JP4009468B2 - Liquid crystal display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a tape carrier package (hereinafter abbreviated as TCP).
[0002]
[Prior art]
Conventionally, a liquid crystal display device is a tape-like insulating film with leads formed on it. A semiconductor chip is mounted on the base film as a TCP connected to the leads. It is well known to have a structure in which an IC is mounted by gag bonding.
[0003]
Such a conventional liquid crystal display device is disclosed, for example, in JP-A-9-127542 (Cited Document 1). FIG. 3 is a plan view of a first conventional liquid crystal display device described in the cited document 1, and FIG. 4 is a cross-sectional view of the first conventional liquid crystal display device described in the cited document 1.
[0004]
3 and 4, in the first conventional liquid crystal display device, a slit 55 is provided on the base film 51, and an electric signal of the driving IC 58 is measured at an exposed portion of the input side electrode portion 7b. It is a configuration.
[0005]
2A is a sectional view of a second conventional liquid crystal display device, and FIG. 2B is a plan view of the second conventional liquid crystal display device.
[0006]
Referring to FIGS. 2A and 2B, the second conventional liquid crystal display device is electrically connected to a liquid crystal cell 9 by using a driver IC 4 for driving with a pressure contact technique. The driver IC 4 for driving the liquid crystal is often in the form of a tape carrier package (hereinafter referred to as TCP).
[0007]
In the conventional TCP, an IC terminal 2 is formed on a tape carrier 1 and then a protective resist 3 is applied to the IC terminal 2 surface side. The IC 4 was mounted and fixed with the sealing resin 5. The completed TCP 1 is electrically connected to the liquid crystal cell terminal 6 of the liquid crystal cell 9 and the connection substrate terminal 8 of the connection substrate 7 using a pressure contact technique.
[0008]
The TCP structure is such that an IC input / output lead is formed on a tape carrier 1 and an IC chip 4 is mounted and resin-sealed. The connection to the liquid crystal cell 9 and the circuit board 7 for electric signal input (hereinafter referred to as a connection board) to the TCP is to press-contact the IC terminal surface of the tape carrier 1 using a press-contact technique.
[0009]
By applying this technique, TCP characteristics such as analysis of TCP defects occurring after TCP mounting are measured. At this time, the front side of the tape carrier 1 is visible on the surface, and the IC terminal 2 is on the mounting surface side. Although direct input and output electrical signals of TCP cannot be measured, measurement is performed indirectly using the liquid crystal cell terminal 6 exposed on the liquid crystal cell 9 side or the connection substrate terminal 8 exposed on the connection substrate 7 side. Do.
[0010]
[Problems to be solved by the invention]
However, this conventional liquid crystal display device has the following problems. That is, in the first conventional liquid crystal display device, when the slit 5 is provided in the base film 1, the mechanical strength of the slit 5 portion decreases, and the input side electrode portion 7 b is disconnected when the TCP is mounted on the printed circuit board 11. There is a possibility. Further, since the slits 5 are exposed on the surface, there is a possibility that the input side electrode 7B is corroded due to a decrease in moisture resistance, or short-circuit defects frequently occur due to conductive dust adhering to the input side electrode 7B.
[0011]
As a result, with this conventional technology, when measuring TCP characteristics such as failure analysis of defects found after TCP mounting, the tape carrier surface becomes the surface, so it is possible to directly check the signal from TCP. There was no current situation.
[0012]
Further, according to the second conventional liquid crystal display device technique, the front side of the tape carrier 1 can be seen on the surface when trying to measure TCP characteristics such as analysis of TCP defects occurring after TCP mounting, and the IC terminal 2 is mounted on the mounting surface. Therefore, it is not possible to directly measure TCP input and output electrical signals.
[0013]
For this reason, the liquid crystal cell terminal 6 exposed on the liquid crystal cell 9 side or the connection substrate terminal 8 exposed on the connection substrate 7 side is used for indirect measurement. There is a risk of causing measurement errors and measurement errors due to poor contact with each other, or destroying both terminals. In addition, as the liquid crystal cell is being narrowed, the exposed area of the liquid crystal cell terminal 6 on the liquid crystal cell 9 side is reduced, and the TCP output signal may not be measured.
[0014]
Accordingly, a main object of the present invention is to provide a liquid crystal display device that solves the above problems.
