KR20080025949A - Electronic chip embedded printed circuit board and manufacturing method thereof - Google Patents

Abstract

An electronic chip embedded printed circuit board and a manufacturing method thereof are provided to improve heat discharging efficiency of the embedded board by stacking a metal layer on a surface of an electronic chip and connecting a via for discharging heat to the metal layer. A manufacturing method of an electronic chip embedded printed circuit board includes the steps of: punching a cavity on a core substrate and closing a surface of the cavity(P10); embedding an electronic chip stacked with a metal layer on a surface in the cavity(P20); stacking an insulating layer on the core substrate(P30); and forming a via passing through the insulating layer and contacting with the metal layer(P40). The core substrate is a CCL(Copper Clad Laminate) stacked with a copper clad layer on a surface thereof. The method further includes a step of forming an inner layer circuit by selectively removing the copper clad layer before the step of P10.

Description

Electronic chip embedded printed circuit board and manufacturing method thereof

1 is an exploded perspective view showing a package substrate with improved heat radiation characteristics according to the prior art.

2 is a cross-sectional view showing a printed circuit board having improved heat dissipation characteristics according to the prior art.

3 is a flow chart showing a method for manufacturing a printed circuit board embedded with an electronic device according to an embodiment of the present invention.

4 is a flowchart illustrating a manufacturing process of an electronic device-embedded printed circuit board according to an exemplary embodiment of the present invention.

5 is a flowchart illustrating a process of laminating a metal layer on a semiconductor device according to an exemplary embodiment of the present invention.

6 is a cross-sectional view showing a printed circuit board embedded with an electronic device according to an embodiment of the present invention.

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

110: core substrate 112: inner layer circuit

114: cavity 116: tape

120: electronic device 122: metal layer

130: insulating layer 132: via hole

133: Via 134: outer layer circuit

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

While efforts are being made to provide more functions in a limited area, development of printed circuit boards with electronic devices is drawing attention as a part of next-generation multifunctional and small package technologies. In addition to the advantages of multifunctionality and miniaturization, printed circuit boards with electronic devices include aspects of high functionality, which can minimize the distance between wirings at high frequencies of 100 MHz or higher, and in some cases, FC (Flip chip) This is because it provides a way to improve the reliability problems resulting from the connection of electronic devices using wire bonding or solder balls used in BGA (Ball grid array).

Recently, interest in the so-called 'solderless' process, which eliminates the use of lead in the manufacturing process of the substrate, has increased, which has led to the quest for fundamental solutions to environmental problems that have been a major issue for the last decade. have.

One of the most important factors in the technology of embedding high-density electronic devices such as ICs on a substrate is the ability of a printed circuit board to rapidly dissipate heat generated in an IC. Generally, the thermal conductivity of printed circuit boards varies depending on the material and structure, but it is known to be about 6.5W / mK, which is significantly lower than the thermal conductivity of silicon (Si), the main material of IC, 124W / mK. If necessary, the heat radiation to the outside of the substrate is required.

1 is an exploded perspective view showing a package substrate with improved heat dissipation characteristics according to the prior art, and FIG. 2 is a cross-sectional view showing a printed circuit board with improved heat dissipation characteristics according to the prior art. In the prior art illustrated in FIG. 1, a copper foil layer is formed on the surface of a package substrate on which a semiconductor device or the like is mounted to form a coating film to release heat to the outside. In the prior art illustrated in FIG. It is intended to improve heat dissipation characteristics by impregnating a metal core layer made of aluminum foil (Al foil) in the resin layer of the CCL so that heat dissipation is efficiently performed through the metal layer.

However, the above-described prior arts are applied to a structure in which an electronic device is mounted on a surface, and there is a limit in application to the structure in which the electronic device, which is a heating element, is embedded in a substrate. In the case of an electronic device with a large heat generation such as a CPU, attention must be paid to heat dissipation even in the surface mounting. Thus, when an electronic device with a large heat generation is incorporated, a new and improved technology is required.

The present invention provides a printed circuit board with an electronic device capable of more effectively dissipating heat generated from the electronic device in a board having a high-density, high-performance electronic device such as an IC, and a manufacturing method thereof.

According to an aspect of the invention, (a) perforating the cavity (cavity) on the core substrate, closing one surface of the cavity, (b) embedding an electronic device in which a metal layer is laminated on the surface, (c) A method of manufacturing an electronic device-embedded printed circuit board is provided, comprising: laminating an insulating layer on a core substrate, and (d) forming a via penetrating the insulating layer to be in contact with the metal layer.

The core substrate is a copper clad laminate (CCL) having a copper foil layer laminated on a surface thereof, and may further include forming an inner layer circuit by selectively removing the copper foil layer before step (a).

