JP2016178629A5 - - Google Patents

Description

Piezoelectric vibration device

  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 enclosed on one side of a cavity (concave part) on the front and back of a container, and an IC chip (electronic component element) is provided on the other side. It has an implemented structure. 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 chip 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 (IC chip) is mounted. Become smaller. For this reason, since the position and area of the external connection terminals that can be formed on the upper surface (outer bottom surface) of the frame portion are also limited, a junction region between the external connection terminals and the external circuit board while preventing a short circuit between the external connection terminals. It is becoming more difficult to secure these at the same time.

  In addition, in the piezoelectric vibration device as described above, it is difficult to secure the bonding area of the external connection terminal as well as downsizing as described above, so the amount of solder applied for bonding to the external circuit board is different between the external connection terminals. If it varies, the influence will increase. In other words, due to variations in the amount of solder applied, when a piezoelectric vibration device is mounted on an external circuit board and solder is melted and joined, the piezoelectric vibration device is mounted tilted from the external circuit board or rotated and mounted. The risk of being increased.

  The present invention has been made in view of such a point, and corresponds to downsizing, and in a piezoelectric vibration device, a piezoelectric device having improved mounting stability on an external circuit board while securing a bonding region with the external circuit board. The object is to provide a vibrating device.

  In order to achieve the above object, the present invention is directed to a substrate portion whose upper side is one main surface and whose lower side is the other main surface, and which extends downward from the outer peripheral portion of the other main surface of the substrate portion and has a flat outer peripheral edge and inner peripheral edge A base provided with a substantially rectangular frame portion, external connection terminals formed at four corners of the upper surface of the frame portion, a piezoelectric vibration element mounted on one main surface of the substrate portion, and the frame portion In a piezoelectric vibration device including an electronic component element mounted in a concave portion surrounded by the other main surface of the substrate portion and a lid for hermetically sealing the piezoelectric vibration element, the four corners of the inner peripheral edge of the frame portion are provided. Is formed such that a columnar conductive via extending along the height direction of the inner peripheral wall is embedded, and a part of the side surface of the columnar conductive via is exposed to the recess, and the inner bottom surface of the recess A wiring pattern extending to the four corners is formed on each of the external connection terminals and the wirings. The pattern, consisting the are connected by respective conductive vias.

  According to the above invention, the external connection terminals at the four corners of the frame portion are formed with the columnar conductive vias formed at the four corners of the inner peripheral edge of the frame portion. Even if the area of the external connection terminal formed on the upper surface of the frame portion is restricted, the solder application area bonded to the external circuit board can be expanded to the conductive via. For this reason, not only the planar solder joint part by an external connection terminal but the three-dimensional solder joint part by a solder fillet forming along a conductive via is obtained.

  In addition, since this solder fillet is formed at four locations along the columnar conductive vias formed at the four corners of the inner peripheral edge of the frame portion, tension is generated by solder bonding in a balanced manner in the center direction of the piezoelectric vibration device. The anchor action by the solder fillet formed by the conductive via can be further enhanced.

  As a result, the solder joint strength with the external circuit board can be increased by the anchor portions made of the solder fillets at the four corners of the inner peripheral edge of the frame portion, while corresponding to the miniaturization of the piezoelectric vibration device.

  In addition, even if the amount of solder applied to the external connection terminals at the four corners varies, the application of solder can be adjusted from the external connection terminals to the conductive vias, so the solder at the external connection terminals at the four corners can be adjusted. When the coating amount is made uniform and the piezoelectric vibration device is mounted on the external circuit board and the solder is melted and joined, the piezoelectric vibration device may be mounted tilted or rotated from the external circuit board. Can be suppressed.

  In the above configuration, an intersection of line segments connecting the conductive vias may be located near the center of gravity of the base.

  In this case, in addition to the above-described effects, the four corner anchor portions made of solder fillets are formed symmetrically with respect to the center line passing through the center of gravity of the base and parallel to each side of the frame portion. It can be made to act so that the tension | tensile_strength by solder joining arises uniformly toward the gravity center point of a vibration device.

