JP2007150394A - Piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive piezoelectric device which is miniaturized. <P>SOLUTION: The piezoelectric device 10 is provided with a substrate 12 arranged near the center in a thickness direction; a resonator package 28 in which a cavity S1 for housing a piezoelectric resonator 20 so that the substrate 12 is used as a bottom on the upper surface of the substrate 12 is formed on the upper surface of the substrate 12; and an electronic component arranged on the lower surface of the substrate 12 and electrically connected to a piezoelectric resonation piece 20. The resonator package 28 is arranged so as to form vacant regions 16, 16 on the upper surface of the substrate 12, and a plurality of inspection terminal portions 18, 18 electrically connected to the piezoelectric resonation piece 20 and/or the electronic component are provided on the vacant regions 16, 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a piezoelectric device including a piezoelectric vibrating piece and an electronic component arranged with a substrate interposed therebetween.

Piezoelectric devices are widely used in small information devices such as HDDs (hard disk drives), mobile computers, and IC cards, and mobile communication devices such as mobile phones, car phones, and paging systems.
FIG. 6 shows a conventional example of this piezoelectric device, and is a schematic longitudinal sectional view of the piezoelectric oscillator 1 (see, for example, Patent Document 1).
The piezoelectric oscillator 1 in this figure includes a substrate 2 disposed near the center in the thickness direction, a piezoelectric vibrating piece 3 connected to the upper surface of the substrate 2, and a semiconductor element 4 connected to the lower surface of the substrate 2. ing.

The piezoelectric vibrating reed 3 is accommodated in a vibrator package 5 in which a cavity S is formed with the substrate 2 as a bottom, and is electrically connected to the semiconductor element 4 through a via hole 7 provided in the substrate 2. ing.
The semiconductor element 4 is connected to the substrate 2 through an electrode pattern (not shown).
It is connected to the terminals 8 and 8 exposed to the outside and sealed with resin.

As described above, the piezoelectric oscillator 1 distinguishes between the cavity S in which the piezoelectric vibrating piece 3 is accommodated and the region 6 in which the semiconductor element 4 is disposed, and impurities adhere to the piezoelectric vibrating piece 3 to change the frequency characteristics. To prevent that. The substrate 2 is also used as a bottom portion of the vibrator package 5 and is also used as a substrate for connecting the semiconductor element 4, so that the piezoelectric oscillator 1 can be reduced in height.

Japanese Patent Laid-Open No. 2000-77942

However, in such a piezoelectric oscillator 1, in the manufacturing process, after connecting the piezoelectric vibrating piece 3 and the semiconductor element 4 to the substrate 2, the probe pin is applied to the terminals 8 and 8 to inspect the operation characteristics. ing. If there is a problem in the operation characteristics, it is unclear whether there is a problem on the piezoelectric vibrating piece 3 side or a problem on the semiconductor element 4 side. Even if there is a problem only in one of them, both 3 and 4 have to be discarded, which has been a factor that cannot reduce the manufacturing cost.

  An object of the present invention is to provide an inexpensive piezoelectric device while reducing the size.

According to the first aspect of the present invention, the substrate is disposed near the center in the thickness direction, and is disposed on the upper surface of the substrate so as to accommodate the piezoelectric vibrating reed with the substrate at the bottom. A piezoelectric device comprising: a vibrator package having a cavity formed thereon; and an electronic component disposed on a lower surface of the substrate and electrically connected to the piezoelectric vibrating piece, wherein the vibrator package includes the substrate This is achieved by a piezoelectric device which is arranged so as to form a vacant area on the upper surface of the substrate and in which a plurality of inspection terminal portions electrically connected to the piezoelectric vibrating piece and / or the electronic component are provided. The

