Patent Publication Number: US-6992745-B2

Title: Signal transmission film, control signal part and liquid crystal display including the film

Description:
BACKGROUND OF THE INVENTION 
   (a) Field of the Invention 
   The present invention relates to signal transmission film, a control signal part and a liquid crystal display including the signal transmission film. 
   (b) Description of the Related Art 
   A liquid crystal display is one of the flat display devices widely used at the present time. The liquid crystal display comprises two substrates on which a plurality of electrodes are formed, a liquid crystal layer sandwiched between the two substrates and two polarizing films for polarizing the light attached to each outward surface of the substrates. The liquid crystal display controls the light transmittance, thereby to display picture images by applying different voltages to the electrodes while forming electric fields for varying the orientation of the liquid crystal molecules of the liquid crystal layer. In such a liquid crystal display, thin film transistors are formed in one of the two substrates, which is called as a TFT substrate, and switch the voltages applied to the electrodes. 
   A display region for displaying picture images is situated in the center of the TFT substrate. A plurality of signal lines, or a plurality of gate lines and data lines are formed in the directions of row and column, respectively. The gate lines and the data lines cross each other, thereby to define a plurality of pixel element regions. Each pixel element has a pixel electrode to which the data signal is applied via the data line. The thin film transistor sends the data signal transmitted via the data line to the pixel electrode by the gate signal transmitted via the gate line. 
   A plurality of gate pads connected to the gate lines and a plurality of data pads connected to the data lines are formed outside of the display region. These pads are connected to the external driving integrated circuits thereby to receive gate signals and data signals from the external driving integrated circuits and send them to the gate lines and the data lines. 
   A printed circuit board for gate signal transmission and a printed circuit board for data signal transmission are attached to the thin film transistor substrate using an anisotropic conducting film through an heat and compression process thereby to send the gate and the data signals to the thin film transistor. The thin film transistor and the printed circuit board for data signal transmission are connected by a data signal transmission film on which the data driving integrated circuit is mounted. The data driving integrated circuit converts an electric signal into a data signal and sends the data signal to the data line. And also, the thin film transistor and the printed circuit board for gate signal transmission are connected by a gate signal transmission film on which the gate driving integrated circuit is mounted. The gate driving integrated circuit converts an electric signal into a gate signal and sends the gate signal to the gate line. 
   Herein, gate control signals for controlling the gate signal could be outputted from the printed circuit board for data signal transmission not from the printed circuit board for gate signal transmission. And, these gate control signals could be transmitted to the gate signal transmission film. 
   The gate control signals are various kinds of control signals such as a gate-on-voltage, a gate-off-voltage and a common voltage for reference voltage to the difference of the data voltage in the thin film transistor. 
   These gate control signals inputted into the gate driving integrated circuit, while driving the liquid crystal display, have various kinds of magnitudes of voltage and are transmitted through gate control signal connection wires. The gate control signal connection wires are arranged abreast and closely on the thin film transistor substrate. Accordingly, a high voltage signal wire transmitting a high voltage such as the gate-on-voltage and a low voltage signal wire transmitting a low voltage such as the gate-off-voltage are arranged abreast and closely. 
   In this arrangement of the wires, a potential difference is formed between the high voltage signal wire and the low voltage signal wire while driving the liquid crystal display. However, this potential difference causes an electrolysis reaction with moistures permeated into the wires during manufacturing and operating the liquid crystal display, by a rule of the galvanic cell, thereby to damage the high voltage signal wire and results in inferior devices. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a signal transmission film, a control signal part and a liquid crystal display including the signal transmission film that prevents wires from damage due to electrolysis. 
   This object are provided, according to the present invention, by forming a thick lead located between a high voltage signal wire and a low voltage signal wire of the thin film transistor substrate in the control signal transmission film. In other words, the present invention provides the lead of several to several tens microns on the signal transmission film by printing and patterning a copper wire on a high molecular film. Herein, the lead is arranged on the control signal transmission film to be spatially located between the high voltage signal wire and the low voltage signal wire in the signal wires of several hundreds to several thousands. 
   According to one aspect of the present invention, a signal transmission film comprises a first signal lead transmitting a first signal voltage; a second signal lead transmitting a second signal voltage smaller than the first signal voltage; and a lead formed between the first signal lead and the second signal lead. 
   The lead could have a thickness of several to several tens microns, the same voltage as the first signal voltage could be applied to the lead and the lead could be a dummy lead. 
   According to another aspect of the present invention, a control signal part comprises a control signal wire part comprising a substrate, a first and a second signal wires on the substrate; a control signal transmission part comprising a film corresponding to the substrate, a first and a second signal leads on the film and a lead on the film, wherein the first and the second signal leads being connected to the first and the second signal wires and the lead being located spatially between the first and the second signal wires. The first signal lead transmits a first signal voltage and the second signal lead transmits a second signal voltage lower than the first signal voltage. 
   The lead could have a thickness of several to several tens microns. And, each of the signal lead could overlap at least one portion of the signal wire corresponding to itself. 
   The same voltage as the first signal voltage could be applied to the lead. The lead could overlap at least one portion of the wire. 
   A wire connected to the lead could be formed on the substrate. The wire could be connected to the first signal wire, or isolated from the first signal wire. 
   The wire could be formed by less oxidative conductive materials than the second signal wire. And, the wire could be formed by ITO or IZO. 
   The first signal lead could extend to the lead thereby to be in one body with the lead. And, the lead could be a dummy lead. 
   According to the other aspect of the present invention, a liquid crystal display comprises a display region on a substrate, wherein the display region comprising a gate line, a data line crossing the gate line thereby to define a pixel element region, a thin film transistor connected to the gate line and the data line in the pixel element region and a pixel electrode electrically connected to the thin film transistor; a control signal wire part on the substrate, wherein the control signal part comprising a first and a second signal wires; a control signal transmission part comprising a film corresponding to the substrate, a first and a second signal leads on the film and a lead on the film, wherein the first and the second signal leads being connected to the first and the second signal wires and the lead being located spatially between the first and the second signal wires. 
   The first signal lead transmits a first signal voltage and the second signal lead transmits a second signal voltage smaller than the first signal voltage. 
   The lead could have a thickness of several to several tens microns. Each of the signal lead could overlap at least one portion of the signal wire corresponding to itself. The same voltage as the first signal voltage could be applied to the lead. 
   The control signal transmission part could comprise a data driving integrated circuit or a gate driving integrated circuit. 
   The first signal voltage could be a gate-on-voltage or a power supplying voltage. 
   The second signal voltage could be a gate-off-voltage or a grounding voltage. 
