TWI742768B - Back cover assembly, method for making same and electronic device - Google Patents

Abstract

An embodiment of the present invention provides a back cover assembly, which includes a back cover and a functional layer. The back cover includes a bottom portion and a side portion bent from the bottom portion. The functional layer is located at the side portion and partially extends to the bottom portion. The side portion defines a sensing key area and a display area. The function layer includes a sensing key layer and a micro LED display layer. The sensing key area is provided with the sensing key layer, and the display area is provided with the micro LED display layer. Another embodiment of the present invention also provides a method for making the back cover assembly and an electronic device using the back cover assembly.

Description

Back cover assembly, its preparation method and electronic device

The present invention relates to the field of display technology, in particular to a back cover assembly, a preparation method thereof, and an electronic device.

Conventionally, in order to achieve the side display function of an electronic device (for example, a mobile phone), most of the front display screens are extended to the side, and the corners of the display screen still need to be covered by a back cover located below the display screen. In addition, the conventional mobile phone needs to have holes on the back cover to retain the physical buttons. This limits the material selection of the back cover and reduces its impact resistance. Therefore, how to maintain the impact resistance of the back cover (without openings) while maintaining the side display function of the mobile phone has become a design consideration in the future.

An embodiment of the present invention provides a back cover assembly, which includes: a back cover, the back cover includes a bottom and a side portion bent and extended from the bottom; and a functional layer located on the side portion and partially extending to The bottom Wherein, the side part defines a sensing key area and a display area, the functional layer includes a sensing key layer and a micro LED display layer, the sensing key area is provided with the sensing key layer, and the display area is provided with The micro-LED display layer.

The back cover assembly is provided with a micro LED display layer at least on the side of the back cover, so that the side of the back cover assembly can have a display function. In addition, the back cover assembly is also provided with an induction key layer at least on the side edge to replace the physical keys, thereby eliminating the need to open holes on the back cover and enhancing the impact resistance of the back cover. Therefore, the back cover assembly can have better strength without opening holes in the back cover, and also has a side display function.

Another embodiment of the present invention also provides a method for manufacturing a back cover assembly, which includes: providing a back cover, the back cover including a bottom and a side edge portion bent and extended from the bottom; and providing a functional layer so that The functional layer is located at the side portion and partially extends to the bottom; wherein the side portion defines a sensing button area and a display area, and the functional layer includes a sensing button layer and a micro LED display layer. The sensing key zone is provided with the sensing key layer, and the display area is provided with the micro LED display layer.

In the preparation method of the back cover assembly, on the one hand, a micro LED display layer is formed at least on the side edge of the back cover, so that the side edge of the back cover assembly can have a display function. In addition, in this method, at least the side part is also provided with a sensing button layer to replace the physical button. Therefore, the method does not need to open holes on the back cover, and the impact resistance of the back cover is enhanced. Therefore, the back cover assembly can have better strength without opening holes in the back cover, and also has a side display function.

Another embodiment of the present invention also provides an electronic device, which includes a protective cover, a display assembly, and a back cover assembly stacked in sequence, wherein the back cover assembly is the aforementioned back cover assembly, and the back cover defines a container. The display component is located in the accommodating space.

Since the above-mentioned back cover assembly can have better strength without opening the back cover, and at the same time have the side display function, the electronic device applying it also has the side display function. In addition, since the back cover does not require openings and has better impact resistance, the display components contained therein can be well protected.

10, 20, 30: back cover assembly

12: back cover

123: display area

125: Induction button area

121: accommodating space

122: bottom

124: Side

13: functional layer

14: Micro LED display layer

142: Substrate

144: drive element

146: Micro LED

16: decorative layer

18: Inductive button layer

182: sensing element

1821: the first protective layer

1822: first electrode layer

1823: Piezoelectric material layer

1824: second electrode layer

1825: second protective layer

40: Upper mold

42: bump

44: Blow Hole

50: Lower mold

70: The first fixture

72: The second lower fixture

141: Substrate

143: Wiring

145: binding pad

147: Encapsulation layer

100: electronic device

80: Protective cover

90: display component

Fig. 1 is an exploded view of a back cover assembly according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the structure of the back cover in FIG. 1.

