KR20160097948A

KR20160097948A - Flexible printed circuit board and manufacturing method thereof

Info

Publication number: KR20160097948A
Application number: KR1020150020465A
Authority: KR
Inventors: 정명희; 정주환; 김광윤; 유제광; 정율교
Original assignee: 삼성전기주식회사
Priority date: 2015-02-10
Filing date: 2015-02-10
Publication date: 2016-08-18

Abstract

A flexible printed circuit board and a method of manufacturing the same are disclosed. A flexible printed circuit board according to an aspect of the present invention includes an inner layer substrate portion including a soft region, an outer layer substrate portion stacked on an inner layer substrate portion excluding a soft region, and a lamination layer stacked on at least one surface of the inner layer substrate portion corresponding to the soft region The laminate includes an adhesive layer in which an electric conductor is anisotropically mixed with the inner layer substrate portion and a polyimide layer laminated on the adhesive layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a flexible printed circuit board

The present invention relates to a flexible printed circuit board and a method of manufacturing the same.

Recently, the importance of miniaturization, thinning, and external design of electronic products is increasing. In order to realize an electronic product satisfying this requirement, importance of a printed circuit board inserted into the electronic product is emphasized.

Such a printed circuit board includes a single side PCB on which wiring is formed on only one side of the insulating layer according to the number of layers, a double side PCB on which wiring is formed on both sides of the insulating layer, And may be classified as a multi-layer PCB.

In addition, according to the application materials, Rigid PCB using Rigid Material, Flexible PCB using Flexible Material, Competition using hard material and soft material in combination Can be classified as Rigid Flexible PCB

Among such printed circuit boards, the use of a flexible printed circuit board as a substrate to be inserted into electronic products has been increasing to cope with downsizing and thinning of electronic products. In addition, in recent years, development of watches, bracelets and necklaces of wearable products has been progressing more than smart phones and tablet PCs with various functions, and various structures and designs A substrate is required.

Korean Patent Laid-Open No. 10-2013-0097473 (published on Mar. 03, 2013)

An embodiment of the present invention is a multilayer structure comprising a laminate including an adhesive layer in which an electric conductor is anisotropically mixed with an inner layer substrate and a polyimide layer laminated on an adhesive layer is laminated on at least one surface of an inner layer substrate portion corresponding to a soft region, To a printed circuit board and a method of manufacturing the same.

Here, the polyimide layer is laminated on the adhesive layer so that a part of the adhesive layer is exposed to the outside, and the electronic module can be bonded to the exposed portion of the adhesive layer.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a flexible printed circuit board according to an embodiment of the invention.
2 is a flowchart showing a method of manufacturing a flexible printed circuit board according to an embodiment of the present invention;
3 to 6 are views showing major steps in a method of manufacturing a flexible printed circuit board according to an embodiment of the present invention.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, when a component is referred to as "comprising ", it means that it can include other components as well, without excluding other components unless specifically stated otherwise. Also, throughout the specification, the term "on" means to be located above or below the object portion, and does not necessarily mean that the object is located on the upper side with respect to the gravitational direction.

In addition, the term " coupled " is used not only in the case of direct physical contact between the respective constituent elements in the contact relation between the constituent elements, but also means that other constituent elements are interposed between the constituent elements, Use them as a concept to cover each contact.

It is also to be understood that the terms first, second, etc. used hereinafter are merely reference numerals for distinguishing between identical or corresponding components, and the same or corresponding components are defined by terms such as first, second, no.

The sizes and thicknesses of the respective components shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to those shown in the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a flexible 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, wherein like reference numerals designate like or corresponding components And redundant explanations thereof will be omitted.

1 is a view showing a flexible printed circuit board according to an embodiment of the present invention.

1, a flexible printed circuit board 1000 according to an embodiment of the present invention includes an inner layer substrate portion 100, an outer layer substrate portion 200, and a stacked body 300, 400).

On the other hand, the flexible printed circuit board 1000 according to the present embodiment includes a soft region F and a hard region R. [ In this case, the soft region F is a relatively soft portion in the flexible printed circuit board 1000 according to the present embodiment, and can be deformed relatively flexibly relative to the warp. Such a soft region F may be formed by extending a first insulating layer 110 and an inner layer circuit layer 101 to be described later and the inner layer circuit layer 101 of the soft region F may be formed by a separate cover layer 500). &Lt; / RTI >

On the other hand, one or more outer layer substrate portions 200 are laminated on the innerlayer substrate portion 100 as a portion other than the soft region F as the hard region R to form a build-up layer, The deformation may be relatively restricted.

The inner layer substrate portion 100 is a portion including the soft region F and can form a core in the flexible printed circuit board 1000 according to the present embodiment. In this case, the inner layer substrate unit 100 may be a laminated plate in which a copper thin plate is laminated on at least one surface of a polyimide (PI) -based first insulating layer 110, such as FCCL (FLEXIBLE COPPER CLAD LAMINATE).

