JP3523502B2 - Container for piezoelectric vibrator, piezoelectric vibrator and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrator using a piezoelectric vibrator container for accommodating a piezoelectric vibrator piece and a method for manufacturing the same.

[0002]

2. Description of the Related Art A piezoelectric vibrator is manufactured, for example, by hermetically housing a piezoelectric vibrator piece 21 in a piezoelectric vibrator container as shown in a sectional view of FIG.

The piezoelectric vibrator container for hermetically containing the piezoelectric vibrator piece 21 is made of, for example, a ceramic such as an aluminum oxide sintered body, and has a mounting portion 22a on which the piezoelectric vibrator piece 21 is mounted. A space between the substantially flat insulating base 22 and the insulating base 22 made of a translucent material such as glass and joined to the upper surface of the insulating base 22 via a sealing material 23 such as low melting point glass. A lid 24 for accommodating the piezoelectric vibrator piece 21 in the
It consists of and. The insulating base 22 has a through hole 25 for evacuating the space between the insulating base 22 and the lid 24 to form a vacuum from the upper surface to the lower surface. The piezoelectric vibrator piece 21 is placed inside the container composed of the insulating base 22 and the lid 24.
, The space for accommodating the piezoelectric vibrator piece 21 is evacuated to a vacuum through the through hole 25 formed in the insulating substrate 22, and then the brazing material such as a lead-tin alloy is filled in the through hole 25. By filling the sealing member 26 made of (4) and sealing the through hole 25, the piezoelectric vibrator piece 21 is hermetically housed in the piezoelectric vibrator container.

In order to fill the through hole 25 formed in the insulating substrate 22 with the sealing member 26 made of a brazing material such as a lead-tin alloy and seal the through hole 25, A metal layer 27 made of a metallization of a refractory metal such as tungsten or molybdenum powder is deposited on the entire inner surface, and a plated metal layer such as nickel or gold having excellent wettability with a brazing material is formed on the surface of the metal layer 27 ( (Not shown) is deposited, and a brazing material such as a lead-tin alloy having a diameter larger than that of the through hole 25 is brought into contact with the lower surface side opening of the through hole 25 to heat the brazing material. A method of sealing by melting is adopted.

[0005]

However, according to this conventional piezoelectric vibrator, the insulating base of the container for the piezoelectric vibrator is used.
Since the metal layer 27 is adhered to the entire inner surface of the through hole 25 formed in 22, when the through hole 25 is sealed by the sealing member 26 made of a brazing material such as a lead-tin alloy. Since the molten sealing member 26 wets and spreads over the entire inner surface of the through hole 25 and reaches the opening of the through hole 25, a part of the sealing member 26 reaching this opening is the upper surface or the lower surface of the insulating substrate 22. May project to. As a result, for example, the sealing member 26 protruding on the upper surface of the insulating substrate 22 comes into contact with the piezoelectric vibrator piece 21 housed in the container to stop the oscillation of the piezoelectric vibrator piece 21, or even if it oscillates, The problem that normal vibration of the vibrator piece 21 is disturbed, or that the sealing member 26 protruding on the lower surface of the insulating substrate 22 interferes with the mounting of the piezoelectric vibrator on an external circuit board or the like. Had a point.

The present invention has been devised in view of the above conventional problems, and an object of the present invention is to provide a sealing member with an insulating base even if a through hole provided in the insulating base is sealed with a sealing member. Piezoelectric vibrator container that can accurately vibrate the piezoelectric vibrator piece housed inside without protruding to the upper or lower surface of the device and can be mounted well on an external circuit board, as well as using this container Another object of the present invention is to provide a piezoelectric vibrator and a method for manufacturing the piezoelectric vibrator.

[0007]

[0008]

The piezoelectric vibrator of the present invention comprises:
A substantially flat plate-shaped insulating base having a mounting portion for the piezoelectric vibrator piece on the upper surface and having a through hole provided from the upper surface to the lower surface, and the piezoelectric base in the space between the insulating base and the upper surface of the insulating base. The through-hole includes a first hole on the upper surface side and a second hole on the lower surface side having an opening larger than the first hole, and The piezoelectric vibrator piece is placed in the space of the piezoelectric vibrator container in which a metal layer for attaching the sealing metal member is attached around the opening of the first hole on the side of the second hole. It is characterized in that the sealing metal member is housed and attached to the metal layer of the through hole via a brazing material.

Further, in the piezoelectric vibrator of the present invention, in the piezoelectric vibrator having the above structure, the sealing metal member is the first
Is smaller than the opening of the hole.