According to the configuration of the first invention, the piezoelectric device is formed with a substrate disposed near the center in the thickness direction and a cavity that is disposed on the upper surface of the substrate and accommodates the piezoelectric vibrating reed with the substrate at the bottom. And the electronic component disposed on the lower surface of the substrate. For this reason, since the substrate for distinguishing the cavity for housing the piezoelectric vibrating piece and the region for placing the electronic component and the substrate constituting the bottom of the vibrator package can be made common, the piezoelectric device can be arranged in the thickness direction. Can be downsized.
The vibrator package is arranged so as to form an empty area on the upper surface of the substrate, and a plurality of inspection terminal portions electrically connected to the piezoelectric vibrating piece and / or the electronic component are provided in the empty area. Yes. Therefore, for example, in the case where an inspection terminal portion electrically connected to the piezoelectric vibrating piece is provided in the empty area, after the piezoelectric vibrating piece is connected to the substrate and the vibrator package is formed, the electronic component is Before the connection, the probe pin can be applied to the inspection terminal portion to inspect the operation characteristics of the piezoelectric vibrating piece alone. In addition, since the inspection terminal portion is provided on the upper surface of the substrate, the probe pin can be easily brought into contact with each other, and poor contact of the probe pin can be prevented.
Thus, the present invention can provide an inexpensive piezoelectric device while reducing the size.

According to a second invention, in the configuration of the first invention, the substrate has a substantially rectangular outer shape in the horizontal direction, and the piezoelectric vibrating piece has a substantially rectangular outer shape in the horizontal direction and is near the center of the substrate. The angle formed by the central axis parallel to the side surface of the piezoelectric vibrating piece and one of the diagonal lines of the substrate is set to approximately 0 degrees.
According to the configuration of the second aspect of the invention, the substrate is a portion having a straight line with the longest diagonal because the horizontal outer shape is substantially quadrangular. Therefore, with respect to the diagonal line having the longest straight line, the piezoelectric vibrating reed whose horizontal outer shape is substantially rectangular is set so that the angle of the central axis parallel to the side surface becomes approximately 0 degrees, and If arranged near the center, the piezoelectric vibrating piece can be formed large on the substrate. Therefore, the space can be formed without enlarging the substrate by the amount that the piezoelectric vibrating piece can be enlarged, and the piezoelectric device can be downsized.

According to a third aspect of the present invention, in the configuration of the first aspect, the substrate has a substantially rectangular outer shape in the horizontal direction, and the piezoelectric vibrating piece has a substantially rectangular outer shape in the horizontal direction, and has a side surface thereof. A parallel central axis is arranged on a diagonal line of the substrate.
According to the configuration of the third aspect of the invention, the substrate is a portion having a straight line with the longest diagonal because the horizontal outer shape is substantially quadrangular. Therefore, if a central axis parallel to the side surface of the piezoelectric vibrating piece having a substantially rectangular outer shape is arranged on the diagonal line having the longest straight line, the piezoelectric vibrating piece can be formed large on the substrate. Therefore, the space can be formed without enlarging the substrate by the amount that the piezoelectric vibrating piece can be enlarged, and the piezoelectric device can be downsized.

According to a fourth invention, in the configuration of the first invention, the substrate has a substantially rectangular outer shape in the horizontal direction, and the piezoelectric vibrating piece has a substantially circular outer shape in the horizontal direction.
According to the configuration of the fourth aspect of the invention, the piezoelectric vibrating piece has a substantially circular outer shape in the horizontal direction. Therefore, on the substrate having a substantially rectangular outer shape in the horizontal direction, empty areas are efficiently formed at the four corners of the substrate. However, the piezoelectric vibrating piece can be formed large. Accordingly, the horizontal outer shape of the substrate may be reduced by the amount that the piezoelectric vibrating piece can be formed efficiently and large, and the piezoelectric device can be reduced in size.

According to a fifth invention, in any one of the first to fourth inventions, the vibrator package is disposed so as to spatially partition the plurality of inspection terminal portions from each other.
According to the configuration of the fifth invention, the vibrator package is disposed so as to spatially partition the plurality of inspection terminal portions from each other. Therefore, in order to inspect the operation characteristics of the piezoelectric vibrating piece or the electronic component, when the plurality of probe pins are brought into contact with the plurality of inspection terminal portions, the plurality of inspection terminal portions are spatially partitioned from each other. It is possible to prevent the probe pins from contacting each other.

