JPH07231009A - Connection structure of electronic parts and connecting method therefor and liquid crystal display module - Google Patents

Abstract

PURPOSE:To mount an LSI on an inexpensive film substrate such as PET film having a high precision interconnecting pattern made of ITO, etc., with applying little heat and reduce the size in the form of a package. CONSTITUTION:Connecting electrodes (bumps) 12 of an LSI 11 are connected to a connecting part 2a of a transparent conductor film 2 such as ITO film formed on a transparent film such as PET, and a light-setting resin 6 such as ultraviolet-setting resin is inserted between the LSI 11 and substrate 1 by coating, etc. The resin 6 is irradiated with light 16 such as ultraviolet ray to harden, thereby fixing the LSI 11 to the substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure and a connecting method for electronic parts such as LSI mounted on a film substrate, and a liquid crystal display provided by connecting a driver board mounted with the LSI by such a connecting method. It's about modules.

[0002]

2. Description of the Related Art For example, in a liquid crystal display device, a liquid crystal display panel, a circuit board and the like are modularized in order to facilitate handling at the time of assembly. As an example of a typical mounting mode of a conventional liquid crystal display module, a segment and a common LSI (Large Scale I) for segment and common are provided on two sides of the periphery of the liquid crystal display panel.
A plurality of driver boards each having an integrated circuit (large integration circuit) mounted thereon are joined together, and further, the driver boards are joined to control circuit boards respectively.

Usually, a TAB (Tape Automated Bond) is used for bare chip mounting on a driver substrate.
ing) method is used. In this TAB method, a square hole or a slit (opening) which is a device hole is provided in advance at a position where a chip (LSI) of a base film (driver board) is inserted, and a copper (Cu) foil is bonded onto the hole. This is a method in which the inner leads protruding in a finger shape into the device holes and the bump electrodes on the chip (LSI) side are bonded to each other after being laminated via the above to form a pattern.

[0004]

However, in the conventional TAB method, the film substrate made of polyimide is melted with solder or the like at the time of bonding of LSI and bonded through bumps. Since high heat is applied, a device hole or a slit (opening) is formed in the device portion so that the film is not melted by the high heat, and a circuit (wiring pattern) is formed inside thereof.
The u-foil is used as an inner lead to project in a finger shape to bond and hold the device (LSI), resulting in an increase in cost.

Also, the Cu foil as the inner lead is
Since the device (LSI) is held, a certain level of strength is required, and therefore a thickness of 10 to 30 μm or more is required. However, since the Cu foil for forming the wiring pattern is patterned by wet etching, it is difficult to form a fine pattern by the isotropic etching.
If the Cu foil becomes thick, a fine pattern cannot be formed. Therefore, in patterning the Cu foil, the pitch of 70 μm was the limit.

Therefore, since it is not possible to form a pattern with a fine pitch, the LSI corresponding thereto becomes large, and there is a problem that the mounting form cannot be made small.

Therefore, an object of the present invention is to provide an inexpensive and high-definition film substrate to an LSI with almost no heat applied.
An object of the present invention is to provide a connection structure and a connection method for an electronic component, which can be mounted on a board and can be mounted in a small size.

Another object of the present invention is to provide a liquid crystal display module equipped with a driver substrate on which an LSI is mounted by connecting the device by such a connecting method.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a connection structure of an electronic component in which a connection electrode is joined to a connection portion of a wiring pattern provided on a film substrate, for example, The wiring pattern is formed of a transparent conductive film such as ITO on a transparent film substrate such as PET, and the connection electrodes such as bumps of the electronic component such as LSI are bonded to the connection portions of the wiring pattern formed of the transparent conductive film. At the same time, this electronic component is fixed to the transparent film substrate via a photocurable resin such as ultraviolet light.

The invention according to claim 2 is a method of connecting an electronic component, wherein a connection electrode of the electronic component is joined to a connection portion of a wiring pattern provided on the film substrate,
For example, IT formed on a transparent film substrate such as PET
The connection electrode such as a bump of the electronic component such as an LSI is joined to the connection portion of the wiring pattern formed of a transparent conductive film such as O, and photocuring such as ultraviolet light is performed between the electronic component and the transparent film substrate. Of the photo-curable resin is applied to the transparent film substrate to cure the photo-curable resin by irradiating the photo-curable resin with light such as ultraviolet rays to fix the electronic component to the transparent film substrate.

According to a third aspect of the present invention, in a liquid crystal display module provided with a driver substrate on which an integrated circuit is mounted, which is joined to a side portion of the liquid crystal display panel, the driver substrate is, for example, ITO. A transparent film substrate such as PET in which connection electrodes such as bumps of the integrated circuit such as LSI are bonded to the connection portion of the wiring pattern by the transparent conductive film and the integrated circuit is fixed through a photocurable resin such as ultraviolet rays. It is characterized by being.

