JP5668235B2 - Electronic component and electronic device - Google Patents

Description

  The present invention relates to an electronic component and an electronic device, for example, an electrochemical cell such as an electric double layer capacitor.

An electric double layer capacitor is a device that stores electricity by polarizing ions in an electrolyte and supplies electric power by discharging the ions.
With this storage / discharge function, the electric double layer capacitor is used, for example, for a clock function of an electronic device, a backup power source such as a semiconductor memory, and a standby power source of an electronic device such as a microcomputer or an IC memory.

In particular, a surface-mountable electric double layer capacitor can be reduced in size and thickness, and is suitable for a thin portable terminal.
In order to meet such a demand for downsizing and thinning, in Patent Document 1 below, as described below, a polarizing electrode and an electrolyte are housed in a container having a recess, and the opening is sealed with a sealing plate. Stopped electric double layer capacitors have been proposed.

FIG. 6 is a side sectional view of a conventional electric double layer capacitor 100.
A metal layer 111 is provided on the bottom surface of the ceramic concave container 102 in which the recess 113 is formed, and the positive electrode 106 is joined to the upper surface of the metal layer 111. The metal layer 111 penetrates the concave container 102 and is electrically connected to the positive electrode terminal 112 on the bottom surface of the concave container 102, so that the positive electrode 106 is electrically connected to the positive electrode terminal 112 through the metal layer 111. Connected to.

Further, the sealing plate 103 is bonded to the opening of the recess 113 by the metal bonding metal layer 108 to seal the recess 113.
A metal layer 115 functioning as a current collector is formed on the lower surface of the sealing plate 103 using plating or the like, and the negative electrode 105 is bonded to the surface of the metal layer 115.
A metal layer 109 is formed on a side surface of the concave container 102 to connect the bonding metal layer 108 and the negative electrode terminal 110 on the bottom surface of the concave container 102.
The negative electrode 105 is electrically connected to the negative electrode terminal 110 through the metal layer 115, the bonding metal layer 108, and the metal layer 109.

A separator 107 that prevents these short circuits is provided between the negative electrode 105 and the positive electrode 106, and an electrolyte is sealed in the recess 113.
The electric double layer capacitor 100 stores electricity when voltage is applied to the negative electrode terminal 110 and the positive electrode terminal 112, and discharges the stored electric charge to supply power to a memory or the like.

By the way, since the metal layers 109 and 111 penetrate from the inner wall of the recess 113 to the atmosphere side, when the electric double layer capacitor 100 is heated at the time of reflow or the like, the vapor pressure of the electrolyte rises, and the ceramic and the metal layers 109, There was a possibility that the electrolyte leaked from between 111.
In particular, when the concave container 102 is formed by laminating ceramic sheet materials in the height direction, the metal layer 109 penetrates the concave container 102 along the sheet material layer. There was a possibility of electrolyte leakage from the joint.

JP 2001-216852 A

An object of the present invention is to provide a highly reliable electric double layer capacitor or the like that prevents the first internal electrode from falling out of the concave container even if pressure acts on the first internal electrode .

In the first aspect of the present invention, a concave container having a concave portion, which is formed by laminating ceramic sheets and firing and integrating, a first conductor formed on the bottom surface of the concave portion, A sealing plate bonded to the upper end of the recess to seal the recess, a second conductor formed on the surface of the recess, and a first electrode disposed on the surface of the first conductor; A second electrode disposed on the surface of the second conductor and facing the first conductor at a predetermined distance; a first connection terminal formed outside the concave container; and Two connection terminals, a first internal electrode connected to the first conductor and the first connection terminal, formed inside the main body of the concave container, and formed inside the main body of the concave container, A second internal electrode connected to a second conductor and the second connection terminal; and Comprising an electrolyte in contact with To the second electrode poles, the said first internal electrodes, the side of the cross sectional area of the side to be bonded to the first conductor is bonded to the first connection terminal Provided is an electronic component characterized in that it is formed larger than an area .
According to a second aspect of the present invention, the bottom of the concave container having the concave portion is formed in a plurality of layers by the ceramic sheet, and a cylindrical through-hole in which the first internal electrode is disposed for each layer. The diameter of the through-hole of each said layer is formed so that it may become large as it approaches the layer on the said recessed part side from the layer outside the bottom face of the said concave container. Provide electronic components.
According to a third aspect of the present invention, in the electronic component according to the first or second aspect, the first internal electrode includes a metal layer formed inside the main body of the concave container. provide.
According to a fourth aspect of the present invention, there is provided an electronic component according to any one of the first to third aspects of the present invention, power storage means for storing power in the electronic component, and other functions that perform a predetermined function. There is provided an electronic apparatus comprising: the electronic component; and power supply means for supplying power to the other electronic component using the stored electric charge.

