High-power-density power supply and manufacturing method

Abstract

The invention provides a high-power-density power supply and a manufacturing method, and relates to the technical field of hybrid integrated power supply packaging. According to the high-power-density power supply, on the basis of a co-fired multi-layer ceramic plate, at least one conduction band plating layer thickening area is formed by thickening a local conduction band and a bonding pad on the surface layer, so that a substrate structure which can meet the large-current overcurrent requirement under the condition that high wiring and packaging density can be achieved is formed. Meanwhile, the heat dissipation micro-channel is arranged at the bottom of the main heating magnetic element with the heat dissipation bottleneck, so that the thermal resistance between the magnetic element and the ceramic-based conduction band local thickening substrate is greatly reduced under the condition that the bonding strength and the insulating capacity are kept unchanged; the bottleneck problem that in the prior art, a heating magnetic element is poor in heat dissipation performance is solved, the current density and the power density of products of the type are greatly improved, and the design requirement for further miniaturization of the products of the type can be met.

Description

Technical Field

[0001] This application relates to the field of hybrid integrated power packaging technology, and in particular to a high power density power supply and its manufacturing method. Background Technology

[0002] Existing hybrid integrated circuit power supply products primarily use ceramic substrates for packaging components and bare chips. With the increasing demand for miniaturization in these power supply products, co-fired multilayer ceramic substrates, such as HTCC (High-temperature co-fired ceramics) and LTCC (Low-temperature co-fired ceramics), are gradually being adopted. These ceramic substrates can achieve high wiring and packaging density, but due to limitations in manufacturing technology, the wiring thickness of a single conductive layer on the substrate is relatively thin (approximately 10μm), which cannot meet the high-current overcurrent requirements of the products.

[0003] Furthermore, the heat-generating components inside existing hybrid integrated circuit power supply products mainly include power transistors and magnetic devices (such as can-type transformers and can-type inductors). Power transistors are typically directly soldered onto a ceramic substrate, which in turn is directly soldered onto a metal casing. The entire heat transfer path from the power transistor to the metal casing is made of a highly conductive material with a thermal conductivity exceeding 20 W / (m·K). The cross-sectional area of ​​the entire heat transfer path is also relatively large. Therefore, the junction-to-case thermal resistance between the power transistor and the metal casing is low, and the heat generated on the power transistor can usually be transferred to the outside of the product relatively quickly. However, magnetic devices, because their materials are conductive, cannot be directly fixed to the conductive substrate surface pads or the metal casing. They require isolation through a thermally conductive insulating film. Since the selection of a thermally conductive insulating film must simultaneously consider adhesive strength, insulation capability, and thermal conductivity, the thermal conductivity of the available films is generally not outstanding. The thermal conductivity of existing thermally conductive insulating films that meet the requirements is usually below 1 W / (m·K), which results in a large thermal resistance between the heat-generating magnetic device and the metal casing. This significantly limits the overall heat dissipation performance of such products, preventing further improvement in their power density.

[0004] In summary, for hybrid integrated circuit power supply products, improving the overcurrent capability and heat dissipation capability of the heating magnetic devices are key to improving product performance and achieving further miniaturization. Summary of the Invention

[0005] In view of the above problems, this application provides a high power density power supply and its manufacturing method, which solves the bottleneck problems of low overcurrent capacity and poor heat dissipation performance of heating magnetic devices in the prior art, and significantly improves the current density and power density of such products, thus meeting the design requirements for further miniaturization of such products. The specific solution is as follows:

[0006] The first aspect of this application provides a high power density power supply, the high power density power supply comprising: a metal casing and a metal cover plate, the metal casing and the metal cover plate forming a cavity; a ceramic-based conductive strip locally thickened substrate, a thermally conductive fixing layer, ceramic balls and magnetic devices located within the cavity;

[0007] The ceramic-based conductive strip locally thickened substrate is welded to the bottom of the metal shell. The surface of the ceramic-based conductive strip locally thickened substrate opposite to the bottom of the metal shell includes at least one conductive strip plating thickened area. The ceramic-based conductive strip locally thickened substrate is a co-fired multilayer ceramic plate and a plating thickened structure located on one side of the co-fired multilayer ceramic plate. The area where the plating thickened structure is located is the conductive strip plating thickened area.

