JP2008294002A - Electrochemical cell with terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrochemical cell with a terminal excellent in durability and capable of reflow-soldering, and having a minimum occupied space when it is surface-mounted to a substrate. <P>SOLUTION: A terminal 1 welded to a cell case not in the vicinity of a substrate comprises three surfaces which are a surface A in contact with the cell case flat surface and in parallel to it, a surface B continuous from the surface A and facing a cell thickness direction not on the same plane, and a surface C continuous from the surface B and not on the same plane, and facing the same parallel direction as the surface A. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a button-type or coin-type electrochemical cell, and more particularly to a terminal-attached electrochemical cell having terminals for surface mounting on a circuit board.

  In recent years, mobile devices such as mobile phones have been remarkably reduced in size, thickness, and functionality, and accordingly, components mounted on the devices have been rapidly increasing in density and functionality.

  In addition, the method of mounting these components on a printed circuit board has been further progressed in surface mounting. In particular, with respect to the soldering process, as a method that can solder a large number of electronic components at a high density, soldering can be performed. A method of performing soldering (hereinafter referred to as reflow soldering) using a reflow heat source set at a temperature equal to or higher than the melting point of solder after printing on the substrate in advance is often employed.

  On the other hand, various batteries are used for these mobile devices. For example, primary batteries such as alkaline batteries and lithium batteries, or various secondary batteries such as lithium ion batteries and nickel metal hydride batteries are used as the main power source. / Or recharging. In addition to the main power supply application, various primary or secondary batteries are used for a memory backup, a real-time clock backup application, and the like. In many cases, these batteries are incorporated in a device in advance.

  Conventionally, when these batteries are mounted on a device, the batteries themselves have poor resistance to high temperatures, so reflow soldering as described above is impossible, and soldering is performed manually after reflow soldering parts other than the battery. After attaching or reflow soldering the holder, the battery is manually attached to the holder, which has a problem in terms of work efficiency.

  Under such circumstances, research on a battery that enables reflow soldering has been conducted intensively. For example, it is disclosed in Japanese Patent Application Laid-Open No. 8-17470 and Japanese Patent Application Laid-Open No. 8-306384 concerning the application of the joint applicant of the present application. As shown, batteries that can be reflow soldered have been developed.

  While many of the common electronic components are square, these battery shapes are generally coin-shaped or button-shaped, so there is a lot of dead space when surface-mounted on the board, and surface mounting on the board. Therefore, there is a problem that a large space is occupied by a terminal for performing the above operation. In particular, in recent years when electronic devices are remarkably reduced in size, it is strongly desired to solve the above problems.

  The inventors of the present invention have completed the present invention as a result of intensive studies in view of the above-described actual situation. An object of the present invention is to provide an electrochemical cell with a terminal that has excellent heat resistance and can be reflow soldered, and has a minimum occupied space when surface-mounted on a substrate.

  The above purpose is to form a button-type or coin-type electrochemical cell having two cell cases as a positive electrode and a negative electrode, and to weld the two cell cases to surface-mount the electrochemical cell on a substrate. One of the two cell cases is a cell case that is not close to the substrate when the electrochemical cell is surface-mounted on the substrate. The other is a case close to the substrate when the electrochemical cell is surface-mounted on the substrate, and one of the two terminals is an A surface welded to a flat surface of the cell case not adjacent to the substrate, and the A surface. The B surface facing the cell height direction and the C surface for soldering facing the B surface and facing the same parallel direction as the A surface, and the other of the two terminals Is close to the substrate The other terminal welded to the cell case adjacent to the substrate is welded to the cell case adjacent to the substrate. A soldering C surface of one terminal welded to a cell case that has at least one step between the surface and the soldering surface continuous with the surface, and the substrate; The soldering surface of the other terminal welded to the cell case adjacent to the terminal is soldered to the substrate when the electrochemical cell with terminal is surface-mounted on the substrate. Achieved by the cell.

  In the present invention, a terminal 1 welded to a cell case that is not close to the substrate faces the cell surface in the thickness direction that is in contact with and parallel to the cell case flat surface, and is continuous with the A surface and is not coplanar. The B surface and the B surface are continuous and not in the same plane, and have three surfaces, the C surface facing in the same parallel direction as the A surface.

  Here, the same parallel direction means that the A plane and the C plane exist in the same spatial direction with respect to two spaces separated by a plane including the B plane. The A plane and the C plane need not be parallel.

  The shape of the terminal is not particularly limited, and examples thereof include those having a substantially U-shaped cross section including all of ABC. At this time, the difference in length between the A plane and the C plane on the cross section is not particularly limited. Further, the vertical height of the B surface is preferably larger than the shoulder height of the cell, and more preferably larger than the cell height. However, if it is too high, the total height of the cell with terminals becomes large. In consideration of dimensional balance, soldering strength, etc., the vertical height of the B surface is preferably about the level difference of the terminal welded to the cell case close to the substrate + cell thickness ± 200 μm.

