A high-power module for surface-emitting laser chips

Abstract

The present invention relates to a high-power module for surface-emitting laser chips, including multiple cold plates, each of which is encapsulated with a number of surface-emitting laser chips, and multiple cold plates are stacked to form a high-power semiconductor laser module with a stacked heat dissipation structure. The high-power module of the present invention is a new attempt at high thermal density integration of surface-emitting laser chips. Compared with traditional stacked lasers, it can also achieve high-power and high thermal density heat dissipation, because the requirements of surface-emitting laser chips on the use environment are lower than those of edge-emitting laser chips, allowing high-power lasers to be applied to some harsh use environments.

Description

Technical Field

[0001] The invention relates to the field of laser technology, in particular to a high-power module for a surface-emitting laser chip. Background Art

[0002] In the past, in the field of high-power semiconductor lasers, edge-emitting semiconductor lasers based on GaAs materials have always dominated and are widely used in industry, medicine, scientific research and other fields. However, edge-emitting semiconductor lasers have fatal defects. Although the expected life span is tens of thousands of hours, the probability of optical catastrophic damage is extremely high in the pulse state, which has a serious impact on the life span. Its actual service life is far from the ideal expectation. At the same time, with the increase of power and the increase of the two-dimensional stacking of edge-emitting modules, the actual effect will continue to decline. Therefore, it is necessary to develop new semiconductor lasers that can be used in the industrial field.

[0003] Since 1980, a large number of new achievements in semiconductor physics research have emerged in the scientific community, such as crystal epitaxial growth technology (such as metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE) and chemical beam epitaxy (CBE), which have enabled semiconductor lasers to successfully apply new quantum well and strained quantum well structures. At the same time, semiconductor laser chip packaging technology and beam shaping technology have made great progress and achieved major breakthroughs, which have greatly expanded the types and wavelengths of semiconductor lasers. At present, according to the relationship between the light-emitting direction and the plane of the epitaxial wafer where the laser chip is located, lasers can be divided into edge emitting semiconductor lasers (EEL-Edge Emitting Laser Diode), vertical cavity surface emitting lasers (VCSEL-VerticalCacity Surface Emitting Laser) and the latest horizontal cavity surface emitting lasers (HCSEL-HorizontalCacity Surface Emitting Laser). Laser), in which the light emission direction of VCSEL and HCSEL is perpendicular to the direction of the epitaxial wafer and is emitted from the top surface of the reaction area, while the light emission direction of the edge-emitting semiconductor laser is parallel to the direction of the epitaxial wafer and is emitted from the edge of the reaction area. Due to structural reasons, the two surface-emitting laser chips have the advantages of high surface reflectivity, long expected life, low failure rate, ability to withstand high operating temperatures and uniform body heating. At the same time, its packaging is simple, similar to the LED packaging process. With the development of technology, the power of single surface-emitting lasers is getting closer and closer to bars, so it is becoming more and more eye-catching in the high-power field.

[0004] Nowadays, high-power semiconductor lasers have become a hot spot for various countries to pursue with their broad application prospects and huge potential market. However, their reliability, stability, consistency and other issues have largely limited their practical applications. One of the problems faced by high-power semiconductor lasers is the performance of the laser, that is, the output photoelectric conversion efficiency of the laser (that is, the ratio of output optical power to input electrical power).

[0005] In addition to being related to the laser epitaxial material and packaging, these problems are largely affected by the overall heat density and heat dissipation efficiency - heat will affect the chip loss-gain ratio, affect the chip's luminous efficiency, and also have a certain impact on the output wavelength. Traditional stacked lasers are only suitable for the high-heat density integration of edge-emitting laser chip bars. The small luminous area of ​​edge-emitting laser chips has strict requirements on the use environment. Due to the small luminous area, they are easily damaged by environmental interference. The optical path shaping of the edge-emitting integrated module is tooling. Some micro-lenses are on the module, which requires more micro-machining. Subsequent assembly also requires a lot of precise tooling operations, which will result in a high defect rate.

[0006] At present, the heat sinks of lasers on the market have internal microchannels for heat dissipation. However, the internal flow channel water pressure adjustment is troublesome, and the component process is relatively complicated. Currently, not many manufacturers can achieve this. Since the microchannel is a microchannel, it is very easy to get blocked when the fluid is not clean, and the only way is to replace the blocking plate, and the maintenance cost is relatively high. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a high-power module for surface-emitting laser chips to solve the problems of the existing high-power modules such as lack of reliability, stability, consistency, and strict requirements for the use environment.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] A high-power module for surface-emitting laser chips comprises a plurality of cold plates, each of which is packaged with a number of surface-emitting laser chips, and the plurality of cold plates are stacked to form a high-power semiconductor laser module with a stacked heat dissipation structure.

