KR101037334B1 - Manufacturing Method of Printed Circuit Board by Plasma Electrolytic Oxidation and Printed Circuit Board and Electronic Component Module - Google Patents

Abstract

The present invention relates to a method for manufacturing a printed circuit board using a plasma electrolytic oxidation method, a printed circuit board and an electronic component module, and more particularly, to form an aluminum oxide layer using a plasma electrolytic oxidation method on an aluminum base, The present invention relates to a metal printed circuit board for an electronic component in which a sealing layer is formed of mid, and a method of manufacturing the same. The circuit board of the present invention is a base of a metal material; A metal oxide layer formed on one or both surfaces of the base by plasma electrolytic oxidation; A sealing layer of the wholly aromatic polyimide formed on the metal oxide layer and filling the pores of the metal oxide layer; And a metal wiring layer formed on the sealing layer. .

Description

Manufacturing method of printed circuit board using plasma electrolytic oxidation, printed circuit board and electronic device module

The present invention relates to a method for manufacturing a printed circuit board using a plasma electrolytic oxidation method, a printed circuit board and an electronic component module, and more particularly, to form an aluminum oxide layer using a plasma electrolytic oxidation method on an aluminum base, The present invention relates to a metal printed circuit board for an electronic component in which a sealing layer is formed of mid, and a method of manufacturing the same.

A printed circuit board (PCB) serves to mechanically support a plurality of electronic components and electrically connect the mounted electronic components to each other. In recent years, as the light and short size of mobile communication devices and electronic products is rapidly progressing, the technology of printed circuit boards is rapidly changing to products having multilayer high density and multifunction. In particular, LED lighting, light emitting diode back light unit LED BLU, audio power module, power module for PDP, motor controller, thermoelectric material, high power semiconductor device, etc., emit a lot of heat during operation and Since the reliability of electronic components such as chips is reduced and the lifespan is shortened, the heat generation problem is most important in this field, and if the effective heat dissipation structure is not adopted, the reliability of the product may occur. Therefore, the device must be mounted on a material that can easily dissipate heat generated during startup. Currently, metal printed circuit boards are mainly used.

The prior art is to form an aluminum oxide layer on an aluminum base by an anodizing method, but it is difficult to obtain sufficient insulating properties required for a metal printed circuit board and has a problem in brittleness. In order to solve this problem, a method of forming an aluminum oxide layer using a plasma electrolytic oxidation method that is resistant to brittleness and can be thickened has been proposed. The aluminum oxide layer by the plasma electrolytic oxidation method has a higher dielectric constant than the insulating layer used for a general metal printed circuit board, so that the breakdown voltage can be increased even at a thin thickness, so that the thickness can be reduced to lower the thermal resistance to increase the heat dissipation effect. . However, since the aluminum oxide layer using the plasma electrolytic oxidation method has many pores in the surface and the layer, the seed layer forming material is diffused and deposited in the pores in the process of sputtering the seed layer to form the wiring layer. The insulation of the substrate becomes very poor or even electrically energized. Therefore, after the aluminum oxide layer is formed by using plasma electrolytic oxidation, sealing is required to fill pores of the aluminum oxide layer.

Conventionally, the method used for such sealing is a metal oxide such as aluminum oxide (Al 2 O 3), silicon oxide (SiO 2), zirconium oxide (ZrO 2), or the like in the aluminum oxide layer formed by plasma electrolytic oxidation. There are methods of depositing by chemical vapor deposition (CVD), coating of ceramics by thermal spray or sol-gel method, and coating of epoxy, which is a kind of polymer compound.

The sealing method using a metal oxide has the advantage that the thermal conductivity decreases due to the sealing layer, but the disadvantage is that the PVD or CVD equipment used for the sealing process is very expensive and the time to form the sealing layer is very long. In general, when the metal oxide is deposited by the PVD method, the deposition rate is about 10 s per second, and forming the metal oxide sealing layer 5 μm takes about 2 hours in addition to the preparation time such as vacuum exhaust. Therefore, the sealing method using a metal oxide causes a significant increase in manufacturing cost.