Step (a) includes attaching the tape to one side of the core substrate, the tape may comprise a polyimide (PI) film is coated with a silicone adhesive on the surface. In this case, step (c) includes (c1) laminating an insulating layer on the other surface of the core substrate, (c2) removing the tape, and (c3) laminating the insulating layer on one surface of the core substrate. can do.

In order to deposit a metal layer on the surface of the electronic device, first, step (b) comprises: (b1) inserting and fixing the electronic device in the cavity; and (b2) opening a portion corresponding to the position of the electronic device to the core substrate. (B3) printing a metal paste on the mask, and second, the electronic device may laminate the metal layer on the surface of the wafer substrate and then dice the wafer substrate ( dicing).

In order to form the via for heat dissipation, the step (d) comprises: (d1) exposing a metal layer by drilling a via hole in the insulating layer corresponding to the position where the electronic device is embedded, and (d2) filling the via hole with metal. It may include. In this case, in parallel with the step of filling the via hole with metal by plating or the like, step (d2) includes: (e) plating the surface of the insulating layer to laminate the plating layer, and (f) selectively removing a part of the plating layer. It may include forming an outer layer circuit.

According to another aspect of the present invention, a core substrate, a cavity perforated in the core substrate, an electronic element embedded in the cavity, a metal layer laminated on the surface of the electronic element, and an insulating layer laminated on the core substrate to cover the electronic element And a heat dissipation via penetrating the insulating layer to contact the metal layer in correspondence with the position where the electronic device is embedded.

The semiconductor device may further include a conductive via configured to electrically connect the inner layer circuit and the outer layer circuit through the inner layer circuit formed on the surface of the core substrate and the outer layer circuit formed on the surface of the insulating layer and the insulating layer.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

Hereinafter, preferred embodiments of an electronic device-embedded printed circuit board and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings. In describing the accompanying drawings, the same or corresponding components are the same drawings. The numbering and duplicate description thereof will be omitted.

3 is a flowchart illustrating a method of manufacturing an electronic device-embedded printed circuit board according to an exemplary embodiment of the present invention, and FIG. 4 is a flowchart illustrating a process of manufacturing an electronic device-embedded printed circuit board according to an exemplary embodiment of the present invention. 5 is a flowchart illustrating a process of laminating a metal layer on a semiconductor device according to an exemplary embodiment of the present invention. 4 and 5, the core substrate 110, the inner circuit 112, the cavity 114, the tape 116, the electronic device 120, the metal layer 122, the insulating layer 130, and the via hole ( 132, vias 133, and outer circuit 134 are shown.

In this embodiment, the metal layer 122 is laminated on the surface of the electronic device 120 embedded in the printed circuit board, and the heat dissipation via hole 132 is connected to the metal layer 122 to improve the heat dissipation efficiency of the substrate. It features.

In order to manufacture such an electronic device-embedded printed circuit board, first, an inner layer circuit 112 is formed on the surface of the core substrate 110. As shown in FIG. 4A, when the copper clad laminate (CCL) is used as the core substrate 110, the inner layer circuit 112 may be selectively removed by exposing, developing, or etching the copper foil layer stacked on the surface thereof. ) (P9). In addition, an IVH penetrating through the core substrate 110 may be formed to electrically connect the circuit patterns formed on both surfaces of the core substrate 110.

Next, as shown in FIG. 4B, the cavity 114 is formed by drilling a position where the electronic device 120 of the core substrate 110 is to be embedded. Since the cavity 114 corresponds to a space in which the electronic device 120 is to be embedded, it is preferable to consider the size of the electronic device 120 so that the space required for the cavity 114 may be secured. In order to embed the electronic device 120 in the cavity 114, one side of the cavity 114, that is, one surface of the core substrate 110 is closed (P10).

Closing of the cavity 114 can be made simply by attaching the tape 116 to one surface of the core substrate 110 as shown in FIG. The tape 116 for closing the cavity 114 is a member that is temporarily used before the position of the electronic device 120 is fixed by building up the insulating layer 130 afterwards. This remaining adhesive is preferably used. In addition, since the electronic device 120 is fixed to the tape 116 and heat is applied to the substrate in the process of building up the insulating layer 130, the material of the tape 116 may be excellent in heat resistance. For example, a tape 116 made of a polyimide (PI) film coated with a silicone adhesive may be used (P12).

After closing one side of the cavity 114 perforated on the core substrate 110, the electronic device 120 is embedded in the cavity 114 as shown in FIG. 4 (d) (P20). In order to embed the electronic device 120 in the cavity 114, the electronic device 120 is inserted into the cavity 114 and attached to the tape 116 to fix the electronic device 120 (P22). As described later, in order to stack the metal layer 122 on the surface of the electronic device 120, a portion where the metal layer 122 is not stacked, that is, a surface on which an electrode of the electronic device 120 is formed, is attached and fixed to the tape 116. It is good to let.

