Variable thickness glass, method of making the same, and foldable electronic device

Abstract

The application provides a preparation method of a glass with different thicknesses, comprising the following steps: performing a first strengthening treatment on a glass substrate to obtain a first pretreated glass, wherein the glass substrate comprises a first part and a second part adjacent to the first part, the thickness of the first part is less than the thickness of the second part; performing a first etching treatment on the first part after the first strengthening treatment to thin the first part, to obtain a second pretreated glass, the volume expansion rate of the first part after the first strengthening treatment and the first etching treatment is less than the volume expansion rate of the second part; performing a second strengthening treatment on the second pretreated glass to obtain a third pretreated glass; and performing a second etching treatment on the third pretreated glass to obtain a glass with different thicknesses, wherein the glass with different thicknesses comprises a first strengthened part obtained from the first part and a second strengthened part obtained from the second part, the thickness of the first strengthened part is less than the thickness of the second strengthened part, and the peak-to-valley value of the surface of the first strengthened part is less than or equal to 0.1 mm. The application also provides a glass with different thicknesses and a foldable electronic device.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electronic equipment, and particularly relates to a glass with different thicknesses, a preparation method thereof and a foldable electronic equipment. BACKGROUND

[0002] The surface of the flexible screen of the foldable electronic equipment is generally provided with a glass cover plate, which protects the flexible screen and prolongs the service life of the flexible screen. In addition to the equal-thickness glass cover plate, a glass cover plate with different thicknesses has also been developed, which has a wider application scenario. However, when the glass cover plate with different thicknesses is strengthened, the expansion amount of different thickness regions in the strengthening process is large due to the difference in thickness, and the glass cover plate with different thicknesses after strengthening is deformed and wrinkled, which is not conducive to its use. SUMMARY

[0003] Therefore, the present application provides a glass with different thicknesses, a preparation method thereof and a foldable electronic equipment.

[0004] In a first aspect, the present application provides a preparation method of a glass with different thicknesses, comprising:

[0005] performing a first strengthening treatment on a glass substrate to obtain a first pretreated glass, wherein the glass substrate comprises a first part and a second part adjacent to the first part, and the thickness of the first part is less than the thickness of the second part;

[0006] performing a first etching treatment on the first part after the first strengthening treatment to thin the first part to obtain a second pretreated glass, wherein the volume expansion rate of the first part after the first strengthening treatment and the first etching treatment is less than the volume expansion rate of the second part;

[0007] performing a second strengthening treatment on the second pretreated glass to obtain a third pretreated glass;

[0008] performing a second etching treatment on the third pretreated glass to obtain a glass with different thicknesses, wherein the glass with different thicknesses comprises a first strengthened part obtained from the first part and a second strengthened part obtained from the second part, the thickness of the first strengthened part is less than the thickness of the second strengthened part, and the peak-to-valley value of the surface of the first strengthened part is less than or equal to 0.1 mm.

[0009] In a second aspect, the present application provides a glass with different thicknesses, comprising a first strengthened part and a second strengthened part adjacent to the first strengthened part, the thickness of the first strengthened part is less than the thickness of the second strengthened part, and the peak-to-valley value of the surface of the first strengthened part is less than or equal to 0.1 mm.

[0010] In a third aspect, the present application provides a foldable electronic device, comprising a display device, the display device comprising the uneven thickness glass prepared by the preparation method of the first aspect or the uneven thickness glass of the second aspect, and a flexible screen arranged on the surface of the uneven thickness glass, the flexible screen having a bending area, and the first strengthening part is arranged corresponding to the bending area.

[0011] The present application can make the expansion amount of the first part and the second part after processing similar by multiple strengthening and segmented etching, thereby avoiding the occurrence of the distortion problem of the first strengthening part, and can make the first strengthening part have good surface flatness and light and shadow effect, and obtain the uneven thickness glass with excellent appearance light and shadow effect, which is beneficial to the use of the uneven thickness glass in the foldable electronic device. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be described below.

[0013] Figure 1 The preparation method flow chart of the uneven thickness glass provided by an embodiment of the present application.

[0014] Figure 2 The cross-sectional schematic diagram of the glass substrate provided by an embodiment of the present application.

[0015] Figure 3 The cross-sectional schematic diagram of the glass substrate provided by another embodiment of the present application.

[0016] Figure 4 The cross-sectional schematic diagram of the uneven thickness glass provided by an embodiment of the present application.

[0017] Figure 5 The cross-sectional schematic diagram of the uneven thickness glass provided by an embodiment of the present application. Figure 4 The enlarged view of the dashed area.

[0018] Figure 6 The structural schematic diagram of the foldable electronic device in an unfolded state provided by an embodiment of the present application.

[0019] Figure 7 The exploded schematic diagram of the display device provided by an embodiment of the present application.

[0020] Figure 8 The component schematic diagram of the foldable electronic device provided by an embodiment of the present application.

[0021] Label explanation:

[0022] Glass substrate-110, first part-111, second part-112, glass with different thicknesses-100, first strengthened part-10, second strengthened part-20, first outer surface-11, second outer surface-12, display device-200, flexible screen-210, bending area-211, non-bending area-212, foldable electronic device-300, RF circuit-310, memory-320, input unit-330, display unit-340, sensor-350, audio circuit-360, speaker-361, microphone-362, WiFi module-370, processor-380, power supply-390. DETAILED DESCRIPTION

[0023] The following are exemplary embodiments of the present application. It should be noted that for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements are also considered within the scope of protection of the present application.

[0024] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. For the purpose of simplifying the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples. Such repetition is for the purpose of simplification and clarity, and in itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0025] Please refer to Figure 1 The flow chart of the preparation method of the glass with different thicknesses provided by an embodiment of the present application comprises:

[0026] S101: The glass substrate is subjected to first strengthening treatment to obtain a first pretreated glass. The glass substrate comprises a first part and a second part adjacent to the first part. The thickness of the first part is less than the thickness of the second part.

[0027] S102: The first part after the first strengthening treatment is subjected to first etching treatment to thin the first part to obtain a second pretreated glass. After the first strengthening treatment and the first etching treatment, the volume expansion rate of the first part is less than the volume expansion rate of the second part.

