Printed circuit board

Abstract

To provide a printed circuit board that, while realizing a cavity for mounting electronic components, can control warpage in a multilayer substrate, can mount various kinds of electronic components, and can improve reliability.SOLUTION: A printed circuit board includes a reinforcing layer 110, a first insulation layer 111 arranged on an upper side of the reinforcing layer 110, a second insulation layer 112 arranged on a lower side of the reinforcing layer 110, a first cavity C1 penetrating at least a part of the first insulation layer 111, a second cavity C2 penetrating at least a part of the second insulation layer 112, a first electronic component 161 arranged in the first cavity C1, and a second electronic component 162 arranged in the second cavity C2, where the reinforcing layer 110 has higher rigidity than the first insulation layer 111, and the thicknesses of the first insulation layer 111 and the second insulation layer 112 are substantially different from each other.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to printed circuit boards. [Background technology]

[0002] Recently, with the development of artificial intelligence (AI) technology, multi-chip packages containing memory chips such as HBM (High Bandwidth Memory) and processor chips such as CPU (Central Processing Unit), GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), and FPGA (Field Programmable Gate Array) are being used to process data that has increased exponentially. In particular, the number of CPU and GPU cores in server products has increased dramatically, leading to larger boards and multi-layered boards, resulting in larger sizes. Research is ongoing to control bending properties while mounting a variety of electronic components. Summary of the Invention [Problem to be solved by the invention]

[0003] One of the various objects of the present disclosure is to provide a printed circuit board that allows for controlled warpage in a multilayer board while realizing cavities for mounting electronic components and the like.

[0004] Another of the various objects of the present disclosure is to provide a printed circuit board onto which various types of electronic components can be mounted.

[0005] Another of the various objects of the present disclosure is to provide a printed circuit board that can improve reliability. [Means for solving the problem]

[0006] One of the various solutions proposed through the present disclosure is to provide a printed circuit board including a reinforcing layer, a first insulating layer disposed above the reinforcing layer, a second insulating layer disposed below the reinforcing layer, a first cavity penetrating at least a portion of the first insulating layer, a second cavity penetrating at least a portion of the second insulating layer, a first electronic component disposed in the first cavity, and a second electronic component disposed in the second cavity, wherein the reinforcing layer is more rigid than the first insulating layer, and the first insulating layer and the second insulating layer have substantially different thicknesses from each other.

[0007] Another of the various solutions proposed through the present disclosure is to provide a printed circuit board including a reinforcing layer containing a metal material, a first insulating layer disposed on the upper surface of the reinforcing layer, a second insulating layer disposed on the lower surface of the reinforcing layer, a first cavity penetrating the upper and lower surfaces of the first insulating layer and having the upper surface of the reinforcing layer as its bottom surface, a second cavity penetrating the upper and lower surfaces of the second insulating layer and having the lower surface of the reinforcing layer as its bottom surface, a first electronic component disposed in the first cavity, and a second electronic component disposed in the second cavity. [Effects of the Invention]

[0008] Among the various effects of the present disclosure, one effect is that it is possible to provide a printed circuit board that can control warpage in a multilayer board while realizing cavities for mounting electronic components and the like.

[0009] Another advantage of the present disclosure is that it provides a printed circuit board on which various types of electronic components can be mounted.

[0010] Another advantage of the present disclosure, among other advantages, is that it is possible to provide a printed circuit board that can improve reliability. [Brief explanation of the drawings]

[0011] [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] FIG. 1 is a cross-sectional view of a printed circuit board according to an example. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present disclosure will be described below with reference to the accompanying drawings. The shapes and sizes of elements in the drawings may be scaled (or highlighted or simplified) for clarity.

[0013] electronic equipment FIG. 1 is a block diagram illustrating an example of an electronic device system.

[0014] Referring to the drawing, 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 later) to form various signal lines 1090.

[0015] 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). Furthermore, these chip-related components 1020 can be combined with one another. The chip-related components 1020 can also be in the form of a package including the above-mentioned chips and electronic components.

[0016] The network-related components 1030 may 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 as such, as well as any of numerous other wireless or wired standards and protocols. The network-related components 1030 may also be combined with the chip-related components 1020.

[0017] The other components 1040 may include high-frequency inductors, ferrite inductors, power inductors, ferrite beads, low-temperature co-firing ceramics (LTCC), electro-magnetic interference (EMI) filters, multi-layer ceramic capacitors (MLCC), etc. However, the other components 1040 may include, but are not limited to, passive elements in the form of chip components used for various other applications. The other components 1040 may also be combined with the chip-related components 1020 and / or the network-related components 1030.

[0018] 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 other electronic components include, but are not limited to, a camera module 1050, an antenna module 1060, a display 1070, and a battery 1080. Other electronic components 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), a digital versatile disk (DVD), and the like. In addition, other electronic components used for various purposes may also be included depending on the type of electronic device 1000.

[0019] 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.

[0020] FIG. 2 is a perspective view schematically illustrating an example of an electronic device.

