JP2016208192A - Piezoelectric vibration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To meet miniaturization and eliminate an adverse effect such as the occurrence of a mutual short-circuit among an external connection terminal, an external connection terminal for a piezoelectric vibration element and conduction paths therefor.SOLUTION: A crystal oscillator 1 includes: a base 2 having a substrate part 20, a first frame part 21 and a second frame part 22; a crystal vibration element 3 housed in a first recess 2A; an IC 4 housed in a second recess 2B; and a lid 5 which seals the first recess 2B air-tightly. At the four corners of the inner periphery edge of the frame part, an arc-shaped inside notch with a radius R1 is formed. At the four corners of the outer periphery edge of the substrate part and the frame part, an arc-shaped outside notch with a radius R2 is formed. The relationship of the radius R1 of the inside notch with the radius R2 of the outside notch is R1<R2.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a surface mount type piezoelectric vibration device.

  As a piezoelectric vibration device, for example, a surface-mount type crystal resonator or a crystal oscillator is widely used. For example, a surface-mount crystal oscillator has a piezoelectric vibration element made of crystal and an electronic component element such as an integrated circuit element mounted in a recess provided in a base (container) made of an insulating material. Is hermetically sealed. A plurality of external connection terminals are formed on the outer bottom surface of the base, and some of these external connection terminals are electrically connected to the piezoelectric vibration element and the electronic component element. The piezoelectric vibration device is mounted on the external circuit board by being electrically and mechanically bonded to the mounting pad on the external circuit board by a conductive bonding material such as solder at the external connection terminal.

  Among such piezoelectric vibration devices, as disclosed in Patent Document 1, there is a so-called H-type package structure in which a crystal vibration element and an electronic component element are accommodated in separate spaces. More specifically, in the crystal oscillator described in Patent Document 1, a crystal piece (piezoelectric vibration element) is sealed on one side of the cavity (recess) on the front and back of the container, and an IC (electronic component element) is mounted on the other side. It has a structured. The external connection terminals are formed at the four corners of the upper surface (the bottom surface of the crystal oscillator) of the frame portion surrounding the cavity on the side where the IC is mounted.

JP 2009-27469 A

  In the piezoelectric vibration device as described above, the area of the outer bottom surface of the base is relatively smaller than the base of the flat outer bottom surface where the cavity does not exist, due to the restriction of the cavity on the side where the electronic component element is mounted. . For this reason, the position and area of the external connection terminal that can be formed on the upper surface (outer bottom surface) of the frame portion are limited, and the conduction path for drawing out from the electronic component element or the piezoelectric vibration element to the external connection terminal is also the same. Location and area are also limited.

  In particular, some piezoelectric vibration devices include an external connection terminal for a piezoelectric vibration element that is connected only to the piezoelectric vibration element on the side surface of the base in order to measure the electrical characteristics of the piezoelectric vibration element alone. However, these external connection terminals for the piezoelectric vibration element and the conduction path for drawing out to the external connection terminal for the piezoelectric vibration element also have an adverse effect such as a short circuit between the external connection terminal formed on the outer bottom surface of the base. In the present situation, it is becoming more difficult to form the piezoelectric vibration device in a lost state as the piezoelectric vibration device is reduced in size.

  The present invention has been made in view of such a point, and corresponds to downsizing and has an adverse effect such as short-circuiting between the external connection terminal, the piezoelectric vibration element external connection terminal, and these conduction paths. An object of the present invention is to provide a piezoelectric vibration device with higher reliability that has been eliminated.

  In order to achieve the above object, the present invention provides a substantially rectangular substrate portion in plan view in which the upper side is one main surface and the lower side is the other main surface, and the outer peripheral edge extends downward from the outer peripheral portion of the other main surface of the substrate portion. There is a base having a frame portion whose inner peripheral edge is substantially rectangular in plan view and external connection terminals formed at four corners of the upper surface of the frame portion, and is mounted on one main surface of the substrate portion. A piezoelectric vibration device comprising: an electronic component element mounted in a recess surrounded by the frame part and the other main surface of the substrate part; and a lid for hermetically sealing the piezoelectric vibration element. In the four corners of the inner peripheral edge, arc-shaped inner notch portions having a radius R1 extending along the height direction of the inner peripheral wall are formed, and columnar conductive vias filling the inner notch portions are formed. The columnar conductive via is formed with a part of the side surface exposed in the recess. A wiring pattern formed on the inner bottom surface of the recess and connected to the electronic component element is connected to the external connection terminal by a columnar conductive via, and the substrate portion and the frame portion are connected to each outer peripheral edge. Are formed in substantially the same rectangular shape in plan view, and at the four corners of each outer peripheral edge, arc-shaped outer notches having a radius R2 extending along the height direction of each outer peripheral wall are formed. An external connection terminal for a piezoelectric vibration element connected to the piezoelectric vibration element is formed on the upper surface of the notch, and the relationship between the radius R1 and the radius R2 is R1 <R2.

  According to the above invention, the external connection terminal for the piezoelectric vibration element that can measure the characteristics of only the piezoelectric vibration element is formed in the outer notch at the corner of the outer peripheral edge of the base, and the columnar shape that connects the wiring pattern and the external connection terminal Conductive vias are formed in the inner notches at the corners of the inner periphery of the base frame. For this reason, each lead-out path can be separated at the corner of the widest outer peripheral edge and the inner peripheral edge of the base frame, so that the notch can be arranged. There is no reduction in mechanical strength.

