KR102667824B1 - Circuit board and antenna module - Google Patents

Abstract

A circuit board according to an embodiment includes a first insulating layer; a circuit pattern disposed on the upper surface of the first insulating layer; a second insulating layer disposed on an upper surface of the first insulating layer; a first protective layer disposed on the lower surface of the first insulating layer; and a second protective layer disposed on the upper surface of the second insulating layer, wherein a first connector and a second connector are bonded to the lower surface of the first insulating layer and the upper surface of the second insulating layer by an adhesive member. are respectively disposed, the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers and the first and second protective layers, and the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers. and is smaller than the minimum melting temperature of the first and second protective layers.

Description

Circuit board and antenna module including the same {CIRCUIT BOARD AND ANTENNA MODULE}

The embodiment relates to a 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 above the glass transition temperature of each layer of the circuit board that makes up the antenna, but since each layer contains different materials, the glass transition temperature is different for each layer, making it difficult to select an appropriate process temperature. , there is a problem that distortion may occur during bending due to differences in glass transition temperature.

Additionally, as the connector is mounted on an uneven surface after bending, there is a problem that defects occur during the connector mounting process.

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

The embodiment seeks to provide a circuit board that can be easily bent and improve connector mounting efficiency and an antenna module including the same.

A circuit board according to an embodiment includes a first insulating layer; a circuit pattern disposed on the upper surface of the first insulating layer; a second insulating layer disposed on an upper surface of the first insulating layer; a first protective layer disposed on the lower surface of the first insulating layer; and a second protective layer disposed on the upper surface of the second insulating layer, wherein a first connector and a second connector are bonded to the lower surface of the first insulating layer and the upper surface of the second insulating layer by an adhesive member. are respectively disposed, the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers and the first and second protective layers, and the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers. and is smaller than the minimum melting temperature of the first and second protective layers.

A circuit board according to another embodiment includes a first insulating layer; a circuit pattern disposed on the upper surface of the first insulating layer; an adhesive layer disposed on the upper surface of the first insulating layer; a second insulating layer disposed on the upper surface of the adhesive layer; a first protective layer disposed on the lower surface of the first insulating layer; and a second protective layer disposed on the upper surface of the second insulating layer, wherein a first connector and a second connector are bonded to the lower surface of the first insulating layer and the upper surface of the second insulating layer by an adhesive member. are respectively disposed, the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers, the first and second protective layers, and the adhesive layer, and the melting temperature of the adhesive member is: 2 is smaller than the minimum melting temperature of the insulating layer, the first and second protective layers, and the adhesive layer.

The circuit board according to the embodiment can control the glass transition temperature, melting temperature, and thickness of each layer of the insulating layer, protective layer, and adhesive layer that constitute the circuit board. Accordingly, the glass transition temperature of the insulating layer, protective layer, and adhesive layer is lower than the melting temperature of the adhesive member at which the adhesive member melts, and the melting temperature of the insulating layer, protective layer, and adhesive layer is lower than the melting temperature of the adhesive member at which the adhesive member melts. In a larger scale, the thermoforming of the circuit board and the bonding, that is, mounting, of the connector using the adhesive member can be performed through the same process.

Therefore, since two processes can be performed in one process, process efficiency can be improved, and the connector can be mounted simultaneously with bending of the circuit board, making the connector more stable than mounting it separately on an unstable circuit board after bending. It can be implemented with .

1 is a diagram illustrating a mobile terminal to which a circuit board according to an embodiment is applied.
Figure 2 is a cross-sectional view for explaining the stacked structure of a circuit board according to an embodiment.
Figure 3 is a top view of the lower insulating layer of a circuit board according to an embodiment.
FIG. 4 is a top view of the upper surface of the upper insulating layer of a circuit board according to an embodiment.
FIG. 5 is a top view of the upper surface of the lower insulating layer of a circuit board according to an embodiment.
FIG. 6 is a cross-sectional view taken along area A-A' of FIGS. 3 and 4.
FIG. 7 is a cross-sectional view taken along area B-B' of FIGS. 3 and 4.
Figure 8 is a cross-sectional view for explaining bending of a circuit board according to an embodiment.
FIG. 9 is a cross-sectional view illustrating a stacked structure of a circuit board according to another embodiment.
Figure 10 is a cross-sectional view illustrating bending of a circuit board according to another 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, order, 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 the other component, but also is connected to the other 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 "on top or bottom" of each component, top or bottom 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 “up (above) or down (down),” it can include not only the upward direction but also the downward direction based on one component.

