KR20140082599A - Method for manufacturing metal printed circuit board - Google Patents

Abstract

A method for manufacturing a metal printed circuit board, according to the present invention, comprises the steps of printing a circuit pattern on a release film; applying a thermal-conductive insulation layer on the circuit pattern; performing thermo-compression after positioning a thermal-conductive base layer on the thermal-conductive insulation layer; and removing the release film.

Description

[0001] METHOD FOR MANUFACTURING METAL PRINTED CIRCUIT BOARD [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a metal printed circuit board, in which a circuit pattern and a thermally conductive insulating layer are formed on a release film using a printing method and hot- To a method of manufacturing a metal printed circuit board.

Although LEDs (Light Emitting Diodes) are used as simple display devices in various colors in the form of point light sources, they are increasingly used in various fields such as monitors and area display devices of laptops / desktop computers due to their light efficiency and long life . Especially recently, it is about to expand its use range for lighting and LCD TV backlight.

In the case of LCD TV backlight and LED lighting, an array is formed on a substrate using a plurality of light emitting devices for reasons of high luminance per unit area and plane light emission. It is an important factor for LED lifetime and quality maintenance to effectively emit heat generated from LED by the array configuration.

LED array substrate uses metal core printed circuit board (MCPCB) instead of copper clad laminate (CCL) used in conventional PCB for smooth heat dissipation. Usually, such a MCPCB has a three-layer structure of a metal base layer, a dielectric layer, and a copper foil.

The dielectric layer may be made of an epoxy resin filled with thermally conductive particles to increase the thermal conductivity. The electrode circuit is formed by forming a resist pattern using a lithography technique or the like and etching the same as a conventional printed circuit board (PCB). However, the etching process for forming such an electrode circuit has a complicated manufacturing process, and there is a problem that a large amount of etching wastewater is generated during the process. In addition, the LED board based on MCPCB has a disadvantage that the heat dissipation performance is largely limited due to the epoxy dielectric layer.

In Korean Utility Model No. 20-0404237, an electrode circuit is formed by etching using MCPCB, and an opening to an insulating layer is formed at a portion where the LED is mounted, and a heat sink slug is attached to the opening, and the remaining LED member is mounted thereon However, it is not only difficult to cleanly remove the bonded insulating layer, but also it is a technique that is not economically feasible because it is contrary to the trend of the assembling method as described above.

Korean Patent No. 696063 discloses an LED array substrate in which only LED chips are extracted without using packaged LEDs and mounted on a separate substrate constituting a recess mounting portion, an insulating layer, a bonding die, a reflector, and an electrode. However, such a substrate can not be unified in terms of its characteristics, and involves complicated processing such as machining, formation of various layers, pattern formation, and direct molding on the substrate, and is contrary to the trend of assembly method. to be.

Korean Patent No. 696063

An object of the present invention is to provide a method of manufacturing a flexible printed circuit board by coating an insulating layer on a thermally conductive base layer and then printing an electrode circuit on the insulating layer, A method of manufacturing a metal printed circuit board excellent in electrical characteristics and adhesion is provided by forming a circuit pattern and a thermally conductive insulating layer on a substrate using a printing method and performing hot pressing with the thermally conductive base layer .

The present invention provides a method of manufacturing a circuit board, comprising: printing a circuit pattern on a release film; Applying a thermally conductive insulating layer on the circuit pattern; Placing a thermally conductive base layer on the thermally conductive insulating layer and then thermally pressing the thermally conductive base layer; And removing the release film. The present invention also provides a method of manufacturing a metal printed circuit board.

According to the present invention, a circuit pattern and a thermally conductive insulating layer are formed on a release film by a printing method and hot-pressed with the thermally conductive base layer to form a metal printed circuit board Is provided. More specifically, according to the present invention, when forming a circuit pattern, an insulating layer can be formed while maintaining excellent conductivity of a cured metal paste, conductivity can be maintained at high efficiency, high adhesion can be provided, There is provided a metal printed circuit board capable of minimizing damages such as cracks due to thermal expansion between release materials due to curing.