  In particular, the size of the radius R1 of the inner notch portion and the radius R2 of the outer notch portion are configured to be large and small, and the radius R2 of the outer notch portion is set to the radius R1 of the inner notch portion. By making it larger, it is possible to configure the inspection probe, the terminal of the measuring jig, and the like so as to easily come into contact with the external connection terminal for the piezoelectric vibration element formed on the upper surface of the outer notch. At this time, columnar conductive vias filled in the inner notches are formed at the four corners of the inner peripheral edge of the frame portion, so that the external connection terminal for the piezoelectric vibration element and the conductive via are not short-circuited. Must be configured. Therefore, by setting the radius R1 of the inner notch portion to be smaller than the radius R2 of the outer notch portion, the distance between the inner notch portion and the outer notch portion can be easily secured. That is, it is possible to prevent a short circuit between the lead-out paths formed in the respective notches (the conductive via and the external connection terminal for the piezoelectric vibration element), and to reliably improve the mutual insulation.

  In addition, by reliably increasing the insulation between the lead-out paths (the conductive via and the external connection terminal for the piezoelectric vibration element), the influence of stray capacitance can be reduced, and the adverse effect of electrical characteristics on the piezoelectric vibration device can also be reduced. In addition, when the base is made of a ceramic material, the risk of short-circuiting between adjacent wiring patterns with different polarities increases due to the downsizing of the base and displacement of the laminated sheet and the position of the wiring pattern. There was concern. In the present invention, it is possible to prevent the short-circuiting of the wiring patterns and terminals having different polarities, and to reliably improve the insulation.

  As described above, the piezoelectric device with higher reliability that prevents the short circuit between the lead-out paths without reducing the size of the piezoelectric vibration device and improves the contact property of the external terminal for the piezoelectric vibration element without reducing the strength of the base. A vibrating device can be provided.

  In the above configuration, the four corners of the inner peripheral edge of the frame portion may be configured such that arcs with a radius R3 are formed, and the relationship between the radius R3 and the radius R2 is R2 <R3.

  In this case, in addition to the above-described effects, the outer cut-off portion is configured so that the size of the radius R2 of the outer notch portion and the radius R3 of the four corners of the inner peripheral edge of the frame portion is established. Since the distance between the notch and the four corners of the inner peripheral wall can be easily secured, it is possible to prevent short circuit between each lead-out path (the conductive via and the external connection terminal for the piezoelectric vibration element) to ensure insulation. Can be increased.

  In particular, by making radius R3 of the four corners of the inner peripheral edge of the frame portion larger than radius R2 of the outer notch portion, positions where arc-shaped inner notch portions are formed at the four corners of the inner peripheral edge of the frame portion. Therefore, it is possible to form a columnar conductive via that fills the inner notch in a more stable state. When the base is made of ceramic material, processing of the ceramic sheet by punching the inner notch at the inner periphery of the frame or shifting the position when filling the inner notch with metallized material There was concern that the risk of disconnection due to slippage would increase. In the present invention, by increasing the radius R3 of the four corners of the inner peripheral edge of the frame portion, a columnar conductive via filled in the inner notch can be formed in a stable state as described above. The risk of disconnection due to processing deviation of the ceramic sheet is reduced, and a more reliable conduction path can be secured.

  Further, in the above configuration, the external connection terminal for the piezoelectric vibration element is not formed in the outer cutout portion of the frame portion, and the external connection terminal for the piezoelectric vibration element is formed only in the outer cutout portion of the substrate portion. It may be.

  In this case, in addition to the above-described effects, an external connection terminal for a piezoelectric vibration element that can measure the characteristics of only the piezoelectric vibration element that is not electrically short-circuited with the external circuit board or the lid can be configured on the outer surface of the base.

  In the above configuration, the base may be made of a ceramic material, and the conductive via may be made of a metallized material of tungsten or molybdenum having a higher Young's modulus than the ceramic material.

  In this case, in addition to the above-described effects, even if the width of the frame portion is reduced due to downsizing, the hardness of the four corners of the frame portion can be increased and the strength of the entire base can be increased. Further, the inclination of the base can be suppressed.

  As described above, the piezoelectric vibration device with higher reliability corresponding to downsizing and eliminating the adverse effects such as short-circuiting between the external connection terminal, the external connection terminal for the piezoelectric vibration element, and their conduction paths. Can be provided.

It is sectional drawing which shows schematic structure of the crystal oscillator which concerns on embodiment of this invention. It is a bottom view which shows schematic structure of the crystal oscillator which concerns on embodiment of this invention. FIG. 3 is a bottom view of a state where the IC of FIG. 2 is not mounted. FIG. 4 is a partially enlarged view of FIG. 3. It is a side view of the P direction of FIG. 1, FIG. It is the perspective view which showed the external view of the conductive via of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments of the present invention described below, as a piezoelectric vibration device, for example, a surface-mount crystal oscillator incorporating an IC having an oscillation circuit will be described as an example.

  An embodiment of the present invention will be described with reference to FIGS. The crystal oscillator 1 is a substantially rectangular parallelepiped package, and is substantially rectangular in a plan view and substantially H-shaped in cross section. The crystal oscillator 1 includes a base 2, a crystal resonator element 3, an IC 4, and a lid 5 as main constituent members. In this embodiment, the external size of the crystal oscillator 1 in plan view is about 1.6 mm × 1.2 mm in length and width, and the crystal oscillator 1 includes an IC 4 having an oscillation circuit as an electronic component element. Note that the external size of the above-described crystal oscillator in plan view is an example, and the present invention can be applied to package sizes other than the external size. Hereinafter, the outline of each member constituting the crystal oscillator 1 will be described in detail.

  The base 2 is a substantially rectangular container in plan view having a long side and a short side made of an insulating material. The base 2 has a flat plate-shaped (substantially rectangular in plan view) substrate portion 20 and extends upward along the outer peripheral portion 200 of one main surface 201 of the substrate portion 20, and an outer peripheral edge 210 and an inner peripheral edge 211 are substantially rectangular in a plan view. The first frame portion 21 and a second frame portion 22 (frame portion) that extends downward along the outer peripheral portion 200 of the other main surface 202 of the substrate portion 20 and has an outer peripheral edge 220 and an inner peripheral edge 221 that are substantially rectangular in plan view. It is a main component (substantially H-shaped cross section).

