KR101917759B1 - Method for manufacturing flexible printed circuits board and flexible printed circuits board - Google Patents

Abstract

A method of manufacturing an inner layer non-shielding manufacturing method of a flexible printed circuit board, comprising the steps of: (a) exposing a portion of an inner copper layer of an inner layer substrate member so that an inner layer land (LAND) Forming a multilayered structure in which the inner layer substrate member and the outer layer substrate member are laminated; (b) processing holes in the multi-layer structure for interlayer energization of the multi-layer structure; (c) forming a copper plating layer on a surface region of the multilayered structure including the inner surface of the hole; And (d) partially removing the copper-plated layer so that the copper-plated layer formed on the exposed portion of the inner copper foil layer is not removed, thereby forming the outer circuit pattern and the inner layer land.

Description

TECHNICAL FIELD [0001] The present invention relates to a flexible printed circuit board,

The present invention relates to an inner layer non-shielding manufacturing method of a flexible printed circuit board and a flexible printed circuit board.

A multi-layer flexible printed circuit board is a three-dimensional circuit board having an inner layer and an outer layer circuit. It is an essential circuit board structure for miniaturization and weight reduction of electronic products because it enables high-density component mounting and wire distance reduction by three-dimensional wiring in electronic products. Conventionally, in the process of fabricating the circuit pattern of the outer layer at the time of manufacturing the multilayer flexible printed circuit board, the inner layer land (LAND) formed in the inner layer is damaged, resulting in the failure of the entire product.

Thus, in order to prevent such inner layer lands from being damaged, conventionally, the inner layer lands are shielded so that there is no problem in progressing the outer layer process. Illustratively, the STRIP MASK method, the outer layering method, the peelable INK method, and the like are applied to manufacture the multilayer flexible printed circuit board in order to protect the innerlayer land.

To begin with, STRIP MASK will be described. The ink (INK) which is hardened or removed by heat or IR (Infra Red) light is called STRIP MASK. It is printed on the product (inner layer) The method of protecting inner layer LAND from the process using solution such as etching is called STRIP MASK method. The printing of the ink is carried out by selectively clogging or opening the mesh of the plate making the ink flow down through the open part of the netting, which is dried and cured. Thereafter, the necessary process proceeds, and after the necessary process is performed, the inner layer LAND can be exposed by manually removing the printed STRIP MASK. However, according to the STRIP MASK method, it is difficult to remove the STRIP mask, a large amount of residual defects occur, a large space restriction is imposed on the STRIP MASK method, and when the STRIP MASK is lifted, And there is a problem that a removing force is required to remove the STRIP mask.

In order to protect the inner layer of the LAND, a thin CARRIER FILM is added between the outer layer and the inner layer bond to prevent the inner layer and the outer layer from adhering to each other. The CARRIER FILM is applied to the outer layer of the bond layer. After performing the required process, the outer layer is processed in a half-cut, and the half-cut process is torn off using tape or the like to leave the CARRIER film on the inner layer LAND . However, according to such an outer layer cutting method, there is a problem that a burr due to the half-cut machining occurs in the half-cut area, and there is a problem that a removal force for machining the half-cut is required.

In the peelable INK method, INK is printed on the inner layer, the necessary process is performed, and then the INK is removed and peeled. However, according to the peelable INK method, there is a problem that the liquid penetrates into the inner layer LAND in the etching process which proceeds to one of the required processes, the copper foil must be removed, and a force for removing the ink is required.

The background technology of the present application is disclosed in Korean Patent Laid-Open Publication No. 2013-0130503.

The present invention has been made in order to solve the above problems of the prior art and it is an object of the present invention to provide an inner layer non-shielding manufacturing method of a flexible printed circuit board capable of easily manufacturing a flexible printed circuit board without shielding the inner layer LAND, And to provide a substrate.

It should be understood, however, that the technical scope of the embodiments of the present invention is not limited to the above-described technical problems, and other technical problems may exist.

