Mounting structure of SiP module and heat dissipation implementation method thereof

Abstract

This invention provides a mounting and fixing structure for a SiP module and a method for heat dissipation. The mounting and heat dissipation structure includes a multilayer board assembly, a heat-conducting plate, and a mounting base plate. The multilayer board assembly includes a power board with power devices and thermally conductive vias penetrating the power board corresponding to the heat dissipation pads. The thermally conductive vias are filled with thermally conductive material. The side of the heat-conducting plate facing the power board has thermally conductive bosses that correspond to the areas of the thermally conductive vias. Each thermally conductive boss has several blind vias. The multilayer board assembly and the heat-conducting plate are integrally encapsulated with potting resin to form a potting body. The thermally conductive bottom surface of the heat-conducting plate facing away from the power board is exposed outside the potting body and is attached to the mounting base plate. The heat dissipation method includes: setting thermally conductive vias and filling them with thermally conductive material; attaching the thermally conductive bosses to the bottom layer of the power board using thermally conductive pads and fixing them with mounting studs; and stacking the circuit layers and then integrally encapsulating them with the heat-conducting plate. This invention relates to the field of packaging technology.

Description

Technical Field

[0001] This invention relates to the field of packaging technology, and further to the field of integrated circuit manufacturing and semiconductor device manufacturing equipment, and particularly to a mounting and fixing structure for a SiP module and a method for heat dissipation. Background Technology

[0002] System-in-Package (SiP) technology integrates multiple active electronic components, passive devices, and circuit boards into a single package in a three-dimensional stacked manner. It offers significant advantages such as high integration, small size, excellent vibration resistance, and high reliability, and has been widely applied in aerospace, military equipment, and industrial servo control. Current SiP module manufacturing processes typically include PCB assembly, multilayer board stacking, resin potting, cutting and shaping, and laser-etched interconnection. For SiP modules with internally encapsulated power devices, such as servo controller modules, heat dissipation has always been a key factor limiting power density improvements. Current common heat dissipation methods involve exposing the tops of the power devices to the module's outer surface and then directly mounting thermal pads and heat sinks on top to conduct heat to the outside.

[0003] However, the aforementioned existing heat dissipation methods have significant limitations in practical applications. When modules are used in applications requiring high vibration and shock resistance, such as servo motor control systems or aircraft landing brake systems, the added heat sinks are difficult to securely fix. Especially in single-unit system modules, the heat sinks are at risk of detaching in vibration environments, seriously affecting the safety and reliability of the system. For modules containing multiple power devices of varying heights and dispersed locations that require heat dissipation, if existing exposed heat dissipation technology is used, the tops of all power devices must be exposed on the module surface, resulting in an excessively large opening area on the top of the module. Non-power devices may also be exposed due to process requirements, making them susceptible to air corrosion and electromagnetic radiation in harsh environments. This significantly reduces the module's sealing and environmental adaptability, while also greatly increasing the difficulty of manufacturing the heat dissipation device. Furthermore, for pinless single-unit control modules that require mounting and fixing, existing heat dissipation methods cannot simultaneously meet the requirements of mounting and heat dissipation. When layout and wiring constraints prevent power devices from being placed on the outer layer of the circuit board, existing heat dissipation methods are also completely unsuitable.

[0004] More importantly, as integrated circuit manufacturing processes evolve towards the nanometer scale, the internal control modules of semiconductor device-specific equipment such as lithography machines and etching machines are developing towards higher density integration and higher reliability. In such high-end equipment, SiP modules not only need to solve the aforementioned contradiction between heat dissipation and fixation, but also need to maintain signal integrity under complex operating conditions such as strong electromagnetic interference, micro-vibration and vacuum. Existing SiP module packaging structures are difficult to simultaneously meet the stringent requirements of high-end semiconductor manufacturing equipment for high-density integration, efficient heat dissipation and extreme environmental adaptability at the module level.

