KR100760774B1 - Tape carrier package for flat display device and Plasma display device having the same - Google Patents

Abstract

The present invention discloses a plasma display device and a TCP thereof, wherein a grounding means capable of being connected to a chassis is provided in a TCP connecting the electrode and the circuit board. The grounding means is a part of an insulating layer that insulates the conductive pattern and the integrated circuit chip from the outside in at least some of the areas overlapping the ground lead pattern formed separately by being connected to the ground terminal of the integrated circuit chip, the ground signal line among the conductive patterns, and the ground signal line. It can be made by installing an electrical connection medium with the outside. The grounding means shall be electrically accessible to the cover plate or chassis when the TCP is fixed and in contact with the cover plate and chassis.

According to the present invention, it is possible to increase the stability of the ground and to suppress side effects such as noise due to electromagnetic interference.

Description

Tape carrier package for flat display device and plasma display device having the same {Tape carrier package for flat display device and Plasma display device having the same}

1 and 2 are cross-sectional views showing a lower portion of a cross section of a vertically cut panel forming a screen in a state where a chassis and a panel are combined in conventional plasma display devices;

3 is a schematic plan view of a TCP in a roll tape forming an embodiment of the present invention;

4 to 7 is a schematic cross-sectional view showing a portion where the ground pin is formed in the embodiments of the present invention;

8 is an exploded perspective view showing an embodiment of the present invention plasma display device;

9 is a comparison diagram showing a signal waveform and a conventional signal waveform applied to an address electrode over time when ground is reinforced by an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: panel 11, 13: substrate

20,25: heat conductive medium 30: chassis base

33,270 reinforcement 37

40,140: protection plate

50,250: Tape carrier package (TCP) 51,220: Chip

161: circuit board 70: conductive paste

230: base film 240: resin layer

211: Ground terminal 235,239: Pin

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape carrier package used in a flat panel display device (hereinafter referred to as 'TCP') and a plasma display device employing the same. More specifically, TCP grounding between a panel electrode and a circuit portion of a plasma display device is provided. It's about structure.

Plasma display panels are formed by forming electrodes on two opposing substrates, overlapping them at regular intervals, injecting a discharge gas therein, and sealing the plasma display panel (PDP). Refers to a flat panel display device.

The plasma display device is formed by forming a plasma display panel and installing elements necessary for screen realization such as a driving circuit connected to each electrode of the panel.

In a plasma display panel, each pixel is represented through discharge in that pixel region. The discharge is generated in the discharge cell space by the voltage applied to the electrode, and generates atoms in the plasma or excited state in the space. The power required for discharging is partially lost to light, but most of it is converted to heat.

On the other hand, the driving circuit connected to the electrodes of the plasma display panel consumes a lot of power to implement the screen. The consumption of power eventually means heat generation, and when the driving circuit is overheated, the life of the circuit element may decrease, and it is easy to cause malfunction in the circuit operation. A circuit malfunction may cause a problem of degrading the screen quality, for example, by causing a discharge to occur even in a pixel portion which should not be discharged.

In particular, a large amount of heat is likely to occur in a driving integrated circuit chip that controls an address electrode to which high voltage is frequently applied in a short period. In addition, in order to realize a high-quality image, a large number of address electrodes are formed. There is a limitation in processing capacity in a unit integrated circuit chip that drives the address electrodes, and it is difficult to form a large number of pads on one chip. To this end, a large number of driving integrated circuit chips are required in proportion to the number of address electrodes.

The formation of these integrated circuit chips on one circuit board is limited in forming space, the distance between the integrated circuit chip and each electrode is increased, and the distance varies depending on the position of the electrode, which increases the possibility of signal distortion. Problems such as the point, the heating element is concentrated. Accordingly, a tape carrier package (TCP) in which a signal line connecting the circuit board and the address electrode of the panel is a flexible film and an integrated circuit chip for driving the address electrode is formed in the middle of the signal line is formed in the plasma display device. It is commonly used. TCP generally refers to a kind of packaging method formed by bonding a TCP tape having a conductive pattern formed thereon and an integrated circuit chip having a bump formed on an insulating polyamide film that is a base film, or a package that is a resultant formed by the method. Of course, TCP may be used as a signal line of the sustain electrode in addition to the signal line for the address electrode.