[0015]
[Means for Solving the Problems]
The liquid crystal display device of the present invention is a liquid crystal display device comprising a liquid crystal driving driver IC connected to a tape carrier by pressure welding technology, and an electric signal input / output unit on the surface of the tape carrier and the tape carrier. In a liquid crystal display device in which a through hole electrically connected to an IC terminal of the driver IC for driving the liquid crystal is provided on the back surface and measuring input / output of an electric signal from the surface of the tape carrier , the metal is disposed on the through hole. In order to prevent short-circuit between each other and corrosion of the metal itself, a transparent insulating film is provided, and the insulating film is electrically connected to the through hole when the electrical signal of the tape carrier is confirmed. It is composed of a film that is easy to do.
[0016]
In the liquid crystal display device of the present invention, a through portion of the through hole from the back surface of the tape carrier toward the surface of the tape carrier is formed by a plating means that fills with metal.
[0017]
Further, the surface probe of the through hole of the liquid crystal display device of the present invention is in contact with the measurement probe to measure the input / output of an electric signal, and the liquid crystal display device of the present invention is configured as described above. The surface exposed portion of the through hole is configured to have an area that can be contacted by the measurement probe, and the surface exposed portion of the through hole of the liquid crystal display device of the present invention can be contacted by the measurement probe. It is the structure which secured the thickness of.
[0018]
In the liquid crystal display device of the present invention, the insulating film is made of silicon resin, and the positions of the through holes are staggered. Further, the positions of the through holes are arranged obliquely.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
A liquid crystal display device according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0020]
In the liquid crystal display device of the present invention, a through hole is provided in a TCP tape carrier, and an IC terminal formed on the tape carrier is electrically connected to the through hole. The electric signal of the IC terminal portion can be read through the terminal.
[0021]
FIG. 1A is a sectional view of a liquid crystal display device according to an embodiment of the present invention. FIG. 1B is a plan view of the liquid crystal display device according to the embodiment of the present invention.
[0022]
Referring to FIGS. 1A and 1B, in the liquid crystal display device according to the embodiment of the present invention, a hole of a through hole 20 corresponding to the position of the IC terminal 12 is previously formed in the tape carrier 11. . After the IC terminal 12 is formed on the tape carrier 11, a protective resist 13 is applied to the IC terminal 12 surface side.
[0023]
Further, the IC 14 is mounted and fixed with the sealing resin 15. The through hole 20 is filled with a metal 21 using a plating technique or the like to form the through hole 20 on the surface of the tape carrier 11.
[0024]
At this time, the metal 21 filled in the through hole 20 is electrically connected to the IC terminal 12. The portion of the through hole 20 is used for measuring an electrical signal of an IC input / output during characteristic measurement such as TCP failure analysis after mounting. The surface probe of the through hole 20 can be contacted with a measurement probe. Ensure the area and thickness of the minute.
[0025]
On the through hole 20, a transparent insulating film 22 is applied in order to prevent problems such as short-circuit between the metals 21 and corrosion of the metal 21 itself. The insulating film 22 is preferably made as thin and soft as possible (silicon resin or the like) so as to be easily broken because it is electrically connected to the through hole 20 when the TCP electrical signal is confirmed. It is assumed that the TCP having the above structure is electrically connected to the liquid crystal cell terminal 16 and the connection substrate terminal 18 using a pressure contact technique.
[0026]
Next, a method for measuring the input / output electrical signals of the TCP of the liquid crystal display device according to the embodiment of the present invention will be described.
[0027]
When measuring the electrical signal of the input / output of TCP that has been mounted on the liquid crystal cell 19 of the liquid crystal display device according to the embodiment of the present invention, the electrical signal is transmitted through the through hole 20 that is visible through the insulating film 22. Measure. At the time of measurement, the thin and soft insulating film 22 is broken with the probe of the measuring instrument, and is directly brought into contact with the through hole 20 to measure an electric signal.
[0028]
Next, in the liquid crystal display device according to the embodiment of FIGS. 1A and 1B of the present invention, the dimension between through holes is not limited, but high-density mounting technology is advancing. The dimensions are also a problem.
[0029]
Therefore, in the liquid crystal display device according to another embodiment of the present invention, when the width of the IC terminal 12 of the TCP becomes a high-density terminal, the position of the through hole is “staggered arrangement” or “diagonal arrangement”. In this way, the position is shifted.
[0030]
Thus, by dispersing the positions of the through holes 20, it is possible to maintain the mechanical strength of the tape carrier 11, and by protecting the metal 21 exposed from the through holes 20 with the insulating film 22, the liquid crystal It is possible to maintain the moisture resistance of the display device itself and to prevent occurrence of short circuit due to adhesion of conductive foreign matter.
