CN108878617B

CN108878617B - LED (light emitting diode) special-shaped heat dissipation substrate and preparation method and application thereof

Info

Publication number: CN108878617B
Application number: CN201710321310.7A
Authority: CN
Inventors: 张佑专; 张冕; 汪洋; 宋延林
Original assignee: Institute of Chemistry CAS
Current assignee: Institute of Chemistry CAS
Priority date: 2017-05-09
Filing date: 2017-05-09
Publication date: 2020-04-24
Anticipated expiration: 2037-05-09
Also published as: CN108878617A

Abstract

The invention relates to the technical field of LEDs, and discloses an LED special-shaped heat dissipation substrate and a preparation method and application thereof. The substrate comprises a non-flat heat dissipation metal layer, a printed function adjustment layer, a printed conductive layer and a protective layer sequentially stacked from bottom to top; A method for preparing the above-mentioned LED special-shaped heat-dissipating substrate is disclosed. The method includes the following steps: (1) providing a metal substrate with a non-plate type structure as a non-plate type heat-dissipating metal layer, and optionally in the non-plate type heat-dissipating metal layer. forming an oxide layer on the flat surface; (2) forming a printing function adjustment layer on the plate obtained in step (1), and then performing a first heat treatment; (3) forming a printed conductive layer on the heat-treated printing function adjustment layer by printing layer, and then perform a second heat treatment; (4) forming a protective layer on the heat-treated printed conductive layer. The invention double improves the heat dissipation of the LED substrate, the LED works stably, has a long service life, and has a simple preparation process and is environmentally friendly.

Description

LED (light emitting diode) special-shaped heat dissipation substrate and preparation method and application thereof

Technical Field

The invention relates to the technical field of LEDs, in particular to an LED special-shaped heat dissipation substrate and a preparation method and application thereof.

Background

Through the development of many years, the LED technology is more and more applied to daily life, and especially, the application of the LED lighting technology is more and more diversified. Because of the characteristics of energy conservation, safety, long service life, quick response and the like, the LED illumination becomes the mastery force of the new generation illumination. Among them is the ever-increasing market demand for high power LEDs. However, the light conversion efficiency of the LED is low and is only 15-20%, a large amount of heat can be generated, and the light emitting efficiency and the service life of the LED can be guaranteed only by timely and fast guiding out the heat. This requires that the LED substrate has good thermal conductivity, i.e., good heat dissipation performance.

In the existing market, a method for improving the heat dissipation performance of an LED substrate generally arranges a separate heat sink for the LED substrate in a manner of externally connecting the heat sink, such as riveting, grooving, embedding, and adhering, so as to improve the heat dissipation performance of the LED substrate.

In addition, the conventional LED substrate mainly has four layers: the metal layer, the heat conduction insulating layer, the conducting layer and the solder mask and character layer. The heat-conducting insulating layer has the greatest influence on the heat-conducting property of the LED substrate, the existing heat-conducting insulating layer is mainly formed by bonding and mixing epoxy resin, polyolefin resin or polyimide resin with inorganic material particle fillers such as aluminum oxide and aluminum nitride, and although the resin or high polymer material has good insulating and bonding curing effects, the defect of low heat dissipation caused by poor heat-conducting property is overcome, and the application of the heat-conducting property of the aluminum substrate is greatly limited; on the other hand, the conductive layer of the conventional substrate is mainly manufactured by a conventional process for etching copper, and a series of process steps such as film formation, exposure, development, etching, elution and the like are required, so that the process is commonly referred to as a subtractive process in the field, a large amount of acid and the like are required in the conventional process, and the conventional process not only has chemical pollution, but also has a complicated whole process flow.

Disclosure of Invention

The invention aims to solve the problems that in the prior art, the heat dissipation performance of an LED substrate is poor, a large amount of chemical pollution exists in the process of preparation, the process flow of the preparation process is complex, and the heat dissipation effect is still poor after an external radiator is adopted on the LED substrate.

In order to achieve the above object, the present invention provides an LED special-shaped heat dissipation substrate, wherein the LED special-shaped heat dissipation substrate includes a non-flat heat dissipation metal layer, a printing function adjustment layer, a printing conductive layer, and a protection layer, which are sequentially stacked from bottom to top.