In such a TCP-type signal line, the integrated circuit chip portion is directly in contact with the heat sink chassis to cool a portion of the integrated circuit chip that generates a lot of heat.

1 and 2 illustrate a lower portion of a cross section in which a panel constituting a screen is vertically cut in a state where a chassis and a panel are combined in a conventional plasma display device.

As shown, the portion of the integrated circuit chip 51 of the TCP 50 is bent of the chassis base 30 to form a stepped reinforcement part 33 or chassis reinforcement material 37 and cover plate 40 (Fig. 1). (Not shown) is fixed and contacted. In order for the thermal contact to be efficient or for buffering, the area where the chassis and the integrated circuit chip 51 touch each other, and the part where the cover plate 40 and the integrated circuit chip 51 touch the thermal conductive medium 25 and thermal grease ) May be interposed.

Since the TCP 50 is arranged every certain number of address electrodes, the integrated circuit chip 51 of the TCP, which is a heat generating unit, is evenly distributed on the reinforcing material 37, the reinforcing part 33, and the cover plate 40 horizontally installed on the screen. Will be distributed.

However, the TCP thus formed is not provided with a separate ground member in the driver circuit chip portion. Therefore, it is possible to ground through the ground terminal of the substrate only after being connected to the substrate. TCP has a number of unwanted elements such as parasitic capacitance, parasitic inductance, resistance, etc. between the signal lines due to the constituent property in which a plurality of signal lines are formed side by side on the flexible film surface, and thus, signal noise and Signal distortion may occur and deteriorate the image quality. In addition, it may be formed long and may cause problems of interference and electromagnetic waves caused by external elements. Of course, shields can be formed separately to block these elements to some extent, but this leads to increased parts and complicated process.

In addition, these problems can be more pronounced when applying a single scan method in which TCP is connected only to the upper or lower side of the address electrode and connected to the circuit unit.

The present invention provides a plasma display device and a TCP having a configuration capable of alleviating the problem of signal distortion and external electromagnetic waves or the occurrence of electromagnetic interference by itself when using TCP in the above-described conventional plasma display device. For the purpose of

An object of the present invention is to provide a plasma display device and a TCP having a configuration capable of reducing signal distortion and deterioration in image quality generated when using TCP without a separate shield.

The present invention for achieving the object is characterized in that the grounding means that can be connected to the chassis in the TCP connecting the electrode and the circuit board is provided.

In this case, the grounding means may insulate the conductive pattern and the integrated circuit chip from the outside in at least some of the areas overlapping the ground lead pattern formed separately by being connected to the ground terminal of the integrated circuit chip, the ground signal line among the conductive patterns, and the ground signal line. This can be achieved by installing an electrical connection medium to the outside in part of the layer.

In the present invention, the grounding means in the TCP may be a hole formed on the flexible insulating tape and a conductor filling the hole so that a part of the wire connected to the ground terminal or the wire is exposed, and the conductor filling the hole is in the form of a pin or a ball or an amorphous shape. It may be a pressed metal powder and the like.

In the present invention, the grounding means should be able to contact the cover plate or chassis electrically when the TCP is fixedly contacted with the cover plate and chassis. Therefore, if the heat conducting medium is interposed between the TCP and the chassis or the cover plate, the heat conducting medium should be a conductor.

In addition, in order to make electrical contact more stable, the grounding means formed in the TCP preferably has a portion protruding over the flexible insulating tape, and protrudes the portion in contact with the TCP in the cover plate, the chassis reinforcement, and the reinforcement portion. It can also be formed.

TCP for the plasma display device of the present invention for achieving the above object is characterized in that the grounding means is provided on the body portion except for both ends connected to the electrode and the circuit board of the panel.

