JP2004212447A - Electric module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric module which can prevent the electrostatic breakdown of a driving circuit element and also the disconnection of a wiring pattern by a single member, and is very advantageous to cost reduction and miniaturization. <P>SOLUTION: A flexible wiring board 4 connected to a projecting part 1a of one of the glass substrates of a liquid crystal display element LC is formed with a tongue part 4c and an insulating protective sheet 8 is stuck on the surface of the side covered by a shielding case 11 for this flexible wiring board 4. This insulating protective sheet 8 is provided with a short tongue part 8a corresponding to the above tong part 4c, and these tong part 4a and short tong part 8a are superimposed and drawn out of the case through the opening in the assembled state in which the assembly body W bonding the flexible wiring board 4 stuck with the insulating protective sheet 8 to the liquid crystal display element LC is housed in the housing case 10 and covered by the shielding case. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric module using a flexible wiring board.
[0002]
[Prior art]
Conventionally, a liquid crystal display element is housed in a shield case, and a drive circuit board made of a flexible wiring board such as a tape carrier package (TCP) is connected to the liquid crystal display element, and this drive circuit board is connected to an external control circuit board. There is a liquid crystal display module that is pulled out of the shield case in order to do so. (For example, see Patent Document 1)
[0003]
[Patent Document 1]
JP-A-11-258622 (4 pages, FIGS. 1 and 2)
[0004]
[Problems to be solved by the invention]
In the above-described liquid crystal display module, usually, a shield case is formed of a conductive material such as metal to prevent electromagnetic interference, an opening is provided in the shield case, and the drive circuit board is drawn out of the shield case through the opening. I have. Therefore, in an assembling operation process or the like, the flexible driving circuit board may come into contact with the sharp edge of the opening formed by cutting out the metal, and the wiring pattern may be cut or the driving circuit board itself may be damaged.
[0005]
In addition, if a drive circuit element such as an LSI provided on a drive circuit board or the like in a shield case is provided close to a shield case made of a conductive metal, a human body or the like can pass through the shield case. The charged electric charge flows to the drive circuit element, and the drive circuit element is likely to be damaged by electrostatic discharge.
[0006]
The cutting of the wiring pattern described above can be prevented by attaching a rubber bush or the like to the opening of the shield case or attaching a protective sheet for reinforcement to the drive circuit board. In addition, electrostatic breakdown of the drive circuit element can be prevented by interposing an insulating sheet between the shield case and the drive circuit element, or by separating the two.
[0007]
However, if individual measures for preventing the above-mentioned troubles are individually adopted, the number of manufacturing steps and the number of parts increase, causing a significant increase in cost. In addition, measures to keep the drive circuit element away from the shield case go against the size reduction of the liquid crystal display module, which has recently been strongly demanded.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to provide an electric module that can prevent electrostatic damage of a drive circuit element and cut a wiring pattern with a single member, and is extremely advantageous for cost reduction and miniaturization.
[0009]
[Means for Solving the Problems]
An electric module according to the present invention is a flexible wiring board that electrically connects an electric device housed in a housing and an external circuit disposed outside the housing through the opening provided in the housing. An electric module comprising: a driving circuit element provided in the housing for driving the electric device; and an insulating protection sheet interposed between the driving circuit element and the housing. The insulation protection sheet may extend outside the housing through a space between an edge of an opening of the housing and the flexible wiring board.
[0010]
According to this electric module, since the insulating protection sheet is interposed between the drive circuit element and the housing, the electrostatic circuit of the drive circuit element due to the static electricity through the housing does not need to enlarge the housing to separate them. Destruction can be prevented. Further, since the insulating protective sheet is extended and interposed between the opening edge of the housing and the flexible wiring board, the wiring pattern of the flexible wiring board does not directly contact the opening edge, and the number of components is not increased. In addition, the disconnection of the wiring pattern can be prevented. As a result, only by interposing one sheet, it is possible to prevent both the electrostatic breakdown of the drive circuit element and the cutting of the wiring pattern, and it is possible to provide an electric module which is extremely advantageous for cost reduction and miniaturization. .
