JP2004063943A - Conductive pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive pattern forming method which can improve the transfer properties of a conductive paste and position accuracy in transfer. <P>SOLUTION: A pattern groove 25 of a intaglio plate 21 is charged with conductive paste 23 and a uniform adhesion layer 34 is formed over the entire intaglio plate, including a recessed part generated by drying of paste. After the intaglio plate 21 and a transfer object 41 are stuck via the adhesion layer 34, the intaglio plate 21 is peeled and the paste is transferred to the transfer object. Therefore, the paste inside the intaglio plate pattern groove is transferred properly on the object of transfer. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a conductive pattern forming method for forming a conductive pattern on a substrate using an intaglio, for example.
[0002]
[Prior art]
Along with the miniaturization of electronic components, a printing method for miniaturizing conductive lines constituting a conductive pattern of an electronic component and reducing line resistance, for example, a film shape obtained by processing a fine wiring pattern on a flexible film Intaglio printing methods using intaglio have been proposed.
[0003]
Further, in order to improve the releasability when the conductive paste is transferred from the intaglio onto the substrate, it has been proposed to form a double-layer release layer on the surface of the intaglio (for example, JP-A-2000-353866). Gazette).
[0004]
[Problems to be solved by the invention]
However, in the transfer method using the conventional intaglio pattern described above, the paste in the intaglio cannot be completely transferred onto alumina (Al ₂ O ₃ substrate or the like) as an object to be transferred. Thickness variation occurs.
[0005]
Further, in the conventional intaglio printing method, after filling the processing grooves on the intaglio with the conductive paste, the organic solvent in the paste is evaporated and dried, and in order to cope with the decrease in the volume of the paste accompanying the drying, processing is performed again. It is necessary to form a pattern by transferring the paste onto the substrate after repeating the process of filling the recessed portion in the groove with the conductive paste and drying the conductive paste a plurality of times. For this reason, a complicated process is required.
[0006]
Furthermore, in such a method, if the conductive paste is not filled many times, the paste and the adhesive layer formed on the substrate to face the intaglio surface are not bonded well, and conversely, the bonding is good. When pressure is applied to make the pattern, there is a problem that the pattern is likely to be misaligned due to misalignment between the intaglio plate and the transfer target. Therefore, when the applied pressure is large, there is a problem that the transfer pattern is easily shifted and the pattern shape is deteriorated.
[0007]
In addition, when handling during transfer to the transfer target, a gap occurs between the intaglio plate and the transfer target, and the positional accuracy is reduced. Therefore, there is a problem that the handling is restricted and the workability is also reduced.
[0008]
Furthermore, when a spinner is used to form an adhesive layer on a substrate, the adhesive layer is likely to be thicker around the substrate, so that when the intaglio is bonded, poor adhesion is likely to occur at the center. For this reason, pressure is required more than usual, which also causes displacement.
[0009]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a conductive pattern forming method capable of improving transferability of a conductive paste and positional accuracy during transfer.
[0010]
Another object of the present invention is to provide a method for forming a conductive pattern, which facilitates handling of a product in a process in a transfer state and improves workability.
[0011]
[Means for Solving the Problems]
For example, the following configuration is provided as a means for achieving the object and solving the above-described problem. That is, a method of forming a conductive pattern using an intaglio having a pattern groove corresponding to a conductive pattern formed on a substrate, wherein a filling step of filling a conductive paste in the pattern groove formed in the intaglio, A drying step of drying the conductive paste, a step of forming an adhesive layer with an adhesive on the surface of the intaglio after the drying, a step of bonding the intaglio and the substrate on which the adhesive layer is formed, and Peeling off the bonded intaglio and substrate, transferring the filled conductive paste onto the substrate, and baking the transferred conductive paste to form the conductive pattern. Features.
[0012]
For example, when the adhesive layer is formed, a space in the pattern groove, which is generated by a decrease in volume of the conductive paste due to the drying, is filled with the adhesive.
[0013]
Also, for example, the filling of the conductive paste into the space in the pattern groove in the filling step is performed only once.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a flowchart showing the intaglio surface treatment step according to the present embodiment. FIG. 2 shows a step of forming a conductive pattern using an intaglio according to the present embodiment.
[0015]
In the first step shown in FIG. 1, that is, in step S11, an intaglio pattern is formed. Specifically, in a film, plate, drum, or the like made of resin or metal, a concave groove pattern groove (also referred to as a processing groove as appropriate) corresponding to a wiring pattern formed on a substrate by laser processing or mechanical processing. Form.
[0016]
In the following step S12, a conductive paste is filled into the pattern grooves (working grooves) using a metal or resin blade (squeegee), and the surface of the intaglio after the paste filling is scratched with, for example, a squeegee. Remove excess paste.
[0017]
FIG. 2A shows the state of filling and scraping of the paste in the intaglio. As shown in the figure, a paste 23 is filled into a pattern groove 25 formed in the intaglio 21 using a squeegee 22. Further, excess paste on the surface of the intaglio 21 is scraped off and removed.
[0018]
In step S13 in FIG. 1, the intaglio filled with the paste in step S12 is dried, for example, in a dryer to evaporate the organic solvent component in the paste. At this time, the volume of the paste in the intaglio pattern groove is reduced due to the evaporation of the organic solvent component. FIG. 2B shows the state at that time. In the figure, the symbol t represents a “dent” caused by a decrease in volume during drying.