[0021] Referring to the drawing, the electronic device may be, for example, a smartphone 1100. The smartphone 1100 houses a motherboard 1110, to which various components 1120 are physically and / or electrically connected. Furthermore, other components, such as a camera module 1130 and / or a speaker 1140, which may or may not be physically and / or electrically connected to the motherboard 1110, are housed inside the smartphone 1100. Some of the components 1120 may be the above-described chip-related components, such as, but not limited to, a component package 1121. The component package 1121 may be in the form of a printed circuit board on which electronic components, including active and / or passive components, are mounted on a surface. Alternatively, the component package 1121 may be in the form of a printed circuit board in which active and / or passive components are embedded. Meanwhile, the electronic device is not necessarily limited to the smartphone 1100, but may be other electronic devices as described above.

[0022] printed circuit board FIG. 3 is a cross-sectional view of a printed circuit board according to an example.

[0023] Referring to FIG. 3, an example printed circuit board includes a reinforcing layer 110, a first insulating layer 111 arranged on the upper side of the reinforcing layer 110, a second insulating layer 112 arranged on the lower side of the reinforcing layer 110, a first cavity C1 penetrating at least a portion of the first insulating layer 111, a second cavity C2 penetrating at least a portion of the second insulating layer 112, a first electronic component 161 arranged in the first cavity C1, and a second electronic component 162 arranged in the second cavity, wherein the reinforcing layer 110 has higher stiffness than the first insulating layer 111, and the first insulating layer 111 and the second insulating layer 112 may have substantially different thicknesses.

[0024] The printed circuit board according to an example further includes a reinforcing layer 110 between the first insulating layer 111 and the second insulating layer 112 that form the core of the board, thereby ensuring the stiffness of the printed circuit board and improving the bending characteristics of the printed circuit board. Stiffness is the property of resisting shape or volume deformation when subjected to an external force. High stiffness may result in greater resistance to external force, resulting in less shape or volume deformation. In the printed circuit board according to an example, the reinforcing layer 110 may be more rigid than the first insulating layer 111 and the second insulating layer 112, which may mean that the material contained in the reinforcing layer 110 is more rigid than the material contained in the first insulating layer 111 and the second insulating layer 112. In other words, the reinforcing layer 110 may include a material having a stiffness higher than that of the first insulating layer 111 and the second insulating layer 112. Without being limited thereto, the reinforcing layer 110 may have a stiffness higher than that of the build-up insulating layer 113 described below. Furthermore, the reinforcing layer 110 may have a higher elastic modulus than the first insulating layer 111 and the second insulating layer 112. The elastic modulus can be defined as the ratio of stress to deformation and can be used as a measure of the rigidity of a material. Therefore, when the reinforcing layer 110 is more rigid than the first insulating layer 111 and the second insulating layer 112, it can mean that the material of the reinforcing layer 110 has a higher elastic modulus than the material of the first insulating layer 111 and the second insulating layer 112. The elastic modulus of the reinforcing layer 110 and the first insulating layer 111 can be determined by directly analyzing test specimens of the reinforcing layer 110 and the first insulating layer 111, respectively, but is not limited thereto. The material used as the reinforcing layer 110 can be analyzed to use the elastic modulus of this material as a comparison, or the material used as the first insulating layer 111 can be analyzed to use the elastic modulus of this material as a comparison. As a non-limiting example, when the reinforcing layer 110 includes a metal material, the metal material may have a higher elastic modulus than the organic insulating material included in the first insulating layer 111 or the second insulating layer 112.

[0025] The reinforcing layer 110 may include a material having higher rigidity than the first insulating layer 111 or the second insulating layer 112. As a non-limiting example, the reinforcing layer 110 may include a metal material. That is, the printed circuit board according to one example may be a so-called metal core substrate in which the reinforcing layer 110 includes a metal material. Examples of the metal material include copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof. Also, alloys such as stainless steel (SUS) or invar may be used. When the reinforcing layer 110 includes a metal material, it may have higher rigidity than the first insulating layer 111 and the second insulating layer 112, which include organic insulating resins. Meanwhile, when the reinforcing layer 110 includes a metal material, the reinforcing layer 110 may be connected to a ground to improve grounding characteristics, and may also be used as a heat dissipation means. In addition to improving bending characteristics, the reinforcing layer 110 may have various other effects due to its rigidity.

[0026] However, the reinforcing layer 110 may include a glass material, without being limited thereto. In this case, the printed circuit board according to one example may be a glass-core type substrate in which the reinforcing layer 110 includes a glass plate or the like. The glass may include, but is not limited to, pure silicon dioxide (approximately 100% SiO), soda-lime glass, borosilicate glass, aluminosilicate glass, etc. Furthermore, other additives may be added to form glass with specific physical properties. These additives may include not only calcium carbonate (e.g., lime) and sodium carbonate (e.g., soda), but also magnesium, calcium, manganese, aluminum, lead, boron, iron, chromium, potassium, sulfur, and antimony, as well as carbonates and / or oxides of these and other elements. In this case, the reinforcing layer 110 is a layer that is distinct from materials including glass fiber (glass fiber, glass cloth, glass fabric), such as copper clad laminate (CCL) and prepreg (PPG), and may be understood as, for example, sheet glass. Even when the reinforcing layer 110 has a glass core such as a glass plate, the reinforcing layer 110 can have higher rigidity than the first insulating layer 111 and the second insulating layer 112 containing an organic insulating resin.

