CN113912401A

CN113912401A - Method for preparing shell, shell and electronic equipment

Info

Publication number: CN113912401A
Application number: CN202010647744.8A
Authority: CN
Inventors: 赵岩峰
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-07-07
Filing date: 2020-07-07
Publication date: 2022-01-11

Abstract

The application discloses a method for preparing a shell, the shell and electronic equipment. The method comprises the following steps: sequentially carrying out tape casting and punch forming treatment on the ceramic raw material slurry to form a punching blank; laminating a plurality of the stamping blanks, and performing lamination isostatic pressing treatment to form a laminated green body, wherein the lamination number of the stamping blanks is not less than 3, and the colors of the plurality of the stamping blanks are not completely the same; cutting the laminated green body along a direction in which the pressed blanks are laminated to obtain a plate-shaped green body, the pressed blanks being laminated along a length or width direction of the plate-shaped green body; and carrying out glue discharging treatment and sintering treatment on the green body to obtain the shell assembly. According to the method, the design is carried out on the stacking and cutting directions of the green body, the preparation of the strip-shaped shell assembly with multicolor contrast colors can be realized by using a simple die, and the method has the advantages of higher production yield, simple process, lower equipment cost and the like.

Description

Method for preparing shell, shell and electronic equipment

Technical Field

The present application relates to the field of electronic devices, and in particular, to a method for manufacturing a housing, and an electronic device.

Background

In recent years, ceramic materials have been widely used in housing components of electronic devices because of their excellent appearance, no electromagnetic shielding, and good mechanical properties. Compared with a glass shell, the ceramic shell has better mechanical property, and the ceramic as a shell material has no shielding effect on signals, so that the ceramic shell material is a preferred shell material in the future 5G mobile phone era.

However, the method for manufacturing the housing, the housing and the electronic device still need to be improved.

Disclosure of Invention

The present application is directed to solving, at least to some extent, one of the technical problems in the related art.

The present application was completed based on the following findings of the inventors:

at present, the method for realizing various colored appearances on the surface of a ceramic shell generally has the defects of difficult maintenance of the hand feeling and the glossiness of the ceramic material or complex preparation process. Specifically, one method for forming a color on the surface of the ceramic case is to spray paint or other color textures such as an optical coating (PVD coating) on the surface of the ceramic case. But is restricted by the binding force of the ceramic, the paint and the PVD coating, the surface of the ceramic material with the surface coating layer has poor wear resistance, and the coating layer is covered with ceramic glaze, so that the hand feeling and the glossiness of the ceramic are distorted. The other method is that powder with different colors is respectively pressed to prepare green bodies, then different green bodies are pressed together by using a mould to form a contrast green body, and then sintering and polishing are carried out to obtain the color-matching green body. However, the color impact effect is reflected in the XY direction of the ceramic back plate, i.e., the color. The process can realize different color block areas or sizes, has higher requirements on mold design, needs to realize preparation by using a complex mold, needs to open the mold again for preparing a new mold in different designs, and has higher production cost.

In view of the above, in one aspect of the present application, a method of making a housing assembly is presented. The method comprises the following steps: sequentially carrying out tape casting and punch forming treatment on the ceramic raw material slurry to form a punching blank; laminating a plurality of the stamping blanks, and performing lamination isostatic pressing treatment to form a laminated green body, wherein the lamination number of the stamping blanks is not less than 3, and the colors of the plurality of the stamping blanks are not completely the same; cutting the laminated green body along a direction in which the pressed blanks are laminated to obtain a plate-shaped green body, the pressed blanks being laminated along a length or width direction of the plate-shaped green body; and carrying out glue discharging treatment and sintering treatment on the green body to obtain the shell assembly. According to the method, the design is carried out on the stacking and cutting directions of the green body, the preparation of the strip-shaped shell assembly with multicolor contrast colors can be realized by using a simple die, and the method has the advantages of higher production yield, simple process, lower equipment cost and the like.

