JP2011129334A - Coin-shaped electric element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coin-shaped electric element capable of being mounted on a substrate by an automatic soldering technique in a soldering reflow method, reducing cost by not using a lead plate, and reducing a mounting area. <P>SOLUTION: The coin-shaped electric element 1 has an outer can 21, a cap 22, and an element body 10. The outer can 21 and the cap 22 seal an inner space by caulking process of an opening edge part of the outer can 21 with a gasket 23 interposed. The coin-shaped electric element 1 has an almost square shape with corner parts of an arc shape in an external appearance in a plan view in the outer can 21. In the coin-shaped electric element, the flat region 21a of the opening edge part 21a in the outer can 21 has a height level in a Z-axis direction of the same or 0.1 [mm] or less in mutual level difference against the exposed part 22a of the cap 22, when the bottom face 21c of the outer can 21 is made a reference. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coin-type electrical element, and more particularly to a coin-type electrical element that can be mounted on a substrate using an automatic soldering technique based on a solder reflow method.

Coin-type batteries, which are a type of coin-type electrical element, are small and light, and have excellent storage characteristics (self-discharge characteristics), and thus are used as backup power sources for various electronic devices. Generally, a coin-shaped electric element is mounted on a substrate by using an automatic soldering technique based on a solder reflow method.
As shown in FIG. 6A, in the coin-shaped electric element (coin-shaped battery) 91 according to the first prior art, spot welding is performed on each of an outer can 921 as a positive electrode and a cap 922 as a negative electrode. Bonded lead plates 961 and 962 are provided. Cream solder 953 and 954 are applied to the conductive lands 951 and 952 on the substrate 950 to be mounted, and the respective leading end portions 961a and 962a of the lead plates 961 and 962 bonded to the coin-shaped electric element 91 are attached. It is placed on the cream solder 953, 954. In this state, the cream solder 953 and 954 are heated and melted in a reflow furnace, whereby the mounting of the coin-shaped electric element 91 on the substrate 950 is completed (see Patent Document 1).

By the way, cost reduction and reduction of a mounting area are calculated | required with respect to coin type electric elements including a coin type battery. In response to such a demand, a form in which one of the lead plates is omitted has been proposed (see Patent Document 2).
As shown in FIG. 6B, in the coin-shaped electric element 92 according to the second conventional technology in which one of the lead plates is omitted, the lead plate 961 is joined only to the outer can 921. The tip portion 961a of the lead plate 961 and the flat portion 922a of the cap 922 are brought into contact with the cream solder 953 and 954 applied on the conductive lands 951 and 952 of the substrate 950. As shown in FIG. 6B, in the second conventional technique, the lead plate 962 is omitted from the first conventional technique shown in FIG. It is possible to reduce the area.

Japanese Patent No. 3744907 JP 2002-298804 A

However, also in the coin-shaped electric element 92 according to the second prior art shown in FIG. 6B, it is necessary to join the lead plate 961 for mounting on the substrate 950, which further reduces the cost and mounting area. The demand for reduction cannot be fully met.
Note that the lead plate 961 is simply omitted from the coin-shaped electric element 92 shown in FIG. 6B and the conductive land 951 is directly joined to the conductive land 951 using the lower portion of the outer can 921 in the Z-axis direction. It is difficult to actually carry out due to the step between the edge of the outer can 921 and the cap 922 on the lower side in the direction.

  The present invention has been made to solve the above-described problems, and can be mounted on a board using an automatic soldering technique by a solder reflow method, and the cost can be reduced by not using a lead plate. An object of the present invention is to provide a coin-shaped electric element capable of reducing the mounting area.

In order to achieve the above object, the present invention employs the following configuration.
The coin-shaped electrical element according to the present invention includes an outer can, a cap, and an element body.
The outer can is made of a conductive material, has a shallow dish shape, and functions as one pole. The cap is made of a conductive material, has a shallow dish shape, seals the opening of the outer can through a gasket, and functions as the other pole. The element body is housed in an internal space formed by the outer can and the cap.

