JP2019191178A - Mainspring of timepiece component - Google Patents

Abstract

To provide a mainspring of a timepiece component of forming a thin film for plating or protection on a surface of a silicon substrate so that the thin film is difficult to be peeled, in the mainspring of the timepiece component of processing the silicon substrate by etching or the like and then forming the thin film for plating or protection on the surface.SOLUTION: A mainspring of a timepiece component is made of single crystal material, a plurality of recesses 7 whose opening width is smaller than inner peripheral width are disposed on a surface, and a thin film 6 is formed on the surface so as to enter the recesses 7. The recesses 7 are disposed on each of an outer peripheral and an inner peripheral.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a machine part used in precision equipment such as a watch.

  2. Description of the Related Art In recent years, a method of manufacturing a precise mechanical component by applying MEMS (Micro-Electro-Mechanical Systems) technology for performing fine processing such as film formation, exposure, and etching on a silicon substrate has been used.

  In general, after processing a silicon substrate using MEMS technology, in order to improve durability and characteristics, a film is often formed on the surface of the processed silicon substrate with metal plating or resin.

In this case, a technique for roughening the surface of the silicon substrate is disclosed so that the metal or resin coating is not peeled off. (For example, Patent Document 1)
In the pretreatment method for plating a semiconductor substrate described in Patent Document 1, in order to form an antireflection film by a copper plating layer on a silicon substrate, the silicon substrate is previously immersed in an alkaline solution to roughen the surface of the silicon substrate. In addition, an uneven portion is formed to improve the adhesion between the copper plating layer and the surface of the silicon substrate.

Japanese Patent Laid-Open No. 3-120394 (first page, FIG. 2)

  However, in the conventional technique shown in Patent Document 1, the surface of the silicon substrate of the optical component is roughened and the uneven portion is formed, so that the contact area between the copper plating layer and the surface of the silicon substrate increases, but the uneven portion Since the shape of the V-shaped groove has a small anchor effect and the structure of fixing between the copper plating layer and the surface of the silicon substrate does not change, the copper plating is peeled off when the optical component is subjected to expansion and contraction or external impact. There is.

  As described above, a known technique for forming a concavo-convex portion on the surface of a silicon substrate, which is a material of a mechanical component, and forming a thin film for plating or protection is based on the expansion and contraction motion of the mechanical component itself or an external impact applied to the mechanical component Peeling off, and stress concentrates on the peeled portion, so that impact resistance and characteristics are likely to deteriorate. Furthermore, there is a problem that the thin film piece peeled off by an impact from the outside penetrates into another mechanism to cause an adverse effect. In addition, since the opening and outer shape are formed and then roughened by immersion in an alkaline solution, the surface of the opening formed earlier is also roughened, and it is difficult to control the dimensional accuracy of the final shape. There were also challenges.

  The object of the present invention is to solve the above-mentioned problems, and in a method of forming a thin film for plating and protection on the surface after processing the silicon substrate by etching or the like, the thin film for plating or protection is peeled off on the surface of the silicon substrate. It is to provide a manufacturing method that is difficult to form.

In order to solve the above problems, the mainspring of the watch part of the present invention is:
Consists of a single crystal material, the surface is provided with a plurality of recesses whose opening width is smaller than the inner circumferential width,
A thin film is formed on the surface so as to enter the recess,
The recess, characterized in that it is arranged on the inner peripheral portion and the outer peripheral portion.

  According to the present invention, since a plurality of recesses are formed on the surface of the silicon substrate, the thin film for plating and protection can be made difficult to peel off.

It is the top view and sectional drawing which show the structure of the machine component in 1st Embodiment of this invention. It is the top view and sectional drawing of a part of machine component shown in FIG. It is sectional drawing to which some mechanical components shown in FIG. 2 were expanded. It is a flowchart which shows the manufacturing process of the machine component shown in FIG. It is sectional drawing which shows the manufacturing method of the machine component shown in FIG. It is sectional drawing which shows the manufacturing method of the machine component following FIG. FIG. 7 is a cross-sectional view showing a method for manufacturing the machine part subsequent to FIG. 6. It is sectional drawing which shows the manufacturing method of a machine part following the FIG. 7, and the completed machine part. It is the top view and sectional drawing of a part of mechanical component in 2nd Embodiment of this invention. It is a top view of a part of machine parts in other modifications of a 2nd embodiment of the present invention. It is the top view, sectional drawing, and perspective view of a part of machine parts in a 3rd embodiment of the present invention. It is a top view of a part of machine parts in other modifications of a 3rd embodiment of the present invention. It is a flowchart which shows the 2nd manufacturing method of this invention. It is sectional drawing which shows the 2nd manufacturing method of this invention. It is a perspective view which shows the structure of the machine component in 4th Embodiment of this invention.

  In the present invention, when a thin film for plating or protection is formed on the surface of a silicon substrate which is a material of a machine part, a plurality of recesses are provided on the surface of the silicon substrate, and the inner part is formed from the width of the opening of the recess. The thin film is formed with a wide width, and the thin film enters the concave portion to produce an anchor effect, so that the thin film is hardly peeled off.