   The lead is a dummy lead. And, a wire connected to the lead could be formed on the substrate. 
   The lead could overlap at least one portion of the wire. 
   The wire could be formed by conductive materials less oxidative than the second signal wire, ITO or IZO. 
   And also, the wire could be formed by conductive materials for forming the gate line, the data line or the pixel electrode. 
   The liquid crystal display could comprise a insulating layer covering the wire on the substrate, a contact hole exposing the portion of the wire in the insulating layer and an auxiliary pad connected to the wire through the contact hole, wherein the lead is connected to the wire to fully cover the contact hole in a length direction of the contact hole. Herein, the lead could cover at least one side of the contact hole in a width direction of the contact hole. And also, the lead could be located inside region of the contact hole thereby to expose both sides of the contact hole. 
   The liquid crystal display could comprise a gate signal transmission film connected to the substrate, wherein the wires are formed by connecting a first wire connected to the gate signal transmission film and a second wire connected to the control signal transmission part. Herein, the first and the second wires could be connected to each other by a manner in which the first wire is formed on the substrate, a first insulating layer covering the first wire and a first contact hole exposing an end of the first wire in the first insulating layer are further comprised, and the second wire is connected to the first wire through the first contact hole on the first insulating layer. And, further, a second insulating layer covering the second wire, a second contact hole exposing the pad of the second wire and a third contact hole exposing the pad of the first lower wire and auxiliary pads connected to the pads of the first and the second wires through the second and the third contact holes could be comprised. 
   In the liquid crystal display, the first signal wire could comprise a lower wire having a pad on the substrate, a first insulating layer covering the lower wire, an upper wire having a pad on the first insulating layer, a first contact hole exposing the lower wire in the first and the second insulating layers, a second contact hole exposing the upper wire in the second insulating layer and a auxiliary pad connected to both the pad of the lower wire and the pad of the upper wire. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention, and many of the advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or the similar components, wherein: 
       FIG. 1  is an outline view of a liquid crystal display including a control signal part; 
       FIG. 2  is a plan view showing a wiring structure of a control signal part in which a high voltage redundancy wire is not formed; 
       FIG. 3  is a cross-sectional view of the wiring structure of the control signal part taken along the line III–III′ of  FIG. 2 ; 
       FIG. 4  is a plan view of a control signal part according to a first embodiment of the present invention; 
       FIG. 5  is a cross-sectional view of the control signal part taken along the line V–V′ of  FIG. 4 ; 
       FIG. 6  is a plan view of a control signal part according to a second embodiment of the present invention; 
       FIG. 7  is a cross-sectional view of the control signal part taken along the line VII–VII′ of  FIG. 6 ; 
       FIG. 8  is a plan view of a liquid crystal display according to a third embodiment of the present invention; 
       FIG. 9  is a cross-sectional view of the liquid crystal display taken along the line IX–IX′ of  FIG. 8 ; 
       FIG. 10  is a plan view of a liquid crystal display according to a fourth embodiment of the present invention; 
       FIG. 11  is a cross sectional view of the liquid crystal display taken along the line XI–XI′ of  FIG. 10 . 
       FIG. 12  is a plan view of an overlapping structure of a signal lead and a signal wire; 
       FIG. 13  is a cross sectional view of the overlapping structure taken along the line XIII–XIII′ of  FIG. 12 ; 
       FIG. 14  is a plan view of another overlapping structure of a signal lead and a signal wire; 
       FIG. 15  is a cross sectional view of the overlapping structure taken along the line XV–XV′ of  FIG. 14 . 
       FIG. 16  is a plan view of another pattern of the signal wire of the control signal part; 
       FIG. 17  is a cross sectional view of the signal wire taken along the line XVII–XVII′ of  FIG. 16 . 
       FIG. 18  is a plan view of another pattern of the pad of the signal wire; and 
       FIG. 19  is a cross sectional view of the pad taken along the line XIX–XIX′ of  FIG. 18 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will be explained with reference to the accompanying drawings. 
     FIG. 1  is an outline view of a liquid crystal display having a thin film transistor substrate on which gate control signal wires are formed. 
   A color filter substrate  100  is combined with a thin film transistor substrate  200 . A data driving integrated circuit  310  for outputting data signals to data lines  130  and a gate driving integrated circuit  410  for outputting gate signals to gate lines  140  are situated outside of the thin film transistor substrate  200 . The data driving integrated circuit  310  is mounted on a data signal transmission film  300  which is connected to a printed circuit board for data signal transmission  500  and the thin film transistor substrate  200  electrically. And, the gate driving integrated circuit  410  is mounted on a gate signal transmission film  400  which is connected to the thin film transistor substrate  200  electrically. 
   These gate and data transmission films  300  and  400  are electrically connected to the thin film transistor substrate  200  using an anisotropic conducting film (ACF) through a heat and compression process. Herein, leads formed in the films  300  and  400  are electrically connected to wires formed in the thin film transistor substrates  200  in a one to one correspondence through conductive materials (not shown) of the ACF. 
   Gate control signals for controlling the driving of the gate driving integrated circuit  410  are transmitted to the gate driving integrated circuit  410  via gate control interconnection wires  520 . In gate control interconnection wires  520 , wires of a printed circuit board for data signal transmission  500 , control signal leads of the data signal transmission film  300 , control signal wires of the thin film transistor substrate  200  and control signal leads of the gate signal transmission film  400  are connected to each other electrically. Arrows on the gate control interconnection wires  520  show the transmission direction of the gate control signals. 
   The gate control signals are gate-on-voltage (Von), gate-off-voltage (Voff), common voltage for reference voltage to the difference of the data voltage in the thin film transistor (Vcom), gate clock (CPV), start vertical signal (STV), line reverse signal (RVS), gate on enable (OE), grounding voltage (VGND), etc. These gate control signals control the driving of the gate driving circuit  410 . 
   Of these gate control signals, each of the gate-on-voltage and the power supply voltage is 10V to 20V, while each of the gate-off-voltage and the grounding voltage is below 0V. 
   A high voltage signal wire for transmitting a high voltage such as the gate-on-voltage and a low voltage signal wire for transmitting a low voltage such as gate-off-voltage are arranged closely. In such a case, a potential difference is formed between the two wires when the liquid crystal display operates. The potential difference is equivalent to a voltage difference between the high voltage such as the gate-on-voltage and the low voltage such as the gate-off-voltage. 
   Moisture permeates into the wires during the manufacture and operation of the liquid crystal display. Especially, the moisture permeates into the wires at the location where the gate and the data transmission films  300  and  400  are attached to the thin film transistor  10 , and concentrates on the step difference parts of the wires. 
