Heat sink structure for LD assembly packaging and preparation method thereof

Abstract

The invention provides a heat sink structure used for LD assembly packaging and a preparation method thereof, the heat sink structure comprises a metal heat sink main body, the metal heat sink main body is provided with at least two mutually independent cavities, each cavity is filled with a composite phase change material, the bottom of each cavity is provided with a plurality of first through holes, and the first through holes are communicated with the metal heat sink main body. The first through hole is used for fixing an LD assembly; wherein the composite phase change material is composed of a supporting plate, a heat conduction material and a phase change material; and at least two metal cover plates, each metal cover plate is respectively fixed with each cavity, and the metal cover plates are respectively used for sealing each cavity. According to the scheme, through the design of the heat sink structure and the optimized combination of the composite phase change material, when the temperature changes in the working process of the LD assembly, the composite phase change material can generate phase change in a short time, so that the composite phase change material can fully exert the heat storage and heat absorption capability, and the temperature of the LD assembly packaged on the surface of the heat sink structure is controlled in time; therefore, the stability of the light emitting efficiency of the LD assembly is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation of LD components, and particularly relates to a heat sink structure for LD component packaging and a preparation method thereof. Background Art

[0002] An LD component (laser diode) is a semiconductor device that generates focused monochromatic light by stimulated emission, and has the advantages of high photoelectric conversion efficiency, long service life, small volume, etc., and has been widely used in fields such as material processing, aerospace, medical beauty, and optical fiber communication.

[0003] When packaging an LD component, due to the small packaging volume and the airtight packaging space without heat dissipation conditions such as air convection, and the large heat generation of the LD component, if reasonable heat diffusion is not carried out, local overheating will occur, which will have an adverse impact on the light output efficiency of the LD component.

[0004] Based on this, there is an urgent need to provide a heat sink structure for LD component packaging and a preparation method thereof. Summary of the Invention

[0005] Embodiments of the present invention provide a heat sink structure for LD component packaging and a preparation method thereof, which can solve the problem that the large heat generation of the LD component easily affects the light output efficiency of the LD component.

[0006] In a first aspect, the present invention provides a heat sink structure for LD component packaging, including:

[0007] A metal heat sink body, on which there are at least two independent cavities, each cavity is filled with a composite phase change material, and there are a number of first through holes at the bottom of the cavity, and the first through holes are used to fix the LD component; wherein, the composite phase change material is composed of a support plate, a heat conduction material and a phase change material;

[0008] At least two metal covers, each metal cover is fixed to each cavity respectively, and is used to seal each cavity respectively.

[0009] Preferably, both the metal heat sink body and the metal cover are made of aluminum alloy.

[0010] Preferably, the metal heat sink body is provided with three independent cavities, and the upper surface of each cavity is in an open state.

[0011] Preferably, the filling volume of the composite phase change material is not more than 95% of the cavity volume.

[0012] Preferably, in the composite phase change material, the support plate is made of metal copper, the heat conduction material is expanded graphene flakes, and the phase change material is paraffin or barium hydroxide.

[0013] Preferably, the porosity of the support plate is greater than 85%, the thickness is 7-9 mm, and the heat transfer coefficient is greater than 6 W / (m 2 K);

[0014] The particle size of the heat conductive material is 90-110 mesh, and the expansion volume is 180-210 mL / g;

[0015] The thermal cycle life of the phase change material is not less than 2000 times, and the attenuation of heat storage and heat release capacity is less than 10%.

[0016] Preferably, a heat dissipation film is compounded on the bottom of each cavity and the inner and outer surfaces of each metal cover plate.

[0017] More preferably, the heat dissipation film is a graphene film, and the thickness of the heat dissipation film is 0.4-0.6 mm.

[0018] Preferably, a plurality of second through holes are further provided at the edge of the metal heat sink body, and the second through holes are used to fix the heat sink structure.

