JP5335978B2 - IC chip manufacturing method and IC chip mounting method - Google Patents

Description

The present invention relates to a method for manufacturing an IC chip having bumps as connection terminals, and a mounting method using the IC chip.

  Conventionally, for example, an anisotropic conductive adhesive film has been used as means for mounting an IC chip on a wiring (glass) substrate such as a liquid crystal display device (see, for example, Patent Document 1).

  In order to mount an IC chip using this anisotropic conductive adhesive film, an anisotropic conductive adhesive film is interposed between the connection terminal (bump) of the IC chip and the electrode terminal of the wiring base, and the thermocompression bonding head. The IC chip is heated and pressed by thermocompression bonding.

However, conventionally, a connection failure may occur with respect to a specific bump among the bumps provided on the IC chip.
For example, as shown in FIG. 7 (a), poor connection between the bumps 103 and 104 provided on the edge of the chip body 102 of the IC chip 101 (within ellipses A and B) provided on the short side. May occur.

  Further, as shown in FIG. 7B, among the bumps 203 to 205 provided on the long side portion of the chip body 202 of the IC chip 201, the IC chip 201 in which the bumps are provided in a staggered manner on one long side. In such a case, connection failure may occur in the outer bump 204 (in the ellipse C).

JP-A-8-7658

  The present invention has been made to solve the above-described problems of the prior art, and it is possible to connect an IC chip using an anisotropic conductive adhesive capable of improving conduction reliability without causing a connection failure. The purpose is to provide technology.

In order to achieve the above object, the present invention provides an IC chip having a plurality of mounting terminals having different heights as connection electrodes on a rectangular connection side surface of a chip body and mounted by an anisotropic conductive adhesive. After a plurality of electrode portions having a predetermined thickness are provided on the edge portion of the connection side surface, electrodes in regions other than the region in which the height of the mounting terminal is increased among the plurality of electrode portions. By removing the surface layer portion of the portion by etching to reduce the height of the electrode portion in the region, the height of the mounting terminal of the short side edge portion of the connection side surface is set to the height of the long side edge portion of the connection side surface. This is a method of manufacturing an IC chip having a step of making it higher than the height of the mounting terminal.
The present invention is a method of manufacturing an IC chip having a plurality of mounting terminals with different heights as connection electrodes on a rectangular connection side surface of a chip body, and mounted with an anisotropic conductive adhesive, After the electrode portions having a predetermined thickness are provided in a plurality of rows along a predetermined edge portion of the connection side surface, electrodes in regions other than the region in which the height of the mounting terminal is increased among the plurality of rows of electrode portions By removing the surface layer portion of the portion by etching to reduce the height of the electrode portion in the region, the height of the outer mounting terminal is set to the predetermined edge of the connection side surface with respect to the predetermined edge portion of the connection side surface. This is a method of manufacturing an IC chip having a step of making it higher than the height of the mounting terminal on the inner side with respect to the part.
In the present invention, the difference between the height of the mounting terminal provided at the short side edge of the connection side surface and the height of the other mounting terminal is the particle size of the conductive particles of the anisotropic conductive adhesive used. It is also effective when it is 5% to 95%.
In the present invention, the difference between the height of the mounting terminal provided outside the edge of the connection side surface and the height of the other mounting terminal is 5% of the particle size of the conductive particles of the anisotropic conductive adhesive used. It is also effective when it is ˜95%.
In the present invention, an anisotropic conductive adhesive is disposed between a wiring board on which a predetermined connection electrode is formed and an IC chip manufactured by any of the methods described above, and heating and pressurizing are performed. The IC chip mounting method includes a step of bonding the wiring board and the IC chip and electrically connecting the electrodes to each other.

For the present invention, among the plurality of mounting terminals provided on the chip body as a connection electrode, and the short side edge region of the connecting side of the rectangular shape, the mounting terminals along a predetermined edge of the connection side since the height of the mounting terminal of the edge outside area when provided in a plurality of rows has to be higher than the height of the other mounting terminals, thermocompression bonding using an anisotropic conductive adhesive , It is possible to sufficiently compress the specific conductive particles, which were insufficiently crushed by the prior art.
As a result, according to the present invention, since the compression state of the conductive particles on each mounting terminal can be made uniform, conduction reliability can be improved in various types of IC chips.
In particular, according to the present invention, since the conduction reliability can be improved without using conductive particles having a large diameter, it is useful for an IC chip having fine pitch bumps.

