KR101099436B1 - Method of forming wiring pattern - Google Patents

Abstract

The present invention relates to a method of forming a wiring pattern on a circuit board, the method of forming a wiring pattern of the present invention comprises the steps of: a) preparing a primer layer by coating the epoxy resin composition on the substrate in a semi-cured state; b) first printing the ink of the first conductive metal on the substrate of step a) to immerse the seed wiring layer in the primer layer; c) calcining the substrate of step b) to completely cure the epoxy resin composition of the primer layer; And d) second printing with ink containing a second conductive metal on the seed wiring layer of step c) to prepare a conductive wiring layer. The present invention can form a wiring pattern so that the adhesion between the substrate and the conductive wiring layer is excellent.

Board, Conductive, Wiring Pattern, Inkjet, Epoxy

Description

How to Form Wiring Patterns {METHOD OF FORMING WIRING PATTERN}

The present invention relates to a method of forming a wiring pattern by printing a conductive metal on a circuit board.

With the development of industrial technology, various functions and miniaturization are required, and thus light, strong and small circuit boards are required. In order to secure this requirement, a fine wiring pattern can be basically implemented, and the reliability of the implemented wiring pattern must be secured.

Recently, a technique mainly used to secure reliability of a fine wiring pattern is a technology of forming a wiring pattern of a circuit board by inkjet printing. Since the inkjet printing method directly forms the wiring pattern on the substrate, it is possible to omit the vacuum film formation, photolithography, etching, and resist peeling process, which had to be done in the conventional lithography method, so that the circuit board can be manufactured at a low price. have.

However, in the inkjet printing method, when ink is injected into a nozzle having a diameter of 50 μm without processing a substrate, the diameter of an ink drop increases about 1.5 times when ink is ejected from the nozzle, and the ink is printed on a circuit board. When the droplets fall, there is a phenomenon of spreading, and as a result, the width of the wiring pattern is increased by several times the diameter of the injection nozzle.

Therefore, in the case of forming the wiring pattern by the inkjet printing method, in order to finely control the width of the wiring pattern, a method of adjusting the viscosity of the ink, the discharge amount, the diameter of the inkjet nozzle, or improving the characteristics of the circuit board (surface of the circuit board) is required. It is mainly done. In this case, a method of forming a fine wiring pattern by improving the characteristics of the circuit board may include a method of heating the circuit board during ink injection. However, the method of heating the substrate not only causes the nozzle to be clogged when the ink is ejected from the nozzle because the distance between the nozzle and the circuit board is close, and also causes the coffee stain effect of the wiring pattern shape.

On the other hand, a technique of forming a fine wiring pattern by increasing the contact angle between the ink and the circuit board by simply hydrophobizing the substrate without heating the circuit board is proposed, but such a technique overlaps the ink droplets and the ink droplets and thus the wiring lines. When forming, the force between the ink droplets and the ink droplets is greater than the force between the substrate and the ink droplets, so that the ink cannot be attached to the substrate and the ink agglomeration occurs due to the attraction between the ink droplets, resulting in irregular shape of the wiring pattern. There is this.

In order to solve the problems caused when the wiring pattern is formed by the above-described conventional inkjet printing method, the inventors coat and heat-treat the surface of the circuit board with an epoxy resin composition and then form the wiring pattern on the surface-treated circuit board ink. The conventional problem can be solved by suppressing the spreading property and improving the adhesion between the ink and the substrate.

That is, in order to suppress the spreadability of the ink, the contact angle between the substrate and the ink must be increased. For this purpose, the present inventors coated the epoxy resin composition on the circuit board, semi-cured, and formed a wiring pattern.

However, when wiring wiring lines are formed on a circuit board in which the epoxy resin composition is in a semi-cured state, conductivity decreases as the epoxy resin composition penetrates into the wiring pattern formed by the behavior of the epoxy resin composition.

Accordingly, the present inventors can suppress the spreading of the ink and improve the adhesion between the ink and the substrate as well as improve the conductivity of the circuit board in forming the wiring pattern on the circuit board coated with the epoxy resin composition. It is an object of the present invention to provide a method capable of forming the same.

