JP2008300659A - Manufacturing method of electric double-layer capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an electric double-layer capacitor for suppressing the generation of wrinkles caused by the shrinkage of a sheet-like adhesive for attaching a planar electrode terminal to a metallized laminate coating, thereby reducing a liquid leakage defect rate. <P>SOLUTION: In a manufacture process of heat-pressing and sealing the metallized laminate coating 4 through an insulating sheet-like adhesive 3 to the planar electrode terminal 2 led out of a stacked capacitor body 1, the sheet-like adhesive 3 wider than the electrode terminal 2 is tentatively fixed to the metallized laminate coating 4, the electrode terminal 2 is preheated to a temperature determined by a melting point of the sheet-like adhesive 3, and the metallized laminate coating 4 is heat-pressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electric double layer capacitor in which a multilayer capacitor main body and a plate electrode terminal are sealed with a metallized laminate sheath, and more specifically, a metal electrode via an insulating sheet adhesive on the plate electrode terminal. The present invention relates to a method for manufacturing an electrode terminal sealing process in which a laminated laminate exterior is heated and pressed.

  An electric double layer capacitor (capacitor) is a capacitor using a thin film of electrolyte formed on the surface of a plus electrode and a minus electrode, and is roughly classified into a wound type and a laminated type. A multilayer electric double layer capacitor having a large storage capacity is used as a power source for an instantaneous voltage drop countermeasure device or the like. If a multilayer electric double layer capacitor with a large storage capacity is used as the power supply for an instantaneous voltage drop countermeasure device (instantaneous voltage drop countermeasure device) that compensates for the voltage drop that affects the production line in the factory due to lightning strikes, etc. Maintenance costs can be significantly reduced compared to when used.

  Multilayer type electric double layer capacitors lead plate electrode terminals with positive and negative poles in parallel from a flat plate type capacitor body with activated carbon electrodes stacked, and the capacitor body and electrode terminals are sealed with a metalized laminate exterior. This structure is common. For the metallized laminate exterior, an aluminum laminate film in which an adhesive resin film such as a plastic film is laminated on an aluminum foil is used. The capacitor body and the plate electrode terminal are sandwiched between two metallized laminate sheaths from the top and bottom in the plate thickness direction, and the peripheral portions of the two metallized laminate sheaths are heated and pressed, so that the capacitor body and the plate electrode terminals are Seal. The capacitor body is impregnated with the electrolytic solution. The plate-like electrode terminal is sealed with two metallized laminate exteriors at the root portion from the capacitor body.

  When the plate-like electrode terminal is sealed with the metallized laminate exterior, an insulating sheet-like adhesive is interposed between the electrode terminal and the metallized laminate exterior. This sheet-like adhesive is used for the purpose of preventing the electrolytic solution of the capacitor body from leaking along the electrode terminal, and for the purpose of insulating the electrode terminal and the aluminum foil of the metallized laminate exterior. The sheet-like adhesive is a resin film having adhesiveness such as a polypropylene film formed into a rectangular thin plate, and is used for manufacturing a multilayer electric double layer capacitor as follows.

  A sheet-like adhesive is disposed on a portion to be sealed which is a lead-out base portion of the plate electrode terminal led out from the capacitor body. The width | variety of a sheet-like adhesive agent is made larger than the width | variety of an electrode terminal, and a sheet-like adhesive agent is protruded from the width direction both ends of the to-be-sealed part of an electrode terminal. In this state, the capacitor body and the electrode terminal are sandwiched between two metallized laminates. The protruding tip portion of the electrode terminal protruding from the metallized laminate exterior is heated with a heating block or the like with a built-in heater, and the sealed portion of the electrode terminal is preheated to a temperature at which the sheet adhesive is melted. After this preheating, the peripheral part of the metallized laminate exterior is pressurized with a heating head from above and below, and is heated. With this heating press, the sheet-like adhesive is melted and sealed to the sealed portion of the electrode terminal, and at the same time, the adhesive resin film on the inner surface side of the metallized laminate exterior is also melted, and the sealing process is completed.

  In the case of the above sealing process, the sheet-like adhesive that seals the portion to be sealed of the electrode terminal may generate wrinkles due to heat at the time of electrode terminal preheating, and the electrolytic solution of the capacitor body may leak from the generated wrinkles. is there. This will be described with reference to FIGS.

