Patent Application
20110164391
This application claims the benefit of Korean Patent Application No. 10-2010-0000910, filed Jan. 6, 2010, entitled “A printed circuit board comprising embedded electronic component within and a method for manufacturing the same”, which is hereby incorporated by reference in its entirety into this application.
1. Technical Field
The present invention relates to an electronic component-embedded printed circuit board and a method of manufacturing the same.
2. Description of the Related Art
Various technologies are required to realize a printed circuit board in a market which requires semiconductor packages having decreased profiles and a variety of functions.
For example, in the manufacturing of a flip chip ball grid array (FCBGA) package, the electroconductive terminals or lands of ICs are directly soldered to the lands corresponding to the die bonding region on the surface of a substrate using reflowable solder bumps or balls. In this case, electronic components are functionally connected to other elements of an electronic system through electroconductive channels including substrate traces, and the substrate traces generally serve to transport signals transmitted between electronic components such as ICs and the like. In the case of FCBGA, ICs located at the upper end of a substrate and capacitors located at the lower end thereof are surface-mounted, respectively. In this case, the length of a circuit path for connecting the IC with the capacitor, that is, a connection circuit, is increased by the thickness of the substrate, so that impedance is increased, thereby deteriorating electrical performance. Further, since a part of the lower end of the substrate must be used to mount chips, design flexibility is limited, for example, users desiring to mount a ball array over the entire surface of the lower end thereof will be left unsatisfied.
In order to solve the above problems, electronic component packaging technologies for shortening the circuit path by embedding electronic components in a substrate are becoming popular. Since electronic component-embedded printed circuit boards (PCBs) are provided in the organic substrate thereof with active/passive electronic components mounted on a conventional substrate in the form of package, a kind of next-generation three dimensional packaging technology, which can satisfy the multi-functionality attributable to the insurance of a residual surface area, the low loss of high frequency/high efficiency attributable to the minimization of signal transfer lines, and the miniaturization of the printed circuit board, can be developed, and a novel highly-functional packaging trend can be induced.
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Here, the conventional electronic component-embedded printed circuit board is problematic in that its performance of radiating the heat generated from an electronic component is decreased because an insulating material is used, and in that its total production cost is increased because the insulating material constituting an insulation layer is expensive.
Further, the conventional electronic component-embedded printed circuit board is problematic in that it is difficult to ensure its structural stability because it is greatly warped due to the difference in thermal expansion coefficient between the insulating material and the electronic component.
Accordingly, the present invention has been made to solve the above-mentioned problems, and the present invention provides an electronic component-embedded printed circuit board which can improve its performance of radiating the heat generated from an electronic component by employing a metal substrate coated with an anodic oxide film and which can ensure its overall structural stability by disposing two electronic components in two stages, and a method of manufacturing the same.
An aspect of the present invention provides an electronic component-embedded printed circuit board, including: a metal substrate including an anodic oxide film formed over the entire surface thereof; two electronic components disposed in a cavity formed in the metal substrate in two stages; an insulation layer formed on both sides of the metal substrate to bury the electronic components disposed in the cavity; and circuit layers including vias connected with connecting terminals of the electronic components and formed on the exposed surfaces of the insulation layer.
Here, the electronic component-embedded printed circuit board may further include a support plate which is formed in the cavity to divide the cavity into two parts in a thickness direction and which supports the two electronic components on both sides thereof.
Further, the electronic component-embedded printed circuit board may further include an adhesive layer applied onto both sides of the support plate to fix the two electronic components.
Further, the electronic component-embedded printed circuit board may further include one or more openings passing through the support plate.
Further, the support plate may be extended from the metal substrate and be integrated therewith.
Further, the electronic component-embedded printed circuit board may further include: two metal substrates disposed in two stages; and an adhesive layer attaching the two metal substrates to each other.
Further, the electronic component-embedded printed circuit board may further include through-holes which pass through the insulation layer and the metal substrate and which communicate with the circuit layers.
Further, the metal substrate may be made of aluminum (Al), and the anodic oxide film may be made of alumina (Al2O3).
Another aspect of the present invention provides a method of manufacturing an electronic component-embedded printed circuit board, including: forming a cavity in a metal substrate and then forming an anodic oxide film over the entire surface of the metal substrate; disposing two electronic components in the cavity in two stages; forming an insulation layer on both sides of the metal substrate to bury the electronic components disposed in the cavity; and forming circuit layers including vias connected with connecting terminals of the electronic components on the exposed surfaces of the insulation layer.
