Semiconductor packages

Abstract

A semiconductor package according to an embodiment includes an insulating layer, a first metal layer penetrating an upper surface and a lower surface of the insulating layer, and a second metal layer disposed on the first metal layer, wherein the first metal layer includes concave upper and lower surfaces, and the second metal layer includes a convex lower surface corresponding to the concave upper surface of the first metal layer, and a first height between the convex lower surface of the second metal layer and the lower surface of the insulating layer is smaller than a second height between the upper surface of the insulating layer and the lower surface of the insulating layer.

Description

Technical Field

[0001] The embodiments relate to a circuit board, and more particularly, to a circuit board including a large-area through electrode and a semiconductor package including the same.

Background Art

[0002] As the miniaturization, weight reduction, and integration of electronic components accelerate, the circuit line width is being miniaturized. In particular, as the design rules of semiconductor chips are integrated on the nanometer scale, the circuit line width of the package substrate or circuit board on which the semiconductor chips are mounted is being miniaturized to less than several micrometers.

[0003] In order to increase the circuit integration density of printed circuit boards, that is, to miniaturize the circuit line width, various manufacturing methods have been proposed. For the purpose of preventing the loss of circuit line width in the etching step for forming a pattern after copper plating, methods such as the SAP (semi-additive process) method and the MSAP (modified semi-additive process) have been proposed.

[0004] After that, in order to implement a finer circuit pattern, an Embedded Trace Substrate (hereinafter referred to as "ETS") method of embedding a copper foil in the insulating layer has been used in the industry. Since the ETS method manufactures in a type of embedding the copper foil circuit in the insulating layer instead of forming it on the surface of the insulating layer, there is no circuit loss due to etching, which is advantageous for miniaturizing the circuit pitch.

[0005] On the other hand, recently, efforts have been made to develop an improved 5G (5th generation) communication system or a pre-5G communication system to meet the demand for wireless data traffic. Here, the 5G communication system uses a millimeter wave (mmWave) band (sub6 giga (6 GHz), 28 giga (28 GHz), 38 giga (38 GHz) or higher frequencies) to achieve a high data transmission rate.

[0006] Furthermore, to mitigate path loss in the ultra-high frequency band and increase the transmission distance of radio waves, beamforming, massive MIMO (Multi-Input / Output Multiplexing), and array antennas are being developed for 5G communication systems. Considering that such frequency bands can be composed of hundreds of active antennas of the same wavelength, the antenna system becomes relatively large.

[0007] Since such antennas and AP modules are patterned or mounted on printed circuit boards, low loss on the printed circuit board is extremely important. This means that the multiple boards that make up the active antenna system—namely the antenna board, antenna feed board, transceiver board, and baseband board—must be integrated into a single compact unit.

[0008] On the other hand, in recent years, circuit boards including large-area through-holes have been developed to improve heat dissipation and shielding characteristics. Large-area through-holes can be formed by filling large-diameter through-holes with metallic material. However, filling the inside of such large-diameter through-holes with metallic material is not easy, and as a result, conventional large-area through-holes include dimple regions on one surface that are recessed inward from the through-hole. These dimple regions can affect the processing of through-holes during additional lamination, which in turn affects the reliability of the printed circuit board. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] In this embodiment, we aim to provide a circuit board with a new structure and a semiconductor package including the same.

[0010] In this embodiment, we aim to provide a circuit board with a novel structure that can remove surface contamination from the electrode portion, and a semiconductor package including the same.

[0011] In this embodiment, the aim is to provide a circuit board with a novel structure that includes through-electrodes manufactured with the minimum number of plating steps while simplifying the plating process, and a semiconductor package including the same.

[0012] The technical problems to be solved in the proposed embodiments are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those with ordinary skill in the art to which the proposed embodiments belong, based on the following description. [Means for solving the problem]

[0013] The semiconductor package according to the embodiment includes an insulating layer, a first metal layer penetrating the upper and lower surfaces of the insulating layer, and a second metal layer disposed on the first metal layer, wherein the first metal layer includes a concave upper surface and a concave lower surface, and the second metal layer includes a convex lower surface corresponding to the concave upper surface of the first metal layer, and the first height between the convex lower surface of the second metal layer and the lower surface of the insulating layer is smaller than the second height between the upper surface of the insulating layer and the lower surface of the insulating layer.

[0014] Furthermore, the first metal layer includes a first portion disposed in a through-hole penetrating the insulating layer and a second portion disposed on the upper surface of the insulating layer; the second metal layer includes a third portion disposed on the first portion of the first metal layer within the through-hole and a fourth portion disposed on the third portion of the second metal layer and the second portion of the first metal layer; the first portion of the first metal layer and the third portion of the second metal layer include through electrodes; and the second portion of the first metal layer and the fourth portion of the second metal layer include a first electrode portion.

[0015] Furthermore, the uppermost edge of the upper surface of the second portion of the first metal layer is located lower than the upper surface of the fourth portion of the second metal layer.

[0016] Furthermore, the lowest end of the upper surface of the first portion of the first metal layer is located lower than the upper surface of the insulating layer, and the lowest end of the lower surface of the third portion of the second metal layer is located lower than the upper surface of the insulating layer.

[0017] Furthermore, the first electrode portion includes a first region that overlaps with the through electrode in the thickness direction and a second region other than the first region, and the number of layers in the first region is different from the number of layers in the second region.

[0018] Furthermore, the through electrode has a shape that extends long in the longitudinal direction, the first width of the through electrode in the longitudinal direction is greater than the second width of the through electrode in the width direction, and the height from the bottom surface of the first portion of the first metal layer to the bottom end of the top surface of the first portion of the first metal layer satisfies the range of 30% to 95% of the second width.

[0019] Furthermore, the through electrode and the first electrode portion include a seed layer, the seed layer including a fifth portion disposed between the first portion of the first metal layer and the inner wall of the through hole, and a sixth portion disposed between the upper surface of the insulating layer and the second portion of the first metal layer.

[0020] Furthermore, the height from the lower surface of the sixth portion of the seed layer to the uppermost end of the second portion of the first metal layer satisfies the range of 50% to 85% of the thickness of the first electrode portion.

[0021] On the other hand, the semiconductor package according to the embodiment includes a first electrode portion, a first insulating layer disposed on the first surface of the first electrode portion, a second electrode portion disposed on the first surface of the first insulating layer, a first through electrode penetrating the first insulating layer, a second insulating layer disposed on the first surface of the first insulating layer, a third electrode portion disposed on the first surface of the second insulating layer, and a second through electrode penetrating the second insulating layer, wherein the thickness of the first electrode portion is greater than the thickness of the second electrode portion, and the thickness of the third electrode portion is greater than the respective thicknesses of the first electrode portion and the second electrode portion.

[0022] Furthermore, the second electrode portion includes a concave recess facing the second surface opposite to the first surface of the first insulating layer, and the second through electrode includes a convex portion that fills the recess of the second electrode portion. [Effects of the Invention]

[0023] The embodiment includes a through electrode that penetrates the insulating layer. In this embodiment, a plating process is performed multiple times to fill the through hole that penetrates the insulating layer. Through this, the embodiment forms a through electrode that fills a large area of ​​through hole.

[0024] In this embodiment, the current density, which is the plating condition for the multiple plating steps, is adjusted. Through this, the embodiment forms a first metal layer in the primary plating step and a second metal layer in the secondary plating step, which constitute a part of the through electrode and the first electrode portion, respectively. In this case, the first metal layer in the embodiment may be formed with a relatively low current density, and the second metal layer may be formed with a relatively high current density. As a result, in the embodiment, it is possible to prevent the through electrode or the first electrode portion from containing dimple regions in a circuit board including a large-area through electrode. Through this, the reliability of the product can be improved in the embodiment.

[0025] Furthermore, in the embodiment, the upper surface of the first pad is formed solely of the second metal layer by controlling the current density as described above. This solves the problem of contamination caused by the upper surface of the first electrode portion including both the first and second metal layers, thereby improving customer satisfaction. In addition, the embodiment solves the problem of increased plating time caused by the upper surface of the first electrode portion including only the first metal layer, thereby improving product yield.

[0026] In addition, in the embodiment, it includes a first through electrode and a second electrode portion disposed on one side of the first electrode portion. The embodiment also includes a second through electrode and a third electrode portion disposed on one side of the second electrode portion. At this time, the first through electrode or the second electrode portion disposed inside includes a dimple region. And the second through electrode disposed outside is formed by filling the dimple region of the first through electrode or the second electrode portion. Thereby, in the embodiment, the third electrode portion has a greater thickness than the first electrode portion and the second electrode portion, and the second electrode portion can have a smaller thickness than the first electrode portion and the third electrode portion. Thereby, in the embodiment, the process of forming a large-area through electrode can be simplified, and the product yield can be improved thereby.

Brief Description of Drawings

[0027] [Figure 1] It is a diagram showing a circuit board according to a comparative example. [Figure 2] It is a diagram showing the surface of the electrode portion of FIG. 1. [Figure 3] It is a plan view of a circuit board according to a first embodiment. [Figure 4a] It is a cross-sectional view of the circuit board of FIG. 3 in the A-A' direction. [Figure 4b] It is a cross-sectional view of the circuit board of FIG. 3 in the B-B' direction. [Figure 5] It is a detailed configuration diagram of the first electrode portion and the through electrode shown in FIG. 3. [Figure 6] It is a diagram showing the upper surface of the first electrode portion of FIG. 5. [Figure 7] It is a first cross-sectional view of a circuit board according to a second embodiment. [Figure 8] It is a second cross-sectional view of a circuit board according to a second embodiment. [Figure 9] It is a diagram specifically showing the first substrate layer of FIGS. 7 and 8. [Figure 10] It is a diagram for explaining the manufacturing method of the circuit board according to the second embodiment in order of steps. [Figure 11] It is a diagram for explaining the manufacturing method of the circuit board according to the second embodiment in order of steps. [Figure 12] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 13] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 14] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 15] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 16] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 17] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 18] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 19] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 20] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 21] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 22] This is a diagram illustrating the manufacturing method of a circuit board according to the second embodiment, in order of steps. [Figure 23] This figure shows a semiconductor package according to an example. [Modes for carrying out the invention]

[0028] The embodiments disclosed herein will be described in detail below with reference to the accompanying drawings, but identical or similar components will be given the same reference numeral regardless of the drawing reference numerals, and redundant descriptions will be omitted. The suffixes “module” and “part” used for components in the following description are added or used interchangeably to facilitate the preparation of the specification and do not have any mutually distinguishing meaning or role in themselves. Furthermore, in the description of the embodiments disclosed herein, if a specific description of such prior art is deemed to interfere with the gist of the embodiments disclosed herein, such detailed description will be omitted. In addition, the accompanying drawings are provided to facilitate understanding of the embodiments disclosed herein, and it should be understood that the accompanying drawings do not limit the technical idea disclosed herein and include all modifications, equivalents or substitutes that fall within the idea and technical scope of the present invention.