1 to 3 show an embodiment of a piezoelectric oscillator 10 as an example of the piezoelectric device of the present invention. FIG. 1 is a schematic plan view of the piezoelectric oscillator 10 and FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. FIG. 3 and FIG. 3 are schematic sectional views taken along line BB in FIG. In FIG. 1, the lid 34 is made transparent to show the internal configuration for convenience of understanding.
2 and 3, the piezoelectric oscillator 10 includes a substrate 12, a vibrator package 28 disposed on the upper surface 12a of the substrate 12, and an electronic component 30 disposed on the lower surface 12b of the substrate 12. I have.

The substrate 12 is disposed near the center of the piezoelectric oscillator 10 in the thickness direction, and the vibrator package 2
This is a substrate for separating the 8 side and the electronic component 30 side.
It becomes the board | substrate which comprises the bottom part.
The substrate 12 is formed by, for example, laminating a plurality of flat substrates 13, 14, 15 formed by molding an aluminum oxide ceramic green sheet as an insulating material, and then sintering. That is, a plurality of conductors that electrically connect each component of the piezoelectric oscillator 10 are routed so as not to contact each other by using each layer of the layer structure. In this embodiment, the substrate 12 has three layers. The layers 13, 14 and 15 are formed.
The substrate 12 is formed corresponding to the outer shape of the electronic component 30. Since the electronic component 30 of the present embodiment is a rectangular semiconductor element as will be described later, the substrate 12 has a horizontal outer shape. It is almost square. That is, the horizontal direction in the present embodiment is a direction parallel to the mounting surface. As shown in FIG. 1, when viewed in plan from the top to the bottom in the thickness direction of the piezoelectric oscillator 10, the outer shape of the substrate 12 Is a substantially square.

The vibrator package 28 is formed with a cavity S1 for accommodating the piezoelectric vibrating piece 20 with the substrate 12 at the bottom, and is disposed on the upper surface 12a of the substrate 12.
That is, a resonator package substrate 32 having a through hole 32a is laminated on the uppermost substrate 13 of the substrate 12 to form a cavity S1 having an upward opening. The piezoelectric vibrating piece 20 is accommodated in the housing.

As shown in FIGS. 1 and 2, a lid 34 is joined to the end face of the substrate 32 on the opening side so that the cavity S1 is hermetically sealed. In the present embodiment, a plate-like lid 34 having a substantially rectangular outer shape in the horizontal direction is fixed to the opening end of the substrate 32 with a brazing material 37.
The lid 34 is preferably described later via a conductor (not shown) drawn around each of the substrates 12 and 32 using a conductive metal, for example, a metal-based Fe—Ni—Co alloy. By grounding through the electronic component 30, a shielding effect can be provided. When the metal lid 34 is used in this way, a seam ring made of Kovar or the like can be used for the brazing material 37.

The piezoelectric vibrating piece 20 is connected to a region exposed to the cavity S <b> 1 on the upper surface 12 a of the substrate 12. That is, on the upper surface 12a exposed to the cavity S1, a plurality of mount electrodes 26, 26 formed by, for example, nickel plating and gold plating on a tungsten metallization are provided. The piezoelectric vibrating piece 20 is connected using conductive adhesives 36 and 36 such as epoxy.

Specifically, the piezoelectric vibrating piece 20 is made of, for example, quartz, and a piezoelectric material such as lithium tantalate or lithium niobate can be used in addition to quartz. In the case of the present embodiment, the piezoelectric vibrating piece 20 is a so-called AT-cut vibrating piece having a substantially rectangular shape in the horizontal direction and formed in a substantially rectangular shape as a whole. Therefore, the vibrator package 28 and the cavity S1 correspond to the shape of the piezoelectric vibrating piece 20, and the horizontal shape is substantially square.
The whole is formed in a substantially rectangular shape.
Excitation electrodes 24 having different polarities are formed at substantially central portions of the upper and lower surfaces of the piezoelectric vibrating piece 20 (the excitation electrodes on the lower surface are not shown), and the excitation electrodes 24 on the upper and lower surfaces are arranged at both ends in the width direction. Lead electrodes 22 and 22 having different polarities from each other are formed, and the lead electrodes 22 are formed.
, 22 are joined to the mount electrodes 26, 26 by the conductive adhesives 36, 36 described above. The excitation electrode 24 and the extraction electrode 22 are formed by, for example, gold plating on a base layer (not shown) made of chrome plating.

