JP2003318517A - Method of forming conductor layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductor layer forming method which is capable of forming a fine conductor layer with high accuracy and reducing the equipment cost and the running cost related to the formation of the conductor layer. <P>SOLUTION: Partitions 4 demarcating paste filling regions 5 are provided to an object 3, the paste filling regions 5 are filled with conductive paste 6, then baking heat is applied to the conductive paste 6 filling the paste filling regions 5 to form a conductor layer 7. The partitions 4 are dissipated by the heat to form the conductor layer 7 having a desired pattern or a desired shape corresponding to the paste filling regions 5 in the object 3. <P>COPYRIGHT: (C)2004,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 layer having a desired pattern or shape on an object such as various substrates and ceramic green sheets.

[0002]

2. Description of the Related Art In recent years, as electronic devices such as mobile phones and personal computers have become smaller and more sophisticated, miniaturization of electronic parts has been required, and high density has been achieved for substrates on which electronic parts are mounted. Implementation is required. In order to satisfy the demand for miniaturization of electronic components, it is inevitable to miniaturize the internal conductors that make up the component circuit, and in order to satisfy the demand for high-density mounting on the substrate, miniaturization of the conductor pattern is inevitable. is there.

A thick film forming method and a thin film forming method are mainly used for forming the internal conductor and the conductor pattern.
In the former thick film forming method, a method of printing a conductive paste in a predetermined shape through a screen is generally adopted, and in the latter thin film forming method, a film is formed by an evaporation method or a cathode sputtering method, and then a photolithography technique is used. A method of patterning into a predetermined shape is generally adopted.

[0004]

However, in the conventional thick film forming method, the equipment cost and the running cost can be kept low, but the conductor layer including the internal conductor, the conductor pattern, and the like can be reduced to 50.
It is difficult to form with a thickness, diameter, width and adjacent spacing of less than μm. Moreover, in the conventional thin film forming method, 20
It is possible to form with a thickness, diameter, width and adjacent spacing of less than μm, but the equipment cost and running cost are much higher than when the thick film forming method is performed.

The present invention was created in view of the above circumstances, and an object of the present invention is to form a fine conductor layer with high accuracy, and to keep the equipment cost and running cost for forming the conductor layer low. Another object of the present invention is to provide a method for forming a conductor layer that can be used.

[0006]

In order to achieve the above object, the method of forming a conductor layer according to the present invention comprises a step of filling a concave portion of an intaglio plate with a fluid capable of being hardened by a physicochemical change, and Transferring the fluid filled in the recesses to the object, curing the fluid during the transfer or after transfer by physicochemical changes to form partition walls defining the paste filling area, and heating and baking And a step of filling the paste-filled area with a conductive paste capable of achieving the above, and a step of applying heat for firing the conductive paste in the paste-filled area to generate a conductor layer.

According to this conductor layer forming method, the partition wall portion defining the paste filling area is formed on the object, the conductive paste is filled in the paste filling area, and then the conductive paste in the paste filling area is baked. By generating heat to generate a conductor layer, a conductor layer having a desired pattern or shape corresponding to the paste filling region can be formed on the object.

The above and other objects, constitutional features, and operational effects of the present invention will become apparent from the following description and the accompanying drawings.

[0009]

1 to 10 show an embodiment of a conductor layer forming method to which the present invention is applied.

FIG. 1 shows a partial vertical section of an intaglio 1 used for forming a conductor layer, and an inverted image of a predetermined pattern or shape is drawn on one surface thereof by a recess 1a having an inverted trapezoidal vertical section. In other words, an image of a predetermined pattern or shape corresponding to the conductor layer 7 is drawn by the surface where the recess 1a does not exist. The intaglio 1 is made of glass, plastic, ceramics, metal, or other materials,
Is formed by a processing method suitable for the intaglio material, for example, ablation processing by laser light, a dry etching method, a wet etching method, or the like.

Although it depends on the intaglio material and the method of processing the recesses, it is possible to obtain values of 20 μm or less for the diameters of the holes and the widths of the grooves forming the recesses 1a, their depths, and the adjacent intervals. Further, in the transfer step described later, in order to favorably escape the fluid 2 filled in the concave portion 1a, in the case of the concave portion 1a formed of a hole, the aspect ratio (hole depth / hole diameter) is 0.1. It is preferable to set to 10 to 10, and in the case of the concave portion 1a composed of a groove, its aspect ratio (groove depth / groove width) may be set to the same range.