[0029] Terms including ordinal numbers such as "first," "second," etc., can be used to describe a variety of components, but the components are not limited by such terms. The terms are used solely for the purpose of distinguishing one component from another.

[0030] When it is stated that one component is “linked” or “connected” to another component, it should be understood that it may be directly “linked” or “connected” to the other component, and that other components may exist in between. On the other hand, when it is stated that one component is “directly linked” or “directly connected” to another component, it should be understood that there are no other components in between.

[0031] A singular expression can include multiple expressions unless the context clearly indicates otherwise.

[0032] In this application, terms such as “includes” or “having” are intended to specify the presence of features, figures, steps, actions, components, parts, or combinations thereof as described in the specification, and should be understood not to preemptively exclude the presence or possibility of adding one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0033] The embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0034] Prior to describing this embodiment, a comparative example that is comparable to this embodiment will be described.

[0035] Figure 1 shows a circuit board relating to a comparative example, and Figure 2 shows the surface of the electrode portion of Figure 1.

[0036] Referring to Figures 1 and 2, the comparative example circuit board includes a large area through-electrode.

[0037] Specifically, the circuit board of the comparative example includes an insulating layer 10, a first electrode portion 50, a second electrode portion 20, and a through electrode 40.

[0038] The first electrode portion 50 is positioned on the upper surface of the insulating layer 10.

[0039] The second electrode portion 20 is positioned on the lower surface of the insulating layer 10, opposite to the upper surface.

[0040] The through electrode 40 is positioned to penetrate the insulating layer 10. The through electrode 40 penetrates the insulating layer 10 and connects the first electrode portion 50 and the second electrode portion 20.

[0041] The through electrode 40 includes a plurality of electrode parts that are horizontally separated from each other while being commonly connected to the first electrode portion 50 and the second electrode portion 20.

[0042] Each of the multiple electrode parts constituting the through-electrode 40 is a large-area through-electrode. For example, the circuit board includes large-area through-electrodes. The large-area through-electrodes have a larger area than ordinary through-electrodes. For example, the through-electrode 40 includes multiple large-area through-electrode parts, the width in a first direction (e.g., the longitudinal direction) being greater than the width in a second direction (e.g., the width direction).

[0043] The through-electrode 40 described above is formed by filling the inside of the through-hole with a metallic substance. However, with a large-area through-electrode like the one described above, it is difficult to completely fill the inside of the through-hole in a single plating process. For example, when forming a large-area through-electrode like the one described above, if the inside of the through-hole is filled in only one plating process, a dimple phenomenon occurs in the region of the first electrode portion 50 that overlaps with the through-electrode 40 in a third direction (for example, the thickness direction). Here, the dimple phenomenon refers to the phenomenon in which the central part of the through-electrode 40 or the upper surface of the first electrode portion 50 that overlaps with the through-electrode 40 in a third direction is not flat but formed as a depression.

[0044] As a result, in the comparative example, the through electrode 40 and the first electrode portion 50 are formed by performing multiple plating processes.

[0045] Specifically, the first electrode portion 50 and the through electrode 40 are formed integrally. For example, the first electrode portion 50 and the through electrode 40 are composed of a first metal layer and a second metal layer formed by two plating processes in the through hole and on the upper surface of the insulating layer 10.

[0046] As a result, the through electrode 40 includes a first portion 41 of the first metal layer and a first portion 42 of the second metal layer. The first electrode portion 50 also includes a second portion 51 of the first metal layer and a second portion 52 of the second metal layer.

[0047] In other words, when forming the through electrode 40 and the first electrode portion 50, if only the first metal layer is formed, the through hole is not completely filled, resulting in the occurrence of dimples in the through electrode 40 and the first electrode portion 50. Therefore, in the comparative example, secondary plating is performed on the dimpled portion of the first metal layer to form a second metal layer that fills the dimpled portion.

[0048] In this comparative example, the thickness of the second portion 51 of the first metal layer constituting the first electrode portion 50 and the thickness of the second portion 52 of the second metal layer are not considered at all, and only the dimple portion is simply filled.

[0049] As a result, the upper surface of the first electrode portion 50 in the comparative example consists of multiple metal layers formed by multiple plating processes. Specifically, the upper surface of the first electrode portion 50 in the comparative example includes a region consisting of the second portion 51 of the first metal layer and a region consisting of the second portion 52 of the second metal layer. The interface between the second portion 51 of the first metal layer and the second portion 52 of the second metal layer can be visually distinguished.

[0050] Specifically, as shown in Figure 2, the upper surface of the first electrode portion 50 has a line A formed thereon that separates the interface between the second portion 51 of the first metal layer and the second portion 52 of the second metal layer, and this line A affects the product reliability of the first electrode portion 50. For example, line A is visible from the outside, and as a result it is recognized as dirt, acting as a factor that impairs the design of the circuit board.

[0051] Therefore, in the embodiment, a large-area through electrode is included, and while the large-area through electrode is formed by multiple plating processes, dirt that may form on the surface of the first electrode portion of the large-area through electrode is removed.

[0052] Figure 3 is a plan view of the circuit board according to the first embodiment, Figure 4(a) is a cross-sectional view of the circuit board in Figure 3 in the A-A' direction, and Figure 4(b) is a cross-sectional view of the circuit board in Figure 3 in the B-B' direction.

[0053] Prior to this explanation, in recent years, in order to improve the performance of through-holes that perform heat dissipation, shielding, and signal transmission, the size of the through-holes has been increased, and consequently, the size of the through-holes filling the through-holes has also tended to increase. In this embodiment, we aim to provide a circuit board that can remove the dimple region of the through-hole or the electrode while removing dirt formed on the surface of the electrode, even when the size of the through-hole is increased in accordance with this trend.

[0054] Referring to Figures 3 and 4, the circuit board according to the first embodiment includes an insulating layer 110, a first electrode portion 120, a second electrode portion 130, a through electrode 140, and a first surface treatment layer 125. The through electrode 140 can also be described as a "via" for interlayer electrical connection.

[0055] The through electrode 140 may have a large surface area. For example, the through electrode 140 may be a large surface area having a certain area or more.

[0056] For example, the through-electrode 140 has a width in the first direction (e.g., longitudinal direction) that is greater than its width in the second direction (width direction). For example, the width of the through-electrode 140 in the first direction (e.g., longitudinal direction) may be more than twice the width in the second direction (width direction). The embodiment makes it possible to remove surface contamination and dimple areas that occur in such a large-area through-electrode. Accordingly, the following description will focus on the large-area through-electrode 140 and the first electrode portion 120 and second electrode portion 130 connected thereto. However, the embodiment is not limited thereto, and in addition to the first electrode portion 120, the second electrode portion 130, and the large-area through-electrode 140, traces, general-size through-electrodes, chip mounting pads, core pads, and BGA pads may also be formed on the circuit board.

[0057] The insulating layer 110 can have a flat plate structure. In this case, the drawing shows that the insulating layer 110 has a single layer structure, but it is not limited to this. For example, the insulating layer 110 can have a layer structure of two or more layers, thereby the circuit board can be a multilayer board. However, the embodiment is for the outermost insulating layer among the multilayer insulating layers, and for removing dimple areas formed on the through electrode or electrode portion formed on the outermost insulating layer, as well as for removing dirt. Accordingly, in the first embodiment, the description will focus on the outermost insulating layer among the multilayer insulating layers, and the first electrode portion 120, the second electrode portion 130, and the through electrode 140 formed on the outermost insulating layer.

[0058] The insulating layer 110 can include all printed circuit boards, wiring boards, and insulating substrates made of insulating material on which an electrical circuit can be arranged and on which a circuit pattern can be formed on the surface, and on which an electrical circuit can be arranged.

[0059] For example, the insulating layer 110 may be rigid or flexible. For example, at least one of the insulating layers 110 may include glass or plastic. More specifically, at least one of the insulating layers 110 may include chemically strengthened / semi-strengthened glass such as soda-lime glass or aluminosilicate glass, or reinforced or ductile plastics such as polyimide (PI), polyethylene terephthalate (PET), propylene glycol (PPG), or polycarbonate (PC), or may include sapphire.

[0060] Furthermore, the insulating layer 110 may include an optically isotropic film. For example, at least one of the insulating layers 110 may include COC (Cyclic Olefin Copolymer), COP (Cyclic Olefin Polymer), optically isotropic polycarbonate (PC), or optically isotropic polymethyl methacrylate (PMMA).

[0061] Furthermore, the insulating layer 110 may be formed from a material containing an inorganic filler and an insulating resin. For example, as the material constituting the insulating layer 110, a resin containing a thermosetting resin such as epoxy resin, a thermoplastic resin such as polyimide, and a reinforcing material such as an inorganic filler such as silica or alumina may be used. Specifically, ABF (Ajinomoto Build-up Film), FR-4, BT (Bismaleimide Triazine), PID (Photo Imagable Dielectric resin), BT, etc., may be used.

[0062] Furthermore, the insulating layer 110 may bend with a partially curved surface. That is, the insulating layer 110 may bend with a partially flat surface and a partially curved surface. More specifically, the insulating layer 110 may bend with a curved end, or bend or fold with a surface that includes random curvature.

[0063] A circuit pattern may be arranged on the surface of the insulating layer 110. The circuit pattern layer can mean the "electrode portion" described below. That is, the "electrode portion" described below can mean, but is not limited to, a circuit pattern layer, a circuit pattern, a pattern layer, a pad, a trace, etc.

[0064] For example, a first electrode portion 120 may be placed on the first surface of the insulating layer 110. A second electrode portion 130 may be placed on the second surface of the insulating layer 110.

[0065] The first electrode portion 120 and the second electrode portion 130 may be wiring that transmits electrical signals. Alternatively, the first electrode portion 120 and the second electrode portion 130 may be heat transfer patterns that transmit heat. For this purpose, the first electrode portion 120 and the second electrode portion 130 may be formed from a metallic material with high electrical conductivity or high thermal conductivity.

[0066] For this purpose, the first electrode portion 120 and the second electrode portion 130 can be made of at least one metallic substance selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn). Alternatively, the first electrode portion 120 and the second electrode portion 130 can be made of a paste or solder paste containing at least one metallic substance selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn), which have excellent bonding strength. Preferably, the first electrode portion 120 and the second electrode portion 130 can be made of copper (Cu), which has high electrical or thermal conductivity and is relatively inexpensive.

[0067] The first electrode portion 120 and the second electrode portion 130 can be manufactured using conventional circuit board manufacturing processes such as additive process, subtractive process, MSAP (Modified Semi Additive Process), and SAP (Semi Additive Process), and a detailed explanation is omitted here.

[0068] A through electrode 140 is formed in the insulating layer 110. That is, the through electrode 140 penetrates the upper and lower surfaces of the insulating layer 110.

