KR102671758B1 - Printed circuit board and method thereof - Google Patents

Abstract

Provides printed circuit boards and their manufacturing methods. One embodiment of the present invention includes preparing a substrate in which a base metal layer and a carrier copper foil are laminated on the upper and lower surfaces of a core substrate; etching a portion of the carrier copper foil to form a first opening, so that the carrier copper foil is provided with a plurality of reinforcement portions and strip portions separated by the first opening; Removing the strip portion of the carrier copper foil; forming a via hole in a region of the substrate from which the strip portion was removed; and forming a circuit pattern in one area of the substrate.

Description

Printed circuit board and method thereof}

Embodiments of the present invention relate to printed circuit boards and methods of manufacturing the same.

In order to manufacture a semiconductor package, a printed circuit board on which a semiconductor chip with an electric circuit can be mounted is required. A printed circuit board has a circuit pattern on one or both sides for electrical signals output from a semiconductor chip and transmitted to an external device or from an external device to a semiconductor chip.

Recently, in the electrical and electronic industries, printed circuit boards are an essential component and their utilization is increasing. Accordingly, methods to minimize the defect rate in mass production of printed circuit boards are being sought.

Embodiments of the present invention relate to a printed circuit board and a method of manufacturing the same, and specifically relate to a printed circuit board and a method of manufacturing the same that can reduce the defect rate.

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the present invention.

One embodiment of the present invention includes preparing a substrate in which a base metal layer and a carrier copper foil are laminated on the upper and lower surfaces of a core substrate; etching a portion of the carrier copper foil to form a first opening, so that the carrier copper foil is provided with a plurality of reinforcement portions and strip portions separated by the first opening; Removing the strip portion of the carrier copper foil; forming a via hole in a region of the substrate from which the strip portion was removed; and forming a circuit pattern in one area of the substrate.

In one embodiment, the plurality of reinforcing parts may include a first reinforcing part and a second reinforcing part disposed on an outer portion of the substrate.

In one embodiment, the plurality of reinforcement parts may further include a third reinforcement part disposed between the first reinforcement part and the second reinforcement part.

In one embodiment, the printed circuit board is manufactured by a reel-to-reel device, and the plurality of reinforcement parts may be in contact with a roller of the reel-to-reel device.

In one embodiment, a second opening may be formed in the base metal layer, corresponding to the first opening of the carrier copper foil.

In one embodiment, the thickness of the plurality of reinforcement parts may be 2 to 7 times the thickness of the base metal layer.

In one embodiment, the step of cutting the substrate may be further included after forming the circuit pattern.

Another embodiment of the present invention includes a core substrate; a base metal layer laminated on the upper and lower surfaces of the core substrate; first and second reinforcement parts disposed on the base metal layer at both outer edges of the substrate; a via hole penetrating the substrate; and a circuit pattern formed on the base metal layer. It provides a printed circuit board including a.

In one embodiment, the first reinforcement part and the second reinforcement part are made of copper foil, and the thickness of the first reinforcement part and the second reinforcement part may be 2 to 7 times greater than the thickness of the base metal layer.

In one embodiment, it may further include a third reinforcement part disposed between the first reinforcement part and the second reinforcement part.

In one embodiment, a first metal layer and a second metal layer thicker than the first metal layer may be further disposed on the base metal layer.

As described above, the printed circuit board according to embodiments of the present invention has a plurality of reinforcing parts on the board, which prevents damage to the printed circuit board and improves workability.

Of course, the scope of the present invention is not limited by this effect.

1 is a schematic diagram showing a portion of a device that can be used in a method of manufacturing a printed circuit board according to an embodiment of the present invention.
2 to 11 are schematic cross-sectional views sequentially showing a method of manufacturing a printed circuit board according to an embodiment of the present invention.

Since various transformations can be made to these embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. The effects and features of the present embodiments and methods for achieving them will become clear by referring to the detailed description below along with the drawings. However, the present embodiments are not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, the following embodiments will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be assigned the same reference numerals and duplicate descriptions thereof will be omitted.

In the following embodiments, terms such as first and second are used not in a limiting sense but for the purpose of distinguishing one component from another component.

In the following examples, singular expressions include plural expressions, unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have mean the presence of features or components described in the specification, and do not exclude in advance the possibility of adding one or more other features or components.

