How does screen printing create thick-film ceramic resistors?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

conductive ceramics Figure 1: Schematic diagram of a zirconia oxygen sensor used to monitor automobile exhaust gases. The sensor, approximately the size of a spark plug, is fitted into the exhaust manifold of an automobile engine. The thimble-shaped zirconia sensor, sandwiched between thin layers of porous platinum, is exposed on its interior to outside air and on its exterior to exhaust gas passing through slits in the sensor shield. The two platinum surfaces serve as electrodes, conducting a voltage across the zirconia that varies according to the difference in oxygen content between the exhaust gas and the outside air.

Screen printing creates thick-film ceramic resistors by utilizing specialized "inks" composed of pulverized conductor particles—such as ruthenium dioxide or bismuth ruthenate—and glaze particles dispersed in organic binders. These organic components provide the necessary flow properties for the printing process.1

Once the ink is printed onto a substrate, the material undergoes a firing process. During this stage, the organic binders burn away, and the remaining glazes fuse to form the final film. By adjusting the ratio of conductor particles within the ink, manufacturers can precisely control and vary the electrical resistance of the resulting thick films.1