  In the present embodiment, as a more preferable form, the substrate portion 20, the first frame portion 21, and the second frame portion 22 are each formed with a rectangular shape whose outer peripheral edges are substantially the same in plan view, and are the same only at the four corners of each outer peripheral edge. Arc-shaped outer notches 20c, 21c, and 22c having a radius R2 are formed. That is, arc-shaped outer notches 20c1, 20c2, 20c3, and 20c4 having a radius R2 are formed at the four corners of the outer peripheral edge of the substrate portion 20, and the radius R2 is provided at the four corners of the outer peripheral edge of the first frame portion 21. Arc-shaped outer notches 21c1, 21c2, 21c3, and 21c4 are formed, and arc-shaped outer notches 22c1, 22c2, 22c3, and 22c4 of radius R2 are formed at the four corners of the outer peripheral edge of the second frame portion 22. Has been. The outer cutout portions 20c1, 20c2, 20c3, and 20c4 of the substrate portion 20, the outer cutout portions 21c1, 21c2, 21c3, and 21c4 of the first frame portion 21, and the outer cutout portions 22c1 of the second frame portion 22 are provided. 22c2, 22c3, and 22c4 are overlapped when stacked as will be described later, thereby forming an integrated outer notch portion of the base 2.

  In addition, arc-shaped inner notches 22d having a radius R1 are formed at the four corners of the inner peripheral edge of the second frame portion 22. In other words, at the four corners of the inner peripheral edge of the second frame portion 22, an arcuate inner side with a radius R <b> 1 that extends along the height direction of the inner peripheral wall of the second frame portion 22 (through the second frame portion 22). Notches 22d1, 22d2, 22d3, and 22d4 are formed.

  At this time, the outer cutout portion of the substrate portion 20 in which the radius R1 of the inner cutout portions 22d1, 22d2, 22d3, and 22d4 of the second frame portion 22 and at least crystal vibration element external connection terminals 9a and 9b described later are formed. The relationship of the radius R2 is such that R1 <R2. In this embodiment, since the radius R2 of the outer notch of the substrate part 20, the first frame part 21, and the second frame part 22 is configured to be the same diameter, the outer side of the second frame part 22 in FIG. The comparison is made with the radius R2 of the notch.

  For this reason, even if the widths of the first frame portion 21 and the second frame portion 22 are reduced due to miniaturization, the outer notch portions 20c, 21c, 22c, and the inner notch portions are provided only at the four corners having a margin in width. By forming 22d, the mechanical strength of the entire base is not weakened. In addition, since the sealing area between the first frame portion 21 and the lid 5 is not narrowed more than necessary, the hermetic sealing performance of the crystal resonator element 2 is not deteriorated.

  In this embodiment, each of the substrate part 20, the first frame part 21, and the second frame part 22 is a ceramic green sheet (alumina), and these three sheets are laminated and integrally formed by firing. Yes. Each of these sheets (substrate section sheet, first frame section sheet, second frame section sheet) is divided not only into a single layer but also into a plurality of layers according to the extension form of the internal wiring between the layers. May be formed.

  A sealing portion 6 is formed on the upper surface of the first frame portion 21 of the base 2. The sealing portion 6 is bonded to the metal lid 5 with a bonding material such as a gold-tin brazing material.

  A space surrounded by the inner peripheral edge 211 of the first frame portion 21 of the base 2 and the one principal surface 201 of the substrate portion is a first recess 2A. The first recess 2 </ b> A is substantially rectangular in plan view and has the same shape as the inner peripheral edge 211 of the first frame portion 21. A pair of crystal mounting pads 7a and 7b that are conductively bonded to the crystal resonator element 3 are formed in parallel on one end side of the inner bottom surface (one main surface 201 of the substrate portion 20) of the first recess 2A (see FIG. Only one is shown).

  One end side of the crystal resonator element 3 is conductively bonded and mounted on the crystal mounting pads 7a and 7b via the conductive adhesive 8. The crystal mounting pads 7a and 7b are connected to a pair of first wiring patterns 71a and 71b (piezoelectric vibration element connecting first wiring patterns), respectively, and extend to the central portion of the first recess.

  The pair of first wiring patterns 71 a and 71 b are formed at the end portions of the first wiring patterns 71 a and 71 b and penetrate a pair of columnar conductive vias 10 a and 10 b (perpendicular to the thickness direction of the substrate unit 20). Via the piezoelectric vibration element connecting conductive vias), they are connected to the second wiring patterns 11a and 11b (piezoelectric vibration element connecting wiring patterns) for mounting the IC formed in the second recess 2B described later. For this reason, it is connected at the shortest distance in the thickness direction of the substrate part 20, and the temperature of the IC 4 can be transmitted to the crystal resonator element 3 more accurately in a short time. In addition, since the conductive vias 10a and 10b (conductive vias for connecting piezoelectric vibration elements) do not constitute an intermediate wiring inside the substrate part 20, the heat distribution to the base 2 including the substrate part 20 and the heat between the wiring patterns are prevented. Can be suppressed. As a result, a temperature difference between the IC 4 and the crystal resonator element 3 can be hardly generated.

  As shown in FIG. 6 (a), the piezoelectric vibration element connecting conductive vias 10a and 10b are formed in a columnar shape having a flat surface and a bottom surface with a circular area x1, and a side surface height h1. In addition, the piezoelectric vibration element connecting conductive vias 10a and 10b are exposed only in the planes 10a1 and 10b1 of the piezoelectric vibration element connecting conductive vias in the first recess 2A, and are connected to the piezoelectric vibration elements in the second recess 2B described later. Only the bottom surfaces 10a2 and 10b2 of the conductive vias are exposed.

