KR102327463B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device, and more particularly, to a connection structure between an LED assembly used as a light source of a liquid crystal display device and a flexible cable.
A feature of the present invention is that in the process of electrically connecting the PCB of the LED assembly and the flexible cable to each other by soldering, a connection pattern is formed on the PCB to be integrally connected through the pad and the first extension pad, and the flexible cable is By forming an opening hole connected through the connection terminal and the second extension pad to connect the connection pattern, the opening hole, and the first and second extension pads to each other by soldering, the PCB and the flexible cable can be connected more stably. can
Accordingly, even when the flexible cable is bent, it is possible to prevent a faulty wire disconnection of the flexible cable, thereby preventing a malfunction in the driving operation of the LED or damage to the circuit unit.

Description

Liquid crystal display device

The present invention relates to a liquid crystal display device, and more particularly, to a connection structure between an LED assembly used as a light source of a liquid crystal display device and a flexible cable.

Liquid crystal display devices (LCDs), which are advantageous for video display and have a large contrast ratio, are actively used in TVs and monitors, etc. shows the principle of image realization by

Such a liquid crystal display device consists of a liquid crystal panel bonded together with a liquid crystal layer interposed between two parallel substrates as an essential component, and a difference in transmittance is realized by changing the arrangement direction of liquid crystal molecules with an electric field in the liquid crystal panel. do.

However, since the liquid crystal panel does not have a self-luminous element, a separate light source is required to display the difference in transmittance as an image.

1 is a cross-sectional view of a liquid crystal display device using a general LED as a light source.

As shown, a general liquid crystal display device includes a liquid crystal panel 10 , a backlight unit 20 , a guide panel 30 , a cover bottom 50 , and a top cover 40 .

The liquid crystal panel 10 is a part that plays a key role in image expression and is composed of first and second substrates 12 and 14 bonded face to face with a liquid crystal layer interposed therebetween.

A backlight unit 20 is provided behind the liquid crystal panel 10 .

The backlight unit 20 includes a light source arranged along the longitudinal direction of at least one edge of the guide panel 30 , a white or silver reflecting plate 25 seated on the cover bottom 50 , and on the reflecting plate 25 . It includes a light guide plate 23 to be seated and an optical sheet 21 interposed thereon.

The liquid crystal panel 10 and the backlight unit 20 have a top cover 40 surrounding the upper edge of the liquid crystal panel 10 and the backlight unit 20 in a state in which the edge is surrounded by a guide panel 30 having a rectangular frame shape. The cover bottom 50 covering the rear surface is combined in front and rear, respectively, and is integrated.

In addition, unexplained reference numerals 19a and 19b denote polarizing plates attached to the front and rear surfaces of the liquid crystal panel 10 to control the polarization direction of light, respectively.

In this case, the light sources of the backlight unit 20 include a Cold Cathode Fluorescent Lamp (CCFL), an External Electrode Fluorescentt Lamp, and a Light Emitting Diode (LED, hereinafter referred to as LED). use etc.

In particular, the LED 29a has features such as small size, low power consumption, and high reliability, and is widely used as a light source for display.

The LED 29a is mounted on an LED PCB (printed circuit board: 29b, hereinafter referred to as PCB) to form an LED assembly 29, and the LED assembly 29 is fixed in position by an adhesive or the like to form a plurality of LEDs. The light emitted from the 29a is made to face the light incident surface of the light guide plate 23 .

Accordingly, the light emitted from each of the LEDs 29a enters the light incident surface of the light guide plate 23 and is then refracted toward the liquid crystal panel 10 inside the optical sheet ( 21), it is processed into a more uniform high-quality surface light source and supplied to the liquid crystal panel 10 .

On the other hand, the LED driving circuit (not shown) for controlling the on / off (on / off) of the LED (29a), such as applying a driving voltage to the LED (29a) of the LED assembly (29) is usually a cover bottom (50) It is closely attached to the rear surface to minimize the overall size of the liquid crystal display.

