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Title:
A PCB-MOUNTED RADIATOR AND AN LED PACKAGE USING THE PCB, AND THE MANUFACTURING METHOD THEREOF
Document Type and Number:
WIPO Patent Application WO/2005/083807
Kind Code:
A1
Abstract:
A printed circuit board includes a substrate on which an insertion hole and a circuit are formed, and a metal dissipating plate fixedly inserted in the insertion hole. A light emitting diode package may be made using the printed circuit board, including a plastic printed circuit board provided with an insertion hole and a circuit portion; a light emitting diode chip emitting light when an electric signal is applied thereto from the circuit portion; a dissipating plate fixedly inserted in the insertion hole, the light emitting diode chip being mounted on the dissipating plate; a light reflector/collector for collecting/reflecting light emitted from the light emitting diode chip; a bonding wire for electrically connecting the circuit portion to the light emitting diode chip; and an epoxy resin molded on the board to protect the chip and the wire.

Inventors:
PARK CHAN-IK (KR)
KIM JAI-WON (KR)
OH DAE-GEUN (KR)
LEE MYEONG-KEUN (KR)
Application Number:
PCT/KR2004/000987
Publication Date:
September 09, 2005
Filing Date:
April 29, 2004
Export Citation:
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Assignee:
LUXPIA CO LTD (KR)
PARK CHAN-IK (KR)
KIM JAI-WON (KR)
OH DAE-GEUN (KR)
LEE MYEONG-KEUN (KR)
International Classes:
H01L23/36; H01L23/367; H01L23/42; H01L33/64; H05K1/02; H05K3/40; (IPC1-7): H01L33/00; H01L23/42
Foreign References:
JPH0786456A1995-03-31
JP2002353515A2002-12-06
JP2003092011A2003-03-28
JPH10303464A1998-11-13
Attorney, Agent or Firm:
YOU ME PATENT & LAW FIRM (825-33 Yoksam-dong Kangnam-Ku, Seoul 135-080, KR)
Download PDF:
Claims:
What is claimed is:
1. A printed circuit board comprising: a substrate on which an insertion hole and a circuit are formed; and a metal dissipating plate fixedly inserted in the insertion hole.
2. The printed circuit board of claim 1, wherein a plating layer is formed covering edges of the insertion hole and top and bottom surfaces of the dissipating plate, thereby making the dissipating plate integrated with the substrate.
3. The printed circuit board of any one of claims 1 and 2, wherein the printed circuit board is used as a package base element.
4. The printed circuit board of any one of claims 1 and 2, wherein the dissipating plate is provided with a reflecting groove for reflecting light.
5. A light emitting diode package comprising: a plastic printed circuit board provided with an insertion hole and a circuit portion; a light emitting diode chip emitting light when an electric signal is applied from the circuit portion; a dissipating plate fixedly inserted in the insertion hole, the light emitting diode chip being mounted on the dissipating plate ; means for collecting and reflecting light emitted from the light emitting diode chip; a bonding wire for electrically connecting the circuit portion to the light emitting diode chip; and epoxy resin molded on the board to protect the chip and the wire.
6. The light emitting diode package of claim 5, wherein the means for collecting and reflecting light comprises a reflecting groove formed on the dissipating plate.
7. The light emitting diode package of claim 5, wherein the printed circuit board is provided with a through hole for electrically connecting a top with a bottom.
8. A method for making a printed circuit board, comprising the steps of: forming an insertion hole on a substrate on both surfaces of which a copper layer is formed; inserting a metal dissipating plate in the insertion hole ; forming a first plating layer on the substrate to cover the dissipating plate ; etching the plating layer and the copper layer to form a circuit portion; and forming a second plating layer on the circuit portion, the plating layer being formed of metal used for soldering or wirebonding.
9. The method of claim 8, wherein a through hole for electrically connecting top and bottom of the board is formed simultaneously with forming of the insertion hole.
10. The method of claim 9, wherein a resin layer is formed covering the through hole to block a physical path of the through hole.
Description:
A PCB-MOUNTED RADIATOR AND AN LED PACKAGE USING THE PCB, AND THE MANUFACTURING METHOD THEREOF BACKGROUND OF THE INVENTION a) Field of the Invention The present invention relates to a plastic printed circuit board (PCB), and more particularly, to a high heat-dissipating PCB that can improve the reliability and productivity by installing a dissipating plate therein, connecting the heat-dissipating plate to a circuit part by plating them together, and increasing a sealing property of a boarder area of a dissipating plate insertion portion, and to a semiconductor package using the PCB and a method for making the PCB. b) Description of the Related Art A PCB is formed of material that is enhanced in heat-resistance, and with a precise circuit-forming technology, and it has been used as a substrate element of a semiconductor package replacing a prior lead frame/ceramic package assembly in addition to its inherent use as a substrate for mounting a separate semiconductor package.

When the PCB is used as the substrate of the semiconductor package, the semiconductor package can be small-sized, and makes it easy to install a compound circuit. Furthermore, the process for making the semiconductor package can be simplified, saving manufacturing costs.

However, when the PCB is formed of plastic, and is used as a substrate for mounting a separate semiconductor chip, it has a disadvantage in terms of heat- dissipating efficiency as compared with a lead frame/ceramic substrate assembly.

Therefore, plastic is excluded from material lists for a semiconductor package requiring a high-dissipating property.

Fig. 1 shows a conventional PCB with a dissipating plate.

A PCB 2 is provided with a plurality of minute holes 3 for mounting a semiconductor chip 1. A dissipating path 4 is formed on an inner wall of each of the minute holes. The dissipating path 4 extends from a front surface to a rear surface of the PCB, being formed by plating electroless copper. After the dissipating path 4

is formed, the minute holes 3 are filled with epoxy resin 5, which may be mixed with conductive material. The electroless copper plating portion 6 is formed on front and rear surfaces of the holes 3 filled with the epoxy resin 5, thereby realizing the dissipating means on the PCB. However, it is difficult to make this type of the dissipating structure, and furthermore, the holes are too minute to obtain a sufficient dissipating effect.

Fig. 2 shows another prior art. As a dissipating means, a dissipating plate 7 formed of, for example, aluminum is attached on a PCB 8. An electric circuit is formed on the dissipating plate 7 of the PCB 8, while being insulated from the dissipating plate. Therefore, the top and bottom of the dissipating plate 7 are electrically insulated from each other and the circuit cannot extend to the bottom, so it is very difficult to install an outer terminal for realizing a semiconductor package.

In other prior arts, a separated metal dissipating plate is prepared and attached on the PCB through a screw, solder, or adhesive method.

SUMMARY OF THE INVENTION Accordingly, it is an objective of the present invention to provide a high dissipating PCB integrally provided at a surface with a dissipating plate to be effectively applied to a semiconductor package, solving the problems of the prior arts.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment (s) of the invention, and together with the description serve to explain the principles of the invention. In the drawings: Fig. 1 is a sectional view of a PCB where a conventional dissipating structure is applied; Fig. 2 is a sectional view of a PCB where another conventional dissipating structure is applied; Fig. 3 is a sectional view of a PCB with a dissipating plate according to a preferred embodiment of the present invention;

Figs. 4a through 4g, are sectional views illustrating a series of processes for making a PCB according to a preferred embodiment of the present invention; and Fig. 5 is a sectional view of an LED package according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Accordingly, it is an objective of the present invention to provided a high heat-dissipating PCB that can improve reliability and productivity by installing a dissipating plate therein, connecting the heat-dissipating plate to a circuit part by plating them together, and increasing a sealing property of a boarder area of a dissipating plate insertion portion, and to provide a method for making the PCB and the semiconductor package with the PCB.

It is another objective of the present invention to provide a semiconductor package using the PCB, and more particularly, to provide a semiconductor package with heat dissipating, light collecting, and light reflecting functions to provide a high brightness property.

To achieve the above objectives, the present invention provides a printed circuit board includes a substrate on which an insertion hole and a circuit are formed, and a metal dissipating plate fixedly inserted in the insertion hole. The insertion portion is plated to enhance a seal effect.

According to another aspect of the present invention, there is provided a light emitting diode package as a semiconductor package that may be made using the printed circuit board. The light emitting diode package comprises a plastic printed circuit board provided with an insertion hole and a circuit portion; a light emitting diode chip emitting light when an electric signal is applied from the circuit portion; a dissipating plate fixedly inserted in the insertion hole, the light emitting diode chip being mounted on the dissipating plate ; a light reflector/collector for collecting/reflecting light emitted from the light emitting diode chip; a bonding wire for electrically connecting the circuit portion to the light emitting diode chip; and epoxy resin molded on the board to protect the chip and the wire.

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Fig. 3 shows a PCB with a dissipating plate according to a preferred embodiment of the present invention. In the drawing, a dissipating plate is inserted in an insertion hole, but is not inserted in another insertion hole.

As shown in the drawing, the inventive PCB 10 comprises an insertion hole 11 in which a dissipating plate is inserted; a through hole 12 through which circuits formed on top and bottom surfaces are electrically connected to each other; a dissipating plate 13 forcedly fitted in the insertion hole 11; a copper layer 14 formed under all circuits, including edges of the top and bottom surfaces and an edge of the insertion hole 11; plating layers 15 and 16 covering the dissipating plate 13, the copper layer 14, and the inner wall of the through hole 12; and a resin shielding layer for covering a predetermined width of the through hole 12 to block a physical path formed through the through hole 12.

The plating layer 15 covers the entire surface of the PCB including top and bottom surfaces of the dissipating plate, before the circuit portion is formed by etching the copper layer 14. The plating layer 16 is used for bonding a wire, being plated on the circuit portion after the circuit portion is formed by etching.

Figs. 4a through 4g show sectional views of a series of processes for making a PCB according to the present invention.

Referring first to Fig. 4a, a base substrate P on which the copper layer 14 is formed is first prepared. As shown in Fig. 4b, the insertion hole 11 in which the dissipating plate is inserted and the through hole 12 for electrically connecting the top and bottom surfaces of the substrate P are formed on the base substrate P.

As shown in Fig. 4c, the dissipating plate 13 prepared through a separate process is inserted in the insertion hole 11. At this point, the outer circumference of the dissipating plate 13 closely contacts the inner wall of the insertion hole 11 through a forced fitting process. A thickness of the dissipating plate 13 is identical to that of the substrate P on which the copper layer 14 is formed.

As shown in Fig. 4d, in a state where the dissipating plate 13 is inserted in the insertion hole 13 of the base substrate P, the electroless plating layer 15 is formed covering an entire surface of the base substrate P including the top and bottom surfaces of the dissipating plate 13 and the inner wall of the through hole 12.

Accordingly, all of the gaps and grooves formed on the base plate are filled with the plating layer 15 to realize partial flattening. In addition, the plating layer 15 is electrically physically connected to the copper layer 14 formed on the top and bottom of the dissipating plate 13.

Therefore, the dissipating plate is integrated with the base substrate P. As shown in Fig. 4b, a circuit portion E is formed on the substrate through a wet etching process using a photo resist.

The circuit portion E includes an edge contacting the dissipating plate 13, an edge contacting the through hole 12, and a circuit wire extending from a top edge of the through hole for wire bonding.

As shown in 4f, the metal plating layer 16 is formed covering the circuit portion E. Preferably, the metal plating layer 16 rnay be formed of gold. When the PCB is applied as a package of an LED chip, the metal plating layer is preferably formed of silver having an effective optical reflection rate. Preferably, before the metal plating layer 16 is formed, a nickel plating layer is formed as a barrier with respect to the copper layer formed under the circuit portion.

As shown in Fig. 4g, the resin layer 17 for covering the through hole 12 to block the physical path of the through hole 12 is formed, thereby completing the manufacturing process of the PCB. The resin layer 17 can be easily formed through a process for developing the photo resist resin layer and hardening the resin layer.

Fig. 5 shows an LED package where the PCB with the dissipating plate according to the present invention is applied.

The LED package comprises a PCB having a dissipating plate 13 provided with a reflecting groove 18; an LED chip 19 attached on a bottom of the reflecting groove 18 by thermal conductive adhesive; a bonding wire 20 for bonding the LED chip 19 on the circuit portion of the LED chip 19; a transparent epoxy resin 21 molded on the PCB to protect the LED chip and the wire from outer impact or moisture; and a through hole 12 for connecting the top and bottom circuit portion of the PCB. The through hole 12 is cut along a cutting line 22.

The PCB 10 with the dissipating plate 13 is prepared according to the above- described present invention. However, the dissipating plate 13 is provided with a reflecting groove 18. Accordingly, since the dissipating plate 13 is provided with

the reflecting groove 18, the dissipating plate functions to collect light and dissipate heat, thereby realizing a high luminescent LED package.

As another embodiment of the present invention, the dissipating plate 13 is forcedly fitted in an insertion hole to form a variety of dissipating paths of a chip mounting portion regardless of the formation of the reflecting groove, the thickness and shape of the base substrate P, and the number of insertions in a single unit of the base substrate.

The inventive PCB 10 with the dissipating plate 13 can be utilized as a high- dissipating package of an electronic device including a variety of semiconductor devices as well as the LED chip 19.

In addition, the dissipating plate 13 can be provided on a surface-mounting type of substrate to provide high dissipating efficiency.

According to the present invention, since the metal dissipating plate is provided on the PCB in a tight seal state, the application can be enhanced as a semiconductor package device requiring the high dissipation.

Particularly, by forming an optical reflecting groove, a high luminescent LED package that can simultaneously realize light collection and heat dissipation can be provided. Therefore, the productivity, quality, and function of the application can be improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.