JP2016161394A - Timepiece component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a timepiece component capable of providing meaningful information such as the serial number and the model number of the timepiece component without reducing strength even in the case of the timepiece component made of silicon and without increasing manufacturing time.SOLUTION: A timepiece component 10 is mainly made of silicon, and at least one portion is made of a silicon oxide formed by oxidizing silicon, and oxidation intensity of the inner part and oxidation intensity of the surface is different from each other. Identification patters 35a to 35d are configured by the combination of diagrams, symbols or characters or the combination thereof. Then, even silicon made of brittle material can provide the identification patterns 35a to 35d in the timepiece component 10, and the enhancement of strength as the timepiece component 10 and the improvement of the temperature performance can be performed together.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a mechanical part, and more particularly to a timepiece part used in a drive mechanism of a mechanical timepiece.

  In a conventional mechanical timepiece, a speed governor (balance balance) composed of a hairspring and a balance wheel (with a balance spring) is used in order to keep the operation of the machine regularly at a constant speed. The balance wheel regularly reciprocates by the expansion and contraction of the isochronous balance spring.

  The balance is connected to a mechanism called an escapement made up of an escape wheel and an ankle, and energy is transmitted from the power spring in the barrel to sustain the vibration.

  Generally known hairspring is often formed by processing metal. For this reason, the shape as designed may not be obtained due to variations in processing accuracy or the influence of internal stress of the metal.

  Since the balance spring needs to regularly vibrate the balance with the balance, if the shape as designed is not obtained, the balance wheel also cannot move isochronously, resulting in a deviation in the rate of the watch. The rate of the watch indicates the degree of advance or delay of the watch per day.

  In recent years, attempts have been made to manufacture timepiece parts by etching a silicon substrate. It is said that there is an advantage that it can be made lighter than a conventional watch part using metal parts, and an advantage that mass production is possible. Thereby, it is expected that a small and lightweight watch can be manufactured.

  When etching a silicon substrate, a reactive ion etching (RIE) technique, which is a dry etching technique, is used. In recent years, a deep RIE (Deep RIE) technique has been developed, and etching with a high aspect ratio is possible. It has become.

According to this deep digging RIE technique, since the etching does not go under the portion masked by the photoresist or the like, the mask pattern can be faithfully reproduced in the vertical depth direction.
For this reason, when etching a silicon substrate, it has become possible to accurately manufacture a timepiece component in a shape as designed.

  In the first place, silicon has a characteristic that it has a temperature characteristic better than that of metal and is less likely to be deformed with respect to ambient temperature than a metal used as a material for a conventional balance spring. For this reason, it is considered to apply this technique to a speed control mechanism of a timepiece.

  However, since silicon is a brittle material, the mainspring may be damaged when the watch is subjected to a large impact. Silicon balance springs in consideration of these points are known (see, for example, Patent Document 1 and Patent Document 2).

The prior arts shown in Patent Documents 1 and 2 are techniques for separately forming a film such as silicon dioxide on the surface of a silicon base material. When a silicon watch part is manufactured with such a technique, impact resistance is improved. This is because silicon is susceptible to brittle fracture on the cleavage plane, but is prevented by coating with a film having no crystallinity.

  By the way, when assembling timepiece parts such as the hairspring and the gears, it is convenient that each timepiece part has a unique mark or the like. Examples of such marks and the like are meaningful such as symbols, characters, patterns, etc. indicating specifications, serial numbers, or assembly directions. By doing so, it is possible to eliminate parts mistakes and assembly mistakes during the assembly of the watch mechanism.

  When providing such marks on parts, in the case of metal watch parts, avoid parts that require precision, such as places that engage with other parts or places that engage with the rotating shaft, and In many cases, an easy-to-recognize part is selected and a mark or the like is drawn by making a shallow scratch on the surface of the part using a hard instrument having a sharp tip, such as a “marking needle”. The provision of this shallow flaw is called “marking”, and the work process is called “marking”.

However, the watch part made of silicon cannot perform the scribing. This is because silicon is a brittle material and thus breaks during scuffing.
In view of this, it is considered to draw a mark or the like on a silicon watch part by a known laser marking technique in which the surface of an object is locally dissolved by laser irradiation to engrave characters or the like.

Utility Model Registration No. 3154091 (page 3, Fig. 2) Japanese Patent No. 5378654 (page 3, FIG. 1)

  However, when the laser marking technique is applied to the conventional techniques shown in Patent Documents 1 and 2 above, a film of silicon dioxide or the like formed on the surface of the base material made of silicon is scattered during laser irradiation, and the clock mechanism is I knew it would go in. Doing so may cause a fatal damage to the watch itself.

  In addition, if the laser output varies during laser irradiation, the silicon base material may be damaged, and the strength of the component may be reduced.

  Furthermore, the timepiece parts are very small, and laser marking itself during and after the production of the timepiece parts, such as installation and positioning on the laser marking device, is a very time-consuming work. Time increases, resulting in an increase in the cost of the watch.

  An object of the present invention is to provide a watch part that can identify a watch part without reducing the strength and increasing the manufacturing time even if it is a silicon watch part in view of the above-mentioned problems of the prior art. It is to be.

  In order to achieve the above-described object, the timepiece component according to the present invention employs the following configuration.

It is a watch component mainly composed of silicon, and only a part is made of silicon oxide formed by oxidizing silicon, and the oxidation strength of some parts is different from the oxidation strength of other parts. According to the present invention, an identification pattern is configured by a figure, a symbol, a character, or a combination thereof.

  Further, such a timepiece component is any one of a escape wheel and ankle constituting the escapement, a hairspring and balance wheel constituting the speed control mechanism, and a gear constituting the wheel train. There may be.

  With such a configuration, it is possible to identify a watch part made of silicon. Further, by having an identification pattern made of silicon oxide, the strength of the timepiece part is improved and the temperature characteristics can be improved.

  According to the timepiece component according to the present invention, even if it is made of silicon, the strength is high, and the timepiece component can be identified without increasing the manufacturing time.

It is explanatory drawing explaining the drive mechanism of the mechanical timepiece in which the timepiece component of this invention is integrated. It is the top view and sectional drawing which illustrate the timepiece component of this invention, illustrating a hairspring. It is the top view and sectional drawing explaining the timepiece component of this invention, Comprising: It is the figure which expanded the whisker part. It is the top view and sectional drawing explaining the timepiece component of this invention, Comprising: It is the figure which expanded the whisker part. It is the top view and sectional drawing explaining the timepiece component of this invention, Comprising: It is the figure which expanded a part of mainspring part. It is a top view which illustrates the timepiece component of the present invention by exemplifying a hairspring. It is sectional drawing explaining the timepiece component of this invention, Comprising: It is the figure which expanded a part of mainspring part. It is a figure explaining the method of forming the identification pattern which consists of silicon oxides in the predetermined part of timepiece components, Comprising: It is explanatory drawing explaining the implantation angle in ion implantation of oxygen ion. It is a figure explaining the method of forming the discernment pattern which consists of silicon oxides in the predetermined part of timepiece parts, Comprising: The amount of ion implantation in ion implantation, and the state of oxidation are used using the profile of ion implantation, and oxidation It is explanatory drawing demonstrated. It is sectional drawing explaining the manufacturing method of the timepiece components of this invention, Comprising: It is a figure explaining the 1st manufacturing method. It is sectional drawing explaining the manufacturing method of the timepiece component of this invention, Comprising: It is a figure explaining the 2nd manufacturing method. It is sectional drawing explaining the manufacturing method of the timepiece component of this invention, Comprising: It is a figure explaining the 3rd manufacturing method.

  In the timepiece part of the present invention, the main member forming the shape of the timepiece part is silicon, and at least a part of the inside or the surface of the timepiece part is siliconized. The oxidation strength differs between a part of the watch part and the other part. Due to this difference in oxidation strength, a pattern made up of figures, symbols or characters or a combination thereof is formed.

Such a pattern is called an identification pattern. The identification pattern is a figure, symbol or character, or a combination thereof. For example, meaningful information such as the model number, manufacturing number, direction in which the watch parts are assembled at the time of assembly, or a geometry such as a barcode. A pattern is arranged according to a predetermined rule. By making such an identification pattern visible or optically readable, the timepiece component can be identified.

  Thereby, if the timepiece is being assembled, the timepiece parts can be correctly selected, and the mounting direction and the like are not mistaken. Moreover, in the completed watch, the manufacturer and country of manufacture of the watch can be confirmed, so that it can be easily distinguished from counterfeit products.

