JPH10107072A - Structure and method for connecting semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which a semiconductor element can be connected relatively easily and surely even when such a relatively large error that reaches several micrometers exists in parallelism. SOLUTION: In order to connect a semiconductor element 10 in which bumps 15 are formed to parts 11 in which connecting electrodes to be connected to the bumps 15 are formed, anisotropic conductive adhesive layers 16 made of a synthetic resin material containing conductive powder 17 dispersed in the material are respectively applied between the electrodes 12 and bumps 15. While the powder 17 is pressurized so that the bumps 15 can be electrically connected to the electrodes 12 through the powder 17, the adhesive layers 16 are cured. Since the hardness of the powder 17 is higher than those of the bumps 15 and electrodes 12, the adhesive layers 16 are cured in a state where the powder 17 between the bumps 15 and electrodes 12 deforms either the bumps 15 or electrodes 12 and partially gets in the bumps 15 or electrodes 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure and a connection method for connecting a semiconductor device to a substrate or another component such as a semiconductor device using bumps.

[0002]

2. Description of the Related Art As a method of connecting a semiconductor element such as a driving IC chip to a transparent electrode (ITO) of a liquid crystal panel, Japanese Patent Publication No. 4-50745 discloses a method in which a bump is provided on an electrode of a semiconductor element. A method of applying an anisotropic conductive adhesive layer obtained by dispersing a conductive powder having elasticity to a synthetic resin material between a bump and a transparent electrode of a liquid crystal panel as a component is disclosed. . According to the prior art disclosed in the above publication, the conductive powder interposed between the bump and the transparent electrode is solidified with the anisotropic conductive adhesive layer in a state where the conductive powder is pressed between the bump and the transparent electrode. With the bump and the transparent electrode electrically connected via the powder,
The semiconductor element can be fixed to the liquid crystal panel.

[0003]

By the way, in the conventional connection method as described above, the semiconductor element and the semiconductor element pressed mutually by the deformation of the conductive powder elastically deformed between the bump and the transparent electrode. An error in the parallel accuracy or an error in their thickness dimension when assembling with the liquid crystal panel is absorbed. However, as the amount of elastic deformation of the conductive powder itself, an extremely small value of 1 micron or less can be expected. For this reason, the conventional connection method described above sufficiently copes with a large error such as several microns in the parallel accuracy between the semiconductor element and the liquid crystal panel, which are mutually pressurized at the time of connection, or the error in the thickness direction of each component. Cannot be performed, and when such a large error occurs, reliable connection may be difficult.

[0004]

The present invention adopts the following constitution in order to solve the above points. <Structure> The connection structure of a semiconductor element according to the present invention basically includes a semiconductor element in which a bump is formed on an electrode and a component in which a connection electrode for connecting a bump is formed at a position corresponding to the position of the bump. In order to connect to each other, it is applied between the semiconductor element and the component, and includes an anisotropic conductive adhesive layer made of a synthetic resin material in which conductive powder is dispersed, and is interposed between the bump and the connection electrode. In a connection structure of a semiconductor element in which a bump and a connection electrode are electrically connected via a conductive powder, the hardness of the conductive powder is higher than that of at least one of the bump and the connection electrode, and the bump and the connection electrode are hardened. The conductive powder is characterized in that at least one of the bump and the connection electrode is deformed and projected into the inside.

[0005] In the connection structure according to the present invention, the conductive powder for electrically connecting the bump and the connection electrode to each other includes a bump or connection electrode having a hardness lower than the hardness of the conductive powder. Deformed and protrude inside. Therefore, the parallelism error or the thickness dimension error at the time of assembling the semiconductor element and the component to be connected at the time of connection does not depend on the elastic deformation of the conductive powder as in the related art. Absorption can be achieved by deformation of the bumps or connection electrodes that allow deformation larger than the elastic deformation of the body.

Therefore, according to the connection structure of the present invention,
Even if there is a large error, for example, a few microns in parallelism between the semiconductor elements and components connected to each other, this error is absorbed by deformation of the bumps or connection electrodes that partially receive the conductive powder. Therefore, irrespective of this large error, the two can be reliably electrically connected to each other, and can be firmly fixed to each other.