In another aspect of the present application, a housing assembly is presented. The housing assembly includes: the ceramic green layers are not completely same in color, the shell component is provided with a main body surface, and the ceramic green layers are arranged in a plurality of rows along the direction of the length or the width of the main body surface. The shell assembly has at least one of the advantages of high production yield, simple process, low equipment cost and the like.

In yet another aspect of the present application, an electronic device is presented. The electronic device includes: a housing, at least a portion of which is formed by the housing assembly described above, the housing defining an accommodating space; mainboard and display screen, the mainboard and the display screen is located inside the accommodation space. The electronic device has all the features and advantages of the housing assembly described above and will not be described herein. Generally speaking, it has at least one of the advantages of higher production yield, simple process, lower equipment cost, etc.

Drawings

FIG. 1 shows a schematic flow diagram of a method of preparing a housing assembly according to one example of the present application;

FIG. 2 shows a partial schematic flow diagram of a method of preparing a housing assembly according to one example of the present application;

FIG. 3 shows a schematic structural diagram of a green body according to one example of the present application;

FIG. 4 shows a schematic structural view of a housing assembly according to an example of the present application;

fig. 5 shows a schematic structural diagram of an electronic device according to an example of the application.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In one aspect of the present application, a method of making a housing assembly is presented. According to an embodiment of the application, referring to fig. 1, the method comprises:

s100: sequentially carrying out tape casting and punch forming treatment on the ceramic raw material slurry to form a punching blank

According to an embodiment of the application, a punched blank is first formed in this step. Specifically, the ceramic raw material slurry may be subjected to tape casting in this step, and then formed into a punched blank by a punch forming process. The thickness of the resulting punched blank may be 0.1-4.0 mm. Specifically, the ceramic raw material slurry may be subjected to a tape casting process to form a cast green body. And then, carrying out punch forming treatment on the casting blank to obtain a punching blank required by the subsequent step.

Specifically, the ceramic raw material slurry may have a powder raw material and a dispersant and a binder. Wherein the dispersant may comprise at least one of polyacrylic acid, polyethylene glycol and glycerin, and the binder may comprise at least one of PVB, DOP, DBP. The powder raw material is metal oxide in the ceramic raw material slurry to provide appearance effects of color and ceramic texture. Specifically, the powder raw materials can be mixed according to the color formed by the requirement, and specifically comprise white ingredients and colored ingredients. When it is desired to form a white cast body, the powder feedstock may contain only white furnish. The mass ratio of the powder raw material to the dispersing agent to the binder can be (45-55): (1.5-5): (0.8-1.2). The inventors have found that when the binder content in the white furnish is too high or too low, the yield of subsequent operations is affected: specifically, if the binder content is too high, for example, a mass ratio higher than 1.2, removal by degreasing in a subsequent step is not easy enough, which may cause cracking of the sintered product. When the binder content is too low, for example, less than 0.8, the binder is liable to fail to be molded in the subsequent isostatic lamination process, resulting in defects such as cracking of the green body. In particular, the present application requires the formation of a thick green laminate, and therefore, a large isostatic lamination pressure. Therefore, if the ratio of each component in the mixture is not properly adjusted, the yield of the subsequent process may be greatly reduced.

Specifically, the white batch may include 0-0.25 wt% alumina, 1-5 wt% yttria, and the balance hafnium oxide containing zirconia. The white ingredient can be powder, and the D50 particle size of the powder is 0.1-20 μm. Similarly, the color ingredient comprises at least one selected from white zirconia, yttria and alumina, and a colorant, wherein the content of the white zirconia is 90-99 wt%, the content of the yttria is 0.1-5 wt%, the content of the alumina is 0.1-3 wt%, and the content of the colorant is 0.8-8 wt%, and the colorant can comprise at least one selected from erbium trioxide, neodymium trioxide, praseodymium trioxide, cerium oxide, ferric oxide, chromium trioxide, manganese trioxide, zinc oxide, magnesium, silicon, calcium, cobalt, nickel, copper, vanadium, cadmium and tin. The specific components and proportions of the white ingredient and the colored ingredient can be adjusted and controlled by the person skilled in the art according to the required color. In some specific examples, the white ingredients and the color ingredients may be ball milled in advance. The ball milling temperature can be below 30 ℃ respectively and independently, and the ball milling time is 45-58 hours respectively and independently. Therefore, the white ingredients and the colored ingredients can be uniformly mixed respectively, and then the colored ingredients and the white ingredients are mixed according to the required color.

