用于燃油位置传感器的厚膜浆料(英文)

现今的燃油传感器要求在汽车汽油箱的苛刻的化学环境里有低的电子噪声,长的耐磨寿命和高的信号传递。虽然燃油传感器基板的设计师通过结构设计和选择触点、电刷的安装等能够较大的提高性能,但厚膜导体必须符合相关要求。导体浆料是贵重金属粉末混合物(例如Ag,Pd,Au,Pt和它们的合金、以及玻璃或氧化物粉末)悬浮于有机载体中而形成的。这些燃油传感器基板必须在包含水、酒精、有机酸、硫化合物、氟素的燃油中工作,要满足抗银离子迁移、抗化学腐蚀和耐磨性这些重要的特性。论述了一种应用于燃油传感器厚膜电路需求的导体浆料,以及工艺、机械和化学上的要求。并给出了详细的耐磨性、耐硫化及抗化学腐蚀的讨论,讨论了金属合金在导体中的作用,并用微结构分析和化学分析来评估材料。

Requirements for Thick Film Conductor Pastes for Fuel Level Senders

Modem fuel level senders are required to have low electrical noise, long wear life and high signal resolution in the harsh chemical environment of an automotive fuel tank. Though the fuel card designer can influence its performance largely by the construction and selection of the contacts and their metal alloy, the wiper load etc., there are some requirements that have to be met by the thick film conductor. Conductor pastes are a mixture of precious metal powders, such as Ag, Pd, Au, Pt and alloys thereof, glass or oxide powders suspended in an organic vehicle. These senders have to work in fuels that may contain water, alcohols, organic acids, sulfur compounds, fluorine from the tank walls etc., and are very aggressive. Properties like migration resistance, chemical resistance and wear resistance are important properties needed for the conductor. The purpose of this paper is to show an application for a thick film circuit and outlines the requirements for conductors for fuel sender applications. Processing, mechanical, and chemical requirements are presented. A discussion about wear, sulfur resistance and chemical resistance is detailed. The paper will also discuss the effect of metallic alloys on the conductor properties. Micro structural analysis and chemical analysis are used to evaluate the materials.