The method of manufacturing the piezoelectric vibrator of the present invention is
The piezoelectric vibrator has a mounting portion on the upper surface, and includes a first hole on the upper surface side and a second hole on the lower surface side having an opening larger than the first hole, and the second hole of the first hole. The step of preparing a substantially flat plate-shaped insulating substrate provided with a through hole to which a metal layer for attaching the sealing metal member is attached around the opening on the hole side, and A step of mounting a vibrator piece; a step of bonding a lid to the upper surface of the insulating base to store the piezoelectric vibrator piece in a space between the insulating base; and a step of mounting the piezoelectric vibrator piece on the metal layer of the through hole. And a step of attaching the sealing metal member via a brazing material and sealing the through hole.

Further, in the method for manufacturing a piezoelectric vibrator of the present invention, in the above manufacturing method, the sealing metal member is attached by penetrating the sealing metal member whose surface is covered with a brazing material. It is carried out by melting the brazing filler metal after it is housed in the hole.

[0012]

Further, according to the piezoelectric vibrator of the present invention, the piezoelectric vibrator piece is housed in the piezoelectric vibrator container having the above-mentioned structure, and the second hole of the first hole of the through hole formed in the insulating substrate is formed. Since the sealing metal member is attached to the metal layer adhered to the vicinity of the opening on the side of the through hole through the brazing material, it is applied to the vicinity of the opening on the side of the second hole of the first hole of the through hole. When the sealing metal member is attached to the formed metal layer via the brazing filler metal, the molten brazing filler metal wets and spreads only around the opening of the first hole on the second hole side, and the upper and lower surfaces of the insulating substrate Never reach. Further, since the sealing metal member is held in the vicinity of the opening on the second hole side of the first hole by the surface tension of the molten brazing filler metal, the through hole is well sealed by the sealing metal member and the brazing filler metal. At the same time, the brazing material and the sealing metal member do not project to the upper surface or the lower surface of the insulating substrate 1.

Further, when the sealing metal member is smaller than the opening of the first hole, the second hole of the first hole of the through hole is formed.
When the sealing metal member is attached to the metal layer deposited around the opening on the side of the hole through the brazing filler metal, the brazing filler metal melts and the sealing metal member moves freely in the through hole. It will be possible. Then, due to the surface tension of the molten brazing material, the first
The sealing metal member is automatically positioned at the physically most stable position between the hole and the second hole. As a result, the sealing of the through hole becomes extremely strong.

According to the method of manufacturing a piezoelectric vibrator of the present invention,
The upper surface has a portion for mounting the piezoelectric vibrator piece, and is composed of a first hole on the upper surface side and a second hole on the lower surface side having an opening larger than the first hole, and the second hole of the first hole. A substantially flat plate-shaped insulating substrate provided with a through hole to which a metal layer for attaching the sealing metal member is attached around the opening on the side, and the piezoelectric vibrator is mounted on the mounting portion of the insulating substrate. After mounting the piece, the lid is joined to the upper surface of the insulating base to house the piezoelectric vibrator piece in the space between the insulating base and the metal layer attached to the through hole of the insulating base. Since the metal member is attached via the brazing filler metal to seal the through hole, when the sealing metal member is attached via the brazing filler metal to seal the through hole, the molten brazing filler metal is 1
Of the hole of No. 2 spreads only around the opening on the side of the second hole and does not reach the upper and lower surfaces of the insulating substrate. Moreover, since the sealing metal member is held in the vicinity of the opening on the second hole side of the first hole by the surface tension of the molten brazing material, the through hole can be satisfactorily sealed by the sealing metal member and the brazing material. Can be stopped,
The brazing material and the sealing metal member do not project on the upper surface or the lower surface of the insulating base.

Further, after the sealing metal member whose surface is coated with the brazing material is housed in the through hole of the insulating substrate, the brazing material covering the sealing metal member is melted to seal the sealing metal member. When the brazing material is attached, the sealing metal member and the brazing material can be accommodated in the through hole at the same time, and the coated brazing material ensures that the surface of the sealing metal member is melted when the brazing material is melted. Since it gets wet, the sealing metal member can be easily and reliably attached to the through hole.

[0017]

DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an example of an embodiment of a piezoelectric vibrator of the present invention. In the figure, 1 is an insulating substrate, 2
Is a lid, and 3 is a piezoelectric vibrator piece. And the insulating substrate 1
A piezoelectric vibrator is formed by hermetically sealing the piezoelectric vibrator piece 3 in a piezoelectric vibrator container made up of a lid and a lid 2.

First, a piezoelectric vibrator container used in the piezoelectric vibrator of the present invention will be described.

