Tyco Electronics Corporation

Cecilia A Walsh

Paul Becker

Orion Jankowski

Adrian Mikolajczak

Wayne Montoya

Luis A Navarro

James A Rinde

Barry C Mathews

Albert R Martin

Rodrigo Rubiano

A surface-mountable electrical circuit protection device includes layers defining a first PPTC resistive element, a second PPTC resistive element, and at least one heat-generating electrical component such as a planar zener diode chip positioned between, and in thermal contact with, the first and second PPTC elements, such that an electrical current above a threshold level passing through the component causes the component to heat, the heat being transferred to the PPTC resistive elements and tripping at least one, and preferably both of the first or second PPTC elements to a high resistance state. A series of edge-formed terminal electrodes enable surface-mount connection of the first and second PPTC elements and the electrical component to an electrical circuit substrate, such as a printed circuit board. A method for making the device is also disclosed.

Surface mount multi-layer electrical circuit protection device with active element between PPTC layers

An electrical device in which an element composed of a conductive polymer composition is positioned in contact with the first surface of a metal electrode, the first surface having a center line average roughness Rand a reflection density RD, the product Rtimes RD being 0.5 to 1.6 &#x3bc;m. The conductive polymer composition preferably exhibits PTC behavior. In a second embodiment an electrical device has an element composed of a conductive polymer composition in contact with the first surface of a metal electrode produced by providing a base metal foil having an Rof at most 0.45 &#x3bc;m and depositing material onto the base metal foil to form a first surface having a product of Ra times RD of at least 0.14 &#x3bc;m. Other embodiments include electrical devices with metal electrodes made by pulse plating processes, and metal electrodes made by electrodeposition under diffusion-limited conditions. The electrical devices may be circuit protection devices and have improved electrical and physical properties.

Electrical devices containing conductive polymers

An electrical device suitable for use in digital telecommunications applications is provided. The device includes a laminar PTC element composed of a conductive polymer composition sandwiched between two metal foil electrodes. A first insulating layer which is composed of an electrically insulating flexible material conforms to at least part of the perimeter of the PTC element. The device has low resistance, low capacitance, reduced size, and stable resistance, and can meet power cross testing requirements. In addition, assemblies of electrical devices are provided.

Electrical device

An electrical device in which an element composed of a conductive polymer composition is positioned in contact with the first surface of a metal electrode, the first surface having a center line average roughness R and a reflection density RD, the product R times RD being 0.5 to 1.6 &mgr;m. The conductive polymer composition preferably exhibits PTC behavior. In a second embodiment an electrical device has an element composed of a conductive polymer composition in contact with the first surface of a metal electrode produced by providing a base metal foil having an R of at most 0.45 &mgr;m and depositing material onto the base metal foil to form a first surface having a product of R times RD of at least 0.14 &mgr;m. Other embodiments include electrical devices with metal electrodes made by pulse plating processes, and metal electrodes made by electrodeposition under diffusion-limited conditions. The electrical devices may be circuit protection devices and have improved electrical and physical properties.

An electrical device in which an element composed of a conductive polymer composition is positioned in contact with the first surface of a metal electrode, the first surface having a center line average roughness R and a reflection density RD, the product R times RD being at least 0.06 &mgr;m, with an adhesion promoting layer positioned between the first surface of the metal electrode and the polymer element. The conductive polymer composition preferably exhibits PTC behavior. In other aspects, electrical devices using more than one adhesion promoting layer, and electrical devices using an adhesion promoting layer in combination with a crosslinking agent are provided. Other embodiments include electrical devices with metal electrodes made by pulse plating processes, and metal electrodes made by electrodeposition under diffusion-limited conditions. The electrical devices may be circuit protection devices and have improved electrical and physical properties.

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Minnetonka, MN, United States of America

Cecilia A Walsh