The inner layer substrate portion 100 can be formed by processing a copper thin plate laminated on at least one side of the first insulating layer 110 by a method such as exposure and etching. For example, the inner layer circuit layer 101 may be formed by a subtractive process, an additive process, a modified semi-additive process (MSAP), or the like according to a manufacturing process. .

In forming the inner layer circuit layer 101, a through hole 10 plated with an inner wall is formed in the first insulating layer 110 for electrical connection between both surfaces of the first insulating layer 110 to form an interconnection, .

The outer layer substrate portion 200 is a portion to be laminated on the innerlayer substrate portion 100 except for the soft region F and forms a buildup layer in the hard region R. [ In this case, the outer layer substrate unit 200 may be formed of a plurality of layers by repeating a method of applying an adhesive material and pressing the second insulating layer 210 such as a prepreg and the copper thin plate.

The outer layer circuit layer 201 can be formed on the outer layer substrate portion 200 by an etching method using photolithography or an eddy method (plating method). In this case, the outer layer circuit layer 201 may be connected to the outer layer circuit layer 201 and the inner layer circuit layer 101 formed in the other layer through the via 20 or the like passing through the second insulating layer 210, But the present invention is not limited thereto and can be variously modified as needed.

The stacked body 300 is a portion that is stacked on at least one surface of the inner layer substrate 100 corresponding to the soft region F and can perform a shielding function against electromagnetic interference (EMI).

Specifically, the layered structure 300 includes an adhesive layer 310 in which an electric conductor 311 is anisotropically mixed with the inner layer substrate 100 and a polyimide layer 320 laminated on the adhesive layer 310, .

In this case, the conductor 311 is anisotropically disposed in the adhesive layer 310, such as a solder ball made of a metal such as silver (Ag) and palladium (Pd). Accordingly, even if a separate EMI film or the like is not used, the EMI shielding function can be performed only by the stacked body 300 itself.

As described above, the flexible printed circuit board 1000 according to the present embodiment can shield the EMI easily through the stacked body 300, and it is necessary to perform additional processes such as molding and adhesion of the EMI film and the like The productivity of the flexible printed circuit board 1000 can be improved.

Here, the adhesive layer 310 may be formed of an anisotropic conductive film (ACF). Specifically, the anisotropic conductive film is an anisotropic conductive film in which fine conductive particles are mixed with an adhesive resin to form a film state and electricity is conducted in only one direction.

As described above, by using the adhesive layer 310 as an anisotropic conductive film in a film form, the lamination process of the layered product 300 can be performed more easily and effectively.

The electronic module 400 is mounted on the inner layer substrate 100 corresponding to the soft region F and may be a separate modularized electronic device such as an LCD panel. In order to mount the electronic module 400 on the flexible printed circuit board 1000, it is necessary to bond another ACF film to the flexible printed circuit board 1000 after the electronic module 400 is joined to the electronic module 400. [

However, when the adhesive layer 310 is formed of an anisotropic conductive film, the flexible printed circuit board 1000 according to the present embodiment includes the electronic module 400, And a laminating process of a separate ACF film may be omitted.

In the flexible printed circuit board 1000 according to the present embodiment, the polyimide layer 320 is laminated on the adhesive layer 310 such that a part of the adhesive layer 310 is exposed to the outside, (Not shown).

Therefore, when the electronic module 400 is mounted on the flexible printed circuit board 1000, the application of the stacked body 300 is more advantageous in that the manufacturing process of the flexible printed circuit board 1000 according to the present embodiment is further simplified. It can be effective.

Meanwhile, the flexible printed circuit board 1000 according to the present embodiment may further include a coverlay layer 500 and a pad layer 600.

The coverlay layer 500 is a composite film in which a polyimide film is coated with a thermosetting flame retardant epoxy adhesive, and can cover and protect the circuit layers 101 and 201 exposed in the outermost layer.

The pad layer 600 is formed on the outer layer substrate 200 stacked on the hard region R and is electrically connected to the outer layer circuit layer 201 and may be mounted with components such as electronic devices. The pad layer 600 may be connected to the inner layer circuit layer 101 via the via 20 or the like and / or the outer layer circuit layer 201 formed on the other layer.

2 is a flowchart illustrating a method of manufacturing a flexible printed circuit board according to an embodiment of the present invention. 3 to 6 are views showing major steps in a method of manufacturing a flexible printed circuit board according to an embodiment of the present invention.

2 to 6, a method of manufacturing a flexible printed circuit board according to an embodiment of the present invention includes the steps of providing an inner layer substrate portion 100 including a soft region F (S100, FIG. 3 ).

In this case, the inner layer substrate unit 100 may be a laminated plate in which a copper thin plate is laminated on at least one surface of a polyimide (PI) -based first insulating layer 110, such as FCCL (FLEXIBLE COPPER CLAD LAMINATE).

