JP2003124258A - Mounting method of semiconductor chip and mounting structure of semiconductor chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting method of a semiconductor chip and the mounting structure of the semiconductor chip, which are capable of surely conducting the bumps of respective semiconductor chips to connecting terminal units on a substrate, in the case that a plurality of semiconductor chips are mounted on the substrate through an anisotropic conductive film. SOLUTION: A plurality of semiconductor chips, on which a plurality of bumps are formed so as to be projected, are mounted on the substrate, on the surface of which a plurality of connecting terminal units are formed so as to be opposed to each bumps respectively so that the bumps are conducted to each connecting terminals through the anisotropic conductive film. The plurality of semiconductor chips are formed so that thicknesses are different from each other as a whole and when the semiconductor chips are mounted, the chips are welded by pressure onto the substrate sequentially from the chip having a thinner thickness to the same having a thicker thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip mounting method for mounting a plurality of semiconductor chips on a substrate via an anisotropic conductive film, and a semiconductor chip mounting structure.

[0002]

2. Description of the Related Art In a semiconductor chip mounting structure, a plurality of semiconductor chips having a plurality of bumps formed thereon are formed on a substrate on which a plurality of connection terminal portions corresponding to the respective bumps are formed on the surface. In some cases, it is mounted via an anisotropic conductive film. An example of this type of conventional semiconductor chip mounting structure is shown in FIG. This semiconductor chip mounting structure is applied to a liquid crystal display module 100 incorporated in, for example, a liquid crystal television or a mobile phone, and the two semiconductor chips 101 and 102 are used as a glass for one of the liquid crystal display surfaces. Structure mounted directly on the board 3,
The so-called COG (Chip On Glass) system is used.

This liquid crystal display module 100 has two glass substrates 3 and 3'which are overlapped with each other, and a liquid crystal sealing portion is formed between them. One substrate 3 is
It has an extending portion 3A formed so as to protrude from the side portion of the other substrate 3 ', and two semiconductor chips 101 and 102 are mounted on the surface of this extending portion 3A. More specifically, a transparent electrode pattern is formed on the surface of the extending portion 3A so as to be pulled out from the liquid crystal sealing portion, and each portion of the transparent electrode pattern is formed on each semiconductor chip as shown in FIG. A plurality of bumps 11 provided on 101 and 102
A plurality of connection terminal portions 31 corresponding to each of the above. The semiconductor chips 101 and 102 are mounted so that the bumps 11 and the connection terminal portions 31 are electrically connected via the anisotropic conductive film 4.

The two semiconductor chips 102 and 103 are ICs for driving the liquid crystal display module, and have substantially the same thickness as a whole. Further, these two semiconductor chips 101 and 102 are arranged adjacent to each other on the substrate 3 in order to miniaturize the liquid crystal display module 100 and the like, and accordingly, in the liquid crystal display module 100, As the anisotropic conductive film 4, the one common to both the semiconductor chips 101 and 102 is used.

The anisotropic conductive film 4 is, for example, as shown in FIG.
And as shown in FIG. 9B, resin balls 41a
Conductive particles 41 formed by plating a conductive layer 41b such as Ni or Au on the surface of are dispersed and mixed in an adhesive base material 42 having an insulating property such as an epoxy resin. If such an anisotropic conductive film 4 is used, a gap along the thickness direction between the bump 11 and the connection terminal portion 31 will be formed.
By interposing the conductive particles 41 so as to sandwich the conductive particles 41, the bumps 11 and the connection terminal portions 31 can be electrically connected via the conductive particles 41.

In order to mount the semiconductor chips 101 and 102, the anisotropic conductive film 4 is formed on the substrate 3, and the bumps 11 are connected to the connection terminal portions 31 of the semiconductor chips 101 and 102, respectively. It is placed on the substrate 3 in a corresponding manner. After that, the semiconductor chips 101 and 102 are mounted on the substrate 3
Crim on top. When crimping the semiconductors 101 and 102, as shown in FIG. 8, a well-known crimping head D that presses the semiconductor chips 101 and 102 toward the substrate 3 while heating them.
Is generally used. By using such a pressure bonding head D, the adhesive base material 42 is softened, the semiconductor chips 101 and 102 are bonded onto the substrate 3, and the conductive particles 41 are connected to the bumps 11 and the connection terminals. Each bump 11 is sandwiched between the bumps 11 and the portion 31.
The electrical connection between the connection terminal portion 31 and each of the connection terminal portions 31 can be achieved. In this way, the semiconductor chips 101 and 102 are thermocompression bonded onto the substrate 3. The crimping head D is generally larger in size than the semiconductor chips 101 and 102, and the two semiconductor chips 101 and 102 have a substantially total thickness as described above. Since they are equivalent and are arranged adjacent to each other, thermocompression bonding of the two semiconductor chips 101 and 102 to the substrate 3 is performed collectively.