According to the present invention, the first internal electrode in the body of the concave container is formed such that the cross-sectional area on the side to be joined to the first conductor is larger than the cross-sectional area on the side to be joined to the first connection terminal. Therefore, even if pressure acts on the first internal electrode, the first internal electrode can be prevented from falling out of the concave container, and a highly reliable electric double layer capacitor or the like can be provided.

It is side surface sectional drawing of the electric double layer capacitor which concerns on this Embodiment. It is a figure for demonstrating various deformation | transformation. 6 is a side cross-sectional view of an electric double layer capacitor according to Modification 1. FIG. 10 is a side cross-sectional view of an electric double layer capacitor according to Modification 2. FIG. 10 is a side cross-sectional view of an electric double layer capacitor according to Modification 3. FIG. It is side surface sectional drawing of the electric double layer capacitor which concerns on a prior art example.

(1) Outline of Embodiment As shown in FIG. 1, the electrode 5 includes a metal layer 15 formed on the sealing plate 3, a joining metal layer 8 that joins the concave container 2 and the sealing plate 3, and the concave container 2. It is electrically connected to the terminal 10 through the through electrode 21 formed in the main body.
The electrode 6 is electrically connected to the terminal 12 via the metal layer 11 formed on the bottom surface of the recess 13 and the through electrode 22 formed below the recess 13.
The end of the through electrode 21 is bonded to the lower surface of the bonding metal layer 8 and the upper surface of the terminal 10, and the end of the through electrode 22 is connected to the lower surface of the metal layer 11 and the upper side of the terminal 12. Bonded to the surface.
As described above, since the wiring for electrically connecting the electrodes 5 and 6 and the terminals 10 and 12, that is, the through electrodes 21 and 22 are formed in the main body of the concave container 2, the water pressure of the electrolyte is reduced by heating. Even if it rises at 13, the electrolyte does not leak from between the ceramics constituting the concave container 2 and the through electrodes 21, 22.

(2) Details of Embodiment The electrochemical cell constituting the electronic component of the present embodiment will be described with reference to the drawings. In the following, an electric double layer capacitor will be described as an example as an embodiment, but the electronic component may be another type of electrochemical cell such as a nonaqueous electrolyte battery.
For example, an electrode sheet composed of silicon oxide activated by metallic lithium (50 wt%), a conductive additive (40 wt%), and a polyacrylic acid binder (20 wt%) is used as the negative electrode, and the positive electrode is used as the positive electrode. And an electrode sheet composed of an active material (85 wt%) having a spinel type crystal structure of lithium-manganese-oxygen, a conductive assistant (10 wt%), and a PTFE binder (5 wt%), A battery made of an electrolytic solution by dissolving a separator made of glass fiber and 1M LiN (SO2CF3) 2 in PC is possible. Here, the size of the positive electrode and the negative electrode can be 1 mm long × 1.5 mm wide × 0.2 mm thick.
In addition to the above positive electrode active material, Li4Ti5O12, Li4Mn5O12, LiCoO2 or the like can also be used. Alternatively, Li—Si—O, Li—AL, or the like can be used as the negative electrode active material.
In addition, a lithium ion battery can be configured by using an electrolytic solution in which 1M LiBF4 is dissolved in PC. At this time, a conductive additive or a binder can be used in combination with each active material.

  FIG. 1A is a side sectional view of the electric double layer capacitor 1 according to the present embodiment. The electric double layer capacitor 1 has a rectangular parallelepiped shape, and the size is, for example, a rectangular parallelepiped having a height of 1 [mm] or less, a length of about 2.5 [mm], and a width of about 3.0 [mm]. It has a shape. The thickness of the bottom and side walls is about 0.1 to 0.3 mm.

Electric double layer capacitor 1, concave container 2 having recess 13, sealing plate 3 with metal layer 15 formed on the lower surface, electrode 5, electrode 6, separator 7, bonding metal layer 8, metal layer 11, through electrode 21, the through electrode 22, the terminal 10, the metal layer 11, the terminal 12, and an electrolyte (not shown) sealed in the recess 13.
The terminals 10 and 12 are terminals for surface mounting. In the following description, the terminals 10 and 12 are referred to as the downward direction, and the sealing plate 3 side is referred to as the upward direction.
In FIG. 1, a gap is illustrated between the electrode 5, the separator 7, and the electrode 6 so that the joining relationship of the members can be easily understood. However, these members may be packed in the recess 13 without any gap.

  The concave container 2 is made of ceramics using alumina, for example, and is formed by stacking and integrating a plurality of flexible ceramic sheets called green sheets. The thickness of each sheet after firing is about 0.1 to 0.3 mm, and the thickness can be changed as necessary. In the green sheet, an opening corresponding to the recess 13 and a hole corresponding to a through hole in which the through electrodes 21 and 22 are installed are formed. By laminating these green sheets in the thickness direction and firing, 13 and the concave container 2 having through holes for the through electrodes 21 and 22 are formed. A green sheet lamination example will be described later in a second modification.

