CN104244570A - Rigid-flex printed circuit board and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a rigid-flex printed circuit board manufactured by laminating at least two or more bottom substrates having circuit layers on both surfaces thereof, and a method for manufacturing the same, and the rigid-flex printed circuit board The circuit board includes rigid areas in which rigid insulating layers are respectively laminated on both surfaces of the base substrate and flexible areas in which cover layers are respectively laminated on portions of both surfaces of the base substrate on which the rigid insulating layers are not laminated. , wherein the surface roughness is formed on one surface of the covering layers laminated to be in contact with each other among the covering layers.

Description

Rigid-flex printed circuit board and manufacturing method thereof

Cross References to Related Applications

Claim and combine the following domestic priority application and foreign priority application by way of reference:

"Cross References to Related Applications

This application claims the benefit of Korean Patent Application No. 10-2013-0071604 filed on June 21, 2013, the entire contents of which are hereby incorporated by reference into this application. "

technical field

The present invention relates to a rigid flexible printed circuit board and a manufacturing method thereof, and more particularly, to a rigid flexible printed circuit board in which a base substrate is laminated in multiple layers and a manufacturing method thereof. the

Background technique

In general, a printed circuit board (PCB) is a circuit board that serves to electrically connect or mechanically fix predetermined electronic components and includes an insulating layer made of an insulating material such as phenolic resin or epoxy resin and bonded to the insulating layer to A copper foil layer on which a predetermined wiring pattern is formed. the

Here, PCBs can be classified into three types: single-sided PCBs, in which wiring patterns are formed on only one surface of an insulating layer; double-sided PCBs, in which wiring patterns are formed on both surfaces of an insulating layer; and multilayer PCBs, in which other A plurality of insulating layers having wiring patterns thereon are laminated to form the wiring patterns in the plurality of layers. the

Recently, due to the miniaturization, thickness reduction, and high density of electronic products, multilayer printed circuit boards, especially rigid-flexible printed circuit boards (RFPCBs) with flexibility, have become the focus of attention in the PCB market, and interest in this market Still increasing. the

This RFPCB is a technology that combines existing multilayer PCB technology with flexible PCB technology, and has been widely used in devices requiring high-density circuit design (such as notebooks, digital cameras, video cameras, and mobile communication terminals), which This is because it realizes three-dimensional wiring and can be easily assembled. Multi-layer PCB or flexible PCB has problems of space, connection reliability, and component mounting due to the use of independent connectors, while RFPCB can overcome these problems and perform the function of component mounting board and the function of interface at the same time. the

Here, the RFPCB includes a flexible area (where circuit patterns are formed on a flexible polyester or polyimide film) and a rigid area (where an insulating layer is laminated on the flexible film to increase physical rigidity). the

The RFPCB is fabricated by selectively laminating a rigid insulating layer on a double-sided flexible copper-clad laminate (with copper foil on both surfaces) to form a rigid substrate portion laminated with a rigid insulating layer and an un A flexible substrate portion laminated with a rigid insulating layer, and a circuit pattern is formed on the flexible film and the rigid insulating layer. the

However, a conventional RFPCB is formed by repeating the process of applying a cover layer and laminating an insulating layer after forming a circuit pattern on both surfaces of a flexible copper clad laminate and laminating a single-sided flexible copper clad laminate with copper foil on one surface thereof. The process of laminating and forming the circuit pattern is manufactured, but due to the repetition of the lamination process and the circuit pattern forming process, an excessive lamination load occurs and increases the lead time and manufacturing cost. the

[Prior Art Literature]

[Patent Document]

Patent Document 1: Korean Patent Laid-Open Publication No. 2010-0079336

Patent Document 2: Korean Patent Laid-Open Publication No. 2011-0045991

Contents of the invention

The present invention has been devised in order to overcome the above-mentioned problems, and thus an object of the present invention is to provide a rigid-flex printed circuit board that can reduce lamination load, simplify manufacturing process, and reduce manufacturing cost. the

Furthermore, another object of the present invention is to prevent adhesion between surfaces of cover layers laminated to be in contact with each other. the

The rigid-flex printed circuit board according to the first embodiment of the present invention to achieve the object is manufactured by laminating at least two or more base substrates having circuit layers on both surfaces thereof, and includes wherein respectively Rigid regions in which rigid insulating layers are laminated on both surfaces of the base substrate and flexible regions in which cover layers are respectively laminated on portions of both surfaces of the base substrate not laminated with rigid insulating layers, wherein Surface roughness is formed on one surface of the covering layers laminated to be in contact with each other. the