  In this embodiment, the crystal mounting pads 7a and 7b are connected to the pair of first wiring patterns 72a and 72b, respectively, and extend to the two outer notches 20c1 and 20c2 in the four corners of the outer peripheral edge of the substrate portion 20. Has been issued. Crystal vibration element external connection terminals 9a and 9b (piezoelectric vibration element external connection terminals) are formed on the surface (upper surface) of the outer notches 20c1 and 20c2.

  The crystal resonator element external connection terminals 9a and 9b are connected to the first wiring patterns 72a and 72b, respectively, so that they are connected only to the excitation electrode of the crystal resonator element, and the electrical characteristics of only the crystal resonator element are measured. It can be done. In this embodiment, as a more preferable embodiment, the outer cutout portions 21c1 and 21c2 of the first frame portion and the outer cutout portions 22c1 and 22c2 of the second frame portion which are adjacent to the external connection terminals 9a and 9b for the crystal resonator element are provided. Does not form external connection terminals (electrodes), but forms external connection terminals (electrodes) only in the notches 20c1 and 20c2 of the substrate portion. For this reason, the external connection terminal for the crystal resonator element that can measure only the characteristics of the crystal resonator element 3 that does not electrically interfere (short-circuit) with the external circuit board or the lid 5 can be formed on the outer surface of the base 2. In addition, by providing an external connection terminal for a crystal resonator element at the outer notch of the base plate portion located at the center of the side surface of the base at the corner of the base, it is possible to easily contact the terminals of the inspection probe and measurement jig. .

  External connection terminals 9c, 9d, 9e, and 9f are formed at the four corners of the upper surface of the second frame portion 22 of the base 2 (the bottom surface of the base 2) and are joined to mounting pads of an external circuit board (not shown) by solder. Yes. As a more preferable form in this embodiment, these four corner external connection terminals 9 c, 9 d, 9 e, 9 f are formed in a substantially L shape, and the substantially L shape is the four corners of the inner peripheral edge of the second frame portion 22. Has a curved portion and extends along each side of the inner peripheral edge of the second frame portion 22. Since the number of external connection terminals is formed according to the function of the oscillator, four or more configurations may be employed according to the additional function of the oscillator.

  In addition, the columnar conductive vias 10c, so that the inner notches 22d1, 22d2, 22d3, and 22d4 at the four inner peripheral edges of the second frame portion 22 are filled with the inner notches 22d1, 22d2, 22d3, and 22d4, respectively. 10d, 10e, and 10f (external connection terminal connection conductive vias) are embedded. That is, the thickness direction of the second frame portion 22 is connected by columnar conductive vias 10c, 10d, 10e, and 10f (conductive vias for connecting external connection terminals) penetrating perpendicularly to the thickness direction of the second frame portion 22. Can be connected at the shortest distance. In addition, since the conductive vias 10c, 10d, 10e, and 10f (conducting vias for connecting external connection terminals) do not constitute an intermediate wiring inside the second frame portion 22, heat from the base 2 including the second frame portion 22 can be transmitted. Dispersion and heat distribution among the wiring patterns can be suppressed.

  As shown in FIG. 6B, the conductive vias 10c, 10d, 10e, and 10f for connecting the external connection terminals have a radius R1 having the same diameter as that of the inner notch in the plan view shape (plane and bottom surface) of each conductive via. And a small arc 102 having a radius R3 of the same diameter as four corners of an inner peripheral edge 221 of the second frame portion 22 to be described later are formed, and the plane and the bottom surface have an area x2. At the same time, it has a columnar shape with a side surface height of h2. Further, the columnar external connection terminal connecting conductive vias 10c, 10d, 10e, and 10f are formed on the bottom arcs 10c2, 10d2, 10e2, and 10f2 of the external connection terminal connecting conductive vias in the second recess 2B described later. The side surfaces 10c3, 10d3, 10e3, and 10f3 that are in contact with each other are exposed. That is, as shown in FIGS. 3 and 4, the side surfaces of the small arcs 102 of the conductive vias 10 c, 10 d, 10 e, and 10 f are arranged at the four corners of the inner peripheral wall of the second frame portion 22. The plan view shape of the inner peripheral wall 221 of the two-frame portion 22 is the arc portions 22e1, 22e2, 22e3, and 22e4 with radius R3 at four corners (partly overlapped with the side surfaces 10c3, 10d3, 10e3, and 10f3 of the external connection terminal connecting conductive vias). ).

  At this time, the planar view shape of the inner peripheral wall 221 of the second frame portion 22 is a substrate in which arc portions 22e1, 22e2, 22e3, 22e4 having a radius R3 are formed at four corners, and at least crystal resonator element external connection terminals 9a, 9b are formed. The relationship of the radius R2 of the outer notch part of the part 20 is comprised so that it may become R2 <R3. In this embodiment, since the radius R2 of the outer notch of the substrate part 20, the first frame part 21, and the second frame part 22 is configured to be the same diameter, the outer side of the second frame part 22 in FIG. The comparison is made with the radius R2 of the notch.

  In this embodiment, the piezoelectric vibration element connecting conductive vias 10a and 10b are configured such that only the bottom surfaces 10a2 and 10b2 of the piezoelectric vibration element connecting conductive vias are exposed in a second recess 2B to be described later. 10c, 10d, 10e, and 10f are exposed at the bottom surface 10c2, 10d2, 10e2, and 10f2 of the external connection terminal connecting conductive vias and the side surfaces 10c3, 10d3, 10e3, and 10f3 that are in contact with the small arc 102 in the second recess 2B described later. It is configured to do. For this reason, it is possible to improve the heat dissipation of unnecessary heat transmitted from the external environment to the IC 4 via the external connection terminals 9c, 9d, 9e, and 9f without unnecessarily dissipating the heat transmitted from the IC 4 to the crystal resonator element 3. As a result, the heat transfer between the IC 4 and the crystal resonator element 3 can be improved, so that the temperature difference between the IC 4 and the crystal resonator element 3 can be made even more difficult.

