Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/005—Electrodes
  • H01G4/008—Selection of materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/005—Electrodes
  • H01G4/012—Form of non-self-supporting electrodes

Definitions

• the invention relates to a regenerable electrical capacitor, in particular power capacitor, which consists of wound layers of plastic films provided with metal layers of the coverings, metal-free edge strips being arranged on the long sides of the films, in which the metal layers consist of an alloy and perpendicular to the longitudinal direction of the films have variable thickness, in which the thickness of the metal layers is the smallest in the areas adjacent to the metal-free edge strips and increases to the opposite side of the film and in which the foils are wound together in such a way that the metal-free edge strips are arranged on different end faces of the capacitor in the case of two adjacent foils are.
• the metal layers can be made thicker and thus the sheet resistances can be made smaller.
• this procedure is subject to narrow limits, since from a certain thickness of the metal layers proper regeneration is no longer guaranteed. It is therefore generally known that the thickness of at least one metal layer must be kept thin.
• DE 33 05 837 AI discloses a regenerable capacitor which consists of plastic films metallized with aluminum and in which a layer of zinc is arranged next to the metal-free edge strip. Furthermore, a capacitor is described there in which a chrome, silver or titanium layer is arranged below the aluminum layer.
• the object of the present invention is to provide a capacitor which, in comparison to the prior art, has at least the same good, but preferably better regeneration behavior and an equally good or better service life, the operation of which results in minimal deposit losses, and which therefore has a higher utilization of the dielectric material and cost reductions.
• This object is achieved in that the metal layers have a different thickness and alloy composition depending on the direction of travel of the foils and are profiled in steps.
• Fig.l the schematic cross section through two foil layers of the capacitor and Fig.2 the qualitative distribution of the alloy components for a capacitor foil.
• the thickness of the metal layers 3, 4 is shown distorted in comparison to the thickness of the foils 1, 2; in reality, the metal layers 3, 4 are considerably thinner than the plastic films 1, 2.
• the thickness of the metal layers 3, 4 is the least in the area which adjoins the metal-free edge strips 5, 6 and increases from this area in a step-like manner to the opposite side of the film where the metal layers 3, 4 are strongest and where they are contacted with Schoop layers, not shown in the figure.
• the area in which the first stage 7, 8 begins is shifted by an amount z with respect to the geometric center (half the winding width WB / 2 of the foils 1, 2).
• the foils 1, 2 are wound up against one another with a certain offset V.
• the capacitively effective area of the capacitor is determined by the degree of coverage Ü of the metal layers 3, 4, which results from the width x of the metal layers 3, 4 minus the free edge area FR and the offset V.
• the sheet resistance is greatest in the thin area of the metal layers 3, 4 (Rc ⁇ x ) and lowest in the thickest area (Ru ta i n ).
• the metal layers can also contain silver, which is either present as a uniformly incorporated layer (s) / barrier layer (s) or as a doping component, which is either uniformly or unevenly distributed in the Al / Zn alloy.
• the covering losses can be calculated with the following solution:
• the power loss P is consumed. The following applies:
• Equation (7) shows a significantly reduced power loss production compared to the known metallization profiles.
• this advantage is also brought about by changing the main alloy constituents aluminum and zinc (possibly with proportions of silver, for example) as a function of x according to FIG. 2.
• alloy metallization Zn / Al there is also the effect that with small Al components (approximately ⁇ 5% Al) this aluminum component acts as a defect in the Zn lattice structure and Ru ZnA i disproportionately to the existing layer thickness is lifted.
• the assignment of the alloy composition in the x direction can also be optimally designed according to the desired application (AC, DC, SK capacitors), also taking into account the manufacturing aspects of the metal layers. It can be seen from the qualitative course of the alloy components shown in FIG. 2 that the distance z with respect to the central axis is taken into account as a safety covering of the thin covering, which has good regeneration properties.
• the alloy metallizations can also have silver components, which can represent a function of x analogously to the Zn / Al alloy.
• area R max the area of thin metallization
• silver is particularly advantageous in the transition zone from thick to thin metallizations, that is to say in the area of the degree of overlap.
• the optimization of cross-profiling also takes into account the power dissipation as a function of x.
• the calculation of the formula (7) with different sheet resistance ratios R max / R m ⁇ n shows that in particular at high R ma / R m i n - R m emerge a ⁇ / R m m ratios load peaks in the range WB / 2. Because of these relationships, the careful calculation or optimization of all parameters is necessary in order to achieve the advantages shown in the technical product, such as a capacitor winding for Effective use of AC applications with a winding width of approximately 50mm to 170mm.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
• Laminated Bodies (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

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ID=7807156

Family Applications (1)

Country Status (9)

Families Citing this family (9)

Citations (4)

Family Cites Families (6)

• 1996
  • 1996-09-27 DE DE19639877A patent/DE19639877C2/de not_active Expired - Fee Related
• 1997
  • 1997-08-07 EP EP97937430A patent/EP0931325B1/de not_active Expired - Lifetime
  • 1997-08-07 BR BR9712150-9A patent/BR9712150A/pt unknown
  • 1997-08-07 US US09/269,450 patent/US6222721B1/en not_active Expired - Fee Related
  • 1997-08-07 JP JP10515119A patent/JP2001501031A/ja active Pending
  • 1997-08-07 AT AT97937430T patent/ATE193151T1/de not_active IP Right Cessation
  • 1997-08-07 WO PCT/DE1997/001665 patent/WO1998013839A1/de not_active Ceased
  • 1997-08-07 DE DE59701737T patent/DE59701737D1/de not_active Expired - Lifetime
  • 1997-08-07 CA CA002267107A patent/CA2267107A1/en not_active Abandoned
  • 1997-09-17 IN IN1715CA1997 patent/IN192340B/en unknown

Patent Citations (4)

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