KR100643320B1 - Pcb with metal core substrate and method for manufacturing thereof - Google Patents

Abstract

A PCB(Printed Circuit Board) with a metal core substrate and a method for manufacturing the same are provided to improve productivity by shortening a period of a manufacturing process. An insulating layer is formed on an upper surface of a metal substrate(110). A plating layer is formed by applying AC power to the upper surface of the metal substrate(120). A circuit pattern is formed on the plating layer(130). The metal substrate includes one of Al, Mg, and Ti. In the process for forming the insulating layer, the insulating layer is formed by an anodizing method. The anodizing method includes a method using a phosphate electrolyte. In the process for forming the plating layer, the plating layer is formed by an electroplating method.

Description

Metal core printed circuit board and its manufacturing method {PCB with metal core substrate and method for manufacturing according}

1 is a flow chart showing a manufacturing method of a metal core printed circuit board according to the prior art.

Figure 2 is a cross-sectional view showing a plating layer of a metal core printed circuit board according to the prior art.

Figure 3 is a flow chart showing a manufacturing method of a metal core printed circuit board according to an embodiment of the present invention.

Figure 4 is a flow chart showing a manufacturing process of a metal core printed circuit board according to an embodiment of the present invention.

5 is a schematic diagram showing an anodizing process and an electroplating process of a metal core printed circuit board manufacturing method according to an embodiment of the present invention.

6 is a cross-sectional view showing a plating layer of a metal core printed circuit board according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: metal substrate 20: insulating layer

22: pore 30: plating layer

40: circuit pattern 50: outer layer circuit

The present invention relates to a printed circuit board, and more particularly to a metal core printed circuit board and a method of manufacturing the same.

Recently, as electronic products have been miniaturized, increased in density, thinned, and packaged, thinning and fine patterning of printed circuit boards are progressing. In order to reflect such a trend, a structure and a manufacturing method of a printed circuit board differentiated from the prior art are required.

That is, in the manufacture of printed circuit board, not only the process shortening and cost reduction through this, but also thinness and high stiffness to cope with the thinning which is an essential condition of the next generation flip-chip BGA. There is an active research on the substrate material having a metal core, and one of them is a metal core printed circuit board using a metal substrate as a core member of the printed circuit board.

As the metal substrate used in the metal core printed circuit board, an aluminum (Al) substrate is mainly used. Thus, the current general technical trend in forming the inner layer circuit using the aluminum substrate as the core member is shown in FIG. 1.

1 illustrates a process of forming a microcircuit after anodizing a surface of a metal substrate according to the prior art.

In the conventional art of forming an inner layer circuit on the surface of a metal substrate, an oxide layer is formed by using an anodizing process to form an insulating layer on the surface of the metal core layer, and then to apply an adhesive copper plating process to the insulating layer. More specifically, after the 'degreasing-desmut' process as a preprocessing step for applying the copper plating process to the oxide layer, the oxide film is formed through anodizing in a sulfuric acid bath. Proceed with the following processes in the following order: Conditioning-Acid dip-Pre dip-Pd catalyzing-reduction-Electroless Cu plating-Electro Cu plating .

However, such a conventional technique requires a high cost cost and a low productivity since the plating layer is formed through a complicated process. In addition, as shown in FIG. 2, when the plating layer is formed by applying a general catalytic process on the oxide film, the adhesion between the plating layer and the oxide film is very low, so that the phenomenon of lifting occurs in the electroless plating layer, thus forming a fine circuit pattern. It is difficult.

In addition, the manufacturing process of the metal core printed circuit board according to the prior art is very complicated, especially when the electroless plating is carried out using an ordinary palladium (Pd) catalytic process on the amorphous oxide film of the amorphous structure There is a problem that it is very difficult to form a circuit pattern due to the lifting phenomenon of the plating.

The present invention provides a metal core printed circuit board and a method of manufacturing the same, which are excellent in adhesion between the surface of the metal core substrate and the plating layer, and can be manufactured inexpensively and simply by shortening the process.

