Circuit board

Abstract

The present embodiment relates to a circuit board. A circuit board, according to one aspect, comprises: a build-up insulating part including a plurality of insulating layers stacked in a vertical direction; a protective layer disposed on an upper surface of the build-up insulating part and including a placement groove; and a bonding part disposed on the upper surface of the build-up insulating part and disposed inside the placement groove, wherein the bonding part includes a first metal portion at least partially embedded in the protective layer, and a second metal portion formed of a material different from that of the first metal portion and disposed on an outer surface of at least a portion of the first metal portion.

Description

circuit board

[0001] This embodiment relates to a circuit board.

[0002] Recently, technologies related to electronic products, such as AI and servers, are progressing toward multifunctionality and high speed, and to respond to this trend, semiconductor device manufacturing technology is also developing rapidly.

[0003] In particular, as the density of transistors and wiring within semiconductor devices increases, the number of I / O terminals on these devices is growing. To meet this trend, not only are the wiring densities, lengths, and widths of circuit boards becoming finer, but there is also a trend toward high-layer, large-area designs.

[0004] Furthermore, from the perspective of miniaturizing finished electronic products, the thickness of the applied circuit boards is also decreasing, and technologies related to multilayer circuit boards, which configure more circuit layers within a circuit board of the same thickness, are being actively researched. In addition, as the pitch of semiconductor devices narrows and the size of chips increases, chiplet technology for separating semiconductor chips by function is being researched. Moreover, technologies for connecting separated chiplets on circuit boards are being actively researched. Furthermore, by connecting semiconductor chips with different functions on circuit boards, technologies regarding the connection relationship between circuit boards and semiconductor devices are being actively researched, such as the circuit board connecting semiconductor chips to one another, which was previously considered only from the perspective of conventional semiconductor packaging.

[0005] A circuit board is a device in which circuit line patterns are arranged using a conductive material, such as copper, on an electrically insulating substrate; it is a general term for the package board immediately before mounting electronic components. To densely mount many different types of electronic components on a flat surface, the mounting positions of each component are determined, and circuit patterns connecting the components are printed and fixed onto the surface.

[0006] The circuit board includes a build-up insulating portion arranged in a vertical direction. The build-up insulating portion may be electrically connected by wiring layers placed on each surface and vias connecting different wiring layers. In this case, via holes for placing vias may be formed in each of the build-up insulating portions. Additionally, bond fingers may be arranged on the circuit board for electrically connecting external components via flip-chip or wire bonding. Below, the bond fingers are defined as bonding portions.

[0007] A bonding portion can be positioned to be exposed to the outside from the upper surface of a circuit board so as to be electrically connected to a substrate and flip-chip or wire-bonded with an external component. A bonding portion is generally formed through etching. During the etching process, the upper side of the bonding portion may be etched more than the lower side because the etching time for the upper side is relatively longer than that for the lower side. As a result, the bonding portion is generally formed in a trapezoidal shape, that is, the width increases from the top to the bottom of the bonding portion.

[0008] For circuit boards, achieving high performance and high capacity requires a fine pitch—that is, a high number of external components connected per unit area. The more bonding points there are on the circuit board to connect external components, the more effective the fine pitch is realized. To achieve this fine pitch, it is crucial to maintain a minimum spacing between bonding points.

[0009] However, as the bonding sections are formed in a trapezoidal shape, there is a problem where the lower gap between bonding sections becomes narrower compared to the upper gap. In particular, as the height of the bonding section increases, the difference in width between the top and bottom of the section widens, leading to a problem where the gap between bonding sections at the bottom narrows. Generally, there is a minimum standard gap between bonding sections required by customers for circuit boards; however, as the thickness of the bonding section increases, the gap difference at the bottom narrows further, making it difficult to meet customer requirements.

[0010] Furthermore, if the gap between bonding sections narrows at the bottom, the bottoms of the bonding sections may come into contact with each other, potentially causing signal interference, or short circuits. This can lead to product defects and a decrease in the reliability of the circuit board.

[0011] To solve the aforementioned problems, there is an urgent need to develop a structure that implements fine pitch on the circuit board while preventing short circuits between bonding points.

[0012] The present invention provides a circuit board that wraps the bonding portion with a protective layer and exposes only the area to the outside in order to solve the above-mentioned problem.

