KR101109287B1 - Printed circuit board with electronic components embedded therein and method for fabricating the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component embedded printed circuit board and a method of manufacturing the same. A barrier layer is formed on an electrode terminal of an electronic component embedded in a printed circuit board, so that the electrode terminal of the electronic component is reworked when the circuit is formed due to a circuit defect. Provided is an electronic component embedded printed circuit board and a method of manufacturing the same, which can prevent the problem of expensive electronic components being discarded by being removed.

Electronic component, interior, barrier layer, cavity, core board

Description

Printed circuit board with electronic components embedded therein and method for fabricating the same}

The present invention relates to an electronic component embedded printed circuit board and a method of manufacturing the same.

Recently, due to the small size and light weight of electronic products, the development of printed circuit boards incorporating electronic components such as semiconductor devices has attracted attention.

In order to realize printed circuit boards embedded with electronic components, there are many surface mount technologies for mounting semiconductor devices such as IC (Interated Circuit) chips on printed circuit boards. Such technologies include wire bonding and flip chips ( Flip Chip).

Here, the mounting method by wire bonding bonds the electronic component printed on the printed circuit board to the printed circuit board using an adhesive, and the lead frame of the printed circuit board and the metal terminal (ie, pad) of the electronic component. The electronic parts and the wires are then molded with a thermosetting resin or a thermoplastic resin after the metal wires are connected to each other to transmit and receive information therebetween.

In addition, the flip chip mounting method forms external connection terminals (i.e. bumps) of several tens of micrometers to hundreds of micrometers of material such as gold, solder, or other metal on electronic components, and is mounted by conventional wire bonding. In contrast to the method, the bumped electronic component is flipped and mounted so that the surface faces the substrate.

However, such a surface mounting method is to mount the electronic component on the surface of the printed circuit board, and since the overall thickness after mounting cannot be smaller than the sum of the thicknesses of the printed circuit board and the electronic component, there is a difficulty in densification. In addition, the electrical connection is made by using a connection terminal (pad or bump) between the electronic component and the printed circuit board, there is a problem of reliability, such as disconnection or malfunction of the electrical connection due to cutting, corrosion of the connection terminal.

Therefore, the electronic parts are mounted inside the printed circuit board, that is, the inside of the printed circuit board rather than the outside, and a build-up layer is formed to make the electrical connection to achieve miniaturization and high density. In order to minimize the wiring distance and to improve the reliability problem caused by the component connection in the wire bonding or flip chip mounting method has been proposed.

1 is a schematic cross-sectional view of an electronic component embedded printed circuit board in which an electronic component according to the related art is embedded in a printed circuit board.

Referring to FIG. 1, an electronic component embedded printed circuit board according to the related art includes an electrode terminal 15 made of copper (Cu) on a core substrate having a cavity 12 perforated and having an inner circuit layer 11 formed on both surfaces thereof. The electronic component 14 having the () is embedded, and the outer circuit layer 18 having the insulating layer 17 and the via 19 is formed on both sides of the core substrate.

However, the electronic component-embedded printed circuit board according to the prior art is expensive because the electrode terminal 15 made of copper is also removed during the operation of removing and reforming the outer circuit layer 18 having the vias 19 due to a defective circuit. There was a problem in that the electronic component 14 of.

FIG. 2 is a view illustrating a state in which electrode terminals of an electronic component are removed together when reworking a circuit due to a defective circuit of an electronic component embedded printed circuit board according to the related art illustrated in FIG. 1. In the process of removing the outer layer circuit layer 18 having the () by the alkaline etching solution, it can be seen that there is a problem that the electrode terminal 15 connected to the via 19 is also removed by the alkaline etching solution.

Accordingly, an object of the present invention is to provide an electronic component embedded printed circuit board and a method of manufacturing the same, which can protect the electrode terminal of an electronic component when reworking a circuit due to a circuit defect in order to solve the above problems. .

An electronic component embedded printed circuit board according to an exemplary embodiment of the present invention includes a core substrate having a cavity perforated therein and having inner circuit layers formed on both surfaces thereof, an electronic component embedded in the cavity, and the core to cover the electronic component. It includes an insulating layer laminated on both sides of the substrate, characterized in that it comprises a barrier layer formed on the electrode terminal of the electronic component.

Here, the barrier layer is formed on the electrode terminal.

In addition, the barrier layer is characterized in that formed on the top and side of the electrode terminal.

