JP2019193207A - Piezoelectric vibration device - Google Patents

Abstract

To provide a highly reliable piezoelectric vibration device capable of configuring a piezoelectric connection terminal with high connectivity while adapting to smaller containers.SOLUTION: The piezoelectric vibration device includes: a base 2 laminated in three or more layers of an upper layer, a middle layer, and a lower layer; a piezoelectric vibration element and an electronic component element housed in the base housing unit; a lid 5 for hermetically sealing the base housing unit; an external connection terminal formed on a lower surface of the base; a notch formed on the outer peripheral edge of the base and recessed toward the housing unit side; and piezoelectric connection terminals AT1, AT2 formed in the notch in the middle layer of the base. A size of the recess on the housing unit side of the notch in the middle layer of the base is larger than that of the other layers. A notch of the middle layer constitutes a recess 211d that is further recessed toward the housing unit side. The piezoelectric connection terminals AT1, AT2 are formed on the entire inner surface of the recess 211d.SELECTED DRAWING: Figure 1

Description

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

  As a piezoelectric vibration device, for example, a surface-mount type crystal resonator or a crystal oscillator is widely used. For example, in a surface-mount type crystal oscillator, a piezoelectric vibration element made of crystal or the like and an electronic component element such as an integrated circuit element are mounted in a storage portion provided in a base (container) made of an insulating material such as ceramic. The housing is hermetically sealed with a lid. A plurality of external connection terminals are formed on the outer bottom surface of the base. 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.

  In such a piezoelectric vibration device, as disclosed in Patent Document 1, by providing a piezoelectric connection terminal that is connected only to the piezoelectric vibration element, an electric component by other electronic component elements such as an IC is provided. In the past, there has been proposed a method for evaluating electrical characteristics and adjusting the frequency of a piezoelectric vibration element as a single unit without being affected by the characteristics.

Utility Kaihei 5-65110

  However, the piezoelectric vibration device as described above has become difficult to secure the area of the piezoelectric connection terminal with the recent progress of miniaturization and low profile of the container, and the piezoelectric connection terminal is used for characteristic measurement. At present, it is becoming difficult to position the contact pins in contact with each other. In particular, a base composed of a laminated body such as a ceramic also has a problem of deviation of the laminated body. Therefore, stable contact of a contact pin for characteristic measurement with such a piezoelectric connection terminal is a feature of a piezoelectric vibration device. The current situation is that it is becoming increasingly difficult with downsizing and low profile.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a more reliable piezoelectric vibration device capable of configuring a piezoelectric connection terminal with high connectivity while accommodating the downsizing of a container. It is what.

  To achieve the above object, the present invention provides a rectangular parallelepiped base in which a laminate of a substrate portion and a frame portion made of an insulating material is laminated in at least three layers of an upper layer, a middle layer, and a lower layer to form an exterior portion and a storage portion. A piezoelectric vibration element and an electronic component element housed in the housing part of the base, a lid bonded to the upper surface of the frame part of the upper layer of the base and hermetically sealing the housing part by the frame part of the upper layer of the base; External connection terminals formed on the lower surface for connection to the outside, notches formed on the outer peripheral edges of the upper, middle and lower layers of the base and recessed toward the storage portion of the base, notches in the middle layer of the base And a piezoelectric connection terminal that is electrically connected to the piezoelectric vibration element, and the size of the recess toward the storage portion of the notch in the middle layer of the base is determined so that the upper layer and the lower layer of the base are cut. Depression size of the notch to the storage side By laminating the upper layer, middle layer, and lower layer of the base, the notch portion of each layer extends in a single line along the height direction of the base, and the notch portion of the base layer of the base A recess further recessed toward the storage portion is formed, and the piezoelectric connection terminal is formed on the entire inner surface of the recess.

  According to the above invention, the surface area of the piezoelectric connection terminal can be increased, so that the probability of contact with the contact pin is increased, and the contact pin is reliably locked by the recess to be positioned on the piezoelectric connection terminal. Can be made easier. That is, it is possible to configure a piezoelectric connection terminal with high connectivity while accommodating the downsizing of the container.

  Further, in the above configuration, at least one of a part of the notch in the upper layer of the base adjacent to the recess or a part of the notch in the lower layer of the base adjacent to the recess. The piezoelectric connection terminal may be formed by extending the piezoelectric connection terminal.