  FIG. 13A is a cross-sectional view in the width direction of the plate-like electrode terminal 2, and a pair of sheet-like adhesives 3 and a pair of metalized laminate sheaths 4 are arranged above and below in the plate-thickness direction of the electrode terminals 2. . FIG. 13B shows a state immediately before the heat pressing, and the sheet adhesive 3 and the metallized laminate sheath 4 are polymerized on the upper and lower sides of the electrode terminal 2. The electrode terminal 2 is preheated in the state of FIG. 13 (B), and as shown in FIG. 13 (C), the upper and lower two metallized laminate sheaths 4 are heated and pressed by the heating head 5 from above and below. The film pressing surface of the heating head 5 is a heat-resistant rubber surface, and the metallized laminate exterior 4 is evenly pressed and heated. At the time of this heating press, the sheet-like adhesive 3 that protrudes from both ends in the width direction of the electrode terminal 2 shrinks in a wave shape in the width direction due to preheating of the electrode terminal 2, and wrinkles along the length direction of the electrode terminal 2 occur. is there. Such soot may remain after the heat press and may cause leakage of the electrolytic solution impregnated in the capacitor body from which the electrode terminal 2 is led. In addition, wrinkles are relatively unlikely to occur when the plate thickness t of the electrode terminal 2 is as small as 0.5 mm or less, but are likely to occur as the plate thickness t exceeds 0.5 mm.

  As described above, the multilayer electric double layer capacitor has a large storage capacity, and the demand for a power source for an instantaneous voltage drop countermeasure device is increasing, and an increase in the amount of current that can be taken out at once is desired. Therefore, the plate thickness t of the plate electrode terminal 2 tends to increase from 0.5 mm to 1.0 mm, 1.5 mm, etc. year by year. With this tendency, the liquid leakage defect rate due to the above-mentioned defects has been increasing year by year, and the production yield of multilayer electric double layer capacitors has decreased.

As a manufacturing method for reducing such a liquid leakage defect rate, it is known that a sheet-like adhesive is fixed to a portion to be sealed of a plate-like electrode terminal by thermal bonding in advance (for example, see Patent Document 1). In the case of this manufacturing method, when the metalized laminate exterior is heated and pressed, the heat-like adhesive fixed to the plate-like electrode terminal hardly generates wrinkles and does not leak easily.
JP 2002-313677 A

  As described above, when the sheet-like adhesive is fixed to the plate-like electrode terminal by thermal bonding in advance, one sheet-like adhesive is wound around the plate-like electrode terminal, or two plate-like electrode terminals are arranged from the upper and lower sides. It is carried out by sandwiching with a sheet-like adhesive. In either case, both end portions of the sheet-like adhesive protrude from both ends of the plate-like electrode terminal in the width direction. Therefore, both ends of the sheet-like adhesive that protrudes from both ends of the electrode terminal at the time of sealing with the hot press may shrink in the width direction, and wrinkles may occur here.

  Generation of wrinkles due to the shrinkage of the sheet-like adhesive as described above can be suppressed by hot pressing a portion where wrinkles are likely to occur along the end face of the plate-like electrode terminal. For example, in FIG. 13C, when the metallized laminate sheath 4 is heated and pressed by the heating head 5, the protrusions from the end faces of the plate-like electrode terminals 2 in the width direction and the sheet-like adhesive 3 from the electrode terminals 2 are projected. A gap g is formed between the portion n. The gap g is generated in the preheating stage of the electrode terminal 2 and is finally filled with the adhesive 3 melted at the time of hot pressing. However, when the electrode terminal 2 is preheated, wrinkles may occur in the protruding portion n of the sheet-like adhesive 3, and the wrinkles are less likely to occur as the gap g is smaller, and the wrinkles are more likely to occur. Therefore, in order to reduce the gap g, it is conceivable to press so severely that the protruding portion n of the adhesive 3 is pressed against the end face of the electrode terminal 2 at the time of heating press. However, when this is done, the adhesive 3 is strongly pressed at the edge of the electrode terminal 2 to lower the insulation, and the insulation failure such that the metallized layer (aluminum foil) of the metallized laminate exterior 4 and the electrode terminal 2 are short-circuited. It is more likely to occur. The sectional view of the electrode terminal 2 shown in FIG. 13 is conceptual, and the end surface edge of the electrode terminal 2 is chamfered to make it difficult for insulation failure to occur. However, the chamfering effect decreases as the plate thickness increases. Insulation failure is likely to occur. For this reason, it is difficult to keep the gap g small, and it is actually difficult to reduce the liquid leakage failure rate due to wrinkles in the protruding portion n.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for manufacturing an electric double layer capacitor capable of suppressing the occurrence of wrinkles in a sheet-like adhesive and greatly reducing the liquid leakage failure rate. .