  The silicon oxide constituting the identification pattern is formed by, for example, injecting oxygen ions at a predetermined depth into a predetermined portion of a silicon base material, and then performing a heat treatment to cause the silicon and oxygen ions to react. Become.

At this time, the oxidation strength represents how much silicon is oxidized into silicon oxide.
This oxidation strength (oxidation intensity) and the state of distribution are called an oxidation profile.
The oxidation profile is determined by how oxygen ions are implanted into a silicon base material. The oxygen ion implantation concentration (the amount of implantation) and the distribution state are referred to as an ion implantation profile.

  That is, in the identification pattern, oxygen ions are implanted into the silicon base material so as to have a predetermined ion implantation amount profile. Thereafter, the silicon base material is heat-treated to form silicon oxide having a predetermined oxidation profile on the silicon base material.

  At this time, if the ion implantation amount profile is steep (that is, a state in which oxygen ions are implanted in a predetermined portion), the oxidation profile is also steep (that is, a state in which the oxidation strength is locally strong). Become. Further, if the ion implantation amount profile is gradual (that is, a state where oxygen ions are implanted with a spread in a predetermined range), the oxidization profile is also gradual (that is, a state where the oxidation intensity is low in the predetermined range). .

  As described above, the timepiece component of the present invention has a mask or the like according to the identification pattern to be formed, and then forms a portion having different oxidation strength on the silicon base material. The identification pattern is constituted by a symbol or a character or a combination thereof.

  Moreover, the strength of the timepiece part can be improved by providing the identification pattern. That is, by converting a part of the silicon base material into silicon oxide, the brittleness of silicon is improved and the strength is increased.

  Moreover, the temperature characteristic of the timepiece part can be improved by providing the identification pattern. That is, the temperature characteristic of silicon oxide exhibits a temperature characteristic opposite to that of silicon, so that the temperature characteristic of silicon oxide and the temperature characteristic of the silicon base material can act in a direction that cancels each other.

The timepiece part of the present invention described above will be described in detail below with reference to the drawings.
In the description, a hairspring will be described as an example of a watch part. First, a timepiece drive mechanism using the timepiece component of the present invention will be described, and then a timepiece component having an identification pattern will be described. Then, a method for making the oxidation strength different between a part of the timepiece part and another part and a method for manufacturing the timepiece part will be described.

It should be noted that the drawings used for the description are schematic diagrams schematically showing the configuration not related to the invention, and the illustration is omitted. Moreover, the same number is given to the same structure and description is abbreviate | omitted.

[Description of Mechanical Timepiece Drive Mechanism: FIG. 1]
First, a drive mechanism for a mechanical timepiece will be described as a timepiece drive mechanism in which the timepiece component of the present invention is incorporated. FIG. 1 is an explanatory view of a train wheel portion extracted from a drive mechanism of a mechanical timepiece in which a timepiece part of the present invention is incorporated.

  In FIG. 1, a drive mechanism 101 of a mechanical timepiece in which a timepiece component according to the present invention is incorporated includes a barrel 102, an escapement 103, a speed control mechanism (balance) 104, a train wheel 105, and the like. The barrel 102 houses a power mainspring (not shown) inside a thin cylindrical box. A gear wheel called a barrel wheel on the outer periphery of the barrel 102 is provided and meshes with a number wheel constituting the train wheel 105.

  The escapement 103 includes a escape wheel 106 and an ankle 107. The escape wheel 106 is a gear provided with key-shaped teeth, and the teeth of the escape wheel 106 mesh with the ankle 107. The ankle 107 converts the rotational movement of the escape wheel 106 into a reciprocating motion by meshing with the teeth of the escape wheel 106.

  The balance with hairspring 104 includes the hairspring 10, the balance wheel 109, and the like. The hairspring 10 has a long mainspring portion in a wound state and has a coil shape. The hairspring 10 is designed to exhibit excellent isochronism in a state in which the drive mechanism 101 is configured by being incorporated in a mechanical timepiece.

  The balance with hairspring 104 can regularly reciprocate by the expansion and contraction of the hairspring 10 by the spring force. The balance wheel 109 has a ring shape, and adjusts and controls the repetitive motion from the ankle 107 to maintain a constant speed of vibration. The balance wheel 109 includes an arm that extends radially from the balance stem 109 a that is the center of the balance wheel 109 inside the ring shape formed by the balance wheel 109.

  The train wheel 105 is provided between the barrel 102 and the escape wheel 106 and is constituted by a plurality of gears engaged with each other. Specifically, the train wheel 105 includes a second wheel 110, a third wheel 111, a fourth wheel 112, and the like. The barrel of the barrel 102 is engaged with the second wheel 110. A second hand 113 is attached to the fourth wheel & pinion 112, and a minute hand 114 is attached to the second wheel & pinion 110. In FIG. 1, illustration of the hour hand and the ground plate for supporting each gear is omitted.

  In the drive mechanism 101, the center of the power spring is fixed to the center of the barrel 102 (barrel true) so that it cannot reversely rotate, and the outer end of the power spring is fixed to the inner peripheral surface of the barrel. When the power spring wound around the center of the barrel 102 (the barrel barrel true) tries to return to its original position, it is urged by the outer end of the power spring to be unwound in the same direction as the rolled-up direction, and the barrel 102 is rolled up. Rotates in the same direction as the mainspring unwinding. The rotation of the barrel 102 is sequentially transmitted to the second wheel 110, the third wheel 111, and the fourth wheel 112, and is transmitted from the fourth wheel 112 to the escape wheel 106.

  Since the escape wheel 107 meshes with the escape wheel 106, when the escape wheel 106 rotates, the teeth (impact surface) of the escape wheel 106 push up the claws of the ankle 107, thereby the balance in the ankle 107. The tip on the 104 side rotates the balance with hairspring 104. When the balance with hairspring 104 is rotated, the claw of the ankle 107 immediately stops the escape wheel 106. When the balance with hairspring 104 reversely rotates with the force of the hairspring 108, the nail of the ankle 107 is released, and the escape wheel 106 rotates again.

  In this way, the balance with the balance spring 10 having the isochronous force causes the balance 104 to repeat a regular reciprocating rotational movement, and the escapement 103 continues to apply a force for reciprocating the balance with the balance 104. The gears in the train wheel 105 are rotated at a constant speed by regular vibrations from.

  The example shown in FIG. 1 is a part of the drive mechanism of a mechanical timepiece, but the timepiece components constituting the mechanical timepiece are engaged with or overlapped with other adjacent timepiece components. Need to be assembled in a predetermined order. In such assembling, if a mistake is made in the timepiece parts to be used, it may be necessary to reassemble from the beginning, resulting in a great loss of assembling time. Further, if the timepiece parts are damaged during the reassembly, not only the accuracy of the timepiece will be affected, but also the shipping standards will not be satisfied, resulting in a significant increase in manufacturing cost.

  However, with the timepiece part of the present invention, an identification pattern can be provided on the timepiece part, so that the part can be recognized visually or by an optical method, and mistakes in assembly can be eliminated.

  In addition, when the watch parts are assembled and the drive mechanism is configured, the model number, serial number, assembly time, etc. can be confirmed, which makes it easier to manage the process and manage the line during production, and the completed timepiece has entered the market. Later, when repairs are made, the status and specifications of the watch can be checked immediately, so the repair time can be shortened.

  As will be described in detail later, an identification pattern can also be formed inside the watch part, and as such, the identification pattern is not expressed on the appearance of the watch part and can be recognized for the first time by an optical method. By concealing the contents of symbols, characters and marks to be expressed, and the meanings, the distinction from counterfeits can be ensured. This also eliminates counterfeit goods from the market.

[Description of watch part structure: FIG. 2]
Next, a timepiece component (hairspring) provided with an identification pattern will be described with reference to FIG.
FIG. 2 is an explanatory view showing the structure of the hairspring 10. FIG. 2A shows a plan view of the hairspring 10, and FIG. 2B shows an AA ′ cross section shown in FIG.

  The hairspring 10 is made of silicon as a base material. In the mainspring portion 11 having a thin coil shape, a whistle ball 12 provided at an end on the inner peripheral side is provided. The mainspring portion 11 and the whisker ball 12 are connected by a connecting portion 12b. The hair ball 12 is provided with a through hole 12a into which the balance stem 109a shown in FIG.

