JPH09162230A - Electronic circuit device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the resistance value of electronic connection using an anisotropic conductive film. SOLUTION: Recessions 10 are provided in the connecting conductor layers 6 on a circuit substrate 5 for fitting a flip chip 4. At this time, these recessions 10 are similarly formed on the front end face of the bump electrodes 3 of the flip chip 4. Finally, the bump electrodes 3 and the connecting conductor layers 6 with an anisotroical conductive film 7 interposed between them are connected to one another by pressurizing and heating steps.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit device such as a hybrid integrated circuit having a structure in which a flip chip is face-down bonded to a circuit board and a method for manufacturing the same.

[0002]

2. Description of the Related Art A face-down bonding method is known as a method of mounting a semiconductor chip on a circuit board. In the typical method of face-down bonding,
Solder bump electrodes (bump electrodes) are provided in advance on the semiconductor chip, and the solder bump electrodes are soldered to the conductor layer of the circuit board with the surface of the semiconductor chip having the solder bump electrodes facing the circuit board. However, it is difficult to cope with high density by face-down bonding by soldering.
As a method of enabling high density, there is a method of face-down bonding a flip chip using an anisotropic conductive adhesive instead of solder. The anisotropic conductive adhesive is one in which conductive particles (metal particles) are uniformly dispersed in a thermoplastic resin, and there are two types, a film type and a paste type. For example, when face-down boarding a flip chip using an anisotropic conductive film,
As shown in FIG. 1, a flip chip 4 having a metal terminal conductor layer 2 provided on a semiconductor substrate 1 and bump electrodes (projection electrodes) 3 provided by plating on the metal terminal conductor layer 2 is prepared, and an insulating property such as ceramics is provided. Connection conductor layer 6 to the circuit board 5
Prepare the one with. Next, the anisotropic conductive film 7 is arranged between the bump electrode 3 and the connection conductor layer 6, and the upper surface of the flip chip 4 is pressed toward the circuit board 5 and heated. The anisotropic conductive film 7 is made of a thermoplastic resin 8 and Ni.
Since the conductive particles 9 and the like are applied to the bump electrode 3 and the connection conductor layer 6 under pressure and heating, the resin 8
Flows, the conductive particles 9 remain between the bump electrode 3 and the connection conductor layer 6, and the two are electrically connected. The conductive particles 9 are provided in a portion other than between the bump electrode 3 and the connection conductor layer 6.
Since they are insulated from each other by the resin 8, no electrical connection is established at this portion. As a result, the bump electrode 3
Only connection is achieved.

[0003]

When the bump electrode 3 is formed by gold (Au) plating in consideration of mass productivity, the tip surface, that is, the top surface of the bump electrode 3 becomes a spherical surface or a state close to the spherical surface. . As a result, when the anisotropic conductive film is pressed and heated by the bump electrode 3, the conductive particles 9 escape from the bottom of the bump electrode 3, and a sufficient number of particles are provided between the bump electrode 3 and the connection conductor layer 6. The conductive particles 9 may not remain. In such a case, it becomes impossible to connect the bump electrode 3 and the connection conductor layer 6 with low resistance. Although the case where the anisotropic conductive film is used has been described above, the same problem occurs when using the anisotropic conductive paste. Further, not only the mounting of the flip chip 4 on the circuit board 5, but also the case where the bump electrodes of one circuit board and the connection conductor layers of the other circuit board are electrically connected, there is a similar problem.

Therefore, an object of the present invention is to provide an electronic circuit device in which the protruding electrode of the first circuit component member and the conductor layer of the second circuit component member are connected with low resistance, and a manufacturing method thereof.

The invention of a device for achieving the above object is
In an electronic circuit device having a configuration in which the protruding electrode of the first circuit component member is connected to the conductor layer of the second circuit component member, a recess having a shape substantially similar to the shape of the tip surface of the protrusion electrode is formed in the conductor layer. The present invention relates to an electronic circuit device, wherein the tip end surface of the protruding electrode is arranged to face the recess, and the protruding electrode and the conductor layer are connected by an anisotropic conductive object. The invention of a method for achieving the above object, a step of preparing a first circuit component having a protruding electrode, and a conductor layer for connecting the protruding electrode,
A step of preparing a second circuit component member in which a substantially similar recess is formed on the tip surface of the protruding electrode in the conductor layer;
And a step of connecting the protruding electrode and the conductor layer with an anisotropic conductive body, which is related to a method for manufacturing an electronic circuit device.

[0006]

According to the inventions of the respective claims, the protruding electrode is bonded to the conductor layer having the concave portion similar thereto by the anisotropic conductive body. As a result, not only is the protruding electrode accurately and stably positioned on the conductor layer, but also a uniform gap is created over a large area between the two, and the conductive particles of the anisotropic conductive body are stably arranged in this gap. It As a result, a low resistance connection can be made between the protruding electrode and the conductor layer.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an electronic circuit device (hybrid integrated circuit device) including a flip chip and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to FIGS.