  In order to achieve the above object, the present invention provides an electric double layer capacitor in which a metallized laminate exterior is heated and sealed to a plate electrode terminal derived from a multilayer capacitor body through an insulating sheet adhesive. A sealing pre-process for temporarily fixing a sheet-like adhesive wider than the plate-like electrode terminal to the metallized laminate exterior, and preheating the plate-like electrode terminal to a temperature determined by the melting point of the sheet-like adhesive. It has the sealing main process which heat-presses the laminated laminate exterior.

  Here, strip-shaped aluminum foil can be applied to the plate-like electrode terminal led out from the capacitor body. In addition, the plate electrode terminal having a plate thickness of about 0.5 mm to more than 1.0 mm can be applied. Plate electrode terminals of a plus electrode and a minus electrode are led out from the capacitor body, and each is sealed with a metallized laminate exterior via a sheet-like adhesive. Metallized laminate exteriors are broadly classified into embossed and pouch types from the shape that accommodates the capacitor body, and any type can be applied. Sealing In this step, the electrode terminals are preheated and the metallized laminate exterior is heated and pressed to seal the lead-out base portions of the capacitor body and the plate electrode terminals. In a preliminary sealing step preceding this main sealing step, a sheet-like adhesive is temporarily fixed to the metallized laminate exterior. By sealing the plate electrode terminal using the metallized laminate exterior that has undergone the preliminary sealing process, the shrinkage of the sheet adhesive in the main sealing process is temporarily fixed to the metalized laminate exterior. The sheet-like adhesive is unlikely to generate wrinkles.

  In the present invention, in the pre-sealing step, the protruding portion of the sheet-like adhesive from the both ends in the width direction of the plate-like electrode terminal on the metallized laminate exterior laminated on the plate-like electrode terminal via the sheet-like adhesive Only can be temporarily fixed by thermocompression bonding.

  The sealing preliminary process here is a sealing in which the metalized laminate exterior is overlaid on the plate-like electrode terminal derived from the capacitor body via a sheet adhesive, and the electrode terminal is preheated and the metalized laminate exterior is heated and pressed. It is a pre-process of this process. That is, in a state where the main sealing process is performed, only the protruding portion of the sheet adhesive is temporarily fixed to the metallized laminate exterior by thermocompression bonding before the main sealing process is performed. There are usually a plurality of places to be temporarily fixed, and a plurality of places can be temporarily fixed simultaneously, or a plurality of places can be temporarily fixed sequentially.

  Moreover, in the case of the said sealing preliminary | backup process, it is desirable that the width | variety of the protrusion part of a sheet-like adhesive shall be 10 mm or more.

  The protruding portion of the sheet-like adhesive is preferably a polymerized portion where two layers of the sheet-like adhesive protruding from the front and back surfaces of the plate-like electrode terminal overlap each other. The width of such a protruding portion may be as small as about 5 mm, but it is desirable to make it 10 mm or more in order to effectively suppress wrinkle generation due to shrinkage.

  In the present invention, the sheet-like adhesive can be temporarily fixed to the metallized laminate exterior before being assembled to the capacitor body and the sheet-like adhesive in the preliminary sealing step.

  The preliminary sealing step here is a step of temporarily fixing the sheet-like adhesive to the metallized laminate exterior that has been processed and formed. A preliminary sealing step is performed in a preliminary and optional pre-stage where the metallized laminate sheath is used to seal the capacitor body and plate electrode terminals. In the case of this sealing preliminary process, a sheet-like adhesive is temporarily fixed to a predetermined portion of the metallized laminate exterior. The metallized laminate exterior to which the sheet-like adhesive is temporarily fixed is attached to the capacitor main body and the plate-like electrode terminal in the next sealing main step, and the sealing main step by preheating and heating press is executed. The main sealing step here is performed in the same manner as in the prior art. In the main sealing step, the sheet-like adhesive is temporarily fixed to the metallized laminate exterior during preheating of the electrode terminals, so that it does not easily shrink and does not easily become wrinkles.

