TW202026712A - Thin film transistor driving circuit and liquid crystal display device - Google Patents

Abstract

A thin film transistor driving circuit comprises a thin film transistor layer (TFT layer)、an optical filter, a sealant, a welding pad, and a signal pad. The TFT layer includes a bonding lead and a first edge, one end of the bonding lead extends to the first edge. The optical filter is disposed over the TFT layer and spaced from the TFT layer. And edge of the optical filter overhangs above first edge. The sealant is disposed between the TFT layer and the optical filter and is flush with the first edge. The welding pad is disposed onto the outer surface of the sealant, and electrically connected to the bonding lead of the TFT layer. The signal lead is disposed in parallel to a normal direction of the TFT layer, and the signal lead has a first side surface combined with the welding pad. The present disclosure further discloses a liquid crystal display device equipped with the thin film transistor driving circuit.

Description

Thin film transistor drive circuit and liquid crystal display device

The present invention relates to a driving circuit of a liquid crystal display device, in particular to a thin film transistor driving circuit and a liquid crystal display device using the thin film transistor driving circuit.

In the liquid crystal display device, at least one side is used as a signal connection side. At the position corresponding to the signal connection side, multiple bonding pins are arranged on the thin film transistor drive circuit. The COF (Chip on Film) used for feeding is soldered to the bonding pins with signal pins to complete the connection between the thin film transistor drive circuit and the external signal source.

In the area where the aforementioned COF is combined with the thin film transistor drive circuit, the signal feeding circuit needs to be shielded by a decoration and a black matrix resist (BM resist), and a frame area with a large width is formed on the front of the display. In addition, the COF is combined by the front side of the thin film transistor drive circuit, and then bent to the side of the thin film transistor drive circuit, the COF part located on the side of the thin film transistor drive circuit will actually take on an arc-shaped convex shape. At this time, if a laser is used to cut the polarizer, it is easy to accidentally damage the COF by the laser beam. Therefore, the size of the polarizer must be larger than the thin film transistor drive circuit layer in order to prevent the laser beam from damaging the COF, but this also prevents the width of the decoration and the black matrix shading layer from being further reduced.

Due to the signal feed design of the thin film transistor drive circuit, the signal connection side of the liquid crystal display device must be decorated with a black matrix light-shielding layer. Therefore, the front frame area of the display cannot be further reduced, and the cost of arranging decorative parts and black matrix light-shielding layer cannot be reduced.

In view of the above-mentioned problems, the present invention provides a thin film transistor drive circuit and a liquid crystal display device using the thin film transistor drive circuit, which can omit the configuration of decorative parts and can effectively size the front frame area of the display.

The present invention provides a thin film transistor drive circuit, which includes a thin film transistor layer, a filter, a sealing element, a soldering pad and a signal pin. The thin film transistor layer has at least one bonding pin and a first edge, and one end of the bonding pin extends to the first edge of the thin film transistor layer. The filter is arranged on the thin film transistor layer and keeps a distance from the thin film transistor layer, and the edge of the filter protrudes from the first edge of the thin film transistor layer. The sealing member is combined between the thin film transistor layer and the filter, and is flush with the first edge. The soldering pad is located on the outside of the sealing member and is electrically connected to the bonding pin of the thin film transistor layer. The signal pin is arranged parallel to a normal direction of the thin film transistor layer, and the signal pin has a first side surface, which is connected to the bonding pad and extends in a direction away from the filter.

In at least one embodiment of the present invention, the width of the edge of the filter protruding from the first edge is between 0.16 mm and 0.3 mm.

In at least one embodiment of the present invention, the thin film transistor driving circuit further includes a bonding layer located on the side of the filter facing the thin film transistor layer.

In at least one embodiment of the present invention, the bonding layer is a transparent conductive layer.

In at least one embodiment of the present invention, the bonding layer extends to the part of the filter protruding from the thin film transistor layer.

