JP4566832B2 - Surface mount capacitor and method of manufacturing the same - Google Patents

Description

  The present invention relates to a solid electric field capacitor having an anode body made of a valve action metal, a dielectric layer made of an oxide film of the valve action metal, and a cathode layer including a conductive polymer layer made of a conductive polymer. The present invention relates to a surface mount capacitor that can be mounted on a printed circuit board.

  This type of surface-mounted capacitor includes an anode body having an anode body having a plate shape or a foil shape, a capacitor element including a dielectric layer, a resist, and a cathode layer. The resist is made of an insulating resin, and is formed on the surface of the dielectric layer formed on the anode body so as to divide the surface of the anode body into a capacity formation region and an anode lead region. In addition to the capacitor element, the surface mount capacitor includes an anode terminal joined to the anode lead region of the anode body, a cathode terminal joined to the cathode layer formed in the capacitance forming region, and a part of the anode terminal and the cathode terminal. And a resin package for covering.

  The basic structure of a surface mount capacitor is as described above. More specifically, as a surface mount capacitor, a surface mount capacitor having two terminals, an anode terminal and a cathode terminal, and an input and output There are surface mount type transmission line type capacitors having two anode terminals and three terminals of cathode terminals. The transmission line type capacitor may be used as a three-terminal capacitor or a transmission line type filter, but is simply referred to as a transmission line type capacitor in this specification.

  Furthermore, a plurality of the capacitor elements described above are prepared, and these elements are laminated in the thickness direction and electrically connected in parallel, and further, a multilayer capacitor or a multilayer transmission line formed by joining a common terminal to the plurality of elements. There is a type capacitor. The laminated type has a larger capacity than the single layer type.

  In the present specification, any of a two-terminal capacitor, a three-terminal transmission line capacitor, a multilayer capacitor, and a multilayer transmission line capacitor may be simply referred to as a capacitor.

  Conventionally, capacitor elements are manufactured as follows. An oxide film as a dielectric layer is formed by chemical conversion treatment on the surface of the anode body obtained by expanding the surface of the aluminum foil or aluminum plate by etching. Further, a resist made of an insulating resin is formed on the surface of the dielectric layer so as to divide the surface of the anode body into a capacitance forming region and an anode lead region. In the capacity forming region of the anode body, a conductive polymer layer, a graphite layer, and a silver layer are sequentially formed as a cathode layer. Specifically, the resist of the anode body on which the resist is formed and the anode lead region are covered with a masking tape. Thereafter, the anode body partially covered with the masking tape is immersed in a liquid or paste-like conductive polymer tank, and then pulled up and dried to form a conductive polymer layer. Similarly, a flafite layer and a silver layer are formed. Thereafter, when the masking tape is peeled off, a cathode layer composed of a conductive polymer layer, a graphite layer, and a silver layer is formed in the capacitance forming region. Thus, a capacitor element was manufactured.

  In practice, the aluminum foil or aluminum plate for the anode body is connected in a row, and the above process is performed collectively for these anode bodies, and finally the individual capacitor elements are separated. It is.

  In the conventional method for manufacturing a capacitor element described above, the conductive polymer before curing may permeate under the masking tape and may be formed so as to reach the anode lead region from the capacitance forming region. As a result, the insulation between the cathode and the anode is broken, and a leakage current is generated between the two electrodes when the capacitor is used.

  Further, from the viewpoint of productivity, the labor of applying the masking tape and the labor of removing the masking tape significantly reduce the productivity of the capacitor element.

  Therefore, an object of the present invention is to provide a surface mount type capacitor excellent in insulation between the cathode and the anode.

  Another object of the present invention is to provide a method for manufacturing a surface mount capacitor capable of manufacturing the above surface mount capacitor with high productivity.

  According to the present invention, an anode body made of a valve action metal having a plate shape or a foil shape, the surface of which is enlarged, and an oxide film of the valve action metal formed on the surface of the anode body. A dielectric layer, a resist made of an insulating resin formed on the surface of the dielectric layer so as to divide the surface of the anode body into a capacitance formation region and an anode lead region, and formed on the capacitance formation region And a cathode layer including a conductive polymer layer made of a conductive polymer, wherein the conductive polymer existing from the capacitance forming region to the anode lead region is A surface-mounted capacitor is obtained, which is removed by using a laser beam to divide the path.