However, the two semiconductor chips 10
Although the total thicknesses of the layers 1, 102 are substantially equal to each other, for example, when the upper surfaces are not placed on the same plane when placed on the anisotropic conductive film 4, or When the pressure bonding head D and the upper surfaces of the respective semiconductor chips 101 and 102 are not arranged in parallel, when the pressure bonding head D is used to collectively press the two semiconductor chips 101 and 102, The pressing force applied to 102 may vary from part to part. As a result, for example, as shown in FIG. 9A, the conductive particles 41 are crushed between the bumps 11 of the semiconductor chips 101 and 102 and the connection terminal portions 31, so that the surface of the conductive particles 41 is removed. The crack 40 may occur in the conductive layer 41b. In addition, for example, as shown in FIG. 9B, the distance between the bump 11 and the connection terminal portion 31 becomes larger than the diameter of the conductive particle 41, and the conductive particle 41.
May not come into contact with both the bump 11 and the connection terminal portion 31. In these cases, the conductive particles 41 cannot electrically connect the bump 11 and the connection terminal portion 31 to each other, which causes a problem that the semiconductor chips 101 and 102 have a poor connection.

[0008]

The present invention has been conceived under the above-mentioned circumstances, and in the case of mounting a plurality of semiconductor chips on a substrate through an anisotropic conductive film, It is an object of the present invention to provide a semiconductor chip mounting method and a semiconductor chip mounting structure capable of surely connecting the bumps of the respective semiconductor chips to the connection terminal portions on the substrate.

[0009]

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

That is, in the semiconductor chip mounting method provided by the first aspect of the present invention, a plurality of semiconductor chips having a plurality of bumps formed thereon are formed into a plurality of connection terminals corresponding to the respective bumps. A method of mounting the bumps and the connection terminal portions so that the bumps and the connection terminal portions are electrically connected to each other through an anisotropic conductive film on a substrate having a portion formed on the surface, and the plurality of semiconductor chips are It is characterized in that they are formed so as to have different thicknesses as a whole, and when they are mounted, they are pressure-bonded onto the substrate in order from the smallest thickness.

In a preferred embodiment, the substrates are stacked for use as a display portion of a liquid crystal display device.
One of the transparent substrates is a transparent substrate, and each of the semiconductor chips is an IC for driving the liquid crystal display device.

In the semiconductor chip mounting structure provided by the second aspect of the present invention, a plurality of semiconductor chips having a plurality of bumps protrudingly formed are provided with a plurality of connection terminal portions corresponding to the respective bumps. A mounting structure of a semiconductor chip, in which the bumps and the connection terminal portions are mounted on a substrate formed on the surface so as to be electrically connected through an anisotropic conductive film, The chips are characterized in that they are formed so as to have different thicknesses as a whole, and are mounted adjacent to each other via a common anisotropic conductive film.

Generally, when a semiconductor chip is mounted on a substrate via an anisotropic conductive film, a pressure bonding head for pressing the semiconductor chip toward the substrate is used. In the present invention, the plurality of semiconductor chips are mounted adjacent to each other, but since they are formed so as to have different thicknesses as a whole, the thickness of the semiconductor chips is reduced by sequentially pressing them in order from the smallest thickness. When the thicker semiconductor chip is pressed by the pressure bonding head, the pressure bonding head does not come into contact with the already mounted thinner semiconductor chip. As a result, the semiconductor chip having a smaller thickness is not further pressed against the substrate from the mounted state. Moreover, a semiconductor chip having a larger thickness can be pressed against the substrate with a desired pressing force. That is, the pressing force that presses each semiconductor chip against the substrate can be controlled for each semiconductor chip. Therefore, the conductive particles in the anisotropic conductive film can be sandwiched between the bumps of the semiconductor chips and the connection terminal portions with an appropriate pressure. As a result, it is possible to prevent the generation of a crack in the conductive particles or the state in which the conductive particles between each bump and each connection terminal portion do not contact them, as in the conventional example. The bumps and the connection terminal portions can be surely brought into conduction.

Other features and advantages of the present invention will be more apparent from the following description of the embodiments of the invention.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION 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 example of a semiconductor chip mounting structure according to the present invention, and FIG. 2 is a line II-II in FIG.
3 is a sectional view taken along the line III-III in FIG. 1. In addition, FIGS. 4A to 6 are a series of diagrams for explaining a semiconductor chip mounting method according to the present invention. In addition, in these figures, FIG.
The same members and portions as those shown in FIG. 9 are designated by the same reference numerals.

