Printed circuit board

Abstract

The invention provides a printed circuit board. The printed circuit board comprises a first insulating layer; a first metal layer having a portion protruding beyond the first insulating layer and another portion buried in the first insulating layer; and a barrier layer disposed on the first insulating layer. The barrier layer includes an inorganic oxide film.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0180251, filed with the Korean Intellectual Property Office on December 13, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to a printed circuit board. Background Art

[0003] There is an increasing need to implement a lighter and smaller printed circuit board in mobile devices in response to the recent trend of lighter and smaller mobile devices. In addition, according to the growing demand for high-performance printed circuit boards for servers, the demand for high-density circuits that connect logic semiconductors and memory semiconductors to each other or connect logic semiconductors to logic semiconductors to each other is also rapidly increasing. Research has been continuously conducted to implement a printed circuit board that has improved reliability in its connection to electronic components such as semiconductor chips including high-density microcircuits and has improved reliability in its connection to a main board. Summary of the Invention

[0004] One aspect of the present disclosure is to provide a printed circuit board that can be connected to an electronic component including a high-density microcircuit.

[0005] Another aspect of the present disclosure is to provide a printed circuit board in which a microcircuit implementation structure protrudes to the outermost side.

[0006] Still another aspect of the present disclosure is to provide a printed circuit board having improved reliability.

[0007] According to one aspect of the present disclosure, a printed circuit board includes: a first insulating layer; a first metal layer having a part protruding beyond the first insulating layer and another part buried in the first insulating layer; and a barrier layer disposed on the first insulating layer. The barrier layer includes an inorganic oxide film.

[0008] According to another aspect of the present disclosure, a printed circuit board includes: a first insulating layer; and a first metal layer having a protruding portion protruding beyond the first insulating layer, a buried portion buried in the first insulating layer, and a protrusion protruding outward with respect to side surfaces of the buried portion and the protruding portion, wherein the protrusion is in contact with the buried portion and the protruding portion. Brief Description of the Drawings

[0009] The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Figure 1is a block diagram schematically showing an example of an electronic device system; Figure 2 is a perspective view schematically showing an electronic device according to an exemplary embodiment; Figure 3 is a cross-sectional view schematically showing a printed circuit board according to an exemplary embodiment; Figure 4 is a cross-sectional view schematically showing a printed circuit board according to another exemplary embodiment; Figures 5 to 15 is a cross-sectional view schematically showing a method of manufacturing a printed circuit board according to an exemplary embodiment. Detailed Description of the Invention

[0010] Hereinafter, the present disclosure will be described with reference to the accompanying drawings. In the drawings, for clarity, the shapes, sizes, etc. of components may be exaggerated or reduced.

[0011] Electronic device Figure 1 is a block diagram schematically showing an example of an electronic device system.

[0012] Referring to Figure 1 , the electronic device 1000 may accommodate a main board 1010. Chip-related components 1020, network-related components 1030, other components 1040, etc. may be physically and / or electrically connected to the main board 1010. These components may be connected to other electronic components described below through various signal lines 1090.

[0013] The chip-related components 1020 may include: memory chips, such as volatile memories (e.g., dynamic random access memories (DRAMs)), non-volatile memories (e.g., read-only memories (ROMs) or flash memories); application processor chips, such as central processors (e.g., central processing units (CPUs)), graphics processors (e.g., graphics processing units (GPUs)), digital signal processors, cryptographic processors, microprocessors, or microcontrollers; and logic chips, such as analog-to-digital converters (ADCs) or application-specific integrated circuits (ASICs). However, the chip-related components 1020 are not limited thereto, and may also include other types of chip-related components. In addition, the chip-related components 1020 may be combined with each other. The chip-related components 1020 may be packages including the above chips or electronic components.

[0014] The network-related components 1030 may include components that are compatible with or operate according to protocols such as: Wi-Fi (IEEE 802.11 series, etc.), WiMAX (IEEE 802.16 series, etc.), IEEE 802.20, Long-Term Evolution (LTE), Evolution-Data Optimized (Ev-DO), High-Speed Packet Access+ (HSPA+), High-Speed Downlink Packet Access+ (HSDPA+), High-Speed Uplink Packet Access+ (HSUPA+), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), Global Positioning System (GPS), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Digital Enhanced Cordless Telecommunications (DECT), Bluetooth, 3G protocols, 4G protocols, or 5G protocols, and any other wireless and wired protocols specified after the above protocols. However, the network-related components 1030 are not limited thereto, and may also include components that are compatible with or operate according to various other wireless standards or protocols or wired standards or protocols. Additionally, the network-related components 1030 may be combined with the chip-related components 1020.

[0015] The other components 1040 may include high-frequency inductors, ferrite inductors, power inductors, ferrite beads, Low Temperature Co-fired Ceramic (LTCC) components, Electromagnetic Interference (EMI) filters, Multi-Layer Ceramic Capacitors (MLCCs), etc. However, the other components 1040 are not limited thereto, and in addition to the above components, may also include passive components in the form of chip components for various other purposes. Additionally, the other components 1040 may be combined with the chip-related components 1020 and / or the network-related components 1030.

[0016] Based on the type of the electronic device 1000, the electronic device 1000 may include another electronic component that is physically and / or electrically connected to the main board 1010 or not physically and / or not electrically connected to the main board 1010. Examples of another electronic component may include a camera 1050, an antenna 1060, a display 1070, a battery 1080, etc. However, another electronic component is not limited thereto, and may be 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 Disc (CD), a Digital Versatile Disc (DVD), etc. Additionally, based on the type of the electronic device 1000, the electronic device 1000 may include another electronic component for various purposes.

[0017] The electronic device 1000 may be a smart phone, a personal digital assistant (PDA), a digital video camera, a digital camera, a network system, a computer, a monitor, a tablet personal computer (PC), a laptop PC, a netbook PC, a television, a video game console, a smart watch, an automotive component, etc. However, the electronic device 1000 is not limited thereto, and may also be any other electronic device that processes data.

[0018] Figure 2 is a perspective view schematically showing an electronic device according to an exemplary embodiment.

[0019] Referring to Figure 2 , the electronic device may be, for example, the smart phone 1100. The smart phone 1100 may accommodate a main board 1110, and various components 1120 may be physically and / or electrically connected to the main board 1110. Additionally, another electronic component (such as the camera module 1130 and / or the speaker 1140) that is physically and / or electrically connected to the main board 1110 or not physically and / or not electrically connected to the main board 1110 may be accommodated in the smart phone 1100. Some of the components 1120 may be chip-related components, for example, the component package 1121, and are not limited thereto. The component package 1121 may have the form of a printed circuit board on which electronic components including active components or passive components are surface-mounted. Optionally, the component package 1121 may have the form of a printed circuit board in which active components or passive components are embedded. Additionally, the electronic device need not be limited to the smart phone 1100, and may be another electronic device as described above.

[0020] Printed circuit board Figure 3 is a cross-sectional view schematically showing a printed circuit board according to an exemplary embodiment.