Accordingly, a flexible cable (not shown) such as an FPCB is provided on one side of the PCB 29b so that the plurality of LEDs 29a can be electrically connected to the LED driving circuit (not shown), so that the flexible cable (not shown) is connected to the LED driving circuit (not shown) in close contact with the back surface of the cover bottom 50 by using the bending characteristic.

At this time, the PCB 29b and the flexible cable (not shown) are electrically connected to each other by soldering.

However, the backlight unit 20 using such a general LED 29a as a light source has several problems.

Among them, the flexible cable (not shown) and the PCB (29b) have weak connection power, so the flexible cable (not shown) is flexible in the process of being connected to the LED driving circuit (not shown) in close contact with the back of the cover bottom 50 When the bending of the flexible cable (not shown) occurs, an external force is applied to the soldering part (not shown), which is the connection part between the PCB (29b) and the flexible cable (not shown), so that the disconnection of the flexible cable (not shown) is frequent. will occur

For this reason, a malfunction of the driving operation of the LED 29a occurs or damage to the circuit part mounted on the LED driving circuit is caused.

The present invention is to solve the above problems, and a first object is to stably connect a PCB of a backlight unit and a flexible cable.

For this reason, it is a second object to prevent the occurrence of a driving failure of the LED or damage to the circuit portion of the LED driving circuit.

In order to achieve the object as described above, the present invention provides a liquid crystal panel and a PCB positioned below the liquid crystal panel, having a pad and a connection pattern at one end in the longitudinal direction, a plurality of LEDs mounted on the PCB, and the An LED driving circuit for applying a driving voltage to a plurality of LEDs, and one end connected to the LED driving circuit, and a flexible cable having a connecting terminal and an opening corresponding to the connecting pattern at the other end, the pad and the A connection terminal, and the connection pattern and the opening hole are connected by soldering, and at least one of the pads is integrally connected with the connection pattern through a first extension pad.

At this time, at least one of the connection terminals is connected to the opening hole and the second extension pad, and the first and second extension pads are connected by the soldering.

In addition, the soldering completely covers the opening hole and a part of the edge of the opening hole, the connection pattern is formed in a shape selected from a circular shape, a square shape, or a polygonal shape, and the opening hole has a shape corresponding to the shape of the connection pattern. made in the form

A light guide plate is positioned under the liquid crystal panel, the plurality of LEDs mounted on the PCB are positioned to face the light incident surface of the light guide plate, and a plurality of PCBs are arranged side by side under the liquid crystal panel .

As described above, in the process of electrically connecting the PCB and the flexible cable of the LED assembly according to the present invention to each other by soldering, a connection pattern integrally connected through the pad and the first extension pad is formed on the PCB, and , the flexible cable has an opening connected through the connection terminal and the second extension pad so that the connection pattern, the opening hole, and the first and second extension pads are connected to each other by soldering, so that the PCB and the flexible cable are better connected. It has the effect of making a stable connection.

Therefore, even if the flexible cable is bent, it is possible to prevent the breakage of the flexible cable from occurring. It works.

1 is a cross-sectional view of a liquid crystal display device using a general LED as a light source.
2 is an exploded perspective view schematically illustrating a liquid crystal display according to an embodiment of the present invention;
3A is a perspective view schematically illustrating an LED assembly and a flexible cable according to an embodiment of the present invention;
FIG. 3B is a front view schematically illustrating a state in which the LED assembly of FIG. 3A and a flexible cable are connected;
4 is a perspective view schematically illustrating a state in which the flexible cable is bent while the LED assembly and the flexible cable are electrically connected to each other.

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings.

2 is an exploded perspective view schematically illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

As shown, the liquid crystal display device includes a liquid crystal panel 110 and a backlight unit 120, and a guide panel 130 for modularizing the liquid crystal panel 110 and the backlight unit 120, a cover bottom 150, and a top cover. (140).

