JP2005051285A - Package for housing piezoelectric vibrator, and piezoelectric apparatus employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for housing a piezoelectric vibrator capable of easily and surely attaining electric and mechanical connection of electrodes of a piezoelectric vibrator with various sizes to electrode pads even when downsizing of the package prevails, and also to provide a piezoelectric apparatus with high reliability employing the package. <P>SOLUTION: The package is provided with: an insulation base 1 with a recessed part 4 formed thereto; a first step difference part 2 formed between a bottom side and an inner side face at one short side of the recessed part 4 from a side face at one longer side of the recessed part 4 with a length not reaching a side face of the other longer side; a second step difference part 3 formed between the bottom side and an inner side face at the other short side of the recessed part 4 from a side face at the other longer side of the recessed part 4 with a length not reaching a side face of the one longer side; first electrode pads 5 respectively formed around the first and second step difference parts 2, 3 at four corners of the bottom side; second electrode pads respectively formed to upper faces of the first and second step difference parts 2, 3; and wire conductors 9 electrically connected to the first and second electrode pads 5, 6 and introduced to an outer surface of the insulation base 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piezoelectric vibrator housing package for housing a piezoelectric vibrator therein, and a piezoelectric device in which the piezoelectric vibrator is housed in the package.
[0002]
[Prior art]
Conventionally, a piezoelectric vibrator housing package for housing a piezoelectric vibrator such as a quartz crystal vibrator is an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, or a ceramic such as glass ceramic. An insulating base made of a material and having a rectangular recess for accommodating the piezoelectric vibrator in the center of the upper surface thereof, an electrode pad formed at the four corners of the recess and connected to the electrodes of the piezoelectric vibrator, and insulation It is comprised from the cover body attached so that a recessed part may be plugged up around the recessed part of the upper surface of a base | substrate. Normally, the wiring conductor is led out from the electrode pad formed on the bottom surface of the concave portion of the insulating base to the outer surface such as the side face and the bottom face of the insulating base.
[0003]
The piezoelectric vibrator is housed in the recess of the piezoelectric vibrator housing package, and the electrode of the piezoelectric vibrator is electrically and mechanically connected to the electrode pad formed on the bottom surface of the recess through a conductive adhesive. Thereafter, a lid is joined to the periphery of the concave portion on the upper surface of the insulating base via glass or the like to close the concave portion, whereby the piezoelectric vibrator is hermetically sealed in the concave portion to form a piezoelectric device. Then, by connecting the wiring conductor led to the outer surface of the insulating base to an external electric circuit, the piezoelectric vibrator is connected to the external electric circuit, and a time and frequency reference signal is transmitted from the piezoelectric vibrator to the external electric circuit. Etc. are output.
[0004]
In recent years, piezoelectric vibrators for forming this piezoelectric device have come to have a very wide variety of demands on characteristics such as oscillation frequency characteristics, and according to this, types such as dimensions and electrode arrangement forms Has become very large.
[0005]
In order to cope with such a wide variety of piezoelectric vibrators, it is necessary to prepare many types of piezoelectric vibrator housing packages having different sizes of recesses for housing the piezoelectric vibrators, electrode pad arrangements, and the like. is there.
[0006]
However, preparing many types of piezoelectric vibrator housing packages corresponding to the types of piezoelectric vibrators is wasteful and cumbersome in the development stage of communication equipment. There was a problem of prolonged or reduced productivity. For such a problem, a piezoelectric vibrator housing package and a piezoelectric device using the same as shown in FIGS. 2A and 2B have been proposed.
[0007]
The piezoelectric vibrator housing package includes an insulating base 31 having a rectangular recess 34 for housing the piezoelectric vibrator 37 on the upper surface, and a bottom surface of the recess 34 and an inner surface of each short side. A pair of stepped portions 32 formed therebetween, four first electrode pads 35 formed around each stepped portion at the four corners of the bottom surface of the recessed portion 34, and formed on the upper surface of each stepped portion. And a wiring conductor 39 that is electrically connected to the first and second electrode pads 35 and 36 and led out from the inside of the recess 34 to the outer surface of the insulating base 31. is doing.