The metal layer 122 is stacked on the surface of the electronic device 120 embedded in the cavity 114. The metal layer 122 may be stacked in the largest area in order to maximize the heat dissipation efficiency without affecting the electrical function of the electronic device 120. Therefore, the front surface of the surface of the electronic device 120 is formed. When the side and the opposite side are called the back side, it is good to laminate the metal layer 122 on the back side.

In the case of the semiconductor device, in order to manufacture the electronic device 120 having the metal layer 122 stacked on the back side according to the present embodiment, the semiconductor device in the wafer state as shown in FIG. On the other hand, as shown in Fig. 5 (b) after the back lapping (back lapping) and the like after the process, the metal layer 122 is laminated on the back side by a method such as plating or vapor deposition. The semiconductor device in the wafer state in which the metal layer 122 is stacked is diced as shown in FIG. 5C to manufacture the electronic device 120 according to the present embodiment.

In this embodiment, the metal layer 122 to be plated or deposited on the back side of the electronic device 120 is to increase the heat dissipation efficiency, so it is preferable to use a metal having excellent thermal conductivity, and it is not necessary to stack only one type of metal. Two or more kinds of metals may be laminated in multiple layers. For example, the multilayer metal layer 122 may be stacked by using a combination of Cr and Au, Cr and Cu, Ti, and Cu.

Meanwhile, as described above, in addition to the method in which the metal layer 122 is laminated on the back side of the electronic device 120 in the wafer state and then embedded in the cavity 114, the electronic device 120 is embedded in the cavity 114. After that, it is also possible to laminate the metal layer 122 on the surface.

To this end, after the electronic device 120 is embedded in the cavity 114 and fixed, the mask in which the position of the electronic device 120 is opened is laminated on the core substrate 110 (P24), and then the Cu paste or the like is applied to the mask. A metal paste having excellent thermal conductivity, such as Ag paste, may be printed to stack the metal layer 122 on the surface of the electronic device 120 (P26). That is, after the electronic device 120 is embedded, the metal layer 122 is laminated on the surface of the electronic device 120 by applying a mask printing method.

Next, as shown in FIG. 4E, the insulating layer 130 is built up on the core substrate 110 to cover the electronic device 120 embedded in the cavity 114 (P30). As described above, since the tape 116, which is a temporary member for fixing the electronic device 120 to the cavity 114, is attached to one surface of the core substrate 110, first, the core substrate to which the tape 116 is not attached ( The insulating layer 130 is built up on the other surface of the 110 (P32), and after removing the tape 116 attached to one surface of the core substrate 110 (P34), the insulating layer on one surface of the core substrate 110 Build up (130) (P36).

After removing the tape 116 attached to one surface of the core substrate 110 as described above, in order to proceed with the build-up process without processing the surface separately, a material that does not leave a residue when removing the tape 116 is formed. It is good to use.

As such, after the insulating layer 130 is stacked on the surface of the core substrate 110 to embed the electronic device 120 in the cavity 114, the insulating layer 130 penetrates to the position of the electronic device 120. The via 133 is formed (P40). This is to allow heat generated in the electronic device 120 to be discharged to the outside through the metal layer 122, and the via 133 may be in contact with the metal layer 122 stacked on the surface of the electronic device 120. .

In order to form the heat dissipation via 133 in contact with the metal layer 122, as shown in FIG. 4F, the insulating layer 130 at the position where the electronic device 120 is embedded is drilled with a laser drill or the like. By forming the via holes 132, the metal layer 122 stacked on the surface of the electronic device 120 is exposed (P42), and the via holes 132 are filled with a material having excellent thermal conductivity such as metal (P48). That is, the heat dissipation via hole 132 is processed in the back side of the embedded electronic device 120. The shape of the via hole 132 may be various, such as a blind via hole (BVH) or an interstitial via hole (IVH).

Meanwhile, in the formation of the via hole, not only the heat dissipation via hole 132 but also the hole where the electrode of the electronic device 120 is located or the part where the electrical connection between the inner layer circuit 112 and the outer layer circuit 134 is required is formed. Interlayer electrical connections can be implemented.

In order to fill the via hole 132 with metal, it is preferable to plate the surface of the substrate, and in this process, a process of forming a circuit pattern on the surface of the insulating layer 130 may be performed in parallel. That is, after the via hole 132 is processed in the insulating layer 130, the plating layer is laminated on the surface of the insulating layer 130 and the inside of the via hole 132 by plating Cu and the like on the entire surface as shown in FIG. 4G. (P44). Accordingly, metal is filled in the via hole 132, and the plating layer is selectively applied to the plating layer stacked on the surface of the insulating layer 130 by applying a process such as exposure, development, and etching as in the case of the inner circuit 112. By removing it, the outer circuit 134 can be formed as shown in FIG. 4 (h) (P46).

