JP2004111889A - Crystal oscillator lid and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crystal oscillator lid capable of extremely easily connecting a lid to the case of a crystal oscillator without any failure, and improving productivity while preventing the production of any poisonous gas, and thinning the case, and to provide a method for manufacturing the crystal oscillator lid. <P>SOLUTION: This lid 20 of a crystal oscillator 1 tightly seals a ceramic case 10 in which a crystal oscillating piece 30 is housed. The lid is provided with a metallic thin board of the substrate of the lid 20, an Ni plated layer 20b formed only on one surface of the case outside face side of the metallic thin board, and a joint layer 21 formed on the case sealing face side of the metallic thin board. The Ni plated layer 20b is formed only on one side so that any case failure or gas generation in sealing can be prevented, and convenient and efficient junction can be executed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a crystal resonator assembled in a ceramic case, and more particularly to a crystal resonator lid for sealing a ceramic case and a method for manufacturing the crystal resonator lid.
[0002]
[Prior art]
In general, a quartz resonator connects conductive electrodes to both surfaces of a thin piece of quartz diaphragm, applies an electric signal, and supplies a stable frequency while vibrating by a piezoelectric effect, and is used for an oscillator, a filter, and the like.
[0003]
Conventionally, as shown in FIG. 4, a crystal resonator 1 has a crystal resonator element 30 housed in a case 10 in which electrode circuits 12 are arranged in a multilayer between ceramic insulators 11, It is connected to. A lid 20 made of Kovar, which is an alloy of cobalt (Co) and nickel (Ni), is joined to the opening of the case 10 to seal the inside.
[0004]
However, in the quartz resonator 1 of the above-described embodiment, since a lid 20 made of a metal different from ceramic needs to be joined to the opening of the ceramic case 10, a corresponding problem has occurred.
[0005]
The material of the lid 20 is mainly Kovar, which is a pernico-based alloy containing 5% of iron, 29% of Ni, and 17% of Co. Kovar is often used when joining with ceramic because it has similar tensile, contraction, and thermal expansion coefficients to ceramic. However, at this time, in order to join the lid 20 to the case 10, it is necessary to apply heat of about 800 ° C. At this time, since the high heat deforms the crystal vibrating piece 30 stored in the case 10, the lid 20 is It could not be directly joined to the case 10.
[0006]
Therefore, a low-temperature welding method is used in which a ring plated with silver (Ag) is placed in the opening of the case 10 and heat is applied at 200 to 400 ° C. to melt the ring plating film and join the ring to the ceramic. However, when such a silver-plated ring is used, the number of parts and work steps used for assembling the crystal unit is increased, and the production cost is increased due to the use of an expensive silver-plated ring. Rises. In addition, the thickness of the entire enclosing case of the crystal unit is increased, which hinders miniaturization and slimming.
[0007]
Therefore, as shown in FIG. 4, a technique for forming a bonding layer 21 that melts at a low temperature on the sealing surface of the lid 20 and directly bonding the lid 20 to the ceramic case 10 without using an expensive ring is, for example, shown in FIG. It has been proposed in Patent Documents 1 to 3.
[0008]
[Patent Document 1]
Patent application No. 2001-0072177 [Patent document 2]
Patent application No. 2002-0023302 [Patent document 3]
Patent Application No. 2002-0034279
[Problems to be solved by the invention]
However, in the above method, the Ni plating layer 20a is formed outside the lid 20 and the Ni plating layer 20a is located between the lid 20 and the bonding layer 21. When the current flows through the Ni plating layer 20a, a crack occurs in the ceramic case 10 due to the excessive current generated at this time.
[0010]
In addition, the Ni plating layer 20a generates a large amount of a phosphorus (P) -containing gas by a melting reaction at the time of electric welding. When the gas flows into the case 10, it has a fatal effect on the crystal vibrating piece 30, and when the gas flows out, the adhesive strength of the lid 20 is weakened and the health of the worker is impaired. Was.
[0011]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional crystal resonator lid and the method of manufacturing the crystal resonator lid, and an object of the present invention is to attach a lid to a crystal resonator case in a very simple manner. Of a new and improved crystal resonator lid and a crystal resonator lid that can be joined without any problems, increase productivity, generate no toxic gas, and reduce the thickness of the case It is to provide a method.
