JP2013070357A - Surface mounted crystal vibrator and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface mounted crystal vibrator which achieves the downsizing, improves the quality, reduces the manufacturing cost and improves the productivity, and to provide a manufacturing method of the surface mounted crystal vibrator.SOLUTION: In a manufacturing method of a surface mounted crystal vibrator, through terminals 2b, 2c of AgPd are formed on wall surfaces of through holes formed at corners of a rectangular ceramic substrate 1, and metal electrodes of support electrode lower layer parts 3a of AgPd, each of which connects with the through terminal 2c and forms a lower layer of a support electrode 3b, are formed on a surface of the substrate 1. The support electrode 3b, which holds a crystal piece 5 on the support electrode lower layer part 3a, is formed by Ag on each support electrode lower layer part 3a, and a cover 6 is mounted on an insulation film 10 formed at the peripheral inner side of the substrate 1 to hermetically seal the surface mounted crystal vibrator.

Description

  The present invention relates to a surface-mount crystal resonator, and more particularly, to a surface-mount crystal resonator capable of improving productivity and realizing downsizing and a method for manufacturing the same.

[Conventional technology]
Since the surface-mounted crystal unit is small and light, it is built in as a frequency and time reference source, especially in portable electronic devices.
Some conventional surface-mount crystal units have a crystal piece mounted on a ceramic substrate, and are covered with a concave cover upside down and hermetically sealed. In recent years, the frequency deviation Δf / f is relatively loose, and there is an inexpensive consumer use of ± 150 to ± 250 ppm, for example.

  In particular, a general configuration of a conventional surface-mount crystal unit is such that a metal electrode pattern of, for example, AgPd (silver / palladium) is formed on a ceramic substrate. The crystal pieces are lifted by the supporting electrodes.

This is because if the center part of the crystal piece comes into contact with the surface of the ceramic substrate (base), the vibration is hindered and the equivalent resistance value is deteriorated. Therefore, the support electrode on which the crystal piece is mounted needs to be raised to some extent from the base surface. .
The metal electrode and the support electrode are made of AgPd because it is difficult to oxidize.

[Related technologies]
As related prior arts, Japanese Unexamined Patent Application Publication No. 2007-158419 “Surface Mounted Crystal Oscillator” (Nippon Denpa Kogyo Co., Ltd.) [Patent Document 1], Japanese Unexamined Patent Application Publication No. 2003-179456 “Surface Mount Container for Crystal Products and the Same” Quartz product using ”(Nippon Denpa Kogyo Co., Ltd.) [Patent Document 2], Japanese Patent Application Laid-Open No. 2001-110925“ Conductive cap, electronic component and method for forming insulating film of conductive cap ”(Murata Manufacturing Co., Ltd.) [ Patent Document 3].

Patent Document 1 shows a configuration in which a crystal piece 3 is mounted on an IC chip 2, an IC chip 2 or the like is formed on a mounting substrate 4, and a metal cover 5 is provided in a surface mount crystal oscillator. .
Patent Document 2 shows a configuration in which a crystal piece 3 is provided on a single-layer substrate 1A via a crystal terminal 6 and hermetically sealed with a cover 2 in a surface mount container for crystal products.
Further, in Patent Document 3, a rectangular frame-like insulating film 55 is formed on the substrate 51 at a portion where the lower opening end surface of the metal cap 52 contacts the upper surface 51 a of the substrate 51. It has been shown that.

JP 2007-158419 A JP 2003-179456 A JP 2001-110925 A

  However, in the conventional surface mount crystal resonator, the metal electrode and the support electrode are formed of AgPd for the reason that it is difficult to oxidize, but the support electrode needs to have a thickness in order to separate the crystal piece from the base surface. The support electrode has a problem that, for example, AgPd is applied and laminated three times by screen printing, which makes it difficult to manufacture the surface-mounted crystal resonator.

In particular, since AgPd has a low viscosity, it is impossible to form a thick film at one time, and it is necessary to repeat the process of forming a thin film and laminating a thin film.
Further, since AgPd has a low viscosity, a support electrode is formed on the metal electrode. However, the AgPd film of the support electrode may sag and protrude around the metal electrode.
Further, Pd is currently about 22 times as expensive as Ag, and there is a problem that the production cost increases as the amount of Pd used increases.

  The present invention has been made in view of the above circumstances, and provides a surface-mounted crystal resonator capable of improving quality, reducing manufacturing cost, and improving productivity while realizing downsizing. The purpose is to do.

