A coating process for sensing TFT-G5 glass

Abstract

The application provides a coating process for sensing TFT-G5 glass, comprising the following steps: pretreating TFT-G5 glass to obtain a glass substrate; performing radio frequency magnetron sputtering on the surface of the glass substrate under vacuum conditions to obtain a glass substrate with a hard transition layer; performing direct current magnetron sputtering on the glass substrate with the hard transition layer under vacuum conditions to obtain a glass substrate with an ITO functional layer and a hard transition layer; performing low-temperature crystallization annealing on the glass substrate with the ITO functional layer and the hard transition layer, and then performing radio frequency magnetron sputtering on the surface of the glass substrate to obtain a silicon dioxide protective layer. The coating process for sensing TFT-G5 glass provided by the application has an ultra-high surface hardness: Si3N4-Al2O3-ZrO2 composite transition layer, ITO is greater than or equal to 9H, far exceeding conventional processes, and meeting the wear resistance requirements of sensing scenes.

Description

Technical Field

[0001] This invention belongs to the field of TFT glass coating, and in particular relates to a coating process for TFT-G5 glass used for sensing. Background Technology

[0002] TFT-G5 glass is a fifth-generation ultra-thin alkali-free borosilicate glass, a core substrate for optical sensors and touch panels, requiring a surface with high light transmittance, low sheet resistance, and high hardness (pencil hardness ≥4H). Current conventional ITO magnetron sputtering processes have the following drawbacks: 1. Insufficient film density: ITO films prepared by room temperature / low temperature sputtering (<150℃) have a porous columnar crystal structure and a pencil hardness of only 1-2H, which cannot meet the requirements of wear resistance and scratch resistance in sensing scenarios. 2. Weak interfacial adhesion: There is no transition layer at the glass / ITO interface, and the film-substrate adhesion is ≤3B, making it easy to fall off; 3. Conflict between hardness and optical / electrical properties: Although high-temperature annealing (>250℃) can increase the hardness to 3H, it will cause glass warping, decreased light transmittance (<82%), and increased sheet resistance (>150Ω / □), which does not meet the requirements of sensing applications.

[0003] Existing technologies have not developed a dedicated coating process for TFT-G5 glass, and cannot simultaneously solve the technical bottlenecks of insufficient surface hardness, weak film-substrate adhesion, and imbalance of photoelectric performance. Summary of the Invention

[0004] In view of this, the present invention aims to overcome the defects in the prior art and propose a coating process for TFT-G5 glass for sensing, which solves the technical problem that conventional ITO coating conditions cannot meet the surface hardness requirements, and achieves comprehensive performance of hardness ≥9H, light transmittance ≥85%, sheet resistance 50-100Ω / □, and adhesion 5B.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A coating process for TFT-G5 glass used for sensing includes the following steps: Step 1 involves pre-treating the TFT-G5 glass to obtain a glass substrate; Step 2 involves performing radio frequency magnetron sputtering on the surface of the glass substrate under vacuum conditions to obtain a glass substrate with a hard transition layer. Step 3 involves performing DC magnetron sputtering on the glass substrate with the hard transition layer under vacuum conditions to obtain a glass substrate with an ITO functional layer and a hard transition layer. Step 4 involves performing low-temperature crystallization annealing on the glass substrate with the ITO functional layer and hard transition layer, followed by radio frequency magnetron sputtering on its surface to obtain a silicon dioxide protective layer.

[0006] Furthermore, the preprocessing in step (1) specifically includes the following steps: (1) Perform ultrasonic cleaning and deionized water rinsing on the TFT-G5 glass; (2) Immerse the TFT-G5 glass in the cleaning solution and perform ultrasonic alkaline cleaning; (3) Place the TFT-G5 glass into the three-stage deionized water rinsing tank for rinsing. (4) The TFT-G5 glass is magnetron sputtered to obtain the glass substrate.

[0007] Furthermore, the thickness of the TFT-G5 glass in step (1) is 0.5-0.7 mm; the power of the ultrasonic cleaning step in step (1) is 300 W, the frequency is 40 kHz, and the time is 5 min; the time of the deionized water rinsing step in step (1) is 2 min; the time of the ultrasonic alkaline cleaning step in step (2) is 10 min, the power is 400 W, and the frequency is 60 kHz; the cleaning solution in step (2) is a sodium hydroxide solution with a mass fraction of 5%; the time of each rinsing step in step (3) is 5 min; the magnetron sputtering step in step (4) uses a mixture of argon and oxygen with a volume ratio of 9:1, a gas flow rate of 50 sccm, a power of 500 W, and a time of 5 min; the water contact angle of the glass substrate in step (4) is ≤5°, and the surface roughness Ra is ≤0.8 nm.