In the coin-type electric element according to the present invention, the outer can has a shape in which at least one side is a straight line in a plan view, and the outer can has a larger appearance size in a plan view than the cap. Furthermore, the opening of the outer can is sealed (internal space is sealed) by the cap by caulking the opening edge with a part of the cap exposed.
In the coin-type electric element according to the present invention, in the above configuration, when the bottom surface of the outer can is used as a reference, at least a partial region of the opening edge of the outer can and the exposed portion of the cap have the same or no step. Each height level is set to be 1 mm or less.

  As described above, in the coin-shaped electric element according to the present invention, the outer can has a shape in which at least one side is a straight line in a plan view (for example, a quadrangular shape or a hexagonal shape in which a corner portion has an arc shape, or Adopting a substantially quadrangular shape with an arc shape on one side). Here, the element characteristic is proportional to the size of the element, but the area that the element substantially occupies on the substrate is determined by a rectangular region including the mounted element. For this reason, the device performance can be improved in substantially the same occupied area on the substrate in the plan view as in the coin-type electric device according to the prior art, as compared with the circular shape. Conversely, in the case where the device performance is equivalent to that of the conventional device, the coin-type electric device according to the present invention can keep the occupied area on the substrate small.

  In the coin-type electric element according to the present invention, when the bottom surface of the outer can is used as a reference, at least a partial region of the opening edge of the outer can and the exposed portion of the cap have the same or step difference of 0.1. The height level of each other is set to be equal to or less than [mm]. For this reason, the coin-shaped electric element according to the present invention can be bonded to one conductive land with an exposed portion of the cap and to the other conductive land with at least a part of the opening edge of the outer can. As a result, it is possible to mount directly on the substrate using an automatic soldering technique based on a solder reflow method.

  That is, in the coin-shaped electric element according to the present invention, at least a part of the opening edge portion of the outer can and the exposed portion of the cap are the same or have a height difference of 0.1 [mm] or less. Since the thickness level is set, even when joining as described above, the inclination of the coin-shaped electric element on the substrate can be almost eliminated. Therefore, even when the automatic soldering technique based on the solder reflow method is used, the coin-type electric element according to the present invention can be reliably mounted on the substrate. In the coin-type electric element according to the present invention, since it is not necessary to use a lead plate for mounting on the substrate, the cost can be reduced and the occupied area on the substrate can be reduced.

As described above, the coin-type electric element according to the present invention can be mounted on a substrate using an automatic soldering technique by a solder reflow method, and can reduce cost and mounting area by not using a lead plate. Can be reduced.
In the coin-type electrical element according to the present invention, the following variations can be adopted as an example.

In the coin-shaped electrical element according to the present invention, in the outer can, at least a partial region (region joined to the conductive land of the substrate) of the opening edge is a region corresponding to the side formed by the straight line. It can be configured. As a result, when the coin-shaped electrical element according to the present invention is automatically mounted, position recognition can be reliably performed and mounting accuracy can be increased.
In the coin-shaped electrical element according to the present invention, the exposed portion of the cap has a flat surface, and the at least part of the outer can has a level substantially the same as the exposed portion of the cap (step difference). In other words, a configuration in which the flat region is provided with 0.15 [mm ² ] or more is possible. As described above, by providing a flat region of 0.15 [mm ² ] or more in at least a partial region of the outer can, the conventional coin-shaped electric device that joins the conductive land to the substrate via the lead plate is provided. High fixing strength can be ensured to the extent that it is not inferior to the element.