  As a result, the solder joint strength with the external circuit board can be further increased, and the piezoelectric vibration device can be further restrained from being inclined and mounted with rotation.

  In the above configuration, the external connection terminal is formed in a substantially L shape, and the substantially L shape has curved portions at four corners of the inner peripheral edge of the frame portion. The conductive via may extend along a side and be in contact with the curved portion.

  In this case, in addition to the above-described effects, the external connection terminals at the four corners have curved portions at the four corners of the inner peripheral edge of the frame portion, and are approximately L along the direction of each side with the inner peripheral edge of the frame portion. Since it is formed in a letter shape, the area of the external connection terminal can be secured even if the area of the external connection terminal formed on the upper surface of the frame portion is restricted due to the miniaturization of the piezoelectric vibration device, It is possible to suppress a decrease in bonding strength with the external circuit board.

  In addition, since the columnar conductive vias at the four corners are formed in contact with the curved portions of the substantially L-shaped external connection terminals, solder bonding is performed in a well-balanced state along each side direction of the frame portion. It can be made to act so that the tension by. Moreover, it becomes easy to promote the flow of solder from the external connection terminal to the conductive via, and the function of adjusting the solder application state and the function of forming the anchor portion can be enhanced.

  As a result, the solder joint strength with the external circuit board can be further increased, and the piezoelectric vibration device can be further restrained from being tilted and mounted from the external circuit board.

  In the above configuration, the dimension along the inner peripheral edge of the frame portion of the wiring pattern in contact with the conductive via may be larger than the dimension along the inner peripheral edge of the frame portion of the conductive via.

  In this case, in addition to the above-described effects, the amount of solder flowing out from the external circuit board is limited by the relatively narrow conductive via, and the relatively wide wiring pattern causes the solder to flow to the tip of the wiring pattern. As a result, it is possible to prevent the flow of unnecessary solder for joining the external circuit board to the electronic component elements connected at the leading end of the wiring pattern.

  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, columnar conductive vias made of a metallized material of tungsten or molybdenum having a higher Young's modulus than the ceramic material are embedded in the four corners of the inner peripheral edge of the frame portion. 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.

  Further, in the above configuration, 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 arc-shaped notches are formed at four corners of each outer peripheral edge, The external connection terminal may be formed only in the notch portion of the substrate portion and connected to the piezoelectric vibration element only in the notch portion of the substrate portion without forming the external connection terminal in the notch portion of the frame portion.

  In this case, in addition to the above-described effects, even if the width of the frame portion is reduced due to the reduction in size, the notch portions are formed only at the four corners having a margin in width, thereby increasing the strength of the entire base. There is no weakening. In addition, an external connection terminal for a piezoelectric vibration element that can measure only the characteristics of the piezoelectric vibration element that does not electrically interfere with the external circuit board or the lid can be formed on the outer surface of the base. In addition, by providing at the corners of the side surfaces, it is easy to contact the terminals of the inspection probe and the measuring jig.

  As described above, it is possible to provide a piezoelectric vibration device that is compatible with downsizing and has improved mounting stability on an external circuit board while securing a bonding region with the external circuit board.

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 a bottom view which shows schematic structure of the crystal resonator which concerns on other embodiment 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. Main components are the first frame portion 21 and the second frame portion 22 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. (The cross section is substantially H-shaped).

  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 in a rectangular shape whose outer peripheral edges are substantially the same in plan view, and circles only at the four corners of each outer peripheral edge. Arc-shaped notches 20c, 21c, and 22c are formed. That is, the notches 20c1, 20c2, 20c3, and 20c4 are provided at the four corners of the outer peripheral edge of the substrate portion 20, and the notches 21c1, 21c2, 21c3, and 21c4 are provided at the four corners of the outer peripheral edge of the first frame portion 21. Cutout portions 22c1, 22c2, 22c3, and 22c4 are formed at the four corners of the outer peripheral edge of the frame portion 22. For this reason, even if the width of the first frame portion 21 and the second frame portion 22 is reduced due to miniaturization, by forming the notches 20c, 21c, and 22c only at the four corners that have a margin in width, The overall strength of the base is not reduced. 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 the pair of first wiring patterns 71a and 71b, respectively, and extend to the central portion of the first recess.