[0010] As some embodiments, each cold plate is packaged into a separate module; each cold plate is provided with an electrode module; a plurality of surface-emitting laser chips are packaged on each cold plate, arranged in sequence, connected in series with each other, and connected in series with the electrode module; the plurality of surface-emitting laser chips packaged on each cold plate are arranged in a row; the surface-emitting laser chips of multiple cold plates are arranged into a chip array.

[0011] As some embodiments, the surface emitting laser chip is a COS module, including a surface emitting laser and a heat sink, which is integrally welded to a cold plate through the heat sink; the heat generated by the surface emitting laser chip is transferred to the cold plate through the heat sink for heat dissipation; the cold plate is a high thermal conductivity metal plate; a limiting step groove is formed on the surface of the cold plate, and the surface emitting laser chip is aligned and welded in the step groove; there is a step difference distance between the electrode module arranged on the cold plate and the surface of the surface emitting laser chip to avoid a short circuit caused by direct contact of the connecting wires with the cold plate.

[0012] As some embodiments, a collimating lens is provided on the light-emitting surface of the surface-emitting laser chip to adjust the uniformity of the light beam of the surface-emitting laser chip; a collimating lens is provided on the light-emitting surface of a row of surface-emitting laser chips to adjust the uniformity of the light beam of the row of surface-emitting laser chips; a plurality of rows of parallel collimating lenses are provided on the light-emitting surface of the surface-emitting laser chip array to adjust the uniformity of the light beam of the surface-emitting laser chip array; the collimating lens is fixed to one side of the cold plate encapsulated with the surface-emitting laser chip by a collimating lens holder; the setting principle of the collimating lens is: when the emitted light of the surface-emitting laser chip reaches the collimating lens, the light beam width is within the effective surface range of the collimating lens lens width to ensure the light combining efficiency and the uniformity of the light output spot of the overall module.

[0013] As some embodiments, the setting principle of the collimating lens is: the emitted light of the emitting laser chip reaches the collimating lens just within the boundary of the lens width action surface to ensure the light combining efficiency; when the light is combined between adjacent cold plates, the upper and lower rows of light beams do not interfere with each other; there is only a residual position on both sides of the collimating lens in the width direction for gluing and fixing the lens; the emitted light of the surface emitting laser chip is a divergent light beam; the surface emitting laser chip is a HCSEL or VCSEL chip.

[0014] As some embodiments, each cold plate is processed with a coolant flow channel and a water inlet and a water outlet connected to the flow channel, so as to allow the coolant to be introduced into the flow channel from the water inlet and discharged from the water outlet, thereby dissipating heat for the surface emitting laser chip; the flow channel in the cold plate is sealed by a sealing gasket; multiple cold plates are laminated together to compress the sealing gasket.

[0015] As some embodiments, the flow channels in each cold plate are independently arranged, and the flow channels in multiple cold plates are connected in parallel with each other; the water inlets and water outlets of each cold plate are connected; at least one water inlet is connected to a water inlet pipe to connect to the coolant, and at least one water outlet is connected to a water outlet pipe to discharge the coolant and take away the heat.

[0016] As some embodiments, the flow channel in the cold plate is a macro channel flow channel; the flow channel is a slot formed by the top surface or the bottom surface of the cold plate, the slot is sealed by a sealing gasket, and the sealing gasket isolates each flow channel; the sealing gasket is provided with openings corresponding to the water inlet and water outlet of the flow channel in the cold plate, so that the water inlets of the flow channels of each layer of cold plates are connected and the water outlets are connected; bends are designed in the flow channel to lengthen the flow channel to increase the heat exchange efficiency; a number of protruding fins are provided in the flow channel to form a structure similar to a heat sink; a groove reflux structure is provided in the flow channel near the surface emitting laser chip.

[0017] As some embodiments, the flow channel in each cold plate extends along the length direction of the arrangement of the surface emitting laser chips; the surface emitting laser chips are arranged on the outer wall surface in the length direction of the cold plate; a groove structure is further formed on the protruding fins on the back side of the coolant flow direction, thereby forming a groove reflux structure; a number of protruding fins are also arranged in parallel, extending from one side of the packaged chip to the other side along the width direction of the cold plate, and are protrudingly arranged in the flow channel to resist the flow of coolant perpendicular to the flow direction or at a certain angle; the other inner side wall of the flow channel opposite to the chip mounting side forms a bend corresponding to the protruding fins.

[0018] As some embodiments, each layer of cold plate is provided with mounting holes around the flow channel and / or in the flow channel, and the cold plates and the sealing gaskets and the cold plates are fastened and pressed together by fasteners cooperating with the mounting holes; the topmost cold plate of the cold plate stack structure serves as the top sealing plate; the flow channel is provided at the bottom of the top sealing plate, and a mounting groove is provided at the top; another layer of sealing gasket is provided on the bottom wall of the mounting groove to cover and seal the mounting hole position in the flow channel, and a matching isolation plate is built into the mounting groove, and the isolation plate is pressed and sealed with the other layer of sealing gasket and fastened together with the top sealing plate, thereby forming an overall leak-proof structure.