   The moisture in itself has ions. Anions of them move the high voltage signal wire from the low voltage signal wire using the ACF as an electrolyte by the potential difference between the high voltage signal wire and the low voltage signal wire. 
   The high voltage signal wire reacts with the anions electrochemically, thereby to be melted in the electrolyte. Thus, the opening of the high voltage signal wire may result in due to an electrolysis. 
   Such an opening of the wires due to the electrolysis generates in the wires at the location where the gate and the data transmission films  300  and  400  are attached to the thin film transistor  10 , especially, in the wires to be indicated as “A” and “B.” 
   The present invention prevents the damage to the high voltage signal wire by preventing the anions from moving around the high voltage signal wire. 
   This will be explained with reference to the following drawings. 
     FIG. 2  is a plan view showing a wiring structure of gate control signal leads of the data signal transmission film and gate control signal wires of the thin film transistor substrate in which a high voltage signal wire and a low voltage signal wire are arranged closely.  FIG. 3  is a cross-sectional view of the wiring structure taken along the line III–III′ of  FIG. 2 . 
   A thin film transistor substrate  200  with gate control signal wires  201 ,  202 ,  203 ,  204  and  205  is attached to a data signal transmission film  300  with gate control signal leads  301 ,  302 ,  303 ,  304  and  305  using an anisotropic conducting film (ACF) comprising conductive materials and an adhesive resin. Herein, leads of the film  300  are electrically connected to wires of the thin film transistor substrates  10  in a one to one correspondence through conductive materials (not shown) of the ACF. 
   In the data signal transmission film  300 , a low voltage control lead  302  is located at one side of a high voltage signal lead  301  and a gate common voltage signal lead  303  is located at the other side of the high voltage signal lead  301 . A high voltage of about 20V such as a gate-on-voltage is applied to the high voltage control lead  301 , a (low voltage of below 0V such as a gate-off-voltage is applied to the low voltage control lead  302  and a gate common voltage of about  3 V is applied to the gate common voltage lead  303 . 
   The gate common voltage may be a low voltage compared with the gate-on-voltage. However, the gate-off-voltage lower than the gate common voltage will be taken as an example of the low voltage in the following description. 
   And, a high voltage signal wire  201 , a low voltage signal wire  202 , a gate common voltage signal wire  203  and other signal wires  204  and  205 , which are connected to the leads  310 ,  302 ,  303 ,  304  and  305  in a one to one correspondence, are formed on the thin film transistor substrate  200 . 
   To drive a liquid crystal display, the gate control signals are inputted to a gate driving integrated circuit (not shown) via control signal leads  301 ,  302 ,  303 ,  304  and  305  of the data signal transmission film  300 , the signal wires  201 ,  202 ,  203 ,  304  and  205  of the thin film transistor substrate  200  and leads of a gate signal transmission film (not shown). 
   In this process, the gate-on-voltage is applied to the high voltage signal lead  301  and the high voltage signal wire  201  and the gate-off-voltage is applied to the low voltage signal lead  302  and the low voltage signal wire  202 . Accordingly, a potential difference is formed between the high voltage signal lead  301 /the high voltage signal wire  201  and the low voltage signal lead  302 /the low voltage signal wire  202 . The potential difference is equivalent to the voltage difference between the gate-on-voltage and the gate-off-voltage. 
   Moisture permeates into the wires while the liquid crystal display is manufactured or operated. Especially, the moisture permeates into the wires at the location where the gate and the data transmission films  300  and  400  are attached to the thin film transistor  10 , and concentrates on the step difference parts of the wires. 
   The moisture in itself has ions. Anions  500  of them move to the high voltage signal wire  201  from the low voltage signal wire  202  using the ACF  250  as an electrolyte by the potential difference between the high voltage signal wire  201  and the low voltage signal wire  202 . The high voltage signal wire  201  reacts with the anions  500  electrochemically, thereby melting in the electrolyte. As a result, the high voltage signal wire  201  opens due to an electrolysis. 
   However, when a control signal transmission film having a lead located spatially between the high voltage signal wire and the low voltage signal wire of the thin film transistor substrate is used, the lead functions as a wall that prevents the anions from moving into the high voltage signal wire. In such a case, although the moisture permeates into the control signal part where the control signal transmission film is attached to the thin film transistor substrate, the anions can not reach the high voltage signal wire, thereby not to melt the high voltage signal wire due to an electrolysis. 
   This will be explained through the following embodiments of the present invention. 
     FIG. 4  is a plan view of a control signal part according to a first embodiment of the present invention and  FIG. 5  is a cross-sectional view of the control signal part along the line V–V′ of  FIG. 4 . 
   A data signal transmission film  300  with gate control signal leads  301 ,  302 ,  303  and high voltage redundancy leads  310  and  320  is attached to a thin film transistor substrate  200  with gate control signal wires  201 ,  202 ,  203  using an anisotropic conducting film  250  consisting of conductive materials  251  and an adhesive resin  252 . Herein, the wires  201 ,  202 , and  203  of the thin film transistor substrate  200  are electrically connected to the leads  301 ,  302  and  303  of the data signal transmission film  300  in a one to one correspondence through conductive materials  251  of the anisotropic conducting film  250 . 
   In the data signal transmission film  300 , a high voltage signal lead  301  transmitting a gate-on-voltage, a low voltage signal lead  302  transmitting a gate-off-voltage, a common voltage signal lead  303  transmitting the gate common voltage are formed. The high voltage dummy leads  310  and  320  transmitting the same voltage as the high voltage signal lead are formed at both sides of the high voltage signal lead  301 . 
   And, a high voltage signal wire  201 , a low voltage signal wire  202 , a common voltage signal wire  203  are formed on the thin film substrate  10  to be connected to the high voltage signal lead  301 , the low voltage signal lead  302  and the common voltage signal lead  303  in a one to one correspondence. The high voltage dummy leads  310  and  320  do not have corresponding wires on the thin film transistor  10 . 
   The leads  301 ,  302 ,  303 ,  310  and  320  of the data signal transmission film  300  is formed thick by printing and patterning a copper wire of several to several tens microns on a high molecular film for the data signal transmission film. The leads  301 ,  302 ,  303 ,  310  and  320  of the data signal transmission film  300  is far thicker than the wires  201 ,  202  and  203  of the thin film transistor substrate  200 . While the data signal transmission film  300  and the thin film transistor substrate  200  are attached to each other using the anisotropic conducting film  250  through an heat and compression process, the portion of the adhesive resin  252  where the high voltage dummy leads  310  and  320  exist is pushed by the thick leads  310  and  320 , thereby to be compressed. Herein, the adhesive resin  252  becomes so dense that the moving of the anions  500  in the electrolyte could be checked. Accordingly, the high voltage dummy leads  310  and  320  function as walls that prevents the anions around it from moving. 