[0069] As a result, the through electrode 140 may have its first surface in contact with the lower surface of the first electrode portion 120 and its second surface in contact with the upper surface of the second electrode portion 130. For example, the through electrode 140 can connect the first electrode portion 120 and the second electrode portion 130. For example, the through electrode 140 can electrically connect the first electrode portion 120 and the second electrode portion 130 to transmit electrical signals. For example, the through electrode 140 can thermally connect the first electrode portion 120 and the second electrode portion 130 to form a heat transfer (e.g., heat dissipation) path.

[0070] The through electrode 140 may include a plurality of through electrode parts.

[0071] For example, the through electrode 140 may include a plurality of first through electrode parts 141, 142, 143, 144, 145, 146 that extend elongated in a first direction (e.g., longitudinal direction).

[0072] Furthermore, the multiple first through-electrode parts 141, 142, 143, 144, 145, and 146 constituting the through-electrode 140 can be spaced apart from each other in a second direction (width direction) perpendicular to the first direction (e.g., longitudinal direction).

[0073] Each of the first through-electrode parts 141, 142, 143, 144, 145, and 146 constituting the through-electrode 140 may have a first width W1 in a first direction (e.g., the longitudinal direction). Furthermore, each of the first through-electrode parts 141, 142, 143, 144, 145, and 146 constituting the through-electrode 140 may have a second width W2 in a second direction (width direction) that is smaller than the first width W1.

[0074] The first width W1 may be at least twice the second width W2. For example, the first width W1 may be at least four times the second width W2. For example, the first width W1 may be at least ten times the second width W2.

[0075] The first width W1 can be in the range of 100 μm to 3000 μm. For example, the first width W1 can be in the range of 300 μm to 2500 μm. For example, the first width W1 can be in the range of 800 μm to 2000 μm. If the first width W1 is less than 100 μm, the through electrode 140 may be a general-sized general through electrode rather than a large-area through electrode. Specifically, if the first width W1 is less than 100 μm, the through electrode 140 may be formed by a single plating process rather than multiple plating processes as in the examples. If the first width W1 is greater than 3000 μm, the plating time required to form the through electrode 140 may increase sharply. For example, if the first width W1 is greater than 3000 μm, at least five or more plating processes must be performed to completely remove the dimple region, which may increase the manufacturing time of the circuit board and decrease the yield. For example, if the first width W1 is greater than 3000 μm, it may be difficult to completely remove the dimple region of the through electrode 140 even after multiple plating processes.

[0076] The second width W2 can be determined by the processing conditions of the through-holes constituting each of the first through-electrode parts 141, 142, 143, 144, 145, and 146. For example, if the through-holes are formed by laser processing, the second width W2 can be determined by the size of the laser point (not shown). For example, the second width W2 can be in the range of 30 μm to 200 μm. For example, the second width W2 can be in the range of 40 μm to 150 μm. For example, the second width W2 can be in the range of 50 μm to 100 μm. The second width W2 may be the same as the size of the laser point, or it may be different and larger. For example, if the through-holes are processed in a line while moving the laser point in a first direction (e.g., longitudinal direction), the second width W2 can correspond to the size of the laser point. For example, if the through-hole is formed by machining a first row while moving the laser point in a first direction (width direction), and then machining a second row at a position overlapping with the first row, the second width W2 may be larger than the size of the laser point.

[0077] The first through-electrode parts 141, 142, 143, 144, 145, and 146 can be spaced apart from each other by a third width W3 in the second direction (width direction), as described above. In this case, the third width W3 can be determined by the size of the laser point. For example, the third width W3 may be smaller than the size of the laser point. For example, the third width W3 may be larger than half the size of the laser point. This is to solve the reliability problem of multiple through-holes being interconnected due to laser processing tolerances during the process of forming through-holes that are spaced apart from each other in the second direction (width direction).

[0078] On the other hand, the through-electrode 140 described above can be formed by creating through-holes corresponding to the first through-electrode parts 141, 142, 143, 144, 145, and 146 that penetrate the insulating layer 110, and filling the inside of each of the formed through-holes with a conductive material.

[0079] The through-hole can be formed by any one of the following processing methods: mechanical, laser, or chemical. When the through-hole is formed by mechanical processing, methods such as milling, drilling, and routing can be used. When the through-hole is formed by laser processing, UV or CO2 laser methods can be used. When the through-hole is formed by chemical processing, chemicals including aminosilanes and ketones can be used.

[0080] On the other hand, the laser processing method involves concentrating optical energy on the surface to melt and evaporate a portion of the material, thereby creating a desired shape. This method can easily process complex shapes created by computer programs and can also process composite materials that are difficult to cut by other methods.

[0081] Once the through-holes are formed, the interiors of the through-holes can be filled with a conductive material to form the first through-electrode parts 141, 142, 143, 144, 145, and 146. The metallic material forming the first through-electrode parts 141, 142, 143, 144, 145, and 146 may be any one selected from copper (Cu), silver (Ag), tin (Sn), gold (Au), nickel (Ni), and palladium (Pd). The filling of the conductive material can be carried out by any one or a combination thereof of electroless plating, electroplating, screen printing, sputtering, evaporation, inkjet printing, and defencing. Preferably, the through-electrode 140 including the first through-electrode parts 141, 142, 143, 144, 145, and 146 may contain the same metallic material as the first electrode part 120. For example, the through electrode 140 may have the same layer structure as the first electrode portion 120. For example, the through electrode 140 may be formed integrally with the first electrode portion 120. For example, the through electrode 140 and the first electrode portion 120 may be formed simultaneously by a plating process. In this way, the through electrode 140 and the first electrode portion 120 can be considered as a single component. For example, the portion formed in the through hole of the insulating layer may be called the through electrode. And the portion formed on the upper surface of the insulating layer while being connected to the through electrode may also be called the first electrode portion.

[0082] However, in the embodiment, the portion of the metal layer formed by the plating process that is formed within the through-hole of the insulating layer 110 is referred to as the through-electrode 140, and the portion formed on the first surface of the insulating layer 110 and the first surface of the through-electrode 140 is referred to as the first electrode portion 120.

[0083] The first electrode portion 120 and the through electrode 140 can be formed by multiple plating processes. Specifically, the first electrode portion 120 and the through electrode 140 can be formed by forming metal layers by two plating processes, respectively. Therefore, the first electrode portion 120 and the through electrode 140 can each be composed of multiple metal layers formed by multiple plating processes. However, the embodiments are not limited thereto. For example, the first electrode portion 120 and the through electrode 140 can include three or more metal layers by performing three or more plating processes. However, when performing three or more plating processes to form the first electrode portion 120 and the through electrode 140, there is a problem that the plating time increases and the process yield decreases. Therefore, in the embodiments, the optimal first electrode portion 120 and the through electrode 140 can be formed with two plating processes.

[0084] Furthermore, in the embodiment, even when the first electrode portion 120 is formed by multiple plating processes, the upper surface of the first electrode portion 120 is composed of only one of the multiple metal layers formed by the multiple plating processes. This can be achieved by adjusting the plating conditions of the multiple plating processes. In this case, the plating conditions may be the plating current density of the plating process. That is, in the embodiment, when the through electrode 140 and the first electrode portion 120 are formed by two plating processes, the plating current density of the primary plating process and the plating current density of the secondary plating process are made different. In the embodiment, the surface of the first electrode portion 120 can be cleaned by changing the plating current density.

[0085] Preferably, in the embodiment, the current density of the primary plating process is set to be lower than the current density of the secondary plating process. This allows the upper surface of the second electrode portion 130 to be formed with a metal layer formed by the secondary plating process, which has a relatively higher current density, in the embodiment.

[0086] For example, in the comparative example, the current density of the primary plating process and the current density of the secondary plating process were substantially the same. As a result, in the comparative example, the upper surface of the first electrode portion included both the metal layer from the primary plating process and the metal layer from the secondary plating process, causing contamination.

[0087] Furthermore, unlike the embodiment, the current density of the primary plating process can be made relatively high, and the current density of the secondary plating process can be made relatively low. In such a case, the upper surface of the first electrode portion may be composed only of the metal layer from the primary plating process. However, in such a case, the dimple region can be substantially entirely filled in the primary plating process. And there is a problem that filling a large area of ​​through-holes without dimple regions in the primary plating process requires a considerable amount of plating time.

[0088] Therefore, in the embodiment, compared to the comparative example, the current density for the primary plating process is reduced and the current density for the secondary plating process is increased, thereby shortening the plating time while removing the contaminants.

[0089] Figure 5 is a detailed diagram of the first electrode section and through electrode shown in Figure 3, and Figure 6 is a diagram showing the top surface of the first electrode section in Figure 5.

[0090] Referring to Figures 5 and 6, the first electrode portion 120 and the through electrode 140 are formed by multiple plating processes. For example, the first electrode portion 120 and the through electrode 140 include a seed layer 150, a first metal layer 160, and a second metal layer 170.

[0091] The seed layer 150 may be a seed layer for forming the first metal layer 160 and the second metal layer 170 by electroplating. The seed layer 150 may be formed on the first surface of the insulating layer 110 and on the inner wall of a through hole formed in the insulating layer 110.

[0092] That is, the seed layer 150 may include a first portion 141 formed on the inner wall of the through hole and a second portion 121 formed on the first surface of the insulating layer 110. The first portion 141 of the seed layer 150 may constitute the through electrode 140. The second portion 121 of the seed layer 150 may constitute the first electrode portion 120.

[0093] The first metal layer 160 can be formed by performing primary electroplating using the seed layer 150.

[0094] The first metal layer 160 may include a first portion 142 formed on the first portion 141 of the seed layer 150 and a second portion 122 formed on the second portion 121 of the seed layer 150.

[0095] The first portion 142 of the first metal layer 160 can constitute the through electrode 140. The second portion 122 of the first metal layer 160 can constitute the first electrode portion 120. For example, the first portion 142 of the first metal layer 160 can fill a portion of the through hole. Furthermore, the second portion 122 of the first metal layer 160 can be formed on the second portion 121 of the seed layer 150 to have a certain height.

[0096] The first portion 142 of the first metal layer 160 may include concave portions (e.g., recesses). For example, the upper surface of the first portion 142 of the first metal layer 160 may have a curved surface that is recessed downwards. In this case, the lowest end of the upper surface of the first portion 142 of the first metal layer 160 may be lower than the first surface or upper surface of the insulating layer 110. For example, through holes formed in the insulating layer 110 may not be completely filled by the first portion 142 of the first metal layer 160. For example, at least a portion of the through holes (e.g., the concave portion) may not be filled (or embedded) by the first portion 142 of the first metal layer 160. This can be achieved by reducing the current density in the plating conditions for the first metal layer 160 compared to the comparative example.

[0097] On the other hand, the upper surface of the second portion 122 of the first metal layer 160 may have a curved surface. For example, the height of the upper surface of the second portion 122 of the first metal layer 160 may gradually increase as it moves away from the center of the through electrode 140. For example, the upper surface of the second portion 122 of the first metal layer 160 may have the highest height at the position furthest from the center of the through electrode 140.

[0098] The second metal layer 170 can be formed on the first metal layer 160 by electroplating the seed layer 150.

