Printed circuit board

Abstract

A printed circuit board is disclosed. The printed circuit board includes a plurality of insulating layers, a plurality of circuit layers disposed on at least one of an inside and an outside of the plurality of insulating layers, and a reinforcing layer disposed on one surface of the plurality of insulating layers and having a first opening having a first width and a second opening having a second width different from the first width.

Description

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2021-0058672, filed on May 6, 2021, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a printed circuit board, and more particularly, to a printed circuit board including a reinforcement layer. Background Technology

[0003] In applications requiring ultra-thin substrates (such as memory packaging substrates), there are limitations on thinning due to rigidity issues in the drive substrate. To compensate for this, a printed circuit board manufactured using the Embedded Traces Substrate (ETS) method has been developed, in which circuit layers are embedded in the surface on which electronic components are mounted, while the required rigidity of the drive board is ensured by fabricating a reinforcement layer that performs the function of enhancing rigidity. Summary of the Invention

[0004] One aspect of this disclosure is to provide a printed circuit board with enhanced rigidity.

[0005] Another aspect of this disclosure is to provide a printed circuit board including a reinforcing layer in which a plurality of openings of different widths are formed.

[0006] Another aspect of this disclosure is to provide a printed circuit board having multiple reinforcement layers stacked thereon.

[0007] According to one aspect of this disclosure, a printed circuit board may include: a plurality of insulating layers; a plurality of circuit layers disposed on at least one of the interior and exterior of the plurality of insulating layers; and a reinforcing layer disposed on one surface of the plurality of insulating layers and having a first opening and a second opening, the first opening having a first width and the second opening having a second width different from the first width.

[0008] According to one aspect of this disclosure, a printed circuit board may include: a plurality of insulating layers; a plurality of circuit layers disposed on at least one of the interior and exterior of the plurality of insulating layers; a first reinforcing layer disposed on one surface of the plurality of insulating layers; a second reinforcing layer disposed on a surface of the first reinforcing layer opposite to the surface of the first reinforcing layer that contacts the plurality of insulating layers; a first opening having a first width and passing through at least a portion of each of the first reinforcing layer and the second reinforcing layer; and a second opening having a second width different from the first width and passing through at least a portion of the first reinforcing layer. Attached Figure Description

[0009] The above and other aspects, features and advantages of this disclosure will be more clearly understood by taking into account the accompanying drawings and the following detailed description, in which:

[0010] Figure 1 It is a block diagram that schematically illustrates an example of an electronic device system;

[0011] Figure 2 It is a perspective view schematically illustrating an example of an electronic device;

[0012] Figure 3 This is a schematic cross-sectional view illustrating an example of a printed circuit board;

[0013] Figure 4 It is shown schematically. Figure 3 A cross-sectional view of a variant example of a printed circuit board;

[0014] Figure 5 It is shown schematically. Figure 3 A cross-sectional view of another variant example of a printed circuit board;

[0015] Figure 6 It is shown schematically. Figure 3 A cross-sectional view of another variant example of a printed circuit board;

[0016] Figure 7 This is a schematic cross-sectional view illustrating another example of a printed circuit board;

[0017] Figure 8 It is shown schematically. Figure 7 A cross-sectional view of a variant example of a printed circuit board;

[0018] Figure 9 It is shown schematically. Figure 7 A cross-sectional view of another variant example of a printed circuit board;

[0019] Figure 10 It is shown schematically. Figure 7 A cross-sectional view of another variant example of a printed circuit board; and

[0020] Figures 11 to 17 It is a schematic representation of manufacturing. Figure 3 A cross-sectional view of an example printed circuit board. Detailed Implementation

[0021] In the following description, this disclosure will be made with reference to the accompanying drawings. For clarity, the shapes and dimensions of the elements in the drawings may be exaggerated or reduced.

[0022] Figure 1 This is a block diagram that schematically illustrates an example of an electronic device system.

[0023] Reference Figure 1 The electronic device 1000 may house a motherboard 1010. The motherboard 1010 may include chip-related components 1020, network-related components 1030, other components 1040, etc., which are physically or electrically connected thereto. These components can be connected to other electronic components described below via various signal lines 1090.

[0024] Chip-related components 1020 may include memory chips (such as volatile memory (e.g., dynamic random access memory (DRAM)), non-volatile memory (e.g., read-only memory (ROM)), flash memory, etc.), application processor chips (such as central processing units (e.g., central processing units (CPU)), graphics processing units (e.g., graphics processing units (GPUs)), digital signal processors, cryptographic processors, microprocessors, microcontrollers, etc.), and logic chips (such as analog-to-digital converters, application-specific integrated circuits (ASICs), etc.). However, chip-related components 1020 are not limited to these and may also include other types of chip-related components. Furthermore, chip-related components 1020 may be combined with each other.

[0025] Network-related components 1030 may include components compatible with or operating according to protocols such as: Wi-Fi (IEEE 802.11 family, etc.), WiMAX (IEEE 802.16 family, etc.), IEEE 802.20, LTE, Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE+, GSM+, GSM+, GPS+, GPRS+, CDMA+, TDMA+, and DECT+. 3G, 4G, and 5G protocols, as well as any other wireless and wired protocols specified after the aforementioned protocols. However, network-related component 1030 is not limited to this, but may also include various other wireless standards or protocols or wired standards or protocols. In addition, network-related component 1030 may be combined with the aforementioned chip-related component 1020.