[0005] Therefore, the inventors urgently need a mounting and fixing structure for SiP modules and a method for heat dissipation to solve the above problems. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides a mounting and fixing structure for SiP modules and a heat dissipation method thereof. This aims to solve the technical problems inherent in existing SiP modules, such as the tendency for heat sinks to detach, poor module sealing, installation difficulties, and unsuitability for conditions with varying internal device heights or limited layouts, when facing high vibrations, multiple power devices, or mounting and fixing requirements.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a mounting and fixing structure for a SiP module, comprising a laminated plate assembly, a heat-conducting plate, and a mounting base plate. The laminated plate assembly includes at least one power board. At least one power device is disposed on the upper end of the power board. A plurality of heat-conducting vias penetrating the power board are disposed on the power board corresponding to the heat dissipation pads of the power devices. The heat-conducting vias are filled with heat-conducting material. The heat-conducting plate is located below the power board. A heat-conducting boss is disposed on the side of the heat-conducting plate facing the power board, which corresponds to and fits the area where the heat-conducting vias are located. A plurality of blind holes are disposed inside the heat-conducting boss to enhance the bonding force with the potting resin. The laminated plate assembly and the heat-conducting plate are integrally potted with potting resin to form a potting body. A heat-conducting bottom surface is disposed on the side of the heat-conducting plate away from the power board. The heat-conducting bottom surface is exposed outside the potting body and is attached to the mounting base plate.

[0008] Based on the above, the beneficial effect of a SiP module mounting and fixing structure is to solve the technical problems of existing SiP modules when facing high vibration, multiple power devices, or mounting and fixing requirements, where the top of the power devices is exposed and externally heated, resulting in easy detachment of the heat sink, poor module sealing, difficult installation, and inapplicability to conditions with varying internal device heights or limited layout. The main advantages are:

[0009] 1. This invention provides a series of blind holes inside the heat-conducting bosses of the heat-conducting plate, and integrally encapsulates the laminated plate assembly and the heat-conducting plate with potting resin. The potting resin fills the blind holes to form an anchoring structure. At the same time, the mounting studs distributed around the heat-conducting plate are fixedly connected to the heat-conducting plate and embedded in the potting resin, achieving a strong mechanical interlocking between the heat-conducting plate and the laminated plate assembly. This completely changes the existing technology where heat sinks rely solely on bonding or simple fixing. Thus, in application scenarios with high vibration and severe impact requirements, it can effectively avoid the risk of the heat dissipation structure loosening or falling off. Furthermore, by exposing the heat-conducting bottom surface of the heat-conducting plate to the potting body and bonding it to the mounting base plate, and using the mounting ears on the mounting base plate to provide a stable mounting interface for the overall encapsulation structure, this invention solves the problem of the overall encapsulation structure being difficult to fix and install.

[0010] 2. This invention forms a potting body by integrally potting the laminated plate assembly and the heat-conducting plate with potting resin. Only the heat-conducting bottom surface of the heat-conducting plate on the side away from the power plate is exposed outside the potting body for heat conduction and installation. This achieves full-encapsulation and sealing protection for all power devices and other electronic components inside the laminated plate assembly. It avoids the problem of reduced sealing caused by opening a large area on the top layer of the laminated plate assembly to expose the power devices in the prior art. This significantly improves the structure's moisture resistance, corrosion resistance and electromagnetic interference resistance, and enhances the structure's adaptability and reliability in harsh environments.

[0011] 3. This invention constructs a vertical heat conduction path from the heat dissipation pad of the power device through the heat-conducting vias on the bottom layer of the power board, by setting the heat-conducting bosses of the heat-conducting plate to correspond and fit with the heat-conducting vias on the power board and filling them with heat-conducting material. This allows the power device to achieve efficient heat dissipation without being exposed on the top layer of the multilayer board assembly. Therefore, even if the multilayer board assembly contains multiple power devices with inconsistent heights or scattered positions, or if the distribution of power devices is irregular due to layout and wiring limitations on the power board, this invention can still adapt to different device layouts and height differences by adjusting the shape and position of the heat-conducting bosses and the layout of the heat-conducting vias, solving the problem that the prior art cannot be applied in such conditions.

[0012] Furthermore, the wall of the thermally conductive via is provided with an electroplated copper layer, and the thermally conductive material filled in the thermally conductive via is thermally conductive copper paste, which is connected between the heat dissipation pad and the thermally conductive boss.