[0099] The second metal layer 170 may include a first portion 143 formed on the first portion 142 of the first metal layer 160 and a second portion 123 formed on the second portion 122 of the first metal layer 160.

[0100] The first portion 143 of the second metal layer 170 can fill (or embed) the concave portion (or recess) of the first portion 142 of the first metal layer 160. For example, the lower surface of the first portion 143 of the second metal layer 170 may include a convex portion (or protrusion). For example, the lower surface of the first portion 143 of the second metal layer 170 may have a curved surface that is convex in the downward direction. In this case, the lowest end of the lower surface of the first portion 143 of the second metal layer 170 may be located lower than the first surface of the insulating layer 110. This can be achieved by increasing the current density in the plating conditions for the second metal layer 170 compared to the comparative example.

[0101] On the other hand, the upper surface of the second portion 123 of the second metal layer 170 may be flat. For example, the lower surface of the second portion 123 of the second metal layer 170 may be curved. Preferably, the second portion 123 of the second metal layer 170 may have different thicknesses in each region. For example, the thickness of the first region of the second portion 123 that overlaps with the through electrode 140 in a third direction (or perpendicular direction) may be greater than the thickness of the other second regions.

[0102] As described above, the through electrode 140 and the first electrode portion 120 are composed of a seed layer 150, a first metal layer 160, and a second metal layer 170.

[0103] For example, the through electrode 140 may include a first portion 141 of the seed layer 150, a first portion 142 of the first metal layer 160, and a first portion 143 of the second metal layer 170.

[0104] For example, the first electrode portion 120 may include the second portion 121 of the seed layer 150, the second portion 122 of the first metal layer 160, and the second portion 123 of the second metal layer 170. In this case, the first electrode portion 120 may have different layer structures in each region. For example, the first electrode portion 120 may include a first region that overlaps with the through electrode 140 in a third direction (e.g., vertical or thickness direction) and a second region other than the first region. The first region of the first electrode portion 120 may include only the first portion 143 of the second metal layer 170. The second region of the first electrode portion 120 may include the second portion 121 of the seed layer 150, the second portion 122 of the first metal layer 160, and the second portion 123 of the second metal layer 170. For example, the first region of the first electrode portion 120 may have a single-layer structure, and the second region of the first electrode portion 120 may have a three-layer structure.

[0105] On the other hand, the first portion 142 of the first metal layer 160 can have different thicknesses in different regions, as described above. For example, the first portion 142 of the first metal layer 160 can have the maximum thickness in the edge region of the through hole and the minimum thickness in the central region of the through hole.

[0106] In this embodiment, as described above, the position of the lowest end of the upper surface of the first portion 142 of the first metal layer 160 can be adjusted by adjusting the current density of the primary plating process. That is, the lower surface of the first portion 142 of the first metal layer 160 can have a first thickness H1 between it and the lowest end of the upper surface of the first portion 142 of the first metal layer 160. The embodiment adjusts the first thickness H1 by adjusting the current density and removes the dirt through it. The first thickness H1 can be in the range of 30% to 95% of the width W2 of the through electrode 140 in the second direction. For example, the first thickness H1 can be in the range of 35% to 90% of the width W2 of the through electrode 140 in the second direction. For example, the first thickness H1 can be in the range of 40% to 85% of the width W2 of the through electrode 140 in the second direction. If the first thickness H1 is less than 35% of the width W2 of the through electrode 140 in the second direction, the time required for the secondary plating process to form the second metal layer 170 may increase. Also, if the first thickness H1 is less than 35% of the width W2 of the through electrode 140 in the second direction, the dimple region may not be completely filled with the second metal layer 170 alone. If the first thickness H1 is greater than 95% of the width W2 of the through electrode 140 in the second direction, the time required to form the first metal layer 160 by the primary plating process may increase, resulting in a decrease in yield. Also, if the first thickness H1 is greater than 95% of the width W2 in the second direction, a portion of the first electrode portion 120 may consist only of the second portion 122 of the first metal layer 160, which may result in contamination.

[0107] On the other hand, the thickness H2 of the through electrode 140 can correspond to the thickness of the insulating layer 110. The thickness H2 of the through electrode 140 can be in the range of 10 μm to 200 μm. For example, the thickness H2 of the through electrode 140 can be in the range of 15 μm to 150 μm. For example, the thickness H2 of the through electrode 140 can be in the range of 20 μm to 120 μm.

[0108] Furthermore, in the embodiment, as described above, the height of the uppermost part of the second portion 122 of the first metal layer 160 of the first electrode portion 120 can be adjusted by adjusting the current density of the primary plating process. The height H3 of the uppermost part of the second portion 122 of the first metal layer 160 can mean the thickness H3 from the lower surface of the second portion 121 of the seed layer 150 to the uppermost part of the second portion 122 of the first metal layer 160. The height H3 of the uppermost part of the second portion 122 of the first metal layer 160 can be determined by the thickness of the first electrode portion 120. The thickness of the first electrode portion 120 can mean the distance or height between the first surface of the insulating layer 110 and the upper surface of the second portion 123 of the second metal layer 170. For example, the height H3 of the uppermost part of the second portion 122 of the first metal layer 160 can satisfy a range of 50% to 85% of the thickness of the first electrode portion 120. For example, the height H3 of the uppermost end of the second portion 122 of the first metal layer 160 can satisfy a range of 52% to 80% of the thickness of the first electrode portion 120. For example, the height H3 of the uppermost end of the second portion 122 of the first metal layer 160 can satisfy a range of 55% to 78% of the thickness of the first electrode portion 120. If the height H3 of the uppermost end of the second portion 122 of the first metal layer 160 is less than 50% of the thickness of the first electrode portion 120, the area of ​​the dimple region of the through electrode 140 increases, and as a result, the dimple region may not be completely filled by the second metal layer. Also, if the height H3 of the uppermost end of the second portion 122 of the first metal layer 160 is greater than 85% of the thickness of the first electrode portion 120, dirt may occur on the upper surface of the first electrode portion 120.

[0109] As described above, in the embodiment, primary and secondary plating are performed to form the first metal layer 160 and the second metal layer 170 corresponding to the through electrode 140 and the first electrode portion 120. Then, by adjusting the plating conditions of the first metal layer 160, the dimple region that may be included in the through electrode 140 can be completely removed. Furthermore, dirt that may form on the surface of the first electrode portion 120 can be removed.

[0110] On the other hand, the first electrode portion 120 of the embodiment includes a first surface treatment layer 125.

[0111] The first surface treatment layer 125 may be formed on the second portion 123 of the second metal layer 170 of the first electrode portion 120. In this case, the first surface treatment layer 125 may be formed only on the upper surface of the first electrode portion 120. Alternatively, the first surface treatment layer 125 may be formed not only on the upper surface of the first electrode portion 120 but also on the side surfaces.

[0112] The first surface treatment layer 125 may include a 1-1 surface treatment layer 125-1, a 1-2 surface treatment layer 125-2, and a 1-3 surface treatment layer 125-3.

[0113] The first-first surface treatment layer 125-1 may be formed on the first electrode portion 120. The first-second surface treatment layer 125-2 may be formed on the first-first surface treatment layer 125-1. The first-third surface treatment layer 125-3 may be formed on the first-second surface treatment layer 125-2.

[0114] The 1-1 surface treatment layer 125-1 may contain nickel (Ni). Thus, the 1-1 surface treatment layer 125-1 can also be called a nickel metal layer. The 1-1 surface treatment layer 125-1 may be formed from nickel alone, or from an alloy containing nickel with P (phosphorus), B (boron), W (tungsten), or Co (cobalt).

[0115] The first-1 surface treatment layer 125-1 can have a thickness of 2 μm to 10 μm. For example, the first-1 surface treatment layer 125-1 can have a thickness of 3 μm to 8 μm. For example, the first-1 surface treatment layer 125-1 can have a thickness of 4 μm to 6 μm.

[0116] The first- and second surface treatment layers 125-2 may contain palladium (Pd). Thus, the first- and second surface treatment layers 125-2 can be described as a palladium metal layer. The first- and second surface treatment layers 125-2 may contain only palladium, or may further contain palladium plus at least one metal from among cobalt (Co), zinc (Zn), nickel (Ni), and inorganic materials. The first- and second surface treatment layers 125-2 may have a thickness of 0.001 μm to 0.5 μm. For example, the first- and second surface treatment layers 125-2 may have a thickness of 0.005 μm to 0.2 μm. For example, the first- and second surface treatment layers 125-2 may have a thickness of 0.01 μm to 0.1 μm.

[0117] The first to third surface treatment layers 125-3 may contain gold (Au). The first to third surface treatment layers 125-3 may have a thickness of 0.001 μm to 0.5 μm. For example, the first to third surface treatment layers 125-3 may have a thickness of 0.005 μm to 0.2 μm. For example, the first to third surface treatment layers 125-3 may have a thickness of 0.01 μm to 0.1 μm.

[0118] As described above, in the embodiment, multiple plating processes are performed on the circuit board to form through electrodes that fill large-area through holes. In this embodiment, the current density, which is the plating condition for the multiple plating processes, is adjusted. Through this, the embodiment forms a first metal layer in the primary plating process and a second metal layer in the secondary plating process, which constitute a part of the through electrode and the first electrode portion, respectively. In this case, the first metal layer in the embodiment may be formed with a relatively low current density, and the second metal layer may be formed with a relatively high current density. As a result, in the embodiment, it is possible to prevent the through electrode or the first electrode portion from containing dimple areas in the circuit board containing the large-area through electrode, thereby improving reliability. Furthermore, in the embodiment, by controlling the current density as described above, the upper surface of the first pad can be formed with only the second metal layer. As a result, in the embodiment, the problem of contamination caused by the upper surface of the first electrode portion containing both the first and second metal layers can be solved, thereby improving customer satisfaction. Furthermore, in this embodiment, the increase in plating time due to including only the first metal layer on the upper surface of the first electrode portion can be resolved, thereby improving the yield of the product.

[0119] On the other hand, the circuit board of the embodiment may have multiple layer structures. For example, the circuit board of the embodiment may be a multilayer circuit board. The multilayer structure of the circuit board of the embodiment will be described below.

[0120] Figure 7 is a first cross-sectional view of the circuit board according to the second embodiment, and Figure 8 is a second cross-sectional view of the circuit board according to the second embodiment.

[0121] For example, Figure 7 could be a cross-sectional view in the direction A-A' of Figure 3, and Figure 8 could be a cross-sectional view in the direction B-B' of Figure 3.

[0122] Referring to Figures 7 and 8, the circuit board includes multiple insulating layers, multiple electrode sections, and multiple through electrodes.

[0123] For example, the insulating layer 210 may include first to fourth insulating layers 211, 212, 213, and 214. Specifically, the insulating layer 110 may include a first insulating layer 211 disposed on the first surface of the first electrode portion 221, a second insulating layer 212 disposed on the first surface of the first insulating layer 211, a third insulating layer 213 disposed on the second surface of the first electrode portion 221 or the second surface of the first insulating layer 211, and a fourth insulating layer 214 disposed on the second surface of the third insulating layer 213.