As shown in FIG. 1, a semiconductor chip mounting structure A is applied to a liquid crystal display module and has two substrates 3 and 3 ′, one of which is a substrate 3. Two semiconductor chips 1 and 2 are mounted on the upper surface of the semiconductor chip 1 through an anisotropic conductive film 4.

The two substrates 3 and 3'are members for forming a liquid crystal display surface, and are transparent substrates made of, for example, glass or the like, and are superposed on each other. As shown in FIG. 2, a sealing material 33 is formed between the two substrates 3 and 3 ′ so as to maintain a constant gap between them and to surround a portion where they overlap each other. The liquid crystal 30 is held inside the sealing material 33.

Of these substrates 3, 3 ', one substrate 3 is provided with an extending portion 3A for mounting the semiconductor chips 1, 2, and the extending portion 3A is the other portion. It is formed so as to protrude from the side portion of the substrate 3 '. As shown in FIG. 2, the inner surface of each substrate 3, 3'is, for example, I
The transparent electrode patterns 32 and 32 'are formed by vapor-depositing TO (Indium Tin Oxide), and the transparent electrode pattern 32 formed on one of the substrates 3 is the extended portion 3A. It continues to the top. A plurality of connection terminal portions 31 for connecting the semiconductor chips 1 and 2 are provided at various places on the extending portion 3A in the transparent electrode pattern 32.
Are formed. As shown in FIG. 3, the plurality of connection terminal portions 31 are arranged so as to correspond to a plurality of bumps 11 of the semiconductor chips 1 and 2 which will be described later.

Each of the two semiconductor chips 1 and 2 is an IC for driving the liquid crystal display module. As shown in FIG. 3, a plurality of bumps 11 serving as contacts are formed on the back surface of the IC chips so as to project therefrom. There is. Each semiconductor chip 1,
2 is mounted on the substrate 3 so that the bumps 11 and the connection terminal portions 31 are electrically connected to each other through the anisotropic conductive film 4. These two semiconductor chips 1 and 2 are arranged so as to be adjacent to each other on the substrate 3 as shown in FIG. 1 in order to downsize the liquid crystal display module A. In display module A,
As shown in FIG. 3, as the anisotropic conductive film 4, one common to both the semiconductor chips 1 and 2 is used.

Each of the semiconductor chips 1 and 2 has a package formed of, for example, a resin as the exterior thereof, and when the package is formed, the thickness thereof is changed so that the package shown in FIG. As shown, the two semiconductor chips 1 and 2 are configured so that their respective total thicknesses are different from each other. Specifically, the total thickness t of the semiconductor chip 1 is smaller than the total thickness t ′ of the semiconductor chip 1.

As shown in FIG. 3, the anisotropic conductive film 4 has a large number of conductive particles 41 dispersed and mixed in an adhesive base material 42 having an insulating property. The adhesive base material 42 is formed of a thermosetting resin such as an epoxy resin,
There are film-like (solid) and viscous ones in the stage before heat curing. Each conductive particle 41 has, for example, as shown in FIGS. 5 and 6, a particle size of about 3 μm to 1 μm.
Ni on the surface of the resin ball 41a having a thickness of about 5 μm
And a conductive layer 41b such as Au is plated. When the semiconductor chips 1 and 2 are mounted, the anisotropic conductive film 4 is pressed and heated to soften the adhesive base material 42, and then cooled and solidified to form a semiconductor. The back surfaces of the chips 1 and 2 are joined to the front surface of the substrate 3. At this time, the thickness of the anisotropic conductive film 4 is relatively small between the bump 11 and the connection terminal portion 31, and the conductive particles 41 are interposed so as to be sandwiched therebetween, so that the semiconductor chips 1 and 2 are formed. And the connection terminal portion 31 are electrically connected. On the other hand, in the portion where the thickness of the anisotropic conductive film 4 is relatively large, each conductive particle 41
Will remain dispersed and the insulation will be maintained.

The method of mounting the semiconductor chip will be described below step by step.

In order to mount the two semiconductor chips 1 and 2 on the extending portion 3A of the substrate 3, first, as shown in FIGS. 4 (a) and 4 (b), the extending portion of the substrate 3 is formed. An anisotropic conductive film 4 is formed on 3A. More specifically, as shown in FIG. 4A, the anisotropic conductive film 4 is of a type in which the adhesive base material 42 is formed in a film shape, and the connection in the extending portion 3A is performed. The one sized so as to cover a predetermined area including the terminal portion 31 is placed on the substrate 3. Then, the anisotropic conductive film 4 is heated or adhered, for example, so as not to be inadvertently displaced on the substrate 3, as shown in FIG.
Is temporarily fixed to the surface of.

Then, as shown in FIG. 5 and FIG.
The two semiconductor chips 1 and 2 are mounted on the substrate 3 in order of decreasing thickness.