[0013] Based on the above, the beneficial effects of thermal vias are that they conduct the heat generated by power devices downwards from the heat dissipation pads to the bottom layer of the power board, avoiding the limitation that power devices need to be exposed on the top layer of the multilayer board for heat dissipation; the beneficial effect of the electroplated copper layer is that it improves the axial thermal conductivity of the thermal vias; the beneficial effect of the thermally conductive copper paste is that it connects the electroplated copper layer on the via wall with the heat dissipation pads and thermally conductive bosses to form a continuous thermal conductor, achieving efficient heat conduction by making full use of the internal space of the via.

[0014] Furthermore, the heat-conducting protrusion is provided with a clearance groove for avoiding mounting components on the bottom surface of the power board.

[0015] Based on the above, the beneficial effect of the recessed slot is to provide clearance space for the mounting components on the bottom surface of the power board, avoid mechanical interference between the heat-conducting boss and the mounting components on the bottom surface of the power board, and ensure that the rest of the heat-conducting boss can be tightly attached to the bottom layer of the power board.

[0016] Furthermore, a number of mounting studs are distributed around the heat-conducting plate, and the outer surface of the mounting studs is provided with a stepped structure. Positioning holes are provided around the heat-conducting plate for each mounting stud.

[0017] Based on the above, the beneficial effects of the mounting studs are that they provide support and positioning for the stacking of laminates and provide mounting interfaces at both ends for the overall encapsulation structure; the beneficial effects of the stepped structure are that it increases the contact area between the mounting studs and the potting resin and the mechanical locking force, thereby preventing the mounting studs from rotating axially or loosening within the potting compound; and the beneficial effects of the positioning holes are that they precisely limit and fix the installation position of the mounting studs.

[0018] Furthermore, a thermal pad is provided between the bottom surface of the power board and the thermally conductive boss, and a thermally conductive silicone grease layer is coated between the thermally conductive bottom surface and the mounting base plate.

[0019] Based on the above, the beneficial effects of the thermal pad are to fill the contact gap between the two and establish an elastic thermal conduction connection, ensuring that heat can be efficiently transferred from the power board to the thermally conductive boss; the beneficial effects of the thermally conductive silicone grease layer are to fill the microscopic gaps on the contact surface between the two and establish a high thermal conductivity connection interface, ensuring that heat can be smoothly transferred from the thermally conductive bottom surface to the mounting base plate.

[0020] Furthermore, the stacked board assembly also includes several circuit layers, with the power board disposed at the bottom layer of the several circuit layers. The power board and the several circuit layers are respectively provided with positioning through holes around their perimeters that cooperate with the mounting studs, and are mounted on the mounting studs through the positioning through holes, and are stacked at intervals along the axial direction of the mounting studs.

[0021] Based on the above, the beneficial effect of several circuit layers is that they integrate circuit boards with different functions into the same package, which meets the high-density integration requirements of SiP modules; the beneficial effect of fixing the stack by installing studs at intervals is that the gaps formed between each circuit layer are used for potting resin filling, avoiding electrical interference or poor potting caused by interlayer contact or too small spacing.

[0022] Furthermore, the number of mounting studs is four, and the four mounting studs are respectively arranged at the four corners of the heat-conducting plate. The upper and lower ends of the mounting studs are respectively provided with mounting inner holes, which are exposed outside the potting body, so as to realize the fixed connection between the upper and lower ends of the mounting inner holes and the positioning holes and the external structure.

[0023] Based on the above, the beneficial effect of the mounting inner holes located at the upper and lower ends of the mounting studs is to provide a dual function of providing bottom positioning connection for the stacking of the multilayer board assembly and top mounting interface for the overall packaging structure, which facilitates the simultaneous fixation of the module at both the upper and lower ends.

[0024] Furthermore, the heat-conducting plate is made of AL7075 aviation aluminum alloy, and the surface of the heat-conducting plate is provided with a natural-colored anodized layer. The mounting base plate is made of aluminum alloy, and the mounting base plate is provided with mounting lugs for fixed connection with external structures.