Looking at each of these in more detail, the liquid crystal panel 110 is a part that plays a key role in image expression, and includes the first substrate 112 and the second substrate 114 bonded to each other with the liquid crystal layer interposed therebetween. include

At this time, although not shown in the drawing under the premise of the active matrix method, a plurality of gate lines and data lines intersect to define a pixel on the inner surface of the first substrate 112, which is usually called a lower substrate or an array substrate, A thin film transistor (TFT) is provided at each intersection and is connected to the transparent pixel electrode formed in each pixel in a one-to-one correspondence.

And on the inner surface of the second substrate 114 called an upper substrate or a color filter substrate, red (R), green (G), and blue (B) color filters as an example corresponding to each pixel, and these A black matrix is provided around each of the gate lines, data lines, and non-display elements such as thin film transistors. In addition, a transparent common electrode covering them is provided.

In addition, polarizing plates (not shown) that selectively transmit only a specific light are attached to the outer surfaces of the first and second substrates 112 and 114 , respectively.

At least along one edge of the liquid crystal panel 110, the printed circuit board 117 is connected via a connection member 116 such as a flexible circuit board or a tape carrier package (TCP) to guide in the modularization process. The side surface of the panel 130 or the back surface of the cover bottom 150 is appropriately folded to adhere.

In the liquid crystal panel 110, when the thin film transistor selected for each gate line is turned on by the on/off signal of the gate driving circuit, the signal voltage of the data driving circuit is transmitted to the corresponding pixel electrode through the data line, The arrangement direction of liquid crystal molecules is changed by the electric field between the pixel electrode and the common electrode, indicating a difference in transmittance.

In addition, the liquid crystal display device according to the present invention is provided with a backlight unit 120 for supplying light from the rear surface of the liquid crystal panel 110 so that the difference in transmittance is expressed to the outside.

The backlight unit 120 includes an LED assembly 200, a white or silver reflective plate 125, a light guide plate 123 seated on the reflective plate 125, and an optical sheet 121 interposed thereon. .

The LED assembly 200 is positioned on one side of the light guide plate 123 to face the light incident surface of the light guide plate 123 , and the LED assembly 200 includes a plurality of LEDs 210 and a plurality of LEDs 210 at regular intervals. It includes a PCB 220 that is mounted to be spaced apart.

And although not shown in the drawing, an LED driving circuit (not shown) for controlling on/off of the LED assembly 200 is mounted in the liquid crystal display device of the present invention, and the LED driving circuit (not shown) is In general, it is closely attached to the back surface of the cover bottom 150 to minimize the overall size of the liquid crystal display device.

Accordingly, one side of the PCB 220 has a flexible cable such as an FPCB so that a plurality of LEDs 210 can be electrically connected to the LED driving circuit (not shown) closely attached to the rear surface of the cover bottom 150. 230) is provided, and is connected to the LED driving circuit (not shown) in close contact with the rear surface of the cover bottom 150 by using the bending characteristics of the flexible cable 230 .

At this time, a soldering part 227 provided with a plurality of pads 229 (see FIG. 3A ) is provided on one side of the PCB 220 , and a connection terminal 231 (refer to FIG. 3A ) is provided on one side of the flexible cable 230 . Thus, the PCB 220 and the flexible cable 230 are electrically connected to each other by soldering the pad 229 (refer to FIG. 3A) and the connecting terminal 231 (refer to FIG. 3A).

In particular, on the soldering part 227 of the PCB 220 of the present invention, a connection pattern 310 having various structures for improving the connection force between the PCB 220 and the flexible cable 230 is formed. ) and the pad 229 (see FIG. 3A ), the first extension pad 330 is extended and formed.

In addition, an opening hole 320 (refer to FIG. 3A) is formed in the flexible cable 230 corresponding to the connection pattern 310, and an opening hole 320 (refer to FIG. 3A) and a connection terminal 231 (refer to FIG. 3A) are formed. A second extension pad 340 is also formed to extend between them.

