing calculation / processing operations to execute at least one prediction algorithm stored in the storage element. The algorithm may include machine learning algorithms and / or mathematical formulas. The algorithm is capable of implementing a prediction model or simulation model, thereby determining the values ​​of the structural characteristics of the oscillating element 2 contained in the substrates 1a, 1b based on measurements of at least one characteristic of the identified resonant frequency of the oscillating element 2 subjected to vibrational excitation.

[0048] It should also be noted that the prediction model implemented by this algorithm is generally configured in principle to receive the resonant frequency characteristics as input and provide the structural characteristics as output.

[0049] In this determining device 7, when the generator modules 9a, 9b, 9c make mechanical contact with a portion 16 of the substrates 1a, 1b (which includes the attachment end 5a of the oscillating element 2), or ideally when they do not make contact with that portion 16, the generator modules are able to transmit such vibration excitation to the body of the oscillating element 2.

[0050] When generator modules 9a and 9b are in mechanical contact with substrates 1a and 1b to generate vibration excitation of the main body of the oscillating element 2, generator modules 9a and 9b include a transmission mechanism 15 for transmitting the vibration excitation. Figure 4 In the first variant shown, the transmission mechanism 15 is provided with a pointer-shaped mechanical contact end 11 with a pointed tip, or in Figure 3 , Figure 5 and Figure 6 In the second variant shown, the transmission mechanism 15 has a rounded contact end 11 in the shape of a hemispherical or conical cone. This end is preferably made of a material (e.g., ceramic) that can reduce potential damage to the substrates 1a and 1b. The transmission mechanism 15 is thus configured to generate a vibrational excitation to the oscillating element 2, thereby driving the body of the oscillating element 2 to mechanically oscillate around its stable equilibrium position. It should be noted that the transmission mechanism 15 can generate this vibrational excitation using piezoelectric technology.

[0051] When the generator module 9c is not in mechanical contact with the substrates 1a and 1b, it is configured to generate a pulsating airflow 17 toward the oscillating element 2, thereby driving the body of the oscillating element 2 to mechanically oscillate around its stable equilibrium position.

[0052] The determining step 31 includes an arrangement sub-step 32 for arranging the strip 3 on the oscillating element 2 contained in the substrates 1a and 1b in the determining device 7. In this arrangement sub-step 32, the strip 3 on the oscillating element 2 is positioned relative to both the optical measurement module 10 and the generator modules 9a, 9b, and 9c.

[0053] The arrangement sub-step 32 includes a determination stage 33 for determining the measurement portion 20 of the strip 3 on the oscillating element 2. In this determination stage 33, multiple vibration wave displacement measurements are performed on different portions of the strip 3 body to identify the measurement portion 20 most likely to produce a significant vibration response when the strip 3 body is subjected to vibration excitation. In fact, this determination stage 33 is necessary because when the strip 3 is subjected to vibration excitation, the strip 3 may include portions with very small or even zero vibration displacement amplitudes, especially when the frequency varies with time. In this embodiment, the measurement portion 20 is located at one-third of the strip 3 body and includes the free end 5b of the strip 3. When measuring a non-linear speed control mechanism, it is essential to avoid measurements at vibration nodes of the structure.

[0054] Subsequently, the arrangement sub-step 32 includes a positioning stage 34 for positioning the measuring portion 20 of the strip 3 within the optical measurement module 10, specifically between the laser source 12 and the photodiode photosensor 13. Now referring to... Figure 4 , Figure 5 , Figure 7 and Figure 8The laser source 12 is arranged to face the upper surface 18a of the strip 3, and the photodiode photosensor 13 is positioned to face the lower surface 18b of the strip 3. In this configuration, the laser source 12 and the photodiode photosensor 13 are aligned.