  ADVANTAGE OF THE INVENTION According to this invention, the connection technique of the IC chip using the anisotropic conductive adhesive which can improve conduction | electrical_connection reliability without generating a connection failure can be provided.

(A): it is a schematic plan view showing an external configuration embodiment of an IC chip Ru used in the present invention. (B): It is a schematic front view which shows the external appearance structure of the IC chip. (A) (b): It is explanatory drawing which shows the principle of this invention. (A) (b): It is explanatory drawing which shows the principle of this invention. (A): it is a schematic plan view showing an external configuration other embodiment of the IC chip Ru used in the present invention. (B): It is a schematic side view which shows the external appearance structure of the IC chip. (A) (b): It is explanatory drawing which shows the principle of this invention. (A) (b): It is explanatory drawing which shows the principle of this invention. (A): It is a schematic plan view which shows the external appearance structure of the IC chip which concerns on a prior art example. (B): It is a schematic plan view which shows the external appearance structure of the IC chip based on another prior art example.

Hereinafter, preferred embodiments of an IC chip manufacturing method and an IC chip mounting method according to the present invention will be described with reference to the drawings.

  As will be described later, the anisotropic conductive adhesive 7 used in the present invention is one in which conductive particles 9 are dispersed in an insulating adhesive resin 8. It can be applied to any of the shapes.

Figure 1 (a) (b) is a schematic diagram showing an embodiment of an IC chip Ru used in the present invention, FIG. 1 (a) is a plan view, FIG. 1 (b) is a front view. FIGS. 2A and 2B and FIGS. 3A and 3B are explanatory views showing the principle of the present invention.

  As shown in FIGS. 1A and 1B, an IC chip 1 according to the present embodiment is used, for example, in a COG (Cip On Glass) system, and has a rectangular parallelepiped chip body 2. The connecting side surface 2a is formed in a rectangular shape.

  On the edge (long side and short side) of the connection side surface 2a of the IC chip 1, a plurality of mounting terminals 3 and 4 using bumps as below are provided as connection electrodes at a predetermined pitch. Yes.

  In the case of the present embodiment, the mounting terminals 3 and 4 are each formed by forming a bump made of Au (gold) on a patterned electrode part made of Al (aluminum).

Here, in order to form the Au bump on the Al electrode portion, for example, a known plating method described below (see, for example, Japanese Patent No. 2936680) can be used.
That is, in the plating method, an Si substrate on which an Al wiring (electrode part) and an insulating film are formed is prepared, an opening for connecting the Al wiring to the outside is formed in the insulating film, and Ti (titanium) is formed on the entire surface. ) Is sputtered to form a Ti film, and Pd (palladium) is sputtered to form a Pd film. Next, a resist is deposited thereon and patterned to form a resist mask having openings for forming Au bumps.
Further, Au plating is performed on the Pd film from the above-mentioned openings to form an Au plating layer, and then the above-described resist mask is removed, and the Pd film and Ti film are etched using the gold plating layer as a mask. . As a result, an Au bump formed on the Al electrode portion is obtained.

  In the present invention, among the plurality of mounting terminals 3 and 4, the height of the mounting terminal in the region specified in advance is set higher than the heights of the other mounting terminals.

  In the present embodiment, as shown in FIGS. 1A and 1B, the mounting terminals 4 provided on the short side edges (regions indicated by ellipses A and B) of the connection side surface 2a of the IC chip 1 are provided. The height is configured to be higher than the height of the mounting terminal 3 provided at the long side edge of the connection side surface 2a.

  In the case of the present invention, the method of making the height of the mounting terminal 4 at the short side edge of the IC chip 1 higher than the height of the mounting terminal 3 at the long side edge is not particularly limited, but the manufacturing process From the viewpoint of simplicity, for example, as shown in FIG. 3B, a portion where the mounting terminal 4 is provided, that is, a metal raised portion 10 is provided on the Al electrode portion 20, and the electrode portion is multilayered. It is preferable.

  In this case, as a method for forming the raised portion 10, for example, a sputtering method using aluminum can be employed.

  Then, after forming the raised portion 10, a passivation film 21 is formed on the connection side surface 2 a of the IC chip 1, and the same height is formed on the raised portion 10 and the Al electrode portion 20 by the above method. The bump part 30 and the bump part 40 are respectively formed.

  Thereby, the IC chip 1 in which the height of the mounting terminal 4 at the short side edge of the IC chip 1 is higher than the height of the mounting terminal 3 at the long side edge by the raised portion 10 can be obtained.