[0031]
【The invention's effect】
As described above, in the conventional TCP having no through hole, when the input / output measurement of the TCP electrical signal is performed after the TCP is mounted on the liquid crystal cell 9, the IC terminal 2 is directly on the mounting surface side. In other words, the TCP probe input / output signal was indirectly measured by bringing the measurement probe into contact with the liquid crystal cell terminal 6 or the connection substrate terminal 8. In this method, a measurement error and a measurement error due to a contact failure of the measurement probe during measurement are generated, or a portion of the liquid crystal cell terminal 6 is broken.
[0032]
Furthermore, the dimension of the exposed portion of the liquid crystal cell terminal 16 is becoming narrower due to the trend toward narrowing the frame of the liquid crystal display device, and the tip dimension of the contact terminal of the measurement probe is used for measurement using the liquid crystal cell terminal 6. It was necessary to select a small one, but it has its limits. Further, in the measurement of the TCP electric signal using the liquid crystal cell terminal 6 and the connection substrate terminal 8, there are problems such as short circuit and open between the liquid crystal cell terminal 6 and the IC terminal 2 and between the connection substrate terminal 8 and the IC terminal 2. Has a problem of large measurement error due to indirect measurement.
[0033]
In the present invention, the through hole 20 is provided in the tape carrier 11, the IC terminal 12 and the metal 21 filled in the through hole are brought into conduction, and exposed to the surface of the tape carrier 11. It became possible to measure the signal directly.
[0034]
Further, the measurement error, measurement error, and destruction of the liquid crystal cell terminal 16 caused by the contact failure of the measurement probe, which are caused by an indirect measurement method, are eliminated, and even if the liquid crystal cell terminal 16 is not exposed, the output signal of the TCP There is an effect that can be measured.
[0035]
Further, by dispersing the positions of the through holes 20, it is possible to maintain the mechanical strength of the tape carrier 11, and by protecting the metal 21 exposed from the through holes 20 with the insulating film 22, the liquid crystal display device itself. This also has the effect of maintaining the moisture resistance and preventing the occurrence of short-circuit defects due to the adhesion of conductive foreign matter.
[Brief description of the drawings]
1A and 1B are a plan view and a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention.
FIG. 2 is a plan view and a sectional view of a second conventional liquid crystal display device.
FIG. 3 is a plan view of a first conventional liquid crystal display device.
FIG. 4 is a cross-sectional view of a first conventional liquid crystal display device.
[Explanation of symbols]
1 Tape carrier 2 IC terminal 3 Resist 4 IC
5 Sealing resin 6 Liquid crystal cell terminal 7 Connection substrate 8 Connection substrate terminal 9 Liquid crystal cell 11 Tape carrier 12 IC terminal 13 Resist 14 IC
15 Sealing resin 16 Liquid crystal cell terminal 17 Connection substrate 18 Connection substrate terminal 19 Liquid crystal cell 20 Through hole 21 Metal 22 Insulating film

Claims (8)

A liquid crystal display device comprising a liquid crystal driving driver IC connected to a tape carrier by pressure welding technology,
An electrical signal input / output unit is provided on the surface of the tape carrier, and a through hole is provided on the back surface of the tape carrier to be electrically connected to the IC terminal of the driver IC for driving the liquid crystal. In a liquid crystal display device that measures output ,
On the through hole, in order to prevent short-circuit between the metals and corrosion of the metal itself, comprising a transparent insulating film,
2. The liquid crystal display device according to claim 1, wherein the insulating film is made of a film that is easily broken because it is electrically connected to the through hole when an electrical signal of the tape carrier is confirmed .   The liquid crystal display device according to claim 1, wherein a penetrating portion of the through hole from the back surface of the tape carrier toward the surface of the tape carrier is formed by plating means filled with metal.   The liquid crystal display device according to claim 2, wherein an input / output of an electric signal is measured by bringing the measurement probe into contact with a surface exposed portion of the through hole.   The liquid crystal display device according to claim 3, wherein the surface exposed portion of the through hole has an area that can be contacted with the measurement probe.   5. The liquid crystal display device according to claim 3, wherein the surface exposed portion of the through hole has a thickness sufficient to allow contact with the measurement probe. The liquid crystal display device according to claim 1 , wherein the insulating film is a silicon resin. The liquid crystal display device according to claim 1 , wherein the through holes are arranged in a staggered arrangement. The liquid crystal display device according to claim 1 , wherein the positions of the through holes are arranged obliquely.

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