In addition, the barrier layer is characterized in that the nickel (Ni) or gold (Au).

In addition, it is characterized in that it further comprises an outer circuit layer formed on the insulating layer.

In addition, the outer circuit layer may include vias connected to electrode terminals of the electronic component.

According to another aspect of the present invention, there is provided a method for manufacturing an electronic component embedded printed circuit board, the method comprising: (A) providing a core substrate including inner circuit layers formed on both sides of a cavity-perforated insulating resin layer, and (B) electronics. Forming a barrier layer on an electrode terminal of the component; (C) embedding the electronic component in the cavity; and (D) laminating insulating layers on both sides of the core substrate to cover the electronic component. Characterized in that.

At this time, in the step (B), the barrier layer is characterized in that formed on top of the electrode terminal.

In addition, in the step (B), the barrier layer is formed on the upper and side surfaces of the electrode terminal.

In addition, in the step (B), the barrier layer is characterized in that the nickel (Ni) or gold (Au).

In addition, after the step (D), (E) characterized in that it further comprises the step of forming an outer circuit layer on the insulating layer.

Further, in the step (E), the outer circuit layer is characterized in that it comprises a via connected to the electrode terminal of the electronic component.

The present invention provides a barrier layer on the electrode terminal of an electronic component embedded in a printed circuit board to protect the electrode terminal from the alkaline etching solution used to remove the existing circuit when the circuit is to be reformed due to a defective circuit, Furthermore, the problem of having to dispose of expensive electronic components can be prevented.

In addition, the present invention can prevent the side of the electrode terminal by the alkaline etching liquid from being etched by forming the barrier layer not only on the upper surface of the electrode terminal but also on the side surface or the entire exposed surface.

In addition, the present invention provides a simple process for forming the barrier layer.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components as much as possible, even if displayed on the other drawings. In addition, in describing the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

 Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic cross-sectional view of an electronic component embedded printed circuit board according to a preferred embodiment of the present invention, and FIGS. 4 to 10 illustrate a method of manufacturing an electronic component embedded printed circuit board according to a preferred embodiment of the present invention. It is a schematic cross section by each process.

Referring to FIG. 3, the barrier layer 109 is formed on the electrode terminal 108 of the electronic component 107 embedded in the core substrate 105 according to the preferred embodiment of the present invention. It is characterized in that it has a structure that can protect the electrode terminal 108 in the circuit reforming operation due to a poor circuit.

Here, the core substrate 105 is formed with a cavity 103 in which the electronic component 107 is mounted, and includes an inner circuit layer 102 including circuit patterns on both surfaces thereof, and for interlayer connection of the inner circuit layer 102. The through hole 104 is formed.

The electronic component 107 is a semiconductor element, and an electrode terminal 108 connected to the outer circuit layer 112 is formed. Here, the electrode terminal 108 of the electronic component 107 is formed of a conductive metal, for example, copper (Cu), and a barrier layer 109 is formed on the electrode terminal 108.

In this case, the barrier layer 109 is etched and the electrode terminal 108 is etched together when the outer circuit layer 112 including the vias 111 is removed by the alkaline etching solution during the circuit reforming operation. In order to prevent the problem of having to discard, it is preferable that it is formed of a material which is not removed by the alkaline etching solution, for example, nickel (Ni) or gold (Au).

In addition, the barrier layer 109 is preferably formed on the upper surface of the electrode terminal 108. This is to prevent the electrode terminal 108 from being exposed to the alkaline etching solution when the via 111 connected to the electrode terminal 108 is removed by etching. Meanwhile, although the barrier layer 109 is illustrated as being formed on the upper surface of the electrode terminal 108 in FIG. 3, the present invention is not limited thereto, and the upper and side surfaces of the electrode terminal 108 are formed. Or formed on the entire surface of the exposed electrode terminal is also included within the scope of the present invention.

The insulating layers 110a and 110b are formed on both surfaces of the core substrate 105 to support the electronic component 107. The outer circuit layer 113 is formed on the insulating layers 110a and 110b, and a via 111 connecting the electrode terminal 108 and the outer circuit layer 112 is formed.

4 to 10 are schematic cross-sectional views for each process for explaining a manufacturing method of an electronic component embedded printed circuit board according to an exemplary embodiment of the present invention. Referring to this, the manufacturing method is as follows.

First, as shown in FIG. 4, a double-sided copper foil laminate 101 having a copper foil layer formed on both surfaces thereof is prepared based on the insulating resin layer forming the core substrate.