[0025] Based on the above, the advantages of AL7075 aerospace aluminum alloy material are that, as the substrate of the heat-conducting plate, it achieves both high mechanical strength and good thermal conductivity, meeting the requirements of structural load-bearing and efficient heat dissipation; the advantages of the natural anodized layer are that it forms an insulating and anti-corrosion protective layer on the surface of the heat-conducting plate, preventing electrochemical corrosion or electrical short circuits between the heat-conducting plate and the internal circuit or external environment; and the advantages of the mounting ears are that they provide an interface for mechanical fixing of the overall packaging structure to the external mounting structure, facilitating the assembly and disassembly of the module on the application equipment.

[0026] Furthermore, the present invention provides a heat dissipation method for the mounting and fixing structure of a SiP module, comprising the following steps:

[0027] S1: Power devices are mounted on the top layer of the power board, and a thermally conductive via is provided on the power board below the heat dissipation pad of the power device, and thermally conductive material is filled in the thermally conductive via.

[0028] S2: Attach the heat-conducting boss of the heat-conducting plate to the bottom layer of the power board through the heat-conducting pad, and fix the bottom of the mounting studs around the heat-conducting plate into the corresponding positioning holes;

[0029] S3: The power board and other circuit layers are sequentially mounted on the mounting studs through the positioning through holes at their four corners. After being stacked evenly at intervals along the axial direction of the mounting studs, they are encapsulated with resin together with the heat-conducting plate and the mounting studs to form a potting body with the heat-conducting bottom surface exposed.

[0030] S4: Attach the mounting base plate to the heat-conducting bottom surface of the potting body and fix it to form a complete installation and heat dissipation structure;

[0031] S5: The heat generated by the power device is conducted to the external components in sequence through the heat dissipation pad, the thermally conductive material filled in the thermally conductive through hole, the thermally conductive pad, the thermally conductive boss, the thermally conductive plate and the mounting base plate.

[0032] Based on the above, the beneficial effects of step S1 are: pre-constructing a vertical heat conduction channel from the heat dissipation pads of the power devices to the bottom layer of the power board within the power board, laying the structural foundation for heat conduction downwards to the heat-conducting plate; the beneficial effects of step S2 are: pre-pressing the heat-conducting bosses to the bottom layer of the power board with heat-conducting pads and precisely positioning the mounting studs before potting, providing an assembly benchmark for interlayer alignment and continuous and stable heat conduction paths during subsequent circuit layer stacking; the beneficial effects of step S3 are: integrating the stacked board assembly, heat-conducting plate, and mounting studs into a mechanically interlocked overall structure, ensuring both uniform and controllable interlayer spacing of each circuit layer and the stability of the heat dissipation path and the overall sealing of the module; the beneficial effects of step S4 are: providing an installation interface for the potting body to connect with external devices and completing the final heat conduction path construction, facilitating the assembly and disassembly of the potting body in application scenarios; the beneficial effects of step S5 are: functional verification of the complete heat conduction path, ensuring that heat can be efficiently transferred to the mounting base plate along the preset path.

[0033] To make the above features of the present invention and the objectives to be achieved clearer, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0034] Figure 1 : This is a three-dimensional schematic diagram of the present invention;

[0035] Figure 2 : This is a schematic diagram of the power board of the present invention;

[0036] Figure 3 : This is a schematic diagram of the bottom of the power board of the present invention;

[0037] Figure 4 This is a schematic diagram of the heat-conducting plate and mounting studs of the present invention;

[0038] Figure 5 : This is a schematic diagram of the heat-conducting plate and mounting studs of the present invention from another perspective;

[0039] Figure 6 : This is a schematic diagram of the mounting base plate of the present invention;

[0040] Figure 7 : This is a schematic diagram of the potting compound of the present invention;

[0041] Figure 8 : This is a flowchart illustrating the present invention.