[0019] The beneficial effects of the present invention are:

[0020] The high-power semiconductor laser module of the present invention has high-quality laser array bars and an efficient heat dissipation structure, and has high stability and high reliability. At the same time, the packaging structure is simple, efficient, low-cost, and convenient for wide application. The present invention is a new packaging structure for high-power modules of surface-emitting laser chip arrays, which increases the flexibility of high-power integration of surface-emitting laser chips, and can adjust the internal heat dissipation structure and the number of stacked cold plates according to compatible chips.

[0021] Furthermore, the high-power module for surface-emitting laser chips of the present invention is a new attempt for high-heat-density integration of surface-emitting laser chips. Compared with traditional stacked lasers, it can also achieve high-power and high-heat-density heat removal. However, traditional stacked lasers are only suitable for high-heat-density integration of edge-emitting laser chip bars, while this structure is suitable for high-density integration of various surface-emitting laser chips. Compared with the stringent requirements of the use environment for the small light-emitting area of ​​edge-emitting laser chips, the cost of coping with the use environment for high-power surface-emitting laser chips will be reduced a lot due to the large light-emitting surface. The present invention solves the problem of high-power integration of surface-emitting laser chips, allowing high-power lasers to be applied to some harsh use environments.

[0022] The laser of the present invention can directly use medium-sized optical lenses on the surface-emitting integrated module, and conventional processing and tooling can meet the debugging requirements, avoiding the processes of micro-processing and micro-tooling.

[0023] Furthermore, the flow channel in the cold plate of the present invention is a macro channel, therefore: (1) compared with the micro channel, the processing is conventional processing, and the process is relatively much more feasible; (2) in the macro channel flow channel, the cooling medium has no strict requirements while meeting the fluid requirements, and the adaptability is much better; (3) the temperature distribution adjustment is easy to achieve, and the point that needs to be adjusted can be directly located according to the macro channel flow characteristics, while the multi-layer microstructure of the micro channel cannot accurately control the temperature characteristics of a certain point.

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a three-dimensional diagram of a high-power module for a surface-emitting laser chip according to an embodiment of the present invention.

[0026] Figure 2 It is an exploded view of a high-power module for a surface-emitting laser chip according to an embodiment of the present invention.

[0027] Figure 3 It is a schematic diagram of the combined structure of the cold plate inter-unit according to an embodiment of the present invention.

[0028] Figure 4 4 is a perspective view of a single cold plate unit according to an embodiment of the present invention.

[0029] Figure 5 It is a schematic diagram of the single cold plate stratospheric flow channel and temperature gradient according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the various embodiments of the present invention and the features described in the embodiments may be combined with each other. The present invention is further described in detail below in conjunction with the drawings and specific embodiments.

[0031] Please refer to Figure 1-5 As shown, an embodiment of the present invention relates to a high-power module 100 for a surface-emitting laser chip, which can be used as a high-power direct semiconductor laser, for example, as a high-speed cladding module that can be used in a high-speed laser cladding system. The high-power module 100 of the present invention is a high-stability, high-reliability, high-power semiconductor laser module, having a high-quality laser array bar and an efficient heat dissipation structure; and the packaging structure is simple, efficient, and low-cost, and is suitable for a wide range of applications.

[0032] The high-power module 100 of the present invention is a cold plate stack packaging structure as a whole, including a plurality of cold plates stacked together, each cold plate packaging integrating a plurality of surface-emitting laser chips 14 to form a separate module.

[0033] Among them, the top cold plate is used as the top sealing plate 2, the bottom cold plate is used as the bottom sealing plate 3, and several separated cold plates 7 in the middle are stacked up and down. The cold plates of the stacked packaging structure are marked as the middle cold plates 7 and the top and bottom sealing plates 2 and 3, and multiple surface-emitting laser chips 14 are integrated on the outer wall surface. Multiple surface-emitting laser chips 14 are encapsulated on the outer wall surface of the same side of each cold plate. Preferably, the multiple chips integrated in each layer are arranged in a row of surface-emitting laser chips, and the multiple surface-emitting laser chips 14 in each layer can be connected in series from beginning to end and in series with the electrode modules 8 set on each layer of cold plates. Correspondingly, the chips integrated in each layer of the stacked packaging structure are arranged into a surface-emitting laser chip array 4, and a collimating lens 5 is set on the light-emitting surface of the surface-emitting laser chip 14 integrated in each cold plate 7 to adjust the uniformity of the beam of the surface-emitting laser chip. The high-power module 100 (cold plate stacked packaging structure) is also connected to a water inlet pipe 1 and a water outlet pipe 6. The water inlet pipe 1, the top sealing plate 2, the internal flow channels 12 of each cold plate 7 and the bottom sealing plate 3, and the water outlet pipe 6 are connected to form a cooling channel. Preferably, the flow channels 12 inside each cold plate 7 and the flow channels 12 inside the top and bottom sealing plates are connected to the water inlet pipe 1 and the water outlet pipe 6 in parallel at the water inlet and outlet. The top sealing plate 2, the bottom sealing plate 3, and the separated cold plate 7 are all made of materials with high thermal conductivity, such as but not limited to copper. The sealing plates 2, 3 and several separated cold plates 7 are stacked up and down to form a stacked heat sink, and the sealing plates 2, 3 and each cold plate serve as a heat sink, which is used to encapsulate multiple surface-emitting laser chips 14 and dissipate heat for multiple surface-emitting laser chips 14.