Here, the ones of the cover layers laminated so as to be in contact with each other may include an inorganic filler. the

The rigid-flex printed circuit board according to the second embodiment of the present invention may further include a surface roughness layer provided between the cover layers laminated to be in contact with each other among the cover layers. the

Here, the rough surface layer may be formed in the shape of a film. the

At this time, the rough surface layer may include an inorganic filler. the

The method of manufacturing a rigid-flex printed circuit board according to the first embodiment of the present invention to achieve said object includes the steps of: preparing at least two or more base substrates having circuit layers on both surfaces thereof; laminating a cover layer on the flexible area and an insulating layer on the rigid area; laminating the bottom substrate; and pressing the laminated bottom substrate. the

Here, the method of manufacturing a rigid-flex printed circuit board may include a step of forming an outer circuit layer on an outermost rigid insulating layer of the laminated base substrate after the step of pressing the laminated base substrate. the

At this time, surface roughness may be formed on one surface of the covering layers laminated so as to be in contact with each other among the covering layers. the

In addition, one of the covering layers laminated so as to be in contact with each other may include an inorganic filler. the

The method of manufacturing the rigid-flex printed circuit board according to the second embodiment of the present invention may further include a step of inserting a surface roughness layer between ones of the cover layers laminated to be in contact with each other after the step of preparing the base substrate. the

Here, the rough surface layer may include an inorganic filler. the

Description of drawings

These and/or other aspects and advantages of the general inventive concept of the present invention will become apparent and easier to recognize through the following description of the embodiments in conjunction with the accompanying drawings, in which:

1 and 2 are sectional views showing a rigid-flex printed circuit board according to a first embodiment of the present invention;

3A and 3B are pictures showing the surface of the cover layer according to the first embodiment of the present invention;

4 is a sectional view showing a rigid-flex printed circuit board according to a second embodiment of the present invention; and

5A to 5E are cross-sectional views illustrating a method of manufacturing the rigid-flex printed circuit board according to the first embodiment of the present invention. the

Detailed ways

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiments merely illustrate the present invention, and the present invention is not limited to the following embodiments. the

In describing the present invention, specific descriptions of well-known techniques are omitted so as not to unnecessarily obscure the embodiments of the invention. The following terms are defined in consideration of the functions of the present invention, and may be changed according to user's or operator's intention or custom. Therefore, these terms should be defined based on the contents described throughout this specification. the

The technical spirit of the present invention should be defined by the appended claims, and the following embodiments are provided by way of examples to effectively convey the technical spirit of the present invention to those skilled in the art. the

1 and 2 are cross-sectional views showing a rigid-flex printed circuit board according to a first embodiment of the present invention. the

As shown in FIG. 1, the rigid-flex printed circuit board according to the first embodiment of the present invention is composed of a rigid region R and a flexible region F, and includes two or more laminated bottom substrates 110, 120, and 130. And an outer circuit layer 140 formed on the outer sides of the laminated base substrates 110, 120, and 130 having circuit layers 112, 122, and 132 on both surfaces thereof, respectively. the

At this time, the rigid-flex printed circuit board according to the present invention may be composed of eight layers by laminating the first bottom layer having the first circuit layer 112, the second circuit layer 122, and the third circuit layer 132 respectively thereon. The substrate 110 , the second base substrate 120 and the third base substrate 130 and two outer circuit layers 140 are formed. the

Here, the rigid region R and the flexible region F are not clearly distinguished from each other, but are regions arbitrarily designed in manufacturing. the

At this time, as for the difference between the rigid region R and the flexible region F, the rigid region R may be a region where the first rigid insulating layer 113, the second rigid insulating layer 123, and the third rigid insulating layer 133 are laminated, and the flexible Region F may be a region where the first cover layer 114, the second cover layer 124, and the third cover layer 134 are laminated. the

The first bottom substrate 110, the second bottom substrate 120, and the third bottom substrate 130 may be formed by forming copper foil layers on both surfaces of the first flexible film 111, the second flexible film 121, and the third flexible film 131, respectively. And the formed flexible copper clad laminate. the

Here, the first flexible film 111, the second flexible film 121, and the third flexible film 131 may be made of a resin material having flexibility. For example, polyimide resin materials such as polyimide resins, polyetherimide resins, and polyamideimide resins, polyamide resin materials, or polyester resins may be used. In particular, polyimide resin materials are preferably used. In addition, the copper foil layers formed on both surfaces of the flexible film may be patterned through exposure, development, and etching processes to form the first circuit layer 112 , the second circuit layer 122 , and the third circuit layer 132 . the