[0021] Referring to Figure 3 , the printed circuit board according to an exemplary embodiment may include: a first insulating layer 111; a first metal layer 120 including a protruding portion 121 protruding from the first insulating layer 111 and a buried portion 122 buried in the first insulating layer 111; and a barrier layer 130 provided on the first insulating layer 111, and the barrier layer 130 may include an inorganic oxide film. Additionally, in the printed circuit board according to an exemplary embodiment, the first metal layer 120 may have a protrusion 123 protruding outward on its outer peripheral surface. In other words, as Figure 3 shown, the protrusion 123 may protrude outward with respect to the side surface of the buried portion 122 and the side surface of the protruding portion 121.

[0022] The first insulating layer 111 may include an insulating material. The insulating material may include a thermosetting resin such as epoxy resin, a thermoplastic resin such as polyimide, or a material including inorganic fillers, organic fillers, and / or glass fibers (such as glass fabric in the case of glass cloth), and a thermosetting resin and / or a thermoplastic resin. The insulating material may be a photosensitive material and / or a non-photosensitive material. For example, the insulating material of the first insulating layer 111 may be an Ajinomoto build-up film (ABF), but is not limited thereto, and may include a prepreg (PPG), resin-coated copper (RCC), photosensitive dielectric (PID), FR-4, bismaleimide triazine (BT), etc. However, the insulating material is not limited thereto, and if necessary, another material with excellent rigidity may be used.

[0023] The printed circuit board according to an exemplary embodiment may have a so-called coreless structure, and the first insulating layer 111 may be disposed on the outermost side of the printed circuit board according to the exemplary embodiment. More specifically, the first insulating layer 111 may be disposed on the uppermost side of the printed circuit board, and the first metal layer 120 formed in the first insulating layer 111 may be used as a post for connecting to an electronic component such as a semiconductor chip.

[0024] The first metal layer 120 may include a metal material. The metal material may use copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), lead (Pb), titanium (Ti), or an alloy thereof. The metal material may include copper (Cu), but is not limited thereto. The first metal layer 120 may be an area for mounting an electronic component and a semiconductor chip, may be an area for connecting to a main board, etc., and may be connected to a circuit pattern to perform signal connection with another pad. The first metal layer 120 may include a plurality of metal posts, but is not limited thereto, and may also include a plurality of patterns and / or pads. Each metal post or pattern / pad of the first metal layer 120 may perform various functions based on the design. For example, the metal post or pattern / pad may include a ground pattern / pad, a power pattern / pad, a signal pattern / pad, etc. Here, the signal pattern / pad may include pads / patterns for electrical connection of various signals (e.g., data signals) other than ground signals and power signals. In addition, the pattern / pad of the first metal layer 120 may electrically exchange signals with another pattern / pad, and may also perform functions by electrically short-circuiting with another pattern / pad.

[0025] In the case where the first metal layer 120 requires high density and fine pitch to mount an electronic component (such as a semiconductor chip) on the first metal layer 120, each gap between the metal posts and / or patterns of the first metal layer 120 may become smaller. In the case of mounting an electronic component such as a passive component on the first metal layer 120, the gap of the first metal layer 120 may be larger, and the height of the first metal layer 120 may be smaller.

[0026] The first metal layer 120 may be formed using any one of a semi-additive process (SAP), a modified semi-additive process (MSAP), a through-hole filling (TT) method, and a subtractive method, and is not limited thereto. As a non-limiting example, the method of forming the first metal layer 120 may include forming the first metal layer 120 by performing electroless copper plating (e.g., chemical copper plating) and then electroplating (e.g., electrolytic copper plating), forming the first metal layer 120 by firing a paste including a metal material, and the like. The method is not limited thereto, and may also include configurations or methods that can be used by those skilled in the art. As a non-limiting example, each first metal layer 120 may include a seed layer 125 and a plating layer 126.

[0027] The seed layer 125 may be disposed on the outermost side of the first metal layer 120 and may be disposed along the upper side and the side surface of the first metal layer 120. The seed layer 125 may be a result of forming the seed layer 125 along the wall of a through-hole h (see Figures 5 to 13 ; which will be described in the manufacturing method later) formed in the temporary layer T (see Figures 8 to 10 ; which will be described in the manufacturing method later) or the first insulating layer 111. The seed layer 125 may be used as a seed to form the plating layer 126. The seed layer 125 may include an electroless layer (e.g., a chemical copper plating layer) formed by electroless plating, and is not limited thereto. The seed layer 125 may include a sputtering layer formed by sputtering instead of electroless plating, and may include both an electroless layer and a sputtering layer. The seed layer 125 is not limited thereto, and if necessary, any metal (such as copper foil) that can be used as a seed for electroplating may be used without limitation.

[0028] The plating layer 126 may be disposed on the seed layer 125 and may be formed using the seed layer 125 as a plating seed. The plating layer 126 may fill a through-hole formed in the temporary layer or the first insulating layer 111 and may be formed on the seed layer 125, and the seed layer 125 is formed on the inner wall of the through-hole. Accordingly, the plating layer 126 may be disposed on the seed layer 125 and may be formed inwardly or downwardly in the printed circuit board. The plating layer 126 may include an electroplated layer (e.g., an electrolytic copper plating layer) formed by electroplating. However, the plating layer 126 is not limited thereto, and may be formed by firing a paste including a metal material. Thus, the plating layer 126 does not have to be formed by plating. That is, the plating layer 126 is only intended to express the fact that the plating layer 126 is a separate metal layer distinguishable from the seed layer 125, the method of forming the plating layer 126 does not have to be limited by the context itself, and may also include configurations or methods that can be used by those skilled in the art.

[0029] The first metal layer 120 can be used to connect a printed circuit board to an electronic component such as a semiconductor chip, or to connect the printed circuit board to another component such as a motherboard. In particular, the first metal layer 120 may include a protrusion 121 protruding upward from the first insulating layer 111, so as to perform its connection with an electronic component having a fine pitch more smoothly, and in the case of forming an electrical connection path, defects caused by short circuit or disconnection of the connection member can be prevented. In the printed circuit board according to an exemplary embodiment, the protrusion 121 of the first metal layer 120 can be formed by forming a via hole to pass through the first insulating layer 111, the barrier layer 130, and the temporary layer, forming the first metal layer 120 to fill the via hole, and then removing the temporary layer, so that the protrusion 121 of the first metal layer 120 has a certain height.

[0030] The printed circuit board according to an exemplary embodiment can be a so-called coreless board, and a part of the first metal layer 120 provided on the uppermost side of the board can be buried in the first insulating layer 111. However, in the process of forming the first metal layer 120, the temporary layer and the barrier layer 130 can be formed first, and then the first insulating layer 111 can be formed. Therefore, although the printed circuit board according to the exemplary embodiment is a coreless board, the protrusion 121 of the first metal layer 120 can protrude beyond the first insulating layer 111.

[0031] As a non-limiting example, the first metal layer 120 may include a buried portion 122 buried in the first insulating layer 111 and a protrusion 121 protruding upward from the first insulating layer 111. The buried portion 122 can be a part of the first metal layer 120 passing through the region between the upper surface and the lower surface of the first insulating layer 111, and can correspond to the region of the first metal layer 120 provided in the first insulating layer 111. The side surface of the buried portion 122 can be covered by the first insulating layer 111.

