TWI506830B - Heat dissipation substrate with insulating heat sink and its manufacturing method - Google Patents

Description

Heat dissipation substrate with insulating heat dissipation layer and manufacturing method thereof

The invention relates to a heat dissipating substrate with an insulating heat dissipating layer and a manufacturing method thereof, in particular to a method for preparing a ceramic substrate by liquefying and then high-pressure spray coating on a surface of a carrier substrate by a plasma spraying method. An insulating heat dissipation layer composed of the material of the ceramic material.

The heat dissipation substrate with the insulating heat dissipation layer of the present invention is suitable for a light emitting diode (LED) package, but is not limited. Therefore, the LED package will be exemplified below. Generally, an LED die can be selected in a flip chip or a wire bond according to the process requirements, but is not limited, and is electrically connected to a heat dissipation substrate to complete an LED package (LED package). The LED package is further connected to a surface of a heat sink of a light-emitting device to form an LED light-emitting device; generally, the conventional heat-dissipating substrate is composed of a circuit layer (copper layer), The insulating layer and a substrate (such as an aluminum substrate or a ceramic substrate) are sequentially formed by pressing, wherein the circuit layer is provided with a suitable pattern in accordance with the layout of the LED die to arrange and provide the LED crystal grains. The positive and negative power supplies are required. When the LED die emits light, heat is generated, and the heat is generally radiated outward by the heat sink and the heat sink of the connected light-emitting device, so as to avoid excessive heat energy accumulation and affect the LED package. Or the efficiency and longevity of the LED lighting device.

In the conventional heat-dissipating substrate, the conventional heat-dissipating substrate is formed by sequentially pressing a circuit layer (copper layer), an insulating layer and an aluminum substrate, so that the generated thermal energy is transmitted through the circuit layer (copper layer) and the insulating layer. After that, it is conducted to the substrate; however, the insulating layer used in the conventional heat-dissipating substrate is mostly composed of a heat-conductive film, and the thermal conductive film has a poor thermal conductivity and a thick thickness, so that the use efficiency of the conventional heat-dissipating substrate can be relatively reduced. Meet the needs of current use. Therefore, in the related fields such as the LED package or the heat dissipation substrate or the LED light-emitting device used, there has been a long-standing problem of how to achieve a good heat dissipation effect of the heat dissipation substrate without causing a short circuit in the circuit layer.

Taking a conventional Flip Chip or Wire Bond LED package as an example, each LED die is electrically connected to a circuit layer by two different electrode contacts. And electrically connected to the connection point; the circuit layer is preset on an aluminum substrate; an insulating bonding layer is usually disposed between the circuit layer and the surface of the aluminum substrate to enable the circuit layer to be insulated and fixed The surface of the aluminum substrate is not easily peeled off; after completion, the LED package is attached to the surface of a heat sink of an LED light-emitting device by various bonding methods such as soldering or close fitting; however, In the above conventional LED package, the insulating connecting layer is generally formed by using a heat dissipating patch or a heat dissipating paste, and has a low thermal conductivity (about 4 W/mk) and a thick thickness (about 60 μm), so that the heat conduction function is not Preferably, the thermal energy generated by the LED dies during illumination cannot be efficiently conducted to the aluminum substrate for heat dissipation.

In the related art of LED packages and the heat-dissipating substrates used therefor, there are various prior art, such as TW573330, TW M350824, CN201010231866.5, US 6,914,268, US 8,049,230, US 7,985,979, US 7,939,832, US 7, 713, 353, US 7,642, 121, US 7,462,861, US 7,393,411, US 7,335,519, US 7,294,866, US 7,087,526, US 5,557,115, US 6,514, 782, US 6,497,944, US 6,791, 119, US 2002/0163302, US 2004/0113156, etc. ; The above prior art does not propose an effective solution to overcome the problem that the heat dissipation substrate does not short-circuit and can achieve good heat dissipation efficiency.