The principle of the present invention will be described below with reference to FIGS. 2 (a) and 2 (b) and FIGS. 3 (a) and 3 (b).
Here, consider a case where the IC chip 1 is mounted on the wiring substrate 11 provided with the connection electrodes 13 and 14. The connection electrodes 13 and 14 of the wiring board 11 correspond to the mounting terminals 3 and 4 of the IC chip 1, respectively.

  When the IC chip 1 is mounted, as shown in FIG. 2A, the anisotropic conductive adhesive 7 is disposed between the wiring substrate 11 and the IC chip 1 and thermocompression bonding is performed. Heating and pressing are performed from the chip 1 side.

  In this case, the reached temperature of the IC chip 1 is about 200 to 250 ° C., but the reached temperature on the wiring board 11 side is about 100 to 150 ° C., which is lower than that of the IC chip 1. It is in an extended state. For this reason, the shrinkage of the chip body 2 of the IC chip 1 is large after cooling after mounting, for example, as shown in FIG. 2B, the warp of the IC chip 1 becomes larger than the wiring substrate 11, and as a result, Warpage occurs in the entire mounting part.

  In this state, stress is easily applied to the short side edge 2b of the edges of the connection side surface 2a of the IC chip 1, so that the conductive particles 9b of the anisotropic conductive adhesive 7 as shown in FIG. Is smaller than the conductive particles 9 in other regions (long side edge in this example), and the deformation (compression) rate of the conductive particles 9b tends to be insufficient.

  Therefore, as shown in FIG. 3B, a raised portion 10 is provided on the Al electrode portion 20 at the short side edge 2b of the connection side surface 2a of the IC chip 1, and a bump portion is provided on the raised portion 10. By forming 40, the height of the mounting terminal 4 is made higher than the height of the mounting terminal 3 at the long side edge of the connection side surface 2a (= the height of the bump portion 30).

As a result, the distance between the mounting terminal 3 and the connection electrode 13 and the distance between the mounting terminal 4 and the connection electrode 14 can be made equal. The compressibility can be made uniform by pressing the particles 9 and 9b with a uniform force.

In the present invention, the difference in height between the mounting terminals 3 and 4 is not particularly limited, but from the viewpoint of improving the conduction reliability by making the compressed state of the conductive particles 9 and 9b uniform, the conductive particles The particle size of 9 is preferably 5% to 95%, more preferably 30% to 60%.

Specifically, for example, when the particle diameters of the conductive particles 9 and 9b are 3 μm to 5 μm, the height difference between the mounting terminals 3 and 4 can be set to 0.5 μm to 3 μm.

In this case, the elastic modulus of the conductive particles 9 is more effective when a range of ^{100kgf / mm 2 ~1000kgf / mm 2} .

  4 (a) (b), FIG. 5 (a) (b) and FIG. 6 (a) (b) show other embodiments of the present invention. These parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 4A and 4B, the IC chip 1A of the present embodiment has mounting terminals 3, 4A, 5 as connection electrodes on the long side edge of the connection side surface 2a of the chip body 2. Is provided.

  In the present embodiment, two rows of mounting terminals 4A and 5 are arranged in a staggered pattern along one long side edge of the connection side surface 2a of the IC chip 1A.

  Of the mounting terminals 4A and 5, the height of the mounting terminal 4A (area indicated by an ellipse C) provided outside one long side edge of the connection side surface 2a is provided inside the long side edge. The mounting terminal 5 is configured to be higher than the height.

  In this case, the method of making the height of the mounting terminal 4A outside the long side edge of the connection side surface 2a of the IC chip 1A higher than the height of the mounting terminal 5 inside the long side edge is the same as in the above embodiment. The method can be adopted. That is, as shown in FIG. 6B, the mounting terminal 5 has a bump portion 50 formed on the Al electrode portion 20, and the mounting terminal 4A has a raised portion 10 formed on the Al electrode portion 20. A bump portion 40 is formed on the top.

  In the case of the present embodiment, no mounting terminal is provided on the short side edge of the connection side surface 2a of the IC chip 1A.

  In the IC chip 1A in which the two rows of mounting terminals 4A and 5 are arranged in a staggered manner along the long side edge, when heating and pressurization are performed from the IC chip 1A side during mounting, FIG. As shown in b), the central portion of the chip body 2 tends to sink compared to the long side edge.

  For this reason, after mounting the IC chip 1A, a difference occurs in the height between the central portion of the chip body 2 and the long side edge. This difference is particularly large (approximately several μm) at the long side edge 2c on the side where the two rows of mounting terminals 4A and 5 are provided.

