Printed circuit board and insulating film used therein

Abstract

To provide an insulation layer capable of having a low coefficient of thermal expansion and a high dielectric constant and a printed circuit board including the same.SOLUTION: The present invention relates to a printed circuit board including an insulation layer including an insulating resin and a first filler dispersed in the above insulation resin, and a wiring layer disposed on the above insulation layer, the above first filler including a core and a shell coated on the surface of the above core, and the dielectric constant of the above shell is higher than that of the above core.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a printed circuit board and an insulating film used therein. [Background technology]

[0002] As digital electronic products become smaller and more multifunctional, the functionality of cutting-edge components is also improving. Similarly, in the case of PCBs (Printed Circuit Boards), development is underway to make them thinner, more highly integrated, and finer circuits to meet high specifications. In particular, in the case of 5G antenna substrates, characteristics such as low shrinkage and high dielectric constant are required for substrate materials suitable for high-speed communication. Summary of the Invention [Problem to be solved by the invention]

[0003] One of several objects of the present invention is to provide an insulating layer that can have a low coefficient of thermal expansion and a printed circuit board including the same.

[0004] Another of several objects of the present invention is to provide an insulating layer having a high dielectric constant and a printed circuit board including the same. [Means for solving the problem]

[0005] An example printed circuit board includes an insulating layer including an insulating resin and a first filler dispersed in the insulating resin, and a wiring layer disposed on the insulating layer, wherein the first filler includes a core and a shell coated on a surface of the core, and the dielectric constant of the shell may be higher than the dielectric constant of the core.

[0006] Alternatively, according to one example, a printed circuit board may include a plurality of insulating layers, a plurality of wiring layers disposed on or between the plurality of insulating layers, and a via layer that penetrates at least one of the plurality of insulating layers and electrically connects the plurality of wiring layers, wherein at least one of the plurality of insulating layers includes an insulating sheet and an insulating resin disposed on both sides of the insulating sheet, the insulating resin and the insulating sheet each include a first and a second filler, and the density of the second filler per unit volume within the insulating sheet may be higher than the density of the first filler per unit volume within each of the plurality of insulating resins.

[0007] Alternatively, an example insulating film may include an insulating resin, a filler dispersed within the insulating resin and including a core and a shell coated on the surface of the core, wherein the dielectric constant of the shell is higher than the dielectric constant of the core, and the thermal expansion coefficient of the shell is higher than the thermal expansion coefficient of the core. [Effects of the Invention]

[0008] One of the advantages of the present invention is that it is possible to provide an insulating layer having a low thermal expansion coefficient and a printed circuit board including the insulating layer.

[0009] Another advantage of the present invention is that it is possible to provide an insulating layer having a high dielectric constant and a printed circuit board including the insulating layer. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram illustrating an example of an electronic device system. [Figure 2] FIG. 1 is a perspective view schematically illustrating an example of an electronic device. [Figure 3] 1 is a cross-sectional view schematically illustrating a printed circuit board according to a first embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view schematically illustrating a printed circuit board according to a second embodiment of the present invention. [Figure 5]FIG. 10 is a cross-sectional view schematically illustrating a printed circuit board according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional view schematically illustrating a printed circuit board according to a fourth embodiment of the present invention. [Figure 7] 1 is a cross-sectional view schematically illustrating an insulating film that can be used to manufacture an insulating layer of a printed circuit board according to a first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below with reference to the accompanying drawings, in which the shapes and sizes of elements may be exaggerated or reduced for clarity.

[0012] FIG. 1 is a block diagram illustrating an example of an electronic device system. 1, an electronic device 1000 houses a main board 1010. Chip-related components 1020, network-related components 1030, and other components 1040 are physically and / or electrically connected to the main board 1010. These components are also coupled to other electronic components described below to form various signal lines 1090.

[0013] The chip-related components 1020 include, but are not limited to, memory chips such as volatile memory (e.g., DRAM), non-volatile memory (e.g., ROM), and flash memory; application processor chips such as central processors (e.g., CPU), graphics processors (e.g., GPU), digital signal processors, encryption processors, microprocessors, and microcontrollers; and logic chips such as analog-to-digital converters and ASICs (application-specific ICs). Other types of chip-related components may also be included. These chip-related components may also be combined with each other. The chip-related components 1020 may be in the form of a package including the above-mentioned chips.

[0014] The network-related components 1030 include, but are not limited to, Wi-Fi (e.g., IEEE 802.11 family), WiMAX (e.g., IEEE 802.16 family), IEEE 802.20, LTE (long term evolution), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPS, GPRS, CDMA, TDMA, DECT, Bluetooth, 3G, 4G, 5G, and any other wireless and wired protocols designated thereafter, as well as any of numerous other wireless or wired standards and protocols. The network-related components 1030 may also be provided in a packaged form together with the chip-related components 1020.

[0015] The other components 1040 may include, but are not limited to, high-frequency inductors, ferrite inductors, power inductors, ferrite beads, LTCC (Low Temperature Co-Firing Ceramics), EMI (Electro Magnetic Interference) filters, MLCC (Multi-Layer Ceramic Capacitors), etc., and may also include passive components in the form of chip components used for various other applications. In addition, the other components 1040 may be combined with the chip-related components 1020 and / or the network-related components 1030 and provided in the form of a package.