  In the present invention, the terminal 2 welded to the cell case adjacent to the substrate preferably has at least one step between a surface welded to the cell case and a surface grounded to the substrate. The step of the terminal means a vertical distance between the grounding surface of the terminal 2 and the surface welded to the cell case.

  The dimension of the step is not particularly limited, but it is convenient to set it to 200 to 500 μm for the reason described below. When the step is smaller than 200 μm, the distance between the cell case not close to the substrate and the C surface of the terminal welded to the cell case is short. Therefore, after the reflow soldering operation, the cell case not close to the substrate and the cell case There is a high possibility of a short circuit due to direct contact of the C surface of the terminal to be welded or a short circuit through the solder once melted.

  On the other hand, when the thickness is 500 μm or more, the height dimension of the cell with terminal is increased, which is not preferable. If the terminal does not have a step, the C surface of the terminal welded to the cell case that is not adjacent to the other substrate cannot enter the gap between the substrate and the cell case adjacent to the substrate. As a result, the area occupied by the cell with terminals on the substrate increases.

  In the present invention, the positional relationship between the terminal 1 and the terminal 2 is not particularly limited. In order to prevent a short circuit between the terminals, it is preferable to arrange the terminals 1 and 2 so as to form an angle of 180 degrees. However, depending on the space shape of the substrate, for example, the terminals 1 and 2 are 90 degrees. You may arrange so that an angle may be formed. In this case, the terminal 1 and the U-shaped opening may be closed, and a so-called substantially square-shaped opening may be adopted.

  The terminal material used in the present invention is not particularly limited as long as it is a commonly used metal material, but various stainless materials, nickel materials, nickel-iron alloys, copper, and the like are preferably used. Although the thickness of a terminal is not specifically limited, The case where it is the thickness of 50-300 micrometers normally is easy to set welding conditions, and is preferable. Further, at least the surface where the terminal is grounded to the substrate is plated with solder or the like in order to provide sufficient adhesion strength between the substrate and the cell with terminal.

  In the present invention, when at least the B surface of the terminal 1 welded to the cell case that is not close to the substrate has an opening, the area occupied when the cell with terminals is surface-mounted on the substrate can be made smaller. is there. The vertical height Lb of the opening may be at least Lb> H with respect to the height of the cell case having the larger diameter of the positive electrode cell case and the negative electrode cell case, but preferably Lb with respect to the cell height Hc. > Hc is preferred. In this case, since the distance Rb from the opening of the B surface and the cell center can be made equal to or less than the radius R of the single cell, the area occupied by the cell with terminals on the substrate can be reduced.

  The opening may be an opening that is continuous with the eye A and / or the C plane. In this case, the other end portion that is not the B surface side of the A surface and / or the C surface may not be closed. If the other end of the C surface that is not on the B surface side is not closed, the area of the portion that contacts the substrate is reduced, but since it is three-point grounding, reflow soldering is possible without reducing the strength. .

  The power generation element in the present invention is not particularly limited as long as it can store electrochemical energy and extract the energy to the outside, and it does not matter whether it is a primary or secondary species. An organic electrolyte battery made of a protic solvent is preferred.

  For example, a lithium primary battery using manganese dioxide for the positive electrode and metal lithium for the negative electrode, a manganese oxide for the positive electrode, a manganese-lithium alloy system or a manganese-silicon oxide system using a lithium aluminum alloy or silicon oxide for the negative electrode, etc. 3V class batteries, organic capacitors using porous carbon materials such as activated carbon for the positive and negative electrodes and polyacene organic semiconductors, other niobium oxide-lithium alloy systems, manganese oxide-lithium titanate systems, and the like.

  The shape of the power generation element in the present invention is not particularly limited, and examples thereof include those in which a positive electrode and a negative electrode formed into a tablet shape are opposed to each other through a separator impregnated with an electrolytic solution. In this case, the other electrode surface not in contact with the separator is often adhered to the can.

  In addition, the power generating element may be one in which a strip-like positive electrode and a negative electrode formed on a current collector such as a foil or a mesh are wound through a separator, and the outermost periphery of the strip-like electrode is a positive electrode cell case and / or a negative electrode cell case. It is convenient in terms of operation to directly contact the inner surface for sealing.

  The positive electrode cell case and the negative electrode cell case used in the present invention are not particularly limited as long as they are metal materials generally used for batteries, but are preferably various stainless materials excellent in corrosion resistance, pitting corrosion resistance and the like.

  In addition, the positive electrode cell case and the negative electrode cell case are usually subjected to pressing such as caulking through a gasket in order to shut off the power generation element from the outside atmosphere without short-circuiting and maintain airtightness and liquid tightness.

