Browse Prior Art Database

COMBINED LASER AND MANUAL TRIMMER CAPACITOR

IP.com Disclosure Number: IPCOM000006004D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2001-Nov-23
Document File: 1 page(s) / 55K

Publishing Venue

Motorola

Related People

Tuan K. Nguyen: AUTHOR [+2]

Abstract

A manually trimmable capacitor is often subjected to damage if the operator who tuned it applies too much force on the part. Also, excess compression during the tuning process leads to possible drift in capacitance values (from the set value) due to after tuning stress relaxation. Sometimes, when the part is partially damaged during the tuning process, drastic changes in capacitance value may happen in the field due to worsening damage caused by mechanical vibrations and shocks.

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MO7WROLA Technical Developments Volume 11 October 1990

COMBINED LASER AND MANUAL TRIMMER CAPACITOR

by Tuan K. Nguyen and Tom Rollins

   A manually trimmable capacitor is often subjected to damage if the operator who tuned it applies too much force on the part. Also, excess compression during the tuning process leads to possible drift in capacitance values (from the set value) due to after tuning stress relaxation. Sometimes, when the part is partially damaged during the tuning process, drastic changes in capacitance value may happen in the field due to worsening damage caused by mechanical vibrations and shocks.

   A laser trimmable capacitor has the advantage of suppressing the mechanical stresses and damages caused by manual tuning. However, the laser trimmable capacitor has the disadvantage of being tunable only ONE TIME! One cannot conveniently change the capacitance value of the laser trimmable capacitor once it has been set, the first time.

This idea proposes to combine the advantages of no stress tuning (laser trimmable part) with the possibility of performing retune (manual trim part) after the initial trimming process.

   This idea is comprised of two parts, a) a laser trimmable part which will be used for in factory IaSer tuning process, and b) a manually tunable part like the existing art trimmable capacitor which will be used for later change of setting. The two parts are electrically connected either in parallel or in series. A preferred embodiment is the...