Medium-temperature sintering lead-free copper paste suitable for PZT sensor and preparation method of medium-temperature sintering lead-free copper paste

Abstract

The invention relates to the technical field of PZT sensors, in particular to medium-temperature sintering lead-free copper paste suitable for a PZT sensor and a preparation method of the medium-temperature sintering lead-free copper paste, and the lead-free copper paste comprises the following components in parts by mass: 70-80 parts of copper powder, 1-5 parts of lead-free glass, 1-5 parts of an inorganic additive and 15-25 parts of an organic carrier; the copper powder is one or two of superfine spherical powder and flaky micro powder; the lead-free glass is a mixture composed of glass powder A and glass powder B, the softening point of the glass powder A is 480-520 DEG C, and the softening point of the glass powder B is 520-560 DEG C; the inorganic additive is selected from one or two of electronic-grade bismuth oxide powder or superfine zirconium dioxide; the organic carrier comprises the following components in parts by mass: 70-80 parts of a solvent, 10-20 parts of ethyl cellulose, 5-10 parts of a macromolecular resin material and 1-5 parts of a flatting agent; on the premise of ensuring the conductivity, the silver powder is replaced by the copper powder, and meanwhile, the problem of binding force between the softened medium-temperature sintered glass and the ceramic substrate is solved.

Description

technical field [0001] The invention relates to the technical field of PZT sensors, in particular to a lead-free copper paste suitable for medium-temperature sintering of PZT sensors and a preparation method thereof. Background technique [0002] With the development of the electronics industry, the demand for sensors is increasing, the production cost of products is further reduced, corporate profits are gradually decreasing, and the industry is under increasing pressure on product costs. [0003] At present, the production process of the PZT sensor industry is generally as follows: ①. Preparation of ceramic chips; ②. Surface metallization (printing, drying, and sintering of electrode layers, 750-850 ° C); ③. High voltage polarization. It can be seen from the above process: First, the surface metallization sintering temperature is between 750-850 ° C, which has no advantages in energy consumption, time and other costs, especially for some special sensors at this temperature...

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Problems solved by technology

[0005] Replacing silver powder with copper powder will affect the conductivity of the electrode, and further lead to insufficient polarization in the later polarization process, thus affecting the performance of the PZT sensor;

[0006] The reduction of the sintering temperature will have an uncontrollable impact on the softening point of the glass (unless leaded glass is used, but this will not meet the requirements of RoHS), which will not only affect the bonding force between the electrode layer and the ceramic substrate, but also affect the electrode layer. The uniformity of distribution, which further affects the performance of PZT sensors

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