[0034] The surface emitting laser chip may be one of HCSEL and VCSEL. The high power module 100 of the present invention is preferably applied to the HCSEL chip module.

[0035] In a specific embodiment, refer to Figure 3-4In the high-power module 100 for surface-emitting laser chips, including a single module packaged and integrated by multiple surface-emitting laser chips such as HCSEL chips, a single chip 14 is first aligned with the positioning reference, i.e., the limiting side, of a single heat sink (cold plate 7 / sealing plates 2, 3). After being fitted, a plurality of chips (15 as shown in the figure) are sequentially arranged end to end and integrated onto the heat sink (cold plate 7 / sealing plates 2, 3). The chips are then soldered to the heat sink by solder, and the entire module is placed on a gold wire punching device, and the ends are connected and gold wires are punched, and the modules are connected to the electrode modules 8 at both ends by gold wires 11, so that the plurality of chips 14 sequentially arranged end to end form a series electrical connection.

[0036] As an embodiment, each individual cold plate 7 has the same shape, and the upper and lower surfaces of two adjacent cold plates 7 can be sealed together to form a joint layer. The outer surface of the cold plate 7 along the length direction is used to integrate a row of surface-emitting laser chips 14. The chips 14 are arranged closely end to end. A pair of electrode modules 8 are respectively arranged at the two ends of the cold plate 7 or a row of surface-emitting laser chips 14. A limiting step 16 is formed on the surface of each cold plate that encapsulates the surface-emitting laser chip 14 to facilitate the installation and positioning of the surface-emitting laser chip 14 and the electrical connection of the gold wire 11. The limiting step 16 forms a stepped groove on the surface of each cold plate. In each row of chips of the surface-emitting laser chip array 4, each chip 14 is connected end to end, aligned and packaged according to the positioning reference of the module, and welded into the stepped groove. Each cold plate is a multi-chip package integration, which can be freely matched in terms of power.

[0037] A chip array assembly limiting step 16 is processed on each cold plate (sealing plates 2, 3 and separation cold plate 7) as a positioning reference for installing the chip. At the same time, the electrode module 8 is also positioned and glued according to the limiting step 16. Therefore, there is a certain step height difference between the electrode module 8 and the chip bonding surface, which can prevent the gold wire 11 from directly contacting the copper or other high thermal conductivity metal sealing plates 2, 3 or cold plate 7 and causing a short circuit.

[0038] Each cold plate integrates multiple chips, and multiple cold plate stacked structures integrate high-power laser modules. The power matching scheme is diversified, and only the number of cold plates can be adjusted. It has great advantages in cost and power matching flexibility.

[0039] A collimating lens 5 is also provided on the light emitting surface of the surface emitting laser chip 14, and the light emitted by the chip is a divergent beam 15 (such as Figure 3 ), the collimating lens 5 is used to adjust the uniformity of the light beam. The collimating lenses 5 on the separation cold plate 7 and the sealing plates 2 and 3 can adjust the distance and actual size according to actual needs to adjust the uniformity of the light beam and ensure that the light flux width at the distance point is within the critical point of the working range of the collimating lens.

[0040] The chips integrated on each individual cold plate 7 and the sealing plates 2 and 3 are arranged in a row, and a collimating lens 5 is provided corresponding to each layer to adjust the uniformity of the light beam emitted by a row of chips. At the distance point where the collimating lens 5 is located, the light flux width is within the critical point of the working range of the collimating lens to ensure the light combining efficiency.

[0041] After stacking multiple separation cold plates 7 and sealing plates 2 and 3, a collimating lens 5 arranged on the light-emitting surface of each row of chips is arranged in parallel to form multiple layers. Accordingly, the collimating lenses on the light-emitting surface of the surface-emitting laser chip array of the high-power module 100 of the present invention form multiple parallel collimating lens groups.

[0042] Preferably, the collimating lens group arranged on the light-emitting surface of the surface-emitting laser chip array is located at a position such as Figure 3~4 It can be seen from the chip light emitting range that when the divergent light beam 15 emitted by the chip reaches the collimating lens, it is just within the boundary of the lens width, ensuring the light combining efficiency without causing the lens margin to be too large, which will affect the quality of the upper and lower rows of light beams when the adjacent cold plate lasers are combined.