In addition, a micro-arc plasma method (or atmospheric plasma nitridation method, vacuum plasma nitridation method) has been disclosed in the prior art to form an insulating aluminum oxide (Al ₂ O ₃ ) on the surface of an aluminum substrate. Ceramic layer technology, but when the conventional technology is applied to a heat sink substrate for a light emitting diode (LED) package, at least the following disadvantages are caused: first, between the material of the generated ceramic layer and the substrate material used; There is a certain correspondence. For example, when the substrate is an aluminum substrate, the ceramic layer formed is limited to a ceramic layer of aluminum oxide (Al ₂ O ₃ ), which limits the selection of the substrate and the ceramic layer; The ceramic layer is formed by a micro-arc plasma method to penetrate the surface of a substrate (such as an aluminum substrate) to generate oxidation or nitridation with a material of the substrate (such as aluminum) to densely form an oxide (such as alumina). a ceramic layer composed of Al ₂ O ₃ ) or a nitride (such as aluminum nitride AlN), since the oxide or nitride system forms a uniform ceramic film layer between the microarc plasma and the substrate, and is formed as the same Barriers that hinder and affect subsequent oxidation or nitrogen The resulting ceramic layer is relatively thin and cannot be thickened with the insulation withstand voltage requirements of the heat sink substrate. Therefore, the conventional technique of using the micro-arc plasma method to form a ceramic layer on the surface of an aluminum substrate still has the above-mentioned problems and cannot meet the needs of practical use.

It can be seen from the above that the structure of the above prior art is still difficult to meet the requirements of practical use, and therefore there is still a need for further improvement in the related field of LED packaging or heat dissipation substrate. The invention provides a heat dissipation substrate with an insulating heat dissipation layer and a manufacturing method thereof in the field of limited development of the technology, so that the LED package and/or the light-emitting device can achieve good insulation and heat dissipation effects.

The main object of the present invention is to provide a heat dissipation layer with an insulating heat dissipation layer. The substrate and the manufacturing method thereof are suitable for a light-emitting diode (LED) package, which uses a heat-dissipating substrate as a carrier substrate, and the substrate is selected from an aluminum substrate, a magnesium substrate, an aluminum-magnesium alloy substrate, a titanium alloy substrate, a substrate of a copper substrate, a printed circuit board (PCB) type composite substrate having a heat conductive hole; a plasma spraying method using a ceramic material, such as a method selected from the group consisting of atmospheric plasma, vacuum plasma, and low pressure plasma a method of liquefying a ceramic material selected from the group consisting of alumina, magnesia, titania, aluminum nitride, magnesium nitride, titanium nitride, and a high pressure spray coating method according to a predetermined method Spraying time, spraying and coating on at least one predetermined surface of the carrier substrate to form an insulating heat dissipation layer composed of the material of the ceramic material, thereby forming a heat dissipation substrate with an insulating heat dissipation layer, and supplying the LED a package; wherein when the LED die emits light and generates thermal energy, the insulating heat dissipation layer conducts the thermal energy to the carrier substrate to dissipate heat outward, thereby achieving good electrical insulation withstand voltage and heat dissipation work. effect.

In order to achieve the above object, a preferred embodiment of the present invention includes a carrier substrate and at least one insulating heat dissipation layer, wherein the carrier substrate is a substrate for dissipating heat to carry the insulating heat dissipation layer. Wherein the insulating heat dissipation layer is formed on at least one surface of the carrier substrate, which is selected from the group consisting of alumina, magnesia, titania, aluminum nitride, magnesium nitride, and titanium nitride by a plasma spraying method. A ceramic material in the group is first liquefied and then sprayed on the at least one surface of the carrier substrate in a high pressure spray to cover the at least one surface to form an insulating heat dissipation layer composed of the material of the ceramic material.