FIG. 3 is a schematic cross-sectional view of the micro LED display layer in FIG. 1.

Fig. 4 is a schematic cross-sectional view of the sensing element.

FIG. 5 is a schematic cross-sectional view of the sensing element when it is pressed.

Fig. 6 is an exploded view of a back cover assembly according to another embodiment of the present invention.

Fig. 7 is a flow chart of a method for manufacturing a back cover assembly according to an embodiment of the present invention.

FIG. 8A is a schematic diagram of providing a flexible substrate in a method for manufacturing a back cover assembly according to an embodiment of the present invention.

FIG. 8B is a schematic diagram of the wiring formed in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

FIG. 8C is a schematic diagram of forming a binding pad in a manufacturing method of a back cover assembly according to an embodiment of the present invention.

FIG. 8D is a schematic diagram of the transfer step in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

FIG. 8E is a schematic diagram of the packaging step in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

FIG. 8F is a schematic diagram of the peeling step in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

FIG. 8G is a schematic diagram of the conformation step in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

FIG. 8H is a schematic diagram of fixing the micro LED display layer in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

FIG. 8I is a schematic diagram of the conformation step in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

FIG. 8J is a schematic diagram of the conformation step in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

FIG. 8K is a schematic diagram of the binding step in the manufacturing method of the back cover assembly according to an embodiment of the present invention.

Fig. 9 is an exploded view of a back cover assembly according to still another embodiment of the present invention.

FIG. 10 is a flowchart of a method for manufacturing a back cover assembly according to another embodiment of the present invention.

FIG. 11 is an exploded view of an electronic device according to an embodiment of the invention.

FIG. 1 is an exploded view of a back cover assembly 10 according to an embodiment of the invention. The back cover assembly 10 can be used in electronic devices such as mobile phones and tablet computers. As shown in FIG. 1, the back cover assembly 10 includes a back cover 12, a micro LED display layer 14 and a sensor key layer 18 in order from the outside to the inside. The back cover 12 includes the bottom 122 And a side portion 124 bent and extended from the bottom 122. The micro LED display layer 14 and the sensing button layer 18 constitute the functional layer 13. The functional layer 13 is disposed on the side portion 124 and partially extends to the bottom 122. In the back cover assembly 10, the micro LED display layer 14 is located between the sensing button layer 18 and the back cover 12.

The back cover assembly 10 is provided with a micro LED display layer 14 at least on the side portion 124 of the back cover 12, so that the sides of the back cover assembly 10 can have a display function. In addition, the back cover assembly 10 has a sensor key layer 18 hidden on the side of the micro LED display layer 14 away from the back cover 12 to replace the physical keys, thereby eliminating the need to open holes on the back cover 12 and enhancing the back cover 12. The impact resistance of the back cover assembly 10 can maintain the strength of the back cover 12 without opening the back cover 12, and at the same time, it also has the function of side display.

In one embodiment, the back cover 12 and the micro LED display layer 14 and the micro LED display layer 14 and the sensor key layer 18 are bonded and fixed by an adhesive layer (not shown). The adhesive layer can be a single-layer adhesive layer, a laminate of different adhesive layers, or a laminate composed of a substrate layer and adhesive layers respectively located on two opposite surfaces of the substrate layer.

FIG. 2 is a schematic diagram of the structure of the back cover 12 in FIG. 1. As shown in FIG. 2, the back cover 12 is a seamless back cover 12, and the bottom 122 and the side edges 124 are integrated.

The side portion 124 defines a sensing button area 125 and a display area 123. Among them, the sensing key area 125 and the display area 123 are both provided with a micro LED display layer 14, and the sensing key area 125 and the display area 123 are also provided with a sensing key layer 18. The micro LED display layer 14 located in the display area 123 can perform side screen display, and the micro LED display layer 14 located in the sensing key area 125 is a dummy micro LED display layer and is not used for screen display. Similarly, the sensing button layer 18 located in the display area 123 is also a dummy sensing button layer, which is not used for key operations, and only the sensing button layer 18 located in the sensing button area 125 is used for key operations.

