TW200539419A - Thin film transistor electrostatic protective circuit - Google Patents

Abstract

A thin film transistor (TFT) electrostatic protective circuit is installed between a scanning signal line or a data signal line and a common electrode (Vcom). Such an electrostatic protective circuit includes a positive electrostatic protective set and a negative electrostatic protective set. Furthermore, the positive and negative electrostatic protective sets are individually consisted of three TFFs. The most significant feature of the invention is that the positive and negative electrostatic protective sets can still operate normally and maintain their original ESD protection functions when the gate insulation layer of any one TFT is penetrated by an electrostatic voltage. As a result, the invented protective device has an increased ESD withstanding power.

Description

200539419 V. Description of Invention (1)

V. Description of the invention The matrix substrate of the voltage is provided for driving. As shown in the first static electricity prevention Diode (2), it is connected to the source thin film transistor (Vcom) of the scanning source electrode St 2 The foregoing is the overscanning signal that emits a positive electrostatic voltage TF D. Similarly, static electricity is above The T (2) of the damage of the protective circuit TFT junction is due to the manufacturing process of the liquid crystal display device. When combining the active (the substrate with the switching element on it), especially the IC s of the LCD arranged on the active matrix substrate During the manufacturing process, what is not shown in Figure 3 is the conventional TFT electrostatic protection circuit 1 1 5 The protective circuit 1 1 is connected in reverse by two thin film transistors t 1 and t 2 in a diode) manner, and its symbol form is as shown in the figure. In the figure, the gate electrode G of the thin film transistor t 1 and the drain electrode D are short-circuited and the signal line 3 and the data signal line 5 ′ are connected, and the thin film transistor t 1 is connected to a common electrode (Vcom) 6, and the thin film transistor The crystal electrode S is connected to the scanning signal line 3 and the data signal line 5, and the gate electrode G of the body t 2 is short-circuited to the drain electrode D and connected to the common electrode 6. The thin film transistor t of the electrostatic protection circuit 1 1 1 is an electrostatic voltage element, and the thin film transistor t 2 is a discharge negative element. When the positive electrostatic voltage is generated, the electrostatic voltage level is higher than the critical voltage. At this time, the transistor t 1 is turned on, and the positive electrostatic voltage is transmitted through the line 3 and the data signal line 5 through the thin film transistor t 1. When negative static electricity is generated, then The discharge of the conducting thin film transistor t 2 is negative to achieve the electrostatic protection effect. In the structure of the TFT electrostatic protection circuit 11 described above, while the TFT static element protects the internal array TFT s 2, its structure is also at risk of being destroyed by electrostatic voltage. The electrostatic voltage FT element is nothing more than its gate insulation layer being electrostatically charged. Voltage breakdown

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Page 6 200539419 V. Description of the invention (3) A very large leakage current is generated. For example, when the gate insulating layer of the thin film transistor t 1 is broken down by an electrostatic voltage, the gate node of the thin film transistor t 1 will be connected to the source. This result is equivalent to the scanning signal line 3, data signal line 5 and common electrode (Vcom) 6 causing a short circuit, which causes a defect in the structure of the display panel. This defect condition is tested during the display unit segment (Ce 1 1 test), the driver of the product module segment (Μ〇du 1 e Diving) cannot display the daytime surface normally. This problem affects the product yield. The present inventors have studied the existence of this problem in detail. At the same time, the present invention will address this point. Prevent improved design. [Summary of the Invention]

The main purpose of the present invention is to improve the occurrence of the above problems and enhance the effectiveness of the TFT electrostatic protection circuit. The circuit design method of the thin film electrostatic protection circuit of the present invention is mainly to divide the electrostatic protection circuit area into a positive electrostatic protection group and The negative electrostatic protection group is set independently, and the design that separates the positive and negative electrostatic voltages is separated, which is a better design, because it can avoid the simultaneous discharge of positive and negative electrostatic voltages. Its gate insulation layer is broken by electrostatic voltage, which affects the display panel. The daytime display is abnormal. The positive and negative electrostatic protection groups of the present invention are respectively composed of three thin film transistors. This design method makes the TFT electrostatic protection circuit have one more anti-track line. The positive and negative electrostatic protection groups of the TFT electrostatic protection circuit of the present invention can be in any one of them. After a thin film transistor is penetrated by static electricity, the display panel still displays normal and electrostatic protection functions, and the effect of improving the resistance to electrostatic protection can be achieved. The configuration method of the thin film transistor electrostatic protection circuit of the present invention is disposed between the scanning signal line, the data signal line and the common electrode (V c 0m), which includes: 200539419 V. Description of the invention (4) Thin film transistor, wherein The trace signal line source and the first electrode and the third positive electrostatic protection group, the body and a third thin film of the first and second thin film electrical wire transistor body, the data of the three thin film electrical thin film transistor and The common electrode is connected to the thin film transistor, and the drain electrode material signal line of the gate electrode of the common electrode body is different in the embodiment of the present invention, and it is explained, and [the implementation party please refer to the structure, this limitation. The actual negative electrostatic protection group has a body connected to a sixth thin film thin film, a fifth thin four thin film thin film, and a fourth thin film and a fifth thin film. However, it is selected for the Chinese formula in the drawings.] Please refer to Figure 1 for illustration and some other implementations with the drawings. The figure is composed of a first thin-film transistor and a second transistor. The gate of the crystal formed by the thin film transistor is short-circuited with the drain, and is connected to the sweep. The gate of the first thin film transistor is connected, the source of the second thin film transistor is connected, and the third thin film transistor is connected. The source of the crystal is composed of a fourth thin-film transistor and a fifth thin-film transistor, which are composed of two thin-film transistors. The gate and the short-circuit of the crystal are connected to the source of the common-film transistor and the sixth thin-film transistor. The source of the transistor and the source of the sixth thin-film transistor crystal are related to the scanning signal line, purpose, and advantages. It is not difficult to obtain an in-depth understanding from the selected applications below. Examples are allowed in other parts, or in the arrangement of other parts, which are detailed in this manual. The shown is a selected embodiment of the present invention. A thin film transistor electrostatic protection circuit that is not subject to this structure in the patent application is provided in

