KR100754070B1 - Manufacturing method of printed circuit board using Cu fill plating - Google Patents

Abstract

The present invention relates to a method for manufacturing a multilayer printed circuit board, and more particularly, to a method for manufacturing a printed circuit board, characterized in that the vertical electrical connection between the stacked circuits is formed by micro vias filled with copper. In order to form a micro via using a CO2 laser to disclose a method for manufacturing a printed circuit board characterized in that the interlayer connection by filling the inside of the micro via with a conductive material (for example, copper) through a copper peel plating process, According to this method, the problem caused in the manufacturing process of the paste filling method printed circuit board using the conventional screen printing method can be solved. In addition, the present invention can prevent the problem that the reliability of the printed circuit board is degraded by the bubbles formed in the through-hole in the conventional paste filling method, and further increase the number of work times required to perform the screen printing method and It is possible to prevent an increase in costs due to an increase in related facilities.

Micro via, CO2 laser, copper peel plating, inner layer circuit, laminated circuit, outer layer circuit

Description

Manufacturing method of printed circuit board using copper fill plating {Manufacturing method of printed circuit board using Cu fill plating}

1 is a cross-sectional view showing an example of a conventional printed circuit board using paste filling;

2 is a flowchart illustrating a method of manufacturing a printed circuit board according to an embodiment of the present invention;

3A to 3G are process diagrams showing the manufacturing method of FIG. 2 step by step; And

4A through 4C are process diagrams exemplarily illustrating a method of manufacturing the base substrate of FIG. 3E.

<Description of Symbols for Main Parts of Drawings>

110, 140: resin coated copper foil layer (RCC) 112, 142: copper foil layer

114: resin layer 116: micro via

120: laminated substrate 122: laminated circuit

124: filled micro via 130: double-sided copper laminated plate (CCL)

132: internal circuit 134, 144: insulating layer

146 through hole 148 plating layer

150: base substrate 152: inner layer circuit

154: via hole 200: printed circuit board

The present invention relates to a method for manufacturing a multilayer printed circuit board, and more particularly, to a method for manufacturing a printed circuit board, characterized in that the vertical electrical connection between the stacked circuits is formed by micro vias filled with copper.

The miniaturization of equipment and technology integration have steadily developed due to the advancement of electronic devices and products. In addition, manufacturing processes for printed circuit boards (PCBs) used in electronic devices and the like are also gradually developed in response to miniaturization and light weight.

The technical direction of the method of manufacturing a printed circuit board was initially developed from a single-sided board to a double-sided board, and then back to a multi-layer board (MLB). up) A manufacturing method called a construction method is under development.

Recently, the paste filling and bump connection for the interlayer connection of the build-up method has been one of the mainstream. Such a method can satisfy the needs of set companies that require a printed circuit board, and has a great advantage in designing fine patterns and freedom of patterns.

An example of a printed circuit board manufactured using paste filling in the build-up method is shown in FIG. 1. According to FIG. 1, a conventional printed circuit board 100 is formed by alternately stacking a plurality of circuit layers 10 and insulating layers 20 on which circuit patterns 12 are formed, and these interlayer connections are circuit layers. Is made by contact between the connecting portion 14 and the connecting portion 24 of the insulating layer.

The connecting portion 24 of the insulating layer of FIG. 1 is formed using paste filling, which is generally formed using a screen printing process or the like.

The screen printing process involves, for example, a material (e.g., conductive paste or filler) to be filled on a screen (not shown), such as a partially cut film formed corresponding to a desired shape (e.g. through-holes in the substrate, etc.). After the arrangement, the inside of the through-hole is filled with a material to be filled by pushing by means such as squeezing.

In the screen printing process, bubbles are left in the through-holes, which causes the destruction of the through-holes and the disconnection of electrical signals due to the bursting of bubbles in the through-holes during the heating of the components after the production of the finished product of the printed circuit board or after the mounting. Reliability defects may appear.