[0028] S103: The second pretreated glass is subjected to second strengthening treatment to obtain a third pretreated glass.

[0029] S104: The third pre-processed glass is subjected to a second etching treatment to obtain a glass with unequal thicknesses, which includes a first strengthened portion obtained from the first portion and a second strengthened portion obtained from the second portion, the thickness of the first strengthened portion is less than the thickness of the second strengthened portion, and the surface peak-to-valley value of the first strengthened portion is less than or equal to 0.1 mm.

[0030] In the present application, the first pre-processed glass is obtained by subjecting the glass substrate 110 to a first strengthening treatment. The thickness of the first pre-processed glass is not equal, that is, the thickness of the glass substrate 110 is also not equal, which causes the first portion 111 with a relatively thin thickness to be distorted after the first strengthening treatment. The first portion 111 is thinned by the first etching treatment to reduce the expansion amount of the first portion 111, so that the volume expansion rate of the first portion 111 is less than that of the second portion 112. After the second strengthening treatment, the expansion amount of the first portion 111 with a relatively thin thickness is greater than that of the second portion 112 with a relatively thick thickness. After the second etching treatment, the expansion amounts of the first portion 111 and the second portion 112 are the same, and then the first strengthened portion 10 and the second strengthened portion 20 with the same expansion amount are obtained. This avoids the problem of excessive distortion of the first strengthened portion 10 with a relatively thin thickness due to excessive expansion, and avoids the situation that the light and shadow effect of the glass with unequal thicknesses 100 is messy due to distortion, which is conducive to the use of the glass with unequal thicknesses 100 in the foldable electronic device 300.

[0031] In S101, the first pre-processed glass is obtained by subjecting the glass substrate 110 with unequal thicknesses to a first strengthening treatment. The first pre-processed glass is a strengthened glass with unequal thicknesses.

[0032] In the present application, the glass substrate 110 with unequal thicknesses can be prepared by etching, mechanical processing, etc. Of course, the glass substrate 110 with unequal thicknesses can also be directly formed. In an embodiment of the present application, the glass substrate 110 can include, but is not limited to, at least one of aluminum-silicon glass, sodium-calcium glass, boron-silicon glass, etc. The glass substrate 110 has good mechanical properties and good light transmission performance, which is conducive to obtaining a glass with unequal thicknesses 100 with excellent performance. In an embodiment of the present application, the glass substrate 110 can be high-aluminum-silicon glass. In this way, the performance of the glass with unequal thicknesses 100 can be further improved. In an embodiment, the mass content of aluminum oxide in the high-aluminum-silicon glass is greater than 15%, and the mass content of silicon oxide is greater than 58%. In another embodiment, the mass content of aluminum oxide in the high-aluminum-silicon glass is greater than 20%, and the mass content of silicon oxide is greater than 65%. In an embodiment of the present application, the transmittance of the glass substrate 110 in the visible light wavelength range is greater than or equal to 85%, which is conducive to the use of the glass with unequal thicknesses 100 prepared in the foldable electronic device 300. In an embodiment of the present application, the transmittance of the glass substrate 110 in the visible light wavelength range is greater than or equal to 90%.

[0033] Please refer toFigure 2 This is a cross-sectional schematic diagram of a glass substrate provided in one embodiment of this application. The glass substrate 110 includes a first portion 111 and a second portion 112 adjacent to the first portion 111. The thickness of the first portion 111 is less than the thickness of the second portion 112, thus making the glass substrate 110 a glass 100 of unequal thickness. In one embodiment of this application, the second portion 112 is disposed on one side of the first portion 111. In another embodiment of this application, as... Figure 2 As shown, the second part 112 is disposed on opposite sides of the first part 111. In one embodiment of this application, the first part 111 is a flat part. In another embodiment of this application, please refer to... Figure 3 This is a cross-sectional schematic diagram of a glass substrate provided in another embodiment of this application. The first part 111 includes a flattened part and a transition part, with the transition part connecting the second part 112 and the flattened part. Along the direction from the second part 112 to the first part 111, the thickness of the transition part gradually decreases, and the thickness of the flattened part is less than the thickness of the second part 112. The transition part can further improve the light and shadow difference between the first part 111 and the second part 112, achieving a smooth change in light and shadow effects, which is beneficial for the use of unequal thickness glass 100. It is understood that the thickness value in this application is the average thickness. In one embodiment of this application, the first part 111 has a first surface and a second surface disposed opposite to each other, and the second part 112 has a third surface and a fourth surface disposed opposite to each other. The first surface and the third surface are located on the same horizontal plane, while the second surface and the fourth surface are located on different horizontal planes. In another embodiment of this application, the first part 111 has a first surface and a second surface disposed opposite to each other, and the second part 112 has a third surface and a fourth surface disposed opposite to each other. The horizontal plane where the first surface is located is located between the horizontal plane where the third surface is located and the horizontal plane where the fourth surface is located, and the horizontal plane where the second surface is located is located between the horizontal plane where the third surface is located and the horizontal plane where the fourth surface is located.

[0034] The first strengthening treatment improves the strength of the glass substrate 110, resulting in a high-performance pre-treated glass, which is beneficial for the use of glass 100 with unequal thickness. In one embodiment of this application, the first strengthening treatment is carried out in a potassium-containing molten salt, wherein potassium ions replace alkali metal ions in the surface layer of the glass substrate 110 through ion exchange, thereby generating a strengthening layer on the surface of the glass substrate 110 and achieving the strengthening purpose. By using potassium salt as the strengthening molten salt, this application can significantly increase the compressive stress on the surface of the glass substrate 110. Specifically, the potassium salt may include at least one of potassium nitrate, potassium sulfate, and potassium chloride.