The heat dissipating substrate, wherein the plasma spraying method liquefies the ceramic material by a method selected from the group consisting of an atmospheric plasma method, a vacuum plasma method, and a low pressure plasma method.

The heat dissipation substrate, wherein the carrier substrate is a metal substrate having a heat dissipation function, and the metal substrate is selected from the group consisting of an aluminum substrate, a magnesium substrate, an aluminum-magnesium alloy substrate, a titanium alloy substrate, and a copper substrate.

The heat dissipation substrate, wherein the carrier substrate is a printed circuit board (PCB) type composite substrate having a heat conductive hole.

The heat dissipation substrate, wherein the ceramic material comprises a wire or a powder.

In the heat dissipation substrate, the thickness of the insulating heat dissipation layer is set in advance according to the degree of electrical insulation withstand voltage desired by the insulation layer.

In the heat dissipation substrate, the thickness of the insulating heat dissipation layer is preset according to the spraying time of the high pressure spray coating on the surface of the carrier substrate.

In the heat dissipation substrate, the thickness of the insulating heat dissipation layer is set to be 1 to 50 micrometers (μm) so that the electrical insulation withstand voltage reaches 300 volts (V) or more.

The heat dissipation substrate, wherein the outer surface of the insulating heat dissipation layer is further provided with a circuit layer formed by a process selected from the group consisting of a printed circuit board (PCB) circuit process, a screen printing process, and a semiconductor process. On the surface of the insulating heat dissipation layer; the circuit layer includes at least two separate and insulated electrical connection points for electrically connecting with the pads of different electrodes provided by the at least one LED die, so that the at least one LED crystal The particles are electrically connected and disposed on the heat dissipation substrate, wherein when the at least one LED die emits light and generates thermal energy, the insulating heat dissipation layer conducts the thermal energy to the carrier substrate to dissipate heat outward.

In order to achieve the above object, a preferred embodiment of the "method for manufacturing a heat dissipating substrate having an insulating heat dissipating layer" comprises the following steps: providing a carrier substrate, the carrier substrate being a heat dissipating substrate; and providing a ceramic material, The ceramic material is selected from the group consisting of alumina, magnesia, titania, aluminum nitride, magnesium nitride, titanium nitride; providing a plasma spraying device for liquefying the above ceramic material; using a high pressure spray Spraying the above-mentioned liquefied ceramic material and pre-predetermined Spraying on a predetermined surface of the carrier substrate to form an insulating heat dissipation layer formed of the material of the ceramic material and having a predetermined thickness on the surface; hardening the insulating heat dissipation layer to complete a predetermined A heat dissipation substrate having a thickness of an insulating heat dissipation layer.

In order to make the present invention more clear and detailed, the structure and technical features of the present invention are detailed as follows:

Referring to FIG. 1-5, which are respectively a schematic cross-sectional view of two embodiments of a heat dissipation substrate having an insulating heat dissipation layer of the present invention (one is a metal substrate, and the other is a printed circuit board type composite substrate), and the application thereof is applied. A schematic cross-sectional view of three embodiments of an LED package and a heat sink surface. The heat dissipation substrate 12 of the present invention comprises a carrier substrate 11 and an insulating heat dissipation layer 12; wherein the carrier substrate 11 is a heat dissipation substrate for carrying the insulating heat dissipation layer 12; wherein the insulating heat dissipation layer 12 is formed thereon. The at least one surface 111 of the carrier substrate 11 is formed by using a plasma spraying device 20 as shown in FIG. 6B to perform a plasma spraying method for selecting an aluminum oxide, magnesium oxide, titanium oxide, aluminum nitride, A ceramic material 30 of the group of magnesium nitride and titanium nitride is first liquefied, and then sprayed on the at least one surface of the carrier substrate 11 as shown in FIG. 6B to be coated on the at least one surface 111. An insulating heat dissipation layer 12 composed of a material of the ceramic material 30.

