JP2019029857A - Crystal device - Google Patents

Abstract

To provide a crystal device that reduces application of an unintended stress or distortion to a crystal element to improve electrical characteristics.SOLUTION: A crystal device comprises: a crystal piece that has crystal axes consisting of an X-axis, Y-axis, and Z-axis that are orthogonal to each other; a metal pattern that consists of a pair of excitation electrode parts provided on the crystal piece and connection wiring parts extended from the excitation electric parts to an end of the crystal piece; an interposition part that is provided, on its top surface, a connection pad connected to part of the connection wiring parts of the metal pattern and is provided, on its under surface, with a mounting terminal electrically connected to the connection pad; a substrate that has, as a main body, a substrate part provided, on its top face, with a mounting pad connected to the mounting terminal; and a lid body that is joined to the substrate. The interposition part has crystal axes consisting of an X-axis, Y-axis, and Z-axis that are orthogonal to each other, and when the connection part pad of the interposition part and part of the connection wiring parts of the metal pattern are provided at positions facing each other, the Z-axis of the crystal piece and the Z-axis of the interposition part are parallel to each other.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a crystal device of a crystal resonator or a crystal oscillator.

  As a crystal device, a crystal resonator or a crystal oscillator for generating an oscillation signal that vibrates at a predetermined frequency is known. As an example of such a crystal device, there is a crystal oscillator with a thermostat (OCXO) in which a crystal resonator is housed in a thermostat (see, for example, Patent Document 1).

  A crystal device of a crystal resonator or a crystal oscillator has a crystal element in which a metal pattern including a pair of excitation electrode portions and a pair of connection wiring portions is provided on a crystal piece. The crystal element is mounted on the main surface of the interposition part that is disposed on the mounting surface of the base that forms part of the package of the crystal device and faces away from the mounting surface of the base Has been. At this time, the crystal element is bonded while the connection wiring portion and the connection pad provided in the interposition portion are electrically connected by the connection member. A mounting terminal that is electrically connected to the connection pad is provided on the lower surface of the interposition part, and this mounting terminal is the mounting surface of the base (specifically, the upper surface of the substrate part that is the main body of the base). It is bonded while being electrically connected by a mounting pad and a mounting member. Therefore, the interposition part is arranged on the mounting surface of the base (specifically, the upper surface of the substrate part which is the main body of the base), and the crystal element is arranged on the surface of the interposition part facing away from the mounting surface of the base It has become a state. At this time, the quartz crystal element is disposed so as to be opposed to the surface of the interposition part facing away from the mounting surface of the base (see, for example, Patent Document 2).

JP 2006-311496 A Japanese Patent Laid-Open No. 2016-220179

  The crystal element is bonded to the intervening portion while being electrically connected by the connecting member. However, the crystal element changes due to a change in the external environment of the crystal device, specifically, a temperature change in the atmosphere where the crystal device exists. There is a possibility that unintended stress or strain is applied to the element, resulting in lack of frequency stability and deterioration of electrical characteristics.

  An object of the present invention is to provide a crystal device that can reduce unintended stress and strain on a crystal element and improve electrical characteristics.

  The quartz crystal device according to the present invention includes a quartz crystal piece having crystal axes composed of an X axis, a Y axis, and a Z axis orthogonal to each other, and a pair of excitation electrode portions and excitation electrode portions provided on both main surfaces of the quartz crystal piece. A metal pattern composed of a connection wiring portion extending to the edge of the piece and a connection pad connected to a part of the connection wiring portion of the metal pattern are provided on the upper surface and are electrically connected to the connection pad. An intervening portion provided with a mounting terminal on the lower surface, a base body mainly comprising a substrate portion provided with an upper surface on which a mounting pad connected to the mounting terminal of the interposing portion, a lid body joined to the base body, The interposition part has a crystal axis composed of the X axis, the Y axis, and the Z axis orthogonal to each other, and is provided at a position where the connection part of the interposition part and a part of the connection wiring part of the metal pattern face each other. The Z-axis of the crystal Wherein the parts of the Z-axis are parallel to each other.

  According to said structure, a quartz crystal device can reduce that the stress and distortion which are not intended to apply to a quartz crystal element are reduced, and can improve an electrical property.

It is a perspective view of the quartz crystal device concerning this embodiment. It is sectional drawing in the AA cross section of FIG. It is a figure which shows the state in which the interposition part is provided in the base | substrate. It is a figure which shows the state in which the crystal element is provided on the interposition part. It is the top view which planarly viewed the upper surface of the base | substrate used with the crystal device which concerns on this embodiment. (A) is the top view which planarly viewed the upper surface of the crystal element used with the crystal device which concerns on this embodiment, (b) is a top view from the upper surface side of the lower surface of the crystal element used with the crystal device which concerns on this embodiment. It is the top view seen through. (A) is the top view which planarly viewed the upper surface of the interposition part used with the crystal device which concerns on this embodiment, (b) is a top view from the upper surface side of the lower surface of the interposition part used with the crystal device which concerns on this embodiment. It is the top view seen through.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and the dimensional ratios and the like on the drawings do not necessarily match the actual ones. For convenience, a portion on the layer (that is, a surface not having a cross section) may be hatched.

