# Patent

## Title
Chip on film package and display apparatus having the same

## Abstract

A chip on film package includes a base substrate, an input line, an integrated circuit (IC) chip and an output line. The input line is disposed on the base substrate. The IC Chip is electrically connected to the input line. The output line includes a main output and a sub output line. The main output line is electrically connected to the IC chip and extends in a first direction from the IC chip. The sub output line is electrically connected to the IC chip. The sub output line includes at least six bending parts, and is extended in the first direction.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This U.S. non-provisional application claims priority under 35 USC. §119 to Korean Patent Application No. 10-2014-0117193, flied on Sep. 3, 2014, the disclosure of which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
Exemplary embodiments of the present inventive concept relate to a display apparatus, and more particularly, to a chip on film package and a display apparatus having the chip on film package.
DISCUSSION OF RELATED ART
A liquid crystal display apparatus may include a flat panel display FPD. Examples of FDPs may include, but are not limited to, a liquid crystal display (“LCD”), a plasma display panel (“PDP”) and an organic light emitting display (“OLED”).
The liquid crystal display apparatus may apply voltages to liquid crystal molecules to adjust arrangements of the molecules thereby changing optical characteristics of a liquid crystal cell such as birefringence, optical activity, dichroism and light scattering to display an image.
The liquid crystal display apparatus may include a liquid crystal display panel, a printed circuit board and a backlight unit. The liquid crystal display panel may display an image. The printed circuit board may generate a driving signal to drive the liquid crystal display panel. The backlight unit may be disposed on a lower surface of the liquid crystal display panel and may provide light to the liquid crystal display panel.
The liquid crystal display panel may be electrically connected to the printed circuit board. The liquid crystal display panel may be electrically connected to the printed circuit board through a chip on film (COF) package.
The chip on film package may include a circuit wiring formed on a flexible substrate. The chip on film package may be curved, and the printed circuit board may be disposed on a lower surface of the liquid crystal display panel.
SUMMARY
Exemplary embodiments of the present inventive concept provide a chip on film package which prevents a circuit wiring from being cut.
Exemplary embodiments of the present inventive concept provide a display apparatus having the chip on film package.
In accordance with an exemplary embodiment of the present inventive concept, a chip on film package includes a base substrate, an input line, an integrated circuit (IC) chip and an output line. The input line is disposed on the base substrate. The IC chip is electrically connected to the input line. The output line includes a main output and a sub output line. The main output line is electrically connected to the IC chip and extends in a first direction from the IC chip. The sub output line is electrically connected to the IC chip. The sub output line includes at least six bending parts and extends in the first direction.
In an exemplary embodiment of the present inventive concept, the sub output line may have a uniform width.
In an exemplary embodiment of the present inventive concept, the sub output line may have a width of about 11 um to about 13 um.
In an exemplary embodiment of the present inventive concept, the base substrate may be a flexible film.
In an exemplary embodiment of the present inventive concept, the chip on film package may include electrode bumps disposed on lower surfaces of each edge of the IC chip. The IC chip may be connected to the input line and the output line through the electrode bumps.
In an exemplary embodiment of the present inventive concept, the chip on film package may include an encapsulant part surrounding the IC chip and fixing the IC chip on the base substrate. The encapsulant part may encapsulate the electrode bump and portions of the input line and the output line.
In an exemplary embodiment of the present inventive concept, the chip on film package may include a protecting layer covering portions of the input line and the output line.
In an exemplary embodiment of the present inventive concept, the chip on film package may include a by-pass line bypassing the input line, the output line and the IC chip.
In accordance with an exemplary embodiment of the present inventive concept, a display apparatus includes a display panel, a printed circuit board and a chip on film package. The printed circuit board is disposed on a lower surface of the display panel. The chip on film package connects the display panel and the printed circuit board. The chip on film package includes a base substrate, an input line, an integrated circuit (IC) chip and an output line. The input line is disposed on the base substrate. The IC chip is electrically connected to the input line. The output line includes a main output and a sub output line. The main output line is electrically connected to the IC chip and extends in a first direction from the IC chip. The sub output line is electrically connected to the IC chip. The sub output line includes at least six bending parts and extends in the first direction.
In an exemplary embodiment of the present inventive concept, the sub output line may have a uniform width.
In an exemplary embodiment of the present inventive concept, the sub output line may have a width of about 11 um to about 13 um.
In an exemplary embodiment of the present inventive concept, the base substrate may be a flexible film.
In an exemplary embodiment of the present inventive concept, the display apparatus may include electrode bumps disposed on lower surfaces of each edge of the IC chip. The IC chip may be connected to the input line and the output line through the electrode bumps.
In an exemplary embodiment of the present inventive concept, the display apparatus may include an encapsulant part surrounding the IC chip and fixing the IC chip on the base substrate. The encapsulant part may encapsulate the electrode bump and portions of the input line and the output line.
In an exemplary embodiment of the present inventive concept, the display apparatus may include a protecting layer covering portions of the input line and the output line.
In an exemplary embodiment of the present inventive concept, the display apparatus may include a by-pass line bypassing the input line, the output line and the IC chip.
In an exemplary embodiment of the present inventive concept, the display apparatus may include a receiving container. The display panel and the printed circuit board may be disposed in the receiving container.
In accordance with exemplary embodiments of the present inventive concept, the chip on film package may include a plurality of bending parts, and cutting of the circuit wiring by, stress from a curve of the chip on film package may be reduced or prevented.



BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features of the present inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which:
FIG. 1 is a plan view illustrating a display apparatus in accordance with an exemplary embodiment of the present inventive concept;
FIG. 2 is a cross-sectional view illustrating a display panel in accordance with an exemplary embodiment of the present inventive concept;
FIG. 3 is an enlarged cross-sectional view of FIG. 2;
FIG. 4 is a plan view illustrating a chip on film package in accordance with an exemplary embodiment of the present inventive concept; and
FIG. 5 is an enlarged plan view illustrating an area “A” of FIG. 4.



DETAILED DESCRIPTION
Hereinafter, exemplary embodiments of the present inventive concept will be described in more detail with reference to the accompanying drawings.
FIG. 1 is a plan view illustrating a display apparatus in accordance with an exemplary embodiment of the present inventive concept. FIG. 2 is a cross-sectional view illustrating a display panel in accordance with an exemplary embodiment of the present inventive concept. FIG. 3 is an enlarged cross-sectional view of FIG. 2. FIG. 4 is a plan view illustrating a chip on film package in accordance with an exemplary embodiment of the present inventive concept. And, FIG. 5 is an enlarged plan view illustrating an area “A” of FIG. 4.
Referring to FIGS. 1 and 2, a display apparatus in accordance with an exemplary embodiment of the present inventive concept, may include a display panel 100, a printed circuit board 200, a chip on film package 300 and a receiving container 400.
The display panel 100 may display an image.
The display panel 100 may include a plurality of substrates. The substrates may include a transparent insulating substrate. Examples of the transparent insulating substrate may include, but are not limited to, a glass substrate or a plastic substrate.
The display panel 100 may include a plurality of gate lines GL, a plurality of data lines DL and a plurality of pixels.
The gate lines GL may extend in a first direction D1. The data lines DL may extend in a second direction D2 substantially perpendicular to the first direction D1. The gate lines GL may extend in the second direction D2 and the data lines DL may extend in the first direction D1.
The pixels may be arranged in a matrix shape. The pixels may be disposed in areas defined by the gate lines GL and the data lines DL. Each pixel may be connected to a corresponding gate line GL and a corresponding data line DL adjacent to the pixel.
Each pixel may have a rectangular shape extending in the second direction D2, a V-shape, or a Z-shape.
Each pixel may include a switching element. For example, the switching element may be a thin film transistor TFT.
The switching element may be connected to the gate line GL and the data line DL adjacent to the switching element. The switching element may be disposed at a crossing area of the gate line GL and the data line DL.
A liquid crystal layer may be disposed between the substrates. For example, the liquid crystal layer may include liquid crystal molecules. An alignment of the liquid crystal molecules in the liquid crystal layer may be controlled by an electric field. Light transmittance of the pixel may be controlled by different arrangements of the liquid crystal molecules I the liquid crystal layer by applying the electric field.
One or more color filters may be disposed on the substrate. The color of light passing through the color filer may be changed by the color filter and the light may be transmitted to the liquid crystal layer. The color filters may include a red color filter, a green color filter or a blue color filter, for example. Each of the color filters may correspond to one of the pixel areas. The color filters, which may be adjacent to each other, may have different colors from each other.
A black matrix may be disposed on the substrate. For example, the black matrix may be disposed on an area corresponding to the gate line GL, the data line DL and the switching element. The black matrix may include a black material, which may block light.
The liquid crystal display panel may include a color filter on array (“CON”) structure. In the COA structure, the color filter may be disposed on a lower surface of a liquid crystal layer. The liquid crystal display panel may include a black matrix on array (“BOA”) structure. In the BOA structure, the black matrix may be disposed on the lower surface of a liquid crystal layer.
A pixel electrode and a common electrode may be disposed on the substrates. A grayscale voltage may be applied to the pixel electrode and the common electrode, thus forming an electric field. For example, the pixel electrode and the common electrode may include a transparent conductive material, such as indium tin oxide (ITO), indium zinc oxide (IZO) and/or aluminum zinc oxide (AZO).
The pixel electrode and the common electrode may be disposed on a same substrate. The pixel electrode and the common electrode may be formed on different substrates.
Referring to FIG. 2, the printed circuit board 200 may be disposed on the lower surface of the display panel 100.
The printed circuit board 200 may include a timing controller, a power source, and/or a gamma voltage generator. The timing controller may generate a control signal controlling the gate lines GL and the data lines DL from a raw signal input by an outer apparatus such as a computer. The control signal generated from the timing controller may be transmitted to the display panel 100 through the gate line GL and the data line DL.
The printed circuit board 200 may be disposed adjacent to the display panel 100.
The display panel 100 and the printed circuit board 200 may be connected with each other through the chip on film package 300.
A plurality of chip on film packages 300 may connect the display panel 100 and the printed circuit board 200. For example, the number of the chip on film packages 300 may be increased according to a size of the display panel 100.
The chip on film package 300 may be curved to connect the display panel 100 and the printed circuit board 200.
The chip on film package 300 will be described in more detail below with reference to FIGS. 3 to 5.
The display panel 100 and the printed circuit board 200 may be disposed in the receiving container 400.
Although not illustrated in FIGS. 1 and 2, a backlight unit may emit light to the display panel 100. The backlight unit may be disposed in the receiving container 400. The backlight unit may include a light source. The backlight unit may be disposed on a lower surface of the receiving container 400, and may emit light to the display panel 100.
The chip on film package 300 may be disposed in the receiving container 400.
Referring to FIG. 3, the chip on film package 300 may include a base substrate 310, an input line 320, an output line 325 and an IC chip 330.
The base substrate 310 may be a flexible film including a flexible material.
For example, the base substrate 310 may include polyimide, acrylic, polyether nitrile, polyether sulfone, polyethylene terephthalate, polyethylene naphthalate, or polyvinyl chloride.
The IC chip 330 may be disposed on a center of the base substrate 310. While not illustrated in the figures, a plurality of sprocket holes may be disposed along edges of the base substrate 310. The sprocket holes may be aligned along a direction substantially perpendicular to the IC chip 330.