[0124] In this example, the insulating layer 210 is shown as having a four-layer structure, but it is not limited to this. For example, the insulating layer 210 can have more than four layers.

[0125] However, in the above embodiment, the first electrode portion 221 is placed on a reference insulating layer in the laminated structure of the insulating layer 210. Here, the reference insulating layer can mean the insulating layer that is laminated first in the manufacturing process of the circuit board. For example, in the circuit board of the embodiment, the first insulating layer 211 may be the first layer to be laminated, and thus the first insulating layer 211 can become the reference insulating layer.

[0126] The first electrode portion 221 may be a reference electrode portion. For example, the first electrode portion 221 may be a reference electrode portion arranged on the second surface of a reference insulating layer. Here, the reference electrode portion can mean an electrode portion arranged in the center of the laminated structure of the circuit board. Specifically, the circuit board undergoes a first step of forming an insulating layer, an electrode portion, and a through electrode on one side of the reference electrode portion, and a second step of forming an insulating layer, an electrode portion, and a through electrode on the other side of the reference electrode portion. The reference electrode portion may be a pad or electrode portion that serves as a reference for performing the first and second steps. In this case, the circuit board of the embodiment may have the same number of insulating layers arranged on one side of the reference electrode portion as it does on the other side. The reference electrode portion may be arranged in the center of the laminated structure in the thickness direction of the circuit board. However, the embodiment is not limited thereto, and the number of insulating layers arranged on one side of the reference electrode portion as it does not differ from the number of insulating layers arranged on the other side. In this case, the reference electrode portion may be positioned offset from the center of the circuit board to one side or the other. However, in the following description, the first electrode portion 221, which is the reference electrode portion, will be positioned in the center of the circuit board.

[0127] The embodiment may include a first substrate layer positioned on one side of the first electrode portion 221, and a second substrate layer positioned on the other side of the first electrode portion 221. For example, the first substrate layer may include a first insulating layer 211, a second insulating layer 212, a first through electrode 231, a second electrode portion 222, a second through electrode 232, a third electrode portion 223, and a first surface treatment layer 241. For example, the second substrate layer may include a third insulating layer 213, a fourth electrode portion 224, a third through electrode 233, a fourth through electrode 234, a fifth electrode portion 225, and a second surface treatment layer 242.

[0128] In this case, the first substrate layer may have a symmetrical structure with respect to the second substrate layer, centered on the first electrode portion 221. However, the embodiments are not limited thereto, and the first substrate layer and the second substrate layer may have different numbers of insulating layers, thereby having an asymmetrical structure. However, in the following description, the first substrate layer and the second substrate layer will be described as having a mutually symmetrical structure with respect to the first electrode portion 221. In such a case, the first substrate layer and the second substrate layer will have substantially the same layer structure, and the description will focus on the first substrate layer.

[0129] The first electrode portion 221 is arranged on the second surface of the first insulating layer 211. The first electrode portion 221 may have a first thickness H4. The first electrode portion 221 may have a different cross-sectional shape or layer structure than the second electrode portion 222 and the third electrode portion 223, which will be described later. For example, the first electrode portion 221 may have a different cross-sectional shape than the second electrode portion 222 and the third electrode portion 223. For example, the first electrode portion 221 may have a rectangular shape. For example, the first electrode portion 221 may have a different layer structure than the third electrode portion 223. For example, the first electrode portion 221 may have a smaller number of layers than the third electrode portion 223.

[0130] The first through electrode 231 penetrates the first insulating layer 211. The first through electrode 231 can be a large-area through electrode. For example, the first through electrode 231 may include a plurality of bar-shaped first through electrode parts that extend long in a first direction (e.g., longitudinal direction). The plurality of first through electrode parts may be spaced apart from each other in a second direction (width direction) within the first insulating layer 211. The plurality of first through electrode parts constituting the first through electrode 231 may be connected to a first electrode section 221 and a second electrode section 222. For example, the lower surfaces of the plurality of first through electrode parts constituting the first through electrode 231 may be commonly connected to the first electrode section 221, and the upper surfaces of the plurality of first through electrode parts may be commonly connected to the second electrode section 222, which will be described later.

[0131] The second electrode portion 222 may be positioned on the first surface of the first insulating layer 211. The second electrode portion 222 can also be called an inner electrode portion. For example, the second electrode portion 222 may be positioned between the reference electrode portion and the outermost electrode portion. The second electrode portion 222 may have a different cross-sectional shape from the first electrode portion 221. For example, the upper surface of the second electrode portion 222 may be curved. For example, the second electrode portion 222 may have concave recesses in the direction toward the first electrode portion 221. For example, the second electrode portion 222 may have dimple regions. The second electrode portion 222 may have a second thickness H2. In this case, the second thickness H2 of the second electrode portion 222 may mean the thickness of the thickest part of the second electrode portion 222. For example, the second electrode portion 222 may include recesses as described above, thereby having different thicknesses in each region. As a result, the second thickness H2 of the second electrode portion 222 can represent the straight-line distance from the lowest end to the highest end of the second electrode portion 222. The second thickness H2 of the second electrode portion 222 may be smaller than the first thickness H1 of the first electrode portion 221. This will be explained in detail below.

[0132] The second insulating layer 212 is placed on the second electrode portion 222 and the first insulating layer 211.

[0133] The second through electrode 232 may be positioned to penetrate the second insulating layer 212.

[0134] The second through electrode 232 is a large-area through electrode. For example, the second through electrode 232 may include a plurality of bar-shaped second through electrode parts that extend long in a first direction (e.g., the longitudinal direction). The plurality of second through electrode parts may be spaced apart from each other in a second direction (width direction) within the second insulating layer 212. The plurality of second through electrode parts constituting the second through electrode 232 may be connected to the second electrode section 222 and the third electrode section 223. For example, the lower surfaces of the plurality of second through electrode parts constituting the second through electrode 232 may be commonly connected to the second electrode section 222, and the upper surfaces of the plurality of second through electrode parts may be commonly connected to the third electrode section 223, which will be described later.

[0135] A third electrode portion 223 is arranged on the first surface of the second insulating layer 212. The third electrode portion 223 may be the outermost electrode portion. The third electrode portion 223 may have a different layer structure from the first electrode portion 221 and the second electrode portion 222. For example, the number of layers of the third electrode portion 223 may be greater than the number of layers of the first electrode portion 221 or the number of layers of the second electrode portion 222.

[0136] Specifically, in this embodiment, the through-electrode located inside the circuit board undergoes only one plating process to include the dimple region. In this embodiment, the through-electrode located on the outermost side of the circuit board undergoes multiple plating processes. Through this process, in this embodiment, the plating process for the outermost through-electrode ensures that the dimple region of the inner through-electrode is completely filled. As a result, the outermost third electrode portion 223 can have more layers than the first electrode portion 221 and the second electrode portion 222, respectively. The third electrode portion 223 can have a rectangular cross-section. For example, the upper surface of the third electrode portion 223 may be flat. For example, the cross-sectional shape of the third electrode portion 223 may correspond to the cross-sectional shape of the first electrode portion 221. For example, the cross-sectional shape of the third electrode portion 223 may differ from the cross-sectional shape of the second electrode portion 222.

[0137] The third electrode portion 223 may have a third thickness H3. For example, the third electrode portion 223 may have a third thickness H3 that is greater than the first thickness H1 of the first electrode portion 221 and the second thickness H2 of the second electrode portion 222.

[0138] As described above, in the embodiment, the multiple electrode portions arranged on one side of the first electrode portion 221, which is the reference electrode portion, can have different thicknesses from each other. Furthermore, in the embodiment, the inner electrode portion arranged on one side of the first electrode portion 221, which is the reference electrode portion, includes a dimple region, and the dimple region of the inner electrode portion can be filled by other through electrodes arranged on the same side. The structure will be described in detail below.

[0139] Figure 9 is a diagram specifically showing the first substrate layer in Figures 7 and 8.

[0140] Referring to Figure 9, the circuit board includes a first electrode portion 221, a first insulating layer 211, a first through electrode 231, a second electrode portion 222, a second insulating layer 212, a second through electrode 232, and a third electrode portion 223.

[0141] The first electrode portion 221 may have a first thickness H4. For example, the first thickness H4 of the first electrode portion 221 may satisfy a range of 12 μm to 22 μm. For example, the first thickness H4 of the first electrode portion 221 may satisfy a range of 14 μm to 20 μm. For example, the first thickness H4 of the first electrode portion 221 may satisfy a range of 15 μm to 19 μm. The first electrode portion 221 may have a single-layer structure, or conversely, a two-layer structure. For example, the first electrode portion 221 may be formed by etching a copper foil layer having a thickness corresponding to the first thickness H4. This allows the first electrode portion 221 to have a single-layer structure corresponding to the copper foil layer. Conversely, the first electrode portion 221 may include a seed layer and a metal layer electroplated around the seed layer. In such a case, the first thickness H4 of the first electrode portion 221 may be the sum of the thickness of the seed layer and the thickness of the metal layer.

[0142] The second electrode portion 222 is positioned on the first surface of the first insulating layer 211. The second electrode portion 222 can be connected to a first through electrode 231 that penetrates the first insulating layer 211. Preferably, the second electrode portion 222 can have the same layer structure as the first through electrode 231. For example, the second electrode portion 222 can be formed integrally with the first through electrode 231. For example, the first through electrode 231 and the second electrode portion 222 can be formed simultaneously through a plating process. In this way, the first through electrode 231 and the second electrode portion 222 can be considered to be substantially a single configuration. However, in this embodiment, the portion formed within the first through hole is referred to as the first through electrode 231, and the portion positioned on the first surface of the first insulating layer 211 is referred to as the second electrode portion 222.

[0143] The second electrode portion 222 and the first through electrode 231 may include a first seed layer 250 and a first metal layer 260.

[0144] The first seed layer 250 may be a seed layer for forming the first metal layer 260 by electroplating. The first seed layer 250 may be formed on the first surface of the first insulating layer 211 and on the inner wall of the first through hole. That is, the first seed layer 250 may include a first portion 231-1 formed on the inner wall of the first through hole and a second portion 222-1 formed on the first surface of the first insulating layer 211. The first portion 231-1 of the first seed layer 250 may constitute the first through electrode 231. The second portion 222-1 of the first seed layer 250 may constitute the second electrode portion 222.

[0145] The first metal layer 260 may be formed by electroplating using the first seed layer 250. The first metal layer 260 may include a first portion 231-2 formed on a first portion 231-1 of the first seed layer 250 and a second portion 222-2 formed on a second portion 222-1 of the first seed layer 250.

[0146] The first portion 231-2 of the first metal layer 260 can constitute the first through electrode 231, and the second portion 222-2 of the first metal layer 260 can constitute the second electrode portion 222.