[0008]
According to such a package for housing a piezoelectric vibrator, the piezoelectric vibrator 37 is housed in the recess 34 of the insulating base 31 and an electrode (not shown) formed at the end of the piezoelectric vibrator 37 is provided. Depending on the dimensions of the piezoelectric vibrator 37 and the like, the first electrode pad 35 or the second electrode pad 36 in the recess 34 is electrically connected to the first electrode pad 35 or the second electrode pad 36 via an electrical connection means such as a conductive adhesive 38. After that, the insulating base 31 and the lid body 40 are formed by joining and attaching a lid body 40 made of ceramics or the like to the upper surface around the recess 34 via a brazing material such as low melting point glass. A piezoelectric vibrator 37 is hermetically sealed inside the container, thereby forming an electronic device as a product.
[0009]
According to such a package for storing a piezoelectric vibrator, if the piezoelectric vibrator 37 has a large size 37b for low frequency, for example, the electrode can be connected to the second electrode pad 36. In addition, since the electrode 37a can be connected to the first electrode pad 35 if it has a small size 37a for high frequency, it is easy to use any of the piezoelectric vibrators 37a and 37b having different sizes. The piezoelectric device can be formed by hermetically sealing.
[0010]
The connection between the electrode of the piezoelectric vibrator 37 and the first and second electrode pads 35 and 36 is usually made through a conductive adhesive 38. For example, the electrode of the piezoelectric vibrator 37 is positioned and placed on the first and second electrode pads 35 and 36, and a conductive adhesive is supplied to this portion from a conductive adhesive supply device (dispenser) (not shown). By discharging and supplying 38, the electrode of the piezoelectric vibrator 37 and the first and second electrode pads 35 and 36 are electrically and mechanically connected. The dispenser is usually in the shape of a tube having a discharge port at the tip.
[0011]
[Patent Document 1]
JP-A-6-338750
[Problems to be solved by the invention]
However, recently, with the demand for miniaturization, the size of piezoelectric devices has become extremely small, such as a rectangular shape with a length of one side of about several millimeters. In addition, a package for accommodating a piezoelectric vibrator for forming such a small piezoelectric device is becoming smaller.
[0013]
As the piezoelectric vibrator housing package is reduced in size in this way, the distance between the dispenser and the inner surface of the recess 34 becomes narrower, so the dispenser is formed at the electrodes of the piezoelectric vibrator 37 and the four corners of the recess 34. It becomes difficult to position at the connection portion with the first electrode pad 35, and is necessary for electrically and mechanically and securely connecting the electrode of the piezoelectric vibrator 37 and the first electrode pad 35. There is a problem that it is difficult to accurately supply a predetermined amount of the conductive adhesive 38 to a predetermined position.
[0014]
Further, in this manner, the conductive adhesive 38 is difficult to accurately supply the necessary amount of the conductive adhesive 38 from the dispenser to the connection portion between the electrode of the piezoelectric vibrator 37 and the first electrode pad 35. Is supplied, the excess conductive adhesive 38 crawls up the side surface of the stepped portion 32, etc., so that the first electrode pads 35 adjacent to each other at the four corners of the recess 34, or the first electrode pad 35 and the first electrode pad 35. There is a problem that the two electrode pads 36 are electrically short-circuited and the piezoelectric device cannot be normally operated.
[0015]
Further, when such a conductive adhesive 38 crawls up the side surface of the step portion 32, a necessary amount of the conductive adhesive 38 remains in the connection portion between the electrode of the piezoelectric vibrator 37 and the first electrode pad 35. In addition, there is a problem that reliability of electrical and mechanical connection of the piezoelectric vibrator 37 is low.
[0016]
The present invention has been devised in view of such problems, and its purpose is to easily and reliably electrically connect electrodes of piezoelectric vibrators of various sizes to electrode pads even if miniaturization is advanced. It is an object of the present invention to provide a piezoelectric vibrator housing package that can be mechanically connected, and a highly reliable piezoelectric device using the piezoelectric vibrator housing package.
