JP5228876B2 - Quartz crystal resonator and manufacturing method thereof - Google Patents

Description

  The present invention relates to a crystal resonator holding structure and a manufacturing method thereof, and more particularly to a metal support structure for holding a crystal diaphragm and a manufacturing method using the support.

  Since quartz resonators have excellent resonance characteristics, they are widely used as a reference source for frequency and time. A metal thin film electrode is formed on the surface of the quartz diaphragm, and this metal thin film electrode is protected from the outside air. Is hermetically sealed.

  Among these, the crystal resonator used in the thermostatic chamber type crystal oscillator called OCXO currently uses a metallic package. Specifically, a pair of metal lead terminals are planted on the metal base via an insulating material such as glass, and a pair of metal flat plate support members are opposed to the inner lead portion of the metal lead terminal. Attached. The quartz diaphragm is, for example, an AT-cut quartz diaphragm that vibrates through a thickness, and an excitation electrode and an extraction electrode from each excitation electrode are formed on the front and back surfaces. A quartz diaphragm is mounted on the metal support and is electrically and mechanically connected by a conductive bonding material. The metal base is covered with a metal lid and hermetically sealed.

  In addition, OCXO is one in which the frequency is stabilized by controlling the temperature of the crystal unit in a thermostat without affecting the external temperature change, and the frequency stability is 1 × 10 −7 to 1 Since the highest level of frequency stability that can be obtained with a crystal resonator of about × 10 −10 can be obtained, it is used as a reference frequency for radio base stations and transmission lines.

  Patent Document 1 proposes an improved configuration for a crystal structure holding structure for high stability using a metal brazing material such as AuGe (gold-germanium) that can obtain good aging characteristics used in such OCXO. Yes.

JP 2006-186839 A

  When joining using a metal brazing material such as AuGe, the metal brazing material pellets and the metal brazing material balls are used to interpose between the metal support and the quartz crystal vibration plate while heating each in a fixed state. Melt and join metal brazing filler metal. However, in the configuration of Patent Document 1, there is no clear mark when positioning and fixing each member of the metal support, the solid metal brazing material, and the quartz diaphragm, and accurate positioning is not performed. Since they may be joined together or misaligned during the melting of the metal brazing material, the stress sensitivity of the quartz diaphragm received from the metal support also varies, which adversely affects product characteristics such as aging characteristics. was there.

  The present invention has been made to solve the above problems, and has good positioning and bonding properties when bonding a metal support and a quartz diaphragm using a conductive bonding material such as a metal brazing material, and has an aging characteristic. An object of the present invention is to provide a good and more reliable crystal resonator for high stability and a manufacturing method thereof.

Therefore, a crystal resonator according to the present invention includes a base in which at least two metal lead terminals are embedded through an insulating material, a metal support provided on the inner side of the metal lead terminal, and the metal support. air in a mounted on and through the conductive bonding material electrically and mechanically joined by a crystal oscillator for OCXO comprising a plate-shaped quartz plate, a vacuum atmosphere by coating the lid to the base The metal support is made of a metal material having a lower thermal expansion than the quartz made of a nickel iron-based low thermal expansion alloy and the metal support has a higher thermal conductivity than the metal support on the outer surface of the metal support. And a rotation axis obtained by rotating the plate surface by + 30 ° or −30 ° from the center point with respect to the Z ′ axis passing through the center point of the main surface of the crystal plate, and the crystal plate End is A metal support joint mark is formed at at least two of the four crossing points that are opposite to each other, and the metal support joint part of the crystal diaphragm is formed with respect to the crystal diaphragm holding part of the metal support. In the mark portion, the quartz diaphragm holding portion of the metal support and the quartz diaphragm are joined by the conductive joining material.

  With the above-described configuration, the rotation axis obtained by rotating the plate surface by + 30 ° or −30 ° from the center point with respect to the Z ′ axis passing through the center point of the main surface of the crystal plate and the end of the crystal plate A mark of the metal support joint portion is formed at at least two of the four crossing points at which the crossing points cross each other, and the metal support joint of the crystal diaphragm is attached to the crystal diaphragm holding portion of the metal support At least two points having no stress sensitivity in the end portion of the crystal diaphragm by joining the crystal diaphragm holding part of the metal support and the crystal diaphragm with the conductive bonding material at the mark portion of the portion A clear mark is formed on the crystal diaphragm, and the metal support mark of the crystal diaphragm can be bonded to each other in a state where the mark of the metal support of the crystal diaphragm is positioned with respect to the crystal diaphragm holding portion of the metal support. For this reason, the influence of the stress received with respect to the quartz diaphragm from the outside, such as a metal support, can also be suppressed, and the stress with respect to secular change can also be suppressed stably. As a result, it is possible to provide a highly-reliable and highly stable crystal resonator that has good positioning and bondability when bonding a metal support and a quartz diaphragm using a conductive bonding material and has good aging characteristics. .

  In the above configuration, the metal support is made of a nickel iron-based low thermal expansion alloy and has a thermal expansion coefficient close to zero from about half of the thermal expansion coefficient of quartz, or approximates the thermal expansion coefficient of quartz. Used metal materials. For example, Mitsubishi Materials Corporation: MA-INV36 <Fe-36Ni> (common name: Invar / Amber), MA-S-INVER <Fe-32Ni-5Co> (common name: Super Invar), MA902 <Fe-42Ni-Cr -Ti> (common name: NI-SPAN-C) is an optimal metal material. With this configuration, the metal support having a thermal expansion coefficient close to zero from about half the thermal expansion coefficient of the quartz crystal hardly causes thermal expansion of the metal support due to a change in environmental temperature. In addition, by using a metal support that approximates the thermal expansion coefficient of quartz, there is almost no difference in thermal expansion between the quartz diaphragm and the metal support due to changes in environmental temperature. As described above, the stress due to the change in the environmental temperature is not applied from the metal support to the quartz diaphragm, and the stress due to the secular change can be further suppressed. That is, the aging characteristic can be further enhanced.