According to the embodiment of the application, the casting blank with the thickness of 0.1-5.0 mm can be obtained by adjusting the casting process parameters in the step. The casting blank with the thickness within the range can well keep the whole integrity of the blank after subsequent stamping, cutting and sintering treatment, the defects that a laminated green blank sample formed subsequently is too thin, the number of stacked layers is too large or a shell assembly with a larger size is difficult to obtain due to too thin thickness, the technical difficulty of casting treatment is too large, the blank is unstable, cracking and the like are easily caused due to too thick thickness are avoided.

Specifically, before the tape casting process, the ceramic raw material slurry may be subjected to a vacuum degassing process and a viscosity adjusting process. The vacuum degassing treatment can be carried out under the conditions of vacuum degree of-0.5 to-1 MPa, stirring speed of 80 to 120 r/min and stirring time of 15 to 30 min, and specifically, the vacuum plating can be carried out under-0.95 MPa. When the vacuum degree in the vacuum degassing treatment is too low, the defoaming of the slurry is not uniform, and further more defects exist in the casting green body; and the high vacuum degree increases the preparation cost of the product and does not greatly improve the performance.

According to some examples of the present application, the press forming process may be performed in a die. Therefore, the shape of the casting blank can be well kept, and the stamping efficiency and effect are improved. The specific parameters for the press forming process are not particularly limited and can be controlled by one skilled in the art based on the actual conditions and the specific thickness of the cast green body.

S200: laminating a plurality of the press blanks, wherein the number of the laminated press blanks is not less than 3, and performing lamination isostatic pressing treatment to form a laminated green body

According to an example of the present application, a plurality of laminated press blanks are subjected to a lamination setting in this step, and a lamination isostatic pressing process is performed to press the plurality of press blanks into one blank.

Specifically, the colors of the plurality of punched blanks are not completely the same, whereby the effect of the plurality of colors against color can be obtained. The specific color and thickness of the plurality of punched blanks are not particularly limited and can be determined by one skilled in the art according to design requirements. For example, the thicknesses of the plurality of punched blanks may be equal or may not be equal as long as the range defined above is satisfied. The plurality of punched blanks may be arranged in two or more colors cyclically, or the colors of the plurality of punched blanks may be different from each other. The number of punched blanks in this step may be 3-10 layers, for example 7 layers. Thus, a plurality of stacked arrangements of blanks of not exactly the same color can be obtained in this step. The thickness of the punched blank is 0.1-4.0mm, so that the total thickness of the obtained laminated green body can reach 1.0-400mm, and the requirement of electronic equipment such as a mobile phone and the like on the size of a shell component can be met after subsequent cutting treatment.

According to some examples of the present application, the stack isostatic pressing process may be performed at a pressure of 120-200MPa and a temperature of 70-100 ℃. For example, the pressure may be 160-180 MPa. When the pressure is greater than 200MPa, the cost of the laminated isostatic pressing equipment is greatly increased, and the effect of isostatic pressing cannot be remarkably improved. When the pressure is less than 120MPa, the multilayer green body in the obtained laminated green body is easily cracked.

S300: cutting the laminated green body along the direction in which the press blanks are laminated to obtain a plate-like green body

According to an embodiment of the application, a cutting process is performed in this step. Specifically, the laminated green body may be subjected to a cutting process along a direction in which the press blanks are laminated to obtain a plate-shaped green body. Referring to fig. 2, the laminated green body has a plurality of press blanks (10A to 10F, etc., as shown in the drawing) arranged in a stack, and a cutting process is performed in a direction perpendicular to the direction in which the plurality of press blanks are laminated, as indicated by a broken line in the drawing. The plate-like green compact (shown as a view in the thickness direction of the plate-like green compact) shown in the figure, which is obtained by rotating 90 degrees after cutting, has a length or width direction in the direction in which the punched blanks (10A' shown in the figure) are stacked. Therefore, the plate-shaped blank can be seen in the direction of the plane of the plate-shaped blank, and the punched blank after cutting is in a plurality of strip shapes, so that the visual effect of color collision of various colors can be achieved. The thickness of the green body obtained in this step may be 2-5 mm.