  Here, as shown in FIG. 6A, when the mounting terminals 4A and 5 have the same height, the pressing force against the conductive particles 9c of the mounting terminals 4A on the outer side of the long side edge is different from the other regions. The conductive particles 9 are smaller than the conductive particles 9, and the deformation (compression) rate of the conductive particles 9 c is insufficient.

  Therefore, in the present embodiment, as shown in FIG. 6B, the height of the mounting terminal 4A outside the long side edge 2c of the connection side surface 2a of the IC chip 1A is raised above the Al electrode unit 20. By providing the part 10, it is made higher than the height of the mounting terminal 5 inside the long side edge part 2c.

As a result, as in the above-described embodiment, the distance between the mounting terminal 5 and the connection electrode 15 and the distance between the mounting terminal 4A and the connection electrode 14 can be made equal. It is possible to make the compressibility uniform by pressing the conductive particles 9 and 9c with a uniform force at the portion.

In the present invention, the difference in height between the mounting terminals 5 and 4A is not particularly limited. From the viewpoint of improving the conduction reliability by making the compressed state of the conductive particles 9 and 9c uniform, the mounting terminals The difference of 5, 4A is preferably 5% to 95% of the particle size of the conductive particles 9.

Specifically, for example, when the particle diameters of the conductive particles 9 and 9c are 3 μm to 5 μm, the difference between the mounting terminals 5 and 4A can be set to 0.5 μm to 3 μm.

In this case, the elastic modulus of the conductive particles 9 is more effective when a range of ^{100kgf / mm 2 ~1000kgf / mm 2} .

  The present invention is not limited to the above-described embodiment, and various changes can be made.

  For example, the mounting terminals that increase the height among the plurality of mounting terminals are not limited to all those arranged on the edge (short side or long side) of the connection side as in the above-described embodiment. Some of the mounting terminals may be used.

  For example, various changes can be made according to the IC chip, such as making the height of the mounting terminals at the corners of the connection side surface of the chip body higher than the mounting terminals in other regions.

  As for the method of increasing the height of the mounting terminal in a specific region, in addition to the above-described method of providing a raised portion on the electrode portion to form a multilayer, for example, the initial electrode portion is formed thick and mounted. The surface layer portion of the electrode portion in a region other than the region in which the height of the terminal is increased may be removed by etching or the like to reduce the height of the region.

  Furthermore, the present invention can be applied not only to the IC chip of the above embodiment type but also to various types of IC chips.

  Examples of the present invention will be described below in detail together with comparative examples.

[Creation of anisotropic conductive adhesive film]
As an insulating adhesive resin, 30 parts by weight of an epoxy resin (EP828 manufactured by Japan Epoxy Resin Co., Ltd.), 40 parts by weight of a phenoxy resin (PKHH manufactured by InChem), 30 parts by weight of an epoxy curing agent (HX3941HP manufactured by Asahi Kasei Co., Ltd.), conductive particles (Sekisui Chemical) 25 parts by weight of an average particle size of 3 μm manufactured by the company was dissolved and mixed with a mixer using toluene / ethyl acetate as a solvent to obtain a paste.

  And the paste mentioned above was apply | coated on PET film which performed the peeling process, it heated for 8 minutes with the electric oven set to 70 degreeC, and the anisotropic conductive adhesive film whose dry film thickness is 20 micrometers was created.

<Example 1>
Using the IC chip having the staggered mounting terminals shown in FIGS. 4 (a) and 4 (b), the mounting terminal (4A) outside the long side edge is set to 16 μm and the mounting terminal inside the long side edge The height of (5) was 15 μm.

  In this case, the height of the mounting terminal (4A) was increased by 1 μm by forming the electrode part to be 1 μm thicker than usual.

  Here, the width of the mounting terminals (4A) and (5) on the outer side and outer side of the long side edge portion was 15 μm, and the pitch between the mounting terminals was 15 μm.

<Comparative Example 1>
The thickness of the electrode part is set as usual, the height of the mounting terminal (4A) outside the long side edge is set to 15 μm, and the heights of all the mounting terminals are made the same. A chip was used.

<Example 2>
Using the IC chip having the mounting terminals in the straight arrangement shown in FIGS. 1A and 1B, the height of the mounting terminal (4) at the short side edge is set to 16 μm, and the mounting terminal (3 ) Was set to 15 μm.

  In this case, the height of the mounting terminal (4) at the short side edge portion was increased by 1 μm by forming the electrode portion thicker than usual by 1 μm.