The heat dissipating substrate 10, wherein the plasma spraying method utilizes a method selected from the group consisting of an atmospheric plasma method, a vacuum plasma method, and a low-pressure plasma method, and utilizes a matching plasma spraying device 20 This ceramic material 30 is liquefied as shown in FIG. 6B.

An embodiment of the heat dissipation substrate 10 shown in FIG. 1 , wherein the carrier substrate 11 is a metal substrate having a heat dissipation function, as shown in FIG. 1 , the metal substrate system It is composed of one substrate selected from the group consisting of an aluminum substrate, a magnesium substrate, an aluminum-magnesium alloy substrate, a titanium alloy substrate, and a copper substrate.

As shown in FIG. 2, the carrier substrate 11 is a printed circuit board (PCB) composite substrate having a heat conducting hole. The carrier substrate 11 includes an insulating substrate 112 and two circuit layers 113. And 114 and at least one heat conducting hole 115. The insulating substrate 112 has upper and lower surfaces. The two circuit layers 113 and 114 are respectively formed on the two surfaces of the insulating substrate 112, and the circuit layer 113 on one surface is provided with at least one LED crystal. The slabs 40 are electrically connected to the heat dissipating substrate 10 to form an LED package as shown in FIG. 5 . The at least one heat conducting hole 115 is disposed between the two surfaces of the insulating substrate 112 . A heat conductive material 116 is disposed in the 115. The LED package may further be combined with a heat sink 70 as shown in FIG. 5; wherein when the LED die 40 emits light and generates thermal energy, the insulating heat dissipation layer 12 is used to insulate the thermal energy from the heat. The circuit layer 113 on one surface of the substrate 112 is conducted to the circuit layer 114 of the other surface to dissipate heat outward, that is, to the carrier substrate 11 (the heat dissipation substrate 10) and the heat sink 70 to dissipate heat outward. In order to achieve good heat dissipation, and avoid the short circuit. An LED die 40 is illustrated in FIG. 5 as an example but is not intended to limit the invention. In addition, the number and position of the heat conducting holes 115 as shown in FIG. 5 are not limited, but the main position of the heat energy generation between the circuit layer 113 and the LED die 40 is electrically connected. Preferably, when the heat conducting holes 115 are disposed close to the heat energy generation, the heat dissipation effect is relatively enhanced.

The heat dissipation substrate 10, wherein the ceramic material 30 comprises a wire or a powder.

In practical applications, the heat-dissipating substrate 10 has a thickness formed according to the degree to which the insulating heat-dissipating layer 12 is to achieve electrical insulation withstand voltage.

In the heat dissipation substrate 10, the thickness of the insulating heat dissipation layer 12 is preset according to the spraying time of the high pressure spray coating on the surface 111 of the carrier substrate 11.

The heat dissipation substrate 10 has a thickness of the insulating heat dissipation layer 12 of 1 to 50 micrometers (μm) so that the electrical insulation withstand voltage reaches 300 volts (V) or more.

The heat dissipation substrate 10 is as shown in FIG. 3-4, wherein a surface layer 13 is further disposed on the outer surface of the heat dissipation layer 12 of the heat dissipation substrate 10, and the circuit layer 13 is processed by using a printed circuit board (PCB) circuit. A process in the group of the screen printing process and the semiconductor process is formed on the surface of the insulating heat dissipation layer 12, and an LED die 40 can be wire-bonded as shown in FIG. 3 or flip-chip (Flip Chip). The method is electrically connected to the heat dissipation substrate 10 to form an LED package 50 as shown in FIG. 3 or a flip chip LED package 60 as shown in FIG. The LED package 50, 60 can be further combined with a heat sink 70; wherein the LED heat sink 12 is used to conduct the thermal energy to the carrier substrate 11 when the LED die 40 emits light and generates thermal energy. And a heat sink 70 to dissipate heat outward. In order to achieve good heat dissipation, and avoid the short circuit. An LED die 40 is illustrated in FIGS. 3-4 as an example but is not intended to limit the invention.