According to a first aspect of the present invention, there is provided a method of manufacturing a non-shielded inner layer of a flexible printed circuit board, comprising the steps of: (a) forming an inner layer land (LAND) Layer substrate member and the outer-layer substrate member are laminated such that the inner-layer substrate member and the outer-layer substrate member are partially exposed; (b) processing holes in the multi-layer structure for interlayer energization of the multi-layer structure; (c) forming a copper plating layer on a surface region of the multilayered structure including the inner surface of the hole; And (d) partially removing the copper plating layer so as to prevent the copper plating layer formed on the exposed portion of the inner copper foil layer from being removed, thereby forming an outer circuit pattern and an innerlayer land portion.

In addition, the flexible printed circuit board according to the second aspect of the present invention includes: the multilayered structure; A hole formed in the multilayer structure for interlayer energization; And a copper plating layer covering the inner surface of the hole and the exposed portion of the inner copper foil layer to form the outer circuit pattern and the inner layer land portion.

The above-described task solution is merely exemplary and should not be construed as limiting the present disclosure. In addition to the exemplary embodiments described above, there may be additional embodiments in the drawings and the detailed description of the invention.

The copper plating layer is partially removed so that the copper plating layer formed on the exposed portion of the inner copper foil layer formed with the inner layer LAN portion is partially removed to form the outer circuit pattern and the inner layer land portion, The innerlayer land can be extended outward while protecting the innerlayer land using the copper plating layer formed along the surface of the multilayer structure without shielding the innerlayer land, and the innerlayer land portion can be formed. According to the present invention, a flexible printed circuit board can be easily manufactured while protecting the innerlayer land without shielding the innerlayer land by utilizing the conventional flexible printed circuit board manufacturing method without additional tools and additional processes. Therefore, The process ratio and the labor cost can be reduced and the design and manufacture of the product can be simplified compared to the manufacturing method of the flexible printed circuit board.

1 is a schematic flow diagram of a method of manufacturing an inner layer non-shielding of a flexible printed circuit board according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of a multilayer structure manufactured in step S100 of a method for manufacturing an innerlayer non-shielding of a flexible printed circuit board according to an embodiment of the present invention.
3 is a schematic cross-sectional view illustrating step S300 of a method for manufacturing an inner layer non-shielding of a flexible printed circuit board according to an embodiment of the present invention.
4 is a schematic cross-sectional view illustrating step S500 of a method for manufacturing an inner layer non-shielding of a flexible printed circuit board according to an embodiment of the present invention.
5 is a cross-sectional view illustrating a dry film pattern formed in step S700 of a method for manufacturing an inner layer non-shielding of a flexible printed circuit board according to an embodiment of the present invention.
6 is a schematic cross-sectional view for explaining the formation of a dry film layer before a dry film pattern is formed in order to explain the step S700 of the method of manufacturing an inner layer non-shielding of a flexible printed circuit board according to an embodiment of the present invention.
7 is a schematic cross-sectional view for explaining that etching is performed on the copper-plated layer in step S700 of the method for manufacturing an inner layer non-shielding of a flexible printed circuit board according to an embodiment of the present invention.
8 and 9 are schematic cross-sectional views for explaining a step of providing the conductive auxiliary material of the present manufacturing method.
10 is a schematic cross-sectional view for explaining a step of forming an inner layer recognition mark in a method of manufacturing an innerlayer non-shielding of a flexible printed circuit board according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

It will be appreciated that throughout the specification it will be understood that when a member is located on another member "top", "top", "under", "bottom" But also the case where there is another member between the two members as well as the case where they are in contact with each other.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

The present invention relates to an inner layer non-shielding manufacturing method of a flexible printed circuit board and a flexible printed circuit board.

First, a method for manufacturing an inner layer non-shielding of a flexible printed circuit board according to an embodiment of the present invention (hereinafter referred to as "the present manufacturing method") will be described.

FIG. 1 is a schematic flowchart of the present manufacturing method, and FIG. 2 is a schematic cross-sectional view of a multi-layer structure manufactured in step S100 of the present manufacturing method.