[0017]
[Means for Solving the Problems]
The piezoelectric vibrator housing package of the present invention has an insulating base formed with a rectangular recess for housing the piezoelectric vibrator on the upper surface, and a bottom surface of the recess and one short side inner surface, Between the first step portion formed so as not to reach the other long side inner surface from one long side inner surface, and between the bottom surface of the recess and the other short side inner surface, the other A second step portion formed so as not to reach the one long side side inner surface from the long side inner surface, and around the first and second step portions at four corners of the bottom surface The four first electrode pads respectively formed, the second electrode pads formed on the top surfaces of the first and second stepped portions, and the first and second electrode pads electrically Wiring that is connected and led out from the inside of the recess to the outer surface of the insulating substrate. Characterized in that it comprises and.
[0018]
According to the package for housing a piezoelectric vibrator of the present invention, between the bottom surface of the recess and the inner surface of one short side, the inner surface of one long side should not reach the inner surface of the other long side. Between the formed first step portion and the bottom surface of the recess and the other short side inner surface, it was formed so as not to reach the one long side inner surface from the other long side inner surface. Since the second step portion is provided, the first and second step portions formed between the bottom surface of the recess and the one and other short side inner surfaces, and the long side inner surface of the recess A certain amount of space can be secured between them, and this space is located on the opposite side between the short side of one side and the short side of the other side. Even so, it is possible to effectively secure a range in which the dispenser can be moved in the recess. It is possible to position the dispenser easily and accurately on the connecting portion of the electrode of the piezoelectric vibrator, a first electrode pad.
[0019]
In addition, the connection portion between the first electrode pad and the piezoelectric vibrator can be moved away from the first and second step portions, and excess conductive adhesive scoops up the side surfaces of the first and second step portions. Thus, an electrical short circuit between the first electrode pads or between the first electrode pad and the second electrode pad can be effectively prevented.
[0020]
Furthermore, since the dispenser can be easily and accurately positioned at the connection portion between the electrode of the piezoelectric vibrator and the first electrode pad, the conductive adhesive scoops the side surfaces of the first and second step portions. Since it can be prevented from rising, it is possible to reliably supply a sufficient amount of conductive adhesive necessary for electrically and mechanically connecting the electrodes of the piezoelectric vibrator to a predetermined position. The reliability of electrical and mechanical connection can be made excellent.
[0021]
According to another aspect of the invention, there is provided a piezoelectric vibrator housing package configured as described above; a piezoelectric vibrator housed in the recess and electrically connected to the first or second electrode pad; And a lid attached around the recess on the upper surface of the insulating base.
[0022]
According to the piezoelectric device of the present invention, the piezoelectric vibrator housing package having the above configuration, the piezoelectric vibrator housed in the recess and electrically connected to the first or second electrode pad, and the insulation A lid attached to the periphery of the recess on the upper surface of the substrate, so that the electrode of the piezoelectric vibrator is securely connected to the electrode pad of the package for housing the piezoelectric vibrator via a conductive adhesive. In addition, a highly reliable piezoelectric device can be obtained that is electrically and mechanically connected without causing problems such as a short circuit.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Next, a piezoelectric vibrator housing package and a semiconductor device according to the present invention will be described with reference to the accompanying drawings.
[0024]
FIG. 1A is a top view showing an example of an embodiment of a package for housing a piezoelectric vibrator of the present invention, and FIG. 1B is a cross-sectional view taken along a section AA ′. In the figure, 1 is an insulating substrate, 2 is a first stepped portion, 3 is a second stepped portion, 4 is a recess, 5 is a first electrode pad, 6 is a second electrode pad, 9 is a wiring conductor, 10 Is a lid.
[0025]
The piezoelectric vibrator of the present invention is mainly housed in the insulating substrate 1, the first step portion 2, the second step portion 3, the first electrode pad 5, the second electrode pad 6, the wiring conductor 9, and the lid body 10. The package is configured.
[0026]
The insulating substrate 1 is formed by laminating ceramic layers made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, or a glass ceramic. For example, the length of one side is 2 to 20 mm. It is a square shape with a thickness of about 0.5 to 3 mm. A rectangular recess 4 for accommodating the piezoelectric vibrator 7 is provided at the center of the upper surface.