The recess 13 has a rectangular cross section when viewed from above, and the metal layer 11 is formed on the bottom surface of the recess 13. The metal layer 11 is formed, for example, by conductively printing a metal paste mainly composed of a metal powder such as tungsten (W) on a green sheet and firing the concave container 2.
For example, the conductor printing is performed by screen printing with an ink having corrosion resistance such as tungsten and containing a metal material having a high melting point.

More specifically, as shown in FIG. 1B, the surface of the metal layer 11 is covered with the conductive protective layer 16.
When tungsten is used as a current collector for the positive electrode, there is a property that tungsten is dissolved in the electrolyte, and the conductive protective layer 16 is formed to prevent the metal layer 11 from being dissolved in the electrolyte.
The conductive protective layer 16 may be formed of a metal having good corrosion resistance such as aluminum, titanium, or niobium by a thick film method such as a vacuum evaporation method or an RF sputtering method. Further, a conductive resin can be used. In the following modifications, the conductive protective layer 16 is omitted for the sake of simplification but is formed in the same manner.
The conductive protective layer 16 fills the periphery of the metal layer 11 without any gap, so that the electrolytic solution does not touch the metal layer 11.
Thereby, it can prevent that the metal layer 11 elutes and quality falls.

Returning to FIG. 1A, the electrode 6 made of an electrode active material is bonded to the upper surface of the metal layer 11 with a conductive adhesive containing carbon.
The electrode 6 is formed by forming an electrode active material mainly composed of activated carbon into a sheet shape and cutting it into a rectangle. For example, in the case of a carbide or artificial material derived from natural coconut shells or pitch, What activated each carbide | carbonized_material of a resin is used.
The portion in contact with the electrode 6 of the metal layer 11 functions as a current collector.

Under the concave portion 13 of the concave container 2, through-holes having openings on the bottom surface of the concave portion 13 and the bottom surface of the concave container 2 are formed by stacking the green sheets having holes as described above. .
A cylindrical through electrode 22 that electrically connects the metal layer 11 and the terminal 12 is formed in the through hole.
The outer diameter of the through electrode 22 and the inner diameter of the through hole are set to be the same, and no gap is generated between the through electrode 22 and the inner wall of the through hole. The through electrode is also referred to as VIA. Each through electrode has a diameter of about 0.1 to 0.3 mm. An intermediate electrode can be provided between the green sheet layers.

  The through electrode 22 is formed by sintering a metal paste mainly composed of a metal powder such as tungsten (W) into the through hole, injecting and solidifying a conductive paste such as carbon, or a metal rod. It is formed by inserting a material. As the metal bar, for example, aluminum, stainless steel, tungsten, nickel, silver, gold, or a conductive resin containing carbon can be used. The electrode 6 is electrically connected to the terminal 12 through the metal layer 11 and the through electrode 22.

  In this way, both ends of the through hole of the through electrode 22 are sealed with the lower surface of the metal layer 11 and the upper surface of the terminal 12, and the through electrode 22 is formed inside the body of the concave container 2, Even if the vapor pressure of the electrolyte is increased by heating and the inside of the recess 13 is increased, the electrolyte does not leak through the through electrode 22.

A joining metal layer 8, which is a metal layer for joining the sealing plate 3 and the concave container 2, is formed at the end of the opening of the recess 13.
The bonding metal layer 8 is composed of a metallized layer formed on the entire periphery of the end of the opening and a layer of brazing material (nickel, gold, etc.) formed on the metallized layer. The bonding metal layer 8 is sometimes called a seal ring in order to ensure airtightness between the sealing plate 3 and the concave container 2.

The metallized layer is made of, for example, kovar (alloy of Co: 17, Ni: 29, Fe: 54), and a ring-shaped metal layer made of Kovar is formed in advance on the end of the concave container 2. It is formed by placing and firing the metal layer and the brazing material. Thereafter, the surface of the brazing material is nickel-plated.
As will be described later, when the sealing plate 3 is placed in the opening of the recess 13 and heated, the nickel plating layer pre-plated on the surface of the brazing material melts and melts with the metal layer 15 (nickel plating) of the sealing plate 3. The recess 13 is sealed by the sealing plate 3.
It is desirable that at least one of the surface of the brazing material or the metal layer 15 has a lower melting point than the other.
As such a combination, for example, nickel having different compositions produced by electrolytic nickel plating and electroless plating to which phosphorus (P) is added, or electroless plating and phosphorus to which boron (B) is added are used. Nickel having a different composition produced by electroless plating to which (P) is added can be used.