For example, air cannot be drawn out between the paste and the interface between the through-holes while pushing the conductive paste into the through-holes with a squeeze, thereby preventing air from being pushed into the through-holes into bubbles. As a result, the above reliability defects can be brought about.

In addition, when the screen printing method is applied, one worker is required for each facility, and in order to increase the amount of work, there is a difficulty in increasing the number of facilities and the number of work.

In addition, in the conventional manufacturing process of a batch-layer printed circuit board, a process that is inevitably accompanied by etching copper foil on a copper coated layer (CCL) and then laminating and peeling an adhesive film. There was a problem that the increase in number is required.

The present invention is to provide a method for manufacturing a printed circuit board to solve the problems caused in the manufacturing process of the paste-filled printed circuit board using a conventional screen printing method.

The present invention is to provide a method of manufacturing a printed circuit board to form an interlayer connection by forming a micro via using a CO2 laser and then filling the inside of the via with copper peel plating.

In order to achieve this object, the present invention comprises the steps of (A) providing a resin-coated copper foil layer (RCC) coated with a copper foil layer on one surface of the resin layer; (B) irradiating a laser to the surface of the resin layer not coated with the copper foil layer to form at least one micro via in the resin layer; (C) filling the inside of the micro via with copper peel plating; (D) providing a laminated substrate formed by forming a laminated circuit on the copper foil layer of the resin coated copper foil layer; (E) forming a base substrate comprising an inner layer circuit corresponding to the stacked circuit; And (F) arranging at least one laminated substrate on the base substrate, and then laminating the batch substrate to provide a method of manufacturing a printed circuit board using copper peel plating.

In the present invention, step (C) comprises the steps of: (C-1) performing electroless copper plating on the resin coated copper foil layer on which micro vias are formed; (C-2) filling by filling the micro via with copper peel plating; And (C-3) removing the plating layer on the surface of the resin layer.

In addition, in the present invention, the micro via of step (B) is characterized in that it is performed using a CO2 laser beam.

In addition, in the present invention, step (E) comprises the steps of: (E-1) providing a copper clad laminate (CCL) having circuits formed on both surfaces; (E-2) laminating an insulating layer and an additional copper foil layer on the upper and lower surfaces of the copper foil laminated plate, respectively; And (E-3) forming an inner layer circuit connected to the circuit of the copper-clad laminate in the additional copper foil layer to form a base substrate.

Further, in the present invention, the inner circuit includes a via hole formed through the additional copper foil layer and the copper foil laminated plate.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a flowchart schematically illustrating a method of manufacturing a printed circuit board according to an exemplary embodiment of the present invention. Referring to Figure 2, a manufacturing method according to the present invention will be described.

First, after providing the resin copper foil coating layer (RCC) (S110), a plurality of micro vias are formed in a predetermined form on the resin layer of the resin copper foil coating layer (S120). The micro vias can be formed by removing the resin layer to a portion facing the copper foil layer using a CO2 laser.

Next, copper fill plating is performed to copper plate the surface of the resin copper foil coating layer including the inner surface of the micro via (S130).

With respect to the copper-plated resin copper foil coating layer, the copper-plated layer on the surface where the micro via is formed is removed, and a predetermined circuit pattern (hereinafter referred to as a laminated circuit) is formed on the opposite surface (copper layer portion) to form a unit laminated substrate. It forms (S140).

Thereafter, after providing a base substrate having an inner layer circuit corresponding to the laminated circuit of the laminated substrate (S150), a desired printed circuit board is manufactured by stacking at least one laminated substrate based on the base substrate (S150).

The printed circuit board is characterized in that the inner circuit of the base substrate and the laminated circuit of each laminated board are connected by using micro vias, and the micro vias are formed by using a laser such as a CO 2 laser and then copper peel plated to form a conductive material. Filling with (for example, copper) may provide a role of electrically connecting the corresponding circuits (such as a laminated circuit and an inner layer circuit) of each laminated substrate and the base substrate.