  Further, when the sheet-like adhesive is temporarily fixed to the metallized laminate exterior, it can be temporarily fixed by thermal adhesion of the sheet-like adhesive itself. Alternatively, it can be temporarily fixed by a fixing member that is a separate member from the sheet-like adhesive. A heat-resistant double-sided adhesive tape or the like can be applied as the fixing member here.

  According to the present invention, when the plate-like electrode terminal led out from the capacitor body is main-sealed with a heating press of the metallized laminate exterior via the sheet-like adhesive, the metallized laminate exterior is provided prior to the main sealing. Since the sheet-like adhesive is temporarily fixed, it is difficult to shrink due to the preheating of the electrode terminals during the main sealing, so that wrinkles are less likely to occur and the liquid leakage occurrence rate can be reduced. In addition, it is easy to reduce the rate of insulation failure by performing a heat press of the metalized laminate without worrying about the occurrence of wrinkling of the sheet adhesive and without impairing the insulation of the sheet adhesive. There is an effect.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The first embodiment will be described with reference to FIGS. 1 to 7, and then the second embodiment will be described with reference to FIGS. 8 to 12. Throughout all the drawings including FIG. 13, the same or corresponding parts are denoted by the same reference numerals to avoid duplication of explanation.

  1A to 1C conceptually illustrate the production method of the present invention. FIG. 1A shows a conceptual cross-sectional view of the plate-like electrode terminal 2, the sheet-like adhesive 3, and the metallized laminate exterior 4 before being assembled. FIG. 1B is a cross-sectional view in a preliminary sealing process that is a feature of the present invention. FIG. 1C-1 and FIG. 1C-2 are cross-sectional views in the main sealing process that can be performed in the same manner as in the prior art.

  A pair of left and right plate electrode terminals 2 shown in FIG. 1 are metal foils of a plus electrode and a minus electrode led out in parallel in the same direction from the multilayer capacitor body 1 shown in FIG. Hereinafter, the pair of left and right plate-like electrode terminals 2 will be referred to as electrode terminals 2a in FIG. 1 and electrode terminals 2b in FIG. The pair of electrode terminals 2a and 2b are metal foils having the same plate thickness and are arranged in parallel on the same plane.

  The multilayer capacitor body 1 shown in FIG. 2 is rectangular, and a pair of left and right plate electrode terminals 2 are derived from one side. The metallized laminate exterior 4 shown in FIG. 2 is an embossed type, and is composed of a pair of upper and lower sides. The pair of upper and lower metallized laminate sheaths 4 each have a rectangular recess 41 that houses the upper half and the lower half of the capacitor body 1, and a rectangular frame-shaped peripheral edge 42 that surrounds the recess 41. Further, as shown in the cross-sectional view of FIG. 1, the metallized laminate exterior 4 is an aluminum foil metallized layer 4a on the outer surface side and a resin film layer 4b having adhesiveness on the inner surface side.

  The sheet-like adhesive 3 shown in FIG. 1 (A) includes a total of four sheets arranged in pairs on the upper and lower sides of the pair of left and right electrode terminals 2a and 2b. Hereinafter, a pair disposed above and below one electrode terminal 2a is referred to as an adhesive 3a, and a pair disposed above and below the other electrode terminal 2b is referred to as an adhesive 3b as necessary. As shown in FIGS. 2 and 3, the pair of upper and lower sheet-like adhesives 3 a and 3 b are provided at the root portions (sealed portions) of the pair of left and right electrode terminals 2 a and 2 b led out from the capacitor body 1. Arranged on the upper and lower surfaces. Each adhesive 3a, 3b is rectangular and its width is set to be larger than the width of the electrode terminals 2a, 2b. When the adhesives 3a and 3b are stacked on the upper and lower surfaces of the corresponding electrode terminals 2a and 2b, both end portions of the adhesives 3a and 3b protrude from both ends in the width direction of the electrode terminals 2a and 2b. Both end portions that protrude are referred to as protrusion portions 3n. The protruding portions 3n of the upper and lower two sheet-like adhesives 3 disposed on the upper surface and the lower surface of the electrode terminal 2 overlap each other to form a two-layer overlapping portion.

