Structure for fixing printed circuit board and method of fixing thereof

A structure of fixing a printed circuit board includes a mold frame coupled with a display panel, a printed circuit board positioned at a rear surface of the display panel and electrically connected to a pad portion of the display panel, and an insulating film covering an outer surface of the printed circuit board.

The present invention claims the benefit of Korean Patent Application No. 30762/2004 filed in Korea on Apr. 30, 2004, which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device, and more particularly, to a structure of fixing a printed circuit board on a liquid crystal display panel and a method for fixing thereof that provide an insulating film to protect the printed circuit board and fix the printed circuit board without a hook or a screw.

2. Discussion of the Related Art

A display device is considered to be more and more important as visual information transmission increases. In addition, as display devices being increasing used in portable devices, they need to have high resolution images, lightness, thin profile, compact size, and low power consumption.

In general, display devices are classified into a light-emitting type or a non-light-emitting type. The light-emitting type display devices include cathode ray tube (CRT) devices, electro-luminescent (EL) devices, light emitting diode (LED) devices, vacuum fluorescent display (VFD) devices, field emission display (FED) devices, and plasma display panel (PDP) devices, which emit light by themselves. The non-light emitting type display devices include liquid crystal display (LCD) devices, which cannot emit light by itself.

LCD devices use the optical anisotropy and polarization properties of liquid crystal molecules to generate a desired image. In particular, liquid crystal molecules can be aligned in a specific orientation, which can be controlled by applying an electric field across the liquid crystal molecules. Due to optical anisotropy, incident light is refracted according to the orientation of the liquid crystal molecules, thereby generating the desired image.

FIG. 1is a disassembled perspective view schematically showing a liquid crystal display device according to the related art. InFIG. 1, a liquid crystal display device includes a liquid crystal display panel10, driving circuit units20and30, and a backlight unit40, which are enclosed by an upper case50and a lower case60. Although not shown, the liquid crystal display panel10includes an array substrate, a color filter substrate, and a liquid crystal layer formed between the array substrate and the color filter substrate.

In addition, the driving circuit units20and30supply driving signals to the liquid crystal display panel10for displaying an image on the liquid crystal display panel10. The driving circuit units20and30include printed circuit boards21and31to which tape carrier packages (TCP)22and32are attached, respectively. The tape carrier package22is a gate tape carrier package, and the tape carrier package32is a data tape carrier package. Although not shown, the driving circuit units20and30also include other devices, such as a timing controller, a data driver integrated circuit (IC) mounted on the data tape carrier package32, and a gate driver integrated circuit mounted on the gate tape carrier package22.

The backlight unit40is at a rear side of the liquid crystal display panel10and emits light onto the liquid crystal display panel10. In addition, the backlight unit40includes a lamp assembly including a fluorescent lamp (not shown) for generating light, a reflection sheet41for reflecting light emitted from the fluorescent lamp, a light guide plate42for guiding the reflected light, and a plurality of optical sheets43for diffusing and collecting light transferred from the light guide plate42. Further, the backlight unit40is mounted in a mold frame44.

Further, the data tape carrier package32is bent to position the data printed circuit board31at a rear surface of the liquid crystal display panel10. In addition, the gate tape carrier package22is bent once. Since the gate printed circuit board21generally is small, the gate printed circuit board21is positioned along a side surface of the mold frame44by bending the gate tape carrier package22once. By positioning the gate printed circuit board21along the side surface of the mold frame and positioning the data printed circuit board31at the rear surface of the liquid crystal panel10, a display area of the liquid crystal display panel10is increased.

FIG. 2Ais a planar view of a portion of a rear side of a liquid crystal display device without a lower case according to the related art. InFIG. 2A, the data printed circuit board31is attached and affixed to the mold frame44by a hook H. By forming the hook H at a predetermined portion of the mold frame44and inserting the data printed circuit board31into a lower portion of the hook H, the data printed circuit board31is affixed on the mold frame44. However, in a process of assembling and disassembling the printed circuit board31, the tape carrier package32or a chip-on-film (COF) attached to the printed circuit board31can be damaged easily. Thus, it typically takes longer time to assemble or disassemble a printed circuit board, which is affixed by a hook. In addition, whenever the hook needs to be removed, the printed circuit board also can be damaged by the process.

FIG. 2Bis a planar view of a portion of a rear side of another liquid crystal display device according to the related art. InFIG. 2B, the data printed circuit board31is attached and affixed to the mold frame44by screws S. By fastening the screws S through the data printed circuit board31at predetermined portions of the mold frame44, the data printed circuit board31is affixed on the mold frame44. However, it typically takes longer time to ensure the screws S are securely fastened, thereby increasing an operator's work load and reducing productivity.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a structure of fixing a printed circuit board and a method for fixing thereof that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a structure of fixing a printed circuit board and a method for fixing thereof using an insulating film, such as polyethylene terephthalate (hereinafter called “PET”), for affixing and protecting the printed circuit board without a hook or a screw.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the structure of fixing a printed circuit board includes a mold frame coupled with a display panel, a printed circuit board positioned at a rear surface of the display panel and electrically connected to a pad portion of the display panel, and an insulating film covering an outer surface of the printed circuit board.