The invention also provides a method for preparing the LED special-shaped heat dissipation substrate, which comprises the following steps:

(1) providing a metal substrate with a non-flat plate type structure as a non-flat plate type heat dissipation metal layer, and optionally forming an oxide layer on the flat surface of the non-flat plate type heat dissipation metal layer;

(2) forming a printing function adjusting layer on the plate obtained in the step (1), and then carrying out first heat treatment;

(3) forming a printing conductive layer on the printing function adjusting layer subjected to the heat treatment by printing, and then performing a second heat treatment;

(4) and forming a protective layer on the heat-treated printed conductive layer.

The invention also provides application of the LED special-shaped heat dissipation substrate as a lighting base material.

According to the LED special-shaped heat dissipation substrate, the integrally formed heat dissipation structure is arranged on the LED substrate, and the heat dissipation structure can avoid the use of a heat conducting agent with poor heat conducting performance and the like, so that the heat inside the LED substrate is effectively dissipated, the junction temperature of the central chip of the LED is reduced, the LED works more stably, and the service life of the LED is longer.

According to the LED special-shaped heat dissipation substrate, the printing function adjusting layer is formed on the surface of the non-flat plate type heat dissipation metal layer by a method of printing the high-heat-conductivity inorganic material, the printing function adjusting layer can meet the basic insulating property of the LED substrate, and can meet the requirements of temperature resistance stability and wettability of ink during printing, so that the ink cannot be infiltrated to the metal surface during printing, and the quality and the use safety of the LED substrate are ensured; in addition, the high-thermal-conductivity inorganic material is used for replacing resin or high polymer material with poor heat conductivity, so that the heat dissipation of the LED is facilitated, the heat dissipation performance of the LED substrate is effectively improved, and the service life of the LED is prolonged.

According to the LED special-shaped heat dissipation substrate, the integrally formed heat dissipation structure is arranged on the non-flat plate type heat dissipation metal layer of the LED, and the printing function adjusting layer is arranged, so that the heat dissipation performance of the LED substrate is improved, the LED special-shaped heat dissipation substrate is more suitable for LED lighting devices with higher power, and more choices are provided for LED application.

According to the preparation method of the LED special-shaped heat dissipation substrate, the printing conductive layer is formed in a printing mode, a series of process steps of film forming, exposure, development, etching, elution and the like are not needed, the method can be called as an addition process, only the conductive layer is required to be printed on the substrate, the process steps are simple and convenient, the environmental pollution is small, and the method is energy-saving and environment-friendly.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram of an LED special-shaped heat dissipation substrate according to the present invention.

Description of the reference numerals

1 non-flat plate type heat dissipation metal layer 2 oxide layer

3 printing function regulating layer 4 printing conductive layer

5 protective layer

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides an LED special-shaped heat dissipation substrate, which comprises a non-flat plate type heat dissipation metal layer 1, a printing function adjusting layer 3, a printing conductive layer 4 and a protective layer 5 which are sequentially stacked from bottom to top as shown in figure 1.

Preferably, the non-flat plate type heat dissipation metal layer 1 is an integrally formed structure and includes a flat plate and a protruding structure formed on a lower surface of the flat plate.

In the present invention, the protruding structure may be a structure that is conventional in the art and is easy to dissipate heat, and may be, for example, a sheet, a column, a tooth, a spike, a hemisphere, a fan, etc. Preferably, the convex structure is a sheet-like or columnar structure extending vertically downward from the lower surface of the flat plate.

Preferably, the LED special-shaped heat dissipation substrate further comprises an oxide layer 2 positioned between the non-flat plate type heat dissipation metal layer 1 and the printing function adjusting layer 3. The oxide layer 2 may be an oxide film with a nano-scale or micro-scale hole structure grown in situ on the surface of the non-planar heat dissipation metal layer 1. The oxide film can prevent the phenomenon of upper layer and metal layer slippage caused by the excessively smooth metal surface, and can remarkably enhance the binding force between the non-flat plate type heat dissipation metal layer 1 and the printing function adjusting layer 3.