[0016] Depending on the type of electronic device 1000, the electronic device 1000 may include other electronic components that may or may not be physically and / or electrically connected to the main board 1010. Examples of the other electronic components include, but are not limited to, a camera 1050, an antenna 1060, a display 1070, and a battery 1080. These may also include, but are not limited to, an audio codec, a video codec, a power amplifier, a compass, an accelerometer, a gyroscope, a speaker, a mass storage device (e.g., a hard disk drive), a compact disk (CD), and a digital versatile disk (DVD). It goes without saying that the electronic device 1000 may also include other components used for various purposes depending on the type of electronic device 1000.

[0017] The electronic device 1000 may be a smartphone, a personal digital assistant, a digital video camera, a digital still camera, a network system, a computer, a monitor, a tablet, a laptop, a netbook, a television, a video game, a smart watch, an automobile, etc. However, the electronic device 1000 is not limited to these, and may be any other electronic device that processes data.

[0018] FIG. 2 is a perspective view schematically illustrating an example of an electronic device. Referring to FIG. 2 , the electronic device may be, for example, a smartphone 1100. The smartphone 1100 houses a main board 1110, to which various electronic components 1120 are physically and / or electrically connected. The smartphone 1100 also houses a camera module 1130 and / or a speaker 1140. Some of the electronic components 1120 may be the above-mentioned chip-related components, such as, but not limited to, an electronic component-embedded substrate 1121. The electronic component-embedded substrate 1121 may be, but is not limited to, a multilayer printed circuit board in which electronic components are embedded. Meanwhile, the electronic device is not necessarily limited to the smartphone 1100, and may be other electronic devices as described above.

[0019] FIG. 3 is a cross-sectional view schematically illustrating a printed circuit board according to a first embodiment of the present invention. The printed circuit board 100A according to the first embodiment includes an insulating layer 101 including an insulating resin 110 and a first filler 120 dispersed in the insulating resin 110, a build-up insulating layer 102, and a wiring layer 201 disposed on the insulating layers 101 and 102. The first filler 120 includes a core 121 and a shell 122 coated on the surface of the core 121. When the printed circuit board 100A is an antenna substrate, it may also include an antenna pattern 301.

[0020] Hereinafter, each component of the printed circuit board 100A according to the first embodiment will be described in more detail.

[0021] The insulating resin 110 may be any material having electrical insulating properties. For example, a thermosetting resin such as epoxy resin or a thermoplastic resin such as polyimide may be used. Furthermore, these resins may contain an inorganic filler such as silica or a reinforcing material such as glass fiber, as in the first filler 120 of the present invention. For example, a prepreg or a photosensitive material (Photo Imageable Dielectric (PID)) may be used. Using a photosensitive material (PID) is advantageous for manufacturing high-density circuit boards because it is easier to form a fine pattern on the insulating layer 110 than using mechanical processing. Alternatively, an Ajinomoto Build-up Film (ABF) may be used. In this case, the ABF may be provided in the form of, but is not limited to, RCC (Resin Coated Copper).

[0022] The wiring layer 201 may be made of a metal material, such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or an alloy thereof. The wiring layer 201 may perform various functions depending on the design. For example, the wiring layer 201 may include a ground pattern, a power pattern, a signal pattern, or the like. Each of these patterns may have the shape of a line, a plane, or a pad. The wiring layer 201 may be formed by a plating process such as an additive process (AP), a semi-AP (SAP), a modified SAP (MSAP), or a tenting process (TT). As a result, the wiring layer 201 may include a seed layer, which is an electroless plating layer, and an electrolytic plating layer formed based on the seed layer.

[0023] Meanwhile, in the case of the printed circuit boards 100A, 100B, 100C, and 100D according to the first to fourth embodiments of the present invention, the insulating layer 101 may be composed of multiple layers, and may have a structure in which multiple build-up insulating layers 102 are built up on the insulating layer 101.

[0024] Hereinafter, the description based on the insulating layer 101 can be applied to both the insulating layer 101 and the build-up insulating layer 102 shown in FIG. 3 of the present invention.

[0025] Meanwhile, for convenience, the insulating layer 101 and the build-up insulating layer 102 can be referred to as the insulating body 100. The insulating body 100 can be used as a concept including the insulating layer 101 and the build-up insulating layer 102, and when the build-up insulating layer 102 is not included, the insulating body 100 can refer to only the insulating layer 101.

[0026] At least one layer of the insulating body 100 may include the insulating resin 110 in which the above-described first filler 120 is dispersed.

[0027] The other insulating layers in the insulating body 100 that do not include the insulating resin 110 may be made of an insulating material. Examples of insulating materials include thermosetting resins such as epoxy resins and thermoplastic resins such as polyimides. These resins may also contain a reinforcing material such as glass fiber. For example, the other insulating layers in the insulating body 100 that do not include the insulating resin 110 may be made of prepreg, but are not limited thereto. Materials that do not contain a reinforcing material such as glass fiber may include, for example, ABF. If necessary, a photosensitive insulating material such as PID (Photo Imageable Dielectric) may also be used.

[0028] The build-up insulating layer 102 disposed on the outermost layer of the build-up insulating layers 102 can function as a solder resist layer, and can have an opening that exposes at least a part of the wiring layer 201 to the outside.

[0029] The vias 401 penetrate at least a portion of the insulating body 100 and can electrically connect the wiring layers 201. The vias 401 can be made of a metal material, such as copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof. The vias 401 can include signal vias, ground vias, power vias, and the like, depending on the design. Each of the vias 401 can be a via hole completely filled with a metal material, or a via hole with a metal material formed along its wall. The vias 401 can also be formed by a plating process, such as AP, SAP, MSAP, or TT, and can include a seed layer, which is an electroless plating layer, and an electrolytic plating layer formed on the seed layer. Each of the vias can have a tapered shape, in which the width of the bottom surface is larger than the width of the top surface, or a tapered shape, in which the width of the top surface is larger than the width of the bottom surface.