  In this case, in addition to the above-described effects, the piezoelectric connection auxiliary terminal is a part of the notch in the upper layer of the base adjacent to the recess or the notch in the lower layer of the base adjacent to the recess. Since the piezoelectric connection auxiliary terminal is not short-circuited with the lid or the external connection terminal, and the surface area of the piezoelectric connection terminal can be increased, the probability of contact with the contact pin is further increased. Can do.

  As described above, it is possible to provide a more reliable piezoelectric vibration device that can constitute a piezoelectric connection terminal with high connectivity while accommodating the downsizing of the container.

1 is a perspective view showing a schematic configuration of a crystal oscillator according to an embodiment of the present invention. It is sectional drawing along the AA line of FIG. It is the side view seen from the B direction of FIG. It is a side view which concerns on other embodiment of this invention. It is sectional drawing which concerns on other embodiment of this invention. It is sectional drawing 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 to be described below, as a piezoelectric vibration device, for example, a surface-mount crystal oscillator incorporating an IC (electronic component element) 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 has a substantially rectangular shape in plan view and a concave shape in cross section. The crystal oscillator 1 includes a base 2, a crystal resonator element (piezoelectric resonator element) 3, an IC 4, and a lid 5 as main constituent members.

  In this embodiment, for example, the external size of the crystal oscillator 1 in plan view (outside size of the base 2 in plan view) is about 1.6 mm (long side) × 1.2 mm (short side) in length and width. The crystal oscillator 1 incorporates 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 composed of a laminate of a substantially rectangular substrate portion and a frame portion having a long side and a short side made of a ceramic material, and is housed in the exterior portion 2b by a laminate of at least three layers of an upper layer, a middle layer, and a lower layer. It is a rectangular parallelepiped container which forms the part 2a.

  In the present embodiment, the base 2 has a flat plate-like (substantially rectangular in plan view) substrate portion 20 as a lower layer of the base, and an outer peripheral edge 210 extending upward along the outer peripheral portion 200 of the one main surface 201 of the substrate portion 20. The inner peripheral edge 211 is formed in a substantially rectangular shape in plan view and forms a base middle layer. The first frame part 21 extends upward along the outer peripheral part 200 of the first frame part 21, and the outer peripheral edge 220 and the inner peripheral edge 221 are viewed in plan view. It has a three-layer configuration including a second frame portion 22 (frame portion) that is formed in a substantially rectangular shape and serves as an upper layer of the base.

  And by combining the inner bottom surface by the one main surface 201 of these substrate portions 20, the inner space inside the inner periphery of the first frame portion 21, and the inner space inside the inner periphery of the second frame portion, A base storage portion 2a is configured.

  Inside the base 2, a lower surface is formed with a first frame portion 21, and a first storage portion 21a for storing an IC 4 described later is formed. The first storage portion 21a protrudes upward from the bottom surface of the first storage portion, and will be described later. A holding base (not shown) that holds the end of the crystal resonator element 3 is formed. In addition, a second storage portion 22a constituted by the second frame portion 22 is formed above the first storage portion 21a.

  Outside the base 2, the substrate portion 20, the first frame portion 21, and the second frame portion 22 are each formed with a rectangular shape whose outer peripheral edges are substantially the same in plan view, and the heights of the bases at the four corners of each outer peripheral edge. Arc-shaped cutouts 20c, 21c, 22c extending along the direction, and a pair of oval cutouts 20d, 21d extending along the height direction of the base at the center of the long side of each outer peripheral edge , 22d. These notches 20c, 21c, 22c, 20d, 21d, and 22d are recessed toward the storage portions 21a and 22a of the base 2.

  Among these, as shown in FIGS. 1 and 2, the notch portion 21 d formed in the first frame portion 21 that is the middle layer of the base 2 is formed in the second frame portion 22 that is the upper layer of the base 2. Compared with the notch portion 22d and the notch portion 20d formed in the substrate portion 21 which is the lower layer of the base 2, the size of the recess toward the storage portions 21a and 22a of the base 2 is formed larger. .

  Further, in this embodiment, the notch 22d formed in the second frame portion 22 which is the upper layer of the base 2 and the notch 20d formed in the substrate portion 21 which is the lower layer of the base 2 are the base The recess dimensions toward the two storage portions 21a and 22a are formed with the same dimension.

