Hamilton Standard Controls, Inc.

Spectrol Electronics Corporation

Kenneth Brown

Richard E Riley

An abrasion resistant low temperature air fired thick film ink composition is disclosed. The composition includes a glass matrix material having a softening point below about 700.degree. C., a particulate conductive material and a particulate reinforcing material.

Thick film ink composition

A rotary digital contacting encoder (FIG. 1) including a base (5), comprising - a base epoxy disk (501) with three external, pre-molded in place, connector pins (P.sub.1 -P.sub.3) on its exterior side extending through it, and a conductive layer in the form of two concentric layer rings (502 & 503; FIG. 4); and - an encoder element made of a 'Kapton' insulating substrate (510) carrying two, like concentric cog rings (511B & 511A; FIGS. 3 & 7) on its top side. Conductive vias (512 & 513) electrically interconnect each respective cog ring with its respective conductive layer ring and its respective external connector pin, the vias forming conductive paths through the insulating substrate between the conductive layer and the cog rings. The presence of the conductive layer 502/503, which can be screen printed on the base disk, greatly simplifies the relative alignment of the encoder element, conductor pads and terminals. Using the conductive layer the encoder element can be positioned at almost any angular location, while still obtaining proper electrical contact with the terminal pins. The via tunnels are etched out (FIG. 6A) and then filled with conductive materials before the encoder element (510/511A-B) is bonded to the base element (501/502-503).

Rotary digital contact encoder substrate

A rotary digital contacting encoder (FIG. 1) including a base (5), comprising--a base epoxy disk (501) with three external, pre-molded in place, connector pins (P.sub.1 -P.sub.3) on its exterior side extending through it, and a conductive layer in the form of two concentric layer rings (502 & 503; FIG. 4); and--an encoder element made of a 'Kapton' insulating substrate (510) carrying two, like concentric cog rings (511A & 511B; FIGS. 3 & 7) on its top side. Conductive vias (512 & 513) electrically interconnect each respective cog ring with its respective conductive layer ring and its respective external connector pin, the vias forming conductive paths through the insulating substrate between the conductive layer and the cog rings. The presence of the conductive layer 502/503, which can be screen printed on the base disk, greatly simplifies the relative alignment of the encoder element, conductor pads and terminals. Using the conductive layer the encoder element can be positioned at almost any angular location, while still obtaining proper electrical contact with the terminal pins.

Method of manufacturing an electrical component, e.g. a digital

A method is described for providing electrically resistive elements for mounting in an electrical resistor device for engagement with a relatively movable contact member, as in a potentiometer. A pair of termination openings are formed through a substrate of insulating material such as plastic film. A release liner is applied to the undersurface of the substrate to cover the openings. An electrically conductive medium is applied in fluid (paste) form to the top surface of the substrate and is caused to fill the termination openings, as by applying pressure. The conductive medium is solidified and the release liner is removed. A resistive medium for ultimate engagement with the movable contact is applied to the top surface of the substrate in engagement with the termination openings. The resistive track is shaped as desired, either linear or an annular segment, preferably as part of final shaping steps which also remove the resistive element from a continuous strip of the substrate material. The resultant shape of the resistive track includes the conductor-filled termination openings under opposite ends thereof. The resistive element may then be affixed to a more rigid substrate, with its pair of termination openings in alignment and conductivity joined to a respective pair of termination pads on the more rigid substrate.

Method of making a resistive element

A fuel level sensor 16 comprises a vertical member 20 and float 22 wherein said vertical member 20 comprises a steel substrate 26 encased in porcelain 28 with a thick film cermet resistive track 34 deposited thereon. A nickel deposit 36 at the bottom portion of the vertical member 20 facilitates electrical continuity between the substrate 26 and the resistive track 34 such that the substrate acts as a buried conductor enabling proportionality between magnitude of resistance and liquid level while diminishing the likelihood of conductor erosion and float interference.

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Alta Loma, CA, United States of America

Kenneth Brown