Unequal-thickness glass, preparation method thereof and foldable electronic equipment

Abstract

The invention provides a preparation method of unequal-thickness glass, which comprises the following steps: carrying out first strengthening treatment on a glass substrate to obtain first pretreated glass, the glass substrate comprises a first part and a second part adjacent to the first part, and the thickness of the first part is smaller than that of the second part; performing first etching treatment on the first part subjected to the first strengthening treatment to thin the first part so as to obtain second pretreated glass, and after the first strengthening treatment and the first etching treatment, the volume expansion rate of the first part is smaller than that of the second part; performing second strengthening treatment on the second pretreated glass to obtain third pretreated glass; the third pretreated glass is subjected to second etching treatment to obtain unequal-thickness glass, the unequal-thickness glass 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 smaller than that of the second strengthened part, and the peak-valley value of the surface of the first strengthened part is smaller than or equal to 0.1 mm. The invention provides unequal-thickness glass and foldable electronic equipment.

Description

Technical Field

[0001] The present application belongs to the technical field of electronic equipment, and specifically relates to unequal thickness glass and a preparation method thereof and a foldable electronic device. Background Art

[0002] The flexible screen surface of foldable electronic devices is generally provided with a glass cover, which protects the flexible screen and prolongs its service life. In addition to glass covers of equal thickness, glass covers of unequal thickness have also been developed, which have a wider range of application scenarios. However, when glass covers of unequal thickness are strengthened, due to the difference in thickness, the expansion amount of different thickness areas during the strengthening process is very different. After strengthening, the unequal thickness glass covers are twisted, deformed, and wrinkled, which is not conducive to their use. Summary of the invention

[0003] In view of this, the present application provides glass of unequal thickness, a preparation method thereof, and a foldable electronic device.

[0004] In a first aspect, the present application provides a method for preparing glass of unequal thickness, comprising:

[0005] A glass substrate is subjected to a first strengthening treatment to obtain a first pre-treated glass, wherein the glass substrate comprises a first portion and a second portion adjacent to the first portion, wherein the thickness of the first portion is less than the thickness of the second portion;

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

[0007] The second pretreated glass is subjected to a second strengthening treatment to obtain a third pretreated glass;

[0008] The third pretreated glass is subjected to a second etching treatment to obtain unequal thickness glass, wherein the unequal thickness glass includes a first strengthening part obtained from the first part and a second strengthening part obtained from the second part, the thickness of the first strengthening part is less than the thickness of the second strengthening part, and the peak-to-valley value of the surface of the first strengthening part is less than or equal to 0.1 mm.

[0009] In a second aspect, the present application provides a glass of unequal thickness, which includes a first strengthening part and a second strengthening part adjacent to the first strengthening part, the thickness of the first strengthening part is less than the thickness of the second strengthening part, and the peak-to-valley value of the surface of the first strengthening 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, wherein the display device comprises the unequal thickness glass produced by the preparation method described in the first aspect or the unequal thickness glass described in the second aspect, and a flexible screen arranged on the surface of the unequal thickness glass, wherein the flexible screen has a bending zone, and the first strengthening portion is arranged corresponding to the bending zone.

[0011] The present application uses multiple strengthening and segmented etching methods to make the expansion amounts of the first part and the second part of unequal thickness after processing similar, thereby avoiding the occurrence of distortion and deformation of the first strengthened part. The first strengthened part with good surface flatness and light and shadow effects can be produced, and unequal thickness glass with excellent appearance and light and shadow effects can be obtained, which is conducive to the use of unequal thickness glass in foldable electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the implementation modes of the present application, the drawings required for use in the implementation modes of the present application will be described below.

[0013] Figure 1 A flow chart of a method for preparing glass of unequal thickness provided in one embodiment of the present application.

[0014] Figure 2 A schematic cross-sectional view of a glass substrate provided in accordance with one embodiment of the present application.

[0015] Figure 3 A schematic cross-sectional view of a glass substrate provided in another embodiment of the present application.

[0016] Figure 4 A schematic cross-sectional view of glass of unequal thickness provided in one embodiment of the present application.

[0017] Figure 5 for Figure 4 Magnified view of the dashed area.

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

[0019] Figure 7 This is a schematic diagram of an exploded view of a display device provided in one embodiment of the present application.

[0020] Figure 8 A schematic diagram of the composition of a foldable electronic device provided in one embodiment of the present application.

