WO2019062698A1

WO2019062698A1 - Display device and grounding device thereof

Info

Publication number: WO2019062698A1
Application number: PCT/CN2018/107267
Authority: WO
Inventors: 单剑锋
Original assignee: 惠科股份有限公司
Priority date: 2017-09-27
Filing date: 2018-09-25
Publication date: 2019-04-04
Also published as: CN107688259A

Abstract

A display device (10) and a grounding device thereof. The display device (10) comprises a display panel (300), a framework (200), metal frames (103), a printed circuit board (400), and a protective layer (170). The framework (200) is formed by an insulation material, and the display panel (10) is disposed on the framework (200). The metal frames (103) package the framework (200) therein and form a hollow region for accommodating the display panel (300). The printed circuit board (400) is disposed below the framework (200), is not in contact with the metal frames (103), and is electrically connected to the display panel (300) by means of a flexible flat cable (151). A grounding end (153) of the printed circuit board (400) protrudes out of the framework (200) and is electrically connected to the metal frames (103). The protective layer (170) is formed by an insulation material, is attached to and covers the printed circuit board (400) by means of an adhesive material so as to fix the printed circuit board (400), and is used as an electric shield.

Description

Display device and grounding device thereof

Technical field

Embodiments of the present application relate to display devices, and in particular, to a display device and a grounding device thereof.

Background technique

The display device is currently the most popular type of display, and its advantages of being light, thin, power-saving, and easy to miniaturize, so that its traces can be seen everywhere in daily life, such as mobile phones, notebook computers, digital camcorders, tablet computers, etc. Most of the products use display devices. Nowadays, the display device with the highest usage rate belongs to a thin film transistor type display device (TFT-LCD).

Unlike display technologies such as plasma display (PDP) and organic light-emitting diode display (OLED), display devices are non-self-illuminating displays that require additional backlighting. At the same time, a specific signal is converted and outputted through a driving circuit in the display device, and the voltage is switched to change the alignment direction of the liquid crystal molecules of the display panel. The light generated by the backlight passes through the panel to form a pixel, and the light transmittance of each pixel is reflected to form a display screen.

According to the display principle of the above display device, the external noise, electric charge or electric field changes easily interfere with the arrangement of the liquid crystal molecules, causing an abnormality in the displayed image. Therefore, in order to prevent the above interference, the printed circuit board which must be provided with the driving circuit must be shielded from external influences, and during the isolation, it is tried not to interfere with the signal transmitted by itself due to the inability to exclude the accumulated electric charge of the printed circuit board itself.

In the example, there are some solutions to the above problems. Typical display devices include metal frames, frames, display panels, and printed circuit boards. In order to prevent problems that may occur on the printed circuit board, the example is to provide a grounding terminal on the side of the printed circuit board adjacent to the metal frame, and at the same time, a grounding spring is provided to electrically connect the grounding terminal to the metal frame. The grounding elastic piece is fixed on the metal outer frame by another screw, and the electric charge accumulated on the printed circuit board is transferred to the metal outer frame through the grounding elastic piece and released into the external environment.

However, in the above solution, the metal frame is simultaneously connected to the display panel, and the accumulated charge still has a great chance to interfere with the arrangement of the liquid crystal molecules through the contact with the display panel. Therefore, there is still room for improvement.

technical problem

The technical problem to be solved by the embodiments of the present application is to provide a display device that reduces interference of external noise, electric charge or electric field on the arrangement of liquid crystal molecules.

A further technical problem to be solved by the embodiments of the present application is to provide a grounding device for the above display device, which reduces interference of external noise, electric charge or electric field on the arrangement of liquid crystal molecules.

Technical solution

In order to solve the above problems, embodiments of the present application provide a display device including: a display panel; a frame formed of an insulating material, and the display panel is disposed on the frame, wherein the frame is provided with a top of the connecting frame and a bottom of the frame a through hole; a metal frame enclosing the frame therein and forming a hollow region accommodating the display panel; a printed circuit board disposed under the frame and not contacting the metal side frame, and via the flexible flat cable The through hole is electrically connected to the display panel, wherein the grounding end of the circuit board protrudes outside the frame to the outside of the frame, electrically connecting the metal frame; and the protective layer is made of an insulating material. An over-adhesive material is attached and overlaid on the printed circuit board to secure the printed circuit board and act as an electrical barrier.