[0147] Specifically, the first through electrode 231 includes a first portion 231-1 of the first seed layer 250 and a first portion 231-2 of the first metal layer 260. The second electrode portion 222 includes a second portion 222-1 of the first seed layer 250 and a second portion 222-2 of the first metal layer 260.

[0148] In this case, the first through-hole formed in the first insulating layer 211, specifically the first through-hole constituting the first through-electrode 231, is a large-area through-hole. Therefore, it may be difficult to fill the entire first through-hole with the first metal layer 260 alone. As a result, the first metal layer 260 may include dimple regions. For example, the second portion 222-2 of the first metal layer 260 may include recesses. For example, the upper surface of the second portion 222-2 of the first metal layer 260 may include a curved surface. The upper surface of the second portion 222-2 of the first metal layer 260 corresponds to the upper surface of the second electrode portion 222. As a result, the upper surface of the second electrode portion 222 may include recesses or curved surfaces. For example, the second electrode portion 222 may include dimple regions. In this case, generally, if the second electrode portion 222 includes dimple regions, the lamination process of the next layer is performed after filling the dimple regions. However, in such cases, the number of plating steps for each layer increases, which can lead to a decrease in yield. Therefore, in the embodiment, the inner through electrode and the inner electrode portion are made to include dimple regions. In this way, in the embodiment, the outermost through electrode and the outermost electrode portion formed by multiple plating steps can fill the dimple regions of the inner through electrode and the inner electrode portion while simultaneously removing or filling their own dimple regions.

[0149] The second electrode portion 222 may have a second thickness H5. For example, the second thickness H5 of the second electrode portion 222 may be smaller than the first thickness H4 of the first electrode portion 221. The second thickness H5 of the second electrode portion 222 may represent the thickness of the second portion 222-1 of the first seed layer 250 and the second portion 222-2 of the first metal layer 260. The second thickness H5 of the second electrode portion 222 can satisfy a range of 8 μm to 18 μm. For example, the second thickness H5 of the second electrode portion 222 can satisfy a range of 10 μm to 16 μm. For example, the second thickness H5 of the second electrode portion 222 can satisfy a range of 9 μm to 15 μm. If the second thickness H5 of the second electrode portion 222 is smaller than 8 μm, the size of the dimple region of the second electrode portion 222 will be larger, which may later cause reliability problems with the second through electrode 232. For example, the dimple region of the second electrode portion 222 may be filled by the second through electrode 232. In this case, the larger the size of the dimple region of the second electrode portion 222, the larger the size of the dimple region formed on the second through electrode 232 will be. This may result in the inclusion of dimple regions in the second through electrode 232 and the third electrode portion 223, or complicate the plating process for removing them.

[0150] The third electrode portion 223 and the second through electrode 232 are formed by multiple plating processes. For example, the third electrode portion 223 and the second through electrode 232 include a second seed layer 270, a second metal layer 280, and a third metal layer 290.

[0151] The second seed layer 270 may be a seed layer for forming the second metal layer 280 and the third metal layer 290 by electroplating. The second seed layer 270 may be formed on the first surface of the second insulating layer 212 and on the inner wall of the second through hole formed in the second insulating layer 212.

[0152] That is, the second seed layer 270 may include a first portion 232-1 formed on the inner wall of the second through hole and a second portion 223-1 formed on the first surface of the second insulating layer 212. The first portion 232-1 of the second seed layer 270 may constitute the second through electrode 232. The second portion 223-1 of the second seed layer 270 may constitute the third electrode portion 223.

[0153] The second metal layer 280 can be formed by performing primary electroplating using the second seed layer 270.

[0154] The second metal layer 280 includes a first portion 232-2 formed on the first portion 232-1 of the second seed layer 270 and a second portion 223-2 formed on the second portion 223-1 of the second seed layer 270.

[0155] The first portion 232-2 of the second metal layer 280 can constitute the second through electrode 232. The second portion 223-2 of the second metal layer 280 can constitute the third electrode portion 223. For example, the first portion 232-2 of the second metal layer 280 can fill a portion of the interior of the second through hole. Furthermore, the second portion 223-2 of the second metal layer 280 may be formed on top of the second portion 223-1 of the second seed layer 270 to have a certain height.

[0156] The first portion 232-2 of the second metal layer 280 may include a concave portion. For example, the upper surface of the first portion 232-2 of the second metal layer 280 may have a curved surface that is concave downwards. In this case, the lowest end of the upper surface of the first portion 232-2 of the second metal layer 280 may be located lower than the first surface of the second insulating layer 212. For example, the second through-hole formed in the second insulating layer 212 is not completely filled by the first portion 232-2 of the second metal layer 280. For example, at least a portion of the second through-hole (e.g., the concave portion) may not be filled by the first portion 232-2 of the second metal layer 280.

[0157] The first portion 232-2 of the second metal layer 280 may include a convex portion. For example, the lower surface of the first portion 232-2 of the second metal layer 280 may have a curved surface that is convex in the downward direction. For example, the first portion 232-2 of the second metal layer 280 may include an upper surface corresponding to a concave portion of the upper surface of the first electrode portion 221. The lowest end of the first portion 232-2 of the second metal layer 280 (the lowest end of the second through electrode 232) may be located lower than the upper end of the first electrode portion 221.

[0158] On the other hand, the upper surface of the second portion 223-2 of the second metal layer 280 may have a curved surface. For example, the height of the upper surface of the second portion 223-2 of the second metal layer 280 may gradually increase as it moves away from the center of the second through electrode 232. For example, the upper surface of the second portion 223-2 of the second metal layer 280 may have the highest height at the position furthest from the center of the second through electrode 232.

[0159] The third metal layer 290 can be formed on the second metal layer 280 by electroplating the second seed layer 270.

[0160] The third metal layer 290 may include a first portion 232-3 formed on the first portion 232-2 of the second metal layer 280, and a second portion 223-3 formed on the second portion 223-2 of the second metal layer 280.

[0161] The first portion 232-3 of the third metal layer 290 can fill the concave portion of the first portion 232-2 of the second metal layer 280. For example, the lower surface of the first portion 232-3 of the third metal layer 290 may include a convex portion. For example, the lower surface of the first portion 232-3 of the third metal layer 290 may have a curved surface that is convex in the downward direction. In this case, the lowest end of the lower surface of the first portion 232-3 of the third metal layer 290 may be located lower than the first surface of the second insulating layer 212.

[0162] On the other hand, the upper surface of the second portion 223-3 of the third metal layer 290 may be flat. For example, the lower surface of the second portion 223-3 of the third metal layer 290 may be curved in certain areas and curved in other specific areas. Preferably, the second portion 223-3 of the third metal layer 290 may have different thicknesses in different regions. For example, the thickness of the region of the second portion 223-3 that overlaps with the second through electrode 232 in the third direction may be greater than the thickness of the other regions.

[0163] As described above, the second through electrode 232 and the third electrode portion 223 are composed of the second seed layer 270, the second metal layer 280, and the third metal layer 290.

[0164] For example, the second through electrode 232 may include a first portion 232-1 of the second seed layer 270, a first portion 232-2 of the second metal layer 280, and a first portion 232-3 of the third metal layer 290.

[0165] For example, the third electrode portion 223 may include the second portion 223-1 of the second seed layer 270, the second portion 223-2 of the second metal layer 280, and the second portion 223-3 of the third metal layer 290. In this case, the third electrode portion 223 may have different layer structures in each region. For example, the third electrode portion 223 may include a first region that overlaps with the second through electrode 232 in a third direction (e.g., the thickness direction) and a second region other than the first region. The first region of the third electrode portion 223 may include only the first portion 232-3 of the third metal layer 290. The second region of the third electrode portion 223 may include the second portion 223-1 of the second seed layer 270, the second portion 223-2 of the second metal layer 280, and the second portion 223-3 of the third metal layer 290. For example, the first region of the third electrode portion 223 may have a single-layer structure, and the second region of the third electrode portion 223 may have a three-layer structure.

[0166] On the other hand, the first portion 232-2 of the second metal layer 280 can have different thicknesses in different regions, as described above. For example, the first portion 232-2 of the second metal layer 280 can have the maximum thickness in the edge region of the second through hole and the minimum thickness in the central region of the second through hole.

[0167] In this embodiment, as described above, the position of the lowest end of the upper surface of the first portion 232-2 of the second metal layer 280 can be adjusted by adjusting the current density of the primary plating process. That is, the area between the lower surface of the first portion 232-2 of the second metal layer 280 and the lowest end of the upper surface of the first portion 232-2 of the second metal layer 280 can have a first thickness H1. The embodiment adjusts the first thickness H1 by adjusting the current density. This is done to remove the dirt. The first thickness H1 can be in the range of 30% to 95% of the width W2 of the second through electrode 232 in the second direction. For example, the first thickness H1 can be in the range of 35% to 90% of the width W2 of the second through electrode 232 in the second direction. For example, the first thickness H1 can be in the range of 40% to 85% of the width W2 of the second through electrode 232 in the second direction. If the first thickness H1 is less than 35% of the width W2 of the second through electrode 232 in the second direction, the time required for the secondary plating process to form the third metal layer 290 may increase. Also, if the first thickness H1 is less than 35% of the width W2 of the second through electrode 232 in the second direction, the dimple region may not be completely filled with the third metal layer 290 alone. If the first thickness H1 is greater than 95% of the width W2 of the second through electrode 232 in the second direction, the time required to form the second metal layer 280 by the primary plating process may increase, resulting in a decrease in yield. Also, if the first thickness H1 is greater than 95% of the width W2 in the second direction, a portion of the third electrode portion 223 may consist only of the second portion 223-2 of the second metal layer 280, which may result in contamination.

[0168] On the other hand, the thickness H2 of the second through electrode 232 can correspond to the thickness of the second insulating layer 212. The thickness H2 of the second through electrode 232 can be in the range of 10 μm to 200 μm. For example, the thickness H2 of the second through electrode 232 can be in the range of 15 μm to 150 μm. For example, the thickness H2 of the second through electrode 232 can be in the range of 20 μm to 120 μm.

[0169] Furthermore, in the embodiment, as described above, the height of the uppermost part 223-2 of the second metal layer 280 constituting the third electrode portion 223 can be adjusted by adjusting the current density for the primary plating process. The height H3 of the uppermost part 223-2 of the second metal layer 280 can mean the thickness H3 from the lower surface of the second part 223-1 of the second seed layer 270 to the uppermost part 223-2 of the second metal layer 280. The height H3 of the uppermost part 223-2 of the second metal layer 280 can be determined by the thickness of the third electrode portion 223. The thickness of the third electrode portion 223 can mean the distance or height from the first surface of the second insulating layer 212 to the upper surface of the second part 223-3 of the third metal layer 290. For example, the height H3 of the uppermost end of the second portion 223-2 of the second metal layer 280 can satisfy a range of 50% to 85% of the thickness of the third electrode portion 223. For example, the height H3 of the uppermost end of the second portion 223-2 of the second metal layer 280 can satisfy a range of 52% to 80% of the thickness of the third electrode portion 223. For example, the height H3 of the uppermost end of the second portion 223-2 of the second metal layer 280 can satisfy a range of 55% to 78% of the thickness of the third electrode portion 223. If the height H3 of the uppermost end of the second portion 223-2 of the second metal layer 280 is less than 50% of the thickness of the third electrode portion 223, the area of ​​the dimple region of the second through electrode 232 increases, and as a result, the dimple region may not be completely filled. Furthermore, if the height H3 of the uppermost end of the second portion 223-2 of the second metal layer 280 is greater than 85% of the thickness of the third electrode portion 223, dirt may accumulate on the upper surface of the third electrode portion 223.

