JP2010178170A - Piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric oscillator that secures an area of a terminal to which a probe pin is applied even if the piezoelectric oscillator is downsized.
A substrate body, a piezoelectric vibration element disposed in a first cavity portion provided on one main surface of the substrate body, and a first surface provided on the other main surface of the substrate body. An integrated circuit element disposed in the two cavity portions, a lid for sealing the piezoelectric vibration element of the first cavity portion provided on one main surface of the substrate body, and the substrate body A plurality of integrated circuit element mounting pads formed in a second cavity portion provided on the other main surface, and two of the integrated circuit element mounting pads are electrically connected to the piezoelectric vibration element. The crystal terminals are connected to each other, and the crystal terminals are monitor terminals for inspecting the electrical characteristics of the piezoelectric vibration element.
[Selection] Figure 3

Description

  The present invention relates to a piezoelectric oscillator used in an electronic device.

  2. Description of the Related Art Conventionally, a piezoelectric oscillator that is one of electronic components is mounted on an electronic device such as a portable communication device. An example of a piezoelectric oscillator is a crystal oscillator. This crystal oscillator is used as, for example, a reference signal generation source or a clock signal generation source.

As shown in FIG. 9, a conventional piezoelectric oscillator 500 is a laminate composed of a piezoelectric vibration element 520, an integrated circuit element 530 constituting an oscillation circuit and a temperature compensation circuit, and a plurality of insulating layers. And a second cavity portion 512 (see FIG. 10) for housing the integrated circuit element 530 on the other main surface. A substantially rectangular substrate 510 and a lid 540 for hermetically sealing the first cavity 511 are provided.
The piezoelectric oscillator 500 includes a piezoelectric vibration element connecting electrode pad 513 formed on the inner bottom surface of the first cavity portion 511 and a first end portion of the piezoelectric vibration element 520 via a conductive adhesive (not shown). The first cavity portion 511 is hermetically sealed by the lid body 540 after being cantilevered and electrically connected to the inner bottom surface (ceiling) of the second cavity portion 512 (see FIG. 10). The integrated circuit element 530 is flip-chip mounted on the surface) via bumps (not shown).

  Further, as shown in FIG. 10, the second cavity portion 512 has an external connection electrode terminal 515 disposed on each corner of the substrate body 510, the piezoelectric vibration element 520, and the electrical connection. Monitor terminals 518a and 518b to be connected to each other are arranged. In addition, an integrated circuit element mounting pad 514 for mounting the integrated circuit element 530 is disposed around the monitor terminals 518a and 518b. Two of the integrated circuit element mounting pads 514 are electrically connected to the piezoelectric vibration element 520 via the piezoelectric vibration element connection electrode pad 513 and a conductive adhesive (not shown). This is called a crystal terminal. Further, the crystal terminal and the monitor terminal 518 are usually electrically connected by internal wiring of the substrate body 510. Therefore, the monitor terminal 518 is electrically connected to the piezoelectric vibration element 520 through the crystal terminal. The monitor terminal 518 is used as a terminal for inspecting the electrical characteristics of the piezoelectric vibration element 520. This inspection is necessary for the pass / fail determination of the piezoelectric vibration element 520, and the integrated circuit element 530 is mounted only on a product that has passed the pass / fail determination. The actual inspection is performed by bringing the probe pin into contact with the monitor terminal 518.

JP 2003-163540 A

  However, in the conventional piezoelectric oscillator 500, when the width (W) and length (L) of the outer dimensions are reduced to about 2.0 mm × 1.6 mm, for example, the crystal terminal is between the integrated circuit element mounting pads 514. Since the area of the monitor terminal 518 arranged separately becomes small, it may be difficult to measure the electrical characteristics of the piezoelectric vibration element by applying a probe pin to the monitor terminal 518. In FIG. 10, two predetermined crystal terminals 517 and monitor terminals 518 of the integrated circuit element mounting pad 514 are provided separately. A total of ten integrated circuit element mounting pads 514 are arranged, for example, five in the horizontal direction and two in the vertical direction with respect to the paper surface of FIG. If this is described in a matrix, it is an array of 2 rows and 5 columns. The monitor terminal 518 is provided between the rows of the integrated circuit element mounting pads 514. Therefore, when the piezoelectric oscillator 500 becomes smaller, the area of the integrated circuit element 530 that can be mounted in the second cavity portion 512 also becomes smaller. As a result, the row interval of the integrated circuit element mounting pads 514 is also narrowed, and the area of the monitor terminal 518 disposed between the rows cannot be increased.

  Accordingly, an object of the present invention is to provide a piezoelectric oscillator that solves the above-described problems and secures an area of a terminal to which a probe pin is applied even if the piezoelectric oscillator is downsized.