[0019] Second, the present invention also provides a preparation method of a heat sink structure for LD component packaging, and the preparation method includes the following steps:

[0020] (1) Determine the filling amount of the composite phase change material according to the preset target temperature, and prepare the heat conductive material and the phase change material respectively;

[0021] (2) Determine the volume of each cavity in the metal heat sink body according to the filling amount of the composite phase change material;

[0022] (3) After loading the phase change material on the surface of the heat conductive material, fill each cavity with the support plate and the phase change material respectively;

[0023] (4) Fix the metal cover plate with a heat dissipation film compounded on the inner surface on the upper surface of each cavity, and further compound a heat dissipation film on the upper and lower surfaces of each cavity to obtain the heat sink structure for LD component packaging.

[0024] Preferably, in step (3), the loading rate of the phase change material on the surface of the heat conductive material is greater than 85%.

[0025] More preferably, the support plate is embedded between the phase change material and the heat conductive material.

[0026] Preferably, before loading the phase change material on the surface of the heat conductive material, a step of recrystallizing the phase change material is further included.

[0027] More preferably, the heat dissipation film is obtained by directional arrangement using a microfluidic process; the thickness of the heat dissipation film is 0.4 - 0.6 mm, and the thermal conductivity is greater than 2300 W·m -1 ·K -1 .

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] In the present invention, by providing at least two independent cavities on the metal heat sink body, and filling each cavity with a composite phase change material, and then using a metal cover plate matching the cavity to seal each cavity respectively. Through the design of the heat sink structure and the optimized combination of the composite phase change material, when the temperature changes during the operation of the LD component, the composite phase change material can undergo a phase change in a short time, so that the composite phase change material can fully exert its heat storage and heat absorption capabilities, and timely control the temperature of the LD component encapsulated on the surface of the heat sink structure, which is beneficial to ensuring the stability of the light output efficiency of the LD component. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 is an overall physical diagram of the heat sink structure for LD component packaging provided by an embodiment of the present invention;

[0032] Figure 2 is a front and bottom plan view of the metal heat sink body in the heat sink structure for LD component packaging provided by an embodiment of the present invention;

[0033] Figure 3 is a front and bottom plan view of the metal heat sink body with a composite heat dissipation film in the heat sink structure for LD component packaging provided by an embodiment of the present invention;

[0034] Figure 4 is a structural schematic diagram of the metal cover plate in the heat sink structure for LD component packaging provided by an embodiment of the present invention;

[0035] Figure 5 is a front and bottom plan view of the heat sink structure for LD component packaging provided by an embodiment of the present invention;

[0036] Figure 6 and Figure 8It is a test diagram of a packaged LD component of a heat sink structure for LD component packaging provided by an embodiment of the present invention; wherein, the phase change material in the composite phase change material is paraffin wax;

[0037] Figure 7 and Figure 9 It is a test diagram of a packaged LD component of a heat sink structure for LD component packaging provided by an embodiment of the present invention; wherein, the phase change material in the composite phase change material is barium hydroxide;

[0038] In the figure, 100 - metal heat sink body, 200 - metal cover plate, 101 - cavity, 102 - first through hole, 103 - second through hole. Detailed implementation manners

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] As Figure 1 and Figure 2 shown, an embodiment of the present invention provides a heat sink structure for LD component packaging, including:

[0041] A metal heat sink body 100, on which at least two independent cavities 101 are provided, and each cavity 101 is filled with a composite phase change material. A plurality of first through holes 102 are provided at the bottom of the cavity 101, and the first through holes 102 are used to fix the LD component; wherein, the composite phase change material is composed of a support plate, a heat conductive material, and a phase change material;

[0042] At least two metal cover plates 200, each metal cover plate is fixed to each cavity 101 respectively and is used to seal each cavity respectively.

[0043] In the embodiment of the present invention, by providing at least two independent cavities on the metal heat sink body, filling each cavity with a composite phase change material, and then using a metal cover plate matching the cavity to seal each cavity respectively. Through the design of the heat sink structure and the optimized combination of the composite phase change material, when the temperature changes during the operation of the LD component, the composite phase change material can undergo a phase change in a short time, so that the composite phase change material can fully exert its heat storage and heat absorption capabilities, and timely control the temperature of the LD component packaged on the surface of the heat sink structure, which is beneficial to ensuring the stability of the light output efficiency of the LD component.

[0044] According to some preferred embodiments, both the metal heat sink body and the metal cover plate are made of aluminum alloy.

