Thick film circuit insulating dielectric slurry for aluminum substrates, and preparation method thereof

Abstract

The present invention discloses a thick film circuit insulating dielectric slurry for aluminum substrates, and a preparation method thereof. The preparation method comprises: uniformly mixing Ba3(PO4)2, AlPO4, Zn3(PO4)2, Sn2P2O7, Rb2O, B2O3 and Nb2O5 according to a certain ratio, placing into a high temperature electric furnace, heating to a temperature of 1000-1600 DEG C according to a certain temperature increase program, carrying out thermal insulation for 1-6 h, carrying out water quenching, carrying out ball milling on the material to achieve 1-5 [mu] mu to obtain aluminum substrate thick film circuit insulating dielectric composite glass-ceramic powder, mixing the glass-ceramic powder and an organic liquid carrier comprising terpineol, tributyl citrate, ethyl cellulose, span 85 and hydrogenated castor oil according to a certain ratio, and repeatedly rolling by using a three-roller rolling mill to obtain the metal aluminum substrate thick film circuit insulating dielectric slurry. The insulating dielectric slurry has characteristics of good bonding force with the metal aluminum substrate, high breakdown voltage resistance and good insulating property, and meets the requirements of the high-power metal aluminum substrate thick film circuit insulating dielectric material.

Description

technical field [0001] The invention relates to the technical field of thick-film circuits, in particular to an insulating medium slurry for high-power metal aluminum substrate thick-film circuits and a preparation method thereof. Background technique [0002] Thick film technology is to apply materials such as insulating dielectric paste, resistance paste and conductor paste on the substrate by screen printing, and then sinter at high temperature to form a functional film with strong adhesion on the substrate. At present, thick film technology is widely used as a high-power electric heating element in the field of electric heating. As the substrate of high-power electric heating elements, traditional ceramic materials are increasingly unable to meet the heat transfer and heat dissipation needs of components, and ceramic substrates are brittle and have poor machining performance, which is not conducive to large-area printing, cutting and installation. Stainless steel substr...

AI Technical Summary

Problems solved by technology

However, the heating rate of the stainless steel substrate is slow, the density is high, the electric heating element is bulky, and the firing temperature of the thick film circuit element is high, while the metal aluminum substrate has the advantages of light weight, good thermal conductivity, and easy processing. It is very suitable as a high-power electric heating thick film Circuit board use

However, the thermal expansion coefficient of metal aluminum is large, which does not match the current commonly used electronic paste, and the melting point of aluminum is relatively low, only about 660 ° C. The traditional high-temperature sintering process cannot be used when firing electric heating elements.