[0026] 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, multilayer ceramic capacitors (MLCCs), etc. However, other components 1040 are not limited to these, and may also include passive components for various other purposes. Furthermore, other components 1040 may be combined with the aforementioned chip-related components 1020 or network-related components 1030.

[0027] Depending on the type of electronic device 1000, it may include other electronic components that are physically or electrically connected to the motherboard 1010 or not physically or electrically connected to the motherboard 1010. These other electronic components may include, for example, a camera 1050, an antenna 1060, a display 1070, a battery 1080, an audio codec (not shown), a video codec (not shown), a power amplifier (not shown), a compass (not shown), an accelerometer (not shown), a gyroscope (not shown), a speaker (not shown), a mass storage unit (e.g., a hard disk drive) (not shown), an optical disc (CD) drive (not shown), a digital versatile optical disc (DVD) drive (not shown), etc. However, these other electronic components are not limited to these, and may include other electronic components for various purposes, depending on the type of electronic device 1000.

[0028] Electronic device 1000 can be a smartphone, personal digital assistant (PDA), digital camcorder, digital camera, network system, computer, monitor, tablet PC, laptop PC, netbook PC, television, video game console, smartwatch, automotive components, etc. However, electronic device 1000 is not limited to these, but can be any other electronic device capable of processing data.

[0029] Figure 2 It is a perspective view schematically showing an example of an electronic device.

[0030] Reference Figure 2 The electronic device can be, for example, a smartphone 1100. A motherboard 1110 is housed within the smartphone 1100, and various electronic components 1120 can be physically or electrically connected to the motherboard 1110. Additionally, a camera module 1130 and / or a speaker 1140, etc., can be housed within the smartphone 1100. Some of the electronic components 1120 can be the aforementioned chip-related components, such as an electronic component embedded substrate, but are not limited thereto. The electronic component embedded substrate 1121 can have the form of electronic components embedded in a multilayer electronic component embedded substrate, but the construction type is not limited thereto. On the other hand, the electronic device is not necessarily limited to the smartphone 1100, but can be other electronic devices as described above.

[0031] Figure 3 This is a cross-sectional view showing an example of a printed circuit board.

[0032] Reference Figure 3 The printed circuit board 100A1 according to the example includes: a plurality of insulating layers 110; a plurality of circuit layers 120 disposed on at least one of the interior and exterior of the plurality of insulating layers 110; a plurality of via layers 130 penetrating at least a portion of the plurality of insulating layers 110 and connecting the spaces between the plurality of circuit layers 120; a first passivation layer 210 disposed on one surface and another surface of the plurality of insulating layers 110; and a reinforcement layer 300 disposed on one surface of the plurality of insulating layers 110 and having a first opening 510 and a second opening 520, the first opening 510 having a first width W1 and the second opening 520 having a second width W2 different from the first width W1.

[0033] For example, in the printed circuit board 100A1 according to the example, as in the process described later, the reinforcing layer 300 is stacked on one surface of the plurality of insulating layers 110 and can enhance the rigidity of the printed circuit board 100A1, which is beneficial for controlling the warpage of the printed circuit board 100A1.

[0034] Furthermore, the printed circuit board 100A1 according to the example can be manufactured using a release carrier film (DCF), which will be described later. Therefore, the first circuit layer 121 of the plurality of circuit layers 120 can be embedded in another surface of the printed circuit board 100A1. Thus, the first circuit layer 121 can be implemented as a finer circuit layer. Therefore, the pitch and linewidth between the circuit patterns of the first circuit layer 121 can be made smaller than the pitch and linewidth of conventional circuit layers, wherein the pitch can refer to the average of the shortest distances connecting the centers of adjacent circuit patterns to each other, and the linewidth can refer to the average of the horizontal widths of the circuit patterns.

[0035] Furthermore, according to the example, openings of different widths can be formed in the reinforcement layer 300 of the printed circuit board 100A1. For example, a first opening 510 with a first width W1 and a second opening 520 with a second width W2 can be formed, and since the widths of the first opening 510 and the second opening 520 are different, the inner wall of the reinforcement layer 300 can have steps. Because the widths of the first opening 510 and the second opening 520 are different from each other, reliability and adhesion can be further enhanced when the electrical connection metal, which will be described later, is disposed in the first opening 510 and the second opening 520.

[0036] The components of the printed circuit board 100A1 according to the example will be described in more detail below with reference to the accompanying drawings.

[0037] The plurality of insulating layers 110 includes a first insulating layer 111 and a second insulating layer 112 stacked sequentially. An insulating material may be used as the material for the plurality of insulating layers 110, and thermosetting resins such as epoxy resins or thermoplastic resins such as polyimide resins may be used as the insulating material.

[0038] Furthermore, materials containing inorganic fillers (such as silica) and reinforcing materials (such as glass fiber) in thermosetting or thermoplastic resins can be used as insulating materials. For example, prepregs can be used, but are not limited to this, and materials that do not contain reinforcing materials such as glass fiber, i.e., materials containing inorganic fillers (such as silica) in thermosetting or thermoplastic resins, such as Ajinomoto Build-up Film (ABF), can be used. ABF can be provided in the form of resin-coated copper (RCC), but is not limited to this. If desired, photosensitive materials such as PID (photosensitive dielectric) can be used. Figure 3 In this case, only the first insulating layer 111 and the second insulating layer 112 are shown, but multiple insulating layers 110 may be included to include a greater number of insulating layers as needed and designed.