[0027] Because the printed circuit board according to an example includes the stiffening layer 110 as a core layer, the first insulating layer 111 and the second insulating layer 112 may have substantially different thicknesses. The substantially different thicknesses of the first insulating layer 111 and the second insulating layer 112 may mean that the thickness of the first insulating layer 111 is thicker than the thickness of the second insulating layer 112, or conversely, may mean that the thickness of the second insulating layer 112 is thicker than the thickness of the first insulating layer 111. Although FIG. 3 illustrates the first insulating layer 111 disposed above the stiffening layer 110 as being thicker than the second insulating layer 112, this is not necessarily limited thereto, and the second insulating layer 112 may also be thicker than the thickness of the first insulating layer 111. Because the printed circuit board according to an embodiment includes the highly rigid reinforcing layer 110, warping can be prevented during manufacture and use of the printed circuit board even if the first insulating layer 111 and the second insulating layer 112 have substantially different thicknesses, and different types of electronic components can be embedded in the first insulating layer 111 and the second insulating layer 112. The thicknesses of the first insulating layer 111 and the second insulating layer 112 can be measured by photographing a cross section of the printed circuit board in the stacking direction using a scanning microscope, etc., and can be measured as the distance across the top and bottom surfaces of the first insulating layer 111 and the distance across the top and bottom surfaces of the second insulating layer 112. The thicknesses of the first insulating layer 111 and the second insulating layer 112 can be the average value of the thicknesses of the first insulating layer 111 and the second insulating layer 112 measured at any five points, and may not include differences due to errors in the measurement process or manufacturing stage, etc. Since the thicknesses of the first insulating layer 111 and the second insulating layer 112 may be different from each other, the depth of the first cavity C1 formed in the first insulating layer 111 and the depth of the second cavity C2 formed in the second insulating layer 112 may be different from each other.

[0028] The first insulating layer 111 and the second insulating layer 112 may each include an organic insulating material. The insulating material may include a thermosetting resin such as an epoxy resin, a thermoplastic resin such as a polyimide, or a material containing such a resin together with an inorganic filler, an organic filler, and / or glass fiber (glass fiber, glass cloth, and / or glass fabric). For example, insulating materials such as PPG (Prepreg) and CCL (Copper Clad Laminate) may be used as the material for the first insulating layer 111 and the second insulating layer 112. The first insulating layer 111 and the second insulating layer 112 may include the same insulating material, but are not necessarily limited thereto. The first insulating layer 111 and the second insulating layer 112 may also include different insulating materials. As described above, the first insulating layer 111 and the second insulating layer 112 may include an organic insulating material, which allows the reinforcing layer 110, which includes a metal or glass plate, to have higher rigidity than the first insulating layer 111 and the second insulating layer 112.

[0029] The printed circuit board according to an example may include a first cavity C1 penetrating at least a portion of the first insulating layer 111, and may include a second cavity C2 penetrating at least a portion of the second insulating layer 112. The first cavity C1 may be a so-called through cavity penetrating the upper and lower surfaces of the first insulating layer 111, and the first cavity C1 may have the upper surface of the reinforcing layer 110 as its bottom surface. The second cavity C2 may be a through cavity penetrating the upper and lower surfaces of the second insulating layer 112, and the second cavity C2 may have the lower surface of the reinforcing layer 110 as its bottom surface. The first cavity C1 may be formed by laminating the first insulating layer 111 on the reinforcing layer 110, and then processing the reinforcing layer 110 as a cavity stopper. From the same perspective, the second cavity C2 can be formed by laminating the second insulating layer 112 on the reinforcing layer 110 and then processing the reinforcing layer 110 as a cavity stopper. Because the reinforcing layer 110 can be made of a material with higher rigidity than the first insulating layer 111 and the second insulating layer 112, the first cavity C1 and the second cavity C2 can be easily formed in the printed circuit board according to the example without including a separate stopper layer. Meanwhile, unlike printed circuit boards having a metal core as a heat dissipation means, the printed circuit board according to the example can ensure rigidity and improve bending characteristics via the reinforcing layer 110, so the reinforcing layer 110 can form the bottom surfaces of the first cavity C1 and the second cavity C2. When electronic components are placed on a metal core as a heat dissipation means, heat may concentrate on the adhesive means connecting the electronic components, which may also concentrate heat on the electronic components. However, in one example, the printed circuit board includes a reinforcing layer 110 that is more rigid than the first insulating layer 111 and the second insulating layer 112, so that the bottom surfaces of the first cavity C1 and the second cavity C2 can be configured as the reinforcing layer 110.