[0030] In the printed circuit board 100A according to the first embodiment, the first filler 120 dispersed in the insulating resin 110 may be in the form of powder and may have a core-shell structure. By including the first filler 120 in the insulating resin 110, the physical properties of the insulating body 100 can be reinforced.

[0031] The first filler 120 may have a core-shell structure including a core 121 and a shell 122, and typical examples of materials used for the core 121 include silica (SiO2) and alumina (Al2O3). Therefore, the core 121 of the first filler 120 in the printed circuit board 100A according to the first embodiment may include a first inorganic oxide including at least one of silica (SiO2) and alumina (Al2O3).

[0032] Throughout this invention, the term "oxide" refers to a compound that contains one or more atoms of oxygen and other elements, but does not contain carbon.

[0033] Among the first inorganic oxides, silica (SiO2) has a relatively low coefficient of thermal expansion (CTE) of about 0.5 ppm / K, which can significantly contribute to reducing the CTE. Because a material having such a low CTE is used for the core 121, the insulating layer 101 of the printed circuit board 100A according to the present invention also has a low CTE, which can be advantageous in controlling warpage and preventing defects related to thermal expansion with other components.

[0034] As mentioned above, the material of the core 121 can include a material having a low coefficient of thermal expansion (CTE), so that the coefficient of thermal expansion of the core 121 may be relatively lower than the coefficient of thermal expansion of the shell 122 .

[0035] Meanwhile, the material used for the shell 122 of the first filler 120 may be a material with a high dielectric constant (Dk). The shell 122 may include one or more ferroelectric materials. For example, a second inorganic oxide including at least one of BaTiO3, BaSrTiO3, PbZrTiO3, PdLaTiO3, PdLaTiO3, PdLaZrTiO3, PdMgNbO3, and CaCuTiO3, or a mixture thereof, may be used.

[0036] For example, when barium titanate (BaTiO) is used as the shell 122 of the first filler 120, the high dielectric constant of barium titanate allows the insulating layer 101 of the printed circuit board 100A according to the first embodiment to have a high dielectric constant. In this manner, the shell 122 may include a material having a relatively high dielectric constant (Dk) compared to the core 121.

[0037] As a result, at least a portion of the insulating body 100 of the printed circuit board 100A according to the first embodiment can have a structure in which the first filler 120, characterized by the dielectric constant of the shell 122 being higher than the dielectric constant of the core 121, is dispersed within the insulating resin 110.

[0038] In this way, the first filler 120 including the core 121 with a low thermal expansion coefficient and the shell 122 with a high dielectric constant is dispersed in the insulating resin 110, so that the printed circuit board 100A according to the first embodiment can have high dielectric constant (High Dk) characteristics.

[0039] Therefore, the occurrence of warpage of the substrate due to the difference in thermal expansion coefficient between the insulating body 100 and the wiring layer 201, or between the insulating body 100 and the antenna pattern 301, is suppressed, and since it has a high dielectric constant (DK), signal loss during transmission of high-frequency signals can be prevented.

[0040] Furthermore, when the printed circuit board 100A according to the first embodiment is used as a board that can be used for transmitting high frequency signals, such as an antenna board, the area of the antenna pattern 301 can be reduced, thereby providing excellent characteristics in terms of miniaturizing the board and reducing signal loss.

[0041] At least a portion of the insulating body 100 of the printed circuit board 100A according to the first embodiment can have its coefficient of thermal expansion (CTE) and dielectric constant (Dk) adjusted according to needs and designs by adjusting the content of the first filler 120 having the above-mentioned core-shell structure dispersed in the insulating resin 110.

[0042] Therefore, the more the amount of the first filler 120 contained, the lower the thermal expansion coefficient and the higher the dielectric constant of the insulating body 100 can be, and the physical properties of the insulating body 100 and the printed circuit board 100A can be adjusted by adjusting the content as needed.

[0043] In the insulating body 100 of the printed circuit board 100A according to the first embodiment, the coating of the shell 122 formed on the surface of the core 121 is also referred to as a wet process because it can be formed by precipitating an oxide material formed from any number of solution compositions onto the core 121. The surface coating of the core 121 can also be formed via vapor phase deposition.

[0044] The wet treatment or coating may be performed on a conductive metal foil by at least one of spray coating, spin coating, dip coating, gravure coating, doctor blade, draw down rod, wire wound rod, casting knife, air knife, roll, brush, squeeze roll, kiss roll, calendaring, powder coating, electrostatic coating, vapor deposition, and sputtering.

[0045] During the casting or coating process from a solvent, the solvent can be removed using a coagulation or evaporation process. Some polymers, such as polyamic acid or epoxy, may require an additional curing step to achieve the final compound or to reach a desired level of physical properties. The curing step can be performed sequentially with the coating / casting step or as a separate step. In the latter case, a so-called green or B-stage film / coating is first produced.

[0046] The insulating resin 110 in the final structure can be uniaxially or biaxially oriented through common methods such as, but not limited to, stretching, incorporation, and tentering.

[0047] The above description of the printed circuit board 100A according to the first embodiment has been given based on the insulating body 100 having a structure in which the first filler 120 is dispersed in the insulating resin 110. However, this does not necessarily apply to all of the insulating layers 101 and build-up insulating layers 102 in the insulating body 100. For example, the first filler 120 having the above-described core-shell structure may be applied to only at least a portion of the insulating body 100.