  A preliminary sealing process shown in FIG. 1B will be described. The peripheral edge portions 41 of the pair of upper and lower metallized laminate sheaths 4 are overlapped on the upper surface and the lower surface of the lead-out base portion of the pair of left and right plate electrode terminals 2 with the sheet-like adhesive 3 interposed therebetween. For example, the capacitor body 1, the electrode terminal 2, the sheet-like adhesive 3, and the metallized laminate exterior 4 are set in the same sealing equipment (not shown) as in the conventional case. Before the electrode terminal 2 is preheated with this sealing equipment and the metallized laminate sheath 4 is heated and pressed, as shown in FIG. 1B, only the protruding portion 3n of each adhesive 3 is metallized laminate sheath. Temporarily fix to 4. In this temporary fixing, a heating tool 6 as a local heating means is pressed from the top and bottom to a portion where the adhesive protruding portion 3n of the upper and lower metallized laminates 4 is located, and only the protruding portion 3n of the adhesive 3 is made of metal. What is necessary is just to carry out by thermocompression-bonding to the laminated laminate exterior 4.

  When the protruding portion 3n of the adhesive 3 is temporarily fixed to the metallized laminate exterior 4, the process proceeds to the main sealing step of FIG. 1 (C-1), and the electrode terminal 2 is preheated by heating of the heating block 7. For example, when the tip portion of the electrode terminal 2 is heated to about 200 ° C., the lead-out base portion is preheated to 190 ° C. close to the melting point of the adhesive 3 by heat conduction. After this preheating, the heating head 5, which is the main sealing step of FIG. Such preheating and heating press may be performed in the same manner as in the past using the same sealing equipment as in the past.

  At the time of preheating in FIG. 1 (C-1), there is a gap g between the protruding portion 3n of the adhesive 3 and the end surface of the electrode terminal 2 as in the prior art. The protruding portion 3n tends to shrink under the influence of the gap g. However, since the protruding portion 3n at this time is temporarily fixed to the metallized laminate exterior 4, it is constrained by the metallized laminate exterior 4 and does not shrink. Therefore, no wrinkle is generated in the protruding portion 3n, and it is easy to reduce the liquid leakage defect rate. Further, since the shrinkage can be suppressed without reducing the gap g, the possibility of being subjected to dielectric breakdown at the end face edge of the electrode terminal 2 is reduced, and it becomes easy to lower the insulation failure rate. The same applies to other embodiments described later.

  Another embodiment of the sealing preliminary process in FIG. 1B will be described with reference to FIGS.

  In FIG. 4, a cylindrical sheet-like adhesive 3 is inserted into a pair of left and right electrode terminals 2 led out from the capacitor body 1. After this cylindrical adhesive 3 is inserted into the electrode terminal 2, as shown in FIGS. 5A and 5B, it is pressed against the upper and lower surfaces of the electrode terminal 2 to become flat. And the protrusion part 3n becomes a superposition | polymerization part superposed | polymerized in two layers from the both ends of the electrode terminal 2 by the sealing preliminary | backup process of FIG.1 (B). This polymerization portion becomes the protruding portion 3n as it is. The width w of the protruding portion 3n protruding from both ends in the width direction of one electrode terminal 2 is set to be substantially the same. The width w is desirably 10 mm or more as will be described later.

  Also when the cylindrical adhesive 3 of FIG. 4 is used, the sealing preliminary process is performed similarly to FIG. Since the cylindrical adhesive 3 can be easily attached to the corresponding electrode terminal 2, the preliminary sealing process can be executed with good workability.

  In FIG. 6, a common strip-shaped adhesive 3 is disposed on each of the pair of left and right electrode terminals 2 led out from the capacitor body 1. The common adhesive 3 is a common pair of left and right adhesives 3a and 3b disposed on the pair of left and right electrode terminals 2a and 2b shown in FIG. As shown in FIG. 7A, when the common adhesive 3 is disposed on the upper and lower surfaces of the lead-out base portions of the pair of left and right electrode terminals 2a, 2b, both ends of the common adhesive 3 are a pair of left and right electrodes. A protruding portion 3n that protrudes from the outer end faces of the terminals 2a and 2b and superposes into two layers is obtained. Further, as shown in FIG. 7B, the adhesive 3 between the pair of left and right electrode terminals 2a and 2b protrudes from the inner end surfaces of the pair of left and right electrode terminals 2a and 2b and is polymerized into two layers. The protruding portion 3n '. When the width of the outer protruding portion 3n is set to 10 mm, the width of the inner protruding portion 3n '(however the width cannot be specified) is set to 10 mm or more.