According to one aspect of the invention, in the method for manufacturing a printed circuit board using a metal substrate as a core member, (a) forming an insulating layer on the surface of the metal substrate, (b) alternating current on the surface of the metal substrate A method of manufacturing a metal core printed circuit board is provided, comprising: (AC) applying a power source to form a plating layer, and (c) forming a circuit pattern on the plating layer.

The metal substrate may include at least one of aluminum (Al), magnesium (Mg), and titanium (Ti). Step (a) may be performed by an anodizing method. It is preferable that a phosphate electrolyte is used for the anodizing method.

Step (b) may be performed by an electroplating method. The plating layer may include copper (Cu). The method may further include cleaning the surface of the metal substrate before step (a). Washing preferably includes a degreasing and desmuting process.

In addition, a metal including a metal substrate, an insulating layer formed on the surface of the metal substrate and including a plurality of pores, and a plating layer filled in the pores and formed on the surface of the insulating layer corresponding to the position at which the circuit pattern is formed. A core printed circuit board is provided.

The metal substrate may include at least one of aluminum (Al), magnesium (Mg), and titanium (Ti). The insulating layer is preferably formed by anodizing the surface of the metal substrate. The plating layer contains copper (Cu) and is preferably formed by an electroplating method.

Hereinafter, a preferred embodiment of a metal core printed circuit board and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same components will be denoted by the same reference numerals regardless of the reference numerals and redundant description thereof will be omitted.

The printed circuit board of the present invention has high thermal conductivity against heat generated when mounting a chip therein, and thus has excellent heat dissipation effect, while maintaining a high stiffness while reducing the thickness of the core layer, and inexpensive production. It is characterized by having a metal core structure using aluminum (6063 alloy).

3 is a flowchart illustrating a method of manufacturing a metal core printed circuit board according to an exemplary embodiment of the present invention.

The present invention is to simplify the conventional complicated and cumbersome processes to obtain a cost-saving effect through the process shortening, and to form an adhesive copper plating layer on the amorphous oxide film.

That is, in the present invention for manufacturing a printed circuit board using a metal substrate as a core member, first, an insulating layer is formed on the surface of the metal substrate (110). Here, the metal substrate used as the core member is difficult to apply plating directly on the surface such as aluminum (Al), magnesium (Mg), titanium (Ti), etc., and has high oxidation power to facilitate the formation of an insulating layer through anodization, and a printed circuit. High heat generating metals are preferred so that heat generated inside the substrate is released to the outside. Generally, aluminum is preferable in consideration of cost and degree of commercialization, but the present invention is not limited to aluminum as a material of a metal substrate.

The process of forming the insulating layer on the surface of the metal substrate is performed by an anodizing method. Anodizing is a surface treatment method widely used in building materials, telecommunication equipment, optical devices, ornaments, automobile parts, etc., and forms a thin oxide film on the surface of the metal to protect the inside of the metal. It is mainly used for metals that make an oxide film on their own surface because the degree of reaction with oxygen is very high such as aluminum (Al), magnesium (Mg), titanium (Ti), and the like.

Anodizing is a method of artificially producing an oxide film having a uniform thickness by promoting the oxidation of the metal surface by allowing the metal to act as an anode in a solution such as sulfuric acid. The surface of the aluminum is oxidized by oxygen generated at the anode to form a film of aluminum oxide (Al 2 O 3). This film is very hard, highly corrosion resistant, and has a very small porosity layer, which can be dyed in various colors, so that the anodizing treatment is performed on the metal surface not only for practical reasons such as corrosion resistance and abrasion resistance but also for aesthetic reasons. There are many cases.

As described above, in order to anodize the surface of the metal substrate, the surface of the metal substrate may be cleaned (100). Surface cleaning of the metal substrate is a pretreatment process according to the prior art, such as degreasing, desmuting process.

Next, an alternating current (AC) power is applied to the surface of the metal substrate on which the oxide film layer is formed as the insulating layer by anodizing to form a plating layer (120). Usually a copper plating layer is formed and is performed by an electroplating method. However, unlike the prior art in which electroplating is performed using a DC power source, an electroplating method using an AC power source is applied.

