A high power semiconductor laser packaging module and manufacturing method thereof

Abstract

The present application relates to the technical field of semiconductor laser chips, and in particular to a high-power semiconductor laser packaging module and a manufacturing method thereof. A high-power semiconductor laser packaging module includes a chip module, the chip module includes a semiconductor laser chip, a thermal interface material layer is provided below the semiconductor laser chip, a cooling layer is provided below the thermal interface material layer, a cooling channel is provided in the cooling layer, a cooling fluid flows in the cooling channel, a phase change layer is provided below the cooling layer, and a phase change material is provided in the phase change layer. The present application introduces a cooling layer and a phase change layer, and utilizes the heat absorption characteristics of water cooling and superimposed phase change materials to improve the heat dissipation effect of high-power semiconductor lasers. Beam shaping technology is introduced into the high-power laser chip packaging module, and a microlens module and a diffraction grating are used to achieve beam quality shaping and homogenization processing, so that the energy distribution of the output light spot is more uniform, thereby improving the performance of the power semiconductor laser.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor chips, and in particular to a high-power semiconductor laser packaging module and a manufacturing method thereof. Background Art

[0002] With the advancement of science and technology, high-power semiconductor lasers are being used more and more widely in many fields such as industrial processing, medical treatment, scientific research and measurement.

[0003] Chips are also developing towards high frequency, integration and miniaturization, which leads to increasing thermal power consumption of chips. To ensure that the laser has higher efficiency, better spectrum and higher output power, it is necessary to optimize the packaging and heat dissipation process of high-power semiconductor lasers, improve the thermal characteristics of the device, solve the heat dissipation problem and improve the spectrum quality. Summary of the invention

[0004] In order to improve the heat dissipation effect of the chip and enhance the spectrum quality, the present application provides a high-power semiconductor laser packaging module and a manufacturing method thereof.

[0005] One of the purposes of this application is to provide a high-power semiconductor laser packaging module, which adopts the following technical solution:

[0006] A high-power semiconductor laser packaging module comprises a chip module, wherein the chip module comprises a semiconductor laser chip, a thermal interface material layer is arranged below the semiconductor laser chip, a cooling layer is arranged below the thermal interface material layer, a cooling channel is arranged in the cooling layer, a cooling fluid flows in the cooling channel, a phase change layer is arranged below the cooling layer, and a phase change material is arranged in the phase change layer.

[0007] By adopting the above technical solution, the heat generated by the semiconductor laser chip during operation is transferred to the cooling layer through the thermal interface material layer. The cooling fluid flows in the cooling channel to cool the thermal interface material layer, thereby taking away the heat generated by the semiconductor laser chip. During the operation of the laser, when the temperature rises, the phase change material changes from solid to liquid and absorbs heat; when the temperature drops, it changes from liquid to solid and releases heat. In this way, the phase change material layer plays a role in stabilizing temperature fluctuations and preventing the laser from affecting performance due to excessive temperature changes. The cooling layer and the phase change layer are cooled by water and phase change respectively. The two cooling methods are combined to cool the semiconductor laser chip, improve the heat dissipation effect of the chip, and improve the spectral quality.

[0008] Preferably, a side of the thermal interface material layer close to the semiconductor laser chip is coated with a graphene layer.

[0009] By adopting the above technical solution, graphene has high thermal conductivity and can transfer the heat emitted by the semiconductor laser chip to the thermal interface material layer more evenly, preventing the local temperature from being too high and affecting the performance of the semiconductor laser chip.

[0010] Preferably, the thermal interface material layer is composed of an aluminum nitride transition heat sink.

[0011] By adopting the above technical solution, the aluminum nitride heat sink can improve the heat dissipation capacity of the semiconductor laser chip and ensure the stability and reliability of the semiconductor laser chip when working at high power.

[0012] Preferably, the cooling layer is made of copper.

[0013] By adopting the above technical solution, copper has good thermal conductivity and can quickly transfer heat to ensure the cooling effect of the cooling fluid.

[0014] Preferably, the melting point of the phase change material is 45-50°C.

[0015] By adopting the above technical solution, the phase change material undergoes phase change within this temperature range, thereby stabilizing the temperature of the laser and preventing the temperature from being too high, thereby affecting the performance of the laser.

[0016] Preferably, it further comprises a beam shaping module, which comprises a microlens array and a diffraction grating. The microlens array is located at the output end of the semiconductor laser chip, and the diffraction grating is located on a side of the microlens array away from the semiconductor laser chip.