Next, as shown in FIG. 5, an inner circuit layer 102 and a cavity 103 are formed on the double-sided copper foil laminate 101 to manufacture a core substrate 105.

At this time, the through-hole 104 is processed for the interlayer connection of the inner circuit layer 102 formed on both sides. Here, the through hole 104 is formed by a CNC drill (Computer Numerical Control Drill) or a laser drill (CO2 laser drill or Nd-Yag laser drill). When machining the through hole 104 using a CNC drill, deburring removes burrs of the copper foil layer, dust on the inner wall of the through hole 104 or dust on the surface of the copper foil layer generated during drilling. It is preferable to carry out the process. In the case of using a laser drill, the copper foil layer and the insulating resin layer may be simultaneously processed using a Yag laser drill, and the copper foil layer of the portion where the through hole 104 is to be formed is etched and then insulated using a CO 2 laser drill. The resin layer can also be processed. Furthermore, after the through hole 104 is processed, it is preferable to perform a desmear process.

In addition, the inner circuit layer 102 may be formed in a subtractive process or an additive process, a modified semi-additive process (MSAP), or the like according to a manufacturing process. Hereinafter, for convenience of description, the inner circuit layer 102 will be described based on the subtractive method. However, the scope of the present invention is not limited.

That is, the inner circuit layer 102 is coated with a photosensitive photo resist on the copper foil, the photo mask is in close contact with the photo mask to form a pattern on the photo resist through exposure / development using ultraviolet light and It is manufactured by etching (corrosion) unnecessary copper foil using a chemical reaction as an etching resist.

Further, the cavity 103 for mounting the electronic component is formed together when drilling for the formation of the through hole 104, or after the inner circuit layer 102 is formed, through a mechanical drill, a CO 2 drill, or an Nd-Yag laser drill process. It may be formed separately.

On the other hand, since the sidewall of the through hole 104 is an insulating resin layer, the electrolytic copper plating layer is formed after forming the electroless copper plating layer. In the drawings, the electroless copper plating layer and the electrolytic copper plating layer are not distinguished for convenience of description, and the electroless copper plating layer and the electrolytic copper plating layer are illustrated as an inner circuit layer 102 without being separately illustrated on the copper foil layer. .

Here, the electroless copper plating process is performed in the precipitation reaction, for example, a degreasing process, a soft etching process, a pre-catalyst process, a catalyst treatment process, and an activation process. This process includes electroless copper plating and anti-oxidation. In addition, the electrolytic copper plating process is performed using a direct current rectifier, for example, after depositing the double-sided copper foil laminated sheet 101 in a copper plating working cylinder.

Next, as shown in FIG. 6, a tape 106 for supporting the electronic component is attached to one surface of the core substrate 105.

In this case, the tape 106 may be a silicon rubber (Si rubber) or polyimide (PI) adhesive tape. By using an adhesive silicone rubber sheet or polyimide adhesive tape, the electronic component can be positioned at a desired position. In addition, the tape 106 has heat resistance so as not to be deformed by heating or pressing in a process of printing and curing a filler to form an insulating layer after mounting the electronic component on a printed circuit board and protecting the electronic component. It is desirable to have.

Next, as shown in FIG. 7, the electronic component 107 is face-up on the tape 106 formed on one surface of the core substrate 105 such that the electronic component 107 is accommodated in the cavity 103. up).

However, although the electronic component 107 is shown mounted in a face-up state in FIG. 7, a face-down in which the electrode terminal 108 of the electronic component 107 is attached to the tape 106 is shown. Mounting in a) state is also included within the scope of the present invention.

On the other hand, in the electrode terminal 108 of the electronic component 107 to be mounted, the electrode terminal 108 is removed by etching together when the outer circuit layer including the via is removed by the alkaline etching solution during a circuit reforming operation due to a defective circuit. The barrier layer 109 made of a material, for example, nickel (Ni), gold (Au), or the like, which is not removed by an alkaline etching solution, is formed to prevent the problem of disposing expensive electronic components. .

Here, the barrier layer 109 is formed on the upper surface, the upper surface and the side surface, or the exposed surface of the electrode terminal 108 by plating.

Next, as shown in FIG. 8, the first insulation includes a through hole 104 and a space between the electronic component 107 and the cavity 103 on the other surface of the core substrate 105 to which the tape 106 is not attached. Layer 110a is laminated.