As can be seen from the above, in the heat dissipation substrate 10 of the present invention, the carrier substrate 11 can be selected from the group consisting of an aluminum substrate, a magnesium substrate, an aluminum-magnesium alloy substrate, a titanium alloy substrate, a copper substrate, and a printed circuit board (PCB) composite substrate having a heat conductive hole. a substrate in the group, and the ceramic material 30 may be selected from the group consisting of alumina, magnesium oxide, titanium oxide, aluminum nitride, magnesium nitride, and titanium nitride, and is not affected by the material of the carrier substrate 11. limits. Therefore, the heat dissipation substrate 10 of the present invention has at least the following advantages compared with the conventional technique of forming a ceramic layer by a micro-arc plasma method: First, the material of the insulating heat dissipation layer 12 is not affected by the carrier substrate. 11 material limits, such as magnesium The substrate is used as the carrier substrate 11 and alumina is selected as the ceramic material 30 to form an insulating heat dissipation layer 12 of alumina on the surface of the magnesium substrate, and the carrier substrate 11 and the insulating heat dissipation layer 12 (ceramic material 30) are relatively increased. The selectivity of the material; the other is that the thickness of the insulating heat dissipation layer 12 can be relatively thickened with the increase of the spraying time, which is sufficient to overcome the conventional technology. The thickness of the ceramic layer formed by the micro-arc plasma method is relatively thin and cannot be dissipated with heat. The disadvantage of the thickening resistance of the substrate is required to be thickened.

Referring to FIG. 6A-6C, which are schematic flowcharts of a manufacturing method of the heat dissipation substrate 10 having the insulating heat dissipation layer of the present invention, a preferred embodiment of the method for manufacturing the heat dissipation substrate 10 having the insulating heat dissipation layer of the present invention comprises the following steps. A carrier substrate 11 is provided. As shown in FIG. 6A, the carrier substrate 11 is a heat-dissipating substrate selected from the group consisting of an aluminum substrate, a magnesium substrate, an aluminum-magnesium alloy substrate, a titanium alloy substrate, a copper substrate, and a thermal via. a substrate of a group of printed circuit board (PCB) type composite substrates; providing a ceramic material 30 as shown in FIG. 6B, the ceramic material is selected from the group consisting of alumina, magnesia, titania, aluminum nitride, magnesium nitride, One of the groups of titanium nitride; providing a plasma spraying device 20 as shown in FIG. 6B for liquefying the above-mentioned ceramic material 30; using a plasma spraying method, spraying in a high pressure spray pattern as shown in FIG. 6B. The liquefied ceramic material 30 is sprayed on a predetermined surface 111 of the carrier substrate 11 according to a predetermined spraying time to be coated on the surface 111 to form a material composed of the ceramic material 30 and having a predetermined thickness. Insulating heat sink 12 The insulating heat dissipation layer 12 is hardened to complete the heat dissipation substrate 10 having the insulating heat dissipation layer 12 having a predetermined thickness.

The above are only the preferred embodiments of the present invention, and are merely illustrative and not restrictive. Commonly known in the art It will be appreciated by those skilled in the art that many changes, modifications, and equivalents may be made without departing from the spirit and scope of the invention.

10‧‧‧heated substrate

11‧‧‧Carrier substrate

12‧‧‧Insulated heat sink

111‧‧‧ surface

112‧‧‧Insert substrate

113, 114‧‧‧ circuit layer

115‧‧‧thermal hole

116‧‧‧thermal materials

20‧‧‧Plastic spray equipment

30‧‧‧Ceramic materials

40‧‧‧LED dies

50, 60‧‧‧LED package

70‧‧‧heat sink

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing the structure of an embodiment of a heat dissipating substrate (metal substrate) having an insulating heat dissipating layer according to the present invention.

