John Fluke Mfg. Co., Inc.

Other

Roy W Chapel, Jr

I Macit Gurol

David N Duperon

Robert W Hammond

Joseph E Meadows

This invention relates to a proces of manufacturing and adjusting a compound resistor. The compound resistor is formed of a resistive material forming a predominant portion of the resistance and having a small negative temperature coefficient of resistance coupled with an adjustment material having an extremely low resistance and a very high positive temperature coefficient of resistance. After forming the resistive and adjustment portions, a portion of the adjustment material is removed to adjust the composite TCR of the compound resistor substantially to zero without significantly affecting resistance.

Compound resistor manufacturing method

A resistive network formed on a substrate includes film resistors formed of resistive elements, each element having a plurality of portions symmetrically disposed relative to two axes of symmetry. The biaxially symmetric arrangement provides uniform resistance characteristics for the various film resistors, thus improving stability of resistance ratios among resistors of the network. TCR tracking for the film resistors, i.e., the TCR of a ratio of the resistors, is similarly improved. Where the elements of different resistors of the network are interleaved, the temperature of the different resistors is also made more uniform.

Resistor network having bi-axial symmetry

A compound resistor is formed of a resistive material making up a predominant portion of the resistance and having a small negative TCR coupled with an adjustment material having an extremely low resistance and a very high positive temperature coefficient of resistance. After the manufacturing process, a portion of the adjustment material is removed to adjust the composite TCR of the compound resistor substantially to zero without significantly affecting the resistance.

Compound resistor and manufacturing method therefore

A process for producing thermally isolated semiconductor die and die produced by the process, plus improved apparatus using the die are disclosed. The process generally comprises the steps of: forming a desired semiconductor component or circuit in a semiconductor wafer (preferably a silicon wafer of &lt;100&gt; crystal orientation) having a protective layer (SiO.sub.2) on one surface; forming platinum silicide contact windows in said protective layer where external connections to the semiconductor component or circuit is necessary; forming support leads of a layer of adhesive material (which also may have resistive properties, such as Nichrome) and a layer of a structurally strong metal of high electrical conductivity and low thermal conductivity (preferably 304 stainless steel) along predetermined paths extending outwardly toward the edge of the die from said contact windows; simultaneously with the forming of the adhesive layer of said support leads, forming one or more thin film resistors in predetermined regions of said die atop said SiO.sub.2 protective layer, if desired; removing said SiO.sub.2 protective layer from a region defined by said support leads, an island or islands in which said semiconductor component or circuit and said resistors are formed and a surrounding frame; and, removing said silicon from the region between said island or islands and said frame. The resulting semiconductor die comprises a frame surrounding one or more islands in which semiconductor components or circuits are formed, and which support resistors, if included. The islands are entirely supported by the support leads extending between the frame and the islands. In addition to providing support, the support leads also provide for electrical connection to the semiconductor components or circuits and to the resistors. The semiconductor die may be mounted in a package that also forms part of the invention. The package includes a ceramic substrate having an aperture in its center and alignment mesas and ridges on one surface. The ceramic substrate is formed so as to be mounted on the metal header of a conventional semiconductor canister housing. Depending upon their specific nature the resulting die are useful in and/or improve a variety of electrical apparatus. They are particularly useful as the dual RMS sensor element of an RMS converter. They can also be formed so as to be useful as radiation sensors. Or, they can be formed so as to provide a thermal platform whose temperature is controlled and stabilized at a predetermined value. All of these dies and the improved circuits resulting from their use also form part of the invention.

Thermally isolated monolithic semiconductor die

A process for producing thermally isolated monolithic semiconductor die and die produced by the process, plus improved apparatus using the die are disclosed. The process generally comprises the steps of: forming a desired semiconductor component or circuit in a semiconductor wafer (preferably a silicon wafer of &lt;100&gt; crystal orientation) having a protective layer (SiO.sub.2) on one surface; forming platinum silicide contact windows in said protective layer where external connections to the semiconductor component or circuit is necessary; forming support leads of a layer of adhesive material (which also may have resistive properties, such as Nichrome) and a layer of a structurally strong metal of high electrical conductivity and low thermal conductivity (preferably 304 stainless steel) along predetermined paths extending outwardly toward the edge of the die from said contact windows; simultaneously with the forming of the adhesive layer of said support leads, forming one or more thin film resistors in predetermined regions of said die atop said SiO.sub.2 protective layer, if desired; removing said SiO.sub.2 protective layer from a region defined by said support leads, an island or islands in which said semiconductor component or circuit and said resistors are formed and a surrounding frame; and, removing said silicon from the region between said island or islands and said frame. The resulting semiconductor die comprises a frame surrounding one or more islands in which semiconductor components or circuits are formed, and which support resistors, if included. The islands are entirely supported by the support leads extending between the frame and the islands. In addition to providing support, the support leads also provide for electrical connection to the semiconductor components or circuits and to the resistors. The semiconductor die may be mounted in a package that also forms part of the invention. The package includes a ceramic substrate having an aperture in its center and alignment mesas and ridges on one surface. The ceramic substrate is formed so as to be mounted on the metal header of a conventional semiconductor canister housing. Depending upon their specific nature the resulting die are useful in and/or improve a variety of electrical apparatus. They are particularly useful as the dual RMS sensor element of an RMS converter. They can also be formed so as to be useful as radiation sensors. Or, they can be formed so as to provide a thermal platform whose temperature is controlled and stabilized at a predetermined value. All of these dies and the improved circuits resulting from their use also form part of the invention.

Growing community of inventors

Edmonds, WA, United States of America

Roy W Chapel, Jr