JP6679945B2 - Piezoelectric vibration device - Google Patents

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 oscillator or a crystal oscillator is widely used. For example, in a surface mount type crystal oscillator, a piezoelectric vibrating element made of crystal and an electronic component element such as an integrated circuit element are mounted in a recess provided in a base (container) made of an insulating material, and a recess is formed by a lid. 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 a mounting pad on the external circuit board with a conductive bonding material such as solder at an external connection terminal.

  Among such piezoelectric vibrating devices, as disclosed in Patent Document 1, there is a so-called H-type package structure in which a crystal vibrating 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 vibrating element) is enclosed in one side of a cavity (recess) on the front and back sides of a container, and an IC chip (electronic component element) is provided on the other side. The structure is implemented. The external connection terminals are formed at the four corners of the top surface (bottom surface of the crystal oscillator) of the frame portion surrounding the cavity on the side where the IC chip is mounted.

Japanese Unexamined Patent Publication No. 2009-27469

  In the piezoelectric vibrating device as described above, the area of the outer bottom surface of the base is restricted as compared with the flat outer bottom surface base in which the cavity is not present due to the restriction of the cavity on the side where the electronic component element (IC chip) is mounted. Becomes smaller. For this reason, the position and area of the external connection terminals that can be formed on the upper surface (outer bottom surface) of the frame part are also limited, so that the connection area between the external connection terminals and the external circuit board can be prevented while preventing short circuits between the external connection terminals. It is becoming difficult to secure the same at the same time.

  Further, in the piezoelectric vibrating device as described above, it is difficult to secure the bonding area for the external connection terminals as described above, and therefore, the solder coating amount for bonding to the external circuit board may be different between the external connection terminals. If it fluctuates, the degree of influence will increase. In other words, due to variations in the amount of solder applied, when mounting a piezoelectric vibration device on an external circuit board and melting and joining the solder, the piezoelectric vibration device may be mounted at an angle from the external circuit board or may be mounted by rotating. The risk of doing so increased.

  The present invention has been made in view of the above points, and is a piezoelectric vibrating device that has improved mounting stability on an external circuit board while ensuring a bonding area with the external circuit board in a piezoelectric vibration device. The purpose is to provide a vibrating device.

In order to achieve the above-mentioned object, the present invention provides a substrate portion having one main surface on the upper side and the other main surface on the lower side, and extending downward from an outer peripheral portion of the other main surface of the substrate portion, and an outer peripheral edge and an inner peripheral edge being a plane A base provided with a frame portion having a substantially rectangular shape in view, external connection terminals formed at four corners of the upper surface of the frame portion, a piezoelectric vibrating element mounted on one main surface of the substrate portion, and the frame portion. In a piezoelectric vibrating device including an electronic component element mounted in a recess surrounded by the other main surface of the substrate portion and a lid that hermetically seals the piezoelectric vibrating element, at four corners of the inner peripheral edge of the frame portion. the columnar conductive vias extending along the height direction of the inner peripheral edge is embedded, it is formed with a portion of the side surface of the columnar conductive vias are exposed in the concave portion, of said recess Wiring patterns extending at the four corners are formed on the bottom surface, and each external connection terminal and each wiring pattern are formed. The pattern is connected by each of the conductive vias, and the dimension along the inner peripheral edge of the frame portion of the wiring pattern in contact with the conductive via is larger than the dimension along the inner peripheral edge of the frame portion of the conductive via. Largely formed.

  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 to be joined to the external circuit board can be enlarged in the conductive via. Therefore, not only a planar solder joint portion formed by the external connection terminals but also a three-dimensional solder joint portion formed by forming the solder fillet along the conductive via can be obtained.

  Moreover, since the solder fillets are formed at four locations along the columnar conductive vias formed at the four corners of the inner peripheral edge of the frame portion, tension due to solder bonding is generated in the center direction of the piezoelectric vibration device in good balance. And the anchoring action by the solder fillet formed by the conductive via can be further enhanced.

  As a result, it is possible to increase the solder joint strength with the external circuit board by the anchor portions composed of the solder fillets at the four corners of the inner peripheral edge of the frame portion while making the piezoelectric vibration device smaller.

