Littelfuse Japan G.k.

Tyco Electronics Japan G.k.

Littelfuse, Inc.

Tyco Electronics Raychem Kk

Other

Fdk Corporation

Arata Tanaka

Katsuaki Suzuki

Masaaki Iwai

Hiroyuki Koyama

Tsuyoshi Takizawa

Keiichiro Nomura

Masayuki Oohira

Hirofumi Mochizuki

Jianhua Chen

Atsushi Nakagawa

Robert Daniel Hilty

Takashi Hasunuma

Minh V Ngo

Weiqing Guo

Mikio Iimura

Hisashi Usui

Toshiya Ikeno

Kenji Harato

Haruhisa Miyagi

The present invention provides a protection device that can more surely protect an electronic or an electric apparatus even when an inrush current value is large and its magnitude has large dispersion, and that has a recovery property. The protection device of the present invention includes a PTC component; a resistive component; and a first terminal and a second terminal, wherein the first terminal, the PTC component, the resistive component, and the second terminal are electrically connected in series in this order.

Protection device

The present invention provides a protection device including a bimetal component and a PTC component. This protection device includes a resin base, a first terminal, a second terminal, a PTC component, a bimetal component, an arm, an upper plate and a resin cover. A portion of the first terminal configures a first electrode, and a portion of a second terminal configures the second electrode, and the first electrode and the second electrode are exposed outward at the bottom surface of the resin base. In a normal state, the first terminal, the arm and the second terminal are electrically connected in series. When the bimetal component is activated, the first terminal and the arm become electrically cut off while the first terminal, the PTC component, the bimetal component, the arm and the second terminal are electrically connected in series in the mentioned order.

A protective element including (i) a PTC element having an opening passing through in the thickness direction, and (ii) a first electrode and a second electrode positioned on both main surfaces of the PTC element, the protective element characterized in that the first electrode extends from a main surface of the PTC element over an edge thereof and into the opening wherein the PTC element is not prevented from expanding even when secured by a screw or caulking.

Protection element

The present invention provides a protection device which includes: a PTC laminar element which is formed of an insulation resin and has at least one throughhole; electrically conductive metal thin layers which are positioned on each of main surfaces of the laminar element, and a fuse layer which is positioned on a side surface defining at least one of said at least one throughhole and electrically connects the electrically conductive metal thin layers which are positioned on each of main surfaces of the laminar element. The protection device of the present invention allows a larger amount of a current to flow therethrough and can provide a protection from an excessive current.

The present invention provides a protection device which provides a greater degree of freedom in a disposition of the bimetal switch as well as be able to more accurately control an actuation of the bimetal member of the bimetal switch. The protection device characterized in that the device comprises a bimetal switch wherein a first PTC member and a bimetal member are connected electrically in parallel with each other; and a second PTC member; and the bimetal member is disposed to be actuated by tripping of the second PTC member.

Protective device

The present invention provides a protection device which includes a PTC component and a first non-resettable contact component which is connected electrically in parallel to the PTC component. A second non-resettable contact component is connected electrically in series to the PTC component, and when the PTC component is tripped by a current which is diverted by opening the contact of the first non-resettable contact component, the contact of the second non-resettable contact component opens due to heat which is generated by the PTC component.

A thermal cut-off device includes a plastic base, two electrodes, a temperature sensing element, and a plastic cover that fits over the base. The temperature sensing element is curved downward, and may be a bimetal or a trimetal. When the device is subject to an over-temperature condition, the orientation of the curve flips such that the temperature sensing element is then curved upward. When the temperature sensing element is curved upward, it lifts an arm of one of the electrodes, which severs the electrical connection between the electrodes. In this manner the device shuts off during an over-temperature condition in order to protect the circuit in which the device is installed. To prevent corrosion of the temperature sensing element, a first moisture insulation layer is applied to the outer surface of the thermal cut-off device. The moisture insulation layer may be an epoxy adhesive or a UV/visible light-cured adhesive or light/heat cured adhesive. In some embodiments, a second moisture insulation layer is formed on the surface of the temperature sensing element.