[0013] A circuit board according to the present embodiment includes a build-up insulating portion comprising a plurality of insulating layers stacked along a vertical direction; a protective layer disposed on the upper surface of the build-up insulating portion and comprising a placement groove; and a bonding portion disposed on the upper surface of the build-up insulating portion and disposed inside the placement groove, wherein the bonding portion may include a first metal portion in which at least a portion is embedded in the protective layer and a second metal portion provided with a material different from the first metal portion and disposed on the outer surface of at least a portion of the first metal portion.

[0014] The circuit board according to the present embodiment has the following effects.

[0015] First, as the bonding portion for electrically connecting external components is configured by being divided into a first metal portion and a second metal portion, the external components are electrically connected through the second metal portion, thereby providing the effect of excellent electrical connection reliability.

[0016] In addition, since a protective layer is placed in the gap area between the lower sides of the first metal part, even if the gap at the bottom of the bonding part is narrowed, contact or short circuit between the bonding parts does not occur, thereby ensuring product reliability.

[0017] In addition, since it is possible to achieve a fine pitch of the bonding portion exposed to the outside by adjusting the thickness of the protective layer, it is possible to supply a circuit board with guaranteed operational reliability while controlling the minimum spacing or bonding portion thickness required by the client.

[0018] In addition, even if a gap is created between the protective layer and the first metal part during the etching process due to oxidation of the first metal part of the bonding part in the circuit board manufacturing process, the first metal part can be prevented from being exposed to the outside through the second metal part, thereby effectively solving the problem of electrical connection loss due to oxidation of the bonding part.

[0019] In addition, due to these effects, stable wire bonding with external components or flip-chip is achieved, enabling the supply of a package substrate that facilitates smooth electrical signal transmission.

[0020] FIG. 1 is a cross-sectional view of a circuit board according to an embodiment of the present invention.

[0021] FIG. 2 is an enlarged cross-sectional view of a bonding portion in a circuit board according to an embodiment of the present invention.

[0022] FIG. 3 is an image of a bonding portion of a circuit board according to an embodiment of the present invention.

[0023] FIG. 4 is a diagram illustrating the process of forming a bonding portion of a circuit board according to an embodiment of the present invention.

[0024] FIG. 5 is an enlarged cross-sectional view of a bonding portion in a circuit board according to another embodiment of the present invention.

[0025] FIG. 6 is an image of a bonding portion of a circuit board according to another embodiment of the present invention.

[0026] FIG. 7 is an enlarged cross-sectional view of a bonding portion in a circuit board according to another embodiment of the present invention.

[0027] FIG. 8 is a diagram illustrating the process of forming a bonding portion of a circuit board according to another embodiment of the present invention.

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0029] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0030] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0031] Additionally, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as “at least one of A and B and C (or more than one),” it may include one or more of all combinations that can be combined with A, B, and C.

[0032] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments of the present invention.

[0033] These terms are intended merely to distinguish a component from other components and are not limited by the nature, order, sequence, etc., of the said component.

[0034] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0035] Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0036] In addition, the expression that configuration A is positioned between configuration B and configuration C must include the meaning that configuration A is positioned such that at least a portion of it overlaps with configurations B and C in the horizontal and / or vertical directions.

[0037] Expressions referring to directions include horizontal and vertical directions, and the horizontal direction includes a first horizontal direction and a second horizontal direction perpendicular to the first horizontal direction. These are referred to as the first horizontal direction (X-axis), the second horizontal direction (Y-axis), and the vertical direction (Z-axis) according to the Cartesian coordinate system, and the meaning of being superimposed along the horizontal direction must include the meaning of being superimposed along the first horizontal direction and / or superimposed along the second horizontal direction.

[0038] Furthermore, the statement that Configuration A is exposed from Configuration B should be understood as meaning that Configuration A is exposed from Configuration B, not that Configuration A is exposed from the entire product. In other words, when Configuration A is stated to be exposed from Configuration B, it should be understood to mean that Configuration A is covered by at least a portion of Configuration C.

[0039] Furthermore, when it is stated that Component A 'contacts' Component B, this may include not only cases where the component 'contacts' the other component directly, but also cases where it 'contacts' due to another component located between the component and the other component. Therefore, if Component A is to be understood only as 'directly contacting' Component B, it is described as 'directly contacting'.

[0040] In addition, when it is stated that configuration A is 'covered' by configuration B, it should be understood that configuration A is covered by configuration B, and that the part intended for the function and purpose to be resolved is covered, and unless there are special circumstances, it should not be understood that the entire configuration A is covered by configuration B.