  Further, even if there are variations in the amount of solder applied to the external connection terminals at the four corners, the solder application can be adjusted from the external connection terminals to the conductive vias. When the coating amount is uniform and the piezoelectric vibration device is mounted on the external circuit board and the solder is melted and bonded, the piezoelectric vibration device may be tilted from the external circuit board or rotated. Can be suppressed.

Further, from the dimension along the inner periphery of the frame portion of the conductive via Trip dimension along the inner periphery of the frame portion of the wiring pattern in contact with the conductive vias are larger.

  In this case, in addition to the above-described function and effect, the amount of solder flowing out from the external circuit board is limited by the conductive via having a relatively narrow width, and the relatively wide wiring pattern prevents the solder from flowing to the tip of the wiring pattern. It is possible to suppress the outflow, and as a result, it is possible to prevent unnecessary solder for joining with an external circuit board from flowing into the electronic component element connected at the tip of the wiring pattern.

  Further, in the above structure, an intersection of line segments connecting the conductive vias may be located at a 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 is possible to act so that the tension due to the solder joint is uniformly generated toward the center of gravity of the vibration device.

  As a result, it is possible to further enhance the solder joint strength with the external circuit board, and it is possible to further suppress the piezoelectric vibration device from being tilted and rotated from the external circuit board.

  Further, in the above structure, 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, and each of the inner peripheral edges of the frame portion is formed. 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 function and effect, 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 substantially L along the direction of each side with the inner peripheral edge of the frame portion. Since it is formed in a character shape, even if the area of the external connection terminal formed on the upper surface of the frame is restricted due to the miniaturization of the piezoelectric vibration device, the area of the external connection terminal can be secured. It is possible to suppress deterioration of the bonding strength with the external circuit board.

  Further, 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, the solder joints are well-balanced in the state along each side of the frame portion. Can be caused to generate tension. In addition, the flow of solder from the external connection terminal to the conductive via is facilitated, and the function of adjusting the solder application state and the function of forming the anchor portion can be enhanced.

  As a result, it is possible to further increase the solder joint strength with the external circuit board, and it is possible to further suppress the piezoelectric vibration device from being tilted and rotated from the external circuit board.

  Further, in the above structure, 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 Young's modulus higher than that of the ceramic material.

  In this case, in addition to the above-described effects, columnar conductive vias made of a metallized material such as 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 is reduced due to downsizing, the hardness of the four corners of the frame can be increased, and the strength of the entire base can be increased. Moreover, the inclination of the base can be suppressed.

  Further, in the above configuration, the substrate portion and the frame portion, each outer peripheral edge is formed in substantially the same rectangular in plan view, and arc-shaped notch portions are formed at the four corners of each outer peripheral edge, An external connection terminal may not be formed in the cutout portion of the frame portion, and an external connection terminal for a piezoelectric vibrating element connected only to the piezoelectric vibration element may be formed only in the cutout portion of the substrate portion.

  In this case, in addition to the above-described function and effect, even if the width of the frame portion is reduced due to the downsizing, the notch portions are formed only at the four corners with a sufficient width, so that the strength of the entire base is improved. There is no weakening. In addition, an external connection terminal for a piezoelectric vibrating element that can measure the characteristics of only the piezoelectric vibrating 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 it on the corner of the side surface, 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 vibrating device that is compatible with miniaturization and that has improved mounting stability on an external circuit board while ensuring a bonding area 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 showing a schematic structure of a crystal oscillator concerning an embodiment of the present invention. FIG. 3 is a bottom view of a state in which the IC of FIG. 2 is not mounted. FIG. 4 is a partially enlarged view of FIG. 3. FIG. 3 is a side view in the P direction of FIGS. 1 and 2. It is a bottom view showing a schematic structure of a crystal oscillator concerning other embodiments of the present invention.