In the coin-shaped electric element according to the present invention, in the depth direction of the outer can, the abutting portion between the flat region of the opening edge and the outer surface of the side wall has an arc shape with a curvature of 0.4 [mm] or less. It is possible to adopt a configuration in which By adopting such a configuration, it is possible to reduce the occupied area on the substrate while maintaining high fixing strength.
In the coin-shaped electric element according to the present invention, when the outer can is viewed in a plan view, the outer can is configured by a straight line of three sides or four sides, and the butted portion of the straight lines has an arc shape. be able to. By adopting such an outer shape, the coin-shaped electric element according to the present invention can reduce the occupied area on the substrate as compared with the conventional coin-shaped electric element having a circular outer shape.

  In the coin-shaped electrical element according to the present invention, it is further desirable that the step between the exposed portion of the cap and the flat region of the outer can is 0.05 [mm] or less. This is because, in a conventional coin-type electric element (for example, a coin-type battery), the level difference is 0.15 [mm] or more. Therefore, mounting on a substrate using an automatic soldering technique based on a solder reflow method can be more reliably performed without using a lead plate.

  In the coin-shaped electric element according to the present invention, a plating process is performed to improve wettability with solder by limiting the area to at least a part of the opening edge of the outer surface of the outer can. The configuration can be adopted. This is because a conventional coin-shaped electric element having a circular external shape cannot accurately specify the position to be bonded to the conductive land of the board when automatic mounting is performed without using a lead plate. It is conceivable that the entire edge of the opening must be plated, which can be a problem in terms of cost.

  On the other hand, in the coin-shaped electric element according to the present invention, as described above, since the external shape is a shape having a straight line with three or more sides, a rotational shift (about 15) during automatic mounting using a substrate mounting machine. Even if [degree] is taken into consideration, the mounting can be performed in an accurately positioned state, and the plating process can be performed only in the limited region as described above. For this reason, it is excellent in terms of cost.

(A) is a schematic cross section which shows the internal structure of the coin-shaped electric element 1 which concerns on Embodiment 1, (b) is a schematic plan view which shows the planar shape of the coin-shaped electric element 1. FIG. (A) is a schematic side view which shows the state immediately before mounting the coin-shaped electric element 1 on the board | substrate 50, (b) is a schematic side view which shows the state which mounted the coin-shaped electric element 1 on the board | substrate 50. is there. (A) is a schematic top view which shows the state in which the coin-shaped electric element 1 which concerns on Embodiment 1 was mounted in the board | substrate 50, (b) is the coin-shaped electric element 91 as a comparative example in the board | substrate 50. It is a schematic plan view which shows the mounted state. 6 is a schematic plan view showing a planar shape of a coin-shaped electrical element 2 according to Embodiment 2. FIG. (A) is a schematic cross section which shows the internal structure of the coin-shaped electrical element 3 which concerns on Embodiment 3, (b) is a schematic side view which shows the state which mounted the coin-shaped electrical element 3 in the board | substrate 50. is there. (A) is a model side view which shows the state just before mounting the coin-shaped electrical element 91 with a lead concerning the prior art 1 on the board | substrate 950, (b) is a coin-shaped electrical element with a lead concerning the prior art 2. FIG. It is a schematic side view which shows the state just before mounting 92 to the board | substrate 950. FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, the specific example shown below is an example used to explain the configuration of the present invention and the operations and effects produced from the configuration in an easy-to-understand manner. The following specific examples are not limited at all.
[Embodiment 1]
1. Internal Configuration of Coin-shaped Electrical Element 1 The internal configuration of the coin-shaped electrical element 1 according to Embodiment 1 will be described with reference to FIG.

  As shown in FIG. 1A, a coin-type electrical element 1 according to Embodiment 1 is a coin-type lithium secondary battery, and an electrode is formed in an internal space formed by an outer can 21 and a cap 22. The body 10 is housed. The outer can 21 is made of a conductive material such as a stainless material, and has a shallow dish shape. Similarly, the cap 22 is also made of a conductive material such as a stainless material, has a shallow dish shape, and is similarly small in size as the outer can 21.

