Thick-Film Aluminum Electrode Paste with Pretreatment before Metal Plating for Fabricating Chip Resistor

摘要

A thick-film aluminum (Al) electrode paste is provided to fabricate a chip resistor. The paste is a mixture of a vanadium-zinc-boron series glass (V₂O₅—ZnO—B₂O₃ or BaO—ZnO—B₂O₃) along with a metal oxide, aluminum granules, and an organic additive, whose proportions are separately 3˜30 wt %, 0.1˜15 wt %, 50˜70 wt %, and 10˜20 wt %. After being stirred through three rollers and filtered, the paste is pasted on an alumina ceramic substrate. The pasted substrate is dried and sintered for forming a thick-film aluminum electrode. Meanwhile, before processing metal plating that follows, an anti-plating pretreatment is performed. Therein, surface irregularities and nonconductive alumina on the surface are removed. Thus, the electrode obtains smooth flat surface and low oxygen content. The characteristics of the chip resistor using the thick-film aluminum electrode are equivalent to those using thick-film printed silver electrodes and those using thick-film printed copper electrodes sintered in a reducing atmosphere.