  Hereinafter, the mechanical parts of the present invention will be described in detail with reference to FIGS. FIG. 1 is a plan view and a cross-sectional view showing the structure of a mechanical component in the first embodiment of the present invention, FIG. 2 is a plan view and a cross-sectional view of a part of the mechanical component shown in FIG. 1, and FIG. FIG. 4 is a flowchart showing a manufacturing process of the machine part shown in FIG. 1, FIG. 5 is a cross-sectional view showing a method of manufacturing the machine part shown in FIG. 1, and FIG. FIG. 7 is a cross-sectional view showing a machine part manufacturing method following FIG. 6, and FIG. 8 is a cross-sectional view showing a machine part manufacturing method and a completed machine part following FIG. is there.

[First Embodiment]
The structure of the machine component according to the first embodiment of the present invention will be described with reference to FIGS. Hereinafter, although the description will be given by taking “hairspring” as a mechanical wristwatch component as an example of the mechanical component in the embodiment of the present invention, the present invention is not limited to this and can be widely applied to other mechanical components. [Description of the configuration of the hairspring: FIGS. 1 to 3]
This embodiment will be described in detail with reference to FIG. Fig.1 (a) is a top view of the hairspring 1 in 1st Embodiment of this invention, Comprising: The mode when the hairspring 1 is planarly viewed from the axial direction of the rotating shaft body of the mechanical wristwatch which is not shown in figure is shown. ing. For explanation, the hairspring 1 shows only 4 windings.

  In FIG. 1 (a), a hairspring 1 is centered on a whisker ball 3 having a through hole 3a for fitting with a spring, which is a rotating shaft body of a mechanical wristwatch (not shown), and a through hole 3a. The coil-shaped mainspring portion 2 is designed to be wound around the hairball 3, and the hairspring 4 is connected to the winding end of the mainspring portion 2. The winding start of the mainspring portion 2 and the whistle ball 3 are connected by a connecting portion 3b. The beard holder 4 is provided with a through hole 4a for fixing the hairspring 1 to the housing of the mechanical wristwatch.

  The material of the hairspring 1 can be composed of a single crystal material mainly composed of quartz, silicon, silicon oxide, or the like. Here, the single crystal material is a material capable of forming an outer shape through an etching process, and may be made of a plurality of materials. If the material is silicon, it is convenient to construct a light hairspring. In the following description, the case where the material of the hairspring 1 is made of silicon that is light and easy to process will be described as an example.

  Assuming that the material constituting the hairspring 1 is silicon, the manufacturing and processing of the hairspring 1 can use the deep RIE technique known as the processing step of the silicon semiconductor substrate, and manufacture the semiconductor device. A known manufacturing technique similar to the above can be used.

  The mainspring portion 2 is integrally formed, and has a shape that is wound around the hair ball 3. FIG.1 (b) is sectional drawing in A-A 'of the mainspring part 2 shown to Fig.1 (a). In FIG. 1B, four portions of the mainspring portion 2 are shown in an enlarged manner, and description will be given by giving the names of the mainspring arms 20a, 20b, 20c, and 20d to the four portions.

  As shown in FIG. 1B, the spring section of the hairspring 1 is rectangular, and the spring constant of the hairspring 1 is adjusted by changing the rectangular shape. As shown in FIG. 1B, the mainspring portion 2 forms a spiral with an interval k1, and the shape of each of the mainspring arms 20a to 20d differs depending on the mainspring, but the width e is approximately 30 to 80 μm and the height. h is in the range of 70 to 300 μm.

    The detailed structure of the hairspring 1 will be described with reference to FIG. 2 (a) and 2 (b) show only the mainspring arm 20a from the mainspring 1 shown in FIG. 2A is a plan view of the mainspring arm 20a, and FIG. 2B is a cross-sectional view taken along line Lm in FIG. 2A.

  As can be seen from FIG. 2A, the surface of the hairspring 1 is covered with a thin film 6 using a polymer material in order to ensure a long life and high durability of the hairspring 1. Further, as shown in the plan view of FIG. 2A and the cross-sectional view of FIG. 2B, a plurality of recesses 7 are formed at intervals K2 on one surface 2P and the opposite surface 2T of each of the mainspring arms 20a to 20d. Thus, the anchor effect is produced in the bonding with the thin film 6 and the adhesion is strengthened. Here, the recesses 7 are formed on both the upper surface 2P and the lower surface 2T. However, the effect is reduced, but the recesses 7 may be formed only on one of the surfaces. In addition, illustration of this recessed part 7 is abbreviate | omitted in Fig.1 (a), and the recessed part 7 is similarly formed also in mainspring arm 20a-20d of FIG.1 (b).

  The thin film 6 uses a paraxylylene resin, which is a resin having a lower rigidity than silicon. However, it is not limited to this. For example, a plating film or vapor deposition film of an inorganic material may be used. By forming the thin film 6 so as to enter the concave portions 7 on the surfaces of the mainspring arms 20a to 20d, the brittleness of the mainspring portion 2 is reduced and the durability is improved.

The arrangement of the recesses 7 will be described in detail with reference to FIG. The plurality of recesses 7 in the hairspring 1 are provided at intervals K2 on two lines Lm and Ln that pass through the center of the hairspring 1 (not shown) and are spaced from each other by an angle θ. Similarly, the mainspring arms 20b to 20d are provided with a plurality of recesses, and the angle θ is approximately 45 degrees for the mainspring arms 20a and 20b and approximately 30 degrees for the mainspring arms 20c and 20d. Since the shape of the recess 7 is wider than the entrance, in FIG. 2A, the outline of the recess 7 on the entrance side is shown by a solid line and the outline of the back side is shown by a broken line.