  Even when the common adhesive 3 of FIG. 6 is used, the sealing preliminary process is executed as in FIG. Since the common adhesive 3 can be attached to the pair of left and right electrode terminals 2 at the same time, the preliminary sealing process can be executed with good workability.

  Next, the manufacturing method of the present invention shown in FIGS. 8A to 8C will be described. FIG. 8A is a conceptual cross-sectional view of the sheet-like adhesive 3 and the metallized laminate exterior 4 before being assembled. FIG. 8B is a conceptual cross-sectional view of the plate-like electrode terminal 2, the sheet-like adhesive 3, and the metallized laminate exterior 4 in the sealing preliminary process that is a feature of the present invention. 8C-1 and 8C-2 are cross-sectional views in the main sealing step similar to FIGS. 1C-1 and 1C-2.

  In the case of the manufacturing method shown in FIG. 8, the sheet-like adhesive 3 is temporarily fixed to the metallized laminate exterior 4 until the main sealing step. For example, as shown in FIG. 8A, the sheet-like adhesive 3 is temporarily fixed by thermocompression bonding to the electrode terminal sealing portion of the metallized laminate exterior 4 processed and molded into an embossed type. The sheet-like adhesive 3 temporarily fixed to one metallized laminate exterior 4 is the same two sheets as the left and right sheet-like adhesives 3a and 3b shown in FIG. Two pieces are temporarily fixed to the metallized laminate exterior 4 respectively.

  The pair of left and right plate electrode terminals 2 shown in FIG. 8 is a metal foil of a plus electrode and a minus electrode led out in parallel in the same direction from the multilayer capacitor body 1 shown in FIG. The pair of electrode terminals 2 are metal foils having the same thickness and are arranged in parallel on the same plane. Also, the multilayer capacitor body 1 shown in FIG. 9 is rectangular, and a pair of left and right plate electrode terminals 2 are led out from one side. The metallized laminate exterior 4 shown in FIG. 9 is an embossed type, and is composed of a pair of upper and lower sides. The pair of upper and lower metallized laminate sheaths 4 each have a rectangular recess 41 that houses the upper half and the lower half of the capacitor body 1, and a rectangular frame-shaped peripheral edge 42 that surrounds the recess 41. Furthermore, as shown in the cross-sectional view of FIG. 8, the metallized laminate exterior 4 is an aluminum foil metallized layer 4a on the outer surface side and a resin film layer 4b having adhesiveness on the inner surface side.

  As shown in FIG. 8B, two sheet-like adhesives 3 are temporarily fixed to the embossed upper and lower two metallized laminate sheaths 4 by thermocompression bonding, respectively. Such temporary fixing may be performed at an arbitrary time after the metallized laminate exterior 4 is processed and molded and before being set in the sealing equipment in the main sealing process. FIG. 8B is a cross-sectional view when the metallized laminate exterior 4 to which the sheet-like adhesive 3 is temporarily fixed is set in the sealing equipment in the main sealing process. A pair of left and right adhesives 3 temporarily fixed to the upper and lower metallized laminate sheaths 4 are polymerized on a sealed portion which is a lead-out root portion of each pair of left and right electrode terminals 2. Each adhesive 3 is rectangular and its width is set larger than the width of the corresponding electrode terminal 2. When the adhesives 3 are stacked on the upper and lower surfaces of the corresponding electrode terminals 2, both end portions of the adhesives 3 protrude from both ends in the width direction of the electrode terminals 2. Both end portions that project out become the projecting portion 3n. The protruding portions 3n of the upper and lower two sheet-like adhesives 3 superposed on the upper and lower surfaces of the electrode terminal 2 overlap each other to form a two-layered overlapping portion.