The grounding means is preferably provided at the terminal of the integrated circuit chip which is mainly in contact with the cover plate or the chassis, or at the portion where the ground signal line is formed.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 3 is a schematic plan view of a state in which a TCP constituting an embodiment of the present invention is in a roll tape, and FIGS. 4 to 7 are schematic cross-sectional views showing portions in which ground pins are formed in embodiments of the present invention.

Referring to these drawings, the conductive pattern 210 forming a signal line on the base film 230 in the TCP (250) is formed at both ends at the chip 220 connection portion, the integrated circuit chip 220 is connected to An inner lead portion contacting the conductive pattern 210 and the bump 224 connected to the integrated circuit chip 220 is formed. The cover resin layer 240 is covered in the state in which the integrated circuit chip is connected with the conductive pattern.

The grounding pin of the present invention forms a hole in the base film 230 and installs the pin 235 in the hole, or as shown in FIG. 5 by pressing a metal powder 237 or a ball-shaped soft metal as shown in FIG. ) May be formed first before formation. That is, the conductive pattern 210 may be formed on the base film 230 on which the ground pin 235 is formed. The position of the hole is an inner lead portion connected to the ground terminal of the semiconductor chip 220 in the conductive pattern, or a separate ground terminal 211 as indicated by a circle in FIG. 1, or a signal line connected to the terminal and starting from the inner lead portion. Can be part of

The hole formed in the base film 230 is preferably formed wide in a range that is not short-circuited with an adjacent signal line, for ease of grounding, and the signal line for grounding is based on the direction of the conduction pattern of the TCP for convenience of hole formation. It is preferable to be formed in the outermost side.

In Fig. 6, a pin head 2391 is formed which protrudes from a portion where the ground pin 239 is exposed to the outside. This form forms a hole in the base film 230 in the TCP forming step, and inserts a pin 239 having a pin head 2391 having a diameter larger than the hole from the outside toward the inner surface on which the conductive pattern 210 is to be formed. It can be done in a way.

In FIG. 7, the surface of the chassis reinforcement part 270 protrudes from a portion where the ground pin 235 is exposed to the outside. In this form, when the grounding pins 237 and 235 formed as shown in FIG. 4 or 5 maintain substantially the same level as the outer surface of the base film 230, the protruding portion of the surface of the reinforcement part 270 compresses the TCP to provide flexibility. Compared to the base film 230, the ground pin portion contacts the chassis reinforcement 270 at a higher pressure.

In the configuration of FIGS. 6 and 7, the ground pins 239 and 235 and the chassis reinforcement portion 270 are in close contact with each other, thereby reducing contact resistance in the electrical connection for grounding, thereby making grounding more effective.

Of course, the grounding means of the present invention, for example, the conductive pin may be formed on the resin layer 240 for insulation of the conductive pattern of TCP as well as the base film. That is, a resin layer for insulating the conductive pattern and the outer conductor is formed on the opposite side of the base film based on the conductive pattern, and the grounding means may be provided in the resin layer. In this case, the grounding means will be primarily in contact with the cover plate rather than the reinforcement or reinforcement of the chassis base to serve as a ground.

Hereinafter, a module part of the plasma display device according to an exemplary embodiment of the present invention will be described with reference to FIG. 8.

The plasma display device according to the present embodiment includes a plasma display panel including two substrates 11 and 13, a chassis base 30 supporting the panel from the rear of the panel, and a circuit board mounted on the rear of the chassis base and provided with a driving circuit. 161 is provided.

On the front substrate 11 of the panel, sustain electrodes having a straight shape parallel to each other are formed horizontally, and address electrodes having a straight shape parallel to each other are formed on the rear substrate 13. The partition wall is positioned in parallel with the address electrode, and a phosphor layer is disposed above the address electrode.

The chassis is installed behind the rear substrate. The chassis may be provided with a plate-shaped chassis base 30 and a reinforcement 37 to prevent the warpage or deformation of the chassis. The chassis base 30 is once bent backwards at the periphery of the address electrode and bent once again to the opposite side to form a stepped reinforcement, and the integrated circuit chip of TCP 50 at the rear of the reinforcement forming the peripheral end of the chassis base. 51 may be made in contact.