[0032] Additionally, as another non-limiting example, the first metal layer 120 may include protrusions 123, as well as protruding portions 121 and buried portions 122. The protrusions 123 may be in contact with the protruding portions 121 and the buried portions 122. The protrusions 123 may correspond to plating feet of the first metal layer 120 that protrude outward at the outer peripheral surface of the first metal layer 120. The protrusions 123 may be formed to straddle the protruding portions 121 and the buried portions 122 of the first metal layer 120. The lower side of the protrusions 123 may be in contact with the first insulating layer 111, and the upper side of the protrusions 123 may be exposed from the first insulating layer 111 without being covered by the first insulating layer 111. The protrusions 123 may have a portion disposed in the first insulating layer 111 and another portion protruding from the first insulating layer 111. That is, the protrusions 123 may have a portion disposed inside the first insulating layer 111 and another portion disposed outside the first insulating layer 111. In other words, the protrusions 123 may include a portion disposed above one surface (e.g., the upper surface) of the first insulating layer 111 and another portion disposed below one surface of the first insulating layer 111.

[0033] The protrusions 123 may be the result of the first metal layer 120 filling the groove g (see Figure 9 and Figure 10 ; the groove g appears when a portion of the barrier layer 130 is removed). As will be described with reference to Figures 5 to 15 The protrusions 123 may be the result of the following process: after forming a through hole that passes through the temporary layer, the barrier layer 130, and the first insulating layer 111, in the process of removing a portion of the barrier layer 130, while removing a portion of the barrier layer 130 exposed to the inner wall of the through hole, a groove is formed by removing a portion of the temporary layer disposed above the barrier layer 130 and a portion of the first insulating layer 111 disposed below the barrier layer 130, and then the first metal layer 120 is formed in the process of forming the first metal layer 120 to fill the groove.

[0034] In the printed circuit board according to the exemplary embodiment, the first metal layer 120 may include the protrusions 123, so as to thereby increase the area of contact between the first metal layer 120 and the first insulating layer 111, and the protrusions 123 may be disposed on the upper surface of the first insulating layer 111 to produce an anchoring effect or the like, thereby increasing the adhesion and bonding strength between the first metal layer 120 and the first insulating layer 111. The first metal layer 120 connected to an electronic component such as a semiconductor chip may be stably bonded to the first insulating layer 111, and thus the printed circuit board according to the exemplary embodiment may have improved connection reliability.

[0035] The protrusion 123 may have an annular shape corresponding to the shape of the first metal layer 120, and is not limited thereto. As a non-limiting example, the protrusion 123 may have a greater width at its center than at its upper side and / or lower side. The width of the protrusion 123 may be measured by capturing a cut cross-section of the printed circuit board in the stacking direction using a scanning microscope or the like. The fact that the width of the protrusion 123 is greater at its center than at its upper side and / or lower side may indicate that in the cut cross-section of the printed circuit board, the middle region may have a more convex shape than the upper and lower sides. Figure 3 It is shown that the protrusion 123 has a triangular shape, is not limited thereto, and may have a curved surface or an uneven surface. Additionally, the shape of the protrusion 123 is not limited to Figure 3 the shape shown in, and may not be vertically symmetric with respect to the surface on which the barrier layer 130 is formed, which may be caused by a difference between the height of removing the temporary layer and the height of removing the first insulating layer 111 in the process of forming the groove.

[0036] The seed layer 125 of the first metal layer 120 may extend along the outer side of the protrusion 123. That is, the seed layer 125 may be disposed on the outer side of the first metal layer 120 and may extend along the protrusion 121, the protrusion 123, and the buried portion 122. The seed layer 125 may be disposed along the inner wall of the through hole and the inner wall of the groove, and the plating layer 126 may be formed on the seed layer 125. Therefore, the seed layer 125 may be disposed on the outermost side of the first metal layer 120. Here, the seed layer 125 may be thinner than the groove. Thus, the seed layer 125 may be disposed conformally along the inside of the groove and along the boundaries of the first insulating layer 111 and the temporary layer.

[0037] Additionally, it is not always possible to clearly distinguish the boundaries between the protrusion 121, the buried portion 122, and the protrusion 123 of the first metal layer 120. The boundary is a concept for distinction based on position and shape. The first metal layer 120 may be integrally formed, thus making the boundaries between the protrusion 121, the buried portion 122, and the protrusion 123 unclear. That is, the seed layer 125 disposed on the outer side of the protrusion 121 may extend along the outer side of the protrusion 123 to extend outward from the buried portion 122, and the seed layers 125 disposed in each region may be integrated with each other. Additionally, the plating layer 126 disposed in the protrusion 121 may also extend to the protrusion 123 and the buried portion 122, and the plating layers 126 disposed in each region may also be integrally formed.

[0038] The first metal layer 120 may have an upwardly tapered shape, and each of the protrusion 121 and the buried portion 122 may have an upwardly tapered shape. The fact that the first metal layer 120 has an upwardly tapered shape may indicate that the first metal layer 120 has a substantially tapered shape in which the upper width of the protrusion 121 of the first metal layer 120 is smaller than the lower width of the buried portion 122 of the first metal layer 120. The first metal layer 120 may be formed to fill a through hole passing through the temporary layer, the barrier layer 130, and the first insulating layer 111. Accordingly, the first metal layer 120 may have the same shape as the through hole. The process of forming the through hole passing through the temporary layer, the barrier layer 130, and the first insulating layer 111 may be performed vertically. Accordingly, the upper width (the width of the bottom surface of the through hole) may be smaller than the lower width (the width of the outwardly open opening of the through hole), and may have a tapered shape. However, the lower width and the upper width are not limited thereto, and for the first metal layer 120, the lower width and the upper width may be substantially the same as each other to have a non-tapered shape.

[0039] That is, the first metal layer 120 may have an upwardly tapered shape. Here, the protrusion 121 and the buried portion 122 may be tapered in substantially the same direction as each other. The printed circuit board according to an exemplary embodiment may have a coreless structure, and the first metal layer 120 may fill a through hole passing through the temporary layer, the barrier layer 130, and the first insulating layer 111. Accordingly, the first metal layer 120 may have an upwardly tapered shape.

[0040] The barrier layer 130 may be disposed on the first insulating layer 111 and may be used to separate the temporary layer and the first insulating layer 111 from each other as described below in the manufacturing method. After forming the temporary layer, the barrier layer 130 may be formed and the first insulating layer 111 may be formed, and thus a release layer may be formed between the temporary layer and the first insulating layer 111. The protrusion 121 of the first metal layer 120 may be formed by removing the temporary layer disposed above the barrier layer 130. Here, even if the temporary layer and the first insulating layer 111 include substantially the same insulating material, the barrier layer 130 may be disposed between the temporary layer and the first insulating layer 111 to prevent the first insulating layer 111 from being damaged in the process of removing the temporary layer.

[0041] The barrier layer 130 may include a material substantially different from the material of the first insulating layer 111. The barrier layer 130 may include an inorganic oxide film. The barrier layer 130 may be a thin oxide film including a metal oxide. The metal oxide may include aluminum oxide (Al 2 O 3 ), silicon dioxide (SiO 2 ), titanium dioxide (TiO 2 ), zinc oxide (ZnO), zirconium dioxide (ZrO 2 ), hafnium dioxide (HfO 2), and at least one of lanthanum oxide (La 2 O 3 ), and may further include a metal oxide doped with different metal elements. The metal oxide may include aluminum oxide (Al 2 O 3 ). Additionally, the material of the barrier layer 130 is not limited to metal oxides and may include metal materials with low reactivity, such as platinum (Pt) and ruthenium (Ru).