  The pair of first wiring patterns 71a and 71b are formed at the end portions of the first wiring patterns 71a and 71b, and will be described later via a pair of cylindrical conductive vias 10a and 10b penetrating the substrate unit 20. The IC mounting pads 11a and 11b formed in the second recess 2B are connected.

  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 notches 20c1 and 20c2 in the four corners of the outer peripheral edge of the substrate portion 20. Has been. Crystal vibration element external connection terminals 9a and 9b (piezoelectric vibration element external connection terminals) are formed on the surfaces of the 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. As a more preferable form in this embodiment, the crystal frame element external connection terminals 9a and 9b are adjacent to the first frame cutout portions 21c1 and 21c2 and the second frame cutout portions 22c1 and 22c2. Connection terminals (electrodes) are not formed, and external connection terminals (electrodes) are formed only in the notches 20c1 and 20c2 of the substrate portion. For this reason, an external connection terminal for a crystal resonator element that can measure only the characteristics of the crystal resonator element 3 that does not electrically interfere with the external circuit board or the lid 5 can be formed on the outer surface of the base 2. Further, by providing the crystal resonator element external connection terminal at the notch of the base plate 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 the measuring 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.

  Further, at the four corners of the inner peripheral edge of the second frame portion 22, columnar conductive vias 10 c and 10 d extending along the height direction of the inner peripheral wall of the second frame portion 22 (through the second frame portion 22). , 10e, 10f are embedded, and a part of the side surfaces of the columnar conductive vias 10c, 10d, 10e, 10f are exposed in the second recess 2B. In this embodiment, as shown in FIGS. 3 and 4, the plan view shape (plane and bottom surface) of each conductive via has a shape in which a large arc 101 and a small arc 102 are connected, and the small arc of each conductive via. The side surface connected to 102 is configured to be exposed to the second recess 2B. That is, the side surfaces of the small arcs 102 of the conductive vias 10c, 10d, 10e, and 10f are arranged at the four corners of the inner peripheral wall of the second frame portion 22.

  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. The second recess 2 </ b> B is square in plan view and has the same shape as the inner peripheral edge 221 of the second frame portion 22. 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 pads 11 a, 11 b, 11 c, 11 d, 11 e, and 11 f are formed in a matrix on the inner bottom surface of the second recess 2 </ b> B (the lower surface of the substrate portion 20). Yes. That is, as shown in FIGS. 2 and 3, IC mounting pads 11c, 11a, and 11f are formed along the upper long side toward the inner bottom surface of the second recess 2B, and are directed toward the inner bottom surface of the second recess 2B. IC mounting pads 11d, 11b, and 11e are formed along the lower long side. In addition, since the number of IC mounting pads is formed according to the electrode pad of IC4, it is good also as a structure of 6 or more according to the additional function of IC4.

  The IC mounting pads 11c, 11d, 11e, and 11f are formed at positions close to the four corners of the inner bottom surface of the second recess 2B, and are connected to the second wiring patterns 111c, 111d, 111e, and 111f, respectively. The second wiring patterns 111c, 111d, 111e, and 111f extend in the directions of 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. Accordingly, the conductive vias 10c, 10d, 10e, and 10f at the four corners and the second wiring patterns 111c, 111d, 111e, and 111f at the four corners are electrically connected to the IC 4.

  The second wiring patterns 111c, 111d, 111e, and 111f 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 111c, 111d, 111e, and 111f 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. For this reason, it is possible to weaken the flow of solder from the conductive vias 10c, 10d, 10e, and 10f to the second wiring patterns 111c, 111d, 111e, and 111f, so that it is not necessary for bonding the IC 4 to the external circuit board. Solder can be prevented from flowing in. Also, the IC mounting pads 11a, 11b, 11c, 11d, 11e, and 11f are conductively bonded to the electrode pads of the IC 4 through metal bumps 12 made of gold or the like.