[0012]

According to the present invention, the transparent conductive film is formed on the transparent film substrate, the connection electrode of the electronic component is bonded to the connection portion of the transparent conductive film, and the electronic component and the transparent film. The photocurable resin is interposed between the substrate and
Since the photocurable resin is cured by irradiating it with light to fix the electronic component to the transparent film substrate, the electronic component such as an LSI can be mounted on the film substrate with almost no heat applied.

Moreover, by using a thin film of a transparent conductive material such as ITO for forming the wiring pattern on the film substrate,
For example, patterning with a pitch of 70 μm or less is also possible, and the mounting form can be miniaturized. And the connection is
Since a photocurable resin such as ultraviolet light that does not need to be heated is used, an inexpensive film substrate such as PET can be used, and a significant cost reduction can be expected.

According to a third aspect of the present invention, a driver substrate made of a transparent film substrate, in which an integrated circuit in which a connection electrode is joined to a connection portion of a transparent conductive film is fixed via a photocurable resin, is used as a liquid crystal display panel. Since the liquid crystal display module is provided by being bonded to the side portion of, the cost can be significantly reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a connecting structure and connecting method for electronic parts and a liquid crystal display module according to the present invention will be described below with reference to FIGS.

First, FIGS. 1 and 2 show a transparent film substrate on which an electronic component as an example to which the present invention is applied is mounted. 1 is a transparent film substrate, 2 is a transparent conductive film, and 2 is a transparent conductive film.
a is a connection part, 3 is a metal layer, 4 and 5 are wiring patterns, 6 is a photocurable resin, 11 is an LSI (electronic component), 12 is a connection electrode, and 16 is light.

The transparent film substrate 1 is, for example, PET.
An inexpensive transparent material such as (polyethylene terephthalate) or PES (polyether sulfone) is used. And, on the surface of the transparent film substrate 1,
For example, the transparent conductive film 2 is patterned with a transparent conductive material such as ITO (Indium Tin Oxide).

In the embodiment, the portion other than the portion on which the LSI 11 is mounted on the transparent conductive film 2 is, for example, nickel (Ni), gold (Au), or a two-layer metal composed of one metal thereof. The layer 3 is metallized to achieve low impedance (low resistance). As a result, predetermined wiring patterns 4 and 5 are formed. Then, the LSI 11 as an electronic component mounted between the wiring patterns 4 and 5 is mounted, for example, via a photocurable resin 6 which is cured by irradiation with light 16 such as ultraviolet rays.

Here, the LSI 11 is for driving a liquid crystal display, and Au is used as a connecting electrode on the lower surface of the LSI 11.
Alternatively, bumps 12, 12, ... By Au plating are provided. The bumps 12, 12, ... Are bonded to the connection portions 2a, 2a, ... Exposed from the metal layers 3, 3 ,.

The one wiring pattern 4 is connected to the circuit board side (not shown), and the other wiring pattern 5 is connected to the liquid crystal display panel 31 side shown in FIG. is there. Further, in the embodiment, the slit (opening) 1a is formed on the side of the transparent film substrate 1 on which the wiring pattern 5 is provided. That is, this slit 1
Due to the presence of a, the transparent film substrate 1 can be bent in a substantially right angle state.

Next, a method of patterning the transparent film substrate 1 and mounting the LSI 11 will be described.

First, a thin film is formed on the surface of a transparent film substrate 1 made of PET or PES by a transparent conductive material such as ITO, and by a known photolithography method, as shown in FIG. Except for the above, the transparent conductive films 2 and 2 are patterned to form predetermined wiring patterns 4 and 5. The thickness of the transparent conductive film 2 made of ITO is 1500 to 3000Å.

Furthermore, in the embodiment, the transparent conductive film 2 and the end portions of the transparent conductive film 2 are connected to the central portion including the connecting portions 2a and 2a, that is, LS.
The part where I11 is mounted, and the adjacent transparent conductive film 2,
A plating resist (not shown) is formed between the two, and a metal film of Ni or Au or a two-layered metal composed of the two metals is formed by plating on a portion other than this portion. Then, by removing the plating resist, as shown in FIG. 5, the metal layers 3 and 3 are formed on the transparent conductive films 2 and 2 to lower the impedance (lower the resistance). Note that N
The film thickness of the metal layer 3 made of i or Au or its two layers is 1
It is 000 to 30,000Å.

Thereafter, the portion of the transparent film substrate where the slit 1a is formed is removed by etching by the photolithography method, and the slit 1a is provided in this portion.

