CN2692886Y

CN2692886Y - Ridge type silicon monolithic micro-channel heat sink

Info

Publication number: CN2692886Y
Application number: CN 200420034348
Authority: CN
Inventors: 苏伟; 李磊民; 王保安; 杨涛; 高杨; 习重华; 韩宾; 胡莉
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology
Priority date: 2004-04-13
Filing date: 2004-04-13
Publication date: 2005-04-13
Anticipated expiration: 2014-04-13

Abstract

The utility model relates to a ridge type silicon monolithic micro-channel heat sink used for cooling the laser diode. The utility model is characterized in that the heat sink is composed of a bonding silicon substrate radiating fin 2, a glass diversion plate 5 and a silicon diversion plate 6, wherein, the front side of the silicon substrate radiating fin 2 is etched with a V-shaped slot 3, and the back side of the silicon substrate radiating fin 2 is etched with a reverse V-slot microchannel 1 which is in alternative arrangement with the front side V-shaped slot 3. The glass diversion plate 5 is opened with an intake channel 8 and a water outlet channel 9. The silicon diversion plate 6 is opened with a cooling water inlet 7 and a cooling water outlet 10. The reverse V-shaped slot microchannel 1 of the back of the silicon substrate radiating fins 2, the intake channel 8 and the warter outlet channel 9 of the glass diversion plate 5, the cooling water inlet 7 and the cooling water outlet 10 of the silicon diversion plate 6 form a cooling circuit of the heat sink.

Description

Ridge type silicon monolithic micro-channel heat sink

1. technical field

The utility model relates to a kind of ridge type silicon monolithic micro channel heat sink device that is used for laser diode array refrigeration.

2. background technology

1) cooling of laser diode

Compare with traditional laser, diode laser (DL) has many advantages: volume is little, luminous efficiency height, reliability height.If but the average power height of DL, thermal power density is big, and temperature rise will be above allowed band, thereby produces negative effects such as the DL wave length shift and the lost of life.Therefore, freezing capacity is the principal element that limits the DL average power at present.

For any DL, the main source that heat produces comprises that the non-photism in the resistance of DL and electronics and hole is compound.In order to keep the highest efficient, the working temperature of DL must be lower than 25 ℃; The long-term continuous operation of DL also requires temperature below 50 ℃.Typical temperature changes 1 ℃ of wave length shift 0.3nm that can cause DL.Therefore, if the temperature of DL can remain on optimum working temperature or near, it will have the highest efficient, the longest life-span and constant wavelength.On the other hand, if the non-uniform temperature of DL will strengthen the emission spectrum width of DL.Therefore, the working temperature of DL should be consistent as far as possible, during in particular as pumping source.

Under high-power condition, for the temperature with DL drops to the acceptable level, DL is usually with pulse mode work, and duty ratio is 1% in typical case.But if extra chiller is arranged, just can obtain, even realize continuous wave work, thereby improve power output than higher duty ratio.Laser diode (LD) array is a high-power diode laser structure commonly used.In the LD array, the density of LD is quite high, so the refrigeration problem is even more important.

In sum, the power output of LD array is subjected to the restriction of its heat-sinking capability.The design of refrigerator not only requires the cooling effectiveness height, also requires its surface temperature even.As adopt long heat sink of cooling passage, and then be heated along the channel direction cooling fluid, can't guarantee that its surface temperature is even.The LD array requires that heat sink weld size is little, surface smoothness is high (it is bright and clean that the chips welding installed surface need reach minute surface), the fluid passage structure of heat sink inside heat conductivity meticulous, material is good and thermal coefficient of expansion is consistent.

2) microchannel refrigerator

Micro-cooler can be applicable to the field of weight limits and high heat flux density, as aerospace industry, the cooling of photoelectricity part, chemical-process heat transfer etc.Its main purpose is to reduce the probability of electronic equipment because of the overheated damage of breaking down at present, and improves the Performance And Reliability of electronic equipment simultaneously.General the most common to cooler nothing more than the combination that is fin and fan, but various electronic products develop towards the direction that volume is little, in light weight, power consumption is low invariably, therefore for the electronic equipment of a new generation, the design limit of traditional cooler and manufacturing technology can't meet the demands, utilize micro electro mechanical system (MEMS) technology to develop the conception of micro-cooler so just produced.

Improve the heat-sinking capability of micro-cooler, the most direct mode is exactly will encapsulate interior thermal source earlier to reach the encapsulation top layer by internal heat, select the best heat radiation and the type of cooling that it is reached the external world again, wherein can be divided into the free convection air cooling, forced convertion air cooling, force liquid cooling, liquid phase changes, and liquid cooling and low temperature compression refrigerating circulation system etc. are forced in the microchannel.Wherein the heat output of microchannel forced convertion cooling mechanism and convection current are most effective, and it is best and tool application potential to prove heat transfer property in practice.

