JPH05119337A - Mutual connection method for electrode terminal - Google Patents

Abstract

PURPOSE:To improve reliability in the mutual connection of electrode terminals. CONSTITUTION:The electrode terminal formed on a first electric circuit substrate is mutually and electrically connected with the electrode terminal formed on the second electric circuit substrate so as to hold and fix them in the mutual connecting method of the electrode terminal. In the method and concerning one, at least, electric circuit substrate 3, electrically conductive particles 5a coated by adhesive material are electrified so as to be scattered on the electrode terminal 4 formed on the third electric circuit substrate 3, then, the electric circuit substrate 3 is heated, electrically conductive particulates 5c are fixed on the electrode terminal 4 of the electric circuit substrate 3 and the electrode terminal formed on the first circuit substrate and the electrode terminal formed on the second circuit substrate are positioned so as to be heated and press-fitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of spraying conductive fine particles on a wiring board and electrically connecting the electrode terminals of the wiring board facing each other through the conductive fine particles. In particular, the present invention relates to an interconnection method suitable as a chip-on-panel mounting method for connecting a semiconductor chip on a display substrate of a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, as a method of spraying conductive fine particles on a wiring board and electrically connecting electrode terminals of a pair of wiring boards facing each other through the conductive fine particles, as shown in FIG. , The charged conductive fine particles are scattered on the electrode terminals 4 of the one wiring board 3, the conductive fine particles 11a are attached to the electrode terminals, and the electrode terminals of the other wiring board are aligned and then pressed. While using an insulating adhesive,
A method has been used in which the electrode terminals of both wiring boards are interconnected via the conductive fine particles by fixing.

[0003]

However, in the above-mentioned conventional example, the conductive fine particles adhered on the electrode terminals are shown in FIG.
11b, it is easy to move, and therefore, there is a problem that the reliability of the connection is lowered, such as a short circuit between the adjacent electrode terminals 4.

The present invention has been made in view of the problems in the above-mentioned conventional example, and an object thereof is to provide a highly reliable electrode terminal interconnection method.

[0005]

In order to solve the above-mentioned problems, the present invention uses, as connecting particles, conductive fine particles coated with an adhesive, and as a pretreatment for thermocompression bonding, A method is used in which the connecting particles are electrically charged and scattered on the electrode terminals, and then attached to the electrode terminals, and then the first wiring board is heated to adhere and fix the conductive fine particles on the electrode terminals. ..

[0006]

According to the present invention, the conductive fine particles are adhered and fixed on the electrode terminals of at least one of the first wiring board and the second wiring board, and then the first and second wiring boards. Since the electrode terminals are aligned and thermocompression bonded, it is possible to prevent the movement of the connection particles before the thermocompression bonding, for example, at the time of the alignment, and to prevent the deterioration of the connection reliability.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a case of connecting a semiconductor element to an electrode terminal of a liquid crystal display panel using a ferroelectric liquid crystal will be described below with reference to the drawings.

As shown in FIG. 1, particles 5a in which conductive particles 2 are covered with a thermoplastic adhesive 1 are supplied to a particle charging device 6. As a method of transporting the particles 5a, a spray method, a particle transport method using an electric field curtain, or the like can be used. As the particle charging device 6, a device that charges particles by a corona charging method, a friction charging method, or a charging method using a boxer charger can be used. Charged particles 5b
Is an electrode terminal 4 formed on the display substrate 3 of the liquid crystal display device.
The particles are scattered on the surface and adhere to the electrode terminals 4 by the image force of the charged electric charges. At this time, if the electrode terminal 4 is grounded or has a polarity opposite to the charged electric charge, the charged particles 5b are more easily attached to the electrode terminal 4.

Here, the conductive particles may be metal particles, but by using resin particles plated with metal, the specific gravity of the conductive particles can be reduced and the effect of image power can be enhanced. You can

Next, as shown in FIG. 2, the thermoplastic adhesive 1 is melted by heating the substrate 3 or irradiating it with heat rays, and the particles are bonded and fixed to the electrode terminals 4 like particles 5d. ..

Then, as shown in FIG. 3, the electrode terminals 4 of the substrate 3 and the electrode terminals 9 of the semiconductor element 7 are aligned with each other and then thermocompression bonded to connect the electrode terminals 4 and 9 to each other.

The thermoplastic adhesive 1 covering the conductive fine particles 2 may be an insulating adhesive, but by using an adhesive containing metal powder, the conduction resistance between the electrode terminals 4 and 9 can be improved. Can be lower.

