KR20180058573A - Method for manufacturing circuit board and circuit board manufactured by the method - Google Patents

Abstract

Proposed are a method for manufacturing a printed circuit board capable of minimizing a dielectric loss due to a high frequency signal and preventing a loss of the high frequency signal by stacking a plurality of base sheets in which an adhesive layer and an electrode are formed on a rigid film with a low dielectric constant, and a printed circuit board manufactured thereby. The proposed method for manufacturing a printed circuit board includes the steps of: preparing a base sheet; preparing an adhesive sheet; preparing a flame retardant sheet; and thermally pressurizing and laminating a plurality of base sheets, the adhesive sheet, and the flame retardant sheet. The step of preparing the base sheet includes the steps of: forming a sheet adhesive layer on one side of a rigid polypropylene film; and forming an internal electrode on the other side of the rigid polypropylene film.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board manufacturing method and a printed circuit board manufactured thereby, and more particularly, to a printed circuit board manufacturing method used as a circuit using high frequencies and a printed circuit board manufactured thereby.

Generally, a printed circuit board is a substrate that can be bent flexibly by forming a circuit pattern on a thin insulating film, and is widely used in portable electronic devices and automation devices or display products that require flexibility and flexibility in use.

Generally, a printed circuit board is manufactured by bonding or die casting a copper foil to a polyimide (PI) film. At this time, since the polyimide film has characteristics such as high mechanical strength, heat resistance, insulation, and solvent resistance, it is widely used as a base substrate of a printed circuit board.

On the other hand, as the use of a service for transmitting large amount of information in real time such as video call, movie appreciation, real time relay and the like is increasing, the portable terminal has circuits for transmitting large capacity information using a high frequency band (for example, Respectively.

However, when a high-frequency signal is transmitted using a printed circuit board made of a polyimide film, a signal loss of a high-frequency signal is generated due to inherent dielectric loss of the material.

That is, since the polyimide film has a high dielectric constant, a dielectric loss occurs during transmission and reception of a high frequency signal, and a loss of a high frequency signal occurs thereby causing a problem of interruption in using a service such as video call, movie appreciation, have.

In addition, a printed circuit board fabricated from a film having a low dielectric constant can minimize the loss of high frequency signals, but since the melting temperature is low and the heat resistance is lowered, There is a problem that the surface melts due to the high temperature of about 250 캜 and defects occur.

In addition, since a film having a low dielectric constant and high heat resistance is formed at a high price, the manufacturing cost of the printed circuit board is increased, and the competitive power in the market is lost.

Korean Patent Publication No. 10-2016-0097948 (Name: Flexible Printed Circuit Board and Method for Manufacturing the Same)

Disclosure of Invention Technical Problem [8] The present invention has been proposed in order to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a high- And to provide a printed circuit board manufactured by the method.

That is, the present invention constitutes a base sheet having an adhesive layer and internal electrodes formed on a hard polypropylene (PP) film having a low dielectric constant, a plurality of base sheets are laminated to minimize dielectric loss due to high frequency signals, And a printed circuit board manufactured by the method.

According to an aspect of the present invention, there is provided a method of manufacturing a printed circuit board, including the steps of preparing a base sheet, preparing an adhesive sheet, preparing a flame retardant sheet, Wherein the step of preparing the base sheet includes a step of forming a sheet bonding layer on one side of the hard polypropylene film and a step of forming internal electrodes on the other side of the hard polypropylene film.

Here, the hard polypropylene film may be a material to which nylon is added to CPP (Casted polypropylene).

The step of forming the inner electrode may include forming an inner plating layer on the other surface of the hard polypropylene film through electrolytic plating and etching at least a part of the inner plating layer to form a plurality of mutually spaced inner electrodes.

The step of preparing the base sheet may further include the step of bonding a protective film to the sheet adhesion layer formed on one side of the base sheet.

The step of preparing the adhesive sheet includes forming an upper adhesive layer on one side of the adhesive base film and forming a lower adhesive layer on the other side of the adhesive base film, and the adhesive base film may be a hard polypropylene film.