[0017] By adopting the above technical solution, the microlens array is used to focus or collimate the laser beam to improve the spatial distribution of the beam. The diffraction grating follows the microlens array and disperses the incident beam into multiple diffraction orders through the diffraction effect of light to achieve beam homogenization. By adjusting the diffraction angle and period of the diffraction grating, the uniformity and coverage of the beam can be optimized.

[0018] Preferably, the microlens array comprises one or more microlenses.

[0019] By adopting the above technical solution, a single microlens or a combination of multiple microlenses can be selected as needed to adapt to laser beams with different divergence angles and focusing requirements.

[0020] Preferably, it further comprises a shell, in which the chip module and the beam shaping module are packaged, and the shell is provided with electrical and fluid interfaces.

[0021] By adopting the above technical solution, the microlens array and the diffraction grating element are integrated into the packaging module to achieve the shaping and homogenization of the outgoing beam quality, and obtain a laser light intensity distribution with uniform energy density in the far field of the application end.

[0022] Preferably, the phase change layer includes an outer layer body and an inner layer body, the phase change material is located in the inner layer body, the lower surface of the inner layer body is connected to the outer layer body through a phase change rod made of a memory alloy, the length of the phase change rod at a low temperature is greater than the length of the phase change rod at a high temperature, and when the phase change rod is at a low temperature, the upper surface of the inner layer body is in contact with the cooling layer.

[0023] By adopting the above technical solution, the outer layer supports the inner layer, the phase change rod is longer at room temperature, the inner layer contacts the cooling layer and absorbs the heat of the cooling layer. After the cooling fluid absorbs heat, the temperature gradually rises, and the heat absorption capacity decreases. The phase change material absorbs the heat of the cooling fluid to ensure the cooling effect of the cooling fluid. After the phase change material changes from solid to liquid, the heat absorption capacity of the inner layer decreases, and it needs to release heat to restore the heat absorption capacity. After the overall temperature of the inner layer increases, it is transferred to the phase change rod. The heat absorption temperature of the phase change rod increases, and the deformation occurs, and its own length becomes shorter, so that the upper surface of the inner layer is separated from the cooling layer, and the heat transfer effect of the cooling layer to the inner layer is deteriorated. The phase change material in the inner layer can dissipate heat through the gap between the two. After the temperature is lowered, the phase change rod is reset, and the inner layer contacts the cooling layer again to cool the cooling layer. The dynamic change process of the phase change rod accelerates the heat dissipation speed of the phase change material, thereby ensuring the heat absorption efficiency of the phase change material to improve the heat dissipation effect.

[0024] Another object of the present application is to provide a method for manufacturing a high-power semiconductor laser packaging module, using the following technical solution:

[0025] A method for manufacturing a high-power semiconductor laser packaging module, applied to the above-mentioned high-power semiconductor laser packaging module, comprises the following steps:

[0026] S1. Select a suitable semiconductor laser chip and fix it on the thermal interface material layer; this thermal interface material layer is composed of a material with high thermal conductivity, which is used to fill tiny gaps and eliminate air gaps to improve the efficiency of heat conduction from the chip to the outside world;

[0027] S2. A cooling layer is arranged below the thermal interface material layer. Cooling channels are designed inside the cooling layer. Through fluid dynamics optimization, cooling fluid can flow through these channels to take away the heat from the laser chip.

[0028] S3. Arrange a phase change material layer below the cooling layer. This layer of material has the ability to undergo phase change at a specific temperature, can absorb and release heat, and form a chip module;

[0029] S4, integrating the microlens array and the diffraction grating into the beam shaping module to shape and homogenize the output beam of the laser chip;

[0030] S5. Encapsulate the beam shaping module and the chip module in a housing having standardized electrical and fluid interfaces for easy connection and use.

[0031] In summary, the present application includes at least one of the following beneficial technical effects:

[0032] 1. Based on the traditional high-power semiconductor packaging which only has a thermal interface material layer, the cooling layer and phase change layer are innovatively introduced, and the heat absorption characteristics of the phase change material are superimposed on the water cooling, thereby greatly improving the heat dissipation effect of the high-power semiconductor laser;

[0033] 2. Beam shaping technology is introduced in high-power laser chip packaging modules. Microlens modules and diffraction gratings are used to shape and homogenize the beam quality, making the energy distribution of the output light spot more uniform, which helps to improve the performance of power semiconductor lasers in various precision processing and medical treatment applications;

[0034] 3. The phase change layer is set as a double layer, and the two are connected by a phase change rod made of memory alloy. When the temperature of the inner layer is low, the inner layer contacts the cooling layer to absorb heat. When the temperature of the inner layer is high, the phase change rod becomes shorter and the inner layer is separated from the cooling layer. The dynamic change process of the phase change rod accelerates the heat dissipation speed of the phase change material, thereby ensuring the heat absorption efficiency of the phase change material to improve the heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the embodiment;

[0036] Figure 2 is a schematic structural diagram of a chip module in an embodiment;

[0037] Figure 3 Schematic diagram of the structure of the phase change layer in the embodiment.