In FIG. 2, the sensing button area 125 is adjacent to the display area 123. In other embodiments, the back cover 12 may be provided with two sensing key areas 125, which are respectively located on two sides of the display area 123, but it is not limited thereto.

In one embodiment, the bottom 122 of the back cover 12 is substantially rectangular, and the side portions 124 are formed by bending the edges of the bottom 122 in the same direction. The bottom 122 and the side portion 124 are enclosed to define an accommodating space 121 for accommodating the display component 90 of the electronic device 100 and the like. The display component 90 serves as an element for displaying the front image of the electronic device 100, and it can be an LCD display component, an OLED display component, a Micro LED display component, and the like.

In one embodiment, the back cover 12 may be another special-shaped back cover, for example, it may be a back cover 12 whose inner and outer surfaces are both curved and curved.

In one embodiment, the micro LED display layer 14 and the sensing button layer 18 are mainly disposed corresponding to the side portion 124, and a part of it will extend to cover the bottom 122 of the back cover 12. Binding. Wherein, the micro LED display layer 14 and the sensor key layer 18 can be provided only corresponding to the side portions 124 of the back cover 12 on the side of the bottom 122, or can be provided corresponding to the side portions 124 on the opposite sides of the bottom 122, without limitation.

In one embodiment, the material of the back cover 12 is glass or plastic. Among them, the glass may be strengthened glass to enhance the impact resistance of the back cover 12. The plastic may be a composite layer of a plurality of plastic layers. The back cover 12 may be transparent or dyed. In the embodiment shown in Fig. 1, the back cover 12 is made of stained glass.

FIG. 3 is a schematic cross-sectional view of the micro LED display layer 14 in FIG. 1. As shown in FIG. 3, the micro LED display layer 14 includes a flexible substrate 142, a driving element 144 on the substrate 142, and a micro LED 146 electrically connected to the driving element 144. The micro LED display layer 14 is flexible and bendable, so it can be conformed to different shapes of the back cover 12 by a conformal process.

In one embodiment, the material of the substrate 142 is, for example, polyimide (PI), or polyethylene glycol terephthalate (PET) or polycarbonate (PC), etc. .

In one embodiment, the driving element 144 is electrically connected to the circuit board of the electronic device 100 to drive the micro LED 146 to emit light to realize the side display function. Among them, the micro LED 146 may include micro LEDs that emit light of different colors, for example, a red micro LED, a blue micro LED, and a green micro LED. By mixing the three primary colors of red, green and blue, the electronic device 100 realizes Side display function.

In one embodiment, the size of the micro LED 146 is approximately in the range of 1 micrometer to 100 micrometers.

In one embodiment, the sensor key layer 18 includes, for example, a substrate layer (not shown) and a plurality of sensing elements 182 spaced apart on a surface of the substrate layer, or includes a substrate layer and is respectively located on the substrate layer. A plurality of sensing elements 182 are arranged at intervals on the opposite surfaces of the layer. When the user presses the position of the back cover 12 corresponding to the sensing button layer 18, the electronic device 100 can respond to the user's pressing to realize the corresponding button function. Among them, the key function is, for example, the power switch, the volume key addition and subtraction, and so on.

In one embodiment, as shown in FIG. 4, the sensing element 182 includes a first protective layer 1821, a first electrode layer 1822, a piezoelectric material layer 1823, a second electrode layer 1824, and a second protective layer 1825 stacked in sequence. . The material of the piezoelectric material layer 1823 is, for example, polyvinylidene fluoride (PVDF), the material of the first protective layer 1821 and the second protective layer 1825 is, for example, polyester fiber (polyester), and the first electrode layer 1822 and The material of the second electrode layer 1824 is, for example, metal or other conductive materials.