In the concave container 2, through-holes having openings at the end of the opening of the concave 13 and the bottom of the concave container 2 are formed in the side wall surrounding the concave 13 by laminating green sheets with holes. ing.
A cylindrical through electrode 21 that electrically connects the bonding metal layer 8 and the terminal 10 is formed in the through hole.
The outer diameter of the through electrode 21 and the inner diameter of the through hole are set to be the same, and no gap is generated between the through electrode 21 and the inner wall of the through hole.
The material and forming method of the through electrode 21 are the same as those of the through electrode 22.

  Thus, both ends of the through hole of the through electrode 21 are sealed with the lower surface of the bonding metal layer 8 and the upper surface of the terminal 10, and the through electrode 21 is formed inside the main body of the concave container 2. Even if the water pressure of the electrolyte rises due to heating and the pressure inside the recess 13 is increased, the electrolyte does not leak through the through electrode 21.

As described above, in the electric double layer capacitor 1, since the through electrodes 21 and 22 are formed inside the main body of the concave container 2, it is possible to prevent the solder from creeping up.
In the conventional electric double layer capacitor 100 (FIG. 6), the metal layers 109 and 111 are formed on the side surfaces of the concave container 102. Therefore, when the electric double layer capacitor 100 is surface-mounted on the substrate, the solder causes the metal layers 109 and 111 to be mounted. There is a possibility of going up. In particular, when the metal layer 111 crawls up from the solder, it is conceivable that the bonding metal layer 108 and the sealing plate 103 are short-circuited. In this regard, the electric double layer capacitor 1 does not have such a concern.
Furthermore, since the penetration electrodes 21 and 22 are stored in the main body of the concave container 2, corrosion of the penetration electrodes 21 and 22 can be prevented without touching the outside air.

Returning to the description of the electric double layer capacitor 1, the terminals 10 and 12 are formed by printing a conductor with an ink containing tungsten or the like and baking it, and then plating nickel or the like on the surface thereof. Further, a metal such as gold or tin can be plated on the nickel plating for rust prevention. The plating includes electrolytic plating and electroless plating, and may be formed by a vapor phase method such as vacuum deposition.
Thereby, the high solder wettability of the terminals 10 and 12 is ensured, and the electric double layer capacitor 1 can be satisfactorily surface-mounted on the substrate.
In addition, in this Embodiment, although the terminals 10 and 12 were provided in the outer bottom face part of the concave container 2, you may form in an outer side face part, or may form continuously from an outer bottom face to a side face.
The terminals 10 and 12 are formed after the through electrodes 21 and 22 are installed in the through holes.

The sealing plate 3 is a metal member made of Kovar or the like. Since Kovar has a thermal expansion coefficient approximately equal to that of ceramics, it is possible to suppress the stress generated between the sealing plate 3 and the concave container 2 when the electric double layer capacitor 1 is heated during reflow.
On the lower surface of the sealing plate 3, a metal layer 15 is formed by nickel plating in order to bond the sealing plate 3 to the bonding metal layer 8 satisfactorily.
When the metal layer 15 is brazed to the bonding metal layer 8, the sealing plate 3 is physically and electrically bonded to the opening of the recess 13.

The brazing is dissolved by heating the sealing plate 3 while applying pressure, and the sealing plate 3 and the concave container 2 are joined.
More specifically, it is possible to use parallel seam welding in which the roller electrode is brought into contact with the edge of the sealing plate 3 with an appropriate pressure and is rotated while being energized. The bonding metal layer 8 is heated by the contact resistance, and pressurization and heating are performed.

When performing parallel seam welding, it is desirable to select a material with good compatibility between the bonding metal layer 8 and the sealing plate 3. For example, when electroless nickel is used for the bonding metal layer 8, the sealing plate 3 is made of Kovar. Electrolytic nickel is used. Or, conversely, when electrolytic nickel is used for the bonding metal layer 8, the sealing plate 3 is obtained by applying electroless nickel to Kovar. Thereby, it is not necessary to raise the welding power more than necessary. Furthermore, when performing electroless nickel, various reducing agents can be used. Examples include dimethylamine borane, hypophosphorous acid, hydrazine, sodium borohydride and the like. Here, when the nickel used for plating is melted as the brazing material, it is desirable that the melting point of nickel is lower. Therefore, by using hypophosphorous acid as a reducing agent during plating, when the chemical composition of the finished plating is “Ni: 90% -96%, P: 4% -10%”, boron Compared to the case of containing, it has a lower melting point and is suitable for brazing.
Further, in order to fix the seal ring of the bonding metal layer 8 to the ceramic metallized layer, it is also possible to use a brazing material such as gold brazing or silver brazing or a solder material.

An electrode 5 made of an electrode active material is joined to the lower surface of the metal layer 15 by a conductive adhesive containing carbon.
The material and shape of the electrode 5 are the same as those of the electrode 6. The portion of the metal layer 15 that is in contact with the electrode 5 functions as a current collector.
In this way, the electrode 5 is electrically connected to the terminal 10 via the metal layer 15, the bonding metal layer 8, and the through electrode 21.