6 is a cross-sectional view illustrating a printed circuit board having an electronic device according to an exemplary embodiment of the present invention. Referring to FIG. 6, a core substrate 110, an inner layer circuit 112, an electronic device 120, a metal layer 122, an insulating layer 130, a via 133, and an outer layer circuit 134 are illustrated.

In the printed circuit board with the electronic device manufactured according to the above-described method, the metal layer 122 is laminated on the back side of the electronic device 120 to be embedded, and the via 133 for heat dissipation is connected to the metal layer 122. Therefore, the heat generated in the substrate is effectively released to the outside.

That is, in the printed circuit board with the electronic device according to the present embodiment, the electronic device 120 is embedded in the cavity 114 perforated on the core board 110 and used for heat dissipation at the position of the electronic device 120 in the buildup layer. The via 133 is formed.

The metal layer 122 is stacked on the surface of the embedded electronic device 120 so that heat dissipation can be effectively performed. As described above, the metal layer 122 is laminated on the electronic device 120 in a wafer state by plating or vapor deposition. After dicing, or by embedding the electronic device 120 in the cavity 114, and before the build-up of the insulating layer 130 may be implemented by mask printing the metal paste.

Meanwhile, as illustrated in FIG. 6, an inner layer circuit 112 and an outer layer circuit 134 may be formed on the surface of the core substrate 110 and the surface of the build-up layer, respectively, and vias are formed for electrical connection between the circuit layers. Can be. As described above, the via for electrical connection, that is, the conductive via may be formed in the same shape as the heat dissipation via 133 formed at the position where the electronic device 120 is embedded, thus forming the heat dissipation via 133. The conductive via may also be formed in parallel in the process as described above.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention.

According to a preferred embodiment of the present invention as described above, in the case of embedding an electronic device such as a high-performance semiconductor device that generates a lot of heat in a printed circuit board, by stacking a metal layer on the surface of the electronic device and connecting a heat dissipation via thereto The heat dissipation efficiency of the embedded substrate can be increased, and by designing a structure with a focus on the heat dissipation efficiency as compared with the conventional embedded substrate, it can be utilized for high value-added embedded substrate.

Claims (12)

(a) drilling a cavity in the core substrate and closing one surface of the cavity; (b) embedding an electronic device having a metal layer on a surface thereof in the cavity; (c) stacking an insulating layer on the core substrate; And (d) forming a via penetrating the insulating layer to be in contact with the metal layer. The method of claim 1, The core substrate is a copper clad laminate (CCL) is a copper foil layer laminated on the surface, Prior to the step (a), further comprising the step of selectively removing the copper foil layer to form an inner layer circuit. The method of claim 1, The step (a) is a method of manufacturing a printed circuit board with an electronic device comprising the step of attaching a tape to one surface of the core substrate. The method of claim 3, The tape comprises a polyimide (PI) film coated with a silicone adhesive on the surface of the electronic device embedded printed circuit board manufacturing method. The method of claim 3, Step (c) is, (c1) stacking the insulating layer on the other surface of the core substrate; (c2) removing the tape; and (c3) stacking the insulating layer on one surface of the core board. The method of claim 1, Step (b) is, (b1) inserting and fixing the electronic device into the cavity; (b2) stacking a mask having a portion corresponding to the position of the electronic device open on the core substrate; (b3) a method of manufacturing an electronic device-embedded printed circuit board, comprising the step of printing a metal paste on the mask. The method of claim 1, The electronic device is a method of manufacturing an electronic device embedded printed circuit board, characterized in that the metal substrate is laminated on the surface of the wafer substrate, and then manufactured by dicing the wafer substrate. The method of claim 1, Step (d) is, (d1) exposing the metal layer by drilling a via hole in the insulating layer corresponding to a location where the electronic device is embedded; And (d2) A method of manufacturing an electronic device embedded printed circuit board comprising the step of filling a metal in the via hole. The method of claim 8, Step (d2), (e) plating the surface of the insulating layer to stack a plating layer; (f) selectively removing a portion of the plating layer to form an outer layer circuit. A core substrate; A cavity perforated in the core substrate; An electronic device embedded in the cavity; A metal layer laminated on the surface of the electronic device; An insulating layer laminated on the core substrate to cover the electronic device; And a heat dissipation via penetrating the insulating layer to contact the metal layer in correspondence with the position where the electronic device is embedded. The method of claim 10, And an inner layer circuit formed on the surface of the core substrate and an outer layer circuit formed on the surface of the insulating layer. The method of claim 11, And a conductive via for electrically connecting the inner layer circuit and the outer layer circuit through the insulating layer.

Images