[0011]
In the electric module according to the present invention, it is preferable that the flexible wiring board is adhered to the flexible wiring board with an adhesive layer as described in claim 2, whereby the insulating protection sheet is placed at a predetermined position on the flexible wiring board. Can be attached more easily and reliably. And in that case, as described in claim 3, it is more preferable that the adhesive layer is selectively disposed on a surface portion of the insulating protection sheet facing the flexible wiring board inside the housing, and thereby, Since the flexible wiring board in the housing opening does not have the insulating protection sheet attached thereto, its flexibility is not lost, and the flexible wiring board can be freely bent. Therefore, the electric module of the present invention can be easily mounted on a desired product, and when the housing is of a split fitting type, the flexible wiring board abuts on the opening edge when the flexible wiring board is bent, and the lid side It is possible to eliminate the problem that the housing is pushed up to remove it carelessly.
[0012]
Further, the electric module of the present invention is suitable for mounting a drive circuit element on a flexible wiring board by a so-called TAB (Tape Automated Bonding) method or the like.
[0013]
Further, the present invention is suitably applied to a liquid crystal display module having a liquid crystal display element therein.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
A liquid crystal display module as an embodiment of the electric module of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view showing the entire configuration of the liquid crystal display module of the present embodiment, FIG. 2 is a partial perspective view showing the configuration between main members of the liquid crystal display module, and FIG. FIG. 3 is a plan view showing the configuration with a lid-side housing removed.
[0015]
In FIG. 1, a liquid crystal display element LC is formed by joining a pair of glass substrates 1 and 2 on which electrodes (not shown) are formed with a frame-like sealing material (not shown) facing each electrode forming surface, The liquid crystal is sealed between the glass substrates 1 and 2 surrounded by a frame-shaped sealing material. One of the glass substrates 1 of the pair of glass substrates 1 and 2 has a protruding portion 1 a with one end protruding from the end surface of the other glass substrate 2. The present liquid crystal display element LC is a narrow frame liquid crystal display element in which the surrounding frame Af is smaller than the display area Av.
[0016]
On the surface of the protruding portion 1a of the glass substrate 1 (extended surface of the electrode forming surface), connection terminals (not shown) of the wiring 3 connected to the electrodes of the substrates 1 and 2 are arranged in parallel. I have. The liquid crystal display element LC of this example is a single-sided substrate terminal type liquid crystal display element in which connection terminals corresponding to respective electrodes provided on both substrates 1 and 2 are collectively arranged on a protruding portion of one glass substrate 1.
[0017]
A flexible wiring board (FPC) 4 is joined to the protruding portion 1a on which the connection terminal row is formed. A drive circuit element 5 for driving the liquid crystal display element LC is mounted on the flexible wiring board 4 by a TAB (Tape Automated Bonding) method. That is, the surface (hereinafter, referred to as a wiring surface) 4a of the flexible wiring board 4 on which the wiring pattern is formed is adhered to the surface of the protruding portion 1a of the glass substrate 1, and the surface on which the wiring pattern is not formed (hereinafter, the opposite wiring surface). 4b, the back surface of the drive circuit element 5 mounted in the opening (not shown) by the TAB method projects.
[0018]
A connection terminal row (not shown) of the output wiring 6 drawn out from the drive circuit element 5 is formed at an end of the flexible wiring board 4 on the wiring surface 4a to be adhered to the projection 1a of the glass substrate 1. These connection terminal rows are conductively connected to connection terminal rows of the wiring 3 arranged on the surface of the protruding portion 1a of the substrate 1 via a connector (not shown) such as an anisotropic conductive adhesive.
[0019]
A tongue 4c protrudes from an end of the flexible wiring board 4 opposite to the end on the output wiring side. The input wiring 7 connected to the drive circuit element 5 is routed on the wiring surface 4a of the tongue 4c, and a connection terminal (not shown) is formed at an end of each input wiring 7.