A circuit wiring may be disposed on the base substrate 310. For example, the circuit wiring may include the input line 320 and the output line 325.
A thin film may be formed on the base substrate 310 and then patterned to form the input line 320 and the output line 325.
The thin film may be coated on the base substrate 310. A photoresist material may be coated on the thin film, and exposed to light using a mask. An exposed photoresist material may be developed, thus forming a photoresist pattern. A portion of the thin film may be removed using the photoresist pattern as a mask, thus forming a thin film pattern. The photoresist pattern may be removed, thus forming a circuit pattern.
For example, the input line 320 and the output line 325 may include copper (Cu), nickel (Ni), gold (Au) or an alloy thereof.
The IC chip 330 may be electrically connected to the input line 320 and the output line 325.
Electrode bumps 331 may be disposed on lower surfaces of each edge of the IC chip 330.
The IC chip 330 may be flip-chip bonded to the base substrate 310 through the electrode bumps 331. The IC chip 330 may be electrically connected to the input line 320 and the output line 325 through the electrode bumps 331.
The IC chip 330 may be electrically connected to the input line 320 and the output line 325 through a wire.
An encapsulant part 332 may be disposed on a lower surface and a side surface of the IC chip 330. The encapsulant part 332 may surround the IC chip 330. The encapsulant part 332 may surround the IC chip 330 to fix the IC chip 330 on the base substrate 310.
The encapsulant part 332 may encapsulate the electrode bump 331 and a portion of the input line 320 and the output line 325.
The encapsulant part 332 may be formed by an under-fill process.
The encapsulant part 332 may include a material having a relatively high thermal conductivity to release heat generated from the IC chip 330. For example, the encapsulant part 332 may include epoxy resin or silicon resin.
A difference in a CTE (Coefficient of Thermal Expansion) may exist between the IC chip 330 and the base substrate 310. The encapsulant part 332 may reduce or eliminate a defect resulting from the difference in the CTE between the IC chip 330 and the base substrate 310.
A protecting layer 340 may be disposed on the input line 320 and the output line 325. The protecting layer 340 may cover a portion of the input line 320 and the output line 325, and may insulate portions of the input line 320 and the output line 325.
The protecting layer 340 may expose a portion of the input line 320 and the output line 325. The protecting layer 340 may be a solder resist.
A conductive layer 350 may be disposed on edges of the input line 320 and the output line 325. The display panel may be electrically connected to the printed circuit board 200 through the conductive layer 350.
The conductive layer 350 may be an anisotropic conductive film (ACF).
The input line 320 may be connected to the printed circuit board 200 through the ACF. The output line 325 may be connected to the printed circuit board 200 through the ACF.
The chip on film package 300 may be relatively flexible. The chip on film package 300 may be bent or curved. The printed circuit board 200 may be disposed at a first end of the chip on film package 300 and the display panel 100 may be disposed at a second end of the chip on film package 300. The printed circuit board 200 may be disposed under the display panel 100.
Referring to FIGS. 4 and 5, the circuit wiring may be disposed on the base substrate 310. The circuit wiring may include the input line 320, the output line 325 and a by-pass line 328.
The input line 320 may input a control signal transmitted from the printed circuit board. 200 to the IC chip 330. For example, the control signal may be a data signal.
The input line 320 may be electrically connected to a first edge of the IC chip 330. The IC chip 330 may receive the data signal through the input line 320.
The input line 320 may extend in the first direction D1 from the printed circuit board 200 to the IC chip 330.
The output line 325 may output a signal transmitted from the IC chip 330 to the display panel 100. The output line 325 may be connected to the data line DL.
The IC chip for driving the liquid crystal display apparatus may include an input pad connected to the input line 320 and an output pad connected to the output line 325, and the number of output pads may be greater than the number of input pads.
The output line 325 may include a main output line OP1 and a sub output line OP2.
The main output line OP1 may be electrically connected to the IC chip 330 at a second edge of the IC chip 330.
The main output line OP1 may extend in the first direction D1 from the IC chip 330 to the display panel 100.
An edge of the sub output line OP2 may be electrically connected to the first edge of the IC chip 330. Another edge of the sub output line OP2 may be connected to the data line DL.
The sub output line OP2 may extend in an opposite direction from the first direction D1 from the first edge of the IC chip 330.
The sub output line OP2 may include a plurality of bending parts BP so that the sub output line OP2 may be curved and may extend toward the first direction D1
The sub output line OP2 may extend in the opposite direction from the first direction D1 from the first edge of the IC chip 330 toward the printed circuit board 200. The sub output line OP2 may include the bending parts BP so that an extending direction of the sub output line OP2 may be changed in the first direction D1.
A difference between a first direction extended from a first edge of the sub output line OP2 and a second direction extended toward a second edge of the sub output line OP2 may be 180°.
Therefore, the sub output line OP2 may bypass the IC chip 330, and may extend toward the display panel 100.
For example, at least 6 bending parts BP may be included in the sub output line OP2. Therefore, stress from a curved portion of the chip on film package 300 may be reduced or eliminated, so that a cut in the circuit wiring may be prevented. When less than 6 bending parts BP are included, the circuit wiring may be relatively weak because stress from the curve of the chip on film package 300 may cause a cut in the circuit wiring. Thus, for example, the sub output line OP2 may include at least 6 bending parts BP.
The sub output line OP2 may have a uniform width.
For example, the sub output line OP2 may have a width of about 11 um to about 13 um. When the width of the sub output line OP2 is less than 11 um, the circuit wiring may be more easily cut by stress applied when the chip on film package 300 is curved or bent. When the width of the sub output line OP2 is more than 13 um, stress applied when the chip on film package 300 is curved or bent may converge at a bending part BP of the circuit wiring, and a cut may be more likely to occur in the circuit wiring.
The by-pass line 328 may bypass the input line 320, the output line 325 and the IC chip 330.
The by-pass line 328 may input the control signal transmitted from the printed circuit board 200 to a gate driving chip (not illustrated). For example, the control signal input to the gate driving chip may be a gate signal.
The by-pass line 328 may be connected to the gate line GL through the gate driving chip.
While the inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present inventive concept.

