US 6,182,340 B2 · Method of manufacturing a co-fired flextensional piezoelectric transformer

Abstract

A method for manufacturing a cofired multi-layer piezoelectric transformer device includes forming first and second green shapes of a sinterable ceramic composition and applying metallization layer therebetween. Upon cofiring, the composite structure comprises first and second electroactive members bonded together by a conductive layer therebetween. External electrodes are applied and the electroactive members are polarized in a thickness direction, between their two major faces. The first and second electroactive members are arranged such that deformation of one electroactive member results in corresponding deformation of the other electroactive member. The device provides substantial transformation ratios in which relatively high power may be transferred in relation to the size of the unit, operability over wide input and output frequency bandwidths, and electrical isolation of the input voltage and current from the output voltage and current.

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Drawings

Claims8

Dependent claims

A method for manufacturing a piezoelectric transformer comprising the steps of:

obtaining a first sinterable non-oxide ceramic composition;
obtaining a second sinterable non-oxide ceramic composition;
mixing said first sinterable non-oxide ceramic composition with a first organic binder to form a first ceramic mixture;
mixing said second sinterable non-oxide ceramic composition with a second organic binder to form a second ceramic mixture;
forming a first green shape from said first ceramic mixture, said first green shape having two opposing major faces;
forming a second green shape from said second ceramic mixture, said second green shape having two opposing major faces;
applying a metallization material to at least one major face of each of said first and second green shapes, said metallization material comprising a third binder and a refractory metal;
pressing a metallized major face of said first green shape against a major face of said second green shape to form a green composite structure;
placing said green composite structure in a first atmosphere;
said first atmosphere being oxidizing to said first, second and third binders;
said first atmosphere being non-oxidizing to said refractory metal;
raising a temperature of said green composite structure to a temperature wherein said first, second and third binders thermally decompose;
raising a temperature of said green composite structure to a sintering temperature;
maintaining said sintering temperature until said green composite structure forms a sintered ceramic having two opposing major faces and a rare earth metal electrode;
lowering a temperature of said sintered ceramic from said sintering temperature to room temperature;
applying electrodes to said two opposing major faces of said sintered ceramic;
and
polarizing said sintered ceramic to form a piezoelectric transformer.

15 more elements

A method for manufacturing a piezoelectric transformer comprising the steps of:

obtaining a first sinterable ceramic oxide composition;
obtaining a second sinterable ceramic oxide composition;
mixing said first sinterable ceramic oxide composition with a first organic binder to form a first ceramic mixture;
mixing said second sinterable ceramic oxide composition with a second organic binder to form a second ceramic mixture;
forming a first green shape from said first ceramic mixture, said first green shape having two opposing major faces;
forming a second green shape from said second ceramic mixture, said second green shape having two opposing major faces;
applying a metallization material to at least one major face of each of said first and second green shapes, said metallization material comprising a third binder and a metal having a conductive oxide;
pressing a metallized major face of said first green shape against a major face of said second green shape to form a green composite structure;
placing said green composite structure in an oxidizing atmosphere;
raising a temperature of said green composite structure to a temperature wherein said first second and third binders thermally decompose;
raising a temperature of said green composite structure to a sintering temperature;
maintaining said sintering temperature until said green composite structure forms a sintered ceramic having two opposing major faces and a conductive metal oxide electrode;
lowering a temperature of said sintered ceramic from said sintering temperature to room temperature;
applying electrodes to said two opposing major faces of said sintered ceramic;
and
polarizing said sintered ceramic to form a piezoelectric transformer.

13 more elements

Dependencies are inferred from the claim text.

Description8,416 words

Summary3,070 words

#1. Field of Invention

#The present invention generally relates to flextensional piezoelectric transformers and actuators, and more particularly, to a method of manufacturing a flextensional multi-layer piezoelectric transformer/actuator by cofiring the ceramic composition with the electrode forming metallization.

#2. Description of the Prior Art

Brief description of the drawings6 figures

#FIG. 1 is a perspective view showing the construction of a Rosen-type piezoelectric transformer of the prior art;

#FIG. 2 is a perspective view showing the construction of a piezoelectric transformer using adhesives for bonding adjacent laminate layers;

#FIG. 3 is a flow diagram showing the steps of the cofiring process for producing a piezoelectric transformer in accordance with the preferred embodiment of the present invention;

Detailed description5,232 words

#With reference directed toward the appended drawings, a piezoelectric transformer/actuator (generally designated by the reference numeral 2) manufactured embodying the principles and concepts of the present invention will be described.

#As will be described more fully herein below, a piezoelectric transformer/actuator 2 is manufactured, in part, by first mixing a ceramic powder with a binder (step 100); forming green ceramic shapes (step 102); applying electrode materials (steps 104 and 114); and cofiring the composite structure (steps 106, 108, 110 and 112).

#Referring to FIG. 3: FIG. 3 is a flow diagram showing the steps in the preferred embodiment of the present invention, with individual steps denoted by three-digit reference indicia. The first step in the preferred embodiment of the present invention is to mix 100 a ceramic powder with an appropriate amount of a binder. This mixture of a powder and binder forms a sinterable ceramic composition which can produce an electrical ceramic upon firing the mixture.

Facts

Application

09/177,767Filed 23 Oct 1998

Granted

6 Feb 2001

Term ended

23 Oct 2018

Estimated · how

20 years from earliest known nonprovisional domestic filing. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination. Patent term adjustment is unavailable; no adjustment was added.

Classification6 codes

H10N 30/045
Treatments to modify a piezoelectric or electrostrictive property, e.g. polarisation characteristics, vibration characteristics or mode tuning: by…
H10N 30/097
Forming inorganic materials: by sintering
H10N 30/40
Piezoelectric or electrostrictive devices: with electrical input and electrical output, e.g. functioning as transformers
Y10T 29/42
Metal working: piezoelectric device making

Method of manufacturing a co-fired flextensional piezoelectric transformer

Life of this patent

Method of manufacturing a co-fired flextensional piezoelectric transformer

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims8

Description8,416 words

Drawings

Classification6 codes

Life of this patent

Description8,416 words