The first rigid insulating layer 113, the second rigid insulating layer 123, and the third rigid insulating layer 133 can be laminated in the rigid region R and the first covering layer 114, the second covering layer 124, and the second covering layer 114 can be laminated in the flexible region F. Three cover layers 134 are used to form the first bottom substrate 110, the second bottom substrate 120, and the third bottom substrate 130, so as to protect two flexible films respectively located on the first flexible film 111, the second flexible film 121, and the third flexible film 131. The first circuit layer 112, the second circuit layer 122, and the third circuit layer 132 on the surface. Here, the first cover layer 114, the second cover layer 124, and the third cover layer 134 may be made of polyimide. the

Meanwhile, since the first base substrate 110 , the second base substrate 120 , and the third base substrate 130 are laminated, there are contact portions between the first cover layer 114 , the second cover layer 124 , and the third cover layer 134 . the

Here, surface roughness may be formed on contact surfaces between the first covering layer 114, the second covering layer 124, and the third covering layer 134 to prevent the first covering layer 114, the second covering layer 124, and the third covering layer from Adhesion between cover layers 134 . At this time, the first covering layer 114, the second covering layer 124, and the third covering layer 134 having surface roughness may include an inorganic filler. Surface roughness may be formed on contact surfaces between the first covering layer 114, the second covering layer 124, and the third covering layer 134 due to the accumulation of the inorganic filler on the surface. the

At this time, the inorganic filler may be carbon, and contained in an amount of 9.87% to form an appropriate surface roughness. the

In particular, the inorganic filler is preferably included in only one layer among the first cover layer 114 , the second cover layer 124 , and the third cover layer 134 that are in contact with each other to reduce lead-time and manufacturing costs. Here, since the inorganic filler is included only in the second cover layer 124 of the second base substrate 120 and then formed on the top and bottom surfaces of the second cover layer 124 in contact with the first cover layer 114 and the third cover layer 134 The surface roughness thus prevents adhesion between the first cover layer 114 , the second cover layer 124 , and the third cover layer 134 . the

In addition, as shown in FIG. 2 , the inorganic filler may include only the first cover layer 114 formed on the bottom surface of the first flexible film 111 of the first bottom substrate 110 and the third flexible film formed on the third bottom substrate 130. 131 in the third covering layer 134 on the top surface. That is, since the inorganic filler includes only the first cover layer 114 formed on the bottom surface of the first flexible film 111 in contact with the second cover layer 124 of the second base substrate 120 and the top surface of the third flexible film 131 Surface roughness is formed in the third covering layer 134 on the surface, thereby preventing adhesion among the first covering layer 114 , the second covering layer 124 , and the third covering layer 134 . the

Meanwhile, as shown in FIGS. 3a and 3b, carbon may accumulate on the surface of the covering layer 124 or on the surface of the first covering layer 114 formed on the bottom surface of the first flexible film 111 and on the surface of the third flexible film 111. On the surface of the third covering layer 134 on the top surface of the flexible film 131 to form surface roughness, and preferably the carbon accumulated on the surface has a size of 150nm to 500nm to effectively prevent the first covering layer 114, the second Adhesion between cover layer 124 and third cover layer 134 . the

That is, since the inorganic filler is included in the covering layer 124 or is included in the first covering layer 114 formed on the bottom surface of the first flexible film 111 and the third covering layer 134 formed on the top surface of the third flexible film 131 In order to form surface roughness on the surface, an air gap may be formed between the first covering layer 114 , the second covering layer 124 , and the third covering layer 134 that are in contact with each other. the

Therefore, in the prior art, since the first covering layer 114, the second covering layer 124, and the third covering layer 134 are adhered to each other, the flexible region F will be damaged when the flexible region F is bent, but in this In the invention, when the flexible region F bends, it can prevent the adhesion between the first covering layer 114, the second covering layer 124, and the third covering layer 134 and prevent the adhesion between the first covering layer 114, the second covering layer 124, and the third covering layer 134. An air gap is formed between the three cover layers 134 to prevent damage. the

Meanwhile, an outer circuit layer 140 may be formed on outer sides of the first bottom substrate 110 , the second bottom substrate 120 , and the third bottom substrate 130 . the