[0027]
Further, the inner side of the recess 4 is formed between the bottom surface of the recess 4 and the inner surface of one short side so as not to reach the inner surface of one long side. The first step 2 is formed between the bottom surface of the recess 4 and the other short side inner surface so as not to reach the one long side inner surface from the other long side inner surface. A second step portion 3 is formed.
[0028]
Even if the first and second stepped portions 2 and 3 have different dimensions or the like of the piezoelectric vibrator 7, they are accommodated in the recess 4 and the electrodes are connected to the electrode pads. It is for making possible.
[0029]
These first and second stepped portions 2 and 3 are usually formed of the same material as the insulating base 1.
[0030]
For example, if the insulating base 1, the first step portion 2 and the second step portion 3 are made of an aluminum oxide-based sintered body, a raw material powder such as aluminum oxide is formed into a sheet shape together with an organic binder. These green sheets are punched so as to form an opening that becomes a recess 4 and first and second stepped portions 2 and 3 when stacked, and then these green sheets are formed. The sheets are integrally formed by stacking and firing.
[0031]
Four first electrode pads 5 are formed around the first and second stepped portions 2 and 3 at the four corners of the bottom surface of the recess 4.
[0032]
A second electrode pad 6 is formed on each of the upper surfaces of the first and second step portions 2 and 3.
[0033]
Each of the first and second electrode pads 5 and 6 is electrically connected to a wiring conductor 9 led out from the inside of the recess 4 to the outer surface of the insulating base 1.
[0034]
The first electrode pad 5, the second electrode pad 6 and the wiring conductor 9 are made of a metal material such as tungsten, molybdenum, copper, or silver. For example, when made of tungsten, a metal paste of tungsten is used. It is formed by printing on the insulating sheet 1 and the green sheets forming the first and second stepped portions 2 and 3.
[0035]
Then, an electrode (not shown) of the piezoelectric vibrator 7 is electrically and mechanically connected to the first electrode pad 5 or the second electrode pad 6 via the conductive adhesive 8.
[0036]
In this case, the first and second stepped portions 2 and 3 are formed at both ends of the recess 4, and the four first portions are formed around the first and second stepped portions 2 and 3 at the four corners of the bottom surface. And the second electrode pad 6 is formed on each of the upper surfaces of the first and second stepped portions 2 and 3, so that the piezoelectric vibrator 7 is, for example, a large size 7b. If present, it can be accommodated in the recess 4 by connecting to the second electrode pad 6 or by connecting to the first electrode pad 5 if the piezoelectric vibrator 7 has a small size 7a, Storage corresponding to many types of piezoelectric vibrators 7 becomes possible. The number of piezoelectric vibrators 7 housed in the recess 4 is usually one.
[0037]
The connection between the electrode of the piezoelectric vibrator 7 and the first and second electrode pads 5 and 6 is made through a conductive adhesive 8. For example, the electrode of the piezoelectric vibrator 7 is positioned and placed on the first and second electrode pads 5 and 6, and the conductive adhesive 8 is discharged and supplied to this portion from a dispenser (not shown). The electrodes of the piezoelectric vibrator 7 and the first and second electrode pads 5 and 6 are electrically and mechanically connected.
[0038]
According to the package for housing a piezoelectric vibrator of the present invention, it is ensured that one long side inner surface does not reach the other long side inner surface between the bottom surface of the recess 4 and one short side inner surface. The first stepped portion 2 formed between the bottom surface of the recess 4 and the inner surface of the other short side is set so as not to reach the inner surface of the other long side. Since the formed second stepped portion 3 is provided, the first and second stepped portions 2 and 3 formed between the bottom surface of the recessed portion 4 and the one and the other short side inner surface, and the recessed portion A certain amount of space can be secured between the long side inner surface and the piezoelectric vibration because this space is located on the opposite side between one short side and the other short side. Even if miniaturization of the child storage package progresses, the range in which the dispenser can be moved within the recess 4 is effectively secured. Will be able to Rukoto, the electrodes of the piezoelectric vibrator 7a, the dispenser connection portion of the first electrode pads 5 can be easily and accurately positioned.