Insulated thermal cut-off device

A protection device comprises a resin base, PTC component, bimetal component, arm and upper plate which are housed in a resin housing wherein the base includes a terminal integrated with the base by insert molding. A resin cover is formed by insert molding to cover the PTC component, bimetal component, arm and upper plate which are superposed in this order over the terminal within a space in the base. The space in the resin base is substantially closed by the upper plate, the base and the cover are integrally bonded to define the resin housing, the terminal and the arm are electrically connected in series in a normal state, and in an abnormal state where the bimetal component is activated, the terminal and the arm are electrically cut off, while the terminal, PTC component, bimetal component, and arm are electrically connected in series in this order.

The present invention provides a means in which contact between contacts in a 'double-break (or double-make) contact structure' occurs in two places in the same state as much as possible. A contact structure includes two fixed members () each of which has a fixed contact () and a movable member () containing a movable contact () which contacts or separates from the fixed contact of each of the fixed members. The movable member is in the form of a strip as a whole, its one end is supported so as to allow the above mentioned contact and separation of the movable member, and the other end of the movable member has the movable contact, and the movable member has a narrowed section between its two ends.

Contact structure

There is provided a PTC device having a sufficient function to detect the possibility of the substrate reaching an extraordinary high temperature more rapidly, and prevent the substrate from reaching such an extraordinary high temperature beforehand. The PTC deviceincludes a layered supportthat functions as a heat transfer medium and a polymer PTC elementdisposed thereon wherein the polymer PTC element is disposed on one surfaceof the layered support (in a thermally connected condition) and the polymer PTC element and the layered support are molded in a resin such that the other surface' of the layered support is exposed.

PTC device

There is provided a polymer PTC device including a polymer PTC element having a lower resistance. The production process of a PTC device which includes a PTC element () having a polymer PTC component () and metal electrodes () placed on both sides thereto; and a lead () connected electrically to at least one of the metal electrodes, is characterized in that the polymer PTC component is formed of an electrically conductive polymer composition which comprises a polymer material and conductive fillers dispersed therein, and the connection of the lead to the metal electrode is performed at a temperature which is lower than the melting point of the polymer material.

Process for producing PTC device

There is provided a PTC device which allows compact connection as much as possible. Such PTC device includes a polymer PTC element () including (A) a polymer PTC component () an electrically conductive filler, and a polymer material; and (B) a metal electrode () placed on at least one surface of the polymer PTC component. Also present are a lead () of which at least a part is positioned on the metal electrode of the PTC element; a protective coating () which surrounds an exposed area of the PTC element, and a hardened solder paste which is present as a connection area () which electrically connects the metal electrode and said at least a part of the lead.

There is provided a polymer PTC device which has a further improved performance. Such PTC device comprises (A) a polymer PTC element containing (a1) an electrically conductive filler and (a2) a polymer material, and (B) at least one metal electrode disposed on at least one surface of the polymer PTC element, and the electrically conductive filler is an Ni alloy filler which has oxidation resistance under a high temperature and dry atmosphere, and the polymer material is a thermoplastic crystalline polymer.

Polymer PTC element

The present invention provides a novel method for electrical connection between a polymer PTC device and a metal lead element to thereby prevent the problems of the connection by caulking or soldering. For this purpose, the present invention provides a process for producing a connection structure by laser welding, said connection structure having (A) a PTC device () including (i) a laminar polymer PTC element () and (ii) a metal foil electrode () disposed on a main surface of the laminar polymer PTC element (), and (B) a metal lead element () electrically connected to the metal foil electrode. The metal foil electrode () has at least two metal layers, one of which, the X-th layer, has laser beam absorption a % that is the lowest among the metal layers of the metal foil electrode (). The X-th layer is present between a first metal layer () of the metal foil electrode and the laminar polymer PTC element (). First metal layer () is located farthest from the laminar polymer PTC element () and has a laser beam absorption of b %, where b&#x3e;a.

Process for producing PTC element/metal lead element connecting structure and PTC element for use in the process

A PTC device is provided which is capable of surely functioning as the PTC device even in a wiring through which a large current flows. A combined PTC device () is composed of two PTC devices each containing a lamellar PTC element () which is composed of a polymeric PTC material and a pair of electrodes (and) which are arranged apart from each other on one side of the PTC element. The electrodes () of one PTC device are respectively opposite to the electrodes () of the other PTC device, and terminals () are arranged between the respective opposite electrodes. The respective opposite electrodes and the terminal between them are electrically connected with each other.

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Ryugasaki, Japan

Arata Tanaka