US3857074A — Electrical capacitors and method of making same

Claim 1

Independent Claim 160 words

AN ELECTRICAL CAPACITOR COMPRISING AT LEAST TWO ALUMINUM METAL LAYERS, A DIELECTRIC LAYER OF SYNTHETIC RESIN MATERIAL INTERPOSED BETWEEN EACH ADJACENT PAIR OF METAL LAYERS, SAID METAL AND DIELECTRIC LAYERS BEING SUBSTANTIALLY FLAT AND ARRANGED BETWEEN A FIRST AND SECOND OUTER COVER FOIL TO FORM A STACK, WITH EACH OF SAID METAL LAYERS, WHICH SERVES AS ONE ELECTRODE OF THE CAPACITOR, EXTENDING TO ONE EDGE OF THE STACK BUT NOT TO THE OPPOSITE EDGE SO AS TO LEAVE A METAL-FREE EDGE ZONE AT SAID OPPOSITE EDGE, AND EACH OF SAID METAL LAYERS, WHICH SERVES AS THE OTHER ELECTRODE OF THE CAPACITOR, EXTENDING TO SAID OPPOSITE EDGE BUT NOT TO SAID ONE EDGE OF THE STACK, SO AS TO LEAVE A METAL-FREE EDGE ZONE AT SAID ONE EDGE, AND A CONNECTING WIRE EXTENDING LONGITUDINALLY ON SAID FIRST COVER FOIL ALONG EACH OF SAID METAL-FREE EDGE ZONES, AT LEAST SPECIFIC POINTS ON THE LENGTH OF SAID WIRES BEING FUSED THROUGH SAID FIRST

Claim 2

Dependent Claim 160 words

AN ELECTRICAL CAPACITOR COMPRISING AT LEAST TWO ALUMINUM METAL LAYERS, A DIELECTRIC LAYER OF SYNTHETIC RESIN MATERIAL INTERPOSED BETWEEN EACH ADJACENT PAIR OF METAL LAYERS, SAID METAL AND DIELECTRIC LAYERS BEING SUBSTANTIALLY FLAT AND ARRANGED BETWEEN A FIRST AND SECOND OUTER COVER FOIL TO FORM A STACK, WITH EACH OF SAID METAL LAYERS, WHICH SERVES AS ONE ELECTRODE OF THE CAPACITOR, EXTENDING TO ONE EDGE OF THE STACK BUT NOT TO THE OPPOSITE EDGE SO AS TO LEAVE A METAL-FREE EDGE ZONE AT SAID OPPOSITE EDGE, AND EACH OF SAID METAL LAYERS, WHICH SERVES AS THE OTHER ELECTRODE OF THE CAPACITOR, EXTENDING TO SAID OPPOSITE EDGE BUT NOT TO SAID ONE EDGE OF THE STACK, SO AS TO LEAVE A METAL-FREE EDGE ZONE AT SAID ONE EDGE, AND A CONNECTING WIRE EXTENDING LONGITUDINALLY ON SAID FIRST COVER FOIL ALONG EACH OF SAID METAL-FREE EDGE ZONES, AT LEAST SPECIFIC POINTS ON THE LENGTH OF SAID WIRES BEING FUSED THROUGH SAID FIRST

Claim 3

Dependent Claim 30 words

A capacitor according to claim 1, wherein at least one of said two cover foils has a thickness sufficient to provide the mechanical resistance necessary for handling of the capacitor.

Claim 4

Dependent Claim 16 words

A capacitor according to claim 1, wherein the stack is held together solely by said wires.

Claim 5

Dependent Claim 66 words

A capacitor according to claim 1, wherein each of the metal layers forming the one electrode has a regenerably thin, capacitive zone having a surface coNductiviity of at most 3 mho and a reinforced contacting zone having a surface conductivity of approximately 15 mho, and each of the metal layers forming the other electrode is a non-regenerable layer with a surface conductivity of approximately 15 mho.

Claim 6

Dependent Claim 33 words

A capacitor according to claim 1, wherein said first cover foil is a thermoplastic foil having a short-term thermal resistance which is lower than the short-term thermal resistance of the second cover foil.

Claim 7

Dependent Claim 33 words

A capacitor according to claim 5, wherein said first cover foil is made of polyethylene terephthalate, and the second cover foil is made of a polysulphone having a melting point of above 200*C.

Claim 8

Dependent Claim 69 words

A capacitor according to claim 5, wherein the second cover foil which has a higher short-term thermal resistance is composed of two layers with one layer being a thick layer having a relatively low short-term resistance and the other of the two layers, which face the metal layer, being a thin layer of approximately 1 Mu in thickness and of a material having a relatively high short-term thermal resistance.

Claim 9

Dependent Claim 27 words

A capacitor according to claim 1, wherein each of said connecting wires is deformed in the region in which it is in contact with the metal layer.