[0170] As described above, in the embodiment, primary and secondary plating are performed to form the second metal layer 280 and the third metal layer 290 corresponding to the second through electrode 232 and the third electrode portion 223. The embodiment then adjusts the plating conditions of the second metal layer 280 to completely remove any dimple regions that may be present in the second through electrode 232. Thus, the embodiment makes it possible to remove any dirt that may form on the surface of the third electrode portion 223.

[0171] The third electrode portion 223 may have a third thickness H6. The third electrode portion 223 may be thicker than the first electrode portion 221 and the second electrode portion 222. That is, the third thickness H6 may be greater than the first thickness H4 and the second thickness H5.

[0172] The third thickness H6 can satisfy a range of 19 μm to 29 μm. For example, the third thickness H6 can satisfy a range of 21 μm to 27 μm. For example, the third thickness H6 can satisfy a range of 22 μm to 26 μm.

[0173] On the other hand, the third electrode portion 223 of the embodiment includes the first surface treatment layer 241.

[0174] The first surface treatment layer 241 may be formed on the second portion 223-3 of the third metal layer 290 of the third electrode portion 223. In this case, the first surface treatment layer 241 may be formed only on the upper surface of the third electrode portion 223. Alternatively, the first surface treatment layer 241 may be formed not only on the upper surface of the third electrode portion 223 but also on the side surfaces.

[0175] The first surface treatment layer 241 may include a 1-1 surface treatment layer 241-1, a 1-2 surface treatment layer 241-2, and a 1-3 surface treatment layer 241-3.

[0176] The first-1 surface treatment layer 241-1 may be formed on the third electrode portion 223. The first-2 surface treatment layer 241-2 may be formed on the first-1 surface treatment layer 241-1. The first-3 surface treatment layer 241-3 may be formed on the first-2 surface treatment layer 241-2.

[0177] The 1-1 surface treatment layer 241-1 may contain nickel (Ni). Thus, the 1-1 surface treatment layer 241-1 can also be called a nickel metal layer. The 1-1 surface treatment layer 241-1 may be formed from nickel alone, or from an alloy containing nickel with P (phosphorus), B (boron), W (tungsten), or Co (cobalt).

[0178] The first-1 surface treatment layer 241-1 can have a thickness of 2 μm to 10 μm. For example, the first-1 surface treatment layer 241-1 can have a thickness of 3 μm to 8 μm. For example, the first-1 surface treatment layer 241-1 can have a thickness of 4 μm to 6 μm.

[0179] The first- and second surface treatment layers 241-2 may contain palladium (Pd). Thus, the first- and second surface treatment layers 241-2 can be described as a palladium metal layer. The first- and second surface treatment layers 241-2 may contain only palladium, or may further contain palladium plus at least one metal from among cobalt (Co), zinc (Zn), nickel (Ni), and inorganic materials. The first- and second surface treatment layers 241-2 may have a thickness of 0.001 μm to 0.5 μm. For example, the first- and second surface treatment layers 241-2 may have a thickness of 0.005 μm to 0.2 μm. For example, the first- and second surface treatment layers 241-2 may have a thickness of 0.01 μm to 0.1 μm.

[0180] The first to third surface treatment layers 241-3 may contain gold (Au). The first to third surface treatment layers 241-3 may have a thickness of 0.001 μm to 0.5 μm. For example, the first to third surface treatment layers 241-3 may have a thickness of 0.005 μm to 0.2 μm. For example, the first to third surface treatment layers 241-3 may have a thickness of 0.01 μm to 0.1 μm.

[0181] In the second embodiment, as described above, a first through electrode 231 and a second electrode portion 222 are arranged on one side of the first electrode portion 221. Furthermore, a second through electrode 232 and a third electrode portion 223 are arranged on one side of the second electrode portion 222. In this embodiment, the inner first through electrode 231 or the second electrode portion 222 includes a dimple region. The outer second through electrode 232 is formed by filling the dimple region of the first through electrode 231 or the second electrode portion 222. As a result, in this embodiment, the third electrode portion 223 has a greater thickness than the first electrode portion 221 and the second electrode portion 222, and the second electrode portion 222 has a thinner thickness than the first electrode portion 221 and the third electrode portion 223. This simplifies the process of forming large-area through electrodes in this embodiment, thereby improving the product yield.

[0182] Figures 10 to 22 are diagrams illustrating the manufacturing method of a circuit board according to the second embodiment in order of steps.

[0183] Referring to Figure 10, in the embodiment, basic materials for manufacturing a circuit board are prepared. For example, in the embodiment, a carrier board 300 can be prepared. The carrier board 300 may include a carrier film 310 and copper foil 320 formed on the carrier film 310. The copper foil 320 may be, but is not limited to, copper (foil) bonded to the carrier film 310. Also, although the drawings show the copper foil 320 being placed on only one side of the carrier film 310, it is not limited to this. For example, the copper foil 320 may be placed on the other side of the carrier film 310 as well. The steps shown in Figures 11 to 20, which will be described below, can be performed on the other side of the carrier film 310 as well as one side.

[0184] Referring to Figure 11, in the embodiment, a step of laminating a first insulating layer 211 on the first surface of the copper foil 320 can be performed. Then, in the embodiment, once the first insulating layer 211 is laminated, a step of forming a plurality of first through holes VH1 in the first insulating layer 211 can be performed. Each of the plurality of first through holes VH1 may have a bar shape that extends long in a first direction (for example, the longitudinal direction).

[0185] Referring to Figure 12, in the embodiment, the first seed layer 250 can be formed on the first surface of the first insulating layer 211 and on the inner wall of the first through hole VH1. The first seed layer 250 can be formed by chemical copper plating, but is not limited thereto.

[0186] The first seed layer 250 may include a first portion 231-1 formed on the inner wall of the first through hole VH1 and a second portion 222-1 formed on the first surface of the first insulating layer 211.

[0187] Next, in the embodiment, a step of forming a first mask M1 on the first seed layer 250 can be carried out. The first mask M1 may include an opening (not shown) that exposes a region that overlaps with the first through hole VH1 in the thickness direction.

[0188] Referring to Figure 13, in the embodiment, the process of forming the second electrode portion 222 and the first through electrode 231 can be carried out by performing a step of plating on the region exposed through the opening of the first mask M1 to form the first metal layer 260.

[0189] The first metal layer 260 may include a first portion 231-2 formed within the first through hole VH1 and a second portion 222-2 formed on the second portion 222-1 of the first seed layer 250.

[0190] As a result, the first through electrode 231 includes the first portion 231-1 of the first seed layer 250 and the first portion 231-2 of the first metal layer 260. The second electrode portion 222 includes the second portion 222-1 of the first seed layer 250 and the second portion 222-2 of the first metal layer 260. In this case, the second portion 222-2 of the first metal layer 260 may include a recess. For example, the upper surface of the second portion 222-2 of the first metal layer 260 may include a curved surface. The upper surface of the second portion 222-2 of the first metal layer 260 corresponds to the upper surface of the second electrode portion 222. As a result, the upper surface of the second electrode portion 222 may include a recess or a curved surface.

[0191] Next, referring to Figure 14, the step of removing the first mask M1 can be performed.

[0192] Then, once the first mask M1 is removed, the first seed layer 250 can be removed. Specifically, in this embodiment, the portion of the first seed layer 250 that does not overlap with the first metal layer 260 in the thickness direction can be removed.

[0193] Then, once the first seed layer 250 is removed, in this embodiment, the process of laminating the second insulating layer 212 onto the first surface of the first insulating layer 211 can be carried out.

[0194] Next, referring to Figure 15, in the embodiment, a step can be performed to form a plurality of second through-holes VH2 in the second insulating layer 212. At this time, the second through-holes VH2 may expose the upper surface of the first through-electrode 231 or the second electrode portion 222. Subsequently, in the embodiment, once the second through-holes VH2 are formed, a step can be performed to form a second seed layer 270 on the inner wall of the second through-holes VH2 and the first surface of the second insulating layer 212.

[0195] The second seed layer 270 may be a seed layer for forming the second metal layer 280 and the third metal layer 290, which constitute the second through electrode 232 and the third electrode portion 223, by electroplating. The second seed layer 270 may be formed on the first surface of the second insulating layer 212 and on the inner wall of the second through hole VH2 formed in the second insulating layer 212.

[0196] The second seed layer 270 may include a first portion 232-1 formed on the inner wall of the second through hole VH2 and a second portion 223-1 formed on the first surface of the second insulating layer 212.

[0197] Next, referring to Figure 16, in the embodiment, the step of forming the second mask M2 on the second seed layer 270 can be performed.

[0198] The second mask M2 may include an opening (not shown) formed in a region that overlaps with the second through-hole VH2 in the thickness direction.

[0199] Next, referring to Figure 17, the embodiment can perform a step of forming a second metal layer 280 by performing primary electroplating using the second seed layer 270.

[0200] The second metal layer 280 may include a first portion 232-2 formed on the first portion 232-1 of the second seed layer 270 and a second portion 223-2 formed on the second portion 223-1 of the second seed layer 270.

[0201] The first portion 232-2 of the second metal layer 280 can constitute the second through electrode 232. The second portion 223-2 of the second metal layer 280 can constitute the third electrode portion 223. For example, the first portion 232-2 of the second metal layer 280 can fill a portion of the interior of the second through hole. Furthermore, the second portion 223-2 of the second metal layer 280 may be formed on top of the second portion 223-1 of the second seed layer 270 with a certain height. In this case, the first portion 232-2 of the second metal layer 280 may include a convex portion. For example, the lower surface of the first portion 232-2 of the second metal layer 280 may have a curved surface that is convex in the downward direction. For example, the first portion 232-2 of the second metal layer 280 may include an upper surface corresponding to a concave portion of the upper surface of the first electrode portion 221. The lowest end of the first portion 232-2 of the second metal layer 280 (the lowest end of the second through electrode 232) can be positioned lower than the upper end of the first electrode portion 221.

[0202] Next, referring to Figure 18, in the embodiment, a step of forming a third metal layer 290 on the second metal layer 280 can be performed. The third metal layer 290 can be formed on the second metal layer 280 by electroplating the second seed layer 270. In this case, the third metal layer 290 has a greater thickness than the third electrode portion 223 of the embodiment, and as a result, as shown in Figure 19, a step of flattening the upper surface of the third metal layer 290 by grinding with a grinder G can be performed.