[0021] Description of labels:

[0022] Glass substrate-110, first part-111, second part-112, glass of unequal thickness-100, first strengthening part-10, second strengthening 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 ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

[0024] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts 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 repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0025] See also Figure 1 , is a flow chart of a method for preparing glass of unequal thickness provided in one embodiment of the present application, comprising:

[0026] S101: performing a first strengthening treatment on a glass substrate to obtain a first pretreated glass, wherein the glass substrate comprises a first portion and a second portion adjacent to the first portion, and a thickness of the first portion is smaller than a thickness of the second portion.

[0027] S102: performing a first etching treatment on the first portion after the first strengthening treatment to thin the first portion to obtain a second pretreated glass, wherein after the first strengthening treatment and the first etching treatment, the volume expansion rate of the first portion is less than the volume expansion rate of the second portion.

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

[0029] S104: The third pretreated glass is subjected to a second etching treatment to obtain unequal thickness glass, wherein the unequal thickness glass includes a first strengthening part obtained from the first part and a second strengthening part obtained from the second part, wherein the thickness of the first strengthening part is less than the thickness of the second strengthening part, and the surface peak-to-valley value of the first strengthening part is less than or equal to 0.1 mm.

[0030] In the present application, a first pretreated glass is obtained by performing a first strengthening treatment on a glass substrate 110; the thickness of the first pretreated glass is not equal, that is, the thickness of the glass substrate 110 is also not equal, resulting in distortion and deformation of the thinner first portion 111 after the first strengthening treatment, and the first portion 111 is thinned by a first etching treatment to reduce the expansion of the first portion 111, so that the volume expansion rate of the first portion 111 is smaller than the volume expansion rate of the second portion 112; after the second strengthening treatment, the expansion of the thinner first portion 111 is greater than the expansion of the thicker second portion 112, and after the second etching treatment, the expansion of the first portion 111 and the second portion 112 reaches the same level, thereby obtaining a first strengthening portion 10 and a second strengthening portion 20 with the same expansion, avoiding the problem of distortion and deformation caused by excessive expansion of the thinner first strengthening portion 10, and avoiding the messy light and shadow effects of the unequal thickness glass 100 caused by distortion and deformation, which is conducive to the use of the unequal thickness glass 100 in a foldable electronic device 300.

[0031] In S101 , a first strengthening treatment is performed on a glass substrate 110 of unequal thicknesses to obtain a first pre-treated glass, where the first pre-treated glass is a strengthened glass of unequal thicknesses.

[0032] In the present application, the glass substrate 110 of unequal thickness can be prepared by etching, machining, etc., and of course, the glass substrate 110 of unequal thickness can also be directly formed. In one embodiment of the present application, the glass substrate 110 may include, but is not limited to, at least one of aluminosilicate glass, soda-lime glass, borosilicate glass, etc. The above-mentioned glass substrate 110 has good mechanical properties and good light transmittance, which is conducive to obtaining unequal thickness glass 100 with excellent performance. In one embodiment of the present application, the glass substrate 110 can be high aluminosilicate glass. This can further improve the performance of the unequal thickness glass 100. In one embodiment, the mass content of aluminum oxide in the high aluminosilicate 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 aluminosilicate glass is greater than 20%, and the mass content of silicon oxide is greater than 65%. In one 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 unequal thickness glass 100 prepared in the foldable electronic device 300. In one 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] See also Figure 2 , is a cross-sectional schematic diagram of a glass substrate provided in one embodiment of the present application, wherein the glass substrate 110 includes a first portion 111 and a second portion 112 adjacent to the first portion 111, and the thickness of the first portion 111 is less than the thickness of the second portion 112, so that the glass substrate 110 is a glass substrate 100 of unequal thickness. In one embodiment of the present application, the second portion 112 is disposed on one side of the first portion 111. In another embodiment of the present application, as Figure 2 As shown, the second portion 112 is disposed on opposite sides of the first portion 111. In one embodiment of the present application, the first portion 111 is a flat portion. In another embodiment of the present application, see Figure 3 , is a cross-sectional schematic diagram of a glass substrate provided in another embodiment of the present application, wherein the first portion 111 includes a flat portion and a transition portion, and the transition portion connects the second portion 112 and the flat portion. Among them, along the direction from the second portion 112 to the first portion 111, the thickness of the transition portion gradually decreases, and the thickness of the flat portion is less than the thickness of the second portion 112; the transition portion can further improve the light and shadow difference between the first portion 111 and the second portion 112, achieve a gentle change in the light and shadow effect, and facilitate the use of unequal thickness glass 100. It can be understood that the thickness value in the present application is the average thickness. In one embodiment of the present application, the first portion 111 has a first surface and a second surface arranged oppositely, and the second portion 112 has a third surface and a fourth surface arranged oppositely, the first surface and the third surface are located in the same horizontal plane, and the second surface and the fourth surface are located in different horizontal planes. In another embodiment of the present application, the first part 111 has a first surface and a second surface arranged opposite to each other, the second part 112 has a third surface and a fourth surface arranged 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] Through the first strengthening treatment, the strength of the glass substrate 110 is improved, and the first pretreated glass with excellent performance is obtained, which is conducive to the use of unequal thickness glass 100. In one embodiment of the present application, the first strengthening treatment is carried out in a molten salt containing potassium salt, wherein potassium ions replace alkali metal ions in the surface layer of the glass substrate 110 through ion exchange, so that a strengthening layer is generated on the surface of the glass substrate 110, thereby achieving the purpose of strengthening. The present application uses potassium salt as a strengthening molten salt to significantly improve 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 one embodiment of the present application, the temperature of the first strengthening treatment is 360°C to 400°C. Specifically, the temperature of the first strengthening treatment may 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. In one embodiment, the temperature of the first strengthening treatment may be 360°C to 380°C. In another embodiment, the temperature of the first strengthening treatment may be 380°C to 400°C. In one embodiment of the present application, the temperature of the first strengthening treatment is lower than the temperature of the second strengthening treatment, so that the distortion and deformation of the first part 111 after the first strengthening treatment can be reduced, thereby further improving the light and shadow effect of the unequal thickness glass 100. In one embodiment of the present application, the time of the first strengthening treatment is 10min to 20min. Specifically, the time of the first strengthening treatment may be, but is not limited to, 10min, 12min, 15min, 18min, 19min or 20min. In one embodiment, the time of the first strengthening treatment is 10min to 15min. In another embodiment, the first strengthening treatment lasts for 15 minutes to 20 minutes. In one embodiment of the present application, the first strengthening treatment lasts for less than the second strengthening treatment, so that the distortion of the first portion 111 after the first strengthening treatment can be reduced, thereby further improving the light and shadow effect of the unequal thickness glass 100.