[0041] FIG. 1 is a cross-sectional view of a circuit board according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a bonding portion (500) in a circuit board according to an embodiment of the present invention, and FIG. 3 is an image of a bonding portion (500) of a circuit board according to an embodiment of the present invention.

[0042] Referring to FIGS. 1 to 3, a circuit board according to an embodiment of the present invention may include a build-up insulating portion, a build-up wiring portion, and a protective layer.

[0043] The circuit board may include a build-up insulating portion. The build-up insulating portion may be arranged such that a plurality of insulating layers are stacked along a vertical direction. The build-up insulating portion may include a first insulating layer (110) and a second insulating layer (120) disposed on the first insulating layer (110). However, this is merely one example, and the insulating layers may include not only the first insulating layer (110) and the second insulating layer (120) but also additional insulating layers exceeding these.

[0044] The first insulating layer (110) and the second insulating layer (120) may be made of the same material. The first insulating layer (110) and the second insulating layer (120) may be made of the same height. However, they are not limited thereto, and the first and second insulating layers (120) may be made of different materials and / or different heights.

[0045] The build-up insulation may be any insulator, such as a photocurable and / or thermosetting insulator. If the build-up insulation is thermosetting, the thermosetting insulator may be an insulator in which inorganic and / or organic fillers are dispersed within a resin, such as ABF (Ajinomoto Build-up Film), a product released by Ajinomoto Corporation, or a prepreg (PPG) containing glass fibers within a resin may be used. Additionally, the resins mentioned above may be, for example, epoxy resin, bismaleimide triazine resin (BT resin), phenolic resin, etc., and the inorganic and / or organic fillers may be provided with materials such as silica or plastic. Furthermore, in addition to the above, the insulator may include a reinforcing material provided with glass fibers or aramid fibers. If multiple insulators are photocurable insulators, each of the multiple insulators may be a PID (Photo Imageable Dielectric).

[0046] Meanwhile, in this embodiment, a coreless structure in which the core layer within the circuit board is omitted was described as an example, but the circuit board may include a core layer.

[0047] The circuit board may include a build-up wiring portion for transmitting electrical signals and / or power to an electronic device such as a semiconductor chip. The build-up wiring portion may include one or more wiring portions and one or more vias.

[0048] One or more wiring sections may include one or more circuit layers and one or more bonding sections (500).

[0049] One or more circuit layers may be disposed on the surface of the build-up insulation to be electrically connected to one or more vias or to form a circuit. Here, the meaning of being disposed on the surface may also include the meaning that at least a portion of a plurality of wiring portions is embedded within a plurality of insulation layers or protective layers and exposed to the outside from the surface. The surface of the build-up insulation includes a first surface, a second surface, and a side between the first surface and the second surface. Here, the first surface of the insulation layer may be understood as the upper surface, and the second surface of the insulation layer may be understood as the lower surface. The meaning of a circuit layer being disposed on the surface is that it is disposed on at least one of the first surface, the second surface, or the side between the first and second surfaces of the build-up insulation. The structure may have a circuit layer disposed on the first surface and the second surface of the insulation layer of a portion of the build-up insulation, respectively, while a circuit layer disposed on only the first surface or the second surface of a different portion of the build-up insulation.

[0050] A plurality of circuit layers (200) may include a first circuit layer (220) disposed on the lower surface of the first insulating layer (110) and a second circuit layer (210) disposed on the upper surface of the first insulating layer (110). Here, the first circuit layer (220) and the second circuit layer (210) may each be spaced apart. Depending on the external components connected to the circuit board, the first circuit layer (220) and the second circuit layer (210) may be designed in an appropriate number. The first circuit layer (220) and the second circuit layer (210) may each be arranged to be electrically connected by vias. A detailed explanation thereof will be provided later.

[0051] The first circuit layer (220) may be positioned so that a portion of the bottom surface is exposed to the outside. The first circuit layer (220) may be positioned so that a portion of it is exposed to the outside when an external component is electrically connected. A protective layer may be positioned on the side and a portion of the bottom surface of the first circuit layer (220). A first protective layer (410) may be positioned on the side and a portion of the bottom surface of the first circuit layer (220).

[0052] A plurality of bonding portions (500) are arranged to protrude in a vertical direction, and one side may be electrically connected to a circuit layer and one side may be electrically connected to an external component. A bonding portion (500) may be electrically connected to a second circuit layer (210). A bonding portion (500) may have its lower side electrically connected to a second circuit layer (210) and its upper side electrically connected to an external component. A portion of the lower side of the bonding portion (500) may be placed on the upper surface of a build-up insulating portion and a portion of the lower side may be placed on the upper surface of a via.

