JP2001077154A - Semiconductor chip mounting method, semiconductor chip mounting structure, and chip-integrated liquid crystal display module - Google Patents

Abstract

(57) Abstract: Provided is a method of mounting a semiconductor chip capable of ensuring high connection reliability by ensuring that a semiconductor chip is electrically connected to a wiring pattern. SOLUTION: A connection terminal portion 11A on a mounting board 10A,
The bumps BP of the semiconductor chip IC are abutted against the anisotropic conductive film 30 against 21A, and these connection terminal portions 1
This is a method for mounting a semiconductor chip in which a semiconductor chip IC is bonded to a mounting substrate 10A while conducting an electrical connection between 1A, 21A and a bump BP by an anisotropic conductive film 30. While the insulating layer 40 is formed on the terminal portions 11A and 21A, each portion of the insulating layer 40 has a smaller area than the bump BP and is connected to the connection terminal portions 11A and 21A.
A is formed beforehand, and after forming an anisotropic conductive film 30 on the surface of the insulating layer 40 while filling the opening 40A, a semiconductor is formed via the anisotropic conductive film 30. The chip IC is mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mounting a semiconductor chip on a mounting substrate via an anisotropic conductive film via a semiconductor chip, a mounting structure of a semiconductor chip constituted by such a mounting method, and The present invention relates to a chip-integrated liquid crystal display module having a structure in which a semiconductor chip such as a driver IC is directly mounted on a glass substrate or the like.

[0002]

2. Description of the Related Art For example, a liquid crystal display module incorporated in a liquid crystal television or a mobile phone has a structure in which a semiconductor chip such as a driver IC is directly mounted on one glass substrate serving as a liquid crystal display surface, so-called COG (Chip On Chip). Glas
s) There is a method. FIG. 7 is a schematic perspective view showing an example of a general COG type liquid crystal display module. The liquid crystal display module X has a liquid crystal sealing portion between two overlapping glass substrates 100 and 200. It is composed. One of the substrates 100 is a portion extending from a side portion 200A of the other substrate 200 as a mounting substrate (extending portion 100).
A). The extending portion 100A is provided with the transparent electrode pattern 11 so as to be pulled out from the liquid crystal sealing portion.
The semiconductor chip IC is bonded to the transparent electrode patterns 110 and 210 in a state where they are exposed.

FIG. 8 is an enlarged cross-sectional view showing an enlarged cross section taken along the line II of FIG. 7. When the mounting structure of the semiconductor chip IC is referred to with reference to FIG. In the protruding portion 100A, the transparent electrode patterns 110, 2
An anisotropic conductive film 300 is formed so as to cover the ten connection terminal portions 110A and 210A. After the semiconductor chip IC presses and heats the anisotropic conductive film 300, the semiconductor chip IC is pressed against the connection terminal portions 110A and 210A while aligning the bumps BP from above the anisotropic conductive film 300. Then, it is joined on the extension 100A via the finally solidified anisotropic conductive film 300.

FIG. 9 is an enlarged cross-sectional view showing the vicinity of the bump BP shown in FIG. 8 in a further enlarged manner. As shown in FIG. The conductive particles 300A are dispersed and mixed in the adhesive base material 300B, and have conductivity in the thickness direction.
The insulating property is maintained in the plane direction. By using such an anisotropic conductive film 300, a gap along the thickness direction between the bump BP and the connection terminal portions 110A and 210A is in a state where the conductive particles 300A are interposed together with the adhesive base material 300B. The semiconductor chip IC and the transparent electrode patterns 110 and 210 can be conducted through the conductive particles 300A.

[0005]

In a semiconductor chip IC for driving a liquid crystal, the number of bumps BP serving as a contact tends to increase as the definition of a liquid crystal display increases. When the number of bumps BP increases, the bump pitch becomes narrower, and the outer size of the bump BP itself also inevitably decreases. Then, the facing width of each of the bumps BP facing the connection terminal portions 110A and 210A decreases, and when the semiconductor chip IC is pressed from above the anisotropic conductive film 300, the gap between the bump BP and the connection terminal portions 110A and 210A is reduced. A sufficient number of conductive particles 300A cannot be interposed,
Alternatively, there is a possibility that a part of the conductive particles 300A may flow out from the gap in the lateral direction. As a result, for example, the semiconductor chip IC and the transparent electrode patterns 110, 2
Therefore, an electrical trouble that hardly conducts between the semiconductor chip IC and the semiconductor chip IC occurs, and high connection reliability cannot be obtained as a mounting structure of the semiconductor chip IC.