The electronic component 30 is electrically connected to the piezoelectric vibrating piece 20, and in the case of this embodiment, is an approximately rectangular semiconductor element that houses an oscillation circuit formed by an integrated circuit (not shown).
As shown in FIG. 2, the electronic component 30 includes a mount electrode 26 to which the above-described piezoelectric vibrating piece 20 is connected and an input / output terminal (not shown) provided on the surface on the substrate 12 side.
At least the piezoelectric vibrating piece 20 is oscillated by making electrical connection using 0 or the layer structure of the substrate 12. Further, a power supply voltage terminal and a ground terminal (not shown) are also provided on the surface of the electronic component 30 on the substrate 12 side, and these terminals are provided with via holes 46 and a layer structure of the substrate 12 as shown in FIG. Are electrically connected to the terminal portions 42 and 42 provided on the mounting surface. Of course, the number of terminals may be larger or smaller depending on the type of the electronic component 30.

The electronic component 30 is connected to the lower surface 12b of the substrate 12, that is, the surface opposite to the piezoelectric vibrating piece 20 side by using bumps or the like. Specifically, after the electronic component 30 is accommodated in the downward concave space formed by laminating the substrate 39 having the through holes 39a on the mounting surface side of the lowermost substrate 15 of the substrate 12, the resin 33 is sealed.

Here, with respect to the piezoelectric oscillator 10, as shown in FIGS. 1 and 3, the vibrator package 28 is disposed so as to form the empty area 16 on the upper surface 12 a of the substrate 12.
In the case of this embodiment, as described above, the substrate 12 has a substantially rectangular outer shape in the horizontal direction, and the piezoelectric vibrating piece 20 also has a substantially rectangular outer shape in the horizontal direction. Therefore, as shown in FIG. Is arranged in the vicinity of the center of the substrate 12 and is parallel to the side surface 20a of the piezoelectric vibrating piece 20.
2 and the diagonal line L1 of the substrate 12 are set to approximately 0 degrees so that a plurality of empty areas 16, 16, 16, 16 are formed at the four corners of the substrate 12.

More preferably, a central axis L2 passing through the horizontal center O1 of the piezoelectric vibrating piece 20 and parallel to the side surface 20a is arranged on the diagonal line L1 of the substrate 12, and a plurality of empty regions 16 are formed at the four corners of the substrate 12.
, 16, 16, 16 are formed. Specifically, in the horizontal direction, the central portion O1 of the piezoelectric vibrating piece 20 and the central portion O2 of the substrate 12 are combined to form the side surface 20 of the piezoelectric vibrating piece 20.
It is arranged so that a is along the diagonal line L1. As described above, the piezoelectric vibrating piece 20 is arranged along the diagonal line L1 having the longest straight line of the substrate 12, and the center portion O1 of the piezoelectric vibrating piece 20 and the center portion O2 of the substrate 12 are matched to each other. The vibrating piece 20 is formed large without protruding from the substrate 12. Therefore, the space 16 can be formed without enlarging the substrate 12 as much as the piezoelectric vibrating piece 20 can be enlarged, and the horizontal size can be reduced.

Of the plurality of empty areas 16, 16, 16, 16, the piezoelectric vibrating reeds are respectively provided in the two empty areas 16, 16 on the lower side in FIG. 1 (that is, areas close to the mount electrodes 26, 26). 20 and / or inspection terminal portions 18 and 18 electrically connected to the electronic component 30 are provided.
The inspection terminal portions 18 and 18 are terminals for enabling inspection of at least the operating characteristics or the like of only one of the piezoelectric vibrating piece 20 and the electronic component 30, but depending on the manufacturing process, the piezoelectric vibrating piece 20 In the case of this embodiment, the inspection terminal portions 18, 18 are connected to the piezoelectric vibrating piece 20 and the electronic component 3.
0 is electrically connected to both.

That is, as shown in FIG. 1, the plurality of inspection terminal portions 18, 18 are electrically connected to the mount electrodes 26, 26 provided on the same upper surface 12 a of the substrate 12 through the electrode patterns 19, 19. ing. Further, as shown in FIG. 3, a plurality of inspection terminal portions 18,
18 is also electrically connected to an inspection terminal (not shown) of the electronic component 30 using the via holes 44 and 44 and the layer structure of the substrate 12.