The chassis base 30 is fixed to the rear surface of the rear substrate 13 by a double-sided tape 21 or the like. The thermal conductive medium 20 is interposed between the chassis base 30 and the rear substrate 13 together with the double-sided tape 21.

A plurality of circuit boards 161, a power supply, and the like are installed behind the chassis base 30. The circuit board 161 is provided with integrated circuit chips and other electrical and electronic element devices required for driving the panel. The circuit board and the other circuit board are connected to other signal lines as needed.

A plurality of lead electrodes are formed around the plasma display panel attached to the front of the chassis. The lead electrode is formed outside the sealing part along the periphery of the panel to connect a plurality of electrodes such as an address electrode and a sustain electrode formed over the two substrate surfaces of the panel with the driving circuit. On the other hand, the driving circuit connected to the electrodes formed on the panel to drive them is mounted on the back of the chassis while being installed in the circuit board 161 or the like. An important driving circuit portion of the address electrode drawn out to the upper and lower sides of the panel is formed on the integrated circuit chip 51 of the tape carrier package (TCP) 50. In this embodiment, the ground pin is formed in the TCP and is already connected with the chassis stiffener 37 before being connected with the substrate. In order to stabilize the connection with the chassis, the conductive paste 70 is used at the portion where the TCP 50 and the chassis reinforcing material 37 contact each other. When the conductive paste has adhesiveness, the cover plate 140 coupled with the chassis above the TCP to fix the TCP may not be installed. The conductive paste may also be excellent in thermal conductivity by having metal particles.

In a configuration without a cover plate, there is no need to use a separate heat conducting medium, a heat dissipation grease, etc., thereby reducing the process cost and the cost of the component due to the reduction in the number of components. In addition, since the cover plate is not used, electromagnetic vibration, which is generated by applying an alternating voltage to the sustain electrode in the panel, is transferred to the circuit board 161 and the cover plate 141 through the chassis base 30 and the boss. It is possible to reduce the phenomenon that the chassis and cover plate 141 cause structural vibration.

9 is a comparison diagram showing a signal waveform and a conventional signal waveform applied to an address electrode over time when ground is reinforced by an embodiment of the present invention. As shown in the ellipse, in the embodiment of the present invention on the right side, the noise deviating from the normal waveform is displayed with a small amplitude, and in the conventional example on the left, the amplitude of the noise appearing before the start of the regular waveform is relatively large. have.

According to the present invention, when the TCP serves as a signal line between the electrode of the panel and the driver substrate, a more stable grounding can be performed to reduce noise generation in a signal applied to the electrode of the panel.

According to the present invention, by reducing the noise of the signal applied to the panel electrode in the plasma display device, it is possible to reduce the deterioration in image quality due to mis-discharge, and to maintain a stable image quality.

According to the present invention, since an additional configuration for reducing noise can be reduced in the plasma display device, the design is easy, and since a separate shield for noise prevention is not required, component cost and process cost burden can be reduced.

Claims (13)

delete delete delete delete delete delete delete delete delete delete delete delete A plasma display panel having a plurality of pixel driving electrodes, A circuit unit formed to drive the electrode, including a signal line for connection with the electrode, In the plasma display device comprising a chassis for supporting the panel and the circuit portion, The signal line is formed on the base film, the base film, and the conductive pattern forming an exposed terminal for connection with a portion connected at both ends of the base film, and integrated connected to the connection terminal of the conductive pattern at an intermediate position of the both ends. It is made of a tape carrier package (TCP) having a circuit chip, the tape carrier package is provided with a grounding means which is electrically connected directly to the chassis, The portion of the chassis connected with the tape carrier package is one of a cover plate, a bent reinforcement portion of the chassis base, a chassis reinforcement material, And a protrusion is formed on a surface of the cover plate, the reinforcing part, and the reinforcing material which contacts the grounding means.

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