The outer can 21 and the cap 22 are arranged with the opening 23 facing each other with the gasket 23 interposed therebetween. And the internal space in which the electrode body 10 was accommodated is airtightly sealed by crimping the opening edge part in the armored can 21. FIG.
The electrode body 10 is configured by sequentially stacking a positive electrode active material pellet 11, a separator 13, and a negative electrode active material 12 in the Z-axis direction. The upper surface of the positive electrode active material pellet 11 is in contact with the inner surface of the outer can 21, and the lower surface of the negative electrode active material 12 is in contact with the inner surface of the cap 22. Therefore, the outer can 21 functions as a positive electrode of the coin-shaped electric element 1, and the cap 22 functions as a negative electrode of the coin-shaped electric element 1.

The positive electrode active material pellet 11 is mainly composed of, for example, a lithium / manganese composite oxide, and the negative electrode active material 12 is, for example, a lithium-aluminum (Li-Al) alloy negative electrode.
In addition to the electrode body 10, an electrolytic solution is injected into the internal space formed by the outer can 21 and the cap 22 (not shown). The electrolytic solution is, for example, a 1: 1 mixed solution of propylene carbonate (PC) and diethylene glycol dimethyl ether (Di-DME) as a nonaqueous solvent, and lithium bis (trifluoromethylsulfonyl) imide (LiN (CF ₃ SO ₃ ) as an electrolyte. ₂ ) What dissolved ₂ ) by the density | concentration of 1 [mol / L] is used.

As shown to Fig.1 (a), as for the partial area | region 21b of the opening edge part of the armored can 21, the front-end | tip part is made flat (flat area | region 21a), and the said flat area | region 21a is compared with another area | region. located in the Z axis direction lower side Te, when referenced to the bottom surface 21c of the outer can 21, the height level H ₁ of the flat region 21a is, the height level H ₃ of the exposed portion 22a of the cap 22 It is set equally. In other words, in the outer can 21, the height level H ₁ of the flat region 21 a is higher than the height level H ₂ of the other opening edge.

[Equation 1] H ₁ ≈H ₃
[Equation 2] H ₁ > H ₂
Moreover, in the coin-shaped electric element 1, the flat area | region 21a in the exterior can 21 has an area of 0.15 [mm < ² >] or more, for example.
Further, in the outer can 21, the flat region 21 a and the side wall outer surface have an arc shape with a curvature of 0.4 [mm] or less (R0.4 or less).

2. Planar shape of coin-shaped electric element 1 As shown in FIG. 1B, in the coin-shaped electric element 1 according to the first embodiment, a substantially quadrangular shape (a shape in which the four sides 21d to 21g are configured by straight lines). The width in the Y-axis direction is the width W ₁ [mm], and the width in the X-axis direction is the width W ₂ . Here, the width W ₁ and the width W ₂ may have the same dimensions or different dimensions. In other words, the planar shape of the coin-shaped electric element 1 is a square or a rectangle, and a corner R is attached to the abutting portion of each side to form an arc.

Also, the exposed portion 22a of the cap 22 is rectangular.
Next, the partial region 21b including the flat region 21a in the outer can 21 is subjected to a plating process such as Sn or Sn / Cu in a state where the region is limited (hatched portion). This is for the purpose of improving the wettability of the solder when mounted on the substrate 50 described later.

3. Mounting of Coin Type Electric Element 1 on Substrate 50 The mounting of the coin type electric element 1 on the substrate 50 will be described with reference to FIG.
As shown in FIG. 2A, two conductive lands 51 and 52 are formed on the main surface on the upper side in the Z-axis direction of the substrate 50. Further, on each of the conductive lands 51 and 52, cream-like solder is formed. 53 and 54 are applied. 2A shows a state in which only two conductive lands 51 and 52 are provided on the main surface of the substrate 50, other circuit wirings (not shown) are also formed.