  A piezoelectric oscillator according to the present invention is provided on a substrate body, a piezoelectric vibration element disposed in a first cavity portion provided on one main surface of the substrate body, and on the other main surface of the substrate body. An integrated circuit element disposed in the second cavity portion, a lid for sealing the piezoelectric vibration element in the first cavity portion provided on one main surface of the substrate body, A plurality of integrated circuit element mounting pads formed in a second cavity portion provided on the other main surface of the substrate body, and a predetermined two of the integrated circuit element mounting pads, A crystal terminal electrically connected to the piezoelectric vibration element is used, and the crystal terminal is used as a monitor terminal for inspecting electric characteristics of the piezoelectric vibration element.

  The piezoelectric oscillator according to the present invention is characterized in that, in the above configuration, the integrated circuit element mounting pads serving as monitor terminals for inspecting the electrical characteristics of the piezoelectric vibration element are arranged on a diagonal line.

  As described above, in the piezoelectric oscillator according to the present invention, two of the integrated circuit element mounting pads are crystal terminals electrically connected to the piezoelectric vibration element, and the crystal terminal is a monitor terminal for inspecting the electrical characteristics of the piezoelectric vibration element. Therefore, there is no need to place the monitor terminal between the integrated circuit element mounting pads, so even if the piezoelectric oscillator is downsized, the crystal terminal and the monitor terminal are arranged separately like the conventional piezoelectric oscillator. Compared to the above, the area of the monitor terminal can be increased. Therefore, it is possible to measure the electrical characteristics of the piezoelectric vibration element by applying the probe pin to the monitor terminal. Further, by using two of the integrated circuit element mounting pads as monitor terminals, there is no need to arrange the monitor terminals between the rows of the integrated circuit element mounting pads, and it is possible to cope with further miniaturization of the piezoelectric oscillator.

  Furthermore, in the piezoelectric oscillator according to the present invention, since the monitor terminal for inspecting the electrical characteristics of the piezoelectric vibration element is disposed diagonally with the integrated circuit element mounting pad, the stray capacitance generated between the two monitor terminals is prevented. It can also be made smaller.

It is a schematic sectional drawing of the piezoelectric oscillator which shows embodiment of this invention. It is the conceptual diagram which showed the piezoelectric oscillator of this invention from the electrode terminal side for external connection. It is a conceptual diagram which shows the state before integrated circuit element mounting of the piezoelectric oscillator of FIG. It is a conceptual diagram which shows the 1st modification of the piezoelectric oscillator of this invention. It is a conceptual diagram which shows the 2nd modification of the piezoelectric oscillator of this invention. It is a conceptual diagram which shows the 3rd modification of the piezoelectric oscillator of this invention. It is a conceptual diagram which shows the 4th modification of the piezoelectric oscillator of this invention. It is a conceptual diagram which shows the 5th modification of the piezoelectric oscillator of this invention. It is a disassembled perspective view which shows one form of the conventional piezoelectric oscillator. It is the top view which showed arrangement | positioning of the monitor terminal of the conventional piezoelectric oscillator from the mounting side.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view of a piezoelectric oscillator showing an embodiment of the present invention. FIG. 2 is a conceptual diagram showing the piezoelectric oscillator from the external connection electrode terminal side. FIG. 3 is a conceptual diagram showing a state before the integrated circuit element of the piezoelectric oscillator of FIG. 2 is mounted. In each drawing, for clarity of explanation, some of the components are not shown, and the dimensions of the components shown are also exaggerated.

  As shown in FIGS. 1 and 2, the piezoelectric oscillator 100 of the present invention mainly includes a substrate body 110, a piezoelectric vibration element 120, an integrated circuit element 130, and a lid body 140. The substrate body 110 includes a substrate part 110a, a first frame part 110b, and a second frame part 110c. The first frame portion 110b is provided on one main surface of the substrate portion 110a having a rectangular shape in plan view, and the second frame portion 110c is provided on the other main surface. As a result, the first cavity portion 111 is formed on one main surface of the substrate portion 110a, and the second cavity portion 112 is formed on the other main surface. In addition, the board | substrate part 110a, the 1st frame part 110b, and the 2nd frame part 110c which comprise this board | substrate body 110 consist of ceramic materials, such as glass-ceramics and an alumina ceramic, for example.

  In addition, as shown in FIGS. 1 to 3, two pairs of piezoelectric vibration element connecting electrode pads 113 are provided on one main surface of the substrate portion 110 a on which the first cavity portion 111 is formed. ing. For example, six integrated circuit element mounting pads 114 are provided on the other main surface of the substrate part 110a on which the second cavity part 112 is formed. In the present invention, two of the integrated circuit element mounting pads 114 are the crystal terminals 117 electrically connected to the piezoelectric vibration element 120, and the crystal terminals 117 are the piezoelectric vibration elements 120. This is a monitor terminal 118 for inspecting the electrical characteristics.