[0035] In an embodiment of the present application, the temperature of the first strengthening treatment is 360-400°C. Specifically, the temperature of the first strengthening treatment can be, but is not limited to, 360°C, 365°C, 370°C, 375°C, 380°C, 385°C, 390°C, 395°C or 400°C, etc. In an embodiment, the temperature of the first strengthening treatment can be 360-380°C. In another embodiment, the temperature of the first strengthening treatment can be 380-400°C. In an embodiment of the present application, the temperature of the first strengthening treatment is lower than the temperature of the second strengthening treatment, which can reduce the distortion of the first portion 111 after the first strengthening treatment, thereby further improving the light and shadow effect of the uneven thickness glass 100. In an embodiment of the present application, the time of the first strengthening treatment is 10-20 min. Specifically, the time of the first strengthening treatment can be, but is not limited to, 10 min, 12 min, 15 min, 18 min, 19 min or 20 min, etc. In an embodiment, the time of the first strengthening treatment is 10-15 min. In another embodiment, the time of the first strengthening treatment is 15-20 min. In an embodiment of the present application, the time of the first strengthening treatment is less than the time of the second strengthening treatment, which can reduce the distortion of the first portion 111 after the first strengthening treatment, thereby further improving the light and shadow effect of the uneven thickness glass 100.

[0036] In an embodiment of the present application, the surface compressive stress of the first pretreated glass is greater than or equal to 800 MPa. Specifically, the surface compressive stress of the first pretreated glass can be, but is not limited to, 800 MPa, 820 MPa, 835 MPa, 850 MPa, 860 MPa or 875 MPa, etc. It can be understood that any one surface of the glass substrate 110 can be subjected to the first strengthening treatment, and the surface that does not need to be strengthened can be provided with a protective layer to avoid strengthening. The surface compressive stress of the first pretreated glass is the surface compressive stress of the surface subjected to the first strengthening treatment.

[0037] In an embodiment of the present application, the first pretreated glass has a first strengthening layer located in the surface layer, and the thickness of the first strengthening layer is 7-13 μm. Specifically, the thickness of the first strengthening layer can be, but is not limited to, 7 μm, 8 μm, 9 μm, 9.5 μm, 10 μm, 11 μm, 11.5 μm, 12 μm or 13 μm, etc. In an embodiment, the thickness of the first strengthening layer is 7-10 μm. In another embodiment, the thickness of the first strengthening layer is 10-13 μm.

[0038] In an embodiment of the present application, the first pre-processed glass comprises a third portion and a fourth portion adjacent to the third portion. The first portion 111 forms the third portion after the first strengthening treatment, and the second portion 112 forms the fourth portion after the first strengthening treatment. In an embodiment of the present application, the third portion and the fourth portion each have a first strengthened layer on the surface, and the thickness of the first strengthened layer is 7 μm to 13 μm. In an embodiment, the thickness of the first strengthened layer on the surface of the third portion is equal to the thickness of the first strengthened layer on the surface of the fourth portion. In an embodiment of the present application, the surface compressive stress of the third portion and the fourth portion is greater than or equal to 800 MPa. In an embodiment, the surface compressive stress of the third portion is equal to the surface compressive stress of the fourth portion.

[0039] In S102, because the thickness of the first portion 111 and the second portion 112 is different, the first portion 111 with smaller thickness expands too much after the first strengthening treatment, and the third portion is deformed, i.e., the light and shadow effect of the third portion is not good, which affects the light and shadow effect of the first pre-processed glass. By performing the first etching treatment on the first portion 111 (i.e., the third portion) after the first strengthening treatment, the thickness of the first portion 111 (i.e., the third portion) after the first strengthening treatment is reduced, so that the volume expansion rate of the first portion 111 after the first strengthening treatment and the first etching treatment is less than the volume expansion rate of the second portion 112 after the first strengthening treatment and the first etching treatment, which is beneficial to obtain the first strengthened portion 10 and the second strengthened portion 20 with similar expansion rates.

[0040] In the present application, the first pre-processed glass can be cleaned before the first etching treatment to remove the molten salt in the first strengthening treatment. Specifically, the first pre-processed glass can be cleaned with water or a cleaning agent.

[0041] In the present application, because the third portion is thinned, and the fourth portion is not subjected to the first etching treatment, a shielding layer can be arranged on the surface of the fourth portion to prevent etching. The material of the shielding layer can be selected as needed, and will not be described here. In the present application, the shielding layer can be arranged on the surface of the fourth portion by silk printing, lamination, deposition or exposure development, and the first pre-processed glass with the shielding layer is subjected to etching treatment.

[0042] In an embodiment of the present application, the first etching treatment is to thin the first part 111 by using an etching solution. Specifically, the etching solution can be but is not limited to hydrofluoric acid, and the shielding layer is an acid-resistant layer. The first pretreated glass provided with the shielding layer can be immersed in the etching solution, or the etching solution can be sprayed on the surface of the first pretreated glass provided with the shielding layer. In an embodiment of the present application, the temperature of the first etching treatment is 25-30°C. Specifically, the temperature of the first etching treatment can be but is not limited to 25°C, 25.5°C, 26°C, 27°C, 27.5°C, 28°C, 29°C or 30°C, etc. In an embodiment, the temperature of the first etching treatment can be 25-27°C. In another embodiment, the temperature of the first etching treatment can be 28-29°C. In an embodiment of the present application, the time of the first etching treatment is 1-3 min. Specifically, the time of the first etching treatment can be but is not limited to 1 min, 1.5 min, 2 min, 2.5 min or 3 min, etc. In an embodiment, the time of the first etching treatment is 1-2 min. In another embodiment, the time of the first etching treatment is 2-3 min.

[0043] In an embodiment of the present application, after the first etching treatment, the shielding layer on the surface of the first pretreated glass is removed by using a stripping solution. In an embodiment, the pH value of the stripping solution can be 13-14, the removal temperature is greater than 80°C, and the removal time can be 3-5 min.

[0044] In the present application, the volume of the first part 111 is V1, and the volume of the second part 112 is V2; after the first strengthening treatment, the first part 111 becomes the third part, the volume of the third part is V3, and the second part 112 becomes the fourth part, the volume of the fourth part is V4; after the first etching treatment, the volume of the third part decreases and becomes the fifth part, the volume of the fifth part is V5, and the fourth part remains unchanged, the volume is still V4; therefore, after the first strengthening treatment and the second etching treatment, the volume expansion rate of the first part 111, i.e. the volume expansion rate of the first part 111 becoming the fifth part, is (V5-V1) / V1; after the first strengthening treatment and the second etching treatment, the volume expansion rate of the second part 112, i.e. the volume expansion rate of the second part 112 becoming the fourth part, is (V4-V2) / V2, wherein (V5-V1) / V1 is less than (V4-V2) / V2, the volume expansion rate of the first part 111 with thinner thickness is less than that of the second part 112, which is beneficial to leveling the expansion rates of the two parts after the second strengthening treatment and the second etching treatment, thereby obtaining the unequal-thickness glass 100 with excellent light and shadow effect. The first etching treatment can reduce the volume of the third part, for example, when the third part is a cuboid, the length, width and thickness of the third part are reduced by the first etching treatment to thin the third part.

