KR102612304B1 - Printed circuit board and antenna module - Google Patents

Abstract

A printed circuit board according to an embodiment includes: a first board; a first circuit pattern disposed on the first substrate; a second substrate on the first substrate; a second circuit pattern disposed on the second substrate; and a printed circuit board including an adhesive layer between the first substrate and the second substrate, wherein the glass transition temperatures of the first substrate, the first circuit pattern, and the adhesive layer are different from each other, and the printed circuit board includes the printed circuit board. A bending area where the circuit board is bent in one direction is defined, and the printed circuit board includes a hole formed in the bending area.

Description

Printed circuit board and antenna module including same {PRINTED CIRCUIT BOARD AND ANTENNA MODULE}

The embodiment relates to a printed circuit board and an antenna module including the same.

Recently, efforts have been made to develop improved 5G (5th generation) communication systems or pre-5G communication systems to meet the demand for wireless data traffic.

To achieve high data rates, 5G communication systems use ultra-high frequency (mmWave) bands (sub 6 GHz, 28 GHz, 38 GHz or higher frequencies). This high frequency band is called mmWave due to the length of the wavelength.

In order to alleviate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, integration technologies such as beamforming, massive MIMO, and array antenna are used in the 5G communication system. It is being developed.

Considering that these frequency bands can consist of hundreds of active antennas of wavelengths, antenna systems can be relatively large.

This means that several boards that make up an active antenna system, that is, the antenna board, antenna feed board, transceiver board, and baseband board, must be integrated into one compact unit.

Meanwhile, if such an antenna can be applied to an electronic device such as a mobile phone, it can be arranged with at least one area bent according to the space occupied by other components.

At such high temperatures, the antenna can be bent by 3D forming using a jig, etc.

At this time, the process is carried out at a temperature higher than the glass transition temperature of each layer of the printed circuit board constituting the antenna, but at this time, since each layer contains different materials, the glass transition temperature is different for each layer, so an appropriate process temperature must be determined. It is difficult to choose, and there is a problem that distortion may occur during bending due to differences in glass transition temperature.

In addition, there is a problem in that there are restrictions on the materials of printed circuit board construction due to the glass transition temperature.

Therefore, a printed circuit board with a new structure that can solve the above problems is required.

The embodiment seeks to provide a printed circuit board that can be easily bent and can reduce deformation during bending, and an antenna module including the same.

A printed circuit board according to an embodiment includes: a first board; a first circuit pattern disposed on the first substrate; a second substrate on the first substrate; a second circuit pattern disposed on the second substrate; and a printed circuit board including an adhesive layer between the first substrate and the second substrate, wherein the glass transition temperatures of the first substrate, the first circuit pattern, and the adhesive layer are different from each other, and the printed circuit board includes the printed circuit board. A bending area where the circuit board is bent in one direction is defined, and the printed circuit board includes a hole formed in the bending area.

The printed circuit board according to the embodiment may have a hole in the area where the printed circuit board is bent.

In detail, holes can be formed on one side and the other side of the printed circuit board, respectively, to completely or partially etch the board and/or the circuit pattern.

Accordingly, during the bending process performed at a temperature above the glass transition temperature, the area where the glass transition temperature is different in each layer of the printed circuit board can be minimized.

In detail, by forming a hole in the bending area, distortion may occur during bending due to a difference in the glass transition temperature of the substrate, circuit pattern, and adhesive layer in the bending area. However, in the embodiment, by forming a hole in the bending area, , When bending, the part where the glass transition temperature is different in the bending area can be minimized.

Accordingly, when bending a printed circuit board, the difference in glass transition temperature of each layer structure in the bending area can be minimized, resulting in distortion can be prevented, and an appropriate process temperature can be effectively measured during bending.

