JP5210093B2 - Piezoelectric oscillator - Google Patents

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. A crystal oscillator is used as an example of this piezoelectric oscillator. For example, it is used as a reference signal generation source or a clock signal generation source.

As shown in FIG. 5, 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. 6) for housing the integrated circuit element 530 on the other main surface. A substantially rectangular substrate part 510 and a lid 540 for hermetically sealing the first cavity part 511 are provided.
The piezoelectric vibration element connecting electrode pad 513 formed on the inner bottom surface of the first cavity portion 511 is cantilevered at one end of the piezoelectric vibration element 520 via a conductive adhesive (not shown). After the electrical connection, the first cavity portion 511 is hermetically sealed by the lid 540, and bumps (see FIG. 6) are formed on the inner bottom surface (ceiling surface) of the second cavity portion 512 (see FIG. 6). The integrated circuit element 530 is flip-chip mounted via a not-shown).

As shown in FIG. 6, the second cavity portion 512 is electrically connected to the external connection electrode terminals 515 disposed on the corners of the side portions of the substrate portion 510 and the piezoelectric vibration element 520. Monitor terminals 518a and 518b to be connected are arranged. Further, 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 and are called crystal terminals. Further, the crystal terminal and the monitor terminal 518 are usually electrically connected by internal wiring of the substrate portion 510.
JP 2003-163540 A

  However, in the case of the conventional piezoelectric oscillator 500, when the electrical characteristics of the piezoelectric oscillator after mounting the integrated circuit element 530 becomes defective, it is necessary to measure the electrical characteristics of the piezoelectric vibration element 520 in order to identify the cause of the failure. In the measurement, a monitor terminal 518 disposed in the second cavity portion 512 electrically connected to the piezoelectric vibration element 520 is used. However, when the integrated circuit element 530 is mounted in the second cavity portion 512 as shown in FIG. 5, a part of the monitor terminal 518 is hidden in the integrated circuit element 530. In such a case, in order to measure the electrical characteristics of the piezoelectric vibration element 520, it is necessary to bring a measurement probe or the like into contact with the monitor terminal 518 in a state where the integrated circuit element 530 is mounted. Therefore, the area where the monitor terminal 518 is exposed to the outside from the integrated circuit element 530 is small, and further, the gap between the wall portion of the substrate portion 510 and the side surface of the integrated circuit element 530 is narrow, so that the measurement probe is brought into contact with the monitor terminal. It becomes difficult. In order to simplify this measurement, the integrated circuit element 530 had to be peeled off and measured. Further, when the piezoelectric oscillator 500 is downsized, the second cavity portion 512 on which the integrated circuit element 530 is mounted is similarly reduced. As a result, the electrical characteristics of the piezoelectric vibration element 520 cannot be measured after the integrated circuit element 530 is mounted in the second cavity portion 512. That is, when the piezoelectric oscillator is downsized, there is a problem that the electrical characteristics of the piezoelectric vibration element 520 cannot be measured unless the integrated circuit element 530 is peeled off.

  Accordingly, the present invention provides a piezoelectric oscillator that solves the above-described problems and has a monitor terminal arrangement structure that can measure the electrical characteristics of the piezoelectric vibration element even after the integrated circuit element is mounted, and is not affected by external noise. For the purpose.

A piezoelectric oscillator according to the present invention includes a piezoelectric resonator element, a substrate portion having a cavity portion on one main surface that accommodates the piezoelectric resonator element, a lid that seals the cavity portion, and the substrate portion. A wall portion formed on the entire periphery of the edge portion of the other main surface, an integrated circuit element mounting pad formed on the other main surface of the substrate portion, and an integrated circuit element mounted on the integrated circuit element mounting pad; A crystal terminal electrically connected to the piezoelectric vibration element by internal wiring on the other main surface of the integrated circuit element mounting pad and the substrate portion; and a first monitor terminal connected to the crystal terminal by internal wiring And a second monitor terminal extending from the first monitor terminal to each side surface of the board portion via a connection wiring, and the connection wiring is cut in a mounted state on an external mounting board. characterized in that it is To.