When forming a conductor layer using the intaglio 1 shown in FIG. 1, first, as shown in FIG. 2, the intaglio 1 is placed so that the recess 1a faces upward, and the recess 1a flows into the recess 1a. Animal 2
To fill. For filling the fluid 2, the fluid 2 is supplied onto the intaglio 1 and a squeegee is moved along the recess forming surface of the intaglio 1 to push the fluid 2 into the recess 1a.
It is possible to use a method in which the roller to which the fluid 2 is attached is moved along the recess forming surface of the intaglio 1 to push the fluid 2 into the recess 1a and then scrape off the excess fluid 2.

The fluid 2 is capable of being hardened by a physicochemical change and, after hardening, can be lost by heat during firing which will be described later. Curing by light, curing by releasing heat, curing by solvent evaporation, and the like.

The thermosetting fluid 2 contains at least a thermosetting resin such as phenol resin, epoxy resin or alkyd resin, and a solvent,
Those obtained by softening a thermosetting resin can be used. The photocurable fluid 2 is a radical polymerization type or cationic polymerization type photocuring initiator that generates an active species by ultraviolet rays or the like, and a radical polymerization type or cationic polymerization type light that reacts with the active species. A material containing at least a reactive resin and a solvent can be used. Further, as the fluid 2 that can be cured by releasing heat, those obtained by softening a thermoplastic resin such as a fluororesin or an acrylic resin can be used. Furthermore, a fluid 2 that can be cured by solvent evaporation
As the material, a thermosetting resin, a thermoplastic resin, or a material containing at least a synthetic rubber and a solvent (solvent or water) can be used. Of course, if it is possible to cure due to physico-chemical changes and to eliminate the heat after curing, use a fluid other than the above.
It may be used as.

Next, as shown in FIG. 3, the recess forming surface of the intaglio 1 is brought close to the object 3, and the exposed surface of the fluid 2 filled in the recess 1a is brought into contact with the surface of the object 2. And
As shown in FIG. 4, the intaglio 1 is separated from the object 3 to transfer the fluid 2 filled in the recess 1 a to the object 3.
Since heat for firing the conductive paste 6 is applied to the conductive paste 6 in the firing process described later, the target 3 is a substrate such as a ceramic substrate having heat resistance to the firing temperature, or is simultaneously fired with the conductive paste 6. A ceramic green sheet that can be used is preferably used.

In the transfer step, the fluid 2 is physically applied before the intaglio 1 is separated from the object 3 (during transfer) or after the intaglio 1 is separated from the object 3 (after transfer). The partition wall portion 4 is formed by being hardened by a chemical change.

Specifically, when the fluid 2 is heat-curable, the heat required for curing is applied during the transfer, or the heat required for curing is applied after the transfer. Give. In the former case, the intaglio 1 made of a material that can withstand heat for curing is used.

When the fluid 2 is photocurable, the light required for curing is applied during the transfer, or the light required for curing is applied after the transfer. In the former case, the intaglio 1 made of a material capable of transmitting light for curing is used.

Further, when the fluid 2 can be cured by releasing heat, the fluid 2 is left for a time necessary for heat dissipation during the transfer, or left for a time necessary for heat dissipation after the transfer. . In the former case, it is possible to radiate heat to the outside through the intaglio 1, and in both cases, a method of accelerating heat release by blowing air may be adopted.

Further, when the fluid 2 is one that can be hardened by solvent evaporation, it is left in the state during transfer for the time required for evaporation, or left in the state after transfer for the time required for evaporation. . In the former case, it is possible to evaporate through a minute gap between the intaglio 1 and the object 3 if it takes time, and in both cases, a method of promoting evaporation by blowing air or the like may be adopted. I do not care.

As shown in FIG. 5, the partition wall 4 defines a paste filling region 5 on the surface of the object 3, that is, a recess formed by the wall surface of the partition wall 4 and the surface of the object 3. It is for. When the curing process is performed during the transfer, the vertical cross-sectional shape of the partition wall portion 4 becomes substantially the same as the vertical cross-sectional shape of the recess 1a, and when the curing treatment is performed after the transfer, the vertical cross-sectional shape of the partition wall portion 4 is the recess. The shape is similar to the vertical cross-sectional shape of 1a. Depending on the viscosity of the fluid 2 to be used and the curing time, if the curing treatment is performed after the transfer, the shape of the partition wall portion 4 may be largely lost. In such a case, it is desirable to perform the curing treatment during the transfer. .

Next, as shown in FIG. 6, the paste filling region 5 defined by the partition wall portion 4 is filled with the conductive paste 6 so as to have a thickness dimension substantially the same as the height dimension of the partition wall portion 4. An ink jet printing method, a screen printing method, or the like can be used for filling the conductive paste 6.