1 is a diagram illustrating a mobile terminal to which a printed circuit board according to an embodiment is applied.
2 to 4 are top views of a printed circuit board according to an embodiment.
5 and 6 are cross-sectional views of a printed circuit board according to an embodiment.
7 to 9 are diagrams for explaining a bending process of a printed circuit board according to an embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical idea of the present invention is not limited to some of the described embodiments, but may be implemented in various different forms, and as long as it is within the scope of the technical idea of the present invention, one or more of the components may be optionally used between the embodiments. It can be used by combining and replacing.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless explicitly specifically defined and described, are generally understood by those skilled in the art to which the present invention pertains. It can be interpreted as meaning, and the meaning of commonly used terms, such as terms defined in a dictionary, can be interpreted by considering the contextual meaning of the related technology.

Additionally, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular may also include the plural unless specifically stated in the phrase, and when described as “at least one (or more than one) of A, B, and C,” it can be combined with A, B, and C. It can contain one or more of all possible combinations.

Additionally, when describing the components of an embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and are not limited to the essence, sequence, or order of the component.

And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to that other component, but also is connected to that component. It may also include cases where other components are 'connected', 'coupled', or 'connected' by another component between them.

Additionally, when described as being formed or disposed "above" or "below" each component, "above" or "below" refers not only to cases where two components are in direct contact with each other, but also to one This also includes cases where another component described above is formed or placed between two components.

Additionally, when expressed as “top (above) or bottom (bottom),” it can include the meaning of not only the upward direction but also the downward direction based on one component.

Hereinafter, a printed circuit board according to an embodiment will be described with reference to the drawings.

1 is a diagram illustrating a mobile terminal to which a printed circuit board according to an embodiment is applied.

Referring to FIG. 1, the mobile terminal may include a main antenna 2100, a sub-antenna 2200, a battery 3000, and a main board 4000.

The printed circuit board 1000 may be connected to the main antenna 2100 and the sub antenna 2200.

The main antenna 2100 and the sub-antenna 2200 may include respective circuit boards on which chips serving as antennas are mounted.

The main antenna 2100 may be connected to the main board 4000 and the sub-antenna 2200 may be connected to the main board 4000 through the printed circuit board 1000 according to the embodiment. That is, the printed circuit board 1000 according to the embodiment may be a wire connecting the main antenna 2100 and the sub-antenna 2200 with the main board 4000.

For this purpose, the printed circuit board 1000 may be flexible. That is, the printed circuit board 1000 may be a flexible printed circuit board (FPCB).

Connectors 1100 may be formed on one end and the other end of the printed circuit board 1000. The printed circuit board 1000 can be connected to the main antenna 2100, the sub-antenna 2200, and the main board 4000, respectively, through the connector 1100.

In detail, a portion of the circuit pattern of the printed circuit board described below is exposed through the connector 1100, and the circuit pattern, the main antenna 2100, the sub-antenna 2200, and the main board 4000 are exposed. By contacting each, the main antenna 2100, the sub-antenna 2200, and the main board 4000 can be electrically connected.

Meanwhile, the printed circuit board 1000 according to the embodiment may be formed integrally with the main antenna 2100 and the sub-antenna 2200. That is, the circuit boards of the main antenna 2100 and the sub-antenna 2200 and the printed circuit board 1000 according to the embodiment may be formed as one body. That is, the printed circuit board 1000 according to the embodiment may be an extension part extending from the circuit boards of the main antenna 2100 and the sub antenna 2200.

That is, the embodiment described below includes a printed circuit board 1000 serving as wiring, and circuits of the printed circuit board, the main antenna 2100, and the sub antenna 2200. It is about an integrated antenna module in which the substrate is formed as one body.

Referring to FIGS. 2 to 6 , a printed circuit board according to an embodiment may include a substrate 100, a circuit pattern 200, and an adhesive layer 300.

The glass transition temperatures of the substrate, the circuit pattern, and the adhesive layer may be different from each other.

The substrate 100 may be rigid or flexible. For example, the substrate 100 may include a flexible material. That is, the printed circuit board may be a flexible printed circuit board (FPCB).