The inner layer substrate portion 100 can be formed by processing a copper thin plate laminated on at least one side of the first insulating layer 110 by a method such as exposure and etching.

Next, the outer layer substrate portion 200 is laminated on the innerlayer substrate portion 100 excluding the soft region F (S200, FIG. 4). In this case, the outer layer substrate unit 200 may be formed of a plurality of layers by repeating a method of applying an adhesive material and pressing the second insulating layer 210 such as a prepreg and the copper thin plate. The outer layer circuit layer 201 can be formed on the outer layer substrate portion 200 by an etching method using photolithography or an eddy method (plating method).

Next, a multilayer body 300 including an adhesive layer 310 which is anisotropically mixed with the inner layer substrate unit 100 and a polyimide layer 320 laminated on the adhesive layer 310 Is laminated on at least one surface of the inner layer substrate portion 100 corresponding to the soft region F (S300, Fig. 5).

As described above, in the method of manufacturing a flexible printed circuit board according to the present embodiment, not only EMI can be easily shielded through the laminate 300, but additional processes such as molding and adhesion of an EMI film and the like need to be performed The productivity of the flexible printed circuit board 1000 can be improved.

The manufacturing method of the flexible printed circuit board according to the present embodiment may further include mounting the electronic module 400 on the inner layer substrate portion 100 corresponding to the soft region F (S400, FIG. 6) .

In order to mount the electronic module 400 on the flexible printed circuit board 1000, a separate ACF film or the like may be laminated on the electronic module 400, It is necessary to bond the flexible printed circuit board 1000 with the flexible printed circuit board 1000.

However, in the method of manufacturing a flexible printed circuit board according to the present embodiment, the adhesive layer 310 is formed on the layered product 300 itself. In particular, when the adhesive layer 310 is formed of an anisotropic conductive film, And a laminating process of a separate ACF film may be omitted.

The polyimide layer 320 is laminated on the adhesive layer 310 such that a part of the adhesive layer 310 is exposed to the outside and the electronic module 400 is laminated on the adhesive layer 310. In this case, (Not shown).

Therefore, when the electronic module 400 is mounted on the flexible printed circuit board 1000, the application of the stacked body 300 may be more effective, for example, the manufacturing method of the flexible printed circuit board according to the present embodiment is simplified. have.

In the meantime, the main configuration of the flexible printed circuit board according to the exemplary embodiment of the present invention has been described in detail with reference to the flexible printed circuit board according to the exemplary embodiment of the present invention. .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

F: soft zone
R: Hard area
10: Through hole
20: Via
100: inner layer substrate portion
101: Inner layer circuit layer
110: first insulating layer
200: outer layer substrate portion
201: outer layer circuit layer
210: second insulating layer
300:
310: adhesive layer
311: conductor
320: polyimide layer
400: electronic module
500: Coverage layer
600: pad layer
1000: Flexible printed circuit board

Claims

An inner layer substrate portion including a soft region;
An outer layer substrate portion laminated on the innerlayer substrate portion except for the soft region; And
And a laminated body laminated on at least one surface of the inner layer substrate portion corresponding to the soft region,
The laminate
An adhesive layer which is anisotropically mixed with the conductive material to be laminated on the inner layer substrate portion, and
And a polyimide layer laminated on the adhesive layer.

The method according to claim 1,
Wherein the adhesive layer is made of an anisotropic conductive film (ACF).

3. The method according to claim 1 or 2,
Wherein the inner layer substrate portion includes a first insulating layer and an inner layer circuit layer formed on at least one surface of the first insulating layer,
Wherein the outer layer substrate portion includes a second insulation layer laminated on the inner layer substrate portion and an outer layer circuit layer formed on the second insulation layer.

3. The method according to claim 1 or 2,
An electronic module mounted on the inner layer substrate portion corresponding to the soft region;
Further comprising a flexible printed circuit board.

5. The method of claim 4,
Wherein the polyimide layer is laminated on the adhesive layer so that a part of the adhesive layer is exposed to the outside,
Wherein the electronic module is bonded to an exposed portion of the adhesive layer.

Providing an inner layer substrate portion including a soft region;
Stacking an outer layer substrate portion on the innerlayer substrate portion except for the soft region; And
Stacking a laminate including an adhesive layer that is anisotropically mixed with a conductive material in the inner layer substrate and a polyimide layer that is laminated on the adhesive layer, on at least one side of the inner layer substrate portion corresponding to the soft region;
Wherein the flexible printed circuit board comprises a flexible printed circuit board.

The method according to claim 6,
Mounting an electronic module on the inner layer substrate portion corresponding to the soft region;
Further comprising the steps of:

8. The method of claim 7,
Wherein the polyimide layer is laminated on the adhesive layer so that a part of the adhesive layer is exposed to the outside,
Wherein the electronic module is bonded to an exposed portion of the adhesive layer.