  According to the present invention, there is also provided an anode body made of a valve action metal having a plate shape or a foil shape, the surface of which is enlarged, and an oxide film of the valve action metal formed on the surface of the anode body. A dielectric layer, a resist made of an insulating resin formed on the surface of the dielectric layer so as to divide the surface of the anode body into a capacitance formation region and an anode lead region, and on the capacitance formation region In a method for manufacturing a surface mount capacitor having a cathode layer including a conductive polymer layer formed of a formed conductive polymer, the conductive high current existing from the capacitance forming region to the anode lead region. A method for manufacturing a surface mount capacitor is obtained, which includes a step of removing molecules by using a laser beam or the like so as to divide the path.

  The surface mount capacitor according to the present invention is excellent in insulation between the cathode and the anode.

  The method for producing a surface mount capacitor according to the present invention can produce a surface mount capacitor excellent in insulation between the cathode and the anode with high productivity.

  Hereinafter, a surface mount capacitor according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to the drawings.

  1A and 1B are a plan view and a cross-sectional view showing a capacitor element before completion, which is a main part of a surface mount transmission line type capacitor according to an embodiment of the present invention. 2A and 2B are a plan view and a cross-sectional view showing a completed capacitor element which is a main part of the surface mount capacitor according to the embodiment of the present invention. In the figure, the ratio of each dimension such as the layer thickness is different from the actual for convenience of explanation.

  FIGS. 1A and 1B show a state in which the capacitor element has completed the formation of the cathode layer 40 including the conductive polymer layer 41, the graphite layer 42, and the silver layer 43. Referring to FIGS. 1 (a) and 1 (b), the capacitor element has a plate shape or a foil shape, and an anode body 10 made of aluminum as a valve action metal whose surface is enlarged, and anode body 10 The dielectric layer 20 made of an aluminum oxide film which is an oxide film of a valve action metal formed on the surface of the electrode body, and the surface of the anode body 10 are divided into three regions of a capacitance forming region 11c and two anode lead regions 11a and 11b. Two resists 30 made of an insulating resin formed on the surface of the dielectric layer 20 so as to be divided, a conductive polymer layer 41 made of a conductive polymer formed on the capacitance forming region 11c, a graphite layer 42 and a cathode layer 40 including a silver layer 43. In FIG. 1B, reference numeral 12 denotes a surface enlargement layer in the anode body 10.

  The conductive polymer 41 ′ other than the capacitance forming region 11 c is a gap under the masking tape (not shown) wound on the resist 30 and the anode lead regions 11 a and 11 b in the step of forming the conductive polymer layer 41. It has penetrated through. The conductive polymer 41 'is not only unnecessary for the operation of the capacitor element, but also breaks the electrical insulation between the cathode and the anode. Therefore, in the present invention, at least the conductive polymer that breaks the electrical insulation between the cathode and the anode is removed.

  Referring to FIGS. 2 (a) and 2 (b), in this capacitor element, the conductive polymer existing from the capacitance forming region 11c to the anode lead region 11a (11b) For example, it is removed using a laser. In the figure, the symbols A, B, and BB indicate the removed conductive polymer.

  The removed conductive polymer among the conductive polymers existing on the resist 30 is indicated by a symbol A. On the other hand, the reference numeral 41 ″ indicates the conductive polymer remaining without being removed. Although the conductive polymer 41 ″ remains, the conductive polymer A is removed, thereby removing the conductive polymer 41 ″ from the capacitance forming region 11c. The path to the anode lead region 11a (11b) is divided, and as a result, electrical insulation between the cathode and the anode is ensured. Needless to say, all of the conductive polymer existing on the resist 30 may be removed.