  As an example of this embodiment, when the width dimension W of the frame portions of the first frame portion 21 and the second frame portion 22 is 0.15 mm in the direction along the line AA in FIG. The recess dimension W1 of 21d is formed as 0.075 mm, and the recess dimension W2 between the notch 22d and the notch 20d is formed as 0.05 mm.

  By stacking the notch portion 20d, the notch portion 21d, and the notch portion 22d formed in this way, each notch portion extends in a single line along the height direction of the base 2, and the notch portion. Only 21d constitutes a recess 211d that is further recessed toward the storage portion side.

  Piezoelectric connection terminals AT1 and AT2 that are connected only to a pair of excitation electrodes 31 and 32 of the crystal resonator element 3 to be described later are formed on the entire inner surface of the recess 211d. That is, the piezoelectric connection terminals AT1 and AT2 are not only the surface portion of the side surface of the notch portion 21d but also the lower surface portion of the second frame portion 22 that is in contact with and adjacent to the notch portion 21d and the upper side of the substrate portion 21. At least a conductive material to be described later is formed on the surface portion.

  As described above, according to the present invention, the notch where the piezoelectric connection terminals AT1 and AT2 are formed has a recess toward the storage portion of the base as compared with the notch formed in the upper layer and the lower layer of the base. A feature is that the recess 211d is formed to have a large size, and a conductive material that forms the piezoelectric connection terminals AT1 and AT2 is formed on the entire inner surface of the recess 211d.

  With these configurations, the surface area of the piezoelectric connection terminals AT1 and AT2 can be increased, so that the probability of contact with the contact pins for characteristic measurement is increased, and a part of the contact pins is securely locked by the recess 211d. The positioning to the piezoelectric connection terminals AT1 and AT2 can be facilitated. That is, it is possible to configure the piezoelectric connection terminals AT1 and AT2 having high connectivity while corresponding to downsizing of the base 2 serving as a container.

Note that the present invention is not limited to this embodiment, and a part of the notch 22d formed in the second frame portion 22 which is the upper layer of the base 2 adjacent to the recess 211d and the substrate portion 21 which is the lower layer of the base 2 are formed. Piezoelectric connection auxiliary terminals AT11 and AT21 (not shown for AT21) from which the piezoelectric connection terminals AT1 and AT2 are extended may be formed in at least one of the cutout portions 20d. . FIG. 4 shows an example thereof. Piezoelectric connection auxiliary terminals AT11 and AT21 are formed on both a part of the notch 22d and a part of the notch 20d. In this case, the piezoelectric connection auxiliary terminals AT11 and AT21 are not short-circuited with a lid or an external connection terminal described later, and the surface area of the piezoelectric connection terminals AT1 and AT2 can be increased, thereby further increasing the probability of contact with the contact pins. be able to.

  External connection terminals GT for connection to an external circuit board are formed at the four corners of the lower surface of the substrate portion 20 which is the lower layer of the base 2. As shown in FIG. 3, these external connection terminals GT are formed by extending a conductive material, which will be described later, on the surface portions of the side surfaces of the notches 20 c at the four corners.

  As shown in FIG. 2, a plurality of wiring patterns H connected to an integrated circuit element 2 to be described later are arranged on the upper surface (the inner bottom surface of the first storage portion 21 a) of the substrate portion 20, which is the lower layer of the base 2. Is formed. The wiring pattern H is electrically led to the external connection terminal GT through the conductive material of the notches 20c at the four corners.

  On the upper surface of the first frame portion 21 (the bottom surface of the second storage portion 22a), which is the middle layer of the base 2, there is formed a holding base (not shown) and a wiring pattern on which a crystal resonator element 3 described later is mounted and electrically connected. Has been. The wiring pattern connected to the crystal resonator element is electrically led out to the wiring pattern H on the upper surface of the substrate unit 20 through a conductive via (not shown) penetratingly connected to the lower part. A part of the wiring pattern connected to the crystal resonator element is electrically led to the piezoelectric connection terminals AT1 and AT2. For this reason, it is possible to measure the electrical characteristics of only the crystal resonator element 3 described later by bringing the contact probe of the piezoelectric resonator element characteristic device into contact with the piezoelectric connection terminals AT1 and AT2.

  On the upper surface of the second frame portion 22, which is the upper layer of the base 2, a sealing portion (not shown) for joining a lid 5 described later is formed. In this embodiment, the sealing portion is configured by metallization, and the sealing portion and the lid 5 described later are joined by a joining material such as a metal brazing material 51.