And when manufacturing this piezoelectric oscillator 10, it carries out as follows. That is, the substrate 12
The above-described via holes 40, 44, 46 are formed in each of the substrates 13, 14, 15, and conductive patterns for forming the mount electrodes 26, 26, the inspection terminal portions 18, 18 and the electrode patterns 19, 19 are formed. After pasting and laminating each of the substrates 13, 14, 15, the substrate 32 for the vibrator package, and the substrate 39 for accommodating the electronic component 30, the whole package is formed by sintering.

Next, after the portions of the lead electrodes 22 and 22 of the piezoelectric vibrating piece 20 are connected to the mount electrodes 26 and 26, the cavity S 1 is sealed with the lid 34, and the electronic component 30 is connected to the lower surface 12 b of the substrate 12. Before the inspection, the probe pins P, P are connected to the inspection terminal portions 18, 18 as shown in FIG.
The operation inspection of only the piezoelectric vibrating piece 20 is performed.
Alternatively, before the piezoelectric vibrating piece 20 is connected to the substrate 12, the electronic component 30 is connected to the lower surface 12 b of the substrate 12, and the probe pins P and P are brought into contact with the inspection terminal portions 18 and 18. You may make it perform operation | movement inspection.
As described above, the inspection terminal portions 18 and 18 of the present embodiment contact the probe pin after connecting either one of the piezoelectric vibrating piece 20 or the electronic component 30, and then inspect one of them. Either one is connected. One component to be inspected may be the piezoelectric vibrating piece 20 or the electronic component 30.

In the case of the present embodiment, as shown in FIG. 1, the vibrator package 28 is disposed so as to spatially partition the plurality of inspection terminal portions 18 and 18 from each other. That is, since the plurality of inspection terminal portions 18 and 18 are electrically connected to the mount electrodes 26 and 26 having different polarities, the two probe pins that are brought into contact with the inspection terminal portions 18 and 18 contact each other. In order to prevent this, the transducer package 28 is disposed and spatially partitioned between the one inspection terminal portion 18 and the other inspection terminal portion 18.

The embodiment of the present invention is configured as described above, and the vibrator package 28 is arranged so as to form the empty areas 16 and 16 on the upper surface 12a of the substrate 12, and the piezoelectric vibrating piece is provided in the empty areas 16 and 16. 20 and / or a plurality of inspection terminal portions 18 electrically connected to the electronic component 30;
18 is provided. Therefore, for example, in the case where the inspection terminal portion 18 electrically connected to the piezoelectric vibrating piece 20 is provided in the empty area, the vibrator package 28 is formed after the piezoelectric vibrating piece 20 is connected to the substrate 12. Before connecting the electronic component 30, the inspection terminal portions 18 and 1
A probe pin can be applied to 8 to inspect the operating characteristics of the piezoelectric vibrating piece 20 alone. Further, since the inspection terminal portions 18 and 18 are provided on the upper surface 12a of the substrate 12, the probe pins can be easily brought into contact with each other, and poor contact of the probe pins can be prevented.

4 and 5 are modifications of the embodiment of the present invention. FIG. 4 is a schematic plan view of the piezoelectric oscillator 50, and FIG. 5 is a sectional view taken along the line CC of FIG. In addition, the part of the parallel oblique line of FIG. 4 has shown each electrode part for the convenience of understanding, and does not represent a cross section.
In these drawings, the portions denoted by the same reference numerals as those used in the embodiment of FIGS. 1 to 3 have the same configuration, and therefore, a duplicate description will be omitted, and the following description will focus on the differences.
The piezoelectric oscillator 50 is different from the piezoelectric oscillator 10 shown in FIGS.
This is only about the shape of the vibrator package 51.

