CN207038524U - A kind of LED chip flat-plate heat pipe integrated encapsulation structure - Google Patents

Abstract

The utility model discloses a kind of LED chip flat-plate heat pipe integrated encapsulation structure, and it includes radiating fin, flat-plate heat pipe, circuit layer, some LED chips and chip encapsulation material.The flat-plate heat pipe evaporating surface is ALN insulated ceramic plates, and cryosurface is red copper shell plates, and evaporating surface is provided with the porous capillary liquid sucting core structure of radial inner groovy, and cryosurface is provided with thin layer porous wick structure structure, and evaporating surface is directly bonded with cryosurface.The LED chip is set directly in flat-plate heat pipe evaporating surface ALN insulated ceramic plates.Evaporating surface of the metal plate as flat-plate heat pipe is substituted using ALN insulated ceramic plates, insulating barrier need not be set, the thermal stress of package substrate and LED chip is greatly reduced, system thermal resistance is significantly reduced, improves radiating efficiency, extends LED service life and functional reliability.

Description

A kind of LED chip flat-plate heat pipe integrated encapsulation structure

Technical field

A kind of high-power multi-core piece LED encapsulating structure is the utility model is related to, more particularly, to a kind of LED chip flat board Heat pipe integrated encapsulation structure.

Background technology

As LED semiconductor lightings develop to highly integrated, high power direction, the chip encapsulated in LED-baseplate is increasingly Chip heat flow density more and more highers that are more, thus triggering.At present, high-power LED integrated packaging structure, especially multi-chip integrate Encapsulating structure, the most frequently used package substrate are copper base, aluminium base, and its thermal conductivity is up to 398W/mK, 180W/mK, got over respectively To be more difficult to meet the needs of great power LED cooling.

The radiating problem occurred for high-power multi-core piece LED encapsulation structure, have researcher at present and propose to use flat board The encapsulation of heat pipe and LED chip is radiated, as patent CN201220000690.7, CN201020539446.9, CN200920313589.5, CN200920302793.7 etc..But flat-plate heat pipe evaporating surface disclosed above and cryosurface be by The welding of upper and lower two pieces of metal cover boards is put together, LED chip material thermal expansion coefficient mismatches with metal material thermal coefficient of expansion, It is easily caused serious thermal stress Problem of Failure；It is required to make insulating barrier in metal material surface before making circuit layer simultaneously, by It is poor in the thermal conductance of insulating barrier, thermal resistance is significantly increased, so as to bring problem for the radiating of LED chip.

AlN ceramic is physico with its high heat conductance, insulating properties and with LED chip material thermal expansion coefficient good match Learn performance, it is resolved that it can be used for insulating substrate, enclosed chip, the heat dispersion substrate of large power semiconductor device.Using AlN ceramic Evaporating surface and directly being encapsulated with LED chip as flat-plate heat pipe is bonded, and has had not yet to see relevant report.

Utility model content

Technical problem underlying to be solved in the utility model is to provide a kind of LED chip flat-plate heat pipe integration packaging knot Structure, heat conduction is fast, the thermal stress of package substrate and LED chip is smaller.

In order to solve above-mentioned technical problem, the utility model provides a kind of LED chip flat-plate heat pipe integration packaging knot Structure, including transparent silica gel, multiple LED chips, circuit layer, flat-plate heat pipe, radiating fin；

The LED chip is distributed in the upper surface of the circuit layer in a manner of matrix arrangement, and the circuit layer is directly set Put on the evaporating surface of flat-plate heat pipe, cryosurface and the radiating fin of the flat-plate heat pipe formed it is detachable be fastenedly connected, institute State transparent silica gel to be directly arranged on some LED chips and circuit layer, LED chip is packaged in transparent silica gel；

