CN209515738U - The radiator structure of high-power GaN-based LED - Google Patents

Abstract

The utility model provides a kind of radiator structure of high-power GaN-based LED, it includes LED core blade unit, conducting resinl, graphene film, covers copper ceramic substrate, heat-conducting silicone grease, radiator, and LED core blade unit is connect using upside-down mounting mode with layers of copper on copper ceramic substrate is covered.Wherein using chemical vapour deposition technique in designed graphical DBC grown on substrates graphene, as the heat dissipating layer contacted with chip sides, under the premise of not influencing chip top and bottom heat transfer itself, utilize the lateral high heat conductance of graphene, it will be then transmitted on substrate in the heat rapid lateral transport to graphene heat dissipating layer of chip surrounding side, increase new heat conduction path；Heat conduction path is shortened using the interconnection mode of flip-chip, enhances integrally-built heat dissipation performance, realizes effective heat dissipation of local high heat flux density hot spot, to reduce the maximum temperature of LED component, promotes the luminous efficiency and service life of GaN base LED.

Description

The radiator structure of high-power GaN-based LED

Technical field

The utility model belongs to technical field of semiconductors, and in particular to a kind of radiator structure of high-power GaN-based LED.

Background technique

LED is widely used in new-energy automobile field, and use in the car includes third brake lamp, left and right taillight, side To lamp and instrument board, the indicator light of sound equipment etc., market is very huge.In recent years, the material of LED and structure have all obtained biggish Development.Just GaN base LED luminous efficiency can reach 231lm/W at present, if under identical luminous intensity, compared to biography System LED component has more significant advantage, can play good energy saving effect.It can be seen that GaN base LED component In new-energy automobile, this field plays key player.

The generally existing heat management problems of great power LED, high heat can cause very big harm in efficiency to device and service life. Great power LED in use, if heat cannot shed in time, will lead to the raising of PN junction junction temperature, LED dominant wavelength or λ p are just It can drift about to long wavelength, influence luminescent color, original intensity can also decline.The excessively high fast prompt drop of luminous efficiency that can make LED of temperature It is low, generate apparent light decay.And excessively high temperature can make the encapsulating material of LED to rubber-like transformation and thermal expansion coefficient it is rapid It rises, open a way so as to cause LED and fails.Due to the extensive use of LED in the car, negatively affected in conjunction with LED fever bring, The problem of greatly may cause secure context.

In order to guarantee the reliability service of great power LED, just have to solve its heat dissipation problem.Traditional radiator structure has silicon Base flip chip structure, metal circuit board structure and micro-pumping structure, but all have the defects that certain, such as silicon base chip, silicon The heating conduction of piece is limited；The pcb board heating conduction of metal circuit board structure is very poor；Micro-pumping structure is excessively complicated, no Suitable for all devices.So research heat sinking mode has a very important significance.

Utility model content

The purpose of this utility model is to provide a kind of radiating structures of high-power GaN-based LED, are covering copper ceramic base Graphene film is grown according to designed graphic structure chemical vapour deposition technique on plate, is obtained based on the graphical of graphene Copper ceramic substrate is covered, graph position corresponds to the installation site of chip, allows chip be embedded in designed figure just, makes LED core Piece is in contact except the surrounding of front and back with graphene film, increases sinking path, improves the heat-sinking capability of LED entirety.

In order to achieve the above objectives, the utility model uses following technical scheme.

The radiator structure of the high-power GaN-based LED, including LED core blade unit, conducting resinl, graphene film, cover copper Ceramic substrate, heat-conducting silicone grease, radiator, wherein covering copper ceramic substrate with upper layers of copper and lower layers of copper, LED core blade unit uses Dress mode is connect with layers of copper on copper ceramic substrate is covered, and it is described by heat-conducting silicone grease connection radiator to cover layers of copper under copper ceramic substrate Covering has the pattern grooves for accommodating LED core blade unit in the upper layers of copper of copper ceramic substrate, on upper layers of copper surface, production has patterned Graphene film, LED core blade unit are inverted in the pattern grooves, and the front of LED core blade unit passes through conducting resinl and upper copper Layer connection, the surrounding of LED core blade unit are contacted with the graphene film in upper layers of copper, by covering copper pottery between LED core blade unit Circuit in porcelain substrate realizes connection.