  In addition, external connection electrode terminals 115 are provided at the four corners of the second frame portion 110c forming the second cavity portion 112, which are conductively fixed to the external mounting substrate when the piezoelectric oscillator 100 is mounted. Yes.

  The piezoelectric vibration element 120 is disposed in the first cavity portion 111, and has a rectangular piezoelectric element plate in plan view, and excitation electrodes (not shown) provided at the center of both main surfaces of the piezoelectric element plate. The lead electrode is mainly composed of an extraction electrode (not shown) extending from the excitation electrode to one short side end of the piezoelectric element plate. As shown in FIG. 1, the piezoelectric vibration element 120 having such a configuration includes a first cavity portion 111 by electrically connecting and fixing an extraction electrode and a piezoelectric vibration element connection electrode pad 113 with a conductive adhesive 121. It is mounted inside.

  The lid 140 is a flat plate made of a metal such as 42 alloy, Kovar or phosphor bronze, for example, and is arranged on the top surface of the first frame portion 110b so as to cover the first cavity portion 111. It is joined to the frame part 110b. With the lid 140, the inside of the first cavity portion 111 is hermetically sealed.

  The integrated circuit element 130 is disposed in the second cavity portion 112, and six integrated circuit elements formed on the other main surface of the substrate portion 110a on which the second cavity portion 112 is formed. It is mounted on the mounting pad 114 via bumps 131 made of gold or solder. Note that a total of six integrated circuit element mounting pads 114 are arranged with respect to the second frame portion 110c, for example, three in the horizontal direction and two in the vertical direction with respect to the paper surface of FIG. If this is described in a matrix, it is an array of 2 rows and 3 columns. Further, predetermined two of the six integrated circuit element mounting pads 114 are crystal terminals 117, and the crystal terminals 117 serve as monitor terminals 118 for inspecting the electrical characteristics of the piezoelectric vibration element 120. In the integrated circuit element 130, an electronic circuit including an oscillation circuit, a temperature compensation circuit, and the like is provided. This electronic circuit is electrically connected to the piezoelectric vibration element 120 and external connection electrode terminals 115 formed at the four corners of the second frame portion 110c.

  Here, two of the integrated circuit element mounting pads 114 in the present invention are monitor terminals 118. For example, in FIG. 3, two monitor terminals 118 are arranged one by one in the center of the integrated circuit element mounting pad 114 (the second column in the matrix manner). Such an arrangement of the monitor terminal 118 allows the area of the monitor terminal 118 to be larger than the area of the other integrated circuit element mounting pads 114 even in the structure in which the piezoelectric oscillator 100 is small. Therefore, since the electrical characteristic inspection of the piezoelectric vibration element 120 can be measured without the integrated circuit element 130 before the integrated circuit element 130 is mounted, it can be easily measured by applying probe pins to the two monitor terminals 118. It becomes.

  Further, as a first modification of the present invention, as shown in FIG. 4, a monitor terminal 118 is arranged on the diagonal line of the integrated circuit element mounting pad 114. Here, the diagonal line is an arrangement in which the distance between the two monitor terminals 118 is the longest. By arranging in this way, it is possible to reduce the stray capacitance generated between the two monitor terminals 118. As a result, a piezoelectric oscillator capable of obtaining stable oscillation without being affected by stray capacitance can be obtained. The first modification shown in FIG. 4 also has the same effect as that of the embodiment of the present invention.

  Furthermore, the 2nd modification in this invention is shown in FIG. The substrate body 110 in the second modification example is described in a matrix form in the second cavity portion 112. Of the integrated circuit element mounting pads 114 of 2 rows and 3 columns, the center terminal of the first row is the monitor terminal. 118 and the terminal at either end of the second row are the monitor terminals 118. The second modification also has the same effect as the embodiment of the present invention.

  Moreover, the 3rd modification in this invention is shown in FIG. The substrate body 110 in the third modification example is arranged in a matrix with the second cavity portion 112. Of the integrated circuit element mounting pads 114 of 2 rows and 3 columns, the terminal at the end of the first row facing each other. In addition, the monitor terminal 118 is used as the terminal at the end of the second row. The third modification also has the same effect as the embodiment of the present invention.

  Moreover, the 4th modification in this invention is shown in FIG. The substrate body 110 in the fourth modification example is described in a matrix form in the second cavity portion 112. Among the integrated circuit element mounting pads 114 of 2 rows and 3 columns, two adjacent ones in one row are arranged. The terminal is a monitor terminal 118. The fourth modification also has the same effect as the embodiment of the present invention.