[0053] The bonding portion (500) may include a first metal portion (510) and a second metal portion (520).

[0054] The first metal part (510) may be arranged so that its width increases from the top to the bottom. The first metal part (510) may be arranged so that the width of the bottom surface is longer than the width of the top surface. For example, the cross-section of the first metal part (510) may have a trapezoidal shape. However, it is not limited to this, and if the width of the top surface of the first metal part (510) is narrower than the width of the bottom surface, some areas may be formed to be curved or have a curved surface. If the width of the top surface of the first metal part (510) is defined as the first width and the width of the bottom surface of the first metal part (510) is defined as the second width, the first width length may have a shorter length than the second width length.

[0055] A plurality of first metal parts (510) may be arranged spaced apart from each other. In this case, the spaced-apart area between the bonding parts (500) is defined as a spaced-apart area. The length of the spaced-apart area between the upper surfaces of the first metal parts (510) may be longer than the length of the spaced-apart area between the lower surfaces of the first metal parts (510).

[0056] The first metal part (510) may be positioned so that at least a portion protrudes from the upper surface of the protective layer. The first metal part (510) may be positioned so that an upper portion protrudes from the upper surface of the protective layer. The first metal part (510) may be positioned so that at least a portion is embedded in the protective layer. The first metal part (510) may be positioned so that a lower portion is embedded in the protective layer.

[0057] The first metal part (510) can be placed in a placement groove (413) formed by the first protective layer (410). The placement groove (413) is an area formed by the step difference between the first-1 protective layer (411) and the first-2 protective layer (412). As the first metal part (510) is placed in the placement groove (413), the electrical connection portion of the external element is positioned below the upper surface of the first-1 protective layer (411), which is the uppermost part of the first protective layer (410), thereby preventing interference or collision from the outside and improving the reliability of the electrical connection.

[0058] The first metal part (510) may be formed to have a first height (L1). In this case, as will be described later, a part of the protective layer may be formed to have a second height (L2). The length of the first height (L1) may have a length exceeding the length of the second height (L2). That is, the upper part of the first metal part (510) may protrude from the upper surface of the protective layer by the difference between the first height (L1) and the second height (L2). If the first height (L1) of the first metal part (510) and the second height (L2) of a part of the protective layer are the same, not only is it difficult to distinguish the area for connecting the external elements (610, 620), but there is also a problem of reduced product reliability as the second metal part (520) may be detached from the upper surface of the protective layer during the plating process of the second metal part (520). In addition, if the first height (L1) of the first metal part (510) is lower than the second height (L2) of a part of the protective layer, the first metal part (510) is embedded within the protective layer, and thus the second metal part (520) is plated within the embedded space. In this case, not only is there a problem of the protective layer being damaged during the plating process, but even after the second metal part (520) is plated, the bonding part (500) area where the external element (610, 620) is connected is positioned lower than the protective layer, making it structurally difficult to connect the external element (610, 620).

[0059] The first metal part (510) may be made of the same material as the circuit layer. The first metal part (510) may be made of a metal material. For example, the first metal part (510) may be made of copper. However, this is just one example, and there is no restriction on the material as long as it can be electrically connected to the external component and the circuit layer.

[0060] The second metal part (520) may be disposed on at least a portion of the outer surface of the first metal part (510). The second metal part (520) may be disposed to wrap around at least a portion of the outer surface of the first metal part (510). The second metal part (520) may be disposed to wrap around at least a portion of the upper surface and side surface of the first metal part (510). If the first height (L1) of the first metal part (510) is higher than the second height (L2) of a portion of the protective layer, the second metal part (520) may be disposed to wrap around the outer surface of the area where the first metal part (510) protrudes above the protective layer. Here, the meaning of "wrapping" is that the second metal part (520) is positioned on the protruding area of ​​the first metal part (510) so that the area protruding from the upper surface of the protective layer of the first metal part (510) is not exposed to the outside. For example, this may mean that the second metal part (520) is plated on the protruding area of ​​the first metal part (510). Since oxidation occurs when the first metal part (510) is exposed to the outside, causing a problem where signal transmission is not properly performed when connecting external components, the second metal part (520) may be positioned to wrap the protruding area of ​​the first metal part (510) so that the first metal part (510) is not exposed to the outside in order to prevent oxidation and improve product reliability.