  The mainspring portion 11 has a coil shape that is wound around the beard ball 12 via the connection portion 12 b of the beard ball 12. Further, the hairspring 10 includes a hairspring 13 provided at an end portion on the outer peripheral side of the mainspring portion 11 having a thin coil shape.

  The hairspring 10 in this embodiment is at least partially formed of silicon oxide. In FIG. 2A, the identification pattern 5 made of silicon oxide is provided on the beard 13 as an example. In the example shown in FIG. 2A, the identification pattern 5 is a circular pattern in plan view. Of course, the shape of the identification pattern 5 is not limited to a circle, and is merely an example.

The identification pattern 5 is based on figures, symbols, characters, or a combination thereof, and visualizes meaningful information such as a model number, a manufacturing number, and a direction in which a watch part is assembled at the time of assembly. Thus, by providing the identification pattern 5, it is possible to know information on the hairspring 10 and to read what timepiece part was used visually or optically during or after the timepiece mechanism is assembled. be able to.

  The identification pattern 5 is converted to silicon oxide from the surface of the hairspring 13 constituting the hairspring 10 having silicon as a base material toward the inside. A silicon oxide is formed by locally bonding silicon and oxygen toward the inside of the silicon base material.

  The example shown in FIG. 2A is a case where a silicon oxide portion is also provided on the surface of the beard 13 made of a silicon base material. In this example, the surface 13a of the whiskers 13 is flat, and the shape of the whiskers 13 is not changed.

In order to convert a predetermined portion of the hairspring 10 having silicon as a base material into silicon oxide, for example, oxygen ions are implanted and heated to react silicon and oxygen ions.
In the implantation of oxygen ions, the implantation amount, implantation angle and acceleration voltage are set, and a mask having an opening in which oxygen ions are implanted is used. Oxygen ions are implanted at a depth. This method will be described later.

In FIG. 2B, the symbol t indicates the thickness dimension of the hairspring 10. The thickness dimension of the hairspring 10 is determined according to the thickness dimension of a silicon layer in a laminated substrate (SOI substrate) described later or the dimension in the thickness direction formed from a silicon single crystal substrate.
In FIG. 2B, the symbol w indicates the width dimension of the hairspring 10 in plan view. The width dimension of the hairspring 10 may be varied according to the position of the mainspring portion 11. In other words, the width dimension of a part of the mainspring portion 11 in the hairspring 10 may be w, and the width dimension of another part may be a dimension larger than w.

  By the way, Young's modulus is a proportional constant of strain and stress in the coaxial direction in the elastic range where the Hooke's law is established, and when an external force is applied to the object in the direction of pulling the object. In the relationship between the elongation of the object and the external force applied to the object. The Young's modulus is also referred to as a longitudinal elastic modulus, bending rigidity, or deflection rigidity.

  Specifically, for example, when a force (F) is applied to an object having a cross-sectional area (S), the Young's modulus (E) when the original length (L) of the object is extended by (ΔL) is: E = (F / S) / (ΔX / X).

  Thus, the hairspring 10 determines the thickness dimension t and the width dimension w of the base material and the mainspring portion so as to have a predetermined Young's constant.

  As described above, since any part of the inside or the surface of the timepiece made of silicon can be siliconized, the shape of the timepiece part itself does not change and can have the shape as designed.

  In addition, since the hardness of silicon oxide can be examined by conducting experiments and simulations in advance, it is possible to determine which part of the watch part will be converted to silicon oxide at the design stage of the watch part. In view of the information from the above, the Young's modulus of the watch part can be determined.

Then, even if the identification pattern is provided, the timepiece component can have the shape and Young's modulus as designed. Of course, since the silicon base material and the silicon oxide are bonded to each other, they are not separated from each other, and the timepiece component can maintain the designed performance for a very long time.

[Description of Identification Pattern 1: FIG. 3]
Next, the identification pattern provided on the hairspring of the hairspring will be described with reference to FIG.
FIG. 3 is an enlarged view of the beard 13 shown in FIG. 2 (a), and FIG. 3 (a) is a plan view. 3 (b), 3 (c), and 3 (d) are cross-sectional views taken along the cutting line BB 'in FIG. 3 (a), and the shapes of the silicon oxides constituting the identification pattern 5 respectively. It explains the difference. In FIG. 3, reference numerals 5 a and 5 b are identification patterns, and reference numeral 13 b is a back surface facing the front surface 13 a of the whistle 13.

  As shown in FIG. 3A, the identification pattern 5 is a circular pattern in plan view. For example, the size of the circle is determined based on a predetermined rule, such as changing the size of the circle of the identification pattern 5 for each size of the hairspring 10. By doing so, there is no need to make a mistake in selecting the hairspring when assembling the watch.

  The example shown in FIG. 3B is an example in which the identification pattern 5 is formed from the surface 13a of the whistle 13 toward the inside. In this example, the depth of the identification pattern 5 is slightly closer to the surface 13a than the center of the whiskers 13.

  In the example shown in FIG. 3C, the first identification pattern 5 a is formed from the front surface 13 a of the whisker 13 toward the inside, and the second identification pattern 5 b is formed from the back surface 13 b of the whistle 13. It is an example formed toward the internal direction. In this example, the identification patterns 5a and 5b are formed so as to overlap in a plan view.

  The example shown in FIG. 3D is an example in which the identification pattern 5 is formed continuously from the front surface 13a to the back surface 13b of the whisker 13, and the silicon beard 13 is made of silicon oxide. Is a shape that penetrates.

  Thus, even if the identification pattern 5 provided on the beard 13 is circular in a plan view as shown in FIG. 3A, the depth is as shown in FIGS. 3B to 3C. The shape can be changed in the direction. When the identification pattern 5 is recognized visually or by an optical method, the shape shown in FIG. 3B may be used as long as it is performed only from the front surface 13a side. The shape shown in FIG. 3C or FIG.

  In addition, since the identification pattern 5 selectively silicon oxides a part of the silicon base material, the boundary between the silicon and the silicon oxide is gradually increased inside the silicon base material. Silicon oxide is converted from silicon (that is, it has an oxidation profile). In FIG. 3, in view of the situation, the boundary between silicon and silicon oxide is indicated by a dotted line inside the silicon base material. The same applies to the drawings used for the following description.

  The depth of the identification pattern 5 can be determined depending on how the identification pattern 5 is recognized. In general, when silicon oxide is irradiated with light having a certain wavelength, it is known that the color of reflected light changes depending on the thickness of the silicon oxide. Using this feature, it is possible to discriminate characters, symbols, and the like based on the difference between the portion made of silicon and the reflected light.

For example, when the visual recognition is under illumination of a predetermined brightness, the reflected light can be visually recognized using the naked eye or a magnifying glass, and the information represented by the characters and symbols represented by the identification pattern 5 can be confirmed. . The information expressed by the identification pattern 5 can also be confirmed by irradiating visible light, infrared light, laser, or the like and optically reading the intensity of the reflection. Since such a technique for optically reading information is widely known, detailed description thereof is omitted.

  The shape of the silicon base material of the identification pattern 5 in the depth direction may be different when checked with the naked eye and when checked optically using light or a laser. In such a case, the depth and shape of the identification pattern 5 provided on the whisker 13 may be determined by confirming in advance by experiments or the like.

In addition, when the identification pattern 5 is optically recognized, infrared rays may be irradiated from the back surface 13b if infrared rays are used. This is because silicon has a characteristic of transmitting infrared rays of a predetermined wavelength, and even if silicon oxide is on the front surface 13a side as shown in FIG. Can be recognized by infrared irradiation and optical reading.
In this way, when optically confirming the identification pattern, the installation of the optical system can be changed according to the light to be used, and the degree of freedom of arrangement of the apparatus and the like increases.

[Description of Identification Pattern 2: FIG. 4]
Next, another example of the identification pattern provided on the hairspring of the hairspring will be described with reference to FIG.
FIG. 4 is an enlarged view of the whisker 13 shown in FIG. 2A as in FIG. 3, and FIG. 4A is a plan view. FIG. 4B is a cross-sectional view taken along a cutting line CC ′ in FIG. Reference numerals 13 c and 13 d are side faces of the whisker 13, and reference numeral P is a virtual point indicating the center of the identification pattern 15.

  As shown in FIG. 4A, the identification pattern 15 is a circular pattern in plan view, but unlike the example shown in FIG. 3, silicon oxide is exposed on the surface 13a of the whisker 13. Absent. In this case, as described above, the identification pattern 15 can be optically recognized using infrared rays.