The conductive paste 6 is 700 to 150.
It is a known material that can be heated and baked in the range of 0 ° C., and specifically, silver, gold, platinum, palladium, nickel, copper,
At least one metal powder selected from aluminum, iron and the like, at least one organic binder selected from acrylic resin, phenol resin, alkyd resin, rosin ester and various celluloses, alcohol-based, hydrocarbon-based and ether-based And at least one organic solvent selected from ester type and the like as an essential component and various additives as necessary.

Next, as shown in FIG. 7, the object 3 after the paste filling is put into a firing furnace (not shown), and the conductive paste 6 in the paste filling area 5 is fired. Apply heat. As a result, the organic binder and the like in the conductive paste 6 disappears and the metal powder sinters to form the conductor layer 7, and the partition wall 4 is heated by the heat during firing.
Disappears due to thermal decomposition, and only the conductor layer 7 remains on the object 3.

When the conductive paste 6 and the partition wall 4 have high wettability, as shown in FIG. 6, the conductive paste 6 filled in the paste filling region is in close contact with the wall surface of the partition wall 4. Since the conductor 7 is fired as it is, the edge 7a of the conductor layer 7 is rounded as shown in FIG. 8 due to the contraction effect during firing, but the vertical cross-sectional shape of the conductor layer 7 obtained by the firing process is an inverted trapezoid or an approximate shape thereof. Becomes On the other hand, when the wettability between the conductive paste 6 and the partition 4 is low, the conductive paste 6 filled in the paste filling area does not adhere to the wall surface of the partition 4 as shown in FIG.
As shown in FIG. 0, the vertical cross-sectional shape of the conductor layer 7 obtained by the firing process is rectangular or an approximate shape.

As described above, according to the above-described conductor layer forming method, the partition wall portion 4 which defines the paste filling area 5 in the object 3 is formed.
After filling the paste-filled region 5 with the conductive paste 6, heat is applied to the conductive paste 6 in the paste-filled region 5 to sinter it to generate the conductor layer 7 and the heat causes the partition wall portion 4 to be formed. Is eliminated, the conductor layer 7 having a desired pattern or shape corresponding to the paste filling region 5 can be formed on the object 3.

That is, by forming the partition wall portion 4 defining the paste filling area 5 on the object 3 by using intaglio printing, the conductor layer 7 having a desired pattern or shape can be formed on the object 3 and the partition wall. The thickness of the conductor layer 7 depends on the part 4,
The fine conductor layer 7 can be formed on the object 3 with high accuracy by controlling the diameter, the width, the adjacent space, and the like. Moreover, since the formation of the partition wall, the filling and firing of the conductor paste are the basic techniques for forming the conductor layer, the facility cost and running cost for forming the conductor layer can be kept low.

In the above embodiment, the recess 1 of the intaglio 1 is used.
An inverted trapezoidal vertical section is shown as a, and FIG.
Even if the concave section 1b having a rectangular vertical cross section shown in FIG. 12 and the concave section 1c having a U-shaped vertical cross section shown in FIG. 12A are used, conductor layers 7-1, 7- 2 can be formed.

When the concave portion 1b having a rectangular vertical cross-sectional shape shown in FIG. 11A is used, the vertical cross-sectional shape of the partition wall portion 4-1 is also rectangular or its approximate shape as shown in FIG. 11B. Become.
If the conductive paste 6 and the partition wall 4-1 have high wettability,
As shown in FIG. 11C, the vertical cross-sectional shape of the conductor layer 7 obtained by the firing process is a rectangle or its approximate shape. On the other hand, when the wettability between the conductive paste 6 and the partition wall portion 4-1 is low, FIG. As shown in (D), the vertical cross-sectional shape of the conductor layer 7 obtained by the firing process is a rectangular shape with rounded edges or an approximate shape thereof.

On the other hand, the vertical sectional shape shown in FIG.
When the V-shaped recess 1c is used, as shown in FIG. 12 (B), the partition wall 4-2 also has an inverted U-shape or an approximate shape. If the conductive paste 6 and the partition wall 4-2 have high wettability, the conductive paste 6 may be filled so that the thickness of the partition paste is substantially the same as the height of the partition wall 4-2. Since there is a risk that the conductive paste 6 will be connected to the upper surface of the partition 2, in this case, the conductive paste 6 is filled so as to have a thickness dimension smaller than the height dimension of the partition wall 4-2, and this is fired to form a conductor. It is desirable to obtain the layer 7-2 (see FIG. 12C). On the other hand, when the wettability between the conductive paste 6 and the partition wall portion 4 is low, the above fear does not occur,
As shown in FIG. 12D, the vertical cross-sectional shape of the conductor layer 7-2 obtained by the firing process is a rectangular shape with rounded edges or an approximate shape thereof.