[0030] On the other hand, in Figure 3, the inner walls of each of the first cavity C1 and the second cavity C2 are shown as being substantially perpendicular to the bottom surfaces of each of the first cavity C1 and the second cavity C2, but this is not necessarily limited to this, and the first cavity C1 and the second cavity C2 may also have a tapered shape so that the width on the bottom side is narrower than the width on the opposite side.

[0031] The thicknesses of the first insulating layer 111 and the second insulating layer 112 may be substantially different, so that the depths of the first cavity C1 and the second cavity C2 may be substantially different. The substantially different depths of the first cavity C1 and the second cavity C2 mean that the depth of the first cavity C1 may be deeper than the depth of the second cavity C2, and conversely, the depth of the second cavity C2 may be deeper than the depth of the first cavity C1. The depths of the first cavity C1 and the second cavity C2 can be measured by photographing a cross section of the printed circuit board in the stacking direction using a scanning microscope or the like, and can be measured as the distance between the top surface of the first insulating layer 111 and the bottom surface of the first cavity C1, and the distance between the bottom surface of the second insulating layer 112 and the bottom surface of the second cavity C2. The depth of the first cavity C1 and the depth of the second cavity C2 may be measured as the average value of the depths of the first cavity C1 and the second cavity C2 measured at any five points.

[0032] The printed circuit board according to an example may include a first electronic component 161 disposed in the first cavity C1 and a second electronic component 162 disposed in the second cavity C2. The first electronic component 161 and the second electronic component 162 may each be various types of electronic components, such as active components and / or passive components. In the case of active components, they may be various types of integrated circuit (IC) dies in which hundreds to millions of components are integrated into a single chip. Passive components may be chip-type capacitors such as multi-layer ceramic capacitors (MLCCs) including silicon capacitors, or chip-type inductors such as power inductors (PIs). However, the present invention is not limited thereto, and other types of active and / or passive components may be disposed. However, the first electronic component 161 and the second electronic component 162 are not limited thereto and may be any component or element that can be mounted on a printed circuit board and connected to other semiconductor chips or electronic components to perform a function. The first electronic component 161 and the second electronic component 162 may be connected to different semiconductor chips, or may be connected to a single semiconductor chip to transmit and receive power or signals.

[0033] In this case, the first electronic component 161 and the second electronic component 162 may include different electronic components, and the first electronic component 161 and the second electronic component 162 may have substantially different thicknesses. In the printed circuit board according to an example, the reinforcement layer 110 may include a highly rigid material, so that the first insulating layer 111 and the second insulating layer 112 may have different thicknesses, and the first cavity C1 and the second cavity C2 may have different depths, so that the first electronic component 161 mounted in the first cavity C1 and the second electronic component mounted in the second cavity C2 may have different thicknesses. In other words, the printed circuit board according to an example has the reinforcement layer 110 including a highly rigid material in the center, so that the bending characteristics can be easily controlled even when different types of components are mounted.

[0034] The printed circuit board according to an example may further include an adhesive layer 170 interposed between the first electronic component 161 and the reinforcing layer 110 and between the second electronic component 162 and the reinforcing layer 110. A known adhesive means may be used for the adhesive layer 170, and the first electronic component 161 and the second electronic component 162 may be attached to the bottom surfaces of the first cavity C1 and the second cavity C2, respectively, via the adhesive layer 170. The adhesive layer 170 may be an adhesive film such as a conventional die attach film (DAF), but is not limited thereto. For example, a known tape may also be used, and any means capable of attaching electronic components or other components such as semiconductor chips to the printed circuit board may be used without limitation.

[0035] Meanwhile, in one example, the printed circuit board may further include a third cavity C3 penetrating the reinforcing layer 110, the first insulating layer 111, and the second insulating layer 112, and may further include a third electronic component 163 disposed within the third cavity C3.

[0036] In this case, the reinforcing layer 110 forming the inner wall of the third cavity C3 may have a width greater on the upper and lower sides thereof than on the center of the reinforcing layer 110. This may be achieved by stacking a first insulating layer 111 and a second insulating layer 112 on the upper and lower surfaces of the reinforcing layer 110, removing at least a portion of the first insulating layer 111 and the second insulating layer 112 to expose the upper and lower surfaces of the reinforcing layer 110, and then removing the reinforcing layer 110 from the upper and lower surfaces of the reinforcing layer 110. In this case, if an etching process is performed in the step of removing the reinforcing layer 110 after removing the first insulating layer 111 and the second insulating layer 112, the width of the upper and lower surfaces of the reinforcing layer 110 may be greater than the width of the center of the reinforcing layer 110.

[0037] On the other hand, since the third cavity C3 can penetrate the reinforcing layer 110, the first insulating layer 111 and the second insulating layer 112, the depth of the third cavity C3 can be deeper than the depths of the first cavity C1 and the second cavity C2, and the depth of the third cavity C3 can be greater than the sum of the depths of the first cavity C1 and the second cavity C2.