  Further, the conductive polymer B present on the resist 30 is removed together with the portion C located under the conductive polymer B in the resist 30 by using, for example, a laser. By removing a portion C of the resist 30 near the anode lead region 11a (11b), the anode lead region 11a (11b) is expanded, and an expanded anode lead region 11a ′ (11b ′) is formed. Yes. The expansion of the anode lead region 11a (11b) brings about advantages such as easy joining of an anode terminal and an interposer at the time of lamination.

  Further, the whole D of the dielectric layer 20 on the anode lead region 11a (11b) and the whole E of the surface-enlarging layer 12 of the anode body 10 on the anode lead region 11a (11b) are formed using, for example, a laser. Has been removed. This part is preferably removed regardless of whether or not it is covered by a conductive polymer. By removing the dielectric layer 20 and the surface-enlarging layer 12 in the anode lead region 11a (11b), the anode terminal and interposer (at the time of lamination) joined to the anode lead region 11a (11b) through a subsequent process are removed. The resistance value is reduced, and good electrical connection is realized.

  Further, the conductive polymer BB present at the plate surface end portion 111b (111a) of the anode body 10 in the anode lead region 11b (11a) is a portion DD located below the conductive polymer BB in the dielectric layer 20. Along with the portions EE and FF located under the conductive polymer BB in the anode body 10, the anode body 10 is removed using, for example, a laser. Thus, by punching out part of the anode body 10 itself, a path of a conductive polymer (not shown) penetrating from the capacitance forming region 10c to the anode lead region 11b (11a) through the side surface of the anode body 10 is obtained. It is possible to sever. A portion (BB + DD + EE + FF, BB + CC + DD + EE + FF) to be removed at the plate surface end 111b (111a) has a square shape when viewed in a direction perpendicular to the plate surface of the anode body 10. However, in the present invention, the shape may be a partial circle, a partial ellipse, or a partial polygon. The shape is selected in consideration of, for example, a change in impedance value along the path from the anode lead region 11b (11a) to the capacitance forming region 11c.

  The portions A to E are evaporated by heating with laser light irradiated in a direction substantially perpendicular to the plate surface of the anode body 10. On the other hand, the portions BB to EE are burned out by laser light irradiated in a direction substantially perpendicular to the plate surface of the anode body 10. Alternatively, the portions BB to EE may be mechanically punched in a direction substantially perpendicular to the plate surface of the anode body 10.

  Next, a method for manufacturing the surface mount capacitor will be described. This method is characterized by a method for manufacturing a capacitor element.

  First, the capacitor element shown in FIGS. 1A and 1B is manufactured through the same steps as in the prior art. That is, the capacitor element includes the anode body 10, the dielectric layer 20, and the dielectric layer 20 so as to divide the surface of the anode body 10 into three regions of a capacitance forming region 11c and two anode lead regions 11a and 11b. Two resists 30 made of an insulating resin formed on the surface of the metal, a conductive polymer layer 41 made of a conductive polymer formed on the capacitance forming region 11c, a graphite layer 42, and a silver layer 43. And a cathode layer 40. In FIG. 1B, reference numeral 12 denotes a surface enlargement layer in the anode body 10.

  The conductive polymer 41 ′ existing outside the capacitance forming region 11 c is a gap under the masking tape (not shown) wound on the resist 30 and the anode lead regions 11 a and 11 b in the step of forming the conductive polymer layer 41. It has penetrated through. The conductive polymer 41 'is not only unnecessary for the operation of the capacitor element, but also breaks the electrical insulation between the cathode and the anode. Therefore, in the present invention, at least the conductive polymer that breaks the electrical insulation between the cathode and the anode is removed.

  As shown in FIGS. 2A and 2B, for example, a laser is used to break the path of the conductive polymer existing from the capacitance forming region 11c to the anode lead region 11a (11b). And remove. In the figure, the symbols A, B, and BB indicate the removed conductive polymer.

  Although the conductive polymer 41 ″ remains, the path from the capacitance forming region 11c to the anode lead region 11a (11b) is cut off by removing the conductive polymer A. As a result, the cathode-anode It is needless to say that all of the conductive polymer existing on the resist 30 may be removed.

