JP2006108434A - Drive circuit substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive circuit substrate having a structure which can shield noise from through holes. <P>SOLUTION: The drive circuit substrate 5, wherein a plurality of conductive layers are laminated has a wiring pattern W1 disposed on the first major surface S1 of the drive circuit substrate 5, a connection CP which electrically connects the wiring pattern W1 with at least one conductive layer S3 (SgL) via a through hole TH, passing through from the first major surface S1 to a second major surface S5 of the driving circuit substrate 5, the land LP of a ground potential enclosing the circumference of the through hole TH that is insulated from the connection CP on the second major surface S5 of the drive circuit substrate 5, and a shielding member SP which covers the land LP and shields the through hole TH. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive circuit board, and more particularly to a drive circuit board that supplies a drive signal to a display panel.

A display device represented by a liquid crystal display device or the like includes a display panel and a drive circuit board that supplies a drive signal to the display panel. The display panel and the drive circuit board are electrically connected via a flexible substrate. (For example, refer to Patent Document 1).
JP 2003-295842 A

  The drive circuit board has, for example, a structure in which a plurality of conductive layers are stacked, and has a connection terminal connected to a component surface, that is, a flexible board, and various wiring patterns on the surface thereof. Such a drive circuit board has a through-hole penetrating from the front surface to the back surface. That is, the connection terminal on the substrate surface is electrically connected to a desired conductive layer through the through hole.

  However, noise may be generated from through holes for electrical connection with conductive layers such as signal lines, power supply lines, and clock signal lines.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a drive circuit board having a structure capable of shielding noise from a through hole.

A drive circuit board according to an aspect of the present invention
A drive circuit board in which a plurality of conductive layers are laminated,
A connection terminal disposed on the first main surface of the drive circuit board;
A connection portion for electrically connecting the connection terminal and at least one conductive layer through a through hole penetrating from the first main surface to the second main surface of the drive circuit board;
On the second main surface of the drive circuit board, a land portion having a ground potential that surrounds the periphery of the through hole while being insulated from the connection portion;
A shield member that covers the land portion and shields the through hole;
It is provided with.

  According to the present invention, it is possible to provide a drive circuit board having a structure capable of shielding noise from a through hole.

  A drive circuit board according to an embodiment of the present invention will be described below with reference to the drawings. Here, a driving circuit board applicable to a display device such as a liquid crystal display device will be described.

  As shown in FIG. 1, the liquid crystal display device 1 includes a liquid crystal display panel 2 having a substantially rectangular flat plate shape. The liquid crystal display panel 2 is configured by sandwiching a liquid crystal layer as a light modulation layer between a pair of substrates, that is, an array substrate 3 and a counter substrate 4.

  The array substrate 3 includes a switching element SW such as a thin film transistor disposed for each display pixel PX in the vicinity of the intersection of the scanning line Sc and the signal line Sg, a pixel electrode PE connected to the switching element SW, and the like. The counter substrate 4 includes a counter electrode CE and the like. The array substrate 3 and the counter substrate 4 are disposed with the pixel electrode PE and the counter electrode CE facing each other, and a gap is formed between them. The liquid crystal layer LQ is formed of a liquid crystal composition sealed in the gap between the array substrate 3 and the counter substrate 4.

  A drive circuit board 5 that supplies a drive signal to the liquid crystal display panel 2 is electrically connected to one side edge of the liquid crystal display panel 2 via a pair of flexible elongated rectangular flat printed wiring boards 6.

  As shown in FIGS. 2 and 3, the drive circuit board 5 has a structure in which a plurality of conductive layers are stacked. For example, the drive circuit board 5 includes a first conductive layer (first main surface) S1, a second conductive layer S2, a third conductive layer S3, a fourth conductive layer S4, and a fifth conductive layer each having a conductive pattern. (Second main surface) S5 is laminated in order.

  The first conductive layer S <b> 1 that is the surface of the drive circuit board 5 corresponds to a component surface connected to the printed wiring board 6. The first conductive layer S1 has conductive patterns such as a plurality of connection terminals T connected to the printed wiring board 6 and various wiring patterns W having one ends connected to the connection terminals T.

  The second conductive layer S2 has a conductive pattern such as a ground layer Gnd having a ground potential. The third conductive layer S3 has a conductive pattern such as a plurality of signal lines SgL for outputting various drive signals, for example. The fourth conductive layer S4 has a conductive pattern such as a power supply line PwL that supplies power, a ground line GndL of the ground potential, and the like. The fifth conductive layer S5 corresponds to the back surface of the drive circuit board 5.

