JP2003188497A - Method of forming conductor circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which a high-density fine conductor circuit can be formed appropriately. <P>SOLUTION: After a water-repellent film is formed on the surface of an insulating substrate, the water-repellent film is partially removed by projecting a laser beam upon portions to be removed of the film in accordance with the wiring pattern of a conductor circuit to be formed on the insulating substrate. Then the wiring pattern of the conductor circuit is written on the insulating substrate by spraying ink grains containing independently dispersed hyperfine grains upon exposed areas of the insulating substrate formed by removing the water-repellent film by using an inkjet nozzle. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a conductor circuit suitable for forming a conductor circuit having a fine wiring pattern with a line width of 20 .mu.m on a predetermined insulating substrate.

[0002]

[Related Background Art] With higher performance and higher functionality of semiconductor integrated circuits, and further miniaturization of chip components such as various resistors and capacitors, wiring patterns of conductor circuits in printed circuit boards on which these electronic components are mounted The miniaturization of the width and the land forming the connection terminal portion has been advanced.
In particular, in the case of realizing multi-pin flip chip connection on a build-up substrate, it is required to reduce the wiring pitch of the conductor circuit to 20 μm and the via / land diameter to about 30/50 μm.

[0003]

However, in the conventional technique of forming a conductor circuit by a subtractive method (pattern etching treatment of a conductor film) or an additive method (for example, screen printing), the pattern width of the conductor circuit and its space are used. The limit is to set the width to about 30 μm. Recently, a technique has also been proposed in which a conductor circuit is transferred and formed using a toner containing conductive fine particles and an electrostatic latent image carrier (photosensitive drum) drawn by laser beam irradiation. However, there is a problem in that the structure of the device itself is large.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a conductor circuit forming method suitable for easily and effectively forming a high-density and fine conductor circuit. Especially.

[0005]

In order to achieve the above-mentioned object, the method for forming a conductor circuit according to the present invention is such that when a conductor circuit is formed on a predetermined insulating substrate, a water repellent film is formed on the surface of the insulating substrate. After the formation of the water-repellent film, the water-repellent film is irradiated onto the water-repellent film in accordance with the wiring pattern of the conductor circuit to be formed on the insulating substrate to remove the water-repellent film at the laser light irradiation site, It is characterized in that the wiring pattern is drawn by injecting ink particles containing electrically conductive independent dispersed ultrafine particles onto an area exposed by the removal of the water repellent film of the substrate by using an inkjet nozzle.

That is, the method for forming a conductor circuit according to the present invention uses an ink jet nozzle, for example, copper, silver,
A conductive circuit pattern is drawn on a predetermined insulating substrate while ejecting ink particles of a minute diameter containing conductive ultrafine particles of conductive materials such as gold, palladium, and nickel that are atomized to the nano level. , Especially on the surface of the insulating substrate,
A water-repellent film is formed in advance by coating with a fluororesin, and the water-repellent film is irradiated with laser light in accordance with the wiring pattern of the conductor circuit to be formed on the insulating substrate. The water-repellent film is removed, and the ink particles are jetted to the region exposed by the removal of the water-repellent film, so that the water-repellent film defines a drawing pattern width of the ink particles, and a high-density and fine conductor. It is characterized by forming a circuit.

[0007]

DETAILED DESCRIPTION OF THE INVENTION A method of forming a conductor circuit according to an embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a view showing a schematic processing procedure of a method for forming a conductor circuit according to this embodiment, and 1 shows an insulating substrate (insulating base) on which a conductor circuit is formed. The insulating substrate 1 is made of, for example, a so-called printed wiring circuit board of polyimide type or glass epoxy type.

The conductive circuit is formed on the insulating substrate 1 by ultrafine particles (nanoparticles) obtained by atomizing a conductive material such as copper, silver, gold, palladium and nickel to a nano level.
By injecting a paste-like ink in which the above are independently dispersed as ink droplets 3 having a small diameter using an inkjet nozzle 2 as shown in FIG. 2, a predetermined conductor pattern 4 is drawn on the insulating substrate 1. Done. The conductor pattern 4 is drawn by, for example, X-on which the insulating substrate 1 is placed.
This is performed while moving the Y table according to the wiring pattern of the conductor circuit to be formed on the insulating substrate 1. Incidentally, X-
Instead of moving the insulating substrate 1 using the Y table, it is of course possible to draw the wiring pattern while displacing the inkjet nozzle 2 in the XY direction.