[0042] Reference numerals: 1-Layer board assembly, 11-Power board, 111-Power device, 1111-Heat pad, 112-Thermal via, 12-Interface expansion circuit layer, 13-Power circuit layer, 14-Communication circuit layer, 15-DSP circuit layer, 2-Heat plate, 21-Thermal boss, 211-Blind via channel, 212-Recessed slot, 22-Mounting stud, 221-Step structure, 222-Mounting inner hole, 23-Thermal bottom surface, 24-Positioning hole, 3-Mounting base plate, 31-Mounting lug, 4-Thermal pad, 5-Potent. Detailed Implementation

[0043] See Figures 1-8 As shown,

[0044] A mounting and fixing structure for a SiP module includes a multilayer board assembly 1, a heat-conducting plate 2, and a mounting base plate 3. The multilayer board assembly 1 includes at least one power board 11. At least one power device 111 is disposed on the upper end of the power board 11. A plurality of heat-conducting vias 112 penetrating the power board 11 are disposed on the power board 11 at positions corresponding to the heat dissipation pads 1111 of the power device 111. The heat-conducting vias 112 are filled with a thermally conductive material. The heat-conducting plate 2 is located below the power board 11. A heat-conducting boss 21 is provided on the side facing the power plate 11, corresponding to the area where the heat-conducting through hole 112 is located. The heat-conducting boss 21 has a plurality of blind hole channels 211 inside to enhance the bonding force with the potting resin. The laminated plate assembly 1 and the heat-conducting plate 2 are integrally potted with potting resin to form a potting body 5. A heat-conducting bottom surface 23 is provided on the side of the heat-conducting plate 2 away from the power plate 11. The heat-conducting bottom surface 23 is exposed outside the potting body 5 and is attached to the mounting base plate 3.

[0045] In this embodiment, the power device 111 is specifically a device with model parameter P. D The thermal resistance R of a 75W MOSFET with a Tj (-55~175°C) junction to the bottom pad of the package is... θJCThe temperature is 2.0°C / W. To ensure efficient heat conduction, 16 thermally conductive vias 112 with an inner diameter of 0.6 mm and a height of 1.2 mm are evenly distributed below the heat dissipation pad 1111 of each power device 111. The copper plating layer on the via wall is 25 μm thick. The thermally conductive material filled in the thermally conductive vias 112 is thermally conductive copper paste with a thermal conductivity of 13.5 W / m·K, thereby constructing a low thermal resistance heat conduction channel from the bottom of the power device 111 directly to the bottom layer of the power board 11.

[0046] In this embodiment, the wall of the thermal via 112 is provided with an electroplated copper layer, and the thermally conductive material filled in the thermal via 112 is thermally conductive copper paste. The thermally conductive material is connected between the heat dissipation pad 1111 and the thermally conductive boss 21.

[0047] In this embodiment, to accurately calculate and verify the efficiency of the heat conduction path, the total thermal resistance from the MOS junction to the mounting base 3 was theoretically calculated. The contact area of ​​the thermal pad 4 corresponding to a single power device 111 is 19.84 mm², the thermal conductivity is 3.0 W / m·K, and the thickness is 0.2 mm. The heat conduction plate 2 uses AL7075 (thermal conductivity 130 W / m·K), the height of the thermal guide 21 is 3 mm, and the minimum conductive cross-sectional area corresponding to a single power device 111 is 15 mm². A thermal grease layer is applied between the thermally conductive bottom surface 23 and the mounting base 3, with a contact area of ​​1350 mm², a thickness controlled between 25-50 μm, and a thermal conductivity of 6.0 W / m·K. Based on the above parameters, the total thermal resistance R from the junction of the power device 111 to the mounting base 3 was calculated using a series thermal resistance model. θJA Approximately 10.1℃ / W, this theoretical value provides reliable data support for the module's thermal design.

[0048] In this embodiment, the Ron(Max) of the power device 111 (MOSFET) is 3.7mΩ, the peak bus current is 25A, and the effective value is approximately 17.68A. Based on this, the conduction loss of the power device 111 is calculated to be approximately 1.16W. The bus voltage is 28V, and the switching frequency is 10KHz. According to the power device 111 datasheet, the sum of the rise and fall times of the switch is Tr+Tf=37ns+95ns=132ns. Based on this, the switching loss is calculated to be approximately 0.462W. The total power consumption of a single power device 111 is approximately 1.16W+0.462W=1.622W. Based on the heat dissipation design with a total thermal resistance of 10.1℃ / W calculated above, the heat dissipation requirements of the power device 111 can be met, ensuring that its junction temperature operates within a safe range.