[0039]
In addition, the connecting portion between the first electrode pad 5 and the piezoelectric vibrator 7a can be moved away from the first and second step portions 2 and 3, and the excess conductive adhesive 8 is removed from the first and second step portions. Effectively preventing the first electrode pads 5 or the first electrode pad 5 and the second electrode pad 6 from being electrically short-circuited by scooping up the side surfaces of the portions 2 and 3 Can do.
[0040]
Further, since the dispenser can be easily and accurately positioned at the connection portion between the electrode of the piezoelectric vibrator 7 a and the first electrode pad 5, the conductive adhesive 8 is used in the first and second step portions 2. , 3 can be prevented from creeping up, so that a sufficient amount of the conductive adhesive 8 necessary to electrically and mechanically connect the electrodes of the piezoelectric vibrator 7a is reliably supplied to a predetermined position. Thus, the electrical and mechanical connection reliability of the piezoelectric vibrator 7a can be improved.
[0041]
The distance between the first step 2 and the other long side inner surface of the recess 4 and the distance between the second step 3 and the one long side inner surface of the recess 4 are determined by the dispenser It is necessary to leave enough space to allow easy movement.
[0042]
For example, in the case of a dispenser having a generally used outer diameter of 0.2 to 1.0 mm, the distance between the first step portion 2 and the other long side inner surface of the recess 4 The distance between the second step portion 3 and the inner surface on one long side of the recess 4 is preferably at least half the nozzle diameter of the dispenser, that is, at least 0.1 to 0.5 mm.
[0043]
The distance between the first stepped portion 2 and the other long side inner surface of the recess 4 and the distance between the second stepped portion 3 and one long side inner surface of the recess 4 are as follows: The side surfaces of the first and second stepped portions 2 and 3 may be inclined so as to increase from the lower end to the upper end of the first and second stepped portions 2 and 3. This makes it easier and more reliable to secure a space where the dispenser can move in the recess 4, and further enhances the electrical and mechanical connection reliability of the piezoelectric vibrator 7. it can.
[0044]
Further, if the first and second electrode pads 5 and 6 are in contact with the inner side surface on the long side of the recess 4, these areas can be more effectively ensured. It is preferable to ensure the reliability of electrical and mechanical connection.
[0045]
In addition, the first and second stepped portions 2 and 3 are provided with a relatively rough surface whose arithmetic average roughness Ra exceeds 1 μm on the side surface, and the conductive adhesive 8 is formed by the first and second stepped portions 2 and 3. It is also possible to more effectively prevent the scooping up along the side surfaces of the stepped portions 2 and 3.
[0046]
Further, the first and second stepped portions 2 and 3 are formed such that the corner portion on the side that does not reach the inner surface on the long side of the concave portion 4 is formed in an arc shape, and cracks or the like are caused when the dispenser bumps accidentally. It may be possible to more effectively prevent the occurrence of mechanical destruction.
[0047]
Then, the lid 10 is formed on the upper surface of the insulating base 1 by bonding the lid 10 with a brazing material such as low melting point glass so as to close the concave 4, thereby forming the concave 4 of the insulating base 1 and the lid 10. The piezoelectric vibrator 7 is hermetically sealed inside the container to form a piezoelectric device.
[0048]
In this piezoelectric device, the portion of the wiring conductor 9 led to the outer surface of the insulating base 1 is connected to an external electric circuit so that the electrode of the hermetically sealed piezoelectric vibrator 7 is externally connected via the wiring conductor 9. It is electrically connected to the electrical circuit.
In such a piezoelectric device, the exposed surface of the wiring conductor 9 is prevented from oxidative corrosion, and the connection between the wiring conductor 9 and each electrode of the piezoelectric vibrator 7 and the connection to the external electric circuit board are strengthened. Therefore, normally, it is preferable to sequentially deposit a nickel plating layer having a thickness of about 10 to 20 μm and a gold plating layer having a thickness of about 0.1 to 3 μm.
[0049]
These plating layers may be applied so as to cover the surfaces of the first and second electrode pads 5 and 6. These plating layers can be formed by a plating method such as a conventionally known electrolytic method or electroless method.