[0039] Multiple circuit layers 120 may be disposed on at least one of the interior and exterior of multiple insulating layers 110. The multiple circuit layers 120 may include a second circuit layer 122 protruding from one surface of the multiple insulating layers 110, a first circuit layer 121 embedded from another surface of the multiple insulating layers 110, and an inner circuit layer 123 disposed within the multiple insulating layers 110. Figure 3 Taking the printed circuit board 100A1 as an example, the plurality of circuit layers 120 may include a first circuit layer 121 embedded in the upper surface of a first insulating layer 111, an inner circuit layer 123 embedded in the upper surface of a second insulating layer 112, and a second circuit layer 122 disposed protruding from the lower surface of the second insulating layer 112. Metallic materials can be used as the materials for the plurality of circuit layers 120. Copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof can be used as metallic materials. The plurality of circuit layers 120 may perform various functions according to the design. For example, the plurality of circuit layers 120 may include ground patterns, power patterns, signal patterns, etc. Each of these patterns may have a line, surface, or pad shape. The plurality of circuit layers 120 may be formed by plating processes (such as addition process (AP), semi-AP (SAP), modified SAP (MSAP), via sealing (TT), etc.), and may therefore include a seed layer (electroplated layer) and an electrolytic plating layer formed based on the seed layer. When multiple insulating layers 110 are provided in RCC form, the multiple circuit layers 120 may also include metal foils such as copper foil, and a primer resin may be present on the surface of the metal foil if desired. Figure 3In this case, only the first circuit layer 121, the second circuit layer 122, and the inner circuit layer 123 are shown; however, the multiple circuit layers 120 may include a greater number of circuit layers as needed and designed. In this case, the inner circuit layer 123 may include a greater number of circuit layers.

[0040] The plurality of via layers 130 may include a first via layer 131 that penetrates the first insulating layer 111 and electrically connects the first circuit layer 121 and the inner circuit layer 123, and a second via layer 132 that penetrates the second insulating layer 112 and electrically connects the inner circuit layer 123 and the second circuit layer 122. Metallic materials may be used as the material for the plurality of via layers 130. Suitable metallic materials include copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof. Depending on the design, the plurality of via layers 130 may include signal vias, ground vias, power vias, etc. Each via of the plurality of via layers 130 may be formed by completely filling the via with a metallic material, or by forming a metallic material along the wall surface of the via. Multiple via layers 130 can also be formed by plating processes (such as addition process (AP), semi-AP (SAP), modified SAP (MSAP), sealing (TT), etc.), and therefore may include a seed layer (electroplated layer) and an electroplated layer formed based on the seed layer. Each via of the multiple via layers 130 may have a tapered shape in which the width of one surface is greater than the width of the other surface. Specifically, each via in the multiple via layers 130 may have a tapered shape in which its width narrows in the direction from one surface (e.g., the lower surface) to another surface (e.g., the upper surface) of the multiple insulating layers 110. Figure 3 In this case, only the first via layer 131 and the second via layer 132 are shown, but depending on the design requirements, the multiple via layers 130 may include a greater number of via layers.

[0041] The first passivation layer 210 protects the internal structure from external physical and chemical damage. The first passivation layer 210 may be disposed on one and another surface of the plurality of insulating layers 110, and may each have a plurality of third openings 530. The third openings 530 may be formed at a location where at least a portion overlaps in the stacking direction with the first openings 510 and 520 of the reinforcement layer 300, which will be described later, and may expose the outermost circuit layer. For example, the third opening 530 of the first passivation layer 210 disposed on one surface of the plurality of insulating layers 110 may expose at least a portion of the second circuit layer 122, and the third opening 530 of the first passivation layer 210 disposed on another surface of the plurality of insulating layers 110 may expose at least a portion of the first circuit layer 121.

[0042] The width of the third opening 530 of the first passivation layer 210 may be greater than or less than the linewidth of the first circuit layer 121 and the second circuit layer 122 (at least a portion of which is exposed through the third opening 530). (Refer to...) Figure 3 An embodiment discloses a structure in which the width of the third opening 530 is the same as the linewidth of the first circuit layer 121 and the second circuit layer 122, but the width of the third opening 530 may be less than or greater than the linewidth of each of the first circuit layer 121 and the second circuit layer 122.

[0043] An insulating material can be used as the material for the first passivation layer 210. In this case, a thermosetting resin such as epoxy resin, a thermoplastic resin such as polyimide resin, or a material in which a thermosetting or thermoplastic resin is mixed with an inorganic filler can be used, such as ABF, but not limited to these. A photosensitive insulating material such as a photosensitive dielectric (PID) can also be used.

[0044] Although not shown, a surface treatment layer may be provided in the area of ​​the first circuit layer 121 and the second circuit layer 122 exposed by the third opening 530 of the first passivation layer 210. The surface treatment layer prevents oxidation of the first circuit layer 121 and the second circuit layer 122 exposed by the third opening 530 and ensures the reliability of the electrical connection metals to be subsequently installed. As the surface treatment layer, nickel (Ni) plating, gold (Au) plating, or organic solderability protection (OSP) surface treatment layer may be used, but is not limited to these.

[0045] The reinforcement layer 300 functions to enhance the rigidity of the printed circuit board 100A1. The reinforcement layer 300 can be disposed on one surface of a plurality of insulating layers 110, for example, on a first passivation layer 210 disposed on one surface of the plurality of insulating layers 110. The reinforcement layer 300 needs to have a certain thickness to ensure the rigidity of the printed circuit board 100A1. Therefore, the reinforcement layer 300 can be thicker than each of the first insulating layer 111 and the second insulating layer 112 of the plurality of insulating layers 110. Additionally, the reinforcement layer 300 can be thicker than the first passivation layer 210.