  The present invention for solving the problems of the above conventional example is a surface-mounted crystal resonator in which a crystal piece is mounted on a rectangular ceramic substrate, and includes first and second support electrodes that hold the crystal piece, A through terminal formed on the wall surface of the through hole formed in the corner of the substrate; a first and second lower layer formed on the lower surface of the first and second support electrodes on the surface of the substrate; A first connection terminal that connects the end of the first lower layer part and the through terminal at the shortest corner from the end, and the through of the shortest corner from the end of the second lower layer and the end A second connection terminal that connects the terminal and a cover that covers the crystal piece and hermetically seals the inside, and the through terminal, the lower layer portion, and the connection terminal are formed of an anti-oxidation metal film, The second support electrode is made of silver.

  According to the present invention, in the surface-mounted crystal resonator, the first and second connection terminals are connected to each other by connecting the first connection terminal and the second connection terminal to the diagonal through terminals of the substrate. Compared with the edge part of 2 lower layer parts, the edge part of the 1st and 2nd lower layer part to which the 1st and 2nd connection terminal is not connected was shortened.

  The present invention is characterized in that in the surface-mounted crystal resonator, a band-shaped insulating film on which a cover is mounted is formed inside the periphery of the substrate.

  The present invention is characterized in that, in the surface-mounted crystal resonator, the oxidation-preventing metal film is formed of an alloy containing silver as a main component.

  The present invention is characterized in that, in the above surface-mounted crystal resonator, the oxidation-preventing metal film is formed of an alloy with palladium containing silver as a main component.

  According to the present invention, in the above surface-mounted crystal resonator, the crystal piece is beveled, the short side has an inclination, and the first and second support electrodes are on the first and second lower layer portions, In order to form a space portion in the central portion of the lower layer portion, the space portion is separated into two and formed at the end of the lower layer portion.

  According to the present invention, in the surface mount crystal resonator, the conductive material is formed on one of the separated support electrodes formed on the end portions of the first and second lower layer portions connected to the first and second connection terminals. A quartz piece that has been beveled is fixed through an adhesive.

  According to the present invention, in the surface mount crystal resonator, the surface area of one of the support electrodes is separated on the end portions of the first and second lower layer portions that are not connected to the first and second connection terminals. The surface area of the other supporting electrode is larger.

  The present invention relates to a method of manufacturing a surface-mounted crystal resonator in which a crystal piece is mounted on a rectangular ceramic substrate, wherein through terminals are formed on the wall surface of a through-hole formed in a corner portion of the substrate, and The first and second lower layer portions below the first and second support electrodes holding the crystal piece on the surface, the end portion of the first lower layer portion, and the through terminal at the shortest corner from the end portion, And a second connection terminal for connecting the end portion of the second lower layer portion and the through terminal at the shortest corner portion from the end portion is formed of an antioxidant metal film. The first and second support electrodes are formed of silver on the first and second lower layer portions, a cover for covering the crystal piece and hermetically sealing the inside is provided.

  According to the present invention, in the method for manufacturing the surface-mounted crystal resonator, the first connection terminal and the second connection terminal are connected to the diagonal through terminals of the substrate, and the first and second connection terminals are connected. Compared to the end portions of the first and second lower layer portions, the end portions of the first and second lower layer portions to which the first and second connection terminals are not connected are formed shorter.

  The present invention is characterized in that, in the method for manufacturing a surface-mounted crystal resonator, the first and second support electrodes are formed once using a metal mask.

  The present invention is characterized in that, in the method of manufacturing a surface-mounted crystal resonator, the oxidation-preventing metal film is made of an alloy containing silver as a main component.

  The present invention is characterized in that, in the method for manufacturing a surface-mounted crystal resonator, the oxidation-preventing metal film is formed of an alloy with palladium containing silver as a main component.

  The present invention is the above-described method for manufacturing a surface-mounted crystal resonator, which is a method for manufacturing a surface-mounted crystal resonator in which a beveled crystal piece having a short side is inclined is mounted. However, on the first and second lower layer portions, the space portion is formed in the central portion of the lower layer portion, and is separated into two and formed at the end portion of the lower layer portion.

  According to the present invention, in the method for manufacturing the surface-mounted crystal resonator, one of the separated support electrodes formed on the end portions of the first and second lower layer portions connected to the first and second connection terminals is provided. A beveled crystal piece is fixed to the top via a conductive adhesive.

  In the method for manufacturing a surface-mounted crystal resonator according to the present invention, the surface area of one of the support electrodes is formed on the end portions of the first and second lower layer portions that are not connected to the first and second connection terminals. It is characterized by being larger than the surface area of the other support electrode separated.

  According to the present invention, the first and second support electrodes for holding the crystal piece, the through terminals formed on the wall surface of the through hole formed in the corner portion of the substrate, and the first and second electrodes on the surface of the substrate. A first connection terminal that connects the first and second lower layer portions formed in the lower layer of the two support electrodes, an end portion of the first lower layer portion, and a through terminal at the shortest corner from the end portion; And a second connection terminal for connecting the end portion of the second lower layer portion and the through terminal at the shortest corner portion from the end portion, and a cover that covers the crystal piece and hermetically seals the inside. In addition, since the lower surface portion and the connection terminal are formed of an anti-oxidation metal film and the first and second support electrodes are made of a surface mounted crystal resonator, the quality is improved while realizing miniaturization, The manufacturing cost can be reduced and the productivity can be improved.