The evaporating surface of the flat-plate heat pipe is a plane ALN insulated ceramic plates, and the cryosurface direction of the flat-plate heat pipe is steamed The side of fermentation, along the recessed formation cavity in direction away from evaporating surface；The side of the evaporating surface towards cavity has porous Capillary wick structure, the porous capillary liquid sucting core structure include a Circular Plate, and the surface of the Circular Plate axially has Loose structure；The inner groovy being radially distributed that the annulus plate surface is provided with, the both ends of the inner groovy are respectively communicated to The inner periphery and the outer periphery of Circular Plate；The cryosurface is provided with thin layer porous wick structure structure towards the side of evaporating surface；

The porous capillary liquid sucting core structure and thin layer porous wick structure structure are placed in the cavity directly against merging, institute State the upper and lower surface that evaporating surface and thin layer porous wick structure structure are located at the Circular Plate respectively so that the Circular Plate center of circle The cavity at place forms a seal cavity；The outer peripheral sidewall of the cryosurface, which is reserved with, to be vacuumized and liquid feeding mouth.

In a preferred embodiment：The multiple LED chip be packaging pin in the same direction and LED chip upward；LED core Welded with evaporating surface by golden tin silver paste solder the bottom surface of piece；One side of the LED chip away from evaporating surface is provided with the encapsulation Pin, the both positive and negative polarity after the plain conductor connection in series-parallel that packaging pin passes through high conductivity directly with circuit layer are connected respectively.

The utility model has advantages below compared with the structure of other packaging LED chips direct on flat-plate heat pipe：

1) evaporating surface of the traditional metal materials as flat-plate heat pipe, AlN insulated ceramic plates are substituted using AlN insulated ceramic plates Not only there is high-insulativity, high thermal conductivity, its thermal coefficient of expansion and LED chip match materials are good, so as to greatly reduce envelope Fill the thermal stress of substrate and LED chip；

2) relative to conventional LED package structure, the utility model sets LED chip knot directly on flat-plate heat pipe evaporating surface Structure, it is provided with a layer insulating less between circuit layer and flat-plate heat pipe, LED heat is realized using the good thermal conductivity of ALN It is quick to scatter and disappear, system thermal resistance is significantly reduced, greatly improves radiating efficiency, and then the junction temperature of LED chip is reduced, extend LED service life and reliability.

Brief description of the drawings

Fig. 1 is the utility model LED chip flat-plate heat pipe integrated encapsulation structure sectional view；

Fig. 2 is the utility model LED chip integration packaging to flat-plate heat pipe evaporating surface sectional view；

Fig. 3 is the exploded perspective view of the utility model flat-plate heat pipe；

Fig. 4 is the utility model flat-plate heat pipe evaporating surface circuitous pattern and chip welding region schematic diagram；

Fig. 5 is the utility model flat-plate heat pipe evaporating surface circuit and golden tin silver paste welding region schematic diagram；

Fig. 6 is the utility model LED chip integration packaging to flat-plate heat pipe evaporating surface top view；

Fig. 7 is the utility model flat-plate heat pipe evaporating surface inner groovy liquid sucting core structure schematic diagram；

Fig. 8 is that the utility model manufactures the mould schematic diagram that evaporating surface inner groovy liquid sucting core structure uses；

Fig. 9 is that the utility model manufactures the mould schematic diagram that cryosurface liquid sucting core structure uses.

Embodiment

In order at large illustrate contexture of the present utility model, technology contents, realize purpose and operating method, tie below Embodiment is closed, and coordinates accompanying drawing to illustrate.

As shown in figure 1, a kind of LED chip flat-plate heat pipe integrated encapsulation structure, including transparent silica gel 1, multiple LED chips 2, Circuit layer 3, flat-plate heat pipe 4, radiating fin 5；

The LED chip 2 is distributed in the upper surface of the circuit layer 3 in a manner of matrix arrangement, and the circuit layer 3 is direct It is arranged on the evaporating surface 41 of flat-plate heat pipe 4, the cryosurface 42 of the flat-plate heat pipe 4 forms detachable tight with radiating fin 5 It is solidly connected, the transparent silica gel 1 is directly arranged on some LED chips 2 and circuit layer 3, LED chip 2 is packaged in transparent In silica gel 1；

