JPH054787B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a method for mounting a plurality of tape carrier devices on various display panels such as liquid crystal, plasma, and EL.

<Prior Art> FIG. 3 is an exploded perspective view of essential parts of a display device using a typical conventional tape carrier device mounting method. A plurality of tape carriers 11 and 12 are provided to protrude from edges 10a and 10b of the display panel 10. Large-scale integrated circuits (hereinafter abbreviated as LSI) 13 and 14 for driving the panels are mounted on the surfaces of the tape carriers 11 and 12, respectively, and wiring is similarly formed on the tape carriers 11 and 12. The LSIs 13 and 14 are connected to the display panel 10 through leads.

That is, the panel drive signal terminals 13a, 14a of the LSIs 13, 14 are electrically connected to a plurality of panel drive signal leads 15, 16 made of copper foil or the like formed on the tape carriers 11, 12.
These leads 15 and 16 are connected to the edge 10 of the panel 10.
A and 10b are electrically connected to the terminals of the panel 10 by soldering or heat seal connection.

Input signal terminal 13 to LSI 13, 14 formed on one surface of each tape carrier 11, 12
input signal lead 23 connected to b, 14b,
24 protrudes from the ends of the tape carriers 11, 12 and is electrically connected to the ends 18a, 19a of the wirings 18, 19 formed on one surface of the adjacent external substrate 17. As the external board 17, a flexible printed circuit board (hereinafter abbreviated as FPC), a general printed wiring board (hereinafter abbreviated as PWB), or the like is used. The wirings 18 and 19 connected to the leads 23 and 24 are selectively connected to a common wiring 22 for input signals of the LSIs 13 and 14 formed on the back surface of the external substrate 17 via conductive holes 20 and 21. The wiring 22 is connected to a video signal source, a power source, and the like. As described above, LSI1 is
3 and 14, the Hanel 10 is driven.

Further explanation will be given using the cross-sectional view shown in FIG. As described above, the panel drive signal lead 26 and the input signal lead 27 are formed on the tape carrier 25, and the LSI 28 is connected to them. The on-panel drive signal wiring 30 formed on the display panel 29 and the panel drive signal lead 26 are electrically connected via a connecting material 31 such as solder or an anisotropic conductive film. A common wiring 33 for input signals is formed on the back surface of the external board 32, and a conduction hole 34
It is connected to the wiring 35 on the surface via. The surface wiring 35 and the input signal lead 27 are electrically connected via a connecting material 36 such as solder or an anisotropic conductive film.

The tape carrier 25 is thin and easily bent, and easily peels off at the connection material 31 on the drive signal side when external force is applied. Therefore, the cured resin 37 to prevent peeling,
38 is applied to the connection between the display panel 29 and the tape carrier 25. and protective fixing parts 39, 40
The tape carrier 25 and the substrate 32 are sandwiched between the tape carrier 25 and the substrate 32 to prevent the tape carrier 25 from swinging and protect it from external force.

<Problems to be Solved by the Invention> In the above-mentioned conventional mounting method, when the connectable limit pitch of the drive-side connection material 31 is larger than the pitch of the drive signal lines 30 on the panel, the drive signal lines 30 on the display panel are For reasons such as the panel size becoming extremely large compared to the screen size, or the tape carrier 25 and substrate 32 protruding significantly outside the display panel 29, the display device must be expanded to a connectable pitch. The module size becomes large. In addition, cured resin 37, 38,
Protective fixing parts 39, 40, a separate board 32 for the common input line, etc. are required, which increases the cost of materials and the assembly process for assembling them, leading to an increase in cost. In the adhesive part of the above mounting method, the cured resin 37,
Since the tape carrier 25 and panel 29 are firmly attached at 38, even if the LSI 28 breaks down during use, it is impossible to replace the LSI chip. Because it protrudes, its strength is unstable. Furthermore, because the connection length is long, there is a large difference in thermal expansion between the panel 29 and the tape carrier 25, and when heat is applied to another board, it warps and applies force to the bonded part, so the thermal cycle reliability test is low. There are various problems inherent in this method.

<Objective of the Invention> An object of the present invention is to solve the above-mentioned problems and provide a compact, low-cost, high-strength, high-reliability device mounting method on a display panel that allows LSI chips to be replaced. .

<Means for Solving the Problems> In order to achieve the above object, the present invention arranges a plurality of tape carriers on which devices are mounted on a panel in parallel, and the leads patterned in an L-shape on the tape carrier body. The device is characterized in that a common input signal wiring group to each device is formed on the panel by connecting the wiring on the panel and the wiring on the panel.

<Embodiment> FIG. 1A shows the structure of a mounting method of a tape carrier device showing one embodiment of the present invention, and is a perspective view of a main part of a panel-shaped display device in which a plurality of tape carriers are mounted. Display devices to which the present invention can be applied include liquid crystal displays, plasma displays, EL displays, electrochromic displays, and the like.

Panel drive signal leads 2 and input signal leads 3 made of copper foil or the like are patterned on a tape carrier 1 with a small thermal expansion coefficient made of an organic resin film or the like on which an LSI 4 for driving and controlling the display panel is mounted. , one end of these leads is connected to the LSI 4 to which inner lead bonding is applied. The leads 2 and 3 can be arranged in fine pitches and at high density by using techniques such as thin film pattern processing, and are made of copper foil, tin foil, or tin-plated copper foil.