[0046] A first opening 510 and a second opening 520 may be formed in the reinforcing layer 300. The first opening 510 and the second opening 520 may be formed by a blasting process described later, and may be formed to have a first width W1 and a second width W2, respectively. The first width W1 of the first opening 510 may represent the width of the first opening 510 in a cross-section perpendicular to the stacking direction. In this disclosure, when its cross-section is circular, the width may represent the diameter of the circle; when its cross-section is square, the width may represent the length of one side; and when its cross-section is rectangular, the width may represent the average length of each side.

[0047] The first width W1 can be greater than the second width W2. Furthermore, compared to the third width W3 of the third opening 530 formed in the first passivation layer 210, the second width W2 can be greater than the third width W3. As a result, the first width W1 can be greater than the second width W2, and the second width W2 can be greater than the third width W3. Since the second width W2 is greater than the third width W3, when the electrical connection metal is later disposed in the third opening 530, the reliability and adhesion of the electrical connection metal can be improved, and peeling can be prevented. Similarly, since the first width W1 is greater than the second width W2, the reliability and adhesion of the electrical connection metal can be improved, and peeling can be prevented.

[0048] The first opening 510 and the second opening 520 may be connected to each other, and at least some regions thereof may overlap each other in the stacking direction. Additionally, since the first width W1 may be greater than the second width W2, therefore... Figure 3 In the illustrated embodiment, when viewed from the stacking direction of the printed circuit board 100A1, a second opening 520 may be formed in the first opening 510. Therefore, since the first opening 510 and the second opening 520 have different first widths W1 and second widths W2, the inner wall of the reinforcing layer 300 may have a step. Because the inner wall of the reinforcing layer 300 has a step, the adhesion of the electrical connection metal disposed in the first opening 510 and the second opening 520 can be further improved, and reliability can also be improved.

[0049] Furthermore, the third opening 530 may also be formed to connect to the second opening 520, and at least some areas thereof may overlap in the stacking direction. (Refer to...) Figure 3 In the embodiment shown, in the stacking direction, the first opening 510 may include both the second opening 520 and the third opening 530, and the first opening 510, the second opening 520 and the third opening 530 may be connected to each other and integrally formed.

[0050] Insulating materials can be used as the material for reinforcing layer 300, and thermosetting resins such as epoxy resins or thermoplastic resins such as polyimide resins can be used as insulating materials. The material of reinforcing layer 300 may include insulating materials, and materials that do not include reinforcing materials such as glass fibers, i.e., materials containing inorganic fillers (such as silica) in thermosetting or thermoplastic resins, such as ABF, etc. ABF may be provided in the form of RCC, but is not limited thereto. Photosensitive insulating materials such as PID can be used as needed. Additionally, in the case of reinforcing layer 300, to ensure the rigidity of the printed circuit board 100A1, reinforcing layer 300 may include a material with greater rigidity than the plurality of insulating layers 110 and the first passivation layer 210; therefore, reinforcing layer 300 may have relatively greater rigidity than the plurality of insulating layers 110 and the first passivation layer 210.

[0051] Figure 4 It is shown schematically. Figure 3 A cross-sectional view of a variant example of a printed circuit board.

[0052] Reference Figure 4 In the printed circuit board 100A2 according to the variant example, compared with the printed circuit board 100A1 according to the example above, the second passivation layer 220 may be further disposed on the reinforcement layer 300. In this case, a plurality of fourth openings 540 having a fourth width W4 may be formed in the second passivation layer 220.

[0053] Specifically, a plurality of fourth openings 540 having a fourth width W4 may be formed in the second passivation layer 220, and at least a portion of the fourth openings 540 may be formed to overlap with each of the first opening 510, the second opening 520, and the third opening 530 in the stacking direction. (Refer to...) Figure 4 In the illustrated embodiment, the fourth opening 540 may be connected to the first opening 510, and when viewed from the stacking direction, the fourth opening 540 includes all of the first opening 510, the second opening 520, and the third opening 530. That is, the first opening 510, the second opening 520, the third opening 530, and the fourth opening 540 may be connected to each other as a single unit.

[0054] The material used for the second passivation layer 220 can be an insulating material used for the first passivation layer 210, but the materials of the first passivation layer 210 and the second passivation layer 220 need not be the same.

[0055] When the second passivation layer 220 is provided, a structure is shown in which the first passivation layer 210, the reinforcement layer 300, and the second passivation layer 220 are sequentially stacked on one side of a plurality of insulating layers 110 of the printed circuit board 100A2. This further enhances the rigidity of the side on the outer surface of the printed circuit board 100A2 where the electrical connection metal is disposed (the side opposite to the side where the electronic components, described later, are disposed). With this structure, a structural thinning is possible in this disclosure compared to a structure where the reinforcement layer is disposed on the side where the electronic components are disposed. This is because the reinforcement layer 300 and the second passivation layer 220 can be disposed in the gap between the substrates initially used for where the electrical connection metal is to be disposed.

[0056] The description of other repeating constructions is equally applicable to the description of the example printed circuit board 100A1, and therefore will be omitted.

[0057] Figure 5 It is shown schematically. Figure 3 A cross-sectional view of another variant example of a printed circuit board.

[0058] Reference Figure 5 In a printed circuit board 100A3 according to another variant example, compared to the printed circuit board 100A2 according to the above variant example, the metal layer 400 may be further disposed on the reinforcement layer 300. In this case, the metal layer 400 may be covered by the second passivation layer 220.