Insulating substrate 1 which constitutes a container for a piezoelectric vibrator
Is made of an electrically insulating material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a silicon nitride sintered body, a mullite sintered body, or a glass ceramic sintered body. It is a substantially rectangular plate-shaped body having a concave mounting portion 1a formed in the central portion on the upper surface side, and the piezoelectric vibrator piece 3 is mounted on the bottom surface of the concave mounting portion 1a.

The insulating substrate 1 generally has a width of about 2 to 5 mm, a length of about 5 to 10 mm, and a thickness of 0.3.
~ 0.6 mm, the width of the concave mounting portion 1a is 1 ~ 4
mm, length 4-9 mm, depth 0.2-0.5 m
It is about m. Further, with the demand for miniaturization and thinning of piezoelectric vibrators, the miniaturization and thinning thereof are progressing more and more.

When the insulating substrate 1 is made of, for example, an aluminum oxide sintered body, an organic binder, a solvent, a plasticizer, and a dispersant suitable for aluminum oxide and raw material powders of silicon oxide, calcium oxide, magnesium oxide and the like. Etc. are added and mixed to form a slurry-like ceramic slurry, and a plurality of ceramic green sheets are obtained by forming this ceramic slurry into a sheet shape by adopting a conventionally known doctor blade method. It is manufactured by subjecting green sheets to appropriate punching, stacking them on top of each other, and finally firing them in a reducing atmosphere at a temperature of about 1600 ° C.

A wiring conductor 4 extending from one end of the bottom surface of the mounting portion 1a to the lower surface of the insulating base 1 is adhered to the insulating base 1. With this wiring conductor 4, the mounting portion 1a
The electrode of the piezoelectric vibrator piece 3 is adhered and fixed to a portion of the bottom surface of the piezoelectric vibrator piece 3 which is led out, through a conductive adhesive 5 such as silver-polyimide resin, silver-epoxy resin, or silver-silicone resin. Then, by joining the portion of the wiring conductor 4 which is led to the lower surface of the insulating substrate 1 to a wiring conductor such as an external circuit board (not shown) via a conductive adhesive such as solder, each electrode of the piezoelectric vibrator piece 3 is connected. It will be connected to an external circuit board or the like.

The wiring conductor 4 is composed of a metallized conductor layer made of a metal powder such as tungsten, molybdenum, silver or copper. For example, a metal paste obtained by adding and mixing an appropriate organic binder, a solvent, or the like to a metal powder such as tungsten is printed and applied in advance in a predetermined pattern on a ceramic green sheet to be the insulating substrate 1, and this is also applied to the insulating substrate. 1
The ceramic green sheet is fired together with the ceramic green sheet to be attached and formed so as to extend from the one end side of the bottom surface of the mounting portion 1a of the insulating base 1 to the lower surface of the insulating base 1.

A through hole 6 is formed in the insulating base 1 from the bottom surface to the lower surface of the mounting portion 1a.

The through-hole 6 is for evacuating the space for accommodating the piezoelectric vibrator piece 3 after the piezoelectric vibrator piece 3 is housed inside the container consisting of the insulating base 1 and the lid 2. It functions as a hole. The through hole 6 is composed of a first hole 6a on the upper surface side of the insulating base body 1 and a second hole 6b on the lower surface side having an opening larger than the first hole 6a, and at the same time, the through hole 6 of the first hole 6a is formed. A sealing metal member 7, which will be described later, is attached to the periphery of the opening on the second hole 6b side, specifically, to the lower surface of the step formed between the first hole 6a and the second hole 6b. A metal layer 8 for is deposited.

The first hole 6a and the second hole 6b
Is preferably a hole having a circular opening, and the first hole 6a is
The diameter of about 0.1 mm to 0.5 mm, the second hole 6b is the first
The diameter is about 0.1 to 0.5 mm larger than the diameter of the hole. However, the openings of the first holes 6a and the second holes 6b do not necessarily have to be circular, and the openings may be triangular, quadrangular, or other shapes. Also, the first
If the metal layer 8 deposited around the opening of the hole 6a on the second hole 6b side does not reach the upper surface of the insulating substrate 1,
It does not matter if a part of it goes into the first hole 6a.

In the metal layer 8 of the through hole 6, the piezoelectric vibrator piece 3 is housed in the space between the insulating base 1 and the lid 2.
After the space for accommodating the piezoelectric vibrator piece 3 is evacuated to a vacuum, the sealing metal member 7 is attached via the brazing material 9.
As a result, the through hole 6 is sealed and the piezoelectric vibrator container is hermetically sealed.

The metal layer 8 to which the sealing metal member 7 for sealing the through hole 6 is attached is made of a metallized metal layer using a metal powder of tungsten, molybdenum, silver, copper or the like. In order to improve the wettability with the brazing material 9, a plating metal layer (not shown) made of nickel, gold or the like is attached to the surface of the brazing material 9 as needed.