The conductive lands 51 and the conductive lands 52 on the main surface of the substrate 50 are provided in consideration of the distance between the flat region 21a of the outer can 21 of the coin-shaped electric element 1 to be mounted and the exposed portion 22a of the cap 22. It has been.
The coin-shaped electric element 1 is lowered downward in the Z-axis direction so that the exposed portion 22 a of the cap 22 faces the conductive land 52 and the flat region 21 a of the outer can 21 faces the conductive land 51.

  As shown in FIG. 2B, the coin-shaped electrical element 1 is completely lowered, the exposed portion 22a of the cap 22 and the solder 54 come into contact with each other, and the flat region 21a of the outer can 21 (see FIG. 2A) The solder 53 comes into contact. At this time, the exposed portions 22a of the cap 22 and the flat region 21a of the outer can 21 are brought into contact with the solders 53 and 54 in a slightly depressed state until they are slightly buried.

In coin-type electric device 1 according to the first embodiment, as described above [Equation 1], the flat region 21a of the outer can 21 the height level H _1, the height level H ₃ of the exposed portion 22a of the cap 22 As shown in FIG. 2 (b), the flat region 21a of the outer can 21 is reliably brought into contact with the solder 53 without using a lead plate when performing automatic mounting using a substrate mounting machine, as shown in FIG. (Part indicated by arrow A). At that time, the bottom surface 21 c of the outer can 21 is substantially parallel to the main surface 50 a of the substrate 50.

The substrate 50 is put into a reflow furnace in the state of FIG. 2B on which the coin-shaped electric element 1 is placed, and heat of about 230 [° C.] to 270 [° C.], for example, is applied for a short time. Thus, the mounting of the coin-shaped electric element 1 is completed.
4). Advantages of Coin-shaped Electrical Element 1 The coin-shaped electrical element 1 according to Embodiment 1 has a quadrangular external shape in which each corner is arcuate in plan view, as shown in FIG. . For this reason, in the coin-shaped electrical element 1 according to the first embodiment, the substantial occupied area on the substrate is larger than the case where the coin-shaped electrical element according to the prior art has a circular external shape in plan view. Therefore, the device performance (battery capacity) can be increased. That is, it is excellent from the viewpoint of area efficiency. This will be specifically described with reference to FIG.

As shown in FIG. 3A, as in the coin-shaped electrical element 1 according to the first embodiment, the substantial area occupied by the element on the substrate 50 is (width W ₁ × width W ₂ ), In the form in which the corner portion is R, the true area (element size) A1 of the coin-shaped electric element ₁ is as follows.
[Formula 3] A ₁ = (W ₁ × W ₂ ) − (4R ² −πR ² )
On the other hand, as shown in FIG. 3B, in the case of having a circular external shape like the coin-shaped electric element 91 according to the prior art, the substantial area occupied by the element on the substrate 50 is (D ² ) And the true area (element size) A ₉₁ is as follows.

[Number ^{_{4] A 91 = πD 2/}} 4
Here, when assuming that the width W ₁ and the width W ₂ , and the diameter D are equal to each other, and the substantial occupied area on the substrate 50 of the coin-shaped electrical element 1 and the coin-shaped electrical element 91 is the same, towards 3 coin type electric device 1 shown in (a) is the true surface area (element size) _{a 1} is approximately 20 [%] increase. Therefore, the coin-shaped electric element 1 having an outer shape of a substantially quadrangle (a shape in which the four sides 21d to 21g are configured as straight lines) is about 20 [compared to the coin-shaped electric element 91 having a circular outer shape. %] Device performance can be improved.

  Further, in the coin-shaped electric element 1 according to the first embodiment, as shown in the above [Equation 1], when the bottom surface 21c of the outer can 21 is used as a reference, the outer can The flat area 21a in 21 is set to the same height level. For this reason, as shown in FIGS. 2A and 2B, when the coin-shaped electric element 1 according to the first embodiment is mounted on the substrate 50 using the automatic soldering technique based on the solder reflow method, the conductive The exposed portion 22 a of the cap 22 is bonded to the land 52, and the flat region 21 a of the outer can 21 can be bonded to the conductive land 51.