As shown in FIG. 5, when the sensing element 182 is pressed, the piezoelectric material layer 1823 generates strain due to the action of mechanical stress, and the piezoelectric material layer 1823 generates a charge change. The change in charge generated by the piezoelectric material layer 1823 is used for tactile sensing to sense the position and pressure.

Since in the back cover assembly 10, the back cover 12 is a seamless back cover, and at least the side portion 124 of the back cover 12 is provided with a micro LED display layer 14 and a sensor button layer 18, so as to achieve the goal of not digging holes. Under the circumstance, it not only maintains the strength of the back cover 12, but also has the function of side display.

FIG. 6 is an exploded view of a back cover assembly 20 according to another embodiment of the present invention, which is different from the back cover assembly 10 in FIG. 1 in that: in FIG. 6, the back cover 12 is transparent, and the back cover assembly 20 It also includes a decoration layer 16 between the sensor key layer 18 and the micro LED display layer 14. The micro LED display layer 14 and the decoration layer 16 and the decoration layer 16 and the sensor key layer 18 are bonded and fixed by an adhesive layer (not shown).

In one embodiment, the decoration layer 16 includes a resin layer (not shown), an ink layer (not shown), and an adhesion-promoting layer (not shown) stacked in sequence. The resin layer can be a highly extensible resin layer, and the adhesion-promoting layer can be a modified adhesion-promoting layer.

An embodiment of the present invention also provides a method for preparing the back cover assembly 10 (20). As shown in Figure 7, the method includes the following steps.

Step S11: A back cover 12 is provided, and the back cover 12 includes a bottom portion 122 and a side portion 124 bent and extended from the bottom portion 122.

Step S12: Provide a miniature LED display layer 14.

In one embodiment, step S12 includes providing a flexible substrate 142, disposing a driving element 144 on the substrate 142, transferring the micro LED 146 to the substrate 142, and making the micro LED 146 and the driving The element 144 is electrically connected.

As shown in FIG. 8A, since the substrate 142 is flexible, a hard substrate 141 can be provided under the substrate 142 as a support. The hard substrate 141 is, for example, glass.

As shown in FIG. 8B, the step of disposing the driving element 144 on the substrate 142 may include forming a plurality of wires 143 on the substrate 142, and the material of the wires 143 is, for example, metal.

As shown in FIG. 8C, the step of disposing the driving element 144 on the substrate 142 further includes forming a plurality of binding pads 145. Wherein, one end of each wire 143 close to the edge of the substrate 142 can be provided with a binding pad 145, and the other end of the wire 143 can be provided with a plurality of binding pads 145.

As shown in FIG. 8D, a plurality of micro LEDs 146 are transferred on the substrate 142. Among them, each micro LED 146 can be transferred to a binding pad 145 correspondingly. The arrangement of the micro LEDs 146 can be a row of red light emitting micro LEDs, a row of blue light emitting micro LEDs, and a row of green light emitting micro LEDs periodically and repeatedly, but it is not limited to this.

As shown in FIG. 8E, after the plurality of micro LEDs 146 are transferred to the substrate 142, an encapsulation layer 147 is formed on the side of the micro LEDs 146 away from the substrate 142 to protect the micro LEDs 146 from water vapor. Thereby, the substrate 142, the wiring 143, the bonding pad 145, the micro LED 146, and the packaging layer 147 jointly constitute a micro LED display layer 14.

As shown in FIG. 8F, the base material 142 of the micro LED display layer 14 and the substrate 141 supporting it are peeled off for subsequent bonding with the back cover 12.

Step S13: The micro LED display layer 14 is disposed on the back cover 12 by using a conformal process. Wherein, at least the display area 123 is formed with a micro LED display layer 14.

As shown in FIG. 8G, the micro LED display layer 14 is attached to the inner surface of the side portion 124 of the back cover 12. Wherein, the micro LED display layer 14 can be disposed on the inner surface of one side of the back cover 12 or on the inner surface of a plurality of sides of the back cover 12.