A tape carrier 1 is placed on the edge of the display panel 5.
A sufficient area is provided for stacking the panels, and panel drive signal wiring 6 and input signal common wiring 7 are formed in this area. Panel drive signal wiring 6
transmits a drive signal from the LSI 4 to a display section such as a liquid crystal cell, and drives the liquid crystal cell or the like to display a display. The input signal common wiring 7 is a wiring that is commonly connected to each of the LSIs 4 arranged in parallel along the edge of the display panel 5, and is arranged parallel to the direction in which the LSIs 4 are arranged in parallel in order to transmit input signals to the LSIs 4. has been done. Drive signal wiring 6
Both of the input signal common wiring 7 are fabricated by electroless plating of Ni on a transparent conductive film.

The LSI 4 is inserted into a through hole provided in the tape carrier 1, and electrically and mechanically fixed and held and connected by leads extending from the bottom surface of the tape carrier 1 to the through hole. 1st
FIG. B is a plan view showing an example of the arrangement pattern of the drive signal wiring 6 on the display panel 5. FIG. Even if the arrangement pitch A of the drive signal wiring lines 6 is smaller than the connection limit arrangement pitch B, conversion between these pitches can be achieved without extremely increasing the panel size. still,
In the figure, 5a shows the outer shape of the display screen, and 3a shows the input signal connection part.

Panel drive signal leads 2 and panel drive signal wiring 6, input signal leads 3 and input signal common wiring 7 arranged on at least two sides of the LSI 4
are electrically connected to each other by an anisotropic conductive film (not shown) that is inserted into the joint when the tape carrier 1 is mounted on the display panel 5. This anisotropic conductive film is composed of a sheet in which Ni (nickel) particles are dispersed, and not only contributes to electrical bonding, but also controls the overall adhesion between the tape carrier 1 and the panel 5. Note that the anisotropic conductive film is not supplied to the entire surface of the tape carrier 1 but only to the joint portion. Further, a resist 8 is printed on the back surface of the tape carrier 1 to maintain insulation between the input signal lead 3 and the input signal common wiring 7.

In the tape carrier device mounting method with the above structure, even if the connection limit pitch of the connection material between the leads directly connected to the display panel drive side, that is, the LSI 4, and the wiring on the panel is larger than the signal pitch of the drive wiring on the panel, the panel size is It does not become extremely large compared to its size, and the tape carrier and the separate board for the common input line do not protrude significantly outside the panel.

For these reasons, the module size can be made smaller than before.

The tape carrier 1 has a solid display panel 5 on its entire surface.
It is mounted on the top, and is connected to the display panel 5 on the entire bottom surface so as to be integrated with the display panel 5. Therefore, it is strong against external forces and does not require reinforcement with hardened resin or protective fixing parts unlike conventional structures. In addition, a common input signal line is formed on the panel, and a separate board for wiring this is not required.

Therefore, the number of parts is significantly reduced, and the cost of materials and production costs required for assembly are reduced. Therefore, it is possible to significantly reduce costs compared to the conventional technology. As mentioned above, a cured resin for reinforcing the strength of the tape carrier is not required, and the anisotropic conductive film bonding the tape carrier 1 and the display panel 5 can be easily peeled off by applying heat or the like. Yotsute LSI
Even if a defect occurs in the LSI 4, the LSI 4 can be easily replaced. Furthermore, since the tape carrier, panel, and common input signal line are integrated, and the tape carrier is protected from external forces, reliability in terms of strength is extremely high.

Since the connection is divided around the tape carrier 1, the connection length of the tape carrier 1 is short, so the difference in thermal expansion between the tape carrier and the panel is small, and there is no separate board that can warp when heated. Therefore, it is strong in reliability tests such as thermal cycles.

FIG. 2 is a perspective view of a mounting system for a tape carrier device showing another embodiment of the present invention, and the same reference numerals as in FIG. 1 indicate the same contents.

In this embodiment, the leads 2 and 3 directly connected to the LSI 4 are formed to protrude slightly outward at the end of the tape carrier 1. This is effective for facilitating alignment of the leads 2, 3 and the wirings 6, 7 on the display panel 5 below them. Also, a part of the tape carrier 3 is separated and cut at the notch 1a'.
As a result, the tape carrier 1 is divided into a plurality of regions, and the difference in thermal expansion is absorbed in these regions due to the presence of the notches 1a.

<Effects of the Invention> As explained in detail above, according to the present invention, the arrangement pitch of the common input signal wiring group can be easily converted to the arrangement pitch of the individual input signal leads,
Since the space factor gain can be obtained, it is possible to obtain a small and low-cost display panel with an integrated drive circuit.It also has high mechanical strength and reliability in use, and the structure and assembly process are simple, making it suitable for mass production. A suitable implementation method is established.

[Brief explanation of drawings]

FIG. 1A is a perspective view showing the structure of a tape carrier device mounting system according to an embodiment of the present invention. FIG. 1B is a plan view of a main part explaining the wiring pattern of FIG. 1. FIG. 2 is a perspective view showing the structure of a tape carrier device mounting system according to another embodiment of the present invention. FIG. 3 is a perspective view showing a conventional mounting method. FIG. 4 is a sectional view of the main part of FIG. 3. 1... Tape carrier, 2... Panel drive signal lead, 3... Input signal lead, 4...
LSI, 5...display panel, 6...panel drive signal wiring, 7...common wiring for input signals.

Claims (1)

[Claims] 1. In a tape carrier device mounting structure in which a plurality of tape-shaped carriers each carrying a device are arranged in parallel along the edge of a display panel, a common input signal wiring group to the device is connected to the edge of the display panel. Leads for individual input signals to the device are arranged in a pattern along an edge of the display panel and arranged in a substantially L-shape on the carrier,
A tape carrier device that is electrically connected to the common input signal wiring group via a conductive adhesive at a portion superimposed in parallel with the common input signal wiring group, and electrically connected to the device at a portion substantially perpendicular to the common input signal wiring group. implementation structure.