  In this embodiment, as a more preferable form, the sealing portion 6, the crystal mounting pads 7a and 7b, the first wiring patterns 71a, 71b, 72a, 72b, the IC mounting pads 11a, 11b, 11c, 11d, 11e, 11f, the second For the wiring patterns 111c, 111d, 111e, 111f, conductive vias 10a, 10b, 10c, 10d, 10e, 10f, and external connection terminals 9a, 9b, 9c, 9d, 9e, 9f, ceramic materials (Young's modulus is about 300 GPa or so) ) It is made of a metallized material of tungsten (Young's modulus is about 411 GPa) or molybdenum (Young's modulus is about 329 GPa) having a higher Young's modulus. 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. And a region constituting a circuit portion. In this embodiment, a so-called SPXO IC having only an oscillation circuit is used, but it is a so-called VCXO IC having a frequency adjustment circuit as an additional function, or a temperature detection unit and a temperature compensation circuit are added functions. The IC may be a so-called TCXO IC provided as the above, an IC provided with other additional functions, 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 5 of the metal lid 4 and the base joint portion 6 are melt-cured to perform hermetic sealing. The IC 4 is electromechanically connected to the IC 4 via the metal bumps 12 on the IC mounting pads 11a, 11b, 11c, 11d, 11e, and 11f formed on the inner bottom surface of the second recess 2B of the base 2. It 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, even if the surface-mount type crystal oscillator 1 is downsized, the conductive via 10c is limited even if the area of the external connection terminals 9c, 9d, 9e, and 9f is restricted. , 10d, 10e, and 10f, it is possible to enlarge the solder application area joined to the external circuit board. 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.

  Next, an example applied to a quartz crystal vibrator (piezoelectric vibrator) with a temperature sensor using a temperature sensitive element such as a thermistor as an electronic component element will be described with reference to FIG. The crystal unit with temperature sensor 1 </ b> X is a substantially rectangular parallelepiped package. Like the crystal oscillator 1, the crystal unit 1 </ b> X is substantially rectangular in plan view and substantially H-shaped in cross section. The crystal resonator 1X includes a base 2, a crystal resonator element 3 (not shown), an electronic component element, and a lid 5 (not shown) as main components. A thermistor 4X as an element is incorporated. Hereinafter, regarding the crystal resonator 1X of the present invention, the same parts as those of the crystal oscillator are denoted by the same reference numerals and a part of the description is omitted, and the difference from the crystal oscillator will be mainly described.

  The base 2 is a substantially rectangular container in plan view having a long side and a short side made of an insulating material like the above-described crystal oscillator, and has a flat plate-like (substantially rectangular in plan view) substrate portion 20 and one main surface of the substrate portion. A first frame portion 21 (not shown) whose outer peripheral edge and inner peripheral edge are substantially rectangular in plan view, and extends downward along the outer peripheral portion of the other main surface of the substrate portion. The second frame portion 22 whose inner peripheral edge is substantially rectangular in plan view is a main component (substantially H-shaped cross section).

  Although not shown, a space surrounded by the inner peripheral edge of the first frame portion 21 of the base 2 and one main surface of the substrate portion is a first recess 2A (not shown), and the first The quartz crystal resonator element 3 is conductively bonded to the quartz crystal mounting pads 7a and 7b (not shown) formed on the inner bottom surface of the recess 2A via a conductive adhesive 8 (not shown). The crystal resonator element 3 is bonded to a sealing portion 6 (not shown) on the upper surface of the first frame portion 21 of the base 2 by a bonding material such as a metal lid 5 and a gold-tin brazing material and hermetically sealed.

  A space surrounded by the inner peripheral edge of the second frame portion 22 of the base 2 and the other main surface of the substrate portion is a second concave portion 2B having a rectangular shape in plan view, and the inner bottom surface of the second concave portion 2B includes A crystal connection pad 13a and a crystal connection pad 13b are formed opposite one of the four corners of the inner bottom surface of the second recess 2B, and the other of the four corners of the inner bottom surface of the second recess 2B. A thermistor mounting pad 13c and a thermistor mounting pad 13d are formed so as to face the diagonal positions. The crystal connection pads 13a and 13b are led to the crystal mounting pads 7a and 7b by a pair of cylindrical conductive vias 10g and 10h penetrating the substrate part 20 and first wiring patterns 71a and 71b (not shown).