The present invention comprises the steps of: a) coating the epoxy resin composition in a semi-cured state on the substrate to form a primer layer to achieve the above object; b) first printing the ink of the first conductive metal on the substrate of step a) to immerse the seed wiring layer in the primer layer; c) calcining the substrate of step b) to completely cure the epoxy resin composition of the primer layer; And d) second printing on the seed wiring layer of the substrate by using ink containing a second conductive metal to form the conductive wiring layer.

Here, the semi-cured state of the epoxy resin composition means a state until the chain of the epoxy resin is completely closed in the curing reaction of the epoxy resin.

In addition, the state in which the seed wiring layer is recessed in the primer layer means that the seed wiring layer is recessed to expose the surface of the primer layer.

On the other hand, the present invention is a substrate; A primer layer formed on the substrate, the epoxy resin composition is cured; A seed wiring layer printed with an ink including a first conductive metal and recessed in the primer layer; And it is printed with an ink containing a second conductive metal, and provides a circuit board comprising a conductive wiring layer laminated in the same pattern on the seed wiring layer.

In the wiring pattern forming method of the present invention, since the seed wiring layer is recessed after coating the epoxy resin composition on the substrate in a semi-cured state, the adhesion between the substrate and the ink (seed wiring layer) can be improved, and the contact angle between the substrate and the ink is increased. Spreadability of the ink on the substrate can be suppressed. In addition, since the conductive resin layer is formed on the seed wiring layer after the epoxy resin composition is completely cured so as not to behave, the conductivity of the substrate can be improved.

Hereinafter, the present invention will be described in detail.

According to the present invention, since the epoxy resin composition is coated (surface treatment) on the substrate in a semi-cured state and a wiring pattern is formed, the epoxy resin composition is completely cured to form a wiring pattern, thereby suppressing the spreading of the ink. The wiring pattern may be formed so as to have excellent conductivity, and the specific method thereof is as follows.

a) forming a primer layer on the substrate

The epoxy resin composition is semi-cured on the substrate (surface treatment) to form a primer layer. The primer layer is formed to have a seed wiring layer to be described later has a high adhesion to the substrate and to suppress the spreading of the ink when forming the seed wiring layer, the specific manufacturing process is as follows.

a-1) epoxy resin composition coating

The epoxy resin composition is coated onto the substrate. In this case, a method of coating the epoxy resin composition is not particularly limited, and specific examples thereof include spin coating, roll coating, dip coating, spray coating, and ink jet. ) Coating and the like.

a-2) Coated Substrate First Drying

The substrate coated with the epoxy resin composition is first dried to remove the solvent contained in the epoxy resin composition. At this time, if the primary drying time is too short, curing occurs in the trapped state of the solvent, which may cause out gasing later, thereby decreasing the reliability of the substrate. On the contrary, if the primary drying time is too long, the primary drying time may be reduced. It is preferable that it is-10 minutes. In addition, the primary drying temperature depends on the solvent used in the epoxy resin composition, and is not particularly limited as long as it can remove (volatile) the solvent used and the epoxy resin composition is not cured. desirable.

a-3) Primary dried substrate Primary heat treatment

The first dried substrate is first heat treated to semi-cure the coated epoxy resin composition. Here, the semi-cured state of the epoxy resin composition means a state before the chain of the epoxy resin is completely closed in the curing reaction of the epoxy resin (that is, a state before the end of the chain behavior). For example, the state from after the solvent contained in an epoxy resin composition is dried to the -OH group to produce | generate in 0 to 50% of range in the hardened epoxy resin composition is mentioned.

Generally, the epoxy resin composition undergoes a curing reaction by the mechanism shown in Scheme 1 below, in which a large amount of -OH groups are formed after the epoxy resin composition is completely cured. Therefore, when the epoxy resin composition is coated on the substrate and then completely cured, a large amount of -OH groups are present on the surface of the substrate. Thus, when a wiring pattern is formed on a substrate having a large amount of -OH groups, a solvent (particularly, (Aqueous solvent) is chemically bonded to the -OH group and the contact angle between the substrate and the ink decreases, so that the spreadability of the ink increases, making it difficult to form a fine wiring pattern. At this time, the preferred contact angle range of the substrate and the ink is 40 to 60 degrees, the contact angle is reduced to less than 20 degrees when a large amount of -OH group.

The R may be represented by the following basic structure, and R ₁ may be an aliphatic amine, an aromatic amine, dicyandiamide (DICY), panolnoblock, or the like.