[0049] If this invention is applied to applications with higher power consumption, the total thermal resistance can be further reduced by adjusting the shape and coverage area of ​​the thermally conductive protrusion 21, optimizing the density and layout of the thermally conductive vias 112, and selecting thermally conductive pads 4 and thermally conductive grease layers with higher thermal conductivity, thereby meeting the heat dissipation design requirements under higher power density.

[0050] In this embodiment, the heat-conducting boss 21 is provided with a clearance groove 212 for avoiding mounting components on the bottom surface of the power board 11.

[0051] In this embodiment, in order to further improve the bonding strength between the heat-conducting plate 2 and the potting resin and prevent detachment under extreme vibration environment, the blind hole channel 211 inside the heat-conducting boss 21 is a plurality of blind holes with a diameter of 1-2 mm and varying depths. During the potting process, the potting resin with good fluidity (thermal conductivity 0.6 W / m·K) will fill these blind hole channels 211 and the stepped structure 221 of the mounting stud 22. After curing, a strong mechanical interlocking structure is formed, anchoring the heat-conducting plate 2 and the laminated plate assembly 1 into one piece.

[0052] In this embodiment, a plurality of mounting studs 22 are distributed around the heat-conducting plate 2. The outer surface of the mounting studs 22 is provided with a stepped structure 221. Positioning holes 24 are provided around the heat-conducting plate 2 for each mounting stud 22.

[0053] In this embodiment, there are four mounting studs 22, which are made of the same AL7075 aviation aluminum material as the heat-conducting plate 2. They are distributed at the four corners of the heat-conducting plate 2, and their bottom ends are fixed in the positioning holes 24 by threaded connection to ensure stacking accuracy. The stepped structure 221 is an annular boss or knurling machined on the outer circle of the mounting stud 22 to increase the contact area with the potting resin and the pull-out resistance.

[0054] In this embodiment, a thermal pad 4 is provided between the bottom surface of the power board 11 and the thermally conductive boss 21, and a thermally conductive silicone grease layer is coated between the thermally conductive bottom surface 23 and the mounting base plate 3.

[0055] In this embodiment, to ensure good contact between the thermally conductive boss 21 and the bottom surface of the power board 11, the thermally conductive pad 4 is selected as a soft thermally conductive pad with a thickness of 0.2 mm and a thermal conductivity of 3.0 W / m·K to absorb assembly tolerances and surface unevenness. At the same time, before the mounting base plate 3 is assembled with the thermally conductive bottom surface 23, a layer of thermally conductive silicone grease with a thickness of about 25-50 μm (thermal conductivity of 6.0 W / m·K) is uniformly applied to minimize contact thermal resistance.

[0056] In this embodiment, the stacked board assembly 1 further includes several circuit layers. The power board 11 is disposed at the bottom layer of the several circuit layers. The power board 11 and the several circuit layers are respectively provided with positioning through holes that cooperate with the mounting studs 22. The power board 11 is sleeved on the mounting studs 22 through the positioning through holes and stacked at intervals along the axial direction of the mounting studs 22.

[0057] In this embodiment, in order to achieve a high degree of integration of the servo controller, the stacked board group 1, except for the bottom power board 11, has an interface expansion circuit layer 12, a power circuit layer 13, a communication circuit layer 14, and a DSP circuit layer 15 stacked and encapsulated from top to bottom. Each board has positioning through holes at the four corners corresponding to the positions of the mounting studs 22. Precise stacking and positioning are achieved by using the mounting studs 22. The layers are electrically interconnected by laser engraving or wire bonding.

[0058] In this embodiment, there are four mounting studs 22, which are respectively arranged at the four corners of the heat-conducting plate 2. The upper and lower ends of the mounting studs 22 are respectively provided with mounting inner holes 222, which are exposed outside the potting body 5, so as to realize the fixed connection between the upper and lower ends of the mounting inner holes 222 and the positioning hole 24 and the external structure, respectively.