Next, as shown in FIG. 6, on the transparent film substrate 1, the transparent conductive films 2 and the connecting portions 2a at the two end portions,
A photo-curable resin 6 such as ultraviolet light is applied to almost the central portion including 2a, and Au or A is used as a connecting electrode from above.
L with u-plated bumps 12, 12, ...
Align SI11. That is, the transparent conductive films 2, 2,
The connection portions 2a, 2a, exposed from the metal layers 3, 3, ...
, And the bumps 12, 12, ... Of the LSI 11 are joined respectively.

Then, for example, as shown in FIG. 7, the transparent film substrate 1 is formed by a pair of pressure jigs 71, 72 which are vertically paired.
The LSI 11 is pressed while the photo-curable resin 6 is interposed therebetween. At this time, by using a transparent material such as a transparent resin for at least the lower pressing jig 71, irradiation of light such as ultraviolet rays described below is performed from below.

Thus, in a state where the LSI 11 is pressed while the photocurable resin 6 is interposed on the transparent film substrate 1, light 16 such as ultraviolet rays is irradiated from both the upper and lower sides of the transparent film substrate 1 as shown by the arrow in FIG. Irradiate almost the center of the.
At this time, the light 16 from below is applied to the pressing jig 71 made of a transparent material, the transparent film substrate 1, and the transparent conductive film 2.
2 reaches the photo-curable resin 6 after passing through the photo-curable resin 6, the photo-curable resin 6 is cured and the LSI is formed on the transparent film substrate 1.
11 is fixed.

By the way, in the embodiment, since the metal layer 3 is provided up to the vicinity of the connecting portion 2a at the end of the transparent conductive film 2, as shown by the arrow in FIG.
It is necessary to irradiate almost the central portion of the transparent film substrate 1 to cure the photocurable resin 6 on the metal layer 3. However, if the metal layer 3 is set back further outward so that the photocurable resin 6 is barely placed on the metal layer 3, it is sufficient to irradiate the light 16 from below.

Further, in the embodiment, the photocurable resin 6 is applied to the transparent film substrate 1 and then the LSI 11 is aligned. However, conversely, after the LSI 11 is aligned on the transparent film substrate 1. The photocurable resin 6 may be applied and interposed between them. The electronic components to be mounted are not limited to LSIs, and other ICs (Inte
It may be a gated circuit (integrated circuit) or the like.

As described above, the photo-curable resin 6 such as ultraviolet rays is applied to almost the central portion including the connecting portion 2a of the transparent conductive film 2 made of ITO of the transparent film substrate 1 made of PET or PES, and the connecting portion 2a is applied. The bumps 12 of Au or Au plating of the LSI 11 are joined, and light 16 such as ultraviolet rays is irradiated from below the transparent film substrate 1 to cure the photocurable resin 6 interposed between the LSI 11 and the LSI 11. Is fixed to the transparent film substrate 1, and the LSI 11 can be mounted on the transparent film substrate 1 with almost no heat applied as in the conventional case.

Further, since the transparent conductive film 2 made of ITO is used to form the wiring patterns 4 and 5 on the transparent film substrate 1, it is possible to perform patterning with a pitch of 70 μm or less, for example. Can be realized. Further, as in the example, the transparent conductive film 2 is metallized (the metal layer 3 is formed), so that the impedance can be lowered.

Moreover, since the connection uses the photocurable resin 6 such as ultraviolet rays which does not need to be heated, an inexpensive transparent film substrate 1 made of PET or PES can be used, and a significant cost reduction can be expected. Also, regarding the reliability of the connection of the LSI 11, since the flexible transparent film substrate 1 is used, variations in height of the bumps 12 are absorbed to some extent, and the reliability is high.

FIG. 3 shows an example of a liquid crystal display module 30 in which the transparent film substrate 1 on which the LSI 11 is mounted is connected to the liquid crystal display panel 31 as described above. The liquid crystal display panel 31 seals the liquid crystal 34 between the upper and lower transparent substrates 32 and 33 made of glass or film with a seal material 35 formed around the upper and lower transparent substrates 32 and 33. A transparent conductive film 36 for driving a liquid crystal display made of ITO is patterned. The end of the transparent conductive film 36 serves as the connection terminal 36a.

For such a liquid crystal display panel 31,
An end portion of the wiring pattern 5 ahead of the slit 1a of the transparent film substrate 1 as the driver substrate is anisotropically connected to the connection terminal 36a of the transparent conductive film 36 for driving the liquid crystal display made of ITO on the upper surface of the lower transparent substrate 33. It is connected via a conductive adhesive 37.

In this anisotropic conductive adhesive 37, the conductive particles 37a, 37a, ...
7b, and by heating with pressure, the connection terminals 36a of the transparent conductive film 36 of the liquid crystal display panel 31 and the transparent film substrate 1 of the transparent film substrate 1 via the conductive particles 37a, 37a ,. The binder 37b is hardened and fixed to each other while electrically connecting to the wiring pattern 5.

