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

Edge processing method for large-size ultrathin high-precision lithium niobate wafer

An edge processing, lithium niobate technology, used in metal processing equipment, chemical instruments and methods, machine tools suitable for grinding workpiece edges, etc. Low hardness and other problems, to achieve good lubrication and cooling effect, improve the explosive edge and corner, improve the effect of poor finish

Active Publication Date: 2021-11-30
TDG HLDG CO LTD
View PDF17 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Compared with silicon crystals and sapphire crystals, lithium niobate has lower fracture toughness and hardness, for example, its fracture toughness is one-third of silicon and one-tenth of sapphire, so lithium niobate crystals are more stable than silicon during processing. Crystals and sapphire crystals are more susceptible to damage, especially in the wafer edge processing process, which is more likely to cause problems such as wafer chipping, edge chipping, and poor roundness, which seriously affect subsequent processing processes such as grinding and polishing.
In addition, due to the larger the wafer size and the smaller the thickness, the difficulty of wafer processing is higher, which further increases the probability of damage to large-sized ultra-thin lithium niobate wafers during processing, resulting in high wafer scrap rates and low processing efficiency. Low, greatly increasing the production cost of the enterprise
[0004] The invention patent with the publication number CN103381568A discloses a method for polishing the edge of a glass sheet, which mainly uses a cutter wheel to polish the edge of the glass sheet. The runner is made of metal and cannot perform nano-scale edge polishing
[0005] The invention patent with the publication number CN109894962A discloses an edge polishing method. The main edge polishing needs to use a chemical solution at 50°C to 80°C to clean the wafer. However, in actual operation, when the lithium niobate wafer is cleaned at high temperature, it is easy to chip breakage
[0006] The invention patent with the notification number CN101930908B discloses a method for polishing the edge of a semiconductor wafer, which mainly presses the semiconductor wafer and the polishing drum together, and performs edge polishing under the action of the polishing liquid, but in actual operation, this method mainly performs The edge polishing process of a single wafer, the processing efficiency is low
[0007] Therefore, there is a lack of an edge processing method for obtaining high-precision large-scale ultra-thin lithium niobate wafers in the prior art

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Edge processing method for large-size ultrathin high-precision lithium niobate wafer
  • Edge processing method for large-size ultrathin high-precision lithium niobate wafer
  • Edge processing method for large-size ultrathin high-precision lithium niobate wafer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039]a) Put the lithium niobate wafer into the edge chamfering machine, use the 800# R-type metal grinding wheel to process the edge of the wafer for the first time, and use the 1500# R-type metal grinding wheel to process the second wafer with a removal amount of 0.15mm Edge processing, the removal amount is 0.05mm to obtain R-type lithium niobate wafers;

[0040] b) Place the chamfered lithium niobate wafer in a sealed container filled with a uniform mixed solution of nitric acid and hydrofluoric acid for chemical etching. The etching temperature is 20°C and the etching time is 2 hours to obtain niobium with sufficient edge stress removed. Lithium oxide wafer;

[0041] c) Put the corroded lithium niobate wafer 1 on the edge polishing fixture 4, put a piece of 0.5mm thick cork paper 2 on the wafer 1 as a spacer, and then put another wafer 1, repeat this action for stacking, At the same time, the wafer 1 is close to the positioning baffle 3, so that the wafer 1 is kept at th...

Embodiment 2

[0045] a) with embodiment 1;

[0046] B) with embodiment 1;

[0047] c) Place the etched lithium niobate wafer 1 on the edge polishing jig 4, put a piece of 0.3mm thick cork paper 2 on the wafer 1 as a spacer, then put another wafer 1, and repeat this action for stacking, At the same time, the wafer 1 is close to the positioning baffle 3, so that the wafer 1 is kept at the same central position. After the wafers are stacked, the wafer is fixed with a force of 3 kg to obtain a lithium niobate wafer to be roughly polished. For details, see figure 2 ;

[0048] D) with embodiment 1;

[0049] e) Same as in Example 1, obtain a lithium niobate wafer with edge polishing, diameter 200.02mm, roundness 0.01mm, edge finish 0.85nm, input 150 pieces, output 146 pieces, fragmentation 4 pieces, yield 97.33 %.

Embodiment 3

[0051] a) with embodiment 1;

[0052] B) with embodiment 1;

[0053] c) Put the etched lithium niobate wafer 1 on the edge polishing fixture 4, put a piece of 1mm thick cork paper 2 on the wafer 1 as a spacer, then put another wafer 1, repeat this action to stack the wafers, and at the same time The wafer 1 is close to the positioning baffle 3, so that the wafer 1 is kept at the same central position. After the wafers are stacked, the wafer is fixed with a force of 3 kg to obtain a lithium niobate wafer to be roughly polished. For details, see figure 2 ;

[0054] D) with embodiment 1;

[0055] e) Same as in Example 1, obtain a lithium niobate wafer with edge polishing, diameter 200.00mm, roundness 0.06mm, edge finish 0.83nm, input 92 pieces, output 88 pieces, fragmentation 1 piece, missing corner 3 Chips, the yield rate is 95.65%;

[0056] Comparative example 1,2,3, as table 1 and Figure 4 As shown, the thicker the tipping paper, the larger the gap between wafers, the m...

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
thicknessaaaaaaaaaa
densityaaaaaaaaaa
diameteraaaaaaaaaa
Login to View More

Abstract

The invention discloses an edge processing method for a large-size ultrathin high-precision lithium niobate wafer. The method comprises the steps that the edges of wafers are processed into R-shaped angles by adopting edge chamfering; chemical corrosion is carried out on the lithium niobate wafers by adopting a mixed solution of nitric acid and hydrofluoric acid; the corroded wafers are stacked in an edge polishing clamp, and the wafers are spaced through tipping paper; edge rough polishing processing is carried out on the stacked wafers, and an adopted polishing solution is a mixed solution composed of water, silicon dioxide, ethylenediamine tetraacetic acid salt, oxidized cysteine and sodium tripolyphosphate; and the wafers with the edges being roughly polished are subjected to edge fine polishing processing, an adopted fine polishing solution is a mixed solution composed of water, silicon dioxide, methylenediphosphonic acid, isowhite amino acid and triethylhexyl phosphoric acid, finally the large-size ultrathin lithium niobate wafer can be obtained, the edge smoothness is high, the roundness is good, and the yield is high.

Description

technical field [0001] The invention relates to a lithium niobate crystal material, in particular to a large-size ultra-thin high-precision lithium niobate wafer edge processing method. Background technique [0002] Lithium niobate (LiNbO 3 , hereinafter referred to as LN) is a chemical substance, which belongs to the trigonal crystal system, ilmenite type (distorted perovskite type) structure, and the relative density is 4.30g / cm 3 , Mohs hardness 5, Curie point 1140 ℃, is a multifunctional material integrating piezoelectric, ferroelectric, pyroelectric, nonlinear, photoelectric, photoelastic, photorefractive and other functions. Due to its excellent physical properties, LN has received more and more attention, and has been widely used in aviation, aerospace, civil optoelectronic products and other fields. Among them, as a piezoelectric crystal material, wafers produced through annealing, polarization, orientation, cutting, spheronization, reference plane, multi-wire cutt...

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): B24B9/06B24B41/06B24B29/00B24B49/00B24B41/00C30B33/10
CPCB24B9/065B24B41/06B24B29/005B24B49/006B24B41/007C30B33/10
Inventor 沈浩徐秋峰朱海瀛宋岩岩张伟明汪万盾张芹
Owner TDG HLDG CO LTD