In the case of using a board mounting machine for mounting on the board 50, a plurality of coin-shaped electric elements 1 are supplied to the board mounting machine in a state of being inserted into an embossed tape. Then, the coin-shaped electric elements 1 are taken out from the embossed tape one by one by a board mounting machine, and mounted after performing position correction on the board 50. At this time,
Positioning of the coin-shaped electric element 1 in the rotational direction is performed in a state of being inserted into the embossed tape. The rotational displacement of the coin-shaped electrical element 1 in the embossed tape is about 15 [°], and the position correction by the board mounting machine is based on the silhouette of the coin-shaped electrical device 1 in plan view with the rotational displacement of about 15 [°]. To correct. In such a position correction in the substrate mounting machine, when the external shape is substantially square like the coin-shaped electric element 1 according to the first embodiment, the correction becomes easy and a reliable position correction is possible.

  On the other hand, in a coin-shaped electrical element having a circular appearance in plan view, the coin-shaped electrical element rotates in the embossed tape even if positioning in the rotational direction is performed while being inserted in the embossed tape. When the coin-shaped electric element is taken out from the embossed tape, it changes greatly from the initial position. In addition, in the coin-shaped electric element having a circular appearance in plan view, correction cannot be performed based on the silhouette of the coin-shaped electric element in plan view when mounted. Therefore, in the coin-type electric element having a circular appearance in plan view, the opening edge of the outer can and the exposed portion of the cap are the same or the difference in level is 0. It is necessary to set each other's height level so as to be 1 [mm] or less, and it is necessary to perform plating over the entire periphery of the opening edge of the outer can.

  That is, in the coin-shaped electric element 1 according to the first embodiment, the flat region 21a in the outer can 21 and the exposed portion 22a of the cap 22 are set at the same height level. The inclination of the coin-shaped electric element 1 with respect to the main surface 50a of 50 (the inclination of the bottom surface 21c of the outer can 21) can be almost eliminated. Therefore, even when the automatic soldering technique based on the solder reflow method is used, the coin-type electric element 1 can be reliably mounted on the substrate 50. In the coin-shaped electrical element 1 according to the first embodiment, since it is not necessary to use a lead plate for mounting on the substrate 50, the cost can be reduced and the occupied area on the substrate 50 can be reduced. Can be planned.

As described above, the coin-type electrical element 1 according to the first embodiment can be mounted on the substrate 50 using the automatic soldering technique by the solder reflow method and does not use a lead plate. Down and reduction of mounting area can be achieved.
[Embodiment 2]
The configuration of the coin-shaped electric element 2 according to the second embodiment will be described with reference to FIG. The coin-shaped electric element 2 according to the second embodiment is different from the coin-shaped electric element 1 according to the first embodiment in the external shape, and the internal configuration is basically changed. Since there is not, illustration and description are omitted.

  As shown in FIG. 4, the coin-shaped electric element 2 according to the second embodiment has a planar shape in which a square and a semicircle are added. That is, in the coin-shaped electrical element 2, the three sides 31d, 31e, and 31g are configured with straight lines, and the side 31f on the left side in the X-axis direction has an arc shape, which is the same as the coin-shaped electrical element 1 according to the first embodiment. This is a difference in appearance. In other words, the coin-shaped electric element 2 according to the present embodiment has a planar shape combining three straight lines and one arc.

Also in the coin-shaped electrical element 2 according to the second embodiment, the exposed portion of the cap 32 has a similar shape to the overall appearance shape, and is insulated from the outer can 31 by the gasket 33. .
In the coin-shaped electrical element 2 according to the second embodiment, a plating process is performed on a partial region 31b of the opening edge located on the right side in the X-axis direction, and a flat region 31a is provided at the tip. The flat region 31 a is set to the same height level with respect to the exposed portion of the cap 32, similarly to the flat region 21 a of the outer can 21 in the coin-shaped electric element 1.