Here, in the forming of the cavity, a support plate for dividing the cavity into two parts in a thickness direction may be formed by leaving the central portion of the metal substrate to a predetermined thickness when the cavity is formed by removing the predetermined portion of the metal substrate through an etching process.
Further, in the disposing of two electronic components, an adhesive layer may be applied onto both sides of the support plate to fix the two electronic components.
Further, in the forming of the cavity, one or more openings passing through the support plate may be formed when the support plate is formed.
Further, the forming of the circuit layers may further include: forming through-holes which pass through the insulation layer and the metal substrate and which communicate with the circuit layers.
Further, in the forming of the cavity and the anodic oxide film, the metal substrate may be made of aluminum (Al), and the anodic oxide film may be made of alumina (Al2O3).
Still another aspect of the present invention provides a method of manufacturing an electronic component-embedded printed circuit board, including: forming cavities in two metal substrates and then forming anodic oxide films over the entire surfaces of the two metal substrates through an anodic oxidation process; disposing electronic components in the cavities; applying insulation layers onto the one sides of the respective two metal substrates to bury the electronic components disposed in the cavities; attaching the two metal substrates provided with the insulation layers to each other using an adhesive layer; and forming circuit layers including vias connected with connecting terminals of the electronic components on the exposed surfaces of the insulation layers.
Here, the forming of the circuit layers may further include: forming through-holes which pass through the insulation layers and the metal substrates and which communicate with the circuit layers.
Further, in the forming of the cavity and the anodic oxide film, each of the metal substrates may be made of aluminum (Al), and each of the anodic oxide films may be made of alumina (Al2O3).
Various objects, advantages and features of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings.
The terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept of the term to describe the best method he or she knows for carrying out the invention.
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
The objects, features and advantages of the present invention will be more clearly understood from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant descriptions thereof are omitted. Further, in the description of the present invention, when it is determined that the detailed description of the related art would obscure the gist of the present invention, the description thereof will be omitted.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.
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The metal substrate 110 serves as the core of the electronic component-embedded printed circuit board and may be made of a metal having high rigidity and excellent thermal conductivity, such as aluminum (Al), magnesium (Mg), titanium (Ti) or the like. Further, an anodic oxide film 120 may be formed over the entire surface of the metal substrate 110 in order to prevent the short of the metal substrate 110, circuit patterns or the like. Here, the anodic oxide film 120 can be formed by a metal acting as an anode in a sulfuric acid solution to accelerate the oxidation of the surface of the metal. This process is referred to as an anodic oxidation process. For example, when the metal substrate 110 is made of aluminum (Al), an anodic oxide film made of alumina (Al2O3) can be formed over the entire surface of the metal substrate 110 through the anodic oxidation process. The metal substrate can improve the radiation performance of the printed circuit board because it has excellent thermal conductivity, and can reduce the warpage of the printed circuit board because it has relatively high rigidity.
Meanwhile, the metal substrate 110 must be provided therein with a cavity 130 for disposing the electronic components 140. Although methods of forming the cavity 130 are not particularly limited, the cavity 130 may be formed by removing the predetermined portion of the metal substrate 110 through a wet etching process or a dry etching process. Further, the metal substrate 110 may be provided therein with a support plate 170 for stably supporting the two electronic components. The support plate 170 is formed in the cavity 130 such that the cavity 130 is divided into two parts in a thickness direction, and the two electronic components are disposed on both sides of the support plate 170, respectively. Here, the support plate 170 can be formed by leaving a part of the metal substrate 110 at the time of forming the cavity 130 in the metal substrate 110 through an etching process, and, in this case, the support plate 170 is integrated with the metal substrate 110. When the support plate 170 and the metal substrate 110 are integrally formed, there is an advantage in that the heat generated from the electronic components 140 can be effectively radiated through the support plate 170.
Further, an adhesive layer 180 may be applied on both sides of the support plate 170 to fix the electronic components on the both sides thereof. In order to uniformly apply the adhesive layer 180 on both sides of the support plate 170, one or more openings 175 passing through the support plate 170 may be formed. Since the electronic components 140 are fixed on both sides of the support plate 170 using the adhesive layer 180, a process for positioning the electronic components 140 can be stably and efficiently performed. Meanwhile, the raw material of the adhesive layer 180 is not particularly limited, but an epoxy resin including SiO2 as a filler may be used to form the adhesive layer 180.