The step of preparing the flame retardant sheet may include the steps of preparing a flame retardant base film, forming an outer plated layer on one side of the flame retardant base film, and etching the at least a portion of the outer plated layer to form an outer electrode. At this time, the flame retardant base film may be an FR4 film.

The step of laminating comprises laminating a plurality of base sheets, laminating an adhesive sheet on top of the base sheet laminated on the top, laminating a flame retardant sheet on the underside of the base sheet laminated on top and bottom of the adhesive sheet, And laminating the laminated base sheet, the adhesive sheet and the flame-retardant sheet through a heat-pressing process.

A method of manufacturing a printed circuit board according to an embodiment of the present invention includes the steps of forming at least one through hole passing through a laminate in which a plurality of base sheets, an adhesive sheet and a flame retardant sheet are laminated, and forming a connecting plated layer in the inner wall of the through hole As shown in FIG.

According to an aspect of the present invention, there is provided a printed circuit board comprising: a base laminate having a plurality of base sheets laminated; an adhesive sheet formed on the base laminate; a first flame retardant sheet formed on an upper portion of the adhesive sheet; The base sheet includes a rigid polypropylene film, a sheet bonding layer formed on one side of the rigid polypropylene film, and an inner electrode formed on the other side of the rigid polypropylene film. Here, the hard polypropylene film may be a material in which nylon is added to CPP (Casted Polypropylene), and the inner electrode may be a metal material including copper (Cu).

The adhesive sheet may include an adhesive base film, an upper adhesive layer formed on one side of the adhesive base film, and a lower adhesive layer formed on the other side of the adhesive base film, and the adhesive base film may be a hard polypropylene film.

The first flame retardant sheet and the second flame retardant sheet may include a flame retardant base film, external electrodes formed on one side of the flame retardant base film, and the flame retardant base film may be an FR4 film.

A printed circuit board according to an embodiment of the present invention includes at least one through hole passing through a laminated body in which a base laminate, an adhesive sheet, a first flame retardant sheet, and a second flame retardant sheet are laminated and formed on the inner wall of the through hole, And a connection plating layer for connecting the internal electrodes and the external electrodes formed on the first and second flame retardant sheets.

According to the present invention, a printed circuit board manufacturing method and a printed circuit board manufactured by the method are capable of minimizing dielectric loss due to a high frequency signal and preventing loss of a high frequency signal by stacking a plurality of base sheets having a low dielectric constant It is effective.

In addition, the printed circuit board manufacturing method and the printed circuit board manufactured thereby can form a base sheet using a rigid polypropylene film, so that a dielectric constant is lower than that of a conventional printed circuit board constituting a base sheet made of polyimide, It is possible to manufacture a hard type printed circuit board having mechanical strength while minimizing loss.

Also, the printed circuit board manufacturing method and the printed circuit board manufactured thereby can produce a printed circuit board having high heat resistance together with a low dielectric constant by laminating a flame-retardant sheet on the top and bottom of a laminate in which base sheets are laminated It is effective.

1 is a flowchart illustrating a method of manufacturing a printed circuit board according to an embodiment of the present invention;
FIGS. 2 to 5 are diagrams for explaining the base sheet preparing step of FIG. 1; FIG.
6 is a view for explaining the step of preparing the adhesive sheet of Fig. 1;
7 to 9 are views for explaining the flame retardant sheet preparation step of FIG. 1;
Figs. 10 and 11 are diagrams for explaining the laminating step of Fig. 1; Fig.
12 is a view for explaining a through hole forming step of FIG. 1;
13 is a view for explaining the connection plating layer forming step of FIG. 1;
14 is a view for explaining a printed circuit board according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention. . In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Referring to FIG. 1, a printed circuit board manufacturing method includes preparing a base sheet 100 (S100), preparing an adhesive sheet 200 (S200), preparing a flame retardant sheet (S300) (S400) of joining the adhesive sheet 100, the adhesive sheet 200 and the flame retardant sheet, forming the through hole 400 (S500), and forming the connection plating layer 500 (S600) .

