JP5210081B2 - 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. 4, 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. 5) 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 electrical connection, the first cavity portion 511 is hermetically sealed by the lid body 540, and bumps (see FIG. 5) are formed on the inner bottom surface (ceiling surface) of the second cavity portion 512 (see FIG. 5). The integrated circuit element 530 is flip-chip mounted via a not-shown).

As shown in FIG. 5, 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 conventional piezoelectric oscillator 500, it is necessary to measure the electrical characteristics of the piezoelectric vibration element 520 in order to identify the cause of failure when a failure occurs in the electrical characteristics inspection of the piezoelectric oscillator after the integrated circuit element 530 is mounted. 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, since the area where the monitor terminal 518 is exposed to the outside from the integrated circuit element 530 is small, and the gap between the wall portion of the substrate portion 510 and the side surface of the integrated circuit element 530 is narrow, the measurement probe is brought into contact with the monitor terminal 518. 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.

Therefore, 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 that can also be reduced in size. The purpose is to do.

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. Mounted on two pairs of wall portions formed only on two opposite sides of the other main surface of the rectangle, an integrated circuit element mounting pad formed on the other main surface of the substrate portion, and the integrated circuit element mounting pad Integrated circuit element, a crystal terminal electrically connected to the piezoelectric vibration element by an internal wiring on the other main surface of the integrated circuit element mounting pad and the substrate portion, and a lead wiring from the crystal terminal via a lead wiring And two first monitor terminals formed on the edge of the other main surface of the substrate portion where the wall portion is not provided between the two wall portions, and the two first monitor terminals wherein said wall portion is not provided from Characterized in that it is configured to include a second monitor terminal extending to each side of the substrate portion of the side of the other main surface of the plate portion.

  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. Even if 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 element is mounted, the second monitor terminal formed on the side surface of the substrate portion is used. It becomes possible to measure. Further, by disposing the second monitor terminal on the side surface of the substrate portion, it is possible to measure the electrical characteristics of the piezoelectric vibration element even after mounting the piezoelectric oscillator.

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 thereof. FIG. 3 is a plan view of the piezoelectric oscillator of FIG. 2 before the integrated circuit element 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 FIG. 1, the piezoelectric oscillator of the present invention is mainly configured by a substrate part 110 that accommodates a piezoelectric vibration element 120, an integrated circuit element 130, a lid 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. In addition, two pairs of wall portions 150 formed on two opposite sides are formed on the other main surface of the substrate 110a. The substrate 110a, the frame 110b, and the wall 150 are made of a ceramic material such as glass-ceramic or alumina ceramic.

On the main surface of the substrate 110a exposed to the piezoelectric vibration element connection surface side exposed in the cavity 111, two pairs of piezoelectric vibration element connection electrode pads 113 are provided, and the integrated circuit element mounting of the substrate 110a is performed. A plurality of integrated circuit element mounting pads 114 are provided on the surface-side main surface.

The wall part 150 is formed on two sides facing each other along the edge of the substrate part 110. At both corners of the wall 150, there are provided external connection electrode terminals 115 that are conductively fixed to an external electronic substrate when the piezoelectric oscillator is mounted. The wall 150 is formed in a U shape so as to protrude from the side where the wall is not formed. The two wall portions 150 are not limited to the U-shape, and may be formed in parallel to the two sides of the substrate portion 110.

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 external connection electrode terminals 115 formed at the corners of both ends of the piezoelectric vibration element 120 and the wall 150.

  Further, the integrated circuit element mounting pads 114 arranged on the substrate part 110 surrounded by the two wall parts 150 are arranged in parallel to the wall part 150 in two rows. Three integrated circuit element mounting pads 114 are arranged in one row. 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. One first monitor terminal 118 is formed on each of two sides where the wall 150 is not formed. A second monitor terminal 119 is disposed on the side surface of the substrate portion 110 extending from each terminal of the first monitor terminal 118.

  Since the first monitor terminal 118 and the second monitor terminal 119 are arranged as described above, the piezoelectric oscillator according to the present invention is integrated by the second monitor terminal 119 formed on the side surface of the substrate portion 110. Even when it becomes difficult to measure the electrical characteristics of the piezoelectric vibration element 120 by the first monitor terminal 118 formed on the other main surface of the substrate portion 110 after the circuit element 130 is mounted, the measurement is performed by the second monitor terminal 119. It becomes possible. In addition, the electrical characteristics of the piezoelectric vibration element 120 can be measured even after the piezoelectric oscillator is mounted on the electronic substrate by the second monitor terminal 119.

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 a side view. 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 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 110 ... Container body 110a ... Board | substrate 110b ... Frame body 111 ... Cavity part 113 ... Electrode pad for piezoelectric vibration element connection 114 ... Integrated circuit element mounting pad 115 ... External connection Electrode terminal 116 ... Lead wire 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 ... Cover body 150 ... Wall

Claims (1)

A piezoelectric vibration element;
A substrate portion having a cavity portion on one main surface accommodating the piezoelectric vibration element;
A lid for sealing the cavity portion;
A pair of two wall portions formed on only two opposite sides of the other principal surface of the rectangle of the substrate portion;
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 an internal wiring on the other main surface of the integrated circuit element mounting pad and the substrate portion;
Two first monitor terminals formed on an edge portion of the other main surface of the substrate portion where the wall portion between the two wall portions is not provided via a lead wire from the crystal terminal; ,
A second monitor terminal extending from the two first monitor terminals to each side surface of the substrate portion on the side of the other main surface of the substrate portion where the wall portion is not provided ;
A piezoelectric oscillator comprising:

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