THIN-FILM THERMISTOR MANUFACTURING PROCESS Russian patent published in 1999 - IPC

FIELD: electronic engineering. SUBSTANCE: process includes evaporation of resistive layer onto insulating substrate, formation of contact pads abutting against one of insulating substrate sides, formation of regular zigzag-shaped (meander) structure with adjusting jumpers from resistive layer using photolithography method, measurement of resistive layer value, and adjustment of resistance to desired value by making predetermined number of cuts followed by covering thin-film structure with protective coat; thin-film resistive structure is made of two materials of different resistivity and temperature coefficient of resistance; three contact pads are formed at joints between materials and at their edges on one side of insulating substrate; extreme contact pads are arranged in immediate proximity; power lead is formed for each contact pad; resistance and temperature coefficient of resistance are measured between contact pad arranged at joint between thin-film materials and two other contact pads; desired temperature coefficient of resistance and total resistance of thermistor are found from equations , where R₁ is resistance of thin-film structure made of first material; R₂ is that of structure made of second material; R₀ is desired total resistance of thermistor; α₁ is thermal coefficient of resistance of thin-film structure made of first material; α₂ is that of thin-film structure made of second material; α₀ is desired temperature coefficient of thermistor; resistances R₁ and R₂ are adjusted to desired values found from calculations, contact pads are interconnected, and one of electrically connected leads is removed. EFFECT: provision for adjusting total resistance and temperature coefficient of resistance to desired values in single procedure. 1 dwg