The connection pattern 310 of the PCB 220 and the opening hole 320 (refer to FIG. 3A ) of the flexible cable 230 are electrically connected to each other by soldering. The connection force between the PCB 220 and the flexible cable 230 is improved through the opening hole 320 of the flexible cable 230 (see FIG. 3A ).

In particular, the connection pattern 310 is integrally connected to the pad 229 through the first extension pad 330 , and the opening hole 320 (refer to FIG. 3A ) is connected to the connection terminal 231 through the second extension pad 340 . , see Fig. 3a), the connection force by soldering of the connection pattern 310 and the opening hole 320 (see Fig. 3a) is further improved, and the connection force between the PCB 220 and the flexible cable 230 is improved. This will be further improved.

Accordingly, it is possible to prevent a faulty disconnection of the flexible cable 230 from occurring, thereby preventing a malfunction in the driving operation of the LED 210 or damage to the circuit unit.

We will look at this in more detail later.

The light guide plate 123 to which the light emitted from the plurality of LEDs 210 is incident is spread evenly over a wide area of the light guide plate 123 while the light incident from the LEDs 210 travels through the light guide plate 123 by total reflection several times. A surface light source is provided to the liquid crystal panel 110 .

The light guide plate 123 may include a pattern having a specific shape on the rear surface to supply a uniform surface light source.

Here, the pattern may be variously configured such as an elliptical pattern, a polygonal pattern, a hologram pattern, etc. in order to guide the light incident into the light guide plate 123 . The pattern is formed on the lower surface of the light guide plate 123 by a printing method or an injection method.

The reflection plate 125 is located on the rear surface of the light guide plate 123 , and reflects the light passing through the rear surface of the light guide plate 123 toward the liquid crystal panel 110 to improve the luminance of the light.

The optical sheet 121 on the light guide plate 123 includes a diffusion sheet and at least one light collecting sheet, and by diffusing or condensing the light passing through the light guide plate 123 , a more uniform surface light source is provided to the liquid crystal panel 110 . to get hired

The liquid crystal panel 110 and the backlight unit 120 are modularized through a top cover 140 , a guide panel 130 , and a cover bottom 150 , and the top cover 140 is an upper surface and a side surface of the liquid crystal panel 110 . It has a rectangular frame shape in which the cross section is bent in a “L” shape to cover the edge, and the front of the top cover 140 is opened to display an image implemented in the liquid crystal panel 110 .

In addition, the cover bottom 150, on which the liquid crystal panel 110 and the backlight unit 120 are seated, which is the basis for assembling the entire liquid crystal display device, is formed in a rectangular plate shape having an edge portion bent vertically.

In addition, the guide panel 130 in the shape of a square frame that is seated on the cover bottom 150 and surrounds the edges of the liquid crystal panel 110 and the backlight unit 120 includes the top cover 140 and the cover bottom 150 and the top cover 140 . are combined

At this time, the top cover 140 is also referred to as a case top or top case, the guide panel 130 is also referred to as a support main or main support, or a mold frame, and the cover bottom 150 is also referred to as a bottom cover or a lower cover. also lose

At this time, the backlight unit 120 having the above-described structure is usually called a side light type, and depending on the purpose, the LEDs 210 may be arranged in multiple layers on the PCB 220 . In addition, it is also possible to further provide a plurality of LED assemblies 200, respectively, so as to correspond to each other along both edges of the cover bottom 150 facing each other.

In addition, the light guide plate 123 may be deleted and the plurality of LED assemblies 200 may be disposed under the liquid crystal panel 110 in a direct type method.

The above-described liquid crystal display device can more stably connect the LED assembly 200 and the flexible cable 230, thereby preventing a disconnection defect of the flexible cable 230, so that the LED 210 is defective in driving. it can be prevented

3A is a perspective view schematically illustrating an LED assembly and a flexible cable according to an embodiment of the present invention, and FIG. 3B is a front view schematically illustrating a state in which the LED assembly and the flexible cable of FIG. 3A are connected.