Hereinafter, a 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 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 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 circuit board 1000 according to the embodiment. That is, the 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 circuit board 1000 may be flexible. That is, the 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 circuit board 1000. The 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, the circuit pattern of the circuit board described below is connected to the main antenna 2100, the sub-antenna 2200, and the main board 4000 through the connector 1100, respectively. The antenna 2100, the sub-antenna 2200, and the main board 4000 may be electrically connected.

Meanwhile, the 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 circuit board 1000 according to the embodiment may be formed as one body. That is, the 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 circuit board 1000 serving as wiring, and the circuit board and the circuit boards of the main antenna 2100 and the sub antenna 2200 are integrated. It is about an integrated antenna module formed by.

Referring to FIGS. 2 to 8 , the circuit board 1000 according to the embodiment may include an insulating layer, a circuit pattern, a ground pattern, a connector, and a protective layer.

The insulating layer may include a first insulating layer 110 and a second insulating layer 120.

The first insulating layer 110 and the second insulating layer 120 are substrates on which electric circuits that can change wiring are formed, and are made of an insulating material that can form a circuit pattern 200 on the surface of the insulating layer. It can include all manufactured prints, wiring boards, and insulating boards.

The first insulating layer 110 and the second insulating layer 120 may be rigid or flexible. For example, the first insulating layer 110 and the second insulating layer 120 may include glass or plastic. In detail, the insulating layer includes chemically strengthened/semi-strengthened glass such as soda lime glass or aluminosilicate glass, or polyimide (PI), polyethylene terephthalate (PET), or propylene. It may contain reinforced or soft plastics such as propylene glycol (PPG), polycarbonate (PC), or sapphire.

Additionally, the first insulating layer 110 and the second insulating layer 120 may include an optically isotropic film. For example, the first insulating layer 110 and the second insulating layer 120 are made of COC (Cyclic Olefin Copolymer), COP (Cyclic Olefin Polymer), wide isotropic polycarbonate (polycarbonate, PC), or wide isotropic polymethyl methane. It may include crylate (PMMA), etc.

Additionally, the first insulating layer 110 and the second insulating layer 120 may have a partially curved surface and be curved. That is, the insulating layer can be bent while partially having a flat surface and partially having a curved surface. In detail, the ends of the first insulating layer 110 and the second insulating layer 120 may have a curved surface and may be curved, or may have a surface including random curvature and may be curved or bent.

Additionally, the first insulating layer 110 and the second insulating layer 120 may be flexible substrates with flexible characteristics. Additionally, the first insulating layer 110 and the second insulating layer 120 may be curved or bent substrates. At this time, the insulating layer represents the electrical wiring connecting the circuit components based on the circuit design with a wiring diagram, and can reproduce the electrical conductor on the insulating material. In addition, it is possible to mount electrical components and form wiring that connects them in a circuit, and to mechanically fix components other than the electrical connection function of the components.

Additionally, the first insulating layer 110 and the second insulating layer 120 may include a low dielectric material. For example, the insulating layer may include liquid crystal polymer or fluorine-based resin.

As the first insulating layer 110 and the second insulating layer 120 contain 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. Therefore, when the circuit board is used for the purpose of transmitting high-frequency signals, the signal transmission characteristics of the circuit board can be improved by reducing the dielectric constant.

Meanwhile, the first insulating layer 110 and the second insulating layer 120 may have a thickness of about 12 μm to about 75 μm. In detail, the thickness of the insulating layer may be about 12㎛ to 25㎛.

The thickness of the first insulating layer 110 and the first insulating layer 120 is a thickness considered for bending of the circuit board described below.

The circuit pattern may be disposed on an insulating layer. In detail, referring to FIGS. 2 and 5 , the circuit pattern 200 may be disposed on the lower insulating layer 110 .

In the drawing, the circuit pattern 200 is disposed on the first insulating layer 110, and the second insulating layer 120 is disposed on the first insulating layer 110 on which the circuit pattern 200 is disposed. Although this arrangement is shown, the embodiment is not limited thereto, and the insulating layer includes a plurality of insulating layers sequentially stacked, and the circuit pattern includes a plurality of multilayer circuits respectively disposed on the plurality of insulating layers. It may also contain patterns.

Hereinafter, the description will focus on an embodiment in which the circuit pattern 200 is disposed on the first insulating layer 110 and the second insulating layer 120 is disposed on the circuit pattern 200.

Referring to FIG. 5 , the circuit pattern 200 may include a transmission pattern 210 and a dummy pattern 220. The transmission pattern 210 may be a transmission wire that transmits an electrical signal, and the dummy pattern 220 may be a connection wire that electrically connects the upper ground pattern and the lower ground pattern described below.