Page 8 200539419 V. Description of the invention (5) Scanning signal line 3, data signal line 5 and-common f pole (The scanning signal line and data signal line are respectively connected to a driver: trace contact 8 and data line Contact 9, "FT static electricity protection: package,-the second thin film transistor T ... %% ;: film-bound transistor D1 thin film transistor, where the first :: meaning; body D3 a total of three ^ First, the first crystal transistor T 1 — 200539419 V. Description of the invention Because of electrostatic electricity, two thin bodies τ 1 are source voltage thin film transistors, but critical electricity two, three thin electrostatic voltages, positive static electricity 4, T 5 The voltage of the positive static film transistor is 1. The voltage at which the conventional (6) voltage is higher than that of the TF film transistor is almost equal to the moment when the transistor T is turned on. The body T 3 has a gate voltage. Therefore, the second film transistor T is discharged by the second, voltage, Ding 6 is the electrical protection group 1 τ 1 and Ding 2 when the thin film T of the circuit is critical. The closed state 3 excludes the positive and T 3 which are not the same as in the previous study.

Voltage, this electrostatic voltage is enough to turn on and make it conductive. The first thin-film transistor is the drain voltage of transistor T 1 and the source voltage of transistor 1 and the third bit, and the voltage level is higher than that of TF crystal. T 3 is turned on. At this time, the first, T, and D 3 are all on, and the orthorhombic T 2 and T 3 are discharged. In this six: When the thin film transistor T is static, if the gate insulation layer of any of f_, two, and three is protected by static FT electrostatic protection circuit 1 200539419 5. The description of the invention will not affect the driving of the segment. 5. Two electric crystals and three thin-film electric protection groups 1 are operated by electrostatic electricity, which meets the above restrictions of the upper level of anti-capacity. This invention belongs to the present invention, so that the application can be achieved. (7) Module driving of the display unit (Module Driving), when the negative electrostatic voltage generates six thin-film transistors D4, the body conduction state will break the negative electrostatic crystals T1, T2, T4 and the positive electrostatic protection group 1 One of them has nothing to do with the display panel. The electrostatic protection circuit of the present invention takes advantage of this feature. The embodiment is disclosed, and therefore, the scope of any change in the numerical value is mentioned. The above detailed description can make the aforementioned purpose well known, (Cell test) or the product module can display the day and time normally. At this time, the T5 and T6 of the negative electrostatic protection group 14 are turned on and are excluded by this voltage. At this time, the first, second, and 3 are all off. The negative static electricity 3 has the same function. The three transistors and the remaining two thin-film transistors can still trap structures and protect static electricity. The design of the protective circuit is equivalent to an increase in the durability against static electricity to illustrate the present invention. It is not intended to replace or replace equivalent components. It should still be known to the artist who understands the provisions of the patent law of the present invention and proposes a patent. »

Page 11 200539419

The diagram briefly explains the 1st, 2nd, 3rd, and 4th [illustrated (Xi Ting Ding main film transistor pixel capacitor storage capacitor scanning signal data signal TF Ding Jing driving chip Three thin films, fifth thin film scanning signals, common electrode driver chip, drain electrode, D drawing system, T drawing system, drawing system description] Partial moving matrix electrostatic device 1 device 1 b line 3 line 5 electrical protection data line invention part Electrostatic protection circuit Transistor transistor Transistor wire 3 6 Data line Invented electrostatic FT switch Element Static electricity protection Electricity protection circuit schematic diagram Active matrix liquid crystal display device protection circuit Not intended to protect the circuit corresponding to the circuit pattern liquid crystal Display device 1 0 Protective circuit 1 1 Circuit 7 contacts 9 points) Protective circuit 1 group 1 3 T 1 T 3 D 5 contacts

Liquid crystal capacitor Is 1 a. Thin film transistor 2 Equipotential contact 4 Common electrode 6 Driver chip knows trace contact 8% 2 4

Negative electrostatic protection circuit group Second thin film transistor T 2 Fourth thin film transistor T 4 Sixth thin film transistor D 6 Data signal line 5 Drive chip scanning line contact 8 Gate G Source S

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Claims (1)

200539419 200539419 VI. Scope of patent application 4 · According to the thin film transistor electrostatic protection circuit described in item 1 of the scope of patent application, the thin film transistor electrostatic protection circuit connected to the scanning signal line and the data signal line connected The common current of the thin film transistor electrostatic protection circuit is equipotential. Page 14