As shown in FIG. 3A , the LED assembly 200 includes a plurality of LEDs 210 and a plurality of LEDs 210 are spaced apart from each other at a predetermined interval, and a PCB 220 mounted by a surface mount technology (SMT). ) is included.

At this time, the plurality of LEDs 210 are respectively connected in series through a power wiring (not shown) formed on the PCB 220 to receive power. At this time, the plurality of LEDs 210 are red (R), green, respectively. It emits light having colors of (G) and blue (B), and by turning on the plurality of RGB LEDs 210 at once, white light by color mixing can be realized.

Alternatively, by using the LED 210 configured with an LED chip (not shown) that emits all RGB colors, white light may be implemented in each LED 210, or the LED 210 including a chip emitting white. It is also possible to implement each of the complete white light.

Here, the PCB 220 includes a power wiring layer 225 , an insulating layer 223 and a PCB base 221 on which metal wiring (not shown) is formed, and the PCB base 221 includes a power wiring layer 225 and an insulating layer. 223 and other components are mounted as an upper layer and supported, and serves to radiate heat generated from a plurality of LEDs 210 toward the bottom.

The PCB base 221 may be formed of a metal having high thermal conductivity, such as aluminum (Al) or copper (Cu), or a heat transfer material may be applied to improve the heat dissipation function.

Alternatively, a heat sink (not shown) such as a heat sink may be provided on the rear surface of the PCB base 221 to receive heat from each LED 210 and radiate the heat to the outside more efficiently.

A power wiring layer 225 including a plurality of metal wirings (not shown) formed by patterning a conductive material is formed on the PCB base 221 , and is insulated between the PCB base 221 and the power wiring layer 225 . The layer 223 is positioned to electrically insulate between the PCB base 221 and the power wiring layer 225 .

A plurality of LEDs 210 mounted on the PCB 220 are respectively connected in series through a metal wiring (not shown) of the power wiring layer 225 to receive power.

At this time, the plurality of LEDs 210 are controlled on/off by an LED driving circuit (not shown), and the LED driving circuit (not shown) is usually in close contact with the back side of the cover bottom (150 in FIG. 2 ). Thus, the overall size of the liquid crystal display is minimized.

Accordingly, a soldering part 227 having a plurality of pads 229 is provided on one side of the PCB 220 so that the plurality of LEDs 210 can be connected to the LED driving circuit (not shown) in an interconnected state. It is connected to the LED driving circuit (not shown) through a separate flexible cable 230 .

Looking at this in more detail, the soldering part 227 is composed of a plurality of pads 229 each provided at one end of each metal wiring (not shown), and between these pads 229 and the LED driving circuit (not shown). is provided with a flexible cable 230 for electrical connection, and a connection terminal 231 is formed at one end of the flexible cable 230 and is directly connected to the pad 229 by soldering.

At this time, on the soldering part 227 of the PCB 220 of the present invention, a connection pattern 310 having various structures for improving the connection force between the PCB 220 and the flexible cable 230 is formed, and the connection pattern 310 is formed. ), the flexible cable 230 has an opening hole 320 formed therein.

Here, the connection pattern 310 on the PCB 220 is provided at the outermost end of the soldering part 227 , and the opening hole 320 of the flexible cable 230 is provided inside the connection terminal 231 .

Therefore, the LED assembly 200 and the flexible cable 230 of the present invention are connected to the PCB 220 and the flexible cable 230 through the opening hole 320 of the flexible cable 230 and the connection pattern 310 of the PCB 220 . Since the connection force of the cable 230 is improved, even when the flexible cable 230 is bent, the flexible cable 230 and the PCB 220 are stably fixed to each other.