The circuit pattern 200 may be formed of a metal material with high electrical conductivity. To this end, the circuit pattern 200 includes at least one selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn). It may be formed of a metallic material. In addition, the circuit pattern 200 is made of at least one material selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn), which has excellent bonding strength. It may be formed from a paste containing one metal material or a solder paste. Preferably, the circuit pattern 200 may be formed of copper (Cu), which has high electrical conductivity and is relatively inexpensive.

The circuit pattern 200 can be manufactured using typical circuit board manufacturing processes such as the additive process, subtractive process, MSAP (Modified Semi Additive Process), and SAP (Semi Additive Process) methods. And detailed description is omitted here.

Meanwhile, at least one via (V) is formed in the insulating layer. In detail, the via V is formed penetrating at least one of the first insulating layer 110 and the second insulating layer 120. The via V may penetrate only one of the plurality of insulating layers. Alternatively, the via V may be formed to commonly penetrate at least two insulating layers among the plurality of insulating layers. Accordingly, the via (V) electrically connects circuit patterns and/or ground patterns disposed on the surfaces of different insulating layers.

The via (V) may be formed by filling the inside of a through hole penetrating at least one of the plurality of insulating layers with a conductive material (CM).

The through hole may be formed by any one of mechanical, laser, and chemical processing. If the through hole is formed by machining, methods such as milling, drilling, and routing can be used. If the through hole is formed by laser processing, UV or CO ₂ laser methods can be used. When formed through chemical processing, the insulating layer 100 can be opened using chemicals containing aminosilanes, ketones, etc.

On the other hand, the laser processing is a cutting method that takes the desired shape by concentrating optical energy on the surface to melt and evaporate part of the material. Complex shapes can be easily processed using a computer program, and other methods include cutting. Even difficult composite materials can be processed.

In addition, processing using the laser has the advantage that the cutting diameter is possible up to a minimum of 0.005 mm and the thickness range that can be processed is wide.

As the laser processing drill, it is preferable to use a YAG (Yttrium Aluminum Garnet) laser, a CO ₂ laser, or an ultraviolet (UV) laser. The YAG laser is a laser that can process both the copper foil layer and the insulating layer, and the CO ₂ laser is a laser that can only process the insulating layer.

Once the through hole is formed, the inside of the through hole is filled with a conductive material to form the via (V). The metal material forming the via (V) may be any material selected from copper (Cu), silver (Ag), tin (Sn), gold (Au), nickel (Ni), and palladium (Pd). , the conductive material filling may use any one or a combination of electroless plating, electrolytic plating, screen printing, sputtering, evaporation, ink jetting, and dispensing.

Meanwhile, the thickness of the circuit pattern 200 may be about 10 μm to about 20 μm. In detail, the thickness of the circuit pattern 200 may be about 11㎛ to 15㎛.

The thickness of the circuit pattern 200 is a thickness taken into consideration for bending of the circuit board, which will be described below.

The ground pattern may be disposed on top and bottom of the insulating layer. In detail, referring to FIGS. 2 to 4, the ground pattern is disposed on the first ground pattern 310 disposed on the lower portion of the first insulating layer 110 and the upper portion of the second insulating layer 120. It may include a second ground pattern 320.

The thickness of the ground pattern may be about 20㎛ to about 30㎛. In detail, the thickness of the ground pattern may be about 23㎛ to 29㎛.

The thickness of the ground pattern is a thickness considered for bending of the circuit pattern described below.

The first ground pattern 310 and the second ground pattern 320 may include the same or similar material as the circuit pattern described above. Additionally, the first ground pattern 310 and the second ground pattern 320 may be formed through the same or similar process as the circuit pattern.

The connector 1100 may be disposed above and below the insulating layer. In detail, referring to FIGS. 2 to 6, the connector 1100 has a first connector 1110 disposed on the lower portion of the first insulating layer 110 and an upper portion of the second insulating layer 120. It may include a second connector 1120 disposed.

The first connector 1110 and the second connector 1120 may be connected to pad portions disposed on the lower part of the first insulating layer 110 and the upper part of the second insulating layer 120, respectively. .

In detail, a first pad portion 351 is disposed on the lower part of the first insulating layer 110, and the first connector 1110 is disposed on the first pad portion 351 to form the lower connector 1110. It may be connected to the first terminal portion 1110a. In addition, a second pad portion 352 is disposed on the top of the second insulating layer 120, and the second connector 1120 is disposed on the second pad portion 352 to form a second connector 1120. It may be connected to the first terminal portion 1120a.