  The structure of the recess 7 and the thin film 6 will be further described with reference to FIGS. 3 (a) and 3 (b). Fig.3 (a) is the figure which expanded the periphery of the recessed part 7 of sectional drawing shown in FIG.2 (b). The opening width d of the recess 7 formed on one surface 2P of the mainspring arm 20a is 4.5 μm, and the inner peripheral width D is 5 μm. That is, the diameter of the entrance of the recess 7 is 500 nm narrower than the inner diameter.

  Since the diameter of the entrance of the recess 7 is narrower than the inside diameter, the thin film 6 enters the inside of the recess 7 and is caught at the entrance. That is, an anchor effect occurs at the interface between the thin film 6 and the silicon substrate 200 that is the base material of the mainspring arm 20a, and the thin film 6 is difficult to peel off from the silicon substrate 200 as the base material. The thickness t1 of the thin film is 3 μm, and the depth t2 of the recess 7 is 1 μm. Note that a concave portion and a thin film are similarly formed on the surface T2 which is the other surface, and an anchor effect is generated.

  As shown in FIG. 3A, since the thin film 6 enters the recess 7, the depressed portion X is formed in the thin film 6 around the recess 7. However, the depressed portion X is illustrated for explanation unless particularly necessary. Omitted.

  Next, the structure of the side surface of the mainspring arm 20a will be described with reference to FIG. FIG. 3B is an enlarged view of the periphery of the side portion 2s in the cross-sectional view of the mainspring arm 20a shown in FIG. As shown in FIG. 3B, a thin film 6 is formed on the side 2s of the mainspring arm 20a to a thickness t1 (3 μm), and the surface of the side 2s is a scalloped surface es formed during deep RIE processing. Is formed. The scalloped surface es is a wavy uneven surface. The contact area between the mainspring arm 20a and the thin film 6 is increased by the scalloped surface es of the mainspring arm 20a. By increasing the adhesion area, the adhesive force of the mainspring arm 20ah of the thin film 6 increases and the thin film 6 is difficult to peel off, although not as much as the effect of the recess 7 formed on the surface 2P.

[Description of Effects in First Embodiment: FIG. 3A]
The effect in 1st Embodiment is demonstrated using Fig.3 (a). As shown in FIG. 3 (a), according to the method of manufacturing the hairspring 1 of the present invention, a plurality of recesses 7 are provided in the silicon substrate 200 of the material of the hairspring 1, and the opening width d of the plurality of recesses 7 is a recess. Since the thin film 6 is formed so as to enter the whisker silicon substrate 200 and the plurality of recesses, an anchor effect is generated between the thin film 6 and the silicon substrate 200. This anchor effect makes it difficult for the thin film 6 to be peeled off from the mainspring 1 in response to shrinkage of the hairspring 1 or impact from the outside, etc. The durability as the hairspring 1 is improved. Further, it is possible to eliminate the need for an intermediate film or a coupling agent as a base for the thin film 6.

  In addition, since the depth t2 of the plurality of recesses 7 provided on the surface of the hairspring 1 is smaller than the thickness of the thin film 6, the recesses that are anchor portions are sufficiently filled with the thin film material, and the anchor effect is sufficiently exerted. It will be difficult to peel off. Furthermore, the concave shape of the surface is not noticeable, and the aesthetic appearance is not impaired.

  Furthermore, it is difficult to control the dimensional accuracy of the final shape with the conventional technique of forming a thin film for plating or protection after immersing the material in an alkaline solution to roughen the surface. It is possible to solve.

[Description of First Manufacturing Method: FIG. 4]
A method for manufacturing a machine part according to the present invention will be described with reference to FIG. FIG. 4 is a flowchart showing a manufacturing process of the hairspring 1 which is a machine part of the present invention. As shown in FIG. 4, the manufacturing method of the hairspring 1 includes steps ST10 to ST30.

  Step ST10 is a multiple recess forming step for forming a plurality of recesses 7 using a recess forming mask 8 having an opening narrower than an outer shape forming mask, which will be described later, on a silicon substrate which is a material of the hairspring 1, and includes step ST1. The recess mask forming process and the recess etching process of step ST2. Step ST20 is an outer shape forming step of forming the entire shape of the hairspring 1 from the silicon substrate using the outer shape forming mask 9 having an opening wider than the opening of the concave portion forming mask 8, and includes the step ST3. It comprises an outer shape mask forming process and an outer shape etching process in step ST4. Step ST30 is a thin film forming step of forming the thin film 6 on the surface of the hairspring 1 having the entire shape formed.

[Description of each step: FIGS. 5 to 8]
The details of steps ST10 to ST30 will be described below with reference to FIGS. 5 to 6A relate to step ST10, FIGS. 6B to 8B relate to step ST20, and FIG. 8C relates to step ST30.

[Description of Multiple Recess Forming Step (Step ST10): FIGS. 5 to 6 (a)]
FIG. 5 to FIG. 6A are cross-sectional views for explaining the step of forming a plurality of recesses (step ST10) of the hairspring 1. For the sake of explanation, the cross-sectional views shown in FIGS. 5 to 6A show portions corresponding to the AA ′ cross section of the hairspring 1 shown in FIG. Is the same.