[0012]
[Means for Solving the Problems]
According to the present invention, there is provided a crystal resonator lid for sealing a ceramic case accommodating a crystal resonator element; a metal thin plate serving as a base material of the lid, and one surface of the metal thin plate on an outer surface side of the case. And a bonding layer formed on the case enclosing surface side of the thin metal plate.
[0013]
Further, in order to obtain the above-mentioned crystal resonator lid, a step of forming a Ni plating layer on one side of a thin metal plate serving as a base material of the lid, and an idle roller in which the Ni thin plate and the bonding layer are formed with the Ni plating layer outside. Using a pair of joining rollers to which a heater is connected to join the sheet metal and the joining layer by pressing at a high temperature, and joining the joined sheet metal. A method for manufacturing a crystal resonator lid includes a step of making a thickness constant using a pair of pressure rollers and a step of punching a metal sheet having a constant thickness into a lid shape using a press. At this time, it is preferable that the pair of joining rollers to which the heater is connected be set to a temperature lower than the melting point of the joining layer.
[0014]
When the crystal resonator element is sealed in the ceramic case using the crystal resonator lid thus obtained, the lid is electrically welded because there is no Ni plating layer on the sealing surface of the lid and only the bonding layer is formed. At this time, an electric action can be directly applied to the joining layer of the metal alloy, and simple and efficient welding can be performed. Furthermore, when current flows through the Ni plating layer, cracks occur in the ceramic case, gas generated when the Ni plating layer is melted has an adverse effect on the quartz vibrating piece, Problems such as weakening of adhesive strength and harm to worker's health can be solved.
[0015]
Here, the material of the metal sheet is preferably a Kovar alloy having a coefficient of thermal expansion and a coefficient of thermal contraction similar to that of the ceramic of the case. The joining layer is preferably made of a metal alloy that can be joined at a temperature that does not affect the internal quartz-crystal vibrating piece when the lid is joined to the case and that melts at low temperature. For example, an alloy composed of 78 to 82% by weight of Sn, 9 to 11% by weight of Zn, and 9 to 11% by weight of Ag can be used as the metal alloy that is melted by low-temperature heat.
[0016]
The bonding layer has excellent welding characteristics, for example, 68 to 72% by weight of Ag, 24 to 25% by weight of Cu, 2 to 4% by weight of Bi, 2 to 3% by weight of Sn, and 0.02 to 0.4% of Ge. % Can also be used.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a crystal resonator lid and a method of manufacturing the crystal resonator lid according to the present embodiment will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted.
[0018]
FIG. 1 is an exploded perspective view showing a lid of a crystal resonator 1 according to the present embodiment and a ceramic case in which a crystal resonator element to be enclosed is incorporated. FIG. (B) is a sectional view after sealing. As shown in FIGS. 1 and 2, the case 10 has a multilayer structure in which electrode circuits 12 are arranged between ceramic insulators 11, and a housing space is formed therein. A crystal vibrating piece 30 is fixed to the electrode circuit 12 provided on the inner bottom of the case 10, and the crystal vibrating piece 30 is connected to the both-side electrode circuit 12 and the electric wire 31.
[0019]
To the opening of the case 10, for example, a lid 20 processed as a base metal thin plate using Kovar, which is an alloy of iron (Fe), Ni, and Co, is joined to seal the inside of the case 10. However, in the lid 20 according to the present embodiment, the plating layer is formed only on the outer surface of the case opposite to the sealing surface of the case 10, and the plating layer is not formed on the sealing surface, but the bonding layer 21 is formed on the sealing surface. Thus, the impact of current generated during electric welding is minimized, and the lid 20 can be directly joined to the upper portion of the case 10 by low-temperature heat.
[0020]
That is, in the lid 20, a Ni plating layer 20b is formed on the outer surface of the case of a thin metal plate made of a metal alloy, and a bonding layer 21 having a constant thickness is formed on the sealing surface of the lid 20 where no plating layer is formed. Is formed. Of course, the Ni plating layer 20b employs a special plating method for forming a plating film only on one surface of the lid 20.
[0021]
The bonding layer 21 is preferably a metal alloy that can be directly heat-sealed to the opening of the case 10 by low-temperature heat (200 to 400 ° C.). Since the bonding layer 21 is formed on the sealing surface of the lid 20 where the Ni plating layer 20b is not formed in this manner, when the lid 20 is electrically welded, a current directly applies an electric action to the metal alloy bonding layer 21 to perform welding. Therefore, extremely efficient welding is performed.