1 is a view showing a manufacturing process of a metal printed circuit board according to the present invention.

A method of manufacturing a metal printed circuit board according to the present invention includes: printing a circuit pattern on a release film; Applying a thermally conductive insulating layer on the circuit pattern; Placing a thermally conductive base layer on the thermally conductive insulating layer and then thermally pressing the thermally conductive base layer; And removing the release film. For example, as shown in Fig. 1, a circuit pattern is printed on a release film, a thermally conductive insulating layer is coated on the circuit pattern, the thermally conductive base layer is laminated on the circuit pattern, The metal printed circuit board according to the invention can be manufactured.

The releasing film may be a releasing coat film whose releasing force is controlled. Here, the releasing coat film can be produced by applying a releasing agent onto the heat-resistant film.

The heat-resistant film may be a film formed of PEN, PET, PE, PI, PC, or Al. However, the heat-resistant film is not limited thereto and heat resistant films of various materials may be used.

As the releasing agent, a silicone or an acrylic releasing agent can be used. In the case of the silicone releasing agent, the releasing agent has a heat resistance characteristic in which severe shrinkage does not occur during a thermocompression bonding process, and the releasing force can be easily controlled. In addition, various types of release agents known in the art may be used.

The release agent may be applied using microgravure, gravure, slot die, reverse kiss, or rotary screen coating method. In addition, various methods capable of applying a release agent in the field can be applied.

The circuit pattern is a conductive printed circuit pattern formed by printing a metal paste by a printing method and may be printed by a gravure printing method, a flexo printing method, an offset printing method, a screen printing method, a rotary screen printing method, or an inkjet printing method However, it is not necessarily limited to this, and it is of course possible to print in various ways.

The circuit pattern may be formed of a metal paste. More specifically, an ink made of a metal such as Ag, Cu, Ag / Cu, Sn, Ag / Cu / Zn, Au, Ni, or Al excellent in electrical conductivity or doping, .

As a specific example, a circuit pattern may be printed and heat-treated using an Ag complex, Ag salts, or an Ag-acid / base complex, which is an Ag transparent electronic ink. As another example, a circuit pattern may be printed using Ag Nano paste, Ag Flake paste, or Ag Granule paste, and heat treatment may be performed. Here, besides curing by heat treatment, UV curing or e-beam may be used.

The ink for forming the circuit pattern is not limited to the above-described example. It is needless to say that any ink that is conductive in the technical field of the present invention and can be printed by a printing method is applicable.

In forming the circuit pattern, as another example, the position is controlled by including a primary printing step of printing the primary circuit pattern and a secondary printing step of printing a secondary circuit pattern on the primary pattern A circuit pattern can also be printed. Specifically, by sequentially performing the primary and secondary circuit patterns, a pattern can be realized more precisely.

In addition to the above-described method, the circuit pattern may be formed by depositing or sputtering Al, Ag, Cu, Ni, etc., which are electrically conductive metals, using a mask pattern.

The method may further include a step of plating on the circuit pattern between the step of printing the circuit pattern and the step of applying the thermally conductive insulating layer on the circuit pattern, Electroless plating can be performed.

As described above, the circuit pattern may be used alone, or may be adjusted to the plating thickness of the plated copper according to the amount of the applied current, so that the seed pattern characteristic may be maintained.

Here, the circuit pattern may be formed by printing an ink containing a catalyst such as Pd colloid, PdCl _2, etc. on a circuit pattern, followed by electroless copper plating or nickel plating to form a printed circuit board circuit. In addition, when a high capacity (W ↑) LED (LED) with high current consumption is used, the copper electroplating can be plated with an appropriate plating thickness according to the current consumption.

As described above, the electroplating can be performed by electroless plating, electroplating, deep coating or the like, and there is no limitation on the metal used for plating, but copper may be preferable. The deep coat method may be preferable when treating Sn, Zn, and the like. It is needless to say that the present invention can be applied variously to Ni, Sn, Pd, Zn, Ag, and Au in addition to Cu.