Specifically, the conforming process may include: fixing the device to be conformed (ie, the micro LED display layer 14), pressing down the upper mold 40 to fix the micro LED display layer 14 in the surface of the back cover 12, and blowing Gas shaping. As shown in FIG. 8H, the back cover 12 is fixed in the lower mold 50 by the first lower jig 70 and the second lower jig 72, and the edge of the micro LED display layer 14 is fixed between the upper mold 40 and the lower mold 50 between.

As shown in FIG. 8I, the upper mold 40 is pressed down so that the bumps 42 on the upper mold 40 press the micro LED display layer 14 down to the bottom 122 of the back cover 12.

As shown in FIG. 8J, a blow hole 44 is provided on the upper mold 40. As shown in FIG. The blowing hole 44 is located between the protrusion 42 and the first lower jig 70. After the micro LED display layer 14 is fixed to the bottom 122 of the back cover 12, blow air to the blowing hole 44 so that the micro LED display layer 14 is shaped and attached to the side portion 124 of the back cover 12.

As shown in FIG. 8K, after the micro LED display layer 14 is bonded to the back cover 12, a bonding process is also included to lead out the bonding pad 145 at one end of the wiring 143 for use with other components (eg, circuit board) Make electrical connections.

Step S14: Disposing a sensing button layer 18 on the side of the micro LED display layer 14 away from the side portion 124. Wherein, at least the sensing key area 125 is formed with a sensing key layer 18.

In one embodiment, an adhesive layer may be used to adhere the sensing button layer 18 and the micro LED display layer 14 away from the side portion 124.

In another embodiment, the back cover 12 provided in step S1 is transparent, and step S4 includes using an adhesive layer to attach a decorative layer 16 to the surface of the micro LED display layer 14 away from the side portion 124, and then using The adhesive layer adheres the sensing button layer 18 and the surface of the decoration layer 16 away from the micro LED display layer 14.

In the manufacturing method of the back cover assembly 10 (20), a conformal manufacturing process can be used to bond the micro LED display layer 14 and the back cover 12 for different shapes of the back cover 12. In addition, the micro LED display layer 14 selects the micro LED 146 as the side display element. Because the micro LED 146 is very small in size and the flexible substrate 142 supports it, the micro LED display layer 14 is flexible and can release conformity. Process stress.

FIG. 9 is an exploded view of the back cover assembly 30 according to still another embodiment of the present invention. As shown in FIG. 9, the difference from the back cover assembly 20 in FIG. 6 is that: in FIG. 9, in the back cover assembly 30, the micro LED display layer 14 included in the functional layer 13 and the sensor key layer 18 are located in the same film layer. The display area 123 is provided with a micro LED display layer 14, and the sensing button area 125 is provided with a sensing button layer 18. In addition, in the back cover assembly 30, the material of the back cover 12 is plastic.

In one embodiment, the back cover 12 is transparent, and the back cover assembly 30 further includes a decoration layer 16 between the back cover 12 and the film layer composed of the micro LED display layer 14 and the sensor key layer 18.

FIG. 10 is a flowchart of a manufacturing method of the back cover assembly 30 according to still another embodiment of the present invention. As shown in Figure 10, the method includes the following steps.

Step S21: Provide a back cover 12. The back cover 12 includes a bottom portion 122 and a side portion 124 bent and extended from the bottom portion 122.

Step S22: forming a functional layer 13 on the back cover 12.

In step S22, In-Mold Electronics (IME) technology can be used to form the sensor key layer 18 and the micro LED display layer 14 on the same film, and then shoot out into the film with the decoration layer 16 formed on another film.

Specifically, step S22 includes: printing a decorative layer 16 on a first film, forming the sensor key layer 18 on an area on a second film, and on another area on the second film The micro LED display layer 14 is formed, and the first film formed with the decoration layer 16 and the second film formed with the induction button layer 18 and the micro LED display layer 14 are in-molded together with plastic materials , Form the back cover assembly 30. Wherein, at least the sensing key area 125 is provided with a sensing key layer 18, and at least the display area 123 is provided with a micro LED display layer 14.