[0008] The magnetic device is fixed on the thickened area of ​​the conductive strip coating by the thermally conductive fixing layer;

[0009] The ceramic balls are distributed between the magnetic device and the thickened area of ​​the conductive strip coating, and the ceramic balls are located in the thermally conductive fixing layer;

[0010] The upper surface of the ceramic ball contacts the magnetic device, and the lower surface of the ceramic ball contacts the thickened area of ​​the conductive strip coating, so as to form a heat dissipation microchannel between the magnetic device and the thickened area of ​​the conductive strip coating.

[0011] In one possible implementation, the co-fired multilayer ceramic plate is an HTCC plate or an LTCC plate.

[0012] In one possible implementation, the thickened coating structure includes a copper layer, a nickel layer, a palladium layer, and a gold layer stacked sequentially, with the copper layer disposed adjacent to the co-fired multilayer ceramic plate.

[0013] In one possible implementation, the thickness of the copper layer ranges from 30 μm to 50 μm.

[0014] In one possible implementation, the magnetic device includes a can transformer and / or a can inductor.

[0015] In one possible implementation, the ceramic ball is made of aluminum nitride.

[0016] In one possible implementation, the ceramic sphere is a sphere of equal diameter;

[0017] The diameter tolerance of the spheres of equal diameter is less than 10 μm.

[0018] In one possible implementation, the diameter of the ceramic ball ranges from 0.2 mm to 0.5 mm.

[0019] A second aspect of this application provides a manufacturing method for fabricating a ceramic-based conductive strip locally thickened substrate as described in any of the preceding claims, the manufacturing method comprising:

[0020] An electroplated masking layer is applied to a co-fired multilayer ceramic plate;

[0021] The copper plating on the conductive strips and pads of the co-fired multilayer ceramic plate that require high current is locally thickened.

[0022] Remove the electroplated masking layer;

[0023] The co-fired multilayer ceramic plate is subjected to chemical plating, namely nickel plating, palladium plating, and gold plating in sequence;

[0024] Remove the electroplated connecting lines from the co-fired multilayer ceramic plate.

[0025] A third aspect of this application provides a manufacturing method for manufacturing a high power density power supply as described in any of the preceding claims, the manufacturing method comprising:

[0026] The system provides a metal casing, a ceramic-based conductive strip locally thickened substrate, a thermally conductive fixing layer, ceramic balls, magnetic devices, and a metal cover plate; the metal casing and the metal cover plate form a cavity; the ceramic-based conductive strip locally thickened substrate, the thermally conductive fixing layer, the ceramic balls, and the magnetic devices are located within the cavity; the surface of the ceramic-based conductive strip locally thickened substrate opposite to the bottom of the metal casing includes at least one conductive strip plating thickened area;

[0027] The ceramic-based conductive strip with a locally thickened substrate is welded to the bottom of the metal casing;

[0028] Power components are assembled in the thickened area of ​​the conductive strip coating on the ceramic-based substrate with locally thickened conductive strip, and signal components are assembled in other areas on the ceramic-based substrate with locally thickened conductive strip; the other areas are non-conductive strip coating thickened areas.

[0029] The ceramic balls are mixed into the thermally conductive adhesive in a certain proportion and stirred evenly;

[0030] The magnetic device is fixed to the thickened area of ​​the conductive strip coating using a thermally conductive adhesive mixed with the ceramic balls.

[0031] Apply a certain amount of pressure and rub back and forth to make the ceramic balls at the bottom of the magnetic device form a single layer arrangement;

[0032] A counterweight is added to the surface of the magnetic device to cure the thermally conductive fixing adhesive, forming the thermally conductive fixing layer with the ceramic ball.

[0033] The metal cover plate is then subjected to sealing welding.