[0038] The third electronic component 163 may be one or more of various types of electronic components, such as an active component and / or a passive component. In the case of an active component, it may be various types of integrated circuit (IC) dies, in which hundreds to millions of components are integrated into a single chip. The passive component may be a chip-type capacitor, such as a multi-layer ceramic capacitor (MLCC) like a silicon capacitor, or a chip-type inductor, such as a power inductor (PI). However, the third electronic component 163 is not limited thereto, and other types of active and / or passive components may be disposed. However, the third electronic component 163 is not limited thereto, and any component or element that can be mounted on a printed circuit board and connected to other semiconductor chips or electronic components to perform a function may be used. The first electronic component 161 and the second electronic component 162 may be connected to different semiconductor chips, or may be connected to a single semiconductor chip to transmit and receive power or signals.

[0039] In this case, the third electronic component 163 may include an electronic component different from the first electronic component 161 and the second electronic component 162, and the thickness of the third electronic component 163 may be greater than the thicknesses of the first electronic component 161 and the second electronic component 162. As a non-limiting example, the thickness of the third electronic component 163 may be greater than the sum of the thicknesses of the first electronic component 161 and the second electronic component 162. In other words, the printed circuit board according to an example may include the reinforcing layer 110 with high rigidity, allowing various types of electronic components to be mounted thereon.

[0040] Meanwhile, the lower surface of the third electronic component 163 may be substantially coplanar with the lower surface of the second insulating layer 112. This may be the result of using a temporary adhesive layer on the lower surface of the second insulating layer 112 in the step of mounting the third electronic component 163 in the third cavity C3. That is, since the third cavity C3 has a through-cavity structure, the third electronic component 163 is fixed to the lower surface of the second insulating layer 112 with a temporary adhesive layer and then fixed with the build-up insulating layer 113 described below. Therefore, the lower surface of the third electronic component 163 may be substantially coplanar with the lower surface of the second insulating layer 112. In this case, two surfaces being substantially coplanar may mean that the two surfaces are arranged on the same plane, that is, they form a so-called coplanar surface. However, this is not limited to this, and although not shown in Figure 3, if the third electronic component 163 is fixed toward the upper surface of the first insulating layer 111, the upper surface of the third electronic component 163 may be substantially coplanar with the upper surface of the first insulating layer 111, in which case the build-up via layer 133 described later may penetrate the second insulating layer 112, thereby connecting the third electronic component 163 to the lower side.

[0041] According to an example, the printed circuit board may further include a filler 150 disposed on a side of the reinforcing layer 110. The filler 150 may include an insulating material, and may include an organic insulating material different from the first insulating layer 111 and the second insulating layer 112. For example, the filler 150 and the first insulating layer 111 and the second insulating layer 112 may be layers that are physically or materially separated from each other. This may be a material for fixing the reinforcing layer 110 in a jig, and may include, but is not limited to, an underfill or EMC (Epoxy Molding Compound), and any resin that can be used in the field of printed circuit boards may be used without limitation.

[0042] When the reinforcing layer 110 includes a metal material, a filler 150 including an insulating material may cover the side surface of the reinforcing layer 110 to prevent the side surface of the reinforcing layer 110 from being exposed to the side surface of the printed circuit board and being connected to the outside. On the other hand, when the reinforcing layer 110 includes a glass material, the filler 150 may be disposed on the side surface of the reinforcing layer 110 to prevent cracks or breakage that may occur when the side surface of the reinforcing layer 110 is exposed to the side surface of the printed circuit board.

[0043] Since the first insulating layer 111 and the second insulating layer 112 can be laminated after the filler 150 is formed on the side surface of the reinforcing layer 110, the thickness of the reinforcing layer 110 and the thickness of the filler 150 can be substantially the same, and the top and bottom surfaces of the reinforcing layer 110 and the top and bottom surfaces of the filler 150 can be substantially coplanar with each other. The positional relationship between the first through via 131, the filler 150, and the reinforcing layer 110 will be described later.

[0044] In one example, the printed circuit board may further include pads 121 arranged on the first insulating layer 111 and the second insulating layer 112, respectively, and may further include a first through via that penetrates the first insulating layer 111, the second insulating layer 112, and the reinforcing layer 110 and is spaced apart from the reinforcing layer 110 to connect the pads 121 to each other, and may further include a second through via 132 that penetrates the first insulating layer 111, the second insulating layer 112, and the reinforcing layer 110 and is in contact with the reinforcing layer 110 to connect the pads 121 to each other.

[0045] The pads 121 may be formed on the upper surface of the first insulating layer 111 and the lower surface of the second insulating layer 112, respectively, and may include a metal material. Examples of the metal material include copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), lead (Pb), titanium (Ti), and alloys thereof. The metal material preferably includes, but is not limited to, copper (Cu). Each pad 121 may perform various functions depending on the design. For example, the pads may include, but are not limited to, a signal pad, a power pad, a ground pad, and the like, and may also function as a pad for mounting electronic components and chips.