The processing of micro-channel heat sink can be used body microfabrication method, wherein comprise technology such as photoetching, thin film deposition, wet etching and encapsulation, the many parallel little grooves of processing on silicon substrate or metal substrate, form the passage of sealing again by encapsulation, two ends engage with manifold again, as the gateway of cooling liquid.The another side of silicon substrate and chip join, the direct heat that chip is produced is passed to heat sink, and is taken away by cooling fluid, can realize very little thermal resistance.In addition, the coefficient of heat conduction of silicon materials is high more a lot of than general baseplate material, and its thermal coefficient of expansion and GaAs are approaching, can suppress the inefficacy that coefficient of thermal expansion does not match and causes.

3) relevant patent

In association area, Shanghai Optics and Precision Mechanics institute, Chinese Academy of Sciences has applied for patent " micro-channel heat sink cooling " (application number is 96116264.3), Changchun Institute of Optics, Fine Mechanics and Physics, CAS has applied for patent " preparation of seal-packaged single-chip microchannel heat sink cooling laser diode array " (application number is 02109136.6), these two patents adopt the method for using the laser processing microchannel on sheet metal, and processing cost is than higher.Chongqing Normal College has applied for patent " microchannel cooling assembly of high-power laser diode array " (application number is 98102464.5), and this patent has adopted the structure of stack, each LD bar all be installed in one independent flat heat sink on.What these patents adopted all is prismatic rectangle microchannel, and correspondingly, the surface that mounts power device is flat, therefore is not easy to a plurality of LD bars are installed at one on heat sink.

3. summary of the invention

The purpose of this utility model provides a kind of silicon monolithic micro-channel heat sink of the LD of being used for array cooling, thereby makes it produce high power output.

A kind of ridge type silicon monolithic micro-channel heat sink is characterized in that this heat sink silicon substrate fin, glass by bonding divides water plate and silicon to divide water plate three parts to constitute, wherein:

The front of silicon substrate fin is etched with V-shaped groove, and back-etching has the inverted v-shaped groove microchannel with front V-shaped groove interlaced arrangement;

Glass divides and has intake chamber and effluent trough on the water plate;

Silicon divides and has cooling water inlet and coolant outlet on the water plate;

Intake chamber and the effluent trough on the water plate divided in the inverted v-shaped groove microchannel at the silicon substrate fin back side, glass, and silicon divides cooling water inlet and the coolant outlet on the water plate to constitute heat sink cooling circuit.

Described V-shaped groove and inverted v-shaped groove comprise approximate V-arrangement, as zigzag, shape, Shape, Shape, Shape, Multiple analogous shape such as shape.Inverted v-shaped groove also can be described as dovetail groove.

The bottom that further scheme is a V-shaped groove has insulation tank.

This ridge type silicon monolithic micro-channel heat sink can be used for the heat radiation cooling of multiple microelectronic component, and when cooling off as high-power laser diode array is dispelled the heat, the front of the diffusing substrate fin of silicon is etched with V-shaped groove, is used to install the LD bar.The back-etching of silicon fin has trapezoidal microchannel, is used for the cooling of LD bar.Therefore positive V-shaped groove and the back-etching of being etched with has the silicon substrate fin with the trapezoidal microchannel of front V-shaped groove interlaced arrangement to form the waveform substrate, and the thickness basically identical of this waveform substrate every bit, can realize the Homogeneouslly-radiating cooling.The KOH anisotropic wet etch is all adopted in V-shaped groove and microchannel.If adopt precision optical machinery processing, can process the microchannel of any angle, but cost is higher.

Because lean on very closely between microchannel and the LD bar that is cooled, the thermal resistance that this is heat sink is very little, can takes away the heat that the LD bar produces rapidly, thereby the temperature of LD bar is controlled at reasonable levels.This is heat sink to be suitable for the cooling of other high power density device equally.

Because the cost of chiller shared ratio in LD array cost is quite big, therefore a plurality of LD bars need be installed on the silicon monolithic chiller, thereby the refrigeration cost of each LD bar is shared in reduction.

Anisotropic wet etch has been widely used in the etching of V-arrangement and rectangle microflute.It is different to the etching speed of the crystal face of different crystal orientations that the anisotropic etching principle of silicon is exactly some etching agent (for example KOH and EPW).(110) crystal face reaches as high as 600: 1 with the ratio of the etching speed of (111) crystal face, also can reach 200: 1 usually in practice.For＜110〉silicon chip in crystal orientation, because (110) crystal face is 35.3 ° with angle between (111) and (111) crystal face, so can etch 109.5 ° V-shaped groove.On the other hand, because (110) crystal face is orthogonal with (111) crystal face, therefore can etch microchannel with Surface Vertical.Because the restriction of crystal plane direction, the direction of silicon chip upper and lower surface mask all need strict control, and the angle axial and microchannel, the back side of front V-shaped groove is 35.3 °.The KOH anisotropic etching can reach very high surface roughness.