<Recess mask forming step (step ST1)>
As shown in FIG. 5A, a resist R is applied to the upper surface 200u and the lower surface 200b of the silicon substrate 200 having at least an area and a thickness that allow the hairspring 1 to be taken out. The size of the silicon substrate 200 is preferably such that a large number of hairsprings 1 can be taken out. The resist R is a resin-based liquid resist frequently used in photolithography, and is applied to the silicon substrate 200 with a thickness of 1 μm. Here, the resist is formed on the upper surface 200u and the lower surface 200b. However, when the concave portion 7 is formed only on one surface, the resist may be applied only on one surface.

  Next, as shown in FIG. 5B, the applied resist R is cured and then patterned by photolithography, and after exposure, unnecessary patterns are removed with an alkaline aqueous solution. A recess-forming mask 8 having a plurality of openings 8 w for forming a plurality of recesses 7 in the mainspring portion 2 is formed. Thus, step ST1 is completed.

<Recess etching process (step ST2)>
Next, as shown in FIG. 5C, an etching gas G1 is applied for a predetermined time to the silicon substrate 200 on which the recess forming mask 8 having a plurality of openings 8w is formed, and a plurality of the recess forming masks 8 are formed. Along the opening 8w, isotropic dry etching is performed downward on the silicon substrate 200 in plan view. Then, as shown in FIG. 5C, the portions of the plurality of openings 8w of the recess forming mask 8 of the substrate 200 are etched, and a plurality of recesses 7 are formed.

FIG. 5D is an enlarged cross-sectional view of the partial view M5 of FIG. As shown in FIG. 5D, when isotropic dry etching of silicon is performed, the etching proceeds in the lateral direction, and the etching amount directly under the resist film is small, so that the inner peripheral width D is opened in the silicon substrate 200. A plurality of recesses 7 larger than the width d are formed.

  Although not shown, the recess inner side surface 7n is etched again with the etching gas G1 while protecting the recess bottom surface 7s with the passivation gas G2 if necessary. In this process, the inner surface 7n of the recess is etched, and a plurality of recesses 7 having an inner peripheral width D larger than the opening width d are formed.

  Thereafter, as shown in FIG. 6A, the resist R is removed using an alkaline aqueous solution. Eight pairs of recesses 7 are formed in the upper surface 200u and the lower surface 200b of the silicon substrate 200, and step ST2 is completed. Step ST1 and step ST2 are finished, and step ST10 is finished.

[Description of Outline Forming Step (Step ST20): FIGS. 6B to 8B]
FIG. 6B to FIG. 8B are cross-sectional views for explaining the outer shape forming process (step ST20). For the sake of explanation, the cross-sectional views shown in FIGS. 6B to 8B show only the portion along the AA ′ cross section of the hairspring 1 shown in FIG.

<Outer shape mask formation process (step ST3)>
First, as shown in FIG. 6B, a resin-based liquid resist R is applied to a thickness of 1 μm on the upper surface 200u and the lower surface 200b of the silicon substrate 200 on which the eight pairs of recesses 7 are formed. In the liquid resist R around the recess 7 of the liquid resist R, since the liquid resist R enters the recess 7, a depressed portion X is generated.

  Next, as shown in FIG. 6C, the liquid resist R is patterned by photolithography so as to cover a portion corresponding to the width e of the mainspring arms 20a to 20d to be the mainspring portion 2 of the silicon substrate 200. An outer shape forming mask 9 having 9w is formed. As described above, the outer shape forming mask 9 has a shape that forms the entire hairspring 1 although not shown.

<Outline etching process (step ST4)>
Next, as shown in FIG. 7A, the silicon substrate 200 is etched using a method known as a Bosch process. Specifically, the etching gas G1 and the passivation gas G2 are alternately applied for a predetermined time to the silicon substrate 200 on which the outer shape forming mask 9 is formed, and the silicon substrate 200 is applied to the outer shape line c shown in FIG. Etch along.

  FIG. 7B shows details of the outer shape by the above-described Bosch process. FIG. 7B is an enlarged cross-sectional view of the partial view M6 of FIG. As shown in FIG. 7B, the portion of the silicon substrate 200 exposed through the opening 9w of the outer shape forming mask 9 is etched from the top to the bottom as viewed in the drawing. In the Bosch process, the bottom surface 200g is etched with the etching gas G1 while protecting the side wall 20bs and the side wall 20cs with the passivation gas G2, so that the silicon substrate 200 is etched into an elongated shape as shown in FIG. 7B. It is etched and finally cut by the outline c.

  Further, as shown in FIG. 7B, since the isotropic etching is performed in the process in which the etching gas G1 etches the bottom surface 200g, the side wall 20bs and the side wall 20cs are horizontal as viewed in the drawing of FIG. It is also etched in the direction. Since an etching mark is generated in the horizontal direction every time the two kinds of gases are switched, scallop surfaces es having the same number of corrugations as the number of gas switches are formed on the side walls 20bs and the side walls 20cs.

As shown in FIG. 8A, the mainspring arms 20a to 20d are finally separated from the substrate 200 by etching.