2 is a cross-sectional view showing the structure of an embodiment of a heat dissipating substrate (printed circuit board type composite substrate) having an insulating heat dissipating layer according to the present invention.

3 is a cross-sectional view showing the structure of an embodiment of the heat sink substrate with an insulating heat dissipation layer applied to the LED package and a heat sink surface of the present invention.

4 is a cross-sectional view showing another embodiment of a heat dissipating substrate having an insulating heat dissipating layer applied to an LED package and a heat sink surface of the present invention.

FIG. 5 is a cross-sectional view showing the structure of a heat dissipating substrate having an insulating heat dissipating layer applied to an LED package and a heat sink surface according to an embodiment of the present invention.

6A-6C are schematic flow diagrams showing a method of manufacturing a heat dissipation substrate having an insulating heat dissipation layer according to the present invention.

10‧‧‧heated substrate

11‧‧‧Carrier substrate

12‧‧‧Insulated heat sink

111‧‧‧ surface

20‧‧‧Plastic spray equipment

30‧‧‧Ceramic materials

Claims (9)

A heat dissipation substrate having an insulating heat dissipation layer for use in a light emitting diode (LED) package, comprising a carrier substrate, an insulating heat dissipation layer, a circuit layer and at least one LED die, wherein: the carrier substrate is a substrate for dissipating heat is used to carry the insulating heat dissipation layer; the insulating heat dissipation layer is formed on a surface of the carrier substrate, and is selected from the group consisting of alumina, magnesia, titania, and aluminum nitride by a plasma spraying method. And a ceramic material of the group of magnesium nitride and titanium nitride is first liquefied, and then sprayed on the at least one surface of the carrier substrate by high pressure spray to form a surface composed of the ceramic material. An insulating heat dissipation layer; the circuit layer is disposed on an outer surface of the insulating heat dissipation layer, the circuit layer comprising at least two separate and insulated electrical connection points for bonding pads of different electrodes provided by the at least one LED die Corresponding to the electrical connection, so that the at least one LED die can be electrically connected and disposed on the heat dissipation substrate; wherein when the at least one LED die emits light and generates thermal energy, the insulating heat dissipation layer is used to conduct the thermal energy to Radiating outwardly to the carrier substrate. The heat-dissipating substrate according to claim 1, wherein the plasma spraying method liquefies the ceramic material by a method selected from the group consisting of an atmospheric plasma method, a vacuum plasma method, and a low-pressure plasma method. . The heat-dissipating substrate according to claim 1, wherein the carrier substrate is a metal substrate having a heat-dissipating effect, and the metal substrate is selected from the group consisting of an aluminum substrate, a magnesium substrate, an aluminum-magnesium alloy substrate, a titanium alloy substrate, and a copper substrate. A substrate consisting of a group of substrates. The heat-dissipating substrate according to claim 1, wherein the carrier substrate is a non-metal substrate having a heat-dissipating effect, and the non-metal substrate is a printed circuit board (PCB) composite substrate having a heat-conducting hole. The heat dissipation substrate of claim 1, wherein the ceramic material comprises a wire or a powder. The heat dissipation substrate according to claim 1, wherein the thickness of the insulating heat dissipation layer is set in advance according to the degree of electrical insulation withstand voltage desired by the insulation layer. The heat dissipation substrate according to claim 1, wherein the thickness of the insulating heat dissipation layer is set in advance according to a spraying time of the high pressure spray coating on the surface of the carrier substrate. The heat dissipation substrate according to claim 1, wherein the thickness of the insulating heat dissipation layer is set to be 1 to 50 micrometers (μm) so that the electrical insulation withstand voltage reaches 300 volts (V) or more. The heat-dissipating substrate according to claim 1, wherein the circuit layer is formed in the insulating heat dissipation layer by using a process selected from the group consisting of a printed circuit board (PCB) circuit process, a screen printing process, and a semiconductor process. On the surface.