  Here, the width of the mounting terminal (4) at the short side edge was 14 μm, and the bump pitch was 25 μm.

  On the other hand, the width of the mounting terminal (3) at the edge on the long side was 14 μm, and the pitch between the bumps was 25 μm.

<Comparative example 2>
An IC chip having the same configuration as in Example 2 except that the thickness of the electrode part is set as usual, the height of the mounting terminal (4) on the short side edge side is set to 15 μm, and the bumps are all the same height. Was used.

[Evaluation]
As a wiring board, TEG (Test Element Group) in which an ITO electrode having a thickness of 0.2 μm was formed on a transparent glass plate having a thickness of 0.5 mm was used.

  And each IC chip was thermocompression-bonded on the wiring board using what was mentioned above as an anisotropically conductive adhesive film.

  In this case, the pressure bonding conditions were a temperature of 200 ° C., a pressure of 30 MPa, and a time of 10 seconds. Further, aging was performed for 500 hours under the conditions of a temperature of 85 ° C. and a relative humidity of 85%, and a continuity test between the mounting terminals was performed. . The results are shown in Tables 1 and 2.

  On the other hand, the collapsed state of the conductive particles in the IC chip after thermocompression bonding was visually observed using a microscope.

  In this case, the case where the conductive particles are uniformly crushed is indicated by “◯”, and the state where the conductive particles are not uniformly crushed between the mounting terminals and the state where the conductive particles are not sufficiently crushed is indicated by “X”.

[Evaluation results]
About Example 1 and Example 2, after aging, the resistance increase is controlled to 6Ω or less, and between the mounting terminals on the outer side of the long side (Example 1) and the short side (Example 2). It turns out that conduction is stable for a long time.

  Further, it was confirmed that the conductive particles were uniformly crushed between the mounting terminals.

  On the other hand, in Comparative Example 1, a resistance increase of 23Ω was observed after aging, and there was a portion where the conductive particles were not sufficiently crushed between the mounting terminals outside the long side edge.

Further, in Comparative Example 2, a resistance increase of 18Ω was observed after aging, and there was a portion where the degree of collapse of the conductive particles was not sufficient between the mounting terminals on the short side edge.
From the above, the effect of the present invention could be verified.

DESCRIPTION OF SYMBOLS 1 IC chip 2 Chip body 2a Connection side surface 2b Short side edge 3,4,4A, 5 Mounting terminal 7 Anisotropic conductive adhesive 9,9b, 9c Conductive particle

Claims (5)

A method of manufacturing an IC chip having a plurality of mounting terminals with different heights as connection electrodes on a rectangular connection side surface of a chip body, and mounted with an anisotropic conductive adhesive,
After providing a plurality of electrode portions having a predetermined thickness on the edge of the connection side surface, the surface layer portion of the electrode portion in a region other than the region in which the height of the mounting terminal is increased among the plurality of electrode portions is removed by etching. The height of the mounting terminal at the short side edge of the connection side is made higher than the height of the mounting terminal at the long side edge of the connection side by reducing the height of the electrode part in the region. A method of manufacturing an IC chip having A method of manufacturing an IC chip having a plurality of mounting terminals with different heights as connection electrodes on a rectangular connection side surface of a chip body, and mounted with an anisotropic conductive adhesive,
After the electrode portions having a predetermined thickness are provided in a plurality of rows along a predetermined edge of the connection side surface, regions of the plurality of rows of electrode portions other than the region where the height of the mounting terminal is increased By removing the surface layer portion of the electrode portion by etching to reduce the height of the electrode portion in the region, the height of the outer mounting terminal with respect to the predetermined edge portion of the connection side surface is set to the predetermined value of the connection side surface. An IC chip manufacturing method comprising a step of making the height higher than the height of an inner mounting terminal with respect to an edge. The difference between the height of the mounting terminal provided at the short side edge of the connection side surface and the height of the other mounting terminal is 5% to 95% of the particle size of the conductive particles of the anisotropic conductive adhesive used. The method of manufacturing an IC chip according to claim 1, wherein The difference between the height of the mounting terminal provided outside the edge of the connection side surface and the height of the other mounting terminal is 5% to 95% of the particle size of the conductive particles of the anisotropic conductive adhesive used. An IC chip manufacturing method according to claim 2 . An anisotropic conductive adhesive is disposed between the wiring board on which the predetermined connection electrode is formed and the IC chip manufactured by the method according to any one of claims 1 to 4 .
An IC chip mounting method including a step of bonding the wiring board and the IC chip and electrically connecting the electrodes by heating and pressing.

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