However, in the present invention, since the epoxy resin composition coated on the substrate is semi-cured so that a large amount of -OH groups do not exist on the surface of the substrate, even if a wiring pattern (seed wiring layer) is formed, the spreadability of the ink can be suppressed, so that a fine wiring pattern can be suppressed. It can be formed.

Here, since the primary heat treatment temperature for semi-curing the epoxy resin composition is too low, the curing of the epoxy resin composition does not occur, but if too high, it is fully cured and the spreadability of the ink may be increased as the -OH group is generated. It is desirable to adjust. In addition, even if the first heat treatment time is too short or on the contrary too long, since the degree of curing of the epoxy resin composition may be changed to affect the spreadability of the ink, the first heat treatment time is preferably adjusted to 1 to 60 minutes.

Thus, when the epoxy resin composition is coated on the substrate to form a primer layer, the thickness of the formed primer layer is preferably 1 to 30 μm, and particularly preferably 1 to 10 μm.

On the other hand, the substrate used in the present invention is not particularly limited as long as it is commonly used in the field of circuit boards, specific examples thereof may be polyimide, epoxy, PET and the like.

In addition, the epoxy resin composition coated on the substrate comprises an epoxy resin, a curing agent, and a solvent, wherein the epoxy resin is not particularly limited, but it is preferable to use non-fluorine or non-silicon hydrocarbon-based epoxy resin, which is an environmentally friendly material. .

The non-fluorine or non-silicone hydrocarbon epoxy resin means an epoxy resin that does not contain fluorine or silicon, and specific examples thereof include epoxy resins and phenol furnaces obtained by epoxidizing a condensate of phenol or alkyl phenols with hydroxybenzaldehyde. Volac type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin of formula 1, bisphenol F type epoxy resin, linear aliphatic epoxy resin, alicyclic type Epoxy resin, heterocyclic epoxy resin, epoxy resin containing spiro ring, xylox epoxy resin, polyfunctional epoxy resin, novolac epoxy resin of formula (2), naphthol noblock type epoxy resin, bisphenol A / bisphenol F / bisphenol AD / bisphenol AD To glycidyl of bisphenol A / bisphenol F / bisphenol AD Le, bishydroxybiphenyl epoxy resin, dicyclopentadiene epoxy resin, naphthalene epoxy resin, flame retardant epoxy resin, cyclic epoxy resin, rubber modified epoxy resin, aliphatic polyglycidyl epoxy resin, glycidyl amine type Epoxy resin, DCPD type epoxy resin of following formula (3), etc. are mentioned.

At this time, n in the formula 1 and 2 is 0.1 to 30.

In this case, n in Formula 3 is 4 to 6.

Here, specific examples of the epoxy resins represented by Formulas 1 and 2 include bisphenol A (n: 1-2, Xinhua T & C, 500R), bisphenol A (n: 0.12-0.13, Kukdo Chemical, YD-128), bisphenol A ( n: 0.15 to 0.16, Kukdo Chemical, YD-134), Bisphenol A (n: 2.1 to 2.2, Kukdo Chemical, YD-011), Bisphenol A (n: 5.4 ~ 5.5, Kukdo Chemical, YD-014), Bisphenol A (n: 11.0 to 12.0, Kukdo Chemical, YD-017).

The epoxy resin may be used alone or in combination of two or more, the amount of the epoxy resin is preferably 50 to 80 parts by weight, based on the total weight 100 of the epoxy resin composition, and particularly preferably 30 parts by weight.

On the other hand, the curing agent included in the epoxy resin composition is not particularly limited as long as it cures the epoxy resin, specific examples are amine-based for room temperature; Organic acid anhydrides for high temperature; Aliphatic polyamines such as diethylenetriamine, triethylenetetramine, metaphenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone; Acid anhydride systems such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnazix anhydride, pyromellitic anhydride, HET anhydride, and dodecenyl anhydrous succinic acid can be used. It is preferable that the usage-amount of such a hardening | curing agent is 5-50 weight part with respect to 100 weight part of epoxy resin compositions, and it is good that it is 10-30 weight part especially.

In addition, the solvent included in the epoxy resin composition is not particularly limited, and specific examples thereof include methyl ethyl ketone (MEK), xylene, toluene, pyridine, quinoline, anisole, mesitylene, and the like. The amount of the solvent is preferably 20 to 70 parts by weight based on 100 parts by weight of the epoxy resin composition, and particularly 20 to 60 parts by weight.