Further, the conducting resinl is the epoxide resin conductive adhesive of graphene powder filling.

Further, the graphene film is with a thickness of 18~20 μm.

Further, the conducting resinl in pattern grooves is covered on a thickness of 10 ± 0.5 μm.

Further, the LED core blade unit include Sapphire Substrate front stack gradually production n-type GaN layer, GaN base quantum well layer and p-type GaN layer, on p-type GaN layer surface, production has p-type electrode, and also making on n-type GaN layer surface has N-shaped Electrode.

Further, the radiator is fin shape, and material is metallic aluminium.

Compared with prior art, having the advantages that

1, the increased graphene film of the utility model increases new under the premise of no change original heat dissipation channel Heat is quickly and effectively transmitted to whole by sinking path by the transverse heat transfer ability that graphene is excellent from the side of chip On a graphene film, and then substrate is transmitted to radiator by graphene film, effectively reduces the highest temperature of device Degree.

2, conducting resinl made of the epoxide resin material that the utility model is filled using graphene powder is as LED core blade unit With cover the interconnection material between copper ceramic substrate, enhance capacity of heat transmission of the chip to substrate, while the mode of LED chip upside-down mounting The integrally-built heat-sinking capability of device is also improved, is risen in the high heat flux density caused by high quantity, highdensity chip package Very important effect is arrived.

Detailed description of the invention

Fig. 1 be the utility model proposes high-power GaN-based LED radiator structure schematic diagram.

Fig. 2 be the utility model proposes chip structure schematic diagram.

Fig. 3 a be the utility model proposes the graphical DBC substrate schematic diagram based on graphene.

Fig. 3 b be the utility model proposes the radiator structure of the high-power GaN-based LED with graphene film locally show It is intended to.

Fig. 4 is traditional high-power GaN-based LED radiator structure and heat conduction path schematic diagram.

Fig. 5 be the utility model proposes high-power GaN-based LED heat conduction path schematic diagram.

Fig. 6 be the utility model proposes high-power GaN-based LED upper surface heat conduction path schematic diagram.

Specific embodiment

The utility model is described in further detail with reference to the accompanying drawings and examples.

Referring to Fig. 1 and Fig. 2, the utility model proposes a kind of radiator structures of high-power GaN-based LED, including LED chip Unit 21, graphene film 13, covers copper ceramic substrate, heat-conducting silicone grease 11, radiator 12 at conducting resinl 7, wherein covering copper ceramic substrate With upper layers of copper 8 and lower layers of copper 10, LED core blade unit 21 is connect using upside-down mounting mode with layers of copper 8 on copper ceramic substrate is covered, and covers copper Layers of copper 10 connects radiator by heat-conducting silicone grease 11 under ceramic substrate.Cover copper ceramic substrate (Direct Bonded Copper, It DBC) is that there is upper layers of copper 8 in the upper surface of AlN ceramic 9, lower surface has the substrate of lower layers of copper 10.It is described to cover copper ceramics Design has the pattern grooves for accommodating LED core blade unit 21 in the upper layers of copper 8 of substrate, and on upper 8 surface of layers of copper, production has patterned Graphene film 13, LED core blade unit 21 are inverted in the pattern grooves, and the front of LED core blade unit 21 passes through conducting resinl 7 It is connect with upper layers of copper 8, the surrounding of LED core blade unit 21 is contacted with the graphene film 13 in upper layers of copper 8, LED core blade unit 21 Between by cover the circuit in copper ceramic substrate realize connection.

The utility model grows patterned graphene on copper ceramic substrate in designed cover using chemical vapour deposition technique Film under the premise of not influencing chip top and bottom heat transfer itself, is utilized as the heat dissipating layer contacted with LED chip side The lateral high heat conductance of graphene is then passed in the heat rapid lateral transport to graphene heat dissipating layer of chip surrounding side It is delivered on substrate, increases new heat conduction path；Heat conduction path is shortened using the interconnection mode of flip-chip, enhancing is whole The heat dissipation performance of structure realizes that effective heat dissipation of local high heat flux density hot spot mentions to reduce the maximum temperature of LED component Rise the luminous efficiency and service life of GaN base LED.