  After that, as shown in FIG. 8B, the outline forming mask 9 is removed using an alkaline aqueous solution. As a result of step ST10, eight pairs of recesses 7 are formed in the mainspring arms 20a to 20d. For the sake of explanation, an element composed of the mainspring portion 2 including the mainspring arms 20a to 20d in this state, the beard ball 3 and the whiskers 4 is referred to as an unprocessed mainspring 1p. Although not shown in FIG. 8 (b), the unprocessed hairspring 1p has the mainspring portion 2 cut out from the silicon substrate 200 by etching, and the through-hole 3a of the whistle ball 3 and the through-hole 4a of the whisker 4 penetrate. Is formed. Step ST4 is complete | finished above and ST20 is complete | finished.

[Description of Thin Film Forming Step (Step ST30): FIG. 8 (c)]
FIG. 8C is a cross-sectional view for explaining the thin film forming step (step ST30). In step ST30, the thin film 6 is formed on the unprocessed hairspring 1p.

<Step ST30>
Although not shown, the untreated hairspring 1p is washed with pure water or the like to remove impurities. Next, as shown in FIG. 8C, a thin film 6 that is a resin layer made of a paraxylylene-based resin film is formed on the unprocessed mainspring 1p by a thin film formation process using a vapor deposition polymerization method. Specifically, the thin film 6 is formed by a thin film forming process so as to enter the plurality of recesses 7 formed in the unprocessed spring mainspring 1p including the entire surface of the unprocessed spring mainspring 1p. In this embodiment, the thickness of the thin film 6 is 3 μm. Thus, step ST30 is completed. Note that, in the hairspring 1 shown in FIG. 8C, the depressed portion X of the thin film 6 is not shown for the sake of explanation. After the steps ST10 to ST30 described above, a completed form of the hairspring 1 is obtained.

  In the above description, the balance spring for a mechanical wristwatch has been described as an example of a mechanical part by the manufacturing method of the present invention, but the present invention is not limited to this, and various physical quantities frequently used in small information terminals and the like. It is widely available for manufacturing sensors.

[Second Embodiment]
The structure of the hairspring 1 in the second embodiment of the present invention will be described with reference to FIGS. 9A and 9B. The hairspring 1 in the second embodiment is obtained by changing the position or shape of the mainspring 1 in the first embodiment from the arrangement or shape of the plurality of recesses 7 formed in the mainspring 2a.

[Description of the structure of the hairspring 1 in the second embodiment: FIGS. 9A (a) to 9A (b)]
Hereinafter, the structure of the hairspring 1 will be described in detail with reference to FIGS. 9A (a) and 9A (b). 9A (a) is a plan view of the mainspring arm 21a of the hairspring 1, and FIG. 9A (b) is a cross-sectional view taken along line Lm ′ of FIG. 9A (a).

As shown in FIG. 9A (b), one concave portion 7 is formed on each of the one surface 2Pa and the other surface 2Ta of the mainspring arm 21a. Although not shown, the same applies to the mainspring arms 21b to 21d.

  The arrangement of the recesses 7 will be described in detail with reference to FIG. 9A (a). The plurality of recesses 7 in the hairspring 1 are staggered one by one on the lines Ln ′ and Lm ′ that pass through the center of the hairspring 1 (not shown) and are spaced apart from each other by θ1, in other words, one by one. Is provided.

  Although not shown, the same applies to the mainspring arms 21b to 21d. θ1 is approximately 30 degrees for the mainspring arms 21a to 21b and approximately 20 degrees for the mainspring arms 21c and 21d. The linear interval k2 between the recesses is approximately 10 to 30 μm. Since other elements and structures in the hairspring 1 are the same as those in the hairspring 1 in the first embodiment, description thereof is omitted.

[Description of the effect of the hairspring 1 in the second embodiment: FIGS. 9A (a) and 9A (c)]
The effect of the hairspring 1 in the second embodiment will be described with reference to FIGS. 9A (a) and 9A (c). As shown in FIG. 9A (a), the plurality of recesses 7 of the hairspring 1 are alternately provided on one surface 2Pa and the other surface 2Ta of the mainspring arm 21a shown in FIG. 9A (b). The positions of the concave portions that give the anchor effect are dispersed, and the thin film 6 becomes more difficult to peel off.

  Further, as shown in FIG. 9A (c), the diameter of the concave portion 7a can be set to be large like the mainspring portion 2aa. If the diameter of the recess 7a can be increased, the difference between the inner peripheral width Da and the opening width d can be set large, the anchor effect of the thin film 6 on the mainspring arm 21a can be increased, and the durability of the hairspring 1 can be further improved.

[Description of the structure of the hairspring 1 in another modification of the second embodiment: FIGS. 9B (a) to 9B (c)]
The structure of the hairspring 1 according to another modification of the second embodiment will be described with reference to FIGS. 9B (a) to 9B (c). FIGS. 9B (a) to 9B (c) are plan views showing the structure of the plurality of recesses 7 of the hairspring 1 in the first to third modifications of the second embodiment.

<First Modification>
FIG. 9B (a) is a first modification of the second embodiment. As shown in FIG. 9B (a), in the mainspring portion 2a1, the diameters of the plurality of concave portions 7L on the outer peripheral portion of the mainspring arm 21a1 are larger than the diameters of the plurality of concave portions 7 on the inner peripheral portion. The reason for this is that the force that peels the thin film 6 such as the stress applied to the thin film 6 when the mainspring is driven is greater at the outer peripheral portion of the mainspring arm 21a1 than at the inner peripheral portion, so that the thin film 6 and the outer peripheral portion of the mainspring arm 21a1 This is to produce a larger anchor effect.