Referring to FIG. 2, in step S100 of preparing the base sheet 100, a sheet bonding layer 140 is formed on one side of the base substrate film 120, and an internal electrode 160 is formed on the other side, 100). At this time, the base film is a rigid polypropylene film (hereinafter referred to as a hard PP film) as an example. Here, in step S100 of preparing the base sheet 100, another adhesive layer may be formed between the base substrate film 120 and the internal electrodes 160. [

3 and 4, a step S100 of preparing the base sheet 100 includes a step S110 of preparing a base substrate film 120, a step of forming a sheet bonding layer 120 on the lower surface of the base substrate film 120, A step S150 of forming an inner plating layer 180 on the upper surface of the base substrate film 120 and a step of forming an inner electrode 160 by etching the inner plating layer 180 (S170).

In step S110 of preparing the base substrate film 120, a hard base film 120 having a low dielectric constant and a low dielectric constant is prepared. At this time, the hard PP film may be composed of a CPP (Casted polypropylene) film having a predetermined mechanical strength or a CPP film to which nylon is added, and is formed to have a thickness of about 60 μm.

In the step S130 of forming the sheet bonding layer 140, a sheet bonding layer 140 for bonding to the other base sheet 100 is formed on the lower surface of the base substrate film 120. [ That is, the sheet adhesion layer 140 is formed of a composite material in which a polyimide or polypropylene similar to the hard PP film is mixed with an additive (for example, acrylade) in order to increase the adhesive force with the polymer and the metal.

In detail, since the printed circuit board is constituted by stacking a plurality of base sheets 100, the sheet adhesive layer 140 is formed by stacking the inner electrodes 160 (that is, copper) exposed on the upper surface of the other base sheet 100 And a base substrate film 120. The base substrate film 120 is made of a metal.

Accordingly, the sheet adhesion layer 140 is formed of a composite material in which additives such as polyimide and acrylate are mixed to increase the adhesive strength between the internal electrode 160, which is a metallic material, and the base substrate film 120, which is a polymer material.

In step S150 of forming the inner plating layer 180, an inner plating layer 180 is formed on the base substrate film 120. [ At this time, the inner plating layer 180 is formed (S150) by electrolytically plating copper (Cu) to form an inner plating layer 180 on the base substrate film 120. Here, the inner plating layer 180 is an element constituting the inner electrode 160, and is formed to have a thickness of approximately 3 mu m.

In the step of forming the internal electrode 160 (S170), a part of the internal plating layer 180 is removed through an etching (etching) process to form the internal electrode 160 on the base substrate film 120.

5, step S100 of preparing the base sheet 100 includes forming an inner thin film seed layer on the base substrate film 120 before forming the inner plating layer 180 (S150) (S140). That is, in step S140 of forming the inner thin film seed layer, an inner thin film seed layer is formed on the upper surface of the base substrate film 120 through a deposition process or a sputtering process. At this time, in step S150 of forming the inner plating layer 180, copper (Cu) is plated on the inner thin film seed layer to form an inner plating layer 180 on the inner thin film seed layer.

In step S100 of preparing the base sheet 100, a protective film may be laminated on the sheet adhesion layer 140 formed on one side of the finished base sheet 100. [ At this time, the protective film is a release paper, PETPolyethylene phthalate, for example, and is formed to have a thickness of about 75 mu m.

In step S200 of preparing the adhesive sheet 200, an adhesive layer is formed on both sides of the adhesive base film 220. [ Referring to FIG. 6, in step S200 of preparing the adhesive sheet 200, a lower adhesive layer 260 for bonding with the base material stacked on the uppermost layer is formed on the lower side of the adhesive base film 220. [ In step S200 of preparing the adhesive sheet 200, an upper adhesive layer 240 is formed on the adhesive base film 220 for adhesion with the flame-retardant sheet.