[0036] In one 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 may be, but is not limited to, 800 MPa, 820 MPa, 835 MPa, 850 MPa, 860 MPa or 875 MPa, etc. It is understandable that the first strengthening treatment may be performed on any surface of the glass substrate 110, and a protective layer may be provided on the surface that does not need to be strengthened to avoid strengthening. The surface compressive stress of the first pretreated glass is the surface compressive stress of the surface that is subjected to the first strengthening treatment.

[0037] In one embodiment of the present application, the first pretreated glass has a first strengthening layer located on the surface layer, and the thickness of the first strengthening layer is 7 μm to 13 μm. Specifically, the thickness of the first strengthening layer may 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. In one embodiment, the thickness of the first strengthening layer is 7 μm to 10 μm. In another embodiment, the thickness of the first strengthening layer is 10 μm to 13 μm.

[0038] In one embodiment of the present application, the first pretreated glass includes a third part and a fourth part adjacent to the third part. The first part 111 is formed into the third part after the first strengthening treatment, and the second part 112 is formed into the fourth part after the first strengthening treatment. In one embodiment of the present application, the surfaces of the third part and the fourth part both have a first strengthening layer, and the thickness of the first strengthening layer is 7μm to 13μm. In one embodiment, the thickness of the first strengthening layer on the surface of the third part is equal to the thickness of the first strengthening layer on the surface of the fourth part. In one embodiment of the present application, the surface compressive stress of the third part and the fourth part is greater than or equal to 800MPa. In one embodiment, the surface compressive stress of the third part is equal to the surface compressive stress of the fourth part.

[0039] In S102, since the thicknesses of the first part 111 and the second part 112 are different, the first part 111 with a thinner thickness expands too much after the first strengthening, resulting in distortion and deformation, that is, the light and shadow effect of the third part is not good, which affects the light and shadow effect of the first pretreated glass; by performing the first etching treatment on the first part 111 (that is, the third part) after the first strengthening treatment, the first part 111 (that is, the third part) after the first strengthening treatment is thinned, so that the volume expansion rate of the first part 111 after the first strengthening treatment and the first etching treatment is less than the volume expansion rate of the second part 112 after the first strengthening treatment and the first etching treatment, which is conducive to obtaining the first strengthening part 10 and the second strengthening part 20 with similar expansion rates.

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

[0041] In the present application, since the third part is subjected to a thinning process and the fourth part is not subjected to the first etching process, a shielding layer can be provided on the surface of the fourth part to prevent it from being etched. The material of the shielding layer can be selected as needed and will not be described in detail here. In the present application, the shielding layer can be provided on the surface of the fourth part by means of silk screen printing, lamination, deposition, or exposure and development, and the first pre-treated glass provided with the shielding layer is subjected to an etching process.