  As described above, the piezoelectric oscillator according to the present invention includes the second monitor terminals extending from the two first monitor terminals to the respective side surfaces of the substrate portion in a state before the piezoelectric oscillator is mounted on the external mounting substrate. Therefore, even when the piezoelectric oscillator is downsized and it becomes difficult to measure the electrical characteristics of the piezoelectric vibration element with the first monitor terminal formed on the other main surface of the substrate portion after the integrated circuit element is mounted, It becomes possible to measure with the second monitor terminal formed on the side surface of the part.

  Furthermore, in the piezoelectric oscillator according to the present invention, the connection wiring connecting the first monitor terminal and the second monitor terminal in a state of being mounted on the external mounting board is cut in a state of being mounted on the external mounting board. It is possible to obtain a stable piezoelectric oscillator that is not affected by external noise by blocking external noise that affects integrated circuit elements and piezoelectric vibration elements that are installed inside the piezoelectric oscillator through the second monitor terminal. It becomes.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic sectional view showing an embodiment of the piezoelectric oscillator of the present invention. FIG. 2A is a plan view showing the piezoelectric oscillator from the mounting side, and FIG. 2B is a side view from the short side thereof. 3 is a plan view of the piezoelectric oscillator of FIG. 2 before the integrated circuit element is mounted. FIG. 4 is a conceptual diagram showing a state where the piezoelectric oscillator is mounted on an external mounting board (not shown). 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 is mainly configured by a substrate part 110 containing a piezoelectric vibration element 120, an integrated circuit element 130, a lid body 140, and a wall part 150. The substrate unit 110 is configured by providing a frame 110b on one main surface of a substrate 110a having a rectangular shape in plan view. Thereby, the cavity part 111 is formed on one main surface of the board | substrate 110a. Further, on the other main surface of the substrate 110a, a wall portion 150 is formed around the entire edge of the main surface. The substrate 110a, the frame 110b, and the wall 150 are made of a ceramic material such as glass-ceramic or alumina ceramic.

  Further, as shown in FIG. 3, two pairs of piezoelectric vibration element connection electrode pads 113 are provided on the main surface of the substrate 110a exposed in the cavity portion 111 on the piezoelectric vibration element connection surface side. A plurality of integrated circuit element mounting pads 114 are provided on the main surface of the substrate 110a on the integrated circuit element mounting surface side.

  The wall part 150 is formed so as to cover the periphery of the integrated circuit element 130 on the entire periphery of the edge part of the substrate part 110. At the four corners of the wall 150, there are provided external connection electrode terminals 115 that are conductively fixed to the external mounting substrate when the piezoelectric oscillator 100 is mounted.

  The piezoelectric vibration element 120 includes a piezoelectric element plate having a rectangular shape in plan view, an excitation electrode (not shown) provided at the center of both main surfaces of the piezoelectric element plate, and one of the piezoelectric element plates from the excitation electrode. And an extraction electrode (not shown) extending to the short side end. The piezoelectric vibration element 120 having such a configuration is mounted in the cavity portion 111 by electrically connecting and fixing the extraction electrode and the piezoelectric vibration element connecting electrode pad 113 with the conductive adhesive 121.

  The lid 140 is a flat plate made of a metal such as 42 alloy, Kovar, or phosphor bronze, for example, and is arranged in a form covering the opening of the cavity 111 on the cavity 111 opening-side top surface of the frame 110b. It is joined to the frame 110b. The inside of the cavity 111 is hermetically sealed by the lid 140.

  The integrated circuit element 130 is mounted on a plurality of integrated circuit element mounting pads 114 provided on the integrated circuit element mounting surface main surface of the substrate 110a. 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 resonator element 120 and external connection electrode terminals 115 formed at the four corners of the wall 150.

  Further, the integrated circuit element mounting pads 114 arranged on the substrate part 110 surrounded by the wall part 150 are arranged in two rows in parallel with the wall part 150, and three pads are arranged in one line. Two predetermined ones of the integrated circuit element mounting pads 114 are crystal terminals 117. One of the crystal terminals 117 is connected to the piezoelectric vibration element 120 via an internal wiring (not shown), and the other is connected to the first monitor terminal 118 via an internal wiring (not shown). .