1 and 2, the present manufacturing method includes a step of exposing a portion of the inner copper foil layer 12 of the inner layer substrate member 1 to an inner layer land (LAND) And a step (SlOO) of manufacturing a multilayer structure in which the substrate member 2 is laminated.

Step S100 includes forming the innerlayer substrate member 1. The inner layer substrate member 1 includes an inner copper foil layer 12 formed on each of the upper and lower surfaces of the base film 11 and the base film 11 and an upper surface of the inner copper foil layer 12 formed on the upper surface of the base film 11. [ And a cover layer 13 formed on the lower surface of the inner copper foil layer 12 formed on the lower surface of the base film 11. Illustratively, the base film 11 may be a polyimide film. However, the type of the base film 11 is not limited to this, and a film made of a resin such as a polyester film other than polyimide may be applied as the base film 11. The inner copper foil layer 12 may be made of a material containing copper (Cu). Further, the inner copper foil layer 12 can form an inner circuit pattern. The coverlay layer 13 may be formed such that a predetermined exposed region 121 is formed and the exposed region 121 may include an innerlayer land having an accessable structure such as a connector or the like .

Step S100 may include forming an outer layer substrate member on each of the upper and lower surfaces of the innerlayer substrate member 1. The step of forming the outer layer substrate member may include a step of preparing the outer layer substrate member 2 and a step of laminating the prepared outer layer substrate member 2 with the innerlayer substrate member 1. [

The outer layer substrate member 2 may have an outer copper foil layer 21 and a prepreg 22 disposed between the inner layer substrate member 1 and the outer copper foil layer 21. [ In addition, the outer layer substrate member 2 can be cut to a portion that exposes a portion of the inner copper foil layer 12 that is to be exposed, prior to lamination with the inner layer substrate member 1. [

3 is a schematic cross-sectional view for explaining step S300 of the present manufacturing method.

Referring to FIGS. 1 and 3, the manufacturing method includes a step S300 of processing a hole 3 in a multilayer structure for interlayer energization (interlayer electrical connection) of the multilayer structure. Referring to Fig. 3, the hole 3 may be formed so as to completely penetrate the inner layer substrate member 1 and the outer layer substrate member 2 of the multilayered structure. Illustratively, step S300 can form the hole 3 by cutting with a drill. The copper plating layer 4 may be formed on the inner circumferential surface of the hole 3 to be formed in step S500 to be described later. The copper plating layer 4 may be electrically connected to the layers requiring coins.

4 is a schematic cross-sectional view for explaining step S500 of the present manufacturing method.

Referring to FIGS. 1 and 4, the manufacturing method includes forming a copper plating layer 4 on the surface region of the multilayered structure including the inner surface of the hole 3 (S500). The copper plating layer 4 may be made of a material containing copper (Cu). In other words, the step S500 can plated copper (cu) on the inner surface of the hole 3 and the exposed surface of the multi-layer structure.

FIG. 5 is a cross-sectional view for explaining formation of a dry film pattern in step S700 of the present manufacturing method, and FIG. 6 illustrates a dry film layer formed before a dry film pattern is formed in order to explain step S700 of the present manufacturing method And FIG. 7 is a schematic cross-sectional view for explaining that etching for the copper-plated layer in the step S700 of the present manufacturing method is performed.

1, the copper plating layer 4 is partially removed so that the copper plating layer 41 formed on the exposed portion 121 of the inner copper foil layer 12 is not removed, And forming the inner layer land portions 121 and 41 (S700).

5, in operation S700, dry film patterns 51 and 52 corresponding to the outer circuit patterns 42 and the inner layer land portions 121 and 41 are formed on the copper plating layer 4, To form a second layer.

Illustratively, referring to FIG. 6, forming the dry film pattern may include forming a dry film layer 5 on the outer surface of the copper plating layer 4. At this time, the dry film layer 5 may be formed so as to cover the hole 3. Thereafter, the step of forming the dry film pattern is carried out by exposing the dry film layer 5 in accordance with a pattern (circuit shape) to be formed, curing only a necessary part (pattern) ) Can be removed. Thus, the dry film patterns 51 and 52 can be formed.