In addition, the first connector 1110 is connected to the first ground pattern 310 by a second terminal portion 1110b connected to the first ground pattern 310, and the second connector 1120 is connected to the first ground pattern 310. It may be connected to the second ground pattern 310 by a second terminal portion 1120b connected to the second ground pattern 320.

That is, the first and second connectors may be connected to the pad portion and the ground patterns while being insulated from each other.

The first pad portion 351 and the second pad portion 352 may include the same or similar material as the ground pattern described above. In detail, the first pad portion 351 and the second pad portion 352 may be formed simultaneously with the ground pattern. That is, the first pad portion 351 may be formed by patterning the ground pattern of the pad region together when patterning the first ground pattern, and the second pad portion 352 may be formed by patterning the second ground pattern. When patterning, it can be formed by patterning the ground pattern of the pad area together.

The first connector 1110 and the second connector 1120 may be connected through the via described above.

In detail, referring to FIG. 6, the first connector 1110, that is, the area of the first insulating layer 110 corresponding to the first pad portion 351, penetrates the first insulating layer 110. A via (V) is formed, and the first pad portion 351 and the transmission pattern 210 of the circuit pattern are formed by the via (V) and the conductive material (CM) filled inside the via (V). can be connected

In addition, the second connector 1120, that is, the area of the second insulating layer 121 corresponding to the second pad portion 352, has a via (V) penetrating the second insulating layer 120. The second pad portion 352 and the transmission pattern 210 of the circuit pattern may be connected by the via (V) and the conductive material (CM) filled inside the via (V).

Accordingly, the first connector 1110 and the second connector 1120 can be electrically connected to each other by being connected to the same transmission pattern through the via and the conductive material.

Additionally, the first ground pattern 310 and the second ground pattern 320 may be connected through the via described above.

In detail, referring to FIG. 7, a via (V) penetrating the first insulating layer 110 is formed in one area of the first insulating layer 110 corresponding to the first ground pattern 310, and , the first ground pattern 310 and the dummy pattern 220 of the circuit pattern may be connected by the via (V) and the conductive material filled inside the via (V).

In addition, a via (V) penetrating the second insulating layer 120 is formed in one area of the second insulating layer 120 corresponding to the second ground pattern 320, and the via (V) and a conductive material filled inside the via (V). The second ground pattern 320 and the dummy pattern 220 of the circuit pattern may be connected by the circuit pattern.

Accordingly, the first ground pattern 310 and the second ground pattern 320 may be electrically connected to each other by being connected to the same dummy pattern through the via and a conductive material.

The protective layer may be disposed on the upper part of the first insulating part 110 and the lower part of the second insulating layer 120. In detail, the protective layer may include a first protective layer 410 disposed on an upper portion of the first insulating portion 110 and a second protective layer 420 disposed on a lower portion of the second insulating portion 120. You can.

The first protective layer 110 may be disposed to protect the surface of the uppermost insulating layer, and the second protective layer 120 may be disposed to protect the surface of the lowermost insulating layer.

The first protective layer 110 and the second protective layer 120 may be disposed to expose a portion of the circuit pattern 200 . In detail, the first protective layer 110 and the second protective layer 120 may be disposed to expose the area where the first connector 1110 and the second connector 1120 are placed, that is, the terminal area, respectively. .

The first protective layer 110 and the second protective layer 120 may include at least one material selected from polyimide (PI), epoxy resin, or acrylic resin. For example, the protective layer may be a multilayer material in which epoxy resin or acrylic resin is adhered to the bottom of a polyimide film.

Meanwhile, the terminal portions of the first connector 1110 and the second connector 1120 may be bonded to the pad portion and the ground electrode through an adhesive member. In detail, the terminal portions of the first connector 1110 and the second connector 1120 may be bonded to the pad portion and the ground electrode through a conductive adhesive member.

For example, the terminal portions of the first connector 1110 and the second connector 1120 may be bonded to the pad portion and the ground electrode through a soldering process. That is, the terminal portions of the first connector 1110 and the second connector 1120 may be electrically connected to the pad portion and the ground electrode through an adhesive member containing a tin-lead alloy soldering material.

Meanwhile, as shown in FIG. 8, at least one area of the circuit board according to the embodiment may be bent in one direction. In detail, the circuit board may be bent in at least one direction for connection to another member connected through a connector.

Additionally, the circuit board according to the embodiment can perform connector mounting and bending at the same time. That is, the circuit board according to the embodiment forms an adhesive member for adhering the connector to the circuit board, forms a jig for forming the circuit board, and then heats it to a certain temperature, thereby mounting the connector and forming the circuit board. can proceed simultaneously.