  According to the present invention, the through terminal is formed on the wall surface of the through hole formed in the corner portion of the substrate, and the first and second support electrodes below the first and second support electrodes holding the crystal piece on the surface of the substrate. A second lower layer, a first connection terminal connecting the end of the first lower layer and the through terminal at the shortest corner from the end, an end of the second lower layer, and the end The second connection terminal for connecting the through terminal at the shortest corner is formed of an oxidation-preventing metal film, and the first and second support electrodes are made of silver on the first and second lower layers. The surface mount crystal unit is manufactured by covering the crystal piece and providing a cover that hermetically seals the inside. Therefore, while miniaturization is achieved, quality is increased, manufacturing cost is reduced, and productivity is increased. There is an effect that can be improved.

  According to the present invention, the crystal piece is beveled, the short side has an inclination, and the first and second support electrodes are on the center portion of the lower layer portion on the first and second lower layer portions. Since the surface-mount crystal unit and the method for manufacturing the same are formed in the end portion of the lower layer part so as to form the space part, the lens-shaped abdomen of the crystal piece is pushed out into the space part. As a result, the conductive adhesive is sufficiently pressed on the support electrode, and the adhesive strength of the crystal piece is increased.

It is plane explanatory drawing of the electrode pattern in this crystal oscillator. It is sectional explanatory drawing in the state in which the electrode pattern in this crystal oscillator was formed. It is a plane explanatory view of the insulating film pattern of this crystal oscillator. It is sectional explanatory drawing in the state in which the insulating film in this crystal oscillator was formed. It is a plane explanatory view of a support electrode pattern of this crystal oscillator. It is sectional explanatory drawing in the state in which the support electrode pattern in this crystal oscillator was formed. It is a plane explanatory view of crystal piece mounting in this crystal resonator. It is sectional explanatory drawing of the state in which the cover was mounted in this crystal oscillator. It is a plane explanatory view of the electrode pattern in another crystal oscillator. It is a plane explanatory view of crystal piece mounting in another crystal resonator. It is sectional explanatory drawing in the short side of another crystal oscillator. It is sectional explanatory drawing in the long side in the state in which the cover was mounted in another crystal oscillator.

Embodiments of the present invention will be described with reference to the drawings.
[Outline of the embodiment]
In the surface mount crystal resonator according to the embodiment of the present invention, an AgPd through terminal is formed on a wall surface of a through hole formed in a corner portion of a rectangular ceramic substrate, and is supported by connecting to the through terminal on the surface of the substrate. An AgPd metal electrode that forms a lower layer of the electrode is formed, and an Ag support electrode that holds a crystal piece is formed on the metal electrode, reducing the manufacturing cost while realizing downsizing, Productivity is improved.

  In particular, since the support electrode is formed using a metal mask instead of a screen mask so that the Ag film is formed thick once, the manufacturing cost can be reduced and the manufacturing process can be simplified.

[Premise of this embodiment]
Conventionally, the support electrode for holding the crystal piece has been formed of AgPd because AgPd printing is excellent in environmental resistance and the AgPd film is difficult to oxidize.
In the embodiment of the present invention, a quartz cover is covered with a metal cover, and the inside of the package is purged with N 2 to be hermetically sealed. Therefore, even if the support electrode in the package is made of Ag, oxidation hardly occurs.
The N2 purge is an operation of sending nitrogen into the package and expelling oxygen and the like.
However, since the metal electrode and the through terminal drawn from the package are exposed to air, it is necessary to form them with AgPd.

[Electrode pattern of this crystal resonator: Fig. 1]
A surface-mounted crystal resonator (present crystal resonator) according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory plan view of an electrode pattern in the present crystal unit.
As shown in FIG. 1, the electrode pattern of the metal electrode of this crystal resonator is formed on the ceramic substrate (base) 1, the pattern of the support electrode lower layer portion 3 a that is the lower layer of the support electrode, and the four corners of the base 1. The through terminals 2b and 2c and the pattern of the connection terminal 2a for connecting the support electrode lower layer portion 3a and the through terminal 2c are basically provided.
Here, the through terminal to which the connection terminal 2a is connected is designated as 2c, and the through terminal to which the connection terminal 2a is not connected is designated as 2b.