Since the metal layer 8 is deposited in the through hole 6 around the opening of the first hole 6a on the second hole 6b side, the sealing metal member 7 will be mounted. The material 9 spreads only around the opening on the side of the second hole 6b of the first hole 6a to which the metal layer 8 is adhered, so that the sealing metal member 7 is placed on the metal layer 8 via the brazing material 9. The brazing material 9 does not reach the upper and lower surfaces of the insulating substrate 1 when the through hole 6 is sealed by the attachment.

Further, since the sealing metal member 7 is held around the opening of the first hole 6a on the side of the second hole 6b by the surface tension of the molten brazing material 9, the brazing material 9 and the sealing metal member 7 are sealed. The metal member 7 projects from the upper surface of the insulating substrate 1 to hinder the vibration of the piezoelectric vibrator piece 3, or projects from the lower surface of the insulating substrate 1 to hinder the mounting of the piezoelectric vibrator on the external circuit board. There is no such thing.

It should be noted that the through hole 6 is formed by forming a hole for the through hole 6 in the ceramic green sheet to be the insulating base 1 in advance to a predetermined size and shape.
The mounting portion 1a is formed from the bottom surface to the lower surface of the mounting portion 1a so as to include a first hole 6a on the upper surface side and a second hole 6b on the lower surface side larger than the opening of the first hole 6a.

For the metal layer 8, a metal paste obtained by adding and mixing an appropriate organic binder and a solvent to a metal powder such as tungsten is printed and applied in a predetermined pattern on a ceramic green sheet to be the insulating substrate 1 in advance. By firing this together with the ceramic green sheet that becomes the insulating substrate 1, in the through hole 6 formed in the insulating substrate 1, the periphery of the opening on the second hole 6b side of the first hole 6a, specifically, Is adhered to the lower surface of the step portion formed between the first hole 6a and the second hole 6b.

Further, the lid body 2 which constitutes the container for the piezoelectric vibrator.
Is a substantially rectangular flat plate made of a translucent material such as glass or sapphire. The lid 2 is made of a translucent material because the piezoelectric vibrator piece 3 that penetrates the lid 2 and is housed inside the container
This is because it is possible to adjust the vibration frequency of the piezoelectric vibrator piece 3 by irradiating the laser beam with the laser beam. If it is not necessary to adjust the vibration frequency of the piezoelectric vibrator piece 3 by such a laser beam, the lid body 2 does not necessarily need to be a translucent material, and a metal such as an iron-nickel-cobalt alloy or the like can be used. It may be formed of ceramics such as an aluminum oxide sintered body.

If the lid 2 is made of glass or sapphire, a wide area plate made of glass or sapphire having a thickness corresponding to the thickness of the lid 2 is cut into a predetermined size or shape, or The cross section is the size corresponding to the lid 2.
It is manufactured by cutting a shaped bar made of glass or sapphire into a predetermined thickness. In this case, in order to prevent minute breaks or the like from occurring at the corners of the lid body 2,
It is preferable to chamfer each of the corners formed in the above. By doing so, the minute chips generated in the lid 2 penetrate into the container and the piezoelectric vibrator piece 3
It is possible to prevent the vibration of the.

The lid 2 is bonded to the upper surface of the insulating base 1 through the sealing material 10 made of low melting point glass or the like to form a piezoelectric vibrator container, and a space between the lid 2 and the insulating base 1. The piezoelectric vibrator piece 3 is housed therein.

To join the lid 2 to the insulating substrate 1 via the sealing material 10, for example, first, the outer peripheral portion of the upper surface of the insulating substrate 1 and / or
Alternatively, the sealing material 10 is previously applied to the outer peripheral portion of the lower surface of the lid body 2, then the lid body 2 is placed on the upper surface of the insulating substrate 1 with the sealing material 10 interposed therebetween, and finally, The sealing material 10 is heated and softened and melted, and then cooled and solidified.

To apply the sealing material 10 to the upper peripheral portion of the insulating substrate 1 and / or the lower peripheral portion of the lid body 2 in advance, for example, when the sealing material 10 is made of low melting point glass, A screen-printing method is used to apply a glass paste, which will serve as the sealing material 10, to the outer peripheral surface of the upper surface of the insulating substrate 1 and / or the outer peripheral surface of the lower surface of the lid body 2. The glass paste is heated to soften and melt. After that, a method of applying the sealing material 10 to the outer peripheral portion of the upper surface of the insulating substrate 1 and / or the outer peripheral portion of the lower surface of the lid body 2 by cooling and solidifying is adopted.