[0048] In this case, the remaining insulating body 100, to which the first filler 120 of the core-shell structure is not applied, may comprise a general insulating material. Examples of insulating materials include thermosetting resins such as epoxy resins and thermoplastic resins such as polyimides. These resins may also contain inorganic fillers such as silica or reinforcing materials such as glass fibers. For example, prepreg may be used, but is not limited to this. For example, Ajinomoto Build-up Film (ABF) may be used. ABF may be provided in the form of Resin Coated Copper (RCC), but is not limited to this. If necessary, a photosensitive material such as Photo Imageable Dielectric (PID) may be used.

[0049] FIG. 4 is a cross-sectional view schematically illustrating a printed circuit board according to a second embodiment of the present invention. The printed circuit board 100B according to the second embodiment differs in the structure of at least a portion of the insulating body 100. Specifically, at least a portion of the insulating body 100 of the printed circuit board 100B according to the second embodiment is configured such that the insulating resin 110 used in the printed circuit board 100A according to the first embodiment is arranged to include a plurality of layers of first and second insulating resins 111 and 112, and an insulating sheet 130 is further arranged between the first and second insulating resins 111 and 112.

[0050] Therefore, the description of the printed circuit board 100A according to the first embodiment can be applied to the insulating resin 110 contained in at least a portion of the insulating body 100 and the first filler 120 dispersed in the insulating resin 110. Hereinafter, differences from the printed circuit board 100A according to the first embodiment will be mainly described.

[0051] At least a portion of the insulating body 100 of the printed circuit board 100B according to the second embodiment may further include an insulating sheet 130 disposed between the first and second insulating resins 111 and 112. In this case, as shown in the enlarged view of FIG. 4 , the insulating sheet 130 may function as a core within each insulating layer 101 or build-up insulating layer 102 of the printed circuit board 100B, and a structure in which multiple layers of insulating sheets 130 and multiple layers of insulating resins 110 are alternately arranged within the insulating layer 101 or build-up insulating layer 102 may be provided. While FIG. 4 illustrates the configuration of the printed circuit board 100B including the first and second insulating resins 111 and 112 having a two-layer structure and the insulating sheet 130 having a single-layer structure, a greater number of insulating resins or insulating sheets may also be included. This will be described in more detail in the description of the fourth embodiment below.

[0052] Each of the first and second insulating resins 111 and 112 may include a first filler 120 dispersed therein. The first filler 120 includes a core 121 and a shell 122 coated on the surface of the core 121. The core 121 may include a material having a low coefficient of thermal expansion (CTE), such as silica (SiO2), and the shell 122 may include a material having a high dielectric constant (DK), such as barium titanate (BaTiO3).

[0053] In this way, the first filler 120 including the core 121 with a low thermal expansion coefficient and the shell 122 with a high dielectric constant is dispersed in the insulating resin 110, so that the printed circuit board 100B according to the second embodiment can have high dielectric constant (High Dk) characteristics.

[0054] Therefore, the occurrence of warpage of the substrate due to the difference in thermal expansion coefficient between the insulating body 100 and the wiring layer 201, or between the insulating body 100 and the antenna pattern 301, is suppressed, and the high dielectric constant (DK) makes it possible to prevent signal loss during transmission of high-frequency signals.

[0055] The insulating sheet 130 may be manufactured into a sheet having a thickness of several micrometers by mixing ceramic powder, a binder, and a solvent to prepare a slurry, and then using a doctor blade method to form the slurry.

[0056] The ceramic powder contained in the insulating sheet 130 may be referred to as a second filler 140. The second filler 140 may have the same components and shape as the first filler 120 dispersed in the insulating resin 110. That is, the second filler 140 may also have a core-shell structure. Therefore, the second filler 140 may also have a core 141 and a shell 142 coated on the surface of the core 141.

[0057] The second filler 140 in the insulating sheet 130 may include a silica-based inorganic oxide and a barium titanate-based inorganic oxide. Throughout the present invention, the term "silica-based inorganic oxide" refers to an inorganic oxide containing silica (SiO2), and the term "barium titanate-based inorganic oxide" refers to an inorganic oxide containing barium titanate (BaTiO3). Specifically, the core 141 of the second filler 140 may include a silica-based inorganic oxide, and the shell 142 may include a barium titanate-based inorganic oxide.

[0058] Furthermore, the material of the second filler 140 is not limited to the above-mentioned silica-based inorganic oxide. Specifically, the core 141 of the second filler 140 may include a first inorganic oxide containing at least one of silica (SiO2) and alumina (Al2O3), which are used as the material of the core 121 of the first filler 120.

[0059] Furthermore, the material of the shell 141 of the second filler 140 is not limited to the barium titanate-based inorganic oxide, and may further include one or more other materials with a high dielectric constant (Dk) as a ferroelectric material, which is the material used for the shell 122 of the first filler 120. For example, the second inorganic oxide may include at least one selected from the group consisting of BaTiO3, BaSrTiO3, PbZrTiO3, PdLaTiO3, PdLaTiO3, PdLaZrTiO3, PdMgNbO3, and CaCuTiO3, or a mixture thereof.

[0060] As such, the second filler 140 of the insulating sheet 130 may contain the same components as the first filler 120. In this case, the insulating sheet 130 may contain barium titanate (BaTiO3)-based oxide and silica (SiO2-) having a relatively high density compared to the insulating resin 110 containing the first filler 120, since a slurry is prepared using the second filler 140 containing the first and second inorganic oxides and then formed into a film.

[0061] Throughout the present invention, density may refer to the volume occupied by a corresponding component within a unit volume, rather than simply meaning density (volume / mass) in physical terms. In other words, it may refer to the volume ratio of a corresponding component to other components to which it belongs.

