KR20080043207A - Method of fabricating an active-device-embedded printed circuit board - Google Patents

Abstract

A method of fabricating an active-device-embedded printed circuit board is provided to reduce a cost and simplify a process by electrically connecting an embedded semiconductor die to a wire of a substrate through a stud bump without additional via hole drilling for the electrical connection. A method of fabricating an active-device-embedded printed circuit board includes the steps of: forming stud bumps(20) on bonding pads(11) of a semiconductor die(10) by using wire bonding equipment; attaching a substrate of the semiconductor die with the stud bumps on a predetermined position of an insulating layer(40) of an inner substrate(50) with patterned copper clad circuits(30) by using an adhesive tape or a paste adhesive to expose the stud bumps; arranging insulating layers on both surfaces of the inner substrate mounting the semiconductor die and laminate pressing the insulating layers, wherein the stud bumps pass through the insulating layer to be exposed; and coating copper foils(85,86) on the insulating layers for the copper foil and the exposed stud bump to be conducted and forming copper circuits through patterning.

Description

METHOOD OF FABRICATING AN ACTIVE-DEVICE-EMBEDDED PRINTED CIRCUIT BOARD

1A illustrates a semiconductor die to be embedded in a substrate in accordance with the method of the present invention.

1B is a cross-sectional view of fabricating a stud bump using wire bonding equipment on an aluminum bonding pad on a semiconductor die in accordance with the present invention.

Fig. 2A is a view in which a copper foil pattern is formed on a substrate on which a semiconductor die is to be embedded;

2B illustrates a portion of a substrate on which a semiconductor die is to be mounted.

2C illustrates a semiconductor die mounted on a substrate.

Fig. 2D is a view showing laminate compression of an insulating layer on both upper and lower surfaces of an inner layer substrate on which a semiconductor die is mounted.

Figure 2e is a view showing a state in which the copper plated on the surface of the stud bump exposed through the insulating layer

Fig. 2F shows that the copper foil and the semiconductor die of the substrate are energized with each other by selectively corroding the copper foil of the outer layer to form a copper foil circuit.

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

10: semiconductor die

20: stud bump

11: bonding pad

30: copper foil circuit

40: resin insulation layer

50: inner layer substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of printed circuit boards, and more particularly to a technology for manufacturing printed circuit boards incorporating active devices.

Recently, in order to improve the portability and maximize the function of electronic devices, a technology for embedding an active component or a passive component into a substrate has been introduced. As such, when the component is embedded in the substrate, the substrate can be miniaturized, the mounting density of the component is increased, and the high frequency characteristics of the electronic circuit are improved.

The current embedded PCB technology is mainly focused on the technology of embedding passive devices due to the process characteristics, and manufacturing passive components by inserting existing chip-shaped components into the substrate and applying thin film or thick film technology. There is a technique to do. Representative on-board passive components include resistors, capacitors, and inductor coils.

Recently, active element embedding technology has been developed to significantly reduce the size and thickness of a system by inserting not only the above-mentioned passive components but also semiconductor chips into the substrate. As a technique for embedding an active element such as a semiconductor die in a substrate, the following method is known in the art. That is, after fabrication of the inner layer substrate, the die is attached to the predetermined position using an adhesive, and then an insulating layer such as prepreg or resin coated copper (RCC) foil is aligned and pressed.

Subsequently, via holes are processed in the outer layer of the substrate using a laser, and wirings with chips are formed through plating and etching processes. At this time, the pad of the part where the via hole is processed on the die should be deposited or plated with a metal such as copper by 5 μm or more so that the laser beam can be stopped during laser processing. If the thickness is too thick, the cavity should be machined on the insulating layer.

As another conventional technique, there is a method of forming a pad for flip chip bumping on an inner layer substrate, directly mounting a semiconductor chip, and then laminating the above. However, the latter method has a difficulty in applying the conventional flip chip bumping method to the inner layer substrate, and there is a technical disadvantage that a separate special material is required for the underfill.

In addition, the above-described prior art requires the use of laser processing, flip chip bumping, or ACF materials to form a wiring path between the chip and the board circuit, and thus requires additional semiconductor processes, mounting processes, and special materials. This has the disadvantage of increasing the process time.

Accordingly, an object of the present invention is to provide a technology that can simplify the process and reduce the process cost to embed a die in a substrate using only the technology and materials of general semiconductor process and PCB process.

In order to achieve the above object, the present invention provides a method for manufacturing a printed circuit board containing a semiconductor die, comprising the steps of: (a) forming a stud bump on the bonding pad of the semiconductor die using wire bonding equipment; (b) mounting the substrate of the semiconductor die using an adhesive tape or paste adhesive to expose the stud bumps at a predetermined position on the insulating layer of the inner layer substrate having the copper foil circuit patterned on the semiconductor die having the stud bumps formed thereon; step; (c) laminating a laminate press by aligning an insulating layer on both sides of an inner substrate on which the semiconductor die is mounted, and press laminating the stud bumps to be exposed through the insulating layer; And (d) forming a copper foil circuit on the insulating layer so as to conduct electricity with the stud bumps exposed through the insulating layer.

In still another embodiment of the present invention, there is provided a method of manufacturing a printed circuit board having a semiconductor die, the method comprising: (a) forming a stud bump on a bonding pad of a semiconductor die by using wire bonding equipment; (b) mounting the substrate of the semiconductor die using an adhesive tape or a paste adhesive to expose the stud bumps on the insulating layer of the inner layer substrate having the copper foil circuit patterned on the semiconductor die having the stud bumps formed thereon; (c) Laminating an insulating layer coated with copper foil on both surfaces of the inner layer substrate on which the semiconductor die is mounted, and arranges the insulating layer so as to contact the stud bump, and the stud bump passes through the insulating layer and the copper foil. Press laminating to make contact; And (d) forming a copper foil circuit by forming a corrosion pattern on the copper foil on the surface of the laminated substrate.