<Second Modification>
FIG. 9B (b) is a second modification of the second embodiment. As shown in FIG. 9B (b), in the mainspring portion 2a2, the plurality of concave portions 7 on the outer peripheral portion of the mainspring arm 21a2 are more densely provided than the plurality of concave portions 7 on the inner peripheral portion. The reason for this is to produce a larger anchor effect on the thin film 6 and the outer peripheral portion of the mainspring arm 21a1 as in the first modification of the second embodiment.

<Third Modification>
FIG. 9B (c) is a third modification of the second embodiment. As shown in FIG. 9B (c), in the mainspring portion 2a3, the plurality of concave portions 7F on the outer peripheral portion of the mainspring arm 21a3 have a star shape as an example. This is because the second embodiment of the second embodiment. This is because, as in the modified example, the coupling area between the thin film 6 and the outer peripheral portion of the mainspring arm 21a1 is enlarged, and a larger anchor effect is produced. In addition, the shape of the plurality of recesses 7F can be other than the star shape, and generally the anchor effect can be further enhanced if the shape is more complicated.

[Third Embodiment]
The structure of the hairspring 1 according to the third embodiment of the present invention will be described with reference to FIGS. 10A and 10B. The hairspring 1 in the third embodiment is obtained by changing the shape of a plurality of concave portions formed in the mainspring portion 22a from the previous embodiment.

[Description of the structure of the hairspring 1 in the third embodiment: FIGS. 10A (a) to 10A (c)]
Hereinafter, the structure of the hairspring 1 will be described in detail with reference to FIGS. 10A (a) to 10A (c). 10A (a) is a plan view of the mainspring arm 22a of the hairspring 1, and FIG. 10A (b) is a cross-sectional view taken along line BB ′ of FIG. 10A (a). FIG. 10A (c) is a perspective view schematically showing the BB ′ cross section of FIG. 10A (a). For the sake of explanation, the thin film 6 is not shown in FIGS. 10A (a) and 10A (c). Hereinafter, the shape of the plurality of recesses 7b will be described with reference to FIGS. 10A (a) to 10A (c).

  As shown in FIGS. 10A (a) and 10A (b), the plurality of recesses 7b in the hairspring 1 are formed in a corridor shape on one surface 2Pb and the other surface 2Tb of the mainspring arm 22a. As shown in FIG. 10A (a), the concave portion 7b shown by hatching is formed in a gallery shape along the shape of the mainspring portion 2b.

  Moreover, as shown to FIG. 10A (c), the recessed part 7b is formed in the corridor shape which has an elliptical cross section. The interval K2 between the recesses 7b is approximately 10 to 20 μm. Although not shown, the same applies to the mainspring arms 22b to 22d. Since other elements and structures in the hairspring 1 are the same as those in the first embodiment, the description thereof is omitted.

[Description of the effect of the hairspring 1 in the third embodiment: FIG. 10A (a)]
The effect of the hairspring 1 in the third embodiment will be described with reference to FIG. As shown to Fig.10A (a), the some recessed part 7b in the hairspring 1 is formed in the linear corridor shape.

  That is, the concave portion 7 of the hairspring 1 in the first embodiment and the concave portion 7a of the hairspring 1 in the second embodiment are formed in a dot shape, but the concave portion 7b of the hairspring 1 in the present embodiment is linear. Since it is formed, the anchor effect between the thin film 6 and the hairspring 1 is generated in a long range, and the durability of the hairspring 1 is further improved.

[Description of the structure of the hairspring 1 in another modification of the third embodiment: FIGS. 10B (a) to 10B (b)]
The structure of the hairspring 1 according to another modification of the third embodiment will be described with reference to FIGS. 10B (a) and 10B (b). FIGS. 10B (a) and 10B (b) are plan views showing the structures of the plurality of recesses 7b1, 7b2 of the hairspring 1 in the first and second modified examples of the third embodiment.

<First Modification>
FIG. 10B (a) is a first modification of the third embodiment. As shown in FIG. 10B (a), in the mainspring portion 2b1, the width w2 of the gallery-like recess 7b1 in the outer peripheral portion of the mainspring arm 22a1 is wider than the width w1 of the gallery-like recess 7b in the inner peripheral portion. The reason for this is that the force that peels the thin film 6 such as the stress applied to the thin film 6 when the mainspring is driven is greater at the outer peripheral portion of the mainspring arm 22a1 than at the inner peripheral portion, so that the thin film 6 and the outer peripheral portion of the mainspring arm 22a1 This is to produce a larger anchor effect.

<Second Modification>
FIG. 10B (b) is a second modification of the third embodiment. As shown in FIG. 10B (b), in the mainspring portion 2b2, the corridor-like concave portion 7b2 in the outer peripheral portion of the mainspring arm 22a2 is narrower than the corridor-like concave portion 7b in the inner peripheral portion, and two are provided in parallel. It has been. This is because the anchor effect between the thin film 6 and the mainspring arm 21a1 is expanded at the outer peripheral portion of the mainspring arm 22a2. In addition, the number of the corridor-like recesses 7b2 in the outer peripheral portion may be three or more.