That is, first, as shown in FIG. 5, the semiconductor chip 1 having a small thickness is formed on the substrate 3 by the bumps 1
Thermocompression bonding is performed so that 1 corresponds to each connection terminal portion 31. In this step, the semiconductor chip 1 is previously placed on the anisotropic conductive film 4 by a suction collet or the like, and the well-known pressure bonding head D is used to heat the semiconductor chip 1 and apply a predetermined pressing force to the substrate. Press toward 3. As a result, the adhesive base material 42 is softened, and then cooled and solidified to bond the back surface of the semiconductor chip 1 to the front surface of the substrate 3. On the other hand, the conductive particles 41 are sandwiched between each connection terminal portion 31 and each bump 11 of the semiconductor chip 1 with an appropriate pressure, and each bump 11 and each connection terminal portion 31 are electrically connected. Is possible.

Then, as shown in FIG. 6, the semiconductor chip 2 is thermocompression-bonded onto the substrate 3 by using the pressure-bonding head D in the same procedure as the case of the semiconductor chip 1. At this time, since the semiconductor chip 2 is thicker than the semiconductor chip 1, even if the semiconductor chip 1 and the semiconductor chip 2 are mounted adjacent to each other as described above, the pressure bonding head D is While pressing the semiconductor chip 2,
It does not come into contact with the previously mounted semiconductor chip 1. Thereby, the conductive particles 41 can be sandwiched between each connection terminal portion 31 and each bump 11 of the semiconductor chip 2 with an appropriate pressure, and each connection terminal portion 31 and the semiconductor chip 1 previously mounted. Conductive particles 41 between each bump 11 of the
Can be prevented from being further pressurized.

Therefore, the conductive particles 41 can be sandwiched between the connection terminal portions 31 and the bumps 11 on both the semiconductor chips 1 and 2 with an appropriate pressure. That is, as in the conventional example, each connection terminal portion 31 and each bump 1
It is possible to prevent the distance between the first and second conductive particles 41 from becoming larger than the diameter of the conductive particles 41, and at the same time, to connect each connection terminal portion 31.
It is possible to prevent the conductive particles 41 from being crushed between the bumps 11 and the bumps 11 and cracking in the conductive layer 41b. As a result, the bumps 11 and the connection terminal portions 31 can be surely brought into conduction with each other, and defective connection of the semiconductor chip can be prevented.

Of course, the scope of the present invention is not limited to the above embodiments. For example, in the present embodiment, the semiconductor chip mounting structure is applied to the liquid crystal display module, but it can also be applied to other devices.

Further, for example, in this embodiment, two semiconductor chips are mounted on the substrate, but three or more semiconductor chips may be mounted.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of a semiconductor chip mounting structure according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4A and FIG. 4B are a series of diagrams for explaining a semiconductor chip mounting method according to the present invention.

FIG. 5 is a series of diagrams for explaining a semiconductor chip mounting method according to the present invention.

FIG. 6 is a series of diagrams for explaining a semiconductor chip mounting method according to the present invention.

FIG. 7 is a schematic perspective view showing an example of a conventional semiconductor chip mounting structure.

8 is a cross-sectional view taken along the line VIII-VIII of FIG.

9A and 9B are enlarged views of a main part of FIG. 8.

[Explanation of symbols]

1, 2 semiconductor chips 3 substrates 4 Anisotropic conductive film 11 bumps 31 Connection terminal part A Semiconductor chip mounting structure

Claims (3)

[Claims] 1. A plurality of semiconductor chips having a plurality of bumps formed thereon are formed on a substrate having a plurality of connection terminal portions corresponding to the respective bumps formed on the surface thereof. A method of mounting such that the connection terminal portions are electrically connected through an anisotropic conductive film, and the plurality of semiconductor chips are formed so as to have different thicknesses as a whole, and are mounted. In this case, a method for mounting a semiconductor chip is characterized in that the semiconductor chips are pressure-bonded on the substrate in order of decreasing thickness. 2. The substrate is one of two transparent substrates stacked for a display section of a liquid crystal display device, wherein each of the semiconductor chips drives the liquid crystal display device. The method for mounting a semiconductor chip according to claim 1, wherein the mounting method is a semiconductor integrated circuit. 3. A plurality of semiconductor chips having a plurality of bumps formed thereon are formed on a substrate having a plurality of connection terminal portions corresponding to the respective bumps formed on the surface thereof. A mounting structure of a semiconductor chip mounted so as to be electrically connected to each of the connection terminal portions via an anisotropic conductive film, wherein each of the semiconductor chips is formed to have a different total thickness. In addition, a semiconductor chip mounting structure, which is mounted adjacent to each other via a common anisotropic conductive film.