Claim 10

Dependent Claim 74 words

A capacitor according to claim 8, wherein said connecting wires are of a material selected from a group consisting of tinned nickel-silver, bronze, and copper, said wires are tinned and have a diameter of approximately 0.7 mm, and wherein each of said wires is passed in at least two places through the metal layer extending therebeneath and embedded into the second cover foil with the adjacent points being spaced apart at approximately 2 mm.

Claim 11

Dependent Claim 33 words

A capacitor according to claim 9, wherein the surface of each wire intermediate said points, which surface faces the stack, is embedded in the stack only as far as the nearest metal layer.

Claim 12

Dependent Claim 85 words

A capacitor according to claim 8, wherein said connecting wires are made of a material selected from a group consisting of tin and aluminum bronze which material has a relatively low melting point, and said wires have a diameter of more than 0.7 mm, and wherein each of said wires is passed in at least two places through the metal layer extending therebeneath and embedded into the second cover foil with the adjacent points being spaced apart at a distance of more than 2 mm.

Claim 13

Dependent Claim 31 words

A capacitor according to claim 11, wherein the surface of each wire, which surface faces said stack, intermediate said points is embedded in the stack only to the nearest metal layer.

Claim 14

Dependent Claim 78 words

A capacitor according to claim 1, wherein said second cover foil has a thickness of approximately 50 Mu , which foil supports said metal and dielectric layers which layers have a total thickness of only a few Mu , wherein said first cover foil has a thickness of approximately 190 Mu , and wherein said connecting wires have a 0.8 mm diameter and are provided with an undulating profile with a profile depth of approximately 250 Mu .

Claim 15

Dependent Claim 74 words

A capacitor according to claim 1, wherein said stack includes up to six metal layers separated from one another by dielectric layers having a thickness of 50 Mu , said metal layers extending alternatively to opposite edges of the stack, each of said connecting wires being connected in a mechanically stable and electrically conducting manner to all of the metal layers extending into the edge zone therebeneath to form one of the capacitor electrodes.

Claim 16

Dependent Claim 38 words

A capacitor according to claim 1, wherein a plurality of dielectric layers is present in the stack, and wherein the edge zones of said dielectric layers are welded to one another to provide a water-tight peripheral weld seam.

Claim 17

Dependent Claim 51 words

A capacitor according to claim 1, wherein said dielectric layer is a polypropylene foil of 100 Mu thickness which is provided on both sides with metallized coatings to form said metal layers, and wherein each of said covering foils has a thickness In the range of 50 to 300 Mu .

Claim 18

Dependent Claim 65 words

A capacitor according to claim 1, wherein at least one of said cover foils consists of a polysulphone having a melting point of more than 200* C., wherein one of said metal layers is a vapor-deposited coating on said one foil, and wherein said dielectric layer is made of polyphenylene oxide which is mechanically connected to said one metal layer and carries another metal layer.

Claim 19

Dependent Claim 42 words

A capacitor according to claim 1, which includes at least one synthetic resin component which extends transversely to the connecting wires, and which component is fused to said first cover foil adjacent to said connecting wires so as to encase said wires.

Claim 20

Dependent Claim 103 words

A capacitor according to claim 1, wherein said first cover foil is approximately 190 Mu thick and consists of polyethylene terephthalate, wherein said second cover foil has a thickness of 50 Mu and is a material selected from a group consisting of polyethylene terephthalate, polysulphone, polycarbonate, and polystyrene, wherein one metal layer is provided by a metal coating on said second cover foil, wherein said dielectric layer has a thickness of approximately 1 Mu and consists of polypheneylene oxide applied on said second cover foil over the metal coatings, and wherein a second metal layer is a coating applied to said dielectric layer.

Claim 21

Dependent Claim 33 words

A capacitor according to claim 1, wherein each of said connecting wires has at least one base element attached thereto, and wherein said base elements extend through all the layers of the capacitor.

Claim 22

Dependent Claim 37 words

A capacitor according to claim 20, wherein each said base elements projects through the second cover foil for a distance of up to 150 Mu and which includes a plate mechanically connected to the projecting base elements.

Claim 23

Dependent Claim 38 words

A capacitor according to claim 1, wherein said connecting wires do not extend beyond the edges of the cover foils and are partially but not completely surrounded by the synthetic resin material of said covering and dielectric foils.

Claim 24

Dependent Claim 155 words

A process of manufacturing a capacitor comprising the steps of providing a first and second cover foil, at least two metal layers, and at least one dielectric layer, arranging the metal and dielectric layers between the first and second cover foil with a dielectric layer interposed between adjacent metal layers to form a substantial flat stack with adjacent metal layers being offset relative to each other so that each metal layer has a free edge zone which is not covered by an adjacent metal layer, positioning a connecting wire over the first cover foil to overlie each of the two free edge zones, and applying heat and pressure to each of the wires to fuse at least a portion of each of the wires through the first cover foil and into an electrical connection with all metal layers disposed therebeneath and to fuse at least a portion of one wire to the second cover foil.