[0042] In one embodiment of the present application, the first etching treatment uses an etching liquid to thin the first part 111. Specifically, the etching liquid may be, but is not limited to, hydrofluoric acid, and the shielding layer is an acid-resistant layer. Among them, the first pre-treated glass provided with a shielding layer may be immersed in the etching liquid, or the etching liquid may be sprayed on the surface of the first pre-treated glass provided with a shielding layer. In one embodiment of the present application, the temperature of the first etching treatment is 25°C to 30°C. Specifically, the temperature of the first etching treatment may 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 one embodiment, the temperature of the first etching treatment may be 25°C to 27°C. In another embodiment, the temperature of the first etching treatment may be 28°C to 29°C. In one embodiment of the present application, the time of the first etching treatment is 1min to 3min. Specifically, the time of the first etching treatment may be, but is not limited to, 1min, 1.5min, 2min, 2.5min or 3min, etc. In one embodiment, the time of the first etching treatment is 1min to 2min. In another embodiment, the first etching process lasts for 2 minutes to 3 minutes.

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

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

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

[0046] In one embodiment of the present application, the etching depth of the first etching process is 1 μm to 2 μm. When the third portion is subjected to the first etching process, the third portion has two surfaces arranged opposite to each other in the thickness direction. If the first etching process is performed on one of the surfaces, the etching depth is 1 μm to 2 μm. If the first etching process 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-sided etching amount. Specifically, the etching depth of the first etching process 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 one 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 a first strengthening layer; the first etching treatment etches the first strengthening layer on the surface of the third part, so the surface of the fifth part has a second strengthening layer. In one embodiment of the present application, the fourth part has a first strengthening layer located on the surface, the thickness of the first strengthening layer is 7μm to 13μm, and the surface compressive stress of the fourth part is greater than or equal to 800MPa. In one embodiment of the present application, the fifth part has a second strengthening layer located on the surface, the thickness of the second strengthening layer is 3μm to 10μm, and the surface compressive stress of the fifth part is greater than or equal to 600MPa. Specifically, the thickness of the second strengthening layer may 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 portion may be, but is not limited to, 600 MPa, 620 MPa, 635 MPa, 650 MPa, or 660 MPa, etc. In one embodiment, the thickness of the second strengthening layer may be 3 μm to 6 μm. In another embodiment, the thickness of the second strengthening layer may be 7 μm to 10 μm.

[0048] In S103, the second pretreated glass is subjected to a second strengthening treatment to further enhance its strength.

[0049] In one embodiment of the present application, the second strengthening treatment is carried out in a mixed molten salt, and the mixed molten salt includes at least one of a sodium salt and a lithium salt and a potassium salt. The mixed molten salt can not only improve the glass strengthening, but also reduce the distortion caused by strengthening, which is conducive to obtaining a third pre-treated glass with better light and shadow effects. In one 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 one embodiment of the present application, the mass content of potassium salt in the mixed molten salt is 80% to 99%. Specifically, the mass content of 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 potassium salt in the mixed molten salt can effectively improve the glass strengthening and obtain a better strengthening effect. In one embodiment, the mass content of potassium salt in the mixed molten salt may be 80% to 90%. In another embodiment, the mass content of potassium salt in the mixed molten salt may be 90% to 99%.

[0050] In one 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 may 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. Since the first etching treatment reduces the expansion of the first part 111, the strengthening temperature can be increased in the second strengthening treatment to enhance the strengthening effect, while the first part 111 will not produce obvious distortion. In one embodiment, the temperature of the second strengthening treatment may be 380°C to 400°C. In another embodiment, the temperature of the second strengthening treatment may be 400°C to 430°C. In one embodiment of the present application, the time of the second strengthening treatment is 10min to 40min. Specifically, the time of the second strengthening treatment may be, but is not limited to, 10min, 15min, 20min, 25min, 30min, 35min or 40min. In one embodiment, the time of the second strengthening treatment is 10min to 25min. In another embodiment, the second strengthening treatment lasts for 20 min to 40 min.

[0051] After the first strengthening treatment, the first etching treatment and the second strengthening treatment, the first part 111 becomes the seventh part, and the second part 112 becomes the sixth part. In one embodiment of the present application, the third pre-treated glass includes 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 pre-treated glass, and a protective layer can be set on the surface that does not need to be strengthened to avoid strengthening.