[0034] By employing the above technical solution, this application provides a high power density power supply and its manufacturing method. Based on a co-fired multilayer ceramic substrate, at least one thickened conductive strip plating area is formed by thickening the surface conductive strip and pads. This creates a substrate structure that can achieve high wiring and packaging density while also meeting high current overcurrent requirements. Simultaneously, by setting heat dissipation microchannels at the bottom of the main heat-generating magnetic components, which present a heat dissipation bottleneck, the thermal resistance between the magnetic devices and the locally thickened ceramic substrate is significantly reduced while maintaining bonding strength and insulation capability. This solves the bottleneck problem of poor heat dissipation performance of heat-generating magnetic components in existing technologies, significantly improving the current density and power density of such products, and meeting the further miniaturization design requirements of these products. Attached Figure Description

[0035] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent when taken in conjunction with the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0036] Figure 1 A cross-sectional schematic diagram of a high power density power supply provided in an embodiment of the present invention;

[0037] Figure 2 A cross-sectional schematic diagram of the thickened area of ​​the conductor coating on a ceramic-based substrate with locally thickened conductors, provided in an embodiment of the present invention;

[0038] Figure 3 A cross-sectional schematic diagram of the heat dissipation structure of the thermally conductive insulating film in a prior art transformer.

[0039] Figure 4 This is a cross-sectional schematic diagram of a heat dissipation structure for a magnetic device provided in an embodiment of the present invention;

[0040] Figure 5 A partial structural schematic diagram of a heat dissipation microchannel formed between a magnetic device and a thickened area of ​​the conductive strip coating, provided for an embodiment of the present invention;

[0041] Figure 6 This is a schematic flowchart illustrating a method for fabricating a ceramic-based conductive strip locally thickened substrate according to an embodiment of the present invention.

[0042] Figure 7A schematic flowchart illustrating a method for manufacturing a high power density power supply according to an embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the curing of a magnetic device weight provided in an embodiment of the present invention. Detailed Implementation

[0044] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0045] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0046] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] refer to Figure 1 , Figure 1 This is a cross-sectional schematic diagram of a high power density power supply provided in an embodiment of the present invention. The high power density power supply provided in this embodiment of the present invention includes: a metal shell 11 and a metal cover plate 20, wherein the metal shell 11 and the metal cover plate 20 form a cavity; a ceramic-based conductive strip locally thickened substrate 15, a thermally conductive fixing layer 17, a ceramic ball 18, and a magnetic device 19 located in the cavity.

[0048] The ceramic-based conductive strip locally thickened substrate 15 is welded to the bottom of the metal casing 11. The surface of the ceramic-based conductive strip locally thickened substrate 15 on the side opposite to the bottom of the metal casing 11 includes at least one conductive strip plating thickened area 16. The ceramic-based conductive strip locally thickened substrate 15 is a co-fired multilayer ceramic plate and a plating thickened structure located on one side of the co-fired multilayer ceramic plate. The area where the plating thickened structure is located is the conductive strip plating thickened area 16. For example, as... Figure 1 The ceramic-based conductive strip locally thickened substrate 15 shown is welded to the bottom of the metal shell 11 through a welding layer 14.

[0049] The magnetic device 19 is fixed on the thickened area 16 of the conductive strip coating by the thermally conductive fixing layer 17.

[0050] The ceramic balls 18 are distributed between the magnetic device 19 and the thickened area 16 of the conductive strip coating, and the ceramic balls 18 are located in the thermally conductive fixing layer 17.

[0051] The upper top surface of the ceramic ball 18 contacts the magnetic device 19, and the lower top surface of the ceramic ball 18 contacts the thickened area 16 of the conductive strip coating, so as to form a heat dissipation microchannel between the magnetic device 19 and the thickened area 16 of the conductive strip coating.

[0052] Specifically, current hybrid integrated circuit power supply products primarily use ceramic substrates for component and bare chip packaging. With the increasing demand for miniaturization in these products, co-fired multilayer ceramic substrates, such as HTCC and LTCC substrates, are gradually being adopted. These ceramic substrates can achieve relatively high wiring and packaging density, but due to limitations in their manufacturing processes, the wiring thickness of a single conductive layer on the substrate is relatively thin (approximately 10μm), which cannot meet the high current overcurrent requirements of the products.

[0053] Based on this, in this embodiment of the invention, on the basis of the co-fired multilayer ceramic plate technology, targeted secondary reprocessing is carried out. At least one conductor plate thickening area 16 is formed by thickening the surface local conductor and pad. While retaining the high-density wiring capability and packaging density of the original co-fired multilayer ceramic plate, the high current carrying capacity of the co-fired multilayer ceramic plate is increased to meet the high current carrying requirements of related products.

