JP3424272B2 - Flexible circuit board for wiring circuit board connection - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit board connecting circuit board on which electronic components are mounted in a conductive state and connected to a wiring pattern of the printed circuit board. 2. Description of the Related Art For example, in a glass substrate used for an electronic display device such as a liquid crystal module, a COG (chip-on-glass) in which a semiconductor element or an electronic component is bonded to a wiring pattern of the glass substrate. Packaging technology is mainly used. As a means for connecting such an electronic display device and a display control device, a flexible substrate that can correspond to the shape of a product is used. [0003] By the way, among the above-mentioned connecting flexible substrates, there are provided those which are configured such that electronic components such as chip components can be mounted thereon. That is, the function of the flexible substrate is not only a connection function but also a function of a wiring circuit, and the flexible substrate can be effectively used. FIG. 5 shows such a flexible substrate. In FIG. 5, a flexible substrate 1 is formed by covering both surfaces of a connection conductor 2 with a film-like protective body 3. On the back surface of the flexible substrate 1, there is provided a connection terminal portion 2a in which a part of the back surface of the connection conductor 2 is exposed, and the connection terminal portion 2a is formed on a circuit pattern 5 formed on a glass substrate 4.
Is connected to A window 6 is formed in the film-like protective body 3 in the intermediate portion of the flexible substrate 1, and a component mounting portion 2 b is provided through which a part of the surface of the connecting conductor 2 is exposed. At the same time, the chip component 7 is mounted on the component mounting portion 2b in a conductive state. However, in the case of the above-described conventional configuration, the chip component 7 is mounted on the flexible region of the flexible substrate 1, so that the chip component 7
Cannot be automated, which increases costs. Also,
When the flexible substrate 1 is used for a movable portion or is used in a bent state, a large stress is applied to a connection portion between the chip component 7 and the flexible substrate 1, so that the reliability of the electrical connection is reduced. The problem of lowering occurs. In this case, the above problem can be solved by mounting the chip component 7 on the glass substrate 4, but the glass substrate 4 becomes large. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a configuration in which chip components are mounted in a conductive state and connected to a printed circuit board, so that cost can be reduced and connection reliability of the chip components can be reduced. Quality can be improved,
Another object of the present invention is to provide a flexible printed circuit board connecting board that can prevent the printed circuit board from being enlarged. [0007] According to an aspect of the present invention is composed of a plurality of connecting conductors, the film-like protective member having flexibility which covers the connecting conductor, the window to the film-like protective member Department
A connection terminal portion part of the back surface of the connection conductor is exposed is provided with the component mounting portion partially exposed on the surface of the connection conductor provided by forming, Ji to the component mounting portion
In the printed circuit board connection flexible board, wherein the connection component is mounted in a conductive state and the connection terminal portion is connected to a wiring pattern of the printed circuit board, the component mounting portion is connected to the connection terminal portion and the connection conductor. provided at a site directly <br/> opposite sides of the Rutotomoni, co the said chip parts
Coating resin . The component mounting portion on which the chip component is mounted on the flexible substrate is provided at a portion directly facing the connection terminal portion connected to the printed circuit board with the connection conductor interposed therebetween . The part is on the printed circuit board via the flexible board. Therefore, even if the chip component is mounted on the flexible substrate, the chip component is mounted on a stationary part, so that the chip component can be easily mounted on the flexible substrate and the flexible substrate is bent. Even so, chip components are not subject to stress. An embodiment in which the present invention is applied to a flexible substrate connected to a TFT-LCD (thin film transistor liquid crystal display element) module will be described below with reference to FIGS. FIG. 2 shows the overall structure of the TFT-LCD module. In FIG. 2, a glass substrate 11 serving as a printed circuit board has a display unit 1 made of a TFT-LCD.
2 is mounted. A semiconductor element 13 for driving the display unit 12, a chip capacitor 14, and the like are provided in a portion of the glass substrate 11 around the display unit 12. The wiring pattern 1 is formed on the glass substrate 11.