[0022]
Therefore, there is a problem that a crack is generated in the case 10 when an electric current passes through the Ni plating layer 20a, and a melting reaction occurs in the Ni plating layer 20a to generate a P-containing gas. The problem of causing a fatal effect and the problem that gas leaks out to weaken the adhesive force of the lid 20 and harm the health of workers are solved, and a crystal oscillator with high productivity is provided. Obtainable.
[0023]
Further, since the lid 20 is directly bonded to the case 10 by the bonding layer 21 made of a metal alloy, the lid 20 is placed on the case 10 without using a silver-plated ring as in the related art, and the low temperature (200 to 400 C), the bonding layer 21 is firmly adhered to the periphery of the opening of the case 10 while melting. Therefore, while the joining operation of the lid 20 is extremely simple, the overall thickness is reduced and the size and the slimness of the crystal unit can be reduced, and an expensive silver-plated ring is not used. Costs can be reduced.
[0024]
Meanwhile, the metal alloy used for the bonding layer 21 can be variously configured. For example, it is preferable to use an alloy containing 78 to 82% by weight of tin (Sn), 9 to 11% by weight of zinc (Zn), and 9 to 11% by weight of Ag.
[0025]
As described above, the bonding layer 21 containing Sn as a main component and having proper amounts of Zn and Ag added thereto easily melts even at a low temperature of about 200 to 400 ° C., and has excellent welding characteristics as well as melting point and wettability. It has excellent mechanical properties, electrical properties, thermal properties, etc., and has almost no toxicity, so there is no danger of causing environmental pollution. Thus, the lid 20 can be firmly joined to the opening of the case 10, and the joining operation is extremely simple, so that the high quality quartz crystal resonator 1 can be provided.
[0026]
Therefore, when the lid 20 is placed on the case 10 without using a silver-plated ring and is pressed by an electrode roller while being moved via a conveyor, the joining layer 21 is formed on the bonding layer 21 via the electrode roller. A direct current is applied, and the bonding layer 21 is welded while being heated and melted by the contact resistance. Alternatively, when the joining layer 21 is welded using a laser beam, the joining layer 21 is melted and adheres firmly to the periphery of the opening of the case 10, so that the joining operation of the lid 20 is simple, but the sealing case of the sealing case is Since the thickness is reduced, the size and slimness of the crystal unit can be reduced.
[0027]
Meanwhile, the metal alloy of the bonding layer 21 can be formed by another method. For example, the main components are 68 to 72% by weight of Ag, 24 to 25% by weight of copper (Cu), 2 to 4% by weight of bismuth (Bi), 2 to 3% by weight of Sn, and 0.02 to 0.4% by weight of germanium (Ge). It can also be comprised from the alloy mentioned.
[0028]
As described above, the bonding layer 21 containing Ag and Cu as main components melts at a high temperature of 760 ° C. to 800 ° C., but has not only excellent welding characteristics but also extremely excellent bonding strength, long fatigue life, There is an advantage that the wettability can be improved, oxidation can be prevented, and the lid 20 can be firmly joined to the upper portion of the case 10.
[0029]
On the other hand, a method of forming the bonding layer 21 on the lid 20 will be described. As shown in the explanatory view of FIG. 3, for example, a thin metal plate in which a Ni plating layer 20b is formed on one surface of a lid 20 using Kovar as a base material is wound around a reel 40a so that the Ni plating layer 20b is outside the reel. After the bonding layer 21 made of a thin plate-shaped alloy is wound on a reel 40b, the lid 20 on which the Ni plating layer 20b is formed and the bonding layer 21 are passed through an idle roller 41 to become one.
[0030]
Next, high pressure is applied while passing between the pair of joining rollers 42 with a heater, and the joining layer 21 is joined by hot rolling to the surface of the lid 20 where the plating layer 20b is not formed. After passing between the pressure rollers 43 so as to maintain a constant thickness, a punch 44 is punched by a press 44 to manufacture a lid 20 of a fixed size having a bonding layer 21 formed on its sealing surface.