Electroplating using an alternating current power source is a kind of pulse plating, in which copper is deposited in pores of an oxide layer, which is an insulating layer. Normally, electroplating uses a direct current (DC) power source. However, when an insulating layer is formed on the surface of a metal substrate as in the present invention, copper is deposited in the pores of the oxide film layer using a direct current (DC) power source to form a plating layer. There is a limit to allowing growth.

When electroplating by applying an alternating current (AC) power to the metal substrate, copper is precipitated from the pores of the oxide layer using the polarization of the oxide layer as an insulating layer, and as a result, a plating layer is formed on the oxide layer.

Thus, by depositing copper from the pores of the oxide film layer to form a plating layer, the adhesion between the copper plating layer and the oxide film layer is excellent and the problem of lifting of the conventional electroless plating layer can be solved.

Finally, a circuit pattern is formed on the plating layer formed on the surface of the metal substrate to complete the printed circuit board. Since a method of forming a circuit pattern on the copper plating layer is apparent to those skilled in the art, a detailed description thereof will be omitted.

By replacing the conventional electroplating process with electroplating using alternating current (AC) power, the manufacturing process of metal core printed circuit boards can be greatly shortened, resulting in improved productivity and cost reduction. Can be.

4 is a flowchart illustrating a manufacturing process of a metal core printed circuit board according to an exemplary embodiment of the present invention. Referring to FIG. 4, a metal substrate 10, an insulating layer 20, a plating layer 30, a circuit pattern 40, and an outer layer circuit 50 are illustrated.

An anodizing process is applied to the surface of the metal substrate 10 such as aluminum as shown in FIG. 4A to form an oxide film as the insulating layer 20, as shown in FIG. Next, without performing the electroless plating process as in the prior art, immediately depositing copper in the pores of the insulating layer 20 as shown in FIG. Form.

In this way, all the pretreatment processes performed for the electroless plating process are removed and the electroplating is performed immediately after the formation of the oxide film by anodizing, thereby greatly shortening the process. In order to apply the electroplating process directly to the oxide film layer, electroplating is performed using an AC power source instead of a conventional DC power source.

When AC power is used, copper ions are deposited in the porous layer of the oxide film, so that the adhesion between the oxide film layer and the copper plating layer is very excellent, and electroless plating is not performed. The electroless plating pretreatment process, the palladium (Pd) catalyst process, and the electroless plating process, which occupy most of the cost ratio, are all removed, resulting in cost reduction and productivity improvement.

Next, the circuit pattern 40 is formed by applying patterning, etching, or the like to the plating layer as shown in FIG. 4D, and the outer layer circuit 50 is laminated as shown in FIG. Complete the circuit board.

5 is a schematic diagram showing an anodizing process and an electroplating process in a method of manufacturing a metal core printed circuit board according to an exemplary embodiment of the present invention. FIG. 5A illustrates an anodizing process using a phosphate electrolyte, and FIG. 5B illustrates an electroplating process using an alternating current (AC) power source.

In the present invention, the surface of the metal substrate is anodized to form an anodized film layer, and then a copper plating layer formed by electroplating is formed thereon. As the electrolyte solution used in the anodizing process, a phosphate electrolyte is preferably used. .

There are many electrolytes used for anodizing, but the main ones are hydroxyl, sulfuric acid, phosphoric acid, etc., and the porosity of the oxide layer varies depending on the type of electrolyte. In the case of a film having a low porosity, an excellent insulating layer may be formed and used when manufacturing an electric capacitor.

In the present invention, since the copper is deposited in the pores of the oxide film layer to improve the adhesion between the oxide film layer and the plating layer, the electrolyte solution used in the anodizing process is a large pore formed in the oxide film layer, that is, an electrolyte having high porosity. It is advantageous to use a phosphoric acid electrolyte. However, the anodizing electrolyte solution according to the present invention is not necessarily limited to the phosphoric acid electrolyte solution, and of course, other types of electrolyte solutions may be used within a range apparent to those skilled in the art.

Electroplating is performed by applying alternating current (AC) power to a metal substrate on which an oxide layer as an insulating layer is formed on the surface through anodizing. As a result, copper is deposited from within the pores of the insulating layer, thereby improving adhesion between the plating layer and the oxide film.