[0203] As a result, the third metal layer 290 can include a first portion 232-3 formed on the first portion 232-2 of the second metal layer 280 and a second portion 223-3 formed on the second portion 223-2 of the second metal layer 280.

[0204] The first portion 232-3 of the third metal layer 290 can fill the concave portion of the first portion 232-2 of the second metal layer 280. For example, the lower surface of the first portion 232-3 of the third metal layer 290 may include a convex portion. For example, the lower surface of the first portion 232-3 of the third metal layer 290 may have a curved surface that is convex in the downward direction. In this case, the lowest end of the lower surface of the first portion 232-3 of the third metal layer 290 may be located lower than the first surface of the second insulating layer 212.

[0205] As a result, in the embodiment, the process of forming the second seed layer 270, the second metal layer 280, and the third metal layer 290 to form the second through electrode 232 and the third electrode portion 223 can be carried out. For example, the second through electrode 232 may include the first portion 232-1 of the second seed layer 270, the first portion 232-2 of the second metal layer 280, and the first portion 232-3 of the third metal layer 290. For example, the third electrode portion 223 may include the second portion 223-1 of the second seed layer 270, the second portion 223-2 of the second metal layer 280, and the second portion 223-3 of the third metal layer 290.

[0206] Next, as shown in Figure 20, in this embodiment, the step of forming a first surface treatment layer 241 on the third electrode portion 223 can be performed.

[0207] The first surface treatment layer 241 may be formed on the second portion 223-3 of the third metal layer 290 of the third electrode portion 223. In this case, the first surface treatment layer 241 may be formed only on the upper surface of the third electrode portion 223. Alternatively, the first surface treatment layer 241 may be formed not only on the upper surface of the third electrode portion 223 but also on the side surfaces.

[0208] Specifically, in the embodiment, a step can be performed to sequentially form a first-first surface treatment layer 241-1, a first-second surface treatment layer 241-2, and a first-third surface treatment layer 241-3 on the third electrode portion 223.

[0209] Next, referring to Figure 21, in the embodiment, the carrier substrate 300 can be removed, thereby forming the first electrode portion 221 on the second surface of the first insulating layer 211. The first electrode portion 221 can be formed using the copper foil 320 that constitutes the carrier substrate 300, but is not limited to this. On the other hand, in the embodiment, the step of forming the first electrode portion 221 on the carrier substrate 300 can also be performed before forming the first insulating layer 211 shown in Figure 11.

[0210] Next, referring to Figure 22, in this embodiment, a step can be performed to form a second substrate layer on the other side of the first electrode portion 221, corresponding to the first substrate layer formed on one side of the first electrode portion 221.

[0211] Figure 23 shows a semiconductor package according to an embodiment.

[0212] Referring to Figure 23, the semiconductor package may include the circuit board shown in Figure 4 or Figure 7.

[0213] On the other hand, the circuit board may include protective layers. For example, the circuit board may include a first protective layer 310 formed on the first surface of the second insulating layer 212 and including an opening (not shown) that exposes the first surface treatment layer 241. For example, the circuit board may include a second protective layer 315 formed on the second surface of the fourth insulating layer 214 and including an opening (not shown) that exposes the second surface treatment layer 242.

[0214] Specifically, the semiconductor package may include a first adhesive member 320 disposed on a first surface treatment layer 241 exposed through an opening in the first protective layer 310 of the circuit board. The semiconductor package may also include a second adhesive member 350 disposed on the second surface treatment layer 242 of the circuit board.

[0215] The first adhesive member 320 and the second adhesive member 350 may have different shapes from each other. For example, the first adhesive member 320 may be hexahedral. For example, the cross-section of the first adhesive member 320 may be quadrilateral. For example, the cross-section of the first adhesive member 320 may be rectangular or square. The second adhesive member 320 may be spherical. For example, the cross-section of the second adhesive member 350 may be circular or semicircular. For example, the cross-section of the second adhesive member 350 may be partially or entirely rounded. As an example, the cross-sectional shape of the second adhesive member 350 may be flat on one side and curved on the other side opposite to the flat side. On the other hand, the second adhesive member 350 may be, but is not limited to, a solder ball.

[0216] A chip 330 may be mounted on the first adhesive member 320. For example, the chip 330 may include a drive IC chip. For example, the chip 330 may refer to a variety of chips including sockets or elements other than the drive IC chip. For example, the chip 330 may include at least one of the following: a diode chip, a power supply IC chip, a touch sensor IC chip, an MLCC chip, a BGA chip, or a chip capacitor. For example, the chip 330 may be a power management integrated circuit (PMIC). For example, the chip 330 may be a memory chip such as a volatile memory (e.g., DRAM), a non-volatile memory (e.g., ROM), or a flash memory. For example, the chip 330 may be an application processor (AP) chip such as a central processor (e.g., CPU), a graphics processor (e.g., GPU), a digital signal processor, an encryption processor, a microprocessor, or a microcontroller, or a logic chip such as an analog-to-digital converter or an application-specific IC (ASIC). Here, the drawings show only one chip mounted on the semiconductor package, but this is not limited to this. A semiconductor package may include multiple chips, which may include a first AP chip corresponding to a central processor (CPU) and a second AP chip corresponding to a graphics processor (GPU).

[0217] A molding layer 340 may be formed on the circuit board. The molding layer 340 may be positioned to cover the mounted chip 330. For example, the molding layer 340 may be, but is not limited to, an EMC (Epoxy Mold Compound) formed to protect the mounted chip 330.

[0218] The embodiment includes a through electrode that penetrates the insulating layer. In this embodiment, a plating process is performed multiple times to fill the through hole that penetrates the insulating layer. Through this, the embodiment forms a through electrode that fills a large area of ​​through hole.

[0219] In this embodiment, the current density, which is the plating condition for the multiple plating steps, is adjusted. Through this, the embodiment forms a first metal layer in the primary plating step and a second metal layer in the secondary plating step, which constitute a part of the through electrode and the first electrode portion, respectively. In this case, the first metal layer in the embodiment may be formed with a relatively low current density, and the second metal layer may be formed with a relatively high current density. As a result, in the embodiment, it is possible to prevent the through electrode or the first electrode portion from containing dimple regions in a circuit board including a large-area through electrode. As a result, the reliability of the product can be improved in the embodiment.

[0220] Furthermore, in the embodiment, by controlling the current density as described above, the upper surface of the first pad can be formed with only the second metal layer. As a result, in the embodiment, the problem of contamination caused by the upper surface of the first electrode portion including both the first and second metal layers can be solved, thereby improving customer satisfaction. In addition, in the embodiment, the problem of increased plating time caused by the upper surface of the first electrode portion including only the first metal layer can be solved, thereby improving product yield.

[0221] Furthermore, the embodiment includes a first through electrode and a second electrode portion arranged on one side of the first electrode portion. The embodiment also includes a second through electrode and a third electrode portion arranged on one side of the second electrode portion. In this case, the first through electrode or the second electrode portion arranged on the inside includes a dimple region. The second through electrode, arranged on the outside, is formed by filling the dimple region of the first through electrode or the second electrode portion. As a result, in the embodiment, the third electrode portion can have a greater thickness than the first and second electrode portions, and the second electrode portion can have a thinner thickness than the first and third electrode portions. As a result, in the embodiment, the process of forming a large-area through electrode can be simplified, thereby improving the yield of the product.

[0222] The features, structures, and effects described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, and effects exemplified in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary skill in the art to which the embodiment belongs. Therefore, content related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

[0223] Furthermore, although the above description has focused on embodiments, these are merely illustrative examples and do not limit the present invention. Anyone with ordinary skill in the art to which the present invention belongs will understand that various modifications and applications not exemplified above are possible, without departing from the essential characteristics of these embodiments. For example, each component specifically shown in the embodiments can be modified and implemented. Such differences related to modifications and applications should be interpreted as being included within the scope of the present invention as defined in the attached claims.

Claims

1. First electrode section and A first insulating layer disposed on the first electrode portion, A second electrode portion disposed on the first insulating layer, A first through electrode that penetrates the first insulating layer and connects the first and second electrode portions, A second insulating layer disposed on the second electrode portion, A third electrode portion is disposed on the second insulating layer, It includes a second through-electrode that penetrates the second insulating layer and connects the second and third electrode portions, The first through electrode includes a plurality of through electrode parts arranged apart from each other within the first insulating layer. The second electrode portion is, The first through electrode includes a plurality of first parts that overlap perpendicularly with the plurality of through electrode parts of the first through electrode, and a second part that does not overlap perpendicularly with the plurality of through electrode parts of the first through electrode, The second part of the second electrode portion overlaps perpendicularly with the separation region between the plurality of through electrode parts of the first through electrode, connecting the plurality of through electrode parts. Each of the upper surfaces of the plurality of first parts of the second electrode portion has a concave surface that is concave toward the second through electrode. The upper surface of the second part of the second electrode portion has a convex shape toward the second insulating layer and includes convex surfaces that connect the concave surfaces of the plurality of first parts. The lowest end of the concave surface is located lower than the upper surface of the first insulating layer. The uppermost end of the convex surface is located higher than the upper surface of the first insulating layer. The width of each of the plurality of through-electrode parts of the first through-electrode in the first horizontal direction is four times or more the width of each of the plurality of through-electrode parts of the first through-electrode in the second horizontal direction perpendicular to the first horizontal direction. The plurality of through-electrode parts of the first through-electrode are spaced apart from each other in the second horizontal direction within the first insulating layer, on a circuit board.

2. The third electrode portion is, The circuit board according to claim 1, wherein the circuit board has a convex surface that overlaps perpendicularly with the second through electrode and is convex toward the second through electrode.

3. The circuit board according to claim 2, wherein the lower surface of the second through electrode has a convex surface that contacts the upper surface of the first portion of the second electrode portion.

4. The thickness of the first electrode portion is greater than the thickness of the second electrode portion. The circuit board according to claim 1, wherein the thickness of the third electrode portion is greater than the thickness of the first electrode portion and the second electrode portion, respectively.

5. The circuit board according to claim 1, wherein the first height between the lowest end of the concave surface of the second electrode portion and the lower surface of the first insulating layer is smaller than the second height between the upper surface of the first insulating layer and the lower surface of the first insulating layer.

6. The circuit board according to claim 1, wherein the second through electrode includes a plurality of through electrode parts spaced apart from each other in a first horizontal direction or a second horizontal direction within the second insulating layer.

7. The circuit board according to claim 6, wherein the plurality of through-electrode parts of the first through-electrode and the plurality of through-electrode parts of the second through-electrode are connected to each other via the second electrode portion.

8. The uppermost end of the convex surface of the second electrode portion is The circuit board according to claim 2, wherein the second through electrode is positioned higher than the lowest end of the convex surface.

9. The circuit board according to claim 3, wherein the lowest end of the convex surface of the second through electrode is located lower than the upper surface of the first insulating layer.

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