  The crystal device and the crystal element of the present disclosure may be either upward or downward, but hereinafter, the term “upper surface” in FIG. 1 and FIG. . In addition, when simply referred to as a plan view or a plan view, unless otherwise specified, the image is viewed in the vertical direction fixed for convenience.

<Embodiment>
1 to 4 are diagrams relating to a crystal device according to the present embodiment. FIG. 1 is a perspective view of a quartz crystal device according to the present embodiment, and FIG. 2 is a cross-sectional view taken along a line AA in FIG. FIG. 3 is a diagram illustrating a state in which an intervening portion is provided on the base, and FIG. 4 is a diagram illustrating a state in which the intervening portion is provided on the base and a crystal element is provided on the intervening portion. It is. FIG. 5 is a plan view of a substrate used in the quartz crystal device according to the present embodiment. FIG. 6 is a plan view of a crystal element used in the crystal device according to the present embodiment. FIG. 7 is a plan view of the interposition part used in the quartz crystal device according to the present embodiment.

  A crystal device is an electronic component having a substantially rectangular parallelepiped shape as a whole. For example, the quartz device has a long side or short side length of 0.6 mm to 10.00 mm and a vertical thickness of 0.2 mm to 3.2 mm.

  The quartz crystal device mainly includes, for example, a base 110 in which a recess is formed, a crystal element 120 and an interposition part 150 accommodated in the base 110, and a lid 130 that closes the recess. Further, in the crystal device, the interposition part 150 is mounted on the base body 110 by the mounting member 141, and the crystal element 120 is mounted on the interposition part 150 by the connection member 142.

(Description of substrate)
The base 110 includes, for example, a substrate portion 110a that is the main body of the base 110, a frame portion 110b that is provided along the edge of the upper surface of the substrate portion 110a, a pair of mounting pads 111, and a plurality of mounting terminals 112. ,have.

  The board part 110a is for mounting the interposition part 150. The substrate part 110a has a substantially thin rectangular parallelepiped shape. The substrate portion 110a has a pair of mounting pads 111 on the upper surface and a plurality of mounting terminals 112 on the lower surface. In addition, the substrate unit 110a is provided with a plurality of internal wirings (including portions exposed on the upper surface of the substrate unit 110a) that are not particularly illustrated, and two of the internal wirings are the upper surfaces of the substrate unit 110a. The mounting pads 111 provided on the board and the predetermined two mounting terminals 112 provided on the lower surface of the substrate portion 110a are electrically connected to each other.

  Here, the upper surface of the substrate part 110a refers to the surface on which the interposition part 150 is mounted, and the lower surface of the substrate part 110a refers to the surface of the substrate part 110a facing away from the upper surface of the substrate part 110a. .

  The frame part 110b is for forming a space for accommodating the crystal element 120 and the interposition part 150 in the base 110, and is provided in a frame shape along the edge of the upper surface of the substrate part 110a. The frame part 110b is formed integrally with the substrate part 110a.

  The mounting pad 111 is provided on the upper surface of the substrate part 110a in the frame part 110b. At this time, for example, two mounting pads 111 are provided side by side along the edge of one short side of the substrate part 110a.

  The mounting terminals 112 are for mounting a crystal device on a circuit board or the like shown in the drawings, and a plurality of mounting terminals 112 are provided on the lower surface of the substrate portion 110a. For example, four mounting terminals 112 are provided, and are arranged at the four corners of the lower surface of the substrate portion 110a.

  A plurality of internal wirings (not shown) are provided on the substrate part 110a. Two of the internal wirings electrically connect the pair of mounting pads 111 and two predetermined mounting terminals 112, respectively. A part of the internal wiring may be exposed on the upper surface of the substrate portion 110a and the lower surface of the substrate portion 110a. When only two internal wirings are provided on the substrate part 110a, the mounting pad 111 and the mounting terminal 112 are electrically connected to each other. Further, when there are three or more internal wirings, the other predetermined internal wiring electrically connects the lid body and the mounting terminal that are electrically joined to the upper surface of the frame portion.

(Explanation of intervening part)
FIG. 7 is a plan view of the interposition part 150 used in the quartz crystal device according to the present embodiment. FIG. 7A is a plan view of the upper surface of the interposition part 150 used in the crystal device according to this embodiment, and FIG. 7B is an upper surface of the lower surface of the interposition part 150 used in the crystal device according to this embodiment. It is the top view seen through plane from the side. Therefore. FIG. 7A shows the surface of the interposition part 150 on which the crystal element 120 is mounted, and FIG. 7B shows the surface of the interposition part 150 mounted on the substrate part 110a. FIG. 3 is a diagram for explaining the state of the interposition part 150 and the base 110 in an easy-to-understand manner. FIG. 4 is a diagram for explaining the state of the interposition part 150 and the crystal element 120 in an easy-to-understand manner.