[Second manufacturing method]
The 2nd manufacturing method concerning this invention is demonstrated using FIGS. 11-12. Hereinafter, the second manufacturing method will be described by taking the hairspring as an example. The second manufacturing method is characterized in that the multiple recess forming step and the outer shape forming step are performed simultaneously. FIG. 11 is a flowchart of the manufacturing process, and FIG. 12 is a cross-sectional view illustrating the manufacturing process.

[Description of Flowchart in Second Manufacturing Method: FIG. 11]
Hereinafter, a flowchart showing the manufacturing process will be described in detail with reference to FIG. As shown in FIG. 11, the manufacturing method of the hairspring 1 includes steps ST10a and ST30.

  Step ST10a is a step of forming a plurality of recesses on the silicon substrate, which is a material of the hairspring 1, using a recess / outer shape mask, and simultaneously forming the outer shape of the hairspring 1, and the step ST1a The mask forming process and the recess / outer shape etching process of step ST2a for simultaneously etching the plurality of recesses and the outer shape. Step ST30 is a thin film forming process for forming a thin film on the unprocessed hairspring 1p having the recesses and the outer shape, and is the same as in the first embodiment.

<Recess / Outside Mask Formation Step (Step ST1a)>
Next, the manufacturing process of step ST1a is demonstrated using FIG. First, as shown in FIG. 12A, a resist R is applied to the upper surface 200u and the lower surface 200b of the silicon substrate 200 with a thickness of 1 μm. Since the size of the silicon substrate 200 and the resist R are the same as those in the first embodiment, description thereof is omitted.

  Next, as shown in FIG. 12B, the applied resist R is cured, and then patterned by photolithography. After the exposure, unnecessary patterns are removed with an alkaline aqueous solution, and a plurality of openings are formed in the silicon substrate 200. A recess / outline forming mask 89 having a portion 8w and a plurality of openings 9w is formed.

  The opening 8w of the recess / outline formation mask 89 is an opening for forming a plurality of recesses in the silicon substrate 200, which is the material of the hairspring 1, and the opening 9w extends from the silicon substrate 200 to the hairspring 1. The opening 8w has an opening narrower than the opening 9w. Thus, step ST1a is completed.

<Recess / Outline Etching Process (Step ST2a)>
Next, as shown in FIG. 12C, isotropic dry etching gas G <b> 1 is applied for a predetermined time to the silicon substrate 200 on which the recess / outline formation mask 89 is formed, and the recess / outline formation mask 89. Isotropic dry etching is performed on the plurality of openings 8w and the plurality of openings 9w. Then, as shown in FIG. 12C, the plurality of openings 8w and the plurality of openings 9w of the recess / outline formation mask 89 of the silicon substrate 200 are subjected to isotropic dry etching, and a plurality of openings 8w are formed in the plurality of openings 8w. The recesses 7 are formed, and a plurality of recessed portions 9d are formed in the plurality of openings 9w. Note that SF ₆ or the like can be used as the isotropic dry etching gas G1.

Next, a known Bosch process is applied to the recessed portion 9 d formed in the silicon substrate 200, and dry etching for forming the hairspring 1 from the silicon substrate 200 is performed. That is, as shown in FIG. 12D, first, a passivation gas G2 is applied to the silicon substrate 200 on which the recess / outline formation mask 89 is formed for a predetermined time to form a protective film covering the entire silicon substrate 200. As the passivation gas G2, C ₄ F ₈ or the like can be used.

Next, as shown in FIG. 12D, the anisotropic dry etching is performed by applying the anisotropic etching gas G1 to the silicon substrate 200, and the passivation formed on the bottom portion 9db of the recessed portion 9d of the silicon substrate 200 is performed. Destroy layers. As an anisotropic etching gas G1,
Oxygen plasma, fluorine radicals, or the like can be used.

  Next, isotropic dry etching is performed by applying an isotropic dry etching gas G1 to the silicon substrate 200. As a result, the bottom surface 9db of the indented portion 9d of the silicon substrate 200 that has already lost the protective film is intensively etched, and the indented portion 9d of the silicon substrate 200 is intensively etched downward as seen in the drawing of FIG. The On the other hand, since the opening 8w is narrower than the opening 9w, the plurality of recesses 7 of the silicon substrate 200 are not etched within a predetermined time by the passivation gas G2.

  As described above, by applying the passivation gas G2, the anisotropic dry etching gas G1, and the isotropic dry etching gas G1 in order for a predetermined time, the outer shape of the substrate 200 shown in FIG. Cut along line c.

  The formation of the outer shape after FIG. 12D is the same as that in the first manufacturing method, and a description thereof will be omitted. Thus, the mainspring arms 20a to 20d are separated from the silicon substrate 200 by dry etching.

  After that, the recess / outline formation mask 89 is removed to form an unprocessed hairspring 1p. Details are the same as those in the first embodiment, and a description thereof will be omitted. Thus, step ST2a and step ST10a are completed. Thereafter, in step ST30, a thin film 6 is formed on the surface of the unprocessed hairspring 1p by a thin film forming process. The details are the same as those in the first manufacturing method, and a description thereof will be omitted. After the steps ST10a to ST30 described above, a completed form of the hairspring 1 is obtained.

