Abstract: Tunable dielectric materials including an electronically tunable dielectric ceramic and a low loss glass additive are disclosed. The tunable dielectric may comprise a ferroelectric perskovite material such as barium strontium titanate. The glass additive may comprise boron, barium, calcium, lithium, manganese, silicon, zinc and/or aluminum-containing glasses having dielectric losses of less than 0.003 at 2 GHz. The materials may further include other additives such as non-tunable metal oxides and silicates. The low loss glass additive enables the materials to be sintered at relatively low temperatures while providing improved properties such as low microwave losses and high breakdown strengths.

Abstract: A thick film resistor strain gauge is applied to a stainless steel shell portion of a spark plug. There are two preferable ways of applying a thick film resistor to the metal shell. In a first embodiment, the thick film resistor may be directly printed on to the shell portion with special screen printing equipment. In a second embodiment, the thick film resistor is printed and applied as a decal to the shell portion. The thick film resistors may be included in a quarter, a half, or a full wheatstone bridge strain gauge circuit. One of two embodiments of an automatic drift compensating circuit is used to determine the change in resistance experienced by the thick film resistors affixed to the spark plug. Either one of the automatic drift compensation circuits output a voltage signal which is proportional to the pressure changes occurring inside the engine cylinder into which the spark plug is threaded.

Abstract: A thick film resistor strain gauge is applied to a stainless steel shell portion of a spark plug. There are two preferable ways of applying a thick film resistor to the metal shell. In a first embodiment, the thick film resistor may be directly printed on to the shell portion with special screen printing equipment. In a second embodiment, the thick film resistor is printed and applied as a decal to the shell portion. The thick film resistors may be included in a quarter, a half, or a full wheatstone bridge strain gauge circuit. One of two embodiments of an automatic drift compensating circuit is used to determine the change in resistance experienced by the thick film resistors affixed to the spark plug. Either one of the automatic drift compensation circuits output a voltage signal which is proportional to the pressure changes occurring inside the engine cylinder into which the spark plug is threaded.

Abstract: A thick film resistor strain gauge is applied to a stainless steel shell portion of a spark plug. There are two preferable ways of applying a thick film resistor to the metal shell. In a first embodiment, the thick film resistor may be directly printed on to the shell portion with special screen printing equipment. In a second embodiment, the thick film resistor is printed and applied as a decal to the shell portion. The thick film resistors may be included in a quarter, a half, or a full wheatstone bridge strain gauge circuit. One of two embodiments of an automatic drift compensating circuit is used to determine the change in resistance experienced by the thick film resistors affixed to the spark plug. Either one of the automatic drift compensation circuits output a voltage signal which is proportional to the pressure changes occurring inside the engine cylinder into which the spark plug is threaded.

Abstract: Tunable dielectric materials including an electronically tunable dielectric ceramic and a low loss glass additive are disclosed. The tunable dielectric may comprise a ferroelectric perskovite material such as barium strontium titanate. The glass additive may comprise boron, barium, calcium, lithium, manganese, silicon, zinc and/or aluminum-containing glasses having dielectric losses of less than 0.003 at 2 GHz. The materials may further include other additives such as non-tunable metal oxides and silicates. The low loss glass additive enables the materials to be sintered at relatively low temperatures while providing improved properties such as low microwave losses and high breakdown strengths.

Abstract: A thick film resistor strain gauge is applied to a stainless steel shell portion of a spark plug. There are two preferable ways of applying a thick film resistor to the metal shell. In a first embodiment, the thick film resistor may be directly printed on to the shell portion with special screen printing equipment. In a second embodiment, the thick film resistor is printed and applied as a decal to the shell portion. The thick film resistors may be included in a quarter, a half, or a full wheatstone bridge strain gauge circuit. One of two embodiments of an automatic drift compensating circuit is used to determine the change in resistance experienced by the thick film resistors affixed to the spark plug. Either one of the automatic drift compensation circuits output a voltage signal which is proportional to the pressure changes occurring inside the engine cylinder into which the spark plug is threaded.

Abstract: A novel thick film resistor configuration and a method for fabricating thick film resistors, by which such resistors can be processed to achieve targeted electrical properties in an as-fired condition. The configuration and method of this invention involve creating a thick film resistor in the form of a series of short resistors whose combined resistance values approximately equal the predetermined resistance value required of the thick film resistor by its hybrid electronic circuit, yet with the use of minimal post-firing trimming. Such a configuration and method enable the production of thick film resistors from the same ink composition but with significantly different aspect ratios, yet which exhibit minimal differences between TCR values. Consequently, thick film resistors configured and fabricated in accordance with this invention are characterized by enhanced production throughput, repeatability, and reliability.

Abstract: Thick film resistor ink compositions and a method for formulating and processing such inks are provided for producing thick film resistors having highly repeatable and stable resistance characteristics. The inks are specifically formulated to produce resistors whose resistivities are determined in part by the sintering temperature employed in the processing of the resistors. The processing of the inks involves using infrared radiation techniques to rapidly sinter the inks at highly controllable temperatures, so as to enable the resistance of a resistor to be predictably altered by the sintering operation, such that in-process adjustments can be made to the processing method. Thick film resistors produced in accordance with this invention are characterized by high stability to environmental influences and low TCR values on the order of about .+-.50 ppm/.degree.C.

Abstract: An apparatus and process for producing fired resistors having uniform resistance characteristics, wherein a continuous closed-loop feedback network detects deviations from standard resistivity values and continuously corrects the composition by varying the proportions of high and low resistance material ratios or blends of such materials being screened onto the substrates (212), and detects deviations in screened-on film thickness for continuously correcting either the speed of operation of a screener assembly (No. 1, No. 2) or the squeegee head pressure in order to obtain a predetermined film thickness. The process continuously adjusts the resistance values through on-the-production-line control of mixture ratios of high and low resistive paints, to produce final fired resistors (170) having the required resistance values, temperature coefficients of resistivity, improved stability, and improved TCR tracking values.

Abstract: An apparatus and process for producing fired resistors having uniform resistance characteristics, wherein a continuous closed-loop feedback network detects deviations from standard resistivity values and continuously corrects the composition by varying the proportions of high and low resistance material ratios or blends of such materials being screened onto the substrates (212), and detects deviations in screened-on film thickness for continuously correcting either the speed of operation of a screener assembly (No. 1, No. 2) or the squeegee head pressure in order to obtain a predetermined film thickness. The process continuously adjusts the fired resistance values through on-the-production-line control of mixture ratios of high and low resistive paints, to produce final fired resistors (170) having the required resistance values, temperature coefficients of resistivity, improved stability, and improved TCR tracking values.