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

  An embodiment of the present invention will be described with reference to FIGS. The crystal oscillator 1 is a substantially rectangular parallelepiped-shaped package, and has a substantially rectangular shape in a plan view and a substantially H-shaped cross section. The crystal oscillator 1 includes a base 2, a crystal vibrating element 3, an IC 4, and a lid 5 as main constituent members. In the present embodiment, the external size of the crystal oscillator 1 in plan view is approximately 1.6 mm × 1.2 mm in length and width, and the crystal oscillator 1 incorporates an IC 4 having an oscillation circuit as an electronic component element. The above-mentioned outer shape size of the crystal oscillator in plan view is an example, and the present invention can be applied to package sizes other than the outer 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 long sides and short sides made of an insulating material. The base 2 extends upward along the outer peripheral portion 200 of the one main surface 201 of the flat plate-shaped (generally rectangular in plan view), the outer peripheral edge 210 and the inner peripheral edge 211 are substantially rectangular in plan view. Main components are the first frame portion 21, 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 a plan view. (H-shaped cross section).

  In this embodiment, as a more preferable form, the substrate portion 20, the first frame portion 21, and the second frame portion 22 are formed such that each outer peripheral edge is formed into a rectangle that is substantially the same in plan view, and only four corners of each outer peripheral edge are circular. Arc-shaped notches 20c, 21c and 22c are formed. That is, the notches 20c1, 20c2, 20c3, 20c4 are provided at the four corners of the outer peripheral edge of the substrate portion 20, and the notch portions 21c1, 21c2, 21c3, 21c4 are provided at the four corners of the outer peripheral edge of the first frame portion 21. Notch portions 22c1, 22c2, 22c3, 22c4 are formed at four corners of the outer peripheral edge of the frame portion 22. Therefore, even if the widths of the first frame portion 21 and the second frame portion 22 are reduced due to downsizing, by forming the cutout portions 20c, 21c, and 22c only at the four corners with a sufficient width, Does not weaken the strength of the entire base. Further, the sealing area between the first frame portion 21 and the lid 5 is not narrowed more than necessary, so that the hermetic sealing performance of the crystal vibrating element 2 is not deteriorated.

  In this embodiment, each of the substrate portion 20, the first frame portion 21, and the second frame portion 22 is a ceramic green sheet (alumina), and these three sheets are laminated and integrally formed by firing. There is. It should be noted that each of these sheets (the sheet of the substrate portion, the sheet of the first frame portion, the sheet of the second frame portion) is divided into not only a single layer but also a plurality of layers according to the extension form of the internal wiring between the stacked layers. You may form it.

  The sealing portion 6 is formed on the upper surface of the first frame portion 21 of the base 2. The sealing portion 6 is joined to the metallic lid 5 with a joining material such as a gold tin brazing material.

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

  One end side of the crystal vibrating element 3 is conductively bonded and mounted on the crystal mounting pads 7a and 7b via a 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.

  Then, the pair of first wiring patterns 71a, 71b are formed at the end portions of the first wiring patterns 71a, 71b, and pass through the pair of columnar conductive vias 10a, 10b penetrating the substrate portion 20, and will be described later. Is connected to the IC mounting pads 11a and 11b formed in the second recess 2B.

  Further, 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 cutout portions 20c1 and 20c2 of the four corners of the outer peripheral edge of the substrate portion 20. Has been done. External connection terminals 9a and 9b for crystal vibrating element (external connection terminals for piezoelectric vibrating element) are formed on the surfaces of the cutout portions 20c1 and 20c2.

  The external connection terminals 9a and 9b for the crystal vibrating element are connected to the first wiring patterns 72a and 72b, respectively, so that they are connected only to the excitation electrodes of the crystal vibrating element and the electrical characteristics of only the crystal vibrating element are measured. It is possible. In the present embodiment, as a more preferable form, the cutout portions 21c1 and 21c2 of the first frame portion and the 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 externally provided. The connection terminals (electrodes) are not formed, and the external connection terminals (electrodes) are formed only in the cutout portions 20c1 and 20c2 of the substrate portion. Therefore, an external connection terminal for a crystal vibrating element that can measure the characteristics of only the crystal vibrating 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 external connection terminal for the crystal vibrating element in the cutout portion of the substrate portion located at the center of the side surface of the base at the corner portion of the base, it is possible to easily contact the terminals of the inspection probe and the measurement jig.

  External connection terminals 9c, 9d, 9e, 9f to be joined to mounting pads of an external circuit board (not shown) by solder are formed at four corners of the upper surface (bottom surface of the base 2) of the second frame portion 22 of the base 2. There is. In a more preferable form in this embodiment, the external connection terminals 9c, 9d, 9e, 9f at the four corners are formed in a substantially L shape, and the substantially L shape is at 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, the number of external connection terminals may be four or more according to the additional function of the oscillator.