[0043] The collimating lens 5 is fixed to the chip light-emitting surface of the middle cold plate 7 and the top and bottom sealing plates 2 and 3 by the collimating lens holder 9. The middle multiple cold plates 7 and the multiple parallel collimating lenses of the top and bottom sealing plates 2 and 3 are fixed to the collimating lens holder 9. The collimating lens holder 9 is in the shape of a panel, and a mounting window is provided in the middle for mounting the collimating lens. The collimating lens holder 9 is fixed to one side of the stacked packaging structure of the multiple cold plates by screws or fasteners, so that each fixed collimating lens 5 is located on the light-emitting surface of each layer of integrated chips.

[0044] The surface emitting laser chip array 4 is a COS module (an integrated module of chip and heat sink) welded to the cold plate 7 and the top and bottom sealing covers 2 and 3, which is convenient for wire bonding and can also transfer the heat generated by the surface emitting laser chip directly to the cold plate (such as a copper plate) through the heat sink for uniform heat dissipation.

[0045] Each cold plate has a water cooling channel 12 formed inside. The water cooling channel 12 is directly processed on the cold plate. It is a channel that is recessed from the top or bottom surface to a certain depth along the thickness direction of the cold plate and extends along the length direction of the cold plate or the arrangement direction of the integrated chips. When the channel 12 flows in a laminar manner along the thickness direction of the cold plate, each layer is isolated from each other. Each row of chips has a water channel (cooling water or other coolant) flowing through it.

[0046] As an embodiment, the coolant flow channel 12 is processed into a flow channel groove along the entire thickness direction of the cold plate 7, the top groove is open, and the bottom wall of the flow channel groove has a certain thickness, which is used to isolate the flow channels between each layer of chips, and only the front and rear water inlets and outlets are connected to the upper and lower layers. The flow channel extends along the length direction of the cold plate as a whole, and a number of bends are formed in the flow channel to increase the length of the flow channel.

[0047] Furthermore, a fin structure for local heat dissipation enhancement is added to the flow channel of the middle cold plate 7 and the top and bottom sealing plates 2 and 3 to increase the liquid cooling contact area on the chip packaging side. In particular, a groove reflux structure is constructed on the back side of the flow direction, which can increase the local heat exchange efficiency, thereby increasing the flow of the coolant in the middle cold plate 7 and the top and bottom sealing plates 2 and 3. Specifically, in the flow channel 12 of the middle cold plate 7 and the top and bottom sealing plates 2 and 3, corresponding to the side of the chip packaging, a plurality of protruding fins are formed on the inner side wall of the flow channel 12. One side of the protruding fin 18 faces the water inlet, that is, the water flow direction, and the other side faces the water outlet, that is, the back side of the flow direction. A small groove structure is further formed on the back side of the flow direction to increase the coolant contact area on the chip packaging side. At the same time, a groove reflux structure is constructed on the back side of the flow direction, that is, corresponding to the packaged chip, which can increase the local heat exchange efficiency.

[0048] In this embodiment, a row of grooves 19 are arranged in parallel from one side close to the chip to the other side. Several protruding fins are also arranged in parallel, extending from one side of the packaged chip to the other side along the width direction of the cold plate, and are protrudingly arranged in the flow channel 12 to resist the flow of coolant perpendicular to the flow direction or at a certain angle. The other inner side wall of the flow channel 12 opposite to the chip mounting side forms a back concave bend corresponding to the protruding fin 18, thereby forming a wavy or curved wall surface, and the connection between adjacent back concave bends forms a protruding tooth 20. A plurality of screw holes 17 or mounting holes are arranged on the edge of the flow channel (including the protruding teeth 20), which are locked with screws 23 or other fasteners and screw holes 17, thereby fixing the layers together. A sealing gasket 10 is installed on the top of each flow channel to cover the top of the flow channel 12, so that the flow channel 12 on the cold plate 7 forms an independent flow channel, which is sealed from top to bottom and all around, and only the water inlet and outlet are connected with the water outlet of other layers. The protruding fins 18 and the protruding teeth 20 are arranged in a staggered manner in the curved flow channel to increase the length of the flow channel. The curved and extended flow channel 12 and / or the protruding fins 18 and / or the grooves 19 and / or the protruding teeth 20 flowing to the back side form a flow channel buffer structure, which lengthens the flow of the coolant, forms a reflux structure, strengthens the heat dissipation effect, and improves the heat dissipation efficiency.

[0049] The two ends of the flow channel 12 correspond to the water inlet 120 and the water outlet 121. The water inlet and outlet 120, 121 of the flow channel 12 of each layer of cold plate are connected to each other and are respectively connected to the water inlet 120 and the water outlet 121 of the top and bottom sealing plates 2 and 3. The coolant is introduced by the water inlet pipe 1 and finally flows out from the water outlet pipe 6. Preferably, the water inlets of each layer of cold plate and the top and bottom sealing plates are aligned up and down, and the water outlets are aligned up and down, and the internal flow channels 12 are parallel. In this embodiment, the water inlet 120 and the water outlet 121 of each middle layer of cold plate 7 are through holes that penetrate the thickness and are respectively arranged near the two ends in the length direction.