In the following embodiments, when a part such as a membrane, region, or component is said to be above (or above) or below (below) another part, it does not only mean that it is directly above or below the other part, but also that there is another part in between. This also includes cases where membranes, regions, components, etc. are interposed. The standards for top and bottom are explained based on the drawings.

In the drawings, the sizes of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, so the following embodiments are not necessarily limited to what is shown.

1 is a schematic diagram showing a portion of a device that can be used in a method of manufacturing a printed circuit board according to an embodiment of the present invention.

Referring to FIG. 1, a printed circuit board according to an embodiment of the present invention can be manufactured using a reel-to-reel device. A reel-to-reel device is a device that carries out a process while moving a substrate through continuous reel driving. The reel-to-reel device may include a supply roller 511 for loading the substrate 100, a receiving roller 512 for unloading the substrate 100, and various other rollers 513. The rollers 513 may be provided in a variety of ways, such as a transfer roller for moving the substrate 100 and a buffer roller for controlling tension. Although FIG. 1 shows only a reel-to-reel device corresponding to one stage, reel-to-reel devices can be arranged sequentially to correspond to a plurality of stages. In this case, the substrate 100 may be continuously processed by repeating loading and unloading at each manufacturing stage of the printed circuit board.

Embodiments of the present invention are not limited to being manufactured by a reel-to-reel device as shown in FIG. 1. For example, embodiments of the present invention can also be applied to a method of manufacturing a printed circuit board that is processed in a flat state.

2 to 11 are schematic cross-sectional views sequentially showing a method of manufacturing a printed circuit board according to an embodiment of the present invention. The cross-sectional views of FIGS. 2 to 10 may be cross-sectional views cut perpendicular to the direction in which the reel-to-reel process is performed.

Referring to FIG. 2, first, a substrate 100 is prepared in which a base metal layer 110 and a carrier copper foil 120 are laminated on the upper and lower surfaces of the core substrate 101.

The core substrate 101 is made of an insulating material such as glass cloth, epoxy resin, polyimide, polymer, liquid crystal polymer, polytetrafluoroethylene (PTFE), It can be made of polymethyl methaacrylate, polycarbonite, or a combination of some of them. The core substrate 101 may be made of a rigid material or a flexible material.

The base metal layer 110 may be made of copper, copper alloy, or other conductive metal. The base metal layer 110 has the same size as the core substrate 101 and can be laminated through a laminating process in which heat and pressure are applied to adhere to the core substrate 101. In some embodiments, an adhesive layer may be formed between the base metal layer 110 and the core substrate 101. As another example, the base metal layer 110 may be formed on the upper and lower surfaces of the core substrate 101 through various deposition processes. For example, the base metal layer 110 may be deposited using a sputtering or thermal evaporation process.

Since the base metal layer 110 is used as a medium through which current flows when electrolytic plating is performed later, it is preferably formed thinly to save cost. In some embodiments, the base metal layer 110 disposed on one side of the core substrate 101 may have a thickness of about 2 to 5 um. For example, the thickness of the base metal layer 110 may be about 3 um. For adhesion with the carrier copper foil 120, ultrafine irregularities may be formed on the surface of the base metal layer 110.

A carrier copper foil 120 may be disposed on the upper surface of the base metal layer 110. The carrier copper foil 120 may be introduced to protect the base metal layer 110 in the process before forming the circuit pattern on the base metal layer 110. The carrier copper foil 120 may be made of copper or a copper alloy. The carrier copper foil 120 is patterned in a later process and serves to strengthen the rigidity of the substrate 100, and the thickness of the carrier copper foil 120 may be greater than the thickness of the base metal layer 110. For example, the thickness of the carrier copper foil 120 may be 2 to 7 times the thickness of the base metal layer. In some embodiments, the thickness of the carrier copper foil 120 may be about 18 um. The carrier copper foil 120 may be laminated on the upper surface of the base metal layer 110 through a laminating process that adheres by applying heat and pressure.

Next, referring to FIGS. 3 and 4 , the carrier copper foil 120 is etched to form a first opening (H1), thereby forming the carrier copper foil 120 into a plurality of reinforcement portions 121, 122, 123 and a strip. It is formed as part 125.

First, referring to FIG. 3, photoresist (PR) is applied to the upper surface of the carrier copper foil 120, the portion where the first opening (H1) will be formed is unexposed through a mask process, and the photoresist is developed and patterned. The photoresist (PR) may be a dry film resist (DFR). Of course, depending on the characteristics of the photoresist, the portion where the first opening H1 will be formed may be exposed and patterned.