  The intervening portion 150 uses a crystal member having a crystal axis composed of an X axis (electrical axis), a Y axis (mechanical axis), and a Z axis (optical axis) that are orthogonal to each other. It has become. The main surface of the interposition part 150 has the same cut angle as the main surface of the crystal piece 121 of the crystal element 120 described later. For example, in quartz, an orthogonal coordinate system including the X axis, the Y axis, and the Z axis is expressed as X When the orthogonal coordinate system XY′Z ′ system is defined by rotating around 30 to 50 ° (as an example, 35 ° 15 ′) around the axis, the XZ ′ plane is parallel to the XZ ′ plane. The main surface of the interposition part 150 is, for example, a rectangle whose short side is parallel to the Z ′ axis and whose long side is parallel to the X axis.

  Further, the thickness of the interposition part 150 in the vertical direction is larger than the thickness of the crystal piece 121 of the crystal element 120 in the vertical direction, for example. As shown in FIG. 2, when the interposition part 150 is mounted on the substrate part 110 a of the base 110, the interposition part 150 is cantilevered on the other short side of the interposition part 150. It is in the state. In the present embodiment, the thickness of the interposition part 150 in the vertical direction is made thicker than the thickness of the crystal piece 121 in the vertical direction in this way, so that it is on the upper surface of the interposition part 150 and on one short side of the interposition part 150. When the crystal element 120 is mounted, it is possible to reduce the lower surface of the interposition part 150 from coming into contact with the substrate part 110a of the base 110 due to the bending of the crystal element 120 due to its own weight. As a result, it is possible to suppress a change in the electrical characteristics of the crystal device due to an unintended stress being applied to the crystal element 120 from the interposition part 150 due to contact between the interposition part 150 and the substrate part 110a of the base 110.

  The main surface of the interposition part 150 refers to the surface having the widest area in the interposition part 150. When the interposition part 150 is mounted on the substrate part 110a of the base body 110, the main surface of the interposition part 150 facing the substrate part 110a is the lower surface of the interposition part 150, and the interposition part faces the opposite side of the lower surface of the interposition part 150. The main surface 150 is the upper surface of the interposition part 150.

  Further, when the upper surface of the interposition part 150 is viewed in plan, and the lower surface of the interposition part 150 is viewed in plan from the upper surface side, the center of the surface of the interposition part 150 (specifically, the intersection of diagonal lines with the interposition part 150 being planar) The portion including one short side of the interposition portion 150 is defined as a first region A1 and the portion including the other short side of the interposition portion 150 with respect to a virtual line CL1 parallel to the short side of the interposition portion 150 passing through Let it be the second region A2. Here, one short side of the interposition part 150 refers to a short side in which a pair of mounting terminals 151 are provided side by side.

  The interposition part 150 is provided with a pair of mounting terminals 151 on the lower surface of the interposition part 150, and a pair of connection pads 152 on the upper surface of the interposition part 150. The interposition part 150 is provided with a conductive part 153 for electrically connecting the mounting terminal 151 and the connection pad 152. In addition, a groove 154 is formed in the interposition part 150.

  The mounting terminal 151 is provided at a position facing the mounting pad 111 provided on the upper surface of the substrate part 110 a and along one short side of the lower surface of the interposition part 150. Therefore, the mounting terminal 151 is provided in the first region A1 of the interposition part 150. The mounting terminal 151 is electrically connected to the mounting pad 111 provided on the upper surface of the substrate part 110a by the mounting member 141.

  The connection pad 152 is for mounting the crystal element 120 on the upper surface of the interposition part 150, and is provided in a part of the connection wiring part 124 of the crystal element 120, specifically, at a position facing the connection part 124a. ing. Further, the connection pad 152 is electrically connected to the connection portion 124 a of the crystal element 120 by the connection member 142.

  At this time, the axial direction in which the connection pads 152 are arranged and the axial direction in which the connection portions 124a of the crystal element 120 are arranged are the same direction. Specifically, when the direction in which the pair of connection pads 152 are aligned is parallel to the Z ′ axis, the direction in which the connection portions 124 a of the crystal element 120 are aligned is also parallel to the Z ′ axis. Since the cut angle of the crystal piece 121 of the crystal element 120 and the cut angle of the interposition part 150 are the same, the Z ′ axis is parallel. For example, two connection pads 152 are provided along the edge of the other short side of the interposed portion 150 on the upper surface of the interposed portion 150.

  The conductive portion 153 is for electrically connecting the mounting terminal 151 and the connection pad 152, and has one end connected to the mounting terminal 151 and the other end connected to the connection pad 152. Further, for example, a part of the conductive portion 153 is a via or a through hole, although not particularly illustrated, for electrically connecting the lower surface of the interposition portion 150 and the upper surface of the interposition portion 150. In the present embodiment, a via or a through hole is provided to electrically connect the conductive portion 153 provided on the lower surface of the interposition portion 150 and the conductive portion 153 provided on the upper surface of the interposition portion 150. However, if the conductive portion 153 provided on the lower surface of the interposition portion 150 and the conductive portion 153 provided on the lower surface of the interposition portion 150 can be electrically connected, the interposition portion A part of the conductive portion 153 may be provided on the side surface of 150.