Here, the outer circuit layer 140 may be formed on the top of the rigid insulating layer 113 of the first bottom substrate 110 and the bottom of the rigid insulating layer 133 of the third bottom substrate 130 . At this time, the copper foil layer may be formed on the top of the rigid insulating layer 113 of the first bottom substrate 110 and the bottom of the rigid insulating layer 133 of the third bottom substrate 130 by casting, laminating, or sputtering and patterned to An outer circuit layer 140 is formed. In addition, vias may be formed to electrically connect the outer circuit layer 140 with the circuit layer 112 of the first bottom substrate 110 or to electrically connect the outer circuit layer 140 with the circuit layer 132 of the third bottom substrate 130 . the

4 is a sectional view showing a rigid-flex printed circuit board according to a second embodiment of the present invention. the

As shown in FIG. 4, the rigid-flex printed circuit board according to the second embodiment of the present invention includes a rigid region R and a flexible region F, and consists of a first bottom substrate 110, a second bottom substrate 120, and a third bottom substrate 130, and an outer circuit layer 140 formed on the outer sides of the first bottom substrate 110 and the third bottom substrate 130, the first bottom substrate, the second bottom substrate, and the third bottom substrate have first circuit layers respectively located on two surfaces 112, the second circuit layer 122, and the third circuit layer 132, the first cover layer 114, the second cover layer 124, and the third cover layer 134, and the first rigid insulating layer 113, the second rigid insulating layer 123, and The third rigid insulating layer 133 . the

Other components are the same as those of the rigid-flex printed circuit board according to the first embodiment described above. Hereinafter, only components different from those of the rigid-flex printed circuit board according to the first embodiment will be described in detail. the

The rigid-flex printed circuit board according to the second embodiment of the present invention further includes a rough surface layer 150 interposed between the first cover layer 114 , the second cover layer 124 , and the third cover layer 134 . the

Here, the rough surface layer 150 may include an inorganic filler. Surface roughness is formed on the surface of the rough surface layer 150 due to the accumulation of inorganic fillers on the surface of the rough surface layer. the

In addition, the rough surface layer 150 may be formed in a film shape to efficiently perform a manufacturing process. the

That is, the rough surface layer 150 is interposed between the cover layer 114 of the first base substrate 110 and the cover layer 124 of the second base substrate 120 and between the cover layer 124 of the second base substrate 120 and the cover layer 134 of the third base substrate 130 Between them, an air gap can be formed between the first cover layer 114, the second cover layer 124, and the third cover layer 134 that are laminated to be in contact with each other, and can prevent the flexible area F from being 114 , the second cover layer 124 , and the third cover layer 134 cause damage due to adhesion. the

5a to 5e are cross-sectional views illustrating a method of manufacturing the rigid-flex printed circuit board according to the first embodiment of the present invention. the

As shown in FIG. 5a, in the rigid-flex printed circuit board according to the first embodiment of the present invention, a circuit board having a first circuit layer 112, a second circuit layer 122, and a third circuit layer 132 on both surfaces thereof is prepared. At least two or more bottom substrates 110 , 120 , and 130 . the

Here, the base substrates 110 , 120 , and 130 may be divided into a first base substrate 110 , a second base substrate 120 , and a third base substrate 130 . the

First, a flexible copper clad laminate having copper foil layers on both surfaces of the first flexible film 111, the second flexible film 121, and the third flexible film 131 is prepared, and formed on the first flexible film 111, the second flexible film The copper foil layers on both surfaces of the flexible film 121 and the third flexible film 131 are patterned by exposure, development and etching processes to form the first circuit layer 112 , the second circuit layer 122 and the third circuit layer 132 . the

Then, as shown in FIG. Two covering layers 124 and a third covering layer 134 are used to manufacture the first bottom substrate 110, the second bottom substrate 120, and the third bottom substrate 130, so as to protect the corresponding first flexible film 111, the second flexible film 121, and the first circuit layer 112 , the second circuit layer 122 , and the third circuit layer 132 on both surfaces of the third flexible film 131 . the

At this time, the second base substrate 120 is laminated between the first base substrate 110 and the third base substrate 130 in a subsequent process, and is subjected to mutual influence by the first cover layer 114 , the second cover layer 124 , and the third cover layer 134 . touch. the

Therefore, in order to prevent adhesion between the first cover layer 114, the second cover layer 124, and the third cover layer 134, the cover layer 124 of the second base substrate 120 may be impregnated with an inorganic filler. Since the inorganic filler gathers on the surface to form surface roughness on the surface of the cover layer 124 of the second base substrate 120, the friction between the first cover layer 114, the second cover layer 124, and the third cover layer 134 can be prevented. Adhesion. the