  A pair of upper and lower metallized laminate sheaths 4 on which the sheet-like adhesive 3 is temporarily fixed are set together with the capacitor body 1 in the same manner as in a conventional sealing facility (not shown), for example, as shown in FIG. ) And the main sealing step shown in FIG. First, the electrode terminal 2 is preheated by heating the heating block 7 in FIG. For example, when the tip portion of the electrode terminal 2 is heated to about 200 ° C., the lead-out base portion is preheated to 190 ° C. close to the melting point of the adhesive 3 by heat conduction. After this preheating, the heating head 5, which is the main sealing step of FIG.

  At the time of preheating in FIG. 8C-1, there is a gap g between the protruding portion 3 n of the adhesive 3 and the end surface of the electrode terminal 2 as in the conventional case. The protruding portion 3n tends to shrink due to the influence of the gap g, but the protruding portion 3n is temporarily fixed to the metallized laminate exterior 4. For this reason, it is very small so that it does not shrink due to being constrained by the metalized laminate exterior 4 and does not become wrinkles even if it shrinks. Therefore, no wrinkle is generated in the protruding portion 3n, and it is easy to reduce the liquid leakage defect rate. Further, since the shrinkage can be suppressed without reducing the gap g, the possibility of being subjected to dielectric breakdown at the end face edge of the electrode terminal 2 is reduced, and it becomes easy to lower the insulation failure rate.

  Another embodiment of the preliminary sealing step of FIG. 8B will be described with reference to FIGS.

  The sheet-like adhesive 3 shown in FIGS. 10 (A) and 10 (B) has two sheets of adhesive 3 temporarily fixed to one metallized laminate exterior 4 shown in FIG. It has become. As this common adhesive 3, the adhesive having the same length as the entire length of one side of the metallized laminate exterior 4 can be used. Further, the common adhesive 3 is temporarily fixed to the metallized laminate sheath 4 by thermocompression bonding, and the common adhesive 3 is partially attached to the metallized laminate sheath 4 only at both ends and the central portion thereof. Can be temporarily fixed. An example of this partially temporarily fixed form is shown in FIGS. 11A and 11B and FIGS. 12A and 12B.

  A sheet-like adhesive 3 shown in FIGS. 11A and 11B has an extended end portion 3 ′ in which both ends in the length direction of the common adhesive 3 in FIG. 10 are extended by about 1 to 2 cm. The sheet-like adhesive 3 in FIG. 11 is in a state in which it is in contact with the inner peripheral surface of the metallized laminate exterior 4, and the extended end portions 3 ′ at both ends are folded back to the outer peripheral surface side. For example, it is temporarily fixed with a double-sided adhesive tape.

  The sheet-like adhesive 3 shown in FIGS. 12A and 12B has a cylindrical shape. The cylindrical adhesive 3 is flattened so as to have a length approximately equal to the entire length of the peripheral edge 42 on one side of the metallized laminate exterior 4 and is inserted into the peripheral edge 42. The flat cylindrical adhesive 3 is brought into contact with the upper surface and the lower surface of the peripheral portion 42, and both bent ends of the cylindrical adhesive 3 are locked to both ends of the peripheral portion 42 and temporarily fixed.

  Even when the common adhesive 3 in FIGS. 10 to 12 is used, the same sealing preliminary process as that in FIG. 8 is performed. Such a common adhesive 3 can be attached to the pair of left and right electrode terminals 2 at the same time, so that the preliminary sealing process can be executed with good workability.

  [Example] A multilayer electric double layer capacitor was manufactured by the manufacturing method shown in FIGS. A 1 mm thick aluminum foil is used for the plate-like electrode terminal, and both ends in the width direction are chamfered. The plate-like electrode terminal was overlaid with a sheet-like adhesive and an aluminum laminate sheath, and sealed by heating and pressing. In the case of the method of the present invention in which the sheet-like adhesive is temporarily fixed to the aluminum laminate exterior, the width of the protruding portion of the sheet-like adhesive from the plate-like electrode terminal (the length in the protruding direction) is changed stepwise. As a result, the following results were obtained.

In the case where the width of the protruding portion is 5 mm, the liquid leakage defect rate is about 33% which is the same as the conventional method.
-When the width of the protruding portion was 10 mm, the liquid leakage failure rate was improved to 5%.
-When the width of the protruding portion was 15 mm, the liquid leakage failure rate was further improved to 2%.
-When the width of the protruding portion was 20 mm, the liquid leakage failure rate was greatly improved to 0.1%.