Referring to fig. 3, in the green body obtained in this step, the colors of the strip shape (i.e., the punched blank 10A' after cutting) may be arranged in the direction of the width of the plate-shaped green body (W as shown in the drawing). Alternatively, the colors of the bars may be arranged along the length of the green article (shown as L in the figure), which is not shown.

S400: carrying out glue discharging treatment and sintering treatment on the green body to obtain the shell component

According to an embodiment of the application, a binder removal process and a sintering process are performed in this step to form the housing assembly. Specifically, the specific parameters of the binder removal treatment and the sintering treatment are not particularly limited, and those skilled in the art can set the parameters according to the specific thickness of the green body, etc., as long as the sintered ceramic shell component can be finally obtained.

For example, the degreasing temperature of the gel removal treatment can be 300-600 ℃, and the time can be 0.5-4 h. The sintering temperature of the sintering treatment is 1300-1550 ℃. The occurrence rate of defects such as glue discharging and sample distortion, cracking and the like after sintering at the temperature and time is low, and a shell assembly with high yield can be obtained. And the colors of different stamping blanks in the shell assembly can be kept better, and the problem of obvious color difference and the like at the junction is solved.

According to the embodiment of the application, after the sintering treatment, the post-treatment operation can also be carried out. For example, both sides of the sintered green body may be polished to obtain a smooth-surfaced ceramic material. Alternatively, the cutting and trimming process may be performed after sintering, depending on the specific requirements of the housing assembly. In particular, the edges of the sintered green body may be numerically controlled arc trimmed, i.e., the edges of the plate-shaped green body are cut to form arcuate edges for forming arcuate sidewalls of the housing assembly. Because the appearance effect of multiple colors can be presented at the side wall of the finally obtained shell: the thickness of the green compact can be made thicker in the cutting process, so that two or more punched blanks can be made at the side wall portion constituting the case assembly by thinning the thickness of the green compact and trimming the arc in the cutting process based on the sintered green compact. Thereby, a case assembly having a multi-color contrast effect also in the thickness direction can be obtained, and as shown in fig. 4, the case assembly 100 can have a ceramic green layer 110 of two punched blanks at the side wall. After the cutting and trimming process, the method may further include: and polishing the cut area to make the whole surface of the shell smooth and have good hand feeling.

According to the embodiment of the application, after the cutting processing area is polished, the film coating processing can be further performed, specifically, the surface of the blank after cutting and polishing can be subjected to laser processing, plating (such as an AF film), cleaning and the like, so that the fingerprint resistance and the glossiness of the finally obtained shell are increased, and the hand feeling is further improved.

In summary, in this method, the cutting direction and the stacking direction of the press green layers are designed, the number of stacked layers is increased to obtain a stacked green body having a large thickness, and further, a ceramic green body having a stripe pattern of a plurality of colors and a large size can be obtained only by isostatic pressing and cutting, and further, a ceramic case assembly having a color impact effect can be obtained easily. The method regulates and controls the thickness and the method of the formed laminated green body and the components of the ceramic raw material slurry, so that the product yield of the method can be ensured while the thickness of the green body is improved.

In another aspect of the present application, a housing assembly is presented. Referring to fig. 4, the housing assembly 100 includes a plurality of ceramic green sheets 110, the colors of the plurality of ceramic green sheets are not completely the same, and the housing assembly has a body surface, and the plurality of ceramic green sheets are arranged in a plurality of rows along a direction of a length or a width of the body surface. The shell assembly has at least one of the advantages of high production yield, simple process, low equipment cost and the like.

