JPH0416767B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a method for manufacturing a ceramic element, in particular,
The present invention relates to a method of manufacturing a light shutter or other ceramic element having an electrode array, which is formed by forming a large number of mutually opposing electrodes on both sides of a translucent ceramic wafer or an alumina wafer.

(Prior Art) Generally, a ceramic element having an electrode array,
For example, when manufacturing an optical shutter, it is required to form a large number of opposing electrodes on both surfaces of a ceramic wafer in order to reduce the drive voltage of the shutter and improve optical uniformity.

(Problem to be Solved by the Invention) However, it is extremely difficult to extract a large number of mutually independent electrodes from both surfaces of a wafer by wire bonding because the electrode pitch is extremely small, several hundred μm or less. However, the thinner the wafer, the more easily it is damaged, making mass production virtually impossible.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method that can easily and in large quantities produce a ceramic element having an electrode array having a structure in which electrodes facing each other are connected to each other.

(Means for Solving the Problems) As a means for solving the above problems, the present invention provides a method for connecting a plurality of electrodes formed facing each other on both surfaces of a ceramic wafer via conductive parts formed on the end faces thereof. In manufacturing a connected ceramic element, before or after forming a plurality of electrodes on both surfaces of a ceramic wafer, (a) a plurality of ceramic wafers are stacked and tightly fixed with a flammable bonding agent to form a block; (b) forming a large number of recesses extending in the stacking direction on the end face of each ceramic wafer, and (c) forming a large number of recesses in the thickness direction on the end face of each ceramic wafer; After applying a conductive paste to the end surface with the recess formed therein, the paste is fired to form a conductive layer on the end surface of the ceramic wafer, and the process of separating the ceramic wafers into individual ceramic wafers; The present invention provides a method for manufacturing a ceramic element, which comprises the step of removing the conductive layer formed on the end face other than the recessed portion of the formed conductive layer.

Before or after the formation of the conductive layer, electrode layers are formed on both surfaces of the ceramic wafer, and then a large number of electrodes are formed by photolithography. It is preferable to employ a dry thin film forming method such as a vapor deposition method, a sputtering method, or an ion plating method.

As the combustible bonding agent, any material can be used as long as it burns and disappears when the conductive base is baked to form the conductive layer, and typical examples include wax.

(Function) The method of the present invention involves stacking a large number of ceramic wafers and tightly fixing them with a flammable bonding agent such as wax to form a block. and prevent damage during machining.
In addition, by using a flammable bonding agent such as wax as a means of closely fixing the ceramic wafers, the conductive layer is formed by baking after applying the conductive paste, and at the same time, the separation into individual ceramic wafers can be automatically performed. , to simplify the work.

Hereinafter, the present invention will be specifically described with reference to the accompanying drawings. This example describes a case where a conductive layer is formed in a recessed portion.

In the figure, 1 is a ceramic wafer, 2 is an electrode, 3 is a recess, and 4 is a conductive part. The ceramic element shown in FIG. 1 consists of a ceramic wafer 1, electrodes 2 formed on both surfaces thereof facing each other, and a conductive part 4 connecting the electrodes 2 facing each other, and the electrodes 2 are spaced apart from each other at a predetermined distance. They are formed parallel to each other. The front and back facing electrodes 2 are shown in FIGS. 2 and 3.
As shown in the figure, conduction is provided by a conductive portion 4 formed in a recess 3 formed in the thickness direction on the end surface 1a where the electrodes 2 intersect. Note that the intersection between the surface of the wafer 1 and the bottom surface of the recess 3 is inclined.
The electrode 2 and the conductive portion 4 are completely connected.

Since the ceramic element with the above structure has conductive electrodes on both its front and back surfaces, it is only necessary to bond the electrode on one side, and therefore mounting to a package and wire bonding can be performed in the same way as an IC chip. can.