That is, the piezoelectric vibrating piece 56 of the present modification has a substantially circular outer shape as shown in FIG. Specifically, the outer shape of the piezoelectric vibrating piece 56 is substantially circular, and a substantially circular excitation electrode 58 that is slightly smaller around the center is formed on the upper and lower surfaces (the excitation electrode on the lower surface is not shown). Further, the excitation electrode 58 on the upper surface is connected to the extraction electrode 59 formed at the left end of FIG.
The excitation electrode (not shown) on the lower surface is connected to the extraction electrode 59 formed at the right end of FIG. 4, and the extraction electrodes 59, 59 at the left and right ends have different polarities.
The piezoelectric vibrating piece 56 is arranged so as not to protrude from the substrate 12 with the central portion O3 and the central portion O2 of the substrate 12 being aligned in the horizontal direction.

The vibrator package 51 and its cavity S1 are formed by the substantially circular piezoelectric vibrating piece 5.
6, the vibrator package 51, the cavity S1, and the piezoelectric vibrating piece 56 are concentric circles. That is, the substrate 52 and the lid body 54 that constitute the vibrator package 51 are also substantially circular and are concentric with the piezoelectric vibrating piece 56. The vibrator package 51 is different from the vibrator package 28 shown in FIGS. 1 to 3 only in the shape, and is the same as the vibrator package 28 in other points.

The modification of the embodiment of the present invention is configured as described above, and by making the horizontal outer shape of the piezoelectric vibrating piece 56 substantially circular, on the substrate 12 whose horizontal outer shape is substantially square, The piezoelectric vibrating piece 56 can be formed large while forming the empty areas 16 at the four corners of the substrate 12. Therefore, the outer shape of the substrate 12 in the horizontal direction may be reduced by the amount that the piezoelectric vibrating piece 56 can be formed efficiently and large, and the piezoelectric oscillator 50 can be reduced in size.

The present invention is not limited to the above-described embodiment. Each configuration of each embodiment and each modification may be combined or omitted as appropriate, and may be combined with other configurations not shown.

The schematic plan view of a piezoelectric oscillator as an illustration of the piezoelectric device of the present invention. The AA line schematic sectional drawing of FIG. BB schematic sectional drawing of FIG. It is a modification of embodiment of this invention, Comprising: The schematic plan view of a piezoelectric oscillator. The CC sectional view taken on the line of FIG. The prior art example of a piezoelectric device is shown, and the schematic longitudinal cross-sectional view of a piezoelectric oscillator.

Explanation of symbols

10, 50 ... Piezoelectric device (piezoelectric oscillator), 12 ... Substrate, 16 ... Free space,
18 ... inspection terminal part, 20, 56 ... piezoelectric vibrating piece, 26 ... mount electrode, 28,
51 ... vibrator package, 30 ... electronic component, S1 ... cavity

Claims (5)

A substrate disposed near the center in the thickness direction;
A vibrator package disposed on the upper surface of the substrate and having a cavity for accommodating the piezoelectric vibrating reed with the substrate at the bottom;
A piezoelectric device comprising an electronic component disposed on a lower surface of the substrate and electrically connected to the piezoelectric vibrating piece,
The vibrator package is disposed so as to form an empty area on the upper surface of the substrate,
A plurality of inspection terminal portions that are electrically connected to the piezoelectric vibrating piece and / or the electronic component are provided in the empty area. The substrate has a substantially rectangular outer shape in the horizontal direction,
The piezoelectric vibrating piece has a substantially quadrangular outer shape in the horizontal direction and is disposed near the center of the substrate,
2. The piezoelectric device according to claim 1, wherein an angle formed by a central axis parallel to a side surface of the piezoelectric vibrating piece and one of diagonal lines of the substrate is set to approximately 0 degrees. The substrate has a substantially rectangular outer shape in the horizontal direction,
2. The piezoelectric device according to claim 1, wherein the piezoelectric vibrating piece has a substantially quadrangular outer shape in a horizontal direction and a central axis parallel to a side surface of the piezoelectric vibrating piece is disposed on a diagonal line of the substrate. . The piezoelectric device according to claim 1, wherein the substrate has a substantially rectangular outer shape in the horizontal direction, and the piezoelectric vibrating piece has a substantially circular outer shape in the horizontal direction. The piezoelectric device according to any one of claims 1 to 4, wherein the vibrator package is arranged so as to spatially partition the plurality of inspection terminal portions from each other.

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