  As shown in FIG. 4B, the identification pattern 15 is formed at a predetermined position inside the whiskers 13. In this example, the depth position at which the identification pattern 15 is formed is near the center of the beard 13, and the center point P of the identification pattern 15 is near the center of the beard 13.

  The identification pattern 15 is formed inside the beard 13 so that the cross section thereof is circular. That is, the identification pattern 15 is formed in a spherical shape around the center point P inside the whiskers 13.

  In this way, when trying to optically recognize the identification pattern 15 using infrared rays, it looks the same circular shape when viewed from any one of the front surface 13a, the back surface 13b, the side surfaces 13c, and 13d of the whiskers 13, Can be confirmed regardless of the direction of recognition

  As will be described in detail later, if oxygen ions are implanted so as to concentrate at the center point P of the identification pattern 15 in the whiskers 13, the oxygen ions implanted by heating react with surrounding silicon. Since the reaction spreads uniformly from the center point P to the surroundings, it can be formed in a spherical shape in the silicon base material.

  The identification pattern 15 shown in FIG. 4 is provided not on the surface of the beard 13 but inside thereof. Such a case is suitable when the surface of the hairspring is particularly desired to be beautiful. Watches also have a decorative aspect, and there are watches that use a transparent part of the watch exterior to show the user the internal watch parts. For such a watch, it is convenient to make the identification pattern invisible to the naked eye. Moreover, as explained, it is also advantageous for counterfeiting measures.

[Description of Identification Pattern 3: FIG. 5]
Next, the identification pattern provided in the mainspring portion of the hairspring will be described with reference to FIG.
FIG. 5 is an enlarged view of a part of the mainspring portion 11 shown in FIG. 5 (a), FIG. 5 (d), FIG. 5 (g), and FIG. 5 (j) show an enlarged portion of the mainspring portion 11 that wraps around the whistle ball 12 in one round. It is a top view. Reference numeral 25 denotes an identification pattern. Reference numeral 11a is the front surface of the mainspring portion 11, and reference numeral 11b is the opposite back surface.

5B and 5C are cross-sectional views taken along a cutting line DD ′ in FIG. 5A, and the difference between the two is a place where the identification pattern 25 is formed.
As shown in FIG. 5B, the identification pattern 25 made of silicon oxide extends over the entire width w direction (see FIG. 2) of the surface 11a of the mainspring portion 11 and is provided from the surface 11a toward the inside. .
In the example shown in FIG. 5C, the first identification pattern 25a is provided across the entire width w direction of the surface 11a of the mainspring portion 11 and from the surface 11a toward the inside, and the second identification pattern 25b. Is provided across the entire width w direction of the back surface 11b of the mainspring portion 11 and from the back surface 11b toward the inside. These two constitute an identification pattern 25. In this example, the identification patterns 25a and 25b are formed so as to overlap in plan view.

5E and 5F are cross-sectional views taken along the cutting line EE ′ in FIG. 5D, and the difference between the two is the location where the identification pattern 25 is formed.
As shown in FIG. 5E, the identification pattern 25 made of silicon oxide is provided from a part of the front surface 11a of the mainspring portion 11 to the back surface 11b.
In the example shown in FIG. 5 (f), the first identification pattern 25 c is provided from a part of the front surface 11 a of the mainspring portion 11 toward the inside, and the second identification pattern 25 d is provided on the back surface 11 b of the mainspring portion 11. From one part to the inside. These two constitute an identification pattern 25. In this example, the identification patterns 25c and 25d are formed so as to overlap in plan view.

5 (h) and 5 (i) are cross-sectional views taken along the cutting line FF ′ in FIG. 5 (g), and the difference between the two is the place where the identification pattern 25 is formed.
As shown in FIG. 5 (h), the first identification pattern 25e and the second identification pattern 25f are provided from the corner of the main surface 11a to the corner of the back surface 11b.
In the example shown in FIG. 5 (i), a first identification pattern 25g and a second identification pattern 25h are provided from the corner of the surface 11a of the mainspring portion 11 to the inside, and the third identification pattern. 25i and a fourth identification pattern 25j are provided from the corner of the back surface 11b of the mainspring portion 11 toward the inside, and these four constitute the identification pattern 25. In this example, the identification patterns 25g and 25h and the identification patterns 25i and 25j are formed so as to overlap in plan view.

The cross-sectional views along the cutting line GG ′ in FIG. 5 (j) are FIGS. 5 (k) and 5 (l).
As shown in FIG. 5 (k), the identification pattern 25 made of silicon oxide extends over the entire width w direction of the surface 11a of the mainspring portion 11 and is provided near the center of the mainspring portion 11.
In the example shown in FIG. 5 (l), the first identification pattern 25k is provided across the entire width w direction of the surface 11a of the mainspring portion 11 and slightly closer to the surface 11a inside the mainspring portion 11. The identification pattern 25m extends over the entire width w direction of the back surface 11b of the mainspring portion 11 and is provided slightly closer to the back surface 11b inside the mainspring portion 11. In this example, the identification patterns 25k and 25m are formed so as to overlap in plan view.

In the example shown in FIGS. 5 (j) to 5 (l), since most of the silicon oxide portions are inside the mainspring portion 11, the optical system using infrared rays is used similarly to the example shown in FIG. Can be recognized. This example is also suitable as a watch part for which a beautiful watch part is to be used because characters and symbols are not conspicuous on the surface of the watch part, and is also effective as a countermeasure against counterfeit goods.

As described above with reference to FIG. 5, the identification pattern 25 may be provided in the mainspring portion 11 constituting the hairspring 10. As already described, since the reflection of light is different between silicon and silicon oxide, it can be recognized as an identification pattern due to the difference in color.
Note that the identification pattern 25 illustrated in FIG. 5 is an example, and can be freely determined in view of the specifications, performance, and size of the watch part.

[Description of Identification Pattern 4: FIG. 6]
Next, another example of the identification pattern provided on the mainspring portion of the hairspring will be described with reference to FIG.
FIG. 6 is a plan view similar to the hairspring 10 shown in FIG. 2A, and reference numeral 35 denotes an identification pattern. In the example shown in FIG. 6, identification patterns such as characters and symbols are formed over a wide range so that the identification pattern 35 can be identified when the entire mainspring 11 wound around the whistle ball 12 is viewed. .

  As shown in FIG. 6, identification patterns 35 a to 35 d are provided on the mainspring portion 11 of the hairspring 10. The identification pattern 35 a is an alphabet “C”, the identification pattern 35 b is an alphabet “T”, and an identification pattern. Reference numeral 35c denotes the alphabet “Z”. If the three characters “C”, “T”, and “Z” are meaningful information, for example, an abbreviation of a company name, a mark that can specify the manufacturer can be used.

  The identification pattern 35d indicates the symbol “← (arrow)”, and can represent the characteristic structure of the timepiece component, the assembling method, and the like. In the example of FIG. 6, the arrow indicates the direction of the whistle ball 13.

  As in the example shown in FIG. 6, if the identification pattern 35 is formed so that it can be distinguished when the entire watch part is viewed, it is possible to determine the manufacturer of the watch, This is convenient because you can avoid mistakes in the parts when assembling.

[Description of Identification Pattern 4: FIG. 7]
Next, another example of the identification pattern provided on the mainspring portion of the hairspring will be described with reference to FIG.
FIG. 7 is an enlarged view of a part of the mainspring portion 11 shown in FIG. 2A, and shows an enlarged portion of the mainspring portion 11 that wraps around the hair ball 12 in a certain turn. It is sectional drawing. Reference numeral 35 denotes an identification pattern. Reference numerals 11c and 11d are side surfaces of the mainspring portion 11, respectively.

The example shown in FIG. 7 is an example in which the identification pattern 35 is formed on the cross section of the silicon base material constituting the mainspring portion 11, and a meaningful character or symbol is formed in the cross section.
In the example shown in FIG. 7A, silicon is oxidized into silicon oxide from the three surfaces of the front surface 11a, the back surface 11b, and the side surface 11c of the mainspring portion 11 and represents the letter “C”.
In the example shown in FIG. 7B, silicon is oxidized from the four surfaces of the front surface 11 a and the back surface 11 b of the mainspring portion 11 and the two side surfaces 11 c and 11 d toward the inside. Silicon oxide is also formed on the entire inner central portion in the width w direction. These represent the kanji “day”.