[0038] Description of reference numerals:

[0039] 1. Semiconductor laser chip; 2. Thermal interface material layer; 3. Cooling layer; 31. Cooling channel; 4. Phase change layer; 41. Outer layer; 42. Inner layer; 43. Phase change rod; 5. Graphene layer; 61. Microlens array; 62. Diffraction grating; 7. Outer shell. DETAILED DESCRIPTION

[0040] The present application is further described in detail below in conjunction with all the accompanying drawings.

[0041] Embodiment 1

[0042] The present application embodiment discloses a high-power semiconductor laser packaging module, referring to Figure 1, including chip module and beam shaping module.

[0043] The chip module includes a semiconductor laser chip 1, a graphene layer 5, a thermal interface material layer 2, a cooling layer 3 and a phase change layer 4 which are arranged in sequence. The heat generated by the semiconductor laser chip 1 is uniformly transferred to the thermal interface material layer 2 through the graphene layer 5, and the cooling layer 3 and the phase change layer 4 absorb heat and cool the thermal interface material layer 2.

[0044] Reference Figure 1 and Figure 2 The thermal interface material layer 2 is made of an aluminum nitride transition heat sink, and the thickness of the aluminum nitride transition heat sink is 1-2 mm. Aluminum nitride has high thermal conductivity and is used to fill tiny gaps and eliminate air gaps to improve the efficiency of heat conduction from the semiconductor laser chip 1 to the outside world. Graphene material is plated on the heat sink surface of the thermal interface material layer 2 to form a graphene layer 5, and the thickness of the graphene material is 50-100um.

[0045] Reference Figure 1 and Figure 2 The cooling layer 3 is made of copper material and has good thermal conductivity. The cooling layer 3 includes a cooling channel 31 evenly arranged below the thermal interface material layer 2. A cooling fluid flows in the cooling channel 31, and the cooling fluid can be water or a coolant, which is used to absorb heat from the thermal interface material layer 2.

[0046] Reference Figure 1 and Figure 2 The width and depth of the cooling channel 31 are designed to be 200 microns and 100 microns respectively, and the channel spacing of the cooling channel 31 is 400 microns. Through water cooling, the flow rate is controlled at 2-5 mL / min to ensure efficient heat transfer.

[0047] Reference Figure 1 and Figure 2 , the cooling fluid transfers heat from the thermal interface material layer 2 to the phase change layer 4. The phase change layer 4 is provided with a phase change material with a balanced temperature. During the operation of the laser, when the temperature rises, the phase change material changes from a solid state to a liquid state, absorbing heat; when the temperature drops, it changes from a liquid state to a solid state, releasing heat. In this way, the phase change material layer plays a role in stabilizing temperature fluctuations, preventing the laser from affecting performance due to excessive temperature changes.

[0048] Reference Figure 1 and Figure 2 The phase change material is an organic germanium compound with a melting point of 45-50°C, such as 48°C. The phase change material can effectively absorb heat and release it when the laser is turned off to maintain temperature stability.

[0049] Reference Figure 2 and Figure 3The phase change layer 4 includes an outer layer body 41 and an inner layer body 42. The outer layer body 41 is connected to the cooling layer 3 and supports the inner layer body 42. The outer layer body 41 is hollow inside, and the bottom of the inner layer body 42 is connected to the bottom of the outer layer body 41 through the phase change rod 43, and the upper surface of the inner layer body 42 is exposed to the surface of the outer layer body 41 for contacting the cooling layer 3. The inner layer body 42 is hollow, and the phase change material is placed in the inner layer body 42. The inner layer body 42 is made of low thermal conductivity materials such as chromium, etc.; the upper and lower surfaces of the inner layer body 42 are made of high thermal conductivity materials such as copper, etc.

[0050] Reference Figure 2 and Figure 3 The contact area between the upper surface of the inner layer 42 and the cooling layer 3 is large, and has good heat transfer. The phase change material in the inner layer 42 absorbs the heat of the cooling layer 3 and undergoes phase change itself.