  Each of the substrate part 20, the first frame part 21, and the second frame part 22 configured as described above is a ceramic green sheet (alumina). Each of the external connection terminal GT, the wiring pattern H, the wiring pattern connected to the crystal resonator element, the piezoelectric connection terminals AT1 and AT2, the piezoelectric connection auxiliary terminals AT11 and AT21, and the sealing portion is the upper surface of the metallized layer made of tungsten or molybdenum. Further, the structure is made of a conductive material in which a nickel plating layer and a gold plating layer are formed. The base 2 is configured by integrally forming these three sheets by firing in a stacked state.

  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. More specifically, as shown in FIG. 5, one layer of a sheet (second substrate portion 23) corresponding to another frame is added between the first frame portion 21 and the second frame portion 22, and four layers are added. You may comprise as a base which consists of these laminated bodies.

  The IC 4 mounted on the inner bottom surface of the first storage portion 21a is a one-chip integrated circuit element incorporating an inverter amplifier (oscillation amplifier) such as a C-MOS. Constitute. A plurality of pads are formed on the bottom side of the IC 4. The IC 4 connects the plurality of pads of the IC 2 and the wiring pattern H formed on the base 2 through, for example, FCB through metal bumps C such as gold. In this embodiment, a configuration in which metal bumps are joined is used as an example, but metal wire bumps may be used.

  The IC 4 used in this embodiment is not limited to a so-called SPXO IC that includes only an oscillation circuit unit that amplifies the frequency signal of the crystal resonator element 3, but also a so-called VCXO IC that includes a frequency adjustment circuit as an additional function. It may be an IC, or a so-called TCXO IC having a temperature compensation function or the like as an additional function. Further, an IC in which these are combined may be used. The IC 4 may be bipolar other than CMOS, bi-CMOS, or the like.

  Above the IC 4, the crystal resonator element 3 is mounted at a predetermined interval in the second storage portion 22 a that is the same space of the storage portion 2 a. The quartz resonator element 3 is, for example, a rectangular AT-cut quartz diaphragm, and excitation electrodes 31 and 32 and extraction electrodes (not shown) are formed on the front and back surfaces thereof. These electrodes are, for example, a three-layer laminated thin film composed of a chromium or nickel base electrode layer, a silver or gold intermediate electrode layer, and a chromium or nickel upper electrode layer, or a chromium or nickel base electrode It is a two-layer laminated thin film composed of a layer and a silver or gold upper electrode layer. Each of these electrodes can be formed by a thin film forming means such as a vacuum deposition method or a sputtering method.

  The crystal resonator element 3 and the base 2 are bonded using, for example, a silicone-based conductive resin adhesive (conductive bonding material) that is in a paste form and contains fine metal pieces such as a silver filler. The conductive resin adhesive is applied to the upper surface of a part of the wiring pattern on the upper part of the holding base, and the conductive resin adhesive is interposed between the crystal vibrating element 3 and the holding base and is cured to electrically connect each other. Mechanically joined. As described above, one end of the crystal resonator element 3 is joined to the holding base 21b of the base while the opposite end of the crystal resonator element 3 is joined to the base holding base 21b while providing a gap from the bottom surface of the first storage portion 21a of the base 2. Held. In this embodiment, the structure bonded by a silicone-based conductive resin adhesive is used as an example. However, as this conductive bonding material, other conductive resin adhesives, bump materials such as metal bumps and metal plating bumps, brazing A material may be used.

  The lid 5 for hermetically sealing the base 2 has a configuration in which a metal brazing material (sealing material) is formed on a core material made of, for example, Kovar. The joining material 51 made of this metal brazing material is joined to the sealing portion of the base 2. The external shape of the metal lid 5 in plan view is substantially the same as or slightly smaller than that of the ceramic base.

  The sealing part of the base 2 in which the IC 4 and the crystal resonator element 3 are stored in the storage part 2a is covered with a metal lid 5, and the bonding material 51 of the metal lid 5 and the sealing part of the base are melted. The surface mount type crystal oscillator 1 is completed by curing and hermetically sealing.

  The surface-mount type crystal oscillator 1 configured as described above is bonded to a wiring pattern of a circuit board (not shown) using a bonding material such as solder.