  Each columnar conductive via is inscribed in the curved portions (four corners of the inner peripheral edge of the second frame portion 22) inside the four corners of the substantially L-shaped external connection terminals 9c, 9d, 9e, 9f. 10c, 10d, 10e, and 10f are formed and connected to each other. As a more preferable form in this embodiment, as shown in FIG. 3, each of the four corners inscribed in this portion and the curved portions inside the substantially corner-shaped external connection terminals 9c, 9d, 9e, 9f at the four corners. Intersections of line segments connecting the columnar conductive vias 10c, 10d, 10e, 10f, that is, the first line segment Q connecting the central part of the conductive via 10c and the central part of the conductive via 10e at the diagonal position, and the conductive via The external connection terminals and the conductive vias are arranged so that the intersection of the central portion of 10d and the second line segment R connecting the central portion of the conductive via 10f at the diagonal position coincides with the center of gravity O of the base. Are formed with respect to the base 2.

  A space surrounded by the inner peripheral edge 221 of the second frame portion 22 of the base 2 and the other main surface 202 of the substrate portion is a second recess 2B (recess). The second recess 2B has a substantially rectangular shape in plan view having arc-shaped side surfaces with a radius R3 at four corners, and an inner peripheral edge 221 of the second frame portion 22 having arc-shaped portions 22e1, 22e2, 22e3, 22e4 with radius R3 at the four corners. It becomes the same planar view substantially rectangular shape. The second recess 2B has a smaller size in plan view than the first recess 2A, and the second recess 2B is in a positional relationship enclosed in the first recess 2A in plan view transmission.

  IC mounting second wiring patterns 11a, 11b, 11c, 11d, 11e, and 11f (wiring) are mounted on the inner bottom surface (the lower surface of the substrate portion 20) of the second recess 2B and mounted with a rectangular IC4 in plan view. Pattern) is formed. That is, as shown in FIGS. 2 and 3, the second wiring patterns 11c, 11a, and 11f are formed from the left side along the upper long side toward the inner bottom surface of the second recess 2B. Second wiring patterns 11d, 11b, and 11e are formed from the left side along the lower long side toward the bottom surface. Since the number of the second wiring patterns is formed according to the electrode pad of the IC 4, the number of the second wiring patterns may be six or more according to the additional function of the IC 4.

  In this embodiment, the second wiring patterns 11a, 11b, 11c, 11d, 11e, and 11f (wiring patterns) for mounting the IC are the first wiring patterns 71a and 71b formed in the conductive vias 10a and 10b and the first recess 2A. The piezoelectric vibration element connection second wiring patterns 11a and 11b (piezoelectric vibration element connection wiring patterns) connected to the crystal vibration element 3 and the external connection connected to the external connection terminals 9c, 9d, 9e, and 9f. Terminal connection second wiring patterns 11c, 11d, 11e, and 11f (external connection terminal connection wiring patterns) are formed. The area of each of the second wiring patterns 11a, 11b for connecting the piezoelectric vibration elements is made smaller than the area of each of the second wiring patterns 11c, 11d, 11e, 11f for connecting the external connection terminals. Yes. For example, in this embodiment, as shown in FIG. 3, the piezoelectric vibration element connecting second wiring pattern 11 a and the piezoelectric vibration element connecting second wiring pattern 11 b are substantially the same on the upper surface of the other main surface 202 of the substrate unit 20. The external connection terminal connection second wiring pattern 11c, the external connection terminal connection second wiring pattern 11d, the external connection terminal connection second wiring pattern 11e, and the external connection terminal connection second wiring pattern 11f. Are configured with substantially the same area, and the area of each of the second wiring patterns 11a, 11b for connecting a piezoelectric vibration element is the same as the area of each of the second wiring patterns 11c, 11d, 11e, 11f for connecting each external connection terminal. About 70 to 90%.

  As described above, the area of each piezoelectric vibration element connecting second wiring pattern 11a, 11b is smaller than the area of each external connecting terminal connecting second wiring pattern 11c, 11d, 11e, 11f. It is configured. For this reason, without dissipating heat from the IC 4, it is transmitted to the conductive vias 10 a and 10 b (piezoelectric vibration element connecting conductive vias), and the first wiring pattern 71 a is transmitted from the conductive vias 10 a and 10 b (piezoelectric vibration element connecting conductive vias). , 71b (piezoelectric vibration element connecting first wiring pattern) can be quickly transmitted to the crystal vibration element 3. As a result, a temperature difference between the IC 4 and the crystal resonator element 3 can be hardly generated. In addition, adverse effects due to stray capacitance on the crystal resonator element 3 can be reduced more effectively.

  The area of each of the external connection terminal connection second wiring patterns 11c, 11d, 11e, and 11f is configured to be larger than the area of each of the piezoelectric vibration element connection second wiring patterns 11a and 11b. For this reason, part of the heat generated in the IC 4 is dissipated to the external connection terminal connecting second wiring patterns 11c, 11d, 11e, and 11f, and only the temperature of the IC 4 is unilaterally increased with respect to the crystal resonator element 3. Can be suppressed. Moreover, since the junction area | region with IC4 can be ensured by the 2nd wiring pattern 11c, 11d, 11e, 11f for external connection terminal connection, the reliability of connection with IC4 and a wiring pattern can be improved. The reliability of the connection between the IC 4 and the wiring pattern can be improved.

  The second wiring patterns 11c, 11d, 11e, and 11f (wiring patterns for connecting external connection terminals) are formed at the four corners of the inner bottom surface of the second recess 2B where the above-described columnar conductive vias 10c, 10d, 10e, and 10f are present. Is extended in the direction.