[0045] In the embodiments of the present invention, both the metal heat sink body and the metal cover plate are made of aluminum alloy. For example, it can be made of 6063 aluminum alloy material, so as to ensure the overall lightness and good heat conductivity of the heat sink structure.

[0046] According to some preferred embodiments, three mutually independent cavities are provided on the metal heat sink body, and the upper surface of each cavity is in an open state.

[0047] In the embodiments of the present invention, it is found that, as Figure 1 and Figure 2 shown, by providing three mutually independent cavities on the metal heat sink body, sharing a cavity wall between every two adjacent cavities, and controlling the wall thickness between each adjacent cavity to be 2-4 mm, and further filling a composite phase change material in each cavity. In this way, when the temperature changes, the cavity wall between adjacent cavities can act as a heat conducting material, which can not only make the composite phase change material in each cavity uniformly absorb heat from different directions, so as to quickly undergo a phase change to absorb heat, which is beneficial to further improving the heat dissipation efficiency of the heat sink structure; moreover, it can avoid the problem of heat sink structure thermal runaway or damage caused by uneven cavity heat in the heat sink structure.

[0048] According to some preferred embodiments, the filling volume of the composite phase change material does not exceed 95% of the cavity volume; in the composite phase change material, the support plate is made of metal copper, the heat conducting material is expanded graphite flakes, and the phase change material is paraffin or barium hydroxide.

[0049] In the embodiments of the present invention, the composite phase change material uses a metal copper plate as the support plate, supplemented with a certain amount of heat conducting material and phase change material. Specifically, the support plate is made of electrolytic copper with a purity >99.9%, a porosity greater than 85%, a thickness of 7-9 mm, and a heat transfer coefficient greater than 6 W / (m 2K), the PPI (number of pores per inch) is 10-20. This not only helps ensure that the composite phase change material as a whole has a certain mechanical strength and durability, but also helps make the temperature distribution inside the heat sink body uniform. The thermal conductive material is made from expanded graphite flakes at high temperature. During the expansion process, the interlayer lattice defects of the graphite flakes increase, forming a unique network pore system and expanded graphite flakes with a large apparent volume. The expanded graphite flakes not only maintain the hexagonal crystal structure of natural graphite but also possess excellent properties such as high temperature resistance, corrosion resistance, anisotropy, and good thermal conductivity of natural graphite. The particle size of the expanded graphite flakes is preferably 90-110 mesh, and the expansion volume is preferably 180-210 mL / g. In this way, it can ensure that the expanded graphite flakes have good thermal conductivity. When the temperature changes, the thermal conductive material can quickly transfer heat to the phase change material, thereby ensuring its rapid response to temperature changes, further ensuring uniform temperature distribution inside the heat sink structure, and avoiding local overheating. At the same time, in order to ensure that the phase change material has good temperature response performance, the thermal cycle life of the phase change material should be not less than 2000 times, and the attenuation of heat storage and heat release capacity is less than 10%. The phase change material in the embodiments of the present invention is preferably 64# fully refined paraffin wax.

[0050] Considering that the composite phase change material will expand in volume after phase change, therefore, when filling the composite material, it should be ensured that there are no obvious bubbles inside the composite phase change material, the surface is smooth and flat after filling, without obvious unevenness. At the same time, the filling volume of the composite phase change material should not be greater than 95% of the cavity volume. In this way, not only can the composite phase change material play its role fully, but also it can provide sufficient space for the volume change caused by the phase change transformation of the composite phase change material, so that the heat sink structure has better stability.

[0051] In summary, in the embodiments of the present invention, by using high-performance phase change materials, thermal conductive materials, and support plate materials together as the composite phase change material, and through the reasonable design of the metal heat sink body structure, and further filling the composite phase change material into the cavity of the metal heat sink body, the high-efficiency heat dissipation performance of the heat sink structure is achieved. It can not only absorb a large amount of heat in a short time but also extend the heat dissipation cycle, which is beneficial to ensuring the reliability of the light-emitting performance of the LD component.