Incidentally, the ink jet nozzle 2 is
For example, it is built in a piezo drive type inkjet head that is driven without generating heat and ejects ink particles having a small diameter of about 20 μm while maintaining the dispersion of the nanoparticles. Then, the conductor pattern 4 is formed as a series of drawing points by the relative movement with the XY table described above.

In the method of forming a conductor circuit according to the present invention, when a conductor circuit is drawn on the insulating substrate 1 by jetting an ink containing conductive nanoparticles using the above-mentioned ink jet nozzle 2, FIG. First, the surface of the insulating substrate 1 is treated to be water repellent by using a fluorine resin (water repellent treatment 11), and the surface of the insulating substrate 1 is treated to be a water repellent film as shown in FIG. 3 (a). Coating at 5.

Then, the water repellent film 5 formed on the surface of the insulating substrate 1 is irradiated with laser light as shown in FIG. 3 (b) according to the wiring pattern of the conductor circuit to be formed on the insulating substrate 1, The water repellent film 5 at the laser light irradiation site is removed (laser light drawing processing 12), thereby exposing the surface of the insulating substrate 1 according to the wiring pattern. In the laser light drawing process 12, the insulating substrate 1 whose surface is coated with the water repellent film 5 is placed on the XY table 12a, and the XY table 12 is controlled under the control of the drawing controller 13.
It is performed by irradiating a laser beam from the laser device 12b while moving and driving a.

At this time, the insulating substrate 1 is irradiated with laser light.
If the surface of the insulating substrate 11 is excavated and roughened as shown in FIG. 3C, the surface of the insulating substrate 11 is cleaned to remove the excavated dust (cleaning process 14), and then the insulating substrate 1 is dried (drying process 15). However, if only the water repellent film 5 on the insulating substrate 1 is removed by irradiation of laser light and the laser light irradiation site on the surface of the insulating substrate 1 is exposed, the above-mentioned cleaning / drying treatments 14 and 15 are unnecessary. Is.

Thereafter, the insulating substrate 1 from which the water repellent film 5 has been partially removed according to the wiring pattern by laser light irradiation is placed on the XY table 16a, and the ink jet nozzle 2 having the above-mentioned ink jet nozzle 2 is placed. Ink particles containing the conductive nanoparticles are jetted onto the insulating substrate 1 using the device 16b to draw and form a conductor circuit (conductor circuit drawing process 16). This conductor circuit is drawn by the drawing control device 1
Under the control of 3, the XY table 16a is driven according to the wiring pattern to be formed on the insulating substrate 1. Especially, the drawing of the conductor circuit by the ejection of ink particles
The mounting position of the insulating substrate 1 with respect to the XY table 16a is defined in advance with high accuracy by using, for example, a positioning mark provided on the insulating substrate 1. As a result, ink particles are ejected only on the region where the insulating substrate 1 is exposed by the above-mentioned laser light irradiation, and as shown in FIG. 3D, a conductor circuit is drawn with the ink 6 containing conductive nanoparticles. .

Thereafter, if necessary, the water repellent film 5 is washed and removed (washing treatment 17), and the insulating substrate 1 is dried (drying treatment 18). As shown in FIG. A conductive circuit drawn with the ink 6 containing the conductive nanoparticles is formed on the surface 1. The water repellent film 5
When the water-repellent film 5 is made of an insulating fluororesin, the water-repellent film 5 can be left as it is. Therefore, in this case, the washing / drying processes 17 and 18 are unnecessary.

Thus, as described above, when the ink 6 containing the conductive nanoparticles is jetted from the ink jet nozzle 2 to form the conductor circuit on the insulating substrate 1, the water repellent film 5 is previously formed on the surface of the insulating substrate 1. After forming and irradiating the water repellent film 5 with a laser beam to form an exposed region corresponding to the wiring pattern of the conductor circuit to be formed on the insulating substrate 1, the exposed region contains conductive nanoparticles. Since the ink 6 is ejected, the ink 6 does not spread on the surface of the insulating substrate 1 and the drawing line width does not become thick.