Optionally, at least one of the four sides of the metal frame has a slot.

Optionally, the slot fits the ground end.

Optionally, the grounding end is electrically connected to the slot through an electrically conductive adhesive material.

Optionally, the ground end is fixed to the slot through an electrically conductive adhesive material.

Optionally, the ground end is penetrated by a metal piece

Optionally, the grounding end is electrically connected to the slot by a metal piece.

Optionally, the ground end is fixed to the slot by a metal member.

Optionally, the protective layer extends over at least one side of the metal frame having the socket with the grounded end.

Optionally, the protective layer is attached to the at least one side of the metal frame having the slot that fits the ground end.

On the other hand, the embodiment of the present application provides the grounding device of the display device, including: a metal frame, the frame of the display device is packaged therein, and a hollow region for accommodating the display panel of the display device is formed; And protruding outside the frame, and the grounding end protrudes outside the frame to the outside of the frame, electrically connecting the metal frame; and the protective layer is made of an insulating material. An over-adhesive material is attached and overlaid on the printed circuit board, the printed circuit board is fixed and serves as an electrical barrier; the protective layer extends over and adheres to at least one of the four sides of the metal frame .

Optionally, at least one of the four sides of the metal frame has a slot.

Optionally, the slot fits the ground end.

Optionally, the ground end is electrically connected to the socket by an adhesive material having conductivity.

Optionally, the ground end is fixed to the slot by an adhesive material having conductivity.

Optionally, the ground end is penetrated by a metal member.

Optionally, the ground end is fixed to the slot by a metal member.

Beneficial effect

The display device and the grounding device provided by the embodiments of the present application improve the structure of the components by using screws, grounding elastics and the like, and the space occupied by the components is omitted, so that the display device can be more compact. In addition, the construction of the conductive film is omitted, and the manufacturing process is made simpler without affecting the grounding effect of the printed circuit board.

DRAWINGS

The above and other features and advantages will become more apparent to those skilled in the art from the <RTIgt; In addition, the size ratios and the arrangement positions of the components shown in the drawings are used to facilitate the detailed explanation of the relationship therebetween, and are not intended to limit the size and positional relationship of the components. In the drawings of the present application:

FIG. 1 is a schematic view showing the circuit board of the display device grounded through a metal outer frame in the example.

FIG. 2 is a schematic view showing the bottom structure of the display device shown in FIG. 1. FIG.

3A is a schematic structural view of a display device according to an embodiment of the present application and an internal structure diagram of a broken line region thereof.

3B and 3C are schematic diagrams showing a partial structure of a display device according to an embodiment of the present application.

FIG. 3D is a schematic partial structural view of a bottom portion of a display device according to an embodiment of the present application.

4A and 4B are schematic diagrams showing a partial structure of a bottom portion of a display device according to an embodiment of the present application.

4C is a side elevational view of a bottom portion of a display device of an embodiment of the present application.

4D is a schematic partial structural view of a bottom portion of a display device according to an embodiment of the present application.

4E is a side elevational view of a bottom portion of a display device of an embodiment of the present application.

Fig. 5 is a side elevational view showing the bottom portion of the display device of the embodiment of the present application.

FIG. 6 is a partial schematic structural view of a display device according to an embodiment of the present application.

Fig. 7 is a side elevational view, partly in perspective, of the display device of the embodiment of the present application.

8A and 8B are partial structural views of a display device according to an embodiment of the present application.

Embodiments of the invention

Exemplary embodiments are described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

In the description of the present application, it is to be understood that the orientation or positional relationship of the terms "upper", "lower", "left", "right", "inside", "outside", etc. is based on the drawings. The orientation or the positional relationship is merely for the convenience of the description of the present application and the simplification of the description, and is not intended to suggest that the device or component referred to has a specific orientation and therefore is not to be construed as limiting the application.

In the description of the present application, it should be noted that the terms "installation", "connected", and "connected" are to be understood broadly, and may be fixed or detachable, for example, unless otherwise specifically defined and defined. Connections, or integral connections; may be mechanical connections or electrical connections; they may be directly connected or indirectly connected via an intermediate medium. The terms "attach" and "stick" should be understood broadly, and may be, for example, a partial attachment, a complete adhesion attachment, or a detachable attachment. The specific meanings of the above terms in the present application can be understood in the specific circumstances for those skilled in the art.