In yet another aspect, the structure of fixing a printed circuit board includes a mold frame coupled with a display panel, a printed circuit board positioned at a rear surface of the display panel and electrically connected to a pad portion of the display panel, a first insulating film attached to the mold frame and the printed circuit board, the first insulating film covering an outer surface of the printed circuit board and having a protruding portion, and a second insulating film attached to the mold frame and the first insulating film, the second insulating film covering the protruding portion.

In another aspect, the method for fixing a printed circuit board on a display panel includes coupling a mold frame with the display panel, the display panel having a printed circuit board positioned at a rear surface of the display panel and electrically connected to a pad portion of the display panel, attaching a first insulating film to the mold frame and the printed circuit board, the first insulating film covering an outer surface of the printed circuit board and having a protruding portion, and attaching a second insulating film to the mold frame and the first insulating film, the second insulating film covering the protruding portion.

In yet another aspect, the method for fixing a printed circuit board on a display panel includes coupling the display panel with a mold frame, the display panel having the printed circuit board electrically connected thereto, positioning the printed circuit board on a rear surface of the display panel, and attaching a first insulating film to a first portion of the mold frame, the first insulating film covering an outer surface of the printed circuit board.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 3is an exemplary view schematically showing a structure of fixing a printed circuit board according to an embodiment of the present invention. InFIG. 3, a printed circuit board131may have a tape carrier package (not shown) attached thereon and may be a data printed circuit board. In particular, the tape carrier package may be bent such that the printed circuit board131is positioned at a rear surface of a liquid crystal display panel (not shown). An insulating film170may be coupled to the printed circuit board131and may cover the entire outer surface of the printed circuit board131, thereby fixing and protecting the printed circuit board131. An insulating film170may include polyethylene terephthalate (PET).

In addition, the PET170may be coupled to the printed circuit board131to form an integral body using a double-sided tape (not shown) along an edge region of the printed circuit board131. This edge region may be along a short side of a mold frame144. As a result, the PET170may affix and protect the printed circuit board131. In addition, the printed circuit board131may be easily affixed by fixing the PET170to the printed circuit board131using the double-sided tape without a fixing means, such as a hook and a screw.

FIGS. 4A and 4Bare exemplary views schematically showing a structure of fixing a printed circuit board according to another embodiment of the present invention. As shown inFIGS. 4A and 4B, a first PET270A may include a protruding portion P protruding toward a mold frame244and a printed circuit board231may have a tape carrier package (not shown) attached thereon. The printed circuit board231may be a data printed circuit board. The first PET270A may cover the entire outer surface of the printed circuit board231and may be coupled to the printed circuit board231to form an integral body using a first double-sided tape280A along an edge region of the printed circuit board231. The first PET270A also may be cover an upper surface of the mold frame244adjacent to a gate pad portion of a LCD display panel.

In addition, a second PET270B may cover a portion of the mold frame244(hereinafter called a “mold frame of a long side”) which overlaps the protruding portion P. The second PET270B also may cover the protruding portion P. In particular, the second PET270B may be coupled to the protruding portion P and the mold frame244using a second double-sided tape280B. The first PET270A may be a source PET, and the second PET270B may be a gate PET.

Thus, the printed circuit board231may form an integral body with the first PET270A, and may be fixed and protected by the first PET270A. Further, in order to prevent the printed circuit board from moving, the first PET270A may include the protruding portion P overlapping a portion of the mold frame244and the second PET270B may cover the protruding portion P. Accordingly, the printed circuit board231is securely affixed and protected without much difficulty.

Moreover, a method for fixing a printed circuit board may include mounting the first PET270A on the mold frame244, overlapping the protruding portion P of the first PET270A with a side portion of the mold frame, and mounting the second PET270B on the mold frame244covering the protruding portion P. In particular, the first PET270A and the printed circuit board231may form an integral body using the first double-sided tape280A. In addition, the first PET270A may be mounted along a long side of the mold frame244.

Further, aligning the second PET270B to cover the protruding portion P of the first PET270A and an upper corner portion of the mold frame244may be performed before attaching the second PET270B to the mounting frame244using the second double-sided tape280B. As a result, as shown in drawings, the first PET270A is securely fixed and the printed circuit board231is prevented from moving. Accordingly, a hook, which may cause damages to a tape carrier package or a chip-on-film, is not used. However, if reinforcement is desired, a hook or a screw may be used to additionally fix the printed circuit board.

In addition, productivity increases without increasing fabrication cost because assembling and disassembling a printed circuit board may be carried easily in comparison to the fixing methods using a hook or a screw and because an insulating film is not expensive.

It will be apparent to those skilled in the art that various modifications and variations can be made in the structure of fixing a printed circuit board and the method for fixing thereof of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.