As shown in FIG. 7, if a meaningful character or symbol is provided on the cross section of the mainspring portion 11, the timepiece part or the timepiece itself can be identified. For example, by associating the alphabet “C” with a company name, company pet name, or their initials, it can represent the manufacturer of a watch part, or the kanji “day” can be associated with Japan. It can represent watch parts manufactured in Japan.

  “C” and “day” shown in FIG. 7 are, of course, examples, and may be another character, symbol, geometric pattern, or the like. Characters, symbols, marks, and the like may be arranged according to the rules decided by the manufacturer or the like. If the contents are kept secret by the manufacturer or the like, it is easy to distinguish them from counterfeits. The identification pattern may be a geometric pattern such as a barcode arranged according to a predetermined rule.

  Furthermore, since characters and marks are expressed on the cross-section of the timepiece part, the appearance is the same as when the identification pattern 35 is not provided, and it is also suitable for a timepiece part that requires beauty.

  As already explained, since silicon transmits infrared light, even if it expresses meaningful characters and marks on the cross-section of a watch part, it can be easily recognized if it is irradiated with infrared light and optically observed. it can.

[Improvement of strength by silicon oxide]
Next, it will be described that a timepiece component is improved by converting a part of a silicon base material into silicon oxide.

  As already described, it is known that the technique of coating the surface of the silicon base material with another film, as represented by the prior art, increases the strength of the silicon base material. This is because silicon is susceptible to brittle fracture on the cleavage plane, but is prevented by coating with a film having no crystallinity.

  In the timepiece component of the present invention, a part of the timepiece component having silicon as a base material is formed into silicon oxide by providing an identification pattern. In other words, since the silicon oxide having no crystallinity is provided on the surface or inside thereof, the brittleness is improved and the silicon base material can be hardly broken.

In particular, the balance spring of a watch part is easy to expand and contract, so when an unexpected impact such as a fall or a collision with another object is applied to the watch, it will not contact or collide with other watch parts. Easy to get up. For this reason, the silicon hairspring was easily broken. However, by providing the mainspring portion 11 with the identification patterns 25 and 35 as in the hairspring 10 shown in FIGS. 5 and 7, the brittleness is improved, the hairspring 10 itself is less likely to be destroyed, and the impact resistance of the watch is increased. Can be improved.
That is, by providing the identification pattern on the mainspring portion, it is possible to achieve both recognition of the timepiece component and improvement in strength.

[Improvement of temperature characteristics of watch parts]
Next, it will be described that the temperature characteristics of a timepiece component are improved by converting a part of a silicon base material into silicon oxide.

  As is well known, the temperature characteristic of silicon oxide exhibits a temperature characteristic opposite to that of silicon. In general, the Young's modulus shows a temperature characteristic that fluctuates according to temperature fluctuations. For this reason, watch parts manufactured using silicon as a base material (in short, using a material having a crystal structure of silicon alone) are subject to a change in Young's modulus with a change in temperature, depending on the environmental temperature. Performance will fluctuate. As already described, since a timepiece component such as the hairspring 10 is required to have a very precise accuracy, a variation in performance due to a temperature change causes a variation in the accuracy of the timepiece.

  In the timepiece part of the present invention, since the identification pattern used for the identification is made of silicon oxide, a part of the silicon base material is silicon oxide. The temperature characteristics of the silicon base material can act to cancel each other. Thereby, it can be set as the timepiece component excellent in temperature characteristics.

  In particular, in a timepiece component, a hairspring is required to have a certain time by repeating expansion and contraction movements at a certain period, so fluctuations in the Young's modulus due to the temperature lowers the accuracy of the timepiece. . However, like the hairspring 10 shown in FIG. 5, by providing the identification pattern 25 on the mainspring portion 11, the temperature characteristics are improved as described above, and the hairspring 10 itself is hardly affected by temperature changes. The accuracy of the watch can be improved.

Of course, since the temperature characteristics cancel each other in a state where silicon and silicon oxide are intimately connected to each other, it is possible to obtain a timepiece component having a temperature characteristic even better than that of the prior art while maintaining the outer shape of the balance spring as designed. .
That is, by providing the identification pattern on the mainspring portion, it is possible to achieve both recognition as a watch part and improvement in temperature characteristics as a watch part.

  Thus, by providing an identification pattern on the timepiece component, it is possible to achieve both the recognition of the timepiece component and the improvement of strength and the improvement of temperature characteristics.

[Description of Identification Pattern Forming Method: FIGS. 8 and 9]
Next, a method for forming an identification pattern made of silicon oxide on a predetermined portion of a timepiece component using silicon as a base material will be described.
In the formation of the identification pattern, a manufacturing method in which oxygen ions are implanted and heat treatment will be described. In this case, a silicon base material, such as a mask having an opening in which oxygen ions are implanted, is introduced into the ion implantation apparatus to obtain a predetermined degree of vacuum. Then, oxygen ions are implanted. As already described, when oxygen ions are implanted, the implantation amount, implantation angle, and acceleration voltage are set.

  First, an implantation angle in oxygen ion implantation will be described with reference to FIG. Next, the ion implantation amount and the oxidized state in the ion implantation will be described with reference to FIG. 9 using the ion implantation amount and the oxidation profile.

[Explanation of ion implantation angle: FIG. 8]
FIG. 8 is an explanatory view for explaining the implantation angle in the ion implantation of oxygen ions.
In FIG. 8, reference numeral 200 denotes a silicon substrate from which a timepiece component (in this case, the hairspring 10) is cut out, for example, a silicon wafer. FIG. 8 shows a state in which the shape of the hairspring 10 has been processed through a manufacturing process to be described later. As an example, a substrate 200 from which four hairsprings 10 are cut out is shown.

  The symbol θ1 is a twist angle, and θ2 is a tilt angle. Reference numeral 60 denotes a stage on which the substrate 200 can be placed and fixed, and the twist angle and tilt angle can be individually adjusted, and is provided inside the ion implantation apparatus.

  The hairspring 10 is connected to a frame portion 220 formed on the surface of the substrate 200 by a support portion 221. In the example shown in FIG. 8, the manufacturing process proceeds, and the frame portion 220 is the surface of the substrate 200. The gap 230 is a space portion where the substrate 200 is not present. However, even if the substrate 200 is held by the support portion 221, the hairspring 10 is not separated from the substrate 200 and dropped (for example, FIG. 10). (See (h).)

When oxygen ions are implanted into the substrate 200 from which the timepiece component such as the hairspring 10 is cut out, the twist angle (θ1) and tilt angle (θ2) of the substrate 200 are adjusted.
The twist angle is an angle that is changed by rotating the substrate 200 around an axis (normal line 61 of the substrate 200) perpendicular to the spreading direction (plane direction) of the surface formed by the substrate 200. That is, the angle in the rotation direction when the substrate 200 is viewed in plan.

  Specifically, in an ion implantation apparatus that implants oxygen ions, the stage 60 that supports the substrate 200 can be adjusted by rotating it around the normal 61 of the surface formed by the stage 60 by an angle θ1.

  The tilt angle is an angle at which the direction of the normal line 61 of the substrate 200 intersects with the direction 62 of implantation of oxygen ions implanted into the substrate 200 (the angle formed by the direction of the normal line 61 and the direction of implantation 62). That is, the angle at which the substrate 200 is tilted.

  More specifically, the stage 60 can be adjusted by changing the tilt angle of the stage 60 by the angle θ2 so that the angle formed by the spreading direction of the surface with respect to the reference (for example, horizontal) changes.

  When oxygen ions are implanted into the substrate 200, oxygen ions can be implanted into the substrate 200 at a desired position and depth by adjusting the twist angle and tilt angle in the surface direction of the stage 60, that is, the substrate 200.

  For example, when the tilt angle (θ2) is 0 (zero) degree, the probability that oxygen ions will penetrate (pass through) the substrate 200 and the intended position (and depth) by colliding with silicon atoms. Etc.) tend to increase the probability that oxygen ions cannot be implanted.

  On the other hand, by adjusting the tilt angle (θ2), the probability that oxygen ions will penetrate through the substrate 200 can be lowered, and the probability that oxygen ions can be implanted into the intended position can be increased. . As a result, it is possible to manufacture a watch part having a target structure in which oxygen ions are implanted at an intended position.