In the example shown in Fig. 1, as described above, there have been partial solutions proposed in response to the aforementioned problems. A typical display device 10 includes a metal outer frame 100, a frame 200, a display panel 300, and a printed circuit board 400. The display panel 300 is disposed on the upper surface of the frame 200, and the printed circuit board 400 is disposed on the lower surface of the frame 200. The display panel 300 and the frame 200 are electrically connected through a flexible flat cable 510. The metal bezel 100 is fitted over the outside of the bezel 200 from top to bottom and has a hollow region exposing the display panel 300.

In order to prevent the above-mentioned problem that the printed circuit board 400 accumulates electric charges, as shown in FIG. 2, the ground terminal 430 is disposed on the side of the printed circuit board 400 adjacent to the metal outer frame 100, and the ground terminal 430 is fixed by the screw 435. On the frame 200. At the same time, the grounding spring 440 is disposed to electrically connect the ground terminal 430 to the metal outer frame 100. The grounding spring 440 is fixed to the metal frame 100 through another screw (not shown in the drawing). Through the above arrangement, the electric charge accumulated on the printed circuit board 400 can be transferred to the metal outer frame 100 through the grounding elastic piece and released into the external environment.

However, in the above solution, the metal frame is simultaneously connected to the display panel, and the accumulated charge still has a great chance to interfere with the alignment of the liquid crystal molecules through the contact with the display panel. Compared with the example, the setting of the embodiment of the present application can avoid interference with the arrangement of liquid crystal molecules.

As shown in FIG. 3A, the display device 900 has a display panel 130. The display panel 130 is disposed on the frame 110. Alternatively, the frame 110 may be any insulating material capable of supporting without deformation, but is not limited thereto. The metal side frames 101 are disposed on the four side walls of the frame 110, and the metal side frames 101 may be directly fixed to the four side walls of the frame 110, or a space may be left between the frames 110 for providing other lines or components. In the case of the above-described indwelling space, the metal side frame 101 can be fixed to the relative position between the frame 110 by other means. The top side protection frame 102 is disposed above the frame 110 and the display panel 130. Alternatively, the top side protection frame 102 may be any insulating material capable of supporting without deformation, but is not limited thereto. The top side protection frame 102 has a hollow area for exposing the display panel 130. The area of the hollow area is smaller than that of the display panel 130. Therefore, when the top side protection frame 102 is disposed above the frame 110 and the display panel 130, the stability of the display panel to the frame 110 can be further improved. The top side protection frame 102 can be fixed to the frame 110 in any suitable manner. For example, the top side protection frame 102 can directly adhere to the frame 110 by using an adhesive material, or the top side protection frame 102 and the metal side frame 101 can have corresponding connection components. When the top side protection frame 102 is disposed, the relative positions of the top side protection frame 102 and the metal side frame 101 can be fixed through the connection assembly, and further fixed to the frame 110, but the method is not limited to the above.

Alternatively, the metal side frame 101 and the top side protection frame 102 may be replaced with an integrally formed metal frame 103 as shown in the example of FIG. Hereinafter, the metal frame 103 is provided instead of the metal side frame 101 and the top side protective frame 102 as an example, but the actual implementation is not limited thereto.

The printed circuit board 150 is disposed below the frame 110, for example, directly under the frame 110 or at a portion of the bottom of the frame 110, so that the printed circuit board 150 is partially buried in the frame 110. The printed circuit board 150 may not be in contact with the metal frame 103 when disposed. The printed circuit board 150 can transmit a signal required to display an image to the display panel 130 through the flexible flat cable 151. As shown in FIG. 3A , the flexible flat cable 151 can be electrically connected to the display panel 130 along the surface of the frame 110 through the indwelling space between the metal frame 103 and the frame 110 . Alternatively, as shown in FIG. 3B and FIG. 3C , the flexible flat cable 151 can be electrically connected to the display panel 130 through the through hole 120 by providing a vertical through hole 120 in the frame 110 .

The through-hole 120 is internally connected to the display panel 130 by the inside of the frame, and the inner wall of the through-hole 120 is also provided. It can be an insulating material that makes it possible for the signal transmitted by the flat cable 510 to be less susceptible to interference. In the case of external connection via the frame 110, it is optionally necessary to add a protective layer 170 on its surface as will be described later to prevent signal interference.