In addition, other additives, such as a curing accelerator, a viscosity regulator, a coupling agent, an antifoaming agent, and a dispersing agent, may be included in the epoxy resin composition in an amount of 0.1 to 1 parts by weight based on 100 wt% of the epoxy resin composition.

b) Recessing the seed wiring layer in the primer layer of the substrate

The seed wiring layer is recessed in the primer layer by first printing the ink on the substrate on which the primer layer is formed with ink containing the first conductive metal. Here, the seed wiring layer is formed by printing with the ink containing the first conductive metal, but increases adhesion with the substrate rather than the wiring role through which the current flows, and as a result, the conductive wiring layer, which will be described later, exhibits excellent conductivity and also excellent adhesion with the substrate. By acting as a base wiring, the specific manufacturing process is as follows.

b-1) Primary print on primer layer

The seed wiring layer is prepared by first printing with an ink containing a first conductive metal on the primer layer of the substrate. At this time, the primary printing method is not particularly limited, but is preferably selected from the group consisting of dispensing method, screen printing, gravure printing, and inkjet printing, and among them, inkjet printing which can easily form a fine wiring pattern It is good to use.

Here, the ink may be used without particular limitation as long as it is commonly used in the art to form a wiring pattern on a circuit board. Such an ink may be largely composed of a first conductive metal and a solvent, which are classified as aqueous or non-aqueous inks according to the solvent used. Diethylene glycol butyl ether acetate, ethanol aqueous solution, ethylene glycol, etc. may be used as a solvent of the water-based ink, and solvents of the non-aqueous ink may be hexane, octane, tetradecane, hexadecane, 1-hexadecine, 1-octadecine. At least one selected from toluene, xylene, and chlorobenzoic acid may be used, but is not limited thereto.

Meanwhile, the first conductive metal included in the ink may be silver (Ag), copper (Cu), gold (Au), platinum (Pt), nickel (Ni), palladium (Pd), iron (Fe), and alloys thereof. It may be composed of one or more metal nanoparticles selected from the group consisting of. The size of the metal nanoparticles is preferably 5 to 50nm, more specifically 15 to 30nm to form a fine wiring pattern.

b-2) primary printed substrate secondary heat treatment

The solvent of the ink present in the seed wiring layer is removed, and the first printed substrate is subjected to a second heat treatment to immerse the seed wiring layer in the primer layer.

When the seed wiring layer is printed on the primer layer of the substrate, since the epoxy resin composition of the primer layer is in a semi-cured state, when the ink reaches the primer layer, it begins to penetrate the primer layer. When the substrate is heat-treated, the solvent contained in the ink is volatilized, and the epoxy resin composition has a high flowability, so that the conductive metal contained in the ink completely penetrates into the primer layer to form a seed wiring layer. As the seed wiring layer is recessed in the primer layer as described above, the adhesion between the substrate and the seed wiring layer becomes very excellent.

Here, the process of recessing the seed wiring layer in the primer layer may be repeated 2 to 4 times, the secondary heat treatment process is carried out in a temperature range of 90 ~ 180 ℃ 1 to maintain the semi-cured state of the epoxy resin composition of the primer layer It is recommended to perform for 30 minutes.

In other words, when the seed wiring layer is immersed in the primer layer only once, the seed wiring layer may be completely buried in the primer layer so that the seed wiring layer is not exposed on the surface of the primer layer. Since it is difficult to stack the wiring layer and the wiring pattern is not properly formed, the conductivity of the substrate may also be degraded.

Therefore, in order to recess the seed wiring layer to be exposed on the surface of the primer layer, the process of recessing the seed wiring layer in the primer layer is preferably repeated 2 to 4 times. Accordingly, the epoxy resin composition of the primer layer maintains the semi-cured state. Is a good thing. In this case, when repeating the process of recessing the seed wiring layer, it is preferable to first print the seed wiring layer on the printed seed wiring layer and then print the seed wiring layer again on the printed seed wiring layer to form a fine wiring pattern.

In addition, when the seed wiring layer is printed again on the first printed seed wiring layer, the second heat treatment process is performed in proportion to the number of printing (that is, the heat treatment after one printing-> heat treatment after two printing-> heat treatment after three printing) ) It can be performed in the finishing stage after printing only a plurality of times (ie, printing once-> printing twice-> printing three times-> heat treatment).