In at least one embodiment of the present invention, the thin film transistor driving circuit further includes a light shielding layer disposed between the bonding layer and the filter, and the width of the light shielding layer is greater than or equal to the bonding layer.

In at least one embodiment of the present invention, the thin film transistor driving circuit further includes a light-shielding layer covering the filter, and the bonding layer partially covers the light-shielding layer.

In at least one embodiment of the present invention, the thin film transistor driving circuit further includes a light-shielding layer disposed in parallel with the bonding layer, wherein the light-shielding layer is arranged along the edge of the filter, and the bonding layer extends inwardly following the light-shielding layer.

In at least one embodiment of the present invention, the soldering pad extends toward the filter to be bonded to the bonding layer.

In at least one embodiment of the present invention, the sealing element is arranged around the edge of the thin film transistor layer and covers the bonding pins.

In at least one embodiment of the present invention, the signal pin further includes a connecting end surface extending on the first side surface, which is coupled to the side of the filter facing the thin film transistor layer.

In at least one embodiment of the present invention, the signal pin further includes a second side surface that forms an angle with the first side surface, and the second side surface is combined with the filter.

In at least one embodiment of the present invention, the thin film transistor drive circuit further includes a polarizer combined with the filter.

Based on the aforementioned thin film transistor drive circuit, the present invention also provides a liquid crystal display device, including the aforementioned thin film transistor drive circuit and a liquid crystal display medium. The liquid crystal display medium is combined on the thin film transistor layer and is located between the filter and the thin film transistor layer.

In the liquid crystal display device of the present invention, the signal pins are hidden under the filter, and the thin film transistor layer will not have an area that is not covered by the filter due to the requirement of disposing the signal pins. In other words, the liquid crystal display device will not need to widen the frame and other related structures to cover the area not covered by the filter due to the arrangement of the signal pins. In the thin-film transistor drive circuit, only a light-shielding layer of appropriate width needs to be arranged on the edge of the filter to shield the signal pins, the circuit connected to the signal pins, and lateral light leakage.

In the drawings, for clarity, the width of some elements, regions, etc. are enlarged. Throughout the specification, the same reference numerals denote the same elements. It should be understood that when an element is referred to as being "on" or "connected" to another element, it can be directly on or connected to the other element, or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements.

It should be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, components, regions, or portions, these elements, components, regions, and/or portions are not Should be limited by these terms. These terms are only used to distinguish one element, component, region, or section from another element, component, region, layer or section. Therefore, the “first element,” “component,” “region,” or “portion” discussed below may be referred to as a second element, component, region, or portion without departing from the teachings herein.

In addition, relative terms such as "lower" or "bottom surface" and "upper" or "top surface" may be used herein to describe the relationship between one element and another element, as shown in the figure. It should be understood that relative terms are intended to include different orientations of the device other than those shown in the figures. For example, if the device in one figure is turned over, elements described as being on the "lower" side of other elements will be oriented on the "upper" side of the other elements. Therefore, the exemplary term "lower" may include an orientation of "lower" and "upper", depending on the specific orientation of the drawing. Similarly, if the device in one figure is turned over, elements described as "below" other elements will be oriented "above" the other elements. Thus, the exemplary terms "below" or "below" can include an orientation of above and below.

As shown in FIGS. 1 and 2, a thin film transistor driving circuit disclosed in the first embodiment of the present invention includes a thin film transistor layer 110, a filter 120, a sealing member 130, and at least one solder pad 140 And a signal pin 150.

As shown in FIG. 1 and FIG. 2, the thin film transistor layer 110 has a thin film transistor array (not shown in the figure) for receiving external signals for switching. The thin film transistor layer 110 has one or more bonding pins 112, and each bonding pin 112 has at least one end extending to a first edge 114 of the thin film transistor layer 110. The first edge 114 may be any edge of the thin film transistor layer 110; generally, in the liquid crystal display device 100 that is arranged upright, the first edge 114 may be an edge corresponding to the bottom of the liquid crystal display device 100, but it is not excluded It corresponds to the edge of the liquid crystal display device 100 in the lateral direction.