In this way, the transparent film substrate 1 is connected to the liquid crystal display panel 31 in a state where the transparent film substrate 1 is bent at a substantially right angle through the slits 1a to form the liquid crystal display module 30. The other wiring pattern 4 of the transparent film substrate 1 is connected to the control circuit board side (not shown).

As described above, in the liquid crystal display module 30, as a driver substrate provided by being joined to the side portion of the liquid crystal display panel 31, the bump 12 made of Au or Au plating is joined to the connecting portion 2a of the transparent conductive film 2 made of ITO. A transparent film substrate 1 made of PET or PES in which the LSI 11 is fixed via a photocurable resin 6 such as ultraviolet rays.
By using, it is possible to contribute to a significant cost reduction.

In the above embodiments, part of the circuit is metallized with Ni or Au in order to lower the impedance, but the present invention is not limited to this.
It is not always necessary to perform metallization. Further, the application of the present invention is not limited to the liquid crystal display module of the embodiment, but is arbitrary, and it is needless to say that the specific detailed structure and the like can be appropriately changed.

[0039]

As described above, according to the connecting structure and the connecting method of the electronic parts according to the inventions of claims 1 and 2, the connecting part of the transparent conductive film formed on the transparent film substrate is connected to the connecting electrode of the electronic part. Since the electronic components can be fixed to the transparent film substrate by irradiating the photo-curable resin interposed between the electronic components and the transparent film substrate with light to cure it, almost all the heat is applied. It is possible to mount an electronic component such as an LSI on a film substrate without using it.

Moreover, since the thin film of the transparent conductive material such as ITO is used for forming the wiring pattern on the film substrate, for example, the patterning of 70 μm pitch or less is also possible, and the miniaturization of the mounting form can be realized. Since the connection uses a photocurable resin such as ultraviolet light that does not need to be heated, an inexpensive film substrate such as PET can be used, and thus a significant cost reduction can be achieved.

According to the liquid crystal display module of the third aspect of the invention, an integrated circuit in which a connecting electrode is joined to the connecting portion of the transparent conductive film is provided as a driver substrate provided to be joined to the side portion of the liquid crystal display panel. Since a transparent film substrate in which is fixed via a photocurable resin is used, it is possible to contribute to a significant cost reduction.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a transparent film substrate on which an electronic component as an example to which the present invention is applied is mounted.

FIG. 2 is a vertical sectional side view of the transparent film substrate of FIG.

FIG. 3 is a vertical side view showing an example of a liquid crystal display module in which the transparent film substrate of FIG. 1 is connected to a liquid crystal display panel.

FIG. 4 is a vertical sectional side view showing a state in which a transparent conductive film is formed on a transparent film substrate.

5 is a vertical cross-sectional side view showing a state in which a metal layer is formed on the transparent conductive film of FIG.

6 is a vertical cross-sectional side view showing an example of how to mount the electronic component according to the present invention on the transparent film substrate of FIG.

FIG. 7 is a vertical cross-sectional side view showing an example of a state where electronic components are mounted on the transparent film substrate of FIG. 5 and pressed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 transparent film substrate 2 transparent conductive film 2a connection part 3 metal layer 4,5 wiring pattern 6 photocurable resin 11 LSI 12 connection electrode 16 light 30 liquid crystal display module 31 liquid crystal display panel 32, 33 transparent substrate 34 liquid crystal 35 sealant 36 Transparent conductive film 36a Connection terminal 37 Anisotropic conductive adhesive 37a Conductive particle 37b Binder

Claims (3)

[Claims] 1. In a connection structure of an electronic component, wherein a connection electrode is joined to a connection portion of a wiring pattern provided on a film substrate, the wiring pattern is formed by a transparent conductive film on a transparent film substrate, and the transparent conductive film is formed by the transparent conductive film. A connection structure for an electronic component, wherein the connection electrode of the electronic component is joined to the connection portion of a wiring pattern, and the electronic component is fixed to the transparent film substrate via a photocurable resin. 2. A method of connecting an electronic component, wherein a connection electrode of an electronic component is joined to a connection portion of a wiring pattern provided on a film substrate, wherein the wiring pattern is formed of a transparent conductive film formed on a transparent film substrate. While joining the connection electrode of the electronic component to the connection portion, a photo-curable resin is interposed between the electronic component and the transparent film substrate, and the photo-curable resin is irradiated with light to be cured. A method for connecting electronic components, comprising fixing the electronic components to the transparent film substrate. 3. A liquid crystal display module comprising a driver substrate on which an integrated circuit is mounted, which is bonded to a side portion of a liquid crystal display panel, wherein the driver substrate is integrated at a connection portion of a wiring pattern made of a transparent conductive film. A liquid crystal display module, which is a transparent film substrate in which connecting electrodes of circuits are joined and the integrated circuit is fixed via a photocurable resin.