[0045] In an embodiment of the present application, the first part 111 after the first strengthening treatment and the first etching treatment has a volume shrinkage of 0.05% to 0.1%. The first part 111 after the first strengthening treatment is the third part, and the volume of the third part is V3. The third part after the first etching treatment becomes the fifth part, and the volume of the fifth part is V5. The volume shrinkage of the third part after becoming the fifth part is (V3-V5) / V3, and (V3-V5) / V3 is in the range of 0.05% to 0.1%. Specifically, the volume shrinkage of the first part 111 after the first strengthening treatment and the first etching treatment can be, but is not limited to, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%, etc.

[0046] In an embodiment of the present application, the etching depth of the first etching treatment is 1 μm to 2 μm. When the first etching treatment is performed on the third part, the third part has two oppositely arranged surfaces in the thickness direction. If the first etching treatment is performed on one of the surfaces, the etching depth is 1 μm to 2 μm. If the first etching treatment is performed on both surfaces, the etching depth on each surface is 1 μm to 2 μm. That is, the etching depth is the etching amount in the thickness direction, and the etching depth is the single surface etching amount. Specifically, the etching depth of the first etching treatment can be, but is not limited to, 1.1 μm, 1.2 μm, 1.5 μm, 1.6 μm, 1.9 μm, or 2 μm, etc.

[0047] In an embodiment of the present application, the second pretreated glass includes a fourth part and a fifth part adjacent to the fourth part, and the thickness of the fifth part is less than the thickness of the fourth part. Since the first etching treatment is not performed on the fourth part, the surface of the fourth part still has the first strengthening layer. The first etching treatment etches the first strengthening layer on the surface of the third part, so that the surface of the fifth part has a second strengthening layer. In an embodiment of the present application, the fourth part has the first strengthening layer located on the surface layer, the thickness of the first strengthening layer is 7 μm to 13 μm, and the surface compressive stress of the fourth part is greater than or equal to 800 MPa. In an embodiment of the present application, the fifth part has the second strengthening layer located on the surface layer, the thickness of the second strengthening layer is 3 μm to 10 μm, and the surface compressive stress of the fifth part is greater than or equal to 600 MPa. Specifically, the thickness of the second strengthening layer can be, but is not limited to, 3 μm, 4 μm, 5 μm, 5.5 μm, 6 μm, 7 μm, 7.5 μm, 8 μm, or 9 μm, etc. The surface compressive stress of the fifth part can be, but is not limited to, 600 MPa, 620 MPa, 635 MPa, 650 MPa, or 660 MPa, etc. In an embodiment, the thickness of the second strengthening layer can be 3 μm to 6 μm. In another embodiment, the thickness of the second strengthening layer can be 7 μm to 10 μm.

[0048] In S103, the strength of the second pretreated glass is further improved by performing the second strengthening treatment on the second pretreated glass.

[0049] In an embodiment of the present application, the second strengthening treatment is performed in a mixed molten salt including at least one of a sodium salt and a lithium salt and a potassium salt. The mixed molten salt can not only improve the strengthening of the glass, but also reduce the distortion caused by the strengthening, which is beneficial to obtain the third pretreated glass with better light and shadow effect. In an embodiment, the mixed molten salt can be a potassium salt and a sodium salt. In another embodiment, the mixed molten salt can be a potassium salt, a sodium salt and a lithium salt. Specifically, the potassium salt can include at least one of potassium nitrate, potassium sulfate and potassium chloride, the sodium salt can include at least one of sodium nitrate, sodium sulfate and sodium chloride, and the lithium salt can include at least one of lithium nitrate and lithium sulfate. In an embodiment of the present application, the mass content of the potassium salt in the mixed molten salt is 80% to 99%. Specifically, the mass content of the potassium salt in the mixed molten salt can be, but is not limited to, 80%, 82%, 84%, 85%, 87%, 88%, 90%, 93%, 95%, 97% or 99%, etc. The high content of the potassium salt in the mixed molten salt can effectively improve the strengthening of the glass and obtain better strengthening effect. In an embodiment, the mass content of the potassium salt in the mixed molten salt can be 80% to 90%. In another embodiment, the mass content of the potassium salt in the mixed molten salt can be 90% to 99%.

[0050] In an embodiment of the present application, the temperature of the second strengthening treatment is 380°C to 430°C. Specifically, the temperature of the second strengthening treatment can be, but is not limited to, 380°C, 385°C, 390°C, 395°C, 400°C, 410°C, 415°C, 420°C or 430°C, etc. Since the first etching treatment reduces the expansion amount of the first part 111, the strengthening temperature can be increased in the second strengthening treatment to improve the strengthening effect, and meanwhile the first part 111 will not produce obvious distortion. In an embodiment, the temperature of the second strengthening treatment can be 380°C to 400°C. In another embodiment, the temperature of the second strengthening treatment can be 400°C to 430°C. In an embodiment of the present application, the time of the second strengthening treatment is 10 min to 40 min. Specifically, the time of the second strengthening treatment can be, but is not limited to, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min or 40 min, etc. In an embodiment, the time of the second strengthening treatment is 10 min to 25 min. In another embodiment, the time of the second strengthening treatment is 20 min to 40 min.

[0051] After the first strengthening treatment, the first part 111 becomes the seventh part, and the second part 112 becomes the sixth part. In an embodiment of the present application, the third pretreated glass comprises the sixth part and the seventh part adjacent to the sixth part, and the thickness of the seventh part is less than the thickness of the sixth part. It can be understood that the second strengthening treatment can be performed on any surface of the second pretreated glass, and a protective layer can be provided on the surface that does not need to be strengthened to avoid strengthening.