Next, the sealing method using the spray or sol-gel method has the advantage that the thermal conductivity is relatively low and the manufacturing cost is also lower than that of the sealing method using the metal oxide. However, the ceramic layer formed by the spray or sol-gel method is very vulnerable to brittleness and is printed. In the manufacturing process of the circuit board, there are problems such as cracking during post-processing due to punching or routing or minute cracks due to thermal fatigue.

Finally, sealing by epoxy coating is a method of coating epoxy on aluminum oxide layer formed by plasma electrolytic oxidation method to fill pores in aluminum oxide layer and then harden it. Compared with the other two kinds of sealing methods, the manufacturing cost is low, brittle, high dielectric breakdown voltage and high reliability.

However, in spite of these advantages, the sealing by epoxy coating causes some problems when forming the wiring layer. Since the epoxy layer sealing the aluminum oxide layer formed by the plasma electrolytic oxidation method does not remain in the epoxy itself after curing, the electrolytic copper foil should be attached using an adhesive layer such as another epoxy or thermosetting resin as the wiring layer. In this case, since the thermal conductivity of the thermosetting resin used as the adhesive layer is low, the overall thermal conductivity of the heat radiation circuit board is lowered. In order to improve this, manufacturing costs are increased by using additional processes and materials such as mixing a ceramic filler with an epoxy used as a sealing layer and a thermosetting resin used as an adhesive layer.

As another method of forming a wiring layer, a method of depositing a seed layer using PVD on an epoxy layer encapsulated with an aluminum oxide layer formed by plasma electrolytic oxidation and forming a wiring layer using electroplating thereon There is this. However, in the case of electroplating after depositing Cu as a seed layer on the cured epoxy sealing layer, the adhesion between the epoxy sealing layer and the wiring layer is very low, ranging from 0.05 kgf / cm to 0.2 kgf / cm based on the ASTM D2861 measuring method. In addition, in order to improve adhesion between the epoxy sealing layer and the wiring layer, an alloy such as Cr, NiCr, TiW, etc. may be deposited between 5 nm and 50 nm between the two layers. However, even in this case, the adhesive force between the epoxy sealing layer and the wiring layer is 0.2 kgf / cm to 0.4 kgf / cm, and considering that the adhesive force between the insulating layer and the wiring layer required for a typical metal printed circuit board (PCB) is 1.3 kgf / cm. low.

The present invention is to solve the above problems of the conventional heat dissipation circuit board, to provide a metal printed circuit board excellent in heat dissipation function is excellent in brittle and excellent insulation and low thermal resistance.

In another aspect, the present invention is to provide a method for manufacturing a printed circuit board excellent in heat dissipation and insulation performance without the time required to form a sealing layer, easy to form a wiring layer to reduce the manufacturing cost of the heat radiation circuit board .

It is still another object of the present invention to provide a sealing layer of a metal oxide layer having excellent insulation and heat dissipation properties and strong brittleness and excellent adhesion to a metal wiring layer.

The printed circuit board according to an embodiment of the present invention to achieve the above object is a base of a metal material; A metal oxide layer formed on one or both surfaces of the base by plasma electrolytic oxidation; A sealing layer of the wholly aromatic polyimide formed on the metal oxide layer and filling the pores of the metal oxide layer; And a metal wiring layer formed on the sealing layer. .

The base metal includes one of aluminum, magnesium, zirconium, titanium, or an alloy thereof, and the sealing layer is preferably formed by a vacuum coating method.

According to an embodiment of the present invention, it is preferable to include an adhesive layer of chromium (Cr), NiCr, or TiW between the sealing layer and the metal wiring layer.

The metal wiring layer may be formed by depositing a copper seed layer by sputtering on the sealing layer and using electroplating on the seed layer.

According to another embodiment of the present invention, the sealing layer is made of barium titanate (BaTiO 3), aluminum nitride (AlN), aluminum oxide (Al 2 O 3) or silica (SiO 2) having a particle size of 0.1 μm to 5 μm in polyimide or epoxy. It can be formed by blending the ceramic powder. The effect of the blending of the ceramic powder is to improve the low thermal conductivity of the resin series and is not limited to the wholly aromatic polyimide, but is also applicable to the epoxy.