When the glass paste serving as the sealing material 10 is printed on the outer peripheral portion of the lower surface of the lid body 2 by screen printing, a part of the glass paste is printed on the central portion of the lower surface of the lid body 2 during printing. May be scattered and adhere. If such scattering occurs, a protrusion made of glass will be formed on the lower surface of the central portion of the lower surface of the lid body 2 after the insulating base body 1 and the lid body 2 are joined, and the piezoelectric vibrator piece 3 housed inside the container is covered with the lid. Body 2
In the case of adjusting the vibration frequency of the piezoelectric vibrator piece 3 by irradiating the piezoelectric vibrator piece 3 through the laser beam, the protrusion prevents accurate transmission of the laser beam passing through the lid body 2, and Make adjustments difficult. Therefore, in the case of adjusting the vibration frequency of the piezoelectric vibrator piece 3 by irradiating the piezoelectric vibrator piece 3 housed in the container through the lid body 2 with a laser beam, the sealing material 10 is insulated. It is preferable to pre-deposit only on the upper surface of the substrate 1.

Next, the piezoelectric vibrator of the present invention will be described.

The piezoelectric vibrator of the present invention is the above-mentioned insulating substrate 1.
A piezoelectric vibrator piece 3 is hermetically housed in a piezoelectric vibrator container made up of a lid 2 and a lid 2.

The piezoelectric vibrator piece 3 has its electrodes on the insulating substrate 1.
It is mounted on the mounting portion 1a of the insulating base 1 by being bonded to the wiring conductor 4 led out to one end side of the mounting portion 1a via a conductive adhesive 5.

Then, the lid 2 is bonded to the upper surface of the insulating base 1 via the sealing material 10 made of, for example, low melting point glass, so that the piezoelectric vibrator piece is provided in the space between the insulating base 1 and the lid 2. 3 are accommodated.

Further, the space between the insulating substrate 1 in which the piezoelectric vibrator piece 3 is housed and the lid 2 is evacuated to prevent the gas inside the space from disturbing the vibration of the piezoelectric vibrator piece 3. It is evacuated, and at the same time, the metal member 8 for sealing is attached to the metal layer 8 in the through hole 6 formed in the insulating substrate 1 via the brazing material 9 to hermetically seal it. At this time, the piezoelectric vibrator can obtain a high Q value because the space inside the container accommodating the piezoelectric vibrator piece 3 is evacuated to a vacuum.

The sealing metal member 7 for sealing the through hole 6 of the insulating substrate 1 is a sphere made of metal such as copper. The brazing material 9 which attaches the sealing metal member 7 to the metal layer 8 is, for example, a lead-tin alloy containing 90% by weight of lead and 10% by weight of tin.

The sealing metal member 7 has a periphery of an opening of the first hole 6a on the second hole 6b side with respect to the through hole 6, specifically, the first hole 6a and the second hole 6a. Since the brazing material 9 is attached to the metal layer 8 adhered to the lower surface of the step formed between the first and second holes 6a and 6b, It spreads only around the side openings.

As a result, the brazing material 9 and the sealing metal member 7 are formed due to the surface tension of the brazing material 9 at the time of melting.
Are held and fixed in the vicinity of the opening of the first hole 6a on the second hole 6b side. Therefore, the through-hole 6 is satisfactorily sealed by the sealing metal member 7 and the brazing material 9, and the brazing material 9
And the sealing metal member 7 project from the upper surface of the insulating substrate 1 to hinder the vibration of the piezoelectric vibrator piece 3, or project from the lower surface of the insulating substrate 1 to mount the piezoelectric vibrator on an external circuit board. Does not interfere with.

Further, since the through hole 6 is sealed with the sealing metal member 7 and the brazing material 9, compared with the conventional case where the through hole is sealed with the brazing material alone, the through hole 6 is sealed. It is possible to reduce the volume of the brazing filler metal required for stopping. As a result, the amount of gas normally generated when melting the brazing filler metal 9 can be reduced, and
Since the sealing metal member 7 can effectively prevent this gas from entering the inside of the container, the adverse effect of the gas generated from the brazing material 9 on the piezoelectric vibrator piece 3 should be extremely small. You can also At the same time, less energy is required to melt the brazing material, and stable sealing can be performed in a short time. Therefore, the piezoelectric vibrator of the present invention is economically excellent.

When the size of the sealing metal member 7 is smaller than the opening of the first hole 6a by about 0.04 to 0.2 mm, the sealing metal member 7 is used as the brazing material for the metal layer 8. The metal member 7 for sealing is held by the molten brazing filler metal 9 when it is attached via the through hole 9 so as to be freely movable in the through hole 6, and due to the surface tension of the molten brazing filler metal 9, the through hole 6 is formed. Since it is automatically aligned and fixed to the physically most stable position between the first hole 6a and the second hole 6b in the inside, the inside of the through hole 6 can be made extremely strong and stable. It becomes possible to seal. Therefore, the sealing metal member 7 is
It is preferable that the size thereof is smaller than the opening of the first hole 6a by about 0.04 to 0.2 mm.