Here, each part of an electrode pattern is demonstrated concretely.
The through terminals 2b and 2c are in a ceramic sheet state before being separated into bases, and through holes (through holes) are formed at the intersections of break lines that define the areas of the individual crystal resonators. A metal film is formed on the walls of the through holes. Is formed to serve as an electrode for connecting the front and back of the base.
The through terminals 2b and 2c have a fan-shaped pattern except for the through-hole portions on the front and back of the base so that not only the wall surface of the through-hole but also other electrodes can be easily connected.

The connection terminal 2a is linearly connected to the through terminal 2c at the corner closest to the end of the support electrode lower layer 3a.
Further, the connection terminals 2a are connected to through terminals 2c that are positioned diagonally. In FIG. 1, one connection terminal 2a is connected to the lower left through terminal 2c, and the other connection terminal 2a is connected to the upper right through terminal 2c.
By connecting the connection terminal 2a diagonally, even if the cover is displaced in the vertical direction in FIG. , Can improve the quality.

Further, the support electrode lower layer portion 3a has a shorter end portion to which the connection terminal 2a is not connected than an end portion to which the connection terminal 2a is connected.
That is, the distance (A) to the long side of the base adjacent to the end of the support electrode lower layer 3a to which the connection terminal 2a is connected and the length of the base adjacent to the end of the support electrode lower layer 3a to which the connection terminal 2a is not connected. Comparing the distance (B) to the side, the distance (B) is longer than the distance (A).

  Therefore, in the upper left and lower right of FIG. 1, the cover to be mounted thereafter is enlarged by widening the space to the long side close to the end of the support electrode lower layer 3 a (the end to which the connection terminal 2 a is not connected). Even if it is slightly deviated in the up-and-down direction of 1, the end portion is not contacted, and the quality can be improved.

[Cross section of electrode pattern of this crystal unit: Fig. 2]
FIG. 2 shows a cross-sectional explanatory diagram in a state where the electrode pattern is formed on the base 1. FIG. 2 is a cross-sectional explanatory view showing a state where an electrode pattern is formed in the present crystal unit.
As shown in FIG. 2, the support electrode lower layer 3a and the connection terminal 2a are integrally formed of AgPd on the surface of the base 1, and through terminals 2b and 2c for connecting the front and back of the base 1 are also formed at the same time. .

On the back surface of the base 1, an electrode pattern of the mounting terminals 4 connected to the through terminals 2b and 2c is formed of AgPd.
The mounting terminal 4 connected to the through terminal 2c is an electrode to which a voltage is applied, and the mounting terminal 4 connected to the through terminal 2b is a GND electrode connected to the ground level.

[Insulating film formation of this crystal resonator: FIG. 3]
Next, the formation of the insulating film of the present crystal unit will be described with reference to FIG. FIG. 3 is an explanatory plan view of an insulating film pattern of the present crystal resonator.
As shown in FIG. 3, the insulating film 10 is formed of glass or the like in a belt shape so as to circulate on the inner surface of the outer surface of the base 1, and crosses the connection terminals 2 a on the base 1.
The insulating film 10 is formed on the inner side away from the outer peripheral end of the base 1 and does not cover the corners where the through terminals 2b and 2c are formed.
However, the insulating film 10 may be extended to the center side of the through terminals 2b and 2c in consideration of the displacement of the cover. The center side is a line end portion when the corners of the base 1 are connected by diagonal lines.

[Cross section of insulating film formation of this crystal unit: FIG. 4]
FIG. 4 shows a cross-sectional explanatory diagram in a state where an insulating film is formed. FIG. 4 is a cross-sectional explanatory view showing a state in which an insulating film is formed in the present crystal unit.
As shown in FIG. 4, an insulating film 10 is formed on the surface of the base 1 so as to go inside the outer periphery. The insulating film 10 is also formed on the connection terminal 2a.

[Supporting electrode pattern of this crystal resonator: FIG. 5]
Next, the support electrode pattern of the present crystal resonator will be described with reference to FIG. FIG. 5 is an explanatory plan view of the support electrode pattern of the present crystal resonator.
As shown in FIG. 5, the support electrode 3b is formed on the support electrode lower layer portion 3a by being laminated on the support electrode lower layer portion 3a.

Since the support electrode 3b uses Ag, the viscosity is high, and a thick metal film can be formed by a single application using a metal mask. The thickness of the support electrode 3b formed by one application corresponds to three layers of a metal film (low viscosity) using conventional AgPd.
That is, in order to form the support electrode 3b having the same thickness, it is only necessary to apply the Ag film once in the present embodiment. However, the conventional AgPd film needs to be applied three times, and a lot of Pd is used. It is expensive and the work process is complicated.
Further, since the supporting electrode 3b uses Ag having a high viscosity, the supporting electrode 3b does not leak out from the supporting electrode lower layer 3a, and the possibility of short-circuiting can be reduced even if the metal cover is slid and mounted.