The substrate 100 may include resin. The substrate 100 may include an insulating material. For example, the substrate 100 may include polyimide (PI), polyethylene terephthalate (PET), propylene glycol (PPG), polycarbonate (PC), etc.

Additionally, the substrate 100 may include a low dielectric material. For example, the substrate 100 may include liquid crystal polymer or fluorine-based resin.

As the substrate 100 contains a low dielectric material such as liquid crystal polymer or fluorine resin, signal loss according to the dielectric constant of the material can be reduced, thereby improving the signal transmission characteristics of the printed circuit board. You can do it.

The substrate 100 may include a first substrate 110 and a second substrate 120. In detail, the substrate may include a first substrate 110 and a second substrate 120 that support each circuit pattern.

The thickness of the substrate 100 may be about 12㎛ to about 75㎛. In detail, the thickness of the substrate 100 may be about 12㎛ to 25㎛.

The circuit pattern 200 may be disposed on the substrate 100 . In detail, the circuit pattern 200 may be disposed on one surface of the first substrate 110 and the second substrate 120. In detail, the circuit pattern 200 may be formed by plating on one surface of the first substrate 110 and the second substrate 120.

In detail, the circuit pattern 200 includes a first circuit pattern 210 disposed on one side of the first substrate 110 and a second circuit pattern 220 disposed on one side of the second substrate 120. may include.

The first circuit pattern 210 and the second circuit pattern 220 are disposed on the first substrate 110 and the second substrate 120, respectively, so that a current or signal is generated on the printed circuit board. It can act as a moving wiring.

That is, the first circuit pattern 210 and the second circuit pattern 220 may each be a wiring pattern that extends from one end of the substrate 100 to the other end and transmits current in one direction.

The first circuit pattern 210 and the second circuit pattern 220 may be implemented with a fine line width. For example, the first circuit pattern 210 and the second circuit pattern 220 may be implemented with a line width of about 10 μm to about 30 μm.

The first circuit pattern 210 and the second circuit pattern 220 are manufactured using typical printed circuit board manufacturing processes such as the additive process, subtractive process, and MSAP (Modified Semi Additive Process). Process) and SAP (Semi Additive Process) methods, etc., and detailed explanations are omitted here.

The first circuit pattern 210 and the second circuit pattern 220 may include at least one metal material. For example, the first circuit pattern 110 and the second circuit pattern 220 are gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), and copper (Cu). ) and zinc (Zn).

The first circuit pattern 210 and the second circuit pattern 220 are made of gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), and copper (Cu), which have excellent bonding properties. ), and may be formed of a paste or solder paste containing at least one metal material selected from zinc (Zn).

The adhesive layer 300 may be disposed between the first substrate 110 and the second substrate 120. In detail, the adhesive layer 300 may be disposed between the first substrate 110 and the first substrate 120 to bond the first substrate 110 and the second substrate 120.

The adhesive layer 300 may include various materials having adhesive properties, for example, (Poly Tetra Fluoro Ethylene), PI (Polyimide), LCP (Liquid Crystal Polymer), TPI (Thermal Plastic Polyimide), FEP ( It may include substances such as Fluorinated Ethylene Propylene), PFA (Perfluoroalkoxy), ETFE (Ethylene-Tetra Fluoro Ethylene), PVDF (PolyVinyliden Fluoride), ECTFE (Ethylene-ChlorotriFluoroEthylene), and PCTFE (PolyChloroTriFluoroEthylene). Additionally, the adhesive layer 300 may include materials such as epoxy and silicon.

The thickness of the adhesive layer 300 may be about 12㎛ to about 75㎛. In detail, the thickness of the adhesive layer 300 may be about 25㎛ to 50㎛.