[0052] In an embodiment of the present application, the sixth part has a third strengthened layer located at the surface layer, and the thickness of the third strengthened layer is greater than or equal to 15 μm. Specifically, the thickness of the third strengthened layer can be, but is not limited to, 15 μm, 16 μm, 17 μm, 18 μm, or 19 μm, etc. In an embodiment of the present application, the surface compressive stress of the sixth part is greater than or equal to 650 MPa. Specifically, the surface compressive stress of the sixth part can be, but is not limited to, 650 MPa, 670 MPa, 675 MPa, 680 MPa, or 690 MPa, etc. The surface compressive stress of the sixth part is the surface compressive stress of the surface after the second strengthening treatment.

[0053] In an embodiment of the present application, the seventh part has a fourth strengthened layer located at the surface layer, and the thickness of the fourth strengthened layer is 5 μm to 12 μm. Specifically, the thickness of the fourth strengthened layer can be, but is not limited to, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, or 12 μm, etc. In an embodiment, the thickness of the first strengthened layer is 5 μm to 8 μm. In another embodiment, the thickness of the first strengthened layer is 8 μm to 12 μm. In an embodiment of the present application, the surface compressive stress of the seventh part is greater than or equal to 610 MPa. Specifically, the surface compressive stress of the seventh part can be, but is not limited to, 610 MPa, 620 MPa, 625 MPa, 630 MPa, or 640 MPa, etc. The surface compressive stress of the seventh part is the surface compressive stress of the surface after the second strengthening treatment.

[0054] In S104, the volume expansion rate of the first part 111 is less than the volume expansion rate of the second part 112 after the first etching treatment, and the expansion rate of the first part 111 with a smaller thickness is greater than the expansion rate of the second part 112 with a larger thickness after the second strengthening treatment. The first part 111 and the second part 112 are thinned by the second etching treatment, and the expansion rates of the first part 111 and the second part 112 are further reduced to the same level or consistent, so as to avoid the distortion caused by the difference in expansion rates and ensure the light and shadow effect of the glass 100 with different thicknesses.

[0055] In the present application, the third pretreated glass can also be cleaned before the second etching treatment to remove the molten salt in the third strengthening treatment. Specifically, the third pretreated glass can be cleaned with water or a cleaning agent.

[0056] In an embodiment of the present application, the second etching treatment is to thin the third pretreated glass by etching liquid. Specifically, the etching liquid can be but is not limited to hydrofluoric acid. In an embodiment of the present application, the temperature of the second etching treatment is 25-30°C. Specifically, the temperature of the second etching treatment can be but is not limited to 25°C, 25.5°C, 26°C, 27°C, 27.5°C, 28°C, 29°C or 30°C, etc. In an embodiment, the temperature of the second etching treatment can be 25-27°C. In another embodiment, the temperature of the second etching treatment can be 28-29°C. In an embodiment of the present application, the time of the second etching treatment is 5-7 min. Specifically, the time of the second etching treatment can be but is not limited to 5 min, 5.5 min, 6 min, 6.5 min or 7 min, etc. In an embodiment, the time of the second etching treatment is 5-6 min. In another embodiment, the time of the second etching treatment is 6-7 min. In an embodiment of the present application, the time of the second etching treatment is greater than the time of the first etching treatment, so that the volume expansion rates of the first part 111 and the second part 112 after the first strengthening treatment, the first etching treatment, the second strengthening treatment and the second etching treatment can reach the same level, avoiding the expansion rate of the first part 111 being too large to produce distortion and deformation, so as to obtain the unequal thickness glass 100 with excellent light and shadow effect. The second etching treatment can reduce the volume of the third pretreated glass, for example, when the third pretreated glass is a cuboid, the length, width and thickness of the third pretreated glass are reduced by the second etching treatment to thin the third pretreated glass.

[0057] In an embodiment of the present application, the etching depth of the second etching treatment is 1.5-3 μm. When the third pretreated glass is subjected to the second etching treatment, the third pretreated glass has two oppositely arranged surfaces in the thickness direction, if one of the surfaces is subjected to the second etching treatment, the etching depth is 1.5-3 μm, if both surfaces are subjected to the first etching treatment, the etching depth on each surface is 1.5-3 μm; that is, the etching depth is the etching amount in the thickness direction, and the etching depth is the single-side etching amount. Specifically, the etching depth of the second etching treatment can be but is not limited to 1.6 μm, 1.9 μm, 2 μm, 2.2 μm, 2.5 μm, 2.7 μm or 3 μm, etc.

[0058] In an embodiment of the present application, the etching depth of the first etching treatment is less than the etching depth of the second etching treatment, so as to facilitate the volume expansion rates of the first part 111 and the second part 112 after the first strengthening treatment, the first etching treatment, the second strengthening treatment and the second etching treatment to reach the same level, and obtain the unequal thickness glass 100 with excellent light and shadow effect.

[0059] In this application, the first part 111 before the first etching treatment is the third part, and the first part 111 after the first etching treatment is the fifth part. The volume shrinkage rate of the first part 111 before and after the first etching treatment is (V3-V5) / V3. The volume of the third pre-treated glass before the second etching treatment is V6, and the third pre-treated glass after the second etching treatment is the unequal thickness glass 100. The volume of the unequal thickness glass 100 is V7, and the volume shrinkage rate of the third pre-treated glass before and after the second etching treatment is (V6-V7) / V6. In one embodiment of this application, (V3-V5) / V3 is less than (V6-V7) / V6, which is beneficial to make the volume expansion rates of the first part 111 and the second part 112 after the first strengthening treatment, the first etching treatment, the second strengthening treatment, and the second etching treatment reach the same level, thereby obtaining the unequal thickness glass 100 with excellent light and shadow effects.

[0060] In this application, glass 100 of varying thickness is obtained after a second etching process; please refer to Figure 4 This is a cross-sectional schematic diagram of an unequal-thickness glass according to an embodiment of this application. The unequal-thickness glass 100 includes a first reinforced portion 10 obtained from a first portion 111 and a second reinforced portion 20 obtained from a second portion 112. The thickness of the first reinforced portion 10 is less than the thickness of the second reinforced portion 20. It can be understood that the first portion 111 becomes the first reinforced portion 10 after undergoing a first strengthening process, a first etching process, a second strengthening process, and a second etching process, and the second portion 112 becomes the second reinforced portion 20 after undergoing a first strengthening process, a second strengthening process, and a second etching process.