[0020]
An insulating protection sheet 8 is attached to the non-wiring surface 4b of the flexible wiring board 4. Short tongue portions 8 a are formed on the insulating protection sheet 8 so as to correspond to the tongue portions 4 c of the flexible wiring board 4. The insulating protection sheet 8 is attached on the non-wiring surface 4b of the flexible wiring board 4 with its short tongue 8a aligned with the tongue 4c. The protruding length of the short tongue 8a is set shorter than the protruding length of the tongue 4c.
[0021]
The insulating protection sheet 8 of this example is made of an insulating resin sheet such as PET (polyether terephthalate) and is adhered to the non-wiring surface 4b of the flexible wiring board 4 via the adhesive layer 9 as shown in FIG. . Here, the adhesive layer 9 is selectively disposed in a region excluding the short tongue 8a and the end on the side where the short tongue 8a protrudes in the insulating protection sheet 8.
[0022]
As described above, the assembly W formed by joining the flexible wiring board 4 on which the insulating protection sheet 8 is adhered to the liquid crystal display element LC is placed in a resin storage case 10. The inside of the storage case 10 is partitioned by a rib 10a into a liquid crystal display element storage room 10b in which the liquid crystal display element LC is inserted and a wiring substrate storage room 10c. A notch 10e is formed in a side wall 10d of the wiring board storage chamber 10c facing the rib 10a. The notch 10 e becomes a part of an opening for drawing out the tongue 4 c of the flexible wiring board 4 to the outside of the storage case 8.
[0023]
FIG. 3 shows a state in which the above-described assembly W is inserted in the storage case 10. The short tongue 8 a of the insulating protection sheet 8 is aligned with one side edge of the tongue 4 c of the flexible wiring board 4. Are superimposed. The short tongue portion 8a and the tongue portion 4c both have their respective tips projecting beyond the notch 10e of the storage case 10 to the outside of the case. Here, the tip of the short tongue portion 8a of the insulating protection sheet 8 only needs to slightly protrude from the notch portion 10e as in this example.
[0024]
As shown in FIG. 1, a shield case 11 made of a conductive material is mounted on the storage case in which the assembly W is inserted. The shield case 11 of this example is formed by processing a metal plate into a sheet metal, and a display window 11a is formed in the main surface of the case so as to correspond to the display area Av of the liquid crystal display element LC. The area of the display window 11a is set to be slightly smaller than the display area Av of the liquid crystal display element LC.
[0025]
Further, the shield case 11 has four side walls on its periphery, and a cutout portion 11c corresponding to the cutout portion 10e of the storage case 10 is formed on a side wall 11b corresponding to the side wall 10d of the storage case 10 among them. ing. As shown in FIG. 4, the notch 11c forms an opening Op with the notch 10 of the storage case 10 in a state where the shield case 11 is correctly mounted on the storage case 10. Through the opening Op, the short tongue portion 8a of the insulating protection sheet 8 and the tongue portion 4c of the flexible wiring board 4 are drawn out of the case in a free state in which they are not restricted to each other.
[0026]
According to the liquid crystal display module of the present embodiment configured as described above, electrostatic breakdown via the shield case 11 of the drive circuit element 5 mounted on the flexible wiring board 4 by the TAB method is reliably performed by the insulating protection sheet 8. At the same time, the problem that the tongue 4c of the flexible wiring board 4 comes into contact with the sharp edge 11d of the opening Op on the shield case 11 side is prevented by the short tongue 8a of the insulating protection sheet 8 interposed therebetween. The possibility that the tongue 4c is damaged is also eliminated.
[0027]
Since the tongue 4c of the flexible wiring board 4 protruding from the opening Op is not fixed to the short tongue 8a of the insulating protection sheet 8 by the adhesive layer 7, the flexibility is not lost, and the present liquid crystal display module For example, the tongue portion 4c of the flexible wiring board 4 can be easily bent when mounting on a product such as a car navigation system, and the mounting workability is improved. Also, at the time of this bending, even if the tongue 4c abuts on the edge 11d of the notch 11b in the shield case 11 via the short tongue 8a of the insulating protection sheet 8, the tongue 4a flexes at the corner. Since the shield case 11 is bent following, there is no need to push up the shield case 11 to inadvertently remove it.