[Cross section of support electrode pattern of this crystal unit: FIG. 6]
FIG. 6 shows a cross-sectional explanatory diagram in a state where the support electrode pattern is formed. FIG. 6 is a cross-sectional explanatory view showing a state in which a support electrode pattern is formed in the present crystal unit.
As shown in FIG. 6, the support electrode 3b is formed on the support electrode lower layer 3a to be thicker than the support electrode lower layer 3a.

[Crystal piece mounting of this crystal unit: Fig. 7]
Next, mounting of the crystal unit of the present crystal resonator will be described with reference to FIG. FIG. 7 is an explanatory plan view of the crystal piece mounted in the present crystal resonator.
The crystal piece 5 is AT-cut, and opposing excitation electrodes 5a are formed on both main surfaces.
Further, the crystal piece 5 is formed with an extraction electrode 5b extending from the excitation electrode 5a to opposite ends in the opposite direction and folded back over the entire width in the width direction.
Then, a pair of diagonal portions (end portions) extending from the extraction electrode 5b are fixed to the support electrode 3b by the conductive adhesive 7 as a conductive material, and the extraction electrode 5b and the support electrode 3b are electrically connected. Mechanically connected.

[Cross section of this crystal unit: Fig. 8]
Next, a cross section in a state where a cover is mounted on the crystal resonator will be described with reference to FIG. FIG. 8 is an explanatory cross-sectional view of a state where a cover is mounted on the present crystal unit.
As shown in FIG. 8, the crystal piece 5 is mounted on the support electrode 3 b via the conductive adhesive 7, and is further made of metal via a resin as an insulating sealing material on the insulating film 10. The cover 6 is mounted.

The cover 6 has a concave shape, the end face of the opening is bent in an L shape, the concave shape is turned upside down, and the L-shaped portion is interposed between the sealing agent resin and the insulating film 10. Bonded on top.
In the case of sealing with the cover 6, since it is hermetically sealed by N2 purge, the support electrode 3b formed of Ag is not oxidized, and there is no problem in quality.

[Method of manufacturing the present crystal unit]
Next, a method for manufacturing the present crystal resonator will be described.
[First step / Sintered ceramic fabric]
First, a sheet-shaped ceramic cloth that is the basis of the sheet-shaped ceramic base is formed.
In the sheet-like ceramic fabric, break lines that divide adjacent regions corresponding to the individual ceramic bases 1 are formed, and through holes are formed at the four corners (corners).
And the sheet-like ceramic material | fabric in which the through-hole was formed is baked, and a sheet-like ceramic base is obtained.

[Second step / circuit pattern formation]
Next, an AgPd alloy metal paste having a thickness of about 10 μm is formed in a region corresponding to the circuit pattern of the sheet-like ceramic base by printing using a screen mask.
As shown in FIG. 1, the circuit pattern has a metal pattern formed on one main surface (front surface), a pattern of mounting terminals 4 formed on the other main surface (back surface), and a wall surface of the through hole. Through terminals 2b and 2c are formed.

And the metal paste made into AgPd alloy is baked at about 850 degreeC, the binder in a metal paste is evaporated, and AgPd alloy is fuse | melted and solidified, and the sheet-like ceramic base in which the metal pattern was formed is obtained.
Since the firing temperature of the ceramic is about 1500 to 1600 ° C. and the AgPd alloy is 850 ° C. below this, the AgPd alloy paste is applied after firing the ceramic, and the AgPd alloy paste is fired together with the ceramic.
This is due to the fact that when an AgPd alloy paste is applied to a ceramic fabric and fired at the firing temperature of the ceramic, the AgPd alloy paste becomes too hot and cannot form a circuit pattern.

[Third Step / Insulating Film 10 Formation]
Next, formation of the insulating film 10 will be described.
A glass paste is formed by printing as an insulating film 10 inside each rectangular area (corresponding to each base 1) of the sheet-like ceramic base on which a metal pattern or the like is formed.
Then, it is fired at a temperature of about 850 ° C. to solidify the glass.

[Fourth process / support electrode 3b formation]
Next, the formation of the support electrode 3b will be described.
As shown in FIGS. 5 and 6, the support electrode 3b is formed of an Ag metal film on the support electrode lower layer 3a of AgPd using a nickel (Ni) metal mask.
Since the support electrode 3b is an Ag metal film, the support electrode 3b has a high viscosity, and a thick film can be formed by a single film formation. Therefore, the support electrode 3b does not protrude from the support electrode lower layer portion 3a.

[Fifth process / Crystal crystal mounting]
Next, the crystal piece 5 in which the extraction electrode 5b extends from the excitation electrode 5a is fixed and mounted on each support electrode 3b of the sheet-like ceramic base on which the metal pattern or the like is formed, and is electrically mounted. • Connect mechanically.