[0042] The barrier layer 130 may be formed using a thin film deposition method (such as an atomic layer deposition (ALD) method or a molecular vapor deposition (MVD) method). Since the barrier layer 130 is formed using a thin film deposition method, the barrier layer 130 may include an oxide film thinner than the first insulating layer 111. As a non-limiting example, the barrier layer 130 may include a thin oxide film with a thickness less than 0.1 μm (e.g., a thickness of about 0.001 μm to 0.05 μm). The barrier layer 130 may be thinner than the first insulating layer 111 and may also be thinner than the seed layer 125. Additionally, Figure 3 shows that the barrier layer 130 has a thickness similar to that of the seed layer 125, and is not limited thereto. The seed layer 125 may be thicker than the barrier layer 130. As a non-limiting example, the seed layer 125 may include a plating layer with a thickness less than 1 μm (e.g., a thickness of about 0.1 μm to 0.5 μm).

[0043] The thickness of the barrier layer 130 may be measured by capturing a cross-section of the printed circuit board in the stacking direction using a scanning microscope, etc. For example, the thickness of the barrier layer 130 may be the average value of the barrier layer 130 measured at five random points in the vertical direction (i.e., the stacking direction of the printed circuit board). This measurement method may also be applied to the thickness measurement of the seed layer 125. The seed layer 125 may be conformally disposed along the outer surface of the first metal layer 120. Therefore, the thickness of the seed layer 125 may be interpreted as the distance across the outer and inner surfaces of the seed layer 125 and may include measurement errors or errors occurring during its manufacturing process.

[0044] Since the barrier layer 130 may be formed using a thin film deposition method, the barrier layer 130 may be disposed along the upper surface of the first insulating layer 111. More specifically, the first insulating layer 111 may be formed after the barrier layer 130 is formed on the temporary layer. Therefore, the first insulating layer 111 may be stacked on the barrier layer 130 after the barrier layer 130 is formed along the temporary layer.

[0045] The barrier layer 130 may be in contact with at least a portion of the side surface of the first metal layer 120. Specifically, the barrier layer 130 may be in contact with the protrusion 123 of the first metal layer 120. Such a configuration may be the result of forming the protrusion 123 to fill a groove, which is an area where a portion of the barrier layer 130 and a portion of the first insulating layer 111 are removed.

[0046] To form a protrusion on a conventional coreless board, a process of further forming a separate metal layer on the outermost buried pattern of the coreless board may be performed, or a process of removing a portion of the outermost insulating layer may be performed. However, in the printed circuit board according to an exemplary embodiment, the barrier layer 130 may be disposed on the first insulating layer 111. Accordingly, the protrusion 121 and the buried portion 122 of the first metal layer 120 may be integrated with each other, and the first insulating layer 111 may be protected by the barrier layer 130.

[0047] Accordingly, the printed circuit board according to the exemplary embodiment may overcome the alignment problem of the protrusions having a fine pitch and may minimize an undercut defect, which is a defect occurring at the interface between two metal layers. In addition, in the process of removing the temporary layer, the printed circuit board according to the exemplary embodiment does not require a process of removing a portion of the first insulating layer 111. Accordingly, the first insulating layer 111 may be protected in the process of removing the temporary layer. As a result, defects such as a gap occurring between the outermost insulating layer and the first metal layer 120 may be avoided.

[0048] That is, different from the conventional method of performing multiple plating to have a coreless structure and a protruding structure, the present disclosure has a structural feature achieved by forming a protrusion using a single plating, and problems (such as misalignment and deviation) occurring between the protrusion and the buried portion may be avoided by having such a structure.

[0049] In addition, different from the conventional method of performing a process of removing a portion of the insulating layer to have a coreless structure and a protruding structure, the present disclosure has a structural feature achieved by the following: forming vias and grooves in the insulating layer, then using a single plating to form a metal layer to fill the vias and grooves, and easily removing the temporary layer above the barrier layer 130. Accordingly, problems (such as a gap, a depression, or a crack) occurring near the boundary between the metal layer and the insulating layer may be prevented by having such a structure.

[0050] The printed circuit board according to an exemplary embodiment may further include: a second insulating layer 112 disposed below the first insulating layer 111; a first wiring layer 151 disposed on the second insulating layer 112; and a first via layer 155 passing through at least a part of the second insulating layer 112 to connect the first wiring layer 151 and the first metal layer 120 to each other or to connect the first wiring layers 151 to each other.

[0051] The second insulating layer 112 may be a build-up insulating layer. The second insulating layer 112 may include an insulating material. The insulating material may include a thermosetting resin such as epoxy resin, a thermoplastic resin such as polyimide, or a material including inorganic fillers, organic fillers, and / or glass fibers (e.g., glass fabric in the case of glass cloth) and a thermosetting resin and / or a thermoplastic resin. The insulating material may be a photosensitive material and / or a non-photosensitive material. For example, the insulating material of the second insulating layer 112 may be an Ajinomoto build-up film (ABF), but is not limited thereto, and may include prepreg (PPG), resin-coated copper (RCC), photosensitive dielectric (PID), FR-4, bismaleimide triazine (BT), etc. However, the insulating material is not limited thereto, and if necessary, another material having excellent rigidity may be used. The second insulating layer 112 may include an insulating material of substantially the same type as the first insulating layer 111. That is, like the second insulating layer 112, the first insulating layer 111 may also be a build-up insulating layer. In addition, the first insulating layer 111 and the second insulating layer 112 may include substantially the same insulating material as each other.

[0052] The first insulating layer 111 may be thinner than the second insulating layer 112. Since the first metal layer 120 needs to be capable of fine connection, it is advantageous for the first metal layer 120 to include thin and fine pads and pillars. Therefore, in order to pass through the first insulating layer 111, the first insulating layer 111 may be implemented to be thinner than the second insulating layer 112, which is a conventional build-up layer. In addition, the thickness relationship between the first insulating layer 111 and the second insulating layer 112 does not have to be limited thereto, and the thickness of the first insulating layer 111 and the thickness of the second insulating layer 112 may be designed in various ways based on their needs. The thickness of the insulating layer may be measured by capturing a cross-section of the printed circuit board in the stacking direction using a scanning microscope or the like, and may be the average value of the thicknesses of the insulating layer measured at five random points in the vertical direction, but is not limited thereto, and as long as the thicknesses of the first insulating layer 111 and the second insulating layer 112 are compared using the same thickness measurement method.

[0053] In addition, the second insulating layer 112 may include a plurality of insulating layers, and the number and thickness of the layers may be determined by those skilled in the art according to their needs.

[0054] The first wiring layer 151 may include a metallic material. The metallic material may use copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), lead (Pb), titanium (Ti), or an alloy thereof. The metallic material may include copper (Cu), and is not limited thereto. The first wiring layer 151 may include each of an electroless plating layer (e.g., electroless copper plating layer) and an electrolytic plating layer (e.g., electrolytic copper plating layer), and is not limited thereto. The first wiring layer 151 may include a sputtering layer instead of the electroless plating layer, or include both layers. In addition, the first wiring layer 151 may further include a copper foil.