In preparing the flame retardant sheet (S300), the external electrodes 360 are formed on one side of the flame retardant base film 320 having the flame retardancy and the low dielectric constant to prepare the flame retardant sheet.

7 and 8, a step S300 of preparing a flame-retardant sheet includes a step S320 of preparing a flame-retardant base film 320, an outer plating layer 340 on one surface of the flame- (S340), and forming an external electrode 360 (S360).

In preparing the flame retardant base film 320 (S320), a flame retardant base film 320 having a flame retardance and a low dielectric constant is prepared. At this time, the flame retardant base film 320 is an FR4 film as an example. Here, the FR4 film is a composite material of a woven fiberglass cloth and an epoxy resin binder and is formed of a material having high mechanical angle, flame retardancy and low dielectric constant, .

In step S340 of forming the outer plating layer 340, an outer plating layer 340 is formed on the flame-retardant base film 320. [ At this time, the outer electrode 360 is formed (S340) by electrolytically plating copper (Cu) to form an outer plating layer 340 on the flame-retardant base film 320. [ Here, the outer plating layer 340 is an element constituting the outer electrode 360, and is formed to a thickness of about 10 mu m.

The outer electrode 360 is formed in step S360 by removing a part of the outer plating layer 340 through an etching process to form the outer electrode 360 on the flame retardant base film 320. [

9, step S300 of preparing a flame-retardant sheet includes forming an outer thin-film seed layer on the flame-retardant base film 320 (S330) before forming the outer plating layer 340 (S340) As shown in FIG. That is, in step S350 of forming the outer thin film seed layer, an outer thin film seed layer is formed on the upper surface of the flame-retarded substrate film 320 through a deposition process or a sputtering process. At this time, in step S340 of forming the outer plating layer 340, copper (Cu) is plated on the outer thin film seed layer to form an outer plating layer 340 on the outer thin film seed layer.

10, the step (S400) of laminating the base sheet 100, the adhesive sheet 200 and the flame-retardant sheet is performed by stacking the adhesive sheet 200 on the laminated body obtained by laminating the plurality of base sheets 100 The base sheet 100, the adhesive sheet 200 and the flame-retardant sheet are laminated by laminating a flame-retardant sheet on the top of the adhesive sheet 200 and the bottom of the laminate.

11, the laminating step S400 includes a step S420 of laminating a plurality of base sheets 100, a step S440 of laminating the adhesive sheet 200, a step of laminating the flame- (S460) and a hot pressing step S480.

In the step S420 of stacking the plurality of base sheets 100, a plurality of base sheets 100 are laminated. At this time, the plurality of base sheets 100 are laminated by bonding an adhesive layer formed on the lower part of the base sheet 100 to the upper part of the other base sheet 100, in step S420 of stacking the plurality of base sheets 100. [

In the step S440 of laminating the adhesive sheet 200, the adhesive sheet 200 is laminated on the upper side of the laminate in which the plurality of base sheets 100 are laminated. That is, in the step S440 of laminating the adhesive sheets 200, the adhesive sheet 200 is laminated by bonding the lower surface of the adhesive sheet 200 to the upper portion of the base sheet 100 laminated on the uppermost portion of the laminate.

In the step S460 of laminating the flame-retardant sheet, the flame-retardant sheet is laminated on the upper and lower portions of the laminate in which the plurality of base sheets 100 and the adhesive sheet 200 are laminated. That is, in the step of laminating the flame-retardant sheet (S460), the lower portion of the flame-retardant sheet is bonded to the upper portion of the adhesive sheet 200 laminated on the uppermost portion of the laminate. The step of laminating the flame retardant sheet (S460) bonds the adhesive layer of the base sheet 100 laminated on the lowermost portion of the laminate to the lower portion of the other flame retardant sheet. In the step S460 of stacking the flame-retardant sheets, the internal electrodes 160 formed on the plurality of base sheets 100 and the external electrodes 360 formed on the flame-retardant sheet are adjusted so that the flame- Align).