In the method for connecting a semiconductor element according to the present invention, basically, a connection element for connecting a bump is formed at a position corresponding to a position of a semiconductor element having a bump formed on an electrode. In order to connect the components to each other, an anisotropic conductive adhesive layer made of a synthetic resin material in which conductive powder is dispersed is applied between the semiconductor element and the components, and is interposed between the bumps and the connection electrodes. Connection of the semiconductor element, including curing the anisotropic conductive adhesive layer in a state where the conductive powder is pressed between the bump and the connection electrode so as to electrically connect the bump and the connection electrode via the conductive powder to be formed. In the method, each material or structure is selected so that the hardness of the conductive powder is higher than that of at least one of the bump and the connection electrode, and the conductive powder between the bump and the connection electrode is connected to the bump and the connection electrode. By deforming at least one of the electrodes so as to protrude therein, characterized in that curing the adhesive layer.

In the method of manufacturing a semiconductor device according to the present invention,
The conductive powder pressed between the bump and the connection electrode deforms the bump or the connection electrode having a hardness lower than the hardness of the conductive powder and protrudes into the inside. Therefore, the parallelism error or the thickness dimension error at the time of assembling the semiconductor element and the component to be connected at the time of connection does not depend on the elastic deformation of the conductive powder as in the related art. Absorption can be achieved by deformation of the bumps or connection electrodes that allow deformation larger than the elastic deformation of the body.

Therefore, according to the manufacturing method of the present invention,
Even if there is a large error, for example, a few microns in parallelism between the semiconductor elements and components connected to each other, this error is absorbed by deformation of the bumps or connection electrodes that partially receive the conductive powder. Therefore, regardless of this large error, it is possible to relatively easily form a connection structure capable of securely electrically connecting the two and firmly fixing each other mechanically.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. <Concrete Example> FIG. 1 is a cross-sectional view showing a structure of a connection portion to which a connection method according to the present invention is applied, partially cut away. FIG. 1 shows an IC chip as a semiconductor element 10, and a connection electrode 1 as a component 11 to which the semiconductor element 10 is connected.
An example of an active component such as an LED array provided with 2 is shown.

On the lower surface of the semiconductor element 10, for example, an Al electrode 13 serving as an input / output terminal is formed as in the prior art. For example, an Au bump 15 is formed on the electrode 13 via a barrier electrode (not shown) for obtaining ohmic contact.
Are formed so as to project toward the component 11. This Au bump 15 is previously heated to, for example, about 200 to 300 ° C.
Under a high temperature for several hours, and the material is softened by this heat treatment. The connection electrode 12 of the component 11 is made of, for example, an Al electrode.
Are formed at positions corresponding to the positions where the bumps 15 are provided.

An anisotropic conductive adhesive layer 16 is applied between the bump 15 of the semiconductor element 10 and the connection electrode 12 of the component 11 in order to couple the component 10 and the component 11 in an electrically connected state. Is done. The anisotropic conductive adhesive layer 16 includes
For example, it is made of a thermosetting synthetic resin material in which conductive powder 17 made of nickel powder having a particle size of several microns is dispersed, and when pressed, is pressed by the conductive action of conductive powder 17. Only the part allows local conduction in the pressing direction.

The particle size of the conductive powder 17 is set smaller than the sum of the heights of the bump 15 and the connection electrode 12. Thereby, the semiconductor element 10 and the component 11
The generation of a gap between the bump 15 and the connection electrode 12 due to the engagement of the conductive powder 17 between the planes facing each other is prevented, and a connection failure due to the engagement of the conductive powder 17 is prevented. Is prevented. In order to reliably prevent this connection failure, it is desirable that the particle size of the conductive powder 17 be smaller than the height of the bump 15. The conductive powder 17 made of nickel powder has a material hardness higher than the hardness of the bumps 15 and the connection electrodes 12 that have been subjected to the softening treatment.