[0052] In one embodiment of the present application, the sixth part has a third strengthening layer located on the surface, and the thickness of the third strengthening layer is greater than or equal to 15 μm. Specifically, the thickness of the third strengthening layer may be, but is not limited to, 15 μm, 16 μm, 17 μm, 18 μm, or 19 μm, etc. In one 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 may 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 one embodiment of the present application, the seventh part has a fourth strengthening layer located on the surface, and the thickness of the fourth strengthening layer is 5μm to 12μm. Specifically, the thickness of the fourth strengthening layer may be, but is not limited to, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm or 12μm, etc. In one embodiment, the thickness of the first strengthening layer is 5μm to 8μm. In another embodiment, the thickness of the first strengthening layer is 8μm to 12μm. In one embodiment of the present application, the surface compressive stress of the seventh part is greater than or equal to 610MPa. Specifically, the surface compressive stress of the seventh part may be, but is not limited to, 610MPa, 620MPa, 625MPa, 630MPa or 640MPa, 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, after the first etching treatment, the volume expansion rate of the first portion 111 is made smaller than the volume expansion rate of the second portion 112. After the second strengthening treatment, the expansion rate of the thinner first portion 111 is greater than the expansion rate of the thicker second portion 112. The first portion 111 and the second portion 112 are thinned by the second etching treatment, and the expansion rates of the first portion 111 and the second portion 112 are further reduced, so that the expansion amounts of the two portions reach the same level or reach consistency, thereby avoiding distortion caused by the difference in expansion rates and ensuring the light and shadow effects of the unequal thickness glasses 100.

[0055] In the present application, before the second etching process, the third pre-treated glass may be cleaned to remove the molten salt in the third strengthening process. Specifically, the third pre-treated glass may be cleaned with water or a cleaning agent.

[0056] In one embodiment of the present application, the second etching treatment uses an etching liquid to thin the third pre-treated glass. Specifically, the etching liquid may be, but is not limited to, hydrofluoric acid. In one embodiment of the present application, the temperature of the second etching treatment is 25°C to 30°C. Specifically, the temperature of the second etching treatment may 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 one embodiment, the temperature of the second etching treatment may be 25°C to 27°C. In another embodiment, the temperature of the second etching treatment may be 28°C to 29°C. In one embodiment of the present application, the time of the second etching treatment is 5min to 7min. Specifically, the time of the second etching treatment may be, but is not limited to, 5min, 5.5min, 6min, 6.5min or 7min, etc. In one embodiment, the time of the second etching treatment is 5min to 6min. In another embodiment, the time of the second etching treatment is 6min to 7min. In one embodiment of the present application, the time of the second etching treatment is longer than that of the first etching treatment, so that the volume expansion rates of the first portion 111 and the second portion 112 after the first strengthening treatment, the first etching treatment, the second strengthening treatment, and the second etching treatment can be further made to reach the same level, thereby avoiding distortion and deformation caused by excessive expansion rate of the first portion 111, so as to obtain unequal thickness glass 100 with excellent light and shadow effects. The second etching treatment can reduce the volume of the third pre-treated glass. For example, when the third pre-treated glass is a rectangular parallelepiped, the length, width, and thickness of the third pre-treated glass can be reduced by the second etching treatment to thin the third pre-treated glass.

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

[0058] In one embodiment of the present application, the etching depth of the first etching treatment is less than the etching depth of the second etching treatment. This is beneficial for making the volume expansion rates of the first portion 111 and the second portion 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 unequal thickness glass 100 with excellent light and shadow effects.

[0059] In the present application, the first portion 111 before the first etching treatment is the third portion, the first portion 111 after the first etching treatment is the fifth portion, and the volume shrinkage rate of the first portion 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 is (V6-V7) / V6. In one embodiment of the present application, (V3-V5) / V3 is less than (V6-V7) / V6, which is conducive to making the volume expansion rate of the first portion 111 and the second portion 112 after the first strengthening treatment, the first etching treatment, the second strengthening treatment, and the second etching treatment reach the same level, so as to obtain the unequal thickness glass 100 with excellent light and shadow effects.

[0060] In this application, after the second etching process, the glass 100 with different thickness is obtained; see Figure 4 , is a schematic cross-sectional view of unequal thickness glass provided in one embodiment of the present application, wherein the unequal thickness glass 100 includes a first strengthening portion 10 obtained from a first portion 111 and a second strengthening portion 20 obtained from a second portion 112, and the thickness of the first strengthening portion 10 is less than the thickness of the second strengthening portion 20. It can be understood that the first portion 111 becomes the first strengthening portion 10 after the first strengthening treatment, the first etching treatment, the second strengthening treatment, and the second etching treatment, and the second portion 112 becomes the second strengthening portion 20 after the first strengthening treatment, the second strengthening treatment, and the second etching treatment.