The thermally conductive insulating layer may be formed of a thermally conductive insulating layer coating liquid as a thermosetting coating resin ink. Here, in addition to the thermosetting resin, a UV-curable resin can be used for UV curing, and various crosslinking reactions are possible, and the resin composition is not limited. However, it is preferable to have the characteristics of heat resistance and weather resistance. In the case of using a metal flake having high electrical conductivity, it is desirable to impart electrical insulation through surface treatment and to have only thermal conductivity characteristics.

For example, epoxy resin, urethane resin, urea resin, melamine resin, phenol resin, silicone resin, polyimide resin, polysulfone resin, polyester resin, polyphenylene sulfide resin and the like can be used as the resin used for the thermally conductive insulating layer However, it is preferable to use a thermosetting resin, though not necessarily limited thereto.

UV curable resin or radical polymerizable resin can be used, and both of the resin surfaces having good heat resistance and weather resistance can be used, and they can be formed of at least one selected from the modifications of these resins.

With the resin SiO _2, TiO _2, Al₂O₃, BaSO₄, CaCo₃, Al flakes (flake), Ag flakes (flake), oxidized graphene, graphite oxide, oxidized carbon nanotubes, ITO, selected from AlN, BN, and MgO It is preferable to further include a filler. Here, in the case of Al or Ag flakes, it may be preferable that an insulating resin is coated. However, the fillers are not limited to these.

As an example of the thermally conductive insulating layer coating solution, bisphenol A type modified epoxy resin, phenol novolac epoxy resin, hexahydrophthalic anhydride, quaternary ammonium salt, alumina, dispersant, and solvent (MEK) , But the composition is not limited thereto.

The thermally conductive insulating layer can be applied by an S-knife, a gravure, a flexo, a screen, a rotary screen, a slot die, or a microgravure coating method.

Here, the thermally conductive insulating layer may be formed as a single layer or divided into primary and secondary layers.

Specifically, the method includes a first coating step of applying a first thermal conductive insulating layer on the circuit pattern and a second coating step of coating a second thermal conductive insulating layer on the first thermal conductive insulating layer .

Here, in the case of the first application step, it can be applied by a method selected from microgravure, S-knife, gravure, flexo, screen, and rotary screen.

In the case of the second application step, it can be applied by a method selected from slot die, S-knife, and microgravure. However, this is not necessarily the case.

Specifically, in the case of the first coating step, the entire surface can be coated using a printing method such as microgravure, flexo, screen, and rotary screen. In the case of a copper-plated printed circuit board, It may be preferable to use a die coater or an S-knife coater to uniformize the surface roughness. Here, when uniformity of the surface can not be ensured even by the first application of the thermally conductive insulating layer, or if the thickness of the thermally conductive insulating layer needs to be made thick, the second application of the thermally conductive insulating layer may be performed by using a slot die, S-knife, microgravure It may be desirable to use it. Further, in order to optimize the heat dissipation characteristics and the insulation characteristics, it may be preferable to proceed to two stages as described above.

As the thermally conductive base layer, a hot-rolled steel sheet, a cold-rolled steel plate, an aluminum plate, a galvanized steel plate, a copper plate, a stainless steel plate, a tinned gold plate, a brass plate, or a resin coated steel plate may be used. However, A variety of heat sinks can be used in this field.

For example, in order to bond with a thermally conductive base layer such as an Al plate, the thermally conductive insulation layer may be preferable when the semi-hardened B-stage is laminated with the thermally conductive base layer. have.

In the step of laminating the thermally conductive base layer on the thermally conductive insulating layer and thermally bonding the thermally conductive base layer, the thermally conductive base layer may be performed at a temperature of 120 to 200 ° C, preferably at a temperature of 140 to 175 ° C .

As described above, each step of the method of manufacturing a metal printed circuit board according to the present invention can be performed by a roll-to-roll continuous process. In this case, the production speed is increased, So that it can be preferable.

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the scope of the present invention is not limited thereto.