In this case, the first insulating layer 110a includes a space between the through hole 104 and the electronic component 107 and the cavity 103 by pressing a semi-cured insulating layer, for example, a prepreg. Is formed on the other surface of the core substrate 105.

Meanwhile, although FIG. 8 illustrates that the first insulating layer 110a is stacked, the encapsulation for fixing the electronic component 107 after attaching the electronic component 107 on the tape 106 is performed. An encapsulation process may be performed first. The encapsulation process uses a filler (not shown) to fill the space between the cavity 103 and the electronic component 107 so that the electronic component 107 can be fixed at a predetermined position without moving, that is, molding. That's the process. Here, the filling may be performed by screen printing, mask printing, dispensing, or the like, and a thermosetting resin, a thermoplastic resin, or a composite thereof may be used.

Next, as shown in FIG. 9, after inverting the core substrate 105 on which the first insulating layer 109 is formed, the tape 106 is removed, and the second insulating layer 110b is disposed on the core substrate 105 from which the tape is removed. ). In this case, since the second insulating layer 110b is formed in the same manner as the first insulating layer 110a, a detailed description thereof will be omitted.

On the other hand, as shown in Figure 10, in the manufacturing method of the electronic component embedded printed circuit board according to a preferred embodiment of the present invention, the outer circuit layer 112 including the via 111 is the first insulating layer (110a) and It is formed on the second insulating layer 110b. In this case, the vias 111 are formed to connect the electrode terminal 108 or the inner circuit layer 102 and the outer circuit layer 112 of the electronic component 107. This via 111 is processed by any one of a mechanical drill, a laser drill (CO2 laser drill or Nd-Yag laser drill), and wet etching.

By such a process, the electronic component embedded printed circuit board 100 as shown in FIG. 3 is manufactured.

Further, although not shown in the drawings, it will be apparent that the multilayer printed circuit board may be manufactured using vias or bumps around the core substrate 105 in which the electronic component 107 illustrated in FIG. 9 is embedded.

Although the present invention has been described in detail through specific embodiments, this is for describing the present invention in detail, and the electronic component embedded printed circuit board and the method of manufacturing the same according to the present invention are not limited thereto. It will be apparent to those skilled in the art that modifications and improvements are possible.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be apparent from the appended claims.

1 is a schematic cross-sectional view of an electronic component embedded printed circuit board in which an electronic component according to the related art is embedded in a printed circuit board.

FIG. 2 is a view showing a state in which electrode terminals of an electronic component are removed together when reworking a circuit due to a circuit failure of the electronic component embedded printed circuit board of FIG. 1.

3 is a schematic cross-sectional view of an electronic component embedded printed circuit board according to an exemplary embodiment of the present invention.

4 to 10 are schematic cross-sectional views for each process for explaining a method of manufacturing an electronic component embedded printed circuit board according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

101: copper foil laminated plate 102: inner layer circuit layer

103: cavity 104: through hole

105: core substrate 106: tape

107: electronic component 108: electrode terminal

109: barrier layer 110a, 110b: insulating layer

111: Via 112: outer layer circuit layer

Claims (12)

A core substrate having a cavity perforated and having inner circuit layers formed on both surfaces thereof; An electronic component embedded in the cavity; An insulating layer laminated on both surfaces of the core substrate to cover the electronic component; And And a barrier layer formed on the upper and side surfaces of the electrode terminal of the electronic component and formed of a material which is not removed by an alkaline etching solution. delete delete The method according to claim 1, The material which is not removed by the alkaline etching solution is nickel (Ni) or gold (Au) embedded electronic circuit board. The method according to claim 1 or 4, And an outer circuit layer formed on the insulating layer and connected to the conductive electrode terminal through vias. delete (A) providing a core substrate including an inner circuit layer formed on both sides of the cavity-insulated insulating resin layer; (B) forming a barrier layer by plating a material that is not removed by the alkaline etching solution on the upper and side surfaces of the electrode terminal of the electronic component; (C) embedding the electronic component in the cavity; And (D) stacking insulating layers on both sides of the core substrate to cover the electronic component; Method of manufacturing an electronic component embedded printed circuit board comprising a. delete delete The method of claim 7, The material which is not removed by the alkaline etching solution is a nickel (Ni) or gold (Au) manufacturing method of a printed circuit board. The method according to claim 7 or 10, After the step (D), (E) a method of manufacturing an electronic component embedded printed circuit board, further comprising forming an outer circuit layer connected to the insulating layer through an electrode terminal and a via. delete

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