The hot pressing step S480 bonds the plurality of base sheets 100, the adhesive sheet 200 and the flame-retardant sheet through a heat-pressurizing (i.e., hot pressing) process. That is, in the hot pressing step S480, the adhesive (i.e., the sheet adhesive layer 140, the upper adhesive layer 240 and the lower adhesive layer 260) melts and presses the plurality of base sheets 100, the adhesive sheet 200, And the flame retardant sheet.

Since the base sheet 100 and the adhesive sheet 200 are made of a PP film having a melting temperature of about 165 DEG C and the flame retardant sheet is composed of FR4 film having a melting temperature of about 120 DEG C, Step S480 heats the base sheet 100, the adhesive sheet 200 and the flame-retardant sheet by heating to a temperature of about 120 ° C to 165 ° C.

12, forming the through hole 400 (S500) may include forming at least one through hole 400 through the base sheet 100, the adhesive sheet 200, and the laminate in which the flame retardant sheet is stacked do. That is, the step S500 of forming the through hole 400 may include one or more through holes (not shown) for electrically connecting (i.e., energizing) the internal electrode 160 and the external electrode 360 of the stack through a punching process Thereby forming a hole 400.

Referring to FIG. 13, forming a connecting plating layer 500 (S600) forms a connecting plating layer 500 on the inner wall of the through hole 400. Referring to FIG. That is, the step of forming the connection plating layer 500 (S600) may include forming a connection plating layer (not shown) for electrically connecting (i.e., energizing) the internal electrode 160 and the external electrode 360 to the inner wall of the through- (500). At this time, the connection plating layer 500 may be formed on the uppermost and lowermost portions of the flame-retardant sheet in the step S600 of forming the connection plating layer 500. [

14, a printed circuit board manufactured by a printed circuit board manufacturing method includes a base laminate 600, an adhesive sheet 200, a first flame retardant sheet, a second flame retardant sheet, a through hole 400, (500).

The base laminate 600 is formed by stacking a plurality of base sheets 100. The base sheet 100 includes a base substrate film 120, internal electrodes 160 formed on one surface of the base substrate film 120, and a sheet adhesion layer 140 formed on the other surface of the base substrate film 120.

The base substrate film 120 is made of a hard PP film having a low dielectric constant, and can be formed to a thickness of about 60 占 퐉.

The internal electrode 160 is formed of a metal material containing copper (Cu), and is formed to a thickness of about 3 mu m.

The sheet adhesion layer 140 is formed of a composite material in which a polyimide or polypropylene similar to a hard PP film is mixed with an additive (e.g., acrylate) in order to increase the adhesive force with the polymer and the metal.

The adhesive sheet 200 is stacked on top of the base laminate 600. The adhesive sheet 200 is composed of an adhesive base film 220, an upper adhesive layer 240 formed on one side of the adhesive base film 220 and a lower adhesive layer 260 formed on the other side of the adhesive base film 220.

Here, the adhesive base film 220 is made of a hard PP film. The upper adhesive layer 240 and the lower adhesive layer 260 are formed of a composite material in which a polyimide or polypropylene similar to the hard PP film is mixed with an additive (e.g., acrylate).

The first flame retardant sheet is laminated on top of the adhesive sheet 200 and the second flame retardant sheet is laminated on the bottom of the base laminate 600. The first flame retardant sheet and the second flame retardant sheet are composed of a flame retardant base film 320 and external electrodes 360 formed on one surface of the flame retardant base film 320.

Here, the flame-retarded base film 320 may be a FR4 film having a flame retardancy and a low dielectric constant, and is formed to a thickness of about 100 mu m. The external electrode 360 is formed of a metal material containing copper (Cu), and is formed to a thickness of about 10 mu m.

The through hole 400 is formed through a laminate in which a base sheet 100, an adhesive sheet 200 and a flame retardant sheet are laminated. A connection plating layer 500 is formed on the inner wall of the through hole 400 to electrically connect (i.e., energize) the internal terminal of the base sheet 100 and the external terminal of the flame retardant sheet.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but many variations and modifications may be made without departing from the scope of the present invention. It will be understood that the invention may be practiced.