[0055] The arrangement sub-step 32 includes a positioning stage 35 for positioning the strip 3 on the oscillating element 2 relative to the generator modules 9a, 9b, and 9c. In practice, when the transfer mechanism 15 in the generator modules 9a and 9b makes mechanical contact with the substrates 1a and 1b, the contact end 11 of the transfer mechanism 15 is positioned to mechanically connect with the portion of the substrates 1a and 1b containing the attachment end 5a of the oscillating element 2.

[0056] In this case, according to the first variant, the tip of the transmission mechanism 15 is located in one of the multiple regions of the portion 16 defined on both sides of the longitudinal axis of the strip 3, such that the contact interface between the surface of the region and the surface of the tip is not located on or adjacent to the axis.

[0057] In a second variation of the transmission mechanism 15, the transmission mechanism 15 is positioned within a through-hole 19 included in a portion 16, wherein the portion 16 includes an attachment end 5a of the oscillating element 2. In this position, the end of the transmission mechanism 15 contacts the surface of the outer peripheral wall of the through-hole 19.

[0058] In these first and second variations, the transmission mechanism 15 is oriented toward the through-hole 6 containing the oscillating element 2, on either side of the longitudinal axis B of the strip 3, forming an acute angle α with the longitudinal axis B. This acute angle α is greater than or equal to 30 degrees, preferably between 30 and 50 degrees, and most preferably 45 degrees.

[0059] As described above, the transfer mechanism 15 in the generator module 9c can be non-contact. In this configuration, the transfer mechanism 15 is positioned relative to the strip 3 such that the pulsating airflow 17 diffuses toward the measurement portion of the strip 3, which is exposed to the beam 14 emitted by the laser source 12 of the optical measurement module 10.

[0060] The determining step 31 includes a configuration sub-step 36 for configuring the circular beam 14 emitted by the laser source 12. More specifically, in this configuration sub-step 36, the beam 14 is focused on the edge 21 of the strip 3, particularly on the angular edges located in the measuring section 20, such as... Figure 8As shown. Under these conditions, the diameter of the beam 14 is configured to take into account the dimensions of the measuring portion 20 of the strip 3. Therefore, by adjusting the oscillation amplitude of the strip 3, this configuration sub-step 36 helps to improve the optical power modulation effect of the laser beam 14 that can be received by the photodiode photosensor 13. In other words, the circular beam is focused such that the oscillation amplitude of the strip 3 in the plane of the substrates 1a, 1b does not exceed the radius of the beam.

[0061] Subsequently, the determining step 31 includes an application sub-step 37 for applying a time-varying vibration excitation to the oscillating element 2. In this application sub-step 37, generator modules 9a, 9b, and 9c apply an excitation signal to the strip 3 on the oscillating element 2. The amplitude of this excitation signal is sufficient to induce the vibration excitation and can be accurately detected and measured by the optical measurement module 10. Generator modules 9a, 9b, and 9c induce vibration excitation using the following three modes:

[0062] - First mode, generating continuous vibrational excitation at a single given frequency; or

[0063] - The second mode generates vibrational excitation in the body of strip 3 at a time-varying frequency covering a predetermined frequency range. It can scan within a given time interval or cover the entire frequency range;

[0064] - The third mode alternates or combines the first and second modes sequentially.

[0065] The determining step 31 includes an optical measurement sub-step 38 for measuring at least one characteristic of the identified resonant frequency of the oscillating element 2, such as the value of the resonant frequency. In this optical measurement sub-step 38, the optical power received by the photodiode photosensor 13 is measured to deduce the vibration amplitude in the measurement portion 20 of the strip 3. It should be noted that the vibration amplitude reaches its maximum value at this resonant frequency, and therefore the optical power received by the photodiode photosensor 13 also reaches its maximum value.

[0066] In the optical measurement sub-step 38, the computer 8 connected to the laser source 12 and the photodiode photosensor 13 determines at least one characteristic of the resonant frequency based on the following data: the data includes the amplitude spectrum and phase spectrum of the oscillation displacement of the strip 3 (which are functions of the excitation frequency); these data are generated by the computer 8 based on time-based recordings of the oscillation amplitude and phase generated by the beam 14 received by the photodiode photosensor 13.