[0050] Each layer of cold plate 7 and the top and bottom sealing plates 2 and 3 form a stacked heat dissipation structure as a whole. The flow channel 12 is a macro channel. The flow channels in each layer of cold plate are connected in parallel to avoid the problem of large difference in cooling effect between the inlet and outlet of the series coolant flow channel. It can better control the heat dissipation uniformity and the temperature difference between the inlet and outlet, ensure the overall temperature balance of the chip array 4, and avoid problems such as local attenuation affecting the beam quality. Compared with the traditional series flow channel, the parallel flow channel buffer structure will not cause water to absorb a large amount of heat at the front end of the flow channel, resulting in excessively high water temperature when the back end is de-heated, and the fluid de-heating ability is reduced (water temperature rises, temperature difference decreases, and exchange heat decreases), thereby causing the temperature at the front end of the flow channel to be relatively balanced, while the de-heating ability decreases after the back end water temperature rises, resulting in a sharp rise in chip temperature.

[0051] The flow channel 12 in the cold plate of the present invention is designed as a macro channel mode: (1) Compared with the micro channel, the processing belongs to the precision processing range in conventional processing, and the process is relatively much more feasible; (2) For the macro channel flow channel, the cooling medium does not have strict requirements while meeting the fluid requirements, and the adaptability is much better; (3) The temperature distribution adjustment is easy to achieve, and the point that needs to be adjusted can be directly located according to the macro channel flow channel characteristics. The multi-layer microstructure of the micro channel cannot accurately control the temperature characteristics of a certain point.

[0052] The top sealing plate 2 and the bottom sealing plate 3 serve as the topmost cold plate and the bottommost cold plate, respectively, and seal the upper and lower ends of the stack structure and the bottom load-bearing. The thickness can be thicker than the middle cold plate 7, and the other outline dimensions can be consistent with the middle cold plate 7. The shape of the flow channel 12 inside can be set to be the same as the flow channel in each middle cold plate 7, and both are indicated by the reference numeral 12. A water inlet 120 or a water outlet 121 is respectively set at each opposite end in the length direction of the top sealing plate 2 and the bottom sealing plate 3. The water inlet 120 is connected to the water inlet pipe 1, and the water outlet 121 is connected to the water outlet pipe 6. In this embodiment, the water inlet 120 and the water outlet 121 are respectively set at the opposite ends of the top sealing plate 2 and the bottom sealing plate 3, and are connected to the flow channels 12 inside each of them in the thickness direction, and are respectively connected to the water inlet 120 and the water outlet 121 of each middle cold plate 7, and are aligned up and down (but not limited to this arrangement of alignment up and down). As an embodiment, the water inlet pipe 1 introduces the coolant into the water inlet of the flow channel 12 of each layer (sealed plates 2, 3 and multiple cold plates 7) through the water inlet 120 set on the top sealing plate 2 or the bottom sealing plate 3, and after being guided by the parallel flow channels 12 of each layer, it flows out from the channels of each water outlet 121 and finally leads out of the module 100 through the water outlet pipe connected to the water outlet 121 of the bottom sealing plate 3 or the top sealing plate 2. The water inlet pipe 1 and the water outlet pipe 6 can also be connected to the water inlet and water outlet of other layers of cold plates, and the water inlets and water outlets of each layer of cold plates are connected; at least one water inlet of each layer of cold plates is connected to the water inlet pipe 1, and at least one water outlet is connected to the water outlet pipe 6, so that the coolant is introduced from the water inlet pipe 1 to the flow channel 12 of each layer of cold plates, and discharged from the water outlet pipe 6 to take away the heat.

[0053] A sealing gasket 10 is respectively arranged at the top of the slot of the internal flow channel of each cold plate (middle cold plate 7, sealing plates 2, 3), and is directly fastened to the top of the flow channel by screws 23 or other fasteners. Except for the water inlet and the water outlet, the flow channel slot of the flow channel is completely sealed, and the layers of cold plates are further locked and pressed together by screws 23.

[0054] The shape and size of the sealing gasket 10 are adapted to the channel slot, and can be slightly larger than the channel edge. The cold plate is provided with an edge slot, and the sealing gasket 10 covers the channel slot and is limited by the slot. The sealing gasket 10 is further locked with the screw hole 17 provided at the channel edge or inside to lock the sealing gasket 10 on the cold plate channel to seal the channel. The sealing gasket 10 is provided with through holes corresponding to the channel inlet and outlet, so as to facilitate the communication between the inlet and outlet of each layer of the channel.

[0055] The sealing gaskets 10 are respectively located between each layer of cold plates. Screw holes 17 are provided on the outer side of the cold plate flow channel edge or in the flow channel. The sealing gaskets 10 between the two layers of cold plates are locked and pressed by screws 23 to achieve a sealing and fixing effect.