  The drive circuit board 5 having such a configuration has a through hole TH that penetrates from the front surface, that is, the first conductive layer S1, to the back surface, that is, the fifth conductive layer S5, and further, the first through the through hole TH. A connection portion CP for electrically connecting the connection terminal T of the conductive layer S1 and at least one desired conductive layer is provided.

  That is, the wiring pattern W of the first conductive layer S1 extends to the through hole TH. Similarly, the conductive pattern such as the ground layer Gnd of the second conductive layer S2, the signal line SgL of the third conductive layer S3, the power supply line PwL of the fourth conductive layer S4, and the ground line GndL extends to the through hole TH. ing. In other words, one end of each through hole TH passes through any one wiring pattern W of the first conductive layer S1, and the middle part thereof passes through the conductive pattern of at least one conductive layer.

  The connection part CP is formed by a conductive member filled in the through hole TH. That is, the connecting portion CP contacts the wiring pattern W and the conductive pattern through which the through hole TH passes and electrically connects them.

  In the example shown in FIG. 3, the first wiring pattern W1 is connected to the third conductive layer S3 by the connecting portion CP1. That is, the connection terminal T1 of the first conductive layer S1 is electrically connected to the signal line SgL of the third conductive layer S3 via the wiring pattern W1 and the connection portion CP1. The second wiring pattern W2 is connected to the fourth conductive layer S4 by the connection portion CP2. That is, the connection terminal T2 of the first conductive layer S1 is electrically connected to the power supply line PwL of the fourth conductive layer S4 via the second wiring pattern W2 and the connection portion CP2. The third wiring pattern W3 is connected to the fourth conductive layer S4 by the connection portion CP3. That is, the connection terminal T3 of the first conductive layer S1 is electrically connected to the ground line GndL of the fourth conductive layer S4 via the third wiring pattern W3 and the connection portion CP3.

  At this time, noise may be generated from the through hole TH for electrically connecting the wiring pattern W and the conductive pattern such as the signal line SgL and the power supply line PwL. For this reason, the through holes TH for electrical connection with these conductive patterns are insulated.

  That is, in the fifth conductive layer S5, a ring-shaped land portion LP is disposed so as to surround the through hole TH in a state of being electrically insulated from the connection portion CP. The land portion LP is at ground potential. The land portion LP may be electrically connected to a conductive layer having a ground potential, for example, the ground layer Gnd of the second conductive layer S2.

  The land portion LP is covered with a shield member SP. The shield member SP is formed of a plate-shaped metal plate having a shielding property having a size equal to or larger than the outer diameter of the land portion LP, and is formed of, for example, copper foil. Thereby, the through hole TH is shielded. In particular, the through hole TH having the connection portion CP having a potential other than the ground potential, that is, the connection portion CP in contact with the signal line SgL, the power supply line PwL, or the like is covered with the land portion LP and the shield member SP.

  Therefore, it is possible to shield noise from the through hole TH for connecting to conductive patterns such as the signal line SgL and the power supply line PwL. Moreover, the shield member should just be the size at least equivalent to land part LP, and can suppress the increase in cost. Furthermore, it is possible to perform through-hole insulation processing by reflow using a mounting machine, thereby reducing costs.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the gist of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

FIG. 1 is a diagram showing an example of a display device provided with a drive circuit board according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing a stacked structure of the drive circuit board shown in FIG. FIG. 3 is a diagram schematically showing a cross-sectional structure of the drive circuit board shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 5 ... Drive circuit board, S1 ... 1st conductive layer (front surface), S2 ... 2nd conductive layer, S3 ... 3rd conductive layer, S4 ... 4th conductive layer, S5 ... 5th conductive layer (back surface), T ... Connection Terminal, W ... Wiring pattern, CP ... Connection, LP ... Land, SP ... Shield member, TH ... Through hole

Claims (3)

A drive circuit board in which a plurality of conductive layers are laminated,
A connection terminal disposed on the first main surface of the drive circuit board;
A connection portion for electrically connecting the connection terminal and at least one conductive layer through a through hole penetrating from the first main surface to the second main surface of the drive circuit board;
On the second main surface of the drive circuit board, a land portion having a ground potential that surrounds the periphery of the through hole while being insulated from the connection portion;
A shield member that covers the land portion and shields the through hole;
A drive circuit board comprising:   The drive circuit board according to claim 1, wherein the land portion is electrically connected to a conductive layer having a ground potential among a plurality of conductive layers.   The drive circuit board according to claim 1, wherein the connection portion has a potential different from a ground potential.

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