As shown in FIG. 3D, the printed circuit board 150 can have a ground terminal 153. Alternatively, the ground terminal 153 can be disposed to extend outwardly from the edge of the printed circuit board 150, but not at the same edge as the flexible flat cable 151. Inadvertent contact. The display device 900 further includes a conductive film 160. The conductive film 160 can be electrically connected to the grounding end 153 of the printed circuit board 150 and the metal frame 103, so that the accumulated electric charge on the printed circuit board 150 can be moved to the metal frame 103 through the conductive film 160 and released to the external environment. The conductive film 160 is attached to the printed circuit board 150 and the metal frame 103 through an adhesive material. Alternatively, the conductive film 160 is a conductive tape having a single-sided adhesive property or a double-sided adhesive property. The material of the conductive film 160 may be, for example, an aluminum foil, a copper foil, a conductive polymer, or the like, but is not limited thereto.

In addition to the above arrangement, as shown in FIG. 4A, a plurality of grounding ends 153 may be provided to improve the grounding effect. In another embodiment of the present application, a plurality of grounding ends 153 may be respectively disposed at the same edge of the printed circuit board 150, or respectively disposed at different edges, but not at the same edge as the flexible flat cable 151 to avoid inadvertent contact. In the case where a plurality of grounding ends 153 are provided, the conductive film 160 may be divided into a plurality of segments, and the plurality of grounding terminals 153 are electrically connected to the metal frame 103, respectively.

The display device 900 further includes a protective layer 170, which may be composed of an insulating material. As shown in FIG. 4B, when the conductive film 160 is a conductive tape having a single-sided adhesive property, the protective layer 170 may be overlaid on the printed circuit board 150 and attached to the periphery of the printed circuit board 150 through the adhesive layer 180. And a periphery of the conductive film 160 to fix the printed circuit board 150 and the conductive film 160. At the same time, the protective layer 170 can serve as an electrical barrier to isolate the circuits and components on the printed circuit board 150 from the outside world, thereby avoiding external environment factors from interfering with signals and causing abnormal display results. A schematic side view of the above structure is shown in Fig. 4C. The protective layer 170 can further extend and cover the flexible flat cable 151 to act as an electrical barrier to avoid interference from external environmental factors. Further, while the protective layer 170 covers the possibility of the flat cable 151, the flexible flat cable 151 can be fixed by an adhesive material.

The display device provided by the embodiments of the present application, and the grounding device composed of a combination of a printed circuit board, a metal frame, a conductive film and a protective layer in the embodiments can effectively improve the grounding device in the example. problem. In the example, multiple grounding shrapnels are provided to electrically connect the grounding end to the metal frame. In contrast, the portion of the embodiment of the present application that contacts the display panel 130 has only the insulating material frame 110 and the top side protective frame 102. Therefore, the charge transmitted to the metal side frame 101 through the conductive film 160 does not affect the display panel. 130, and does not affect the effect of the charge being transmitted through the metal side frame 101 to the external environment. In addition, the use of the conductive film 160 having adhesive properties instead of the structure of the screw and the grounding shrapnel can reduce several steps in the manufacturing process, and can eliminate the space occupied by the screw and the grounding shrapnel, thereby manufacturing a thinner and lighter display device. On the other hand, the through hole 120 provided in the frame 110 of the embodiment of the present application can prevent the signal from being disturbed without adding the protective layer 170 to the flexible flat cable 151, although the through hole is added during the manufacturing process. The step of the through hole 120 of the frame 110 itself is more protective than the additional protective layer 170.

In addition to the above embodiments, the advantages of the present application can be further enhanced by optimizing several of the components according to actual conditions and requirements, which will be exemplified below by different embodiments.

In one embodiment, the conductive film 160 is optimized, and the conductive film 160 having the double-sided adhesive property is used instead of the conductive film 160 having the single-sided adhesive property, and the rest of the arrangement is the same as the foregoing embodiment. As shown in FIG. 4D, when the conductive film 160 is a conductive tape having double-sided adhesive properties, in addition to electrically connecting the conductive film 160 to the grounding end 153 and the metal frame 103, the conductive film 160 may be adhered to the printed circuit. Around the board 150. Next, the protective layer 170 is adhered to the printed circuit board 150, the grounding end 153, and the metal frame 103 through the adhesive property of the exposed surface of the conductive film 160. Compared with the conductive film 160 having the single-sided adhesive property, the function of the adhesive layer 180 is replaced by the conductive film 160 having the double-sided adhesive property, the thickness of the adhesive layer 180 can be omitted, and the manufacturing process of the display device can be further improved. The step of setting the adhesive layer 180 is omitted. A side view of the above structure is shown in Fig. 4E.