[0062] Alternatively, density can refer to the packing ratio of a given structure relative to other structures to which it belongs.

[0063] Therefore, the ratio of the second filler 140 filling the insulating sheet 130 per unit volume inside the insulating sheet 130 may mean that the ratio is greater than the ratio of the first filler 120 filling the insulating resin 110 per the same unit volume inside the insulating resin 110.

[0064] Alternatively, the volume ratio or volume fraction of the second filler 140 within a certain volume or volume inside the insulating sheet 130 may mean that the volume ratio or volume fraction is greater than the volume ratio or volume fraction of the first filler 120 within the same size or volume of the insulating resin 110. The above description of density may be applied to the description of density below.

[0065] In this way, the second filler 140 including the core 141 with a low thermal expansion coefficient and the shell 142 with a high dielectric constant is dispersed within the insulating sheet 130, so that the printed circuit board 100B according to the second embodiment can have higher dielectric constant (High Dk) characteristics.

[0066] Therefore, the occurrence of warpage of the substrate due to the difference in thermal expansion coefficient between the insulating body 100 and the wiring layer 201, or between the insulating body 100 and the antenna pattern 301, is suppressed, and the high dielectric constant (DK) makes it possible to prevent signal loss during transmission of high-frequency signals.

[0067] As described above, the density of the second filler 140 per unit volume inside the insulating sheet 130 may be higher than the density of the first filler 120 per the same unit volume inside the insulating resin 110.

[0068] Therefore, the insulating body 100 of the printed circuit board 100B according to the second embodiment may have a structure in which the insulating sheets 130 containing the inorganic filler with a relatively high density are disposed between the insulating resins 110.

[0069] The slurry can be produced by uniformly mixing ceramic powder (ceramic raw material), additives that affect electrical properties, and sintering aids with an organic solvent, binder, dispersant, and binder resin. The ceramic raw material is primarily composed of barium titanate oxide (BaTiO3), and additives and sintering aids can be silica (SiO2-), glass, or metal oxides.

[0070] The binder may include any one selected from the group consisting of polyamino acid cellulose, polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), polyacryl esters, and combinations thereof.

[0071] The dispersant may be a non-ionic dispersant selected from the group consisting of fish oil, polyethylene glycol (PEG), alcohol polyoxyethylene ether (AE), monoglyceride, sorbitan ester, non-ionic surfactant, and combinations thereof.

[0072] In this way, by manufacturing the insulating sheet 130 by slurrying the ceramic powder, the insulating sheet 130 can contain, within the same volume, a second filler 140 containing barium titanate-based oxide (BaTiO3) and silica (SiO2-) which has a higher density than the insulating resin 110 described above.

[0073] Therefore, if the printed circuit board 100B is intended to have low coefficient of thermal expansion (Low CTE) and high dielectric constant (High Dk) characteristics, the corresponding characteristics of the printed circuit board 100B can be enhanced by configuring the printed circuit board 100B to include the insulating sheet 130 as described above.

[0074] Meanwhile, in the case of the printed circuit board 100B according to the second embodiment, the insulating body 100 maintains the same coefficient of thermal expansion (CTE) and dielectric constant (Dk) properties, while the amount of the first filler 120 in the insulating resin 110 can be reduced by disposing the insulating sheet 130 between the first and second insulating resins 111 and 112.

[0075] The greater the content of the first filler 120 contained in the insulating layers 101 and 102 inside the printed circuit board 100B, the lower the coefficient of thermal expansion (CTE) and the higher the dielectric constant (DK) can be achieved. However, if the content of the first filler 120 increases above a certain value, the amount of the first filler 120 exposed on the surface of the insulating layers 101 and 102 increases, which may result in a decrease in adhesion to other circuit patterns or wiring layers placed on the surface.

[0076] In this regard, by including an insulating sheet 130 containing a high-density ceramic material in at least a portion of the insulating body 100 of the printed circuit board 100B according to the second embodiment, a relatively small amount of the first filler 120 can be exposed on the surface of the insulating resin 110.

[0077] As a result, the layer of the insulating body 100 including the above-mentioned insulating sheet 130 can maintain a lower coefficient of thermal expansion (CTE) and a high dielectric constant (Dk) while reducing the amount of first filler 120 exposed on the surface of the printed circuit board 100B, thereby ensuring adhesion to the circuit pattern or metal material placed on the surface of the insulating layer 101 or build-up insulating layer 102 within the insulating body 100.

[0078] Furthermore, if the content of the first filler 120 is too high, the board may become brittle and break easily. However, in the case of the printed circuit board 100B according to the second embodiment, by disposing the insulating sheet 130 containing the high-density second filler 140 between the insulating resin 110 of the insulating body 100, the same dielectric constant (Dk) and coefficient of thermal expansion (CTE) can be maintained even if a relatively small amount of the first filler 120 is contained in the insulating resin 110. This prevents damage to the printed circuit board 100B due to the brittleness of the insulating body 100.

[0079] On the other hand, by including the high-density second filler 140 in the insulating sheet 130, the amount of the first filler 120 contained in the insulating resin 110 can be reduced, ensuring adhesion and reducing signal loss during high-frequency signal transmission. Furthermore, a low shrinkage rate and a high dielectric constant can be maintained even during high-speed transmission, and when used in an antenna region where an antenna pattern of an antenna substrate is arranged, the antenna pattern can be made smaller.