[0008] Furthermore, the vacuum degree of the vacuum condition in step 2 is 1×10⁻⁶. -2 -5×10 -4 Pa; The power of the RF magnetron sputtering step in step 2 is 800W, the sputtering voltage is 300V±20V, the sputtering current is 2.6A±0.2A, the deposition rate is 0.5nm / s, the temperature is 180℃±5℃, and the sputtering target is a high-purity silicon-nitrogen composite sintered target.

[0009] Furthermore, the material in the radio frequency magnetron sputtering step of step 2 includes the following composition: Si3N4 92.0-95.0%, Si 3.0-5.0%, Al2O3 1.0-2.0%, ZrO2 0.5-1.0%; the thickness of the hard transition layer in step 2 is 80-120 Å.

[0010] Furthermore, in step 3, the DC magnetron sputtering step uses an ITO target containing 1.5% SiO2 for the bottom layer deposition and an ITO target containing 0.3-0.8% La2O3 and 0.5-1.0% TiO2 for the top layer deposition.

[0011] Furthermore, in step 3, the DC magnetron sputtering step has a bottom layer deposition power of 1200W, a sputtering voltage of 280V±20V, a sputtering current of 4.3A±0.3A, a deposition rate of 1.0nm / s, and a temperature of 160℃±5℃; the thickness of the bottom layer of the hard transition layer is 50Å.

[0012] Furthermore, in step 3, the top layer deposition power is 1800W, the sputtering voltage is 320V±20V, the sputtering current is 5.6A±0.3A, the deposition rate is 1.2nm / s, and the temperature is 200℃±5℃; the thickness of the top layer of the hard transition layer is 150-200 Å.

[0013] Furthermore, the annealing step in step 4 is performed at a temperature of 150-220°C for a time of 60-120 minutes.

[0014] Furthermore, in step 4, the target material for radio frequency magnetron sputtering is a SiO2 target material, with a power of 600W, a sputtering voltage of 250V±20V, a sputtering current of 2.4A±0.2A, and a deposition rate of 0.3nm / s; the thickness of the silicon dioxide protective layer is 30-50 Å.

[0015] Compared with the prior art, the present invention has the following advantages: The coating process for TFT-G5 glass used in sensing described in this invention produces a coating with ultra-high surface hardness: a Si3N4-Al2O3-ZrO2 composite transition layer with ITO ≥ 9H, far exceeding conventional processes and meeting the wear resistance requirements of sensing scenarios; it also has excellent film-substrate adhesion: plasma activation + Si3N4 / ITO gradient interface (SiO2 bonding modification), with adhesion reaching 5B (0 peeling in 100-grid test), solving the problem of film peeling; it has balanced optoelectronic performance: gradient doping + low-temperature crystallization, with transmittance ≥ 85% (550nm) and sheet resistance 180-200Ω / □, adapting to the high transmittance and low power consumption requirements of optical sensors; and it has stable substrate dimensions: at a maximum temperature of 220℃, the warpage of the TFT-G5 glass is ≤ 0.1mm / m, meeting the processing requirements of large-size substrates for fifth-generation production lines. Detailed Implementation

[0016] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0017] The present invention will be described in detail below with reference to embodiments.

[0018] Example 1 A coating process for sensing TFT-G5 glass, comprising the following steps: (1) Substrate pretreatment: Select 0.5mm TFT-G5 glass, first perform ultrasonic alkaline cleaning (5% NaOH, 60℃, 10min), then perform pure water rinsing and Ar / O2 plasma activation (500W, 5min) in sequence, Ra=0.6nm, water contact angle=4°; (2) Si3N4 transition layer: A hard transition layer was obtained by radio frequency sputtering on a glass substrate. The composition of the target material was (mass ratio) Si3N4 93.5%, Si 4.0%, Al2O3 1.5%, ZrO2 1.0%; the vacuum degree was 3×10 -4 Pa, power of 800W, Ar / N2=7:3, temperature of 180℃, and thickness of hard transition layer of 100 Å; (3) ITO functional layer: ITO functional layer was obtained by DC magnetron sputtering on hard transition layer. The thickness of the bottom layer was 50 Å (1200W, O2 / Ar=1:20, 160℃). The target composition was: In2O3 88.0%, SnO2 10.5%, SiO2 1.5%; the thickness of the top layer was 180 Å (1800W, O2 / Ar=1:50, 200℃). The target composition was: In2O3 89.0%, SnO2 9.2%, La2O3 0.5%, TiO2 1.0%, oxygen-deficient vacancies 0.3%; the total thickness was 230 Å. (4) Low-temperature annealing: Under a nitrogen atmosphere (O2=8ppm), anneal at 150℃ for 30min, then raise the temperature to 220℃ and anneal for 60min; (5) SiO2 protective layer: The surface of the ITO functional layer is sputtered by radio frequency with a power of 600W, Ar / O2=8:2, and temperature of 180℃. The thickness of the SiO2 protective layer is 40 Å.