[0031]
The temperature of the heater mounted on the joining roller 42 and the like is automatically adjusted, and the temperature is set to a temperature slightly lower than the melting point of the joining layer 21. By using the hot rolling method in which the lid 20 and the bonding layer 21 passing between the bonding rollers 42 are pressed at a high temperature in this manner, the productivity of the bonding layer 21 can be increased while the bonding operation of the bonding layer 21 is extremely simple. Can be.
[0032]
The preferred embodiments of the crystal resonator lid and the method of manufacturing the crystal resonator lid according to the present embodiment have been described with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person skilled in the art can conceive various changes or modifications within the scope of the technical idea described in the claims, and those changes naturally fall within the technical scope of the present invention. It is understood to belong.
[0033]
【The invention's effect】
As described above, according to the present invention, only the joining layer is formed without forming the Ni plating layer on the sealing surface of the lid. Therefore, when the lid is electrically welded, the electric connection is directly applied to the joining layer of the metal alloy. An effect can be added, and extremely simple and efficient welding can be performed. Therefore, when a current flows through the Ni plating layer, cracks are generated in the ceramic case, gas generated when the Ni plating layer is melted has an adverse effect on the quartz vibrating piece, Problems such as weakening of adhesive strength and harm to worker's health can be solved, and a low-cost and highly reliable quartz oscillator can be provided.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a lid of a crystal unit and a ceramic case according to the present embodiment.
FIGS. 2A and 2B are cross-sectional views showing a joining process of a lid and a ceramic case of the crystal unit according to the present embodiment, wherein FIG. 2A is a sectional view before joining, and FIG.
FIG. 3 is an explanatory diagram of a schematic device showing a manufacturing process of the crystal resonator lid according to the embodiment.
FIG. 4 is a cross-sectional view showing a process before joining a lid of a conventional crystal unit and a ceramic case.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 crystal resonator 10 case 11 ceramic insulator 12 electrode circuit 20 lid 20 b Ni plating layer 21 bonding layer 30 crystal resonator element 31 wire

Claims (10)

In a crystal resonator lid that seals a ceramic case in which a crystal resonator element is stored;
A metal sheet, which is a base material of the lid,
A Ni plating layer formed on the outer surface of the case of the metal thin plate;
A bonding layer formed on the case enclosing surface of the metal sheet;
A crystal resonator lid comprising: The crystal resonator lid according to claim 1, wherein the material of the thin metal plate is a Kovar alloy. The crystal resonator lid according to claim 1, wherein the bonding layer is made of a metal alloy that melts at a low temperature. 4. The crystal unit according to claim 1, wherein a material of the bonding layer is an alloy including 78 to 82% by weight of Sn, 9 to 11% by weight of Zn, and 9 to 11% by weight of Ag. Lid. The material of the bonding layer is an alloy composed of 68 to 72% by weight of Ag, 24 to 25% by weight of Cu, 2 to 4% by weight of Bi, 2 to 3% by weight of Sn, and 0.02 to 0.4% by weight of Ge. The crystal resonator lid according to claim 1, wherein: In a method for manufacturing a crystal resonator lid:
Forming a Ni plating layer on one side of a thin metal plate serving as a base material of the lid;
Using the idle roller to unite the thin metal plate and the joining layer made of an alloy with the Ni plating layer on the outside,
Using a pair of joining rollers to which a heater is connected, to press the high-temperature one-piece sheet metal to join the sheet metal and the joining layer;
A step of using the pair of pressure rollers to make the thickness of the thin metal sheet joined with the joining layer constant,
Forming the metal sheet having a constant thickness on the lid by using a press,
A method for manufacturing a crystal resonator lid, comprising: 7. The method according to claim 6, wherein the metal sheet uses a Kovar alloy. 7. The method according to claim 6, wherein the bonding layer is made of an alloy including 78 to 82% by weight of Sn, 9 to 11% by weight of Zn, and 9 to 11% by weight of Ag. . The bonding layer uses an alloy composed of 68 to 72% by weight of Ag, 24 to 25% by weight of Cu, 2 to 4% by weight of Bi, 2 to 3% by weight of Sn, and 0.02 to 0.4% by weight of Ge. The method for manufacturing a crystal resonator lid according to claim 6, wherein: 7. The method according to claim 6, wherein the pair of joining rollers connected to the heater are set at a temperature lower than a melting point of the joining layer.

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