[0061] Please see Figure 5 ,for Figure 4 An enlarged view of the area indicated by the dashed line shows that the first reinforcing part 10 has a first outer surface 11 and a second outer surface 12 disposed opposite to each other. Point A represents the point with the largest distance between the first outer surface 11 and the second outer surface 12, and point B represents the point with the smallest distance between them. The direction from the first outer surface 11 to the second outer surface 12 is the thickness direction. In the thickness direction, the distance between points A and B is the peak-to-valley value (PV value). This is understandable. Figure 5The PV value of the second outer surface 12 is calculated in the same way as the first outer surface 11. In the present application, the peak-to-valley value of the surface of the first strengthened portion 10 is the peak-to-valley value of the two surfaces (the first outer surface 11 and the second outer surface 12) of the first strengthened portion 10 in the thickness direction, i.e., the peak-to-valley value of the first outer surface 11 is less than or equal to 0.1 mm, and the peak-to-valley value of the second outer surface 12 is less than or equal to 0.1 mm. In an embodiment of the present application, the peak-to-valley value of the surface of the first strengthened portion 10 is less than or equal to 0.05 mm. In another embodiment of the present application, the peak-to-valley value of the surface of the first strengthened portion 10 is less than or equal to 0.02 mm. In the present application, the peak-to-valley value of the surface of the first strengthened portion 10 is detected by a laser interferometer.

[0062] In the related art, the first pretreated glass obtained only by the first strengthening has a serious distortion in the area with a relatively small thickness, so that the first pretreated glass cannot be directly used. In the present application, the first strengthening treatment, the first etching treatment, the second strengthening treatment, and the second etching treatment are sequentially performed, so that the expansion rates of the first strengthened portion 10 and the second strengthened portion 20 reach the same level, thereby avoiding the problem of the distortion caused by the excessive expansion rate of the first strengthened portion 10 with a relatively small thickness, avoiding the occurrence of wrinkles, and thus improving the surface flatness of the first strengthened portion 10 and the light and shadow effect of the uneven thickness glass 100.

[0063] The present application also provides an uneven thickness glass 100, which comprises a first strengthened portion 10 and a second strengthened portion 20, the thickness of the first strengthened portion 10 is less than the thickness of the second strengthened portion 20, and the peak-to-valley value of the surface of the first strengthened portion 10 is less than or equal to 0.1 mm. The uneven thickness glass 100 can be prepared by the preparation method in any of the above embodiments.

[0064] In an embodiment of the present application, the first strengthened portion 10 has a fifth strengthened layer located in the surface layer, and the thickness of the fifth strengthened layer is 3 μm to 10 μm. Specifically, the thickness of the fifth strengthened layer can be, but is not limited to, 3 μm, 4 μm, 5 μm, 5.5 μm, 6 μm, 7 μm, 7.5 μm, 8 μm, or 9 μm, etc. In an embodiment of the present application, the surface compressive stress of the first strengthened portion 10 is greater than or equal to 410 MPa. Specifically, the surface compressive stress of the first strengthened portion 10 can be, but is not limited to, 410 MPa, 420 MPa, 435 MPa, 440 MPa, or 445 MPa, etc.

[0065] In an embodiment of the present application, the second strengthening portion 20 has a sixth strengthening layer located at the surface layer, and the thickness of the sixth strengthening layer is greater than or equal to 11 μm. Specifically, the thickness of the sixth strengthening layer can be, but is not limited to, 11 μm, 12 μm, 13 μm, 14 μm, or 15 μm, etc. In an embodiment of the present application, the surface compressive stress of the second strengthening portion 20 is greater than or equal to 450 MPa. Specifically, the surface compressive stress of the second strengthening portion 20 can be, but is not limited to, 450 MPa, 460 MPa, 475 MPa, 480 MPa, or 490 MPa, etc.

[0066] In an embodiment of the present application, the thickness of the first strengthening portion 10 is 30 μm to 50 μm, which is beneficial to improve the bending performance of the uneven thickness glass 100 and is beneficial to the use of the uneven thickness glass 100 in the foldable electronic device 300. Specifically, the thickness of the first strengthening portion 10 can be, but is not limited to, 30 μm, 33 μm, 35 μm, 39 μm, 40 μm, 43 μm, 45 μm, 47 μm, or 50 μm, etc. In an embodiment, the thickness of the first strengthening portion 10 can be 30 μm to 40 μm. In another embodiment, the thickness of the first strengthening portion 10 can be 40 μm to 50 μm. In yet another embodiment, the thickness of the first strengthening portion 10 can be 35 μm to 45 μm.

[0067] In an embodiment of the present application, the thickness of the second strengthening portion 20 is 70 μm to 220 μm, which is beneficial to improve the strength of the uneven thickness glass 100 without excessively increasing the weight of the uneven thickness glass 100, and is beneficial to the use of the uneven thickness glass 100 in the foldable electronic device 300. Specifically, the thickness of the second strengthening portion 20 can be, but is not limited to, 70 μm, 85 μm, 100 μm, 120 μm, 130 μm, 150 μm, 180 μm, 200 μm, 215 μm, or 220 μm, etc. In an embodiment, the thickness of the second strengthening portion 20 can be 70 μm to 120 μm. In another embodiment, the thickness of the second strengthening portion 20 can be 100 μm to 150 μm. In yet another embodiment, the thickness of the second strengthening portion 20 can be 150 μm to 220 μm.

[0068] In an embodiment of the present application, the bending radius of the uneven thickness glass 100 is less than or equal to 0.5 mm. In the present application, the bending radius is measured in the two-point bending test. The uneven thickness glass 100 has excellent bending performance, which is beneficial to the use of the uneven thickness glass 100 in the foldable electronic device 300. Specifically, the bending radius of the uneven thickness glass 100 can be, but is not limited to, less than or equal to 0.45 mm, less than or equal to 0.42 mm, less than or equal to 0.4 mm, less than or equal to 0.39 mm, less than or equal to 0.38 mm, or less than or equal to 0.35 mm, etc.