Next, referring to FIG. 4, the carrier copper foil 120 is etched to form a first opening H1. Etching may be performed by wet etching using an etchant such as sulfuric acid, hydrogen peroxide, copper chloride, or iron chloride. Through this etching process, a second opening (H2) that overlaps the first opening (H1) may be formed in the base metal layer 110.

The carrier copper foil 120 may be separated into a plurality of reinforcement parts 121, 122, and 123 and a strip part 125 by the first opening H1. That is, the first opening H1 can serve as a separation line. The plurality of reinforcement parts 121, 122, and 123 may include a first reinforcement part 121 and a second reinforcement part 122 disposed on the outside of the substrate 100. Additionally, the plurality of reinforcement units may further include a third reinforcement unit 123 disposed between the first reinforcement unit 121 and the second reinforcement unit 122. The third reinforcement part 123 may be omitted. A strip portion 125 may be disposed between the plurality of reinforcement portions 121, 122, and 123. The strip portion 125 may correspond to a portion of the base metal layer 110 where a circuit pattern is to be formed. The plurality of reinforcement parts 121, 122, and 123 may be in direct contact with the roller when performing the process with a reel-to-reel device.

Referring to FIG. 5, the strip portion 125 disposed on the base metal layer 110 is removed. The plurality of reinforcement parts 121, 122, 123 and the strip part 125 are separated by the first opening H1, and the plurality of reinforcement parts 121, 122, 123 are connected to the base metal layer 110 and Instead of being separated, only the strip portion 125 can be physically removed.

The reason for removing the strip portion 125 may be to improve processability when forming a via hole later and to minimize the amount of etching when forming a circuit pattern. At this time, if the plurality of reinforcement parts 121, 122, and 123 are removed, the rigidity of the substrate 100 may be weakened and may be damaged during the process. In this embodiment, the defect rate that may occur during the process can be minimized by providing a reinforcement portion on the outer portion of the substrate 100.

Next, referring to FIG. 6, a via hole (VH) penetrating vertically through the substrate 100 is formed in a region of the substrate 100 from which the strip portion 125 has been removed. To form a via hole (VH), a mechanical method using a drill can be used or a CO ₂ laser beam can be used.

Next, referring to FIG. 7, the first metal layer 111 is formed on the inner wall of the via hole (VH) using an electroless plating method. The first metal layer 111 may be made of a conductive material such as copper, copper alloy, nickel, palladium, gold, or silver. The first metal layer 111 may be formed thinner than the base metal layer 110. The first metal layer 111 may be formed on the upper and lower surfaces of the base metal layer 110, and the upper and lower surfaces of the base metal layer 110 may be connected to each other by the first metal layer 111.

Next, referring to FIG. 8, in order to fill the via hole (VH) and form a circuit pattern, photoresist (PR) is formed on the upper and lower surfaces of the substrate 100 from which the strip portion was removed, and exposure and development processes are performed. . Here, the photoresist (PR) may be a dry film resist made of a photosensitive material. That is, a dry film resist made of a photosensitive material is placed on the upper surface 100b and the lower surface 100a of the base member 100, and the dry film resist is exposed and developed to form a resist pattern with the dry film resist.

Next, referring to FIG. 9, the second metal layer 113 is formed on the surface of the first metal layer 111 using an electrolytic plating method. The second metal layer 113 may be made of a conductive material such as copper, copper alloy, nickel, palladium, gold, or silver and may be provided as a single layer or multiple layers. The second metal layer 113 may be formed thicker than the first metal layer 111. The second metal layer 113 may be formed to fill the via hole (VH). The thickness of the first metal layer 111 and the second metal layer 113 formed in the via hole (VH) by the second metal layer 113 is increased, so that the base metal layer 110 on the lower surface and the base metal layer on the upper surface of the substrate 100 ( 110) electrical connection can be made stably.

Next, a process of cleaning the surface of the second metal layer 113 may be further performed. To clean the surface of the second metal layer 113, a wet cleaning process or a plasma treatment process can be performed. According to this cleaning process, adhesion with the photoresist (PR) formed on the second metal layer 113 can be strengthened.