   To drive a liquid crystal display, the gate control signal is inputted to a gate driving integrated circuit (not shown) via the leads  301 ,  302  and  303  of the data signal transmission film  300 , the signal wires  201 ,  202  and  203  of the thin film transistor substrate  200  and leads of a gate signal transmission film (not shown). 
   In this process, an equipotential is formed between the high voltage signal lead  301  (or, the high voltage signal wire  201 ) and the high voltage dummy leads  310  and  320 . Because same voltages are applied to both the high voltage signal lead  301  (or, the high voltage signal lead) and the high voltage dummy leads  310  and  320 . And also, because a low voltage such as the gate-off-voltage is applied to the low voltage signal lead  302  (or, the low voltage signal wire  202 ), a potential difference equivalent to a difference between the gate-on-voltage and the gate-off-voltage is formed between the low voltage signal wire  202  (or, the low voltage signal lead  302 ) and the high voltage dummy leads  310  and  320 . 
   Moisture permeates into the wires at the location where the gate and the data transmission films  300  and  400  are attached to the thin film transistor  100  and concentrate on the step difference parts of the wires. The moisture in itself has ions. Anions  500  of them move to the high voltage dummy lead  310  from the low voltage signal wire  202  using the ACF as an electrolyte by the potential difference between the high voltage dummy lead  310  and the low voltage signal lead  202 . 
   Herein, the high voltage dummy leads  310  and  320  may be melted in the electrolyte around the high voltage dummy lead  310  and  320  by an electrochemical reaction with the anions  500 . However, the high voltage dummy leads  310  and  320  are so thick enough to provide sufficient cations to the anions. Thus, the corrosion becomes minimal. 
   The anions moved to the high voltage dummy leads  310  and  320  are blocked by the high voltage dummy leads  310  and  320 , without further moving. In other words, the high voltage dummy leads  310  and  320  prevent the anions of the permeated moisture from moving to the high voltage signal wire  201  by staying between the high voltage signal wire  201  and the low voltage signal wire  202 . 
   And, the anions permeated into the circumference of the high voltage signal wire  201  lost their moving direction and are floating around the high voltage signal wire  201  due to an equipotential between the high voltage signal lead  301  (or, the high voltage signal wire  201 ) and the high voltage dummy leads  310  and  320 . 
   In the control signal part according to the first embodiment of the present invention, the high voltage dummy leads  310  and  320  are separated from the high voltage signal lead  301  on the data signal transmission film  300 . However, the high voltage signal lead  301  could be in one body with the high voltage dummy leads  310  and  320  by making its area extend to the high voltage dummy leads  310  and  320 . In such a case, the extended high voltage signal lead  301  is located spatially around the high voltage signal wire  201 . Herein, although the anions move to the high voltage signal lead  301  and react with the high voltage signal lead  301 , the high voltage signal leads  301  are so large and wide as to provide sufficient cations to the anions, causing little corrosion. 
   In the control signal part according to a second embodiment of the present invention as shown in  FIG. 6  and  FIG. 7 , which is different from the first embodiment of the present invention, the high voltage dummy wires  210  and  220  corresponding to the high voltage dummy leads  310  and  320  of the data signal transmission film  300  could be formed on the thin film transistor substrate  200 . This embodiment has an advantage of forming the wider equipotential region around the high voltage signal wire  201 . 
   Herein, the high voltage dummy wires  210  and  220 , as shown in  FIG. 6 , could be separated from the high voltage signal wire  201 , or connected to the high voltage signal wire  201 . When the high voltage dummy wires  210  and  220  are connected to the high voltage signal wire  201 , the high voltage dummy leads  210  and  220  become redundancy wires for the high voltage signal wire  201 . 
   The high voltage dummy wire on the thin film transistor substrate could be formed by using conventional conductive materials such as conductive materials for forming gate and data wires. Herein, the high voltage dummy wire could be formed by conductive materials less oxidative than the low voltage signal wire, such as one of copper family, one of silver family, one of chromium family, or one of molybdenum family comprising nitride chromium and nitride molybdenum. In such a case, the high voltage dummy wire could be less damaged due to the electrolysis. And, when the high voltage dummy wire is formed by oxidized conductive materials such as ITO or IZO, the high voltage dummy wire could be less reactive with the anions. 
   The high voltage dummy leads  310  and  320  of the data signal transmission film  300  are formed to prevent the electrolysis due to the potential difference between the high voltage signal wire  201  and the low voltage signal wire  202 . Accordingly, it is possible to form only one high voltage dummy wire between the high voltage signal wire  201  and the low voltage signal wire  202  when the low voltage signal wire  202  is located at only one side of the high voltage signal wire  201 . 
   In the above described first embodiment of the present invention, the wire transmitting the gate-on-voltage is taken as one example of the high voltage signal wire and the wire transmitting the gate-off-voltage is taken as one example of the low voltage signal wire. However, another example of the high voltage signal wire could be a wire transmitting a power supply voltage and another example of the low voltage signal wire could be a wire transmitting a grounding voltage. 
   In the control signal part according to the first and the second embodiments of the present invention, the control signal part formed on the data signal transmission film is taken as an example. However, the present invention is also applied to a case in which the control signal part is formed on the gate transmission film. 
   In the above described first and second embodiments of the present invention, only the gate control signal wire transmitting the gate control signal is described. However, the present invention is also applied to a case in which a data control signal wire transmitting the data control signal is formed on the thin film transistor substrate. And, the present invention could be applied to all cases proposed to prevent the melting of the wire due to the electrolysis caused by the potential difference between two wires. 
   The description of a liquid crystal display including the above cited control signal part is as follows. 
     FIG. 8  is a plan view of an liquid crystal display according to a third embodiment of the present invention and  FIG. 9  is a cross-sectional view of the liquid crystal display along the line IX–IX′ of  FIG. 8 . 
   In the liquid crystal display of the third embodiment of the present invention, control signal wires transmitting a gate control signal are formed by conductive materials for forming data wire and high voltage dummy wires corresponding to the high voltage dummy leads are not formed. 
   A gate wire  20 ,  21  and  22  comprising a gate line  20  including a gate electrode  22  and a gate pad  21  connected to the end of the gate line  20  is formed on an insulating substrate  10 . 