In the present invention, the material of the oxide layer 2 can be any oxide grown in situ on the non-planar heat dissipation metal layer 1, such as one or more of aluminum oxide, silicon oxide, titanium oxide and magnesium oxide. The oxide layer 2 can also function as a partial base insulator, and therefore the thickness of the print function adjusting layer 3 can be reduced accordingly.

Preferably, the thickness of the oxide layer 2 is 50nm to 50 μm, preferably 10 to 50 μm, and more preferably 15 to 35 μm.

In the present invention, the material of the non-planar heat dissipation metal layer 1 may be any metal plate material that is conventional in the art, such as aluminum plate, copper plate, iron plate, stainless steel plate, zinc plate or aluminum alloy plate. In order to achieve physical properties of high thermal conductivity and light density and lower manufacturing cost, preferably, the non-flat plate type heat dissipation metal layer 1 is made of an aluminum plate or an aluminum alloy plate.

In the present invention, the material of the printing function adjusting layer 3 may be a high thermal conductive organic material or a high thermal conductive inorganic material. Since the organic material is inferior to the inorganic material in heat transfer performance, in order to form the printing function adjusting layer 3 with good heat transfer performance, it is preferable that the printing function adjusting layer 3 is made of a high heat conductive inorganic material. In order to make the print-function adjustment layer 3 resistant to high temperature, it is preferable that the high thermal conductive inorganic material is an inorganic oxide, and more preferably, the high thermal conductive inorganic material is three or more of an oxide of phosphorus, an oxide of boron, an oxide of silicon, an oxide of vanadium, an oxide of bismuth, an oxide of barium, an oxide of copper, an oxide of zinc, an oxide of calcium, an oxide of potassium, and an oxide of sodium.

Preferably, the high thermal conductive inorganic material is three or more of an oxide of phosphorus, an oxide of boron, an oxide of silicon, an oxide of vanadium, an oxide of barium, and an oxide of zinc.

In the present invention, in the inorganic oxide containing at least three of the above oxides, the print function adjusting layer can withstand high temperatures by adjusting the mixing ratio thereof. In a preferred case, the composition and mixing ratio of the inorganic oxides are, for example: 40 to 70 wt% of an oxide of phosphorus, 10 to 30 wt% of an oxide of boron and 20 to 30 wt% of an oxide of silicon; 50 to 70 wt% of an oxide of phosphorus, 20 to 30 wt% of an oxide of vanadium and 10 to 20 wt% of an oxide of barium; 50 to 75 wt% boron oxide, 15 to 25 wt% barium oxide, and 10 to 25 wt% zinc oxide; 40 to 70% by weight of an oxide of silicon, 10 to 30% by weight of an oxide of barium and 20 to 30% by weight of an oxide of zinc; 40 to 65 wt% of an oxide of phosphorus, 20 to 40 wt% of an oxide of vanadium and 15 to 20 wt% of an oxide of zinc; 40 to 70 wt% of phosphorus oxide, 10 to 30 wt% of vanadium oxide and 20 to 30 wt% of zinc oxide.

Preferably, the thickness of the printing function adjusting layer 3 may be 20 to 220 μm, preferably 30 to 200 μm, and more preferably 50 to 150 μm.

The sum of the thicknesses of the printing function adjusting layer 3 and the oxide layer 2 may be 10 μm or more, preferably 30 μm or more, more preferably 50 μm or more, still more preferably 80 μm or more, and most preferably 100 to 185 μm.

In the present invention, the printed conductive layer 4 may be formed of a mixture containing silver powder, resin, and glass frit.

In the present invention, the content of the silver powder is 40 to 98% by weight, preferably 50 to 95% by weight, more preferably 60 to 90% by weight, based on the total weight of the mixture, and may be, for example, 60% by weight, 62% by weight, 65% by weight, 68% by weight, 70% by weight, 73% by weight, 75% by weight, 78% by weight, 80% by weight, 82% by weight, 85% by weight, 87% by weight, 90% by weight, or any value within a range of any two of these values.