  In addition, at the four corners of the inner peripheral edge of the second frame portion 22, columnar conductive vias 10c and 10d that extend (penetrate the second frame portion 22) along the height direction of the inner peripheral wall of the second frame portion 22. , 10e, 10f are buried, and part of the side surfaces of the columnar conductive vias 10c, 10d, 10e, 10f are formed to be exposed in the second recess 2B. In the present 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 is small. The side surface connected to 102 is configured to be exposed in the second recess 2B. That is, the side surfaces of the small arcs 102 of the conductive vias 10c, 10d, 10e, 10f are arranged at the four corners of the inner peripheral wall of the second frame portion 22.

  Then, each columnar conductive via is inscribed in the inner L-shaped external connection terminals 9c, 9d, 9e, 9f of the four corners (four corners of the inner peripheral edge of the second frame portion 22). 10c, 10d, 10e and 10f are formed and connected to each other. In this embodiment, as a more preferable embodiment, as shown in FIG. 3, the curved portions inside the substantially L-shaped external connection terminals 9c, 9d, 9e, 9f at the four corners and the four corners inscribed in these portions are respectively formed. The intersection of the line segment 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 diagonally located, and the conductive via Each external connection terminal and each conductive via are arranged such that the intersection of the center of 10d and the second line segment R connecting the center of the conductive via 10f at the diagonal position coincides with the center of gravity O of the base. Are formed on the base 2.

  The 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 the second recess 2B. The second concave portion 2B has a square shape in a plan view and has the same shape as the inner peripheral edge 221 of the second frame portion 22. The size of the second recess 2B in plan view is smaller than that of the first recess 2A, and the second recess 2B is in a positional relationship of being included in the first recess 2A in plan view transmission.

  IC mounting pads 11a, 11b, 11c, 11d, 11e, and 11f are mounted in a matrix on the inner bottom surface of the second recess 2B (the lower surface of the substrate portion 20), and the ICs 4 having a rectangular shape in plan view are mounted and conductively bonded. There is. That is, as shown in FIG. 2 and FIG. 3, the IC mounting pads 11c, 11a, 11f are formed along the upper long side toward the inner bottom surface of the second recess 2B and face the inner bottom surface of the second recess 2B. IC mounting pads 11d, 11b, 11e are formed along the lower long side. Since the number of IC mounting pads is formed according to the electrode pads of the IC 4, the number of IC mounting pads may be six or more depending on the additional function of the IC 4.

  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. As a result, the conductive vias 10c, 10d, 10e, 10f at the four corners and the second wiring patterns 111c, 111d, 111e, 111f at the four corners are electrically connected to the IC4.

  The second wiring patterns 111c, 111d, 111e, and 111f are electrically connected to the external connection terminals 9c, 9d, 9e, and 9f via the above-described columnar conductive vias 10c, 10d, 10e, and 10f, respectively. ing. As a more preferable form in this embodiment, as shown in FIG. 4, a dimension W1 (a small arc of the bottom surface of the conductive via) along the inner peripheral edge 221 of the second frame portion 22 on the side surface of the conductive via 10c, 10d, 10e, 10f. 102), the dimension W2 (each second wiring) along the inner peripheral edge 221 of the second frame portion 22 of the second wiring patterns 111c, 111d, 111e, and 111f in the portion in contact with the side surface of the conductive via. The length of the portion that contacts the pattern and the inner peripheral edge of the second frame portion is formed larger. For this reason, it is possible to weaken the flow of solder from the conductive vias 10c, 10d, 10e, 10f to the second wiring patterns 111c, 111d, 111e, 111f, which is unnecessary for bonding the IC 4 to the external circuit board. It is possible to prevent the solder from flowing in. Further, on the IC mounting pads 11a, 11b, 11c, 11d, 11e, and 11f, the electrode pads of the IC 4 are conductively bonded via the metal bumps 12 made of gold or the like.