  In the above configuration, the metal support is made of a nickel iron-based low thermal expansion alloy, and a metal film such as copper having higher thermal conductivity than the metal support is formed on the outer surface. With this configuration, a metal film having a high thermal conductivity is formed on the outer surface of the metal support, so that the metal film can be made against the temperature outside the package body (lid and base) of the crystal unit due to a change in environmental temperature. The temperature is transmitted to the quartz diaphragm without delay, and there is almost no temperature difference. This temperature difference is not particularly affected by radiant heat from the outside of the package body, and is particularly effective for high-stability crystal resonators that are hermetically sealed in a vacuum atmosphere that is strongly affected only by heat transfer through the metal lead terminals and metal support. It is a simple configuration. As a result, more stable frequency temperature characteristics can be obtained. Further, when a crystal resonator is used as the OCXO, it is possible to start up the crystal resonator in a shorter time after the crystal resonator is heated to a predetermined temperature in the thermostat and the frequency is stabilized (improvement of start-up characteristics).

Further, in the above-described configuration, the metal support is formed with a mark of the crystal diaphragm holding portion,
In the state where the mark of the metal support joint portion of the crystal support plate is close to the mark of the crystal support plate holding portion of the metal support, the crystal support plate holding portion of the metal support and the crystal vibration plate are electrically conductive. You may join by a joining material. With this configuration, in addition to the above-described effects, the metal support is also provided with a mark for the crystal diaphragm holding portion. Can be joined to each other in a state where the positioning is more accurately performed. For this reason, it is possible to almost eliminate the influence of the stress applied to the quartz diaphragm from the outside such as a metal support, and it is possible to more stably and hardly receive the influence of the stress on the secular change.

  Further, in the above-described configuration, the mark of the crystal vibration plate holding portion of the metal support is a conductive bonding material reservoir portion of the metal support such as a concave portion, a convex portion, or a hole portion, and the metal support joint portion of the crystal vibration plate The mark is a conductive bonding material connection electrode of the crystal diaphragm, and the crystal of the metal support is in a state where the conductive bonding material connection electrode of the crystal diaphragm is close to the conductive bonding material reservoir portion of the metal support. The diaphragm holding portion and the quartz diaphragm may be joined by the conductive joining material. With this configuration, in addition to the above-described effects, the conductive bonding material connection electrode of the crystal diaphragm is accurately positioned with respect to the conductive bonding material reservoir of the crystal vibration plate holding portion of the metal support. Can join each other. In addition, by forming a conductive bonding material reservoir in the quartz support plate holding portion of the metal support, the conductive bonding material is bonded in a state where it is accumulated in the conductive bonding material reservoir of the metal support. This eliminates unnecessary flow-out of the adhesive bonding material and stabilizes the bonding strength to the crystal diaphragm. In particular, it is more preferable that the conductive bonding material reservoir portions of the metal support have the same shape and the same volume, and the conductive bonding material connection electrodes of the crystal diaphragm also preferably have the same shape and the same area. . As a result, the stress of the holding part joined by the metal support and the conductive bonding material is also uniform, and the stress applied to the quartz diaphragm from the outside such as the metal support is distributed more uniformly and stably, and as a result Stress suppression against aging can be realized even more.

  Further, in the above-described configuration, the conductive bonding material connecting electrode of the crystal diaphragm includes a conductive bonding material reservoir portion of the crystal diaphragm in which the conductive bonding material such as a hole, a groove, and a convex portion is accumulated. May be. With this configuration, in addition to the above-described effects, the conductive bonding material reservoir portion of the crystal diaphragm is accurately positioned with respect to the conductive bonding material reservoir portion of the crystal support plate holding portion of the metal support. Can join each other. In addition, by forming the conductive bonding material reservoir portion of the crystal diaphragm, the conductive bonding material is joined in a state where it accumulates in the conductive bonding material reservoir portion of the crystal vibration plate, so there is no need for a conductive bonding material. It is possible to stabilize the bonding strength with respect to the metal support by eliminating unnecessary flow out. Furthermore, the holding area of the metal support and the crystal diaphragm by the conductive bonding material can be held limited to a specific shape or a specific volume according to the conductive bonding material reservoir portion of the crystal vibration plate, so that it is close to a point. In this state, the metal support and the quartz diaphragm can be joined, and the influence of stress can be further suppressed. In particular, it is more preferable that the conductive bonding material reservoir portions of the quartz crystal vibration plate are formed in the same shape and volume. As a result, the stress of the holding part joined by the metal support and the conductive bonding material is also uniform, and the stress applied to the quartz diaphragm from the outside such as the metal support is distributed more uniformly and stably, and as a result Stress suppression against aging can be realized even more.

  Further, in the above-described configuration, the crystal support plate holding portion of the metal support includes a notch portion or a hole portion in which a part of the mark of the metal support joint portion of the crystal vibration plate is exposed on the outer surface of the metal support. A window may be configured. With this configuration, in addition to the above-described effects, the metal support mark of the crystal diaphragm, the conductive bonding material connecting electrode of the crystal diaphragm, or the crystal vibration through the window to the crystal diaphragm holding part of the metal support It is possible to bond each other in a state where the positioning has been performed more accurately while exposing the conductive bonding material reservoir portion of the plate. For this reason, it is possible to almost eliminate the influence of the stress applied to the quartz diaphragm from the outside such as a metal support, and it is possible to more stably and hardly receive the influence of the stress on the secular change. Further, since the conductive bonding material goes around the window portion, the bonding strength is improved. Since the bonding state of the conductive bonding material can be recognized through the window portion, the structure is effective in preventing bonding failure and conduction failure.