[0069] In an embodiment, a glass substrate 110 is provided, the first part 111 of the glass substrate 110 has a thickness of 30 μm, and the second part 112 has a thickness of 100 μm; the glass substrate 110 is placed in a potassium nitrate molten salt for a first strengthening treatment, the first strengthening treatment is performed at a temperature of 390 °C for 13 min, the volume expansion rate of the first part 111 before and after the first strengthening treatment is 0.12%, and the volume expansion rate of the second part 112 is 0.03%, thereby obtaining a first pretreated glass, the first pretreated glass has a first strengthening layer on the surface, the thickness of the first strengthening layer is 7 μm, the surface compressive stress of the first pretreated glass is 850 MPa, and the first pretreated glass comprises a third part formed by the first part 111 and a fourth part formed by the second part 112. An acid-resistant ink is silk-screen printed on the surface of the fourth part to form a shielding layer, and the first pretreated glass with the shielding layer is placed in a hydrofluoric acid for a first etching treatment, the first etching treatment is performed at a temperature of 28 °C for 2 min, and the volume shrinkage rate of the third part before and after the first etching treatment is 0.07%. The shielding layer on the surface of the fourth part is removed, thereby obtaining a second pretreated glass, the second pretreated glass comprises a fifth part formed by the third part and a fourth part. The second pretreated glass is placed in a mixed molten salt for a second strengthening treatment, the mixed molten salt comprises 90% by mass of potassium nitrate and 10% by mass of sodium nitrate, the second strengthening treatment is performed at a temperature of 380 °C for 10 min, thereby obtaining a third pretreated glass, the third pretreated glass comprises a seventh part formed by the fifth part and a sixth part formed by the fourth part. The third pretreated glass is placed in a hydrofluoric acid for a second etching treatment, the second etching treatment is performed at a temperature of 28 °C for 5 min, the volume shrinkage rate of the seventh part before and after the second etching treatment is 0.03%, and the volume shrinkage rate of the sixth part is 0.01%, thereby obtaining an uneven thickness glass 100, the uneven thickness glass 100 comprises a first strengthening part 10 formed by the seventh part and a second strengthening part 20 formed by the sixth part, the ratio of the volume difference between the first part 111 and the first strengthening part 10 to the volume of the first part 111 is equal to the ratio of the volume difference between the second part 112 and the second strengthening part 20 to the volume of the second part 112, so that the volume expansion rates of the thinner region and the thicker region of the uneven thickness glass 100 are the same. The first strengthening part 10 of the uneven thickness glass 100 is detected by a laser interferometer, the peak-to-valley value is 0.017 mm, the surface is wrinkle-free, the appearance has a good light and shadow effect, the bending radius measured by a two-point bending test is 0.5 mm, the overall bending performance is good, and the uneven thickness glass 100 is beneficial to use in a foldable electronic device 300.

[0070] In a comparative example, the same first strengthening treatment was performed on the same glass substrate 110 to obtain a first pretreated glass. The difference between the volume expansion rate of the first portion 111 before and after the first strengthening treatment and the volume expansion rate of the second portion 112 before and after the first strengthening treatment was 0.09%, the bending radius measured by the two-point bending test was 0.5 mm, the peak-to-valley value of the third portion surface was 0.83 mm, there was obvious distortion, the appearance had wrinkles and poor light and shadow effect, and the product could not be used. In another comparative example, the same first strengthening treatment and first etching treatment were performed on the same glass substrate 110 to obtain a second pretreated glass. The difference between the volume expansion rate of the first portion 111 before and after the first strengthening treatment and the volume expansion rate of the second portion 112 before and after the first strengthening treatment was 0.04%, the bending radius measured by the two-point bending test was 0.5 mm, the peak-to-valley value of the fifth portion surface was 0.56 mm, there was obvious distortion, the appearance had wrinkles and poor light and shadow effect, and the product could not be used. From the above examples and comparative examples, it can be seen that the first strengthening treatment can cause distortion of the product, and the first etching treatment alone cannot improve the distortion. In the present application, the excellent performance and good light and shadow effect of the unequal-thickness glass 100 are obtained by multiple strengthening and segmented etching, which is beneficial to the application of the unequal-thickness glass 100.

[0071] The present application also provides a foldable electronic device 300 comprising the unequal-thickness glass 100 of any of the above embodiments. The above unequal-thickness glass 100 has excellent strength and bendability, thereby improving the service life of the foldable electronic device 300, improving the use performance of the foldable electronic device 300, and improving the product competitiveness. The foldable electronic device 300 in the present application can be, but is not limited to, a mobile phone, a tablet computer, an e-reader, a notebook computer, and the like. Please refer to Figure 6 and Figure 7Fig. 1 is a structural schematic diagram of a foldable electronic device in an unfolded state according to an embodiment of the present application, and Fig. 2 is an exploded schematic diagram of a display device according to an embodiment of the present application. The foldable electronic device 300 includes a display device 200. The display device 200 includes an unequal-thickness glass 100 and a flexible screen 210 disposed on a surface of the unequal-thickness glass 100. The flexible screen 210 has a bending area 211, and a first reinforcing portion 10 is disposed corresponding to the bending area 211. In an embodiment of the present application, the flexible screen 210 includes the bending area 211 and a non-bending area 212 adjacent to the bending area 211, and a second reinforcing portion 20 is disposed corresponding to the non-bending area 212. In another embodiment of the present application, the flexible screen 210 includes the bending area 211 and the non-bending area 212 disposed on opposite sides of the bending area 211, and the unequal-thickness glass 100 includes the first reinforcing portion 10 and the second reinforcing portion 20 disposed on opposite sides of the first reinforcing portion 10. The first reinforcing portion 10 of the unequal-thickness glass 100 has a small thickness and a strong bending performance, and can satisfy folding and unfolding of the display device 200. The second reinforcing portion 20 has a large thickness and a high strength, and can protect the flexible screen 210 and improve the service life of the flexible screen 210, which is beneficial to use of the foldable electronic device 300.