[0059] Specifically, the metal layer 400 may be disposed on the surface of the reinforcing layer 300 opposite to the surface of the reinforcing layer 300 that contacts the first passivation layer 210, and may be covered by the second passivation layer 220. The metal layer 400 may be patterned to expose the fourth opening 540 to form the fourth opening 540.

[0060] Metal layer 400 may be disposed on reinforcement layer 300 to further enhance the rigidity of printed circuit board 100A3, thereby effectively controlling warpage. When reinforcement layer 300 is provided in the form of RCC, metal layer 400 may be patterned by etching copper foil layers included in RCC, but is not limited thereto.

[0061] Metallic materials can be used as the material for the metal layer 400, and the metallic materials can be copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof.

[0062] Additionally, the metal layer 400 may be disposed on the outside of the printed circuit board 100A3 and connected to the ground of the printed circuit board 100A3 to perform EMI (electromagnetic interference) shielding.

[0063] The description of other repeating components is equally applicable to the description of the printed circuit board 100A2 according to the variant example, and therefore its description will be omitted.

[0064] Figure 6 It is shown schematically. Figure 3 A cross-sectional view of another variant example of a printed circuit board.

[0065] Reference Figure 6 In the printed circuit board 100A4 according to another variant example, compared with the printed circuit board 100A3 according to the other variant example above, the electronic component 600 and the first electrical connection metal 710 and the second electrical connection metal 720 may be further provided.

[0066] Specifically, the electronic component 600 can be disposed on the other side of the printed circuit board 100A4. (See reference...) Figure 6 In one embodiment, the electronic component 600 may be disposed on another surface of the plurality of insulating layers 110, specifically on a first passivation layer 210 disposed on the other surface of the plurality of insulating layers 110. In this case, an adhesive layer such as a die-attach film (DAF) may be disposed between the electronic component 600 and the first passivation layer 210 to maintain adhesion, but is not limited thereto, and the electronic component 600 may also be configured to contact the first passivation layer 210 without a separate adhesive layer.

[0067] Electronic component 600 may be an integrated circuit (IC) die in which hundreds to millions or more components are integrated into a single chip. For example, electronic component 600 may be a processor chip such as a central processing unit (e.g., CPU), a graphics processing unit (e.g., GPU), a field-programmable gate array (FPGA), a digital signal processor, a cryptographic processor, a microprocessor, a microcontroller, etc., specifically, an application processor (AP), but not limited thereto, and may be a memory chip such as volatile memory (e.g., DRAM), non-volatile memory (e.g., ROM), flash memory, etc., or a logic chip such as an analog-to-digital converter or an application-specific integrated circuit (ASIC). If desired, electronic component 600 may be a surface-mount passive component, such as a surface-mount inductor, a surface-mount capacitor, etc. Electronic component 600 may be configured such that the surface on which connection pads 120P are disposed faces upward, and the surface opposite to the surface on which connection pads 120P are disposed faces downward. The connection pads 120P of electronic component 600 may comprise a metallic material such as copper (Cu) or aluminum (Al) and may be connected to the first circuit layer 121.

[0068] The first electrical connection metal 710 may be disposed on one side of the printed circuit board 100A4. Specifically, the first electrical connection metal 710 may be disposed on a first passivation layer 210 disposed on one surface of a plurality of insulating layers 110, and may be configured to fill at least a portion of each of the first opening 510, second opening 520, third opening 530, and fourth opening 540. The first electrical connection metal 710 may be electrically connected to the exposed second circuit layer 122. The first electrical connection metal 710 may physically connect and / or electrically connect the printed circuit board 100A4 to an external entity. For example, the printed circuit board 100A4 may be mounted on the motherboard of an electronic device, other BGA substrates, etc., via the first electrical connection metal 710. The first electrical connection metal 710 may physically connect and / or electrically connect the printed circuit board 100A4 to components surface-mounted thereon, and may connect the printed circuit board 100A4 to other substrates on which the printed circuit board 100A4 is mounted, such as a motherboard. The first electrical connection metal 710 may be formed using tin (Sn) or a tin-containing alloy (e.g., solder), but is not limited thereto. The first electrical connection metal 710 may be a pad, solder ball, lead, etc.

[0069] Because the first electrical connection metal 710 is disposed in the first opening 510, the second opening 520, the third opening 530, and the fourth opening 540, which have different widths from each other, the bonding strength and reliability can be further improved. In other words, since the inner walls of each of the first passivation layer 210, the reinforcing layer 300, and the second passivation layer 220 have different widths, the inner walls form steps. Compared with normal openings with smooth inner walls, openings with steps in the inner walls can increase the bonding strength between the electrical connection metal and the insulating layer through anchoring effects, etc.

[0070] Therefore, the first opening 510, the second opening 520, the third opening 530 and the fourth opening 540, which are integrally formed and interconnected, can be formed on one side of the printed circuit board 100A4, and the first electrical connection metal 710 can be disposed in the first opening 510, the second opening 520, the third opening 530 and the fourth opening 540, so as to improve the bonding force and reliability between the inner wall and the first electrical connection metal 710, so as to effectively improve the phenomenon of peeling off the first electrical connection metal 710.

[0071] The second electrical connection metal 720 can electrically connect the electronic component 600 to the first circuit layer 121. The second electrical connection metal 720 can be formed using tin (Sn) or a tin-containing alloy (e.g., a solder similar to the solder of the first electrical connection metal 710), but is not limited thereto. The second electrical connection metal 720 can be a pad, solder ball, lead, etc., and can be a reference... Figure 6 The metal wires in the embodiment shown. Therefore, the electronic component 600 and the first circuit layer 121 can be connected by wire bonding.