[0055] The first wiring layer 151 may include a plurality of pads / patterns and perform various functions based on a design. For example, the first wiring layer 151 may include a ground pattern / pad, a power pattern / pad, a signal pattern / pad, etc. Here, the signal pattern / pad may include pads / patterns for electrical connection of various signals (e.g., data signals) other than ground signals, power signals, etc.

[0056] As a non-limiting example, the first wiring layer 151 may include a first pad 152 and a first pattern 153. The first pad 152 may refer to a structure connected to the first via layer 155, and the first pattern 153 may be a wiring connecting the first pad 152, is not limited thereto, and may be a pattern of various shapes.

[0057] The width L2 in the horizontal direction of the first pad 152 of the first wiring layer 151 (hereinafter referred to as the width L2 of the first pad 152) may be greater than the width L1 between the two ends in the horizontal direction of the protrusion 123 of the first metal layer 120 (hereinafter referred to as the width L1 between the two ends of the protrusion 123), and the horizontal direction may be perpendicular to the stacking direction of the printed circuit board. That is, the width L1 between the two ends of the protrusion 123 of the first metal layer 120 may be smaller than the width L2 of the first pad 152 of the first wiring layer 151. The width L2 of the first pad 152 and the width L1 between the two ends of the protrusion 123 of the first metal layer 120 can be measured by capturing a cut cross-section of the printed circuit board in the stacking direction using a scanning microscope or the like. The first wiring layer 151 may be a stacked wiring layer provided in the printed circuit board. On the other hand, the first metal layer 120 may be provided on the outermost side of the printed circuit board and may be connected to an electronic component such as a semiconductor chip. Therefore, the first metal layer 120 can be finer than the first wiring layer 151. In particular, the width L1 between the two ends of the protrusion 123 of the first metal layer 120 may correspond to the maximum width of the first metal layer 120. Therefore, when the width L1 between the two ends of the protrusion 123 of the first metal layer 120 is greater than the width L2 of the first pad 152, it is not only disadvantageous for bonding the first metal layer 120 to an electronic component with a fine structure, but also increases the possibility of short-circuit defects caused by solder or the like. Therefore, when the width L1 between the two ends of the protrusion 123 of the first metal layer 120 is formed to be smaller than the width L2 of the first pad 152 of the first wiring layer 151, the connection reliability can be more favorable.

[0058] Each of the first via layers 155 may include micro-vias. The micro-vias may be filled vias formed by filling via holes with metal or conformal vias formed by providing metal along the wall surface of the via holes. The micro-vias may be arranged in a stacked type or a staggered type. Each of the first via layers 155 may include a metal, and the metal may include copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or an alloy thereof. For example, the first via layer 155 may include copper (Cu), and is not limited thereto. Each of the first via layers 155 may include an electroless plating layer (for example, an electroless copper plating layer) and an electrolytic plating layer (for example, an electrolytic copper plating layer), and is not limited thereto. The first via layer 155 may include a sputtering layer instead of an electroless plating layer, or include both layers. The first via layer 155 may perform various functions based on the corresponding design of the corresponding layer. For example, the first via layer 155 may include ground vias, power vias, signal vias, and the like.

[0059] In addition, the number of layers included in the second insulating layer 112 may be various numbers. Accordingly, the first wiring layer 151 disposed on the second insulating layer 112 and the first via layer 155 passing through at least a portion of the second insulating layer 112 may also have various numbers of layers.

[0060] In addition, the printed circuit board according to an exemplary embodiment may further include a solder resist layer 160 disposed below the second insulating layer 112. That is, the printed circuit board according to an exemplary embodiment may further include a solder resist layer 160 located at the lowermost side. The solder resist layer 160 may include an insulating material, may include a liquid-type solder resist or a film-type solder resist, is not limited thereto, and another type of insulating material may be used. The solder resist layer 160 may have an opening exposing at least a portion of the first wiring layer 151. A portion of the first wiring layer 151 exposed through the opening may then be used as a pad to be connected to another component such as a main board, and is not necessarily limited thereto.

[0061] The printed circuit board according to an exemplary embodiment may further include a surface treatment layer 140 disposed on the first metal layer 120. The surface treatment layer 140 may be disposed on the first metal layer 120 and may cover an area of the first metal layer 120 exposed from the first insulating layer 111. That is, the surface treatment layer 140 may cover at least a portion of the protrusion 121 and at least a portion (e.g., the top) of the protrusion 123 of the first metal layer 120.

[0062] The surface treatment layer 140 may include any one of nickel (Ni), palladium (Pd), and gold (Au), and may be implemented as a plurality of metal layers. For example, the surface treatment layer 140 may be at least a portion of an electroless nickel electroless palladium immersion gold (ENEPIG) structure and may be at least a portion of an electroless nickel immersion gold (ENIG) structure. The surface treatment layer 140 is not limited thereto, and may include an organic solderability preservative (OSP) structure including an organic material. The surface treatment layer 140 may improve the adhesion between the first metal layer 120 and a connection member such as solder and signal transmission. Figure 3 It is shown that the surface treatment layer 140 includes one layer, is not limited thereto, and the surface treatment layer 140 may be implemented as a plurality of metal layers as described above.

[0063] The surface treatment layer 140 may be thicker than the barrier layer 130. As described above, the barrier layer 130 may be an oxide film deposited on the surface. However, the surface treatment layer 140 may be a plating layer formed by electroless plating and may include a plurality of metal layers. Therefore, the surface treatment layer 140 may be thicker than the barrier layer 130 including a thin oxide film.

[0064] In addition, the printed circuit board according to an exemplary embodiment is not limited to Figure 3The structure shown may also include another structure, or in some cases, some structures may be omitted. That is, the printed circuit board according to the exemplary embodiment may also include structures available to those skilled in the art.

[0065] Figure 4 is a cross-sectional view schematically showing a printed circuit board according to another exemplary embodiment.

[0066] Referring to Figure 4 , in the printed circuit board according to another exemplary embodiment, the protrusion 123 of the first metal layer 120 may have a rounded end. This shape may be because: in the process of forming the groove by removing a part of the barrier layer 130 and a part of the first insulating layer 111, the etching solution penetrates wider. The protrusion 123 may have a rounded end, so the first metal layer 120 of the printed circuit board according to another exemplary embodiment can increase its contact area with the first insulating layer 111.

[0067] In addition, in the structure other than the shape of the first metal layer 120, the same structure as that of the printed circuit board according to the exemplary embodiment can also be applied to the printed circuit board according to another exemplary embodiment, so its redundant description is omitted.

[0068] Method for manufacturing a printed circuit board Figures 5 to 15 is a cross-sectional view schematically showing a manufacturing method of a printed circuit board according to an exemplary embodiment.