The utility model solved＜110〉silicon chip anisotropic etching stop problem certainly.Because the angle between two (111) type end sides in the V-shaped groove on heating panel front V-shaped groove and the lens mount is 109.5 °, intersect at the summit of an obtuse triangle, because the etching speed of (111) type crystal face is much smaller than other type crystal face, therefore can realize stopping certainly of etching, thereby the spacing that guarantees LD bar and lens equates.

The etch period of strict control microchannel stops etching in the utility model before it forms complete triangle, and it is trapezoidal making its shape approximation, and sectional area reaches 85% of envelope triangle area.

The side of the V-shaped groove of heating panel needs five layers of metal layer of evaporation, begins to be respectively 1 μ m Ti, 1 μ m Pt, 9 μ m Au, 1 μ m Pt and 3 μ m Au from the silicon chip surface of insulating layer.The bottom of V-shaped groove has an insulation tank, is used to cut off the connection of heating panel surface metal-layer, is divided into the sheet metal of a series of mutually insulateds, and its degree of depth only need guarantee that the metal level of evaporation does not overlap each other and get final product in groove.

It is that intake chamber and effluent trough adopt laser processing that glass divides through hole on the water plate, can guarantee accurate relative position relation between the through hole like this, thereby makes it become possibility with accurate aligning of microchannel on the heating panel.Adopt the mode of silicon-glass-three layers of bonding of silicon to encapsulate, can avoid closing at processing groove on glass or silicon-silicon bond.

The conductive coefficient of silicon (1.57W/cm ℃) is higher, differs with copper (3.93W/cm ℃) not to be big especially, but can the very narrow microchannel of etching on the silicon chip, so silicon micro-channel is heat sink can access the thermal resistance littler than copper micro-channel heat sink.Compare with the plane formula structure, the ridge type heat radiating fin structure makes the installation of LD array more convenient, and the distance between LD bar and the microchannel is littler simultaneously, thereby reduces thermal resistance.Encapsulate heat sink comparing separately with a LD bar, it is easier with the welding of LD array that one chip is heat sink, and the refrigeration cost of sharing each LD bar is lower.Compare with the precision optical machinery processing method, the wet etching method cost is low, thereby can reduce whole heat sink cost.Trapezoidal microchannel is compared with the triangle microchannel, more meets streamline shape, and the stagnant area is littler, and effective contact area of microchannel and silicon fin is bigger, so thermal resistance is littler.In sum, the ridge type silicon monolithic micro-channel heat sink that relates to of the utility model has little, the easy for installation and low cost and other advantages of thermal resistance.

4. accompanying drawing and explanation

Fig. 1 is the upward view of silicon substrate fin.

Fig. 2 is the A-A profile of micro-channel heat sink.

Fig. 3 divides the vertical view of water plate for glass.

Fig. 4 is the vertical view that silicon divides the water plate.

Among the figure: the 1st, the microchannel that the longitudinal section is approximately trapezoidal (inverted V-shaped), the 2nd, the silicon substrate fin, the 3rd, V-shaped groove, 4 is insulation tank, and 5 for glass divides the water plate, and 6 for silicon divides the water plate, and 7 is the cooling water inlet, and 8 is intake chamber, and 9 is effluent trough, and 10 is coolant outlet.

5. implementation

A specific implementation of the present utility model is shown in Fig. 1-4, and a kind of silicon monolithic micro-channel heat sink that is used for high-power laser diode array comprises that 2, one glass of a silicon substrate fin of bonding divide water plate 5 and a silicon to divide water plate 6.The V-shaped groove that there is series installation LD bar in silicon substrate fin 2 fronts is carved with insulation tank 4 between the V-shaped groove, be used to cut off the contact between the V-shaped groove surface metal-layer.As shown in Figure 1, the width of series of parallel is arranged is that 30 μ m distance is the microchannel of 50 μ m at the back side of silicon substrate fin 2.As shown in Figure 2, cooling water 7 enters the microchannel 1 of series of parallel through intake chamber 8 from entering the mouth, and flows to effluent trough 9 through these microchannels 1, after effluent trough 9 flow out from coolant outlet 10 (not drawing Fig. 2).

Claims

1, a kind of ridge type silicon monolithic micro-channel heat sink is characterized in that this heat sink silicon substrate fin (2), glass by bonding divides water plate (5) and silicon to divide water plate (6) three parts to constitute, wherein:

The front of silicon substrate fin (2) is etched with V-shaped groove (3), and back-etching has the inverted v-shaped groove microchannel (1) with front V-shaped groove (3) interlaced arrangement;

Glass divides and has intake chamber (8) and effluent trough (9) on the water plate (5);

Silicon divides and has cooling water inlet (7) and coolant outlet (10) on the water plate (6);

Intake chamber (8) and the effluent trough (9) on the water plate (5) divided in the inverted v-shaped groove microchannel (1) at silicon substrate fin (2) back side, glass, and silicon divides cooling water inlet (7) on the water plate (6) and coolant outlet (10) to constitute the cooling circuit of heat sink (15).

2, ridge type silicon monolithic micro-channel heat sink according to claim 1 is characterized in that the bottom of V-shaped groove has insulation tank (4).