[0019]
Next, in step S14, an adhesive is filled on the upper surface of the paste whose volume has been reduced by the above-described drying using the squeegee 22 in the same manner as in step S12. Further, in the following step S15, an adhesive layer is formed on the surface of the intaglio plate so as to be uniform.
[0020]
Here, the filling of the adhesive (step S14) and the formation of the adhesive layer (step S15) are described as being performed in separate steps, but the present invention is not limited to this. May be performed.
[0021]
FIG. 2C shows how the adhesive is filled and the adhesive layer is formed in steps S14 and S15 described above. As shown in the figure, the adhesive 33 is filled in the concave portion 35 of the paste whose volume has been reduced using the squeegee 22, and at the same time, the adhesive 33 uniformly forms the adhesive layer 34 on the surface of the intaglio 21. . By forming such an adhesive layer 34, the transferability of the paste described later and the positional accuracy at the time of transfer are improved.
[0022]
The formation of the adhesive layer 34 on the intaglio surface is not limited to the method using the squeegee 22 described above. For example, any method such as application by an application roller, formation of a spin coat by a spinner, and formation of an adhesive layer by screen printing may be used.
[0023]
Next, in step S17, bonding for transferring the paste filled in the pattern grooves as described above onto the transfer target is performed. Specifically, as shown in FIG. 2D, an intaglio 21 having an adhesive layer 34 formed on the entire surface thereof is placed on a transfer target 41 made of, for example, an aluminum oxide (Al ₂ O ₃ ) substrate. Then, the intaglio 21 is pressed against the transfer target (substrate) 41 by pressing in the direction indicated by the arrow 45 in the figure, and the intaglio 21 and the transfer target 41 are bonded to each other.
[0024]
Here, since the adhesive layer 34 is formed on the entire surface of the intaglio 21, even if the pressure applied to the intaglio 21 is slight, the intaglio 21 can be bonded to the transfer object 41.
[0025]
In the following step S18, the intaglio 21 and the transferred object 41 are peeled off, and the paste in the pattern groove is transferred onto the transferred object 41 together with the adhesive layer. That is, the intaglio 21 is peeled off from the intaglio 21 and the transferred material 41 that have been pressed and bonded in step S17. As a result, as shown in FIG. 2E, only the adhesive layer 34 and the paste 46 adhered to the adhesive layer 34 are left on the transfer object 41.
[0026]
Then, in step S19, which is the final step, the transfer target 41 on which the paste 46 has been transferred in step S18 is fired (patterned) under a profile of a predetermined temperature. As a result, as shown in FIG. 2 (f), the adhesive layer is burned off by heating, and the adhesion reaction between the paste and the substrate (transfer object) occurs, so that the wiring pattern 48 is formed on the transfer object 41. (Pattern formation).
[0027]
As described above, according to the present embodiment, after the conductive paste is filled into the pattern grooves of the intaglio, the paste is dried, and the entire surface of the intaglio including the concave portion due to the volume reduction of the paste caused by the drying is uniformly formed. By forming an adhesive layer, bonding the intaglio and the transferred object through the adhesive layer, and then peeling the intaglio, the paste can be transferred to the transferred object in a few steps, and the conductive paste in the intaglio pattern groove can be transferred. Good transfer can be performed on the transfer object without any displacement or the like.
[0028]
That is, even if the volume of the paste in the intaglio pattern groove is reduced, the adhesive is filled into the cavity formed by reducing the volume, and an adhesive layer is formed integrally with the cavity, thereby forming the intaglio. The transferability of the paste filled in the pattern groove to the surface of the transfer object is improved, and complete transfer without displacement of the paste becomes possible.
[0029]
Also, at this time, the adhesion (fixation) between the intaglio and the object to be transferred at the time of transfer is increased by the formation of the adhesive layer on the entire surface of the intaglio. The positional deviation between the substrates can be suppressed, and the product can be easily handled in the transfer state of the intaglio and the transfer target in the process, so that the workability is improved.
[0030]
【The invention's effect】
As described above, according to the present invention, the transferability of the conductive paste and the positioning accuracy at the time of transfer can be improved by a simple process, and the conductive paste can be efficiently transferred from the intaglio to the substrate.
[0031]
Further, according to the present invention, the displacement between the intaglio plate and the substrate can be suppressed, and a decrease in product yield can be prevented.
[Brief description of the drawings]
FIG. 1 is a flowchart showing an intaglio surface treatment step according to an embodiment of the present invention.
FIG. 2 is a view showing a step of forming a conductive pattern by using an intaglio according to the embodiment.
[Explanation of symbols]
21 intaglio 22 squeegee 23 paste 25 pattern groove (machined groove)
33 Adhesive 34 Adhesive layer 35 Depression 41 Transfer object 48 Wiring pattern

Claims (3)

A conductive pattern forming method using an intaglio having a pattern groove corresponding to the conductive pattern formed on the substrate,
A filling step of filling a conductive paste into the pattern grooves formed in the intaglio,
A drying step of drying the filled conductive paste,
After the drying, forming an adhesive layer by an adhesive on the surface of the intaglio,
Bonding the intaglio and the substrate on which the adhesive layer is formed,
Peeling off the bonded intaglio and substrate, and transferring the filled conductive paste onto the substrate;
Baking the transferred conductive paste to form the conductive pattern. 2. The method of claim 1, wherein, when forming the adhesive layer, the adhesive is also filled in a space in the pattern groove, which is generated due to a decrease in volume of the conductive paste due to the drying. 3. 3. The conductive pattern forming method according to claim 2, wherein the filling of the conductive paste into the space in the pattern groove in the filling step is performed only once.

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