[0072] Referring to Figure 8 Fig. 3 is a component schematic diagram of a foldable electronic device according to an embodiment of the present application. The foldable electronic device 300 can include an RF circuit 310, a memory 320, an input unit 330, a display unit 340, a sensor 350, an audio circuit 360, a WiFi module 370, a processor 380, and a power supply 390. The RF circuit 310, the memory 320, the input unit 330, the display unit 340, the sensor 350, the audio circuit 360, and the WiFi module 370 are connected to the processor 380. The power supply 390 is configured to supply power to the foldable electronic device 300. Specifically, the RF circuit 310 is configured to send and receive signals. The memory 320 is configured to store data and instructions. The input unit 330 is configured to input information, and can include a touch panel, operation buttons, and other input devices. The display unit 340 can include a display screen. The sensor 350 includes an infrared sensor and a laser sensor, and is configured to detect a user proximity signal and a distance signal. The speaker 361 and the microphone 362 are connected to the processor 380 through the audio circuit 360, and are configured to send and receive sound signals. The WiFi module 370 is configured to receive and send WiFi signals. The processor 380 is configured to process data of the foldable electronic device 300.

[0073] The above provides the content of the embodiments of the present application in detail, the principles and embodiments of the present application are described and explained in this paper, and the above description is only used to help understand the method and its core idea of the present application; at the same time, for the general technical personnel in the art, according to the idea of the present application, the specific embodiments and application range will be changed, and the above description should not be understood as the limitation of the present application.

Claims

1. A method of manufacturing a glass of unequal thickness, characterized in that, include: A glass substrate undergoes a first strengthening process to obtain a first pre-treated glass. The glass substrate includes a first part and a second part adjacent to the first part. The thickness of the first part is less than the thickness of the second part. The first part after the first strengthening treatment is subjected to a first etching treatment to thin the first part and obtain a second pre-treated glass, wherein after the first strengthening treatment and the first etching treatment, the volume expansion rate of the first part is less than the volume expansion rate of the second part. The second pre-treated glass undergoes a second strengthening process to obtain the third pre-treated glass; The third pre-treated glass undergoes a second etching process to thin the first part and the second part. The etching depth of the first etching process is less than the etching depth of the second etching process. The volume shrinkage rate of the first part before and after the first etching process is less than the volume shrinkage rate of the third pre-treated glass before and after the second etching process, resulting in glass of unequal thickness. The glass of unequal thickness includes a first reinforced part obtained from the first part and a second reinforced part obtained from the second part. The thickness of the first reinforced part is less than the thickness of the second reinforced part, and the peak-to-valley value of the surface of the first reinforced part is less than or equal to 0.1 mm.

2. The preparation method according to claim 1, characterized in that, The temperature of the first etching process is 25°C to 30°C, the time is 1 min to 3 min, and the etching depth is 1 μm to 2 μm. The second etching process is performed at a temperature of 25°C to 30°C for 5 min to 7 min, with an etching depth of 1.5 μm to 3 μm.

3. The preparation method according to claim 1, characterized in that, The first enhancement treatment includes treatment in potassium salt at 360°C to 400°C for 10 to 20 minutes; The second strengthening treatment includes treatment in a mixed molten salt at 380°C to 430°C for 10 to 40 minutes; The mixed molten salt includes at least one of sodium salt and lithium salt, as well as a potassium salt, wherein the mass content of the potassium salt in the mixed molten salt is 80% to 99%.

4. The preparation method according to claim 1 or 3, characterized in that, The first pretreated glass has a first strengthening layer on the surface, the thickness of the first strengthening layer is 7 μm to 13 μm, and the surface compressive stress of the first pretreated glass is greater than or equal to 800 MPa. The third pre-processed glass includes a sixth part and a seventh part adjacent to the sixth part, wherein the thickness of the seventh part is less than the thickness of the sixth part; The sixth part has a third reinforcing layer on the surface, the thickness of the third reinforcing layer is greater than or equal to 15 μm, and the surface compressive stress of the sixth part is greater than or equal to 650 MPa; The seventh part has a fourth reinforcing layer on the surface, the thickness of the fourth reinforcing layer is 5 μm to 12 μm, and the surface compressive stress of the seventh part is greater than or equal to 610 MPa.

5. The preparation method according to claim 1, characterized in that, The second pre-treated glass includes a fourth part and a fifth part adjacent to the fourth part, wherein the thickness of the fifth part is less than the thickness of the fourth part; The fourth part has a first reinforcing layer on the surface, the thickness of the first reinforcing layer is 7 μm to 13 μm, and the surface compressive stress of the fourth part is greater than or equal to 800 MPa. The fifth part has a second reinforcing layer on the surface, the thickness of which is 3 μm to 10 μm, and the surface compressive stress of the fifth part is greater than or equal to 600 MPa.

6. A type of glass with unequal thickness, characterized in that, The glass of unequal thickness is prepared by the preparation method according to any one of claims 1 to 5, comprising a first strengthening portion and a second strengthening portion adjacent to the first strengthening portion, wherein the thickness of the first strengthening portion is less than the thickness of the second strengthening portion, and the peak-to-valley value of the surface of the first strengthening portion is less than or equal to 0.1 mm.

7. The unequal thickness glass as described in claim 6, characterized in that, The first reinforced part has a fifth reinforced layer located on the surface, the thickness of the fifth reinforced layer being 3 μm to 10 μm, and the surface compressive stress of the first reinforced part being greater than or equal to 410 MPa; The second reinforced part has a sixth reinforced layer located on the surface, the thickness of the sixth reinforced layer being greater than or equal to 11 μm, and the surface compressive stress of the second reinforced part being greater than or equal to 450 MPa; The thickness of the first reinforcing part is 30 μm to 50 μm; The thickness of the second reinforcing part is 70 μm to 220 μm.

8. The unequal thickness glass as described in claim 6, characterized in that, The bending radius of the unequal thickness glass is less than or equal to 0.5 mm.

9. A foldable electronic device, characterized in that, The device includes a display device comprising glass of unequal thickness prepared by the preparation method according to any one of claims 1 to 5 or glass of unequal thickness prepared by any one of claims 6 to 8, and a flexible screen disposed on the surface of the glass of unequal thickness, the flexible screen having a bending region, and the first reinforcing portion being disposed corresponding to the bending region.

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