[0061] See also Figure 5 ,for Figure 4 In the enlarged view of the dotted line area, the first reinforcement part 10 has a first outer surface 11 and a second outer surface 12 that are arranged opposite to each other. The point A on the first outer surface 11 with the largest distance from the second outer surface 12 is the point A, and the point B on the first outer surface 11 with the smallest distance from the second outer surface 12 is the point B. 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 point A and point B is the peak-to-valley value (PV value). It can be understood that Figure 5The first outer surface 11 is used as an example for explanation, and the PV value calculation of the second outer surface 12 is the same. In the present application, the peak-to-valley value of the surface of the first reinforcing 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 reinforcing portion 10 in the thickness direction, that is, 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 one embodiment of the present application, the peak-to-valley value of the surface of the first reinforcing 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 reinforcing 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 reinforcing portion 10 is detected by a laser interferometer.

[0062] In the related art, in the first pretreated glass obtained only by the first strengthening, the thinner area is severely distorted and deformed, making the first pretreated glass unable to be used directly; while in the present application, the first strengthening treatment, the first etching treatment, the second strengthening treatment and the second etching treatment are performed in sequence, so that the expansion rates of the first strengthening part 10 and the second strengthening part 20 reach the same level, thereby avoiding the problem of distortion and deformation caused by excessive expansion rate of the thinner first strengthening part 10, avoiding the occurrence of wrinkles, thereby improving the surface flatness of the first strengthening part 10 and improving the light and shadow effects of the unequal thickness glass 100.

[0063] The present application also provides a unequal thickness glass 100, which includes a first strengthening part 10 and a second strengthening part 20, wherein the thickness of the first strengthening part 10 is less than the thickness of the second strengthening part 20, and the peak-to-valley value of the surface of the first strengthening part 10 is less than or equal to 0.1 mm. The unequal thickness glass 100 can be prepared by any of the preparation methods in the above embodiments.

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

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

[0066] In one embodiment of the present application, the thickness of the first strengthening part 10 is 30 μm to 50 μm, which is beneficial to improve the bending performance of the unequal thickness glass 100 and is beneficial to the use of the unequal thickness glass 100 in the foldable electronic device 300. Specifically, the thickness of the first strengthening part 10 may 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. In one embodiment, the thickness of the first strengthening part 10 may be 30 μm to 40 μm. In another embodiment, the thickness of the first strengthening part 10 may be 40 μm to 50 μm. In yet another embodiment, the thickness of the first strengthening part 10 may be 35 μm to 45 μm.

[0067] In one embodiment of the present application, the thickness of the second strengthening part 20 is 70 μm to 220 μm, which is beneficial to improve the strength of the unequal thickness glass 100 without increasing the weight of the unequal thickness glass 100 too much, and is beneficial to the use of the unequal thickness glass 100 in the foldable electronic device 300. Specifically, the thickness of the second strengthening part 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 one embodiment, the thickness of the second strengthening part 20 can be 70 μm to 120 μm. In another embodiment, the thickness of the second strengthening part 20 can be 100 μm to 150 μm. In another embodiment, the thickness of the second strengthening part 20 can be 150 μm to 220 μm.

[0068] In one embodiment of the present application, the bending radius of the unequal thickness glass 100 is less than or equal to 0.5 mm. In the present application, the bending radius is measured in a two-point bending test. The unequal thickness glass 100 has excellent bending performance, which is conducive to the use of the unequal thickness glass 100 in a foldable electronic device 300. Specifically, the bending radius of the unequal 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 one embodiment, a glass substrate 110 is provided, wherein the thickness of the first portion 111 of the glass substrate 110 is 30 μm, and the thickness of the second portion 112 is 100 μm; the glass substrate 110 is placed in potassium nitrate molten salt for a first strengthening treatment, wherein the temperature of the first strengthening treatment is 390° C., and the time is 13 min. The volume expansion rate of the first portion 111 before and after the first strengthening treatment is 0.12%, and the volume expansion rate of the second portion 112 is 0.03%. A first pretreated glass is prepared, wherein the surface of the first pretreated glass has a first strengthening layer, and the thickness of the first strengthening layer is 7 μm. The surface compressive stress of the first pretreated glass is 850 MPa. The first pretreated glass includes a third portion formed by the first portion 111 and a fourth portion formed by the second portion 112. An acid-resistant ink is screen-printed on the surface of the fourth portion to form a shielding layer, and the first pretreated glass with the shielding layer set is placed in hydrofluoric acid for a first etching treatment, wherein the temperature of the first etching treatment is 28° C., and the time is 2 min. The volume shrinkage rate of the third portion before and after the first etching treatment is 0.07%. The shielding layer on the surface of the fourth part is removed to obtain a second pretreated glass, wherein the second pretreated glass includes the fifth part and the fourth part formed by the third part. The second pretreated glass is placed in a mixed molten salt for a second strengthening treatment, wherein the mixed molten salt includes potassium nitrate with a mass content of 90% and sodium nitrate with a mass content of 10%, and the temperature of the second strengthening treatment is 380° C. and the time is 10 minutes to obtain a third pretreated glass, wherein the third pretreatment includes the seventh part formed by the fifth part and the sixth part formed by the fourth part. The third pretreated glass is placed in hydrofluoric acid for a second etching treatment, the temperature of the second etching treatment is 28°C, the time is 5 minutes, the volume shrinkage of the seventh part before and after the second etching treatment is 0.03%, and the volume shrinkage of the sixth part is 0.01%, and the unequal thickness glass 100 is prepared. The unequal thickness glass 100 includes 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 rate of the thinner thickness area and the thicker thickness area of ​​the unequal thickness glass 100 is the same. The first strengthening part 10 of the unequal thickness glass 100 is tested by a laser interferometer, and its peak-to-valley value is 0.017mm, the surface is wrinkle-free, the appearance light and shadow effect is good, and the bending radius measured by the two-point bending test is 0.5mm. The overall bending performance is good, which is conducive to use in the foldable electronic device 300.