At this time, the semiconductor element 7 is operated in a state where the semiconductor element 7 is electrically connected to the electrode terminals 4 of the liquid crystal display panel to judge whether the connection is good or bad. And the semiconductor element can be connected again by the above method.

Further, after connecting the semiconductor element 7 by the above method, as shown in FIG. 4, the glass substrate 3 of the liquid crystal panel and the unbonded portion of the semiconductor element are sealed and bonded by the insulating adhesive 10. By maintaining the interconnection of the electrode terminals and preventing the intrusion of moisture, the connection reliability can be further improved.

When the liquid crystal panel uses a ferroelectric liquid crystal, the liquid crystal panel is cooled from the heated state to the SmC * (chiral smectic C) phase in order to uniformly arrange the ferroelectric liquid crystal molecules. In this embodiment, the liquid crystal panel is heated to 95 ° C. It is effective to use a thermosetting adhesive as the insulating adhesive 10 in order to prevent connection failure due to softening of the insulating adhesive 10 when this heating is performed.

[0016]

As described above, the following effects can be obtained by using the method of interconnecting electrode terminals of the present invention.

That is, on the electrode terminals of the electric circuit substrate,
The conductive particles coated with the adhesive are electrically charged and dispersed, and then the electric circuit substrate is heated to fix the conductive fine particles on the electrode terminals of the electric circuit substrate, whereby It is possible to prevent connection failure due to movement.

Further, when connecting a semiconductor element on a display substrate of a liquid crystal panel, since conductive particles can be fixed only on the electrode terminals, the insulating property between adjacent electrodes is improved, so that finer electrode terminals can be connected. Can be possible.

Furthermore, when a semiconductor element is connected to a display substrate of a liquid crystal panel using a ferroelectric liquid crystal, an unbonded portion between the semiconductor element and the display substrate of the liquid crystal panel is bonded and fixed with an insulating thermosetting adhesive. By doing so, even if the liquid crystal panel is heated, it is possible to prevent the connection failure caused by the softening of the insulating adhesive.

[Brief description of drawings]

FIG. 1 is a diagram showing a structure of conductive fine particles and a method of spraying conductive fine particles according to an embodiment of the present invention.

FIG. 2 is a view showing a state in which the conductive fine particles of FIG. 1 are fixed on electrode terminals.

FIG. 3 is a diagram showing a state in which the electrode terminals on the display substrate of the liquid crystal panel of FIG. 2 are aligned with the electrode terminals of the semiconductor element and thermocompression bonded.

4 is a diagram showing a state in which a display substrate of the liquid crystal panel in FIG. 3 and an unbonded portion of a semiconductor element are sealed and bonded by an insulating adhesive.

FIG. 5 is a diagram showing a conventional interconnection method.

[Explanation of symbols]

1: thermoplastic adhesive, 2: conductive fine particles, 3: liquid crystal panel display substrate, 4: liquid crystal panel electrode terminals, 5a: connection particles before charging, 5b: charged connection particles, 5c: on the substrate Connection particles scattered and attached on the electrode terminals, 5d: connection particles fixed on the electrode terminals, 7: semiconductor element substrate,
8: insulating film, 9: connection pad, 10: insulating adhesive,
11a: conductive fine particles adhered on the electrode terminals, 11b:
Conductive particles that have moved between the electrode terminals.

Claims (4)

[Claims] 1. An interconnection of electrode terminals for electrically connecting and holding and fixing an electrode terminal formed on a first electric circuit substrate and an electrode terminal formed on a second electric circuit substrate. In the method, in at least one of the first electric circuit substrate and the second electric circuit substrate, electrically conductive particles coated with an adhesive are electrified and dispersed on the electrode terminals formed on the electric circuit substrate. After that, the electric circuit substrate is heated to fix the conductive fine particles on the electrode terminals of the electric circuit substrate, and the electrode terminals formed on the first circuit substrate and the second circuit substrate are formed. A method for interconnecting electrode terminals, which comprises aligning the electrode terminals and thermocompression bonding. 2. The one of the first electric circuit substrate and the second electric circuit substrate is a semiconductor element, and the other is an extension of a display substrate of a liquid crystal display device. Method of interconnecting electrode terminals of. 3. The method for interconnecting electrode terminals according to claim 2, wherein the liquid crystal display device is a liquid crystal display device using a ferroelectric liquid crystal. 4. The mutual mutual connection of electrode terminals according to claim 3, wherein unbonded portions of the first electric circuit substrate and the second electric circuit substrate are bonded and fixed by an insulating thermosetting adhesive. How to connect.