Then, as shown in FIG. 5c, the first bottom substrate 110, the second bottom substrate 120, and the third bottom substrate 130 are laminated. the

Then, as shown in FIG. 5d, the laminated first bottom substrate 110, second bottom substrate 120, and third bottom substrate 130 are pressed. the

Thereafter, as shown in FIG. 5e , an outer circuit layer 140 is formed on the top of the first bottom substrate 110 and the bottom of the third bottom substrate 130 . the

Here, a copper foil layer may be formed by casting, lamination, sputtering, etc. The copper foil layer is patterned to form the outer circuit layer 140 . the

In addition, via holes may be formed to electrically connect the outer circuit layer 140 with the first circuit layer 112 of the first bottom substrate 110 or to electrically connect the outer circuit layer 140 with the third circuit layer 132 of the third bottom substrate 130 . the

That is, in the rigid-flex printed circuit board according to the first embodiment of the present invention, by laminating the first base substrate 110 having the circuit layers 112, 122, and 132 on both surfaces thereof, the second base substrate 120, and The third bottom substrate 130 and only pressing the laminated bottom substrate once to manufacture the rigid-flex printed circuit board can reduce the lamination load caused by repeated lamination in the prior art. In addition, lead-time and manufacturing costs can be reduced by simplifying the manufacturing process. the

As described above, the rigid-flex printed circuit board and its manufacturing method according to embodiments of the present invention can simplify the manufacturing method by laminating the base substrate having circuit layers on both surfaces thereof, thereby reducing production lead time and manufacturing cost. the

In addition, adhesion between cover layers laminated to be in contact with each other can be prevented by including an inorganic filler in the cover layer laminated in the flexible region of the rigid-flex printed circuit board to form surface roughness on the surface of the cover layer. attached to prevent damage to the flex area when the rigid-flex PCB is bent. the

Although the invention has been described in detail with reference to preferred embodiments, those skilled in the art will recognize that various modifications can be made to these embodiments without departing from the scope of the invention. the

Accordingly, the scope of the present invention should not be limited to the described embodiments, but is defined by the appended claims and their equivalents. the

Claims (11)

1. A rigid-flex printed circuit board in which at least two or more base substrates are laminated, the base substrate has circuit layers on both surfaces thereof, and the rigid-flex printed circuit board The circuit board includes: a rigid region in which rigid insulating layers are respectively laminated on both surfaces of the base substrate; and a flexible area in which cover layers are respectively laminated on portions of both surfaces of the base substrate not laminated with the rigid insulating layer, wherein the covered layers are laminated Surface roughness is formed on one surface of the cover layers that are in contact with each other. 2. The rigid-flex printed circuit board according to claim 1, wherein one of the cover layers laminated so as to be in contact with each other includes an inorganic filler. 3. The rigid-flexible printed circuit board according to claim 1, further comprising: A rough surface layer is provided between the covering layers laminated so as to be in contact with each other among the covering layers. 4. The rigid-flex printed circuit board according to claim 3, wherein the rough surface layer is formed in a film shape. 5. The rigid-flex printed circuit board according to claim 3, wherein the rough surface layer includes an inorganic filler. 6. A method of manufacturing a rigid-flex printed circuit board, comprising: preparing at least two or more base substrates having circuit layers on both surfaces thereof; laminating a cover layer on the flexible area of the base substrate and an insulating layer on the rigid area; laminating the base substrate; and The laminated bottom substrate is pressed. 7. The method of manufacturing a rigid-flex printed circuit board according to claim 6, comprising: after pressing the laminated bottom substrate, forming outer circuit layer. 8. The method of manufacturing a rigid-flex printed circuit board according to claim 6, wherein surface roughness is formed on one surface of the cover layers laminated to be in contact with each other among the cover layers. 9. The method of manufacturing a rigid-flex printed circuit board according to claim 6, wherein one of the covering layers laminated so as to be in contact with each other includes an inorganic filler. 10. The method of manufacturing a rigid-flex printed circuit board according to claim 6, further comprising: after preparing the base substrate, inserting surface roughness between the cover layers laminated to be in contact with each other among the cover layers layer. 11. The method of manufacturing a rigid-flex printed circuit board according to claim 10, wherein the rough surface layer includes an inorganic filler.