In one embodiment, the material of the back cover 12 is transparent plastic, and the step of printing the decorative layer 16 on the first film can be changed to printing a protective layer (not shown) on the first film.

In one embodiment, the step of forming the sensor key layer 18 on the second film may include printing a circuit layer on the second film and patterning the circuit layer to form a sensor key including a plurality of sensing elements 182 Layer 18.

In one embodiment, the step of forming the micro LED display layer 14 on the second film may include the steps of massively transferring the micro LEDs and packaging. For details, refer to the above step S12, which will not be repeated here.

In one embodiment, the material of the first film and the second film may be polyethylene glycol terephthalate (PET) or polycarbonate (PC).

With the IME technology, the functional layer 13 and the decorative layer 16 or the protective layer are encapsulated and molded at one time, which reduces the assembly process, the structure is simpler, and the production efficiency is improved.

An embodiment of the present invention also provides an electronic device 100. As shown in FIG. 11, the electronic device 100 includes a protective cover 80, a display assembly 90, and a back cover assembly 10 (20, 30) stacked in sequence. The back cover 12 defines an accommodating space 121, and the display assembly 90 can be accommodated in the accommodating space 121. The display component 90 serves as an element for displaying the front image of the electronic device 100, and it can be an LCD display component, an OLED display component, a Micro LED display component, and the like.

In one embodiment, the display element 90 may also include a touch structure, so that the electronic device 100 also has a touch display function.

In an embodiment, the electronic device 100 may be a mobile phone, a tablet computer, or the like. Since the above-mentioned back cover assembly 10 (20, 30) can have better strength without opening the back cover 12, and also has a side display function, the electronic device 100 applying it also has a side display Function. In addition, since the back cover 12 does not require openings and has better impact resistance, the display assembly 90 contained therein can be well protected.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. Without departing from the spirit and scope of the technical solution of the present invention.

10: Back cover assembly

12: back cover

122: bottom

124: Side

13: functional layer

14: Micro LED display layer

18: Inductive button layer

Claims (4)

A method for preparing a back cover assembly includes the following steps: providing a back cover, the back cover including a bottom and a side edge portion bent and extended from the bottom; and providing a functional layer so that the functional layer is located The side part extends partly to the bottom; wherein the side part defines a sensing key area and a display area, the functional layer includes a sensing key layer and a micro LED display layer, and the sensing key area is provided with In the sensing key layer, the display area is provided with the micro LED display layer; the step of providing the functional layer includes forming the micro LED display layer in the display area by a conforming process; the conformation The manufacturing process includes: providing an upper mold, a lower mold, a first lower jig and a second lower jig, the upper mold and the lower mold are disposed oppositely, the first lower jig and the second lower jig The jigs are sequentially arranged on the lower mold, and the upper mold is provided with a bump facing the lower mold and a blow hole between the bump and the first lower jig; the back cover The first lower jig and the second lower jig are fixed in the lower mold; the edge of the micro LED display layer is fixed between the upper mold and the lower mold; The upper mold is pressed down so that the bumps on the upper mold press the micro LED display layer down to the bottom of the back cover; and blow air to the blowing hole to make the The micro LED display layer is shaped and attached to the side edge of the back cover. The manufacturing method of the back cover assembly according to claim 1, wherein the step of providing the functional layer includes: The sensor key layer is formed in the sensor key area; wherein the micro LED display layer is located between the sensor key layer and the back cover. The manufacturing method of the back cover assembly according to claim 2, wherein the back cover is transparent, and the preparation method of the back cover assembly further includes forming between the sensor key layer and the micro LED display layer Decoration layer. The manufacturing method of the back cover assembly according to any one of claims 1 to 3, wherein the step of providing the functional layer includes: providing a flexible substrate; arranging a driving element on the substrate; The micro LEDs are transferred to the substrate to electrically connect the plurality of micro LEDs to the driving element; and an encapsulation layer is formed on the side of the plurality of micro LEDs away from the substrate, wherein the substrate, The driving element, the plurality of micro LEDs, and the packaging layer together constitute the micro LED display layer.

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