Claim 25

Dependent Claim 155 words

A process of manufacturing a capacitor comprising the steps of providing a first and second cover foil, at least two metal layers, and at least one dielectric layer, arranging the metal and dielectric layers between the first and second cover foil with a dielectric layer interposed between adjacent metal layers to form a substantial flat stack with adjacent metal layers being offset relative to each other so that each metal layer has a free edge zone which is not covered by an adjacent metal layer, positioning a connecting wire over the first cover foil to overlie each of the two free edge zones, and applying heat and pressure to each of the wires to fuse at least a portion of each of the wires through the first cover foil and into an electrical connection with all metal layers disposed therebeneath and to fuse at least a portion of one wire to the second cover foil.

Claim 26

Dependent Claim 54 words

A process according to claim 23, which includes subsequently applying a higher electrical voltage across the connecting wires to melt local areas of the metal layers adjacent the connecting wires without damaging the remaining metal layers and then subsequently discharging the high voltage through a circuit which has an extremely low inductance and resistance.

Claim 27

Dependent Claim 45 words

A process according to claim 23, wherein the step of applying heat and pressure applies pressure at spaced portions along each of the connecting wires so that portions of the connecting wires are fused into the stack to a greater depth than the remaining portions.

Claim 28

Dependent Claim 30 words

A process according to claim 25, wherein the step of applying heat and pressure is accomplished by passing a current through two electrodes forced into engagement with each connecting wire.

Claim 29

Dependent Claim 43 words

A process according to claim 26, wherein the step of applying heat and pressure further includes pressing non-conducting rams against each connecting wire intermediate the application of the electrodes so that the connecting wire is deformed as it is fused into said stack.

Claim 30

Dependent Claim 36 words

A process according to claim 26, which includes cooling said second cover foil during the step of applying heat and pressure to limit the depth of penetration of each connecting wire being fused into the stack.

Claim 31

Dependent Claim 69 words

A process according to claim 23, wherein the step of arranging comprises the step of arranging the metal and dielectric layers on the second cover layer to form a capacitor foil with each of the metal layers being in individual elongated strips with a spacing between the strips providing the staggered lateral offset, and then subsequently applying the first cover foil thereon to complete the assembly of the stack.

Claim 32

Dependent Claim 58 words

A process according to claim 29, wherein during the step of applying heat and pressure, the stack is moved in one direction, and the connecting wires are moved in an oppostie direction under a pair of electrodes for each of the respective wires, said electrodes being reciprocated to engage the respective wires to apply heat and pressure thereto.

Claim 33

Dependent Claim 177 words

A process according to claim 30, wherein the capacitor foil has a width corresponding to that of the finish capacitor, and the first cover foil has a length greater than is required in the finish capacitor, said first cover foil and capacitor foil being moved in directions extending perpendicular to each other so that the first cover foil extends somewhat further than is necessary for it to entirely cover the capacitor foil which does not entirely cover the width of the first cover foil, wherein the positioning of the connecting wire is accomplished by moving them parallel and opposite to the direction of movement of the capacitor foil, and which process further includes a subsequent step of removing portions of the capacitor foil subsequent to the step of applying heat and pressure so that the first cover foil extends past the edges of the capacitor foil, and the step of providing perforations extending across the first cover foil adjacent the edge of the capacitor foil so that a finished capacitor can be separated by tearing said perforations.

Claim 34

Dependent Claim 72 words

A process according to claim 30, wherein the step of appying heat and pressure, includes controlling the amount of pressure and heat so that each of the contact wires have portions which are fused into the stack a greater distance than other portions, said first mentioned portion being fused through the metal and dielectric layers while the other portions penetrate only to a depth of the first metal layer to be contacted.

Claim 35

Dependent Claim 35 words

A process according to claim 29, wherein a thin layer of fully fluorinated hydrocarbon is polymerized on a surface of each metalization which is not connected in material locking fashion to a synthetic resin layer.

Claim 36

Dependent Claim 13 words

A process according to claim 32, wherein said fully fluorinated hydrocarbon is hexafluoropropylene.

Claim 37

Dependent Claim 80 words

A process according to claim 23, which further includes prior to the step of applying heat and pressure the step of assemblying a strip of synthetic resin on the connecting wires to extend perpendicular thereto, wherein said step of applying heat and pressure is accomplished by placing electrodes adjacent to the synthetic strip to contact each wire, said electrodes heating the wire for fusing into the stack and fusing the strip to the connecting wires and the first cover foil.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-12-23	1978-06-24	1978-12-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-12-23	1982-06-24	1982-12-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-12-23	1986-06-24	1986-12-24	$7700.00	Window Closed / Lapsed

Electrical capacitors and method of making same

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