[0052] According to some preferred embodiments, as Figures 3 to 5 shown, a heat dissipation film is compounded on the bottom of each cavity and the inner and outer surfaces of each metal cover plate; the heat dissipation film is a graphene film, and the thickness of the heat dissipation film is 0.4-0.6 mm (for example, it can be 0.4 mm, 0.5 mm, or 0.6 mm).

[0053] As Figures 3 to 5As shown, in the embodiments of the present invention, before using the metal cover plate to seal each cavity, a heat dissipation film is further compounded on the inner surface of the metal cover plate, and after the cavity is sealed, a heat dissipation film is further compounded on the bottom of the cavity and the outer surface of the metal cover plate. The heat dissipation film is a graphene film with light weight, high modulus, strong chemical stability and high thermal conductivity, which is beneficial to further enhancing the heat dissipation performance of the heat sink structure and solving problems such as difficult heat dissipation caused by high integration of electronic devices.

[0054] According to some preferred embodiments, several second through holes are further provided at the edge of the metal heat sink main body, and the second through holes are used to fix the heat sink structure.

[0055] In the embodiments of the present invention, continue to refer to Figures 1 to 2 , several second through holes 103 are further provided at the edge of the metal heat sink main body. The second through holes 103 are preferably arranged at the four corner positions of each cavity, and subsequent screws are used to cooperate with the second through holes 103 to realize the fixed packaging of the heat sink structure and other devices.

[0056] The present invention also provides a preparation method of the heat sink structure for LD component packaging described in any one of the above, and the preparation method includes the following steps:

[0057] (1) Determine the filling amount of the composite phase change material according to the preset target temperature, and prepare the heat conduction material and the phase change material respectively;

[0058] (2) Determine the volume of each cavity in the metal heat sink main body according to the filling amount of the composite phase change material;

[0059] (3) After loading the phase change material on the surface of the heat conduction material, fill each cavity with the support plate respectively;

[0060] (4) Fix the metal cover plate with a heat dissipation film compounded on the inner surface on the upper surface of each cavity respectively, and further compound a heat dissipation film on the upper and lower surfaces of each cavity respectively to obtain the heat sink structure for LD component packaging.

[0061] In the embodiment of the present invention, first, a preset target temperature (i.e., the highest temperature at which the LD component can work normally) is determined according to the working temperature of the LD component. When the temperature during the operation of the LD component reaches the target temperature, the composite phase change material in the heat sink structure undergoes a phase change for heat dissipation, so that the temperature of the contact area between the LD component and the heat sink structure is always within the safe temperature range for the operation of the LD component, thereby ensuring the reliability of the performance of the LD component. In the embodiment of the present invention, for example, the preset target temperature can be determined as 68 °C. Then, according to parameters such as the preset target temperature and the heat release amount of the phase change material, the volume of the phase change material is determined. Further, according to the proportional relationship between the thermal conductive material and the phase change material, the thickness parameter of the support plate, and the proportional relationship between the filling amount of the composite phase change material and the cavity, the volume of each cavity in the metal heat sink body is determined to obtain the structure of the metal heat sink body. After the thermal conductive material and the phase change material are compounded, they are jointly filled into each cavity with the support plate. Finally, each cavity is sealed with a metal cover plate with a heat dissipation film on its inner surface, and heat dissipation films are further compounded on the upper and lower surfaces of each cavity respectively to obtain a heat sink structure for LD component packaging.

[0062] In the embodiment of the present invention, it is preferably to use welding to seal each cavity with a metal cover plate. During the welding process, first, the metal heat sink body and the metal cover plate are cleaned with cotton balls dipped in anhydrous ethanol and the surface moisture is removed. Further, the contact surfaces around the metal heat sink body and the metal cover plate are polished clean with 1500-mesh sandpaper. Then, each metal cover plate is respectively placed on the opening on the upper surface of each cavity of the metal heat sink body and observed for any concave-convex gaps. Finally, the heat sink structure is placed on a laser welding table as a whole and fixed with a rack, the movement path of the laser welding head is programmed and the laser welding parameters are set for welding; among them, the laser power of the laser welding is 2000 W, the output power is 1500 W, and the welding speed is 210 cm / min.

[0063] According to some preferred embodiments, in step (3), the loading rate of the phase change material on the surface of the thermal conductive material is greater than 85%.