  Moreover, the 5th modification in this invention is shown in FIG. In the fifth modification, the substrate body 110 is arranged in a matrix with the second cavity portion 112, and the terminals at both ends of one row of the integrated circuit element mounting pads 114 in 2 rows and 3 columns are connected. The monitor terminal 118 is structured. The fifth modification also has the same effect as the embodiment of the present invention. 7 and 8 show a structure in which two monitor terminals 118 are arranged in the first row in a matrix manner, but two monitor terminals 118 may be arranged in the second row. As described above, in the present invention, the two monitor terminals 118 may be arranged at any position among the six integrated circuit element mounting pads 114.

  3 to 8 described above are arrangements of two monitor terminals 118 having a structure in which six integrated circuit mounting pads 114 are arranged in a row, three by three. Without limitation to this, when the integrated circuit element mounting pads are described in a matrix form, a structure in which four four pads are arranged in one row, a structure in which five five pads are arranged in one row, or ten or more pads are arranged. The present invention can also be applied to the structured as described above.

  Since the piezoelectric oscillator 100 according to the present invention is configured as described above, the predetermined two crystal terminals 117 of the integrated circuit element mounting pad 114 are used as the monitor terminals 118 for inspecting the electrical characteristics of the piezoelectric vibration element 120, so that the piezoelectric oscillator Even in the structure in which 100 is reduced, the area of the monitor terminal 118 can be made larger than the area of other integrated circuit element mounting pads 114. Therefore, the electrical characteristic inspection of the piezoelectric vibration element 120 can be easily performed by applying the probe pin to the monitor terminal 118.

  Further, in the present invention, the total number of the integrated circuit element mounting pad 114, the crystal terminal 117, and the monitor terminal 118 can be reduced by two as compared with the conventional piezoelectric oscillator as described above. As a result, wiring for connecting the crystal terminal 117 and the monitor terminal 118 can be eliminated. Therefore, in the piezoelectric oscillator according to the present invention, extra terminals and wirings can be eliminated, and at least it can be configured with only terminals.

  Further, when the piezoelectric oscillator 100 is further reduced, it becomes difficult to dispose the monitor terminal 118 between the integrated circuit element mounting pads 114 in which two rows arranged in the horizontal direction are arranged in two rows. Therefore, by using a part of the integrated circuit element mounting pads 114 arranged in two rows as the monitor terminals 118 as in the present invention, the monitor terminals 118 are provided between the rows of the integrated circuit element mounting pads 114 arranged in two rows. It is not necessary to arrange the piezoelectric oscillator, and it is possible to cope with further downsizing of the piezoelectric oscillator. For example, a piezoelectric oscillator having a width (W) and a length (L) of outer dimensions of about 1.6 mm × 1.2 mm can be supported.

  Further, since the monitor terminal 118 for inspecting the electrical characteristics of the piezoelectric vibration element 120 can be arranged on the diagonal line of the integrated circuit element mounting pad 114, it is possible to reduce the stray capacitance generated between the two monitor terminals 118. Become.

  In addition to the above-described embodiments, various changes and improvements can be made without departing from the scope of the present invention. For example, in the piezoelectric oscillator shown in the above-described embodiment, as a piezoelectric vibration element mounted inside, a piezoelectric vibration element in which an excitation electrode or a lead electrode is provided on the surface of a rectangular piezoelectric substrate in plan view is shown. However, the present invention is not limited to this, and for example, a piezoelectric vibration element having a circular shape in plan view or a form in which various electrodes are provided on a tuning fork-shaped piezoelectric element plate may be used. You may use.

DESCRIPTION OF SYMBOLS 100 ... Piezoelectric oscillator 110 ... Substrate body 110a ... Substrate part 110b ... 1st frame part 110c ... 2nd frame part 111 ... 1st cavity part 112 ... Second cavity 113 113 ... Electrode pad for connecting piezoelectric vibration element 114 ... Integrated circuit element mounting pad 115 ... Electrode terminal for external connection 117 ... Crystal terminal 118 ... Monitor terminal 120 ... Piezoelectric vibration element 121: conductive adhesive 130 ... integrated circuit element 131 ... bump 140 ... lid

Claims (2)

  A substrate body, a piezoelectric vibration element disposed in a first cavity portion provided on one main surface of the substrate body, and a second cavity provided on the other main surface of the substrate body An integrated circuit element disposed in a portion, a lid for sealing the piezoelectric vibration element of the first cavity portion provided on one main surface of the substrate body, and the other main surface of the substrate body A plurality of integrated circuit element mounting pads formed in a second cavity portion provided in a predetermined cavity, and two of the integrated circuit element mounting pads are electrically connected to the piezoelectric vibration element. A piezoelectric oscillator, characterized in that the crystal terminal is a monitor terminal for inspecting the electrical characteristics of the piezoelectric vibration element.   2. The piezoelectric oscillator according to claim 1, wherein the monitor terminal for inspecting the electrical characteristics of the piezoelectric vibration element has the integrated circuit element mounting pad disposed on a diagonal line.

Images