In the present invention, the content of the resin is 1 to 25% by weight, preferably 2.5 to 20% by weight, more preferably 5 to 15% by weight, based on the total weight of the mixture, and may be, for example, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, or any value in the range of any two of these values.

In the present invention, the content of the glass frit is 1 to 35% by weight, preferably 2.5 to 30% by weight, more preferably 5 to 25% by weight, based on the total weight of the mixture, and may be, for example, 5% by weight, 8% by weight, 10% by weight, 12% by weight, 15% by weight, 17% by weight, 20% by weight, 22% by weight, 25% by weight, or any two of these values.

In the present invention, the silver powder may be a nano silver powder or a micro silver powder. In the using process, in the case of preparing the printed conductive layer 4 by using a screen printing method, preferably, micron silver powder with relatively low price is selected; in the case of using an inkjet method to prepare the printed conductive layer 4, it is preferable to use nano silver powder.

In the present invention, the resin may be a resin conventional in the art, and may be, for example, polymethacrylate, ethylcellulose, nitrocellulose, polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, or the like. The resin can increase viscosity and leveling property in the printing process, so that the ink can be leveled uniformly on a printing stock and presents enough luster.

In the invention, the glass powder can be glass powder which is conventional in the field, for example, the glass powder can be low-melting-point glass powder, and the melting point of the glass powder can be 250-580 ℃.

Preferably, the thickness of the printed conductive layer 4 may be 10 to 120 μm, preferably 10 to 100 μm, and more preferably 25 to 50 μm.

In the present invention, the protective layer 5 serves to reduce the contact between the printed conductive layer 4 on the surface of the substrate and air, and to protect the substrate. The protective layer 5 may be formed of a material conventional in the art. Preferably, the protective layer 5 is formed of solder resist ink and character ink.

(1) providing a metal substrate with a non-flat plate type structure as a non-flat plate type heat dissipation metal layer 1, and optionally forming an oxide layer 2 on the plate surface of the non-flat plate type heat dissipation metal layer 1;

(2) forming a printing function adjusting layer 3 on the plate obtained in the step (1), and then carrying out first heat treatment;

(3) forming a printed conductive layer 4 by printing on the heat-treated printing function adjusting layer 3, and then performing a second heat treatment;

(4) a protective layer 5 is formed on the heat-treated printed conductive layer 4.

According to the method of the present invention, in the step (1), the method of forming the oxide layer 2 may be one selected from the group consisting of a micro-arc oxidation method, an anodic oxidation method, an acid-base etching method, a hot water method, and a sol-gel method.

In the preferable case, the aluminum plate or the aluminum alloy plate is selected by a micro-arc oxidation method or an anodic oxidation method.

In the case of using a copper plate, a zinc plate, or a stainless steel plate, it is preferable to use a sol-gel method.

In the case of using an iron plate, preferably, an acid-base etching method or a solvent-gel method is used.

According to the method of the present invention, in the step (2), the method of forming the printing function adjusting layer 3 may be one selected from a spray coating method, a spin coating method, a brush coating method, a blade coating method, and a screen printing method. In order to enable the printing function adjusting layer 3 to have the effects of uniformity and good flatness, the method of forming the printing function adjusting layer 3 is preferably a screen printing method.

According to the method of the present invention, in the step (2), the operating conditions of the first heat treatment are not particularly limited so that the print-function adjusting layer 3 can be formed flatly. Preferably, the operating conditions of the first heat treatment include: the temperature is 400-600 ℃ and the time is 5-180 min, preferably 450-570 ℃ and the time is 15-40 min.

According to the method of the present invention, in the step (3), the method of forming the printed conductive layer 4 may be performed according to a printing method that is conventional in the art. Preferably, the method of forming the printed conductive layer 4 is an inkjet printing method or a screen printing method.

According to the method of the present invention, in the step (3), the operating conditions of the second heat treatment are not particularly limited so as to be able to cure the printed conductive layer 4. Preferably, the operating conditions of the second heat treatment comprise: the temperature is 300-500 ℃ and the time is 5-60 min, preferably, the temperature is 350-480 ℃ and the time is 10-30 min.