[0056] The cold plate stack structure uses the bottom sealing plate 3 as the load-bearing structure, which is assembled upward layer by layer, pressed layer by layer, and screwed into the lower load-bearing structure through the reserved screw holes 17 and screw 23 avoidance structures on each layer, and the middle sealing gasket 10 is pressed together for sealing and fixing. When it comes to the top sealing plate 2, the opening of the flow channel 12 faces downward, and the sealing gasket 10 and the sealing gasket 10 of the lower cold plate are pressed together. The other layers are pressed between the lower sealing gasket 10 and the upper bottom wall. The screw hole 17 in the middle of the flow channel of the top sealing plate 2 is connected to the waterway to avoid water leakage. Therefore, an isolation plate 13 and another layer of sealing gasket 10' are added on the top of the top sealing plate 2 of the stack structure to ensure that the top screw hole structure does not leak water to the outside. The schematic diagram of its partial assembly can be referred to. Figure 2 The isolation plate 13 is fixed to the top sealing plate 2 by a screw fixing track 21, and the screw fixing track 21 is misaligned with the screw hole 17 in the flow channel. After the overall assembly, the module is only connected at the head and tail, and the middle flow channels are isolated from each other, and the overall waterproof structure is made through the sealing gasket 10' to the outside, which is referred to here. Figure 2-3 .

[0057] In this embodiment, in order to avoid the occurrence of gaps in the layers, a single-layer sealing gasket matching structure is used inside to seal and isolate the flow channels 12 of each cold plate, and the layers are pressed downward and fixed through the reserved screw holes.

[0058] The upper surface of the uppermost cold plate 7 is covered with a sealing gasket 10, which is pressed by the top sealing plate 2. A sealing gasket installation groove 22 is provided in the middle of the top sealing plate 2. The isolation plate 13 is inserted into the installation groove to press the sealing gasket 10' to seal on the top sealing plate 2. The shape of the isolation plate 13 matches the shape and size of the installation groove, and is just pressed into the installation groove 22. The periphery is fastened to the sealing gasket 10' on the top wall of the flow channel of the top sealing plate by screws or fasteners. In the layered sealing gasket sealing structure of the present invention, the bottom wall is used for separate isolation and sealing, and the additional isolation plate 13 reduces the risk of water leakage between layers.

[0059] The layers of cold plates (cold plate 7 / sealing plates 2, 3) are fixed together by screws or other fasteners to form an overall heat dissipation structure. A row of surface-emitting laser chips 14 are integrated on the outer wall surface on the same side of each cold plate, arranged into a surface-emitting laser chip array 4.

[0060] The high-power module 100 cold plate stacking solution of the present invention is a stacked heat dissipation structure composed of each layer of cold plates as a whole, and a multi-layer parallel macro channel flow channel can be formed inside, and a buffer structure is formed inside the flow channel; the thermal conductivity efficiency of each layer can be flexibly adjusted according to the chip power and chip size, such as adjusting the flow channel length and the reflux structure, etc., which greatly improves the thermal conductivity efficiency of a single cold plate and reduces costs.

[0061] Reference Figure 5The flow channel structure analysis diagram shown in FIG. 1 shows a non-limiting example in which the high power module 100 of the present invention can solve a 120W / cm 2 High power heat density heat dissipation requirements.

[0062] Reference Figure 5 The high power module 100 of the present invention has good heat dissipation effect. Figure 5 Schematic diagram of the internal flow channel of a single cold plate. As an example, at normal temperature and pressure, a single cold plate 7 needs to dissipate 600W of heat power. Figure 5 It can be seen that the overall temperature distribution of a single internal flow channel is uniform, without local overheating.

[0063] In the example shown in the figure, eight intermediate layers of separated cold plates 7 and two top and bottom plates 2 and 3 can be used to package 10*15 = 150 chips. This structure can be reduced at any time, and the temperature will be better if the number of cold plates is reduced. As an embodiment, in terms of adding cold plates, within the proposed chip operating temperature requirement of 65 degrees Celsius, the flow channel simulation limit can also be increased to 12 cold plates, integrating a structural model of 180 chips.

[0064] The strip packaging of the cold plate of the high-power module 100 of the present invention reduces the tooling volume of the overall processing of the high-power integrated module, and can also save a lot of cost space in subsequent repair and maintenance, and only the faulty cold plate needs to be checked or replaced.