[0059] In this embodiment, the mounting inner hole 222 is a threaded hole. During the final installation of the module, the bottom is connected to the mounting inner hole 222 at the bottom of the mounting stud 22 by passing countersunk screws through the mounting lugs on the mounting base plate 3; the top is connected to the mounting inner hole 222 at the top of the mounting stud 22 by passing screws through the mounting beam of the external chassis. This method of fixing the top and bottom simultaneously enables the module to withstand half-sine impacts of up to 15g and random vibrations with frequencies of 20Hz-2000Hz without structural damage, greatly enhancing its reliability in high-vibration application scenarios such as aerospace.

[0060] In this embodiment, the heat-conducting plate 2 is made of AL7075 aviation aluminum alloy, and the surface of the heat-conducting plate 2 is provided with a natural-colored anodized layer. The mounting base plate 3 is made of aluminum alloy, and the mounting base plate 3 is provided with mounting lugs 31 for fixed connection with external structures.

[0061] In this embodiment, to further verify the effectiveness of the heat dissipation scheme, an electrothermal coupling simulation analysis was performed on a product using a similar heat conduction path and packaging method. The simulation conditions were set as follows: ambient temperature 70°C, and a constant temperature boundary condition of 70°C was applied to the bottom surface of the heat conduction plate 2 to simulate the heat generation of six power devices 111 in turn (two devices per group, working for 0.3 seconds, with an interval of more than 9 seconds). The simulation results show that the junction temperature of the hottest power device 111 inside the module reaches a maximum of 92°C, which is far below its tolerance limit of 175°C. The temperature difference between the inside and outside is only 22°C, which fully demonstrates the low thermal resistance characteristics of this heat dissipation path and the effectiveness of the scheme.

[0062] In this embodiment, the present invention discloses a heat dissipation method for the mounting and fixing structure of a SiP module, comprising the following steps:

[0063] S1: Power device 111 is mounted on the top layer of power board 11, and a heat-conducting via 112 is provided on the power board 11 at a position corresponding to the heat dissipation pad 1111 of the power device 111, and the heat-conducting via 112 is filled with heat-conducting material.

[0064] S2: The heat-conducting boss 21 of the heat-conducting plate 2 is attached to the bottom layer of the power plate 11 through the heat-conducting pad 4, and the bottom of the mounting studs 22 around the heat-conducting plate 2 is fixed in the corresponding positioning holes 24.

[0065] S3: The power board 11 and other circuit layers are sequentially mounted on the mounting studs 22 through the positioning through holes at its four corners. After being stacked evenly at intervals along the axial direction of the mounting studs 22, they are encapsulated with resin together with the heat-conducting plate 2 and the mounting studs 22 to form a potting body 5 with the heat-conducting bottom surface 23 exposed.

[0066] S4: The mounting base plate 3 is attached to the heat-conducting bottom surface 23 at the bottom of the potting body 5 and fixed to form a complete installation and heat dissipation structure;

[0067] S5: The heat generated by the power device 111 is sequentially conducted to the external components through the heat dissipation pad 1111, the thermally conductive material filled in the thermally conductive through hole 112, the thermally conductive pad 4, the thermally conductive boss 21, the thermally conductive plate 2, and the mounting base plate 3.

[0068] The above description is merely the optimal embodiment of the present invention and is not intended to limit the present invention. Any modifications or substitutions made by those skilled in the art without departing from the essence and scope of protection of the present invention should also be within the scope of protection of the present invention.