As shown in FIGS. 1 and 2, the filter 120 is disposed on the thin film transistor layer 110 and maintains a distance G from the thin film transistor layer 110. The edge of the filter 120 protrudes from the first edge 114 of the thin film transistor layer 110. The filter 120 further includes a bonding layer 122 located on the side of the filter 120 facing the thin film transistor layer 110 and extending to a portion of the filter 120 protruding from the thin film transistor layer 110.

As shown in FIGS. 1 and 2, the sealing member 130 is combined between the thin film transistor layer 110 and the filter 120. Generally, the sealing member 130 is disposed around the edge of the thin film transistor layer 110, covers the bonding pin 112, and is flush with the first edge 114. By connecting the thin film transistor layer 110 and the filter 120 through the sealing member 130, the separation distance G can be sealed as a closed accommodating space.

As shown in FIGS. 1 and 2, the bonding pad 140 is located on the outside of the sealing member 130 and is electrically connected to the bonding pin 112 of the thin film transistor layer 110. The bonding pad 140 also further extends toward the filter 120 to be bonded to the bonding layer 122. A specific implementation aspect of the bonding layer 122 is a transparent conductive layer, such as indium tin oxide (ITO layer). The bonding layer 122 is provided to allow other metal or semiconductor elements to be combined with the filter 120; and the transparent conductive layer as the bonding layer 122 helps to hide the bonding layer 122 visually and maintain the original optical of the filter 120 characteristic. If the material of the filter 120 is suitable for direct bonding with other metal or semiconductor components, the bonding layer 122 may also be omitted.

As shown in FIGS. 1, 2 and 3, the signal pin 150 has a first side surface 152 and a connecting end surface 156 extending from the first side surface 152. The signal pin 150 usually extends from the conductive sheet on the edge of the COF (Chip on Film), the first side surface 152 is a side surface of the conductive sheet, and the connecting end surface 156 is the plane of the front edge of the conductive sheet. The signal pin 150 is parallel to the normal direction N of the thin film transistor layer 110, and the first side surface 152 is coupled to the bonding pad 140 and extends in a direction away from the filter 120.

As shown in FIGS. 2 and 3, the connection end surface 156 of the signal pin 150 is further combined with the side of the filter 120 facing the thin film transistor layer 110. The signal pin 150 can be indirectly coupled to the filter 120 through the bonding layer 122, or can be directly coupled to the filter 120. In addition, the portion of the signal pin 150 that exceeds the thin film transistor layer 110 in the normal direction N can be bent to extend along the bottom surface of the thin film transistor layer 110.

As shown in FIG. 4, the width of the edge of the filter 120 protruding from the first edge 114 is greater than the thickness of the signal pin 150 perpendicular to the normal direction N. In a specific embodiment, the width of the edge of the filter 120 protruding from the first edge 114 is between 0.16 mm and 0.3 mm, and the thickness of the signal pin 150 is less than 0.16 mm. Therefore, when viewed from the normal direction N toward the filter 120, the signal pin 150 will be located between the first edge 114 and the edge of the filter 120, and will not be exposed outside the filter 120.

As shown in FIG. 5, based on optical requirements, a polarizer 170 needs to be combined on the filter 120, and the edge of the polarizer 170 is cut so that the edge of the polarizer 170 is flush with the edge of the filter 120 . Cutting work is usually performed by laser. As shown in FIG. 4, since the signal pin 150 is located between the first edge 114 and the edge of the filter 120, when the polarizer 170 is cut, the laser beam L passing through the polarizer 170 will pass through the filter. The outer side of the edge of the sheet 120 without damaging the signal pin 150.