  In this embodiment, as a more preferable embodiment, the sealing portion 6, the crystal mounting pads 7a, 7b, the first wiring patterns 71a, 71b, 72a, 72b, the IC mounting pads 11a, 11b, 11c, 11d, 11e, 11f, the second Regarding the wiring patterns 111c, 111d, 111e, 111f, the conductive vias 10a, 10b, 10c, 10d, 10e, 10f, and the external connection terminals 9a, 9b, 9c, 9d, 9e, 9f, the ceramic material (Young's modulus of about 300 GPa is about 300 GPa). ) Is higher in Young's modulus than tungsten (Young's modulus is 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 an electrolytic plating method, and these are simultaneously formed at once. Therefore, even if the width of the second frame portion 22 is reduced due to downsizing, the hardness of the four corners of the second frame portion 22 is increased due to the existence of the columnar conductive vias 10c, 10d, 10e, and 10f at the four corners. And the strength of the entire base can be increased.

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

  In FIG. 1, a crystal vibrating element 3 is a piezoelectric vibrating 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 vibrating plate. It should be noted that illustration of various electrodes is omitted in FIG. Although not shown in FIG. 1, a pair of excitation electrodes are formed in the substantially central portion of the crystal diaphragm so as to face each other on the front and back sides. An extraction electrode extends 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 extraction electrode serves as an adhesive electrode, and is joined to the above-described crystal mounting pads 7a and 7b via a conductive adhesive 8. In this embodiment, a silicone-based adhesive is used as the conductive adhesive 8, but a conductive adhesive other than silicone 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 having a built-in inverter amplifier (oscillation amplifier) such as CMOS, and is connected to the crystal vibrating element 3 and oscillates to amplify the frequency signal of the crystal vibrating element 3. And a region forming a circuit portion. In this embodiment, a so-called SPXO IC having only an oscillation circuit is used, but a so-called VCXO IC having a frequency adjusting circuit as an additional function, or a temperature detecting unit and a temperature compensating circuit as an additional function. The IC may be a so-called TCXO IC provided as, an IC having an additional function other than this, 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 lid 5 has Kovar as a base material, and the surface of the base material is plated with nickel and gold-tin brazing material. The above is an outline of each component.

  In each of the above constituent members, the crystal vibrating 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. Will be installed. Then, the frequency of the crystal vibrating plate was adjusted to a desired value while the inspection probe was in contact with the crystal vibrating device external connection terminals 9a and 9b of the base 2, and then the crystal vibrating device was stored in the first recess 2A. In this state, the sealing portion 6 of the base is covered with the metallic lid 5, and the sealing material 5 of the metallic lid 4 and the joint portion 6 of the base are melt-cured to hermetically seal. Then, 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 are electromechanically connected to the IC4 via the metal bumps 12 and the IC4 is connected to the IC4. It is mounted on the inner bottom surface of the second recess 2B. Then, necessary adjustments are made to complete the surface mount crystal oscillator 1.

  Then, the surface mount type 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 soldering. At this time, paste-like solder is provided between the substantially L-shaped external connection terminals 9c, 9d, 9e, 9f at the four corners of the bottom surface of the surface mount type crystal oscillator 1 and the mounting pads of the external circuit board (not shown). Is mounted with the intervening. Then, in this state, it is carried into a heating and melting furnace, and by heating and melting the solder, the mounting pads of an external circuit board (not shown) and the substantially L-shaped external connection terminals 9c at the four corners of the bottom surface of the surface-mount type crystal oscillator 1, 9d, 9e, 9f and each columnar conductive via 10c, 10d, 10e, 10f are joined.

  According to the surface mount type crystal oscillator 1 according to the embodiment of the present invention, even if the surface area of the external mount terminals 9c, 9d, 9e, 9f is restricted due to the downsizing of the surface mount type crystal oscillator 1, the conductive via 10c is formed. , 10d, 10e, 10f can enlarge the solder application area to be joined to the external circuit board. Therefore, not only the planar solder joint portion formed by the external connection terminals 9c, 9d, 9e, 9f, but also the three-dimensional solder joint portion formed by forming the 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, it acts so as to generate tension in good balance in the direction of the center of gravity O of the surface-mounted crystal oscillator 1 by solder bonding. Therefore, the anchor action by the solder fillet formed by the conductive vias 10c, 10d, 10e, 10f can be further enhanced. As a result, it is possible to increase the solder joint strength with the external circuit board while making the surface mount crystal oscillator 1 smaller.