   The gate line  20  extends in a horizontal direction and transmits the gate signal outputted from a gate driving integrated circuit (not shown) to pixel region. The gate wire  20 ,  21  and  22  could be formed by conventional conductive materials such as one of copper family, one of silver family, one of chromium family, or one of molybdenum family comprising nitride chromium and nitride molybdenum and could have a single layer structure or multi-layer structure. 
   And, a gate insulating layer  30  consisting of insulating materials such as silicon nitride, silicon oxide, etc. is formed to cover the gate wire  20 ,  21  and  22 . 
   A semiconductor layer  40  consisting of amorphous silicon and corresponding to the gate electrode  22  is formed on the gate insulating layer  30 . 
   And, a data wire  60 ,  61 ,  62  and  63  is formed on the gate insulating layer  40 . The data wire comprises a data line  60  extending in a vertical direction and crossing the gate line  20  to define a pixel region, a data pad  61  connected to the end of the data line  60 , a source electrode  62  protruding from the data line  60  and being connected to the semiconductor layer  40  electrically and a drain electrode  63  corresponding to the source electrode  61  and being connected to the semiconductor layer  40  electrically. 
   And, gate control signal wires  201 ,  202  and  203  are formed on the gate insulating layer  40 . The gate control signal wires  201 ,  202  and  203  are a high voltage  20  signal wire  201  transmitting a high voltage such as a gate-on-voltage, a low voltage signal wire  202  transmitting a low voltage such as a gate-off-voltage and a common voltage signal wire  203  transmitting a common signal voltage. 
   Each of the gate control signal wire  201 ,  202  and  203  comprises a gate control signal line and gate control signal pads connected to both ends of the gate control signal line. The ends of the gate control signal wire  201 ,  202  and  203  could be connected to leads  301 ,  302  and  303  of a data signal transmission film  300  located at an upper portion of the thin film transistor substrate  200  and the other ends of them could be connected to leads  401 ,  402  and  403  of a gate signal transmission film  300  located at an left portion of the thin film transistor substrate  200 . 
   Because of the above arrangement of the wires, the gate control signals transmitted via the leads  301 ,  302  and  303  of the data signal transmission film  300  is sent to a gate driving integrated circuit (not shown) via the gate control signal wires  201 ,  202  and  203  of the thin film transistor substrate  200  and the leads  401 ,  402  and  403  of the gate signal transmission film  400 . 
   The data wires  60 ,  61 ,  62 ,  63  and the gate control signal wires  201 ,  202 ,  203  could be formed in a single layer type or a multi-layer type by conductive materials such as one of copper family, one of silver family, one of chromium family, or one of molybdenum family comprising nitride chromium and nitride molybdenum. 
   Ohmic contact layers  51 ,  52  consisting of impurity-doped amorphous silicon are formed between the semiconductor layer  40  and the source electrode  62  and the semiconductor  40  and the drain electrode  63 , respectively. 
   And, a passivation layer  70  consisting of silicon nitride or silicon oxide are formed on the resultant substrate comprising the data wire  60 ,  61 ,  62  and  63 , the gate control signal wire  201 ,  202  and  203  and the semiconductor layer  40 . 
   A contact hole  71  exposing the drain electrode  63 , a contact hole  73  exposing the data pad  61  and contact holes C 1 , C 2  and C 3  exposing the pads of the gate control signal wires  201 ,  202  and  203 , respectively are formed in the passivation layer  70 . 
   And, a pixel electrode  80  connected to the drain electrode  61  through the contact hole  71  and located in the pixel region, a gate auxiliary pad  81  connected to the gate pad  21  through the contact hole  72 , a data auxiliary pad  82  connected to the data pad  61  through the contact hole  73  are formed on the passivation layer  80 . 
   And also, auxiliary pads  83 ,  85  and  87  connected to the pads of the gate control signal wires  201 ,  202  and  203  through C 1 , C 2  and C 3  are formed on the passivation layer  70 . 
   A gate signal transmission film  400  with a gate driving integrated circuit (not shown) and a data signal transmission film  300  with a data driving integrated circuit (not shown) are attached to the above described thin film transistor substrate  200  using an anisotropic conducting film  250 . 
   Data signal lead  350  for transmitting the data signal and gate control signal leads  301 ,  302  and  303  for transmitting the gate control signals for driving the gate driving integrated circuit are formed in the data signal transmission film  300 . 
   The data signal lead  350  is connected to the data pad  82  on the insulating substrate  10  to transmit the data signal into the data pad  82  connected to the data line  20 . And, the gate control signal leads  301 ,  302  and  303  are electrically connected to the pads of the gate control signal wires  201 ,  202  and  203  located at the upper part of the insulating substrate  10  and transmit the gate control signals into the gate control signal wires  201 ,  202  and  203 . 
   In the data signal transmission film  300 , high voltage dummy leads  310  and  320  are formed to be located spatially between the high voltage signal wire  201  and the low voltage signal wire  202  or, the other signal wire  203 . 
   The leads  301 ,  302 ,  303 ,  310  and  320  of the data signal transmission film  300  is formed thick by printing and patterning a copper wire of several to several tens microns on a high molecular film for the data signal transmission film. The leads  301 ,  302 ,  303 ,  310  and  320  of the data signal transmission film  300  is far thicker than the wires  201 ,  202  and  203  of the thin film transistor substrate  200 . While the data signal transmission film  300  and the thin film transistor substrate  200  are attached to each other using the anisotropic conducting film  250  through an heat and compression process, the portion of the adhesive resin  252  where the high voltage dummy leads  310  and  320  exist is pushed by the thick leads  310  and  320 , thereby to be compressed. Herein, the adhesive resin  252  becomes so dense that the anions  500  cannot move freely in the electrolyte. Accordingly, the high voltage dummy leads  310  and  320  function as walls to prevent the anions around the it from moving. 
   And, the same voltage as the high voltage signal wire  201  is applied to the high voltage dummy lead  301  in order to form an equipotential around the high voltage signal wire  201 . 
   In the gate signal transmission film  400 , gate signal lead  450  and gate control signal leads  401 ,  402  and  403  are formed. The gate control signal leads  401 ,  402  and  403  receive the gate control signals from the gate control signal wires  201 ,  202  and  203  and send them to the gate driving integrated circuit (not shown). The gate signal lead  450  transmits the gate signal to the gate line  20 . 
   The gate control signal leads  401 ,  402  and  403  are connected to the pads of the gate control signal wires  201 ,  202  and  203  at the left portion of the substrate  10  and receive the gate control signals via the gate control signal wires  201 ,  202  and  203 . The gate control signal transmitted via the gate control signal leads  401 ,  402  and  403  of the gate signal transmission film  400  are inputted to the gate driving integrated circuit (not shown) and control the driving of the gate driving integrated circuit. 