[0070] In one comparative example, the same glass substrate 110 is used to perform the same first strengthening treatment to obtain a first pretreated glass. The difference between the volume expansion rate of the first part 111 before and after the first strengthening treatment and the volume expansion rate of the second part 112 before and after the first strengthening treatment is 0.09%, the bending radius measured by the two-point bending test is 0.5 mm, the peak-to-valley value of the third part surface is 0.83 mm, there is obvious distortion, wrinkles in appearance, and poor light and shadow effects, and it cannot be used. In another comparative example, the same glass substrate 110 is used to perform the same first strengthening treatment and first etching treatment to obtain a second pretreated glass. The difference between the volume expansion rate of the first part 111 before and after the first strengthening treatment and the first etching treatment and the volume expansion rate of the second part 112 before and after the first strengthening treatment is 0.04%, the bending radius measured by the two-point bending test is 0.5 mm, the peak-to-valley value of the fifth part surface is 0.56 mm, there is obvious distortion, wrinkles in appearance, and poor light and shadow effects, and it cannot be used. It can be seen from the above embodiments and comparative examples that a distorted product will be obtained through the first strengthening treatment, and the distortion cannot be improved by only the first etching treatment. In the present application, the unequal thickness glass 100 with excellent performance and good light and shadow effects is obtained through multiple strengthening and segmented etching, which is conducive 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 in any of the above embodiments. The unequal thickness glass 100 has excellent strength and bendability, thereby increasing the service life of the foldable electronic device 300, while also improving the performance of the foldable electronic device 300 and the competitiveness of the product. The foldable electronic device 300 in the present application may be, but is not limited to, a portable foldable device with a variable display screen size, such as a mobile phone, a tablet computer, an e-reader, and a laptop computer. Please refer to Figure 6 and Figure 7, is a schematic diagram of the structure of a foldable electronic device in an unfolded state and an exploded schematic diagram of a display device provided in an embodiment of the present application, wherein the foldable electronic device 300 includes a display device 200, the display device 200 includes unequal thickness glass 100 and a flexible screen 210 arranged on the surface of the unequal thickness glass 100, the flexible screen 210 has a bending area 211, and the first strengthening part 10 is arranged corresponding to the bending area 211. In one embodiment of the present application, the flexible screen 210 includes a bending area 211 and a non-bending area 212 adjacent to the bending area 211, and the second strengthening part 20 is arranged corresponding to the non-bending area 212. In another embodiment of the present application, the flexible screen 210 includes a bending area 211 and non-bending areas 212 arranged on opposite sides of the bending area 211, and the unequal thickness glass 100 includes a first strengthening part 10 and a second strengthening part 20 arranged on opposite sides of the first strengthening part 10. The first strengthening part 10 in the unequal thickness glass 100 has a small thickness and strong bending performance, which can meet the folding and unfolding requirements of the display device 200. At the same time, the second strengthening part 20 has a large thickness and high strength, which protects the flexible screen 210 and improves the service life of the flexible screen 210, which is beneficial to the use of the foldable electronic device 300.