[0064] In the embodiment of the present invention, by loading the phase change material on the surface of the thermal conductive material and reasonably controlling the loading rate of the phase change material, it is not only beneficial to reduce the contact thermal resistance between the thermal conductive material and the phase change material and ensure efficient heat exchange, but also the thermal conductive material can quickly transfer heat to the phase change material, ensuring that the phase change material undergoes a phase change in a short time to quickly absorb or release heat.

[0065] According to some preferred embodiments, before loading the phase change material on the surface of the thermal conductive material, there is also a step of recrystallizing the phase change material.

[0066] In the embodiments of the present invention, the phase change material is preferably 64# fully refined paraffin. Before loading the phase change material onto the surface of the heat conductive material, the phase change material is first recrystallized to control the phase change temperature of the phase change material to a preset target temperature. When recrystallizing, for example, first cut the large block of paraffin into cubes with side lengths not exceeding 1 cm, weigh the fragmented paraffin and add it to a single-neck flask, place the flask on an oil bath at a temperature of 80 °C, heat and melt until the solid paraffin is completely melted into a liquid state, adjust the temperature of the oil bath to 64 °C, wait for the oil bath to cool to 64 °C and then keep it warm for 30 min, and the paraffin recrystallizes. After the paraffin recrystallizes, there are two states of paraffin, liquid phase and solid phase, in the flask. After removing the flask, quickly tilt it to pour out the liquid-phase paraffin, and retain the recrystallized solid-phase paraffin as the phase change material. Place the prepared recrystallized paraffin in a beaker, and place the beaker on a heating platform to heat and melt it. Wait for the solid paraffin to completely melt to form a clear and transparent liquid paraffin.

[0067] According to some preferred embodiments, in step (3), the support plate is embedded between the phase change material and the heat conductive material.

[0068] The heat conductive material is prepared by the following method: Place an alumina crucible in a muffle furnace at 800 °C and burn it for 30 min, then take it out. Weigh a certain amount of graphite flakes and place them in the preheated crucible. Spread the graphite flakes evenly on the bottom layer of the crucible to avoid accumulation causing uneven temperature, which will affect the expansion rate. Place the alumina crucible containing the graphite flakes in a tubular furnace and tighten the furnace plug. Set the heating program as a temperature of 800 °C, a heating rate of 5 °C / min, and a holding time of 30 min. Open the Ar gas valve with a gas flow rate of 80 mL / min. After purging for 20 min, start heating and adjust the flow rate to 20 mL / min. After the tubular furnace cools down, open it and take out the crucible to obtain expanded graphene flakes. Then, accurately weigh 50 mg of expanded graphene flakes and spread them flat in a stainless steel tablet press mold with a diameter of 18 mm, keeping the expanded graphene flakes flat and without concavities or convexities. Place the stainless steel tablet press mold in the center of the tablet press, apply a pressure of 3×10 -5 MPa for a working time of 100 s to press the graphite flakes into a cylinder with a height of 4 mm and a diameter of 18 mm, obtaining an expanded graphene flake cylinder.

[0069] The phase change material is loaded onto the surface of the heat conductive material in the following manner: Immerse the prepared expanded graphene flake cylinder in the liquid paraffin obtained after recrystallization to make the expanded graphene flake cylinder fully loaded with high-purity liquid paraffin. Take out the expanded graphene flake cylinder from the liquid paraffin every 1 min and weigh it to make the loading rate of the expanded graphene flake cylinder greater than 85%. Weigh the loaded graphene flake cylinder and record it as M 1 , and the original weight of the graphene flake cylinder is M 0 (M0 = 0.05 g), loading ratio = [(M 1 - M0) / (M 1 + M 0 )] × 100%.