The utility model also proposed the manufacture craft of above structure, be made on graphical sapphire substrate with using For LED core blade unit, comprising the following steps:

Sapphire Substrate 1 used in step 1. embodiment is graphical sapphire substrate (PSS), blue precious with being dry-etched in The light-emitting surface at stone lining bottom and epitaxial growth plane two sides all make recessed hemispherical figure, after surface clean, using MOCVD method in indigo plant The epitaxial growth plane of jewel grows GaN buffer layer, then sequential deposition n-type GaN layer 2, GaN base quantum well layer 3, p-type GaN layer 4.So Afterwards in the metal electrode layer (i.e. p-type electrode 5) that layer of Ni-Au composition is deposited in p-type GaN layer, the evaporating n type in n-type GaN layer Electrode 6, electrode material Pt complete the production of LED core blade unit 21.

Step 2. is using chemical vapour deposition technique directly in DBC grown on substrates graphene.

9 and chip form size phase are devised in upper layers of copper 8 in the corresponding installation site of chip referring to Fig. 3 a The pattern grooves matched, pattern grooves include the square indentations of 91 × 1mm in embodiment.Using chemical vapour deposition technique whole The graphene film that 18~20 μ m-thicks are grown in a upper layers of copper 8, will using printing technology in all corresponding pattern grooves positions PMMA (polymethyl methacrylate) solution is plotted on the surface of graphene film 13, shape size and pattern grooves one Sample, it is grid-shaped, half an hour is then stood in air, and PMMA film on the surface of graphene can be obtained.Above-mentioned complete Fraction of PDMS (dimethyl silicone polymer) liquid is added dropwise at the graphene film surface that pattern is drawn, covers all PMMA and applies The position smeared, then heating, drying solidifies PDMS, forms protective layer, then takes off PDMS protective layer from graphene film 13 It goes.Since the cohesive force of PMMA and PDMS are stronger, while PMMA and graphene of its covering also have a stronger active force, and PDMS It is weaker with the cohesive force of graphene, therefore PMMA and its graphene of covering will be lifted-off together with PDMS, finally in graphite Required figure is left on alkene film 13, to obtain the graphical DBC substrate based on graphene.

The graphene powder that step 3. is prepared using micromechanics stripping method or chemistry redox method, is filled into asphalt mixtures modified by epoxy resin Rouge is to enhance thermal conductivity, for the interconnection between chip and substrate in the conducting resinl 7 of matrix.

Pattern grooves bottom surface of the step 4. on DBC substrate carries out dispensing, is covered with the conducting resinl 7 that graphene powder is filled In pattern grooves, with a thickness of 10 ± 0.5 μm.Then the front of bare chip that step 1 completes is inverted and is placed in pair In the pattern grooves answered, referring to Fig. 3 b, it is heat-treated to chip and is firmly fixed on substrate, and the four of LED core blade unit 21 All graphene films 13 in upper layers of copper 8 contact.LED core blade unit 21 is completed by conducting resinl 7 and covers copper ceramic substrate Interconnection.

Step 5. covers the interconnection of copper ceramic substrate Yu radiator 12.10 surface of layers of copper under radiator 12 and substrate is cleaned, is done After dry, in a small amount of heat-conducting silicone grease 11 in radiator central point, uniformly smear and open, the structure of step 4 is then flattened on radiator 12 Surface, fixation are allowed to fit closely.Complete integrally-built basic encapsulation.

The radiator structure of traditional high-power GaN-based LED is as shown in figure 4, there is high heat flux density on LED core blade unit 21 Hot spot, since chip uses the interconnection mode of upside-down mounting, heat directly conducts to chip front side, passes downwardly through interconnection material and successively pass It is delivered to substrate, radiator.Minor heat is conducted to chip back, and sapphire heating conduction is insufficient, can not be passed by the back side Pass more heat transfer.Such heat conduction path capacity of heat transmission is limited, to the more demanding of radiator, biggish fin is needed to dissipate Hot device or the better radiator of performance, and it is difficult to meet the needs of following great power LED.