[Sixth step / frequency adjustment]
Next, the vibration frequency of each crystal piece 5 as a crystal resonator mounted (fixed) on the sheet-like ceramic base is adjusted by the mass load effect.
Specifically, the measurement terminal (probe) from the measuring instrument is brought into contact with the mounting terminal 4 electrically connected to each crystal piece 5 on the back surface of the sheet-like ceramic base. Then, the excitation electrode 5a on the surface side of the crystal piece 5 with the plate surface exposed is irradiated with gas ions to scrape the surface, and the mass of the excitation electrode 5a is reduced to adjust the vibration frequency from the lower to the higher.
However, it is also possible to adjust the vibration frequency from higher to lower by adding a metal film on the excitation electrode 5a by vapor deposition or sputtering, for example.

[Seventh step / Metal cover joining (sealing sealed)]
Next, on the insulating film 10 on the outer peripheral surface of the rectangular region corresponding to each ceramic base 1 of the sheet-like ceramic base 1A on which the crystal piece 5 is mounted, the opening end face of the concave metal cover 6 ( The lower surface of the flange) is joined via a sealing material.
Here, a resin previously applied or transferred to the opening end face of the cover 6 is used as a sealing material, and the resin is heated and melted for bonding. For example, the opening end surface of the cover 6 is L-shaped, and the so-called seal path is lengthened. As a result, individual crystal pieces 5 are hermetically sealed to form an aggregated sheet-like crystal resonator.

[Eighth step / division]
Finally, the sheet-like ceramic base on which the crystal resonators are assembled is divided vertically and horizontally according to the break line to obtain individual surface mount crystal resonators.

  Further, here, in the state of the sheet-like ceramic base on which the metal pattern or the like is formed, the steps of mounting the crystal piece 5 (fifth step), frequency adjustment (sixth step), and joining the cover 6 (seventh step). Can be performed continuously, so that the productivity can be improved.

Furthermore, in this embodiment, the mounting terminals 4 on the back surface of the ceramic base 1 are four terminals that are electrically independent from each other. On the other hand, in the state of the sheet-like ceramic base, the mounting terminals 4 (four) at the four corners of the adjacent rectangular regions are electrically connected in common via the through terminals 2b and 2c.
Accordingly, even when the mounting terminals 4 at the four corners are connected in common, the measurement terminals are brought into contact with the pair of diagonal mounting terminals 4 connected to the support electrodes 3b of the ceramic bases 1 so that the crystal piece There is an effect that the vibration frequency can be adjusted every five.

In addition, although the insulating film 10 is made of glass, for example, any resin can be applied as long as it has heat resistance compared to the resin of the sealing material.
The metal pattern is an AgPd alloy, but may be, for example, an AgPt (silver / platinum) alloy mainly composed of Ag having relatively good adhesion to the ceramic, and any Ag-based thick film material can be applied.

[Effect of the embodiment]
According to this crystal resonator, the support electrode lower layer 3a, the connection terminal 2a, and the through terminals 2b and 2c are integrally formed of an AgPd alloy, and the Ag support electrode 3b is formed on the support electrode lower layer 3a. Since the quartz piece 5 is hermetically sealed with the cover 6 after being mounted, the support electrode 3b is not exposed to the air and oxidized, and because of the high viscosity Ag, compared with AgPd in a single film formation. Therefore, there is an effect that quality can be improved and productivity can be improved while realizing miniaturization.

  Further, the present crystal resonator has an effect of reducing the manufacturing cost because the support electrode 3b is formed of an Ag film.

[Another embodiment]
Next, a crystal resonator (another crystal resonator) according to another embodiment will be described.
In the present embodiment, the crystal piece 5 has a plate shape, but bevel processing is performed on the crystal piece in order to lower the numerical value of CI (Crystal Impedance) at a low frequency.
The bevel processing is chamfering processing in which the end face of the crystal piece is inclined. By this bevel processing, the abdomen of the crystal piece is formed into a lens shape.

When a beveled crystal piece is mounted on the support electrode 3b, the lens-shaped abdomen comes into contact with it, and the crystal piece rises at the end of the support electrode 3b, and is pressed by a conductive adhesive. It may be insufficient.
If the pressing of the conductive adhesive is insufficient, it will cause insufficient crystal bond strength.

Therefore, in another crystal resonator, a space portion is formed at the center portion so as not to form the center portion of the support electrode 3b, and the crystal piece is supported by the support electrodes 3b at both ends. Since the lens-shaped abdomen of the crystal piece is accommodated in the space, the support electrodes 3b at both ends and the end face of the beveled crystal piece can be brought into contact with each other without being lifted. The adhesive strength can be satisfied.
The support electrode lower layer 3a may be divided into two parts, but the support electrode lower layer 3a is left without being divided in order to stably form the support electrode 3b.