[Explanation of Oxygen Ion Implantation Position and Oxidation Profile: FIG. 9]
Next, an ion implantation amount profile and an oxidation profile of oxygen ions will be described.
FIG. 9 is an explanatory diagram showing the position of oxygen ion implantation into the mainspring portion 11 of the hairspring 10 shown in FIG. 2 and the state of silicon oxide formed by oxidation after the heat treatment.
In the example shown in FIG. 9, the central portion in the thickness direction of the silicon base material is the oxygen ion implantation position.
In FIG. 9, reference numeral 40 denotes ion-implanted oxygen ions, and reference numeral 50 denotes a state in which oxygen ions are heated by heat treatment and oxygen ions react with silicon to form silicon oxide (that is, identification patterns 5, 15, 25 described above). , 35).

  FIG. 9A shows an example in which the change in the implantation amount of the oxygen ions 40 due to the difference in the implantation state of the oxygen ions 40 is abrupt and the implantation amount of the oxygen ions 40 is locally higher than that in FIG. 9B. Is shown.

As shown in FIG. 9A, when the oxygen ions 40 are locally implanted so that the implantation amount of the oxygen ions 40 is locally increased, the ion implantation profile becomes steep. The silicon oxide 50 formed after heating is in a state where it appears only in the band-like portion into which oxygen ions are intensively implanted. At this time, the oxidation strength, which is an oxidation profile of the silicon oxide 50, is locally strong at a position where the implantation amount of the oxygen ions 40 is high, and weak at a position where the ion implantation amount is small.

  On the other hand, FIG. 9B shows an example in which the change in the implantation amount of the oxygen ions 40 due to the difference in the implantation state of the oxygen ions 40 is more gradual and the position where the oxygen ions 40 are implanted is wider than that in FIG. Is shown.

  As shown in FIG. 9B, when the ion implantation is performed so that the oxygen ions 40 are dispersed in the silicon base material, the change in the implantation amount of the oxygen ions 40 becomes gradual, and the ion implantation amount profile is also reduced. Be gentle. The silicon oxide 50 formed after heating is also in a wide state reflecting the portion where oxygen ions are implanted. At that time, the oxidation strength of the silicon oxide 50 also becomes moderate. That is, the silicon oxide 50 is distributed over a wide range of the base material of silicon constituting the hairspring 10.

At this time, the oxidation strength represents how much silicon is oxidized into silicon oxide.
This oxidation strength (oxidation intensity) and the state of distribution are called an oxidation profile.
The oxidation profile is determined by how oxygen ions are implanted into a silicon base material. The oxygen ion implantation concentration (the amount of implantation) and the distribution state are referred to as an ion implantation profile.

  The timepiece parts already described differ in the internal oxidation strength and the surface oxidation strength. That is, in this timepiece part, the ratio of silicon to silicon oxide is different between the inside and the surface of this timepiece part (having an oxidation profile).

  As a result, the degree of oxidation in the timepiece part is not constant (uniform) throughout the timepiece part, but is changed depending on the location in the timepiece part (inside or on the surface). As described above, the timepiece part can be configured such that the ratio of silicon to silicon oxide increases from the surface of the timepiece part to the inside or from the inside to the surface of the timepiece part.

However, the ratio of silicon oxide can be made almost constant over the entire watch part. An example is shown in FIG.
In this example, the change in the implantation amount of the oxygen ions 40 due to the difference in the implantation state of the oxygen ions 40 is more gradual than in FIG. 9B, and the width of the position where the oxygen ions 40 are implanted is further widened.

  As shown in FIG. 9C, ion implantation is performed so that the oxygen ions 40 are further dispersed in the silicon base material, that is, oxygen ions are present almost uniformly in the silicon base material. If it does, although it has some oxide formation profile, the whole silicon | silicone base material can also be siliconized. If it does so, it can also be made the state close | similar to what formed the hairspring 10 with the silicon oxide.

  In this example, since the proportion of silicon in the watch part has decreased, the temperature characteristic of silicon and the temperature characteristic of silicon oxide cannot cancel each other, but the watch part that does not require strict temperature characteristics and gives priority to strength. For example, it can be used for a frame for fixing a movement in a timepiece, a train wheel press (a plate member that presses the train wheel mechanism), or the like.

  Further, as is well known, when silicon oxide is formed by thermal oxidation or CVD (Chemical Vapor Deposition), if the target film thickness increases, the formation takes a long time. End up. This is because in the case of thermal oxidation, the oxidation does not easily proceed when the film thickness exceeds a predetermined thickness. In the case of the CVD method, silicon oxide is deposited at a predetermined rate. This is because the time becomes longer.

  However, in the case of a manufacturing method in which oxygen ions are implanted and heat treatment is performed, as described above, as shown in the example of FIG. Furthermore, if oxygen ions are scattered and implanted in the depth direction of the site where oxygen ions are implanted, almost all of them can be converted to silicon oxide. In addition to thermal oxidation techniques and CVD methods, it can be formed in a shorter time, and it is also possible to form silicon oxide with a thickness (for example, exceeding 100 μm) that cannot be formed by these techniques or takes a long time.

The method for implanting oxygen ions into a predetermined position of a silicon base material has been described above with reference to FIG.
In this way, by adjusting whether oxygen ions are implanted locally or over a wide range, it is possible to adjust the change in the oxidation strength of the silicon oxide in the timepiece part. Thus, by changing the progress of oxidation (degree of oxidation) within a single watch component, the portion that exhibits the temperature characteristics of silicon in the single watch component and the temperature characteristics of silicon oxide are exhibited. And high temperature compensation performance against environmental temperature changes can be ensured. Of course, since silicon oxide has a higher strength than the base material of silicon, the strength of the watch part can also be improved.

[Explanation of oxygen ion implantation example]
Next, an example of process conditions (oxygen ion implantation angle, implantation amount, acceleration voltage) when forming an identification pattern on the watch part already described will be described. Of course, the process conditions described below are only examples because the dimensions in the thickness direction of the base material made of silicon are also related. For example, the thickness dimension t shown in FIG. 2B is 50 μm to 100 μm. Assume the case. It is assumed that the oxygen ion implantation is performed after a mask or the like is applied and the implantation site is determined. Also, so-called rotational injection or step injection, in which injection is performed while changing the angle from a predetermined twist angle (θ1) depending on the shape of the portion to be injected, or the like, may be performed as necessary.

With respect to the whiskers 13 shown in FIG. 3B, the process conditions for implanting oxygen ions are assumed to be ion implantation from the surface 13a side. For example, the implantation amount of oxygen ions is 1E ¹⁷ to 1E ¹⁸ [ion / cm ² ], the acceleration voltage is set to 20 keV, the twist angle (θ1) is set to 22 degrees, and the tilt angle (θ2) is set to 7 degrees.

For the whisker 13 shown in FIG. 3C, the process conditions for implanting oxygen ions are assumed to be ion implantation from the surface 13a side. For example, the implantation amount of oxygen ions is set to 1E ¹⁷ to 1E ¹⁸ [ion / cm ² ], the twist angle (θ1) is set to 22 degrees, and the tilt angle (θ2) is set to 7 degrees. When the identification pattern 5a is formed, the acceleration voltage is set to 20 keV, and when the identification pattern 5b is formed, the acceleration voltage is set to 200 keV.

  The oxygen ion implantation performed for forming the identification pattern 5b may be performed from the back surface 13b side, and in this case, the acceleration voltage may be 20 keV.

The process conditions for implanting oxygen ions with respect to the whiskers 13 shown in FIG. 3D are assumed to be ion implantation from the surface 13a side. For example, the implantation amount of oxygen ions is 1E ¹⁷ to 1E ¹⁸ [ion / cm ² ], the acceleration voltage is set to 20 to 200 keV, and the twist angle (θ1) is set to 22
The angle and the tilt angle (θ2) are set to 0 to 45 degrees.

Then, the tilt angle (θ2) is set to a constant angle within the range of 0 to 45 degrees, and oxygen ions are implanted while changing the acceleration voltage within the range of 20 to 200 keV.
Alternatively, oxygen ions may be implanted while keeping the acceleration voltage constant in the range of 20 to 200 keV and changing the tilt angle (θ2) in the range of 0 to 45 degrees.

With respect to the whiskers 13 shown in FIG. 4B, the process conditions for implanting oxygen ions are assumed to be ion implantation from the surface 13a side. For example, the implantation amount of oxygen ions is set to 1E ¹⁷ to 1E ¹⁸ [ion / cm ² ], the acceleration voltage is set to 200 keV, the twist angle (θ1) is set to 22 degrees, and the tilt angle (θ2) is set to 6 degrees or less.

  5 (b), FIG. 5 (c), FIG. 5 (e), FIG. 5 (f), FIG. 5 (h), FIG. 5 (i), and FIG. Since the process conditions performed on the whiskers 13 in FIGS. 3B to 3D and 4B described above can be applied, description thereof will be omitted.