At this time, a necessary portion (pattern) of the dry film layer 5 to be cured is formed by the portion 52 to be the outer circuit pattern 42 of the copper plating layer 4 and the exposed portion 121 of the inner copper foil layer 12, And a portion 51 covering the portion 41 laminated on the substrate.

7, step S700 is a step of etching (E / T) the copper plating layer 4 along the dry film pattern so as to form the outer circuit pattern 42 and the copper plating layer 41 on the inner layer land . The portion covered with the cured portion (dry film pattern) of the dry film of the copper plating layer 4 is left at the time of etching. Referring to Fig. 7, the outer circuit pattern 42 and the inner copper foil layer 12 are formed by the step S700, The copper plating layer 41 laminated on the exposed portion of the copper plating layer 41 may be left.

In the step S700, after the step of etching the copper plating layer 4, the step of peeling the dry film pattern may be performed. The inner circuit land portions 121 and 41 (including the copper plating layer 41) laminated on the exposed portion 121 of the inner copper foil layer 12 can be formed by the step S700 May be formed.

According to the present manufacturing method, the exposed portion 121 of the inner copper foil layer 12 is exposed using the copper plating layer 4 formed along the surface of the multilayered structure without shielding it with a different material or process The inner layer land portion can be formed by extending the exposed portion 121 outwardly by using the copper plating layer 41 while protecting the exposed portion 121 of the flexible printed circuit board. Process cost and labor cost can be reduced, and the design and manufacture of the product can be simplified. Further, the present manufacturing method can be easily applied only by modifying exposure data (data) in a manufacturing process without adding a new tool (TOOL) and a new process. That is, the present manufacturing method can easily manufacture a flexible printed circuit board while protecting the inner layer land 121 without shielding the inner layer land 121 by using a conventional flexible printed circuit board manufacturing method without adding new tools and new processes .

Such a manufacturing method can be applied to a portion of the product circuit not directly connected to the LAND portion, such as when the inner layer land 121 is GND or a recognition mark.

Generally, a hole is processed in the multilayered structure and copper plating proceeds for energization. (Copper) on the inner layer exposed area is removed by etching all of the copper plating on the exposed part of the outer layer, but the present manufacturing method is different from the copper plating layer on the inner layer land 121 (step S700) 41), so that it can be bonded to the conductive auxiliary material, so that it can be produced without a separate inner layer shielding process.

8 and 9 are schematic cross-sectional views for explaining a step of providing the conductive auxiliary material of the present manufacturing method. 8 is a schematic cross-sectional view for explaining that an EMI shield is provided, and FIG. 9 is a schematic cross-sectional view for explaining that a conductive SUS is provided.

8 and 9, the manufacturing method includes a step after step S700 of providing a conductive auxiliary material on the copper plating layer 41 formed on the exposed portion 121 of the inner copper foil layer 12 .

Illustratively, referring to Fig. 8, the conductive sub-material may be an EMI shield 6. The EMI shield 6 may be a device that shields electromagnetic interference. The EMI shield 6 will be apparent to those skilled in the art and will not be described in detail.

Alternatively, referring to FIG. 9, the conductive auxiliary material may be a conductive SUS 71. As described above, since the copper plating layer 41 for extending the inner layer lands 121 is left on the inner layer lands 121 after the formation of the outer layer circuits, the conventional STRIP MASK, the outer layer etching method, The inner layer land 121 and the conductive SUS 71 can be energized while preventing the inner layer lands 121 from being damaged without performing a shielding step for closing the inner layer lands 121 and closing the inner layer lands 121, can do. Illustratively, referring to Fig. 9, the conductive SUS 7 may be energized with an inner layer land 41 by a conductive bond 72.

10 is a schematic sectional view for explaining a step of forming an inner layer recognition mark of the present manufacturing method.