That is, when the ink 6 containing the conductive nanoparticles is jet-jetted onto the surface of the insulating substrate 1 without making the surface water-repellent, it is jetted from the inkjet nozzle 2 as schematically shown in FIG. Ink grain 6 has a diameter of 20μ
Even if the diameter is as small as m, it cannot be denied that the ink mass 7 spreads to a diameter of about 100 μm when attached to the surface of the insulating substrate 1 due to the wettability of the insulating substrate 1. In this regard, as described above, the water repellent film 5 coated on the surface of the insulating substrate 1 is irradiated with laser light to expose only the region corresponding to the wiring pattern width of the conductor circuit to be formed on the insulating substrate 1. When the ink particles 6 are ejected to the exposed area, the ink is repelled by the water repellent film 5 and adheres only to the exposed area of the insulating substrate 1. As a result, the ink particles 6 having a minute diameter do not spread on the surface of the insulating substrate 1, but adhere to only the exposed region of the insulating substrate 1 which is opened by removing the water repellent film 5 by the irradiation of laser light. It is possible to draw and form a conductor circuit having a fine line width with high accuracy.

Particularly, as described above, if the surface of the insulating substrate 1 is roughened by the irradiation of the laser beam, the adhesion strength of the ink can be effectively increased, so that the conductor excellent in peeling resistance (adhesion). A great practical effect is obtained such that a circuit can be easily formed. Further, since the ink particles 6 containing conductive nanoparticles are jet-jetted to form a conductive circuit by drawing, a conductive circuit having a high electric conductivity, that is, a fine pattern having a small conductive resistance can be easily formed. The effect of.

The present invention is not limited to the above embodiment. For example, the viscosity of the ink containing nanoparticles may be determined according to the nozzle diameter of the inkjet nozzle 2 and the ink ejection output. In addition, water repellent film 5
The type and the thickness thereof may be determined according to the type of the insulating substrate 1, the wiring pattern width of the conductor circuit, and the like. Further, here, the example in which the conductor circuit is formed on the printed circuit board for the printed wiring circuit is shown, but the same can be applied to the case where the conductor circuit is formed on another insulator.

Further, an XY table 12a for drawing control when irradiating the water repellent film 5 with a laser beam, and an XY table used for ejecting ink particles 6 containing nanoparticles on the insulating substrate 1.
Of course, the same table 16a can be used. In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.

[0020]

As described above, according to the present invention, the water repellent film provided on the surface of the insulating substrate is irradiated with laser light,
The water repellent film is patterned according to the wiring pattern of the conductor circuit to be formed on the insulating substrate to expose the insulating substrate, and ink particles containing electrically conductive independent dispersed ultrafine particles are jetted to the exposed region of the insulating substrate. Since the conductor circuit is drawn by jetting, it is possible to simply and effectively form the conductor circuit having a fine wiring pattern with high accuracy. Therefore, its practical advantages are great.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic processing procedure of a method for forming a conductor circuit according to an embodiment of the present invention.

FIG. 2 is a diagram showing a concept of drawing formation of a conductor circuit by ejecting ink particles using an inkjet nozzle.

FIG. 3 is a schematic diagram showing stepwise a procedure for forming a conductor circuit according to the present invention.

FIG. 4 is a diagram showing how ink particles adhering to an insulating substrate spread due to their wettability.

[Explanation of symbols]

1 Insulating substrate (insulating substrate) 2 inkjet nozzle 3 Ink particles containing conductive nanoparticles 5 Water repellent film 12 Laser light drawing processing 16 Conductor circuit drawing process

Continued front page    F-term (reference) 4E351 AA03 AA04 BB01 BB31 CC11                       DD04 DD05 DD06 DD19 DD20                       DD52 EE01 GG20                 5E343 AA02 AA15 AA17 AA18 AA37                       BB03 BB23 BB24 BB25 BB44                       BB48 BB72 DD17 EE32 FF05                       GG08

Claims (2)

[Claims] 1. When forming a conductor circuit on a predetermined insulating substrate, a water-repellent film is formed on the surface of the insulating substrate, and then the conductive circuit is formed according to the wiring pattern of the conductor circuit to be formed on the insulating substrate. The water-repellent processed film is irradiated with laser light to remove the water-repellent processed film at the laser-beam-irradiated portion, and then the region of the insulating substrate exposed by the removal of the water-repellent processed film is made conductive using an inkjet nozzle. 2. A method for forming a conductor circuit, comprising: ejecting ink particles containing ultrafine particles to draw the wiring pattern. 2. The water-repellent film is made of a fluorine-based material, and the conductive ultrafine particles are nano-sized particles of a conductive material such as copper, silver, gold, palladium and nickel. 2. The method for forming a conductor circuit according to claim 1, wherein the inkjet nozzle is for forming a paste-like ink containing the ultrafine particles independently dispersed into particles and ejecting the particles.