Further, in the above-described embodiment, as the fluid 2, a material that can be hardened by a physicochemical change and has physical properties that can be eliminated by heating after hardening is used, and the conductive paste 6 in the paste filling area 5 is used. Although it is shown that the partition wall portion 4 after curing is lost by heat during firing,
A fluid that has a physical property such that it can be hardened by a physicochemical change and that it can be transformed into a dielectric substance by heating after hardening, for example, the fluid 2 is an organic dielectric substance such as a semiconductor polyimide or an unfired dielectric. If a material containing a ceramics dielectric material such as ceramics is used, as shown in FIG. 13, the partition wall portion 4 is hardened or sintered by the heat when the conductive paste 6 in the paste filling area 5 is fired, so that the dielectric property is improved. It can be changed to the partition wall portion 8 and this can be left on the object 3 together with the conductor layer 7. Needless to say, even when such a method is used, the same effects as those of the above-described embodiment can be obtained.

[0032]

As described in detail above, according to the present invention,
A fine conductor layer can be formed on a target object with high precision,
The equipment cost and running cost for forming the conductor layer can be kept low.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view of an intaglio plate.

FIG. 2 is an explanatory view of a step of filling a fluid in the recess of the intaglio plate.

FIG. 3 is an explanatory view of a process of transferring a fluid filled in a concave portion of an intaglio plate to an object.

FIG. 4 is an explanatory diagram of a process of transferring a fluid filled in a concave portion of an intaglio plate to an object.

FIG. 5 is a partial vertical cross-sectional view of an object in which a partition wall portion defining a paste filling area is formed.

FIG. 6 is an explanatory view of a process of filling the paste filling area with a conductive paste.

FIG. 7 is an explanatory diagram of a step of firing a conductive paste filled in a paste filling area to generate a conductor layer and eliminating partition walls.

FIG. 8 is a partially enlarged view of FIG.

FIG. 9 is a diagram showing the shape of a filling paste obtained when the wettability between the conductive paste and the partition wall is low.

FIG. 10 is a diagram showing the shape of a conductor layer obtained when the wettability of the conductive paste and the partition wall is low.

FIG. 11 is a partial vertical cross-sectional view of an intaglio showing a modification of the vertical cross-sectional shape of a recess, a view showing a partition wall formed by the recess, and a view showing a conductor layer formed by the partition wall.

FIG. 12 is a partial vertical cross-sectional view of an intaglio showing another modification of the vertical cross-sectional shape of the recess, a view showing a partition wall formed by the recess, and a view showing a conductor layer formed by the partition wall.

FIG. 13 is an explanatory diagram of a process of firing a conductive paste filled in a paste filling region to generate a conductor layer and changing a partition into a dielectric partition.

[Explanation of symbols]

1 ... Intaglio, 1a ... Recess, 2 ... Fluid, 3 ... Object, 4,
4-1, 4-2 ... Partition portions, 5 ... Paste filling area, 6 ... Conductive paste, 7, 7-1, 7-2 ... Conductor layer, 8 ... Dielectric partition portion.

Claims (9)

[Claims] 1. A step of filling a fluid material capable of being hardened by a physicochemical change into a concave portion of an intaglio plate, and a step of transferring the fluid material filled in the concave portion of the intaglio plate to an object, and during or after transfer. In the state, the fluid is hardened by physicochemical change to form the partition wall that defines the paste filling area, the step of filling the paste filling area with the conductive paste capable of heating and firing, and the conductivity of the paste filling area And a step of applying heat for firing the paste to generate a conductor layer, the method for forming a conductor layer. 2. The method for forming a conductor layer according to claim 1, wherein the fluid is made of a thermosetting material. 3. The conductor layer forming method according to claim 1, wherein the fluid is made of a photo-curable material. 4. The conductor layer forming method according to claim 1, wherein the fluid is made of a material that can be cured by releasing heat. 5. The conductor layer forming method according to claim 1, wherein the fluid is made of a material that can be cured by solvent evaporation. 6. The liquid material has physical properties that can be eliminated by heating after curing, and the partition wall portion is eliminated by heat when firing the conductive paste in the paste filling region. The conductor layer forming method according to any one of 1 to 5. 7. The fluid has a physical property that can be changed to a dielectric substance by heating after curing, and the partition wall portion is changed to a dielectric partition wall portion by heat when firing the conductive paste in the paste filling region. The conductor layer forming method according to claim 1, wherein 8. The fluid comprises an organic dielectric material, The method for forming a conductor layer according to claim 7, wherein. 9. The conductor layer forming method according to claim 7, wherein the fluid contains a ceramic dielectric material.