[0028]
Note that the present invention is not limited to the above embodiment.
For example, the drive circuit element according to the present invention is mounted on the flexible wiring board 4 by TAB in the above embodiment, but is not limited thereto, and may be mounted on a flexible wiring board by COF (Chip On Film). A COG (Chip On Glass) may be mounted on a glass substrate of a display element.
[0029]
Further, the present invention is not limited to the liquid crystal display module, and can be widely applied to various other electric modules that accommodate an electric device in a housing and control the driving of the electric device from outside the housing through a flexible wiring board.
[0030]
【The invention's effect】
According to the electric module of the present invention, since the insulating protective sheet is interposed between the drive circuit element and the housing, the drive circuit element is not affected by static electricity through the housing without enlarging the housing to separate them. Electrostatic breakdown can be prevented. Further, since the insulating protection sheet is extended and interposed between the edge of the opening of the housing and the flexible wiring board, the wiring pattern of the flexible wiring board does not directly contact the opening edge, thereby increasing the number of parts. It is possible to prevent the disconnection of the wiring pattern. As a result, only by interposing one sheet, it is possible to prevent both the electrostatic breakdown of the drive circuit element and the cutting of the wiring pattern, and it is possible to provide an electric module which is extremely advantageous for cost reduction and miniaturization. .
[0031]
Further, in the electric module according to the present invention, as described in claim 2, by attaching the flexible wiring board to the flexible wiring board with an adhesive layer, the insulating protection sheet is moved to a predetermined position of the flexible wiring board. It can be easily and reliably attached. In that case, as described in claim 3, the adhesive layer is selectively disposed on a surface portion of the insulating protection sheet facing the flexible wiring board inside the housing, thereby opening the housing. In the flexible wiring board of the above, since the insulating protective sheet is not attached, the flexibility is not lost, and the flexible wiring board can be bent freely.
[0032]
Therefore, the electric module of the present invention can be easily mounted on a desired product, and when the housing is of a split fitting type, the flexible wiring board abuts on the opening edge when the flexible wiring board is bent, and the lid side It is possible to eliminate the problem that the housing is pushed up to remove it carelessly.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a liquid crystal display module as an embodiment of the present invention.
FIG. 2 is a perspective view showing a configuration between main members in the embodiment.
FIG. 3 is a plan view showing a configuration of the above embodiment with a shield case removed.
FIG. 4 is an enlarged partial perspective view of a main part of the first embodiment.
[Explanation of symbols]
Reference numerals 1, 2, glass substrate 3, routing wiring 4, flexible wiring substrate 5, driving circuit element 6, output wiring 7, input wiring 8, insulating protection sheet 9, adhesive layer 10, storage case 11, shield case LC, liquid crystal display Element Op: Opening

Claims (5)

An electrical device housed in the housing;
A flexible wiring board that electrically connects the electric device and an external circuit disposed outside the housing through an opening provided in the housing,
A drive circuit element provided in the housing for driving the electric device,
An insulating protection sheet interposed between the drive circuit element and the housing,
An electrical module having
The electric module according to claim 1, wherein the insulating protection sheet extends outside the housing through a space between an edge of an opening of the housing and the flexible wiring board. The electric module according to claim 1, wherein the insulating protection sheet is attached to the flexible wiring board via an adhesive layer. The electric module according to claim 2, wherein the adhesive layer is selectively disposed on a surface portion of the insulating protection sheet facing the flexible wiring board inside the housing. The electric module according to any one of claims 1 to 3, wherein the drive circuit element is mounted on the flexible wiring board. The electric module according to any one of claims 1 to 4, wherein the electric device is a liquid crystal display element.

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