## Claims

1. A chip on film package comprising:
a base substrate;
an input line disposed on the base substrate;
an integrated circuit (IC) chip electrically connected to the input line; and
an output line, wherein the output line comprises:
a main output line electrically connected to the IC chip, wherein the main output line extends in a first direction from the IC chip; and
a sub output line electrically connected to the IC chip, wherein the sub output line comprises at least six bending parts, and wherein the sub output line extends in the first direction,

wherein each of the bending parts disposed at a same side as the input line with respect to the IC chip has an obtuse angle.

2. The chip on film package of claim 1, wherein the sub output line has a uniform width.

3. The chip on film package of claim 2, wherein the sub output line has a width of about 11 um to about 13 um.

4. The chip on film package of claim 1, wherein the base substrate is a flexible film.

5. The chip on film package of claim 1, further comprising:
electrode bumps disposed on lower surfaces of each edge of the IC chip,
wherein the IC chip is connected to the input line and the output line through the electrode bumps.

6. The chip on film package of claim 5, further comprising:
an encapsulant part surrounding the IC chip and fixing the IC chip on the base substrate,
wherein the encapsulant part encapsulates the electrode bump and portions of the input line and the output line.

7. The chip on film package of claim 1, further comprising:
a protecting layer covering portions of the input line and the output line.

8. The chip on film package of claim 7, wherein the protecting layer comprises a gap exposing the base substrate.

9. The chip on film package of claim 1, further comprising:
a by-pass line bypassing the input line, the output line and the IC chip.