  In the embodiment of the present invention, the base 2 having a concave cross section in which a frame portion is formed only on one main surface side (upper side) of the substrate portion 20 is described as an example. However, as shown in FIG. The upper frame portion 26 and the lower frame portion 27 are formed on both the main surface side (upper side) and the other main surface side (lower side) of the substrate portion 24 (base middle layer 1) and the substrate portion 25 (base middle layer 2). The present invention may be applied to the base 2A having a substantially H-shaped cross section. In addition, about a board | substrate part (base middle layer), you may form not only in multiple layers but in a single layer according to the extension form of the internal wiring between lamination | stacking.

  In FIG. 6, piezoelectric connection terminals AT3 and AT4 are formed in the notch 24d of the substrate portion 24 (base middle layer 1) and the notch 25d of the substrate portion 25 (base middle layer 2). Compared with the notch portion 26d and the notch portion 27d of the lower frame portion 27, a recess size toward the storage portion of the base is formed to constitute the recesses 241d and 251d. In addition, not only the surface portions of the side surfaces of the notches 24d and 25d, but also the conductive material on the lower surface portion of the upper frame portion 26 and the upper surface portion of the lower frame portion 27 that are in contact with and adjacent to the notch portion 24d. Are formed, and the piezoelectric connection terminals AT3 and AT4 are configured on the entire inner surface of the recesses 241d and 251d.

  With these configurations, the surface area of the piezoelectric connection terminals AT3 and AT4 can be increased, so that the probability of contact with the contact pins for characteristic measurement is increased and a part of the contact pins is securely locked by the recesses 241d and 251d. Thus, positioning to the piezoelectric connection terminals AT3 and AT4 can be facilitated. That is, it is possible to configure the piezoelectric connection terminals AT3 and AT4 having high connectivity while corresponding to downsizing of the base 2A serving as a container.

In the above-described embodiment, the AT cut quartz crystal vibrating plate is used as the piezoelectric vibrating element. However, the present invention is not limited to this, and a tuning fork type quartz vibrating piece may be used. Further, although quartz is used as the piezoelectric vibration element, the present invention is not limited to this, and a piezoelectric single crystal material such as piezoelectric ceramics or LiNbO ₃ may be used. That is, any piezoelectric vibration element can be applied. Further, although an example is shown in which the piezoelectric vibration element is held in a cantilever manner, a configuration in which both ends of the piezoelectric vibration element are held may be employed.

  In the above-described embodiment of the present invention, a crystal oscillator (piezoelectric oscillator) using an IC as an electronic component element is taken as an example, but a function using a temperature sensitive element such as a thermistor or a diode or other functional electronic component element is used. The present invention is also applicable to a crystal resonator (piezoelectric resonator) with parts.

  In this embodiment, sealing with a metal brazing material is taken as an example. However, the present invention is not limited to this, and seam sealing, beam sealing (for example, laser beam, electron beam), glass sealing, etc. Can be applied.

  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)
2,2A Base 3 Crystal oscillator (piezoelectric oscillator)
4 IC
5 lid

Claims (2)

A rectangular parallelepiped base in which a laminate of a substrate portion and a frame portion made of an insulating material is laminated in at least three layers of an upper layer, a middle layer, and a lower layer to form an exterior portion and a storage portion;
Piezoelectric vibration element and electronic component element housed in the base housing part,
A lid bonded to the upper surface of the frame portion of the base upper layer and hermetically sealing the storage portion by the frame portion of the base upper layer;
Formed on the lower surface of the lower layer of the base, and external connection terminals for connecting to the outside,
A notch formed on the outer peripheral edge of the upper layer, middle layer and lower layer of the base and recessed toward the storage portion side of the base,
A piezoelectric connection terminal formed in a notch in the middle layer of the base and electrically connected to the piezoelectric vibration element;
With
The size of the recess to the storage portion side of the notch portion of the middle layer of the base is formed larger than the size of the recess to the storage portion side of the upper layer and the bottom notch portion of the base,
By laminating the upper layer, middle layer, and lower layer of the base, the notch of each layer extends in a single line along the height direction of the base, and the notch of the middle layer of the base further moves toward the storage unit. Consists of a recessed recess,
The piezoelectric vibration device, wherein the piezoelectric connection terminal is formed on the entire inner surface of the recess. The piezoelectric vibration device according to claim 1,
At least one of the notch in the upper layer of the base adjacent to the recess and the notch in the lower layer of the base adjacent to the recess has the piezoelectric connection terminal. A piezoelectric vibration device characterized in that an extended piezoelectric connection auxiliary terminal is formed.

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