[0051] Reference Figure 2 and Figure 3 The phase change rod 43 is made of a memory alloy, such as a nickel-titanium alloy. The length of the phase change rod 43 at room temperature is greater than the length of the phase change rod 43 at high temperature. The high temperature here refers to the temperature threshold when the memory alloy itself is deformed, and the temperature threshold is slightly greater than the melting point of the phase change material, that is, about 50°C. When the phase change rod 43 is at room temperature, the upper surface of the inner layer 42 contacts the cooling layer 3. After the temperature of the phase change rod 43 exceeds its own temperature threshold and deforms, the upper surface of the inner layer 42 separates from the cooling layer 3.

[0052] Reference Figure 2 and Figure 3 , the heat generated by the semiconductor laser chip 1 during normal operation is transferred to the phase change material through the cooling fluid, and the phase change material absorbs heat and undergoes phase change. When the phase change material in the inner layer 42 is completely liquefied, its own heat absorption capacity is greatly reduced. At this time, the phase change material transfers heat to the phase change rod 43 through the lower surface of the inner layer 42. The phase change rod 43 is heated, and its own temperature exceeds the threshold and becomes shorter. The upper surface of the inner layer 42 and the cooling layer 3 fall off, and a gap is formed between the two. The cooling layer 3 and the phase change material can both dissipate heat through the gap, which on the one hand ensures the heat dissipation capacity of the cooling layer 3, and on the other hand accelerates the heat dissipation speed of the phase change material. When the phase change material dissipates heat and re-solidifies, the temperature of the phase change rod 43 is lower than its own threshold, and it becomes longer again. The inner layer 42 contacts the cooling layer 3 again, and the cooling layer 3 absorbs heat and cools down.

[0053] Reference Figure 2 and Figure 3 The chip module includes an output end for emitting laser light, and the beam shaping module is installed at the output end of the chip module to shape and homogenize the output beam. The beam shaping module includes a microlens array 61 and a diffraction grating 62, and the microlens array 61 includes one or more microlenses.

[0054] Reference Figure 1 The microlens array 61 is used to focus or collimate the laser beam to improve the spatial distribution of the beam. As required, a single microlens or a combination of multiple microlenses can be selected to adapt to laser beams with different divergence angles and focusing requirements. Usually, the aperture size of each microlens is set to a range of tens to hundreds of nanometers, and the microlens is made of optical grade polymer or quartz glass to ensure light transmittance and high power resistance.

[0055] Reference Figure 1 The diffraction grating 62 is located on the side of the microlens array 61 away from the semiconductor laser chip 1. Through the diffraction effect of light, the incident light beam is dispersed into multiple diffraction orders to achieve the uniformity of the light beam. It can be designed as a one-dimensional or two-dimensional diffraction grating 62 according to the needs. By adjusting the diffraction angle and period of the diffraction grating 62, the uniformity and coverage of the light beam can be optimized. In this embodiment, quartz glass is selected as the substrate of the diffraction grating 62, the grating period is 1 micron, the etching depth is 0.5 micron, and the grating orientation is 0 degrees (perpendicular to the laser propagation direction).

[0056] Reference Figure 1 ,In actual design, detailed simulation and experimental verification are required according to the specific wavelength and ,application scenario of the laser, as well as the refractive index of the grating material and ,other factors.,The design and fabrication of the diffraction grating 62 is an iterative process that ,requires multiple experiments to optimize the parameters.

[0057] Reference Figure 1 Through the above steps and parameter design, the coherent superposition of sub-beams can be effectively achieved, and a uniform intensity distribution can be obtained in the far field. This helps to improve the performance of power semiconductor lasers in various applications such as precision machining and medical treatment.

[0058] Reference Figure 1 The chip module and the beam shaping module are integrated and packaged in the housing 7. The housing 7 is made of aluminum alloy, has a size of 100mm x 50mm x 20mm, and weighs no more than 100 grams. The electrical interface uses a standard Sub-D9 pin connector, and the fluid interface uses a LEMO connector to achieve fast and convenient electrical and fluid connections. A fan facing the chip module can also be installed on the housing 7 to improve the heat dissipation effect of the chip module.

[0059] The implementation principle of a high-power semiconductor laser packaging module in the embodiment of the present application is as follows: the heat generated by the semiconductor laser chip 1 during operation is transferred to the thermal interface material layer 2 through the graphene layer 5, and the cooling fluid in the cooling layer 3 and the phase change material in the phase change layer 4 cooperate with each other to absorb the heat through water cooling and phase change cooling to reduce the temperature of the semiconductor laser chip 1. The light beam emitted by the semiconductor laser chip 1 is shaped and homogenized by the beam shaping module to improve the beam quality.

