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Patent Searching and Data


Title:
CAPACITOR AND MANUFACTURING METHOD OF CAPACITOR
Document Type and Number:
WIPO Patent Application WO/2001/069615
Kind Code:
A2
Abstract:
It is described a capacitor (8) provided with a thermo shrinkable film (6) directly (5) on the capacitive element (1). That capacitor (8) including a capacitive element (1), plurality of metallic armatures (2), contact terminals (3), the capacitor (8) with a thermo shrinkable cover (6) applied directly on the capacitive element (1). It is also foreseen a manufacturing method of capacitor (8), particularly a manufacturing method of a dry capacitor (8) including a step where a thermo shrinkable tube (6) is applied directly on the capacitive element and a next step where the thermo shrinkable tube (6) is warmed up.

Inventors:
Schabbach, Gilvan (Rua Placido de Castro, 216/Ap 301 Azenha -070 Porto Alegre RS, 90650, BR)
Application Number:
PCT/IB2001/000374
Publication Date:
September 20, 2001
Filing Date:
March 14, 2001
Export Citation:
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Assignee:
Epcos, Brasil Ltda DO. (Rua Bernardo Joaquim Ferreira, 624 Parque dos Anjos -970 GravataĆ­ RS, 94000, BR)
Schabbach, Gilvan (Rua Placido de Castro, 216/Ap 301 Azenha -070 Porto Alegre RS, 90650, BR)
International Classes:
H01G4/18; H01G2/10; H01G4/00; H01G4/06; H01G4/224; H01G4/232; H01G4/28; H01G4/33; (IPC1-7): H01G4/00
Foreign References:
US5403454A1995-04-04
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Claims:
Claims
1. Capacitor (6), particularly a dry capacitor (6) comprehending a capacitive element (1), contact terminals (3), the capacitor (8) characterized due the thermo shrinkable plastic cover (6) applied directly on the capacitive element (1).
2. Capacitor accordingly to claim 1 characterized by the flexible thermo shrinkable cover (6).
3. Capacitor accordingly to claim 1 or 2, characterized by the partial with thermo shrinkable (6) covering of the capacitive element (1).
4. Capacitor (8) manufacturing method, particularly a dry capacitor (8) manufacturing process, the capacitor (8) with a capacitive element (1) and contact terminals (3), the method being characterized by a step where a thermo shrinkable tube (6) is applied directly on the capacitive element and next step where the thermo shrinkable tube (6) is heated and shrinked.
5. Method accordingly to claim 4, characterized by the heating of the thermo shrinkable material (6) putting the capacitor (8) into a heater.
Description:
Capacitor and manufacturer method of capacitor The invention is a subject of one capacitor, specially a dry capacitor, which can be made from metallized plastic film or plastic film and metallic foils as armatures, with one external protection of a shrinkable tube.

Capacitors are electronic components, used in electro- electronic devices. The capacitor is formed by two armatures and one dielectric, in a wound form or stacked form, forming the capacitive element. The capacitive element is connected to the other elements of one electrical circuit called terminals. With an electrical current applied to these terminal, the capacitor is loaded with one electrical load.

There are a lot of different types of capacitors: film capacitors (polyester or polypropylene), ceramic, electrolytic, tantalum, etc. This invention is applicable to anyone, since it is a dry capacitor (without a presence of a liquid substance in its composition), and need a cover as a mechanical and/or electrical protection.

The capacitors normally need an external cover to be handled without mechanical damages during the assembling in the circuit. This cover has the function to protect the capacitor and the neighbor components from short circuits, which could damage the whole circuit, assuring the mechanical robustness to the capacitors during the handling and assure the attachment of the terminals during soldering process.

Technical status description: There is known capacitors in a naked version (without protection cover), boxed in plastic cans and covered by epoxy powder resin.

Most of the plastic capacitors are covered by one of the process mentioned. The naked version has application in some

restricted fields, because is sensitive to mechanical agents and soldering process.

The covering techniques provide the capacitors the necessary protection against external mechanical agents, as well as the contact with the neighbor components, avoiding short circuits.

Invention objectives and short description: The invention objective is to provide to the capacitor one protection system against the mechanical and electrical external agents, in a simple form, cheap, avoiding the use of the plastic can as known, using one shrinkable tube directly on the capacitive element.

The objective is reached using one capacitor, particularly one dry capacitor, formed by one capacitive element, contact terminals, and the capacitor with one thermo shrinkable plastic tube, applied directly on the capacitor.

It is also foreseen a capacitor manufacturing method using a thermo shrinkable material which is applied directly on the capacitive element without using the technic well-known plastic can, making the production cheaper.

The objective is reached using a manufacturing method, particularly a dry capacitor manufacturing method, the capacitor formed by one capacitive element and contact terminals. It's a one step method where a thermo shrinkable tube is directly applied on the capacitive element and a next step is where the thermo shrinkable tube is heated and consequently shrinked.

Drawings short description: Following the present invention is being described with details and based on an execution example represented in the drawings.

The figures show: Figure 1-a view of two capacitive elements still without the protection cover, a version with preformed terminals and other with straight terminals; Figure 2-a view of the capacitive element covered with thermo plastic shrinkable material Figure 3-a view of the capacitive element without the thermo plastic shrinkable material cover Figure 4-a view of the capacitive element with the thermo shrinkable tube prepared to insert to the capacitive element ; Figure 5-a view of the capacitive element recovered with the thermo shrinkable tube; and Figure 6-a view of the finished capacitor after shrinking the thermo shrinkable tube.

Figures detailed description: Figure 1 illustrates the capacitive element or wound 1 without the protection cover 6, formed by the plastic dielectric and metallic armatures 2 or metallic zone 2, which can be of metal deposited by melted metal spray or simply the own component metallic armatures 2. The terminals 3 are connected to the capacitive element 1 and can be preformed 4 or straight 5.

On figure 2 the capacitive element 1 has already the thermo shrinkable plastic material cover 6 serving as the capacitor mechanical protection and electrical insulation 8. The mechanical protection results from the pressure of the mentioned thermo shrinkable 6 on the terminals 3 and on the own assembly 2 of capacitor 8, which guarantees the welding

integrity and by consequence the contact between terminals 3 and the mentioned capacitor 8 and avoiding the use of plastic cans.

The electrical insulation of armatures 2 of capacitor 8 is done by the cover insulating material characteristic used on the capacitive element 1. In case of a capacitor 8 with mechanic preformed terminals 4, the preforming serves to support the component on the PCB board (not shown) where the mentioned component is set up and as delimitation of thermo shrinkable plastic 6.

The invention can be builded with any thermo shrinkable material 6, since this material attempt the electrical and thermo isolation request as well as provides to the capacitor 8 an adequate mechanical resistance.

The areas 7 on the superior and inferior parts of capacitor 8 are open and ambient exposed or can be sealed with resins like epoxy, polyuretan or others.

The manufacturing method of a capacitor 8, as shown on figures 3 and 6, consists to cover the capacitive element 1 with thermo shrinkable material, which usually is supplied in tubes and has to been cut in adequate sizes so that the extremities covers enough the capacitive element 1 boards to provide the capacitor 8 with the adequate mechanical protection after shrinking.

In a next step the capacitor 8 goes through a heater (not shown) which makes the referred thermo shrinkable material 6 shrink, sticking it perfectly to the capacitive element 1 as shown on figure 8.

It is described an example of preferred realization but the present invention includes the possibility of other variations being limited only by the attached claim substances, including the possible equivalents.