5 are formed, and a flexible substrate 16 is connected to the wiring pattern 15. FIGS. 3 and 4 show the front and back surfaces of the flexible substrate 16, respectively. 3 and 4, the flexible substrate 16 has a three-layer structure in which a plurality of copper-foil conductive patterns 17 as connection conductors are sandwiched between two flexible film-like protective bodies, polyimide films 18. It is formed in a structure (see FIG. 1). The conductor pattern 17 is formed by etching with a copper foil adhered to one polyimide film 18. Here, as shown in FIG. 4, a portion of the back surface of the conductive pattern 17 is exposed by forming a window 19 in the polyimide film 18 at one end on the back surface of the flexible substrate 16. A connection terminal portion 17a is provided, and a front end portion of the back surface of the conductor pattern 17 is exposed at the other end portion so that the connector portion 17
b is provided. On the other hand, as shown in FIG. 3, on the surface of the flexible substrate 16, a component mounting portion 17c is provided at a tip portion of which a window 20 is formed so that a part of the surface of the conductor pattern 17 is exposed. ing. In this case, the component mounting portion 17c is set at a portion facing the connection terminal portion 17a. Note that a polyester film 21 for reinforcing the polyimide film 18 is bonded to a portion of the flexible substrate 16 corresponding to the connector portion 17b. The flexible substrate 16 having the above configuration is connected to the wiring pattern 15 formed on the glass substrate 11. That is, in FIG. 1 showing the connection state of the flexible substrate 16 to the glass substrate 11, the connection end 17 in the conductor pattern 17 of the flexible substrate 16 is shown.
b denotes a glass substrate 11 made of solder or anisotropic conductive adhesive.
Are connected to the wiring pattern 15. On the other hand, a chip component 22 as an electronic component is connected to the conductor pattern 17 by a conductive adhesive represented by silver paste, wire bonding, soldering, or the like on the component mounting portion 17c of the conductor pattern 17 of the flexible substrate 16. It is mounted in a conductive state. A coating resin is applied to the portion of the flexible substrate 16 where the chip component 22 is mounted, thereby improving the moisture resistance of the electrical connection. According to the above configuration, the component mounting portion 17c of the tip portion article 2 2 In the flexible substrate 16 is mounted, connected is connected to the glass substrate 11 terminal portions 17
The mounting position of the chip component 22 can be set on the glass substrate 11 with the flexible substrate 16 interposed therebetween, since the chip component 22 is provided at a portion facing the b. Therefore, unlike the conventional example in which the chip component is mounted in the flexible region deviated from the connection portion with the printed circuit board, the mounting portion of the chip component 22 can be set as a stationary portion, and thus the flexible substrate 16 can be set. Automatic mounting of the chip component 22 becomes possible, and the cost can be reduced. In addition, since the chip component 22 does not receive stress due to bending even on the flexible substrate 16, the connection reliability of the chip component 22 can be improved. Further, since the above-described effect can be obtained without mounting the chip component 22 on the glass substrate 11, the size of the glass substrate 11 can be avoided. In the above embodiment, the flexible substrate 1
6 shows an example in which the chip component 22 is mounted, but the electronic component mounted on the flexible substrate 16 may be a discrete component. [0020] As apparent from the foregoing description, according to the wiring circuit flexible board substrate connection of the present invention, the component mounting portion for chip components are mounted in the connecting conductor of the flexible substrate, Since the connection terminals are connected to the wiring circuit board and are directly opposed to each other with the connection conductor interposed therebetween , cost is reduced in a configuration in which the chip components are mounted in a conductive state and connected to the wiring circuit board. It is possible to achieve an excellent effect that it is possible to reduce the size and to improve the connection reliability of the chip component and to prevent the printed circuit board from being enlarged.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a main part showing an embodiment of the present invention. FIG. 2 is a perspective view showing an entire configuration. FIG. FIG. 5 shows a conventional example. FIG. 1 corresponds to FIG. 1. FIG. 1 shows a conventional example. Conductor), 17a is a connection terminal portion, 17c is a component mounting portion, 18 is a polyimide film (film-like protective body),
Reference numeral 22 denotes a chip component (electronic component).

Claims (1)

(57) Patent Claims 1. A plurality of connecting conductors, composed of a film-like protective member having flexibility which covers the connecting conductors, on
Forming a window in the film-like protective body to provide a component mounting part where a part of the surface of the connection conductor is exposed, and providing a connection terminal part where a part of the back surface of the connection conductor is exposed, in the printed circuit flexible board substrate connecting said connecting terminal portion is connected to the wiring pattern of the printed circuit board with chip components on the component mounting portion is mounted in a conductive state, the component mounting portion, and the connection terminal portion and the Connecting conductor
A printed circuit board-connecting flexible substrate, which is provided at a portion directly opposed to and sandwiches the coating , and wherein the chip component is coated with a coating resin .