In joining the semiconductor element 10 and the component 11, the bump 15 of the semiconductor element 10 and the connection electrode 12 of the component 11 are opposed to each other with a space therebetween, and an anisotropic conductive adhesive is provided between them. With the layer 16 interposed,
The semiconductor element 1 is pressed to press the bump 15 and the connection electrode 12 together.
0 and the part 11 are pressed against each other.

By pressing the bumps 15 and the connection electrodes 12, the conductive powder 17 interposed between the bumps 15 and 12 is pressed between them. Conductive powder 17 under pressure
Is higher than the hardness of the bump 15 and the connection electrode 12 that sandwich the conductive powder 17. Therefore, the conductive powder 17 which is subjected to the pressure is, as shown in FIG.
5 and the connection electrode 12 are deformed and protrude into each of them. The amount of deformation of the bumps 15 and the connection electrodes 12 at this time ranges from several microns to several tens of times the value of the elastic deformation of the conductive powder itself as in the related art.

The conductive powder 17 which is pressurized between the bump 15 and the connection electrode 12 is
2 is placed in an electrically conductive state. In this conduction state,
The synthetic resin material of the anisotropic conductive adhesive layer 16 is heated, and the heating causes the anisotropic conductive adhesive layer 16 to harden, so that the semiconductor element 10 and the component 11 are electrically connected to each other. It is fixed with.

For heating the semiconductor element 10 and the component 11 to press each other and to cure the anisotropic conductive adhesive layer 16 therebetween, a heater block similar to the conventional heater block having a heating source may be used. it can. In the processing using such a heater block, the degree of parallelism of the semiconductor element 10 and the component 11 and the accuracy of the respective dimensions in the thickness direction along the pressing direction are serious problems. As shown in FIG.
5 and the connection electrode 12, each of which deforms a relatively large amount. This deformation can absorb a relatively large error in parallelism or dimension.

Therefore, according to the present invention, the semiconductor device 10
Even if there is a variation in the parallelism or the thickness dimension of the component 11 or the component 11, they can be securely connected electrically and firmly fixed mechanically.

The anisotropic conductive adhesive layer 16 is formed on the semiconductor element 10.
It is desirable that the component 11 is temporarily fixed to one of the components 11 before the pressure contact. As the synthetic resin material of the anisotropic conductive adhesive layer 16, a thermosetting synthetic resin material that is cured by a thermoplastic or ultraviolet light can be used instead of the thermosetting synthetic resin material. Further, as the conductive powder 17 dispersed in the synthetic resin material, if the conductive powder 17 shows a hardness higher than at least one of the hardness in relation to the hardness of the bump 15 and the connection electrode 12, for example, platinum, A metal material such as copper can be appropriately used.

FIG. 2 is a drawing similar to FIG. 1 showing the structure of another connecting portion to which the method of the present invention is applied. In the example of FIG. 2, the surface of the semiconductor element 10 on which the electrode 13 is provided is further provided with the internal connection wiring 13 * of the semiconductor element 10, and the surface of the component 11 on which the connection electrode 12 is provided is provided. , A similar internal connection wiring 12 * is provided.

An insulating film 14 is formed so as to cover the electrode 13 and the internal connection wiring 13 * of the semiconductor element 10, and the bump 15 is formed to protrude from the insulating film 14. Also, the connection electrode 12 of the component 11 and the internal connection wiring 12 *
, An insulating film 18 is formed.

Since the insulating films 14 and 18 formed on the semiconductor element 10 and the component 11 are lower than the hardness of the conductive powder 17, the conductive powder 17 is compressed between the bump 15 and the connection electrode 12. Then, a part of the conductive powder 17 penetrates into the bump 15 to deform the bump, and the conductive powder 17 breaks through the insulating film 18, further deforms the connection electrode 12 and contacts the connection electrode 12. . Therefore, the insulating films 14 and 18 reliably prevent unnecessary short-circuits of the internal connection wiring 13 * and the internal connection wiring 12 * to be protected, and the insulating film 18 is formed of the bump 15 passing through the conductive powder 17.
It does not hinder the connection between the electrode and the connection electrode 12.