[0054] Meanwhile, by setting a heat dissipation microchannel at the bottom of the main heat-generating magnetic element 19, which has a heat dissipation bottleneck, the thermal resistance between the magnetic device 19 and the locally thickened substrate 15 of the ceramic substrate is significantly reduced while maintaining the bonding strength and insulation capability. This solves the bottleneck problem of poor heat dissipation performance of the heat-generating magnetic element in the prior art, and greatly improves the current density and power density of this type of product, which can meet the further miniaturization design requirements of this type of product.

[0055] It should be noted that, Figure 1 The number 23 indicates that the cavity is filled with nitrogen gas. Figure 1 The number 12 indicates the housing pin, which enables the corresponding circuit connection. Figure 1 The reference numeral 13 indicates the outer casing insulator, which provides insulation between the outer casing pin 12 and the metal casing 11.

[0056] In an optional embodiment of the present invention, the magnetic device 19 includes a large-sized can transformer and / or can inductor.

[0057] In an optional embodiment of the present invention, the co-fired multilayer ceramic plate is an HTCC plate or an LTCC plate. The LTCC plate and HTCC plate form a ceramic-based multilayer wiring substrate through multilayer ceramic co-firing. In addition to wiring on the top and bottom surfaces of the substrate, wiring can also be performed on the inner layers of the substrate. The wires between different wiring layers can be vertically interconnected through through-holes within the ceramic body, achieving a higher wiring density compared to traditional thick-film and thin-film ceramic substrates.

[0058] refer to Figure 2 , Figure 2 This is a cross-sectional schematic diagram of a thickened conductive strip plating region on a ceramic-based substrate with locally thickened conductive strip, provided as an embodiment of the present invention. The thickened plating structure includes a copper layer 27, a nickel layer 28, a palladium layer 32, and a gold layer 29 stacked sequentially, with the copper layer 27 adjacent to the co-fired multilayer ceramic plate.

[0059] Specifically, in the product structure of this application, a substrate structure that meets the requirements of high current overcurrent is formed by locally thickening the surface wiring and pads of the co-fired multilayer ceramic plate. The bottom copper layer 27 in the thickened plating structure is deposited using an electroplating process and is the main conductive strip thickening layer of this application, with a thickness ranging from 30μm to 50μm. The relatively thick copper layer 27, combined with the extremely low resistivity of copper (the typical resistivity of copper is 1.75×10⁻⁸ (Ω·m)), can meet the high current overcurrent requirements of this type of product.

[0060] The nickel layer 28, palladium layer 32, and gold layer 29 located on the upper layer are deposited sequentially using a chemical plating process. They mainly serve as functional layers for welding and bonding, enabling the pads to simultaneously meet the requirements for welding and bonding.

[0061] It needs to be explained that, Figure 2 The number 24 indicates the bottom wiring layer of the co-fired multilayer ceramic plate. Figure 2 The number 25 indicates the top wiring layer of the co-fired multilayer ceramic plate. Figure 2 The reference numeral 26 indicates a through-hole on the substrate, used for assembling the housing pin 12.

[0062] In an optional embodiment of the present invention, such as Figure 1 As shown, power components 21 are assembled on part of the thickened conductive strip coating area 16. Signal components 22 can also be assembled on other areas outside the thickened conductive strip coating area.

[0063] Specifically, in the field of hybrid integrated circuit power supplies, the power components 21 within the product mainly include power transistors, magnetic devices 19 (such as can transformers, can inductors, etc.), and components of input and output filtering and rectifier circuit units. The electrical interconnections between the power components 21 require the flow of large currents, and the power components 21 generate significant heat. Soldering the power components 21 to the thickened conductive strip plating area 16 on the locally thickened ceramic substrate 15 not only meets the high current requirements between the power components 21 but also increases the heat dissipation capacity of the components.

[0064] In an optional embodiment of the present invention, such as Figure 1 As shown, the magnetic device 19 is fixed on the thickened area 16 of the conductive strip coating by the thermally conductive fixing layer 17.

[0065] Specifically, in this embodiment of the invention, fixing the magnetic device 19 to the thickened copper conductive strip region 16 on the ceramic-based conductive strip thickened substrate 15 has two advantages. First, the bottom of such a large magnetic device 19 can still be properly wired for power routing, significantly improving the product's power density. Second, due to the presence of the highly thermally conductive thickened copper conductive strip in the thickened copper conductive strip region 16, the heat from the magnetic device 19, after being transferred to the pads, can quickly spread laterally and then be conducted to the ceramic-based conductive strip thickened substrate 15 through the large-area copper wiring pads, thus further improving the heat dissipation performance of the magnetic device 19.