The electrodes 5 and 6 face each other in a cavity formed by the recess 13 and the sealing plate 3, and a separator 7 is installed between the electrodes 5 and 6 to prevent a short circuit due to contact of the electrodes 5 and 6. Has been.
As a material of the separator 7, for example, a non-woven fabric made of a heat-resistant resin such as PPS (polyphenylene sulfide), PEEK (polyether ether ketone), PTFE (polytetrafluoroethylene), or the like, or Glass fiber can be used.

Further, an electrolyte is enclosed in a hollow portion constituted by the recess 13 and the sealing plate 3.
The electrolyte is composed of, for example, a solution in which a supporting salt such as (CH 3) · (CH 4) 3 N · BF 4 is dissolved in a nonaqueous solvent such as PC (propylene carbonate). Thus, although a liquid is used as the supporting salt in the present embodiment, a gel-like or solid electrolyte can also be used. Although depending on the sealing method, when a liquid solvent is used as the electrolyte, the boiling point is desirably 200 ° C. or higher. Furthermore, it is desirable that the vapor pressure does not increase due to the heat applied during sealing. A low boiling point solvent having a boiling point of less than 100 ° C. can be added to the electrolytic solution, but at least the vapor pressure at the melting point of the resin is preferably 0.2 MPa-G or less.
In addition, when using a solid electrolyte, the separator 7 becomes unnecessary.

As described above, in the electric double layer capacitor 1, the electrode 5 and the electrode 6 face each other (facing each other) with the separator 7 interposed therebetween, but the electrode 5 is used as a negative electrode and the electrode 6 is used as a positive electrode. The Therefore, the terminal 12 is a negative terminal and the terminal 10 is a positive terminal.
The reason for setting the polarity of the electrode in this way is as follows.

The reason why the electrode 5 is a negative electrode is that if the electrode 5 is a positive electrode, the metal layer 15 (nickel) melts, whereas if the electrode 5 is a negative electrode, the reduction potential is applied and the metal layer 15 is difficult to melt. . Therefore, as the metal layer 15, many metals such as copper, brass, zinc, tin, gold stainless steel, tungsten, and aluminum can be used in addition to nickel.
On the other hand, the metal layer 11 may be made of platinum, stainless steel (SUS444, SUS239J4L, SUS317J4L), etc., as well as tungsten, as a material that does not dissolve.

The electric double layer capacitor 1 configured as described above is surface-mounted on a substrate with the terminal 10 as a negative electrode and the terminal 12 as a positive electrode, and can be used as, for example, a mobile phone memory or a clock backup power source.
In this case, the mobile phone charges the electric double layer capacitor 1 at the same time that the battery of the main power source is mounted, and the electric charge accumulated in the electric double layer capacitor 1 is changed when the battery is replaced or when the voltage of the main power source decreases. Is discharged to supply power to the memory or to maintain a function such as a clock.

The example of the configuration of the electric double layer capacitor 1 has been described above, but various modifications can be made.
For example, in FIG. 2A, the bonding metal layer 8 is formed over the entire upper end portion of the concave container 2.
When the bonding metal layer 8 is formed on the entire surface in this way, the cost increases, but the shift of the sealing plate 3 can be absorbed and the yield is improved.

The example of FIG. 2B is an example in which the bonding metal layer 8 is formed by a bonding metal layer 8a made of brazing material and a bonding metal layer 8b called a seal ring having a size different from that of the bonding metal layer 8a.
If a seal ring is used, the airtightness of the sealing plate 3 and the concave container 2 can be ensured more reliably.
More specifically, the bonding metal layer 8a is formed of silver brazing or the like, and the bonding metal layer 8b is formed of Kovar. Further, although not shown in the drawing, the joint metal layers 8a and 8b are covered with a nickel film by electroless nickel plating.
When the sealing plate 3 is placed on the joining metal layers 8a and 8b covered with nickel and welded with a roller electrode, nickel covering the joining metal layers 8a and 8b and nickel forming the metal layer 15 are welded to form a concave shape. A fillet is formed at the joint between the container 2 and the sealing plate 3.

Moreover, as shown in FIG.2 (c), the edge part of the terminals 10 and 12 is not formed to the edge part of the bottom part of the concave container 2, but the edge part of the terminal 10 and 12 and the edge part of the bottom part of the concave container 2 The parts do not have to be aligned.
In this case, when a large number of electric double layer capacitors 1 are formed on a large sheet material at a time and divided to take out individual electric double layer capacitors 1 (sometimes called chocolate breaks), terminals are associated with the division. 10 and 12 can be prevented from peeling off or cracking.

Further, as shown in FIG. 2 (d), it may be formed continuously from the outer bottom surface to the side surface.
In this case, the end portions of the terminals 10 and 12 are on the side surface of the concave container 2 and are perpendicular to the substrate.
For this reason, when the electric double layer capacitor 1 is reflowed, the solder crawls up and solidifies the vertical portions of the terminals 10 and 12 to improve the bonding strength between the electric double layer capacitor 1 and the substrate.