In addition, since the microvia of the present invention is formed by copper peel plating after laser processing, unlike the conventional structure formed by using paste and bumps, the window forming process for processing vias is eliminated, and at the same time, Compared to the screen-type paste filling process, the number of work-hours and cost can be reduced.

Hereinafter, the manufacturing method disclosed in the flowchart of FIG. 2 will be described in detail with respect to each process step with reference to FIGS. 3A to 3G.

According to the present invention, first, as shown in FIG. 3A, a resin coated copper foil layer 110 (RCC) having a copper foil 112 coated on one surface of the resin layer 114 is provided.

Next, as shown in FIG. 3B, the microvias 116 having a desired shape are formed by removing a part of the resin layer 114 in a predetermined form using a laser such as a CO 2 laser based on the copper foil layer 112. do. At this time, the laser is irradiated to the surface of the resin layer which is not coated with copper foil layer.

The CO2 laser has a property of reflecting from the metal layer, and thus the CO2 laser is reflected from the copper foil layer 112, thereby easily forming the micro via 116 to the interface between the copper foil layer 112 and the resin layer 114.

3C shows a state in which copper plating is applied to the surface of the resin coated copper foil layer including the micro via 116. In this case, copper plating may be performed by sequentially performing electroless copper plating using a seed layer (not shown) after electroless copper plating such as chemical copper plating. As the electrolytic copper plating is performed, the inside of the micro via 116 is filled with a plating material (eg, copper).

Thereafter, as shown in FIG. 3D, the copper foil layer 112 is partially removed to form the laminated circuit 122, and the copper plating layer laminated on the resin layer 114 on the side opposite to the surface on which the laminated circuit 122 is formed. Then, the laminated substrate 120 is formed. At this time, the micro via 124 is provided by copper fill plating and filled with copper.

The process of forming the laminated circuit 122 is basically similar to the process of forming a conventional circuit pattern, for example, a dry film (not shown) over the copper foil layer 112 on which the plating layer 118 is covered. After the formation, the desired pattern can be formed by hardening a part of the dry film using an artwork film or the like as a mask and then etching the copper foil layer 112.

For example, the dry film may be partially removed by curing only the exposed part without curing the part covered by the artwork film, and then using the partially removed dry film as a mask, the copper foil layer (including the plating layer) By etching, a desired circuit pattern (for example, a laminated circuit) can be formed.

Next, as shown in FIG. 3E, a base substrate 150 corresponding to the laminated substrate 120 is provided. The base substrate 150 may be formed by a known process, and an inner layer circuit 152 corresponding to the stacked circuit 122 of the stacked substrate 120 may be formed on a surface thereof. In addition, as illustrated, the base substrate 150 may be formed of a plurality of layers, and at least one via hole electrically connecting the internal circuit 132 and the internal circuit 132 to the inner layer circuit 152 on the surface. 154 may be formed. The manufacturing process of the base substrate 150 will be described later.

Next, according to the present invention, the base substrate 150 and the plurality of laminated substrates 120 provided above may be stacked. For example, as illustrated in FIG. 3F, two stacked substrates 120 may be arranged on the top and bottom surfaces of the base substrate 150.

Such an arrangement is according to an embodiment of the present invention. Alternatively, the laminated substrate is arranged only on one side (eg, top or bottom) of the base substrate, or one or three laminated substrates are formed on both sides (top and bottom, respectively) of the base substrate. Note that you can also arrange

Lastly, the printed circuit board 200 according to the present invention may be completed by heating and stacking the plurality of stacked substrates 120 and the assembly of the base substrate 150 arranged (FIG. 3G).

Meanwhile, the method of manufacturing the base substrate 150 described above will be briefly described with reference to FIGS. 4A to 4C.

First, as shown in FIG. 4A, the internal circuit 132 is formed by partially removing the copper foil of the double-sided copper clad laminate 130 (CCL) having copper foils formed on both surfaces of the insulating layer 134.