[0050]
It should be noted that the present invention is not limited to the above embodiments, and various modifications may be made without departing from the gist of the present invention. For example, in this example, the insulating substrate 1 is formed by laminating two ceramic layers, but the insulating substrate 1 may be formed by laminating three or four ceramic layers. Needless to say.
[0051]
【The invention's effect】
According to the package for housing a piezoelectric vibrator of the present invention, between the bottom surface of the recess and the inner surface of one short side, the inner surface of one long side should not reach the inner surface of the other long side. Between the formed first step portion and the bottom surface of the recess and the other short side inner surface, it was formed so as not to reach the one long side inner surface from the other long side inner surface. Since the second step portion is provided, the first and second step portions formed between the bottom surface of the recess and the one and other short side inner surfaces, and the long side inner surface of the recess A certain amount of space can be secured between them, and this space is located on the opposite side between the short side of one side and the short side of the other side. Even so, it is possible to effectively secure a range in which the dispenser can be moved in the recess. It is possible to position the dispenser easily and accurately on the connecting portion of the electrode of the piezoelectric vibrator, a first electrode pad.
[0052]
In addition, the connection portion between the first electrode pad and the piezoelectric vibrator can be moved away from the first and second step portions, and excess conductive adhesive scoops up the side surfaces of the first and second step portions. Thus, an electrical short circuit between the first electrode pads or between the first electrode pad and the second electrode pad can be effectively prevented.
[0053]
Furthermore, since the dispenser can be easily and accurately positioned at the connection portion between the electrode of the piezoelectric vibrator and the first electrode pad, the conductive adhesive scoops the side surfaces of the first and second step portions. Since it can be prevented from rising, it is possible to reliably supply a sufficient amount of conductive adhesive necessary for electrically and mechanically connecting the electrodes of the piezoelectric vibrator to a predetermined position. The reliability of electrical and mechanical connection can be made excellent.
[0054]
According to the piezoelectric device of the present invention, the piezoelectric vibrator housing package having the above configuration, the piezoelectric vibrator housed in the recess and electrically connected to the first or second electrode pad, and the insulation A lid attached to the periphery of the recess on the upper surface of the substrate, so that the electrode of the piezoelectric vibrator is securely connected to the electrode pad of the package for housing the piezoelectric vibrator via a conductive adhesive. In addition, a highly reliable piezoelectric device can be obtained that is electrically and mechanically connected without causing problems such as a short circuit.
[Brief description of the drawings]
FIG. 1A is a top view illustrating an example of an embodiment of a piezoelectric vibrator housing package of the present invention, and FIG. 1B is a cross-sectional view taken along line AA ′ of FIG.
2A is a top view of a conventional package for housing a piezoelectric vibrator, and FIG. 2B is a cross-sectional view taken along line BB ′ of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Insulating base | substrate 2 ... 1st level | step-difference part 3 ... 2nd level | step-difference part 4 ... recessed part 5 ... 1st electrode pad 6 * .... Second electrode pad 7 ... Piezoelectric vibrator 7a ... Piezoelectric vibrator (small)
7b ... Piezoelectric vibrator (large)
8 ... Conductive adhesive 9 ... Wiring conductor 10 ... Lid

Claims (2)

Between the insulating base having a rectangular recess for accommodating the piezoelectric vibrator on the upper surface, and the bottom surface of the recess and the inner surface of one short side, the length from one inner side to the other Between the first step portion formed so as not to reach the inner side surface on the side, and the bottom surface of the recess and the inner surface on the other short side, the one long side from the inner surface on the other long side A second step portion formed so as not to reach the inner side surface of the side, and four first electrode pads formed around the first and second step portions at the four corners of the bottom surface, respectively. A second electrode pad formed on each of the upper surfaces of the first and second stepped portions, and electrically connected to the first and second electrode pads and insulated from the inside of the recess. And a wiring conductor led out to the outer surface of the substrate. Doko package for housing. The piezoelectric vibrator housing package according to claim 1, a piezoelectric vibrator housed in the recess and electrically connected to the first or second electrode pad, and an upper surface of the insulating base A piezoelectric device comprising: a lid attached around the recess.

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