The shape of the sealing metal member 7 is not necessarily spherical, and may be, for example, a disc, a cylinder, a cone, a pyramid, or various polyhedrons. Furthermore, the material of the sealing metal member 7 does not necessarily have to be made of copper, and may be made of another metal such as a copper alloy, an iron alloy, or a nickel alloy.

Further, the material of the brazing material 9 does not necessarily have to be a lead-tin alloy containing 90% by weight of lead and 10% by weight of tin, and a lead-tin alloy or a gold-tin alloy having a composition ratio other than this is used. It may be a brazing material made of another alloy such as a silver alloy.

Next, a method of manufacturing the piezoelectric vibrator of the present invention will be described.
The description will be made with reference to FIGS. 2A to 2C, which are cross-sectional views of respective steps.

First, as shown in FIG. 2A, a piezoelectric vibrator container including an insulating base 1 and a lid 2 and a piezoelectric vibrator piece 3 are prepared.

The insulating substrate 1 is made of an electrically insulating material such as an aluminum oxide sintered body as described above, and has a mounting portion 1a for mounting the piezoelectric vibrator piece 3 at the center of the upper surface, A wiring conductor 4 to which the electrodes of the piezoelectric vibrator piece 3 are electrically connected is attached from the upper surface to the lower surface of the mounting portion 1a. And, from the upper surface to the lower surface of the mounting portion 1a,
A through hole 6 composed of a first hole 6a on the upper surface side and a second hole 6b on the lower surface side larger than the opening of the first hole 6a is formed. Second hole 6b
A metal layer 8 is deposited around the side opening.

A sealing material 10 made of low-melting glass is preliminarily applied to the outer peripheral portion of the upper surface where the insulating base 1 is joined to the lid 2 in a required thickness and width.

On the other hand, the lid 2 is a flat plate made of a translucent material such as glass or sapphire. It is possible to irradiate the inside of the container with a laser beam through this lid body 2.
For example, the transmittance of a laser beam having a wavelength of 1000 nm is preferably 90% or more.

The piezoelectric vibrator piece 3 is, for example, a crystal cut out in a strip shape. An electrode (not shown) and a metal film for adjusting the vibration frequency are deposited on the surface thereof.

Next, as shown in FIG. 2 (b), the electrodes of the piezoelectric vibrator piece 3 are bonded and fixed to the wiring conductors 4 of the insulating substrate 1 via the conductive adhesive 5 so that the piezoelectric element is mounted on the mounting portion 1a. The oscillator piece 3 is mounted. Further, by joining the lid body 2 to the upper surface of the insulating base body 1 via the sealing material 10, the piezoelectric vibrator piece 3 is housed in the space inside the container composed of the insulating base body 1 and the lid body 2.

To bond and fix the piezoelectric vibrator piece 3 to the wiring conductor 4, for example, an uncured silver-polyimide resin is applied onto the wiring conductor 4 and the piezoelectric vibrator piece 3 is placed on the silver-polyimide resin. It is placed and then heated to a temperature of about 300 DEG C. to heat cure the silver-polyimide resin.

In addition, the lid 2 is joined to the upper surface of the insulating base 1 by placing the lid 2 on the sealing material 10 previously attached to the outer peripheral portion of the upper surface of the insulating base 1, About 30 of this sealing material 10
It is carried out by heating to a temperature of 0 to 400 ° C. to soften and melt it.

The encapsulant 10 for joining the insulating base 1 and the lid 2 does not necessarily have to be applied to the upper surface of the insulating base 1 in advance, for example, to the lower surface of the lid 2 in advance. Alternatively, the insulating base 1 and the lid 2 may be prepared separately.

Then, as shown in FIG. 2C, the piezoelectric vibrator container in which the piezoelectric vibrator piece 3 is housed in the space between the insulating substrate 1 and the lid 2 is placed in a vacuum. After the space inside the container is evacuated to a vacuum through the through hole 6 provided in the insulating substrate 1, the sealing metal member 7 whose surface is covered with the brazing material 9 is placed in the through hole 6.

As described above, the sealing metal member 7 is a sphere made of a metal such as copper, and the brazing material 9 is a lead-tin alloy, for example. Since the surface of the sealing metal member 7 is covered with the brazing filler metal 9, the sealing metal member 7 and the brazing filler metal 9 can be easily inserted into the through hole 6 simply by putting it in the through hole 6. Can be placed. Further, since the sealing metal member 7 is previously covered with the brazing material 9, the sealing metal member 7 is well wetted by the brazing material 9.