[0072] The description of other repeating components is equally applicable to the description of the printed circuit board 100A3 according to the other variant examples above, and therefore their description will be omitted.

[0073] Figure 7 This is a schematic cross-sectional view illustrating another example of a printed circuit board.

[0074] Reference Figure 7 In a printed circuit board 100B1 according to another example, the reinforcement layer 300 may include multiple layers compared to the printed circuit board 100A1 according to the example above.

[0075] Specifically, refer to Figure 7 In some embodiments, the reinforcement layer may include a first reinforcement layer 310 and a second reinforcement layer 320 disposed on the first reinforcement layer 310. As in this embodiment, since the reinforcement layer has multiple layers, the rigidity of the printed circuit board 100B1 can be ensured more effectively.

[0076] The description of the first reinforcement layer 310 is equally applicable to the reinforcement layer 300 in the printed circuit board 100A1 of the above example.

[0077] According to this embodiment, the first opening 510 of the first reinforcing layer 310 may also be formed in the second reinforcing layer 320. That is, the first opening 510 can be formed together in the first reinforcing layer 310 and the second reinforcing layer 320 by a sandblasting process described later. Therefore, the first openings 510 formed in each of the first reinforcing layer 310 and the second reinforcing layer 320 can be connected and have substantially the same width. In this disclosure, substantially the same means not only including cases where they are physically / numerically identical, but also including errors that may occur during the process.

[0078] The second reinforcing layer 320 may be stacked on the first reinforcing layer 310, and the material of the second reinforcing layer 320 may include the same material as the first reinforcing layer 310 described above. However, it is not necessarily required to include the same material as the first reinforcing layer 310.

[0079] The description of other repeating components is equally applicable to the description of the printed circuit board 100A1 in the example above, and therefore their description will be omitted.

[0080] Figure 8 It is shown schematically. Figure 7 A cross-sectional view of a variant example of a printed circuit board.

[0081] Reference Figure 8In the printed circuit board 100B2 according to the variant example, compared with the printed circuit board 100B1 according to the other example described above, the second passivation layer 220 may be further disposed on the second reinforcement layer 320. In this case, a plurality of fourth openings 540 having a fourth width W4 may be formed in the second passivation layer 220.

[0082] Specifically, a second passivation layer 220 having a fourth opening 540 may be disposed on a second reinforcement layer 320, the fourth opening 540 having a fourth width W4, and when viewed from the stacking direction, the fourth opening 540 may be formed to overlap with each of the first opening 510, the second opening 520 and the third opening 530.

[0083] The same descriptions as above can be applied to the second passivation layer 220, the fourth opening 540, and the fourth width W4.

[0084] The description of other repeating components is equally applicable to the description of another example printed circuit board 100B1, and therefore its description will be omitted.

[0085] Figure 9 It is shown schematically. Figure 7 A cross-sectional view of another variant example of a printed circuit board.

[0086] Reference Figure 9 In a printed circuit board 100B3 according to another variant example, compared to the printed circuit board 100B2 according to the above variant example, a plurality of first metal layers 410 and a plurality of second metal layers 420 may be disposed on the first reinforcement layer 310 and the second reinforcement layer 320, respectively. In this case, the first metal layer 410 may be covered by the second reinforcement layer 320, and the second metal layer 420 may be covered by the second passivation layer 220.

[0087] The first metal layer 410 and the second metal layer 420 can respectively perform the function of additionally enhancing the rigidity of the printed circuit board 100B3, and can be additionally connected to ground to perform EMI shielding function.

[0088] The description of the materials and properties of the first metal layer 410 and the second metal layer 420 is equally applicable to the description of the metal layer 400 in the printed circuit board 100A3 according to the other variant example described above.

[0089] The description of other repeating components is equally applicable to the description of the printed circuit board 100B2 according to the variant example, and therefore its description will be omitted.

[0090] Figure 10 It is shown schematically. Figure 7 A cross-sectional view of another variant example of a printed circuit board.

[0091] Reference Figure 10 In the printed circuit board 100B4 according to another variant example, compared with the printed circuit board 100B3 according to the other variant example above, an electronic component 600 and a first electrical connection metal 710 and a second electrical connection metal 720 are also provided.

[0092] The description of electronic component 600, first electrical connection metal 710, and second electrical connection metal 720 according to the printed circuit board 100A4 of the other variant example described above is equally applicable, and therefore its detailed description is omitted.

[0093] The description of other repeating components is equally applicable to the description of the printed circuit board 100B3 according to the other variant examples described above, and therefore their description will be omitted.

[0094] Figures 11 to 17 It is a schematic representation of manufacturing. Figure 3 A cross-sectional view of an example printed circuit board.

[0095] Reference Figure 11 and Figure 12 First, a carrier 800 in which metal foils 821 and 822 are disposed on at least one surface is prepared. Then, a first circuit layer 121 is formed on the metal foils 821 and 822 by a plating process. Next, a first insulating layer 111 for covering the first circuit layer 121 is formed on the first circuit layer 121, and via holes are processed in the first insulating layer 111 using laser drilling or the like. Then, a first via layer 131 and an inner circuit layer 123 are formed by a plating process. Next, a second insulating layer 112 is formed to embed the inner circuit layer 123, and via holes are processed in the second insulating layer 112 using laser drilling or the like. Then, a second via layer 132 and a second circuit layer 122 are formed by a plating process. Next, a first passivation layer 210 having a fourth opening 540 exposing at least a portion of the second circuit layer 122 is formed.