  The second wiring patterns 11c, 11d, 11e, and 11f are electrically connected to the external connection terminals 9c, 9d, 9e, and 9f via the columnar conductive vias 10c, 10d, 10e, and 10f, respectively. ing. In this embodiment, as a more preferable embodiment, as shown in FIG. 4, a dimension W1 along the inner peripheral edge 221 of the second frame portion 22 among the side surfaces of the conductive vias 10c, 10d, 10e, 10f (small arc on the bottom surface of the conductive via). 102) of the second wiring patterns 11c, 11d, 11e, and 11f in contact with the side surfaces of the conductive vias, the dimension W2 along the inner peripheral edge 221 of the second frame portion 22 (each second wiring). The pattern and the length of the portion in contact with the inner peripheral edge of the second frame portion) are formed larger. Therefore, it is possible to weaken the flow of solder from the conductive vias 10c, 10d, 10e, and 10f to the second wiring patterns 11c, 11d, 11e, and 11f, so that there is no need for bonding the IC 4 to the external circuit board. Inflow of solder can be prevented.

  In addition, on the second wiring patterns 11a, 11b, 11c, 11d, 11e, and 11f (wiring patterns) for mounting the IC, the electrode pads of the IC 4 are conductively bonded via the metal bumps 12 made of gold or the like. For this reason, it is possible to further reduce the temperature difference between the IC 4 and the crystal resonator element 3 by increasing the heat transfer between the IC 4 and the crystal resonator element 3.

  In this embodiment, as a more preferable embodiment, the sealing portion 6, the crystal mounting pads 7a and 7b, the first wiring patterns 71a, 71b, 72a and 72b, the second wiring patterns 11a, 11b, 11c, 11d, 11e and 11f, the conductive For vias 10a, 10b, 10c, 10d, 10e, and 10f and external connection terminals 9a, 9b, 9c, 9d, 9e, and 9f, tungsten (Young's modulus is higher than Young's modulus) than ceramic materials (Young's modulus is about 300 GPa). About 411 GPa) or molybdenum (Young's modulus is about 329 GPa). On these outer surfaces, a plating layer is laminated in the order of a nickel plating layer and a gold plating layer. The nickel plating layer and the gold plating layer are formed by electrolytic plating, and these are formed simultaneously. For this reason, even if the width of the second frame portion 22 is reduced due to the reduction in size, the hardness of the four corners of the second frame portion 22 due to the presence of the columnar conductive vias 10c, 10d, 10e, and 10f at the four corners. The strength of the base as a whole can be increased.

  The base 2 used in the embodiment of the present invention has a package structure with a substantially H-shaped cross section as described above. According to such an H-type package structure, since the crystal resonator element 3 and the IC 4 are accommodated in different spaces, it is less susceptible to the influence of gas generated during the manufacturing process and noise generated from other elements. There is an advantage that you can.

  In FIG. 1, a crystal resonator element 3 is a piezoelectric resonator element having a rectangular shape in plan view, in which various electrodes are formed on the front and back main surfaces of an AT-cut crystal resonator plate. In FIG. 1, illustration of various electrodes is omitted. Although not shown in FIG. 1, a pair of excitation electrodes are formed at a substantially central portion of the crystal diaphragm so that the excitation electrodes face each other. An extraction electrode is extended from each of the pair of excitation electrodes toward one short side edge of the front and back main surfaces of the crystal diaphragm. The terminal portion of the lead electrode is an adhesive electrode, and is joined to the above-described crystal mounting pads 7a and 7b via the conductive adhesive 8. In this embodiment, a silicone-based adhesive is used for the conductive adhesive 8, but a conductive adhesive other than a silicone-based adhesive may be used, or another conductive bonding material such as a metal bump may be used. Good.

  The IC 4 used in the present embodiment is a one-chip integrated circuit element incorporating an inverter amplifier (oscillation amplifier) such as a CMOS, and is an oscillation that is connected to the crystal resonator element 3 and amplifies the frequency signal of the crystal resonator element 3. In order to perform temperature compensation so that the frequency fluctuation becomes smaller than the frequency temperature characteristics of the crystal resonator element based on the temperature information of the circuit unit, the temperature detector that detects the temperature change with the ambient temperature, and the temperature information of the temperature detector And a region constituting the temperature compensation circuit portion. In this embodiment, a so-called TCXO IC having a temperature compensation function or the like is used, but a so-called SPXO IC having only an oscillation circuit or a so-called VCXO IC having a frequency adjustment circuit as an additional function. It may be an IC. Furthermore, it is a so-called VCTCXO IC that has a frequency adjustment circuit added to the TCXO IC as an additional function, an OCTCXO IC that has a heater function added to the TCXO IC, and other additional functions. It may be an integrated IC or an IC in which these are combined. Further, the IC 4 may be bipolar other than CMOS, bi-CMOS, or the like.

  In FIG. 1, the lid 5 is a flat plate having a substantially rectangular shape in plan view. The cover 5 is made of Kovar as a base material, and the surface of the base material is plated with nickel plating and gold-tin brazing material. The above is the outline of each component.

  In each of the above components, the crystal resonator element 3 is electrically and mechanically connected to the upper portions of the crystal mounting pads 7a and 7b formed on the inner bottom surface of the first recess 2A of the base 2 via the conductive adhesive 8. Mounted. Then, the quartz resonator element is stored in the first recess 2A after the frequency of the crystal diaphragm is adjusted to a desired value while bringing the inspection probe into contact with the crystal resonator element external connection terminals 9a and 9b of the base 2. In this state, the base sealing portion 6 is covered with a metal lid 5, and the sealing material of the metal lid 4 and the base joint portion 6 are melt-cured to perform hermetic sealing. Then, the second wiring patterns 11a, 11b, 11c, 11d, 11e, and 11f formed on the inner bottom surface of the second concave portion 2B of the base 2 are electrically and mechanically connected to the IC 4 via the metal bumps 12, and the IC 4 Is mounted on the inner bottom surface of the second recess 2B. Then, necessary adjustments are made and the surface-mounted crystal oscillator 1 is completed.