With further reference to Fig. 3, Fig. 7, the evaporating surface 41 of the flat-plate heat pipe 4 is a plane ALN insulated ceramic plates, described flat The cryosurface 42 of plate heat pipe 4 is towards the side of evaporating surface 41, along the recessed formation cavity in direction away from evaporating surface 41；The steaming Fermentation 41 has porous capillary liquid sucting core structure 411 towards the side of cavity, and the porous capillary liquid sucting core structure 411 includes a circle Ring flat-plate, the surface of the Circular Plate axially have loose structure；What what the annulus plate surface was provided be radially distributed Inner groovy, the both ends of the inner groovy are respectively communicated to the inner periphery and the outer periphery of Circular Plate；The cryosurface 42 is towards evaporating surface 41 Side be provided with thin layer porous wick structure structure 421；

The porous capillary liquid sucting core structure 411 and thin layer porous wick structure structure 421 directly against merge be placed in it is described recessed Intracavitary, evaporating surface 41 and thin layer the porous wick structure structure 421 are located at the upper and lower surface of the Circular Plate, made respectively The cavity for obtaining Circular Plate circle centre position forms a seal cavity；The outer peripheral sidewall of the cryosurface 42, which is reserved with, to be vacuumized and liquid feeding mouth 43。

Because the material of evaporating surface 41 of flat-plate heat pipe 4 is ALN insulating ceramicses so that LED chip 2 and the evaporation of flat-plate heat pipe 4 Face 41 ensures good insulation.The material of radiating fin 5 is aluminium alloy, and uniformly coating is appropriate thick for the cryosurface 41 of flat-plate heat pipe 4 It is fastenedly connected after the heat-conducting silicone grease of degree with radiating fin 5 using detachable, and then the moment of LED chip 2 is started and normal work Heat caused by work directly conducts through flat-plate heat pipe 4 causes radiating fin 5, realizes that the quick of heat scatters and disappears.

As shown in Fig. 2 the multiple LED chip 2 be packaging pin in the same direction and LED chip 2 upward；LED chip 2 Welded with evaporating surface 41 by golden tin silver paste solder bottom surface；The one side of the LED chip 2 away from evaporating surface 41 is provided with the encapsulation Pin, directly it is connected respectively with the both positive and negative polarity of circuit layer 3 after the connection in series-parallel of plain conductor 6 that packaging pin passes through high conductivity.Institute The circuit layer 3 stated is directly arranged on the ALN insulating ceramicses of the evaporating surface 41 of flat-plate heat pipe 4, AlN ceramic thickness be 0.5~ 1mm。

The preparation method of above-mentioned LED chip flat-plate heat pipe integrated encapsulation structure, comprises the following steps：

1) red copper sheet material is processed by machining process and produces the cryosurface that red copper shell plates is used as flat-plate heat pipe 4 42, evaporating surface 41 of the ALN insulating ceramicses sheet material as flat-plate heat pipe 4 is produced using laser processing, be respectively washed decontamination, Drying；

2) such as Fig. 8, Fig. 9, produced and porous capillary liquid sucting core structure 411 and the porous suction of thin layer by machining process The first sintering mold 7 and the second sintering mold 8 that wick-containing structure 421 is engaged respectively.Metal powder granulates are filled out respectively first It is charged in the cavity of two first sintering molds 7 and the second sintering mold 8 and red copper shell plates, ALN insulated ceramic plates composition, makes more Hole liquid sucting core structure 421, evaporating surface porous capillary liquid sucting core structure 411 are arranged at cryosurface 42, the center of evaporating surface 41.Again It is respectively put into box atmosphere protection resistance furnace and carries out solid-phase sintering, sintering temperature is 900-950 DEG C, the sintered heat insulating time is 30-60min, it is passed through hydrogen shield.Finally by the first sintering mold 7 in ALN insulated ceramic plates and on red copper shell plates and the Two sintering molds 8 are extracted, so as to obtain porous capillary liquid sucting core structure 411, and thin layer porous wick structure structure 421.Again will Red copper shell plates is connected and sealed with ALN insulated ceramic plates by silver-bearing copper titanium vacuum brazing, its inside vacuumize and Working medium is irrigated, completes the preparation of flat-plate heat pipe.