100: base sheet 120: base substrate film
140: sheet bonding layer 160: internal electrode
180: inner plated layer 200: adhesive sheet
220: adhesive base film 240: upper adhesive layer
260: lower adhesive layer 300: flame retardant film
320: a flame retardant base film 340: an outer plating layer
360: external electrode 400: through hole
500: connection plated layer 600: base laminate

Claims (17)

Preparing a base sheet;
Preparing an adhesive sheet;
Preparing a flame retardant sheet; And
Heating and pressing the plurality of base sheets, the adhesive sheet and the flame-retardant sheet,
The step of preparing the base sheet may include:
Forming a sheet adhesion layer on one side of the rigid polypropylene film; And
And forming an inner electrode on the other surface of the hard polypropylene film. The method according to claim 1,
Wherein the hard polypropylene film is a material in which nylon is added to CPP (Casted Polypropylene). The method according to claim 1,
Wherein forming the internal electrode includes:
Forming an inner plating layer on the other surface of the hard polypropylene film through electrolytic plating; And
And etching at least a portion of the inner plated layer to form a plurality of spaced inner electrodes. The method according to claim 1,
The step of preparing the base sheet may include:
And bonding a protective film to the sheet adhesive layer formed on one side of the base sheet. The method according to claim 1,
Wherein the step of preparing the adhesive sheet comprises:
Forming an upper adhesive layer on one side of the adhesive base film; And
And forming a lower adhesive layer on the other surface of the adhesive base film,
Wherein the adhesive base film is a hard polypropylene film. The method according to claim 1,
The step of preparing the flame-
Preparing a flame retardant base film;
Forming an outer plating layer on one side of the flame-retardant base film; And
And etching at least a part of the outer plating layer to form an outer electrode. The method according to claim 6,
Wherein the flame retardant base film is an FR4 film. The method according to claim 1,
Wherein the lapping step comprises:
Stacking a plurality of base sheets;
Stacking an adhesive sheet on top of the base sheet laminated on the top;
Stacking a flame-retardant sheet on a lower portion of the base sheet stacked on top and bottom of the adhesive sheet; And
And laminating the laminated base sheet, the adhesive sheet and the flame retardant sheet through a heat pressing process. The method according to claim 1,
Further comprising the step of forming at least one through hole passing through a laminate in which a plurality of base sheets, an adhesive sheet and a flame retardant sheet are laminated together. 10. The method of claim 9,
And forming a connection plating layer on the inner wall of the through hole. A base laminate in which a plurality of base sheets are laminated;
An adhesive sheet formed on the base laminate;
A first flame retardant sheet formed on the adhesive sheet; And
And a second flame retardant sheet formed on a lower portion of the base laminate,
Wherein the base sheet comprises:
Hard polypropylene film;
A sheet bonding layer formed on one side of the rigid polypropylene film; And
And an inner electrode formed on the other surface of the hard polypropylene film. 12. The method of claim 11,
Wherein the hard polypropylene film is a material in which nylon is added to CPP (Casted Polypropylene). 12. The method of claim 11,
Wherein the internal electrode is made of a metal material including copper (Cu). 12. The method of claim 11,
The above-
Adhesive base film;
An upper adhesive layer formed on one surface of the adhesive base film; And
And a lower adhesive layer formed on the other surface of the adhesive base film,
Wherein the adhesive base film is a rigid polypropylene film. 12. The method of claim 11,
The first flame retardant sheet and the second flame-
A flame retardant substrate film;
And an external electrode formed on one surface of the flame retardant base film,
Wherein the flame retardant base film is an FR4 film. 12. The method of claim 11,
Further comprising at least one through hole passing through the laminated body of the base laminate, the adhesive sheet, the first flame retardant sheet and the second flame retardant sheet. 17. The method of claim 16,
And a connection plating layer formed on an inner wall of the through hole to connect internal electrodes formed on the base sheet and external electrodes formed on the first and second flame retardant sheets.

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