6 is a cross-sectional view illustrating a plating layer of a metal core printed circuit board according to an exemplary embodiment of the present invention. Referring to FIG. 6, the metal substrate 10, the insulating layer 20, the pores 22, and the plating layer 30 are illustrated.

6 is a cross-sectional view of an oxide film layer and an electroplating layer of a metal core printed circuit board manufactured by applying the anodizing process and the electroplating process according to the present invention.

The printed circuit board manufactured according to the above-described method of manufacturing a printed circuit board includes an insulating layer 20 and an insulating layer formed on the surface of the metal substrate 10 and the metal substrate 10 and including a plurality of pores 22. It consists of the plating layer 30 formed in the surface of 20).

As described above, aluminum (Al), magnesium (Mg), titanium (Ti), or the like may be used as the metal substrate 10, and the insulating layer 20 may be anodized on the surface of the metal substrate 10. Is formed. The plating layer 30 is formed by depositing copper in the pores 22 of the oxide layer, which is the insulating layer 20, by electroplating to which an alternating current (AC) power is applied.

After the plating layer 30 is formed on the oxide layer, which is the insulating layer 20, an inner layer circuit is formed by applying a process obvious to those skilled in the art, such as patterning and etching, to correspond to the position where the circuit pattern is to be formed. Accordingly, the outer layer circuit is stacked.

The plating layer 30 which has undergone the electroplating process using the alternating current (AC) is formed by depositing copper in the porous layer of the oxide film, and thus has a very high adhesion compared with the adhesion of the electroless plating layer. .

Although the technical spirit of the present invention has been described in detail according to the above-described embodiments, the above-described embodiments are for the purpose of description and not of limitation, and a person of ordinary skill in the art will appreciate It will be understood that various embodiments are possible within the scope.

According to the present invention having the configuration as described above, the process is shortened by more than half compared to the conventional metal core substrate manufacturing process, in particular, the costly electroless catalyst treatment process and the electroless plating process can be eliminated to improve productivity Cost reduction is possible.

In addition, although it is very difficult to form a high adhesion copper plating layer on the amorphous anodized film through the conventional electroless plating process, the present invention is highly effective between the oxide film and the copper plating layer by depositing copper in the pores of the oxide film. Adhesion can be obtained.

Claims (12)

In the method for manufacturing a printed circuit board using a metal substrate as a core member, (a) forming an insulating layer on the surface of the metal substrate; (b) applying an alternating current (AC) power to the surface of the metal substrate to form a plating layer; And (c) forming a circuit pattern on the plating layer. The method of claim 1, The metal substrate is a method of manufacturing a metal core printed circuit board containing any one or more of aluminum (Al), magnesium (Mg), titanium (Ti). The method of claim 1, Step (a) is a method of manufacturing a metal core printed circuit board is performed by an anodizing method. The method of claim 3, A method of manufacturing a metal core printed circuit board using a phosphate electrolyte in the anodizing method. The method of claim 1, The step (b) is a method of manufacturing a metal core printed circuit board performed by the electroplating method. The method of claim 1, The plating layer is a manufacturing method of a metal core printed circuit board containing copper (Cu). The method of claim 1, The method of manufacturing a metal core printed circuit board further comprising the step of cleaning the surface of the metal substrate before step (a). The method of claim 7, wherein The cleaning method of manufacturing a metal core printed circuit board comprising a degreasing and desmuting process. A metal substrate; An insulating layer formed on a surface of the metal substrate and including a plurality of pores; A metal core printed circuit board comprising a plating layer filled in the pores and formed on a surface of the insulating layer corresponding to a position where a circuit pattern is formed. The method of claim 9, The metal substrate is a metal core printed circuit board containing any one or more of aluminum (Al), magnesium (Mg), titanium (Ti). The method of claim 9, The insulating layer is a metal core printed circuit board formed by anodizing the surface of the metal substrate. The method of claim 9, The plating layer includes copper (Cu), and a metal core printed circuit board formed by an electroplating method.

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