The utility model proposes a kind of high-power GaN-based LED radiating structure, heat conduction path such as Fig. 5 and Fig. 6 High heat flux density hot spot shown, that chip interior generates, due to the side surrounding of LED core blade unit 21 and connecing for graphene film 13 Touching, under the premise of not destroying original heat conduction path, provides new heat conduction path.Utilize the lateral high fever of graphene The high heat that hot spot generates rapidly is transmitted on entire graphene film 13 by conductance, graphene film 13 and DBC substrate Upper layers of copper 8 comes into contact in a large area, and heat can be made rapidly to be transmitted on substrate, and heat passes sequentially through layers of copper 8, AlN ceramic Substrate 9, lower layers of copper 10, heat-conducting silicone grease 11 to radiator 12.Rapidly reduce the maximum temperature of entire device.

The utility model is connect using the patterned graphene of chemical vapour deposition technique preparation by the surrounding side with chip Touching, plays its excellent transverse heat transfer performance, and the heat that the hot localised points on chip generate is transmitted to rapidly entire surface, is increased The strong lateral thermal conductivity energy of entire radiator structure.Including the graphite prepared using micromechanics stripping method or chemistry redox method Alkene powder is filled into using epoxy resin to enhance its thermal conductivity in the conducting resinl of matrix, mutual for chip and substrate Even, longitudinal capacity of heat transmission of device is enhanced.The enhancing of horizontal and vertical capacity of heat transmission significantly effectively reduces device Maximum temperature, improve the heat dissipation performance of device.The interconnection mode of flip-chip, patterned sapphire substrate are device hair Light efficiency and service life provide very big effect.

The utility model applies the graphene with high heat conductance in high-power GaN-based LED device, solves high-power The heat dissipation bottleneck problem of LED, so that high power lighting lamp bring security risk and service life due to the fever of LED Problem has obtained good improvement.Grapheme material has highly thermally conductive good characteristic, and future may substitute conventional LED devices Radiator structure, while also more excellent scheme is provided for the cost decline of LED illumination product.

Described in the utility model is only the preferred embodiment of the utility model, is not intended to limit the utility model, Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention etc., should be included in this reality Within novel protection scope.

Claims (6)

1. the radiator structure of high-power GaN-based LED, including LED core blade unit (21), conducting resinl (7), graphene film (13), Copper ceramic substrate, heat-conducting silicone grease (11), radiator (12) are covered, wherein covering copper ceramic substrate with upper layers of copper (8) and lower layers of copper (10), LED core blade unit (21) is connect using upside-down mounting mode with layers of copper (8) on copper ceramic substrate is covered, and covers copper under copper ceramic substrate Layer (10) passes through heat-conducting silicone grease (11) connection radiator (12), characterized in that has in the upper layers of copper (8) for covering copper ceramic substrate The pattern grooves for accommodating LED core blade unit (21), on upper layers of copper (8) surface, production has patterned graphene film (13), LED Chip unit (21) is inverted in the pattern grooves, and the front of LED core blade unit (21) passes through conducting resinl (7) and upper layers of copper (8) it connects, the surrounding of LED core blade unit (21) is contacted with the graphene film (13) on upper layers of copper (8), LED core blade unit (21) connection is realized by covering the circuit in copper ceramic substrate between.

2. the radiator structure of high-power GaN-based LED as described in claim 1, characterized in that the conducting resinl (7) is graphite The epoxide resin conductive adhesive of alkene powder filling.

3. the radiator structure of high-power GaN-based LED as described in claim 1, characterized in that the graphene film (13) is thick Degree is 18~20 μm.

4. the radiator structure of high-power GaN-based LED as described in claim 1, characterized in that be covered on leading in pattern grooves Electric glue (7) is with a thickness of 10 ± 0.5 μm.

5. the radiator structure of high-power GaN-based LED as described in claim 1, characterized in that the LED core blade unit (21) It is included in n-type GaN layer (2), GaN base quantum well layer (3) and p-type GaN layer that Sapphire Substrate (1) front stacks gradually production (4), on p-type GaN layer (4) surface, production has p-type electrode (5), and also making on n-type GaN layer (2) surface has n-type electrode (6).

6. the radiator structure of high-power GaN-based LED as described in claim 1, characterized in that the radiator (12) is fin Shape, material are metallic aluminiums.