[0061] The second metal part (520) may be made of a different material than the first metal part (510). The second metal part (520) may be made of a different metal material than the first metal part (510). For example, the second metal part (520) may be made of nickel. However, this is merely an example, and there are no restrictions on the material as long as it can be electrically connected while preventing corrosion and oxidation of the first metal part (510) and enhancing mechanical stability.

[0062] The bonding portion (500) may further include a metal layer (530) disposed on the outer surface of the second metal portion (520). The metal layer (530) may be disposed to surround the outer surface of the second metal portion (520). The metal layer (530) may provide a contact surface for connecting an external element in the form of a wire or flip chip. The metal layer (530) may be made of the same metal material as the wire or flip chip to which the external element is connected. Accordingly, there is an effect of facilitating a smooth electrical connection with the external element.

[0063] A plurality of vias (300) may be a metallic material disposed in via holes formed in each of the build-up insulating portions to electrically connect a plurality of circuit layers (200) and bonding portions (500) facing each other in a vertical direction. Here, the via holes penetrate at least a portion of each of the build-up insulating portions in a vertical direction, and vias may be disposed within the via holes. A plurality of vias (300) may each be disposed to be electrically connected to a circuit layer.

[0064] A plurality of vias (300) may include a first via penetrating at least a portion of the first insulating layer (110) and a second via penetrating at least a portion of the second insulating layer (120). The first via may electrically connect the first circuit layer (220) and the second circuit layer (210). The second via may electrically connect the second circuit layer (210) and the bonding portion (500). The first via may have a shape in which the horizontal width decreases as it goes downward. The second via may have a shape in which the horizontal width increases as it goes upward. However, the shapes of the first via and the second via are merely examples, and the width shape may vary depending on the manufacturing process of the circuit board.

[0065] The lower surface of the first via may contact the upper surface of the first circuit layer (220). The upper surface of the first via may contact the lower surface of the second circuit layer (210). The first via may contact the first circuit layer (220) and the second circuit layer (210) respectively to electrically connect the first circuit layer (220) and the second circuit layer (210).

[0066] The lower surface of the second via may contact the upper surface of the second circuit layer (210). The upper surface of the second via may contact the lower surface of the bonding part (500). The upper surface of the second via may contact the first metal part (510) of the bonding part (500). The upper surface of the second via may contact the lower surface of the first metal part (510) of the bonding part (500). The second via may contact the second circuit layer (210) and the bonding part (500), respectively, to electrically connect the second circuit layer (210) and the bonding part (500).

[0067] The circuit board may include a protective layer disposed on the build-up insulation. When semiconductor devices are electrically connected by a material such as solder on the surface of the circuit board, specifically the upper and / or lower surfaces of the build-up insulation, the protective layer can perform the function of preventing short circuits between solders due to low wettability with the solder, and can prevent problems where external contaminants penetrate into the build-up structure and degrade reliability. A photocurable insulating material may be used for the protective layer. As an example, a solder resist or a PID (Photo Imageable Dielectric) may be used for the protective layer.

[0068] The protective layer may include a first protective layer (410) disposed on the upper surface of the insulating layer disposed at the uppermost position among the build-up insulating portions. The first protective layer (410) may be disposed on the upper surface of the second insulating layer (120). The first protective layer (410) may include a placement groove (413) for a bonding portion (500) to be disposed therein. The bonding portion (500) may be disposed in the placement groove (413). The placement groove (413) is a groove formed by the first protective layer (410) for the bonding portion (500) to be disposed therein. When an external component is connected via a wire or flip chip, the groove may be formed to prevent the bonding area from being interfered with or collided with from the outside by ensuring that it is placed below the uppermost surface of the first protective layer (410) of the circuit board. As the placement groove (413) is formed, the electrical connection reliability of the external component can be improved.

[0069] The first protective layer (410) may be positioned to contact at least a portion of the side of the bonding portion (500). The first protective layer (410) may be positioned to wrap at least a portion of the lower side of the first metal portion (510) of the bonding portion (500). The first protective layer (410) may be positioned so that a portion of the lower part of the first metal portion (510) is embedded. Accordingly, the first metal portion (510) may be positioned so that a portion of the upper part of the first bonding portion (500) protrudes above the first protective layer (410).

[0070] The first protective layer (410) may be disposed in the spaced-out area of ​​the first metal part (510) when the first metal part (510) is spaced apart from each other. In this case, the first protective layer (410) may be disposed in the spaced-out area of ​​the first metal part (510) to be in contact with the first metal part (510). The first protective layer (410) may be disposed to be in contact with a part of the side of the first metal part (510).

