JPH0677285A - Mounting of ic element - Google Patents

Abstract

PURPOSE:To provide a method of mounting an IC element for eliminating complicatedness in manufacturing procedures and rise of cost and additionally being functionally suitable for constitution of a mounting circuit device. CONSTITUTION:In a method of mounting an IC element 9 having an electrode terminal 9 for connection at the main surface thereof to the surface of a circuit board 6 having a wiring circuit 6b formed by a conductive paste, an insulating film 7 of a thermosetting resin group providing a through-cutting hole 7a in the thickness direction at the region corresponding to the electrode terminal 9 for connection of the IC element 9 and an electrode pad 6a at the surface of the circuit board 6 is arranged after alignment between the IC element 9 and the surface of the circuit board 6. This stacked layer body is subjected to thermal and pressurized processings for integration with the IC element 9 and the circuit board 6 and completion of electrical connection between the electrode terminal 9a for connection and electrode pad 6a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting an IC element, and more particularly to a method for mounting an IC element on the surface of a circuit board having a wiring circuit made of a conductive paste.

[0002]

2. Description of the Related Art For the purpose of downsizing a circuit device or a circuit component, for example, on a circuit board surface such as a thick film circuit board,
Means for mounting a molded IC element or the like are known. FIGS. 3 (a) to 3 (c) are examples of a conventional method of mounting an IC chip, and schematically show an embodiment in which an IC element is mounted on a surface of a thick film circuit board or the like. As shown in a sectional view in FIG. 3 (a), an IC element 1 having a structure in which bump electrodes made of solder, gold, and other alloys are collectively formed on the surface of the electrode terminal 1a is shown in FIG. 3 (b). As shown in cross section,
For example, a method of mounting and connecting to the surface of the thick film circuit board 3 on the surface of the electrode pad 3a through the bump 2 is widely used. Further, in this method, as shown in a sectional view in FIG. 3 (c), a structure in which an anisotropic conductive layer 4 is interposed between the bump 2 and the surface of the electrode pad 3a has been attempted. In addition, in the case of the molded IC element, the electrode terminal of the molded IC element is electrically connected to the corresponding electrode pad surface of the thick film circuit board surface by wire bonding, or
Alternatively, the lead terminal derived from the molded IC element
For example, a means for aligning with the corresponding electrode pad surface of the thick film circuit board surface and electrically connecting by soldering is adopted.

[0003]

However, the above-mentioned method of mounting and connecting via the bump 2 has the following problems. That is, the direct mounting / connecting method on the surface of the circuit board via the bumps 2 forming the protruding electrodes can easily be made thinner than the method of electrically connecting by, for example, wire bonding or soldering. Moreover, the restrictions associated with the heat resistance and flexibility of the circuit board can be largely eliminated, but there are still problems in terms of cost increase and reliability.

First, the protruding electrodes (bumps) 2 on the surface of the electrode terminals 1a of the IC element 1 are generally formed by plating a low melting point metal, and the bumps 2 are formed by this plating. Since a manufacturing process (manufacturing condition) similar to the manufacturing is required, it is a fact that a large increase in cost cannot be avoided. Secondly, in the process of mounting / connecting the surface of the circuit board 3 to the surface of the electrode pad 3a, bump electrodes are provided.
When 2 melts and exhibits a soldering function, adjacent electrode pads
Electrical connection (electrical short circuit) easily occurs between 3a or between adjacent circuit patterns, and there is a problem in connection / mounting reliability. That is, when soldering the projecting electrodes 2 by melting and heating, a short circuit or the like between the electrode pads 3a may occur, or if soldering in consideration of this short circuit may cause soldering failure. Therefore, for example, a solder resist layer (pattern) is arranged between the electrode pads 3a to prevent short circuit due to melting of solder. The placement and formation of this solder resist layer (pattern) not only involves the addition of new steps, but also the steps are complicated and the mass productivity is impaired, which causes a problem of increasing costs.

The present invention has been made in view of the above circumstances, and eliminates the complexity of manufacturing operations and the increase in cost.
I suitable for the construction of a mounting circuit device that is functionally highly reliable
It is intended to provide a method for mounting a C element.