[0065] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0066] In the invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection, an electrical connection, or a connection capable of transmitting data; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0067] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, all of which should fall within the scope of the present invention; the scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-power module for a surface-emitting laser chip, comprising a plurality of cold plates, characterized in that: Each cold plate is packaged with a plurality of surface-emitting laser chips, which are arranged in sequence and connected in series on the outer wall surface in the length direction of the cold plate; a plurality of cold plates are stacked to form a high-power semiconductor laser module with a stack-type heat dissipation structure; Each cold plate is processed with a coolant flow channel and a water inlet and a water outlet connected to the flow channel. The coolant is introduced into the flow channel from the water inlet and discharged from the water outlet, thereby dissipating heat for the surface emitting laser chip. The flow channels in each cold plate are independently arranged, and the flow channels in the multiple cold plates are connected in parallel with each other; the water inlets and water outlets of each cold plate are connected with each other; at least one water inlet is connected to a water inlet pipe to receive the coolant, and at least one water outlet is connected to a water outlet pipe to discharge the coolant and take away the heat; The flow channel of each cold plate is directly processed on the cold plate, and is a channel recessed from the top surface or the bottom surface to a predetermined depth along the thickness direction of the cold plate and extending along the length direction of the arrangement of the plurality of surface-emitting laser chips; each row of surface-emitting laser chips corresponds to a flow channel; when the flow channel flows in a laminar manner along the thickness direction of the cold plate, each layer is isolated from each other; The top of the flow channel is open and sealed by a sealing gasket, and multiple cold plates are pressed together to compress the sealing gasket; the sealing gasket isolates each flow channel; A number of protruding fins are arranged in the flow channel to form a structure similar to a heat sink; A groove reflux structure is arranged in the flow channel near the surface emitting laser chip; A groove structure is further formed on the protruding fin on the back side of the coolant flow direction, thereby forming a groove reflux structure; A number of protruding fins are also arranged in parallel, extending from one side of the packaged chip to the other side along the width direction of the cold plate, and are protrudingly arranged in the flow channel to resist the flow of coolant perpendicular to the flow direction or at a certain angle; the other inner side wall of the flow channel opposite to the chip mounting side forms a bend corresponding to the protruding fins.

2. The high power module according to claim 1, characterized in that: Each cold plate is packaged into a separate module; Each cold plate is provided with an electrode module; Multiple surface-emitting laser chips packaged on each cold plate are connected in series with the electrode module; The plurality of surface-emitting laser chips packaged on each cold plate are arranged in a row; the surface-emitting laser chips of the plurality of cold plates are arranged in a chip array.

3. The high power module according to claim 2, characterized in that: The surface emitting laser chip is a COS module, including a surface emitting laser and a heat sink, which is integrally welded to the cold plate through the heat sink; the heat generated by the surface emitting laser chip is transferred to the cold plate through the heat sink for heat dissipation; The cold plate is a high thermal conductivity metal plate; A limiting step groove is formed on the surface of the cold plate, and the surface-emitting laser chip is aligned and welded in the step groove; there is a step difference between the electrode module arranged on the cold plate and the surface of the surface-emitting laser chip to prevent the connecting wires from directly contacting the cold plate and causing a short circuit.

4. The high power module according to claim 2, wherein: The light-emitting surface of the surface-emitting laser chip is provided with a collimating lens to adjust the uniformity of the light beam of the surface-emitting laser chip; A collimating lens is arranged on the light emitting surface of a row of surface emitting laser chips to adjust the uniformity of the light beams of the row of surface emitting laser chips; A plurality of parallel collimating lenses are arranged on the light-emitting surface of the surface-emitting laser chip array to adjust the uniformity of the light beam of the surface-emitting laser chip array; The collimating lens is fixed by a collimating lens bracket on one side of the cold plate encapsulated with the surface emitting laser chip; Setting principle of collimating lens: When the emitted light of the surface-emitting laser chip reaches the collimating lens, the beam width is within the effective surface range of the collimating lens to ensure the light combining efficiency and the uniformity of the light spot of the entire module.

5. The high power module according to claim 4, characterized in that: The setting principle of the collimating lens is: the emitted light from the emitting laser chip reaches the collimating lens just within the boundary of the lens width, ensuring the light combining efficiency; when the light is combined between adjacent cold plates, the upper and lower rows of light beams do not interfere with each other; On both sides of the collimating lens in the width direction, there is only margin space for dispensing glue to fix the lens; The light emitted by the surface-emitting laser chip is a divergent beam; The surface emitting laser chip is a HCSEL or VCSEL chip.

6. The high power module according to claim 1, characterized in that: The flow channels in the cold plate are macrochannel flow channels; The sealing gasket is provided with openings corresponding to the water inlet and water outlet of the flow channel in the cold plate, so that the water inlets and water outlets of the flow channels of each layer of cold plates are connected; a bend is designed in the flow channel to lengthen the flow channel to increase the heat exchange efficiency.

7. The high power module according to claim 1, characterized in that: Each layer of cold plate is provided with mounting holes around the flow channel and / or in the flow channel, and the cold plates and the sealing gasket and the cold plate are fastened and pressed together by fasteners cooperating with the mounting holes; The top cold plate of the stacked heat dissipation structure serves as a top sealing plate; a flow channel is arranged at the bottom of the top sealing plate, and a mounting groove is arranged at the top; another layer of sealing gasket is arranged on the bottom wall of the mounting groove to cover and seal the mounting hole position in the flow channel; an adaptive isolation plate is built into the mounting groove; the isolation plate is pressed to seal the other layer of sealing gasket and is fastened together with the top sealing plate, thereby forming an overall leak-proof structure.

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