To this end, the melting temperature of the adhesive member is to control the glass transition temperature of the first and second insulating layers and the first and second protective layers and the melting temperature of the first and second insulating layers and the first and second protective layers. You can.

In detail, the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers and the first and second protective layers, and the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers and the first and second protective layers. , 2 may be smaller than the minimum melting temperature of the protective layer.

That is, the adhesive member, the first and second insulating layers, and the first and second protective layers may satisfy Equation 1 below.

formula 1

Maximum glass transition temperature of the first and second insulating layers and the first and second protective layers (T _g ) < melting temperature of the adhesive member (T _m ) < of the first and second insulating layers and the first and second protective layers Minimum melting temperature (T _m )

That is, the melting temperature (T _m ) of the adhesive member at which the adhesive member that bonds the terminal portions of the connectors, the pad portion, and the ground electrode is melted is the first insulating layer 110 and the second insulating layer 120. Since it is greater than the maximum glass transition temperature (T _g ) of the first protective layer 410 and the second protective layer 420, the circuit board can be molded while mounting the connector.

In addition, the melting temperature (T _m ) of the adhesive member at which the terminal portions of the connectors, the pad portion, and the ground electrode are melted is the first insulating layer 110 and the second insulating layer 120. ), is smaller than the minimum melting temperature (T _m ) of the first protective layer 410 and the second protective layer 420, so when mounting the connector, the first insulating layer 110 and the second It is possible to prevent the insulating layer 120, the first protective layer 410, and the second protective layer 420 from melting.

For example, the melting temperature (T _m ) of the adhesive member is the temperature at which the adhesive member is melted and may be about 260°C to about 281°C. That is, the maximum glass transition temperature (T _g ) of the first and second insulating layers and the first and second protective layers may be less than 281°C, and the lowest melting temperature of the first and second insulating layers and the first and second protective layers may be less than 281°C. (T _m ) may exceed 260 degrees.

That is, the melting temperature (T _m ) of the adhesive member at which the adhesive member melts is the maximum glass transition temperature (T _g ) of the first and second insulating layers and the first and second protective layers and the first and second insulating layers. and the lowest melting temperature (T _m ) of the first and second protective layers, so the circuit board can be thermoformed at the same time as the connector is mounted on the circuit board.

Therefore, since the mounting of the connector and the molding of the circuit board can be carried out simultaneously, the connector can be mounted stably on the circuit board before molding, that is, before bending, compared to mounting the connector on a circuit board with an unstable shape after bending. It can be mounted stably.

Meanwhile, the thickness of the insulating layer and the protective layer may be formed at a constant ratio. In detail, the total thickness (T1) of the insulating layer including the first insulating layer 110 and the second insulating layer 120 includes the first protective layer 410 and the second protective layer 420. The total thickness (T2) of the protective layer may be formed at a constant ratio.

In detail, the total thickness (T2) of the protective layer is smaller than the total thickness (T1) of the insulating layer, and at this time, the total thickness (T2) of the protective layer is 0.18 to 0.26 times the total thickness (T1) of the insulating layer. It could be a boat.

Additionally, the maximum glass transition temperature of the insulating layer and the protective layer that satisfies Equation 1 may satisfy Equation 2.

formula 2

Maximum glass transition temperature of insulating layer and protective layer = 89.29X ² - 263.6X + 325.1

(where X=T2/T1)

In detail, the insulating layer and the protective layer may include different materials, and as the insulating layer and the protective layer include different materials, the insulating layer and the protective layer may have different glass transition temperatures and melting temperatures. It can have a temperature. Accordingly, since the insulating layer and the protective layer have different glass transition temperatures, melting temperatures, and thicknesses, the thermoforming temperature of the circuit board may vary depending on the difference in thickness of each layer.

Therefore, by controlling the thickness ratio of the insulating layer and the protective layer, the glass transition temperature of the insulating layer and the protective layer is lowered to less than the melting temperature (T _m ) of the adhesive member described above. The melting temperature of can be controlled to be greater than the melting temperature (T _m ) of the adhesive member described above.

That is, the circuit board according to the embodiment can control the glass transition temperature, melting temperature, and thickness of each layer of the insulating layer and protective layer constituting the circuit board. Accordingly, the glass transition temperature of the insulating layer and the protective layer is lower than the melting temperature of the adhesive member at which the adhesive member melts, and the melting temperature of the insulating layer and the protective layer is greater than the melting temperature of the adhesive member at which the adhesive member melts to form a circuit. Along with thermoforming of the substrate, bonding, that is, mounting, of the connector using the adhesive member can be performed through the same process.