  Further, even if the amount of paste-like solder applied to the external connection terminals 9c, 9d, 9e, 9f at the four corners varies, the external connection terminals 9c, 9d, 9e, 9f to the conductive vias 10c, 10d, 10e. , 10f, the solder application can be adjusted, so that the solder application amounts of the external connection terminals 9c, 9d, 9e, 9f at the four corners are made uniform, and the surface mount type crystal oscillator 1 is mounted on the external circuit board. Then, when melting and joining the solder, it is possible to suppress the surface mount type crystal oscillator 1 from being tilted from the external circuit board or being rotated and mounted.

  In particular, even if the area of the external connection terminals 9c, 9d, 9e, 9f is restricted due to the downsizing of the surface mount crystal oscillator 1, the area of the external connection terminals is secured by forming the substantially L shape. Therefore, it is possible to suppress the reduction of the bonding strength with the external circuit board, and it is possible to act so that the tension due to the solder bonding is generated in a well-balanced state along the respective side directions of the second frame portion 22. . Further, the solder outflow from the external connection terminals 9c, 9d, 9e, 9f to the conductive vias 10c, 10d, 10e, 10f is promoted.

  Moreover, the solder fillet is line-symmetrical with respect to the center line AA passing through the center of gravity O of the base and parallel to the long side of the second frame portion and the center line BB parallel to the short side of the second frame portion. Since the anchor portions at the four corners are formed, it is possible to act so that the tension due to the solder joint is uniformly generated toward the center of gravity O of the surface mount crystal oscillator 1. As a result, it is possible to further enhance the solder joint strength with the external circuit board, and it is possible to further suppress the surface mount type crystal oscillator 1 from being tilted from the external circuit board or being rotated and mounted. it can.

  Next, an example applied to a crystal oscillator (piezoelectric oscillator) 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 resonator 1X with a temperature sensor is a substantially rectangular parallelepiped package, and like the crystal oscillator 1, is substantially rectangular in plan view and substantially H-shaped in cross section. The crystal unit 1X includes a base 2, a crystal vibrating element 3 (not shown), an electronic component element, and a lid 5 (not shown) as main components, and serves as a temperature-sensitive electronic component element. The thermistor 4X as an element is built in. With respect to the crystal resonator 1X of the present invention, the same parts as those of the above-mentioned crystal oscillator are designated by the same reference numerals and a part of the description is omitted, and the difference from the above-mentioned crystal oscillator will be mainly described.

  The base 2 is a container having a long side and a short side made of an insulating material and having a substantially rectangular shape in plan view, similar to the above-described crystal oscillator, and having a plate-like (planar rectangular shape in plan view) substrate portion 20 and one main surface of the substrate portion And a first frame portion 21 (not shown) having an outer peripheral edge and an inner peripheral edge that are substantially rectangular in a plan view and an outer peripheral edge that 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 and the inner peripheral edge are substantially rectangular in plan view is a main constituent member (substantially H-shaped in cross section).

  Although not shown, the 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). The quartz crystal vibrating 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 through the conductive adhesive 8 (not shown). The crystal vibrating element 3 is hermetically sealed by being joined to a sealing portion 6 (not shown) on the upper surface of the first frame portion 21 of the base 2 with a metallic lid 5 and a joining material such as gold tin brazing material.

  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 is The crystal connection pad 13a and the crystal connection pad 13b are formed so as to face one diagonal position of 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 of. The crystal connection pads 13a and 13b are led out to the crystal mounting pads 7a and 7b by a pair of cylindrical conductive vias 10g and 10h penetrating the substrate portion 20 and first wiring patterns 71a and 71b (not shown).

  External connection terminals 9c, 9d, 9e, 9f to be joined to mounting pads of an external circuit board (not shown) by solder are formed at four corners of the upper surface (bottom surface of the base 2) of the second frame portion 22 of the base 2. There is. In addition, at the four corners of the inner peripheral edge of the second frame portion 22, columnar conductive vias 10c and 10d that extend (penetrate the second frame portion 22) along the height direction of the inner peripheral wall of the second frame portion 22. , 10e, 10f are buried, and part of the side surfaces of the columnar conductive vias 10c, 10d, 10e, 10f are formed to be 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.