[Another crystal resonator electrode pattern: FIG. 9]
Next, an electrode pattern of another crystal resonator will be described with reference to FIG. FIG. 9 is an explanatory plan view of an electrode pattern in another crystal resonator.
As shown in FIG. 9, another crystal resonator is partially formed by separating the support electrode 3b as compared with the crystal resonator of FIG.
Specifically, the first support electrode 3b1 is formed on the support electrode lower layer 3a on the side to which the connection terminal 2a is not connected, and the second support is formed on the support electrode lower layer 3a on the side to which the connection terminal 2a is connected. Electrode 3b2 is formed.

The area of the second support electrode 3b2 is made larger than the area of the first support electrode 3b1 in contact with the crystal piece. This is for mounting the crystal piece by applying the conductive adhesive 7 on the upper surface of the second support electrode 3b2.
Therefore, the conductive adhesive is not applied to the upper surface of the first support electrode 3b1, and the crystal piece is simply mounted.

[Another crystal unit mounted with a crystal piece: FIG. 10]
Next, mounting of a crystal piece of another crystal resonator will be described with reference to FIG. FIG. 10 is an explanatory plan view of mounting of a crystal piece in another crystal resonator.
A crystal piece 5 ′ in another crystal resonator has a configuration in which an end face is chamfered by a bevel processing and includes a lens-shaped abdomen.
As shown in FIG. 10, the other crystal resonator is basically the same as the crystal resonator shown in FIG. 7, but the first support electrode 3b1 and the second support are separated from the crystal piece 5 '. Mounted on the electrode 3b2, the crystal piece 5 'and the second support electrode 3b2 are joined by the conductive adhesive 7, and are electrically and physically connected.

[Cross section along the short side of another crystal resonator: FIG. 11]
Next, a cross section on the short side of another crystal resonator will be described with reference to FIG. FIG. 11 is a cross-sectional explanatory view of the short side of another crystal resonator.
As shown in FIG. 11, the cross section of the short side of the substrate 1 where the first and second support electrodes 3 b 1 and 3 b 2 are present has a support electrode lower layer portion 3 a formed at the center of the substrate 1, The insulating film 10 is formed, the first support electrode 3b1 and the second support electrode 3b2 are formed on the support electrode lower layer 3a, and the lens-shaped crystal piece 5 'is formed by the conductive adhesive 7 with the second support electrode. It is fixed to 3b2.

Therefore, the crystal piece 5 'is only mounted on the first support electrode 3b1, but is not fixed.
The crystal piece 5 'is fixed by the conductive adhesive 7 with two second support electrodes 3b2 formed along both short sides. However, since the crystal piece 5 'is pressed downward, it comes into contact with the first support electrode 3b1.

[Cross section along the long side of another crystal resonator: FIG. 12]
Next, a cross section on the long side in a state where the cover is mounted on another crystal resonator will be described with reference to FIG. FIG. 12 is a cross-sectional explanatory diagram of the long side in a state where the cover is mounted on another crystal resonator.
As shown in FIG. 12, a lens-shaped crystal piece 5 ′ beveled through a conductive adhesive 7 is mounted on two second support electrodes 3 b 2, and further an insulating property is formed on the insulating film 10. A metal cover 6 is mounted via a resin as a sealing material.
Other basic configurations are the same as those of the quartz crystal resonator of FIG.

[Method of manufacturing another crystal unit]
Another method for manufacturing a crystal resonator is basically the same as the method for manufacturing the present crystal resonator.
The difference is that the crystal piece 5 'is beveled, and when the support electrode is formed, a space is provided in the center, and the divided first support electrode 3b1 and second support electrode 3b2 are divided. Are formed with a metal mask, and a crystal piece 5 'is fixed with a conductive adhesive on the second support electrode 3b2.

[Effect of another crystal unit]
According to another crystal resonator, the structure of the present crystal resonator is basically provided, so that the effect of the present crystal resonator is provided. In addition, the separated first support electrode 3b1 is provided. When the space portion is provided in the central portion by the second support electrode 3b2 and the beveled crystal piece 5 'is mounted, the lens-shaped abdomen of the crystal piece 5' is pushed out into the space portion. The pressing of the conductive adhesive 7 on the second support electrode 3b2 becomes sufficient, and there is an effect of increasing the adhesive strength of the crystal piece 5 '.

  INDUSTRIAL APPLICABILITY The present invention is suitable for a surface-mounted crystal resonator that can improve the quality, reduce the manufacturing cost, and improve the productivity while realizing miniaturization, and the manufacturing method thereof.