[0069] The manufacturing method of the printed circuit board according to the exemplary embodiment may include: a process of forming a temporary layer T on a carrier board C; a process of forming a barrier layer 130 on the temporary layer T; a process of forming a first insulating layer 111 on the barrier layer 130; a process of forming a via hole h passing through the first insulating layer 111, the barrier layer 130, and the temporary layer T; a process of forming a groove g by removing a part of the barrier layer 130, a part of the first insulating layer 111, and a part of the temporary layer T; a process of forming a first metal layer 120 to fill the via hole h and the groove g; and a process of removing the carrier board C and the temporary layer T.

[0070] In the manufacturing method of the printed circuit board according to the exemplary embodiment, the first insulating layer 111 may be formed after the barrier layer 130 is formed on the temporary layer T, so as to prevent the first insulating layer 111 from being damaged in the process of removing the temporary layer T. In particular, even if the temporary layer T and the first insulating layer 111 include substantially the same insulating material, the first insulating layer 111 may not be damaged in the process of removing the temporary layer T. In addition, the first metal layer 120 may be formed after the via hole h and the groove g are formed, so the protrusion 121, the buried portion 122, and the protrusion 123 of the first metal layer 120 can be integrally formed with each other.

[0071] Reference Figure 5 Referring to Figure 5 , a method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of forming a temporary layer T on a carrier board C. In addition, the method may further include: forming a stop layer S on the carrier board C before the process of forming the temporary layer T on the carrier board C. In this case, the temporary layer T may be provided on the stop layer S.

[0072] The carrier board C may support an insulating layer and a wiring layer when forming the insulating layer and the wiring layer, and may be made of an insulating material or a metal material. Figure 5 It is shown that the carrier board C includes a core C1 and seed layers C2 formed on each of the two sides of the core C1, and is not limited thereto. The carrier board C may include one layer, or the seed layers C2 may include two layers. That is, the shown carrier board C is only an example, and the carrier board C may be any carrier board that can be used by those skilled in the art, and the carrier board C may be used in the present disclosure without particular limitation as long as the carrier board C can be used as a support board and can be subsequently separated or removed.

[0073] The method may further include: forming a stop layer S on the carrier board C before the process of forming the temporary layer T. The stop layer S may later perform a function of separating the carrier board C and the first metal layer 120 from each other. The stop layer S may include a metal material, and the metal material may use nickel (Ni), aluminum (Al), tin (Sn), gold (Au), lead (Pb), titanium (Ti), or an alloy thereof. The stop layer S may include nickel (Ni), and is not limited thereto. The stop layer S needs to be separated from the temporary layer T and the first metal layer 120 in a subsequent separation process. Therefore, the stop layer S may be made of a metal material different from that of the temporary layer T. The stop layer S may use any material that can easily separate the first metal layer 120 from the carrier board C in the process of removing the carrier board C, without any particular limitation.

[0074] The temporary layer T may be a temporary structure for forming the protrusion 121 of the first metal layer 120, and may be a temporary structure provided on the carrier board C and removed after forming the first metal layer 120.

[0075] The temporary layer T may include an insulating material. The insulating material may include a thermosetting resin such as epoxy resin, a thermoplastic resin such as polyimide, or a material including inorganic fillers, organic fillers, and / or glass fibers (e.g., glass fabric such as glass cloth) and a thermosetting resin and / or a thermoplastic resin. The insulating material may be a photosensitive material and / or a non-photosensitive material. For example, the insulating material may be an Ajinomoto build-up film (ABF), but is not limited thereto, and may include prepreg (PPG), resin-coated copper (RCC), photosensitive dielectric (PID), FR-4, bismaleimide triazine (BT), etc. However, the insulating material is not limited thereto, and if necessary, another material with excellent rigidity may be used. The temporary layer T may include an insulating material of substantially the same type as the first insulating layer 111. Even if the temporary layer T includes an insulating material of substantially the same type as the first insulating layer 111, the barrier layer 130 may be formed in a subsequent process. Therefore, the temporary layer T may be easily separated from the first insulating layer 111 without damaging the first insulating layer 111.

[0076] In addition, the temporary layer T is not limited thereto, and may include a metal material instead of an insulating material. In this case, the temporary layer T may include a material different from the metal material of the first metal layer 120, and the first metal layer 120 may not react in the process of removing the temporary layer T.

[0077] Referring to Figure 6 , the method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of forming a barrier layer 130 on the temporary layer T.

[0078] The barrier layer 130 may be formed using a thin film deposition method such as an atomic layer deposition (ALD) method or a molecular vapor deposition (MVD) method. When the barrier layer 130 is formed using a thin film deposition method, the barrier layer 130 may include an oxide film thinner than the temporary layer T and the first insulating layer 111. The method of forming the barrier layer 130 may be a deposition method, and the barrier layer 130 may be formed thin along the lower surface of the temporary layer T.

[0079] The barrier layer 130 may include a material different from the materials of the temporary layer T and the first insulating layer 111. Therefore, the temporary layer T may be removed more smoothly while protecting the first insulating layer 111 in the process of removing the temporary layer T (after the process of forming the first metal layer 120).

[0080] Referring to Figure 7 , the method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of forming a first insulating layer 111 on the barrier layer 130.

[0081] The description of the first insulating layer 111 is the same as that provided when describing the printed circuit board above, and the method of forming the first insulating layer 111 can use any method known as a method of forming an insulating layer and available to those skilled in the art without limitation.

[0082] Referring Figure 8 , the method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of forming a via hole h through the first insulating layer 111, the barrier layer 130, and the temporary layer T. The method of forming the via hole h can use any method that can be processed to pass through the first insulating layer 111, the barrier layer 130, and the temporary layer T without limitation. As a non-limiting example, the method can be performed by laser drilling, mechanical drilling, etc., and is not limited thereto, and any method that can pass through the insulating layer can be used without limitation. Additionally, when performing laser drilling, the method can use a carbon dioxide (CO 2 2) laser or a yttrium aluminum garnet (YAG) laser, and is not limited thereto.

[0083] Here, the via hole h can be formed by one processing, and is not limited thereto. The via hole h can also be formed by passing through the first insulating layer 111, then removing a part of the barrier layer 130, and then passing through the temporary layer T. The via hole h can pass through the temporary layer T, the barrier layer 130, and the first insulating layer 111. Therefore, the stopper layer S can be exposed through the via hole h. As Figure 8 shown, the via hole h can be processed from bottom to top. Therefore, the via hole h can have an upwardly tapered shape. Additionally, the degree of taper of the via hole h can be determined by the processing method and conditions.

[0084] Referring Figure 9 , the method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of forming a groove g. The process of forming the groove g can be performed by the following process: removing a part of the barrier layer 130 exposed to the via hole h, a part of the first insulating layer 111 adjacent to the barrier layer 130, and a part of the temporary layer T adjacent to the barrier layer 130.