As shown in FIG. 6, based on the thin film transistor drive circuit disclosed in the first embodiment, the present invention further provides a liquid crystal display device 100 including the thin film transistor drive circuit of any embodiment of the present invention and a liquid crystal display medium 180. The liquid crystal display medium 180 is combined on the thin film transistor layer 110 and is located between the filter 120 and the thin film transistor layer 110 to be driven by the thin film transistor layer 110. A specific implementation aspect of the liquid crystal display medium 180 is a liquid crystal panel having a liquid-crystal cell array, and the thin-film transistor array of the thin-film transistor layer 110 is used to drive the liquid-crystal cell to act and change the optical characteristics. The liquid crystal display device 100 further includes a backlight module 182 disposed under the thin film transistor layer 110 to provide a backlight to the liquid crystal display medium 180.

As shown in FIG. 7, the liquid crystal display device 100 disclosed in the second embodiment of the present invention has a thin film transistor driving circuit and a liquid crystal display medium 180. In the second embodiment, a light shielding layer 190, such as a black matrix resist (BM resist), is further included. The light-shielding layer 190 is disposed between the bonding layer 122 and the filter 120, and the width of the light-shielding layer 190 is greater than or equal to the bonding layer 122, thereby shielding the wiring structure under the bonding layer 122 and shielding the side of the edge of the liquid crystal display medium 180 To leak light.

As shown in FIG. 8, the liquid crystal display device 100 disclosed in the third embodiment of the present invention has a thin film transistor driving circuit and a liquid crystal display medium 180. In the third embodiment, the light shielding layer 190 is disposed between the bonding layer 122 and the filter 120. In actual production, a light-shielding layer 190 is first provided on the bottom surface of the filter 120. The light-shielding layer 190 can completely cover the filter 120, and then the bonding layer 122 is fabricated so that the bonding layer 122 partially covers the light-shielding layer 190.

As shown in FIG. 9, the liquid crystal display device 100 disclosed in the fourth embodiment of the present invention has a thin film transistor driving circuit and a liquid crystal display medium 180. In the fourth embodiment, the light-shielding layer 190 and the bonding layer 122 are arranged side by side. The light-shielding layer 190 is disposed along the edge of the filter 120, and the bonding layer 122 extends inwardly following the light-shielding layer 190.

As shown in FIGS. 10 and 11, the liquid crystal display device 100 disclosed in the fifth embodiment of the present invention has a thin film transistor driving circuit and a liquid crystal display medium 180. In the fifth embodiment, the signal pin 150 is bent to have a first side surface 152 and a second side surface 154 that forms an angle with the first side surface 152. Wherein, the first side surface 152 is parallel to the normal direction N, and the first side surface 152 is coupled to the bonding pad 140. The second side surface 154 is combined with the filter 120, especially the part of the filter 120 that is not blocked by the sealing member 130. The second side surface 154 may be coupled to the filter 120 through the bonding layer 122 or directly coupled to the filter 120. With the first side surface 152 and the second side surface 154 simultaneously providing a bonding force, the signal pin 150 can be fixed more reliably. Similarly, the thin film transistor driving circuit of the fifth embodiment can also be provided with a light shielding layer 190, and the configuration of the light shielding layer 190 can be the configuration disclosed in the second to fourth embodiments.

In the liquid crystal display device 100 of the present invention, the first edge 114 of the thin film transistor layer 110 is retracted and hidden under the filter 120 together with the signal pin 150. Therefore, the thin film transistor layer 110 does not have an area that is not covered by the filter 120 due to the requirement of disposing the signal pins 150. That is to say, the liquid crystal display device 100 does not need to widen the frame and other related structures to cover the area not covered by the filter 120 due to the arrangement of the signal pins 150. In the thin film transistor driving circuit, only a light shielding layer 190 of appropriate width needs to be disposed on the edge of the filter 120 to shield the signal pin 150, the circuit connected to the signal pin 150, and lateral light leakage.