  As shown in FIG. 3, two first monitor terminals 118 are arranged side by side in the central region of the other main surface of the substrate unit 110. A second monitor terminal 119 is disposed on the side surface of the substrate 110 a from each terminal of the first monitor terminal 118 via the connection wiring 116. The first monitor terminal 118 and the second monitor terminal 119 are electrically connected via the connection wiring 116, and part of the connection wiring 116 passes between the substrate 110 a and the wall portion 150. Yes. Thus, before mounting the piezoelectric oscillator on the external mounting substrate, the second monitor terminal 119 formed on the side surface of the substrate unit 110 causes the second main terminal formed on the other main surface of the substrate unit 110 after the integrated circuit element 130 is mounted. Even when it becomes difficult to measure the electrical characteristics of the piezoelectric vibrating element 120 with one monitor terminal 118, it is possible to measure with the second monitor terminal 119.

  Further, as shown in FIG. 4, the connection wiring 116 connecting the first monitor terminal 118 and the second monitor terminal 119 is cut off when mounted on an external mounting board (not shown). The connection wiring 116 is cut by irradiating the connection wiring 116 with laser light before mounting the piezoelectric oscillator on an external mounting substrate (not shown). As a result, the external noise that enters the second monitor terminal 119 and affects the integrated circuit element 130 and the piezoelectric vibration element 120 mounted inside the piezoelectric oscillator is blocked, and a stable piezoelectric oscillator that is not affected by the external noise is obtained. Can be obtained.

  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, a piezoelectric vibration element having an excitation electrode and an extraction electrode provided on the surface of a rectangular piezoelectric element plate in a plan view is shown as a piezoelectric vibration element mounted inside. Without being limited thereto, for example, a piezoelectric vibration element in which various electrodes are provided on a piezoelectric base plate having a circular or tuning fork shape in plan view may be used, or a surface acoustic wave element may be used instead of the piezoelectric vibration element. It doesn't matter.

It is the schematic sectional drawing which showed one form of the piezoelectric oscillator of this invention. (A) is the top view which showed the piezoelectric oscillator of this invention from the mounting side, (b) is the side view from the short side. It is the top view which showed the piezoelectric oscillator of this invention from the mounting side before mounting an integrated circuit element. It is a conceptual diagram which shows the state which mounted the piezoelectric oscillator of this invention on the external mounting board | substrate. It is a disassembled perspective view which shows one form of the conventional piezoelectric oscillator. It is the top view which showed the conventional piezoelectric oscillator from the mounting side before mounting an integrated circuit element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Piezoelectric oscillator 110 ... Substrate part 110a ... Substrate 110b ... Frame body 111 ... Cavity part 113 ... Electrode pad for connecting a piezoelectric vibration element 114 ... Integrated circuit element mounting pad DESCRIPTION OF SYMBOLS 115 ... External connection electrode terminal 116 ... Connection wiring 117 ... Crystal terminal 118 ... First monitor terminal 119 ... Second monitor terminal 120 ... Piezoelectric vibration element 121 ... Conductive adhesive 130 ... Integrated circuit element 131 ... Bump 140 ... Lid 150 ... Wall

Claims (1)

Piezoelectric vibration element, substrate portion having a cavity portion on one main surface that accommodates the piezoelectric vibration element, lid body sealing the cavity portion, and edge portion of the other main surface of the substrate portion A wall portion formed on the entire circumference, an integrated circuit element mounting pad formed on the other main surface of the substrate portion, an integrated circuit element mounted on the integrated circuit element mounting pad, and the integrated circuit element mounting pad; A crystal terminal electrically connected to the piezoelectric vibration element by internal wiring on the other main surface of the substrate portion, a first monitor terminal connected to the crystal terminal by internal wiring, and the first monitor terminal A second monitor terminal extending to each side surface of the substrate portion via a connection wiring , and
The piezoelectric oscillator , wherein the connection wiring is cut in a mounted state on an external mounting board .

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