  Further, in the above-described configuration, the conductive bonding material is made of a gold alloy brazing material such as AuGe, AuSn, or Au, and the excitation electrode formed on the front and back main surfaces of the crystal diaphragm has gold as a main component. An electrode material is preferred. With this configuration, in addition to the above-described effects, the aging characteristics can be further enhanced because the excitation electrode material and the metal brazing material are stable materials that are less susceptible to deterioration of electrical characteristics such as oxidation.

  Further, in the method for manufacturing a crystal resonator according to the present invention, a base in which at least two metal lead terminals are penetrated through an insulating material, a metal support provided on the inner side of the metal lead terminal, A method for manufacturing a crystal resonator comprising a plate-shaped crystal diaphragm mounted on the metal support and electrically and mechanically joined via a metal brazing material, wherein the crystal support is provided on the crystal vibration plate holding portion of the metal support. Forms a metal brazing material reservoir, attaches a solid metal brazing material to the metal brazing material reservoir of the metal support, and the center with respect to the Z ′ axis passing through the center point of the main surface of the crystal diaphragm A metal brazing material reservoir portion is provided at at least two opposing intersections among four intersections where the rotation axis rotated from the point by + 30 ° or −30 ° and the end of the crystal diaphragm intersect. And the brazing metal reservoir A metal brazing material connecting electrode formed on the upper surface of the ball portion, and the metal brazing material reservoir portion of the metal support and the metal brazing material reservoir portion of the quartz crystal plate being in proximity to each other. The quartz crystal plate is mounted to form a pre-sealing crystal resonator, and the metal brazing material is melted by heating the entire pre-sealing crystal resonator by atmospheric heating to melt the metal support and the crystal vibration. It is characterized in that the plates are joined electrically and mechanically.

  By the above manufacturing method, a metal brazing material reservoir is formed in the quartz diaphragm holding part of the metal support, and a clear mark for attaching a solid metal brazing material to the quartz diaphragm holding part of the metal support; Not only can the attached solid metal brazing material be displaced later.

  Further, the rotation axis obtained by rotating the plate surface by + 30 ° or −30 ° from the center point with respect to the Z ′ axis passing through the center point of the main surface of the crystal plate intersects with the end of the crystal plate. By forming a metal brazing material reservoir and a metal brazing material connecting electrode formed on the upper surface of the metal brazing material reservoir at at least two opposing intersections of the four intersections, the crystal diaphragm In addition to being a clear marker for at least two points of the end of the metal that are not stress sensitive, the metal brazing material after melting is joined in a state where it has accumulated in the metal brazing material reservoir. The holding area of the quartz diaphragm by the material can be held limited to a specific shape or a specific volume corresponding to the metal brazing material reservoir.

  In addition, a crystal vibration plate is mounted on the crystal vibration plate holding portion of the metal support in a state where the metal brazing material reservoir portion of the metal support and the metal brazing material reservoir portion of the crystal vibration plate are close to each other. Since the metal brazing material is melted and the metal support and the quartz diaphragm are electromechanically joined to each other, a portion of the metal support to which the solid metal brazing material is attached is formed. It is possible to accurately position and fix the metal brazing material reservoir portion and the metal brazing material connecting electrode formed portion of the quartz crystal diaphragm with respect to each other, and to accurately match at least two points having no stress sensitivity at the ends of the quartz crystal diaphragm. Positioning can be performed. The metal support and the crystal diaphragm can be joined to each other in such a state where the positioning is accurate. Misalignment between the metal brazing materials during heating and melting is eliminated. For this reason, it is possible to almost eliminate the influence of the stress applied to the quartz diaphragm from the outside such as a metal support, and it is possible to more stably and hardly receive the influence of the stress on the secular change.

  Further, by heating the entire crystal unit before sealing by atmospheric heating, not only heating for melting the metal brazing material but also a base having at least two metal lead terminals to which a metal support is attached, Since it can be heated at the same time including the quartz diaphragm, it can also be annealed to remove distortion and degas each member at the same time, so the jointability when joining the metal support and quartz diaphragm using a metal brazing material Can be further enhanced, and aging characteristics can be further enhanced. In particular, the atmosphere heating is preferably performed in a high-vacuum annealing furnace, and the entire heating without oxidation and deterioration of each member can be performed.

  As a result, there is provided a method for manufacturing a highly stable and highly stable crystal resonator having good positioning and bonding properties when bonding a metal support and a crystal diaphragm using a conductive bonding material, and having good aging characteristics. be able to.

  According to the present invention, a highly reliable crystal vibration for high stability with good positioning and bondability when bonding a metal support and a crystal diaphragm using a conductive bonding material such as a metal brazing material and good aging characteristics. A child and a manufacturing method thereof can be provided.

  Next, embodiments of the present invention will be described with reference to the drawings, taking a crystal resonator as an example. FIG. 1 is an exploded perspective view showing an embodiment of the present invention, FIG. 2 is a front view showing a first form in a state where FIG. 1 is assembled, and FIG. 3 is a schematic view showing a manufacturing process in the first form. is there. FIG. 4 is a front view showing a second embodiment in a state where FIG. 1 is assembled, and FIG. 5 is a schematic view showing a manufacturing process in the second embodiment. FIG. 6 is a front view showing a crystal diaphragm of an embodiment of the present invention, and FIGS. 7 and 8 are front views showing a crystal diaphragm of another embodiment of the present invention. FIG. 9 is an exploded perspective view showing another embodiment of the present invention. In addition, in each form, the same number is attached | subjected about the same part, and if there is no need in particular, the description is omitted.