Hereinafter, a method of embedding an active device according to the present invention will be described in detail with reference to FIGS. 1 and 2.

1A illustrates a semiconductor die to be embedded in a printed circuit board. Referring to FIG. 1A, an aluminum bonding pad 11 is formed on a semiconductor die 10 as a result of a conventional semiconductor process. Subsequently, referring to FIG. 1B, the present invention fabricates a stud bump 20 using existing wire bonding equipment on the aluminum bonding pad 11 on the fabricated semiconductor die 10.

Meanwhile, referring to FIG. 2A, an inner layer substrate in which the semiconductor die 10 is to be built is fabricated, and a substrate such as a copper cladded layer (CCL) coated with copper foil 51 on both surfaces with an insulating layer 50 interposed therebetween. The copper foil circuit 30 is formed by forming a pattern. Referring to Fig. 2B, copper foil circuits are formed on both surfaces of the substrate, and the copper foil of the portion 52 on which the semiconductor die 10 is to be mounted is peeled off. Next, referring to FIG. 2C, the semiconductor die 10 is mounted at a predetermined position 52 of the inner layer PCB substrate 50.

At this time, the semiconductor die 10 is attached by using an adhesive tape or a paste adhesive. At this time, the active side of the semiconductor die on which the stud bumps 20 are formed is mounted so as to face the top of the substrate. This is to electrically conduct between the semiconductor chip and the PCB copper foil pattern in a later process.

Referring to FIG. 2D, the insulating layer 40 is laminated on both upper and lower surfaces of the inner substrate 50 on which the semiconductor die 10 is mounted. In a preferred embodiment of the present invention, the insulating layer 40 laminated to the inner substrate 50 is an insulating film such as Ajinomoto Bonding Film (ABF) of Japan Ajinomoto Co., Ltd., or resin coated copper (RCC) or prepreg. Legs and the like can be placed on a substrate and pressed at high temperature and high pressure.

Referring again to FIG. 2D, the resin contained in the insulating layer 40 during the press lamination process fills the blank section on the inner substrate 50 and the active die 10, and the stud bumps 20 The upper portion is exposed through the portion of the insulating layer 40.

Figure 2e is a view showing a state in which the copper foil plating on the surface of the stud bump 20 is exposed through the insulating layer 40. As a result, the stud bump 20 comes into contact with the copper foil 85 to secure an energized state.

As a preferred embodiment of the present invention, in the step of Figure 2d above, instead of the insulating layer 40, copper foil is already formed on the outer surface when laminated at high temperature and high pressure using an insulating layer coated with copper foil, for example, RCC. Therefore, the stud bump 20 and the copper foil 85 may be in electrical contact with each other, as shown in FIG. 2E, without the additional copper foil plating process.

Finally, referring to FIG. 2F, the copper foil of the outer layer is selectively corroded to form a copper foil circuit, thereby forming a circuit in which the copper foil of the substrate and the semiconductor die are energized with each other.

The foregoing has outlined rather broadly the features and technical advantages of the present invention to better understand the claims of the invention which will be described later. Additional features and advantages that make up the claims of the present invention will be described below. It should be appreciated by those skilled in the art that the conception and specific embodiments of the invention disclosed may be readily used as a basis for designing or modifying other structures for carrying out similar purposes to the invention.

In addition, the inventive concepts and embodiments disclosed herein may be used by those skilled in the art as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. In addition, such modifications or altered equivalent structures by those skilled in the art may be variously evolved, substituted and changed without departing from the spirit or scope of the invention described in the claims.

As described above, the present invention reduces the cost of manufacturing the substrate and reduces the manufacturing cost by allowing the substrate to be electrically connected to the substrate using stud bumps formed on the semiconductor die without a separate via processing process for connecting the semiconductor die to the substrate. There is an advantage to simplify.

Claims (3)

In the method for manufacturing a printed circuit board containing a semiconductor die, (a) forming a stud bump on the bonding pad of the semiconductor die using wire bonding equipment; (b) mounting the substrate of the semiconductor die using an adhesive tape or paste adhesive to expose the stud bumps at a predetermined position of the insulating layer of the inner layer substrate having the copper foil circuit patterned on the semiconductor die having the stud bumps formed thereon; ; (c) laminating a laminate press by aligning an insulating layer on both sides of an inner substrate on which the semiconductor die is mounted, and press laminating the stud bumps to be exposed through the insulating layer; And (d) applying copper foil on the insulating layer so as to conduct electricity through the exposed stud bumps through the insulating layer and forming a copper foil circuit through pattern formation; Active device embedded printed circuit board manufacturing method comprising a. In the method for manufacturing a printed circuit board containing a semiconductor die, (a) forming a stud bump on the bonding pad of the semiconductor die using wire bonding equipment; (b) mounting the substrate of the semiconductor die with an adhesive tape or paste adhesive so that the stud bumps are exposed on the insulating layer of the inner layer substrate having the copper foil circuit patterned on the semiconductor die having the stud bumps formed thereon; (c) Laminating an insulating layer coated with copper foil on both surfaces of the inner layer substrate on which the semiconductor die is mounted, and arranges the insulating layer so as to contact the stud bump, and the stud bump passes through the insulating layer and the copper foil. Press laminating to make contact; And (d) forming a copper foil circuit by forming a corrosion pattern on the copper foil on the surface of the laminated substrate; Active device embedded printed circuit board manufacturing method comprising a. An active element embedded printed circuit board manufactured according to claim 1.

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