The process condition for implanting oxygen ions into the mainspring portion 11 shown in FIG. 5 (l) is that ions are implanted from the surface 11a side. For example, the implantation amount of oxygen ions is 1E ¹⁷ to 1E ¹⁸ [ion / cm ² ], the twist angle (θ1) is set to 22 degrees, and the tilt angle (θ2) is set to 7 degrees. When the identification pattern 25k is formed, the acceleration voltage is set to 40 keV, and when the identification pattern 25m is formed, the acceleration voltage is set to 200 keV.

  The oxygen ion implantation performed to form the identification pattern 25m may be performed from the back surface 11b side, and in this case, the acceleration voltage may be 40 keV.

The oxygen ion implantation process for forming the alphabet “C” and the Chinese character “day” shown in FIG. 7 is performed by applying the process conditions already described. For example, in the case of the alphabet “C” shown in FIG. 7A, an oxygen ion implantation mask provided on the hairspring 10 is devised. This can be realized by implanting ions and not implanting oxygen ions in the remaining one surface.
Further, in the case of the Chinese character “day” shown in FIG. 7B, oxygen ions are implanted into four consecutive surfaces of the four outer surfaces of the mainspring portion 11 to form the configuration shown in FIG. Apply conditions.

[Description of watch part manufacturing method 1: FIG. 10]
Next, a method for manufacturing a watch part will be described. In the description, as an example of a timepiece component, a cross section of the hairspring 13 of the hairspring 10 and the outermost peripheral portion of the spring portion 11 shown in FIG. 2 is taken as an example. The identification pattern will be described using an example in which oxygen ions are implanted and heat-treated and formed on the surface of the beard (see FIG. 3B).

As the manufacturing method, the first to third manufacturing methods will be described with reference to FIGS. 10, 11, and 12.
The first manufacturing method is an example using an SOI substrate in which a silicon oxide film is sandwiched between two single crystal silicon layers, and an example in which oxygen ions are implanted into a predetermined part after forming a shape of a watch part. It is.
The second manufacturing method is an example in which an SOI substrate is used, and oxygen ions are implanted into a predetermined part before forming the shape of the watch part.
The third manufacturing method is an example in which a single crystal silicon substrate is used, and oxygen ions are implanted into a predetermined portion before forming the shape of the watch part.

[Description of First Manufacturing Method: FIG. 10]
First, the first manufacturing method will be described.
As shown in FIG. 10A, an oxide film 21 made of a silicon oxide film is provided on a support layer 20 made of single crystal silicon as a base, and an active layer made of single crystal silicon is formed on the oxide film 21. An SOI substrate 201 having 22 is prepared. The timepiece component is formed on the active layer 22.

  Next, as shown in FIG. 10B, a mask 30 based on the shape of the watch part is formed on the active layer 22. The mask 30 is, for example, a photoresist.

Next, as shown in FIG. 10C, in order to provide the mask pattern of the mask 30 on the active layer 22, the surplus portion of the active layer 22 is removed by etching. Etching to the active layer 22 is performed by dry etching using deep RIE technology. As the etching gas used at this time, for example, a mixed gas (SF6 + C4F8) of SF ₆ (sulfur hexafluoride) and C ₄ F ₈ (cyclobutane octafluoride) can be used. FIG. 10C shows a state in which the etching gas comes from the direction of the arrow G.

  As shown in FIG. 10D, the active layer 22 reflecting the shape of the mask 30 is formed by dry etching using deep RIE technology. Etching has not progressed under the mask 30 by the deep RIE technique.

  Next, as shown in FIG. 10E, after the mask 30 is removed by a known method, a mask 35 having an opening 35a in which a portion into which oxygen ions are to be implanted is formed on the active layer 22 is formed. To do. The mask 35 is, for example, a photoresist.

  Next, as shown in FIG. 10F, the oxygen ion implantation amount, implantation angle, and acceleration voltage described above are set, and oxygen ions are implanted so as to obtain a desired ion implantation amount profile. FIG. 10F shows a state where oxygen ions arrive from the direction of arrow F. Then, oxygen ions 40 are implanted into the portion of the active layer 22 where oxygen ions are to be implanted.

Next, as shown in FIG. 10G, after removing the mask 35 by a known method, the oxide film 21 is removed. The oxide film 21 is removed by wet etching using hydrofluoric acid, for example. Since hydrofluoric acid can etch the silicon oxide film but not silicon, only the oxide film 21 can be removed by etching. This method is generally called a lift-off process. The shape of the watch part is formed by this lift-off process.
Note that the oxygen ions 40 ion-implanted into the active layer 22 do not react with silicon, and thus are not removed by wet etching using hydrofluoric acid.

  Although the active layer 22 and the support layer 20 are separated by this lift-off process, the timepiece component (the active layer 22) is not shown in FIG. 10, but for example, the support 220 is shown in FIG. It is connected and only the watch parts do not fall.

  Next, as shown in FIG. 10H, heat treatment is performed to react the oxygen ions 40 with surrounding silicon to form silicon oxide. This heat treatment is also called thermal oxidation and is heated to 1100 ° C. Since the heating time varies depending on the desired thermal oxidation profile, the numerical value is omitted. Thereby, the identification pattern 5 is formed and the timepiece component (hairspring 10) is completed.

[Description of Second Manufacturing Method: FIG. 11]
Next, the second manufacturing method will be described.
As shown in FIG. 11A, an SOI substrate 201 having a support layer 20, an oxide film 21, and an active layer 22 similar to the first manufacturing method is prepared.

  Next, as shown in FIG. 11B, a mask 35 having an opening 35a in which a portion into which oxygen ions are to be implanted is opened is formed on the active layer 22. The mask 35 is, for example, a photoresist.

  Next, as shown in FIG. 11C, the oxygen ion implantation amount, implantation angle, and acceleration voltage, which have already been described, are set, and oxygen ions are implanted so as to obtain a desired ion implantation amount profile. FIG. 11C shows a state in which oxygen ions arrive from the direction of the arrow F. Then, oxygen ions 40 are implanted into the portion of the active layer 22 where oxygen ions are to be implanted.

  Next, as shown in FIG. 11 (d), after removing the mask 35, a mask 30 based on the shape of the watch part is formed on the active layer 22. The mask 30 is, for example, a photoresist.

Next, as shown in FIG. 11 (e), in order to provide the mask pattern of the mask 30 on the active layer 22, excess portions of the active layer 22 are removed by etching. Etching to the active layer 22 is performed by dry etching using deep RIE technology. As the etching gas used at this time, a mixed gas (SF6 + C4F8) is used as in the first manufacturing method. An arrow G in FIG. 11E indicates the arrival direction of the etching gas.
Then, as shown in FIG. 11F, an active layer 22 reflecting the shape of the mask 30 is formed.

  Next, as shown in FIG. 11G, the oxide film 21 is removed by a lift-off process. The oxide film 21 is removed by wet etching using hydrofluoric acid, for example. Even when this lift-off process is performed, only the timepiece part does not fall, as in the first manufacturing method.

  Next, as shown in FIG. 11H, heat treatment is performed to react the oxygen ions 40 with surrounding silicon to form silicon oxide. This heat treatment is heated to 1100 ° C. Since the heating time varies depending on the desired thermal oxidation profile, the numerical value is omitted. Thereby, the identification pattern 5 is formed and the timepiece component (hairspring 10) is completed.

[Description of Third Manufacturing Method: FIG. 12]
Next, the third manufacturing method will be described.
As shown in FIG. 12A, a silicon single crystal substrate 202 made of single crystal silicon is prepared. Such a silicon single crystal substrate is also called a bulk substrate. A watch part is formed on the surface of the silicon single crystal substrate 202.

  Next, as shown in FIG. 12B, a mask 30 based on the shape of the watch part is formed on the silicon single crystal substrate 202. The mask 30 is, for example, a photoresist.

  Next, as shown in FIG. 12C, in order to provide the mask pattern of the mask 30 on the silicon single crystal substrate 202, an excess portion on the upper portion of the silicon single crystal substrate 202 is removed by etching. Etching to the silicon single crystal substrate 202 is performed by dry etching by deep RIE technology. At this time, by controlling the etching time, so-called half etching is performed in which the virtual line Q is removed by etching in the middle of the thickness direction of the silicon single crystal substrate 202.