In a preferable case, in order to prevent the print-function adjusting layer 3 from softening, the first heat treatment temperature in step (2) is higher than the second heat treatment temperature in step (3).

In the present invention, each of the heat treatments in step (2) and step (3) may be carried out in an apparatus conventional in the art. In one embodiment, the first heat treatment process of step (2) and the second heat treatment process of step (3) are both performed in a muffle furnace.

According to the method of the present invention, in the step (4), the method of forming the protective layer 5 may be performed by an operation method that is conventional in the art. Preferably, the method of forming the protective layer 5 is a screen printing method.

According to the method of the invention, before the oxide layer 2 or the printing function adjusting layer 3 is formed on the non-flat plate type heat dissipation metal layer 1, the non-flat plate type heat dissipation metal layer 1 can be cleaned or polished. Specifically, the non-planar heat dissipation metal layer 1 may be cleaned using deionized water, ethanol, or acetone. The polishing treatment may be carried out according to a method conventionally used in the art.

The present invention will be described in further detail by way of examples, but the scope of the present invention is not limited thereto.

Examples 1-8 are provided to illustrate the LED shaped heat sink substrate and the method of making the same according to the present invention.

Example 1

Preparing an LED substrate as shown in fig. 1: a non-flat plate type aluminum plate having a size of 10cm × 20cm and a sheet-like integrally molded structure in which the lower surface of the aluminum plate extends downward by 2cm in a vertical direction was prepared as the non-flat plate type heat-dissipating metal layer 1, and the aluminum plate was cleaned with deionized water, and then placed in an anodic oxidation bath containing an oxalic acid solution (concentration of 0.2mol/L) to be subjected to anodic oxidation treatment, and then subjected to a constant temperature bath of 10 ℃ for 240min to form an oxide layer 2 having a thickness of 20 μm.

5g of a mixture containing 60 wt% of phosphorus oxide, 20 wt% of boron oxide and 20 wt% of silicon oxide was printed with the functional adjustment layer material by a screen printing method, and then placed in a muffle furnace, heated at 500 ℃ for 40min, and cooled to form a printed functional adjustment layer 3 having a thickness of 100 μm.

4g of a mixture containing 75% by weight of silver powder having a particle diameter of 3 μm, 10% by weight of polymethacrylate (number average molecular weight of 8000) and 15% by weight of low-melting glass frit (melting point of 300 ℃ C.) was printed with a conductive layer material by a screen printing method, and then placed in a muffle furnace and heated at 420 ℃ for 30min to form a printed conductive layer 4 having a thickness of 40 μm.

The protective layer 5 is formed on the surface of the printed conductive layer 4 by screen printing using solder resist ink and character ink.

Obtaining the LED substrate shown in figure 1, and obtaining the junction temperature of the central chip of the LED through indirect calculation of the voltage and temperature curves of the LED by referring to an EIA/JEDEC JESD 51-1 method, wherein the junction temperature is 45 ℃.

Example 2

Preparing an LED substrate as shown in fig. 1: preparing a non-flat aluminum alloy plate with the size of 10cm multiplied by 20cm as a non-flat heat dissipation metal layer 1, wherein the lower surface of the aluminum alloy plate vertically extends downwards to form a columnar integrated forming structure with the size of 2cm, polishing the aluminum alloy plate, and then placing the aluminum alloy plate in a Na-containing state₃PO₄The micro-arc oxidation treatment is carried out in a temperature-controlled micro-arc oxidation tank device of NaOH electrolyte (the concentration is 10.0/2.0g/L) at the current density of 10.5A/dm²This is followed for 30min to form an oxide layer 2 of 15 μm thickness.

A functional adjustment layer material was printed by screen printing using 7.5g of a mixture containing 60% by weight of an oxide of phosphorus, 30% by weight of an oxide of vanadium and 10% by weight of an oxide of barium, and then placed in a muffle furnace, heated at 450 ℃ for 25 minutes, and cooled to form a 150 μm thick printed functional adjustment layer 3.