In addition to this, for example, the concave container 2 is composed of ceramics with alumina as a main component, and alumina is 90 wt% or more. However, the glass contains heat-resistant resin, silicon (SiO2) as a main component, AL2O3 is less than 90%, and It is also possible to comprise a heat resistant material such as ceramic glass containing silicon (SiO2).
When the concave container 2 is formed of glass or glass ceramic, wiring is applied to the low melting point glass or glass ceramic by conductor printing, laminated, and then fired at a low temperature.
When the concave container 2 is made of resin, the through electrodes 21 and 22 can be insert-molded.

According to the embodiment described above, the following effects can be obtained.
(1) Since the wiring (through electrode 21) for connecting the electrode 5 and the terminal 10 and the wiring (through electrode 22) for connecting the electrode 6 to the terminal 12 are formed inside the main body of the concave container 2, these It is possible to prevent electrolyte leakage through the wiring. In particular, leakage of the electrolyte can be prevented even when the electric double layer capacitor 1 is heated to increase the vapor pressure of the internal electrolyte.
(2) Since the electric double layer capacitor 1 is formed in the green sheet stacking direction and does not have a horizontal metallized electrode penetrating from the side surface of the concave portion 13 to the outside of the concave container 2, even if the internal pressure rises due to heating, the electrolyte Leakage can be prevented.
(3) Since there is no metal layer (conventional metal layers 109 and 111) connected to the terminals 10 and 12 on the side surface of the electric double layer capacitor 1, it is possible to prevent short-circuiting due to solder rising during surface mounting. .
(4) Since the through electrodes 21 and 22 are formed inside the main body of the concave container 2, corrosion can be prevented without touching the outside air.
(5) Defects caused by electrolyte leakage, solder scooping, and the like can be reduced.

(Modification 1)
In the electric double layer capacitor 1 of the embodiment described above, the through electrode 22 is formed on the bottom surface of the concave container 2.
However, when the electric double layer capacitor 1 is heated to increase the internal pressure of the concave portion 13, the through electrode 22 may fall off due to the internal pressure, or a crack may occur around the through electrode 22. Further, there is a possibility that the electrolytic solution oozes out from the periphery of the through electrode 22.
Therefore, in the first modification, the through electrode 22 is formed outside the bottom surface of the recess 13 so that the internal pressure does not act on the through electrode 22.

FIG. 3 is a side sectional view of the electric double layer capacitor 1 according to the first modification.
The metal layer 11 enters the inner wall from the bottom surface of the recess 13 and reaches the inside of the main body of the concave container 2. The metal layer 11 does not penetrate outside the concave container 2. Therefore, the electrolyte does not leak along the metal layer 11.
One end side of the through electrode 22 is joined to the metal layer 11 in the main body of the concave container 2 of the metal layer 11, and the other end side is joined to the terminal 12.
The metal layer 11 is conductor-printed with a metal paste mainly composed of a metal powder such as tungsten (W) on the surface of the green sheet on the part installed on the bottom surface of the recess 13 and the part installed inside the main body of the concave container 2. It is formed by doing.

Thus, in this modification, since the through electrode 22 is disposed outside the region immediately below the bottom surface of the recess 13, even if the internal pressure of the recess 13 is increased by heating, the pressure is directly applied to the through electrode 22. It is possible to prevent the penetration electrode 22 from falling off or cracking around the penetration electrode 22 without acting.
Furthermore, if the through electrode 22 is disposed outside the region immediately below the region surrounded by the bonding metal layer 8, the through electrode 22 is located farther from the recess 13 and safety can be further improved.

(Modification 2)
Modification 2 also prevents the penetration electrode from falling off due to an increase in the internal pressure of the recess 13.
FIG. 4A is a side sectional view of the electric double layer capacitor 1 according to the second modification.
The upper end of the through-electrode 25 is connected to the lower surface of the metal layer 11 at the bottom surface of the recess 13, and the lower end of the through-electrode 25 is the metal layer 23 formed in the main body at the bottom of the concave container 2. Connected to the upper surface.

The metal layer 23 extends from the region immediately below the bottom surface of the recess 13 to the outside of the region, and is connected to the through electrode 25 in the region directly below the bottom surface of the recess 13 and connected to the through electrode 26 in the external region. .
The through electrode 26 is connected to the terminal 12 via a through hole formed outside the region immediately below the concave portion 13 in the main body of the concave container 2.
Thus, in Modification 2, the center line of the through electrode 25 connected to the metal layer 11 (current collector) and the center line of the through electrode 26 connected to the terminal 12 are set so as not to be on the same extension line. .