  The groove portion 154 is formed in the second region A2 between the mounting terminal 151 and the connection pad 152 in plan view of the interposition portion 150. Accordingly, it can be said that the groove 154 is formed between the virtual line CL1 and the connection pad 152 when the interposition part 150 is viewed in plan.

  The groove portion 154 is formed on the upper surface side of the interposition portion 150, and the depth in the vertical direction penetrates from the upper surface to the lower surface of the interposition portion 150. doing.

  When the crystal element 120 is mounted on the interposition part 150, when viewed in plan from the upper surface of the crystal element 120, the portion of the groove 154 formed in the interposition part 150 that overlaps the crystal piece 121 is substantially rectangular. Yes. At this time, two predetermined sides of the four sides are parallel to the direction in which the connection pads 152 are arranged, specifically, the Z ′ axis, and two other predetermined portions of the overlapping portions of the groove portions 154 are arranged. The side is perpendicular to the direction in which the connection pads 152 are arranged, specifically, parallel to the X axis. At this time, the length of the two predetermined sides is not less than 0.3 times and less than 0.5 times the length of the short side of the crystal piece 121 of the crystal element 120.

  Here, when the crystal element 120 is mounted on the interposition part 150, a portion of the groove 154 formed in the interposition part 150 that overlaps the crystal piece 121 in plan view from the upper surface of the crystal element 120, It may be described as a portion where the groove 154 overlaps.

  For example, two grooves 154 are formed in the interposition part 150. When the crystal element 120 is mounted on the interposition part 150, the groove 154 formed in the interposition part 154 and the crystal piece 121 overlap when viewed from the top surface of the crystal element 120. The overlapping portions of the respective groove portions 154 have substantially the same shape. Further, the crystal piece 121 is symmetrical with respect to a center line CL2 parallel to the long side of the crystal piece 121 passing through the center of the surface of the crystal piece 121 (the intersection of the diagonal lines of the crystal piece 121).

  Such an interposition part 150 is mounted on the upper surface of the substrate part 110 a of the base 110 by the mounting member 141, and the crystal element 120 is mounted on the upper surface of the interposition part 150 by the connection member 152. From another viewpoint, it can be said that the interposition part 150 is disposed between the substrate part 110 a of the base 110 and the crystal element 120.

(Description of mounting members)
The mounting member 141 is for mounting the interposition part 150 on the substrate part 110a of the base 110, and is located between the upper surface of the substrate part 110a of the base 110 and the lower surface of the interposition part 150. At this time, the mounting member 141 is provided in the first region A <b> 1 of the interposition part 150 when viewed in plan from the upper surface side of the interposition part 150.

  The mounting member 141 includes, for example, a first mounting member 141a, a second mounting member 141b, and a third mounting member 141c.

  As shown in the figure, the first mounting member 141a and the second mounting member 141b are mounted with the mounting terminal 151 and the substrate portion provided on the lower surface of the interposed portion 150 while mounting the interposed portion 151 on the substrate portion 110a of the base 110. The mounting pad 111 provided on the upper surface of 110a is electrically connected. Therefore, the first mounting member 141a and the second mounting member 141b are mounting members 141 located in the first region A1 and between the mounting terminal 151 of the interposition part 150 and the mounting pad 111 of the board part 110a. is there.

  For example, a conductive adhesive or a bump is used for the first mounting member 141a and the second mounting member 141b. The conductive adhesive is obtained by mixing a conductive filler with a thermosetting resin. For example, gold or solder is used for the bump.

  The third mounting member 141c is for making the lower surface of the interposition part 150 and the upper surface of the board part 110a substantially parallel when the interposition part 150 is mounted on the substrate part 110a. For example, as shown in the drawing, the third mounting member 141c is between the upper surface of the substrate portion 110a and the lower surface of the interposition portion 150, and in the first region A1 of the interposition portion 150 when viewed in plan. And located near the center of the surface of the interposition part 150.

  For example, a conductive adhesive, an insulating adhesive, or a bump is used for the third mounting member 141c. The conductive adhesive is obtained by mixing a conductive filler in a thermosetting resin, and the insulating adhesive is a thermosetting resin in which no conductive filler is mixed. For example, gold or solder is used for the bump.

  Therefore, the mounting member 141 including the first mounting member 141a, the second mounting member 141b, and the third mounting member 141c is formed on the lower surface of the interposition part 150 when the interposition part 150 is mounted on the substrate part 110a of the base 110. Therefore, it is located between the first region A1 of the interposition part 150 and the upper surface of the substrate part 110a.

  In the present embodiment, the case where the mounting member 141 includes the first mounting member 141a, the second mounting member 141b, and the third mounting member 141c has been described. However, the interposition part 150 is mounted on the substrate part 110a. As long as it is located on the lower surface of the interposition part 150 and in the first region A1 of the interposition part 150, for example, the mounting member 141 may be composed of four.