In particular, in the liquid crystal display of the present invention, the first extension pad 330 is formed between the connection pattern 310 and the pad 229 , and the second extension pad 340 is formed between the opening hole 320 and the connection terminal 231 . is formed. Through this, the connection pattern 310 is integrally connected with the pad 229 through the first extension pad 330 , and the opening hole 320 is formed between the connection terminal 231 and the second connection terminal 231 . As it is connected through the extension pad 340 , the soldering area by soldering the connection pattern 310 and the opening hole 320 is widened, thereby further improving the connection force.

That is, the connection force between the PCB 220 and the flexible cable 230 is further improved.

Accordingly, it is possible to prevent a faulty disconnection of the flexible cable 230 from occurring, thereby preventing a malfunction in the driving operation of the LED 210 or damage to the circuit unit.

Here, with reference to FIG. 3b, the connection between the PCB 220 and the flexible cable 230 will be described in more detail. The pad 229 of the PCB 220 and the connection terminal 231 of the flexible cable 230 are soldered to each other and electrically connected to each other.

In addition, in the PCB 220 and the flexible cable 230 of the present invention, in a state in which the connection pattern 310 of the PCB 220 and the opening hole 320 of the flexible cable 230 are aligned with each other, the PCB ( Solder 350 is coated on the connection pattern 310 of 220 and the opening hole 320 of the flexible cable 230, the connection pattern 310 of the PCB 220 and the opening of the flexible cable 230 Holes 320 are soldered.

At this time, the solder 350 is applied larger than the diameter of the opening hole 320 of the flexible cable 230 , that is, the solder 350 completely covers the opening hole 320 and a part of the edge of the opening hole 320 . is applied to cover a part of the flexible cable 230 along the edge of the opening hole 320 .

Accordingly, the solder 350 is applied to a part of the flexible cable 230 along the edge of the connection pattern 310 of the PCB 220 and the opening 320 of the flexible cable 230 , and the PCB 220 . The connection pattern 310 and the edge of the opening hole 320 of the flexible cable 230 are fixed to each other by soldering.

In this way, by fixing the PCB 220 and the flexible cable 230 to each other through the connection pattern 310 and the opening hole 320, the PCB 220 and the flexible cable 230 of the present invention have a high connection force. Thus, even when the flexible cable 230 is bent, the flexible cable 230 and the PCB 220 are stably fixed to each other.

In particular, the connection pattern 310 is integrally connected through the pad 229 and the first extension pad 330 , and the opening hole 320 is connected through the connection terminal 231 and the second extension pad 340 . Accordingly, the first and second extension pads 330 and 340 are also fixed to each other by soldering.

Through this, as the soldering area of the connection pattern 310 and the opening hole 320 becomes wider, the connection force by the connection pattern 310 and the opening hole 320 is further improved, and through this, the PCB 220 ) and the connection force of the flexible cable 230 is further improved.

Accordingly, it is possible to prevent a faulty disconnection of the flexible cable 230 from occurring, thereby preventing a malfunction in the driving operation of the LED 210 or damage to the circuit unit.

Here, the shapes of the connection pattern 310 and the opening hole 320 may be variously changed depending on the desired shape to correspond to each other, that is, the connection pattern 310 may have a rectangular or polygonal shape in addition to a circular shape as shown. , and the opening hole 320 may also have various shapes, and it is preferable that the shape of the opening hole 320 corresponds to the shape of the connection pattern 310 .

This is to form a larger soldering area between the connection pattern 310 of the PCB 220 and the edge of the opening 320 of the flexible cable 230, and by increasing the area to be fixed by soldering the PCB. This is because it is possible to strengthen the solder adhesion between the connection pattern 310 of 220 and the edge of the opening hole 320 of the flexible cable 230 .

In addition, the connection pattern 310 and the opening hole 320 serve to improve the connection force between the PCB 220 and the flexible cable 230, as well as the pad 229 of the PCB 220 and the flexible cable 230. In the process of soldering the connection terminal 231 , it may be used as an alignment mark in the process of aligning the PCB 220 and the flexible cable 230 .