Therefore, since two processes can be performed in one process, process efficiency can be improved, and the connector can be mounted simultaneously with bending of the circuit board, making the connector more stable than mounting it separately on an unstable circuit board after bending. It can be implemented with .

Hereinafter, with reference to FIGS. 9 and 10, a circuit board according to another embodiment will be described. In the description of the circuit board according to another embodiment, descriptions that are the same or similar to the circuit board according to the previously described embodiment will be omitted, and the same reference numerals will be assigned to the same components.

Referring to FIG. 9, the circuit board according to another embodiment may further include an adhesive layer, unlike the circuit board according to the previously described embodiment.

In detail, referring to FIG. 9, a circuit board 1000 according to another embodiment may include an insulating layer, an adhesive layer, a circuit pattern, a ground pattern, a connector, and a protective layer.

In detail, a circuit board according to another embodiment may have a circuit pattern 200 disposed on the first insulating layer 110, and an adhesive layer 500 may be disposed on the circuit pattern 200. In addition, a second insulating layer 120 is disposed on the adhesive layer 500, and a first ground pattern 310 and a first protective layer 410 are disposed below the first insulating layer 110, A second ground pattern 320 and a second protective layer 420 may be disposed on the second insulating layer 120.

That is, in the circuit board according to another embodiment, unlike the circuit board according to the previously described embodiment, the first insulating layer and the second insulating layer do not have adhesive properties, so the first insulating layer and the second insulating layer A separate adhesive layer may be formed to adhere the layers.

The adhesive layer 500 may include a resin material. For example, the adhesive layer may include epoxy resin or acrylic resin.

Meanwhile, as shown in FIG. 10, at least one area of the circuit board according to another embodiment may be bent in one direction. In detail, the circuit board may be bent in at least one direction for connection to another member connected through a connector.

In detail, the circuit board can perform connector mounting and bending at the same time. That is, by forming an adhesive member for adhering the connector to the circuit board, forming a jig for molding the circuit board, and then heating it to a constant temperature, mounting of the connector and molding of the circuit board can be carried out simultaneously.

To this end, the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers, the first and second protective layers, and the adhesive layer, and the melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers. , may be smaller than the minimum melting temperature of the first and second protective layers and the protective layer.

That is, the adhesive member, the first and second insulating layers, the first and second protective layers, and the adhesive layer may satisfy Equation 3 below.

Formula 3

Maximum glass transition temperature of the first and second insulating layers, the first and second protective layers, and the adhesive layer (T _g ) < melting temperature of the adhesive member (T _m ) < the first and second insulating layers, the first and second insulating layers, and the adhesive layer. Minimum melting temperature of the protective layer and the adhesive layer (T _m )

That is, the melting temperature (T _m ) of the adhesive member at which the terminal portions of the connectors, the pad portion, and the ground electrode are melted is the first insulating layer 110 and the second insulating layer 120. ), is greater than the maximum glass transition temperature (T _g ) of the first protective layer 410, the second protective layer 420, and the adhesive layer 500, so it is possible to mold the circuit board while mounting the connector. You can.

In addition, the melting temperature (T _m ) of the adhesive member at which the terminal portions of the connectors, the pad portion, and the ground electrode are melted is the first insulating layer 110 and the second insulating layer 120. ), is smaller than the minimum melting temperature (T _m ) of the first protective layer 410, the second protective layer 420, and the adhesive layer 500, so when mounting the connector, the first insulating layer ( 110), the second insulating layer 120, the first protective layer 410, the second protective layer 420, and the adhesive layer 500 can be prevented from melting.

For example, the melting temperature (T _m ) of the adhesive member is the temperature at which the adhesive member is melted and may be about 260°C to 281°C. That is, the maximum glass transition temperature (T _g ) of the first and second insulating layers, the first and second protective layers, and the adhesive layer may be less than 281°C, and the first and second insulating layers, the first and second protective layers, and The minimum melting temperature (T _m ) of the adhesive layer may exceed 260 degrees.

That is, the melting temperature (T _m ) of the adhesive member at which the adhesive member melts is the maximum glass transition temperature (T _g ) of the first and second insulating layers, the first and second protective layers, and the adhesive layer, and the first, Since it is formed between the two insulating layers, the first and second protective layers, and the lowest melting temperature (T _m ) of the adhesive layer, the circuit board can be thermoformed at the same time as the connector is mounted on the circuit board.

Therefore, since the mounting of the connector and the molding of the circuit board can be carried out simultaneously, the connector can be mounted stably on the circuit board before molding, that is, before bending, compared to mounting the connector on a circuit board with an unstable shape after bending. It can be mounted stably.