  In this embodiment, the case where the first mounting member 141a and the second mounting member 141b are located between the mounting pad 111 and the mounting terminal 151 is described. However, the mounting terminal 151, the mounting pad 111, and Can be electrically connected, for example, the mounting terminal 151 is provided on the upper surface of the interposition part 150, and the mounting terminal 151 and the mounting pad 111 can be electrically connected by a wire or the like. If so, the first mounting member 141a and the second mounting member 141b may be an insulating adhesive.

(Description of crystal element)
FIG. 6 is a diagram relating to a crystal element used in the crystal device according to the present embodiment. FIG. 6A is a plan view of a top surface of a crystal element used in the crystal device according to the present embodiment as viewed in plan. FIG. 6B is a plan view of the lower surface of the crystal element used in the crystal device according to this embodiment as seen through from the upper surface side. Accordingly, FIG. 6A shows the surface of the crystal element 120 facing the opposite side of the upper surface of the interposition part 150 when the crystal element 120 is mounted on the interposition part 150, and FIG. It is the surface of the crystal element 120 facing the side.

  The crystal element 120 is mounted on the upper surface of the interposition part 150. In the present embodiment, the surface of the crystal element 120 that is substantially parallel to the upper surface of the substrate portion 110 a of the base 110 is defined as the main surface of the crystal element 120. Further, the direction from the crystal element 120 toward the substrate part 110a is defined as the downward direction, and the direction from the substrate part 110a toward the crystal element 120 is defined as the upward direction.

  The main surface of the crystal element 120 facing the upper surface of the interposition part 150 is the lower surface of the crystal element 120, and the main surface of the crystal element 120 facing the opposite side of the lower surface of the crystal element 120 is the upper surface of the crystal element 120. In the present embodiment, the main surface of the crystal element 120 is used in the same meaning as the main surface of the crystal piece 121. Similarly, the lower surface of the crystal element 120 and the lower surface of the crystal piece 121 are used in the same meaning, and the upper surface of the crystal element 120 and the upper surface of the crystal piece 121 are used in the same meaning.

  The quartz crystal element 120 is a part that generates vibration in which an oscillation signal is generated. Further, as described above, the quartz crystal element 120 is mounted on the upper surface of the interposition part 150, and in a space formed by the base body 110 and the lid body 130, in a vacuum or an appropriate gas (for example, nitrogen) atmosphere. It is enclosed.

  The crystal element 120 includes a crystal piece 121 and a metal pattern 122.

  The crystal piece 121 is, for example, a so-called AT cut plate. That is, in a quartz crystal, an orthogonal coordinate system XYZ system composed of an X axis (electric axis), a Y axis (mechanical axis), and a Z axis (optical axis) is 30 ° to 50 ° around the X axis (as an example, 35 ° 15 ′) When rotating to define the XY′Z ′ system, the main surface of the crystal piece 121 is parallel to the XZ ′ plane. The shape of the crystal piece 121 in the plane is, for example, a rectangle. At this time, the crystal piece 121 has a long side parallel to the X axis and a short side parallel to the Z ′ axis.

  The thickness of the crystal piece 121 in the vertical direction is set based on a desired natural frequency for thickness shear vibration. For example, in the case of using the fundamental vibration, if the natural frequency is F (MHz), the basic formula for obtaining the thickness t (μm) of the crystal piece 121 corresponding to the natural frequency F is t = 1670 / F. is there. In practice, the thickness of the crystal piece 121 is a value that is finely adjusted from the value of the basic formula in consideration of the weight of the excitation electrode portion 123 and the like.

  Various dimensions of the crystal piece 121 may be appropriately set based on simulation calculations, experiments, and the like from various viewpoints such as reduction of the equivalent series resistance value. As an example, for example, the length of the long side or the short side is 0.5 (mm) to 9.0 (mm) and the thickness is 40 (μm) to 100 (μm).

  The metal pattern 122 provided on the crystal piece 121 is for applying an alternating voltage from the outside of the crystal element 120. The metal pattern 122 may be a single layer, or a plurality of metal layers may be stacked. Although not particularly illustrated, the metal pattern 122 includes, for example, a first metal layer and a second metal layer laminated on the first metal layer.

  For the first metal layer, a metal having good adhesion to the crystal is used. For example, any one of nickel, chromium, nichrome, or titanium is used. In this way, by using a metal having good adhesion to the crystal, a metal material that is difficult to adhere to the crystal can be used for the second metal layer.

  The second metal layer is made of a stable material having a low electrical resistivity among the metal materials. For the second metal layer, for example, any one of gold, an alloy containing gold as a main component, silver, or an alloy containing silver as a main component is used. By using a metal having a low electrical resistivity for the second metal layer, the resistivity of the metal pattern 122 itself can be reduced, and as a result, an increase in the equivalent series resistance value of the crystal element 120 can be reduced. It becomes possible. Further, by using a stable metal material for the second metal layer, it is possible to reduce the change in the weight of the metal pattern 122 due to the reaction between the surrounding air where the crystal element 120 exists and the metal pattern 122. . As a result, the change in the frequency of the crystal element 120 caused by the weight of the metal pattern 122 can be suppressed, and the electrical characteristics can be stabilized.