Claims

1. A mounting and fixing structure for a SiP module, characterized in that: The assembly includes a laminated plate assembly (1), a heat-conducting plate (2), and a mounting base plate (3). The laminated plate assembly (1) includes at least one power plate (11). At least one power device (111) is disposed on the upper end of the power plate (11). A plurality of heat-conducting vias (112) penetrating the power plate (11) are disposed on the power plate (11) at positions corresponding to the heat dissipation pads (1111) of the power device (111). The heat-conducting vias (112) are filled with heat-conducting material. The heat-conducting plate (2) is located below the power plate (11) and faces the power plate. (11) has a heat-conducting boss (21) on one side that corresponds to the area where the heat-conducting through hole (112) is located. The heat-conducting boss (21) has several blind hole channels (211) inside to enhance the bonding force with the potting resin. The laminated plate assembly (1) and the heat-conducting plate (2) are integrally potted with potting resin to form a potting body (5). The heat-conducting plate (2) has a heat-conducting bottom surface (23) on the side away from the power plate (11). The heat-conducting bottom surface (23) is exposed outside the potting body (5). The heat-conducting bottom surface (23) is attached to the mounting base plate (3). The heat-conducting plate (2) is also provided with a number of mounting studs (22) distributed around its perimeter. The outer surface of the mounting studs (22) is provided with a stepped structure (221). The heat-conducting plate (2) is provided with positioning holes (24) around each mounting stud (22). A thermal pad (4) is provided between the bottom surface of the power board (11) and the thermally conductive boss (21), and a thermally conductive silicone grease layer is coated between the thermally conductive bottom surface (23) and the mounting base plate (3). The stacked board assembly (1) further includes several circuit layers. The power board (11) is disposed at the bottom layer of the several circuit layers. The power board (11) and the several circuit layers are respectively provided with positioning through holes that cooperate with the mounting studs (22) around their perimeters. The power board (11) is sleeved and installed on the mounting studs (22) through the positioning through holes and stacked at intervals along the axial direction of the mounting studs (22).

2. The mounting and fixing structure for a SiP module according to claim 1, characterized in that: The wall of the thermal via (112) is provided with an electroplated copper layer, and the thermally conductive material filled in the thermal via (112) is thermally conductive copper paste. The thermally conductive material is connected between the heat dissipation pad (1111) and the thermally conductive boss (21).

3. The mounting and fixing structure for a SiP module according to claim 1, characterized in that: The heat-conducting boss (21) is provided with a clearance groove (212) for avoiding mounting components on the bottom surface of the power board (11).

4. The mounting and fixing structure for a SiP module according to claim 1, characterized in that: The number of mounting studs (22) is four. The four mounting studs (22) are respectively arranged at the four corners of the heat-conducting plate (2). The upper and lower ends of the mounting studs (22) are respectively provided with mounting inner holes (222). The mounting inner holes (222) are exposed outside the potting body (5) so as to realize the fixed connection between the mounting inner holes (222) at the upper and lower ends and the positioning hole (24) and the external structure respectively.

5. The mounting and fixing structure for a SiP module according to claim 1, characterized in that: The heat-conducting plate (2) is made of AL7075 aviation aluminum alloy. The surface of the heat-conducting plate (2) is provided with a natural color anodized layer. The mounting base plate (3) is made of aluminum alloy. The mounting base plate (3) is provided with mounting lugs (31) for fixed connection with external structures.

6. A method for heat dissipation based on the mounting and fixing structure of the SiP module according to claim 1, characterized in that, Includes the following steps: S1: Power devices (111) are mounted on the top layer of the power board (11), and a heat-conducting via (112) is provided on the power board (11) at a position below the heat dissipation pad (1111) of the power device (111), and a heat-conducting material is filled in the heat-conducting via (112). S2: The heat-conducting boss (21) of the heat-conducting plate (2) is attached to the bottom layer of the power plate (11) through the heat-conducting pad (4), and the bottom of the mounting studs (22) around the heat-conducting plate (2) is fixed in the corresponding positioning hole (24). S3: The power board (11) and other circuit layers are sequentially mounted on the mounting studs (22) through the positioning through holes at its four corners. After being stacked evenly at intervals along the axial direction of the mounting studs (22), they are encapsulated with resin together with the heat-conducting plate (2) and the mounting studs (22) to form a potting body (5) with the heat-conducting bottom surface (23) exposed. S4: The mounting base plate (3) is attached to the heat-conducting bottom surface (23) of the bottom of the potting body (5) and fixed to form a complete installation and heat dissipation structure; S5: The heat generated by the power device (111) is conducted to the external components in sequence through the heat dissipation pad (1111), the thermally conductive material filled in the thermally conductive via (112), the thermally conductive pad (4), the thermally conductive boss (21), the thermally conductive plate (2) and the mounting base plate (3).

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