On the other hand, the process of indenting the seed wiring layer in the primer layer may vary depending on the amount of solids contained in the ink, about one time when the amount of solids contained in the ink is 60 parts by weight or more based on the total weight of 100 ink It is preferable to carry out, and when the amount of solid content is 30 weight part or less, it is preferable to carry out about twice.

c) Full curing of the primer layer of the substrate

The substrate in which the seed wiring layer is recessed in the primer layer is fired to completely cure the epoxy resin composition of the primer layer. At this time, the firing temperature is different depending on the epoxy resin contained in the epoxy resin composition, so long as it is a temperature at which the epoxy resin composition is completely cured. However, when the firing temperature is too low, the epoxy resin composition is not cured completely, so it is preferable to be fired in a temperature range of 120 to 200 ° C. In addition, the firing time depends on the epoxy resin composition, but 30 to 60 minutes is preferred so that complete curing at the above temperature.

d) forming a conductive wiring layer on the substrate

After completely curing the epoxy resin composition of the primer layer, the conductive wiring layer is formed by secondary printing with an ink containing a second conductive metal on the seed wiring layer recessed in the primer layer. At this time, the conductive wiring layer is to perform a wiring role in which a current actually flows, and a specific manufacturing process is as follows.

d-1) Conductive Wiring Layer Lamination

The conductive wiring layer is laminated by second printing with the ink containing the second conductive metal on the seed wiring layer recessed in the primer layer.

When the seed wiring layer is formed by primary printing, the seed wiring layer has excellent adhesion with the substrate as the ink penetrates into the primer layer, but as the epoxy resin composition penetrates the seed wiring layer by the behavior of the epoxy resin composition, the seed wiring layer Will lose its conductivity. That is, since the epoxy composition has fluidity in the semi-cured state, penetration into the seed wiring layer may occur. Thus, a substrate in which the epoxy resin composition is completely cured with the epoxy resin composition penetrated into the seed wiring layer is less conductive. will be.

However, the present invention can secure the conductivity of the substrate by stacking the conductive wiring layer on the seed wiring layer through the secondary printing. At this time, the method of secondary printing is not particularly limited, but is preferably selected from the group consisting of dispensing method, plating method, screen printing, gravure printing, and inkjet printing, and in particular, an inkjet capable of forming a wiring pattern finely. It is advisable to use printing or to use a printing method that is convenient for printing (electrolyte plating or electroless plating).

Meanwhile, the ink used in the second printing may also be composed of the second conductive metal and the solvent, and a description thereof will be omitted because it is the same as the description of the first conductive metal and the solvent used in the first printing. However, the second conductive metal included in the ink used in the second printing may be the same or different from the first conductive metal included in the ink used in the first printing, and it is preferable to use a metal having better conductivity. desirable.

The conductive wiring layer is formed after the epoxy resin composition is completely cured. In this case, even if the epoxy resin composition is completely cured and a large amount of -OH groups are present in the primer layer, the conductive wiring layer is printed on the seed wiring layer rather than being printed on the primer layer. Since the ink does not spread, a fine wiring pattern can be formed. In addition, the conductive wiring layer also exhibits excellent adhesion with the substrate because it is printed on the seed wiring layer having excellent adhesion with the substrate.

d-2) 3rd heat treatment of the substrate on which the conductive wiring layer is laminated

The substrate is subjected to a third heat treatment to remove the solvent of the ink present in the conductive wiring layer and to solidify the stacked conductive wiring layers. In this case, the third heat treatment temperature may vary depending on the ink used, and is not particularly limited as long as the temperature may solidify the ink, but is preferably 150 to 250 ° C. In addition, the third heat treatment time is preferably 30 to 60 minutes.

Meanwhile, the process of preparing the conductive wiring layer on the substrate may be repeated many times so that the conductive wiring layer has an appropriate thickness so that the substrate can be applied to various fields. At this time, the process may be repeated so that the thickness of the conductive wire layer has a thickness of 1 ~ 30㎛.

In other words, the conductive wiring layer should have an appropriate thickness in order to show the resistance required by the substrate according to the application field of the substrate. If the conductive wiring layer does not have a suitable thickness after the second printing, the required resistance does not appear. You can increase the number of secondary prints until the required resistance is achieved. For example, when the substrate is used in the PCB field, if the conductive wiring layer has a thickness of 10 to 15 μm, a required resistance value is required. Therefore, the second printing frequency may be adjusted so that the thickness of the conductive wiring layer is 10 to 15 μm.