  The metal pattern 122 includes an excitation electrode portion 123 and a connection wiring portion 124. And this connection wiring part 124 has the connection part 124a and the wiring part 124b.

  The excitation electrode portion 123 is for applying an alternating voltage to the crystal piece 121. The excitation electrode portion 123 is a pair, and is provided in the vicinity of the center of both main surfaces of the crystal piece 121 so as to face each other. Further, the excitation electrode portion 123 has, for example, a substantially rectangular shape in plan view.

  The connection wiring part 124. This is for applying an alternating voltage to the excitation electrode portion 123 from the outside of the crystal element 120. Further, as described above, the connection wiring portion 124 includes the connection portion 124a and the wiring portion 124b.

  When the crystal element 120 is used as a crystal device, the connection part 124a is for mounting on the interposition part 150, and is electrically connected by a connection pad 152 and a connection member 142 provided on the upper surface of the interposition part 150. The Therefore, the connection part 124 a is provided at a position facing the mounting pad 152 of the interposition part 150. In addition, for example, two connection portions 124a are provided side by side along the edge of one short side of the crystal piece 121 in plan view.

  As described above, since the connection portion 124a is provided at a position facing the connection pad 152 of the interposition portion 150, the crystal element 120 is mounted on the upper surface of the interposition portion 150, and the plane is viewed from the upper surface side of the crystal element 120. When seen through, it can be said that the connection part 124 a and the connection pad 152 are located in the second region A <b> 2 of the interposition part 150.

  The positional relationship between the direction in which the pair of connection portions 124 a are aligned and the crystal axis of the crystal piece 121 is the same as the positional relationship between the direction in which the pair of connection pads 152 are aligned and the crystal axis in the interposition portion 150. . Specifically, when the direction in which the pair of connection pads 152 are aligned is parallel to the Z ′ axis, the direction in which the connection portions 124 a of the crystal element 120 are aligned is also parallel to the Z ′ axis. Since the cut angle of the crystal piece 121 of the crystal element 120 and the cut angle of the interposition part 150 are the same, the Z ′ axis is parallel.

  The wiring part 124 b is for electrically connecting the connection part 124 a and the excitation electrode part 123, one end is connected to the connection part 124 a, and the other end is connected to the excitation electrode part 123.

(Description of connecting member)
The connection member 142 is for electrically connecting the connection portion 124 a of the crystal element 120 and the connection pad 152 of the interposition portion 150 while being mounted on the upper surface of the interposition portion 150 of the crystal element 120. Therefore, the connection member 142 is located between the connection pad 152 provided on the upper surface of the interposition part 150 and the connection part 124 a of the crystal element 120.

  As described above, the connection pad 152 is provided in the second region A2 of the interposition part 150. From another viewpoint, it can be said that the connection member 142 is provided in the second region A2 of the interposition part 150. .

  For the connection member 142, for example, a conductive adhesive or a bump is used. The conductive adhesive is obtained by mixing a conductive filler with a thermosetting resin. For example, gold or solder is used for the bump.

(Description of lid)
The lid 130 is for hermetically sealing the interposition part 150 and the crystal element 120 accommodated in the recessed space of the base 110, and is joined to the upper surface of the base 110 by seam welding or the like. The lid 130 is made of, for example, metal and has a thin rectangular parallelepiped shape.

  The crystal device configured in this way is disposed, for example, with the lower surface of the base 110 facing the mounting surface of the circuit board shown in the figure, and the mounting terminals 112 are mounted on mounting pads (not shown) of the circuit board by soldering or the like. The circuit board is mounted by bonding. For example, an oscillation circuit is configured on the circuit board. The oscillation circuit includes an excitation electrode portion via a mounting terminal 112, internal wiring (not shown), a mounting pad 111, a mounting member 141, a mounting terminal 151, a conductive portion 153, a connection pad 152, a connection member 142, and a connection wiring portion 124. An alternating voltage is applied to 123 to generate an oscillation signal. At this time, the oscillation circuit uses, for example, fundamental wave vibration among thickness shear vibrations of the crystal piece 121. Overtone vibration may be used.

  From the above, the crystal piece 121 having crystal axes composed of the X axis, the Y axis, and the Z axis orthogonal to each other, and the pair of excitation electrode portions 123 and excitation electrode portions 123 provided on both main surfaces of the crystal piece 121. And a connection pad 152 connected to a part of the connection wiring portion 124 of the metal pattern 122 is provided on the upper surface, and the connection pad 152 is connected to a part of the connection wiring portion 124 of the metal pattern 122. Mainly includes an interposition part 150 in which a mounting terminal 151 electrically connected to 152 is provided on the lower surface, and a board part 110a in which a mounting pad 111 connected to the mounting terminal 151 of the interposition part 150 is provided on the upper surface. A base body 110 and a lid 130 joined to the base body 110, and the interposition part 150 has a crystal axis composed of an X axis, a Y axis, and a Z axis perpendicular to each other. Thus, when the connection pad 152 of the interposition part 150 and a part of the connection wiring part 124 of the metal pattern 122 are opposed to each other, the Z axis of the crystal piece 121 and the Z axis of the interposition part 150 are parallel to each other. It has become.

