Shading ceramic and preparation method thereof

Abstract

The invention discloses a light-shielding ceramic and a preparation method thereof. The light-shielding ceramic is composed of a ceramic layer, at least one high-refractive-index film reflection layer and at least one low-refraction-index film reflection layer. Its preparation method is to mix ceramic powder, binder, dispersant and solvent, form it by ball milling, sintering and polishing to obtain a ceramic layer; plate the corresponding high and low refractive index thin film reflection layers on the surface of the above ceramic layer according to requirements, and then . The light-shielding ceramic of the present invention includes a specific ceramic layer and a thin-film reflective layer. The light leaked by the ceramic layer can be totally reflected by the thin-film reflective layer of the present invention, so that the light-shielding ceramic achieves a complete light-shielding effect, and the thin-film reflective layer does not Conductive, overcomes the interference and weakening of fingerprint signal transmission caused by ink shading. The light-shielding ceramic of the present invention is composed of a specific ceramic layer and a specific film reflection layer, the combination of the two is firm, and the surface hardness is high, which can significantly improve the assembly qualification rate of the fingerprint recognition module.

Description

technical field [0001] The invention belongs to the field of material manufacture and application, and relates to a light-shielding ceramic and a preparation method thereof. Background technique [0002] Ceramic materials can be used in fingerprint identification modules or mobile phone exterior parts, but ceramic materials will leak light to varying degrees during use. In order to solve the problem of light leakage, the traditional method is to pre-screen the ink shading layer on the back of the ceramic material to prevent light transmission. However, since the screen printing ink contains a large amount of organic resin, its own low dielectric constant will seriously weaken the transmission strength of the capacitive signal, and even the fingerprint signal cannot be detected; and due to the surface appearance of the screen printing ink, it is easy to have screen printing defects, such as bumps, Pits, bubbles, uneven thickness, etc., will seriously interfere with the accur...

AI Technical Summary

Problems solved by technology

However, since the screen printing ink contains a large amount of organic resin, its own low dielectric constant will seriously weaken the transmission strength of the capacitive signal, and even the fingerprint signal cannot be detected; and due to the surface appearance of the screen printing ink, it is easy to have screen printing defects, such as bumps, Pits, bubbles, uneven thickness, etc., will seriously interfere with the accuracy of signal collection, and even cause damage to the fingerprint identification chip or misjudgment of signal collection, resulting in a low yield of modules

[0003] Since the screen printing ink contains a large amount of organic resin, its own low dielectric constant will seriously weaken the transmission strength of the capacitive signal, and even the fingerprint signal cannot be detected; and because the inorganic filler in the screen printing ink is difficult to disperse evenly, the surface is easily damaged after construction. The occurrence of silk screen defects, such as bumps, pits, air bubbles, uneven thickness, etc., will seriously interfere with the accuracy of signal collection, and even cause damage to the fingerprint recognition chip or misjudgment of signal collection, resulting in a low yield of modules