[0080] FIG. 5 is a cross-sectional view schematically illustrating a printed circuit board according to a third embodiment of the present invention. When compared with the printed circuit board 100B according to the second embodiment, the printed circuit board 100C according to the third embodiment has a different structure of the first filler 120 inside the insulating resin 110.

[0081] Therefore, the same description as for the printed circuit board 100B according to the second embodiment can be applied to the arrangement of the insulating resin 110 and the insulating sheet 130. Hereinafter, differences from the printed circuit board 100B according to the second embodiment will be mainly described.

[0082] 5, the printed circuit board 100C according to the third embodiment, like the printed circuit boards 100A and 100B according to the first and second embodiments, may have a structure in which first fillers 120 are included and dispersed in a powder form within the insulating resin 110. In this case, like the first and second embodiments, the first fillers 120 included in the printed circuit board 100C according to the third embodiment may have a core-shell structure including a core 121 and a shell 122 coated on the surface of the core 121, but the specific structure differs from that of the printed circuit boards 100A and 100B according to the first and second embodiments.

[0083] In the case of the printed circuit board 100C according to the third embodiment of FIG. 5, the first filler 120 has a structure in which the materials of the core 121 and the shell 122 are reversed compared to the printed circuit boards 100A and 100B according to the first and second embodiments.

[0084] Specifically, in the case of the first filler 120 included in at least a portion of the insulating body 100 of the printed circuit board 100C according to the third embodiment, the core 121 included in the first filler 120 may be made of a material having a high dielectric constant (Dk). For example, the core 121 may include a second inorganic oxide selected from the group consisting of at least one of BaTiO3, BaSrTiO3, PbZrTiO3, PdLaTiO3, PdLaTiO3, PdLaZrTiO3, PdMgNbO3, and CaCuTiO3, or a mixture thereof.

[0085] Meanwhile, the shell 122 included in at least some of the first fillers 120 of the insulating body 100 of the printed circuit board 100C according to the third embodiment and coated on the surface of the core 121 may include a material having a low coefficient of thermal expansion (CTE). For example, the shell 122 may include a first inorganic oxide including at least one of silica (SiO2) and alumina (Al2O3).

[0086] As described above, the insulating layers 101 and 102 of the printed circuit board 100C according to the third embodiment also have a structure in which the first filler 120, which includes a material having a low coefficient of thermal expansion (CTE) and a material having a high dielectric constant (Dk), is dispersed within the insulating resin 110, thereby enabling the printed circuit board 100C according to the third embodiment to have characteristics of a low coefficient of thermal expansion (Low CTE) and a high dielectric constant (High Dk).

[0087] Therefore, the occurrence of warpage of the substrate due to the difference in thermal expansion coefficient between the insulating body 100 and the wiring layer 201, or between the insulating body 100 and the antenna pattern 301, is suppressed, and the high dielectric constant (DK) makes it possible to prevent signal loss during transmission of high-frequency signals.

[0088] Furthermore, because it has a high dielectric constant (High-Dk), it can have advantageous characteristics for signal transmission during high-frequency signal transmission, and when used in an antenna substrate, it can be advantageous for miniaturizing the antenna pattern.

[0089] As described above, the printed circuit board 100C according to the third embodiment may have an inverted core-shell structure of the first filler 120 in the insulating resin 110 compared to the printed circuit boards 100A and 100B according to the first and second embodiments.

[0090] Therefore, when the same content of first filler 120 is contained in the same volume of insulating resin 110 of the same insulating layers 101 and 102, it can have a relatively high dielectric constant (Dk) characteristic compared to the printed circuit boards 100A and 100B according to the first and second embodiments.

[0091] This is because the barium titanate-based inorganic oxide in the first and second embodiments 100A and 100B, which is a high-dielectric-constant material thinly coated on the surface of the core 121 as the shell 122, can function as the core 121 of the first filler 120 in the third embodiment 100C.

[0092] Similarly to the structure of the printed circuit board 100B according to the second embodiment, the printed circuit board 100C according to the third embodiment has an insulating sheet 130 disposed between multiple layers of insulating resin 110. The same description of the insulating sheet 130 as described in the second embodiment 100B above can be applied, and as a result, the printed circuit board 100C according to the third embodiment can have an insulating layer including a high-density second filler 140. The second filler 140 can include a material having a high dielectric constant and a low thermal expansion coefficient, and is distributed densely inside the insulating sheet 130.

[0093] The second filler 140 of the insulating sheet 130 may contain the same components as the first filler 120. In this case, the insulating sheet 130 is formed by preparing a slurry using the second filler 140 containing the first and second inorganic oxides and then forming it into a film. As a result, the insulating sheet 130 can contain barium titanate (BaTiO3)-based oxide and silica (SiO2-), which have a relatively high density, compared to the insulating resin 110 containing the first filler 120.

[0094] Therefore, the density of the second filler 140 per unit volume inside the insulating sheet 130 may be higher than the density of the first filler 120 per unit volume inside the insulating resin 110. As a result, the insulating body 100 of the printed circuit board 100C according to the third embodiment may also have a structure in which the insulating sheet 130 including the inorganic filler with a relatively high density is disposed between the insulating resins 110.

[0095] With the structure of the third embodiment 100C described above, even if the content of the first filler 120 in the insulating resin 110 is reduced, the insulating sheet 130 can maintain the characteristics of a high dielectric constant and a low thermal expansion coefficient.

[0096] Furthermore, by reducing the content of the first filler 120, the amount of the first filler 120 exposed on the surface of the printed circuit board 100C can be reduced, thereby ensuring adhesion between the printed circuit board 100C and other external circuit patterns or wiring layers.