Here, when the conductive wiring layer is printed again on the second printed conductive wiring layer, the third heat treatment process may also be performed in proportion to the number of printing (that is, after one printing heat treatment-> after two printing heat treatment-> after three printing heat treatment ) It can be performed in the finishing stage after printing only a plurality of times (ie, printing once-> printing twice-> printing three times-> heat treatment).

As the wiring pattern is formed on the circuit board by the forming method described above, the circuit board of the present invention includes a substrate, a primer layer, a seed wiring layer, and a conductive wiring layer. In the circuit board, since the seed wiring layer is recessed in the primer layer and the conductive wiring layer is stacked on the seed wiring layer, the wiring pattern formed may have excellent adhesion with the substrate, and the circuit board on which the wiring pattern is formed may exhibit excellent conductivity. have.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples and comparative examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

Example 1

Coating the epoxy resin composition on the substrate (Doosan Electronics FR-4 (7408)) using a spin coating method (4000rpm 20 seconds), and first dried at 80 ℃ for 10 minutes and then dried substrate at 120 ℃ for 5 minutes The first heat treatment formed a primer layer in which the epoxy resin composition was present in a semi-cured state. At this time, the epoxy resin composition is 40% by weight of epoxy resin (YD-128 of Kukdo Chemical: 40%, YD-011 of Kukdo Chemical: 30%, DCPD: 30% of Shinhwa T & C Co., Ltd.), 20% by weight of the curing agent (Xinhua). T & C's DDS (Diaminodiphenylsulfone) was used, consisting of 40% by weight of solvent (MEK) and optionally 0.05 parts by weight of aromatic accelerator (aromatic amine).

Primary printing was performed to the board | substrate with which the primer layer was provided by the inkjet printing system. At this time, the ink was used 40LT products of Nano New Material Co., Ltd., in which silver (Ag) was used as the conductive metal, and the diameter of the spray nozzle was 50 μm. The first printed substrate was subjected to secondary heat treatment at 150 ° C. for 2 minutes to immerse the seed wiring layer in the primer layer (at this time, the epoxy resin composition of the primer layer did not exceed the semi-cured state). After the firing at 200 ℃ 30 minutes to completely cure the epoxy resin composition of the primer layer. As a result of confirming the fired substrate under an optical microscope, it was confirmed that the seed wiring layer was recessed in the primer layer (see FIG. 1).

Secondary printing was performed on the seed wiring layer of the fired substrate under the same conditions as the primary printing to form a conductive wiring layer, and then third heat treatment was performed at 250 ° C. for 60 minutes. As a result of confirming the substrate on which the conductive line wiring layer was formed with an optical microscope, it was confirmed that the conductive wiring layer was stacked on the seed wiring layer (see FIG. 2).

[Example 2]

A wiring pattern was formed on the substrate under the same conditions and methods as in Example 1 except that the seed wiring layer forming process was performed once more and the seed wiring layer was printed twice.

Example 3

A wiring pattern was formed on the substrate under the same conditions and methods as in Example 1 except that the seed wiring layer and the conductive wiring layer were formed once more, and the seed wiring layer and the conductive wiring layer were printed twice.

Comparative Example 1

Except for the formation of the conductive wiring layer in Example 1, the process of forming the seed wiring layer on the substrate was performed once to form a wiring pattern on the substrate.

Test Example 1 Conductivity Test

The substrates of Examples 1 to 3 and Comparative Example 1 were measured for resistance using a low resistance meter (M210), and the results are shown in Table 1 below.

TABLE 1

Resistance Example 1 1.87 Example 2 0.92 Example 3 0.51 Comparative Example 1 -

Referring to Table 1, in Example 1, in which both the seed wiring layer and the conductive wiring layer were formed, the conductivity was shown. In addition, when the seed wiring layer and the conductive wiring layer were formed one or more times (Examples 2 and 3), it was confirmed that the conductivity was more excellent.

Example 4

The conductive wiring layer formation process was performed 14 times to form a wiring pattern on the substrate under the same conditions and methods as in Example 1 except that the conductive wiring layer was formed. At this time, the thickness of the conductive wiring layer was 10 µm.