[0067] Once the characteristic of the resonant frequency is determined, step 31 includes a generation sub-step 39 for generating values ​​of the structural characteristics of the oscillating element 2 contained in substrates 1a and 1b. In this generation sub-step 39, the computer 8 determines the structural characteristics based on the resonant frequency characteristics by executing a prediction algorithm.

[0068] The method then includes a calculation step 40, in which a dimensional correction to be applied to the oscillating element 2 is calculated based on values ​​of structural characteristics determined for the oscillating element 2 contained in the substrates 1a and 1b. In this calculation step 40, the dimensional correction to be applied to the oscillating element 2 is estimated and quantified.

[0069] To this end, the calculation step 40 includes a determination sub-step 41, wherein, based on the determined values ​​of the structural characteristics, the material thickness to be added or removed for at least one dimension of the oscillating element 2 formed in the molding step 30 is determined in order to obtain an oscillating element 2 with predetermined values ​​of structural characteristics.

[0070] This dimensional correction is essentially equivalent to removing or adding a certain material thickness to the oscillating element 2 to change at least one of the dimensions E and H of the oscillating element 2, that is:

[0071] - Only change the height H of its strip 3, or

[0072] - Only change the thickness E of its strip 3, or

[0073] - Change both the height H and the thickness E.

[0074] On the oscillating element 2, the dimensional correction can be performed on one or more individual segments of the strip 3, or the dimensional correction can be performed on the entire length of the strip 3.

[0075] Therefore, by determining the size correction, the determining sub-step 41 can participate in shaping the geometry of the oscillating element 2, thereby giving the oscillating element 2 structural characteristics that are substantially similar to or similar to the predetermined values.

[0076] Then, the method includes a modification step 42, wherein the dimensions E and H of the oscillating element 2 are modified based on the calculated dimension correction to obtain an oscillating element 2 with predetermined structural characteristics.

[0077] In this case, if the dimensions E and H of the formed oscillating element 2 are larger than the dimensions required to obtain the oscillating element 2 to be manufactured, then modification step 42 includes a removal sub-step 43, in which material is removed according to the calculated thickness of the material to be removed. This removal process can be performed using an oxidation and then deoxidation process on the oscillating element 2, which is known in the prior art. The purpose of removal sub-step 43 is to reduce the size of the cross-section 4 of the strip 3 over a given length or the entire length of the strip 3 on the oscillating element 2.

[0078] If the dimensions E and H of the oscillating element 2 are smaller than the dimensions required to obtain the oscillating element 2 to be manufactured, then modification step 42 includes an addition sub-step 44, in which material is added according to the calculated thickness of the material to be added. This material can be added using methods known in the art, such as thermal oxidation, electroplating growth, physical vapor deposition, chemical vapor deposition, atomic layer deposition, or any other addition process. The purpose of the addition sub-step 44 is to increase the dimensions E and H of the cross-section 4 of the strip 3 over a given length or the entire length of the strip 3 on the oscillating element 2.

[0079] Therefore, this method enables the high-precision correction of dimensional errors in oscillating elements, which are manufactured using methods such as photolithography and / or DRIE technology.

[0080] the term

[0081] 1a, 1b. A substrate containing at least one oscillating element.

[0082] 2. Oscillating element

[0083] 3. Stripes on the oscillating element

[0084] 4. The cross-sectional dimensions of the strip on the oscillating element differ from the cross-sectional dimensions of the hairspring to be manufactured.

[0085] 5a. The attachment point of the strip on the oscillating element

[0086] 5b. The free end of the strip on the oscillating element

[0087] 6. A through-hole in a substrate, wherein an oscillating element is disposed.

[0088] 7. A device for determining the values ​​of structural characteristics of an oscillating element.

[0089] 8. Computer

[0090] 9a, 9b, 9c. Generator modules that produce time-varying vibration excitation within the main body of the oscillating element.