[0097] FIG. 6 is a cross-sectional view schematically illustrating a printed circuit board according to a fourth embodiment of the present invention. When compared with the insulating body 100 of the printed circuit board 100B according to the second embodiment of FIG. 4, the printed circuit board 100D according to the fourth embodiment differs in the structure of the insulating sheet 130.

[0098] Therefore, the description of the printed circuit board 100B according to the second embodiment can be applied to the respective structures or physical properties of the insulating resin 110 and the first filler 120 in the insulating body 100. Hereinafter, differences from the printed circuit board 100B according to the second embodiment will be mainly described.

[0099] Referring to FIG. 6, in the case of the printed circuit board 100D according to the fourth embodiment, in comparison with the second embodiment 100B, at least a portion of the insulating body 100 may have a plurality of insulating sheets 130 therein, and may include first and second insulating sheets 131 and 132, and the insulating resin 110 may also include a plurality of layers of first to third insulating resins 111, 112, and 113.

[0100] Therefore, in comparison with the insulating layer 101 or build-up insulating layer 102 in each of Figures 4 and 5, where the insulating sheet 130 is arranged between the first and second insulating resins 111 and 112 and can function as a core layer, the fourth embodiment 100D can have a structure in which insulating resins 111, 112, and 113 and insulating sheets 131 and 132 are alternately stacked inside the insulating layer 101 or build-up insulating layer 102.

[0101] The same description as for the insulating sheet 130 of the second and third embodiments 100B and 100C can be applied to the first and second insulating sheets 131 and 132. Therefore, the first and second insulating sheets 131 and 132 can be fabricated to have a film shape after a material having a low coefficient of thermal expansion (CTE), such as silica (SiO2), and a material having a high dielectric constant (DK), such as barium titanate (BaTiO3), are mixed in the form of a slurry.

[0102] In the printed circuit board 100D according to the fourth embodiment, the first and second insulating sheets 131, 132 are arranged between the first to third insulating resins 111, 112, 113 in at least one layer of the insulating body 100, thereby allowing the second filler 140 to be contained at a higher density in the printed circuit board 100D.

[0103] Therefore, it is possible to include a higher density material with a low thermal expansion coefficient and a high dielectric constant material, and accordingly, even if the first to third insulating resins 111, 112, 113 contain a relatively small amount of first filler 120, the second filler 140 in the first and second insulating sheets 131, 132 can exhibit the characteristics of a low thermal expansion coefficient and a high dielectric constant.

[0104] Furthermore, in comparison with the insulating body 100 of the printed circuit board 100B according to the second embodiment of FIG. 4, the printed circuit board 100D according to the fourth embodiment of FIG. 6 may include multiple layers of first and second insulating sheets 131 and 132, thereby reducing the content of the first filler 120 inside while maintaining the same dielectric constant and thermal expansion coefficient as the printed circuit board 100B according to the second embodiment.

[0105] Therefore, as shown in FIG. 6, the first to third insulating resin layers 111, 112, and 113 may each have a lower density of the first filler 120 therein than the insulating resin layers 111 and 112 of the printed circuit board 100B according to the second embodiment.

[0106] This further reduces the amount of first filler 120 exposed on the outer surface of the insulating body 100, thereby achieving the effect of further increasing the adhesion with the wiring layer 201 or antenna pattern 301 arranged on the surface of the insulating body 100.

[0107] On the other hand, Figure 6 shows a structure in which at least one layer of the insulating body 100 includes three layers of first to third insulating resins 111, 112, 113 and two layers of first and second insulating sheets 131, 132 between them, but a greater number of insulating resins 110 and / or insulating sheets 130 may be included, or a smaller number of insulating resins 110 and / or insulating sheets 130 may be included.

[0108] In this manner, by disposing the additional insulating sheet 130, the content of the first filler 120 inside the insulating resin 110 can be further reduced, thereby further ensuring the adhesion between the insulating body 100 and the wiring layer 201 / antenna pattern 301.

[0109] FIG. 7 is a cross-sectional view schematically illustrating an insulating film that can be used to manufacture an insulating layer of a printed circuit board according to a first embodiment of the present invention. 7 may be protected by protective films formed of polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), polyethylene (PE), etc., which may be disposed on the top / bottom of the insulating film 100E as protective layers. When the insulating film 100E is later laminated on a structure such as a printed circuit board, the protective films may be removed.

[0110] The insulating film 100E may include an insulating resin 110 and a first filler 120 dispersed in the form of powder in the insulating resin 110. In this case, the first filler 120 may include, as described above, a core 121 including a material having a low thermal expansion coefficient, and a shell 122 coated on the surface of the core 121 and including a material having a high dielectric constant.

[0111] Accordingly, the insulating film 100E has a low coefficient of thermal expansion (CTE) value, which can suppress the occurrence of warping of the board due to the difference in the coefficient of thermal expansion between the insulating layer and the wiring layer within the printed circuit board later, and a high dielectric constant (DK) which can prevent signal loss during the transmission of high-frequency signals.

[0112] Furthermore, when the insulating film 100E is used as an antenna substrate, it can include an antenna pattern, which can reduce the patch area of the antenna pattern while maintaining signal characteristics, which can be further advantageous for making the antenna pattern smaller and thinner.

[0113] The other contents are substantially the same as those described above, so duplicated contents will be omitted.