  In general, it is known that the thermal expansion coefficient of a crystal member having crystal axes composed of an X axis, a Y axis, and a Z axis orthogonal to each other varies depending on the positional relationship with the crystal axis. In particular, the thermal expansion coefficient when it is perpendicular to the Z axis is about 1.675 times the thermal expansion coefficient when it is parallel to the Z axis. Therefore, in this embodiment, when the temperature in the atmosphere in which the crystal device exists suddenly changes by making the Z axis of the interposition part 150 and the Z axis of the crystal piece 121 substantially parallel in this way. The amount of expansion of the interposition part 150 due to heat and the amount of expansion of the crystal piece 121 due to heat can be made substantially the same. As a result, unintentional stress is applied to the crystal element 120 even if the intervening portion 150 expands due to heat in response to a change in the external environment of the crystal device, specifically, a rapid temperature change in the atmosphere in which the crystal device exists. And distortion can be reduced, and the frequency stability can be improved.

  In the crystal device according to the present embodiment, the X-axis and Y-axis of the crystal piece 121 and the X-axis and Y-axis of the interposition part 150 are parallel. Therefore, in this embodiment, the X-axis, Y-axis, and Z-axis of the crystal piece 121 and the X-axis, Y-axis, and Z-axis of the interposition part 150 are parallel to each other. It can be said that the angle and the cut angle of the interposition part 150 are the same.

  By doing in this way, when the temperature in the atmosphere in which the crystal device exists changes rapidly, the outer shape of the interposition part 150 expands due to heat, and the state where the outer shape of the crystal piece 121 expands due to heat. It becomes possible to be the same. For this reason, compared with the case where the Z-axis of the interposition part 150 and the Z-axis of the crystal piece 121 are made substantially parallel, when the temperature in the atmosphere where the crystal device exists changes rapidly, the interposition part 150 and the crystal Even if the element 120 expands due to heat, it is possible to further reduce the unintended stress and strain applied to the crystal element 120 and to improve the frequency stability.

  Further, in the crystal device according to the present embodiment, a groove 154 is formed between the connection pad 152 and the mounting terminal 151 that is electrically connected in plan view of the interposition part 150.

  Therefore, in the interposition part 150 used in the present embodiment, when seen in a plan view, between the mounting terminal 151 mounted on the mounting pad 111 of the substrate part 110a of the base 110 and the connection pad 152 on which the crystal element 120 is mounted. It can be said that the groove 154 is formed. By doing so, when the temperature in the atmosphere in which the crystal device exists changes rapidly, the state of thermal expansion of the substrate part 110a of the base 110 differs from the state of thermal expansion of the interposition part 150. Even if unintended stress or distortion occurs, it is possible to reduce the influence in the portion where the connection pad 152 on which the crystal element 120 is mounted is provided. For this reason, even when the temperature in the atmosphere where the quartz device is present changes suddenly, it is possible to further reduce the unintended stress and strain applied to the quartz element 120 and to improve the frequency stability. Is possible.

  Further, in the crystal device according to the present embodiment, when the crystal element 120 is mounted on the interposition part 150, the groove portion 154 formed in the interposition part 150 when viewed in plan from the upper surface side of the crystal element 120. The shape of the portion that overlaps the crystal piece 121 is a substantially rectangular shape having four sides, and the predetermined two sides of the four sides of the portion that overlaps the crystal piece 121 of the groove portion 154 formed in the interposition portion 150 are It is parallel to the X axis of the interposition part 150. The other two predetermined sides are parallel to the Z ′ axis.

  In this way, in order to apply an alternating voltage to the excitation electrode portion 123 of the crystal element 120, when the alternating voltage is applied to the mounting terminal 151 of the interposition portion 150, the connection is made from the mounting terminal 151 of the interposition portion 150. Thickness-slip vibration in the direction toward the pad 152 (direction parallel to the X axis) can be suppressed, and it is possible to reduce unintended stress and strain on the crystal element 120 due to the displacement of the connection pad 152. It becomes. As a result, it is possible to suppress a decrease in frequency stability caused by unintentional stress or distortion applied to the crystal element 120.

  The length of the two sides parallel to the Z ′ axis is not less than 0.3 times and less than 0.5 times the length of the short side of the crystal piece 121. In this way, the length of the two sides parallel to the Z ′ axis of the portion where the crystal element 120 and the groove portion 154 overlap is set to be 0.3 times or more the length of the short side of the crystal piece 121. Thus, even if the temperature in the atmosphere in which the quartz device is present changes abruptly and stress is applied to the interposition part 150 from the substrate part 110a of the base 110, the intervening part 150 is applied to the portion where the connection pad 152 is provided. The influence of stress can be further suppressed. In addition, by making the ratio less than 0.5 times as described above, it is possible to reduce damage to the interposition part 150 itself when the crystal device is dropped. Therefore, the length of two sides parallel to the Z′-axis of the portion where the crystal element 120 and the groove 154 overlap with each other is set to a length of 0.3 times or more the length of the short side of the crystal piece 121. By doing so, the frequency stability can be further improved.