For example, when manufacturing an optical shutter, the ceramic element having the above structure is obtained by stacking several or more PLZT or other transparent electro-optic ceramic wafers 1 of a predetermined thickness and coating them with wax or the like, as shown in FIG. Fix it tightly and make it into a block. Next, a large number of recesses 3 in the thickness direction are formed on the end surface of the wafer using a laser beam, a diamond cutter, or other means (see FIG. 5). Next, the end surface 1 with the recess 3 formed therein is
Silver paste is applied to the entire surface of a and baked to form a conductive layer. When the silver paste is fired and baked in air, the wax that holds the wafers together burns away and the wafer blocks are separated into individual wafers. Electrode layers are formed on both the front and back surfaces of each wafer by a dry plating method such as vacuum evaporation or sputtering with aluminum or other suitable electrode material, and then photoresist is coated to form a uniform resist thin film. This thin resist film is exposed with a mask in close contact with the resist film, and the unexposed parts of the resist film are dissolved and removed using a developer to expose the underlying electrode layer, which is then etched.The resist used as an etching mask is then etched. to expose the formed electrode. Next, the end face of the wafer is polished, and the extra conductive layer formed on the protruding part of the end face is removed, leaving only the conductive layer formed in the recessed part as a conductive part, thereby producing a ceramic element having an electrode array. Manufactured.

(Example) A PLZT translucent ceramic wafer with a thickness of 500 μm
Harden 100 sheets with wax and cut the edges with a diamond cutter at 500μm pitch, width 250μm, depth 100μm.
After forming the concave portion, silver paste was applied to the end face, and this was baked in air at 800°C to form a conductive film. Each wafer with this conductive film formed thereon is placed in a vacuum evaporation device, and after aluminum is vapor-deposited on both sides, synthetic rubber thread photoresist (KMR747 manufactured by Kodatsu Corporation) is applied to both sides and dried to form a thin resist film. Then, a photomask is attached to this and exposed to ultraviolet light, developed with a KMR developer, processed with a KMR rinse, and heated to harden the resist. Next, the exposed aluminum was etched using a caustic soda-based etchant, and the resist was removed using a synthetic rubber-based resist remover (OMR502 manufactured by Tokyo Ohka Kogyo Co., Ltd.).The wafers were then stacked and solidified with wax, and the edges of each wafer were polished. After cleaning, the light shutters shown in FIGS. 1 to 3 were obtained.

In this optical shutter, since the opposing electrodes 2 formed on both surfaces of the wafer were connected by a conductive part, mounting and wire bonding could be easily performed.

In the above description, a ceramic element using a square plate-shaped wafer was used as an example, but the same applies to a disc-shaped wafer, in which protrusions or depressions are formed on both end faces of the wafer, and conductive parts are attached to them. may be formed. It goes without saying that alumina and other arbitrary materials can be used as the ceramic material.

(Effects of the Invention) As is clear from the above description, according to the present invention, when forming a conductive layer that connects opposing electrodes on both the front and back surfaces of a ceramic element, the conductive layer is processed for each individual ceramic wafer. Instead of forming a conductive layer, a large number of ceramic wafers are used as a block, so the wax etc. acts as a buffer to prevent damage, and the process from forming the recesses to forming the conductive layer can be simplified. A conductive layer can be formed on a ceramic wafer all at once. In addition, flammable bonding agents such as wax, which are used as means for closely fixing a large number of ceramic wafers, burn and disappear naturally when fired after applying the conductive paste, so a special process is required to separate the individual ceramic wafers. This is unnecessary, and therefore it is possible to facilitate the formation of a conductive layer and to mass-produce ceramic devices.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of a ceramic element according to the present invention, Fig. 2 is a partially enlarged view thereof, Fig. 3 is an enlarged view of a main part of a cross section taken along the - line in Fig. A perspective view of the manufacturing process, and FIG. 5 is a partially enlarged view thereof. 1... Ceramic wafer, 2... Electrode, 3...
Recessed portion, 4... conductive portion.

Claims (1)

[Scope of Claims] 1. In manufacturing a ceramic element in which a plurality of electrodes formed opposite to each other on both surfaces of a ceramic wafer are connected via conductive parts formed on the end faces thereof, both surfaces of the ceramic wafer are Before or after forming a plurality of electrodes on the wafer, (a) stacking a plurality of ceramic wafers and tightly fixing them with a flammable bonding agent to form a block; (c) forming a large number of recesses extending in the thickness direction on the end face of each ceramic wafer; is fired to form a conductive layer on the end surface of the ceramic wafer,
A method for manufacturing a ceramic device comprising the steps of: separating the ceramic wafers into individual ceramic wafers; and (d) removing the conductive layer formed on the end surface of each ceramic wafer other than the recessed portion. .