  The base 1 as a whole has a low-profile long cylindrical shape, and has a structure in which metal lead terminals 11 and 12 are planted through a base body 10 mainly including a metal shell, and an insulating glass G is used as a base body. The metal lead terminals 11 and 12 are integrally formed integrally with each other by being partially filled.

  The metal lead terminals 11 and 12 have an elongated cylindrical shape. For example, the tip portions 11a and 12a on the inner side of the upper part of the base are formed in a nail head shape having a wide width and a flat upper part. Metal supports 13 and 14, which will be described later, are attached to the tip of the inner lead so as to face each other by a welding method (laser welding, spot welding, etc.). For this reason, when mounting the metal support on the metal lead terminal, it can be mounted horizontally and stably without tilting, and the welding area is also expanded, so that the joint strength is improved and the reliability when welding the metal support to the metal lead terminal is improved. Will improve dramatically.

  The metal supports 13 and 14 are, for example, nickel iron-based low thermal expansion alloys, which use a metal material whose thermal expansion coefficient is close to zero from about half the thermal expansion coefficient of quartz, specifically manufactured by Mitsubishi Materials Corporation. MA-INV36 <Fe-36Ni> (common name: Invar / Amber), MA-S-INVER <Fe-32Ni-5Co> (common name: Super Invar), and the like. Alternatively, the metal supports 13 and 14 are made of a metal material that approximates the thermal expansion coefficient of quartz. Specifically, MA902 <Fe-42Ni-Cr-Ti> (common name: NI-SPAN-C) etc. are mention | raise | lifted if it is a thing made from Mitsubishi Materials Corporation. Such metal supports 13, 14 are connected to the metal lead terminals 131, 141, and a quartz diaphragm holding part 132 that holds the quartz diaphragm described later with a substantially U-shaped cross section. , 142.

  A solid metal brazing material 3 described later is attached in advance to the quartz support plate 132, 142 of the metal support by welding or the like, and a metal brazing material reservoir portion 133 of the metal support in which the molten metal brazing material is accumulated. 143 (a mark of the crystal diaphragm holding portion) is formed. In this embodiment, the shape of the metal brazing material reservoirs 133 and 143 of the metal support is configured by, for example, an uneven shape having a convex portion at the center and a concave portion around the convex portion. It should be noted that the metal brazing metal reservoir portions 133 and 143 of the metal support are not limited to such an uneven shape, and may be mutually connected according to the shape of each solid metal brazing material 3 such as a metal brazing material pellet or a metal brazing material ball. It is sufficient that the metal brazing filler metal 3 after being melted can be retained, and only the concave portion, the convex portion, the hole portion, or a combination thereof may be used.

  In addition, window portions 134 and 144 (marks for the crystal diaphragm holding portion) are formed in part of the quartz support plate holding portions 132 and 142 of the metal support. The window portions 134 and 144 can be formed by notches, holes, or the like, and are formed so that part of connection electrodes 23 and 24 of a crystal diaphragm described later is exposed to the outside surface.

  The quartz diaphragm 2 is made of, for example, an AT cut quartz diaphragm, and is configured in a disk shape subjected to a single-side plano polishing process. Two points where the rotation axis obtained by rotating the plate surface by + 30 ° from the center point with respect to the Z ′ axis passing through the center point O of the main surface of the quartz crystal plate intersects the end of the quartz crystal plate and faces each other. At the intersections A and B, recesses 21 and 22 (a mark for the metal support joint and a metal brazing material reservoir portion of the crystal diaphragm) are formed at side ends by a method such as half etching. The recesses 21 and 22 are configured as a metal brazing material reservoir portion in which the molten metal brazing material 3 to be described later accumulates, and it is more preferable that the recesses 21 and 22 have the same shape and the same volume. On the upper surfaces of the recesses 21 and 22, connection electrodes 23 and 24 (marks for metal support joints) to which a metal brazing material 3 described later is connected are also formed. The connection electrodes 23 and 24 are made of an electrode material mainly composed of gold. For example, a gold electrode layer is formed on the upper surface of a base electrode layer of chromium or nickel. The metal brazing material reservoir portion in which the metal brazing material 3 accumulates is not limited to the recesses 21 and 22, but may be any shape as long as the molten metal brazing material can be accumulated, such as a hole portion, a groove portion, It may be a convex portion or a combination of these.

  The metal brazing material 3 (conductive bonding material) is made of, for example, a gold-based alloy brazing material pellet such as AuGe, AuSn, or Au, and is previously attached to the metal brazing material reservoir portions 133 and 143 of the metal support by welding or the like. Yes.

-First form-
Hereinafter, the configuration of the crystal resonator according to the first embodiment and the manufacturing method thereof will be described with reference to FIGS. As shown in FIG. 3 (a), the crystal diaphragm 2 in which only the recesses 21 and 22 and the connection electrodes 23 and 24 are formed is mounted on the metal supports 13 and 14 to which the metal brazing material 3 is attached. . At this time, the concave portions 21 and 22 of the crystal diaphragm are arranged and mounted in the state where the concave portions 21 and 22 of the crystal diaphragm are close to the metal brazing material reservoir portions 133 and 143 of the metal support.