[0096] Reference Figure 13 A first protective layer 910 is formed on the first passivation layer 210 to cover the second circuit layer 122 exposed from the first passivation layer 210.

[0097] The first protective layer 910 may be used to protect the second circuit layer 122 during the sandblasting process, which will be described later, and may have a second width W2 that is the same as the width of the second opening 520 that will be formed later. The first protective layer 910 may be used without limitation, as long as it includes materials that are less affected during the sandblasting process. For example, known dry film resists may be used, and it may also include resins that can be melted by chemical treatment. Optionally, the first protective layer 910 may include metallic materials if necessary.

[0098] Reference Figure 14A reinforcing layer 300, which fills and covers the first protective layer 910, can be formed on the first passivation layer 210. When the reinforcing layer 300 is provided in the form of RCC, copper foil M may be additionally provided. The reinforcing layer 300 may not include reinforcing materials such as glass fibers, as a portion of them is removed by a sandblasting process described later.

[0099] Reference Figure 15 After each of the laminates on the two surfaces of the separation carrier 800, a first passivation layer 210 with an opening may be provided on the other side of the plurality of insulating layers 110. The first passivation layer 210 provided on the other side of the plurality of insulating layers 110 may expose the upper surface of the first circuit layer 121 embedded in the first insulating layer 111.

[0100] Additionally, when the reinforcement layer 300 is provided in the form of RCC, the copper foil M can be etched and removed. However, the copper foil M does not necessarily have to be completely removed, and the copper foil M can be patterned and removed only in partial areas, and can remain in the remaining areas, where the copper foil can enhance the rigidity of the printed circuit board, as previously described. Figure 5 As shown.

[0101] Reference Figure 16 A second protective layer 920 can be stacked on both surfaces of the laminate. Since the second protective layer 920 can be used as a mask for a sandblasting process, it can include materials less affected by the sandblasting process. In this case, a portion of the second protective layer 920 that contacts the reinforcing layer 300 can be selectively removed. Openings 920h can exist in the areas where the second protective layer 920 is selectively removed, and the second protective layers 920 can be spaced apart from each other by the width of the openings 920h. The width of the openings 920h can be substantially the same as a first width W1, which is the width of a first opening 510 later formed in the reinforcing layer 300. Furthermore, when viewed in the stacking direction, the cross-section of the openings 920h can be substantially the same as the cross-section of the first opening 510 later formed in the reinforcing layer 300.

[0102] Figure 17 The results of a sandblasting process using a second protective layer 920 as a mask are shown (according to...). Figure 3(The structure of the printed circuit board 100A1 in this disclosure is shown in the example). After the first opening 510 is formed in the reinforcing layer 300 by a sandblasting process using the second protective layer 920 as a mask, the first protective layer 910 can be removed to form the second opening 520. When the first protective layer 910 comprises a photosensitive material such as a dry film, it can be removed by an exposure / development process, but is not limited thereto. That is, when the first protective layer 910 comprises a resin that reacts with specific chemicals, the first protective layer 910 can be removed by chemical treatment without an exposure / development process. Optionally, when the first protective layer 910 comprises a metallic material, it can also be removed by etching using an etchant that reacts with the first protective layer 910. In this case, the aforementioned surface treatment layer can be disposed on the second circuit layer 122, and due to the protection of the surface treatment layer, only the first protective layer 910 can be removed without damaging the second circuit layer 122.

[0103] As described above, when the sandblasting process is performed on the reinforcement layer 300 in the presence of the first protective layer 910, damage to the second circuit layer 122 can be prevented compared to the case where the sandblasting process directly affects the circuit layer (e.g., the second circuit layer 122), and the thickness of the second circuit layer 122 can be reduced, thereby preventing signal transmission failure.

[0104] As used herein, spatial relative terms such as “side”, “side surface”, etc., are used to refer to the first direction (e.g., relative to the first direction). Figure 3 (to the left of the cross section) or a second direction (e.g., relative to the cross section) Figure 3 The portion of the cross-section (in the rightward direction) or the surface in that direction. Spatial relative terms such as "upper side," "upper part," "upper surface," etc., are used to refer to the portion or surface in a third direction perpendicular to the first and second directions, while spatial relative terms such as "lower side," "lower part," "lower surface," etc., are used to refer to the portion or surface in the direction opposite to the third direction. Furthermore, these spatial relative terms have been used to encompass both cases where the target component is positioned in the corresponding direction but does not directly contact the reference component, and cases where the target component directly contacts the reference component in the corresponding direction. However, for ease of description, these terms may be defined as above, and the scope of the exemplary embodiments is not particularly limited to the terms described above.

[0105] As used herein, the term "connection" may refer not only to "direct connection" but also to "indirect connection" via adhesive layers, etc. The term "electrical connection" may include both cases of "physical connection" and cases of "non-physical connection" of constituent elements. Furthermore, the terms "first," "second," etc., may be used to distinguish one constituent element from another and may not limit the order and / or importance associated with the constituent elements. In some cases, without departing from the scope of the exemplary embodiments, a first constituent element may be referred to as a second constituent element, and similarly, a second constituent element may be referred to as a first constituent element.

[0106] As used herein, the term "embodiment" is provided to emphasize a particular feature, structure, or characteristic and does not necessarily refer to the same embodiment. Furthermore, a particular feature or characteristic may be combined in any suitable manner in one or more embodiments. For example, unless described as contradicting or inconsistent with features in other embodiments, a feature described in a particular exemplary embodiment may be used in other embodiments even if not described in other embodiments.