In another embodiment, the ground terminal 153 is optimized to provide the ground terminal 153 on the lower surface of the printed circuit board 150 instead of extending outside the edge of the printed circuit board, with the rest of the arrangement being the same as in the previous embodiment. As shown in FIG. 5, since the conductive film 160 is a conductive tape and has a certain degree of flexibility, the ground end is disposed on the lower surface of the printed circuit board 150 without affecting the arrangement of the conductive film 160 and the protective layer 170. This setting method can reduce the difficulty of the process of the ground terminal 153.

In another embodiment, the printed circuit board 150, the flexible flat cable 151, and the protective layer 170 are optimized, and an insulating connecting portion 155 is added. The rest of the arrangement is the same as in the previous embodiment. As shown in FIG. 6, the flexible flat cable 151 is replaced with a flexible flat cable whose surface is covered with an insulating protective material in advance, and is defined as a surface insulated cable 1511. An insulating connecting portion 155 is added to the end of the surface insulated cable 1511, that is, to the junction with the printed circuit board 150. The insulative connecting portion 155 has an insulative housing and a hollow region, and the hollow region has a fixable port structure to electrically connect the other components to the surface insulating cable 1511. Further, a printed circuit board 1501 having a corresponding port structure is used instead of the printed circuit board 150, and a printed circuit board 1501 and a surface insulated cable 1511 are connected through a port structure. Thereafter, when the protective layer 170 is provided, the protective layer 170 only needs to be disposed on the printed circuit board 1501 and the conductive film 160 without extending to cover the surface insulating cable 1511. Since the surface of the surface insulated cable 1511 is an insulating protective material, it is less susceptible to other interference. The additional insulating connecting portion 155 can strengthen the stability between the cable and the printed circuit board, wherein the insulating outer casing can use a higher insulating material than the protective layer 170, thereby protecting the relatively weak joint to avoid Shedding or damage caused by collision or other factors in the process. Moreover, since the insulating casing has a strong protection capability, the service life of the display device can be further improved.

In another embodiment, the grounding end 153 of the printed circuit board 150 can be optimized, the grounding end 153 is disposed at the edge of the printed circuit board 150 and extends outward to the boundary of the protruding frame 110, and the remaining settings are the same as in the previous embodiment. . As shown in FIG. 7, the ground end 153 extends from the edge of the printed circuit board 150 as an outer side and directly contacts the bottom of at least one side of the four sides of the metal frame 103. In this case, the electric charge accumulated by the printed circuit board 150 can be directly moved to the metal frame 103 via the ground terminal 153 without additionally providing the conductive film 160. The grounding end 153 and the metal frame 103 can be fixed and maintained electrically connected by an adhesive material, a metal member such as a screw, or any conventional method. Alternatively, the metal frame 103 can have a socket that can be fitted with the grounding end 153 for the grounding end 153 to be directly inserted into the slot for fixing, thereby being electrically connected to the metal frame 103. Alternatively, the grounding end 153 can be electrically connected and fixed to the slot of the metal frame 103 through an electrically conductive adhesive material; or the grounding end 153 can be electrically connected and fixed to the metal through the port structure. The slot of the frame 103; or the grounding end 153 may be penetrated by a metal member such as a screw and electrically connected and fixed to the slot of the metal frame 103. Optionally, the portion of the printed circuit board 150 that protrudes from the frame 110 includes only the ground terminal 153 and is free of other circuitry. After the grounding end 153 is electrically connected to the metal frame 103, the protective layer 170 is disposed upward from the bottom side as an electrical barrier.