  Next, as shown in FIG. 3B, the metal brazing material 3 and the crystal diaphragm 2 are placed against the crystal vibration plate holding portions 132 and 142 of the metal support in a state where the metal brazing material reservoir portion and the concave portion are close to each other. The attached base 1 (pre-sealing crystal resonator) before hermetic sealing is carried into a heating furnace. For example, a high-vacuum annealing furnace is used as the heating furnace, and the whole pre-sealing crystal resonator (base) is heated in a vacuum atmosphere. Then, for example, by heating to a temperature equal to or higher than the melting point of the metal brazing material 3, the molten metal brazing material 3 remains in the recesses 21 and 22 of the crystal vibration plate, and the crystal vibration plate holding portions 132 and 142 of the metal support. And the metal brazing material connecting electrodes 23 and 24 of the crystal diaphragm are joined by the molten metal brazing material 3.

  Next, as shown in FIG. 3 (c), the base before airtight sealing in which the crystal diaphragm holding parts 132, 142 of the metal support and the metal brazing material connection electrodes 23, 24 of the crystal diaphragm are joined. 1 (pre-sealing crystal resonator), and a mask member (not shown) is arranged on the front and back main surfaces of the crystal diaphragm 2, and excitation electrodes 25 and 26 (the back surface 26 is not shown) and an extraction electrode 27 , 28 are provided by means such as vacuum deposition or sputtering. The excitation electrodes 25 and 26 and the extraction electrodes 27 and 28 are integrally formed at the same time and are made of an electrode material mainly composed of gold. For example, a gold electrode layer is formed on the upper surface of a base electrode layer of chromium or nickel. ing.

  In addition, as shown in FIG. 2, the extraction electrodes 27 and 28 are formed so as to connect the external surfaces of the quartz plate holding parts 132 and 142 of the metal support and the excitation electrodes 25 and 26 of the quartz plate. Therefore, the electrical connectivity between the metal supports 13 and 14 and the excitation electrodes 25 and 26 is ensured. In particular, in the embodiment of the present invention, windows 134 and 144 are formed in a part of the quartz support plate holding parts 132 and 142 of the metal support, and a part of the connection plate 23 and 24 of the crystal diaphragm is on the external surface. Since it is formed so as to be exposed, even if the extraction electrodes 27 and 28 are disconnected at a gap portion between the metal support and the crystal diaphragm, the extraction electrodes 27 and 28 are surely provided in the upper surface region where the metal brazing material 3 exists. It can be formed and the electrical connectivity is more reliable.

  In the pre-sealing crystal resonator configured as described above, the base is covered with a lid (not shown) and hermetically sealed, whereby the first-type crystal resonator is completed.

-Second form-
Hereinafter, the configuration of the crystal resonator of the second embodiment and the manufacturing method thereof will be described with reference to FIGS. As shown in FIG. 5 (a), the recesses 21 and 22, the connection electrodes 23 and 24, and the excitation electrodes 25 and 26 (with respect to the back surface 26 are illustrated) with respect to the metal supports 13 and 14 to which the metal brazing material 3 is attached. (Not shown) on which a quartz diaphragm 2 is mounted. At this time, the concave portions 21 and 22 of the crystal vibrating plate are mounted so as to be close to the metal brazing material reservoir portions 133 and 143 of the metal support. At this time, the excitation electrodes 25 and 26 and the connection electrodes 23 and 24 of the crystal diaphragm are disconnected from each other.

  Next, as shown in FIG. 5B, the metal brazing material 3 and the crystal diaphragm 2 are placed against the crystal diaphragm holding parts 132 and 142 of the metal support in a state where the metal brazing material reservoir and the recess are close to each other. The attached base 1 (pre-sealing crystal resonator) before hermetic sealing is carried into a heating furnace. For example, a high-vacuum annealing furnace is used as the heating furnace, and the whole pre-sealing crystal resonator (base) is heated in a vacuum atmosphere. Then, for example, by heating to a temperature equal to or higher than the melting point of the metal brazing material 3, the molten metal brazing material 3 remains in the recesses 21 and 22 of the crystal vibration plate, and the crystal vibration plate holding portions 132 and 142 of the metal support. And the metal brazing material connecting electrodes 23 and 24 of the crystal diaphragm are joined by the molten metal brazing material 3.

  Next, as shown in FIG. 5 (c), the base before airtight sealing in which the crystal diaphragm holding parts 132 and 142 of the metal support and the metal brazing material connection electrodes 23 and 24 of the crystal diaphragm are joined. 1 (pre-sealing crystal resonator), and lead electrodes 27 and 28 are provided on the front and back main surfaces of the crystal vibrating plate 2 by means of vacuum deposition or sputtering while disposing a mask member (not shown). Yes. The excitation electrodes 25 and 26 and the extraction electrodes 27 and 28 are formed separately, but are made of an electrode material mainly composed of gold. For example, a gold electrode layer is formed on the upper surface of a base electrode layer of chromium or nickel. Has been.

  As shown in FIG. 4, the extraction electrodes 27 and 28 connect the external surfaces of the quartz support plate holding portions 132 and 142 of the metal support and the partial upper surfaces of the excitation electrodes 25 and 26 of the quartz plate. Therefore, the electrical connectivity between the metal supports 13 and 14 and the excitation electrodes 25 and 26 is ensured. In particular, in the embodiment of the present invention, windows 134 and 144 are formed in a part of the quartz support plate holding parts 132 and 142 of the metal support, and a part of the connection plate 23 and 24 of the crystal diaphragm is on the external surface. Since it is formed so as to be exposed, even if the extraction electrodes 27 and 28 are disconnected at a gap portion between the metal support and the crystal diaphragm, the extraction electrodes 27 and 28 are surely provided in the upper surface region where the metal brazing material 3 exists. It can be formed and the electrical connectivity is more reliable.