[0019] The performance test data is as follows: ITO Hardness: 9H (no scratches); Light Transmittance: 86.2%; Sheet Resistance: 192 Ω / □; Adhesion: 5B (0 peeling); Warpage: 0.08 mm / m.

[0020] Example 2 A coating process for sensing TFT-G5 glass, comprising the following steps: (1) Substrate pretreatment: Select 0.5mm TFT-G5 glass, first perform ultrasonic alkaline cleaning (5% NaOH, 60℃, 10min), then perform pure water rinsing and Ar / O2 plasma activation (500W, 5min) in sequence, Ra=0.7nm, water contact angle=4.5°; (2) Si3N4 transition layer: A hard transition layer was obtained by radio frequency sputtering on a glass substrate. The composition of the target material was (mass ratio) Si3N4 92.0%, Si 5.0%, Al2O3 2.0%, ZrO2 1.0%; the vacuum degree was 5×10 -4 Pa, power of 800W, Ar / N2=7:3, temperature of 180℃, and thickness of hard transition layer of 80 Å; (3) ITO functional layer: ITO functional layer was obtained by DC magnetron sputtering on hard transition layer. The thickness of the bottom layer was 50 Å (1200W, O2 / Ar=1:20, 160℃). The target composition was: In2O3 88.0%, SnO2 10.5%, SiO2 1.5%; the thickness of the top layer was 150 Å (1800W, O2 / Ar=1:50, 200℃). The target composition was: In2O3 89.0%, SnO2 9.2%, La2O3 0.5%, TiO2 0.5%, oxygen-deficient vacancies 0.5%; the total thickness was 200 Å. (4) Low-temperature annealing: Under a nitrogen atmosphere (O2=9ppm), anneal at 150℃ for 30min, then raise the temperature to 220℃ and anneal for 60min; (5) SiO2 protective layer: The surface of the ITO functional layer is sputtered by radio frequency with a power of 600W, Ar / O2=8:2, temperature of 180℃, and the thickness of the SiO2 protective layer is 30 Å.

[0021] The performance test data is as follows: ITO Hardness: 9H (no scratches); Light Transmittance: 85.5%; Sheet Resistance: 205Ω / □; Adhesion: 5B (0 peeling); Warpage: 0.09mm / m.

[0022] Comparative Example 1 A coating process for sensing TFT-G5 glass, comprising the following steps: (1) Substrate pretreatment: Same as in Example 1; (2) ITO functional layer: The ITO functional layer was obtained by DC magnetron sputtering on the hard transition layer. The target composition was: In2O3 90.0% and SnO2 10.0%; the thickness was 230 Å. (3. Low-temperature annealing: Anneal at 20℃ for 60 minutes.) The performance test data is as follows: ITO Hardness: 2H (obvious scratches); Light Transmittance: 81.5%; Sheet Resistance: 283Ω / □; Adhesion: 3B (area of ​​peeling off in cross-cut adhesion test > 10%); Warpage: 0.32mm / m.

[0023] Comparative Example 2 A coating process for sensing TFT-G5 glass, comprising the following steps: (1) Substrate pretreatment: Same as in Example 1; (2) Si3N4 transition layer: Same as in Example 1; (3) ITO functional layer: ITO functional layer was obtained by DC magnetron sputtering on hard transition layer. The thickness of the bottom layer was 50 Å (1200W, O2 / Ar=1:20, 160℃), and the target composition was: In2O3 90.0% and SnO2 10.0%; the thickness of the top layer was 180 Å (1800W, O2 / Ar=1:50, 200℃), and the target composition was: In2O3 90.0%, SnO2 10.0% and oxygen-deficient vacancies 0.3%; the total thickness was 230 Å. (4) Low-temperature annealing: Same as in Example 1; (5) SiO2 protective layer: Same as in Example 1.

[0024] The performance test data is as follows: ITO Hardness: 3H (slight scratches); Light Transmittance: 84.8%; Sheet Resistance: 267Ω / □; Adhesion: 4B (fracture area <5% in cross-cut adhesion test); Warpage: 0.09mm / m.