Electronic component module according to an embodiment of the present invention is a metal base; A metal oxide layer formed on one or both surfaces of the base by plasma electrolytic oxidation; A sealing layer of the wholly aromatic polyimide formed on the metal oxide layer and filling the pores of the metal oxide layer; And a metal wiring layer formed on the sealing layer; and at least one electronic component mounted on one surface of the printed circuit board.

According to a preferred embodiment of the present invention, the sealing layer comprises a chromium (Cr), NiCr, or TiW adhesive layer between the sealing layer and the metal wiring layer, the sealing layer is formed by a vacuum coating method, the metal wiring layer is A copper seed layer is deposited by sputtering on the adhesive layer and formed using electroplating thereon.

Method for manufacturing a heat dissipation circuit board according to an embodiment of the present invention

Preparing an aluminum base;

Forming an aluminum oxide layer on one or both surfaces of the aluminum base by plasma electrooxidation;

Filling the pores of the aluminum oxide layer with a wholly aromatic polyimide on the aluminum oxide layer to form a sealing layer;
Forming an adhesive layer of chromium (Cr) or NiCr on the sealing layer; And

And depositing a copper seed layer on the adhesive layer by sputtering and forming a wiring layer on the seed layer by using electroplating.

After forming the wiring layer, forming a wiring according to a pattern formation method of a general printed circuit board, such as photolithography.

delete

Method for manufacturing a heat dissipation circuit board according to another embodiment of the present invention comprises the steps of preparing a metal base; Forming a metal oxide layer on one or both surfaces of the metal base by plasma electrooxidation; Filling the pores of the metal oxide layer with a wholly aromatic polyimide on the metal oxide layer to form a sealing layer; And depositing a copper seed layer on the sealing layer by sputtering, and forming a wiring layer using electroplating thereon.

Prior to depositing the seed layer, the step of forming the sealing layer preferably comprises the step of forming an adhesive layer of chromium (Cr), NiCr, or TiW on the sealing layer.

According to the circuit board of the present invention as described above, the metal oxide layer by the plasma electrolytic oxidation method is used as an insulating layer of the substrate to be brittle and excellent in thermal conductivity.

In addition, the circuit board of the present invention, as a result of using the wholly aromatic polyimide as the sealing layer to improve the insulation performance, it has excellent insulation performance and excellent adhesion to the metal wiring layer. Since the adhesive strength with the metal wiring layer is excellent, the copper seed layer can be formed by sputtering without the process of bonding expensive electrolytic copper foil with an adhesive, which is advantageous in terms of cost in forming the wiring layer.

Prior arts lack the performance of some of them in terms of heat dissipation, insulation performance, brittleness, and adhesion to form wiring layers, which are required for heat dissipation circuit boards, or require additional complicated manufacturing processes or long time processes to achieve such performance. The present invention solves the problems of the prior art, such as the need to solve the problems of the prior art, without the need for additional expensive equipment or a long time, strong brittleness, excellent heat dissipation, insulation performance, and at the same time the adhesive force for wiring layer formation In addition, it has all the requirements of a heat dissipation printed circuit board.

1 is a partial cross-sectional view showing pores in an aluminum oxide (Al ₂ O ₃ ) layer formed by plasma electrolytic oxidation (PEO).
2 is a partial cross-sectional view showing the formation of the seed layer directly on the aluminum oxide layer formed by the plasma electrolytic oxidation method.
3 is a partial cross-sectional view showing a wholly aromatic polyimide sealing layer formed using a general coating method.
4 is a partial cross-sectional view showing a wholly aromatic polyimide sealing layer formed using a vacuum coating method.
5 is a partial cross-sectional view showing a wholly aromatic polyimide sealing layer formed by a vacuum coating method and a seed layer formed thereon.
6 is a device conceptual diagram for applying a vacuum coating.
7 is a partial cross-sectional view showing a state in which the LED bare chip mounted on the heat radiation circuit board according to an embodiment of the present invention.
8 is a partial cross-sectional view illustrating a state in which an LED package chip is mounted on a heat dissipation circuit board according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In order to clearly express each layer in the drawings, the thickness and the pore size were enlarged.

The heat dissipation circuit board of the present invention includes a sealing layer of a wholly aromatic polyimide filling the pores of the metal oxide layer formed by the plasma electrolytic oxidation method on the base of the metal material and the metal oxide layer formed thereon and a metal wiring layer formed on the sealing layer It includes. As the metal material, aluminum, magnesium, zirconium, titanium, or an alloy thereof may be used.