  In the pre-sealing crystal resonator configured as described above, the base of the second embodiment is completed by covering the base with a lid (not shown) and hermetically sealing in a vacuum atmosphere, for example.

  According to the above embodiment, by forming the metal brazing material reservoir portions 133 and 143 (marks of the crystal vibration plate holding portion) of the metal support on the crystal vibration plate holding portions 132 and 142 of the metal supports 13 and 14, the solid state In addition to a clear mark for attaching the metal brazing filler metal 3 to the crystal support plate holders 132, 142 of the metal support, the attached solid metal braze material 3 is later removed from the crystal plate support parts 132, 142. There is no misalignment.

  Further, the rotation axis obtained by rotating the plate surface by + 30 ° from the center point with respect to the Z ′ axis passing through the center point O of the main surface of the crystal diaphragm 2 intersects with the end portion of the crystal diaphragm. At the two intersections A and B, the concave portions 21 and 22 where the metal brazing material is accumulated (the metal brazing metal reservoir portion of the crystal diaphragm) and the upper surface of the metal brazing material reservoir portion. By forming the formed metal brazing filler metal connection electrodes 23 and 24 (marks of the metal support joints), it is possible not only to clearly mark the two points having no stress sensitivity in the ends of the crystal diaphragm, but also to melt Since the subsequent metal brazing material 3 is joined in a state where it is accumulated in the recesses 21 and 22, the holding area of the crystal diaphragm 2 by the metal brazing material 3 is set to a specific shape and a specific volume according to the recesses 21 and 22. Limited holding is possible.

  With the above-described configuration, the crystal vibration relative to the metal brazing metal reservoirs 133 and 143 (marks of the crystal diaphragm holding part) of the metal support or the windows 134 and 144 (marks of the crystal diaphragm holding part) of the metal support. Heating is performed in a high-vacuum annealing furnace in a state where the concave portions 21 and 22 of the plates are close to each other, so that the crystal vibrating plate holding portions 132 and 142 of the metal support and the metal brazing material connecting electrodes 23 and 24 of the crystal vibrating plate are melted. By joining with the metal brazing material 3, the concave portions 21 and 22 of the crystal diaphragm 2 and the metal brazing material connection electrode formation 23 are formed on the portions of the metal supports 13 and 14 where the solid metal brazing material 3 is attached. , 24 can be accurately positioned and fixed to each other, and accurate positioning is performed on at least two points having no stress sensitivity at the ends of the quartz diaphragm. It can be joined to each other in state. Further, during melting of the metal brazing material 3, the metal brazing material 3 is not joined to each other by shifting from a point having no stress sensitivity. In particular, the concave portions 21 and 22 of the crystal diaphragm (the marks of the metal support joints, which are attached to the metal brazing material reservoir portions 133 and 143 of the metal support in advance) The metal brazing material reservoir portion) is locked to ensure accurate alignment, and the metal brazing material 3 is not displaced until it is completely melted.

  That is, the stress applied to the quartz diaphragm 2 from the outside such as the metal supports 13 and 14 can be made stable, and the stress against the secular change can be suppressed. In particular, it is more preferable that the recesses 21 and 22 formed at the end portion of the quartz crystal plate have the same shape and the same volume, and the stress of the holding portion joined by the metal supports 13 and 14 and the metal brazing material 3. Also, the stress applied to the quartz diaphragm 2 from the outside such as the metal supports 13 and 14 is distributed more uniformly and stably, and as a result, the stress suppression against the secular change can be further realized.

  As a result, a highly reliable crystal resonator for high stability with higher positioning and bonding properties when bonding the metal supports 13 and 14 and the crystal diaphragm 2 using the metal brazing material 3 and good aging characteristics is provided. can do.

  Further, by heating the whole crystal resonator by atmospheric heating using a vacuum annealing furnace, the metal brazing material 3 is melted, and the metal supports 13 and 14 and the crystal diaphragm 2 are joined electrically and mechanically. Therefore, not only the heating for melting the metal brazing material 3 but also the base 1 having the two metal lead terminals 11 and 12 to which the metal supports 13 and 14 are attached and the crystal diaphragm 2 are heated simultaneously. Therefore, since it is possible to simultaneously remove the distortion of each member and to perform degassing, the metal brazing material 3 is used to join the metal supports 13 and 14 and the quartz crystal plate 2 together. The aging characteristics can be further enhanced. In particular, when the atmosphere heating is performed in a high vacuum annealing furnace, it is possible to perform the entire heating without oxidization or deterioration of each member.

  The metal brazing material 3 is made of a gold-based alloy brazing material such as AuGe, AuSn, Au, and the excitation electrodes 25 and 26 and the extraction electrodes 27 and 28 formed on the front and back main surfaces of the crystal diaphragm 2 are gold. A gold electrode layer is formed on the upper surface of a base electrode layer of chromium or nickel containing as a main component. For this reason, since the excitation electrodes 25 and 26 and the metal brazing material 3 are stable materials in which deterioration of electrical characteristics such as oxidation does not easily occur, the aging characteristics can be further enhanced.

  In addition, the metal supports 13 and 14 are made of a nickel iron-based low thermal expansion alloy and have a thermal expansion coefficient close to zero from about half of the thermal expansion coefficient of quartz. The change hardly causes thermal expansion of the metal supports 13 and 14. Moreover, since it is configured using a material that approximates the thermal expansion coefficient of quartz, the metal supports 13 and 14 hardly cause a difference in thermal expansion between the quartz diaphragm and the metal support due to a change in environmental temperature. As described above, the stress due to the change in the environmental temperature is not applied from the metal supports 13 and 14 to the quartz diaphragm 2, and the stress due to the secular change can be further suppressed. That is, the aging characteristic can be further enhanced.