In this case, as described above, the sealing metal member 7 is preferably smaller than the opening of the first hole 6a, and the brazing material 9 for covering the sealing metal member 7 is further used. The included size is preferably larger than the opening of the first hole 6a.

By making the sealing metal member 7 smaller than the opening of the first hole 6a, when the brazing material 9 is melted and the sealing metal member 7 is attached to the metal layer 8, sealing is performed. The metal member for use 7 can move freely in the through hole 6, and due to the surface tension of the molten brazing material 9, the through hole 6 is formed.
The metal member 7 for sealing is automatically positioned at the physically most stable position between the first hole 6a and the second hole 6b, and the through hole 6 can be firmly sealed. . Further, by setting the size including the brazing material 9 to be larger than the opening of the first hole 6a, the brazing material when the sealing metal member 7 covered with the brazing material 9 is placed in the through hole 6. It is possible to effectively prevent the sealing metal member 7 covered with 9 from passing through the through hole 6 and falling inside the container.

Incidentally, the sealing metal member 7 does not necessarily have to have its surface coated with the brazing material 9. For example, the sealing metal member 7 and the brazing material 9 are separately arranged in the through hole 6. It may be done.

Finally, these are heated to a temperature equal to or higher than the melting point of the brazing material 9 to melt the brazing material 9, so that the sealing metal member 7 is attached to the metal layer 8 via the brazing material 9. The through hole 6 is sealed.

At this time, since the metal layer 8 is applied only to the periphery of the opening on the second hole 6b side of the first hole 6a, the molten brazing filler metal 9 is applied to the first hole 6a. 2 does not wet and spread only around the opening on the hole 6b side, and does not reach the upper and lower surfaces of the insulating substrate 1. Also, this molten brazing material 9
Since the sealing metal member 7 is held around the opening on the second hole 6b side of the first hole 6a by the surface tension of the brazing filler metal 9
The metal member for sealing 7 does not project from the upper surface of the insulating substrate 1 to prevent vibration of the piezoelectric vibrator piece 3, or projects from the lower surface of the insulating substrate 1 to mount the piezoelectric vibrator on the external circuit board. It is possible to provide a piezoelectric vibrator that does not hinder its mounting.

At this time, since the through hole 6 is sealed with the sealing metal member 7 and the brazing material 9, the through hole 6 is sealed as compared with the conventional case where the through hole is sealed with only the brazing material. The volume of brazing filler metal required for stopping is small. As a result, the amount of gas normally generated when the brazing filler metal 9 is melted becomes small, and the sealing metal member 7 effectively prevents the invasion of this gas into the container. It is possible to provide a piezoelectric vibrator in which the gas generated from the brazing material 9 has a very small adverse effect on the piezoelectric vibrator piece 3.

If necessary, the lid 2 is passed through a metal film for adjusting the vibration frequency, which is adhered to the piezoelectric vibrator piece 3 housed in the piezoelectric vibrator container, and the wavelength is, for example, 1000 n.
The piezoelectric vibrator shown in FIG. 1 is completed by irradiating a laser beam of about m and finely adjusting the vibration frequency of the piezoelectric vibrator piece 3 by scattering a part of the metal film for adjusting the vibration frequency. To do.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the gist of the present invention.

[0072]

[0073]

According to the piezoelectric vibrator of the present invention, the piezoelectric vibrator piece is housed in the piezoelectric vibrator container, and the first hole of the through hole formed in the insulating base is opened on the second hole side. Since the sealing metal member is attached to the metal layer adhered to the periphery of the through hole through the brazing material, it is adhered to the periphery of the opening on the second hole side of the first hole of the through hole. When the sealing metal member is attached to the metal layer via the brazing filler metal, the molten brazing filler metal wets and spreads only around the opening on the second hole side of the first hole, and the upper and lower surfaces of the insulating substrate Never reach. In addition, since the sealing metal member is held in the vicinity of the opening on the second hole side of the first hole by the surface tension of the molten brazing material, the through hole is well formed in the sealing metal member and the brazing material. While being sealed, a brazing material or a sealing metal member protrudes from the upper surface of the insulating base to prevent vibration of the piezoelectric vibrator piece, or protrudes from the lower surface of the insulating base to mount the piezoelectric vibrator on an external circuit board. It does not interfere with its implementation.

Further, when the sealing metal member is smaller than the opening of the first hole, the second hole of the first hole of the through hole is formed.
When attaching the sealing metal member to the metal layer deposited around the opening on the side of the hole via the brazing filler metal, the sealing metal member is held by the molten brazing filler metal in the through hole. It becomes free to move, and the surface tension of the molten brazing material makes it
Since it is automatically positioned at the physically most stable position between the hole and the second hole, the through hole can be sealed extremely firmly and stably.