   The gate control signal lead  450  is connected electrically to the gate pad  82  formed on the insulating substrate  10  and transmits the gate signal outputted from the gate driving integrated circuit to the gate line  20  connected to the gate pad  81 . 
   In the gate signal transmission film  400 , high voltage dummy leads  410  and  420  equal to the high voltage dummy leads  310  and  320  of the data signal transmission film  300 . 
   The constitution and operation of the control signal part where the gate signal transmission film  400  is attached to the thin film transistor substrate  200 , are the same as the data signal transmission film  300  attached to the thin film transistor substrate  200 . Therefore, they are not described in the following explanation. 
   When driving a liquid crystal display, the gate control signals are inputted to a gate driving integrated circuit (not shown) via signal leads  301 ,  302 , and  303  of the data signal transmission film  300 , the signal wires  201 ,  202  and  203  of the thin film transistor substrate  200  and signal leads  401 ,  402  and  403  of a gate signal transmission film (not shown). 
   In this process, an equipotential is formed between the high voltage signal lead  301  (or, the high voltage signal wire  201 ) and the high voltage dummy leads  310  and  320 . Because same voltages are applied to both the high voltage signal lead  301  (or, the high voltage signal wire  201 ) and the high voltage dummy leads  310  and  320 . And also, because a low voltage such as the gate-off-voltage is applied to the low voltage signal lead  302  (or, the low voltage signal wire  202 ), a potential difference equivalent to a voltage difference between the gate-on-voltage and the gate-off-voltage is formed between the low voltage signal lead  302  (or, the low voltage signal wire  202 ) and the high voltage dummy leads  310  and  320 . 
   The moisture permeates into the wires at the location where the gate and the data transmission films  300  and  400  are attached to the thin film transistor  100  and concentrates on the step difference parts of the wires. The moisture in itself has ions. Anions  500  of them move to the high voltage dummy lead  310  from the low voltage signal wire  202  using the ACF as electrolyte by the potential difference between the high voltage dummy lead  310  and the low voltage signal lead  202 . 
   Herein, the high voltage dummy leads  310  and  320  may be melted in the electrolytes around the high voltage dummy lead  310  and  320  by an electrochemical reaction with the anions. However, the high voltage dummy leads  310  and  320  are so thick as to provide sufficient cations to the anions, thereby to be little corroded. 
   The anions moved to the high voltage dummy leads  310  and  320  are blocked by the high voltage dummy leads  310  and  320 , thereby not to move further. In other words, the high voltage dummy lead  310  and  320  prevent the anions of the permeated moisture from moving to the high voltage signal wire  201  by staying between the high voltage signal wire  201  and the low voltage signal wire  202 . 
   And, the anions permeated into the circumference of the high voltage signal wire  201  lost their moving direction and exist floating around the high voltage signal wire  201  due to an equipotential between the high voltage signal lead  301  (or, the high voltage signal wire  201 ) and the high voltage dummy leads  310  and  320 . 
   Accordingly, the high voltage signal wire causes little electrochemical reaction with the anions and the damage caused by the anions when driving the liquid crystal display becomes minimal. 
   In the liquid crystal display according to the third embodiment of the present invention, wires corresponding to the high voltage dummy leads  310 ,  320 ,  410  and  420  of the gate and the data signal transmission films  300  and  400  are not formed on the thin film transistor substrate  200 . However, like a liquid crystal display shown in  FIG. 10  and  FIG. 11  according a fourth embodiment of the present invention, the present invention could be applied to a case in which high voltage dummy wires  210  and  220  corresponding to the high voltage dummy leads  310  and  320  of the gate and the data signal transmission films  300  are formed on the thin film transistor substrate  200 . 
   In the liquid crystal display according to the fourth embodiment of the present invention, the gate control signal wires  201 ,  202  and  203  are formed by conductive materials for forming the data wire  60 ,  61 ,  62  and  63  and the high voltage dummy wires  210  and  220  are formed by conductive materials for forming the pixel electrode such as ITO or IZO. 
     FIG. 10  is a plan view of the selected one gate control signal wire of the gate control signal wires and  FIG. 11  is a cross sectional view along the line XI–XI′ of  FIG. 10 . 
   When the fourth embodiment is compared with the third embodiment of the present invention, a structure of the display region is identical but a structure of the gate control signal part is different. Accordingly, the structure of the gate control signal part will be described except for the structure of the display region. 
   A gate insulating layer  30  is formed on an insulating layer  10  and gate control signal wires  201 ,  202  and  203  consisting of conductive materials for forming the data wires  20 ,  21 ,  22  and  23  are formed on the insulating substrate  10 . Each of the gate control signal wires  201 ,  202  and  203  comprises a gate control signal line and gate control signal pads connected to both the sides of the gate control signal line. 
   And, a passivation layer  70  covering the gate control signal wires  201 ,  202  and  203  is formed on the gate insulating layer  30 . 
   In the passivation layer  70 , contact holes C 1 , C 2  and C 3  exposing the pads of the gate control signal wires  201 ,  202  and  203  are formed. And, the gate control signal auxiliary pads  85 ,  83  and  87  connected to the pads of the gate control signal wires  201 ,  202  and  203  are formed through the contact holes C 1 , C 2  and C 3  on the passivation layer  70 . 
   And, on the passivation layer  70 , the high voltage redundancy wires  210  and  220  are formed at both sides of the high voltage signal wire  201  transmitting the gate-on-voltage. The high voltage redundancy wires  210  and  220  are formed by conductive materials for forming the pixel electrode such as ITO or IZO. 
   When the high voltage redundancy wires  210  and  220  are formed by ITO or IZO, as like the fourth embodiment of the present invention, the high voltage redundancy wires  210  and  220  prevent not only the high voltage signal wire  201  but also themselves from being damaged due to the electrolysis. 
   When the high voltage dummy wires  210  and  220  are formed on the thin film transistor substrate, an equipotential region could be formed more widely around the high voltage signal wire  201 . Herein, the high voltage dummy wires  210  and  220 , as shown in figure, could be separated from the high voltage signal wire  201 . On the other hand, the high voltage dummy wires  210  and  220  can be connected to the high voltage signal wire  201 . When the high voltage dummy wires  210  and  220  are connected to the high voltage signal wire  201 , the high voltage dummy leads  210  and  220  become redundancy wires for the high voltage signal wire  201 . 