If the thickness of the adhesive layer 300 is less than about 12㎛, the adhesive strength of the adhesive layer may decrease and film removal may occur. Additionally, when the thickness of the adhesive layer 300 exceeds about 75㎛, the overall thickness of the printed circuit board may be increased by the adhesive layer.

Meanwhile, although not shown in the drawing, the printed circuit board may further include a ground pattern and a protective layer.

In detail, a ground pattern may be disposed on the first circuit pattern 210 and the second circuit pattern 220.

Additionally, protective layers may be disposed on the uppermost and lowermost portions of the printed circuit board, respectively, to protect circuit patterns, ground patterns, etc. of the printed circuit board.

Meanwhile, referring to FIGS. 2 to 4 , the printed circuit board according to the embodiment may include a plurality of holes (H).

In detail, the printed circuit board 1000 may include a plurality of holes exposing one side of the adhesive layer 300 or one side of one or two boards.

In detail, the printed circuit board 1000 may include a bending area (BA). Here, the bending area BA of the printed circuit board 1000 may be defined as an area that is bent in a direction different from the direction in which the printed circuit board extends.

That is, when the printed circuit board 1000 is placed in an electronic device or component, it may be bent in one direction or in multiple directions, taking into account the arrangement relationship with other components.

At this time, for printed circuit boards with a layer structure containing different materials, it is difficult to set an appropriate glass transition temperature during the bending process due to the difference in glass transition temperature of the materials contained in each layer. Additionally, when the bending process is performed at a specific temperature, it is difficult to set an appropriate glass transition temperature during the bending process. Distortion may occur in the bending area depending on the glass transition temperature difference.

Accordingly, the printed circuit board according to the embodiment is characterized by changing the layer structure of the bending area of the printed circuit board to solve this problem.

In detail, the printed circuit board 1000 may include a plurality of holes formed in the bending area BA.

The holes (H) may be arranged in various shapes. For example, referring to FIG. 2, the holes H may be formed in a bar shape extending in a different direction, for example, perpendicular to the direction in which the printed circuit board 1000 extends.

Alternatively, referring to FIG. 3 , the holes H may include a plurality of oval-shaped holes extending in a different direction, for example, perpendicular to the direction in which the printed circuit board 1000 extends.

Alternatively, referring to FIG. 4 , the holes H may include a plurality of circular holes extending in a different direction, for example, perpendicular to the direction in which the printed circuit board 1000 extends.

However, the embodiment is not limited to this, and the holes H may be formed in various shapes to expose the adhesive layer or the substrate.

Referring to FIG. 5, one side of the adhesive layer 300 may be exposed through the hole. In detail, the first circuit pattern 210 and the first substrate 110 may be etched by the first hole H1 to expose one surface of the adhesive layer 300.

Additionally, the second circuit pattern 220 and the second substrate 120 may be etched by the second hole H2 to expose one surface of the adhesive layer 300.

That is, the first hole H1 and the second hole H2 may be formed in the bending area BA.

The first hole H1 and the second hole H2 may be arranged to overlap each other. In detail, the first hole H1 and the second hole H2 may be formed to completely or partially overlap in the bending area BA.

Alternatively, the first hole H1 and the second hole H2 may be arranged so as not to overlap each other. In detail, the first hole H1 and the second hole H2 may be formed at non-overlapping positions in the bending area BA.

Additionally, the first hole H1 and the second hole H2 may have the same size. In detail, the width of the first hole H1 and the width of the second hole H2 may be the same.

Additionally, the sizes of the first hole H1 and the second hole H2 may be different from each other. In detail, the width of the first hole H1 and the width of the second hole H2 may be different from each other.

The first hole (H1) and the second hole (H2) may be formed in an area of about 30% or less of the total area of the entire printed circuit board. In detail, the first hole H1 and the second hole H2 may be formed to have an area of about 10% to about 30% of the total area of the entire printed circuit board.