Therefore, the present invention was conceived under the circumstances described above, and it is possible to obtain a high connection reliability by ensuring that the semiconductor chip is electrically connected to the wiring pattern. It is an object to provide a semiconductor chip mounting method, a semiconductor chip mounting structure, and a chip-integrated liquid crystal display module.

[0007]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

That is, according to the method for mounting a semiconductor chip provided by the first aspect of the present invention, an anisotropic conductive film is formed so as to cover a wiring pattern exposed on a mounting substrate, while the connection of the wiring pattern is performed. The bump of the semiconductor chip is abutted against the terminal part from above the anisotropic conductive film,
A method of mounting a semiconductor chip in which the semiconductor chip is bonded to the mounting substrate while the connection terminal portions and the bumps are electrically connected by the anisotropic conductive film, and before forming the anisotropic conductive film, While an insulating layer is formed on the wiring pattern, openings are formed in various parts of the insulating layer with smaller holes than the bumps and reach the connection terminal portions, and the openings are filled while filling these openings. After the anisotropic conductive film is formed on the surface of the insulating layer, the semiconductor chip is joined to the mounting substrate by pressing the bump from above the opening.

A semiconductor chip mounting structure provided by the second aspect of the present invention is characterized by being manufactured by the semiconductor chip mounting method according to the first aspect.

Further, in the chip-integrated liquid crystal display module provided by the third aspect of the present invention, one of the two transparent substrates superposed for liquid crystal display has a wiring pattern as a wiring pattern. A chip-integrated liquid crystal display module in which a transparent electrode pattern is formed exposed and a semiconductor chip is bonded to one of the substrates as a mounting substrate, wherein the semiconductor chip is mounted on the semiconductor chip according to the second side surface. It is characterized in that it is bonded on the one substrate by a structure.

The mounting structure of the semiconductor chip according to the second aspect is completed through the mounting method according to the first aspect. The chip-integrated liquid crystal display module according to the third aspect applies the mounting structure according to the second aspect, and includes a COG method using a transparent substrate as a glass substrate, or a transparent substrate as a film substrate. This is applied to a COF (Chip On Film) method.

A semiconductor chip mounting method according to the first aspect, a semiconductor chip mounting structure according to the second aspect,
According to the chip-integrated liquid crystal display module according to the third aspect, the wiring pattern, the insulating layer, and the anisotropic conductive film are sequentially formed from the mounting substrate. In the insulating layer formed between the wiring pattern and the anisotropic conductive film, openings having a depth reaching the connection terminals of the wiring pattern are formed in various places. The state where the film is applied is obtained. Then, bumps of the semiconductor chip are butted against connection terminal portions of the wiring pattern while softening the anisotropic conductive film by heating or the like. In other words, by crimping while positioning the bumps of the semiconductor chip on the openings,
The semiconductor chip is bonded to the mounting substrate with the anisotropic conductive film interposed between the bump and the connection terminal. At this time, the anisotropic conductive film interposed between the bump and the connection terminal is in a state of being sealed in the opening, and a sufficient width and thickness for providing conductivity are secured. Therefore, when the semiconductor chip is pressure-bonded from above the anisotropic conductive film, the anisotropic conductive film having a sufficient width and thickness is stably present in the gap between the bump and the connection terminal portion. The semiconductor chip can be reliably made conductive with respect to the wiring pattern without causing an electrical trouble such as no electrical connection with the wiring pattern, and high connection reliability can be obtained as a bonding form of the semiconductor chip to the mounting substrate. be able to.

In a preferred embodiment of the present invention according to the first to third aspects, the thickness of the insulating layer is formed to be smaller than the particle size of conductive particles contained in the anisotropic conductive film. It can be configured.

According to such a configuration, the conductive particles dispersed and mixed in the anisotropic conductive film provide conductivity in the thickness direction, but such conductive particles flow out of the opening. Without, since it is retained in the opening in a state that it partially protrudes from the upper part of the opening, it is possible to make the state in which the bump is in contact with the upper side of the conductive particles and the connection terminal is in contact with the lower side thereof, The semiconductor chip can be reliably conducted to the wiring pattern with such conductive particles interposed therebetween.