Here, the lamination of the green sheets will be described.
In FIG. 4A, a ceramic sheet material (green sheet) constituting the concave container 2 is shown by a broken line. The concave container 2 is formed by laminating and firing sheet materials 41 to 44.
The metal layer 23 is formed by conductor printing on the upper surface of the sheet material 41.
The through electrodes 25 are each formed in a through hole formed in the sheet material 42, and the upper end is connected to the metal layer 11 and the lower end is connected to the metal layer 23.
The through electrode 26 is formed in a through hole formed in the sheet material 41, the upper end is connected to the metal layer 23, and the lower end is connected to the terminal 12.
Note that the through electrode 21 is formed in a through hole concentrically formed in the sheet materials 41 to 44, and the recess 13 is formed by an opening formed in the sheet materials 43 and 44. The metal layer 11 is formed by conductor printing on the upper surface of the sheet material 42.

In the modified example 2, even when the internal pressure of the concave portion 13 is increased during reflow and pressure is applied to the through electrode 25, the lower end of the through electrode 25 is pressed by the sheet material 41, so that the through electrode 25 may fall off. Absent.
Further, the downward pressure applied to the through electrode 25 by the pressure increase by heating is dispersed in the metal layer 23 and acts on the sheet material 41. Therefore, it is possible to reduce the possibility that the ceramic is cracked by applying pressure locally.
Furthermore, since the internal pressure of the concave portion 13 does not act on the through electrode 26, the through electrode 26 does not fall off and the ceramics around the through electrode 26 are not broken.
As described above, in Modification 2, since the pressure applied to the through electrode 26 is dispersed in the main body of the concave container 2, it is possible to effectively suppress breakage or leakage during heating.

Moreover, as shown in FIG.4 (b), an intermediate metal layer can also be provided in the through-hole formation part of a sheet | seat material.
In the illustrated example, intermediate metal layers 51, 52, and 53 are provided in through-hole forming portions on the surfaces of the sheet materials 41, 42, and 43, respectively.
As described above, when the intermediate metal layer is provided, the through electrode 21 is electrically connected even when the accuracy of the formation of the hole for the through electrode 21 is not high, or even when the position of the sheet material is shifted when the sheet materials 41 to 44 are stacked. Connection can be maintained and the yield can be improved.

(Modification 3)
Modification 3 also prevents the through electrode from falling off due to an increase in the internal pressure of the recess 13.
FIG. 5A is a side sectional view of the electric double layer capacitor 1 according to the third modification.
The through electrode 28 has an upper end bonded to the lower surface of the metal layer 11 and a lower end bonded to the upper surface of the terminal 12.
The through hole through which the through electrode 28 passes is set such that the inner diameter of the through hole of the sheet material 42 is larger than the inner diameter of the through hole of the sheet material 41.
For this reason, the through electrode 28 is formed with a step portion in the laminated portion of the sheet materials 41 and 42, and the cross sectional area on the upper end side of the through electrode 28 is larger than the cross sectional area on the lower end side.

Since the through electrode 28 is formed in this way, even if the internal pressure of the concave portion 13 is increased by heating and the pressure acts on the through electrode 28, the through electrode 28 is pulled out by being caught by the sheet material 41 at the stepped portion. There is no.
Moreover, since the said pressure is disperse | distributed to the sheet | seat material 41, possibility that a ceramic will crack is also reduced.

FIG. 5B is a further modification of the modification example 3 in which the through electrode 28 is formed by arranging a plurality of metal pillars having different diameters on the same center line of the through electrode 28.
The diameter of the through hole of the sheet material 42b is set larger than the diameter of the through hole of the sheet material 42a, and the diameter gradually increases from the bottom surface of the concave container 2 toward the bottom surface of the concave portion 13.

The following configuration can be obtained by the present embodiment and the modification described above.
The concave container 2 has a concave portion 13 and functions as a concave container having a concave portion.
The metal layer 11 is formed on the bottom surface of the recess 13 and functions as a first conductor formed on the bottom surface of the recess.
Since the sealing plate 3 is joined to the upper end portion of the concave portion 13 to seal the concave portion 13, and the metal layer 15 and the joining metal layer 8 are formed on the concave portion 13 side, the sealing plate 3 is connected to the upper end portion of the concave portion and The concave portion is sealed, and functions as a sealing plate in which the second conductor (metal layer 15 and bonding metal layer 8) is formed on the surface on the concave portion side.
The electrode 6 functions as a first electrode installed on the surface of the first conductor, and the electrode 5 is installed on the surface of the second conductor, and has a predetermined distance from the first conductor. It functions as a second electrode facing each other.
The terminals 10 and 12 function as a first connection terminal and a second connection terminal formed outside the concave container.
The through electrode 22 is formed inside the main body of the concave container and functions as a first internal electrode connected to the first conductor and the first connection terminal.
The through electrode 21 is formed inside the main body of the concave container and functions as a second internal electrode connected to the second conductor and the second connection terminal.
The electrolyte sealed in the recess 13 functions as an electrolyte in contact with the first electrode and the second electrode.