   The high voltage dummy wire on the thin film transistor substrate could be formed by using conventional conductive materials such as conductive materials for forming gate and data wires. Herein, the high voltage dummy wire could be formed by conductive materials less oxidative than the low voltage signal wire, such as one of copper family, one of silver family, one of chromium family, or one of molybdenum family comprising nitride chromium and nitride molybdenum. In such a case, the high voltage dummy wire could be less damaged due to the electrolysis. And, when the high voltage dummy wire is formed by oxidized conductive materials such as ITO or IZO, the high voltage dummy wire could be less reactive with the anions. 
   And, the high voltage redundancy wires  210  and  220  could be formed by connecting two wires. The one wire of them is located at the upper portion of the substrate  10  to be connected to the data signal transmission film  300  and the other wire of them is located at the left portion of the substrate to be connected to the gate signal transmission film  400 . 
   The high voltage dummy leads  310  and  320  of the data signal transmission film  300  are formed to prevent the electrolysis due to the potential difference between the high voltage signal wire  201  and the low voltage signal wire  202 . Accordingly, it is possible to form only one high voltage dummy wire between the high voltage signal wire  201  and the low voltage signal wire  202  when the low voltage signal wire  202  is located at only one side of the high voltage signal wire  201 . 
   In the liquid crystal displays according to the third and the fourth embodiments of the present invention, the wire transmitting the gate-on-voltage is taken as one example of the high voltage signal wire and the wire transmitting the gate-off-voltage is taken as one example of the low voltage signal wire. However, another example of the high voltage signal wire could be a wire transmitting a power supply voltage and another example of the low voltage signal wire could be a wire transmitting a grounding voltage. 
   In the liquid crystal displays according to the third and the fourth embodiments of the present invention, only the gate control signal wire into which the gate control signal is inputted is described. However, the present invention is also applied to a case in which a data control signal wire into which the data control signal is inputted is formed on the thin film transistor substrate. And, the present invention could be applied to all cases proposed to prevent the melting of the wire due to the electrolysis caused by the potential difference between two wires. 
   In the liquid crystal displays according to the third and the fourth embodiments of the present invention, the gate control signal wires  201 ,  202  and  203  connected to both of the data signal transmission film  300  and the gate signal transmission film  400  is formed by conductive materials for forming the data wire. However the gate control signal wires  201 ,  202  and  203  could be formed by conductive materials for forming the gate wire. 
   In the liquid crystal display of the present invention, the overlapping structure of the leads of the signal transmission film and the wires of the thin film transistor is described as follows. 
     FIG. 12  is a plan view of the overlapping of the signal lead and the signal wire and  FIG. 13  is a cross sectional view along the line XIII–XIII′ of  FIG. 12 . 
   In the thin film transistor substrate, a first insulating layer such as a gate insulating layer  30  is a formed on an insulating layer  10  and signal lines  201 ,  210 ,  220 , a high voltage signal wire  201  and high voltage dummy wires  210  and  220 , are formed on the gate insulating layer  30 . And, a second insulating layer such as a passivation layer  70  is formed on the signal wires  201 ,  210  and  220  and contact holes C 1 , C 2  and C 3  exposing portions of the signal wires  201 ,  210  and  220  are formed in the passivation layer  70 . And, the auxiliary pads  85 ,  86  and  87  connected to the pads of the signal wires  201 ,  210  and  220  are formed through the contact holes C 1 , C 2  and C 3  on the passivation layer  70 . 
   When a signal transmission film  300  is attached to the above described thin film transistor substrate, the high voltage signal lead  301  is connected to the high voltage signal wire  201 . 
   The layers covering the contact hole have step difference located at the contact hole. The auxiliary pad can not fully overlap the step difference. Therefore, the moisture permeated into the wire concentrates on the step difference and further damage the signal wire portion located at the contact hole. Accordingly, it is preferable that the high voltage signal lead  301  is formed to fully overlap the contact hole C 1 , especially, to fully overlap the contact hole C 1  in a length direction of the contact hole C 1 . 
   However, the high voltage signal lead  301  may not fully overlap the contact hole C 1  in a width direction of the contact hole. Although the high voltage signal wire  201  is not fully overlapped with the high voltage signal lead  301  and its side portions are exposed, the anions do not reach the high voltage signal wire  201  and react electrochemically with the high voltage signal wire  201  because an equipotential is formed in the circumference of the high voltage signal wire  201 . 
   This overlapping structure of the leads and wires is not limited to only the overlapping of the high voltage signal lead and the high voltage signal wire but could be applied to the overlapping of all leads and all signal wires.  FIG. 12  and FIG.,  13  show that the high voltage dummy leads  310  and  320  overlap fully the contact holes C 1  and C 2  in a length direction of the contact hole and overlap partially the contact holes C 1  and C 2  in a width direction of the contact hole. 
     FIG. 14  is another plan view of the overlapping of the signal lead and the signal wire and  FIG. 15  is a cross sectional view along the line XV–XV′ of  FIG. 14 . 
   In the thin film transistor substrate, a first insulating layer such as a gate insulating layer  30  is a formed on an insulating layer  10  and a high voltage signal wire  201  is formed on the gate insulating layer  30 . And, a second insulating layer such as a passivation layer  70  is formed on the high voltage signal wire  201  and contact holes C 1  exposing the high voltage signal wire  201  is formed in the passivation layer  70 . And, the auxiliary pad  85  connected to the pad of the high voltage signal wire  201  through the contact holes C 1  is formed on the passivation layer  70 . And also, the high voltage dummy wires  210  and  220  are formed at both sides of the auxiliary pad  85 . 
   When the signal transmission film  300  is attached to the above cited thin film transistor substrate  200 , the lead could cover fully the contact hole exposing the signal wire in a length direction of the contact hole but cover partially the contact hole in a width direction of the contact hole. 
   In the drawing, the high voltage signal lead  301  is located inside region of the contact hole C 1  exposing the high voltage signal lead  301  thereby to expose both sides of the high voltage signal wires  301 . 
   The high voltage dummy wires  210  and  220  are formed by conductive materials for forming the pixel electrode, exposed fully and covered with the high voltage dummy leads  310  and  320  in a width direction. 
   In the liquid crystal display of the present invention, the high voltage dummy leads  310  and  320  are separated from the high voltage signal lead  301  on the data signal transmission film  300 . However, the high voltage signal lead  301  could be in one body with the high voltage dummy leads  310  and  320  by making its area extend to the high voltage dummy leads  310  and  320 . In such a case, the extended high voltage signal lead  301  is located spatially around the high voltage signal wire  201 . Herein, although the anions move to the high voltage signal lead  301  and react with the high voltage signal lead  301 , the high voltage signal leads  301  are so large and wide as to provide sufficient cations to the anions thereby to be little corroded. 