[Description of Effects of Second Manufacturing Method: FIG. 11]
The effect in this manufacturing method is demonstrated using FIG.11 and FIG.12. As shown in FIG. 11, the number of steps of the manufacturing process in the hairspring 1 is two steps less than the number of manufacturing processes in the hairspring 1 in the first manufacturing method, and the process is shortened and the production efficiency is improved. Further, as shown in FIG. 12, since the recess formation and the outer shape etching are simultaneously performed, chemical and mechanical stress applied to the silicon substrate 200 is reduced, and the characteristics of the hairspring 1 are stabilized.

[Fourth Embodiment]
The structure of the machine component according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 13 is a perspective view showing an example in which the mechanical part manufacturing method of the present invention is applied to other parts of a wristwatch using a silicon substrate, and shows a state before the thin film 6 is formed on the surface of the mechanical part. Yes.

  FIG. 13A shows the parts of the wristwatch known as the escape gear body 11p, and FIG. 13B shows the ankle body 31p. As shown in FIG. 13A, a plurality of recesses 7 are provided on one surface 11u of the escape gear body 11p, and a plurality of recesses 7 are provided on the opposite surface 11b, though not shown. . Further, as shown in FIG. 13B, a plurality of recesses 7 are provided on one surface 31u of the ankle body 31p, and a plurality of recesses 7 are provided on the opposite surface 31b, though not shown. . For the sake of explanation, the shape of the plurality of recesses 7 is larger than the actual one and the number is smaller than the actual one.

  FIG. 13C is a perspective view of the recess 7 formed in the escape gear body 11p and the ankle body 31p. As an example, the recess 7 of the ankle body 31p shown in FIG. In FIG. 13C, since the shape of the recess 7 is wider than the entrance, the outline on the entrance side of the recess 7 is shown by a solid line and the outline on the back side is shown by a broken line. The opening width d on the entrance side of the recess 7 is 4.5 μm, and the inner peripheral width D on the back side is 5 μm.

[Description of Effects in Fifth Embodiment: FIG. 13C]
As shown in FIG. 13 (c), the opening width d of the recess 7 formed in the escape gear body 11p and the ankle body 31p is 500 nm narrower than the inner peripheral width D, so that the thin film 6 enters the recess 7 and the thin film 6 and the escape gear. An anchor effect is produced in the connection between the body 11p and the ankle body 31p, and the durability and reliability of the escape gear body 11p and the ankle body 31p are improved.

  Embodiment described above is not limited to this, You may comprise combining each embodiment. Needless to say, the present invention can be arbitrarily changed as long as it satisfies the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Hairspring 11p (Unprocessed) Gangi gear body 11u, 31u One surface 11b, 31b Opposite surface 31p (Unprocessed) ankle body 1p Untreated hairspring 2, 2a, 2a, 2a1, 2a2, 2a3, 2b, 2b1, 2b2 mainspring part 2s mainspring arm side part 20a, 20b, 20c, 20d, 21a, 21a1 to 21a3, 22a1 to 22a2
Mainspring arm 20bs, 20cs Side wall 2P One side 2T The other side 2b Plane 3 Beard ball 3b Beard ball fixing part 3a, 4a Through hole 3b Connection part 4 Beard 6 Thin film 7, 7b, 7b1, 7b2, 7L, 7F Recessed part 7s Concave bottom 7n Concave inner side 8 Concave forming mask 8w Mask 1 opening 9 Contour forming mask 89 Concave / contour forming mask 9w Mask 2 opening 9d Recessed portion 200 Silicon substrate 200u Top surface 200b Bottom surface 200g Bottom surface R Resist c Outline line t1 Thin film thickness t2 Concave depth
t3 Recess cut width d Opening width
D Inner circumferential width of recess e Mainspring arm width h Mainspring height k1 Mainspring interval k2 Recess interval θ, θ1 Recess angle es Scallop surface G1 Etching gas (SF6)
G2 Passivation gas (C4F8)
M5, M6 Partial view Z Corridor X Depression w1, w2 Corridor width 100 Optical component 101A Silicon substrate surface

Claims (6)

Consists of a single crystal material, the surface is provided with a plurality of recesses whose opening width is smaller than the inner circumferential width,
A thin film is formed on the surface so as to enter the recess,
The timepiece component mainspring according to claim 1, wherein the concave portions are arranged on an outer peripheral portion and an inner peripheral portion, respectively . The timepiece mainspring according to claim 1 , wherein a diameter of the plurality of recesses in the outer peripheral portion is larger than a diameter of the plurality of recesses in the inner peripheral portion . The timepiece component according to claim 1 or 2 , wherein the plurality of recesses in the outer peripheral portion are more densely provided than the plurality of recesses in the inner peripheral portion . spring. The timepiece component mainspring according to claim 1 or 2 , wherein the concave portion of the outer peripheral portion is different in shape from the concave portion of the inner peripheral portion . The concave portion of the outer peripheral portion has a shape in which the bonding area with the thin film is larger than the concave portion of the inner peripheral portion.
The mainspring of the timepiece part according to claim 4, wherein the mainspring is a mainspring. The concave portion of the outer peripheral portion has a star shape, and the concave portion of the inner peripheral portion has a circular shape.
The mainspring of the timepiece part according to claim 5, wherein the mainspring is a mainspring.

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