**2. Photoresist process**

technology. The ceramic material is used for various fields. The most general product is a dinnerware. In addition, examples of being used as vehicle parts have also been reported because it is a high-temperature-tolerant material and it has a chemical resistance [1, 2]. Particularly,

In the electronic components field, a miniaturization technology is an important factor. Communication devices such as a PC or smartphone have desired the miniaturization and a high functionalization. To miniaturize a device body, the miniature integrated components and the miniature control circuit are required. By realizing the miniature control system, many components and the large battery can set in the miniature communication devices. Moreover, the miniaturization of the control systems possible a low-loss system because cir-

To achieve the miniature control system, the ceramic material is used for the integrated circuit (IC) packaging [3] and the miniature electronic components. The fine ceramic has some elec-

The conventional fabrication process of the ceramic passive components is the sheet process of the multi-layer ceramic technology [9]. The ceramic components are formed through a firing process. However, the fired ceramic is hard material and it is difficult for any processing. Therefore, it forms the ceramic sheet that is the mixture of the ceramic powder, a binder, and organic solvents, in the first step. The circuit wire patterns are printed on these sheets. After that, the printed sheets are stacked and laminated. In this process, the circuit patterns require a connection between an upper layer and a lower layer. The connection pattern is achieved by forming a through-hole pattern and filling the conductive paste at the printing process. The laminated ceramic sheets are dicing to the designed size, and then, the miniature multi-layer ceramic components are achieved by the firing process. The advantages of this technology are that the three-dimensional (3D) circuit pattern is realized inside the ceramic material, and the

However, the conventional fabrication process has some problem for further miniaturization. The circuit pattern is formed by a screen printing process in general. This technology shows high productivity, it is suitable for the electronic components. The conductive pattern is made from a conductive paste and it is printed through a mesh pattern. The printed paste requires the leveling time for removing the mesh mark. It is the cause of a deformation of the conductive pattern. In the fine pattern, the adjacent conductors are connected and shorted. And then,

Moreover, a high-functional device will be required, and a complex component that has various characteristics will be desired for the miniaturization. To achieve the complex component, the various materials are introduced. However, the conventional research of the different ceramic material pattern is inserting the ceramic sheet [10]. Therefore, it is difficult to

In this chapter, the photoresist process is proposed. It is possible to form the fine and highaspect-ratio conductive pattern. The proposed process uses a photolithography process for the

is used as the piezoelectric ceramic. These ceramic materials sup-

is ferroelectric

the ceramic material is paid attention as electronic components.

port the miniaturization of passive components [4–8].

electronic characteristics can use for the components.

to form a fine and high-aspect-ratio pattern is difficult.

form the one point different material pattern.

ceramic, and Pb (ZrTi) O3

134 Powder Technology

cuits wire that connects to each electronic components become short length.

tronic characteristics. Ferrite ceramic shows magnetic characteristic, BaTiO3

In this chapter, the fabrication process for the ceramic electronic components is proposed. The multilayer ceramic technology is usually used for the fabrication process of the ceramic components, but it has some problems. Therefore, the photoresist process is proposed for the production process. The concept, base process and applications of the photoresist process as is following.

**Figure 1.** Schematic illustration of photoresist process (a) patterned ceramic sheet process, (b) patterning process.

#### **2.1. Concept and base process of photoresist process**

The proposed process uses the photoresist pattern. The first step, the photoresist is exposed for forming the designed pattern. The sacrifice patterns of the photoresist are obtained after development. In a case of a ceramic sheet with a through-pattern, the green sheet of the base material is formed using the doctor blade. At the time, the gap between the blade and the surface of the resist film is adjusted to zero. Therefore, the slurry fills surrounding the sacrifice pattern. Then, the specimens are dried. After the sacrifice pattern is dissolved, the green sheet of the base material with the through-pattern is achieved. To form the pattern, the through-pattern is exposed and developed on the photoresist. The ceramic slurry or conductive paste is filled into the through-pattern, after the dissolving process, the ceramic pattern, or conductive pattern is achieved. **Figure 1** shows the schematic illustration of the process for producing the patterned different material into the green sheet.

A liquid type photoresist and a film type photoresist are chosen for the achieved pattern. For a fine pattern, the liquid type photoresist is used. And then, the film type photoresist is employed for forming the sheet pattern because it realizes the uniform thickness. In this chapter, the different pattern process uses the film type photoresist, and the fine conductive pattern uses the liquid type.

The advantage of this process is that it uses a photolithography process. The photolithography process is used for the IC or microelectromechanical systems (MEMS) sensor fabrication process. Both products have a fine conductive pattern and miniature structure. Therefore, the proposed process that uses the photolithography process is suitable to miniaturize. Moreover, the flexible pattern designing is possible. In addition, the sacrifice resist pattern forms the through-hole pattern. On the other hand, it is a mask pattern that covered on the ceramic sheet. The photoresist mask pattern holds the filling paste as the ceramic slurry or conductive paste. It is possible to form the high-aspect-ratio pattern. These characteristics are used for the production process of the miniature ceramic components.

> space were 10 μm, respectively. The conductive paste that combined with microparticle metal powder (under 0.1 μm) was used. The filled conductive paste was dried on the hot plate keep-

> **Figure 2.** Fabrication process of fine conductive pattern. (1) glass substrate is coated with liquid type photoresist.

Powder Process with Photoresist for Ceramic Electronic Components

http://dx.doi.org/10.5772/intechopen.76881

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The low viscosity paste was required for form the fine pattern, the photoresist pattern held the paste at the drying process. It can form the high-aspect-ratio pattern. The developed photoresist pattern and the conductive pattern on the glass substrate are shown in **Figures 3** and **4**.

ing 60°. After that, the photoresist pattern was removed by remover.

**Figure 3.** Patterned liquid type photoresist for fine conductive pattern.

(2) exposed and developed. (3) filled paste and dissolved.