According to embodiments of the present application, the housing assembly 100 may be a planar sheet, or a 2.5D or 3D curved sheet. Specifically, the housing assembly 100 may be a 2.5D substrate as shown in fig. 4, where the inner surface of the housing assembly 100 is a plane, and the outer surface has an arc-shaped sidewall, where at least two ceramic green layers 110 with different colors are exposed. The specific shape of the housing assembly is not particularly limited and can be determined by one skilled in the art according to actual needs. It is specifically noted that the housing assembly may be prepared using the methods described above. Therefore, the shape of the housing assembly 100 may be obtained by cutting the sintered blank. Since the green compact obtained by cutting by the method is a plate-shaped green compact, the cutting area for performing arc repair and the like on the edge shape of the shell component can be reduced when the shell component is formed, thereby being beneficial to saving the working hours and reducing the production cost.

According to the embodiment of the application, the outer surface of the shell assembly is provided with a plurality of ceramic blank layers with different colors, and the visual effect of stripe color contrast can be formed. The size of the ceramic green sheets 110 and the arrangement manner on the main body surface of the case assembly are not particularly limited, and for example, the thickness of the ceramic green sheets may be 0.1 to 4mm, and the case assembly may have 3 to 10 ceramic green sheets.

In another aspect of the present application, an electronic device is presented. According to an embodiment of the present application, referring to fig. 5, the electronic device 1000 includes a housing 100, at least a portion of the housing 100 is formed by the housing components described above, the housing 100 defines a containing space, and the main board and the display screen are located inside the containing space (not shown in the figure). The electronic device has all the features and advantages of the housing assembly described above and will not be described herein. Generally speaking, it has at least one of the advantages of higher production yield, simple process, lower equipment cost, etc.

The following embodiments are provided to illustrate the present application, and should not be construed as limiting the scope of the present application. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1

An alternate blue-white housing assembly was prepared with 7 layers of ceramic green layers. First, white powder is used to form white ceramic raw material slurry, and white powder and blue powder are used to form blue ceramic raw material slurry. And respectively carrying out vacuum degassing treatment on the ceramic raw material slurry with the two colors under-0.95 MPa to form a 7-layer casting blank with the thickness of 5mm, placing the casting blank in a mold, and carrying out punch forming to form a laminated blank with 7 layers. Then, isostatic pressing treatment was performed at 180MPa together with a die, cutting was performed perpendicular to the direction in which the punched blanks in the laminated green body were laminated, and then the cut plate-shaped green body was rotated by 90 degrees. And then, carrying out glue discharging, sintering, edge cutting, polishing and cleaning to obtain the shell assembly.

Comparative example 1

The shell assembly was formed using a single white blank layer, with the remaining parameters being the same as in example 1.

Comparative example 2

The other parameters were the same as in example 1, except that the ceramic raw material slurry was formed into a green body by dry press molding and laminated. Deformation occurs between the sintered multilayer blanks, and the fringe pattern boundary is distorted. Step of cutting the plate-like green compact the green compact is broken.

The mechanical properties of the housing assemblies obtained in example 1 and comparative example 1 were tested and the results are shown in table 1 below:

TABLE 1

	Density of	Ball drop test	Four bar bend test
				Example 1	6.5g/cm³	32g of falling ball, not less than 80cm	≥1200MPa
Comparative example 1	6.5g/cm³	32g of falling ball, not less than 70cm	≥1200MPa

In contrast, the housing assembly obtained according to example 1 of the present application maintained good mechanical strength compared to a housing assembly made of one monolithic ceramic blank, while the density was unchanged, namely: the structure of the shell component can keep good mechanical properties of the ceramic material on the premise of not increasing the density.

Various examples and features of different examples described in this specification can be combined and combined by one skilled in the art without contradiction.

In the description of the present application, the terms "upper", "lower", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present application but do not require that the present application must be constructed and operated in a specific orientation, and thus, cannot be construed as limiting the present application.

Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims

1. A method of making a housing assembly, comprising:

sequentially carrying out tape casting and punch forming treatment on the ceramic raw material slurry to form a punching blank;

laminating a plurality of the stamping blanks, and performing lamination isostatic pressing treatment to form a laminated green body, wherein the lamination number of the stamping blanks is not less than 3, and the colors of the plurality of the stamping blanks are not completely the same;

cutting the laminated green body along a direction in which the pressed blanks are laminated to obtain a plate-shaped green body, the pressed blanks being laminated along a length or width direction of the plate-shaped green body;

and carrying out glue discharging treatment and sintering treatment on the green body to obtain the shell assembly.

2. The method of claim 1, wherein the punched blank has a thickness of 0.1-4.0mm and the number of layers of punched blank in the laminated green body is 3-10 layers.

3. The method of claim 1 or 2, wherein tape casting the ceramic feedstock slurry comprises:

adjusting casting technological parameters to obtain a casting blank with the thickness of 0.1-5.0 mm;

optionally, before the tape casting treatment, the ceramic raw material slurry is subjected to vacuum degassing treatment and viscosity adjustment treatment in advance, wherein the vacuum degassing treatment is carried out under the conditions that the vacuum degree is-0.5 to-1 MPa, the stirring speed is 80 to 120 revolutions per minute, and the stirring time is 15 to 30 minutes;

optionally, said subjecting said cast body to said press forming process is performed in a die.

4. The method of claim 3, wherein the ceramic feedstock slurry comprises: the adhesive comprises a powder raw material, a dispersing agent and a binder, wherein the dispersing agent comprises at least one of polyacrylic acid, polyethylene glycol and glycerol, and the binder comprises at least one of PVB, DOP and DBP; the mass ratio of the powder raw material to the dispersing agent to the binder is (45-55): (1.5-5): (0.8-1.2);

the powder raw material comprises a white ingredient and optionally a colored ingredient,

the white ingredients comprise: 0-0.25 wt% of alumina, 1-5 wt% of yttrium oxide and the balance of zirconium oxide containing hafnium oxide, wherein the white ingredient is powder, and the D50 particle size of the powder is 0.1-20 μm;

the color ingredients comprise at least one selected from white zirconia, yttria and alumina and a colorant, wherein the content of the white zirconia is 90-99 wt%, the content of the yttria is 0.1-5 wt%, the content of the alumina is 0.1-3 wt%, the content of the colorant is 0.8-8 wt%, the colorant comprises at least one selected from erbium trioxide, neodymium trioxide, praseodymium trioxide, cerium oxide, ferric oxide, chromium trioxide, manganese trioxide, zinc oxide, magnesium, silicon, calcium, cobalt, nickel, copper, vanadium, cadmium and tin, the color ingredients are powder, and the D50 particle size of the powder is 0.1-20 mu m;

optionally, the white ingredients and the color ingredients are ball-milled in advance, the ball-milling temperature is respectively and independently below 30 ℃, and the ball-milling time is respectively and independently 45-58 hours.

5. The method as claimed in claim 1 or 2, wherein the pressure of the laminate isostatic pressing treatment is 120-200MPa and the temperature is 70-100 ℃;

preferably, the pressure is 160-180 MPa.

6. A method according to claim 1 or 2, wherein the thickness of the green body is 2-5 mm.

7. The method as claimed in claim 1 or 2, wherein the degreasing temperature of the gel removing treatment is 300-600 ℃, and the time is 0.5-4 h;

optionally, the sintering temperature of the sintering treatment is 1300 ℃ to 1550 ℃.

8. A housing assembly, comprising:

a plurality of ceramic green layers, the plurality of ceramic green layers not being identical in color,

and the shell component is provided with a main body surface, and a plurality of ceramic blank layers are arranged in a plurality of rows along the length or width direction of the main body surface.

9. The housing assembly of claim 8, wherein said ceramic green layers have a thickness of 0.1-4mm, said housing assembly having 3-10 of said ceramic green layers;

optionally, the housing component is prepared using the method of any one of claims 1-7.

10. An electronic device, comprising:

a housing, at least a portion of which is formed by the housing assembly of claim 8 or 9, the housing defining a receiving space;

mainboard and display screen, the mainboard and the display screen is located inside the accommodation space.