[0085] The groove g may be an area for forming the protrusion 123 of the first metal layer 120. A part of the barrier layer 130, a part of the first insulating layer 111, and a part of the temporary layer T may be removed in a horizontal direction based on the through hole h or in an outward direction of the outer peripheral surface of the through hole h to form the groove g. The method of forming the groove g may be used without limitation as long as the method can remove a part of the insulating material. As a non-limiting example, the process of processing the groove g may include removing a part of the barrier layer 130, a part of the first insulating layer 111, and a part of the temporary layer T and performing a cleaning process. The process of removing a part of the barrier layer 130, a part of the first insulating layer 111, and a part of the temporary layer T may be performed by etching. The cleaning is a method of removing residues generated in the process of forming the through hole h, and may be performed by wet cleaning. After the process of removing a part of the barrier layer 130, a part of the first insulating layer 111, and a part of the temporary layer T, a wet cleaning process may be performed to remove residues generated in the process of forming the through hole h. Therefore, the solution may be concentrated in the area where a part of the barrier layer 130 is removed, and thus the groove g may be formed. When the groove g is formed, the area where the first metal layer 120 contacts the first insulating layer 111 may be larger, and thus the adhesion of the first metal layer 120 may be improved. In addition, a part of the barrier layer 130 may be removed. Therefore, compared with before the groove g is formed, the adhesion force between the temporary layer T and the barrier layer 130 may be reduced. Therefore, subsequently, the barrier layer 130 and the temporary layer T may be more easily separated from each other, and the protrusion 121 of the first metal layer 120 may be easily formed in a subsequent process.

[0086] Figure 10 It is shown that in a vertical cross-section of a printed circuit board according to an exemplary embodiment, the groove g has a triangular shape, and is not limited thereto. For example, the groove g may have a trapezoidal shape. The shape of the groove g may depend on the degree of solution penetration. For example, the groove g may have a curved surface, or an upper side and a lower side that are asymmetric with each other.

[0087] Referring to Figure 10 , a method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of forming the first metal layer 120. The process of forming the first metal layer 120 may include a process of forming a seed layer 125 along the through hole h and the groove g.

[0088] The seed layer 125 may be formed in the through hole h and the groove g, and the seed layer 125 may be disposed along the bottom of the first insulating layer 111. That is, the seed layer 125 may be conformally formed along the through hole h and the groove g. The seed layer 125 may constitute the outermost side of the first metal layer 120, and the process of forming the seed layer 125 may be performed by electroless plating, and is not limited thereto, and may also be performed by sputtering. In addition, the process of forming the seed layer 125 is not limited thereto, and any method of forming the seed layer 125 (for example, electroplating) may be used without limitation.

[0089] Refer to Figure 11 Figure 11 , a method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of forming a first metal layer 120. The process of forming the first metal layer 120 may include a process of forming a plating layer 126 on a seed layer 125.

[0090] The plating layer 126 may be provided on the seed layer 125, and the seed layer 125 may be used as a plating seed to form the plating layer 126. The plating layer 126 may be formed to fill the vias h and the grooves g, and may also be formed on the lower side of the first insulating layer 111. The plating layer 126 may be provided by electroplating, and those skilled in the art may use any method of forming the plating layer 126 without particular limitation.

[0091] Refer to Figure 12 Figure 12 , a method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of forming a first metal layer 120. The process of forming the first metal layer 120 may include completing the first metal layer 120 by removing a part of the seed layer 125 and a part of the plating layer 126.

[0092] The seed layer 125 may be used as a plating lead-in wire for the plating layer 126, and thus is formed above the entire lower surface of the first insulating layer 111. The plating layer 126 may be provided on the seed layer 125 so as to fill both the vias h and the grooves g, and may also be formed on the lower side of the first insulating layer 111. Accordingly, the seed layer 125 and the plating layer 126 may be electrically connected to each other and may not perform their respective functions. Accordingly, a part of the seed layer 125 and a part of the plating layer 126 may be removed so that each of the first metal layers 120 performs an independent function. Here, the process of removing a part of the first metal layer 120 may be performed by etching, and is not limited thereto.

[0093] In addition, refer to Figures 10 to 12 Figures 10 to 12 , which shows that the first metal layer 120 is formed by electroless plating to form the seed layer 125 and then electroplating to form the plating layer 126. It is not necessary to be limited thereto, and the method of forming the first metal layer 120 may not be limited thereto as long as the first metal layer 120 can be formed to fill the vias h and the grooves g. Any method of forming a metal layer that can be used by those skilled in the art may be used without particular limitation.

[0094] Refer to Figure 13, a method of manufacturing a printed circuit board according to an exemplary embodiment may include: a process of forming a second insulating layer 112 under a first insulating layer 111; a process of forming a first wiring layer 151 on the second insulating layer 112; and a process of forming a first via layer 155 that penetrates at least a part of the second insulating layer 112 to connect a first metal layer 120 and the first wiring layer 151 to each other or connect the first wiring layers 151 to each other. In addition, the method may further include a process of forming a solder resist layer 160 on the second insulating layer 112.

[0095] The method of forming the second insulating layer 112, the method of forming the first wiring layer 151 and the first via layer 155, and the method of forming the solder resist layer 160 may use any method of stacking insulating layers and wiring layers that can be used by those skilled in the art without limitation.

[0096] Referring to Figure 14 , a method of manufacturing a printed circuit board according to an exemplary embodiment may include a process of removing a carrier board C, a process of removing a stop layer S, and a process of removing a temporary layer T.

[0097] The process of removing the carrier board C may be performed in various ways based on the type of the carrier board C. For example, the process of removing the carrier board C may be sequentially performed by removing a copper foil after removing a core included in the carrier board, or removing the entire carrier board (i.e., removing the core and the copper foil simultaneously). The process of removing the carrier board C may be performed using a known process for separating the carrier board C without limitation.

[0098] The process of removing the stop layer S may be performed by etching, and is not limited thereto. The process of removing the stop layer S may be performed by different processes based on the material included in the stop layer S, and any process that can remove the material included in the stop layer S may be used without limitation. That is, different processes may be implemented based on the material in the stop layer S. The stop layer S may include a metal different from the metal in the first metal layer 120, so the first metal layer 120 may not be removed in the process of removing the stop layer S.

[0099] The process of removing the temporary layer T may be performed by delamination, and is not limited thereto. The process of removing the temporary layer T (such as by etching) may also be performed by different processes based on the material included in the temporary layer T, and any process that can remove the material included in the temporary layer T may be used without limitation. That is, different processes may be implemented based on the material in the temporary layer T. A barrier layer 130 may be formed between the temporary layer T and the first insulating layer 111, so the first insulating layer 111 may not be damaged in the process of removing the temporary layer T. In addition, in the process of forming a groove g, a part of the temporary layer T and a part of the barrier layer 130 may be removed, so the temporary layer T and the barrier layer 130 may be easily separated from each other.

[0100] Through the process of removing the temporary layer T, the protrusion 121 of the first metal layer 120 can protrude beyond the first insulating layer 111. That is to say, the protrusion 121 of the first metal layer 120 can be used as a metal pillar.

[0101] Referring to Figure 15 , the method for manufacturing a printed circuit board according to an exemplary embodiment may further include a process of forming a surface treatment layer 140 on the first metal layer 120. The surface treatment layer 140 can be formed on the outwardly exposed area of the first metal layer 120, and the surface treatment layer 140 can be formed on at least a part of the protrusion 121 of the first metal layer 120 and at least a part of the groove g. The surface treatment layer 140 can be formed by electroless plating and displacement plating, not necessarily limited thereto, and different manufacturing methods can be used based on the structure of the surface treatment layer 140. In addition, when having an organic film structure including an organic material, the surface treatment layer 140 can be formed by organic film coating. Thus, the method of forming the surface treatment layer 140 can use any method for forming the surface treatment layer 140 that can be used by those skilled in the art without particular limitation.