In yet another embodiment, the structure of the printed circuit board 150, the flexible flat cable 151, and the through hole 120 described above may be optimized. As shown in FIGS. 8A and 8B, the conductive portion 190 is provided on the back side of the printed circuit board 150, that is, on the side facing the frame 110. In addition, the opening of the through hole 120 facing the printed circuit board 150 is set to a specific shape, and optionally, the specific shape is matched with the conductive portion 190. When the printed circuit board 150 is disposed on the lower surface of the frame 110, the conductive portion 190 is fixed in the through hole, and the flexible flat cable 151 directly passes through the conductive portion 190 and passes through the through hole 120 to make the printed circuit board 150 and The display panel 130 is electrically connected. In this case, the junction of the printed circuit board 150 and the flexible flat cable 151 is completely within the through hole 120, and does not need to be additionally insulated from the outside by the protective layer 170. The display panel can be, for example, an LCD display panel, an OLED display panel, a QLED display panel, a curved display panel, or other display panel.

The above content is only described in detail in the alternative embodiments of the present application, and does not limit the scope of the application. Modifications and variations of the above-described embodiments may be made without departing from the spirit and scope of the invention. The scope of the claims should therefore be as described in the claims.

Claims

A display device, comprising:

Display panel

a frame made of an insulating material, and the display panel is disposed on the frame;

a metal frame encapsulating the frame therein and forming a hollow region accommodating the display panel;

a printed circuit board disposed under the frame and not contacting the metal frame, and electrically connected to the display panel through a flexible flat cable, the ground end of the circuit board protruding out of the frame Outside the frame, electrically connecting the metal frame;

The protective layer is made of an insulating material, adhered to the printed circuit board through the adhesive material, and fixed to the printed circuit board as an electrical barrier.
The display device of claim 1, wherein at least one of the four sides of the metal frame has a slot.
A display device according to claim 2, wherein said socket fits said ground.
The display device according to claim 2, wherein the ground end is electrically connected to the socket through the adhesive material having conductivity.
The display device according to claim 4, wherein said ground end is fixed to said socket through said adhesive material having conductivity.
The display device according to claim 2, wherein said ground end is penetrated by a metal member.
The display device according to claim 6, wherein the ground end is electrically connected to the socket through the metal member.
A display device according to claim 7, wherein said ground end is fixed to said socket by said metal member.
The display device of claim 1, wherein the protective layer extends over the at least one side of the metal frame having the socket that fits the ground end.
A display device as claimed in claim 9, wherein said protective layer is attached to said at least one side of said metal frame having said socket that fits said ground.
A grounding device for a display device, comprising:

a metal frame in which the frame of the display device is packaged, and a hollow region accommodating the display panel is formed;

a grounding end protruding to the outside of the frame and exposed outside the frame, and the grounding end protrudes outside the frame outside the frame, electrically connecting the metal frame;

The protective layer is made of an insulating material, adhered to the printed circuit board through the adhesive material, and fixed to the printed circuit board as an electrical barrier;

The protective layer extends over and is attached to at least one of the four sides of the metal frame.
The grounding device according to claim 11, wherein at least one of the four sides of the metal frame has a slot.
The grounding device of claim 12 wherein said socket engages said ground.
The grounding device according to claim 12, wherein said grounding end is electrically connected to said socket by said adhesive material having electrical conductivity.
The grounding device according to claim 14, wherein said ground end is fixed to said socket by said adhesive material having electrical conductivity.
The grounding device according to claim 12, wherein said ground end is penetrated by a metal member.
The grounding device according to claim 16, wherein said grounding end is electrically connected to said socket by said metal member.
The grounding device according to claim 17, wherein said ground end is fixed to said socket by said metal member.
A display device, comprising:

Display panel

a frame made of an insulating material, and the display panel is disposed on the frame;

a metal frame encapsulating the frame therein and forming a hollow region accommodating the display panel;

a printed circuit board disposed under the frame and not contacting the metal frame, and electrically connected to the display panel through a flexible flat cable, wherein a ground end of the circuit board protrudes outward from the frame Outside the frame, electrically connecting the metal frame;

The protective layer is made of an insulating material, adhered to the printed circuit board through the adhesive material, and fixed to the printed circuit board as an electrical barrier;

At least one of the four sides of the metal frame has a slot, and the slot fits the ground end;

The method for electrically connecting and fixing the ground end to the slot is selected from the following:

Electrically connecting and fixing the grounding end to the slot through the electrically conductive adhesive material; and

Through the metal member penetrating the ground end and electrically connected and fixed in the slot;

Wherein the protective layer extends over and is attached to at least one of the four sides of the metal frame having the slot in which the ground end is nested.