Meanwhile, the thicknesses of the insulating layer, the protective layer, and the adhesive layer may be formed at a constant ratio. In detail, the total thickness (T1) of the layer including the first insulating layer 110 and the second insulating layer 120 is the first protective layer 410, the second protective layer 420, and the adhesive layer. It can be formed at a constant ratio with the total thickness (T3) of the layer including (500).

In detail, the total thickness (T3) of the layer is smaller than the total thickness (T1) of the insulating layer, and in this case, the total thickness (T3) of the layer may be 0.18 to 0.26 times the total thickness (T1) of the insulating layer. there is.

Additionally, the maximum glass transition temperature of the insulating layer, the protective layer, and the adhesive layer that satisfies Equation 3 may satisfy Equation 4.

Formula 4

Maximum glass transition temperature of insulating layer, protective layer and adhesive layer = 89.29X ² - 263.6X + 325.1

(where X=T3/T1)

In detail, the insulating layer, the protective layer, and the adhesive layer may include different materials, and as the insulating layer, the protective layer, and the adhesive layer include different materials, the insulating layer, the protective layer, and the adhesive layer may include different materials. The adhesive layer may have different glass transition temperatures and melting temperatures. Accordingly, since the insulating layer, the protective layer, and the adhesive layer have different glass transition temperatures, melting temperatures, and thicknesses, the thermoforming temperature of the circuit board may vary depending on the difference in thickness of each layer.

Therefore, by controlling the thickness ratio of the insulating layer, the protective layer, and the adhesive layer, the glass transition temperature of the insulating layer, the protective layer, and the adhesive layer is lower than the melting temperature (T _m ) of the adhesive member described above. The melting temperature of the insulating layer and the protective layer can be controlled to be greater than the melting temperature (T _m ) of the adhesive member described above.

Meanwhile, in the description of the above-described embodiments, it is shown that the connector is mounted through an adhesive member. However, in the circuit board according to the embodiments, components such as chips that are bonded to the pad portion through an adhesive member are mounted in addition to the connector. Of course, it is also included. That is, the circuit board according to the embodiments may include all examples of circuit components mounted through adhesive members.

That is, the circuit board according to the embodiment can control the glass transition temperature, melting temperature, and thickness of each layer of the insulating layer, protective layer, and adhesive layer constituting the circuit board. Accordingly, the glass transition temperature of the insulating layer, protective layer, and adhesive layer is lower than the melting temperature of the adhesive member at which the adhesive member melts, and the melting temperature of the insulating layer, protective layer, and adhesive layer is lower than the melting temperature of the adhesive member at which the adhesive member melts. In a larger scale, the thermoforming of the circuit board and the adhesion, that is, the mounting, of the connector using the adhesive member can be performed through the same process.

Therefore, since two processes can be performed in one process, process efficiency can be improved, and the connector can be mounted simultaneously with bending of the circuit board, making the connector more stable than mounting it separately on an unstable circuit board after bending. It can be implemented with .

Hereinafter, the present invention will be described in more detail through examples and comparative examples. These embodiments are merely provided as examples to explain the present invention in more detail. Therefore, the present invention is not limited to these examples.

Experiment example One

In FIG. 1, the components excluding the connector were formed to form a circuit board.

Next, jigs were placed on the lower and upper sides of the circuit board, and a certain amount of heat was applied to bend the circuit board.

At this time, the bending temperature of the circuit board according to the total thickness of the insulating layer and the total thickness of the protective layer was measured.

Experiment example 2

In Figure 9, the components excluding the connector were formed to form a circuit board.

Next, jigs were placed on the lower and upper sides of the circuit board, and a certain amount of heat was applied to bend the circuit board.

At this time, the bending process temperature of the circuit board according to the total thickness of the insulating layer, protective layer, and adhesive layer was measured.

Total thickness of protective layer or total thickness of protective layer and adhesive layer
(㎛, a) Total thickness of insulating layer
(㎛, b) a/b Process temperature (℃) Example 1 9 50 0.18 280.5 Example 2 10 50 0.2 276.0 Example 3 11 50 0.22 271.4 Example 4 12 50 0.24 267.0 Example 5 13 50 0.26 262.6 Comparative Example 1 One 50 0.02 319.9 Comparative example 2 2 50 0.04 314.7 Comparative Example 3 3 50 0.06 309.6 Comparative example 4 4 50 0.08 304.6 Comparative Example 5 5 50 0.1 299.6 Comparative Example 6 6 50 0.12 294.8 Comparative example 7 7 50 0.14 289.9 Comparative example 8 8 50 0.16 285.2 Comparative Example 9 14 50 0.28 258.3 Comparative Example 10 15 50 0.3 254.1 Comparative Example 11 16 50 0.32 249.9 Comparative Example 12 17 50 0.34 245.8 Comparative Example 13 18 50 0.36 241.8 Comparative Example 14 19 50 0.38 237.8 Comparative Example 15 20 50 0.4 233.9 Comparative Example 16 30 50 0.6 199.1 Comparative Example 17 50 50 One 150.8 Comparative Example 18 70 50 1.4 131.1

Referring to Table 1, it can be seen that the processing temperature of the circuit boards according to Examples 1 to 6 is between 260°C and 281°C.