Plasma electrolytic oxidation, also known as MAO (microarc oxidation), is used to connect a metal such as aluminum, titanium, or magnesium to an anode in an electrolytic solution of a dilute basic aqueous solution such as KOH, for example, to apply a high voltage DC or DC pulse. Or by applying alternating current of high voltage, oxygen generated from electrolysis reacts with metal surface to form metal oxide. Plasma electrolytic oxidation is more rigid and brittle because the oxide is partially converted from amorphous alumina to a crystal structure such as corundum (α-Al ₂ O ₃ ) by applying a higher voltage than conventional anodizing. Have

The metal oxide layer is formed by using plasma electrolytic oxidation to insulate the base metal, which is a conductive material, and is formed on the first oxide layer, the second oxide layer formed on the first oxide layer, and the third oxide formed on the second oxide layer. Layer. Here, the second oxide layer occupies 90% or more of the total thickness of the metal oxide layer, and the remaining 10% is occupied by the first and third oxide layers. The first oxide layer is formed on the surface of the base metal and includes a transition diffusion layer. The transition diffusion layer is an intermediate phase in which the surface of the metal is changed into an oxide by a plasma oxidation reaction, and the base metal and the coating layer of the plasma electrolytic oxidation coating are bonded with a strong bonding strength (for example, about 70 MPa or more). In this case, the transition diffusion layer may be formed as a very thin layer of about 1 ㎛ or less, the thickness of the first oxide layer may vary depending on the conditions of the manufacturing process.

The second oxide layer is formed on the first oxide layer, and includes a core functional layer formed after the third product layer is formed to a predetermined thickness, and the cemented carbide, wear resistance, corrosion resistance, high dielectric breakdown voltage, etc. of the metal base The characteristics of the layer appear. This second oxide layer is composed of, for example, α-Al ₂ O ₃ and γ-Al ₂ O ₃ phase when the base metal is an aluminum alloy, the closer to the first oxide layer α- Al ₂ O ₃ The fraction of is increased. In addition, the color of the α-Al ₂ O ₃ and γ-Al ₂ O ₃ phase is white, but the core functional layer is black due to the oxide color of the alloying elements depending on the alloying components (Cu, Mg, Si and Zn, etc.) of the base metal. It is colored, milky white and gray.

The third oxide layer is formed on the second oxide layer and includes an amorphous porous layer. The amorphous porous layer is the outermost layer obtained after the plasma electrolytic oxide film treatment. For example, when the base metal is an aluminum alloy, it is formed into a non-equilibrium γ-Al ₂ O ₃ phase.

The layered structure of the metal oxide layer composed of the above three layers is common when the metal oxide layer is formed by the plasma electrolytic oxidation method. Hereinafter, the metal oxide is collectively comprised of the first to third oxide layers. Layer, referred to simply as aluminum oxide layer when the base is aluminum.

Hereinafter, the case where an aluminum base is used is demonstrated. FIG. 1 illustrates a state in which an aluminum oxide (Al ₂ O ₃ ) layer 50 is formed on a base 11 by using a plasma electrolytic oxidation method using aluminum as a base 11. At this time, a plurality of pores 508 is formed on the aluminum oxide layer 50. FIG. 2 is a partial cross-sectional view showing the formation of a seed layer 221 for forming a wiring layer on the aluminum oxide layer 50 formed by the plasma electrolytic oxidation method. As shown, it can be seen that the seed layer is diffusely deposited through the pores 508 so that there is no insulation between the wiring layer and the aluminum base. As described above, although the aluminum oxide layer using the plasma electrolytic oxidation method has high dielectric breakdown voltage properties, the dielectric breakdown voltage is low due to a number of pores formed thereon, or the substrate base and the wiring layer are energized.