[0070] In the embodiments of the present invention, after the phase change material is loaded on the surface of the heat-conducting material, the cavity is filled. First, the heat-conducting material loaded with the phase change material (graphene flake encapsulated paraffin cylinder) is placed in a glass petri dish, and the petri dish is placed on a heating plate. The temperature is set to 100 °C and heated for 30 min until the graphene cylinder softens. At this time, the graphene cylinder is in a state similar to putty and can be molded. Then, it is filled into the cavity, pressed flat, and after being laid flat on the bottom of the cavity, pressure is applied to make the phase change material and the heat-conducting material compact without bubbles. After filling 1 mm, a support plate is laid flat on it, and it is ensured that the support plate completely covers the heat-conducting material loaded with the phase change material. Then, the heat-conducting material loaded with the phase change material is continuously laid flat above the support plate, and the above steps are repeated until the filling amount is 95% of the volume of the cavity, and the filling of the composite phase change material is completed. Thus, in the embodiments of the present invention, the phase change material is first loaded into the heat-conducting material, and it is filled and compounded with the support plate in layers, so that materials with different properties are combined together, which is not only beneficial to providing sufficient heat storage capacity, but also ensures good heat conduction performance, thus ensuring better heat dissipation performance of the heat sink structure.

[0071] According to some preferred embodiments, the heat dissipation film is obtained by directional alignment using a microfluidic process; the thickness of the heat dissipation film is 0.4 - 0.6 mm (for example, it can be 0.4 mm, 0.5 mm or 0.6 mm), and the thermal conductivity is greater than 2300 W·m -1 ·K -1 .

[0072] In the embodiments of the present invention, the heat dissipation film is prepared by directional alignment using a microfluidic process. The preparation method of the heat dissipation film is as follows: N,N-dimethylformamide (DMF) is used as a dispersion aid for graphene oxide (GO). The 20 g / L GO dispersion is centrifuged at 8000 rpm for 15 minutes to remove the supernatant, and the GO solid is dispersed in DMF and centrifuged to remove the supernatant. The cleaning process is repeated five times to obtain the final 20 g / L GO / DMF solution; the GO / DMF solution is loaded onto an injection pump, and the GO / DMF solution is injected into the microfluidic channel at a flow rate of 1 ml / min; the electrospray device injection nozzle is adjusted to keep the distance between the nozzle and the substrate at 2 - 5 cm, and the graphene oxide nanosheet droplets arranged in a highly directional form in the microfluidic channel are injected into the electrospray device. The voltage of the injection nozzle is adjusted to 10 - 15 kV, and the fine graphene oxide droplets are deposited on the aluminum foil. The aluminum foil substrate is heated at 150 °C to remove the solvent to obtain the graphene oxide film (heat dissipation film).

[0073] According to some preferred embodiments, the heat dissipation film is compounded with the inner surface of the metal cover plate and the inner and outer surfaces of the cavity in the following manner. Taking the metal cover plate as an example, first, the heat dissipation film with a matching size is pasted on the inner surface of the metal cover plate. Then, the metal cover plate loaded with the heat dissipation film is placed in a sealed container, and a pressure of 1 MPa is applied to the surface of the heat dissipation film. Subsequently, a vacuum pump is started. After maintaining the vacuum for 20 minutes, a metal cover plate compounded with the heat dissipation film can be obtained. The method of compounding the heat dissipation film on the inner and outer surfaces of the cavity is the same as the above method, and will not be elaborated here.

[0074] It should be noted that when compounding the heat dissipation film on the inner and outer surfaces of the cavity, the heat dissipation film can adopt the covering method (blue area) in the present invention Figures 3 to 4 or the covering method (black area) Figure 5 in it.

[0075] In summary, in the embodiments of the present invention, through the reasonable optimization of the metal heat sink body and the internally compounded phase change material, the high-efficiency heat dissipation of the LD component is realized. The LD component is encapsulated on the heat sink structure. Under the condition of 60 °C, after the heating element LD component works for a period of time, it is found through testing that under the condition of 60 °C, for two heating element LD components with contact surface sizes of about 45 mm * 35 mm, the heat generation of each heating element LD component is 40 W. After working for 80 s, the temperature of the contact area between the heat sink structure and the LD component ≤ 68 °C, and the thermal conductivity of the thermal conduction film is not less than 200 W / (m*K). The heat sink structure in the present invention is applicable to the heat dissipation of electronic components in aircraft with severely limited working space.