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate (base), 2a ... Connection terminal, 2b, 2c ... Through terminal, 3a ... Support electrode lower layer part, 3b ... Support electrode, 3b1 ... 1st support electrode 3b2 ... second support electrode, 4 ... mounting terminal, 5,5 '... crystal piece, 5a ... excitation electrode, 5b ... extraction electrode, 6 ... cover, .. Conductive adhesive, 10 ... Insulating film

Claims (16)

A surface-mount crystal resonator in which a crystal piece is mounted on a rectangular ceramic substrate,
First and second support electrodes for holding the crystal piece;
A through terminal formed on a wall surface of a through hole formed in a corner of the substrate;
First and second lower layer portions formed on the lower surface of the first and second support electrodes on the surface of the substrate;
A first connection terminal for connecting an end of the first lower layer part and a through terminal at the shortest corner from the end;
A second connection terminal for connecting an end of the second lower layer part and a through terminal at the shortest corner from the end;
A cover for covering the crystal piece and hermetically sealing the inside;
The through terminal, the lower layer part and the connection terminal are formed of an anti-oxidation metal film,
A surface-mount crystal resonator, wherein the first and second support electrodes are made of silver.   The first connection terminal and the second connection terminal are connected to the diagonal through terminals of the substrate, and compared to the end portions of the first and second lower layer portions to which the first and second connection terminals are connected, 2. The surface mount crystal resonator according to claim 1, wherein ends of the first and second lower layer portions to which the first and second connection terminals are not connected are shortened.   3. The surface mount crystal resonator according to claim 1, wherein a band-shaped insulating film on which a cover is mounted is formed inside the periphery of the substrate.   4. The surface-mount crystal resonator according to claim 1, wherein the oxidation-preventing metal film is made of an alloy containing silver as a main component.   5. The surface mount crystal resonator according to claim 4, wherein the antioxidant metal film is formed of an alloy with palladium containing silver as a main component. The crystal piece is beveled, the short side has an inclination,
The first and second support electrodes are separated into two on the first and second lower layer portions so that a space portion is formed in the central portion of the lower layer portion, and at the end of the lower layer portion. 6. The surface mount crystal resonator according to claim 1, wherein the surface mount crystal resonator is formed.   A crystal piece beveled through a conductive adhesive on one of the separated support electrodes formed on the end portions of the first and second lower layer portions connected to the first and second connection terminals The surface mount crystal resonator according to claim 6, wherein the surface mount crystal resonator is fixed.   The surface area of one of the support electrodes is made larger than the surface area of the other support electrode that is formed on the end portions of the first and second lower layer portions that are not connected to the first and second connection terminals. The surface mount crystal resonator according to claim 7. A method of manufacturing a surface-mounted crystal resonator in which a crystal piece is mounted on a rectangular ceramic substrate,
While forming a through terminal on the wall surface of the through hole formed in the corner of the substrate,
On the surface of the substrate, the first and second lower layer portions below the first and second support electrodes holding the crystal piece, the end portion of the first lower layer portion, and the shortest corner from the end portion A first connection terminal that connects the through terminal of the portion, and an end of the second lower layer portion and a second connection terminal that connects the through terminal of the shortest corner from the end portion to prevent oxidation Made of metal film,
Forming the first and second support electrodes with silver on the first and second lower layers;
A method for manufacturing a surface-mounted crystal resonator, comprising a cover that covers the crystal piece and hermetically seals the inside.   The first connection terminal and the second connection terminal are connected to the diagonal through terminals of the substrate, and compared to the end portions of the first and second lower layer portions to which the first and second connection terminals are connected, 10. The method for manufacturing a surface-mounted crystal resonator according to claim 9, wherein end portions of the first and second lower layer portions to which the first and second connection terminals are not connected are formed short.   11. The method for manufacturing a surface-mounted crystal resonator according to claim 9, wherein the first and second support electrodes are formed once using a metal mask.   12. The method for manufacturing a surface-mounted crystal resonator according to claim 9, wherein the oxidation-preventing metal film is made of an alloy containing silver as a main component.   13. The method for manufacturing a surface-mounted crystal resonator according to claim 12, wherein the antioxidant metal film is formed of an alloy with palladium containing silver as a main component. A method of manufacturing a surface-mounted crystal resonator in which a beveled crystal piece having a short side inclined is mounted,
The first and second support electrodes are separated into two parts on the first and second lower layer portions so that a space portion is formed in the central portion of the lower layer portion, and at the end of the lower layer portion. 14. The method for manufacturing a surface mount crystal resonator according to claim 9, wherein the surface mount crystal resonator is formed.   A crystal piece beveled through a conductive adhesive on one of the separated support electrodes formed on the end portions of the first and second lower layer portions connected to the first and second connection terminals The method for manufacturing a surface-mount crystal resonator according to claim 14, wherein:   The surface area of one of the support electrodes is made larger than the surface area of the other support electrode that is formed on the end portions of the first and second lower layer portions that are not connected to the first and second connection terminals. A method for manufacturing a surface-mounted crystal resonator according to claim 15.

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