Conventionally, in order to solve this problem, the thermal breakdown material, such as epoxy, was filled in the pores of the metal oxide layer and then cured and thermally treated to increase the dielectric breakdown voltage. However, the epoxy layer sealing the aluminum oxide layer formed by the plasma electrolytic oxidation method hardly adheres the electrolytic copper foil as the wiring layer because no adhesive force remains on the epoxy itself after curing. Therefore, in order to adhere | attach an electrolytic copper foil, the adhesive layer which consists of another epoxy or a thermosetting resin etc. is further needed. In this case, since the thermal conductivity of the thermosetting resin used as the adhesive layer is low, the overall thermal conductivity of the heat radiation circuit board is lowered. In order to improve this, manufacturing costs are increased by using additional processes and materials such as mixing a ceramic filler with an epoxy used as a sealing layer and a thermosetting resin used as an adhesive layer.

As another method of forming the wiring layer, a method of depositing a seed layer using PVD on an epoxy layer encapsulated with an aluminum oxide layer formed by plasma electrolytic oxidation and forming a wiring layer using electroplating thereon There is this. However, in the case of electroplating after depositing Cu as a seed layer on the cured epoxy sealing layer, the adhesion between the epoxy sealing layer and the wiring layer is very low, ranging from 0.05 kgf / cm to 0.2 kgf / cm based on the ASTM D2861 measuring method. In addition, in order to improve adhesion between the epoxy sealing layer and the wiring layer, an alloy such as Cr, NiCr, TiW, etc. may be deposited between 5 nm and 50 nm between the two layers. However, even in this case, the adhesion between the epoxy sealing layer and the wiring layer is very low, about 0.2 kgf / cm to 0.4 kgf / cm. Considering that the adhesive force between the insulating layer and the wiring layer required for a general metal PCB is 1.3 kgf / cm, the adhesive force of the epoxy layer or the adhesive layer is too low, and thus, there is no productability.

The present invention intends to form a sealing layer filled with wholly aromatic polyimide on the metal oxide layer formed by plasma electrolytic oxidation to solve the adhesion problem of the epoxy layer.

Polyimide is a polymer containing an imide group in a repeating unit. Depending on its molecular structure, polyimide is also referred to as Wholly Aromatic Polyimide or Partially Aromatic Polyimide (thermoplastic polyimide). ) And thermosetting polyimide.

Of these, the wholly aromatic polyimide is known as a wholly aromatic polyimide product such as DuPont's Vespel sp, Kapton, Pyralin, Ube Industries' Upilex film, Kanegafuchi Chemical Industry's Apocal, etc., but is not limited thereto. .

Since the wholly aromatic polyimide is a linear polymer that maximizes the heat resistance of the polyimide, it has the property of insolubility (not dissolved in a solvent and not melted by heat) after curing, and also when sputtering the seed layer thereon after curing. Very good adhesion

According to an embodiment of the present invention, after forming a sealing layer for sealing the pores of the aluminum oxide layer formed by plasma electrolytic oxidation method with a wholly aromatic polyimide, physical vapor deposition such as thermal vapor deposition, electron beam deposition, sputtering method in the sealing layer (PVD method) or chemical vapor deposition method (CVD method) to form a seed layer, and then electroplated to form a wiring layer.

When the adhesive layer (not shown) of chromium (Cr), NiCr, and TiW is formed between the sealing layer 210 and the wiring layer, the adhesion of the wholly aromatic polyimide is remarkably improved and the adhesion to the wiring layer is also improved. . Furthermore, when the adhesive layer is laminated on the sealing layer, the sealing layer of the wholly aromatic polyimide is not affected by moisture, and thus, a dense wiring layer is formed. The adhesive layer of chromium (Cr), NiCr, TiW, etc. is preferably formed to a thickness of about 5 nm to 50 nm.

The seed layer 221 mainly forms a metal such as copper (Cu) in a thickness of 0.1 μm to 1.0 μm and uses copper (Cu), nickel (Ni), and silver (Ag) as an electroplating material. After the wiring layer is formed by electroplating, the wiring is formed according to a pattern formation method of a general printed circuit board such as photolithography.

 The heat dissipation circuit board manufactured by the above method provides very high adhesion between the sealing layer and the wiring layer, compared to the case where the metal oxide layer is sealed with epoxy, partially aromatic polyimide, or thermosetting polyimide, and seals the seed layer without the adhesive layer. When laminated alone on the layer can be obtained adhesion of about 0.4 kgf / cm to 0.9 kgf / cm. In addition, when an adhesive layer such as Cr, NiCr, TiW or the like is formed on the sealing layer, the adhesion between the wholly aromatic polyimide sealing layer and the wiring layer is very high, about 1.5 kgf / cm to 2.0 kgf / cm.