  The surface-mounted crystal oscillator 1 configured as described above is mounted on a mounting pad of an external circuit board (not shown) and is electrically and mechanically connected by solder. At this time, between the substantially L-shaped external connection terminals 9c, 9d, 9e, and 9f at the four corners of the bottom surface of the surface-mount type crystal oscillator 1 and a mounting pad of an external circuit board (not shown), a paste-like solder is provided. It is mounted in a state of being interposed. In this state, it is carried into a heating and melting furnace, and the solder is heated and melted to heat and melt the external circuit board mounting pad (not shown) and the substantially L-shaped external connection terminals 9c at the four corners of the bottom surface of the surface-mounted crystal oscillator 1. 9d, 9e, 9f and the columnar conductive vias 10c, 10d, 10e, 10f are joined.

  According to the surface-mounted crystal oscillator 1 according to the embodiment of the present invention, the crystal resonator element external connection terminals 9a and 9b are formed in the outer notches 20c1 and 20c2 at the corners of the outer peripheral edge of the substrate portion 20, and the external connection terminals The conductive vias 10c and 10d for connection are formed in the inner notches 22d1 and 22d2 at the corners of the inner peripheral wall 221 of the second frame portion 22. For this reason, the inner and outer cutouts can be arranged by separating each lead-out path at the position of the widest outer peripheral edge and the inner peripheral edge of the second frame 22, so that the second frame The mechanical strength of the entire base 2 including the portion 22 is not reduced.

In particular, the size of the radius R1 of the inner notches 22d1 and 22d2 and the radius R2 of the outer notches 20c1, 20c2, 21c1, 21c2, 22c1, and 22c2 is configured to be large and small, and the outer notches 20c1. , 20c2, 21c1, 21c2, 22c1, 22c2 have a radius R2 larger than the radius R1 of the inner notches 22d1, 22d2. For this reason, the inspection probe, the terminal of the measuring jig, and the like can be configured to easily come into contact with the crystal resonator element external connection terminals 9a and 9b formed on the upper surfaces of the outer notches 20c1 and 20c2.
Further, the radius R1 of the inner notches 22d1, 22d2 is made smaller than the radius R2 of the outer notches 20c1, 20c2, 21c1, 21c2, 22c1, 22c2. For this reason, it is possible to design the inner notch portions 22d1, 22d2 and the outer notch portions 20c1, 20c2, 21c1, 21c2, 22c1, 22c2 so as to ensure a mutual distance. That is, short-circuiting between the lead-out paths including the external connection terminal connection conductive vias 10c and 10d and the crystal vibration element external connection terminals 9a and 9b formed in each notch is prevented, and the insulation is reliably improved. be able to.

  Further, the radius R2 of the outer notches 20c1, 20c2, 20c3, 20c4, 21c1, 21c2, 21c3, 21c4, 22c1, 22c2, 22c3, 22c4 and the arcs 22e1 at the four corners of the inner peripheral wall 221 of the second frame 22 are shown. , 22e2, 22e3, and 22e4 are configured so as to have a magnitude relationship with the radius R3, and the radius R3 of the arcs 22e1, 22e2, 22e3, and 22e4 at the four corners of the inner peripheral wall 221 of the second frame portion 22 is set to the outside. The notches 20c1, 20c2, 20c3, 20c4, 21c1, 21c2, 21c3, 21c4, 22c1, 22c2, 22c3, and 22c4 are made larger than the radius R2. For this reason, the outer notches 20c1, 20c2, 20c3, 20c4, 21c1, 21c2, 21c3, 21c4, 22c1, 22c2, 22c3, 22c4 and the arcs 22e1, 22e2, at the four corners of the inner peripheral wall 221 of the second frame portion 22 are provided. It can be designed to ensure the mutual distance between 22e3 and 22e4. It is possible to prevent a short circuit between the lead-out paths including the respective external connection terminal connection conductive vias 10c and 10d and the crystal vibration element external connection terminals 9a and 9b, and to reliably improve insulation. It becomes easier to secure positions where arc-shaped inner notches 22d1, 22d2, 22d3, and 22d4 are formed at the four corners of the inner peripheral wall 221 of the second frame portion 22, and the inner notches are filled in a more stable state. Columnar conductive vias 10c, 10d, 10e, and 10f can be formed.

  In addition, even when the surface mount type crystal oscillator 1 is reduced in size and the area of the external connection terminals 9c, 9d, 9e, and 9f is restricted, the conductive vias 10c, 10d, 10e, and 10f are bonded to the external circuit board. The solder application area can be enlarged. Therefore, not only a planar solder joint by the external connection terminals 9c, 9d, 9e, 9f but also a three-dimensional solder joint by forming a solder fillet along the conductive vias 10c, 10d, 10e, 10f. Is obtained.

  Moreover, since this solder fillet is formed along the conductive vias 10c, 10d, 10e, and 10f at the four corners, the solder fillet acts in a balanced manner in the direction of the center of gravity O of the surface-mounted crystal oscillator 1. The anchor action by the solder fillet formed by the conductive vias 10c, 10d, 10e, and 10f can be further enhanced. As a result, it is possible to increase the solder joint strength with the external circuit board while adapting to the miniaturization of the surface-mounted crystal oscillator 1.

  Even if the amount of paste-like solder applied to the external connection terminals 9c, 9d, 9e, and 9f at the four corners varies, the conductive vias 10c, 10d, and 10e are connected to the external connection terminals 9c, 9d, 9e, and 9f. , 10f, the solder coating can be adjusted, so that the amount of solder applied to the external connection terminals 9c, 9d, 9e, 9f at the four corners is made uniform, and the surface mount crystal oscillator 1 is mounted on the external circuit board. Thus, when the solder is melted and bonded, it is possible to suppress the surface-mounted crystal oscillator 1 from being mounted tilted from the external circuit board or rotated.