3) as shown in Figure 4,5, mask prepares circuitous pattern in the evaporating surface 41ALN insulated ceramic plates of flat-plate heat pipe 4 31 and LED chip weld zone 211；

4) after as shown in Figure 5 and Figure 6, covering LED chip weld zone 211, then by magnetron sputtering deposition method in flat board Precipitation conductive metal atom forms circuit layer 3, shape and the phase of masking pattern figure 31 of circuit layer 3 on the evaporating surface 41 of heat pipe 4 Matching, thickness 5-10um；

5) by packaging pin in the same direction and some LED chips 2 upward with after the connection in series-parallel of plain conductor 6 of high conductivity with electricity The both positive and negative polarity of road floor 3 connects respectively, and its chip bottom is welded direct to the evaporation of the flat-plate heat pipe 4 by the way of eutectic weldering On the surface of face 41；

6) transparent silica gel 1 is encapsulated in LED chip 2 and circuit layer 3；

7) after the one layer of 0.1-0.3mm of surface even application of cryosurface 42 of flat-plate heat pipe 4 heat-conducting silicone grease, by flat board heat Pipework condensation face 42 is attached with radiating fin 5 using removable be fastenedly connected, and completes LED chip flat-plate heat pipe integration packaging knot The preparation of structure.

It is described above, only the utility model preferred embodiment, therefore the utility model implementation can not be limited according to this Scope, i.e., the equivalent changes and modifications made according to the utility model patent scope and description, it is new all should still to belong to this practicality In the range of type covers.

Claims (2)

1. a kind of LED chip flat-plate heat pipe integrated encapsulation structure, it is characterised in that including transparent silica gel (1), multiple LED chips (2), circuit layer (3), flat-plate heat pipe (4), radiating fin (5)；

The LED chip (2) is distributed in the upper surface of the circuit layer (3) in a manner of matrix arrangement, and the circuit layer (3) is straight Connect on the evaporating surface (41) for being arranged on flat-plate heat pipe (4), cryosurface (42) and radiating fin (5) shape of the flat-plate heat pipe (4) It is fastenedly connected into detachable, the transparent silica gel (1) is directly arranged on some LED chips (2) and circuit layer (3), will LED chip (2) is packaged in transparent silica gel (1)；

The evaporating surface (41) of the flat-plate heat pipe (4) is a plane AlN insulated ceramic plates, the cryosurface of the flat-plate heat pipe (4) (42) towards the side of evaporating surface (41), along the recessed formation cavity in direction away from evaporating surface (41)；The evaporating surface (41) There is porous capillary liquid sucting core structure (411) towards the side of cavity, the porous capillary liquid sucting core structure (411) includes an annulus Plate, the surface of the Circular Plate axially have loose structure；What the annulus plate surface was provided with is radially distributed interior Groove, the both ends of the inner groovy are respectively communicated to the inner periphery and the outer periphery of Circular Plate；The cryosurface (42) is towards evaporating surface (41) side is provided with thin layer porous wick structure structure (421)；

The porous capillary liquid sucting core structure (411) and thin layer porous wick structure structure (421) directly against merge be placed in it is described recessed Intracavitary, the evaporating surface (41) and thin layer porous wick structure structure (421) are respectively positioned at the upper surface of the Circular Plate and following table Face so that the cavity of Circular Plate circle centre position forms a seal cavity；The outer peripheral sidewall of the cryosurface (42), which is reserved with, to be vacuumized With liquid feeding mouth (43).

A kind of 2. LED chip flat-plate heat pipe integrated encapsulation structure according to claim 1, it is characterised in that：The multiple LED Chip (2) be packaging pin in the same direction and LED chip (2) upward；LED chip (2) bottom surface passes through golden tin with evaporating surface (41) Silver paste solder welds；One side of the LED chip (2) away from evaporating surface (41) is provided with the packaging pin, and packaging pin passes through Both positive and negative polarity after plain conductor (6) connection in series-parallel of high conductivity directly with circuit layer (3) is connected respectively.