[0060] Embodiment 2

[0061] The present application embodiment discloses a method for manufacturing a high-power semiconductor laser packaging module, which is applied to a high-power semiconductor laser packaging module in the above embodiment, and includes the following steps:

[0062] S1. Select a suitable semiconductor laser chip and fix it on the thermal interface material layer; this thermal interface material layer is composed of a material with high thermal conductivity, which is used to fill tiny gaps and eliminate air gaps to improve the efficiency of heat conduction from the chip to the outside world;

[0063] S2. A cooling layer is arranged below the thermal interface material layer. Cooling channels are designed inside the cooling layer. Through fluid dynamics optimization, cooling fluid can flow through these channels to take away the heat from the laser chip.

[0064] S3. Arrange a phase change material layer below the cooling layer. This layer of material has the ability to undergo phase change at a specific temperature, can absorb and release heat, and form a chip module;

[0065] S4, integrating the microlens array and the diffraction grating into the beam shaping module to shape and homogenize the output beam of the laser chip;

[0066] S5. Encapsulate the beam shaping module and the chip module in a housing having standardized electrical and fluid interfaces for easy connection and use.

[0067] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high-power semiconductor laser packaging module, including a chip module, characterized in that: The chip module comprises a semiconductor laser chip (1), a thermal interface material layer (2) is provided below the semiconductor laser chip (1), a cooling layer (3) is provided below the thermal interface material layer (2), a cooling channel (31) is provided in the cooling layer (3), a cooling fluid flows in the cooling channel (31), a phase change layer (4) is provided below the cooling layer (3), a phase change material is provided in the phase change layer (4); the phase change layer (4) comprises an outer layer body (41) and an inner layer body (42), the phase change material is arranged in the inner layer body (42), and the inner layer body (42) has a surface below the surface. The inner layer (42) is connected to the outer layer (41) through a phase change rod (43) made of a memory alloy. The length of the phase change rod (43) when it is at a low temperature is greater than the length of the phase change rod (43) when it is at a high temperature. When the phase change rod (43) is at a low temperature, the upper surface of the inner layer (42) contacts the cooling layer (3). When the phase change rod (43) is at a high temperature, the phase change rod (43) is deformed, and the upper surface of the inner layer (42) is separated from the cooling layer (3). The high temperature refers to a temperature higher than a temperature threshold when the memory alloy itself is deformed, and the low temperature refers to a temperature lower than a temperature threshold when the memory alloy itself is deformed.

2. A high-power semiconductor laser packaging module according to claim 1, characterized in that: A graphene layer (5) is plated on the side of the thermal interface material layer (2) close to the semiconductor laser chip (1).

3. The high-power semiconductor laser packaging module according to claim 1, characterized in that: The thermal interface material layer (2) is composed of an aluminum nitride transition heat sink.

4. The high-power semiconductor laser packaging module according to claim 1, characterized in that: The cooling layer (3) is made of copper.

5. The high-power semiconductor laser packaging module according to claim 1, characterized in that: The melting point of the phase change material is 45-50°C.

6. The high-power semiconductor laser packaging module according to claim 1, characterized in that: It also comprises a beam shaping module, the beam shaping module comprising a microlens array (61) and a diffraction grating (62), the microlens array (61) being located at the output end of the semiconductor laser chip (1), and the diffraction grating (62) being located at a side of the microlens array (61) away from the semiconductor laser chip (1).

7. A high-power semiconductor laser packaging module according to claim 6, characterized in that: The microlens array (61) comprises at least one microlens.

8. The high-power semiconductor laser packaging module according to claim 6, characterized in that: It also comprises a housing (7), wherein the chip module and the beam shaping module are packaged in the housing (7), and the housing (7) is provided with electrical and fluid interfaces.

9. A method for manufacturing a high-power semiconductor laser packaging module, characterized in that: A high-power semiconductor laser packaging module as described in any one of claims 1 to 8, comprising the following steps: S1. Fixing a high-power semiconductor laser chip on a thermal interface material layer; the thermal interface material layer is composed of a material with high thermal conductivity, which is used to fill tiny gaps and eliminate air gaps to improve the efficiency of heat conduction from the chip to the outside world; S2. A cooling layer is arranged below the thermal interface material layer. Cooling channels are designed inside the cooling layer. Through fluid dynamics optimization, cooling fluid can flow through these channels to take away the heat from the laser chip. S3. Arrange a phase change material layer below the cooling layer. The phase change layer is provided with a phase change material with a balanced temperature, which can absorb and release heat to form a chip module. The phase change material is an organic germanium compound with a melting point controlled at 45-50°C. S4, integrating the microlens array and the diffraction grating into the beam shaping module to shape and homogenize the output beam of the laser chip; S5. Encapsulate the beam shaping module and the chip module in a housing having standardized electrical and fluid interfaces for easy connection and use.

Images