  In particular, even if the area of the external connection terminals 9c, 9d, 9e, and 9f is restricted due to the miniaturization of the surface-mounted crystal oscillator 1, the area of the external connection terminals is ensured by making it substantially L-shaped. It is possible to prevent the strength of the joint with the external circuit board from being lowered, and it is possible to cause the tension by the solder joint to be generated in a well-balanced state in the state along each side of the second frame portion 22. . Further, the solder flow from the external connection terminals 9c, 9d, 9e, 9f to the conductive vias 10c, 10d, 10e, 10f is promoted.

  In addition, the solder fillet is symmetrical with respect to the center line AA that passes through the center of gravity O of the base and is parallel to the long side of the second frame and the center line BB that is parallel to the short side of the second frame. Since the four corner anchor portions are configured, the surface mounting type crystal oscillator 1 can be made to act so that the tension due to the solder joint is uniformly generated toward the center of gravity O of the surface mount type crystal oscillator 1. As a result, the solder joint strength with the external circuit board can be further increased, and the surface-mounted crystal oscillator 1 can be further restrained from being tilted and rotated from the external circuit board. it can.

  In the above-described embodiment of the present invention, a crystal oscillator (piezoelectric oscillator) using an IC as an electronic component element is taken as an example. However, a function using a temperature sensitive element such as a thermistor or a diode or other functional electronic component element. The present invention is also applicable to a crystal resonator (piezoelectric resonator) with parts. In the embodiment of the present invention, a base having a substantially H-shaped cross section in which frame portions are formed on both the main surface side (upper side) and the other main surface side (lower side) of the substrate portion is described as an example. A base having a frame portion formed only on the other main surface side (lower side) and a cap-shaped lid having a concave portion on the lower side was used without forming a frame portion on one main surface side (upper side) of the substrate portion. It is good also as a structure.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted 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.

  It can be applied to mass production of piezoelectric vibration devices.

1 Crystal oscillator (piezoelectric oscillator)
2 Base 2A 1st recessed part 2B 2nd recessed part 20 Substrate part 20c, 20c1, 20c2, 20c3, 20c4 Outer notch part 200 Outer peripheral part 201 One main surface 202 Other main surface 21 First frame part 21c, 21c1, 21c2, 21c3 21c4 outer notch 210 outer periphery 211 inner periphery 22 second frame 22c, 22c1, 22c2, 22c3, 22c4 outer notch 22d, 22d1, 22d2, 22d3, 22d4 inner notch 22e1, 22e2, 22e3, 22e4 Arc part 220 Outer part 221 Inner part 3 Crystal oscillator (piezoelectric oscillator)
4 IC
5 Lid 6 Sealing part 7a, 7b Crystal mounting pad 71a, 71b, 72a, 72b First wiring pattern 8 Conductive adhesive 9a, 9b External connection terminal for crystal vibration element (external connection terminal for piezoelectric vibration element)
9c, 9d, 9e, 9f External connection terminal 10a, 10b, 10c, 10d, 10e, 10f Conductive via 10a1, 10b1 Plane of conductive via 10a2, 10b2, 10c2, 10d2, 10e2, 10f2 Bottom of conductive via 10c3, 10d3, 10e3 , 10f3 Side surface of conductive via 101 Large arc in plan view shape of conductive via 102 Small arc in plan view shape of conductive via 11a, 11b, 11c, 11d, 11e, 11f Second wiring pattern for mounting IC 12 Metal bump

Claims (4)

A substantially rectangular substrate portion in plan view in which the upper side is one main surface and the lower side is the other main surface;
A frame portion that extends downward from the outer peripheral portion of the other main surface of the substrate portion and has an outer peripheral edge and an inner peripheral edge that are substantially rectangular in plan view;
There is a base provided with external connection terminals formed at the four corners of the upper surface of the frame portion,
A piezoelectric vibration element mounted on one main surface of the substrate portion;
An electronic component element mounted in a recess surrounded by the frame portion and the other main surface of the substrate portion;
A lid for hermetically sealing the piezoelectric vibration element;
In the piezoelectric vibration device comprising:
At the four corners of the inner peripheral edge of the frame portion, arc-shaped inner notches having a radius R1 extending along the height direction of the inner peripheral wall are formed, and columnar conductive portions filled in the inner notches are formed. A via is formed, and a side surface of a part of the columnar conductive via is exposed in the recess,
A wiring pattern formed on the inner bottom surface of the recess and connected to the electronic component element is connected to the external connection terminal by the columnar conductive via,
Each of the substrate portion and the frame portion is formed in a rectangular shape whose outer peripheral edges are substantially the same in plan view, and at the four corners of each outer peripheral edge is a radius R2 extending along the height direction of each outer peripheral wall. An arc-shaped outer notch is formed, and an external connection terminal for a piezoelectric vibration element connected to the piezoelectric vibration element is formed on the upper surface of the outer notch,
The relationship between the radius R1 and the radius R2 is
A piezoelectric vibration device, wherein R1 <R2. The piezoelectric vibration device according to claim 1,
Four corners of the inner peripheral edge of the frame portion are formed with arcs having a radius R3,
The relationship between the radius R3 and the radius R2 is
A piezoelectric vibration device, wherein R2 <R3. The piezoelectric vibration device according to claim 1 or 2, wherein
The external connection terminal for the piezoelectric vibration element is not formed in the outer cutout portion of the frame portion, and the external connection terminal for the piezoelectric vibration element is formed only in the outer cutout portion of the substrate portion. Piezoelectric vibration device. The piezoelectric vibration device according to any one of claims 1 to 3,
The piezoelectric vibration device according to claim 1, wherein the base is made of a ceramic material, and the conductive via is made of a metallized material of tungsten or molybdenum having a higher Young's modulus than the ceramic material.

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