After stacking the insulating layer 144 and the copper foil layer 142 on the upper and lower surfaces of the double-sided copper clad laminate (CCL) having the internal circuits formed thereon, a through hole 146 penetrating up and down is formed by a drilling process or the like (Fig. 4b). In this case, the insulating layer 144 and the copper foil layer 142 may be laminated individually, or may be laminated in the form of a resin coated copper foil layer (RCC) 140, which is a combination of the insulating layer and the copper foil layer. In this embodiment, the resin-coated copper foil layer 140 will be described with reference to the stacked example.

Thereafter, as illustrated in FIG. 4C, chemical copper plating (eg, electroless copper plating) and electrolytic copper plating are performed on the surface of the laminate including the through-holes to provide a laminate on which the plating layer 148 is formed.

Thereafter, the plating layer 148 including the copper foil layer 142 is partially removed to form an inner layer circuit 152 corresponding to the stacked circuit 122 (see FIG. 3D). Through this process, the base substrate 150 of FIG. 3E may be provided.

As such, the printed circuit board 200 according to the present invention includes a micro via 124 (see FIG. 3D) in which a plurality of laminated substrates 120 to be stacked are filled with copper using copper peel plating. Since the micro vias 124 are connected up and down, a circuit pattern for penetrating and connecting the inside of the printed circuit board 200 up and down may be provided.

As described above, in the present invention, after forming the micro via using a CO2 laser, the micro via filled with the conductive material (copper) is filled with the conductive material through a copper peel plating process, thereby connecting the interlayer connection ( It is possible to provide a method for manufacturing a printed circuit board, characterized in that the vertical connection of the printed circuit board).

According to the present invention, after forming a micro via using a CO2 laser to the laminated substrate to be laminated, the interlayer connection is achieved by filling the inside of the micro via with a conductive material (eg, copper) through a copper peel plating process. The present invention relates to a method for manufacturing a circuit board, thereby solving the problems caused in the process of manufacturing a paste-filled printed circuit board using a conventional screen printing method. In addition, the present invention can prevent the problem that the reliability of the printed circuit board is degraded by the bubbles formed in the through-hole in the conventional paste filling method, and further increase the number of work times required to perform the screen printing method and It is possible to prevent an increase in costs due to an increase in related facilities.

Claims (5)

(A) providing a resin coated copper foil layer (RCC) coated with a copper foil layer on one surface of the resin layer; (B) irradiating a laser to the surface of the resin layer not coated with the copper foil layer to form at least one micro via in the resin layer; (C) filling the inside of the micro via with copper peel plating; (D) providing a laminated substrate formed by forming a laminated circuit on the copper foil layer of the resin-coated copper foil layer; (E) forming a base substrate including an inner layer circuit corresponding to the stacked circuit; And (F) arranging at least one laminated substrate on the base substrate and then laminating them collectively; Method of manufacturing a printed circuit board using a copper peel plating comprising a. The method of claim 1, wherein step (C) comprises: (C-1) performing electroless copper plating on the resin coated copper foil layer on which the micro vias are formed; (C-2) performing filling with copper peel plating into the micro vias; And (C-3) removing the plating layer on the surface of the resin layer; Method of manufacturing a printed circuit board using a copper peel plating comprising a. The method of claim 1, wherein step (B) is performed using a CO 2 laser beam. The method of claim 1, wherein (E) comprises: (E-1) providing a copper clad laminate (CCL) having circuits formed on both surfaces thereof; (E-2) laminating an insulating layer and an additional copper foil layer on the upper and lower surfaces of the copper foil laminated plate, respectively; And (E-3) forming a base substrate on the additional copper foil layer by forming an inner circuit connected to the circuit of the copper foil laminated plate; Method of manufacturing a printed circuit board using a copper peel plating comprising a. 5. The method of claim 4, wherein the inner layer circuit includes a via hole formed through the additional copper foil layer and the copper foil laminated plate.

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