5g of a mixture containing 15 wt% of silver nanoparticles (particle diameter of 30nm), 15 wt% of polyvinylpyrrolidone resin (number average molecular weight of 5000) and 70 wt% of ethanol was used for printing the conductive layer material by the inkjet printing method, and then placed in a muffle furnace and heated at 350 ℃ for 30min to form a printed conductive layer 4 having a thickness of 50 μm.

The LED substrate shown in fig. 1 was obtained and tested according to the testing method of example 1, and the junction temperature of the LED center chip was found to be 50 ℃.

Example 3

Preparing an LED substrate as shown in fig. 1: preparation sizeUsing a 10cm × 20cm non-flat aluminum plate as the non-flat heat dissipation metal layer 1, vertically extending a 2cm tooth-shaped integrally formed structure from the lower surface of the aluminum plate, cleaning the aluminum plate with ethanol solvent, and placing the aluminum plate in a solution containing Na₃PO₄The micro-arc oxidation treatment is carried out in a temperature-controlled micro-arc oxidation tank device of NaOH electrolyte (the concentration is 10.0/2.0g/L) at the current density of 10.5A/dm²This is done for 90min to form an oxide layer 2 of 35 μm thickness.

2.5g of a mixture containing 55% by weight of boron oxide, 25% by weight of barium oxide and 20% by weight of zinc oxide was printed with the functional adjustment layer material by screen printing, and then placed in a muffle furnace and heated at 570 ℃ for 35min to form a printed functional adjustment layer 3 of 50 μm thickness.

2.5g of a mixture containing 30 wt% of silver nanopowder, 20 wt% of polyvinylpyrrolidone and 50 wt% of ethanol was printed with the conductive layer material by ink-jet printing, and then placed in a muffle furnace and heated at 480 ℃ for 15min to form a printed conductive layer 4 having a thickness of 25 μm.

The LED substrate shown in fig. 1 was obtained and tested according to the testing method of example 1, and the junction temperature of the LED center chip was found to be 41 ℃.

Example 4

Preparing an LED substrate as shown in fig. 1: a nonplanar copper plate having a size of 10cm × 20cm was prepared as a nonplanar heat-dissipating metal layer 1, and a lower surface of the copper plate was extended vertically downward by 2cm in a thorn-like integrally molded structure, and the copper plate was cleaned with an ethanol solvent, and then immersed in a silica sol solution and subjected to sol-gel treatment for 5min to form an oxide layer 2 having a thickness of 10 μm.

3.5g of a mixture containing 50% by weight of an oxide of silicon, 30% by weight of an oxide of barium and 20% by weight of an oxide of zinc was sprayed with a functional adjustment layer material by a spray method, and then placed in a muffle furnace and heated at 550 ℃ for 40min to form a printed functional adjustment layer 3 having a thickness of 70 μm.

4g of a mixture containing 70 wt% of a silver powder having a micron size, 10 wt% of ethyl cellulose and 20 wt% of a glass powder having a low melting point was printed with a conductive layer material by a screen printing method, and then placed in a muffle furnace and heated at 450 ℃ for 25min to form a printed conductive layer 4 having a thickness of 40 μm.

The LED substrate shown in fig. 1 was obtained and tested according to the testing method of example 1, and the junction temperature of the LED center chip was found to be 43 ℃.

Example 5

Preparing an LED substrate as shown in fig. 1: a non-flat plate type iron plate with the size of 10cm multiplied by 20cm is prepared as a non-flat plate type heat dissipation metal layer 1, the lower surface of the iron plate vertically extends downwards to form a fan-shaped integrated forming structure with the size of 2cm, deionized water is used for cleaning the iron plate, and then the iron plate is placed into concentrated nitric acid solution to be subjected to acid-base corrosion treatment for 10min so as to form an oxide layer 2 with the thickness of 50 nm.

1.5g of a mixture containing 40 wt% of an oxide of phosphorus, 40 wt% of an oxide of vanadium and 20 wt% of an oxide of zinc was coated with a functional adjustment layer material by a spin coating method, and then placed in a muffle furnace and heated at 600 ℃ for 15min to form a printed functional adjustment layer 3 having a thickness of 30 μm.