[0046] The first through via 131 and the second through via 132 may each include a metal material. The metal material may include copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), and / or alloys thereof. Preferably, the metal material may include copper (Cu), but is not limited to this. The first through via 131 and the second through via 132 may each penetrate the first insulating layer 111, the reinforcing layer 110, and the second insulating layer 112 to connect the pads 121 to each other. The first through via 131 and the second through via 132 may each perform various functions depending on the design. For example, the first through via 131 and the second through via 132 may include a ground via, a power via, a signal via, etc. The first through via 131 and the second through via 132 may have a through via structure rather than a microvia. The first through via 131 and the second through via 132 may each include, but are not limited to, a conformal via formed along the through hole. They may also include, but are not limited to, a filled via that fills the through hole. While FIG. 3 illustrates the first through via 131 and the second through via 132 as including a conformal via, in which case a metal material may be formed along the inner wall of the through hole to provide electrical connection, and a plug may be filled in the center of the through hole, this is not necessarily limited thereto, and as described above, the first through via 131 and the second through via 132 may have, but are not limited thereto, a substantially circular or elliptical shape in plan view. For example, the first through via 131 and the second through via 132 may have a polygonal shape in plan view to ensure adhesion by increasing the specific surface area, or may have a so-called flower shape in which multiple circles or ellipses overlap.

[0047] The first through via 131 may be spaced apart from the reinforcing layer 110, and a filler 150 may be disposed between the first through via 131 and the reinforcing layer 110. If the reinforcing layer 110 includes a metal material, the first through via 131 and the reinforcing layer 110 may be spaced apart from each other so that they are not connected to each other and have an open circuit design. In this case, the first through via 131 may function as a power via or a signal via. The second through via 132 may be in contact with the reinforcing layer 110. If the reinforcing layer 110 includes a metal material, the reinforcing layer 110 may function as a metal layer for grounding, and the second through via 132 may function as a ground via and, in some cases, as a heat dissipation via for heat dissipation properties.

[0048] The structure in which the first through via 131 is separated from the reinforcing layer 110 can be formed by the following manufacturing steps. First, a through hole for the first through via 131 is formed in the reinforcing layer 110, and then the through hole can be filled with a filler 150. Thereafter, the first insulating layer 111 and the second insulating layer 112 are formed on the reinforcing layer 110, respectively, and then a through hole penetrating the first insulating layer 111, the second insulating layer 112, and the filler 150 is formed to form the through hole for the first through via 131. In this way, the through hole can be separated from the reinforcing layer 110, and by forming the first through via 131 in such a through hole, a structure in which the first through via 131 is separated from the reinforcing layer 110 can be obtained.

[0049] The structure in which the second through via 132 contacts the reinforcing layer 110 can be formed through the following manufacturing steps. After forming the first insulating layer 111 and the second insulating layer 112 on the reinforcing layer 110, a through hole can be formed that penetrates the first insulating layer 111, the reinforcing layer 110, and the second insulating layer 112. Thereafter, by forming the second through via 132 in the through hole, a structure in which the second through via 132 contacts the reinforcing layer 110 can be obtained.

[0050] Although FIG. 3 shows pads 121 formed on the first insulating layer 111 and the second insulating layer 112, this is not necessarily limited to this, and wiring patterns other than the pads may also be formed on the same layer.

[0051] In one example, the printed circuit board may further include a build-up insulating layer 113 disposed on the first insulating layer 111 and the second insulating layer 112, a build-up wiring layer 123 disposed on the build-up insulating layer 113, and a build-up via layer 133 penetrating at least a portion of the build-up insulating layer 113 to connect the build-up wiring layer 123 to each other or to connect the build-up wiring layer 123 to the first electronic component 161, the second electronic component 162, or the third electronic component 163 to each other.

[0052] The build-up insulating layer 113 may include one or more insulating layers and may include an organic insulating material. The organic insulating material may include a thermosetting resin such as an epoxy resin, a thermoplastic resin such as a polyimide, or a material containing a resin together with an inorganic filler, an organic filler, and / or glass fiber (glass cloth, glass fabric). For example, the insulating material may preferably include Ajinomoto Build-up Film (ABF), but is not limited thereto. Other polymer materials may also be used. As a non-limiting example, the insulating material may be a non-photosensitive insulating material such as prepreg (PPG), a photosensitive insulating material such as photoimageable dielectric (PID), or an adhesive sheet such as bonding sheet (BS).

[0053] At this time, the build-up insulating layer 113 can fill the first cavity C1 to embed the first electronic component 161, the second cavity C2 to embed the second electronic component 162, and the third cavity C3 to embed the third electronic component 163.

[0054] The build-up wiring layer 123 may include one or more wiring layers and may include a metal. Metals may include copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), and / or alloys thereof. Preferably, but not limited to, copper (Cu). The build-up wiring layer 123 may perform various functions depending on the design. For example, it may include a signal pattern, a power pattern, a ground pattern, etc. These patterns may have various forms, such as a line, a plane, or a pad. The build-up wiring layer 123 may include an electroless plating layer (or chemical copper) and an electrolytic plating layer (or electrolytic copper). Alternatively, it may include a metal foil (or copper foil) and an electrolytic plating layer (or electrolytic copper). Alternatively, it may include a metal foil (or copper foil), an electroless plating layer (or chemical copper), and an electrolytic plating layer (or electrolytic copper). A sputtered layer may be included instead of an electroless plated layer (or chemical copper), or both may be included if desired.