[0071] The first protective layer (410) may include a first-1 protective layer (411) disposed in an area other than the placement groove (413) where the bonding portion (500) is disposed, and a first-2 protective layer (412) disposed in the area of ​​the placement groove (413) where the bonding portion (500) is disposed.

[0072] A portion of the protective layer may be positioned to have a third height (L3). The first-1 protective layer (411) may be positioned to have a third height (L3). The third height (L3) may be a height higher than the first height (L1). The first-1 protective layer (411) may be positioned in an area where the bonding portion (500) is not positioned.

[0073] A portion of the protective layer may be positioned to have a second height (L2). The first-second protective layer (412) may be positioned to have a second height (L2). The second height (L2) may be lower than the first height (L1). The first-second protective layer (412) may be positioned in the area where the bonding portion (500) is positioned.

[0074] The first-1 protective layer (411) may be formed with a thickness greater than that of the first-2 protective layer (412). The first-1 protective layer (411) may be positioned to have a height greater than that of the first-2 protective layer (412). The area where the placement groove (413) is formed in the first protective layer (410) may be the area where the first-2 protective layer (412) is positioned. The placement groove (413) may be formed by the step difference between the first-1 protective layer (411) and the first-2 protective layer (412). The placement groove (413) may be formed by the inner surface of the first-1 protective layer (411) and the upper surface of the first-2 protective layer (412).

[0075] The protective layer may utilize a photocurable insulating material. That is, the first protective layer (410) and the second protective layer (420) are each provided with a solder resist other than the aforementioned ABF, PPG, BT resin, and PID. However, they are not limited thereto and may be provided with various materials capable of performing low wettability with solder and thus preventing short circuits between solders, as described above.

[0076] A bonding portion (500) may be placed in the placement groove (413). A bonding portion (500) may be placed on the upper portion of the first-second protective layer (412). The first-second protective layer (412) may be placed to contact at least a portion of the side of the bonding portion (500). The first-second protective layer (412) may be placed to wrap at least a portion of the lower side of the first metal portion (510) of the bonding portion (500). The first-second protective layer (412) may be placed so that a portion of the lower part of the first metal portion (510) is embedded. Accordingly, the first metal portion (510) may have an area where a portion of the upper part of the first-second bonding portion (500) protrudes above the first protective layer (410).

[0077] The protective layer may include a second protective layer (420) disposed on the lower surface of the insulating layer disposed at the lowest side of the build-up insulating portion. The second protective layer (420) may be disposed on the lower surface of the first insulating layer (110). The second protective layer (420) may include a through hole. A first circuit layer (220) may be disposed in the through hole of the second protective layer (420). At least a portion of the lower surface of the first circuit layer (220) may be exposed through the through hole of the second protective layer (420). An external component may be electrically connected through the first circuit layer (220) exposed in the second protective layer (420).

[0078] Referring to FIG. 3, the configuration of the bonding portion (500) in the circuit board according to an embodiment of the present invention can be observed. The bonding portion (500) may be composed of a first metal portion (510) and a second metal portion (520). The second metal portion (520) may be disposed on the upper surface and a part of the upper side of the first metal portion (510).

[0079] Below, the steps for manufacturing a circuit board according to an embodiment of the present invention are described. FIG. 4 is a diagram illustrating the steps of a process for manufacturing a circuit board according to an embodiment of the present invention.

[0080] Referring to FIG. 4, in order to form a circuit board according to an embodiment of the present invention, a package substrate may be prepared in step (a) having a first insulating layer (110), a second insulating layer (120), a first circuit layer (220), a second circuit layer (210), a first via, a second via, a second protective layer (420), and a first metal part (510) of a bonding part (500). In this state, to form the first protective layer (410), a first protective layer (410) higher than the first metal part (510) may be laminated on the upper surface of the package substrate. The first protective layer (410) may include a protective film, and as an example, may include a Dry Film Solder Resist (DFSR).

[0081] In steps (b) through (d), a photoresist process and an etching process may be performed in the first protective layer (410) in the first-1 protective layer (411) region, that is, in the region where the first metal part (510) of the bonding part (500) is not placed. In the photoresist process, while ultraviolet light is irradiated in the first-1 protective layer (411) region, an etching process and a curing process are performed in the first-2 protective layer (412) region, so that the first-1 protective layer (411) maintains its existing height, and as the height of the first-2 protective layer (412) region is lowered, a placement groove (413) may be formed. In this process, a portion of the upper part of the first metal part (510) of the bonding part (500) may protrude upward from the upper surface of the first-2 protective layer (412). However, if the height of the first metal part (510) is the same as the height of the first-second protective layer (412), the upper surface of the first metal part (510) may be positioned so as to be exposed on the upper surface of the first-second protective layer (412).