10, after the step S700, a copper plating layer 41 is formed on the exposed portion 121 of the inner copper foil layer 12 and the exposed portion 121 of the inner copper foil layer 12, To form the inner layer recognition mark 8, as shown in FIG. The step of forming the inner layer recognition mark 8 may be performed in place of the step of providing the above-described conductive auxiliary material. For example, the inner layer recognition mark 8 can be formed by applying an etching, exposure, and development process or the like for forming the predetermined pattern to the inner layer land portions 41 and 121.

In addition, the present invention can provide a flexible printed circuit board (hereinafter referred to as 'the present flexible printed circuit board') according to one embodiment of the present invention manufactured according to the present manufacturing method described above.

The flexible printed circuit board includes a multilayer structure as described above, a hole 3 formed in the multilayer structure for interlayer energization, an inner surface of the hole 3 and an exposed portion 121 of the inner copper foil layer 12, Pattern 42 and a copper plating layer 4 for forming an inner layer land portion.

The flexible printed circuit board may include a conductive auxiliary material provided on the copper plating layer 41 (inner layer land portion) formed on the exposed portion 121 of the inner copper foil layer 12. Illustratively, the conductive auxiliary material may be an EMI shield 6. Alternatively, the conductive auxiliary material may be the conductive SUS 71.

Alternatively, the flexible printed circuit board may be formed by processing the copper plating layer 41 formed on the exposed portion 121 of the inner copper foil layer 12 and the exposed portion 121 of the inner copper foil layer 12, Mark (8).

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention.

1: Inner layer substrate member
11: base film
12: Inner copper foil layer
13: Coverage layer
2: outer layer substrate member
21: outer copper foil layer
22: prepreg
3: Hall
4: Copper plating layer
41: Copper plating layer formed on the exposed portion of the inner copper foil layer
42: outer circuit pattern
5: Dry film layer
6: EMI shield
71: Conductive SUS
72: Conductive Bond
8: inner layer recognition mark

Claims (10)

A method of manufacturing a flexible printed circuit board,
(a) the inner layer substrate member and the outer layer substrate member are laminated such that a part of the inner copper layer of the inner layer substrate member having the base film, the inner copper foil layer and the coverlay layer successively is formed so that the inner layer land (LAND) Producing a multilayered structure;
(b) processing holes in the multi-layer structure for interlayer energization of the multi-layer structure;
(c) forming a copper plating layer on a surface region of the multilayered structure including the inner surface of the hole;
(d) partially removing the copper plating layer so as not to remove the copper plating layer formed on the exposed portion of the inner copper foil layer to form an outer circuit pattern and an innerlayer land portion; And
(f) forming a dry film pattern on the copper plating layer formed on the exposed portion of the inner copper foil layer by exposure to expose the exposed portion of the inner copper foil layer and the exposed portion of the inner copper foil layer along the dry film pattern The copper plating layer formed on the inner copper foil layer is etched to form a copper plating layer formed on the exposed portion of the inner copper foil layer and the exposed portion of the inner copper foil layer, Forming an inner layer recognition mark including a copper plating layer and an inner copper foil layer by removing a portion in contact with the ray layer and a lower inner copper foil layer,
The step (d)
(d1) forming a dry film pattern on the copper plating layer, the dry film pattern including a portion covering the outer circuit pattern and the inner layer land portion; And
(d2) etching (E / T) along the dry film pattern to form the outer circuit pattern and the inner layer land portion. delete delete delete delete The method according to claim 1,
The step (a)
(a1) an inner copper foil layer formed on the base film, the inner copper foil layer formed on each of upper and lower surfaces of the base film, and an upper surface of the inner copper foil layer formed on the upper surface of the base film, Forming an inner layer substrate member having the cover layer formed on each of the inner layer substrate members;
(a2) forming an outer layer substrate member on each of the upper and lower surfaces of the innerlayer substrate member,
Wherein the outer layer substrate member has an outer copper foil layer and a prepreg disposed between the inner layer substrate member and the outer copper foil layer. delete delete delete delete

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