[0055] The build-up via layer 133 may include a metal. Examples of the metal include copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), and / or alloys thereof. Preferably, the metal may include, but is not limited to, copper (Cu). The build-up via layer 133 may include filled vias that fill the respective via holes, but may also include conformal vias that are arranged along the wall surfaces of the via holes. The microvias may be arranged in a stacked and / or staggered manner. The build-up via layer 133 may perform various functions depending on the design. For example, the build-up via layer 133 may include a ground via, a power via, a signal via, etc. Like the build-up wiring layer 123, the build-up via layer 133 may include an electroless plating layer (or chemical copper) and an electrolytic plating layer (or electrolytic copper). Alternatively, it may include a metal foil (or copper foil) and an electrolytic plating layer (or electrolytic copper). A sputtering layer may be included instead of the electroless plating layer (or chemical copper), or both may be included if necessary. The first electronic component 161, the second electronic component 162, and the third electronic component 163 may be connected to the build-up wiring layer 123 via the build-up via layer 133, respectively.

[0056] The build-up wiring layer 123 and the build-up via layer 133 may be formed by any one of SAP (Semi Additive Process), MSAP (Modified Semi Additive Process), TT (Tenting), or subtractive processes, but are not limited thereto and may be formed by any process that can form a circuit on a printed circuit board. Also, the build-up wiring layer 123 and the build-up via layer 133 may be formed by different processes depending on the application, design, etc.

[0057] According to an example, the printed circuit board may further include a solder resist layer 141 disposed on the build-up insulating layer 113. The solder resist layer 141 may be disposed on the top and bottom sides of the printed circuit board to protect the printed circuit board from the outside. The solder resist layer 141 may be a known solder resist, and may include, but is not limited to, a liquid or film-type material. Other types of insulating materials may be used, such as a thermosetting resin and an inorganic filler dispersed in the thermosetting resin, but may not include glass fiber. The insulating resin may be a photosensitive insulating resin, and the filler may be, but is not limited to, an inorganic filler and / or an organic filler. Other polymer materials may also be used as needed. The solder resist layer 141 may have openings, through which at least a portion of the build-up wiring layer 123 may be exposed. The portion of the build-up wiring layer 123 exposed through the openings may be connected to a device such as a semiconductor chip, or may be connected to a main board or another printed circuit board. That is, the wiring layer exposed through the opening functions as a pad, and a surface treatment layer may be further formed on the pad as needed. Alternatively, a metal bump or post may be further formed on the pad, and the pad may have a pillar-like protruding structure as needed.

[0058] Meanwhile, the printed circuit board according to the example is not limited to the configuration shown in Fig. 3, and other configurations may be further included or may be omitted in some cases. For example, the build-up insulating layer 113, the build-up wiring layer 123, and the build-up via layer 133 may have a so-called rewiring structure having a fine pitch structure in some layers depending on the design, or may have various structures depending on the design, such as a cavity formed in the build-up insulating layer 113 and an electronic component, a connecting structure, a bridge, etc. embedded therein. In other words, a person skilled in the art may further include or omit available configurations.

[0059] 3, the thickness of the first insulating layer 111 located above the reinforcing layer 110 is shown to be greater than the thickness of the second insulating layer 112 located below the reinforcing layer 110, but as mentioned above, this is not necessarily limited to this. In other words, as long as the thicknesses of the first insulating layer 111 and the second insulating layer 112 can be substantially different, the size relationship and vertical arrangement relationship between them are not limited to those shown in FIG.

[0060] In addition, in FIG. 3, the connection direction of the third electronic component 163 is shown as being on the upper side, but this is not necessarily limited to this, and as mentioned above, the third electronic component 163 can also be connected on the lower side.

[0061] In the present disclosure, the cross-sectional meaning may refer to the cross-sectional shape of an object cut vertically or the cross-sectional shape of an object when viewed from the side, and the planar meaning may refer to the shape of an object cut horizontally or the planar shape of an object when viewed from the top or bottom.

[0062] In this disclosure, for convenience, terms such as upper side, top, and top surface are used to refer to the direction toward the surface on which electronic components can be mounted based on the cross section of the drawing, and terms such as lower side, bottom, and bottom surface are used to refer to the opposite direction. However, this is a definition of directions for convenience of explanation, and the scope of the claims is not particularly limited by the description of such directions.

[0063] In this disclosure, the term "connected" encompasses not only direct connection but also indirect connection via an adhesive layer or the like. Furthermore, the term "electrically connected" encompasses both physical connection and non-physical connection. Furthermore, terms such as "first" and "second" are used to distinguish one component from another and do not limit the order and / or importance of the 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 invention.

[0064] In this disclosure, "substantially" can be interpreted to include process errors, positional deviations, measurement errors, and the like that occur during the manufacturing process. For example, "substantially perpendicular" can include not only a perfectly perpendicular state but also an approximately perpendicular state. "Substantially coplanar" can include not only a completely coplanar state but also an approximately coplanar state. "Substantially different" can be understood as the opposite concept of "substantially identical," and can mean that there may be structural differences rather than differences due to errors that may occur during the manufacturing or measurement stages.