Example 1

(Tokai-seiki, SFA-RR350) with an Ag paste (TEC-PF-021) on a heat-resistant silicone release coat film (MRV- Printed, and then dried at 150 캜 for 5 minutes to form a circuit pattern with a thickness of 1 탆.

Using a slot die coater (Pectiv), a thermally conductive insulating layer coating solution (Table 1) as a thermosetting coating resin ink was coated on the circuit pattern to a dry thickness of 50 占 퐉 to form a thermally conductive insulating layer.

Here, the compositions of the thermally conductive insulating layer coating liquid were as shown in Table 1.

[Table 1]

An aluminum plate (AL5052, Sejong Metal Co., Ltd.) having a thickness of 1.5 mm was laminated as a thermally conductive base layer on the thermally conductive insulating layer and thermocompression-bonded by hot press for 60 minutes at a temperature of 170 DEG C, The silicone release coat film was removed to produce a metal printed circuit board.

Example 2

(Tokai-seiki, SFA-RR350) with an Ag paste (TEC-PF-021) on a heat-resistant silicone release coat film (MRV- Printed, and then dried at 150 캜 for 5 minutes to form a circuit pattern with a thickness of 1 탆.

Using a slot die coater (Pectiv), a thermally conductive insulating layer coating liquid (Table 1) as a thermosetting coating resin ink was coated to a dry thickness of 100 mu m on a circuit pattern to form a thermally conductive insulating layer.

An aluminum plate (AL5052, Sejong Metal Co., Ltd.) having a thickness of 1.5 mm was laminated as a thermally conductive base layer on the thermally conductive insulating layer, thermocompression-bonded by hot press at 170 DEG C for 90 minutes, The silicone release coat film was removed to produce a metal printed circuit board.

Example 3

(Tokai-seiki, SFA-RR350) with an Ag paste (TEC-PF-021) on a heat-resistant silicone release coat film (MRV- After printing, the substrate was dried at 150 캜 for 5 minutes to form a circuit pattern with a thickness of 2 탆.

Using a slot die coater (Pectiv), a thermally conductive insulating layer coating liquid (Table 1) as a thermosetting coating resin ink was coated to a dry thickness of 100 mu m on a circuit pattern to form a thermally conductive insulating layer.

An aluminum plate (AL5052, Sejong Metal Co., Ltd.) having a thickness of 1.5 mm was laminated as a thermally conductive base layer on the thermally conductive insulating layer, thermocompression-bonded by hot press at 170 DEG C for 90 minutes, The silicone release coat film was removed to produce a metal printed circuit board.

Comparative Example 1

As a thermally conductive base resin layer, a thermally conductive insulating layer coating liquid (Table 1) was coated on a 1.5 mm thick aluminum plate (AL5052, Sejong Metal Co., Ltd.) using a slot die coater (Pectiv) Mu m to form a thermally conductive insulating layer.

 Next, the circuit pattern was printed by a screen printing method (Tokai-seiki, SFA-RR350) with an Ag paste (Ink Tec, TEC-PF-021) and then dried at 150 캜 for 5 minutes, (MR-50, manufactured by BioVisionChem Co., Ltd.) was laminated as a release film as a release film, thermocompression-bonded by a hot press at a temperature of 170 캜 for 60 minutes, and then heat-resistant silicone release coat The film was removed to produce a metal printed circuit board.

Comparative Example 2

A thermally conductive insulating layer coating solution (Table 1) as a thermosetting coating resin ink was applied on a 1.5 mm thick aluminum plate (AL5052, Sejong Metal Co., Ltd.) with a slot die coater (Pectiv) Mu m to form a thermally conductive insulating layer.

 Next, the circuit pattern was printed by a screen printing method (Tokai-seiki, SFA-RR350) with an Ag paste (Ink Tec, TEC-PF-021), and then dried at 150 캜 for 20 minutes, (MR-50, manufactured by BioVisionChem Co., Ltd.) was laminated as a release film as a release film, thermocompression-bonded by a hot press at a temperature of 170 캜 for 90 minutes, and then heat-resistant silicone release coat The film was removed to produce a metal printed circuit board.