That is, it can be seen that the circuit board according to the embodiments can be bent by thermoforming the circuit board at a process temperature below the melting temperature of the adhesive member. Accordingly, it can be seen that mounting of the connector by melting of the adhesive member and bending by thermoforming of the circuit board can be performed at the same time.

On the other hand, it can be seen that the processing temperature of the circuit boards according to Comparative Examples 1 to 18 is less than 260°C and exceeds 281°C.

That is, the circuit board according to the embodiments allows thermoforming of the circuit board in an area exceeding the melting temperature range of the adhesive member, so that bending according to thermoforming of the circuit board can be performed along with mounting the connector according to the melting of the adhesive member. You can see that they cannot be done at the same time.

That is, if the process temperature is less than 260℃, the connector cannot be mounted because it is less than the melting temperature of the adhesive member, and if the process temperature exceeds 281℃, the layers of the circuit board may melt, so bending according to thermoforming cannot be performed. I can't.

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 appended claims.

Claims (10)

first insulating layer;
a circuit pattern disposed on the upper surface of the first insulating layer;
a second insulating layer disposed on an upper surface of the first insulating layer;
a first protective layer disposed on the lower surface of the first insulating layer; and
Comprising a second protective layer disposed on the upper surface of the second insulating layer,
A first connector and a second connector bonded by an adhesive member are disposed on the lower surface of the first insulating layer and the upper surface of the second insulating layer, respectively,
The melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers and the first and second protective layers,
A circuit board wherein the melting temperature of the adhesive member is smaller than the minimum melting temperature of the first and second insulating layers and the first and second protective layers. According to clause 1,
A circuit board where the melting temperature of the adhesive member is 260°C to 280°C. According to clause 1,
A circuit board wherein the total thickness of the protective layer including the first protective layer and the second protective layer is 0.18 to 0.26 times the total thickness of the insulating layer including the first insulating layer and the second insulating layer. According to clause 1,
A circuit board in which the maximum glass transition temperature of the insulating layer and the protective layer satisfies Equation 2 below.
formula 2
89.29X ² - 263.6X + 325.1
(where X=total thickness of protective layer/total thickness of insulating layer) According to clause 1,
A circuit board further comprising a first ground pattern disposed on a lower surface of the first insulating layer and a second ground pattern disposed on an upper surface of the second insulating layer. first insulating layer;
a circuit pattern disposed on the upper surface of the first insulating layer;
An adhesive layer disposed on the upper surface of the first insulating layer
a second insulating layer disposed on the upper surface of the adhesive layer;
a first protective layer disposed on the lower surface of the first insulating layer; and
Comprising a second protective layer disposed on the upper surface of the second insulating layer,
A first connector and a second connector bonded by an adhesive member are disposed on the lower surface of the first insulating layer and the upper surface of the second insulating layer, respectively,
The melting temperature of the adhesive member is greater than the maximum glass transition temperature of the first and second insulating layers, the first and second protective layers, and the adhesive layer,
A circuit board wherein the melting temperature of the adhesive member is smaller than the minimum melting temperature of the first and second insulating layers, the first and second protective layers, and the adhesive layer. According to clause 6,
A circuit board where the melting temperature of the adhesive member is 260°C to 280°C. According to clause 6,
A circuit board in which the total thickness of the layers including the first protective layer, the second protective layer, and the adhesive layer is 0.18 to 0.26 times the total thickness of the insulating layers including the first insulating layer and the second insulating layer. . According to clause 6,
A circuit board in which the maximum glass transition temperature of the insulating layer, the protective layer, and the adhesive layer satisfies Equation 4 below.
Formula 4
89.29X ² - 263.6X + 325.1
(where X=total thickness of protective layer and adhesive layer/total thickness of insulating layer) antenna substrate; and
It includes the circuit board of any one of claims 1 to 9 extending from the antenna board,
An antenna module in which the antenna substrate and the circuit board are integrally formed.

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