[0065] In the present disclosure, the same material can mean not only that the material is completely the same, but also that the material is of the same type, and thus the composition of the material is substantially the same, although the specific composition ratios thereof may differ slightly.

[0066] The term "one example" used in this disclosure does not mean the same embodiment as the other, but is provided to emphasize and describe each unique feature that is different from the other. However, the above-described one example does not exclude being realized in combination with the features of another example. For example, even if a matter 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 contrary or contradictory description with that matter in the other example.

[0067] The terms used in this disclosure are merely used to describe an example and are not intended to limit the disclosure. In this case, singular expressions include plural expressions unless the context clearly indicates otherwise. [Explanation of symbols]

[0068] 110 Reinforcement layer 111 First insulating layer 112 Second insulating layer 113 Build-up insulation layer 123 Build-up wiring layer 133 Build-up via layer 121 Pad 131, 132 First and second through vias 141 Solder resist layer 150 Filling material 161, 162, 163 1st, 2nd, 3rd electronic components 170 Adhesive layer C1, C2, C3 1st, 2nd, 3rd cavity 1000 electronic equipment 1010 mainboard 1020 Chip related parts 1030 Network related parts 1040 Other parts 1050 camera module 1060 Antenna Module 1070 display 1080 battery 1090 signal line 1100 smartphone 1110 Smartphone Internal Main Board 1120 Smartphone internal electronic components 1121 Smartphone Internal Antenna Module 1130 Smartphone Internal Camera Module 1140 Smartphone Internal Speaker

Claims

1. A reinforcing layer; a first insulating layer disposed on the upper side of the reinforcing layer; a second insulating layer disposed below the reinforcing layer; a first cavity extending through at least a portion of the first insulating layer; a second cavity extending through at least a portion of the second insulating layer; a first electronic component disposed in the first cavity; a second electronic component disposed in the second cavity; the reinforcing layer has a higher rigidity than the first insulating layer; The first insulating layer and the second insulating layer have substantially different thicknesses.

2. The printed circuit board of claim 1 , wherein the depth of the first cavity and the depth of the second cavity are substantially different.

3. The printed circuit board of claim 1 , wherein the thickness of the first insulating layer is greater than the thickness of the second insulating layer.

4. a third cavity penetrating the reinforcing layer, the first insulating layer, and the second insulating layer; The printed circuit board of claim 1 , further comprising: a third electronic component disposed in the third cavity.

5. The printed circuit board of claim 4 , wherein the depth of the third cavity is greater than the depth of the first cavity and the depth of the second cavity.

6. The printed circuit board according to claim 4 , wherein the reinforcing layer forming the inner wall of the third cavity has a width greater at an upper side than at a center portion of the reinforcing layer.

7. The printed circuit board according to claim 4 , wherein the thickness of the third electronic component is greater than the thickness of the first electronic component and the thickness of the second electronic component.

8. The printed circuit board of claim 1 , further comprising a filler disposed on a side surface of the stiffening layer.

9. build-up insulating layers disposed on the first insulating layer and the second insulating layer, respectively; a build-up wiring layer disposed on the build-up insulating layer, The printed circuit board of claim 1 , wherein the build-up insulating layer fills the first cavity and the second cavity.

10. The printed circuit board of claim 1 , wherein the stiffening layer comprises a metal material or a glass material.

11. a reinforcing layer including a metal material; a first insulating layer disposed on an upper surface of the reinforcing layer; a second insulating layer disposed on the lower surface of the reinforcing layer; a first cavity that penetrates the upper and lower surfaces of the first insulating layer and has the upper surface of the reinforcing layer as its bottom surface; a second cavity that penetrates the upper and lower surfaces of the second insulating layer and has the lower surface of the reinforcing layer as its bottom surface; a first electronic component disposed in the first cavity; a second electronic component disposed in the second cavity.

12. a third cavity penetrating the first insulating layer, the second insulating layer, and the reinforcing layer; The printed circuit board of claim 11 further comprising: a third electronic component disposed within the third cavity.

13. pads disposed on the first insulating layer and the second insulating layer, respectively; a first through via that penetrates the first insulating layer, the second insulating layer, and the reinforcing layer and is spaced apart from the reinforcing layer so as to connect the pads to each other; The printed circuit board of claim 11 , further comprising: a second through via that penetrates the first insulating layer, the second insulating layer, and the reinforcement layer and contacts the reinforcement layer so as to connect the pads to each other.

14. The printed circuit board according to claim 13 , further comprising a filler material interposed between the first through via and the reinforcing layer and covering a side surface of the reinforcing layer.

15. build-up insulating layers disposed on the first insulating layer and the second insulating layer, respectively; a build-up wiring layer disposed on the build-up insulating layer, The printed circuit board of claim 11 , wherein the build-up insulating layer fills the first cavity and the second cavity.

16. The printed circuit board according to claim 11 , further comprising an adhesive layer interposed between the reinforcing layer and the first electronic component.

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