US 5,241,741 A · Method of making a positive temperature coefficient device

Abstract

A positive temperature coefficient ("PTC") device body is formed by compression molding of an organic PTC composition consisting of a crystalline polymer with conductive particles dispersed therein. The body is sandwiched between electrodes to which terminals are attached by spot welding or soldering. The PTC device body is aged at normal pressure and at a temperature higher than the peak resistance temperature, that is, the temperature at which its resistance is a maximum, and lower than 250.degree. C. The resistance of the PTC device does not change either before or after exposure to high temperatures, that is, temperatures substantially greater than 250.degree. C., and the PTC characteristics of the device do not decrease despite aging. Therefore PTC devices made according to the present invention can be surface-mounted.

Claims11

Dependent claims

A method of making a PTC device, which comprises:

dispersing a plurality of conductive particles within an organic composition comprising at least one crystalline polymer having positive temperature coefficient characteristics;
forming a body by heating and pressure-molding said organic composition;
aging said body under normal pressure at a temperature no lower than a temperature where said body reaches its highest value of resistance;
attaching an upper electrode and a lower electrode to said body;
and
connecting at least one terminal to each of said upper electrode and said lower electrode.

3 more elements

Dependencies are inferred from the claim text.

Method of making a positive temperature coefficient device

Life of this patent

Method of making a positive temperature coefficient device

Life of this patent

Abstract

Claims11