[0025] In summary, Examples 1-2 both meet the hardness and photoelectric performance requirements of the sensing TFT-G5 glass. However, Comparative Example 1, lacking a transition layer and ITO modification, has a hardness of only 2H, which fails to meet the requirements. Comparative Example 2, lacking ITO modification components, has a hardness of only 3H, which still does not meet the 4H standard. This fully demonstrates that the Si3N4 composite transition layer + modified gradient ITO components of the present invention can effectively solve the technical problem of insufficient hardness of conventional ITO coatings.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coating process for TFT-G5 glass used in sensing, characterized in that: Includes the following steps: Step 1 involves pre-treating the TFT-G5 glass to obtain a glass substrate; Step 2 involves performing radio frequency magnetron sputtering on the surface of the glass substrate under vacuum conditions to obtain a glass substrate with a hard transition layer. Step 3 involves performing DC magnetron sputtering on the glass substrate with the hard transition layer under vacuum conditions to obtain a glass substrate with an ITO functional layer and a hard transition layer. Step 4 involves performing low-temperature crystallization annealing on the glass substrate with the ITO functional layer and hard transition layer, followed by radio frequency magnetron sputtering on its surface to obtain a silicon dioxide protective layer.

2. The coating process for TFT-G5 glass for sensing according to claim 1, characterized in that: The preprocessing in step (1) specifically includes the following steps: (1) Perform ultrasonic cleaning and deionized water rinsing on the TFT-G5 glass; (2) Immerse the TFT-G5 glass in the cleaning solution and perform ultrasonic alkaline cleaning; (3) Place the TFT-G5 glass into the three-stage deionized water rinsing tank for rinsing. (4) The TFT-G5 glass is magnetron sputtered to obtain the glass substrate.

3. The coating process for TFT-G5 glass for sensing according to claim 2, characterized in that: The thickness of the TFT-G5 glass in step (1) is 0.5-0.7 mm; the power of the ultrasonic cleaning step in step (1) is 300 W, the frequency is 40 kHz, and the time is 5 min; the time of the deionized water rinsing step in step (1) is 2 min; the time of the ultrasonic alkaline cleaning step in step (2) is 10 min, the power is 400 W, and the frequency is 60 kHz; the cleaning solution in step (2) is a sodium hydroxide solution with a mass fraction of 5%; the time of each rinsing step in step (3) is 5 min; the magnetron sputtering step in step (4) uses a mixture of argon and oxygen with a volume ratio of 9:1, a gas flow rate of 50 sccm, a power of 500 W, and a time of 5 min; the water contact angle of the glass substrate in step (4) is ≤5°, and the surface roughness Ra is ≤0.8 nm.

4. The coating process for TFT-G5 glass for sensing according to claim 1, characterized in that: The vacuum level in step 2 is 1×10⁻⁶. -2 -5×10 -4 Pa; The power of the RF magnetron sputtering step in step 2 is 800W, the sputtering voltage is 300V±20V, the sputtering current is 2.6A±0.2A, the deposition rate is 0.5nm / s, the temperature is 180℃±5℃, and the sputtering target is a high-purity silicon-nitrogen composite sintered target.

5. The coating process for TFT-G5 glass for sensing according to claim 1, characterized in that: The materials used in the radio frequency magnetron sputtering step in step 2 include the following composition: Si3N4 92.0-95.0%, Si 3.0-5.0%, Al2O3 1.0-2.0%, ZrO2 0.5-1.0%; the thickness of the hard transition layer in step 2 is 80-120 Å.

6. The coating process for TFT-G5 glass for sensing according to claim 1, characterized in that: In step 3, the DC magnetron sputtering step uses an ITO target containing 1.5% SiO2 for the bottom layer deposition and an ITO target containing 0.3-0.8% La2O3 and 0.5-1.0% TiO2 for the top layer deposition.

7. The coating process for TFT-G5 glass for sensing according to claim 1, characterized in that: In step 3, the DC magnetron sputtering step has a bottom layer deposition power of 1200W, a sputtering voltage of 280V±20V, a sputtering current of 4.3A±0.3A, a deposition rate of 1.0nm / s, and a temperature of 160℃±5℃; the thickness of the bottom layer of the hard transition layer is 50 Å.

8. The coating process for TFT-G5 glass for sensing according to claim 1, characterized in that: In step 3, the DC magnetron sputtering step has a top layer deposition power of 1800W, a sputtering voltage of 320V±20V, a sputtering current of 5.6A±0.3A, a deposition rate of 1.2nm / s, and a temperature of 200℃±5℃; the thickness of the top layer of the hard transition layer is 150-200 Å.

9. The coating process for TFT-G5 glass for sensing according to claim 1, characterized in that: The annealing step in step 4 is performed at a temperature of 150-220℃ for 60-120 minutes.

10. The coating process for TFT-G5 glass for sensing according to claim 1, characterized in that: In step 4, the target material for radio frequency magnetron sputtering is a SiO2 target material, the power is 600W, the sputtering voltage is 250V±20V, the sputtering current is 2.4A±0.2A, and the deposition rate is 0.3nm / s; the thickness of the silicon dioxide protective layer is 30-50Å.