  Further, the conductive polymer B present on the resist 30 is removed together with the portion C located under the conductive polymer B in the resist 30 by using, for example, a laser. By removing a portion C of the resist 30 near the anode lead region 11a (11b), the anode lead region 11a (11b) is expanded, and an expanded anode lead region 11a ′ (11b ′) is formed. Yes.

  Further, the whole D of the dielectric layer 20 on the anode lead region 11a (11b) and the whole E of the surface-enlarging layer 12 of the anode body 10 on the anode lead region 11a (11b) are utilized by using, for example, a laser. Remove. This part is preferably removed regardless of whether or not it is covered by a conductive polymer.

  Further, the conductive polymer BB existing at the plate surface end portion 111b (111a) of the anode body 10 in the anode lead region 11b (11a) is a portion DD located below the conductive polymer BB in the dielectric layer 20. Along with the portions EE and FF located under the conductive polymer BB in the anode body 10, for example, it is removed using a laser. Thus, by punching out part of the anode body 10 itself, a path of a conductive polymer (not shown) penetrating from the capacitance forming region 10c to the anode lead region 11b (11a) through the side surface of the anode body 10 is obtained. It is possible to sever. A portion (BB + DD + EE + FF, BB + CC + DD + EE + FF) to be removed at the plate surface end 111b (111a) has a square shape when viewed in a direction perpendicular to the plate surface of the anode body 10.

  The portions A to E are evaporated by heating with laser light irradiated in a direction substantially perpendicular to the plate surface of the anode body 10. On the other hand, the portions BB to EE are burned out by laser light irradiated in a direction substantially perpendicular to the plate surface of the anode body 10. Alternatively, the portions BB to EE may be mechanically punched in a direction substantially perpendicular to the plate surface of the anode body 10.

  The capacitor element was manufactured as described above. Thereafter, an anode terminal is joined to the lower surface of the anode lead region 11a of the obtained capacitor element by ultrasonic welding. Further, the cathode terminal is bonded to the surface of the silver layer 43 below the capacitor element with a conductive adhesive made of silver or the like. Thereafter, the lower surface of the anode terminal and the cathode terminal or at least a part of the lower surface and the side surface are removed, and the insulating resin impregnated tape is covered. Further, the capacitor element covered with the insulating resin impregnated tape is thermally cured to package the capacitor element. A surface mount capacitor was manufactured as described above.

  While the present invention has been described in terms of several embodiments, it will be apparent to those skilled in the art that the present invention can be variously modified within the scope of the claims. For example, the present invention is not limited to a three-terminal transmission line type capacitor having a capacitor element in a single layer, but a two-terminal capacitor having a capacitor element in a single layer, and a two-terminal multilayer having a stacked capacitor element The present invention can be applied to both a type capacitor and a three-terminal multilayer transmission line type capacitor including laminated capacitor elements.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the surface mount type capacitor by the Example of this invention, (a) is a top view which shows the state before completion of the capacitor | condenser element which is the principal part, (b) is the cutting line 1B-1B FIG. It is a figure for demonstrating the surface mount type capacitor by the Example of this invention, (a) is a top view which shows the capacitor | condenser element which is the principal part, (b) is sectional drawing along the cutting line 2B-2B. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Anode body 11a, 11b Anode lead area | region 11c Capacity | capacitance formation area | region 11a ', 11b' Expanded anode lead area | region 111a, 111b Plate | board surface edge part 12 Widening layer 20 Dielectric layer 30 Resist 40 Cathode layer 41 Conductive polymer Layer 41 ', 41 "Conductive polymer 42 Graphite layer 43 Silver layer

Claims (16)