In addition, the shapes of the first and second extension pads 330 and 340 may also have various shapes within the limit of connecting the connecting pattern 310 and the pad 229 or connecting the opening hole 320 and the connecting terminal 231 . As the connection pattern 310 , at least two pads 229 to which the same voltage (input (+) or output (-)) is applied are connected through the first extension pad 330 , and the opening In the hole 320 , at least two connection terminals 231 to which the same voltage is applied are connected through the second extension pad 340 , so that the connection force by soldering the connection pattern 310 and the opening hole 320 . It is desirable to improve this further.

4 is a perspective view schematically illustrating a state in which the flexible cable is bent while the LED assembly and the flexible cable are electrically connected to each other.

As shown, a pad 229 of the PCB 220 and a connection terminal 231 of the flexible cable 230 are soldered to the soldering part 227 of the PCB 220 and electrically connected to each other, and the PCB ( The connection pattern 310 of 220 and the edge of the opening 320 of the flexible cable 230 are also soldered, so that the PCB 220 and the flexible cable 230 are stably fixed to each other.

At this time, the connection pattern 310 is integrally connected to the pad 229 of the PCB 220 through the first extension pad 330 , and the opening hole 320 is connected to the connection terminal through the second extension pad 340 . (231) is connected.

Here, the flexible cable 230 may be bent toward the front in which light is emitted from the plurality of LEDs 210 mounted on the PCB 220. When the flexible cable 230 is bent in this way, the PCB An external force is applied to the soldering portion 227 of the 220 and the flexible cable 230 .

Here, in the conventional liquid crystal display device, an external force applied to a soldering part (not shown) is soldered to a pad (not shown) of a PCB (29b in FIG. 1) and a connection terminal (not shown) of a flexible cable (not shown). transmitted to the region, causing a disconnection defect between the pad (not shown) of the PCB (29b in FIG. 1) and the connection terminal (not shown) of the flexible cable (not shown). Due to this, a malfunction of the driving operation of the LED (29a in FIG. 1 ) occurs or the circuit part is damaged.

In contrast, in the liquid crystal display device of the present invention, the PCB 220 and the flexible cable 230 are stably connected to each other through the connection pattern 310 of the PCB 220 and the opening hole 320 of the flexible cable 230 . By soldering so as to be fixed, the external force applied to the soldering part 227 is transmitted to the part where the connection pattern 310 of the PCB 220 and the opening hole 320 of the flexible cable 230 are soldered, and the PCB 220 ) of the pad 227 and the connection terminal 231 of the flexible cable 230 can be prevented from being applied to an external force.

In particular, the connection pattern 310 is integrally connected to the pad 229 through the first extension pad 330 , and the opening hole 320 is also connected to the connection terminal 231 through the second extension pad 340 . Accordingly, the connection force between the connection pattern 310 of the PCB 220 and the opening hole 320 of the flexible cable 230 is further improved, and the connection force between the PCB 220 and the flexible cable 230 is further improved. will become

Accordingly, it is possible to prevent a faulty disconnection between the pad 229 of the PCB 220 and the connection terminal 231 of the flexible cable 230 from occurring, thereby causing a malfunction in the driving operation of the LED 210 or the circuit unit. damage can be prevented.

[Table 1] below shows that the connection pattern 310 and the pad 229 are integrally formed through the first extension pad 330, and the opening hole 320 and the connection terminal 231 are formed on the second extension pad 340. It is the experimental result of measuring the tensile strength in the case of forming extension through the

division Application specifications Tensile force test result (kg·f) #One #2 #3 #4 #5 Max Min Average Case 1 0.12 0.10 0.09 0.10 0.13 0.13 0.09 0.11 Case 2 0.28 0.39 0.35 0.48 0.48 0.48 0.28 0.36

In [Table 1] above, Case 1 is a configuration in which the connection pattern, the pad, and the opening hole and the connection terminal are separated from each other, and Case 2 is the connection pattern 310, the pad 229, and the opening hole as in the embodiment of the present invention. 320 and the connection terminal 231 are integrally connected through the first and second extension pads 330 and 340, respectively.