  In Modification 2, since the center lines of the through electrodes 25 and 26 are not on the same straight line, the center line on the bottom surface side of the recess of the first internal electrode and the center line on the first connection terminal side are the same. Not on the line.

In the first and second modified examples, since the through electrodes 22 and 26 are formed outside the region immediately below the bottom surface of the recess 13, at least a part of the first internal electrode is directly below the bottom surface of the recess. It is formed outside the region.
Furthermore, it is also possible to form the through electrodes 22 and 26 outside the region immediately below the range surrounded by the bonding metal layer 8, and at least a part of the first internal electrode is formed between the concave container and the sealing plate. It can also be formed outside the region immediately below the range surrounded by the joint portion.

In the first and second modified examples, the metal layers 11 and 23 are formed in the main body of the concave container 2, respectively. Therefore, the first internal electrode is formed of a metal layer formed in the main body of the concave container. Contains.
In Modification 1, since the metal layer 11 penetrates into the side surface of the recess 13 and the through electrode 22 is joined to the invaded portion, the first conductor is the side surface of the concave container. The first internal electrode is joined to the invaded portion of the first conductor.
Furthermore, in Modification 2, the first internal electrode includes a first portion (penetrating electrode 25) bonded to the first conductor and a second portion (penetrating electrode) bonded to the first connection terminal. The electrode 26) and a metal layer (metal layer 23) joined to the first part and the second part.

  Since the through electrode 28 of Modification 3 is formed so that the cross-sectional area on the metal layer 11 side is larger than the cross-sectional area on the terminal 12 side, the first internal electrode is on the side to be joined to the first conductor. The cross-sectional area is formed larger than the cross-sectional area on the side joined to the first connection terminal.

  Since the concave container 2 is formed by laminating ceramic sheet materials, the concave container is formed with openings corresponding to the first internal electrode, the second internal electrode, and the concave portion. It is formed by laminating sheet materials.

The electric double layer capacitor 1 can be used as, for example, a mobile phone memory or a clock backup power source.
In this case, the cellular phone exhibits predetermined functions such as an electronic component composed of the electric double layer capacitor 1, a power storage means for storing the battery of the main power supply and storing the electronic component at the same time, and a memory and a clock. Functions as an electronic device including another electronic component and power supply means for supplying power to the other electronic component using the stored charge, such as discharging the stored charge and supplying power to the memory or clock doing.

DESCRIPTION OF SYMBOLS 1 Electric double layer capacitor 2 Concave container 3 Sealing plate 5 Electrode 6 Electrode 7 Separator 8 Bonding metal layer 10 Terminal 11 Metal layer 12 Terminal 13 Recess 15 Metal layer 16 Conductive protective layer 21, 22 Through electrode 23 Metal layer 25, 26 Through Electrode 28 Through electrode 41 to 44 Sheet material 100 Electric double layer capacitor 102 Concave container 103 Sealing plate 105 Negative electrode 106 Positive electrode 107 Separator 108 Bonding metal layer 109 Metal layer 110 Negative electrode terminal 111 Metal layer 112 Positive electrode terminal 113 Recess 115 Metal layer

Claims (4)

A concave container having a concave portion formed by laminating and integrating ceramic sheets and firing ;
A first conductor formed on the bottom surface of the recess;
A sealing plate bonded to the upper end of the recess to seal the recess, and a second conductor formed on the surface of the recess;
A first electrode installed on a surface of the first conductor;
A second electrode installed on the surface of the second conductor and facing the first conductor at a predetermined distance;
A first connection terminal and a second connection terminal formed outside the concave container;
A first internal electrode formed in the body of the concave container and connected to the first conductor and the first connection terminal;
A second internal electrode formed in the body of the concave container and connected to the second conductor and the second connection terminal;
An electrolyte in contact with the first electrode and the second electrode ,
The first internal electrode is formed such that a cross-sectional area on a side to be joined to the first conductor is larger than a cross-sectional area on a side to be joined to the first connection terminal.
An electronic component characterized by that.   The bottom portion of the concave container having the concave portion is formed in a plurality of layers by the ceramic sheet, and a cylindrical through hole in which the first internal electrode is disposed is formed for each layer, and the through hole of each layer The diameter of the concave container is formed so as to increase from the layer outside the bottom surface of the concave container toward the concave layer.
The electronic component according to claim 1. It said first internal electrode, said claim 1 or characterized in that it comprises a metal layer formed in the main body of the hollow container, electronic component according to claim 2. An electronic component according to any one of claims of claims 1 to 3,
Power storage means for storing power in the electronic component;
With other electronic components that perform the specified function,
Power supply means for supplying power to the other electronic component using the stored charge;
An electronic device comprising:

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