In another preferred embodiment, the periphery of the bump that goes from the bottom surface to the side surface may be formed in a curved shape.

According to such a configuration, for example, when a bump having a small external size is formed, the periphery of the bump may be formed in a curved shape by a semiconductor fine processing technique such as etching. Even if the bump has a peripheral portion, the conductive particles in the opening can always be brought into contact with the relatively flat bottom surface of the bump, and the semiconductor chip can be reliably conducted to the wiring pattern. .

In still another preferred embodiment,
The opening may have a smaller diameter than the periphery of the bump.

According to such a configuration, the relatively flat bottom surface of the bump can be positioned on the opening while avoiding the curved peripheral portion, and the bump remains with respect to such a bottom surface in the opening. In a state where the conductive particles are in contact with each other, the semiconductor chip can be reliably conducted to the wiring pattern.

Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic perspective view showing an embodiment of a liquid crystal display module to which a semiconductor chip mounting structure according to the present invention is applied, and FIG. 2 is an enlarged cross section taken along line II-II of FIG. It is the expanded sectional view shown. In each of the drawings, portions that are not related to the features of the present invention are simplified for convenience. The dimensions in the thickness direction are shown with some emphasis.

As shown in these figures, in the liquid crystal display module A according to the present invention, the two glass substrates 10 and 20 serving as the liquid crystal display surface are overlapped. It has an extension 10A for mounting a semiconductor chip so as to protrude from the side 20a.
The semiconductor chip IC is, for example, a driver IC for driving a liquid crystal, and is integrated by being directly mounted on the extension portion 10A. Such a liquid crystal display module A is referred to as a COG type bonding mode.

From the liquid crystal sealing portion L formed between the two glass substrates 10 and 20 to the extension portion 10A, the transparent electrode pattern 11 as a wiring pattern comprising a large number of signal lines is provided.
21 are formed. On the surface of the extension 10A,
The transparent electrode patterns 11 and 21 are exposed, and as shown in FIG.
The connection terminal portions 11A, 21A of 21 are wired near the mounting location of the semiconductor chip IC. Also, the extension part 10A
An external connection pattern 13 for connecting the semiconductor chip IC to the outside is also exposed on the surface of the semiconductor chip IC. The connection terminal portion 13A of the external connection pattern 13 is wired near the mounting position of the semiconductor chip IC, while the external terminal portion 13B used for connection with the outside is extended to the extension portion 10A.
It is wired near the end.

The semiconductor chip IC is joined to the transparent electrode patterns 11 and 21 and the external connection pattern 13 in a conductive state. For this reason, in the present embodiment, an anisotropic conductive material is used as an adhesive. While the conductive film 30 is used, the insulating layer 40 is formed before the anisotropic conductive film 30 is formed.
Is formed. Explaining with reference to FIG.
0A, the exposed transparent electrode patterns 11, 21 and the external connection pattern 13, the insulating layer 40, the anisotropic conductive film 3
0 are formed in that order. Each pattern 11, 21, 1
3 and the anisotropic conductive film 30, the connecting terminal portions 11A, 11A,
By removing portions corresponding to 21A and 13A, an opening 40A having a depth in the thickness direction is formed. The anisotropic conductive film 30 is formed on the surface of the insulating layer 40 through the opening 40A.
In the state of being attached over the inside. The bump BP of the semiconductor chip IC is press-bonded from above the anisotropic conductive film 30 in a state where the bump BP is aligned with the opening 40A, and the bump BP and the connection terminal portion 11 are interposed via the anisotropic conductive film 30.
A, 21A and 13A are electrically connected.

FIG. 3 is an enlarged cross-sectional view of a main portion showing the vicinity of the bump BP shown in FIG. 2 in further enlargement. Referring to FIG.
The bump BP has a structure protruding above the mounting surface of the semiconductor chip IC, and has a relatively flat bottom surface BP1 and side surfaces BP2. The peripheral portion BP3 that goes from the bottom surface BP1 to the side surface BP2 has a slightly rounded curved shape with a maximum width of about 5 μm because the outer size S of the bump BP is reduced to, for example, about several tens of μm. ing.