  Further, in the crystal device according to the present embodiment, two groove portions 154 of the interposition part 150 are formed, and when the crystal element 120 is mounted on the interposition part 150, the crystal device 120 is viewed in plan view from the upper surface side. Thus, the portion of the groove portion 154 formed in the interposition portion 150 that overlaps the crystal piece 121 has the same shape, and the groove portion 154 formed in the interposition portion 150 overlaps the crystal piece 121. The shape of the portion is symmetrical with respect to the center line CL2 parallel to the long side of the crystal piece 121 passing through the center of the surface of the crystal piece 121.

  With such a configuration, when the temperature in the atmosphere in which the crystal device exists rapidly changes, the distance from each mounting terminal 151 to each groove 154 is made the same in plan view of the interposition part 150. Since the distances from the respective groove portions 154 to the connection pads 152 can be made substantially the same, the amount of distortion in the pair of connection pads 152 can be made almost the same. Therefore, distortion generated in the pair of connection portions 124a bonded to the pair of connection pads 152 can be made substantially the same. When different strains are generated in the pair of connection portions 124a, the balance of the vibration displacement of the thickness shear vibration that is the main vibration is lowered, and the frequency may become unstable. The distortion generated in the pair of connection portions 124a bonded to the pair of connection pads 152 can be made substantially the same, and the balance of the vibration displacement of the thickness shear vibration that is the main vibration is suppressed from being lowered. As a result, the frequency stability can be improved.

  The present invention is not limited to the following embodiments, and may be implemented in various aspects.

  A crystal device having a crystal element is not limited to a crystal resonator. For example, a crystal oscillator having an integrated circuit element (IC) that generates an oscillation signal by applying a voltage to the crystal element in addition to the crystal element may be used. Further, for example, crystal ice may be a crystal device having an electronic element such as a thermistor in addition to a crystal element. Further, for example, the crystal device may be provided with a thermostatic bath. In the quartz device, the structure of the substrate on which the quartz element is mounted may be appropriately configured. For example, the base may have an H-shaped cross section having recesses on the upper and lower surfaces.

  The quartz crystal element may be an AT plate or an SC plate.

  Further, the shape of the excitation electrode portion is not limited, and may be, for example, an ellipse or a circle.

110 ... Base 110a ... Substrate part 110b ... Frame part 111 ... Mounting pad 112 ... Mounting terminal 120 ... Crystal element 121 ... Crystal piece 122 ... Metal pattern 123 ... Excitation electrode part 124... Connection wiring part 124 a .. connection part 124 b... Wiring part 130 .. lid body 141 .. mounting member 142 .. connection member 143. Intervening portion 151... Mounting terminal 152 .. connection pad 153 .. conductive portion 154 .. groove portion A 1... First region A 2. Center line

Claims (5)

A crystal piece having a crystal axis composed of an X axis, a Y axis and a Z axis perpendicular to each other
A metal pattern comprising a pair of excitation electrode portions provided on both main surfaces of the crystal piece and a connection wiring portion extending from the excitation electrode portion to an edge portion of the crystal piece;
A connection pad connected to a part of the connection wiring part of the metal pattern is provided on the upper surface, and an interposition part in which a mounting terminal electrically connected to the connection pad is provided on the lower surface,
A base body mainly composed of a substrate part provided on the upper surface with a mounting pad connected to the mounting terminal of the interposition part;
A lid joined to the substrate;
With
The interposition part has a crystal axis composed of an X axis, a Y axis and a Z axis perpendicular to each other;
When the connection pad of the interposition part and a part of the connection wiring part of the metal pattern are opposed to each other,
A quartz crystal device, wherein a Z axis of the crystal piece and a Z axis of the interposition part are parallel to each other. The crystal device according to claim 1, wherein an X axis and a Y axis of the crystal piece are parallel to an X axis and a Y axis of the interposition part. The interposition part is viewed in plan.
The quartz crystal device according to claim 1, wherein a groove is formed between the connection pad and the mounting terminal electrically connected to the connection pad. When the crystal element is mounted on the interposition part,
In plan view from the upper surface side of the crystal element,
Of the groove formed in the interposition part, the shape of the part overlapping the crystal piece is substantially rectangular,
The predetermined two sides of the four sides of the portion of the groove portion formed in the interposition portion that overlaps the crystal piece are parallel to the X axis of the interposition portion. The crystal device described. Two of the groove portions of the interposition portion are formed,
When the crystal element is mounted on the interposition part,
In plan view from the upper surface side of the crystal element,
Of the groove formed in the interposition part, the shape of the part overlapping the crystal piece is the same shape,
Of the groove formed in the interposition part, the shape of the portion overlapping the crystal piece is symmetrical with respect to the center line parallel to the long side of the crystal piece passing through the center of the surface of the crystal piece. A crystal device characterized by