  The crystal connection pads 13a and 13b formed on one 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 are connected. The thermistor mounting pads 13c and 13d formed on the other diagonal position of 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, on the thermistor mounting pads 13c and 13d, conductive bonding is performed with the electrode pad of the thermistor 4X via a conductive bonding material 14 made of solder or the like. As a result, the conductive vias 10d and 10f and the second wiring patterns 111d and 111f, which are located diagonally to one of the four corners, are electrically connected to the crystal vibrating element 3. The conductive vias 10c and 10e and the second wiring patterns 111c and 111e at the other diagonal positions of the four corners are electrically connected to the thermistor 4X.

  In each of the above constituent members, the crystal vibrating 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. Will be installed. Then, while contacting the crystal connection pads 13a, 13b formed on the inner bottom surface of the second recess 2B of the base 2 with the inspection probe, the frequency of the crystal diaphragm is adjusted to a desired value, and then the first recess 2A is formed. In a state where the crystal vibrating element 3 is housed, 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 melted and cured, Airtight sealing is performed. Then, the thermistor 4X is electromechanically connected to 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. 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 the surface mount type temperature sensor.

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

  In addition, in each of 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 one 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 having a recess on the lower side is used by using a base in which a frame is not formed on the one main surface side (upper side) of the substrate part, but a frame part is formed only on the other main surface side (lower side). May be used.

  The present invention can be embodied in various other forms without departing from the spirit or the main characteristics thereof. Therefore, the above-described embodiments are merely examples in all respects and should not be limitedly interpreted. The scope of the present invention is defined by the scope of the claims, and is not restricted by the text of the specification. Furthermore, 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 crystal unit (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 peripheral part 211 Inner peripheral part 22 Second frame part 22c, 22c1, 22c2, 22c3, 22c4 Notch part 220 Outer peripheral part 221 Inner peripheral part 3 Crystal vibrating element (piezoelectric vibrating 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 terminal 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h Conductive via 101 Large arc of conductive via in plan view 102 Small arc of conductive via in plan view 11a, 11b , 11c, 11d, 11e, 11f IC mounting pads 111c, 111d, 111e, 111f Second wiring pattern 12 Metal bumps 13a, 13b Crystal connection pads 13c, 13d Thermistor mounting pad 14 Conductive bonding material

Claims (5)

A substrate portion whose upper side is one main surface and whose 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 a plan view,
External connection terminals formed at the four corners of the upper surface of the frame,
With a base,
A piezoelectric vibrating 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 a piezoelectric vibrating device consisting of
The four corners of the inner peripheral edge of said frame portion, the state in which columnar conductive vias extending along the height direction of the inner peripheral edge is embedded, a part of the side face of the columnar conductive vias is exposed to the recess Is formed of
Wiring patterns extending at the four corners are formed on the inner bottom surface of the recess,
The respective external connection terminals and the respective wiring patterns are connected by the respective conductive vias,
The piezoelectric vibration device is characterized in that the dimension along the inner peripheral edge of the frame portion of the wiring pattern in contact with the conductive via is formed larger than the dimension along the inner peripheral edge of the frame portion of the conductive via. The piezoelectric vibration device according to claim 1, wherein
A piezoelectric vibrating device, wherein an intersection of line segments connecting the conductive vias is located at a center of gravity of the base. The piezoelectric vibration device according to claim 1 or 2, wherein
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 and extends along each side of the inner peripheral edge of the frame portion. And the conductive via is formed in a state of being in contact with the curved portion. The piezoelectric vibration device according to any one of claims 1 to 3 ,
A piezoelectric vibrating device, 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. The piezoelectric vibration device according to any one of claims 1 to 4 ,
The substrate portion and the frame portion are formed such that each outer peripheral edge has a substantially same rectangular shape in a plan view, and arc-shaped cutout portions are formed at four corners of each outer peripheral edge,
An external connection terminal is not formed in the cutout portion of the frame portion, and an external connection terminal for a piezoelectric vibrating element that is connected only to the piezoelectric vibration element is formed only in the cutout portion of the substrate portion. Piezoelectric vibration device.

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