JPS6048115B2 - Method of manufacturing piezoelectric ceramic substrate - Google Patents

Abstract

PURPOSE:To stabilize the fabrication of a piezoelectric ceramic substrate by a method wherein a green sheet of piezo-electric ceramics 30mu-300mu thick is laminated and baked by using ZrO2 powders with impurity of 95% or larger and with sizing of 2mu-7mu in particle diameter. CONSTITUTION:A green sheet is produced by adding an organic binder and a plastic agent to Pb(Mg1/3Nb2/3)O3-Pb TiO3-PbZrO3 powder, and then after cutting into a fixed shape, ZrO2 powder sized for 2mu-7mu particle diameter and having the impurity of 95% or larger as an inserting powder for reactive use is superimposed, and this chip is baked as determined. Thus, a ceramic substrate with thin plate, especially 100mu or less thick, is produced with high stability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for manufacturing a piezoelectric ceramic substrate that involves spreading powder between sheets for the purpose of preventing reactions when stacking piezoelectric ceramic green sheets having a thickness of 30 to 300 μm. .

Piezoelectric ceramics have a wide range of uses, including spark plugs, ultrasonic vibrators, ceramic filters, sounding bodies, etc. Among them, their use as sounding bodies is remarkable. This is generally called a piezoelectric buzzer, and it belongs to the thin plate class based on the thickness classification of ceramic substrates. Conventionally, the thickness of ceramic substrates used in heating elements such as piezoelectric buzzers has mainly been 200 to 500μ, but there has been a growing demand for improved performance, such as making products lighter and smaller, as well as for low frequency and broadband applications. Ta.

Ceramic material composition and product design cannot meet these demands, and it is therefore necessary to manufacture ceramic substrates with a thickness of 100 μm or less, which is even thinner than conventional ceramic substrates.How can these thin green sheets be fired? is an important point in board manufacturing. Originally, important issues in the production of thin ceramic substrates include the production of green sheets, as well as the peelability of the substrates that occur during the sintering process, point adhesion, surface adhesion, and reactions between the substrates, as well as the smoothness of the substrate surface ( surface irregularities), warping, etc., and it can be said that these problems are more likely to be discovered as the thickness of the green sheet becomes thinner.

The present invention aims to solve these problems by using zirconia (Zr).
00) To produce a constantly stable piezoelectric ceramic substrate by pulverizing bed powder into a desired particle size distribution using a ball mill, drying it, and then classifying this zirconia (Zr00) into a predetermined particle size distribution. It is something that can be done. The manufacturing method of the present invention will be explained below.

First, the ceramic powder composition is Pb (Mg1l3Nb
213) 0. Using -PbTiO3-PbZr03, an organic binder, a plasticizer, etc. are added thereto to create a green sheet. 30 green sheets created in this way
, Owon・φ×O, 090-nrmt, and stacked 20 to 30 sheets in a pod using zirconium oxide (ZrO2) as a reaction powder, and fired at a firing temperature of 1.
300°C, holding time 1Hr) Raising/lowering temperature 200°ClHr
The ceramic substrate was obtained by firing under the following conditions. At this time, the comparison results between the conventional method and the method of the present invention depending on the difference in the zirconium oxide (Zr00) used are shown in the table below.
Shown in 1. In addition, Table 2 below shows the green sheet shape of the above example: 26.0Tmφ×0.

07 order t, and others * indicate the measurement results for each type of bedding powder on ceramic substrates prepared under the same conditions.

According to the method of the present invention, by using zirconium oxide (ZrO2), which has a purity of 95% or more and is classified with a particle size of 2 to 7μ, as a bed powder for preventing reactions when ceramic green sheets are stacked and fired, As is clear, it is possible to stably manufacture thin ceramic substrates, especially substrates of 100 μm or less, and is extremely effective.

Claims (1)

[Claims] 1 Piezoelectric ceramic green sheets with a thickness of 30 to 300 μ are cut into a predetermined shape, and used as a powder for preventing reactions when stacking and firing these sheets, with a purity of 95% or more and a particle size of 2 to 7
A method for manufacturing a piezoelectric ceramic substrate, characterized by using μ-classified zirconium oxide (ZrO_2).