   In the present invention, the gate control signal wires  201 ,  202  and  203  could be formed by connecting two or more wires. In such a case, one wire of them could be formed by conductive materials for forming the data wire and the other wire of them could be formed by conductive materials for forming the gate wire. These wire structure could be applied to the high voltage redundancy wire. This will be explained with reference to the following drawings,  FIG. 16  and  FIG. 17 . 
     FIG. 16  is a plan view of the selected one gate control signal wire of the gate control signal wires and  FIG. 17  is a cross sectional view along the line XVII–XVII′ of  FIG. 16 . 
   A first signal wire  208  consisting of conductive materials for forming the gate wire is formed on the insulating substrate  10  in a first direction. The pad formed at the one end of the first signal wire  208  is located at the upper portion of the substrate to be connected to the data signal transmission film  300 . 
   A gate insulating layer  30  consisting of silicon nitride or silicon oxide is formed on the insulating substrate  10  to cover the first signal wire  208 . 
   In the gate insulating layer  30 , a contact hole  32  exposing the other end of the first signal wire  208 , where the pad is not located, is formed. 
   And, a second signal wire  209  consisting of conductive materials for forming the data wire is formed on the gate insulating layer  30  in a second direction. The pad formed at the one end of the second signal wire  209  is located at the left portion of the substrate to be connected to the gate signal transmission film  400 . The second signal wire  209  is connected to the first signal wire  208  through the contact hole  32  to transmit the gate control signal from the data signal transmission film  300  to the gate transmission film  400 . 
   A passivation layer  70  consisting of silicon nitride or silicon oxide is formed on the  20  gate insulating layer  30 . The passivation layer  70  covers the second signal wire  209 . 
   A contact hole C 9  exposing the pad of the second signal wire  209  is formed in the passivation layer  70  and another contact hole C 8  exposing the pad of the first signal wire  208  is formed in the passivation layer  70  and the gate insulating layer  30 . 
   A first signal auxiliary pad  88  connected to the pad of the first signal wire  208  through the contact hole C 8  and a second signal auxiliary pad  89  connected to the pad of the second signal wire  209  through the contact hole  209  are formed on the passivation layer  70 . 
   When the data signal transmission film  300  is attached to the above described control signal part of the thin film transistor substrate, the leads  308  of the data signal transmission film  300  is arranged and attached to the corresponding first signal auxiliary pad  88 . The data transmission film  300  is attached to the control signal part of the thin film transistor substrate through a heat and compression process using an anisotropic conducting film  250 . Herein, the leads  308  of the data signal transmission film  300  is electrically connected to the first signal auxiliary pad  88  by the conductive materials  251  of the anisotropic conducting film  250 . And in same manner, the leads  409  of the gate signal transmission film  400  is arranged and attached to the corresponding second signal auxiliary pad  89 . The gate transmission film  400  is attached to the control signal part of the thin film transistor substrate through heat and compression process using an anisotropic conducting film  250 . Herein, the leads  409  of the gate signal transmission film  400  is electrically connected to the second signal auxiliary pad  89  by the conductive materials  251  of the anisotropic conducting film  250 . 
   In the third embodiment of the present invention, the wire structure of the connection part in which each of the leads  301 ,  302 ,  303 ,  310 ,  320 ,  401 ,  402 ,  403 ,  410  and  420  of data and the gate transmission films  300  and  400  are connected to each of the wires  201 ,  202 ,  203 ,  210  and  220  of the thin film transistor substrate  200  has a sluggish slop in the step difference of the wire in order to minimize the amount of the permeated moisture. This will be explained with reference to the following drawings,  FIG. 18  and  FIG. 19 . 
     FIG. 18  is a plan view of the wire structure of the connection part of the control signal wire and the lead.  FIG. 19  is a cross sectional view along the line XIX–XIX′ of  FIG. 18 . The lead is connected to each layer of the gate signal wire having double layers through two connection parts. 
   A first signal wire  29  consisting of conductive materials for forming the gate wire and having a pad at the end of itself is formed on an insulating substrate  10 . And, a gate insulating layer  30  consisting of silicon nitride and covering the first signal wire  29  is formed on the insulating substrate  10  to cover the first signal wire  29 . 
   A second signal wire  69  consisting of conductive materials for forming the data wire and having a pad at the end of itself is formed on the gate insulating substrate  30 . 
   The second signal wire  69  is smaller than the first signal wire  29  thereby not to reach the pad of the first signal wire  29  and follows the pattern of the first signal wire  29  to overlap the first signal wire  29 . And, a passivation layer  70  consisting of silicon nitride or silicon oxide is formed on the gate insulating layer  30  to cover the second signal wire  69 . 
   A contact hole C 6  exposing the pad of the second signal wire  69  is formed in the passivation layer  70  and another contact hole C 7  exposing the pad of the first signal wire  29  is formed in the passivation layer  70  and the gate insulating layer  30 . 
   A control signal auxiliary pad  89  connected to the pads of the first and the second signal wires  29  and  69  through the contact holes C 6  and C 7  is formed on the passivation layer  70 . 
   When the data signal transmission film  300  is attached to the above described control signal part, the lead  309  of the data signal transmission film  300  is arranged and attached to the corresponding control signal auxiliary pad  89 . The attachment of the data signal transmission film  300  and the control signal part is carried out through an heat and compression process using an anisotropic conducting film  250 . Herein, the lead  309  of the data signal transmission film  300  is electrically connected to the control signal auxiliary pad  89  of the control signal part by the conductive materials  251  in the anisotropic conducting film  250 . This wire structure of the connection part could decrease the amount of the bad wire connection due to the step difference of the wire and the opening of the wire and minimize the amount of the permeated moisture. 
   As described, in the present invention, the thick dummy lead prevents movements of the anions of moisture permeated during manufacturing or operating the liquid crystal display by forming the thick dummy lead on the control signal transmission film to be located spatially between the high voltage signal wire and the low voltage signal wire on the thin film transistor substrate. And, when the same voltage as the high voltage signal wire is applied to this thick dummy lead to form an equipotential around the high voltage signal wire, the dummy lead prevents the anions from moving to the high voltage signal wire by making the anions floating in the circumference of the high voltage signal wire. Herein, when the lead of the signal transmission film is formed to fully overlap the wire of the thin film transistor substrate, it prevents the moisture from permeating into the wire. 
   While the present invention has been described in detail with reference to the preferred embodiments, those skilled in the area will appreciate that various modifications and substitutions can be made thereto without departing from the sprit and scope of the present invention as set forth in the appended claims.