Next, referring to FIG. 10, the upper surface 100b and the lower surface 100a of the substrate 100 may be entirely etched to complete the circuit pattern. By the etching process, the base metal layer 110 and the first metal layer 111 disposed in the area where the photoresist (PR) was formed in FIG. 9 are removed, the core substrate 101 is exposed, and the circuit pattern (PTN) is formed. It can be completed. The etching process may be performed by wet etching using an etchant such as sulfuric acid, hydrogen peroxide, copper chloride, or iron chloride. Accordingly, a circuit pattern may be formed on the base metal layer 110, the first metal layer 111, and the second metal layer 113.

Next, referring to FIG. 10, the photoresist (PR) can be removed to form an intermediate printed circuit board 10.

The printed circuit board 10 includes a base metal layer 110 laminated on the upper and lower surfaces of the core board 101, a first reinforcement part 121 and a second reinforcement part ( 122), a via hole (VH), and a circuit pattern (PTN) formed on the base metal layer 110.

The first reinforcement part 121 and the second reinforcement part 122 are made of copper foil, and the thickness t2 of the first reinforcement part 121 and the second reinforcement part 122 is the base metal layer ( 110) may be provided to be 2 to 7 times larger than the thickness t1. In some embodiments, the thickness t1 of the base metal layer 110 may be about 2 um to 5 um, and the thickness t2 of the first reinforcement part 121 and the second reinforcement part 122 may be about 18 um. It can be.

In addition, the printed circuit board 10 may further include a third reinforcement part 123 disposed between the first reinforcement part 121 and the second reinforcement part 122. The third reinforcement portion 123 may be disposed in an area of the printed circuit board 10 where the circuit pattern (PTN) is not formed.

A first metal layer 111 and a second metal layer 113 may be stacked on the base metal layer 110. The first metal layer 111 may be formed thinner than the base metal layer 110 and the second metal layer 113. That is, the second metal layer 113 may be formed thicker than the first metal layer 111. The base metal layer 110, the first metal layer 111, and the second metal layer 113 may be made of a conductive material such as copper, copper alloy, nickel, palladium, gold, or silver.

Meanwhile, referring to FIG. 11, after forming the circuit pattern (PTN), a step of removing the reinforcement portion may be further included. The reinforcement part is intended to minimize defects that may occur during the manufacturing process of the printed circuit board, and can be removed after the process is completed.

In addition, after forming the circuit pattern (PTN), a step of cutting the substrate 100 based on the cutting line CL may be further included. That is, after manufacturing a plurality of printed circuit boards 10' at the same time as one printed circuit board 10, it can be separated into a plurality of printed circuit boards 10' at the final stage of the process.

As such, the present invention has been described with reference to the embodiments shown in the drawings, but these are merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. . Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims.

10: printed circuit board, printed circuit board
100: substrate
101: core substrate
111: first metal layer
113: second metal layer
120: Carrier copper foil
121: First reinforcement part
122: Second reinforcement part
123: Third reinforcement part
125: Strip part
513: roller

Claims (13)

In a printed circuit board manufactured by a reel-to-reel device equipped with rollers,
Preparing a substrate in which a base metal layer and a carrier copper foil are laminated on the upper and lower surfaces of a core substrate;
forming a first opening by etching a portion of the carrier copper foil, so that the carrier copper foil is provided with a first reinforcing part, a second reinforcing part, a third reinforcing part, and a strip part separated by the first opening;
Removing the strip portion of the carrier copper foil;
forming a via hole in a region of the substrate from which the strip portion was removed;
forming a first circuit pattern and a second circuit pattern in one area of the substrate; and
The substrate is cut to remove the areas where the first reinforcing part, the second reinforcing part, and the third reinforcing part are disposed, so that the first printed circuit board on which the first circuit pattern is disposed and the second circuit pattern are disposed. It includes the step of separating into a second printed circuit board,
The first reinforcement unit and the second reinforcement unit are disposed on an outer portion of the substrate,
The third reinforcement part is disposed between the first circuit pattern and the second circuit pattern on the inside of the board, and is in contact with the roller. delete delete delete According to paragraph 1,
A method of manufacturing a printed circuit board, wherein a second opening is formed in the base metal layer in response to the first opening in the carrier copper foil. According to paragraph 1,
A method of manufacturing a printed circuit board, wherein the third reinforcement portion has a thickness of 2 to 7 times the thickness of the base metal layer. delete delete delete delete delete delete delete

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