[0107] The terminology used herein describes specific embodiments only, and this disclosure is not limited thereto. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.

[0108] As described above, as one of the various effects of this disclosure, a printed circuit board with enhanced rigidity can be provided.

[0109] As another effect of the various effects of this disclosure, a printed circuit board including a reinforcing layer in which a plurality of openings of different widths are formed can be provided.

[0110] As another effect among the various effects of this disclosure, a printed circuit board having multiple stacked reinforcement layers can be provided.

[0111] While exemplary embodiments have been shown and described above, it will be readily understood by those skilled in the art that modifications and variations may be made without departing from the scope of this disclosure as defined by the appended claims.

Claims

1. A printed circuit board, comprising: Multiple insulating layers; Multiple circuit layers are disposed on at least one of the multiple insulating layers, both inside and outside the insulating layers; as well as A reinforcing layer is disposed on one surface of the plurality of insulating layers and has a first opening and a second opening that exposes a portion of the plurality of circuit layers. The first opening has a first width, and the second opening has a second width smaller than the first width. The first opening and the second opening overlap in the stacking direction of the plurality of insulating layers, and the second opening is disposed closer to the plurality of insulating layers than the first opening. The second opening is fully exposed to the first opening, forming a stepped portion between the inner wall of the first opening and the inner wall of the second opening.

2. The printed circuit board of claim 1, wherein, The thickness of the reinforcing layer is greater than that of each of the plurality of insulating layers.

3. The printed circuit board of claim 1, wherein, At least one of the plurality of insulating layers comprises an insulating resin and a reinforcing material. The reinforcing layer does not contain the reinforcing material.

4. The printed circuit board of claim 1, further comprising an electrical connection metal disposed in the first opening and the second opening to contact a portion of the plurality of circuit layers, and wherein The height of the electrical connection metal in the stacking direction is greater than the thickness of the reinforcement layer in the stacking direction.

5. The printed circuit board of claim 1, wherein, The first opening has a constant dimension in the stacking direction, and the second opening has a constant dimension in the stacking direction.

6. The printed circuit board of claim 5, further comprising a first passivation layer disposed on one surface and another surface of the plurality of insulating layers. wherein The enhancement layer is disposed on one of the first passivation layers. The first passivation layer includes a third opening that exposes a portion of the plurality of circuit layers, and the first opening and the second opening expose the third opening.

7. The printed circuit board of claim 6, wherein, The third opening has a third width. The third width is different from the first width and the second width.

8. The printed circuit board of claim 7, wherein, At least a portion of the third opening overlaps with the first and second openings in the stacking direction. The third width is smaller than the second width.

9. The printed circuit board of claim 8, further comprising: A second passivation layer is disposed on the enhancement layer.

10. The printed circuit board of claim 9, further comprising: A metal layer is disposed on the reinforcing layer.

11. The printed circuit board of claim 10, wherein, The second passivation layer includes a fourth opening having a fourth width. Wherein, at least a portion of the fourth opening overlaps with each of the first, second, and third openings in the stacking direction. The fourth width is greater than the first width, the second width, and the third width.

12. The printed circuit board of claim 1, wherein, The plurality of circuit layers include: A first circuit layer is embedded from the other surface of the plurality of insulating layers; and The second circuit layer protrudes from one of the surfaces of the plurality of insulating layers.

13. The printed circuit board of claim 12, further comprising: A first electrical connection metal is disposed in the first opening and the second opening, and is in contact with the second circuit layer; An electronic component is disposed on the other surface of the plurality of insulating layers; as well as A second electrical connection metal connects the electronic component and the first circuit layer.

14. A printed circuit board, comprising: Multiple insulating layers; Multiple circuit layers are disposed on at least one of the multiple insulating layers, both inside and outside the insulating layers; A first reinforcing layer is disposed on one surface of the plurality of insulating layers; The second reinforcing layer is disposed on the surface of the first reinforcing layer opposite to the surface of the first reinforcing layer that contacts the plurality of insulating layers; A first opening having a first width and passing through the second reinforcing layer and a portion of the first reinforcing layer; as well as The second opening has a width smaller than the first width and penetrates the first reinforcing layer at a position corresponding to a portion of the first opening to form a stepped portion between the inner wall of the first opening and the inner wall of the second opening. The second opening exposes a portion of the plurality of circuit layers.

15. The printed circuit board of claim 14, wherein, At least a portion of the plurality of circuit layers protrudes from the one surface of the plurality of insulating layers, and At least one other portion of the plurality of circuit layers is embedded from the other surface of the plurality of insulating layers.

16. The printed circuit board of claim 14, further comprising a first passivation layer disposed between the plurality of insulating layers and the first reinforcement layer. in, The first passivation layer has a third opening that exposes a portion of the plurality of circuit layers, and The third opening has a third width that is smaller than the second width of the second opening, and is located at a position corresponding to a portion of the second opening.

17. The printed circuit board of claim 16, wherein, A step is formed between the inner wall of the second opening and the inner wall of the third opening.

18. The printed circuit board of claim 14, further comprising: Electrically connected metal is disposed in the first and second openings to contact a portion of the plurality of circuit layers.

19. The printed circuit board of claim 18, wherein, A portion of the plurality of circuit layers protrudes from one of the plurality of insulating layers toward the electrical connection metal.

20. The printed circuit board of claim 14, further comprising: A first metal layer and a second metal layer are respectively disposed on the first reinforcement layer and the second reinforcement layer.

Images