[0114] In the present invention, for convenience, expressions such as "side" and "side surface" are used to mean a left / right direction or a surface in that direction based on the drawings, expressions such as "upper side," "top," and "upper surface" are used to mean a direction or a surface in that direction based on the drawings, and expressions such as "lower side," "lower portion," and "lower surface" are used to mean a direction or a surface in that direction based on the drawings. In addition, "located on the side, upper side, upper portion, lower portion, or lower portion" is used to include not only cases where a target component is in direct contact with a reference component and the direction of the corresponding component, but also cases where a target component is located in the direction of the corresponding component but is not in direct contact with the reference component. However, these definitions of directions are used for convenience of explanation, and the scope of the claims is not particularly limited by such directional descriptions, and the concepts of "upper" and "lower" may change at any time.

[0115] In the present invention, the term "connected" refers not only to a direct connection but also to an indirect connection via an adhesive layer or the like. Furthermore, the term "electrically connected" refers to both a physical connection and a non-physical connection. The terms "first" and "second" are used to distinguish one component from another and do not limit the order and / or importance of the corresponding components. In some cases, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the scope of the present invention.

[0116] The term "one example" used in the present invention does not mean the same embodiment as another example, but is provided to emphasize and describe unique features that are different from each other. However, the above-described one example does not exclude being realized in combination with features of another example. For example, even if a feature described in a particular example is not described in another example, it can be understood as being related to the other example unless there is a description in the other example that is opposite or contradictory to the feature.

[0117] The terms used in the present invention are merely used to explain an example and are not intended to limit the present invention. In this case, the singular expression includes the plural unless the context clearly indicates otherwise. [Explanation of symbols]

[0118] 100A, 100B, 100C, 100D Printed Circuit Boards 110, 111, 112, 113 Insulating resin 120 First Filler 140 Second Filler 121, 141 cores 122, 142 shells 130, 131, 132 Insulation sheets 201 Wiring layer 301 Antenna Pattern 401 Beer

Claims

1. an insulating layer including an insulating resin and a first filler dispersed in the insulating resin; a wiring layer disposed on the insulating layer, the first filler includes a core and a shell coated on the surface of the core; The dielectric constant of the shell is higher than the dielectric constant of the core, The printed circuit board, wherein the shell comprises a second inorganic oxide selected from the group consisting of at least one of BaSrTiO 3 , PdLaTiO 3 , PdLaZrTiO 3 , and PdMgNbO 3 , or a mixture thereof.

2. The printed circuit board of claim 1 , wherein the shell has a coefficient of thermal expansion greater than the coefficient of thermal expansion of the core.

3. The core is made of silica (SiO ２ ) and alumina (Al ２ O ３ 3. The printed circuit board of claim 2, further comprising a first inorganic oxide comprising at least one of:

4. The insulating resin is composed of multiple layers, The printed circuit board according to claim 1 , wherein the insulating layer further includes an insulating sheet disposed between the plurality of layers of the insulating resin.

5. The printed circuit board of claim 4 , wherein the insulating sheet includes a second filler including a silica-based inorganic oxide and a barium titanate-based inorganic oxide.

6. The printed circuit board according to claim 5 , wherein a density of the second filler per unit volume within the insulating sheet is higher than a density of the first filler per unit volume within the insulating resin.

7. the insulating layer and the wiring layer are configured as a plurality of layers and are arranged alternately, The printed circuit board according to claim 6 , further comprising a via layer that penetrates at least one of the insulating layers and electrically connects the wiring layers.

8. A plurality of insulating layers; a plurality of wiring layers disposed on or between the plurality of insulating layers; a via layer that penetrates at least one of the insulating layers and electrically connects the wiring layers, At least one layer of the plurality of insulating layers includes an insulating sheet and an insulating resin disposed on both sides of the insulating sheet, the insulating resin and the insulating sheet contain first and second fillers, respectively; a density of the second filler per unit volume inside the insulating sheet is higher than a density of the first filler per unit volume inside each of the plurality of insulating resin layers; At least one of the plurality of insulating layers includes a plurality of insulating sheets and an insulating resin disposed on both sides of the insulating sheets, The via layer penetrates the plurality of insulating sheets and the at least one layer including insulating resin disposed on both sides of the insulating sheets.

9. The printed circuit board according to claim 8 , wherein each of the first and second fillers includes a core and a shell coated on a surface of the core.

10. The printed circuit board of claim 9 , wherein the shell has a higher dielectric constant than the core.

11. The printed circuit board of claim 10 , wherein the shell has a coefficient of thermal expansion greater than the coefficient of thermal expansion of the core.

12. the core has a higher dielectric constant than the shell; The printed circuit board of claim 9 , wherein the core has a coefficient of thermal expansion greater than the coefficient of thermal expansion of the shell.

13. Each of the insulating sheets of the insulating layers is made up of multiple layers, The printed circuit board according to claim 12 , wherein the layers of insulating resin and the layers of insulating sheets are alternately arranged.

14. The core is made of silica (SiO ２ ) and alumina (Al ２ O ３ ) a first inorganic oxide containing at least one of The shell is BaTiO ３ , BaSrTiO ３ , PbZrTiO ３ , PdLaTiO ３ , PdLaTiO ３ , PdLaZrTiO ３ , PdMgNbO ３ , and CaCuTiO ３ 12. The printed circuit board of claim 11, further comprising a second inorganic oxide selected from the group consisting of at least one of:

15. An insulating resin; a filler dispersed in the insulating resin and including a core and a shell coated on the surface of the core; the shell has a higher dielectric constant than the core; the shell has a coefficient of thermal expansion greater than the coefficient of thermal expansion of the core; An insulating film, wherein the shell comprises an inorganic oxide selected from the group consisting of at least one of BaSrTiO 3 , PdLaTiO 3 , PdLaZrTiO 3 , and PdMgNbO 3 , or a mixture thereof.

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