JPH0256828B2 - - Google Patents

Abstract

PURPOSE:To manufacture a unified solid-state element, which can be driven at low voltage, by exposing internal electrode layers in a laminated chip capacitor type laminate, in which electrostrictive materials and internal electrodes are laminated alternately, on every other layer and in the whole. CONSTITUTION:Electrostrictive materials 11 in sections in which strain is not generated and electrostrictive materials 12 in sections in which strain is generated are laminated alternately together with internal electrodes 13, 14, and a laminate is cut so that the internal electrodes 13 are exposed on one side and the internal electrodes 14 on the other side on every other layer respectively and both internal electrodes 13, 14 are all exposed on both side surfaces. Temporarily mounted external electrodes 15, 16 are applied and baked on both sides so that the electrode 15 is electrically connected to the internal electrodes 13 and the electrode 16 to the internal electrodes 14. Glass powder is attached 17 onto the internal electrodes 13, and external electrodes 21 are formed. Glass powder is also attached 17 similarly onto the internal electrodes 14 on an opposite side surface, and external electrodes are shaped.

Description

Detailed Description of the Invention (Field of Industrial Application) The method of the present invention applies to electrostrictive elements (electromechanical devices) such as drive elements and minute displacement elements that utilize the electrical and mechanical energy conversion capabilities of piezoelectric or electrostrictive materials. The present invention relates to a method of manufacturing a base.

(Prior Art) Conventionally, elements utilizing piezoelectric or electrostrictive effects have been manufactured with structures as shown in FIGS. 1a and 1b. First, a cylindrical piezoelectric or electrostrictive material of 0.2
Slice into ~1.0mm thick pieces and burn electrode 2 on the top and bottom surfaces. A large number of thin plates 1 are glued together using an adhesive 3. If necessary, use bolts or the like to sandwich and fix the top and bottom surfaces. The external electrodes are connected to each other every other layer and to external terminals 4 and 5 on the positive side and negative side. between both terminals
By applying a DC voltage of 200V to 1000V, the element expands at a rate of about 10 ^-3 in the stacking direction of the thin plates. Also, if used in a restrained state, 3.5×10 ⁷ N/
Generates stress of about m ² .

(Problems with the prior art) Although the element of this structure has features such as being small, generating a large force, and having a fairly fast response speed of about 40 μsec, it has several drawbacks. One of them is that there is a limit to the thinness of the thin plate because it is made by slicing, and it requires 200V to drive.
Requires high voltage of around 1000V. Because the thin plates are glued together with adhesive, the total thickness of the adhesive layer, which has a low Young's modulus, increases in inverse proportion to the thickness of the thin plates, which absorbs displacement and generated stress during driving, making it difficult to mass-produce. There are drawbacks.

(Object of the invention) The object of the invention is to eliminate the above-mentioned drawbacks.
An object of the present invention is to provide a manufacturing method for stably mass-producing an integrated solid-state device that can be driven at a low voltage of 100V or less.

(Structure of the Invention) The present invention is a multilayer chip capacitor type laminate in which electrostrictive materials and internal electrodes are alternately stacked,
A step of producing a laminate having two opposing side surfaces on which internal electrode layers are exposed every other layer and two opposing side surfaces on which all internal electrode layers are exposed; Step 1 of forming an external electrode, and forming an insulator on every other internal electrode layer and its vicinity on one side of the two side surfaces where all the internal electrode layers are exposed, and forming the insulator on the other side. A step of forming an insulator on every other internal electrode layer different from the internal electrode layer and its vicinity, and connecting the exposed internal electrodes across the exposed internal electrodes at opposing positions on each of the two side surfaces on which the insulators are formed. forming one or more sets of second external electrodes; This is a method of manufacturing an electrostrictive effect element, characterized in that it includes a step of disconnecting and disconnecting between the two electrodes.

(Detailed explanation of the structure) The manufacturing method of the present invention employs an internal electrode type, so that the distance between the electrodes can be easily narrowed to 100 μm or less, and low voltage driving becomes possible. Moreover, as a result of becoming an integrated solid-state device, the influence of adhesive can be removed, resulting in faster response. Furthermore, by processing the large laminate as it is, it became possible to electrically connect 10 elements at the same time, making it a manufacturing method that could be mass-produced.

(Examples) The present invention will be described in detail below based on Examples. Magnesium lead niobate (Pb (Mg1/3Nb2/
₃ ) A slurry was prepared by adding a small amount of an organic binder to an electrostrictive material pre-fired powder containing lead titanate (PbTiO ₃ ) and lead titanate (PbTiO 3 ) as main components, and dispersing this in an organic solvent. This slurry was coated onto a Mylar film to a thickness of about 100 microns using a casting film-forming device used in the production of conventional multilayer ceramic capacitors and dried. This was peeled off from the film to obtain an electrostrictive material green sheet. Some of the green sheets were further screen-printed with platinum paste as internal electrodes. Several 100 of these green sheets were stacked, pressed together using a hot press, and then fired at 1250°C to obtain an electrostrictive material laminate. This was cut at a position where the internal electrodes were exposed on the surface every other layer, two temporary external electrodes were coated and baked, and the sides were further cut to expose the internal electrodes. The electrostrictive material laminate thus obtained is applied to electrophoresis. FIGS. 2 and 3 are perspective views showing exposed end faces of internal electrodes of this electrostrictive material laminate. A large number of internal electrodes 13 and 14 are alternately connected to two temporary external electrodes 15 and 16 at every other layer.