The electronic components 140 are electrically connected to a printed circuit board and perform specific functions. Examples of the electronic components 140 may include active components such as semiconductor components and passive components such as capacitors. Here, the electronic components 140 may be disposed in a face-up manner in order to connect them to circuit layers 160 formed on the exposed surfaces of the insulation layer 150 through vias 165. Further, since the two electronic components 140 are disposed in the cavity 130 in two stages to form an upward and downward symmetrical structure, there is an advantage in that the stability of a printed circuit board can be ensured and the bi-directional electrical connection of a printed circuit board can be realized.
The insulation layer 150, which serves to bury the two electronic components 140 disposed in the cavity 130, is applied on both sides of the metal substrate 110 in a semi-hardened state, charged in the cavity, and then hardened. Here, the insulation layer 150 may be formed of an insulating material commonly used in printed circuit boards, for example, ABF (Ajinomoto Build-up Film), prepreg or the like.
The circuit layers 160 are formed on the exposed surfaces of the insulation layer 150, and are connected to the connection terminals 145 of the electronic components 140 through the vias 165. Here, the circuit layers 160 including the vias 165 may be formed by a semi-additive process (SAP), a modified semi-additive process (MSAP) or a subtractive process. Further, the two circuit layers 160 formed on the lower and upper exposed surfaces of the insulation layer 150 can be connected to each other by forming through-holes 190 which pass through the insulation layer 150 and the metal substrate 110 and which communicate with the circuit layers 160.
Meanwhile, solder resist layers 193 may be formed on the outermost of the electronic component-embedded printed circuit board 100 according to this embodiment. The solder resist layers 193, which are made of a heat-resistant coating material, serve to protect the circuit layers 160 such that solder is not applied on the circuit layers 160 at the time of soldering. Further, in order to electrically connect the printed circuit board 100 with external circuits, holes 195 may be formed in the solder resist layers 193 to expose pads.
The electronic component-embedded printed circuit board 100 according to this embodiment is advantageous in that the heat generated from the electronic components 140 can be effectively emitted because the metal substrate 110 is used instead of a conventional insulating material, and in that the warpage of the electronic component-embedded printed circuit board 100 can be prevented because the metal substrate 110 has relatively high rigidity. Further, the electronic component-embedded printed circuit board 100 is advantageous in that its overall structural stability can be ensured because the two electronic components 140 are disposed in two stages.
The electronic component-embedded printed circuit board 200 according to the second embodiment of the present invention is different from the above-mentioned electronic component-embedded printed circuit board 100 according to the first embodiment of the present invention in the structure of the metal substrate 110. Therefore, in this embodiment, the metal substrate 110 will be chiefly described, and the description overlapping with the first embodiment will be omitted.
The electronic component-embedded printed circuit board 200 according to this embodiment includes two metal substrates 110, and these two metal substrates 110 are disposed in two stages. Here, each of the two metal substrates 110 is provided with a cavity 130 and an anodic oxide film 120. Further, two electronic components 140 are embedded in their respective substrates 110. In order to realize an upward and downward symmetrical structure of the electronic components 140, the two electronic components may be disposed at corresponding positions.
Meanwhile, an adhesive layer 180 is provided between the two metal substrates 110 disposed in two stages, and serves to fix the two metal substrates 110 to each other. Here, the adhesive layer 180 may be provided between the cavities 130 and between the electronic components 140 as well as between the two metal substrates 110.
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Meanwhile, solder resist layers 193 may be formed on the outermost of the electronic component-embedded printed circuit board 100 in order to prevent solder from being applied on the circuit layers 160. Further, in order to electrically connect the printed circuit board 100 with external circuits, holes 195 may be formed in the solder resist layers 193 to expose pads.
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The method of manufacturing the electronic component-embedded printed circuit board 200 according to the second embodiment of the present invention is different from the above-mentioned method of manufacturing the electronic component-embedded printed circuit board 100 according to the first embodiment of the present invention in the structure of the metal substrate 110. Therefore, in this embodiment, the metal substrate 110 will be chiefly described, and other constituents will be briefly described. Meanwhile, only one metal substrate 110 is shown in
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As described above, according to the present invention, since a metal substrate is used instead of a conventional insulating material, its performance of radiating the heat generated from an electronic component can be improved, and its production cost can be reduced.
Further, according to the present invention, since two electronic components are disposed in two stages, the directions in which the two electronic components are respectively warped can conflict with each other, thus ensuring the overall structural stability of the printed circuit board.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
Simple modifications, additions and substitutions of the present invention belong to the scope of the present invention, and the specific scope of the present invention will be clearly defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2010-0000910 | Jan 2010 | KR | national |