[Test Example 2] Adhesion test (peel test)

After cutting the board | substrate of Example 4 into 1 cm width and 10 cm length, S10 copper foil was attached (adhesive conditions-pressure: 78 kgf / cm <2>, temperature: 170 degree | times, hardening time: 500 second) Peel test with the copper foil board | substrate Adhesion test (test condition-peeling rate: 50 mm / min, peeling angle: 90 degrees) using the apparatus (TE200111) is shown in Table 2 and FIG. 3.

TABLE 2

Peel Strength (kgf / ㎠) Example 4 1-1.5

Referring to Table 2 and Figure 3, the peel strength (Peel Strength) is 1 ~ 1.5kgf / ㎠ it can be confirmed that when the wiring pattern is formed by the wiring pattern forming method of the present invention excellent adhesion between the substrate and the wiring pattern ( Typically, the peel strength required for PCB substrates is greater than 1 kgf / cm 2).

1 and 2 are reference diagrams for confirming that a wiring pattern is formed on a substrate by the wiring pattern forming method of the present invention.

Figure 3 is a reference diagram for showing the result of testing the adhesion of the substrate after the wiring pattern is formed on the substrate by the wiring pattern forming method of the present invention.

Claims (13)

a) coating the epoxy resin composition in a semi-cured state on the substrate to form a primer layer; b) first printing with the ink containing the first conductive metal on the substrate of step a) to immerse the seed wiring layer in the primer layer, so that the seed wiring layer is exposed on the surface of the primer layer. Recessing; c) calcining the substrate of step b) to completely cure the epoxy resin composition of the primer layer; And and d) second printing the ink on the seed wiring layer of the substrate using the ink containing the second conductive metal to form the conductive wiring layer. The method of claim 1, Step a) is Coating an epoxy resin composition on the substrate; First drying the substrate coated with the epoxy resin composition for 3 to 10 minutes to remove the solvent included in the epoxy resin composition; And And heat treating the first dried substrate at 120 to 170 ° C. for 1 to 60 minutes to semi-cure the epoxy resin composition. The method of claim 1, B), Preparing the seed wiring layer by first printing the ink with a conductive metal on the primer layer of the substrate; And And removing the solvent contained in the ink and performing a second heat treatment on the substrate on which the seed wiring layer is provided at 90 to 180 ° C. for 1 to 30 minutes to immerse the seed wiring layer in the primer layer. Method of forming a wiring pattern. The method of claim 1, The step b) is a wiring pattern forming method characterized in that it is repeated 2 to 4 times before completely curing the epoxy resin composition of the primer layer. The method of claim 1, The firing temperature of step c) is a method of forming a wiring pattern, characterized in that it is adjusted to 120 ~ 200 ℃. The method of claim 1, Step d), Stacking the conductive wiring layer by second printing with an ink containing a conductive metal on the seed wiring layer of the substrate; And Removing the solvent contained in the ink to solidify the stacked conductive wiring layers, and performing a third heat treatment on the substrate on which the conductive wiring layers are stacked for 30 to 60 minutes at 150 to 250 ° C. Method of forming a wiring pattern. The method of claim 1, Forming a wiring pattern, characterized in that the conductive wiring layer of step d) is provided in a thickness of 1 ~ 30㎛. The method of claim 1, The epoxy resin composition includes an epoxy resin, a curing agent, and a solvent, wherein the epoxy resin is a non-fluorine or non-silicon hydrocarbon-based epoxy resin. The method of claim 1, The method of forming a wiring pattern, characterized in that the primary printing method of step b) is selected from the group consisting of dispensing method, screen printing, gravure printing and inkjet printing. The method of claim 1, The second printing method of step d) is a method of forming a wiring pattern, characterized in that selected from the group consisting of dispensing method, plating method, screen printing, gravure printing and inkjet printing. Board; A primer layer formed on the substrate, the epoxy resin composition is cured; A seed wiring layer printed with an ink including a first conductive metal and recessed to expose a surface of the primer layer; And A circuit board printed with an ink containing a second conductive metal, the circuit board comprising a conductive wiring layer stacked in the same pattern on the seed wiring layer. The method of claim 11, The circuit board, characterized in that the epoxy resin composition penetrated into the seed wiring layer recessed in the primer layer. The method of claim 11, The circuit board has a wiring pattern formed by the method according to any one of claims 1 to 10.

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