From the above results, it can be seen that if the width of the protruding portion in the protruding direction is set to 10 mm or more, the liquid leakage defect rate can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is conceptual sectional drawing of the plate-shaped electrode terminal 2, the sheet-like adhesive agent 3, and the metallization laminated exterior 4 for demonstrating the manufacturing method which concerns on this invention, (A) is sectional drawing in a preparatory process, (B) Is a sectional view in the preliminary sealing step, and (C-1) and (C-2) are sectional views in the main sealing step. FIG. 2 is an exploded perspective view of a multilayer electric double layer capacitor in the manufacturing method of FIG. 1. It is a front view which shows the relationship between the electrode terminal 2 of FIG. 2, and the sheet-like adhesive agent 3. FIG. It is a perspective view which shows the modification of the sheet adhesive 3 of FIG. (A) is a front view which shows the relationship between the electrode terminal 2 and the sheet-like adhesive 3 of FIG. 4, (B) is a front view at the time of a hot press. It is a perspective view which shows the modification of the sheet adhesive 3 of FIG. (A) is a front view which shows the relationship between the electrode terminal 2 and the sheet-like adhesive 3 of FIG. 6, (B) is a front view at the time of a hot press. BRIEF DESCRIPTION OF THE DRAWINGS It is conceptual sectional drawing of the plate-shaped electrode terminal 2, the sheet-like adhesive agent 3, and the metallization laminated exterior 4 for demonstrating the manufacturing method which concerns on this invention, (A) is sectional drawing in a preparatory process, (B) Is a sectional view in the preliminary sealing step, and (C-1) and (C-2) are sectional views in the main sealing step. FIG. 9 is an exploded perspective view of the multilayer electric double layer capacitor in the manufacturing method of FIG. 8. (A) is a perspective view which shows the modification of the sheet adhesive 3 of FIG. 9, (B) is the sectional drawing. (A) is a perspective view which shows the modification of the sheet adhesive 3 of FIG. 9, (B) is the sectional drawing. (A) is a perspective view which shows the modification of the sheet adhesive 3 of FIG. 9, (B) is the sectional drawing. It is conceptual sectional drawing of the plate-shaped electrode terminal 2, the sheet-like adhesive agent 3, and the metallization laminate exterior 4 for demonstrating the conventional manufacturing method, (A) is sectional drawing in a preparatory process, (B) is sealing. Sectional drawing just before stopping, (C) is a sectional view at the time of sealing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitor body 2 Plate-shaped electrode terminal 3 Sheet-like adhesive 3n Protruding part 4 Metallization laminate exterior 4a Metallization layer, aluminum foil 4b Resin film layer 5 Heating head 6 Heating tool 7 Heating block 10 Fixing member g Crevice

Claims (6)

A method for producing an electric double layer capacitor in which a metalized laminate exterior is heated and sealed via an insulating sheet adhesive to a plate-like electrode terminal derived from a multilayer capacitor body,
A preliminary sealing step for temporarily fixing the adhesive wider than the electrode terminal to the metallized laminate exterior; and preheating the electrode terminal to a temperature determined by the melting point of the adhesive and heating and pressing the metallized laminate exterior The manufacturing method of the electrical double layer capacitor characterized by having a sealing main process.   In the preliminary sealing step, only the protruding portion of the sheet-like adhesive from both ends in the width direction of the electrode terminal is thermocompression-bonded to the metallized laminate exterior that is stacked on the electrode terminal via the adhesive. The method for manufacturing an electric double layer capacitor according to claim 1, wherein the electric double layer capacitor is temporarily fixed.   The method for manufacturing an electric double layer capacitor according to claim 2, wherein the width of the protruding portion is 10 mm or more.   2. The method of manufacturing an electric double layer capacitor according to claim 1, wherein, in the preliminary sealing step, the adhesive is temporarily fixed to the metallized laminate exterior before being assembled to the capacitor main body and the sheet-like adhesive. .   5. The method of manufacturing an electric double layer capacitor according to claim 4, wherein the adhesive is temporarily fixed to the metallized laminate exterior partially by thermal bonding of the adhesive itself.   The method for producing an electric double layer capacitor according to claim 4, wherein the adhesive is partially temporarily fixed to the metallized laminate exterior with a temporary fixing member different from the adhesive.

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