Experimental Example

1) Measurement method

The thickness of the circuit pattern and the thermally conductive insulating layer after drying was measured using a non-contact three-dimensional measuring instrument (NANO SYSTEM NANO SYSTEM, NV-P1010) manufactured according to Examples and Comparative Examples, and a sheet resistance meter [MITSUBISHI (4 probe type) manufactured by CHEMICAL ANALYTECH Co., Ltd., Laresta-GP MCP-610), and the conductivity was measured by calculating the average value. Using a cross-cutter (YOSHIMITSU, MR-YCC1) The adhesive force was measured by cutting the adhesive tape at 100 A / cm < 2 >, and measuring the amount of adhesive tape dropped on the adhesive tape using an adhesive tape (3M, 810)

2) Measurement result

[Table 2]

As can be seen from Table 2, when the electrode forming liquid agent was prepared according to Comparative Examples 1 and 2, the efficiency was reduced by about 75% due to impregnation with the thermally conductive insulating layer. However, according to the present invention, When a circuit pattern and a thermally conductive insulating layer are formed by using a printing method and hot-pressed with the thermally conductive base layer, the basic electrical characteristics of the electrode circuit can be maintained at 90% or more. In addition, high adhesion can be ensured.

As described above, according to the present invention, a circuit pattern and a thermally conductive insulating layer are formed on a release film by a printing method and hot pressed with the thermally conductive base layer to form a metal layer having excellent electrical characteristics and adhesion A printed circuit board can be provided. More specifically, according to the present invention, when forming a circuit pattern, an insulating layer can be formed while maintaining excellent conductivity of a cured metal paste, conductivity can be maintained at high efficiency, high adhesion can be provided, There is provided a metal printed circuit board capable of minimizing damages such as cracks due to thermal expansion between release materials due to curing.

Claims (10)

Printing a circuit pattern on the release film;
Applying a thermally conductive insulating layer on the circuit pattern;
Placing a thermally conductive base layer on the thermally conductive insulating layer and then thermally pressing the thermally conductive base layer; And
And removing the release film. ≪ Desc / Clms Page number 20 > The method according to claim 1,
Wherein the circuit pattern is printed by gravure printing, flexographic printing, offset printing, screen printing, rotary screen printing, or inkjet printing. The method according to claim 1,
Wherein the circuit pattern is formed of a metal paste. The method according to claim 1,
Further comprising a step of plating the circuit pattern between the step of printing the circuit pattern and the step of applying the thermally conductive insulating layer on the circuit pattern. The method of claim 4,
Wherein the plating step is carried out by electrolytic plating or electroless plating. The method according to claim 1,
Characterized in that the thermally conductive insulating layer comprises an epoxy resin, a urethane resin, a urea resin, a melamine resin, a phenol resin, a silicone resin, a polyimide resin, a polysulfone resin, a polyester resin, or a polyphenylene sulfide resin as a resin Wherein the metal substrate is a metal substrate. The method according to claim 1,
The thermally conductive insulating layer may be formed of at least one selected from the group consisting of SiO _2, TiO _2, Al ₂ O _3, BaSO 4, CaCo 3, Al flake, Ag flake, oxide graphene, graphite oxide, carbon oxide nanotube, ITO, , And MgO. ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1,
Wherein the thermally conductive insulating layer is applied by S-knife, gravure, flexo, screen, rotary screen, slot die, or microgravure coating method. The method according to claim 1,
Wherein the thermally conductive base layer is a hot-rolled steel plate, a cold-rolled steel plate, an aluminum plate, a galvanized steel plate, a copper plate, a stainless steel plate, a tin-plated plate, a brass plate, or a resin- . The method according to claim 1,
Wherein the step of laminating the thermally conductive base layer on the thermally conductive insulating layer and thermally bonding the thermally conductive base layer is performed at a temperature of 120 to 200 ° C.

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