In detail, the process of forming the first hole (H1) and the second hole (H2) with an area exceeding about 30% or less of the total area of the entire printed circuit board may be difficult to implement. In addition, when the area of the first hole (H1) and the second hole (H2) is less than about 10% of the total area of the entire printed circuit board, the number of holes is small and a plurality of layer structures with glass transition temperature differences are arranged. This may cause distortion during bending.

Meanwhile, referring to FIG. 6, one side of the substrate may be exposed by the hole. In detail, one side of the first substrate and the second substrate may be exposed by the hole.

In detail, the first circuit pattern 210 and the first substrate 110 may be etched by the first hole H1. At this time, the first substrate 110 may not be completely etched, but may be partially etched, and one surface of the first substrate 110 may be exposed through the first hole H1.

Additionally, the second circuit pattern 220 and the second substrate 120 may be etched by the second hole H2. At this time, the second substrate 120 may not be completely etched, but may be partially etched, and one surface of the second substrate 120 may be exposed through the second hole H2.

The first substrate 110 and the second substrate 120 remaining through the first hole H1 and the second hole H2 may be formed to have a constant thickness. In detail, the residual thickness (t) of the first substrate 110 and the second substrate 120 may be about 20 μm or less. In detail, the remaining thickness (t) of the first substrate 110 and the second substrate 120 may be about 5 μm to about 20 μm.

As the first substrate 110 and the second substrate 120 remain above a certain thickness, damage to the circuit pattern can be prevented when bending the printed circuit board.

When the residual thickness (t) of the first substrate 110 and the second substrate 120 exceeds about 20㎛, warping may occur due to a difference in glass transition temperature between the substrate and the adhesive layer. In addition, when the residual thickness (t) of the first substrate 110 and the second substrate 120 is less than about 5㎛, the circuit pattern may be damaged by deformation of the circuit pattern spaced apart by a hole during a bending process using a jig. Damage may occur.

Meanwhile, Figures 5 and 6 show that the first hole and the second hole etch both the circuit pattern and the substrate, or the first hole and the second hole etch all of the circuit pattern and partially etch the substrate. The example is not limited to this, and one of the first holes and the second holes may etch both the circuit pattern and the substrate, and the other hole may etch all of the raw patterns and partially etch the substrate.

In addition, Figures 5 and 6 show that the first hole and the second hole are formed at a position that overlaps the portion where the circuit pattern is disposed, but the embodiment is not limited thereto, and among the first hole and the second hole Any one hole is disposed in a position that does not overlap the portion of the circuit pattern layout, so that any one of the first hole and the second hole can be formed by etching only the substrate.

Meanwhile, a filling material may be disposed in the first hole (H1) and the second hole (H2).

In detail, a filling material may be disposed inside at least one of the first hole (H1) and the second hole (H2).

The filling material may include a ductile material. For example, the filling material may include a ductile metallic material. For example, the filling material may include a ductile metal material such as copper plating, copper, or silver paste.

Meanwhile, the filling material may be disposed to completely fill or partially fill the inside of at least one of the first hole (H1) and the second hole (H2).

By filling empty parts of the printed circuit board with a ductile metal material using the filling material, heat generated from the printed circuit board can be effectively dissipated by the filling material.

Hereinafter, with reference to FIGS. 6 to 8, a bending process of a printed circuit board according to an embodiment will be described.

First, a printed circuit board can be prepared as shown in Figure 7.

Subsequently, a plurality of holes H1 and H2 may be formed on one side and the other side of the printed circuit board as shown in FIG. 8. The plurality of holes may be formed in an area where the printed circuit board is bent.

These holes may be formed by etching the substrate and the circuit pattern, in whole or in part, when the holes are placed in a position that overlaps the circuit pattern, and if the holes are placed in a position that does not overlap the circuit pattern, the board It can be formed by etching in whole or in part.

The holes can be formed by mechanical drilling or etching by a laser.

The hole may have a diameter of about 50㎛ to about 200㎛, and may be formed in various shapes as shown in FIGS. 2 to 4.