1g of a mixture containing 95 wt% of silver nanopowder, 2.5 wt% of polyethylene glycol and 2.5 wt% of low melting point glass frit was printed with a conductive layer material by screen printing, and then placed in a muffle furnace and heated at 500 ℃ for 10min to form a printed conductive layer 4 having a thickness of 10 μm.

The LED substrate shown in fig. 1 was obtained and tested according to the testing method of example 1, and the junction temperature of the LED center chip was obtained as 30 ℃.

Example 6

Preparing an LED substrate as shown in fig. 1: a non-flat plate type aluminum plate having a size of 10cm × 20cm was prepared as the non-flat plate type heat-dissipating metal layer 1, and a hemispherical integrally molded structure having a lower surface of the iron plate extended vertically downward by 2cm was prepared, the iron plate was washed with deionized water, and then the iron plate was put into hot water of 75 ℃ and subjected to hot water treatment for 25min to form an oxide layer 2 having a thickness of 200 nm.

10g of a mixture containing 40 wt% of an oxide of phosphorus, 30 wt% of an oxide of vanadium and 30 wt% of an oxide of zinc was applied to the functional adjustment layer material by a brush coating method, and then placed in a muffle furnace and heated at 400 ℃ for 180min to form a printing function adjustment layer 3 having a thickness of 200 μm.

10g of a mixture containing 50 wt% of silver nanopowder, 20 wt% of nitrocellulose and 30 wt% of low melting point glass frit was printed with a conductive layer material by screen printing, and then placed in a muffle furnace and heated at 300 ℃ for 60min to form a printed conductive layer 4 having a thickness of 100 μm.

The LED substrate shown in fig. 1 was obtained and tested according to the testing method of example 1, and the junction temperature of the LED center chip was obtained as 45 ℃.

Example 7

Preparing an LED substrate as shown in fig. 1: a non-flat plate type stainless steel plate having a size of 10cm × 20cm, a cylindrical integrally molded structure of which the lower surface extends vertically downward by 2cm, was prepared as the non-flat plate type heat dissipation metal layer 1, and was cleaned with an ethanol solvent, and then was immersed in a silica sol solution and subjected to a sol-gel treatment for 5min to form an oxide layer 2 having a thickness of 10 μm.

1.5g of a mixture containing 40 wt% of an oxide of phosphorus, 40 wt% of an oxide of vanadium and 20 wt% of an oxide of zinc was coated with a functional adjustment layer material by a spin coating method, and then placed in a muffle furnace and heated at 600 ℃ for 5 minutes to form a printed functional adjustment layer 3 having a thickness of 30 μm.

1g of a mixture containing 95 wt% of silver nanopowder, 2.5 wt% of polyvinyl alcohol and 2.5 wt% of low melting point glass frit was printed with a conductive layer material by screen printing, and then placed in a muffle furnace and heated at 500 ℃ for 5min to form a printed conductive layer 4 having a thickness of 10 μm.

Example 8

According to the method of the embodiment 1, except that the oxide layer 2 is not formed, the obtained LED special-shaped heat dissipation substrate is detected according to the detection method of the embodiment 1, and the junction temperature of the LED central chip is obtained to be 32 ℃.

Comparative example 1

The process of example 1 was followed except that a flat aluminum alloy sheet was used in place of the non-flat aluminum alloy sheet. The junction temperature of the central chip of the LED was found to be 52 ℃.

Comparative example 2

The method of example 1 was followed except that the metal layer was not integrally formed and a thermal conductive agent was applied to the junction of the LED substrate and the shaped heat sink. The junction temperature of the central chip of the LED is 75 ℃.