Referring to [Table 1], the connection pattern 310 and the pad 229 are integrally connected through the first extension pad 330 , and the opening hole 320 is connected to the connection terminal ( ) through the second extension pad 340 . 231), it can be seen that the tensile force is improved by about 227% compared to the configuration in which the connection pattern, the pad, and the opening hole and the connection terminal are separated from each other.

That is, in the liquid crystal display device according to the embodiment of the present invention, in the process of electrically connecting the PCB 220 of the LED assembly 200 and the flexible cable 230 to each other by soldering, the pads 229 on the PCB 220 are ) and the connection terminal 231 of the flexible cable 230 are soldered and connected, and at the same time, the connection pattern 310 is integrally connected through the pad 229 and the first extension pad 330 on the PCB 220 . , and an opening hole 320 connected to the flexible cable 230 through a connection terminal 231 and a second extension pad 340 is formed, and the connection pattern 310 and the opening hole 320 and the first Since the first and second extension pads 330 and 340 are also connected to each other by soldering, the PCB 220 and the flexible cable 230 can be more stably connected.

Therefore, even when the flexible cable 230 is bent, it is possible to prevent a disconnection defect of the flexible cable 230 from occurring. can be prevented from doing

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

210 :LED
220: PCB (221: PCB base, 223: insulating layer, 225: power wiring layer)
227: soldering part, 229: pad
230: flexible cable
231: connection terminal
310: connection pattern
320: opening hole
330 and 340: first and second extension pads

Claims (8)

a liquid crystal panel;
a PCB positioned under the liquid crystal panel and provided with a pad and a connection pattern at one end in the longitudinal direction;
a plurality of LEDs mounted on the PCB;
an LED driving circuit for applying a driving voltage to the plurality of LEDs;
One end is connected to the LED driving circuit, and the other end is a flexible cable having a connecting terminal and an opening corresponding to the connecting pattern.
Including, the pad and the connection terminal, the connection pattern and the opening hole are connected by soldering,
At least one of the pads is integrally connected to the connection pattern through the first extension pad,
At least one of the connection terminals is connected through the opening hole and the second extension pad,
The first and second extension pads are fixed to each other by the soldering,
The first extension pad extends from one end of at least one of the pads and is connected to the connection pattern,
The second extension pad extends from one end of at least one of the connection terminals and is connected to the opening hole,
In a plan view, the first and second extension pads have a shape different from that of the opening hole and the connection pattern.
The method of claim 1,
The flexible cable is provided with a plurality of wires respectively connected to the connection terminals,
One end of the second extension pad is in contact with one end of the opening hole,
The plurality of wirings extend in contact with the other end of the opening hole, which is opposite to the second extension pad with respect to the opening hole.
delete The method of claim 1,
The soldering completely covers the opening hole and a portion of an edge of the opening hole.
The method of claim 1,
The connection pattern is formed in a shape selected from a circular shape, a square shape, or a polygonal shape, and the opening hole has a shape corresponding to the shape of the connection pattern.
The method of claim 1,
A light guide plate is positioned under the liquid crystal panel, and the plurality of LEDs mounted on the PCB are positioned to face a light incident surface of the light guide plate.
The method of claim 1,
A liquid crystal display device in which a plurality of PCBs are arranged side by side under the liquid crystal panel. The method of claim 1,
In a plan view, the pad and the connection terminal have the same shape, and the opening hole and the connection pattern have the same shape.
In a plan view, the pad and the connection terminal, the opening hole, and the connection pattern are formed in different shapes from each other,
In a plan view, the first and second extension pads have the same shape as the pad and the connection terminal.

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