According to the method of manufacturing a piezoelectric vibrator of the present invention, the piezoelectric vibrator has a mounting portion on its upper surface, and
A first hole on the upper surface side and a second hole on the lower surface side having an opening larger than the first hole, and a sealing metal member is attached around the opening on the second hole side of the first hole. A substantially flat plate-shaped insulating substrate provided with a through hole to which a metal layer is attached is mounted, a piezoelectric vibrator piece is mounted on the mounting portion, and a lid is bonded to the upper surface of the insulating substrate. After the piezoelectric vibrator piece is housed in the space between the insulating substrate and the insulating substrate, the metal member for sealing is attached to the metal layer adhered to the through hole of the insulating substrate through the brazing material to seal the through hole. Therefore, when the sealing metal member is attached to the metal layer adhered to the through hole via the brazing filler metal to seal the through hole, the molten brazing filler metal is No. 2 spreads only around the opening on the hole side and does not reach the upper and lower surfaces of the insulating substrate. Further, since the sealing metal member is held around the second hole side opening of the first hole by the surface tension of the molten brazing filler metal, the brazing filler metal and the sealing metal member are the upper surface of the insulating substrate. A piezoelectric vibrator that does not protrude from the hindrance to vibrate the piezoelectric vibrator piece, or that does not hinder the mounting when the piezoelectric vibrator is mounted on the external circuit board by protruding from the lower surface of the insulating substrate. Can be provided.

Further, after the sealing metal member having the surface coated with the brazing material is housed in the through hole of the insulating substrate, the brazing material coating the sealing metal member is melted to melt the sealing metal member. By attaching the sealing metal member and the brazing filler metal simultaneously in the through hole, the coated brazing filler metal surely wets the surface of the sealing metal member. The metal member can be easily and surely attached in the through hole.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment of a piezoelectric vibrator container of the present invention and a piezoelectric vibrator using the same.

FIG. 2A to FIG. 2C are cross-sectional views for each step for explaining the method for manufacturing a piezoelectric vibrator of the present invention.

FIG. 3 is a cross-sectional view of a conventional piezoelectric vibrator container and a piezoelectric vibrator using the same.

[Explanation of symbols]

1 ... Insulating substrate 2 ... Lid 3 ... Piezoelectric vibrator piece 6 ... through holes 6a ... First hole 6b ... Second hole 7 ... Metal member for sealing 8 ... Metal layer 9 ... Brazed material

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-86867 (JP, A) Actual development Sho 52-73676 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H03H 9/10 H01L 41/09 H03H 3/02 H03H 9/02

Claims (4)

(57) [Claims] 1. A substantially flat plate-shaped insulating base having a piezoelectric vibrator piece mounting portion on the upper surface and having a through hole extending from the upper surface to the lower surface, and the insulating base bonded to the upper surface of the insulating base. And a lid for hermetically containing the piezoelectric vibrator piece in the space, the through hole includes a first hole on the upper surface side and a second hole on the lower surface side having an opening larger than the first hole. And in the space of the piezoelectric vibrator container in which a metal layer for attaching a sealing metal member is attached to the periphery of the opening of the first hole on the side of the second hole. Piezoelectric vibration
The metal piece for accommodating the child piece is placed in the metal layer of the through hole,
The metal member is attached through a brazing material.
Piezoelectric vibrator . 2. The sealing metal member is configured to open the first hole.
The piezoelectric vibrator according to claim 1, wherein the piezoelectric vibrator is smaller than the mouth . 3. A piezoelectric vibrator piece mounting portion is provided on the upper surface.
In both cases, the opening is larger than the first hole on the upper surface side and the first hole.
And a second hole on the lower surface side of the first hole,
2 for attaching the sealing metal member around the opening on the hole side
Substantially flat plate with a through hole where a metal layer is deposited
The step of preparing an insulating base, and the piezoelectric vibration on the mounting portion.
The process of mounting the child piece, and the lid body is attached to the upper surface of the insulating substrate.
The piezoelectric vibrator piece in the space between the insulating base and
The step of housing and the sealing of the metal layer in the through hole
Attach the metal member via the brazing material and seal the through hole.
A method of manufacturing a piezoelectric vibrator, characterized by comprising the following steps:
Law . 4. The surface of the sealing metal member is attached to the mounting member.
The sealing metal member coated with a filler is placed in the through hole.
After storing, do so by melting the brazing material.
The method for manufacturing a piezoelectric vibrator according to claim 3, wherein