An anode body made of a valve metal having a plate shape or a foil shape, the surface of which is enlarged, a dielectric layer made of an oxide film of the valve metal formed on the surface of the anode body, and A resist made of an insulating resin formed on the surface of the dielectric layer so as to divide the surface of the anode body into a capacitance forming region and an anode lead region, and a conductive polymer formed on the capacitance forming region In a surface mount type capacitor having a cathode layer including a conductive polymer layer comprising:
The conductive polymer that exists so as to reach the anode lead region from the capacitance forming region is removed to break the path ,
In the anode lead region, the conductive polymer present at the end of the plate surface of the anode body is a portion of the dielectric layer located under the conductive polymer and the conductive body of the anode body. Along with the part located under the polymer has been removed,
The conductive polymer present at the end of the plate surface of the anode body in the anode lead region, which is a portion to be removed, the portion of the dielectric layer located under the conductive polymer, The portion of the anode body located under the conductive polymer has a partial circular shape, partial elliptical shape, or partial polygonal shape when viewed in a direction perpendicular to the plate surface of the anode body. Characteristic surface mount capacitor.   2. The surface mount capacitor according to claim 1, wherein the conductive polymer existing on the resist is removed together with a portion of the resist located under the conductive polymer. The anode by the portion of the lead region closer is removed, a surface-mount capacitor according to claim 1 or 2, wherein the anode lead region is expanded of the resist. It said dielectric layer is a surface-mount capacitor according to any one of claims 1 to 3 is removed in the anode lead region. The surface-mount type capacitor according to claim 4 , wherein a surface-enlarging layer of the anode body on the anode lead region is removed. The portion to be removed, a surface-mount capacitor according to any one of the anode body to claim 1 are removed by the laser beam irradiated in a direction substantially perpendicular to the plate surface 5. The portion to be removed, a surface-mount capacitor according to any one of claims 1 to 5 are mechanically punched in a direction substantially perpendicular to the plate surface of the anode body. An anode body made of a valve metal having a plate shape or a foil shape, the surface of which is enlarged, a dielectric layer made of an oxide film of the valve metal formed on the surface of the anode body, and A resist made of an insulating resin formed on the surface of the dielectric layer so as to divide the surface of the anode body into a capacitance forming region and an anode lead region, and a conductive polymer formed on the capacitance forming region In a method for manufacturing a surface mount capacitor having a cathode layer including a conductive polymer layer comprising:
Removing the conductive polymer present so as to reach the anode lead region from the capacitance forming region to break the path ;
In the anode lead region, the conductive polymer present at the end of the plate surface of the anode body includes a portion of the dielectric layer located under the conductive polymer and the conductive body of the anode body. with the portion located under the polymer, it has a step of removing,
The conductive polymer present at the end of the plate surface of the anode body in the anode lead region, which is a portion to be removed, the portion of the dielectric layer located under the conductive polymer, The portion of the anode body located under the conductive polymer has a partial circular shape, partial elliptical shape, or partial polygonal shape when viewed in a direction perpendicular to the plate surface of the anode body. A method for manufacturing a surface mount capacitor. The method for producing a surface-mounted capacitor according to claim 8 , further comprising a step of removing the conductive polymer existing on the resist together with a portion of the resist located under the conductive polymer. The method for manufacturing a surface mount capacitor according to claim 8 , further comprising a step of expanding the anode lead region by removing a portion of the resist near the anode lead region. Said dielectric layer, the manufacturing method of the surface mount capacitor according to any one of claims 8 to 10 comprising the step of removing at the anode lead region. The method for manufacturing a surface-mounted capacitor according to claim 11 , further comprising a step of removing the surface expansion layer of the anode body on the anode lead region. The method for manufacturing a surface mount capacitor according to any one of claims 8 to 12 , wherein the removal is performed by laser light irradiated in a direction substantially perpendicular to a plate surface of the anode body. The method for manufacturing a surface-mounted capacitor according to any one of claims 8 to 12 , wherein mechanical removal is performed in a direction substantially perpendicular to the plate surface of the anode body. Method for manufacturing a surface-mount capacitor according to any one of claims 8 to 14 comprising the step of forming said conductive polymer on substantially the entire surface of the anode body wherein the resist is formed. 16. The method for manufacturing a surface mount capacitor according to claim 15 , further comprising a step of covering the resist and the anode lead region of the anode body with a masking tape before the conductive polymer forming step.

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