Unlock instant, AI-driven research and patent intelligence for your innovation.

Recycling and reuse method for lithium tantalite black sheets

A technology of lithium tantalate to lithium tantalate, applied in the field of crystal post-processing, can solve the problems of increasing operating costs and low efficiency, and achieve the effects of reducing production costs, ensuring piezoelectricity and monodomain properties, and achieving significant economic benefits.

Active Publication Date: 2018-10-09
CHINA ELECTRONICS TECH GRP NO 26 RES INST
View PDF9 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Aiming at the disadvantages of low efficiency and increased operating costs in the existing technology for processing unqualified black chips, the purpose of the present invention is to propose a method for recycling lithium tantalate black chips, which can be used without affecting product performance. Save costs and improve utilization

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0031] In the preparation process of lithium tantalate black sheet, because it is carried out in a reducing atmosphere, oxygen diffuses outward from the crystal, which increases the concentration of oxygen vacancies, and the oxygen vacancies obtain an electron to form an F color center (F+), which enhances the electrical conductivity. Rate. The color center absorbs strongly in the visible light region, making the chip black. At the same time, the valence of some Ta ions changes from +5 to +4, and the electron carriers increase accordingly, so the resistivity decreases.

[0032] On the contrary, the present invention can fill the oxygen vacancy in the lithium tantalate black sheet by oxidizing the unqualified lithium tantalate black sheet in an oxidizing atmosphere. The valency of the Ta ions therein was changed from +4 to +5, again to a conventional "white" wafer.

[0033] In this method, unqualified lithium tantalate black chips are oxidized, also known as "whitening" treat...

Embodiment 1

[0035] Embodiment 1: blackening inhomogeneous lithium tantalate black sheet, color is too black (resistivity is generally lower than 10 10 Ω.cm) lithium tantalate black sheet, the color is too light (resistivity is generally higher than 10 11 Ω.cm) Lithium tantalate black pieces are loaded into quartz boats in turn, and put into a heat treatment furnace, vacuumed to below 100Pa; filled with oxygen to an atmospheric pressure; unqualified tantalum to be treated at a rate of 80 ° C / h The lithium tantalate black sheet was heated from room temperature to 600°C; kept at the holding temperature for 24 hours; after the holding temperature was completed, it was cooled to room temperature at a rate of 80°C / h to obtain a lithium tantalate white sheet with a resistivity of about 1×10 14 Ω.cm; after blackening treatment again, the required qualified lithium tantalate black sheet is obtained.

Embodiment 2

[0036] Embodiment 2: blackening inhomogeneous lithium tantalate black sheet, color is too black (resistivity is generally lower than 10 10 Ω.cm) lithium tantalate black sheet, the color is too light (resistivity is generally higher than 10 11 Ω.cm) Lithium tantalate black slices are loaded into quartz boats in turn, and put into a heat treatment furnace, vacuumed to below 100Pa; filled with oxygen to an atmospheric pressure; unqualified tantalum to be treated at a rate of 90 ° C / h Heating the lithium tantalate black sheet from room temperature to 600°C; keeping it at the holding temperature for 60 hours; after the holding temperature, cooling to room temperature at a rate of 90°C / h to obtain a lithium tantalate white sheet with a resistivity of about 6×10 14 Ω.cm; after blackening treatment again, the required qualified lithium tantalate black sheet is obtained.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
electrical resistivityaaaaaaaaaa
Curie pointaaaaaaaaaa
electrical resistivityaaaaaaaaaa
Login to View More

Abstract

The invention discloses a recycling and reuse method for lithium tantalite black sheets. The method comprises the following steps: putting unqualified lithium tantalite black sheets to be treated intoa thermal treatment furnace, carrying out thermal treatment in an oxygen atmosphere within 400 DEG C to the Curie temperature of lithium tantalite, and cooling so as to obtain lithium tantalite whitesheets; further carrying out blackening treatment on the lithium tantalite white sheets so as to obtain lithium tantalite black sheets, thereby completing recycling and reuse of the unqualified lithium tantalite black sheets. By adopting the method, the lithium tantalite black sheets with unqualified or improper blackening electrical resistivity can be recovered into uniform lithium tantalite white sheets, and a basis can be made to obtain uniform qualified lithium tantalite black sheets; as a thermal treatment temperature is controlled within the Curie temperature of lithium tantalite, the piezoelectricity and the single domain property of a lithium tantalite wafer can be ensured.

Description

technical field [0001] The invention relates to crystal materials, in particular to a method for recycling lithium tantalate black chips, and belongs to the field of crystal post-processing. Background technique [0002] Lithium tantalate (molecular formula LiTaO 3 , referred to as LT) is an important multifunctional crystal material, which has outstanding advantages such as large piezoelectric coefficient, high electromechanical coupling coefficient, small frequency temperature coefficient and low insertion loss. The most important substrate material for surface wave (SAW) filters has huge market prospects in the fields of smart phones and military electronics. [0003] In industry, lithium tantalate crystals are mainly grown by the Czochralski method in an inert atmosphere or an inert atmosphere containing a small amount of oxygen, and then annealed and polarized. Finally, after orientation, spheronization, cutting, grinding, polishing and other processes, lithium tantal...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C30B33/02C30B29/30
CPCC30B29/30C30B33/005C30B33/02
Inventor 龙勇于明晓石自彬丁雨憧徐扬李和新
Owner CHINA ELECTRONICS TECH GRP NO 26 RES INST