  Also in the coin-shaped electric element 2 according to the present embodiment, the basic configuration excluding the planar shape is the same as that of the first embodiment, so that the conventional coin-shaped electric element having a circular outer shape in a plan view is used. In comparison, the element size in the case of the same occupation area can be increased, and the same effect as described above can be obtained. Further, as shown in FIG. 4, in the coin-shaped electrical element 2, when viewed in plan, the sides 31d, 31e, 31g on the right side in the X-axis direction are straight lines, whereas the side 31f on the left side in the X-axis direction is Since it has an arc shape, the direction of the coin-shaped electric element 2 can be easily recognized in the board mounting machine, and the position correction is reliably performed.

[Embodiment 3]
The configuration of the coin-shaped electrical element 3 according to Embodiment 3 will be described with reference to FIG.
As shown in FIG. 5A, also in the coin-shaped electrical element 3 according to the third embodiment, the outer can 41 and the cap 42 are combined with the gasket 43 interposed therebetween, and sealed by this. The electrode body 10 is accommodated in the internal space.

In the coin-shaped electric element 3 according to the present embodiment, the height when the flat region 41a located on the right side in the X-axis direction of the opening edge of the outer can 41 is based on the bottom surface 41c of the outer can 41. The level H ₄ has the following relationship with the height level H ₅ of the exposed portion 42 a of the cap 42.
[Expression 5] H ₄ > H ₅
In coin-shaped electric element 3, the difference between the height level _{H 4} and the height level _{H 5,} i.e., the step between the flat region 41a of the exposed portion 42a and the outer can 41 of the cap 42, 0.1 [mm ], More preferably within 0.05 [mm].

In addition, the outer can 41 is plated only in a partial region 41b including the flat region 41a.
The mounting of the coin-shaped electric element 3 on the substrate 50 will be described with reference to FIG.
As shown in FIG. 5 (b), the height level _{H 4} of the flat region 41a of the outer can 41, due to higher than the height level _{H 5} of the exposed portion 42a of the cap 42, mounted on the substrate 50 In the coin-shaped electrical element 3, the bottom surface 41 c of the outer can 41 is inclined at an angle θ with respect to the main surface 50 a of the substrate 50. However, the inclination of the coin-shaped electric element 3 can be slightly corrected depending on the degree of pushing into the solder 53 and 54 applied on each of the conductive lands 51 and 52.

Here, in the coin-shaped electrical elements 91 and 92 according to the prior art shown in FIGS. 6A and 6B, the step between the opening edge of the outer can 921 and the exposed portion of the cap 922 is 0.15 [mm]. For this reason, when directly mounted on a substrate without using a lead plate, the outer can 921 could not be reliably bonded to the conductive land of the substrate.
On the other hand, in the coin-shaped electrical element 3 according to the present embodiment, the step between the flat region 41a of the outer can 41 and the exposed portion 42a of the cap 42 is within 0.1 [mm], more preferably 0.05. Since it is set within [mm], even when the coin-shaped electric element 3 is mounted using a substrate mounting machine, the flat region 41a of the outer can 41 and the cap 42 are exposed to the solder 53 and 54 with certainty. The part 42a can be brought into contact with each other, and reliable joining after reflow is possible.

In the present embodiment, the same basic configuration as in the first embodiment and the second embodiment is adopted, so that the above effect can be produced as it is.
[Other matters]
In the first to third embodiments, the coin-type battery is applied as an example of the coin-shaped electrical elements 1 to 3, but the present invention is not limited to this, and can be applied to a coin-shaped electrical element. . For example, the present invention can also be applied to a capacitor including an electric double-layer capacitor (Electric Double-layer Capacitor), a redox capacitor, and a hybrid capacitor. The hybrid capacitor includes, for example, a Li ion capacitor.