[0082] In steps (e) and (f), a plating process may be performed to plate a second metal part (520) and a metal layer (530) on the protruding area of ​​the first metal part (510). In step (e), the second metal part (520) may be plated on the exposed outer surface of the first metal part (510) through a plating process, and in step (f), the metal layer (530) may be plated on the outer surface of the second metal part (520) through a plating process.

[0083] A circuit board according to another embodiment of the present invention may include a build-up insulating portion, a build-up wiring portion, and a protective layer. Below, configurations different from the circuit board according to the embodiment of the present invention are described, and redundant descriptions of identical configurations are omitted.

[0084] FIG. 5 is an enlarged cross-sectional view of a bonding portion (500) in a circuit board according to another embodiment of the present invention, FIG. 6 is an image of a bonding portion (500) of a circuit board according to another embodiment of the present invention, and FIG. 7 is an enlarged cross-sectional view of a bonding portion (500) in a circuit board according to yet another embodiment of the present invention.

[0085] Referring to FIGS. 5 to 7, the circuit board according to another embodiment of the present invention may have the first protective layer (410) and the bonding portion (500) formed differently from the circuit board according to the embodiment of the present invention.

[0086] The first protective layer (410) may include a first-1 protective layer (411) and a first-2 protective layer (412). The first-2 protective layer (412) may be spaced apart from the first metal part (510). The first-2 protective layer (412) may be spaced apart from at least a portion of the side of the first metal part (510). A spaced-away space (414) may be formed between the first-2 protective layer (412) and the first metal part (510) of the bonding part (500). For example, as shown in FIG. 5, the side of the first-second protective layer (412) and the first metal part (510) can be completely separated by a spacing space (414), and as shown in FIG. 7, as a portion of the side of the first-second protective layer (412) and the first metal part (510) is separated by the spacing space (414), the portion of the side of the first metal part (510) is spaced apart from the first-second protective layer (412), and the remaining side of the first metal part (510) can have the first-second protective layer (412) placed thereon.

[0087] The second metal part (520) of the bonding part (500) may be disposed on at least a portion of the upper surface and side surface, excluding the lower surface of the first metal part (510). The second metal part (520) may be disposed in the spaced-apart area (414) between the area where the first metal part (510) protrudes from the upper surface of the first protective layer (410). The second metal part (520) may include a second-1 metal part (521) disposed on the outer surface of the area where the first metal part (510) protrudes from the upper surface of the first-2 protective layer (412), and a second-2 metal part (522) disposed in the spaced-apart area (414) between the first metal part (510) and the first-2 protective layer (412). The second-1 metal part (521) and the second-2 metal part (522) may be formed integrally. As the bonding part (500) is placed in the spacing space (414) by the second-2 metal part (522), it can be placed in a state where a portion of it is embedded in the first-2 protective layer (412).

[0088] Below, a circuit board manufacturing step according to another embodiment of the present invention is described. FIG. 8 is a diagram illustrating the process of forming a bonding portion (500) of a circuit board according to another embodiment of the present invention. In the manufacturing step of a circuit board according to another embodiment of the present invention, redundant descriptions of processes identical to those in the manufacturing step of a circuit board according to an embodiment of the present invention are omitted.

[0089] Referring to FIG. 8, steps (a) through (d) may be the same as steps (a) through (d) of FIG. 4.

[0090] In step (e) thereafter, an etching process may be performed on a portion of the protruding area of ​​the first metal part (510). Since the first metal part (510) oxidizes when its outer surface is exposed, an etching process may be performed on a portion of the area so that a portion of the outer surface of the first metal part (510) can be etched.

[0091] Step (f) may be a process accompanying Step (e). During the process of performing the etching process in Step (f), a portion of the first-second protective layer (412) may be affected by the etching process of Step (e), and a portion or all of the side of the first metal part (510) placed on the first-second protective layer (412) may be etched. Accordingly, a gap space (414) may be formed in Step (f).

[0092] Steps (g) and (h) are steps in which the first metal part (510) and the second metal part (520) are plated, respectively, in the same manner as steps (e) and (f) of FIG. 4. However, in step (g), during the plating process, the second metal part (520) may be plated as a single unit, divided into a first-1 metal part placed on the outer surface of the area protruding from the upper surface of the first-2 protective layer (412) and a first-2 metal part placed in the spaced-out space (414). Additionally, in step (h), the metal layer (530) may be plated so as to be placed only on the outer surface of the first-1 metal part.