100: Liquid crystal display device 110: Thin film transistor layer 112: Bonding pin 114: first edge 120: filter 122: Bonding layer 130: seal 140: Welding pad 150: signal pin 152: first side 154: second side 156: connecting end face 170: Polarizer 180: liquid crystal display medium 182: Backlight module 190: shading layer N: Normal direction G: separation distance L: Laser beam

FIG. 1 is a cross-sectional exploded view of the thin film transistor driving circuit in the first embodiment of the present invention. 2 is a cross-sectional view of the thin film transistor driving circuit in the first embodiment of the present invention. Fig. 3 is a cross-sectional exploded view of partial components in the first embodiment of the present invention. Fig. 4 is a cross-sectional view of a partial element in the first embodiment of the present invention. 5 is a cross-sectional view of the thin film transistor driving circuit in the first embodiment of the present invention, showing that the polarizer is cut by a laser beam. 6 is a cross-sectional view of the liquid crystal display device in the first embodiment of the invention. FIG. 7 is a cross-sectional view of the thin film transistor driving circuit in the second embodiment of the present invention. FIG. 8 is a cross-sectional view of the thin film transistor driving circuit in the third embodiment of the present invention. 9 is a cross-sectional view of the thin film transistor driving circuit in the fourth embodiment of the present invention. 10 is a cross-sectional view of the thin film transistor driving circuit in the fifth embodiment of the present invention. Fig. 11 is a cross-sectional exploded view of partial components in the fifth embodiment of the present invention.

110: Thin film transistor layer

112: Bonding pin

120: filter

122: Bonding layer

130: seal

140: Welding pad

150: signal pin

G: separation distance

Claims (14)

A thin film transistor driving circuit, comprising: a thin film transistor layer having at least one bonding pin and a first edge, and one end of the bonding pin extends to the first edge of the thin film transistor layer; a filter The sheet is arranged on the thin film transistor layer and keeps a distance from the thin film transistor layer, and the edge of the filter protrudes from the first edge of the thin film transistor layer; a sealing element is combined with Between the thin film transistor layer and the filter and flush with the first edge; at least one soldering pad is located outside the sealing member and electrically connected to the bonding pin of the thin film transistor layer; And a signal pin is arranged parallel to a normal direction of the thin film transistor layer, and the signal pin has a first side surface, is connected to the bonding pad, and extends in a direction away from the filter. The thin film transistor driving circuit according to claim 1, wherein the width of the edge of the filter that protrudes from the first edge is between 0.16 mm and 0.3 mm. The thin film transistor driving circuit according to claim 1, further comprising a bonding layer located on the side of the filter facing the thin film transistor layer. The thin film transistor driving circuit according to claim 3, wherein the bonding layer is a transparent conductive layer. The thin film transistor driving circuit according to claim 3, wherein the bonding layer extends to a portion of the filter protruding from the thin film transistor layer. The thin film transistor driving circuit according to claim 3, further comprising a light-shielding layer disposed between the bonding layer and the filter, and the width of the light-shielding layer is greater than or equal to the bonding layer. The thin film transistor driving circuit according to claim 3, further comprising a light-shielding layer covering the filter, and the bonding layer partially covers the light-shielding layer. The thin film transistor drive circuit according to claim 3, further comprising a light-shielding layer arranged in parallel with the bonding layer, wherein the light-shielding layer is arranged along the edge of the filter, and the bonding layer is continuous with the light-shielding layer Extend inward. The thin film transistor driving circuit according to claim 3, wherein the bonding pad extends toward the filter to be coupled to the bonding layer. The thin film transistor drive circuit according to claim 1, wherein the sealing member is arranged around the edge of the thin film transistor layer and covers the bonding pin. The thin film transistor driving circuit according to claim 1, wherein the signal pin further includes a connecting end surface extending on the first side surface, and is coupled to a side of the filter facing the thin film transistor layer. The thin film transistor driving circuit according to claim 1, wherein the signal pin further includes a second side surface forming an angle with the first side surface, and the second side surface is combined with the filter. The thin film transistor driving circuit according to claim 1, which further includes a polarizer combined with the filter. A liquid crystal display device, comprising: the thin film transistor drive circuit according to any one of claim 1 to claim 13; and a liquid crystal display medium, combined on the thin film transistor layer, and located between the filter and Between the thin film transistor layers.

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