The insulating film 14 and the insulating film 18 can be formed of a material harder than the conductive powder 17. In this case, the insulating film 18 does not hinder the electrical connection between the bump 15 and the connection electrode 12 passing through the conductive powder 17.
The insulating film 18 is partially removed to partially expose the connection electrode 12 from the insulating film 18 in advance.

Instead of the insulating film 18 shown in FIG.
8 can be applied. That is, before connecting the semiconductor element 10 and the component 11 via the anisotropic conductive adhesive layer 16, the entire surface of the component 11 facing the semiconductor element 10 is coated with the anisotropic conductive adhesive layer 16. A conventionally well-known active layer 18 for increasing the adhesive strength can be formed.

The conductive powder 17 having a hardness higher than the hardness of the connection electrode 12 and the softened bump 15.
Has a hardness sufficient to break through the active layer 18, so that when the conductive powder 17 is pressed between the bump 15 and the connection electrode 12, the conductive powder 17 breaks through the active layer 18. The conductive powder 17 that has penetrated the active layer 18 deforms the bumps 15 and the connection electrodes 12 and protrudes into them, as in the example shown in FIG.

Therefore, even if the active layer 18 is applied to the connection electrode 12 of the component 11, there is no need to perform any special treatment on the active layer 18, and the conductive powder 17 that deforms the bump 15 and the connection electrode 12 can be used. Through the above, the electrode 13 and the connection electrode 12 can be reliably connected, thereby appropriately absorbing dimensional errors and the like of the semiconductor element 10 and the component 11, and
Both can be reliably connected.

FIG. 3 is a drawing similar to FIG. 1 showing the structure of still another connection part to which the method of the present invention is applied. As described above, the hard conductive powder 17 such as nickel powder has a higher hardness than the surface oxide film 19 formed on the surface of the Al connection electrode 12 as shown in FIG. Therefore, even if the surface oxide film 19 having such electrical insulation is formed on the surface of the connection electrode 12, if the conductive powder 17 is pressed between the bump 15 and the connection electrode 12, FIG.
As in the example described with reference to FIG.
Breaks through the surface oxide film 19.

Therefore, even if such a surface oxide film 19 is formed on the surface of the connection electrode 12, the surface oxide film 1
The dimensional error and the like of the semiconductor element 10 and the component 11 can be suitably absorbed and the two can be reliably connected without performing any special processing for removing 9.

FIG. 4 is a drawing similar to FIG. 1 showing another example of the present invention. As shown in FIG. 4, an elastic conductive powder can be used as the conductive powder 17. The conductive powder 17 having elasticity is used for the bump 15
When pressed between the connecting electrodes 12, the conductive material itself undergoes elastic deformation. However, a conductive material having a hardness sufficient to deform the bumps 15 and the connecting electrodes 12 in a compressed state is appropriately selected.

By using the conductive powder 17 having elasticity, the conductive powder can be changed in accordance with a change in thermal expansion or thermal shrinkage of the synthetic resin material after the synthetic resin material of the anisotropic conductive adhesive layer 16 is cured. The body 17 can be deformed. Therefore, better electrical connection can be achieved regardless of the temperature change.

FIG. 5 is a longitudinal sectional view showing still another example of the present invention. The hardness of the bumps 15 is entirely reduced by the conductive powder 1.
7, instead of being formed smaller than that of FIG. 7, as shown in FIG. 5, a structural weak portion 1 having a low apparent hardness, such as a porous structure, is provided at the tip of the bump 15.
5a is formed, and the fragile portion 15a is deformed by the conductive powder 17 so that the semiconductor element 10 and the component 11 are formed.
Can be absorbed. Further, the partial fragile portion 15a can be made of a foreign material having a hardness lower than the hardness of the conductive powder 17.
Further, such a fragile portion can be formed on the surface of the connection electrode 12 of the component 11.