Table 1 below is experimental data comparing the adhesion between the sealing layer and the wiring layer when epoxy is used as the sealing layer forming material and when the wholly aromatic polyimide is used as the sealing layer forming material. In each case, the adhesion between the sealing layer and the wiring layer was compared by the absence of the adhesive layer and the case of chromium or NiCr.

At this time, the seed layer was formed by sputtering, and the other conditions except for the sealing material were the same.

 As can be seen from the above table showing the results of the adhesion, when the sealing layer is formed of the wholly aromatic polyimide, the adhesion between the sealing layer and the wiring layer is excellent, and the adhesion is further improved when the chrome adhesive layer is between the sealing layer and the wiring layer. can confirm. On the other hand, in the case of sealing with epoxy, even when the adhesive layer is used, the adhesion is very low, and thus it is impossible to form the seed layer by the sputtering method.

Therefore, when the metal oxide layer is sealed by epoxy, the adhesion is low enough that the seed layer cannot be formed by the sputtering method, and the wiring layer is formed by attaching expensive electrolytic copper foil. In the case of attaching the electrolytic copper foil, an additional adhesive layer is required, and in order to secure proper thermal conductivity, the ceramic filler needs to be mixed with the adhesive layer, thereby increasing the product production cost.

  This problem also applies to the case where the sealing layer is formed of a polyimide of a series other than the wholly aromatic polyimide. In other words, when the metal oxide layer is sealed with partially aromatic polyimide or thermosetting polyimide, the adhesion between the sealing layer and the seed layer is low, and even if an adhesive layer such as Cr, NiCr or TiW is used, it is required for a general metal printed circuit board. It is far below the 1.3 kgf / cm adhesion force between the insulating and wiring layers. Therefore, the same problem occurs when sealing with epoxy.

On the other hand, according to an embodiment of the present invention, when filling the pores of the metal oxide layer with the wholly aromatic polyimide to form a sealing layer has excellent insulation and thermal conductivity, and also has a high adhesive strength of the seed layer heat dissipation without additional processes Since an excellent heat dissipation circuit board can be manufactured, manufacturing cost is also reduced. In addition, when the adhesive layer of Cr, NiCr, TiW is added, the adhesive force is further improved and the heat dissipation effect is not lowered.

When the pores of the aluminum oxide layer formed by the plasma electrolytic oxidation method using the wholly aromatic polyimide are sealed, the increase in the dielectric breakdown voltage is limited if the wholly aromatic polyimide does not effectively fill the pores of the aluminum oxide layer. Therefore, it is very important to effectively fill the pores of the aluminum oxide layer 50. In the case of coating and sealing the wholly aromatic polyimide by general screen printing, bar coating, dipping, etc., the wholly aromatic polyimide is formed into pores of the aluminum oxide layer by the self-weight and capillary action of the wholly aromatic polyimide. As shown in FIG. 3, the air layer remaining in the pores of the aluminum oxide layer 50 prevents the wholly aromatic polyimide from filling up all the pores in the aluminum oxide layer.

It is preferable to use the vacuum coating method to solve the above problems and to maximize the sealing effect of the wholly aromatic polyimide sealing layer. In the vacuum, since almost no air remains in the pores of the aluminum oxide layer 50, vacuum-vented after coating the wholly aromatic polyimide on the aluminum oxide layer 50 by screen printing or bar coating in a vacuum chamber. When exposed to atmospheric pressure, the total aromatic polyimide is pushed into the pores of the aluminum oxide layer due to the pressure difference between the atmospheric pressure and the pores of the aluminum oxide layer as shown in FIG. You will cry.

The apparatus for vacuum coating is a wholly aromatic polyimide in the vacuum chamber 601, the vacuum pump 610, the vent valve 630, the vacuum gauge 620 and the vacuum chamber 601 as shown in FIG. 6. It consists of a bar coating device or a screen printing device for coating. First, the aluminum base on which the aluminum oxide layer is formed by plasma electrolytic oxidation is placed on the coating apparatus in the vacuum chamber 601. Then, the chamber is closed and the chamber is vacuumed using a vacuum pump. The degree of vacuum in the chamber is suitably about 10 to 200 millibars (mBar).