  In the first and second embodiments of the present invention, the extraction electrodes 27 and 28 that connect the external surfaces of the quartz crystal plate holding portions 132 and 142 of the metal support and the excitation electrodes 25 and 26 of the quartz plate 2 are used. Is formed in a later step. In other words, in the first embodiment, only the metal brazing material connection electrodes 23 and 24 are formed on the crystal diaphragm 2, and the metal supports 13 and 14 and the crystal diaphragm 2 are melt-bonded with a metal brazing material 3 by a heating furnace. Thereafter, the excitation electrodes 25 and 26 and the extraction electrodes 27 and 28 of the quartz diaphragm including the outer surfaces of the quartz diaphragm holding parts 132 and 142 of the metal support are integrally formed. In the second embodiment, the excitation electrodes 25 and 26 and the metal brazing material connection electrodes 23 and 24 of the crystal diaphragm 2 are formed in advance in a disconnected state, and the metal supports 13 and 14 and the crystal diaphragm 2 are made of metal. After melting and joining with the brazing material 3 in a heating furnace, lead electrodes 27 and 28 are formed to connect the external surfaces of the quartz plate holding portions 132 and 142 of the metal support and the excitation electrodes 25 and 26 of the quartz plate. ing.

  Thus, by forming the extraction electrodes 27, 28 and the like in a later process, the metal brazing material 3 diffuses toward the excitation electrodes 25, 26, and the quartz support plate 132, 142 of the metal support and the crystal plate The metal brazing filler metal 3 interposed between the metal brazing filler metal connection electrodes 23 and 24 is in an insufficient state, and the electromechanical joint failure between the metal supports 13 and 14 and the crystal diaphragm 2 does not occur. Furthermore, the electrical connectivity between the metal supports 13 and 14 and the excitation electrodes 25 and 26 is ensured. In particular, a metal brazing material 3 having a very high aging characteristic such as AuGe but having a high melting point and a long melting time is used to heat the quartz diaphragm 2 having excitation electrodes 25 and 26 mainly composed of gold. When joining by atmospheric heating using a furnace, there is a problem that gold is likely to diffuse. However, since the metal brazing material 3 diffuses only within the range of the connection electrodes 23 and 24, excitation is performed while improving the joining property. The metal brazing material 3 never diffuses into the electrode. As described above, in the manufacturing method according to the embodiment of the present invention, the metal brazing material 3 can be easily joined by atmospheric heating, and the characteristics can be improved by annealing at the same time.

-Other embodiments-
In the first and second embodiments, as shown in FIG. 6, the plate surface is rotated + 30 ° from the center point with respect to the Z ′ axis passing through the center point O of the main surface of the crystal diaphragm. The rotation shaft and the end of the crystal diaphragm intersect, and the concave portions 21 and 22 are marks of the metal support joints at the two intersections A and B facing each other, and are metal brazing material reservoirs of the crystal diaphragm. And the configuration of the connection electrodes 23 and 24 to which the metal brazing material 3 is connected is described. However, it is not specified only for these two intersections.

  As shown in FIG. 7, with respect to the Z ′ axis passing through the center point O of the main surface of the crystal diaphragm, the rotation axis obtained by rotating the plate surface by −30 ° from the center point and the end of the crystal diaphragm Is a mark of the metal support joint with respect to the two intersections C and D facing each other, and the metal brazing material reservoir hole portions 211 and 221 which are the metal brazing material reservoir portions of the crystal diaphragm and the metal brazing material The connection electrodes 231 and 241 to which 3 is connected may be configured.

  Further, as shown in FIG. 8, the rotation axis obtained by rotating the plate surface by + 30 ° and −30 ° from the center point with respect to the Z ′ axis passing through the center point O of the main surface of the crystal plate and the crystal vibration. Recesses 213, 223, which are marks of the metal support joints with respect to four crossing points A, B, C, D, which are opposite to each other, and which are metal brazing material reservoirs of the crystal diaphragm, Further, the connection electrodes 23, 24, 231, and 241 to which the groove portions 212 and 222 and the metal brazing material 3 are connected may be configured.

  As shown in FIG. 9, the metal supports 13 and 14 are made of a nickel iron-based low thermal expansion alloy, and a metal film M having a higher thermal conductivity than the metal support is formed on the outer surface. . With this configuration, the metal film M having a high thermal conductivity is formed on the outer surfaces of the metal supports 13 and 14, so that the temperature of the crystal resonator package body (lid and metal, etc.) outside due to a change in environmental temperature can be increased. On the other hand, the metal film M transmits the temperature to the crystal diaphragm 2 without delay, and a temperature difference hardly occurs. As a result, more stable frequency temperature characteristics can be obtained. Further, when a crystal resonator is used as the OCXO, it is possible to start up the crystal resonator in a shorter time after the crystal resonator is heated to a predetermined temperature in the thermostat and the frequency is stabilized (improvement of start-up characteristics).

  In this embodiment, the metal film M is plated with 3 to 10 μm on the front and back main surfaces of the metal supports 13 and 14. By forming the metal film M on the front and back main surfaces of the metal support, there is no bias in the thermal deformation of the entire metal support, which is preferable in that no excessive stress is applied to the crystal diaphragm 2. By using copper plating as the metal film M, it is possible to form a metal film that is relatively inexpensive and easily formed using a commonly used plating bath, and a metal film having excellent heat conductivity can be formed. By forming the copper plating with a thickness of 3 to 10 μm, it is possible to maintain stable heat transfer while suppressing costs, and to maintain the low thermal expansion performance of the entire support and to eliminate the adverse effects of unnecessary thermal stress. When the copper plating is formed thinner than 3 μm, the heat conductivity is lowered. If the copper plating is formed thicker than 10 μm, the risk of plating cracking increases due to bending of the metal support, etc., and the thermal expansion performance of the support as a whole is adversely affected, and unnecessary thermal stress is applied to the crystal diaphragm. The risk of becoming more likely to join increases.