  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. Further, at the four corners of the inner peripheral edge of the second frame portion 22, columnar conductive vias 10 c and 10 d extending along the height direction of the inner peripheral wall of the second frame portion 22 (through the second frame portion 22). , 10e, 10f are embedded, and a part of the side surfaces of the columnar conductive vias 10c, 10d, 10e, 10f are exposed in the second recess 2B. The external connection terminals 9c, 9d, 9e, 9f at the four corners and the conductive vias 10c, 10d, 10e, 10f are connected to each other.

  Crystal connection pads 13a and 13b formed at one diagonal position of the four corners of the inner bottom surface of the second recess 2B are connected to the second wiring patterns 111d and 111f, respectively, and the four corners of the inner bottom surface of the second recess 2B. The thermistor mounting pads 13c and 13d formed at the other diagonal position are connected to the second wiring patterns 111c and 111e, respectively. The second wiring patterns 111c, 111d, 111e, and 111f extend in the directions of 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. Further, the thermistor mounting pads 13c and 13d are conductively bonded to the electrode pads of the thermistor 4X via the conductive bonding material 14 made of solder or the like. Thus, the conductive vias 10d and 10f and the second wiring patterns 111d and 111f at one of the four corners are electrically connected to the crystal resonator element 3. The conductive vias 10c and 10e and the second wiring patterns 111c and 111e at the other diagonal position among the four corners are electrically connected to the thermistor 4X.

  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, after adjusting the frequency of the crystal diaphragm to a desired value while bringing the inspection probe into contact with the crystal connection pads 13a and 13b formed on the inner bottom surface of the second recess 2B of the base 2, the first recess 2A The base sealing portion 6 is covered with a metal lid 5 in a state in which the crystal resonator element 3 is stored, and the sealing material 5 of the metal lid 4 and the base joint 6 are melt-cured. Perform hermetic sealing. Then, the thermistor 4X is electromechanically connected to the upper portion of the thermistor mounting pads 13c and 13d formed on the inner bottom surface of the second recess 2B of the base 2 via the conductive bonding material 14 made of solder or the like, and the thermistor 4X is It is mounted on the inner bottom surface of the second recess 2B. Then, necessary adjustments are made to complete the crystal resonator 1X with a surface mount type temperature sensor.

  In this embodiment, the thermistor is used as the temperature sensitive element, but it may be a crystal vibration device (piezoelectric vibration device) with a functional component using another temperature sensitive element such as a diode or another functional electronic component. .

  In the above-described embodiments 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 will be described as an example. However, a cap-shaped lid that has a base with a frame formed only on the other main surface (lower) and a recess on the lower surface without forming a frame on one main surface (upper) of the substrate It is good also as a structure using.

  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 vibration device)
1X Quartz Crystal (Piezoelectric Vibration Device)
2 Base 2A 1st recessed part 2B 2nd recessed part 20 Substrate part 20c, 20c1, 20c2, 20c3, 20c4 Notch part 200 Outer peripheral part 201 One main surface 202 Other main surface 21 First frame part 21c, 21c1, 21c2, 21c3, 21c4 Notch part 210 Outer part 211 Inner part 22 Second frame part 22c, 22c1, 22c2, 22c3, 22c4 Notch part 220 Outer part 221 Inner part 3 Crystal vibration element (piezoelectric vibration element)
4 IC (electronic component element)
4X thermistor (electronic component element)
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 terminals 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h Conductive via 101 Large circular arc in plan view shape of conductive via 102 Small circular arc in plan view shape of conductive via 11a, 11b , 11c, 11d, 11e, 11f IC mounting pad 111c, 111d, 111e, 111f Second wiring pattern 12 Metal bump 13a, 13b Crystal connection pad 13c, 13d Thermistor mounting pad 14 Conductive bonding material