[0076] In order to verify the influence of different phase change materials on the light output efficiency of the LD component, in the embodiments of the present invention, paraffin and barium hydroxide are used as phase change materials respectively, and the cavities of the metal heat sink body are filled with the composite phase change materials formed with the same thermal conductive material and support plate to obtain the heat sink structure. The LD component is encapsulated on the heat sink structure, and three sensors (such as Figures 6 to 7 ) are respectively arranged on the heat sink structure. The numbers of the sensors correspond to those in Table 1 respectively. The results of the three sensors are read every 10 s to record the light output power of the LD component, the temperature of the LD component and the temperature of the heat sink structure (remote sampling point 1 and proximal sampling point 2). The test results are as Figures 8 to 9 shown.

[0077] Table 1

[0078] LD component temperature Remote sampling point 1 of the heat sink structure Proximal sampling point 2 of the heat sink structure Sensor No. 1 Sensor No. 2 Sensor No. 3

[0079] From Figures 8 to 9From the test data, it can be seen that the heat sink structure using paraffin as the phase change material has excellent heat dissipation effect. The light output efficiency of the LD component encapsulated at its bottom has reached the expected effect. The prepared heat sink meets the requirements and improves the product reliability.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat sink structure for LD component packaging, characterized in that: include: A metal heat sink body, wherein at least two independent cavities are provided on the metal heat sink body, each cavity is filled with a composite phase change material, and a plurality of first through holes are provided at the bottom of the cavity, wherein the first through holes are used to fix the LD component; wherein the composite phase change material is composed of a support plate, a heat conductive material and a phase change material; At least two metal cover plates are provided, each of which is fixed to each cavity and is used to seal each cavity.

2. The heat sink structure according to claim 1, characterized in that: The metal heat sink body and the metal cover plate are both made of aluminum alloy.

3. The heat sink structure according to claim 1, characterized in that: The metal heat sink body is provided with three independent cavities, and the upper surface of each cavity is in an open state.

4. The heat sink structure according to claim 1, characterized in that: The filling volume of the composite phase change material is no more than 95% of the volume of the cavity; and / or In the composite phase change material, the support plate is metal copper, the thermal conductive material is expanded graphene flakes, and the phase change material is paraffin or barium hydroxide.

5. The heat sink structure according to claim 4, characterized in that: The porosity of the support plate is greater than 85%, the thickness is 7-9 mm, and the heat transfer coefficient is greater than 6 W / (m 2 K); The particle size of the thermal conductive material is 90-110 mesh, and the expansion volume is 180-210 mL / g; The thermal cycle life of the phase change material is not less than 2000 times, and the heat storage and heat release capacity decay is less than 10%.

6. The heat sink structure according to claim 1, characterized in that: The bottom of each cavity and the inner and outer surfaces of each metal cover are composited with a heat dissipation film; Preferably, the heat dissipation film is a graphene film, and the thickness of the heat dissipation film is 0.4-0.6 mm.

7. The heat sink structure according to claim 1, characterized in that: A plurality of second through holes are also provided on the edge of the metal heat sink body, and the second through holes are used to fix the heat sink structure.

8. A method for preparing a heat sink structure for LD component packaging according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: (1) determining the filling amount of the composite phase change material according to a preset target temperature, and preparing a thermal conductive material and a phase change material respectively; (2) determining the volume of each cavity in the metal heat sink body according to the filling amount of the composite phase change material; (3) After the phase change material is loaded on the surface of the thermal conductive material, it is filled into each cavity together with the support plate; (4) The metal cover plate with the heat dissipation film on the inner surface is fixed to the upper surface of each cavity, and the heat dissipation film is further compounded on the upper and lower surfaces of each cavity to obtain the heat sink structure for LD component packaging.

9. The preparation method according to claim 8, characterized in that: In step (3), the loading rate of the phase change material on the surface of the thermal conductive material is greater than 85%; and / or The support plate is embedded in the phase change material and between the heat conductive materials.

10. The preparation method according to claim 8, characterized in that: Before the phase change material is loaded on the surface of the thermal conductive material, the method further comprises a step of recrystallizing the phase change material; and / or The heat dissipation film is obtained by directional arrangement using a microfluidic process; the thickness of the heat dissipation film is 0.4-0.6 mm, and the thermal conductivity is greater than 2300 W·m -1 ·K -1 .

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