Thereafter, the coating device 640 is used to coat the wholly aromatic polyimide, and the vacuum is discarded through the vent valve.

The surface of the wholly aromatic polyimide encapsulation layer exposed to atmospheric pressure is temporarily uneven due to the difference in thickness of the polyimide encapsulation layer, but due to the nature of the polyimide, the surface of the wholly aromatic polyimide encapsulation layer becomes self-leveling. In addition, when the planarization by self weight is not effective enough, the polyimide exposed to atmospheric pressure may be solved by planarizing using a bar or a blade and then thermally curing.

Table 2 below is a measurement when the thickness of the aluminum oxide layer by the plasma electrolytic oxidation is 30 ㎛, shows the change in dielectric breakdown voltage when using the vacuum coating method.

[Table 2] Variation of insulation breakdown voltage according to polyimide thickness and chamber vacuum

The following are preferred embodiments of a method of manufacturing the heat dissipation circuit board of the present invention.

   Example 1

First, prepare an aluminum base.

An aluminum oxide layer is formed on one or both surfaces of the aluminum base by plasma electrolytic oxidation. At this time, an aqueous solution in which KOH or NaOH is added to distilled or deionized water is used as an electrolytic solution, and an aluminum oxide layer having a thickness of about 1 μm to 150 μm is formed by a general plasma electrolytic oxidation method.

The pores of the aluminum oxide layer are filled with the wholly aromatic polyimide on the aluminum oxide layer by vacuum coating to form a sealing layer. If the sealing layer is formed to a thickness of 1㎛ by vacuum coating method in the environment of vacuum degree 100mBar can obtain a breakdown voltage of 3.3kV.

A copper seed layer is deposited to a thickness of 0.5 μm by sputtering on the sealing layer, and a wiring layer is formed on the sealing layer using copper electroplating thereon. At this time, the sputtering conditions are a base pressure of 1.3 × 10 ^-5 Torr, a cathode output of 6.0 kW, an argon (Ar) gas flow rate of 600 sccm, and a substrate rotation speed of 0.5 rpm.

Example 2

First, prepare an aluminum base.

An aluminum oxide layer is formed on one or both surfaces of the aluminum base by plasma electrolytic oxidation.

Filling the pores of the aluminum oxide layer with a wholly aromatic polyimide on the aluminum oxide layer to form a sealing layer. When the fully aromatic polyimide sealing layer is formed to a thickness of 1 μm by the vacuum coating method in an environment of a vacuum degree of 100 mBar, a breakdown voltage of 3.3 kV can be obtained.

An adhesive layer of chromium (Cr), NiCr, or TiW is formed on the sealing layer to a thickness of 5 nm to 50 nm.

A copper seed layer is deposited to a thickness of 0.5 μm on the adhesive layer by sputtering, and a wiring layer is formed on the adhesive layer using copper electroplating. At this time, the sputtering conditions are a base pressure of 1.3 × 10 ^-5 Torr, a cathode output of 6.0 kW, an argon (Ar) gas flow rate of 600 sccm, and a substrate rotation speed of 0.5 rpm.

After the interconnection layer is formed, the interconnection layer is formed according to a pattern formation method of a general printed circuit board such as photolithography.

In another embodiment of the present invention, when the aluminum oxide layer formed by the plasma electrolytic oxidation method is sealed with polyimide or epoxy, when a higher thermal conductivity is required, barium titanate (BaTiO ₃₎ is added to the polyimide or epoxy. ), aluminum nitride (AlN), aluminum oxide (Al ₂ O _3), silica (SiO ₂₎ it is preferred to use by blending the ceramic powder and the like. The ceramic powder may have a particle size of about 0.1 μm to 5 μm. When the ceramic powder is used in combination, the thermal conductivity of the aluminum oxide layer sealed with polyimide or epoxy as the insulating layer may be improved, and the withstand voltage characteristics may be improved by increasing the dielectric constant.

The heat dissipation circuit board according to an embodiment of the present invention is formed of an aluminum material base, an aluminum oxide layer formed by a plasma electrolytic oxidation method on the aluminum base, an aluminum oxide layer formed on the aluminum oxide layer, and a wholly aromatic material filling pores of the aluminum oxide layer. It includes a sealing layer of polyimide and a metal wiring layer formed on the sealing layer.