[0093] In the foregoing, although all components constituting an embodiment of the present invention have been described as being combined or operating in combination, the present invention is not necessarily limited to such embodiments. That is, within the scope of the purpose of the present invention, all components may be selectively combined in one or more ways to operate. Furthermore, terms such as "include," "constitute," or "have" described above, unless specifically stated otherwise, mean that the relevant component may be inherent; thus, they should be interpreted as allowing for the inclusion of additional components rather than excluding other components. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Terms commonly used, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the present invention.

[0094] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

[0095] Meanwhile, when a circuit board having the features of the invention described above is used in IT devices or home appliances such as smartphones, server computers, and TVs, it can stably perform functions such as signal transmission or power supply. For example, when a circuit board having the features of the invention performs a semiconductor package function, it can safely protect the semiconductor chip from external moisture or contaminants, and can resolve issues such as leakage current, electrical short circuits between terminals, or electrical open circuits of terminals supplying power to the semiconductor chip. In addition, when it is responsible for signal transmission, it can resolve noise issues. Through this, the circuit board having the features of the invention described above enables the stable operation of IT devices or home appliances, thereby allowing the entire product and the circuit board to which the invention is applied to achieve functional integration or technical interoperability.

[0096] When a circuit board having the features of the invention described above is used in a transportation device such as a vehicle, it can resolve the problem of signal distortion transmitted to the transportation device, or safely protect a semiconductor chip controlling the transportation device from the outside, and further improve the stability of the transportation device by resolving problems such as leakage current, electrical short circuits between terminals, or electrical open circuits of terminals supplying power to the semiconductor chip. Accordingly, the transportation device and the circuit board to which the present invention is applied can achieve functional integration or technical interoperability with each other.

Claims

1. A build-up insulating part including a plurality of insulating layers stacked along the vertical direction; A protective layer disposed on the upper surface of the above-mentioned build-up insulating portion and including a placement groove; It includes a bonding portion disposed on the upper surface of the above-mentioned build-up insulating portion and disposed inside the above-mentioned placement groove, The above bonding portion comprises a first metal portion in which at least a portion is embedded in the protective layer, and a second metal portion made of a material different from the first metal portion and disposed on the outer surface of at least a portion of the first metal portion.

2. In Paragraph 1, A portion of the lower side of the first metal part is positioned to contact the protective layer, and The above first metal part is a circuit board in which the upper surface and a portion of the upper side protrude from the upper surface of the protective layer.

3. In Paragraph 2, The above second metal part is a circuit board arranged to surround the area where the above first metal part protrudes.

4. In claim 1, the first metal part is a circuit board that is not exposed to the outside.

5. In Paragraph 1, The above bonding portion is a circuit board further comprising a metal layer disposed on the outer surface of the second metal portion and made of a material different from the second metal portion.

6. In Paragraph 1, The above-mentioned first metal part is formed at a first height, the above-mentioned bonding part has a placement groove area formed at a second height, and the above-mentioned first height is a circuit board exceeding the above-mentioned second height.

7. In Paragraph 6, The outer region of the placement groove of the bonding portion is formed at a third height, and the third height is a circuit board exceeding the second height.

8. In Paragraph 1, At least a portion of the lower side of the first metal part is arranged to form a spaced-apart space at a certain distance from the protective layer, and The above first metal part is a circuit board in which the upper surface and a portion of the upper side protrude from the upper surface of the protective layer.

9. In Paragraph 8, The above second metal part is, A circuit board comprising a 2-1 metal part disposed on the outer surface of the protruding area of ​​the 1 metal part and a 2-2 metal part disposed in the spaced-out space.

10. A build-up insulating part including a plurality of insulating layers stacked along the vertical direction; A protective layer disposed on the upper surface of the above-mentioned build-up insulating portion and including a placement groove; It includes a plurality of spaced bonding portions disposed in the placement groove on the upper surface of the above-mentioned build-up insulating portion, and comprising a first metal portion and a second metal portion disposed on the outer surface of at least a portion of the first metal portion with a material different from the first metal portion. The plurality of bonding parts are spaced apart from each other to form a spaced-apart region, and The above protective layer is disposed in the above-mentioned spaced area and is a circuit board disposed to surround at least a portion of the first metal part.

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