For tape casting


Tape casting, also known as belt casting method and scraper method, is a relatively mature forming method that can obtain high-quality and ultra-thin ceramic chips. It has been widely used in the production of advanced ceramics such as monolithic capacitor ceramic chips, thick film and thin film circuit substrates. It is a special molding method for ceramic substrate, especially suitable for molding 0.2MM -- 3MM thick ceramic sheet products. The production of such products has many advantages such as fast speed, high automation, high efficiency, uniform organizational structure, and good product quality.

Tape casting, also known as belt casting method and scraper method, is a relatively mature forming method that can obtain high-quality and ultra-thin ceramic chips. It has been widely used in the production of advanced ceramics such as monolithic capacitor ceramic chips, thick film and thin film circuit substrates. It is a special molding method for ceramic substrate, especially suitable for molding 0.2MM -- 3MM thick ceramic sheet products. The production of such products has many advantages such as fast speed, high automation, high efficiency, uniform organizational structure, and good product quality.
Tape casting is a very precise process, and the requirements for the quality of products after tape casting are very strict. The following points can be referred to:
1. Surface finish of scraper
Casting scraper is generally made of tool steel, which has good wear resistance and long service life. However, attention should be paid to maintenance. It must be cleaned after each use to prevent hard objects from scratching the surface and keep the scraper smooth and flat. Smooth and flat scraper is the key to obtain film with uniform thickness and smooth surface.
2. Liquid level of slurry tank
As the liquid level of the slurry tank increases, the pressure in the slurry tank increases, which increases the inflow speed of the slurry through the scraper gap and increases the thickness of the cast film. Therefore, it is very important to maintain a uniform liquid level to control the uniformity of the cast film thickness. Large tape casting equipment usually needs to be equipped with liquid level sensor to control the slurry supply valve and control the change of liquid level height in the minimum range.
3. Slurry uniformity
The slurry used for tape casting must be fully and evenly dispersed. When there are hard blocks and aggregates that are not well dispersed and cannot be filtered out, scar like defects will occur on the membrane belt, or depression will occur due to different drying and sintering shrinkage. Therefore, attention must be paid to the preparation of slurry, and these hard lumps and aggregates must be removed by sieving before use. If there are bubbles in the slurry, defoaming treatment must be carried out before casting.
4. Casting thickness
The thickness of the scraper gap is not consistent with the actual drying and molding thickness. It should be due to the volatilization of solvent during the drying process. When the slurry is stable and other conditions such as flow rate and drying temperature are fixed, there will be a stable proportion. In general, effective parameters can be obtained through tape casting test.
5. Develop and implement the best drying process
The tape cast slurry film can be peeled off from the substrate after drying. Therefore, it is an important factor to establish a suitable drying process to obtain high-quality film. If the drying process is not properly formulated, the cast film will often have defects such as bubbles, pinholes, wrinkles, dry cracks, and even difficult to fall off from the substrate. The principle for formulating drying process is to ensure that the solvent is used slowly, so that the diffusion speed of the solvent in the film is consistent with the surface volatilization speed, and to prevent the late cracks, blisters, wrinkles and other defects caused by premature hardening of the surface.