If the thickness from the surface of the silicon single crystal substrate 202 to the imaginary line Q is the same as the thickness t of the watch part shown in FIG. .

As the etching gas used for the deep digging RIE technique, for example, a mixed gas (SF6 + C4F8) of SF ₆ (sulfur hexafluoride) and C ₄ F ₈ (cyclobutane octafluoride) can be used. FIG. 12C shows a state where the etching gas comes from the direction of the arrow G.

  Next, as shown in FIG. 12D, after removing the mask 30, a mask 35 having an opening 35 a in which a portion into which oxygen ions are to be implanted is formed on the silicon single crystal substrate 202. The mask 35 is, for example, a photoresist.

  Next, as shown in FIG. 12E, the oxygen ion implantation amount, implantation angle, and acceleration voltage described above are set, and oxygen ions are implanted so that a desired ion implantation amount profile is obtained. FIG. 12E shows a state in which oxygen ions arrive from the direction of arrow F. Then, oxygen ions 40 are implanted into the portion of silicon single crystal substrate 202 where oxygen ions are to be implanted.

  Next, as shown in FIG. 12F, after removing the mask 35, heat treatment is performed. The heat treatment is performed to react the oxygen ions 40 and surrounding silicon to form silicon oxide, and is heated to 1100 ° C. Since the heating time varies depending on the desired thermal oxidation profile, the numerical value is omitted. Thereby, the identification pattern 5 is formed.

  Next, as shown in FIG. 12G, a protective film 36 is formed on the surface of the silicon single crystal substrate 202. The protective film 36 is used to protect the pattern of the timepiece part formed by half etching.

Thereafter, the silicon single crystal substrate is removed from the back surface of the silicon single crystal substrate 202. This is performed in order to cut out a watch part from the silicon single crystal substrate 202.
A known technique can be used to remove silicon from the silicon single crystal substrate 202 from the back surface. For example, etching technique and polishing sword technique. For example, in the case of removing by etching, wet etching using HNO ₃ + HF (fluoric nitric acid) or the like, and dry etching using deep RIE technology can be used. In the case of removing by polishing, a CMP (Chemical Mechanical Polishing) method or the like can be used. Of course, these techniques may be combined.

  The technique for removing the back surface of the silicon single crystal substrate 202 can be freely selected in view of the size, specifications, manufacturing cost, etc. of the watch part, but it is a matter of course that the protective film 36 corresponding to the selected technique is used. It is. It goes without saying that the film thickness and covering shape of the protective film 36 on the surface of the silicon single crystal substrate 202 change depending on the selected protective film 36.

  For example, when removing by the CMP method, the protective film 36 may be formed so that the surface of the silicon single crystal substrate 202 becomes flat as illustrated in FIG. This is because the protective film 36 side is in the direction of the stage on which the silicon single crystal substrate 202 is placed in the processing apparatus that performs the CMP method.

  Further, when the back surface of the silicon single crystal substrate 202 is removed by wet etching, the surface of the silicon single crystal substrate 202 is not necessarily flat, and the protective film 36 may be a film along the surface shape. For example, a thin oxide film or the like can be used. Note that a known jig that protects the etchant from flowing into the surface side of the silicon single crystal substrate 202 when performing wet etching may be used.

  Then, using the selected removal technique of the silicon single crystal substrate 202, the processing time such as the etching time and the removal time is controlled to remove the silicon in the thickness direction of the silicon single crystal substrate 202, and the virtual line Q Remove to the position.

  By removing the back surface of the silicon single crystal substrate 202, a timepiece part is cut out. However, the timepiece part is framed by a support portion 221 (see FIG. 8) (not shown in FIG. 8), and only the watch part does not fall. Finally, by removing the protective film 36, the timepiece part (hairspring 10) is completed as shown in FIG.

  The first to third manufacturing methods have been described above, but the method for manufacturing a timepiece part according to the present invention is not limited to this, and improvements and combinations of processes are possible.

  In the present embodiment, when the identification pattern is formed, a manufacturing method in which oxygen ions are implanted into a silicon base material and heat treatment is performed to form silicon oxide has been described in detail. However, the present invention is not limited to this.

  For example, silicon oxide may be formed by thermal oxidation or CVD, and this may be used as an identification pattern. In that case, a silicon oxide may be selectively formed by masking a portion where silicon oxide is not formed with a nitride known as an oxidation resistant mask.

  As already described, the oxidation strength represents how much silicon is oxidized to silicon. In the case of the above-described thermal oxidation, the oxidation strength is uniform inside the formed silicon oxide, but when viewed as a timepiece component, the difference in oxidation strength can be expressed as a difference in silicon oxide distribution. For example, when silicon oxide is formed on the surface of a silicon base material, there is a silicon portion and a silicon oxide portion in a plane, and the difference can be expressed as oxidation strength.

In the case of the above-described CVD method, the oxidation strength inside the formed silicon oxide can be made constant or can be changed. For example, normally, gasified monosilane (SiH ₄ ) and oxygen are reacted in a furnace (Berja) at a predetermined gas flow rate to form silicon oxide. By changing the gas flow rate, the oxidation strength can be changed in the film thickness direction to be formed. For example, the oxidation strength can be reduced in the film thickness direction by reducing the gas flow rate of the oxygen gas stepwise or gradually.

  In addition, when it forms by such a thermal oxidation or CVD method, the thickness of the target silicon oxide may become thick. As a result, the external shape of the watch part may change. In that case, the dimension of the portion where the silicon oxide is to be formed is previously made smaller than the desired size (for example, on the surface of the silicon base material). In the case of forming the silicon oxide, the height direction is reduced), a groove is formed at a position where the silicon oxide is to be formed, and the dimension in the depth direction of the silicon base material is reduced.

  Further, the above description has been given by exemplifying a hairspring as an example of a timepiece part, but of course, the timepiece part of the present invention is not limited to this. For example, gears such as the second wheel 110, the third wheel 111, the fourth wheel 112, and the escape wheel 106 constituting the train wheel 105 shown in FIG.

  At this time, in the gear, although not shown, for example, the peripheral portion of the shaft support portion is siliconized. Thereby, the abrasion of the peripheral part by the shaft and shaft which support a gear and a gear contacting or rubbing can be suppressed.

  In the gear, although not shown, for example, the outer peripheral edge portion may be silicon oxide. The outer peripheral edge of the gear is a so-called tooth tip, and is a part that comes into contact with, rubs against, or collides with another gear. Can be suppressed.

  In the gear, although not shown, the upper end surface (front flat surface) and the lower end surface (lower flat surface) of the gear may be siliconized. As a result, it is possible to suppress wear and damage due to contact with or collision with another timepiece component that contacts or faces the gear in the axial direction.

  Furthermore, as another example of the timepiece component, an ankle 107 that meshes with the escape wheel 106 may be used. As is known, an ankle has a stone called a nail stone embedded in the contact portion with the teeth of the escape wheel. In the timepiece component of the present invention, an ankle is formed in a shape including a claw stone, and a portion corresponding to the claw stone is siliconized. Thereby, the same effect as a claw stone can be acquired. Of course, since the claw stone itself is unnecessary, there is an advantage that the manufacturing process of the ankle can be simplified in addition to the reduction of the number of parts.

  In this way, by configuring the driving mechanism of the mechanical timepiece using a timepiece component in which silicon oxide is provided at a desired position, it is possible to ensure timekeeping accuracy and eliminate the need for rate adjustment. Further, since the rate adjustment is not required, a slow / rapid mechanism for realizing the rate adjustment can be eliminated, so that a mechanical timepiece having a drive mechanism composed of such timepiece parts can be reduced in size. Can be planned.

  The timepiece part of the present invention can identify a timepiece part made of silicon, can be easily assembled, can be counterfeited, and can further improve strength and temperature characteristics. Therefore, it is suitable for a mechanical wristwatch that is compact and lightweight and emphasizes temperature characteristics and impact resistance.

5, 15, 25, 35 Identification pattern 10 Hairspring 11 Spring portion 12 Whiskers 13 Beard

Claims (2)

A watch component mainly composed of silicon,
Only a portion is made of silicon oxide formed by oxidizing silicon, and the oxidation strength of the portion is different from the oxidation strength of other portions,
A timepiece component comprising an identification pattern made of a figure, a symbol, a character, or a combination thereof, using the silicon oxide. The escape wheel and the ankle, the balance spring and the balance wheel constituting the speed control mechanism, or the gear constituting the train wheel are any one of the escape wheel and the ankle. Watch parts described in.

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