[0006]

A method of mounting an IC element according to the present invention is a method of mounting an IC element having a connecting electrode terminal on a main surface on a circuit board surface having a wiring circuit made of a conductive paste. A thermoplastic resin-based insulating film is formed between the IC element and the surface of the circuit board by penetrating and cutting the regions corresponding to the connecting electrode terminals of the IC element and the electrode pads on the surface of the circuit board in the thickness direction. It is characterized in that they are aligned and arranged, and the laminated body is subjected to a heating / pressurizing treatment to integrate the IC element and the circuit board and electrically connect the connecting electrode terminals and the electrode pads.

In the present invention, the thermoplastic resin-based insulating film preferably has a glass transition temperature higher than the glass transition temperature of the base resin of the circuit board, and is integrated by heat / pressure treatment. The adhesive layer may be interposed between the mounting and connection, and after mounting and connecting
The area including the connecting portion may be covered and sealed with a thermosetting resin.

[0008]

In the method of mounting an IC element according to the present invention,
A region corresponding to the electrode terminal and the electrode pad to be connected to each other is penetrated and cut in the thickness direction, and an insulating film made of a thermoplastic resin is interposed between the IC element surface and the circuit board surface, and the corresponding electrode terminal surface-electrode By adopting a structure in which the pad surfaces are in contact with each other, the IC element and the circuit board are integrated by heating and pressing. In other words, the electrode terminals-electrode pads that form each connection part are closely contacted with each other due to the melting and shrinking action of the insulating film, while they are separated by the weir (wall) formed by the insulating film. -The IC element and the circuit board are integrated by the fusion shrinkage action of the insulating film while exhibiting an individualized state (independent connection), and a highly reliable connection / mounting structure is achieved.

[0009]

EXAMPLES Hereinafter, FIGS. 1 (a)-(b) and FIGS. 2 (a)-(b)
An embodiment of the present invention will be described with reference to FIG.

First, as a circuit board for mounting, for example, a conductive material such as Ag, Cr, Au is formed on the surface of an insulating substrate having a thermoplastic resin such as polycarbonate resin, polyetherimide resin, polyethylene terephthalate resin as a base material. A wiring circuit board having a required electrode pad and a wiring circuit made of a conductive composition (conductive paste) containing a conductive powder was prepared. The electrode pads of the printed circuit board are formed in the numbers and positions corresponding to the connecting electrode terminals of the mounting IC element, which will be described later. On the other hand, a thermoplastic resin film in which a region (portion) corresponding to the electrode pad of the printed circuit board is selectively cut (through) holes, for example, a polyetherimide resin film or a polyimide resin film having a thickness of about 50 μm, and An IC element for mounting, for example, a molded IC element was prepared. Where the IC
No bump electrodes are formed on the connection electrode terminal surface of the element surface, and the thickness of the thermoplastic resin film is the same as the connection electrode between the electrode pad surface of the printed circuit board and the IC element surface. It is selected and set so that it can sufficiently contact the terminal surface.

Next, the wiring circuit board, the thermoplastic resin film, and the molded IC element prepared as described above are attached to FIG.
As shown in cross section in (a), position and stack and arrange. That is, the printed circuit board 6 on which the required electrode pads 6a and the wiring circuits 6b are formed is arranged on the surface of the mounting table 5 provided with the heating mechanism. At this time, the printed circuit board 6 has the electrode pad 6a forming surface as the upper surface. Then, the thermoplastic resin film 7 is positioned and arranged on the surface of the arranged printed circuit board 6. That is, a region (portion) corresponding to the electrode pad 6a of the printed circuit board 6 is selectively cut (penetrated).
The thermoplastic resin film 7 having the holes 7a is formed on the electrode pad.
The cutting (through) holes 7a corresponding to 6a are positioned and arranged so as to fit with each other. In this way, the printed circuit board 6
After positioning the thermoplastic resin film 7 on the surface,
For example, the molded IC element 9 is transferred onto the surface of the thermoplastic resin film 7 by a mounter having a pickup head 8 with a heating mechanism, and the thermoplastic resin film 7 cut hole 7a is formed on the surface of the electrode pad 6a of the printed circuit board 6. The corresponding connecting electrode terminals 9a of the molded IC element 9 are respectively positioned and brought into contact with each other via.