Next, a suspension containing charged glass powder is prepared by the following method. Mix 30 g of zinc borosilicate crystallized glass powder, 290 ml of ethanol, and 10 ml of 5% iodine ethanol solution using a high-speed homogenizer.
Iodine acts as an electrolyte, and the glass powder is positively charged. After applying ultrasound for 30 minutes,
Leave to stand for 30 minutes to remove the precipitate and use the remaining suspension.

After covering one side of the exposed end surface of the electrostrictive material laminate with an adhesive tape to prevent it from getting wet with the suspension, the electrostrictive material laminate is submerged in a container filled with the suspension. At a distance of 1 cm in front of the end face of the laminate to which it is to be attached, sink a stainless steel counter electrode plate that is slightly larger than the end face to which it is to be attached. Connect the counter electrode plate to the positive terminal of the DC power supply, and
The temporary external electrode 16 is connected to the counter electrode and set to the same potential in order to prevent any adhesion on the surface.
Connect the temporary external electrode indicated by 15 to the negative terminal, and apply a voltage of 20V for 300 seconds. When the suspension was removed from the suspension and dried, glass powder 17 with a width of 100 microns was obtained on the surface of the electrostrictive material on and around the exposed portion of the internal electrode, as shown in FIG.

After removing the adhesive tape on the back, heat at 705℃ for 10
By holding it for a minute, it is fired and fixed to form a glass film.

Next, a glass coating is formed on the opposite side. After protecting the surface on which the film has already been formed by covering it with adhesive tape, connect the temporary external electrode indicated by number 16 in the figure to the negative terminal of the DC power supply, and apply voltage in the same manner as the first time, to form the inner part indicated by 14. Glass powder is deposited on the exposed part of the electrode and the ceramic around it.
This is fired in the same manner as the first time to form a band-shaped glass coating. FIG. 5 is an external view of the laminate after the glass coating has been formed. Number 18 in the figure indicates a glass coating.

Next, external electrode paste is applied and baked at several locations across the remaining internal electrode exposed portions and the insulator. External electrodes are similarly formed on the back surface of the laminate. FIG. 6 is an external view of an electrostrictive material laminate in which a plurality of external electrodes are formed. Number 21 in the figure is an external electrode. Thereafter, it is cut along the part indicated by the broken line in the figure, and the part indicated by number 20 in the figure is used as an element.

FIG. 7 shows an external view of the element to which electrical connections have been made. Numbers 22 and 23 in the figure indicate negative side and positive side external connection terminals, respectively.

(Effects of the Invention) By the method of the present invention, it has become possible to stably mass-produce an integrated all-solid-state electrostrictive element that exceeds the performance of the conventional single-plate lamination type in all respects. In other words, the driving voltage is from 200V to 1000V
The voltage dropped to below 100V, and the response speed improved from about 40μsec to less than 10μsec. In addition, the technology of laminated ceramic capacitors and the insulation effect of glass coatings using electrophoresis have made it possible to process a large number of devices simultaneously, greatly improving productivity and reliability.

[Brief explanation of drawings]

FIGS. 1a and 1b are external views showing an element having a single-plate laminated structure that utilizes piezoelectric or electrostrictive effects, and the thin plates that are its constituent elements. In the figure, 1 is a thin plate of piezoelectric material or electrostrictive material, 2 is a baked electrode, 3 is an adhesive layer, and 4 and 5 are positive and negative external connection terminals, respectively. FIGS. 2 and 3 are external views showing the front and back sides of an electrostrictive material laminate with temporary external electrodes to which the electrophoresis method is applied. In the figure, 11 is the electrostrictive material in the part that does not generate strain, 12 is the electrostrictive material in the part that generates strain, 13 and 14 are internal electrodes, 15 and 16 are temporary external electrodes, and Figures 4 and 5 are the inside. FIG. 2 is an external view showing an electrostrictive material laminate in which glass powder is deposited every other layer on ceramics in and around exposed electrode parts. In the figure, 17 is the attached glass powder or glass coating;
18 is an attached glass powder or glass coating, and FIG. 6 is an external view showing an electrostrictive material laminate on which external electrodes are formed. In the figure, 21 is an external electrode, and FIG. 7 is an external view showing an electrostrictive effect element. In the figure, 22 and 23 indicate negative side and positive side external connection terminals, respectively.

Claims (1)

[Scope of Claims] 1. A multilayer chip capacitor type laminate in which electrostrictive materials and internal electrodes are alternately laminated, and in addition to two opposing sides where internal electrode layers are exposed every other layer, all the internal electrodes are a step of producing a laminate having two opposing side surfaces with exposed layers, a step of forming first external electrodes on the two side surfaces where the internal electrodes are exposed every other layer, and a step of forming the first external electrodes on the two side surfaces where all the internal electrode layers are exposed. an insulator is formed on every other internal electrode layer and its vicinity on one side, and an insulator is formed on every other internal electrode layer different from the internal electrode layer on which the insulator is formed and an insulator on the other side. a step of forming;
a step of forming at least one set of second external electrodes to connect across the exposed internal electrodes at opposing positions on each of the two side surfaces on which the insulator is formed; between the external electrodes or the first
and a step of cutting between the second external electrodes and between the plurality of sets of second external electrodes. 2. To form the insulator, the laminate and the counter electrode plate are placed in a suspension containing charged insulator powder, and the exposed internal electrode layer covering the insulator and the counter electrode plate are used as electrodes for electrophoresis. A method of manufacturing an electrostrictive effect element according to claim 1, wherein the electrostrictive element is coated with an insulating material and then baked and fixed.