  Examples of the material used for the gasket material include polyetheretherketone, polyphenylene sulfide, and a fluororesin. A material formed by adding glass fiber as necessary may be used to improve moldability.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to these examples.

Example 1
FIG. 1 shows an embodiment of the present invention in which a terminal is welded to a coin-type cell having a diameter of 4.8 mm and a height of 1.4 mm using an organic capacitor whose main component is a polyacene-based organic semiconductor as a power generation element. .

  The total height of the cell with terminals was 1.7 mm. The power generation element was produced by the method disclosed in the example of Japanese Patent Application No. 7-137184, for example. As the terminal, a SUS304 material having a thickness of 100 μm produced by press molding was used. Welding of terminals to cells was performed by a YAG laser welder. In this case, when the area occupied only by the cell main body on the substrate was 100, the area ratio occupied by the terminal-attached cell was 110.

(Example 2)
FIG. 2 shows another embodiment in which an organic capacitor made of a polyacene-based organic semiconductor is used as a power generation element as in the first embodiment. In this case, when the area occupied only by the cell main body on the substrate was 100, the area ratio occupied by the cell with terminals was 103%.

(Example 3)
FIG. 3 shows another embodiment in which an organic capacitor made of a polyacene organic semiconductor is used as a power generation element as in the first embodiment. Terminals 1 and 2 are arranged at an angle of 90 degrees. In this case, when the area occupied only by the cell main body on the substrate was 100, the area ratio occupied by the cell with terminals was 106%.

(Comparative Example 1)
FIG. 3 shows an example of a cell with a terminal in which a terminal having a conventional shape is welded. In this case, when the area indicated only by the cell main body on the substrate was 100, the area ratio occupied by the cell with terminals was 137%.

  As can be seen from the above results, in the conventional terminal cell shown in the cited example, the occupied area of the terminal cannot be reduced without reducing the soldering strength. The effect could not be utilized. On the other hand, in the case of the configuration of the present invention, the area occupied by the terminal-equipped cell on the substrate can be reduced. In particular, when at least the B surface of the substantially U-shaped terminal welded to the cell case that is not close to the substrate has an opening, the effect is particularly great, and many electric devices including electric products that are miniaturized and integrated are used. It can be used effectively for products.

It is drawing of the electrochemical cell with a terminal which concerns on this invention. A hatched portion indicates a surface to which solder plating for grounding the substrate is attached. It is drawing of another embodiment which concerns on this invention. A hatched portion indicates a surface to which solder plating for grounding the substrate is attached. It is drawing of another embodiment which concerns on this invention. A hatched portion indicates a surface to which solder plating for grounding the substrate is attached. It is a figure which shows the conventional cell with a terminal. A hatched portion indicates a surface that contacts the substrate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Positive electrode cell case, 2 ... Negative electrode cell case, 3 ... Terminal 1, 4 ... Terminal 2, 5 ... Gasket, 6 ... Terminal 1-A surface, 7 ... Terminal 1-B surface, 8 ... Terminal 1-C surface, 9: Solder plating part.

Claims (4)

A button-type or coin-type electrochemical cell having two cell cases to be a positive electrode and a negative electrode, and two welded to the two cell cases, respectively, for surface mounting the electrochemical cell on a substrate In an electrochemical cell with a terminal provided with a terminal,
One of the two cell cases is a cell case that is not close to the substrate when the electrochemical cell is surface-mounted on the substrate, and the other of the two cell cases is a substrate when the electrochemical cell is surface-mounted on the substrate. A close case,
One of the two terminals includes an A surface welded to a flat surface of the cell case that is not close to the substrate, a B surface that is continuous with the A surface and faces the cell height direction, and is continuous with the B surface; A soldering C surface facing in the same parallel direction as the A surface,
The other of the two terminals has a surface welded to the cell case adjacent to the substrate, and a soldering surface continuous with the surface.
The other terminal welded to the cell case adjacent to the substrate has at least one step between the surface welded to the cell case adjacent to the substrate and the soldering surface continuous with the surface. And
The soldered C surface of one terminal welded to a cell case that is not close to the substrate and the soldering surface of the other terminal welded to the cell case that is close to the substrate are the electrochemical cells with terminals. Soldered to the board when surface mounting on top,
An electrochemical cell with a terminal characterized by the above. The dimension in the cell height direction of the B surface of one terminal welded to the cell case not adjacent to the substrate is the level difference of the other terminal welded to the cell case adjacent to the substrate + the height of the electrochemical cell ± 200 μm. Degree
The terminal-attached electrochemical cell according to claim 1. The dimension of the step of the other terminal welded to the cell case adjacent to the substrate is in the range of 200 to 500 μm.
The terminal-attached electrochemical cell according to claim 2. One terminal welded to the cell case not close to the substrate and the other terminal welded to the cell case close to the substrate are arranged to form an angle different from 180 degrees.
The terminal-attached electrochemical cell according to any one of claims 1 to 3.

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