In the above description, an example in which the present invention is applied to a connection portion between a semiconductor element and an active component has been described. However, the present invention is not limited to this, and for example, a semiconductor element in which respective electrodes are connected to each other via bumps. The present invention can be applied to a connection between a semiconductor element and various components, such as a connection portion between the semiconductor element and a liquid crystal panel, a connection between semiconductor elements, and the like.

[0033]

According to the present invention, as described above, the conductive powder pressed between the bump and the connection electrode has a hardness lower than that of the conductive powder. Is deformed, it is possible to reliably absorb a thickness dimensional error or a parallelism error between these semiconductor elements or components by a relatively large deformation due to the bumps or the connection electrodes. Therefore, even if there is a large error of several microns in the degree of parallelism, the two can be reliably electrically connected to each other and mechanically fixed to each other irrespective of the large error. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view partially showing a structure of a connecting portion formed by applying a connecting method according to the present invention.

FIG. 2 shows another application example of the connection method according to the present invention.
FIG.

FIG. 3 is a drawing similar to FIG. 1, showing still another application example of the connection method according to the present invention.

FIG. 4 is a view similar to FIG. 1, showing a structure of a connection part formed by applying another example of the connection method according to the present invention, partially cut away;

FIG. 5 is a view similar to FIG. 1, showing still another example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Semiconductor element 11 Component (substrate) 12 Connection electrode 13 Electrode 14, 18, 19 Insulating film 15 Bump 16 Anisotropic conductive adhesive layer 17 Conductive powder

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kayo Hamano 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (8)

[Claims] 1. A semiconductor device having a bump formed on an electrode and a component having a connection electrode connected to the bump at a position corresponding to the position of the bump, the semiconductor device being connected to the semiconductor device. Applied between the component, including an anisotropic conductive adhesive layer made of a synthetic resin material in which conductive powder is dispersed, the conductive powder interposed between the bump and the connection electrode through the conductive powder A connection structure of a semiconductor element in which the bump and the connection electrode are electrically connected, wherein the hardness of the conductive powder is higher than that of at least one of the bump and the connection electrode; A connection structure for a semiconductor element, wherein the conductive powder between electrodes deforms at least one of the bump and the connection electrode and projects into the inside. 2. The semiconductor device according to claim 1, wherein the conductive powder has a granular shape, and a particle size is smaller than a sum of heights of the bump and the connection electrode. Connection structure. 3. A wiring covered with an insulating film having a hardness lower than the hardness of the conductive powder is provided on at least one of the surfaces of the semiconductor element and the component facing each other. The connection structure of a semiconductor element as described in the above. 4. The connection structure for a semiconductor element according to claim 1, wherein the bump has a fragile portion which is deformed to receive at least a part of the conductive powder. 5. The connection structure for a semiconductor element according to claim 1, wherein the conductive powder deforms both the bump and the connection electrode and projects into the inside. 6. A semiconductor device having a bump formed on an electrode and a component having a connection electrode connecting the bump at a position corresponding to the position of the bump, for connecting the semiconductor device and the component. An anisotropic conductive adhesive layer made of a synthetic resin material in which conductive powder is dispersed is applied between the component and the bump, and the bump is passed through the conductive powder interposed between the bump and the connection electrode. And a method for connecting a semiconductor element, comprising curing the anisotropic conductive adhesive layer in a state where the conductive powder is pressed between the two to electrically connect the connection electrodes, and The hardness of the conductive powder is higher than that of at least one of the bump and the connection electrode, and the conductive powder between the bump and the connection electrode is at least one of the bump and the connection electrode. Or one of them is deformed so as to protrude therein, characterized in that curing the adhesive layer, the connection method of a semiconductor device. 7. The hardness of the conductive powder is higher than that of both the bump and the connection electrode, and the conductive powder deforms both the bump and the connection electrode and protrudes into each of the bumps and the connection electrode. The method for connecting a semiconductor element according to claim 6, wherein the adhesive layer is cured in a state where the adhesive layer has been formed. 8. An active layer for increasing an adhesive strength of the adhesive layer to the component is applied to a surface of the component on which the connection electrode is provided, before applying the anisotropic adhesive layer. The method for connecting a semiconductor device according to claim 7, wherein: