KR101220940B1 - Printed circuit board for heat dissipation and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a heat radiation circuit board and a method of manufacturing the same.
That is, the heat dissipation circuit board of the present invention includes a prepreg; A circuit pattern comprising a first copper foil and a first copper plating layer sequentially formed on an upper surface of the prepreg, and having a first space formed by selectively etching the first copper foil and the first copper plating layer; A heat dissipation pattern including a second copper foil and a second copper plating layer sequentially formed on the lower surface of the prepreg, and having a second space formed by selectively etching the second copper foil and the second copper plating layer; Conductive paste is formed in the through-hole penetrating the first copper foil and the prepreg.

Description

Heat dissipation circuit board and its manufacturing method {Printed circuit board for heat dissipation and method for manufacturing the same}

The present invention relates to a heat radiation circuit board and a method of manufacturing the same.

In recent years, LEDs have been applied as backlight light sources of LED televisions, backlight light sources of LCD monitors, light sources of LED illuminators, light sources of automobile headlights, and outdoor landscape light sources.

LED light source has many advantages over conventional light sources in terms of power consumption, lifespan, color rendering, etc., but when the temperature of the LED increases due to the generated heat, the luminous efficiency is lowered, color shift is generated, and the life is shortened. There is a disadvantage.

Therefore, increasing the heat dissipation efficiency of the LED is one of the requirements for improving the reliability and lifetime of the device.

The present invention is to solve the problem that can increase the heat radiation efficiency.

The present invention,

Prepreg;

A circuit pattern comprising a first copper foil and a first copper plating layer sequentially formed on an upper surface of the prepreg, and having a first space formed by selectively etching the first copper foil and the first copper plating layer;

A heat dissipation pattern including a second copper foil and a second copper plating layer sequentially formed on the lower surface of the prepreg, and having a second space formed by selectively etching the second copper foil and the second copper plating layer;

A heat dissipation circuit board including a conductive paste formed in a through hole penetrating the first copper foil and the prepreg is provided.

The circuit pattern includes a heat transfer pad and an electrode pad to which a heat sink slug of the semiconductor package contacts, and the heat release pattern includes a heat release pad corresponding to the heat transfer pad. The conductive paste is connected to the heat transfer pad and the heat release pad.

In addition, the size of the heat release pad is larger than the size of the heat transfer pad.

The heat dissipation circuit board further includes an insulating layer formed in the first space.

In addition, the thickness of the said 2nd copper foil is thicker than the thickness of the said 1st copper foil.

The present invention,

Pressing the prepreg and the first copper foil;

Forming a through hole in the compressed prepreg and the first copper foil;

Pressing a second copper foil on the prepreg;

Filling a conductive paste into the through hole;

Forming a first copper plating layer on the first copper foil, and forming a second copper plating layer on the second copper foil;

Selectively etching the first copper foil and the first copper plating layer to form a circuit pattern, and selectively etching the second copper foil and the second copper plating layer to form a heat transfer pattern. A method for producing is provided.

In the heat dissipation circuit board of the present invention, as described above, the heat transferred through the heat transfer pad in contact with the heat sink slug of the semiconductor package is discharged from the heat release pad exposed to the outside through the conductive paste, so that the heat conduction of the conductive paste is performed. The heat dissipation characteristics are determined by the characteristics, and the heat dissipation efficiency is structurally increased.

In addition, the heat dissipation circuit board of the present invention does not use a heavy aluminum plate, there is an effect that can reduce the weight of the substrate.

In addition, the heat dissipation circuit board according to the present invention has an effect suitable for mounting a high-power LED chip widely used as a backlight light source of an LED television, a backlight light source of an LCD monitor, a light source of an LED lighting device, a light source of an automobile headlight, an outdoor landscape light source, and the like. have.

1 is a schematic cross-sectional view for explaining a heat radiation circuit board according to the present invention
2A to 2F are schematic cross-sectional views illustrating a method of manufacturing a heat dissipation circuit board according to the present invention.
3 is a schematic cross-sectional view for explaining an example of a heat dissipation circuit board according to the present invention.
4 is a schematic plan view for explaining a positional arrangement of a heat transfer pad and a heat release pad to which a heat sink slug contacts a heat radiation circuit board according to the present invention;
5 is a schematic cross-sectional view for explaining an example of a heat radiation circuit board according to the present invention.
6 is a schematic cross-sectional view for explaining a comparative example of a heat dissipation circuit board according to the present invention.
7A and 7B are schematic cross-sectional views illustrating other examples of a heat dissipation circuit board according to the present invention.
8 is a schematic cross-sectional view for explaining an example of the LED heat dissipation system to which the heat dissipation circuit board according to the present invention is applied.
9 is a schematic cross-sectional view for explaining another example of the LED heat dissipation system to which the heat dissipation circuit board according to the present invention is applied.

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

1 is a schematic cross-sectional view for describing a heat dissipation circuit board according to the present invention.

The heat dissipation circuit board according to the present invention includes a prepreg (100); It consists of a first copper foil 110 and a first copper plating layer 161 sequentially formed on the upper surface of the prepreg 100, the first copper foil 110 and the first copper plating layer 161 is selectively etched A circuit pattern 172 having a first space 171 formed thereon; The second copper foil 130 and the second copper plating layer 162 sequentially formed on the lower surface of the prepreg 100, the second copper foil 130 and the second copper plating layer 162 selectively etched A heat dissipation pattern 182 having a second space 181 formed thereon; And a conductive paste 150 formed in the through hole 120 penetrating through the first copper foil 110 and the prepreg 100.

The circuit pattern 172 includes a heat transfer pad to which a heat sink slug of a semiconductor package mounted on a heat dissipation circuit board is in contact, and an electrode pad electrically connected to the semiconductor package.

In addition, the circuit pattern 172 may also include an electrode line.

At this time, most of the heat generated in the semiconductor package escapes to the heat transfer pad.

The heat dissipation pattern 182 may include heat dissipation pads corresponding to the heat transfer pads.

In addition, the heat transfer pad includes the conductive paste 150, and the conductive paste 150 is in contact with the heat release pad.

That is, the conductive paste 150 is connected to the heat transfer pad and the heat release pad.

Therefore, heat generated in the semiconductor package is transferred to the heat transfer pad through the heat sink slug, and the heat transfer pad transfers heat to the heat release pad through the conductive paste 150, and the heat It is released to the outside from the release pad.

The semiconductor package may be a package in which a high output LED chip is mounted.

Therefore, the heat dissipation circuit board according to the present invention has a merit suitable for mounting a high power LED chip widely used as a backlight light source of an LED television, a backlight light source of an LCD monitor, a light source of an LED lighting device, a light source of an automobile headlight, a light source for outdoor landscape, and the like. have.

Meanwhile, the thicknesses of the first and second copper foils 110 and 130 may be configured to be 35 μm to 70 μm.

The thickness of the prepreg 100 may be applied to approximately 0.1㎛.

2A to 2F are schematic cross-sectional views illustrating a method of manufacturing a heat dissipation circuit board according to the present invention.

In the method for manufacturing a heat dissipation circuit board according to the present invention, first, the prepreg 100 and the first copper foil 110 are pressed.

Thereafter, a through hole 120 is formed in the compressed prepreg 100 and the first copper foil 110 (FIG. 2B).

Then, the 2nd copper foil 130 is crimped | bonded to the said prepreg 100. (FIG. 2C)

Here, the second copper foil 130 is pressed into the prepreg 100, so that the through hole 120 becomes a blind hole, but will also be described below in the compressed prepreg 100 and the first copper foil. Since it penetrates 110, it is referred to as a through hole '120'.

Next, the conductive paste 150 is filled in the through hole 120 (FIG. 2D).

The conductive paste 150 is preferably a paste in which copper particles are dispersed.

Subsequently, a first copper plating layer 161 is formed on the first copper foil 110, and a second copper plating layer 162 is formed on the second copper foil 130 (FIG. 2E).

Subsequently, the first copper foil 110 and the first copper plating layer 161 are selectively etched to form a circuit pattern 172, and the second copper foil 130 and the second copper plating layer 162 are etched. It is selectively etched to form a heat transfer pattern 182 (FIG. 2F).

The first copper foil 110 and the first copper plating layer 161 are selectively removed to form a first space 171, and the second copper foil 130 and the second copper plating layer 162 are selectively removed. The second space 181 is formed to be removed.

Therefore, manufacture of the heat radiation circuit board of the present invention as shown in FIG. 1 is completed.

After the process of FIG. 2F, a process of forming an insulating layer in the first space 171 between the circuit patterns 172 may be further included.

In addition, after the process of forming the insulating layer in the first space 171 between the circuit pattern 172, to prevent corrosion of the copper surface on the circuit pattern 172 exposed to the insulating layer, when mounting the LED package In order to improve solder spreadability, a process of performing an organic solderability preservation (OSP) process may be further included.

In addition, since the first and second copper foils 110 and 130 are thermocompressed with the prepreg 100, the thickness of the second copper foil 130 is preferably thicker than the thickness of the first copper foil 110.

3 is a schematic cross-sectional view for explaining an example of a heat dissipation circuit board according to the present invention, Figure 4 is a positional arrangement of the heat transfer pad and the heat dissipation pad contacting the heat sink slug of the heat dissipation circuit board according to the present invention It is a schematic plan view for demonstrating, FIG. 5 is a schematic sectional drawing for demonstrating an example of the heat radiation circuit board which concerns on this invention.

The heat dissipation circuit board according to the present invention may be used as a substrate on which a plurality of semiconductor packages are mounted.

In this case, as shown in FIG. 3, the heat dissipation circuit board 200 includes a set of the above-described heat transfer pads 210 and electrode pads 211 arranged around the heat transfer pads 210. Plural arrays may be provided.

In other words, the circuit pattern of the heat dissipation circuit board 200 includes an array of sets of heat transfer pads and electrode pads.

In addition, as shown in FIG. 4, the heat transfer pad 172a and the heat release pad 182a are positioned to correspond to each other, and the size of the heat release pad 182a may be larger than that of the heat transfer pad 172a. Can be.

That is, the size of the heat dissipation pad 182a may be designed to maximize the area in the range where no electric short occurs, thereby improving heat dissipation efficiency.

In addition, as an example of the heat dissipation circuit board according to the present invention, the insulating layer 175 may be formed in the first space 171 that divides the circuit pattern.

Here, the insulating layer 175 may be formed by printing with insulating ink on the entire upper portion of the heat dissipation circuit board except for the heat transfer pad 210 and the electrode pad 211.

6 is a schematic cross-sectional view for explaining a comparative example of a heat radiation circuit board according to the present invention.

The comparative example of the heat radiation circuit board which concerns on this invention has a structure in which the prepreg layer 11 and the copper foil layer 12 which is a circuit pattern are laminated | stacked on the aluminum plate 10 like FIG.

Since the heat dissipation characteristics of the heat dissipation circuit board of this comparative example largely depend on the thermal conductivity of the prepreg layer 11, developing a material of the prepreg having a relatively high thermal conductivity becomes an essential requirement for excellent heat dissipation.

In addition, since the alumina filler is mixed in order to increase the thermal conductivity of the prepreg layer 11, the raw material is expensive and the weight of the aluminum plate 10 is heavy.

In addition, due to the burr generated during the external router processing, a leakage current flows between the copper foil layer 12 and the aluminum plate 10, resulting in short circuiting and electrical breakdown voltage. There is this.

On the other hand, the heat dissipation circuit board of the present invention, as described above, the heat transferred through the heat transfer pad in contact with the heat sink slug of the semiconductor package is discharged from the heat dissipation pad exposed to the outside through the conductive paste, it is conductive The heat dissipation characteristics are determined by the heat conduction characteristics of the paste, and structurally, the heat dissipation efficiency can be improved.

In addition, the heat dissipation circuit board of the present invention does not use a heavy aluminum plate, as in the comparative example, there is an advantage that the weight of the substrate can be reduced.

7A and 7B are schematic cross-sectional views for describing other examples of a heat dissipation circuit board according to the present invention.

In the heat dissipation circuit board according to the present invention, as shown in FIG. 7A, the conductive paste 150 may be embedded only in the heat transfer pad 210 to which the heat sink slug of the semiconductor package contacts, and as shown in FIG. 7B, the heat transfer pad ( The conductive pastes 151, 152, and 153 may be embedded in the 210 and the electrode pad 211.

In the heat dissipation circuit board of FIG. 7B, conductive pastes 152 and 153 are also embedded in the electrode pads 211 electrically bonded to the leads of the semiconductor package, and heat transmitted through the leads of the semiconductor package is transferred to the electrodes. The pads 211 and the conductive pastes 152 and 153 embedded therein are discharged to the outside through the heat transfer pattern under the heat dissipation circuit board.

8 is a schematic cross-sectional view for explaining an example of the LED heat dissipation system to which the heat dissipation circuit board according to the present invention is applied, and FIG. 9 is a schematic view for explaining another example of the LED heat dissipation system to which the heat dissipation circuit board according to the present invention is applied. It is a cross section.

In the LED heat dissipation system, an LED semiconductor package is mounted so that heat generated from the LED semiconductor package can be smoothly discharged through the heat dissipation circuit board.

First, in the LED heat dissipation system of FIG. 8, an LED semiconductor package is mounted on the heat dissipation circuit board of FIG. 7A, and the LED heat dissipation system of FIG. 8 is an LED semiconductor package mounted on the heat dissipation circuit board of FIG. 7B.

The LED semiconductor package includes a heat sink slug 510; An LED chip 520 mounted on the heat sink slug 510; A lead 530 wire bonded to the LED chip 520; A molding part 550 is formed to expose a portion of the lead 530 and encapsulate the LED chip 520.

In this case, the heat sink slug 510 is exposed to the molding part 550, and when the LED semiconductor package is mounted on a heat dissipation circuit board, the heat sink slug 510 contacts the heat transfer pad 210. do.

Here, an adhesive having excellent heat transfer may be interposed between the heat sink slug 510 and the heat transfer pad 210.

In addition, an area of the lead 530 exposed to the molding part 550 is bonded to the electrode pad 211 of the heat dissipation circuit board by soldering.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (6)

Prepreg;
A circuit pattern comprising a first copper foil and a first copper plating layer sequentially formed on an upper surface of the prepreg, and having a first space formed by selectively etching the first copper foil and the first copper plating layer;
A heat dissipation pattern including a second copper foil and a second copper plating layer sequentially formed on the lower surface of the prepreg, and having a second space formed by selectively etching the second copper foil and the second copper plating layer;
Conductive paste is formed in the through-hole penetrating the first copper foil and the prepreg,
In the circuit pattern,
A heat transfer pad and an electrode pad to which a heat sink slug of the semiconductor package is contacted,
In the heat dissipation pattern,
A heat dissipation pad corresponding to the heat transfer pad is included,
The conductive paste,
A heat dissipation circuit board connected to the heat transfer pad and the heat release pad.

delete The method according to claim 1,
The size of the heat release pad,
A heat dissipation circuit board larger than the size of the heat transfer pad.
The method according to claim 1,
The heat dissipation circuit board further comprising an insulating layer formed in the first space.
The method according to claim 1,
The thickness of the said 2nd copper foil,
A heat radiation circuit board thicker than the thickness of said first copper foil.
Pressing the prepreg and the first copper foil;
Forming a through hole in the compressed prepreg and the first copper foil;
Pressing a second copper foil on the prepreg;
Filling a conductive paste into the through hole;
Forming a first copper plating layer on the first copper foil, and forming a second copper plating layer on the second copper foil;
Selectively etching the first copper foil and the first copper plating layer to form a circuit pattern, and selectively etching the second copper foil and the second copper plating layer to form a heat transfer pattern. Method of preparation.

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