Next, referring to FIG. 9, the printed circuit board can be bent by heating the bending area at a temperature above the glass transition temperature using a jig (J).

At this time, solder paste for mounting the connector may be applied first before bending and then bent. In detail, after forming a hole in the jig J in the area where the connector is mounted, solder paste can be applied to the mounting area through the hole formed in the jig during bending.

Accordingly, the bending process of the printed circuit board and the connector mounting process can be performed simultaneously, thereby reducing process efficiency.

Additionally, by performing the connector mounting process before bending, the connector can be mounted more stably compared to mounting it on the surface of an unstable board after bending.

As described above, the printed circuit board according to the embodiment may have a hole in the area where the printed circuit board is bent.

In detail, holes can be formed on one side and the other side of the printed circuit board, respectively, to completely or partially etch the board and/or the circuit pattern.

Accordingly, during the bending process performed at a temperature above the glass transition temperature, the area where the glass transition temperature is different in each layer of the printed circuit board can be minimized.

In detail, by forming a hole in the bending area, distortion may occur during bending due to a difference in the glass transition temperature of the substrate, circuit pattern, and adhesive layer in the bending area. However, in the embodiment, by forming a hole in the bending area, , When bending, the part where the glass transition temperature is different in the bending area can be minimized.

Accordingly, when bending a printed circuit board, the difference in glass transition temperature of each layer structure in the bending area can be minimized, resulting in distortion can be prevented, and an appropriate process temperature can be effectively measured during bending.

The features, structures, effects, etc. described in the above-described embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

In addition, although the description has been made focusing on the embodiments above, this is only an example and does not limit the present invention, and those skilled in the art will understand the above examples without departing from the essential characteristics of the present embodiments. You will be able to see that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. And these variations and differences in application should be construed as being included in the scope of the present invention as defined in the attached claims.

Claims (10)

first substrate;
A first circuit pattern disposed on the first substrate
a second substrate on the first substrate;
a second circuit pattern disposed on the second substrate; and
Comprising an adhesive layer between the first substrate and the second substrate,
a first hole formed penetrating the first substrate and the first circuit pattern; and a printed circuit board including a second hole formed through the second substrate and the second circuit pattern. According to clause 1,
The glass transition temperatures of the first substrate, the first circuit pattern, and the adhesive layer are different from each other,
The printed circuit board has a defined bending area where the printed circuit board is bent in one direction,
The first hole and the second hole are formed in the bending area of the printed circuit board. According to clause 1,
The first hole and the second hole are formed by partially etching the first substrate and the second substrate, respectively. According to clause 1,
A printed circuit board wherein the first hole and the second hole overlap each other. According to clause 1,
A printed circuit board wherein the thickness of the first substrate and the second substrate remaining due to the first hole and the second hole is 5㎛ to 20㎛. According to clause 1,
A printed circuit board further comprising a filling material disposed in at least one of the first hole and the second hole. According to clause 1,
The first hole and the second hole are formed in an area of 10% to 30% of the total area of the printed circuit board. An antenna board including a circuit board; and
It includes a printed circuit board extending from the antenna board,
The antenna substrate and the printed circuit board are integrally formed,
The printed circuit board is,
first substrate;
A first circuit pattern disposed on the first substrate
a second substrate on the first substrate;
a second circuit pattern disposed on the second substrate; and
Comprising an adhesive layer between the first substrate and the second substrate,
a first hole formed penetrating the first substrate and the first circuit pattern; and a second hole formed penetrating the second substrate and the second circuit pattern. According to clause 8,
The printed circuit board has a defined bending area where the printed circuit board is bent in one direction,
The first hole and the second hole are formed in the bending area. According to clause 8,
The first hole and the second hole are formed by partially etching the first substrate and the second substrate, respectively,
An antenna module wherein the thickness of the first substrate and the second substrate remaining by the first hole and the second hole is 5㎛ to 20㎛.

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