Next, as shown in a sectional view in FIG. 1 (b), the heating mechanism of the mounting table 5 and the heating mechanism of the pick-up head 8 forming the mounter are operated, while the mold IC element 9 is wired by the mounter. It is pressure-bonded to the surface of the substrate 6. The heating / pressurization (pressure bonding) facilitates the integration, and the effects of welding and shrinking the thermoplastic resin film 7 are effectively exerted, so that the electrode pad 6a of the printed circuit board 6 can be obtained.
The surface is closely contacted with the surface of the connecting electrode terminal 9a of the molded IC element 9, and a highly reliable electrical connection is also achieved. Here, although the heating / pressurizing conditions vary depending on the type of the base resin of the printed circuit board 6 and the thermoplastic resin film 7,
For example, in the case of polyethylene terephthalate resin, the heating temperature may be about 350 ° C.

In the above embodiment, as shown in a sectional view in FIG. 2 (a), both main surfaces of the insulating film 7 interposed between the printed circuit board 6 and the molded IC element 9 are thermoset. The adhesive layer 10 may be arranged, and as shown in the sectional view of FIG. 2 (b), after the connection / mounting, the peripheral part of the molded IC element 9 connected / mounted is thermosettable. It is also possible to cover and seal with resin 11. Further, in the present invention, the configuration of the printed circuit board 6 and the configuration of the IC element to be mounted / connected are not limited to those exemplified above.

[0014]

As described above, the IC according to the present invention
According to the element mounting method, it is not necessary to form the protruding electrode on the connection electrode terminal surface of the IC element to be mounted / connected.
Not only can the manufacturing process be simplified and costs can be reduced, but also the possibility of short-circuiting between the electrode pads can be eliminated, and highly reliable mounting and connection can be achieved. Then, a thermosetting adhesive layer may be interposed on the insulating film surface between the printed circuit board and the IC element (see FIG. 2 (a)), or the peripheral portion of the connected / mounted IC element may be thermoset. When the resin is coated and sealed (see Fig. 2 (b)), the curing shrinkage of the resin is also added, so the electrical connectivity of the IC element to the printed circuit board is further improved. obtain.

[Brief description of drawings]

FIG. 1 schematically shows an embodiment of an IC element mounting method according to the present invention, in which (a) is a cross-sectional view showing a state in which an insulating film and an IC element are positioned and arranged on a printed circuit board; (b) is an insulating film and I on the printed circuit board.
Sectional drawing which shows the state which pressurizes and heats after C element is positioned and arranged.

FIG. 2 shows a configuration in which the method for mounting an IC element according to the present invention is connected and mounted in another embodiment example.
Is a cross-sectional view when a thermosetting adhesive layer is inserted between the insulating film surface, and (b) is a cross-sectional view when the peripheral parts of the connected / mounted IC elements are covered / sealed with a thermosetting resin. .

FIG. 3 schematically shows an embodiment of a conventional method for mounting an IC element, (a) is a cross-sectional view showing the configuration of the IC element,
(b) is a sectional view showing a mounted / connected state, and (c) is a sectional view showing a mounted / connected state in another embodiment.

[Explanation of symbols]

1, 9 ... IC element 1a, 9a ... Electrode terminal for connection of IC element 2 ... Bump 3, 6 ... Circuit board 3a, 6a ... Electrode pad of circuit board
4 ... Anisotropic conductive layer 5 ... Mounting table 6b ... Wiring circuit of circuit board 7 ... Insulating film (thermoplastic resin) 7a ... Through hole of insulating film 8 ... Pickup head 10 ... Thermosetting adhesive layer
11 ... Coating / sealing layer made of thermosetting resin

Claims (1)

[Claims] 1. A method of mounting an IC element having a connecting electrode terminal on a main surface on a circuit board surface having a wiring circuit made of a conductive paste, wherein the connecting electrode terminal of the IC element and an electrode on the circuit board surface are provided. A thermoplastic resin-based insulating film, which penetrates and cuts the area corresponding to the pad in the thickness direction, is aligned and arranged between the IC element and the circuit board surface, and the laminated body is subjected to heat / pressure treatment. A mounting method of an IC element, characterized by performing the integration of the IC element and the circuit board and electrically connecting the connection electrode terminal and the electrode pad.