[0102] Referring to Figures 5 to 15 , each drawing shows that the components are only formed on the lower side of the carrier board C. However, a printed circuit board with a symmetric structure can be manufactured by performing the same process on the top of the carrier board C. In this case, two printed circuit boards with the same structure can be manufactured by one carrier board C. Additionally, the method is not limited thereto, and multiple printed circuit boards can be manufactured by forming multiple boards in the form of a strip on one carrier board C and then cutting each printed circuit board.

[0103] As described above, the present disclosure can provide a printed circuit board that can be connected to an electronic component having a high-density microcircuit.

[0104] The present disclosure can also provide a printed circuit board having a microcircuit implementation structure protruding to the outermost side.

[0105] The present disclosure can also provide a printed circuit board having improved reliability.

[0106] In addition, as described above in the description of the printed circuit board, the printed circuit board may further include a conventional structure that can be freely added or omitted as long as the structure does not change the technical spirit of the present disclosure.

[0107] In the present disclosure, the cross-sectional shape can be the cross-sectional shape of an object when the object is vertically cut or the cross-sectional shape of the object when the object is viewed from the side. Additionally, the planar shape can be the shape of the object when the object is horizontally cut, or can be the planar shape of the object when the object is viewed from the top or bottom.

[0108] In the present disclosure, for convenience, the upper side, the upper portion, the upper surface, etc. refer to the direction of the side where an electronic component can be mounted based on the cross-sectional orientation of the accompanying drawings, and the lower side, the lower portion, the lower surface, etc. refer to the opposite direction. However, these directions are defined for ease of explanation, and the scope of the claims is not particularly limited by the directions defined as above.

[0109] In the present disclosure, the connection between two components conceptually includes their indirect connection through an adhesive layer or the like and their direct connection. Additionally, the expression "electrically connected" conceptually includes physical connection and physical disconnection. Furthermore, terms such as "first" or "second" are only used to distinguish one component from another component, and may not limit the order or importance of the components. In some cases, without departing from the scope of the claims set forth herein, the first component may be referred to as the second component. Similarly, the second component may also be referred to as the first component.

[0110] In the present disclosure, the expression "substantially" can be determined by including process errors, positional deviations, measurement errors, etc. that occur in the manufacturing process. In one or more aspects, the term "substantially" ("about", "approximately", etc.) can provide an industry-accepted tolerance for the relativity between the corresponding term and / or item, such as a tolerance of ±1%, ±5%, or ±10% of the stated actual value and other suitable tolerances. For example, "substantially" vertical can include not only the case of being completely vertical but also the case of being approximately vertical. Additionally, "substantially" coplanar can include not only the case of being completely in the same plane but also the case of being approximately in the same plane. Additionally, "substantially" tapered can include not only the case of changing the width at a completely constant inclination rate but also the case where the width of one side and the width of the opposite side change substantially differently from each other.

[0111] In the present disclosure, the same material can include the same type of material and exactly the same material. Therefore, the specific composition ratios of the materials can be slightly different from each other, although their compositions are substantially the same as each other.

[0112] The expression "exemplary embodiment" used herein does not refer to the same exemplary embodiment, and is provided to emphasize each specific feature that is different from the features of another exemplary embodiment. However, the exemplary embodiments provided herein do not exclude implementing in combination with the features of another exemplary embodiment. For example, an element described in a specific exemplary embodiment can be understood as being related to the description of another exemplary embodiment, even if the element is not described in the other exemplary embodiment, unless a contrary or contradictory description is provided therein.

[0113] The terms used herein are only for describing exemplary embodiments and do not limit the present disclosure. Here, unless otherwise clearly explained in the context, the singular terms include their plurals.

[0114] While the exemplary embodiments have been shown and described above, it will be readily apparent to those skilled in the art that modifications and variations can be made without departing from the scope of the present disclosure as defined by the appended claims.

Claims

1. A printed circuit board, comprising: a first insulating layer; a first metal layer having a portion protruding beyond the first insulating layer and another portion buried in the first insulating layer; as well as a barrier layer, disposed on the first insulating layer, Wherein, the barrier layer comprises an inorganic oxide film.

2. The printed circuit board according to claim 1, wherein: The buried another portion of the first metal layer passes through a region between an upper surface and a lower surface of the first insulating layer.

3. The printed circuit board according to claim 1, further comprising: a second insulating layer, disposed below the first insulating layer; A first wiring layer, disposed on the second insulating layer; as well as A first via layer passes through at least a portion of the second insulating layer to connect the first wiring layer and the first metal layer to each other.

4. The printed circuit board according to claim 3, wherein: The first insulating layer and the second insulating layer include the same insulating material as each other.

5. The printed circuit board according to claim 1, wherein The barrier layer is disposed on at least a portion of the first insulating layer and contacts at least a portion of a side surface of the first metal layer.

6. The printed circuit board according to claim 1, wherein The barrier layer is thinner than the first insulating layer.

7. The printed circuit board according to claim 1, wherein: The first metal layer includes a seed layer disposed on an outer side of the first metal layer and a plating layer disposed on the seed layer, and The barrier layer is thinner than the seed layer. 8 . The printed circuit board according to claim 1 , further comprising a surface treatment layer disposed on the first metal layer.

9. The printed circuit board according to claim 8, wherein: The surface treatment layer covers the portion of the first metal layer that protrudes beyond the first insulating layer.

10. A printed circuit board, comprising: a first insulating layer; as well as The first metal layer has a protruding portion protruding beyond the first insulating layer, a buried portion buried in the first insulating layer, and a protrusion protruding outward relative to a side surface of the buried portion and a side surface of the protruding portion, wherein the protrusion is in contact with the buried portion and the protruding portion.

11. The printed circuit board according to claim 10, wherein: The protrusion has a portion disposed inside the first insulating layer and another portion disposed outside the first insulating layer.

12. The printed circuit board according to claim 10, further comprising: a second insulating layer, disposed below the first insulating layer; as well as The first wiring layer is disposed on the second insulating layer and includes a first pad and a first pattern.

13. The printed circuit board according to claim 12, wherein: A width between both ends of the protrusion in a horizontal direction is smaller than a width of the first pad in the horizontal direction.

14. The printed circuit board according to claim 10, wherein: The first metal layer includes a seed layer extending along outer sides of the protrusion, the bump, and the buried portion, and a plating layer disposed on the seed layer. 15 . The printed circuit board of claim 10 , further comprising a surface treatment layer disposed on the first metal layer.

16. The printed circuit board according to claim 15, wherein The surface treatment layer covers at least a portion of the protrusion and at least a portion of the projection.

17. The printed circuit board according to claim 10, wherein: The buried portion has a shape tapered upward.

18. The printed circuit board according to claim 10, further comprising: a barrier layer, disposed on the first insulating layer, Wherein, the barrier layer is in contact with the protrusion.

19. The printed circuit board according to claim 10, wherein: The protruding portion, the buried portion, and the projection are formed integrally with each other.

20. The printed circuit board according to claim 10, wherein The protrusion includes a portion disposed above one surface of the first insulating layer and another portion disposed below the one surface of the first insulating layer.

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