The anisotropic conductive film 30 is made of, for example, nickel,
Conductive particles 30A such as solder are dispersed and mixed in an adhesive base material 30B such as epoxy resin. The properties of the anisotropic conductive film 30 are designed to have conductivity in the thickness direction by the conductive particles 30A, while maintaining insulation in the plane direction. The particle size of the conductive particles 30A is about 5 μm. Such an anisotropic conductive film 30 is softened by pressurizing and heating when the semiconductor chip IC is pressed, and then exerts a strong adhesive force by being solidified by cooling or the like. Further, the anisotropic conductive film 30 is a semiconductor chip IC
Has a sufficient thickness so as to adhere to the mounting surface (lower surface).

The insulating layer 40 is formed by applying, for example, a polyimide resin, which is a photosensitive heat-resistant resin, over the entire surface of the connection terminal portions 11A and 21A, and performing photoetching or the like to form the opening 40A. The thickness T of the insulating layer 40 is about 1 to 5 μm, which is smaller than the particle size of the conductive particles 30A.
Corresponding to the depth of The opening 40A is connected to the connection terminal 11.
It is formed only in portions corresponding to A, 21A and the like.
The diameter D of the opening 40A is smaller than the peripheral portion BP3 of the bump BP, that is, a size corresponding to the width of the bottom surface BP1 of the bump BP. Inside the opening 40A, the anisotropic conductive film 30 softened by pressurization and heating is attached, so that the conductive particles 30
A is sealed in the opening 40A without flowing out of the opening 40A. Since the depth T of the opening 40A is formed smaller than the particle size of the conductive particles 30A,
The conductive particles 30A in the opening 40A are partially protruded from the upper part of the opening 40A, and the bottom surface BP1 of the bump BP is formed.
While the connection terminals 11A, 21
A is brought into contact with A. In short, a sufficient number of conductive particles 30A contributing to conductivity are stably sandwiched in the gap along the thickness direction between the bump BP and the connection terminal portions 11A and 21A.

Next, the operation of the present embodiment will be described with reference to FIGS. 4 to 6.

FIGS. 4 to 6 are explanatory diagrams shown for explaining a method of mounting a semiconductor chip IC. In these drawings, only the main part of the liquid crystal display module is shown. FIG. 5 is a perspective view corresponding to FIG.

First, as shown in FIGS. 4 and 5, a transparent electrode pattern 1 is formed on the extension 10A of the glass substrate 10.
1, 21 and connection terminal portions 11A of the external connection pattern 13,
An insulating layer 40 is formed so as to cover 21A and 13A. Then, the connection terminal portions 11A, 21A, 1 of the insulating layer 40 are formed.
A small opening 40A is formed in a portion corresponding to 3A by photoetching or the like. Although the insulating layer 40 is formed only in the vicinity of the place where the semiconductor chip IC is mounted on the extension 10A in the drawing, the extension 10A
The insulating layer 40 may be formed over the entire surface of the substrate. In such a case, the exposed transparent electrode pattern 1
The insulating layer 40 can function as a protective film such as 1, 21 or the like.

Next, as shown in FIG. 6, after the anisotropic conductive film 30 is adhered over the entire surface of the insulating layer 40, the anisotropic conductive film 30 is softened by applying pressure and heat.
The semiconductor chip IC is pressure-bonded from above the anisotropic conductive film 30 using a suction collet C or the like. At this time, the semiconductor chip I
The bump BP of C is aligned with the opening 40A. The anisotropic conductive film 30 is softened to form the opening 40A.
Inside. Thus, the semiconductor chip I
When C is pressed, as shown in FIG. 3, the bottom surface BP1 of the bump BP is brought into contact with the conductive particles 30A remaining in the opening 40A, and the conductive particles 30A contacting such a bottom surface BP1. Are secured in a sufficient number by being enclosed in the opening 40A. Also, bump BP
The conductive particles 30A in contact with the bottom surface BP1 are also in contact with the connection terminals 11A and 21A (13A) below. That is, the bump BP and the connection terminal 11A,
21A (13A) is initially randomly present in the anisotropic conductive film 30, but is poorly connected to each other by passing through a sufficient number of conductive particles 30A that fit in the opening 40A and remain stably. The conduction state is ensured without fear of occurrence.