[0091] 10. An optical measurement module for optically measuring at least one characteristic of an identified resonant frequency of an oscillating element.

[0092] 11. Mechanical contact terminals of the generator module

[0093] 12. Laser source

[0094] 13. Photodiode optical sensor

[0095] 14. Beam from a laser source

[0096] 15. Vibration excitation transmission mechanism

[0097] 16. The portion of the substrate including the attachment end.

[0098] 17. Pulsating airflow from the generator module

[0099] 18a. Upper surface of the strip

[0100] 18b. Lower surface of the strip

[0101] 19. A through-hole formed in said portion of the substrate.

[0102] 20. Strip Measurement Section

[0103] 21. The edge of the measuring section of the strip.

Claims

1. A method for manufacturing an oscillating element (2) having predetermined structural characteristics, the method comprising the following steps: a) A molding step (30) in which an oscillating element (2) is formed in a substrate (1a, 1b), wherein the size of the formed oscillating element (2) is different from the size required to obtain an oscillating element (2) with predetermined structural characteristics; b) Determining step (31) by generating sub-step (39) to determine the value of the structural characteristics of the oscillating element (2) in the substrate (1a, 1b), wherein the value is generated based on a prediction algorithm applied by computer (8), the prediction algorithm processing at least one characteristic of the identified resonant frequency of the oscillating element (2) when the oscillating element (2) is subjected to vibration excitation in optical measurement sub-step (38); d) Calculation step (40) based on the determined structural characteristics to calculate the dimensional correction amount to be applied to the formed oscillating element (2); e) Modification step (40) based on the calculated size correction amount, modifying the size of the formed oscillating element (2) in order to obtain an oscillating element (2) with predetermined structural characteristics.

2. The method according to claim 1, wherein, The determining step (31) includes an arrangement sub-step (32), in which the oscillating element (2) contained in the substrate (1a, 1b) is arranged in a determining device (7) for determining the values ​​of the structural characteristics of the oscillating element (2).

3. The method according to claim 2, wherein, The arrangement sub-step (32) includes a determination stage (33) in which a measurement portion (20) of the oscillating element (2) is determined, which is capable of providing a significant vibration response when the oscillating element (2) is subjected to vibration excitation.

4. The method according to claim 2 or 3, wherein, The arrangement sub-step (32) includes a positioning stage (34) in which the oscillating element (2) is positioned in the optical measurement module (10), specifically between the laser source (12) and the photodiode photosensor (13).

5. The method according to any one of claims 2 to 4, wherein, The arrangement sub-step (32) includes a positioning stage (35) in which the oscillating element (2) is positioned relative to the generator modules (9a, 9b, 9c).

6. The method according to claim 4 or 5, wherein, The determining step (31) includes a configuration sub-step (36) in which the circular beam (14) emitted by the laser source (12) is configured by focusing the circular beam (14) onto the edge (21) of the oscillating element (2).

7. The method according to claim 6, wherein, The determining step (31) includes an application sub-step (37), in which a time-varying vibration excitation is applied to the oscillating element (2).

8. The method according to claim 7, wherein, In the application sub-step (37), an excitation signal is applied to the oscillating element (2), the amplitude of which is sufficient to cause the vibration excitation and can be accurately detected and measured by the optical measurement module (10).

9. The method according to any one of the preceding claims, wherein, In the optical measurement sub-step (38), the computer (8) connected to the optical measurement module (10) determines at least one characteristic of the resonant frequency based on the following data, namely, the data includes the amplitude spectrum and phase spectrum of the oscillation displacement of the strip (3) on the oscillating element (2), which vary according to the excitation frequency.

10. The method according to any one of the preceding claims, wherein, The calculation step (40) includes a determination sub-step (41) for determining, based on the determined structural characteristics, the material thickness to be added or removed for at least one dimension of the oscillating element (2) formed in the forming step (30) in order to obtain an oscillating element (2) with predetermined structural characteristics.

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