As for the coin-type battery, a lithium secondary battery (manganese dioxide / lithium, vanadium / lithium, niobium / lithium, titanium / lithium ion, lithium ion), an air zinc secondary battery, or the like may be employed.
Moreover, in the said Embodiment 1, as shown in FIG.1 (b), the coin-shaped electrical element 1 which has a substantially square external appearance shape by planar view is employ | adopted, and in the said Embodiment 2, as shown in FIG. In addition, although the coin-shaped electric element 2 having an external shape obtained by adding a square and a semicircle in plan view is employed, the shape in plan view is not limited thereto. In other words, the outer shape in plan view may be a shape having at least three straight lines.

Further, the material of the outer cans 21, 31, 41 and the caps 22, 32, 42 is not limited to this as long as it is a conductive material. For example, it may be possible to use a plated steel plate or the like in relation to the type of the element body or the electrolyte solution injected into the inside of the element body.
In the first, second, and third embodiments, the outer shape of the outer cans 21, 31, and 41 and the exposed portions 22a, 32a, and 42a of the caps 22, 32, and 42 are similar to each other. Are not necessarily similar. The shape of the exposed portion of the cap may be circular or polygonal regardless of the external shape of the outer can.

  In addition, as shown in FIG. 1B and FIG. 4, in the first and second embodiments, the exterior shape of the outer cans 21 and 31 is three sides 31d, 31e, 31g, or four sides 21d to 21g. Although the configuration is a straight line, it is sufficient that at least one side is a straight line. Specifically, it may be a semicircular shape, a circular shape with a part missing, or an elliptical planar shape.

  The present invention is useful for realizing, for example, a coin-shaped electric element such as a coin-shaped battery mounted on a substrate for memory backup or the like.

1,2,3. Coin-shaped electric element 10. Electrode body 11. Positive electrode active material pellets 12. Negative electrode active material 13. Separator 21, 31, 41. Exterior can 22, 32, 42. Cap 23, 33, 43. Gasket 50. Substrate 51, 52. Conductive land 53, 54. solder

Claims (6)

An outer can that is made of a conductive material, has a shallow dish shape, and functions as one pole;
A cap made of a conductive material, having a shallow dish shape, sealing the opening of the outer can in a state through a gasket, and functioning as the other pole,
A coin-shaped electric element having an element body housed in an internal space formed by the outer can and the cap,
The outer can has a shape in which at least one side is a straight line in a plan view, and has a larger appearance size in a plan view than the cap.
The opening of the outer can is sealed by the cap by caulking the opening edge with a part of the cap exposed.
When the bottom surface of the outer can is used as a reference, at least a partial region of the opening edge of the outer can and the exposed portion of the cap are the same or different from each other so that a step is 0.1 mm or less. A coin-shaped electrical element characterized by a set level. 2. The coin-type electric element according to claim 1, wherein in the outer can, at least a partial region of the opening edge is a region corresponding to a side formed by the straight line. The exposed portion of the cap is a flat surface,
The flat area which becomes the same surface as the said exposed part of the said cap is 0.15 mm < ² > or more provided in the said at least one part area | region in the said exterior can. The Claim 1 or 2 characterized by the above-mentioned. Coin-shaped electrical element. In the outer can, in a depth direction thereof, a butt portion between the flat region of the opening edge and an outer surface of the side wall has an arc shape with a curvature of 0.4 mm or less. Item 4. The coin-shaped electric element according to any one of Items 1 to 3. 5. The coin shape according to claim 1, wherein the outer can has three or four sides formed in a straight line in a plan view, and a butted portion between the straight lines has an arc shape. Electrical element. The outer can is subjected to a plating process for improving wettability with solder by limiting a region to at least a partial region of the opening edge of the outer surface. The coin-shaped electric element according to any one of 1 to 5.

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