According to another embodiment of the present invention, the metallization layer forms wirings according to a pattern formation method of a general printed circuit board such as photolithography. An electronic component module having at least one electronic component mounted on one surface of the circuit board as described above is an electronic component module having excellent heat dissipation performance and strong brittleness. Such an electronic component module of the present invention can be manufactured at a low cost because the process is simple and excellent insulation.

The present invention is not limited to the above-described embodiments, and the scope of application is various and various modifications can be made without departing from the gist of the present invention as claimed in the claims.

11 aluminum substrate
50 Al ₂ O ₃ layer formed by plasma electrolytic oxidation
22 wiring layer
33 LED bare chip
34 bonding wire
35 Encapsulant
30 LED package chip
110 Aluminum substrate with aluminum oxide (Al2O3) layer formed using plasma electrolytic oxidation
221 seed layer of metal wiring
210 polyimide sealing layer
508 Pore in Aluminum Oxide (Al ₂ O ₃ ) Layer Formed by Plasma Electrolytic Oxidation
601 vacuum chamber
602 vacuum chamber opening and closing door
603 O-ring sealed between vacuum chamber and opening door
604 vacuum vent
605 vent sphere
610 vacuum exhaust pump
611 vacuum exhaust valve
620 vacuum gauge
630 vent valve
631 Vent Air Filter
632 vent tube
Coating unit with 640 applicator, bar or knife
641 Coating Liquid Spray Nozzles
642 Coating Liquid Canister
650 substrate holder
660 Applicator and Spray Nozzle Control and Drive

Claims (12)

A base of metal material;
A metal oxide layer formed on one or both surfaces of the base by plasma electrolytic oxidation;
A sealing layer of the wholly aromatic polyimide formed on the metal oxide layer and filling the pores of the metal oxide layer;
A metal wiring layer formed on the sealing layer; And
An adhesive layer of chromium (Cr) or NiCr formed between the sealing layer and the metal wiring layer;
Printed circuit board comprising a. The method of claim 1,
The base metal includes one of aluminum, magnesium, zirconium, titanium or alloys thereof, and the sealing layer is formed by a vacuum coating method. delete 3. The method according to claim 1 or 2,
And the metal wiring layer is formed by depositing a copper seed layer on the sealing layer by sputtering and using electroplating on the seed layer. delete A base of metal material;
A metal oxide layer formed on one or both surfaces of the base by plasma electrolytic oxidation;
A sealing layer of the wholly aromatic polyimide formed on the metal oxide layer and filling the pores of the metal oxide layer;
A metal wiring layer formed on the sealing layer; And
A printed circuit board comprising: an adhesive layer of chromium (Cr) or NiCr formed between the sealing layer and the metal wiring layer;
And at least one electronic component mounted on one surface of the printed circuit board. The method of claim 6,
And the sealing layer is formed by a vacuum coating method, and the metal wiring layer is formed by depositing a copper seed layer by sputtering on the adhesive layer and using electroplating thereon. As a method of manufacturing a heat dissipation circuit board,
Preparing an aluminum base;
Forming an aluminum oxide layer on one or both surfaces of the aluminum base by plasma electrooxidation;
Filling the pores of the aluminum oxide layer with a wholly aromatic polyimide on the aluminum oxide layer to form a sealing layer;
Forming an adhesive layer of chromium (Cr) or NiCr on the sealing layer; and
Depositing a copper seed layer by sputtering on the adhesive layer and forming a wiring layer using electroplating on the seed layer;
Method of manufacturing a printed circuit board comprising a. delete The method of claim 8,
And forming a wiring according to a pattern formation method of a general printed circuit board such as photolithography after forming the wiring layer. Preparing a metal base;
Forming a metal oxide layer on one or both surfaces of the metal base by plasma electrooxidation;
Filling the pores of the metal oxide layer with a wholly aromatic polyimide on the metal oxide layer to form a sealing layer;
Forming an adhesive layer of chromium (Cr) or NiCr on the sealing layer; and
And depositing a copper seed layer on the adhesive layer by sputtering, and forming a wiring layer using electroplating thereon. 2. delete

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