Comparing the data of examples 1-8 and comparative examples 1-2, it can be seen that by setting the metal layer of the substrate to be a non-flat plate with an integrally formed heat dissipation structure, the method of the present invention can significantly reduce the junction temperature of the central chip of the LED, reduce the junction temperature by 25-45 ℃, and make the LED operate more stably and have a longer life span, compared to the case where a heat conducting agent is coated at the junction between the LED substrate and the irregular heat sink, under the condition of the same LED output power.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A LED special-shaped heat dissipation substrate, characterized in that the LED special-shaped heat dissipation substrate comprises a non-flat heat dissipation metal layer (1), a printed function adjustment layer (3), and a printed conductive layer (4) sequentially stacked from bottom to top and protective layer (5);

The material of the printing function adjustment layer (3) is a high thermal conductivity inorganic material;

The high thermal conductivity inorganic material is phosphorus oxide, boron oxide, silicon oxide, vanadium oxide, bismuth oxide, barium oxide, copper oxide, zinc oxide, calcium oxide three or more of compounds, potassium oxides, and sodium oxides.

2. The LED special-shaped heat-dissipating substrate according to claim 1, wherein the non-plate type heat-dissipating metal layer (1) is an integral molding structure, and comprises a flat plate and a convex structure formed on the lower surface of the flat plate.

3 . The LED special-shaped heat dissipation substrate according to claim 2 , wherein the protruding structure is a sheet-like or column-like structure extending vertically downward from the lower surface of the flat plate. 4 .

4. The LED special-shaped heat dissipation substrate according to any one of claims 1-3, wherein the LED special-shaped heat dissipation substrate further comprises the non-flat heat dissipation metal layer (1) and the printing function adjustment layer (3) ) between the oxide layers (2).

5. The LED special-shaped heat dissipation substrate according to claim 4, wherein the material of the oxide layer (2) is one or more of aluminum oxide, silicon oxide, titanium oxide and magnesium oxide.

6. The LED special-shaped heat dissipation substrate according to any one of claims 1-3, wherein the material of the non-flat heat dissipation metal layer (1) is aluminum plate, copper plate, iron plate, stainless steel plate, zinc plate or aluminum alloy plate .

7. The LED special-shaped heat dissipation substrate according to any one of claims 1-3, wherein the printed conductive layer (4) is formed of a mixture containing silver powder, resin and glass powder.

8. The LED special-shaped heat dissipation substrate according to any one of claims 1-3, wherein the protective layer (5) is formed of solder resist ink and character ink.

9. A method for preparing the LED special-shaped heat dissipation substrate according to any one of claims 1-8, the method comprising the following steps:

(1) providing a metal substrate with a non-plate structure as the non-plate heat dissipation metal layer (1);

(2) forming a printing function adjustment layer (3) on the plate obtained in step (1), and then performing a first heat treatment;

(3) on the heat-treated printing function adjustment layer (3), forming a printed conductive layer (4) by printing, and then performing a second heat treatment;

(4) A protective layer (5) is formed on the heat-treated printed conductive layer (4).

10. The method according to claim 9, wherein, in step (1), an oxide layer (2) is formed on the flat surface of the non-flat heat dissipation metal layer (1).

11. The method according to claim 10, wherein, in step (1), the method for forming the oxide layer (2) is selected from the group consisting of micro-arc oxidation method, anodization method, acid-base etching method, hot water method and sol One of the gel methods.

12. The method according to claim 9, wherein, in step (2), the method for forming the printing function adjustment layer (3) is selected from the group consisting of spray coating method, spin coating method, brush coating method, blade coating method and silk screen One of the printing methods.

13 . The method according to claim 9 , wherein, in step (2), the operating conditions of the first heat treatment include: a temperature of 400-600° C. and a time of 5-180 min. 14 .

14. The method according to claim 13, wherein the operating conditions of the first heat treatment include: a temperature of 450-570° C. and a time of 15-40 min.

15. The method according to claim 9, wherein, in step (3), the method for forming the printed conductive layer (4) is ink jet printing or screen printing.

16 . The method according to claim 9 , wherein, in step (3), the operating conditions of the second heat treatment include: a temperature of 300-500° C. and a time of 5-60 min. 17 .

17. The method according to claim 9, wherein the operating conditions of the second heat treatment include: a temperature of 350-480° C. and a time of 10-30 min.

18. The method according to claim 9, wherein, in step (4), the method of forming the protective layer (5) is a screen printing method.

19. Application of the LED special-shaped heat dissipation substrate according to any one of claims 1 to 8 as a base material for lighting.