  In addition to the configuration of the above-described embodiment, as a mark for the metal support joint portion of the crystal diaphragm, a material other than the metal brazing material reservoir and the connection electrode of the crystal diaphragm may be formed. A mark other than the metal brazing material reservoir portion of the metal support may be formed as a mark of the crystal support plate holding portion of the metal support. The tip of the inner lead of the lead terminal has only a nail head shape as an example, but it can also be applied to a normal inner lead shape. It is not limited to the AT-cut crystal diaphragm, but may be another crystal diaphragm such as an SC cut. The metal film M may be formed on one main surface of the front and back surfaces of the metal support or may be partially formed. Further, not only copper plating but also a metal film such as gold, silver, or aluminum may be used.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof, and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not limited by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

The disassembled perspective view which shows embodiment of this invention. The front view which shows the 1st form of the state which assembled FIG. The schematic diagram which shows the manufacturing process in a 1st form. The front view which shows the 2nd form of the state which assembled FIG. The schematic diagram which shows the manufacturing process in a 2nd form. The front view which shows the crystal diaphragm of embodiment of this invention. The front view which shows the crystal diaphragm of other embodiment of this invention. The front view which shows the crystal diaphragm of other embodiment of this invention. The disassembled perspective view which shows other embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Base 10 Base main body 11,12 Lead terminal 13,14 Metal support 2 Crystal diaphragm 3 Metal brazing material

Claims (7)

A base formed by penetrating at least two metal lead terminals through an insulating material; a metal support provided on the inner side of the metal lead terminal; and a metal support mounted on the metal support via a conductive bonding material A crystal resonator for OCXO comprising a plate-like crystal diaphragm joined electrically and mechanically,
The base is covered with a lid and hermetically sealed in a vacuum atmosphere,
The metal support is made of a metal material having a lower thermal expansion than quartz made of a nickel iron-based low thermal expansion alloy, and a metal film having a higher thermal conductivity than the metal support is formed on the outer surface of the metal support,
A rotation axis obtained by rotating the plate surface by + 30 ° or −30 ° from the center point with respect to the Z ′ axis passing through the center point of the main surface of the crystal plate intersects with the end of the crystal plate 4. A metal support joint mark is formed at at least two of the point intersections,
The metal support crystal vibration plate holding portion and the crystal vibration plate are bonded to the metal support crystal vibration plate holding portion by the conductive bonding material at a mark portion of the metal support joint portion of the crystal vibration plate. A crystal resonator characterized by being made. The metal support is formed with a mark of the crystal diaphragm holding portion,
In the state where the mark of the metal support joint portion of the crystal support plate is close to the mark of the crystal support plate holding portion of the metal support, the crystal support plate holding portion of the metal support and the crystal vibration plate are electrically conductive. 2. The crystal unit according to claim 1, wherein the crystal unit is bonded by a bonding material. The mark of the crystal support plate holding part of the metal support is a conductive bonding material reservoir of the metal support, and the mark of the metal support connection part of the crystal vibration plate is a conductive bonding material connecting electrode of the crystal plate, In the state where the conductive bonding material connecting electrode of the quartz crystal plate is in proximity to the conductive bonding material reservoir portion of the metal support, the quartz crystal plate holding portion of the metal support and the quartz crystal vibrating plate are the conductive bonding material. The crystal resonator according to claim 2, wherein the crystal resonator is bonded to each other. 4. The crystal resonator according to claim 3, wherein the conductive bonding material connecting electrode of the crystal diaphragm includes a conductive bonding material reservoir portion of the crystal diaphragm in which the conductive bonding material is accumulated. . The crystal support plate holding part of the metal support is configured with a window part in which a part of the mark of the metal support joint part of the crystal support plate is exposed on the outer surface of the metal support. Item 5. The crystal resonator according to any one of Items 1 to 4. The conductive conductive material is made of a gold-based alloy brazing material, and the excitation electrode formed on the front and back main surfaces of the crystal diaphragm is made of an electrode material mainly composed of gold. 5. The crystal resonator according to claim 1. A base formed by penetrating at least two metal lead terminals via an insulating material, a metal support provided on the inner side of the metal lead terminal, and mounted on the metal support and via a metal brazing material A method of manufacturing a quartz crystal resonator comprising a plate-like quartz crystal plate joined mechanically,
A metal brazing material reservoir is formed in the crystal diaphragm holding portion of the metal support, and a solid metal brazing material is attached to the metal brazing material reservoir of the metal support,
A rotation axis obtained by rotating the plate surface by + 30 ° or −30 ° from the center point with respect to the Z ′ axis passing through the center point of the main surface of the crystal plate intersects with the end of the crystal plate 4. A metal brazing material reservoir part and a metal brazing material connecting electrode formed on the upper surface of the metal brazing material reservoir part are formed at at least two opposing intersections of the point intersections,
A crystal vibration plate is mounted on the crystal vibration plate holding portion of the metal support in a state where the metal brazing material reservoir portion of the metal support and the metal brazing material reservoir portion of the crystal vibration plate are close to each other. Configure
A quartz crystal resonator, wherein the entire quartz crystal resonator before sealing is heated by atmospheric heating to melt the metal brazing material and to electrically and mechanically join the metal support and the quartz crystal vibration plate. Production method.

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