First, the flip chip 4 as the first circuit member shown in FIG. 2 is prepared. Flip chip, Figure 1
Similarly, the semiconductor substrate 1, the terminal conductor layer 2, and the bump electrodes (projection electrodes) 3 are formed. The semiconductor substrate 1 includes a well-known semiconductor region for forming a transistor, an IC, etc., an insulating film, etc., but these are not shown for simplicity of description. The terminal conductor layer 2 is 100 μm × 100 μm
Has a pattern in the positive direction and is made of gold (Au). Semiconductor substrate 1 before providing bump electrodes 3
What is made up of and the terminal conductor layer 2 is generally called a semiconductor bare chip. The bump electrode 3 is formed by gold plating. When the bump electrode 3 is formed by gold plating, the tip end surface of the bump electrode 3 has a spherical shape or a protruding curved surface shape. As an example of the size of the bump electrode 3, the planar shape is a square of 100 μm × 100 μm, and the height of the center is about 10 μm. Since the thickness of the terminal conductor layer 2 is 20 μm, the height of the center of the protruding electrode, which is the combination of the terminal conductor layer 2 and the bump electrode 3, is 30 μm.

The conductor layer 6 on the insulating circuit board 5 made of ceramic is made of gold and has a thickness of about 20 μm. The upper surface of the conductor layer 6 has a recess 1 of 120 μm × 120 μm.
0 is formed. The recess 10 has a surface that is substantially similar to the tip surface of the bump electrode 3. A head having a similar tip surface to the bump electrode 3 was attached instead of the capillary of the wire bonder, and the recess 10 was formed by pressing the connecting conductor layer 6 against the head with the wire bonder.

Next, an anisotropic conductive film 7 as an anisotropic conductive object is arranged between the connecting conductor layer 6 of the circuit board 5 and the bump electrode 3 of the flip chip 4, and the upper surface of the flip chip 4 is connected to the circuit. Pressurize toward the substrate 5 and about 16
The bump electrode 3 was electrically connected to the connection conductor layer 6 by the conductive particles 9 by heating at 0 ° C. for 10 seconds. At this time, since the concave portion 10 is formed in the connection conductor layer 6, the bump electrode 3
It becomes difficult for the conductive particles 9 between the recess 10 and the recess 10 to escape from the recess 10, and many conductive particles 9 are connected to each other with low resistance. The thermoplastic resin 8 of the anisotropic conductive film 7 functions as an adhesive and mechanically fixes the flip chip 4 to the circuit board 5.

As is apparent from the above, the function of the recess 10 makes it possible to arrange a large number of conductive particles 9 between the bump electrode 3 and the connection conductor layer 6, which is about 30% that of the conventional case.
Both can be connected with a low resistance value. Moreover, since it is not necessary to form the tip end surface of the bump electrode 3 into a flat surface, the bump electrode 3 can be formed by a complicated process such as a photoetching method.
It is possible to easily form by a plating method without forming. The recess 10 of the connection conductor layer 6 also has a function of positioning the bump electrode 3 and stably holding it.

[0012]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) The first circuit component is the circuit board 5, and the second
The circuit constituent member may be a semiconductor chip. In this case, for example, a bump electrode is provided on the connection conductor layer 6 of the circuit board 5 and a terminal conductor layer of the semiconductor chip corresponding to the recess 10 is provided. The present invention can also be applied when both the first and second circuit components are circuit boards. (2) An anisotropic conductive paste may be interposed as an anisotropic conductive object between the concave portion 10 of the connection conductor layer 6 and the bump electrode 3 to connect them. (3) The bump electrode 3 can have a hemispherical shape.

[Brief description of the drawings]

FIG. 1 is a sectional view showing in principle how a flip chip using a conventional anisotropic conductive film is mounted on a circuit board.

FIG. 2 is a cross-sectional view showing a flip chip according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a circuit board having a connection conductor layer according to an example of the present invention.

4 is a cross-sectional view showing a state in which the flip chip of FIG. 2 is mounted on the circuit board of FIG. 3 with an anisotropic conductive film.

[Explanation of symbols]

 3 Bump Electrodes 4 Flip Chip 5 Circuit Board 6 Connection Conductor Layer 7 Anisotropic Conductive Film 9 Conductive Particles 10 Recess

Claims (2)

[Claims] 1. An electronic circuit device having a structure in which a protruding electrode of a first circuit component member is connected to a conductor layer of a second circuit component member, wherein the conductor layer is substantially similar to the shape of the tip surface of the protruding electrode. Is formed, the tip end surface of the protruding electrode is arranged so as to face the recess, and the protruding electrode and the conductor layer are connected by an anisotropic conductive object. 2. A step of preparing a first circuit component having a bump electrode, and a conductor layer for connecting the bump electrode, wherein the conductor layer has a recess substantially similar to the tip surface of the bump electrode. 2. A method for manufacturing an electronic circuit device, comprising: a step of preparing a second circuit component having the structure formed therein; and a step of connecting the protruding electrode and the conductor layer with an anisotropic conductive body.