Resistor substrate containing carbon fibers and having a smooth surface
AssigneeAlps Electric Co., Ltd.
InventorHisasi Komatsu
Life of this patent
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Abstract
A resistor substrate in which a resistor layer having an electroconductive powder and carbon fibers dispersed in a heat resistant resin is molded into a substrate comprising a heat resistant thermosetting molding material, and the surface of the resistor layer is in a mirror-finished state. The resistor substrate is manufactured by printing the resistor layer on a metal plate and heat-curing the same, molding the resistor layer formed on the metal plate in a die into a substrate shape with a heat resistant thermosetting resin and peeling the metal plate and transferring the resistor layer to the substrate molded from the heat resistant thermosetting resin.
Claims4
A variable resistor for use in a potentiometer having a movable wiper, the resistor comprising:
- a wiper
- an insulation substrate formed from heat resistant thermosetting molding material;
- and
- a resistor layer molded and imbedded in said insulation substrate and positioned such that it has a surface contacted by the movable wiper, said resistor layer having an electroconductive powder and carbon fibers dispersed in a heat resistant resin;
- wherein said surface of the resistor layer contoured by the movable wiper has a surface roughness foremost of said surface which is less than or equal to 0.5 .mu.m;
- and
- wherein said carbon fibers have a length in the range of 21-100 .mu.m, a diameter in the range of 5-40 .mu.m, and a length to diameter ratio which is greater than or equal to 30:7.
A resistor variable comprising:
- A movable wiper
- an insulation substrate formed from heat resistant thermosetting molding material;
- and
- a resistor layer molded and imbedded in said insulation substrate said resistor layer having an electroconductive powder and carbon fibers dispersed in a heat resistant resin and having an exposed surface for contact with said movable wiper,
- wherein, said exposed surface of the resistor layer has a surface roughness which is less than or equal to 0.5 .mu.m over most of said exposed surface for contact with said movable wiper;
- and
- wherein said carbon fibers have a length in the range of 21-100 .mu.m, a diameter in the range of 5-40 .mu.m, and a length to diameter ratio which is greater than or equal to 30:7.
Dependencies are inferred from the claim text.