Therefore, according to the liquid crystal display module A configured through the above mounting method, when the semiconductor chip IC is pressure-bonded from above the anisotropic conductive film 30, the bump BP and the connection terminal portions 11A, 21A, 13A are connected to each other. An anisotropic conductive film 30 having a sufficient width and thickness is stably enclosed in the opening 40A in the gap. The conductive particles 30A in the anisotropic conductive film 30 are also stably secured in the opening 40A. Therefore, the bumps BP and the connection terminals 11A, 21A, 13A are formed through the conductive particles 30A in the openings 40A.
Are reliably brought into conduction, so that the semiconductor chip I
The semiconductor chip IC can be reliably conducted to the transparent electrode patterns 11, 21 and the like without causing any trouble such as an electrical connection failure between C and the transparent electrode patterns 11, 21 and the like. Chip IC substrate 10
High connection reliability can be obtained as a bonding mode for

In the above embodiment, the present invention is applied to the liquid crystal display module A. However, it goes without saying that the present invention is not limited to the liquid crystal display module but can be applied to other mounted components.

The shape of the bump BP is not limited to the shape shown in the figure, and may be a complete straight wall type or mushroom type bump.

Further, as a mounting structure in a general liquid crystal display module, the mounting portion of the semiconductor chip IC is set as the extension 10A.
Needless to say, the present invention can be applied to a case where a semiconductor chip is mounted in a portion other than A.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a liquid crystal display module to which a semiconductor chip mounting structure according to the present invention is applied.

FIG. 2 is an enlarged cross-sectional view showing a cross section taken along line II-II of FIG.

FIG. 3 is an enlarged cross-sectional view of a main part, showing the vicinity of a bump shown in FIG. 2 in a further enlarged manner.

FIG. 4 is an explanatory diagram for explaining a method of mounting a semiconductor chip;

FIG. 5 is an explanatory diagram for explaining a method of mounting a semiconductor chip;

FIG. 6 is an explanatory diagram shown to explain a method of mounting a semiconductor chip;

FIG. 7 is a schematic perspective view showing an example of a liquid crystal display module according to a general COG method.

FIG. 8 is an enlarged cross-sectional view showing a cross-section along line II of FIG. 7 in an enlarged manner.

FIG. 9 is an enlarged cross-sectional view of a main part, in which the vicinity of the bump shown in FIG. 8 is further enlarged.

[Explanation of symbols]

 Reference Signs List 10 glass substrate (mounting substrate) 20 glass substrate 11, 21 transparent electrode pattern (wiring pattern) 11A, 21A connection terminal portion 30 anisotropic conductive film 30A conductive particle 30B adhesive base material 40 insulating layer 40A opening A liquid crystal display module IC Semiconductor chip BP bump

Claims (6)

[Claims] An anisotropic conductive film is formed so as to cover a wiring pattern exposed on a mounting substrate, and a bump of a semiconductor chip is formed on the connection terminal portion of the wiring pattern from above the anisotropic conductive film. A method for mounting the semiconductor chip on the mounting substrate while electrically connecting the connection terminal portions and the bumps with the anisotropic conductive film, the method comprising forming the anisotropic conductive film. Before forming, an insulating layer is formed on the wiring pattern, and openings each having a smaller area than the bumps and reaching the connection terminal portion are formed at various portions of the insulating layer, and the insides of these openings are formed. After forming the anisotropic conductive film on the surface of the insulating layer while filling, the semiconductor chip is joined to the mounting substrate by pressing the bump from above the opening. That,
How to mount semiconductor chips. 2. The method for mounting a semiconductor chip according to claim 1, wherein the thickness of the insulating layer is formed smaller than the particle size of conductive particles contained in the anisotropic conductive film. 3. The method of mounting a semiconductor chip according to claim 1, wherein a peripheral portion of the bump that extends from the bottom surface to the side surface is formed in a curved shape. 4. The method according to claim 3, wherein the opening has a smaller diameter than a peripheral portion of the bump. 5. A semiconductor chip mounting structure manufactured by the semiconductor chip mounting method according to any one of claims 1 to 4. 6. A transparent electrode pattern as a wiring pattern is formed on one of two transparent substrates which are superposed for liquid crystal display, and a semiconductor chip is bonded to the one substrate as a mounting substrate. A chip-integrated liquid crystal display module, wherein the semiconductor chip is joined to the one substrate by the semiconductor chip mounting structure according to claim 5. LCD module.