[0072] See also Figure 8 , is a schematic diagram of the composition of a foldable electronic device provided in one embodiment of the present application. The structure of the foldable electronic device 300 may 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. Among them, 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 respectively connected to the processor 380; the power supply 390 is used to provide power for the entire foldable electronic device 300. Specifically, the RF circuit 310 is used to receive and send signals; the memory 320 is used to store data instruction information; the input unit 330 is used to input information, which may specifically include a touch panel and other input devices such as operation buttons; the display unit 340 may include a display screen, etc.; the sensor 350 includes an infrared sensor, a laser sensor, etc., for detecting user approach signals, distance signals, etc.; the speaker 361 and the microphone 362 are connected to the processor 380 through the audio circuit 360 for receiving and sending sound signals; the WiFi module 370 is used to receive and transmit WiFi signals; the processor 380 is used to process data information of the foldable electronic device 300.

[0073] The above is a detailed introduction to the contents provided in the implementation mode of the present application. This article explains and illustrates the principles and implementation modes of the present application. The above explanation is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation mode and application scope. In summary, the contents of this specification should not be understood as limiting the present application.

Claims

1. A method for preparing glass of unequal thickness, characterized in that: include: A glass substrate is subjected to a first strengthening treatment to obtain a first pre-treated glass, wherein the glass substrate comprises a first portion and a second portion adjacent to the first portion, wherein the thickness of the first portion is less than the thickness of the second portion; performing a first etching treatment on the first portion after the first strengthening treatment to thin the first portion to obtain a second pretreated glass, wherein after the first strengthening treatment and the first etching treatment, the volume expansion rate of the first portion is less than the volume expansion rate of the second portion; The second pretreated glass is subjected to a second strengthening treatment to obtain a third pretreated glass; The third pretreated glass is subjected to a second etching treatment to obtain unequal thickness glass, wherein the unequal thickness glass includes a first strengthening part obtained from the first part and a second strengthening part obtained from the second part, the thickness of the first strengthening part is less than the thickness of the second strengthening part, and the peak-to-valley value of the surface of the first strengthening part is less than or equal to 0.1 mm.

2. The preparation method according to claim 1, characterized in that 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 portion before and after the first etching process is smaller than the volume shrinkage rate of the third pretreated glass before and after the second etching process.

3. The preparation method according to claim 1 or 2, characterized in that: The first etching treatment has a temperature of 25° C. to 30° C., a time of 1 min to 3 min, and an etching depth of 1 μm to 2 μm; The temperature of the second etching treatment is 25° C. to 30° C., the time is 5 min to 7 min, and the etching depth is 1.5 μm to 3 μm.

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

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

6. The preparation method according to claim 1, characterized in that: The second pretreated glass includes a fourth portion and a fifth portion adjacent to the fourth portion, and the thickness of the fifth portion is less than the thickness of the fourth portion; The fourth portion has a first strengthening layer located on the surface, the thickness of the first strengthening layer is 7 μm to 13 μm, and the surface compressive stress of the fourth portion is greater than or equal to 800 MPa; The fifth portion has a second strengthening layer located on the surface, the thickness of the second strengthening layer is 3 μm to 10 μm, and the surface compressive stress of the fifth portion is greater than or equal to 600 MPa.

7. A glass of unequal thickness, characterized in that: The unequal thickness glass includes a first strengthening part and a second strengthening part adjacent to the first strengthening part. The thickness of the first strengthening part is smaller than the thickness of the second strengthening part. The peak-to-valley value of the surface of the first strengthening part is smaller than or equal to 0.1 mm.

8. The unequal thickness glass according to claim 7, characterized in that: The first reinforcement portion has a fifth reinforcement layer located on the surface, the fifth reinforcement layer has a thickness of 3 μm to 10 μm, and the surface compressive stress of the first reinforcement portion is greater than or equal to 410 MPa; The second reinforcement portion has a sixth reinforcement layer located on the surface, the thickness of the sixth reinforcement layer is greater than or equal to 11 μm, and the surface compressive stress of the second reinforcement portion is greater than or equal to 450 MPa; The thickness of the first reinforcement portion is 30 μm to 50 μm; The second reinforcement portion has a thickness of 70 μm to 220 μm.

9. The unequal thickness glass according to claim 7, characterized in that: The bending radius of the unequal thickness glass is less than or equal to 0.5 mm.

10. A foldable electronic device, characterized in that: The invention comprises a display device, wherein the display device comprises unequal thickness glass obtained by the preparation method according to any one of claims 1 to 6 or unequal thickness glass according to any one of claims 7 to 9, and a flexible screen arranged on the surface of the unequal thickness glass, wherein the flexible screen has a bending zone, and the first strengthening portion is arranged corresponding to the bending zone.

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