[0066] A layer of ceramic spheres 18 is distributed between the magnetic device 19 and the thickened conductive strip coating area 16, and the ceramic spheres 18 are located in the thermally conductive fixing layer 17. The ceramic spheres 18 can be spheres of equal diameter. The upper top surface of the ceramic spheres 18 contacts the magnetic device 19, and the lower top surface of the ceramic spheres 18 contacts the thickened conductive strip coating area 16, so as to form a heat dissipation microchannel between the magnetic device 19 and the thickened conductive strip coating area 16.

[0067] In the field of existing hybrid integrated circuit power supplies, common magnetic devices mainly include can-type transformers and can-type inductors. The body material of these magnetic devices is typically ferrite. Ferrite itself is conductive and cannot be directly fixed to pads on a conductive substrate or metal casing. Therefore, in existing technologies, such as... Figure 3 As shown, Figure 3This is a cross-sectional schematic diagram of the heat dissipation structure of a thermally conductive insulating film in a prior art transformer. Typically, a thermally conductive insulating film 30 is used to insulate and fix the magnetic device 19. Because the selection of the thermally conductive insulating film 30 requires consideration of both insulation capacity and fixing strength, the thermal conductivity of the available film layers is usually not high, typically below 1 W / m·K. This results in a large thermal resistance between the heat-generating magnetic component 19 and the metal casing 11, significantly limiting the overall heat dissipation performance of this type of product and preventing further increases in its power density.

[0068] Based on this, such as Figure 4 and Figure 5 As shown, Figure 4 This is a cross-sectional schematic diagram of a heat dissipation structure for a magnetic device provided in an embodiment of the present invention; Figure 5 This is a partial structural diagram of a heat dissipation microchannel formed between a magnetic device and a thickened area of ​​the conductive strip coating, provided in an embodiment of the present invention. In the high-power-density power supply of this application, the thermally conductive insulating film 30 structure used in the prior art is eliminated. Instead, a certain proportion of high thermal conductivity ceramic balls 18 of equal diameter are mixed into the thermally conductive insulating adhesive to bond and fix the magnetic device 19. After bonding, the heat generated by the magnetic device 19 can be transferred downwards not only through the thermally conductive insulating adhesive but also directly downwards through the high thermal conductivity ceramic balls 18 between the magnetic device 19 and the thickened area 16 of the conductive strip coating.

[0069] like Figure 5 As shown, in the high power density power supply of this application, the presence of ceramic balls 18 serves two purposes. First, utilizing the high thermal conductivity of the ceramic ball 18 material (taking aluminum nitride as an example, the thermal conductivity of the material itself is between 170-230 W / m·K, and the thermal conductivity of the thermally conductive microchannels locally formed by the ceramic balls 18 is more than 170 times that of the thermally conductive insulating film 30 in the prior art), a high thermal conductivity heat dissipation microchannel is directly formed between the bottom of the magnetic device 19 and the thickened pads of the conductive strip. Second, due to the presence of the bottom ceramic balls 18, a certain gap is generated between the magnetic device 19 and the pads on the locally thickened substrate 15 of the ceramic base conductive strip. The gaps between the gaps are completely filled with thermally conductive insulating glue, which is equivalent to naturally forming an insulating and thermally conductive layer with a thickness equal to the maximum diameter of the ceramic balls 18.

[0070] In summary, compared with the structure of the thermally conductive insulating film 30 used in the prior art, the bottom thermally conductive insulating structure of the magnetic device 19 of this application, while maintaining the same bonding strength and insulation capability, has significantly reduced the thermal resistance between the magnetic device 19 and the locally thickened substrate 15 of the ceramic base conductive strip due to the presence of several high thermal conductivity ceramic balls 18 that are in direct contact with the upper and lower surfaces. This solves the bottleneck problem of poor heat dissipation performance of the heat-generating magnetic element in the prior art.

[0071] In an optional embodiment of the present invention, the ceramic ball 18 is made of aluminum nitride.

[0072] Specifically, the ceramic ball 18 in this embodiment of the invention is made of a material with high thermal conductivity. Taking aluminum nitride ceramic material as an example, the thermal conductivity of the material itself is between 170-230 W / m·K.

[0073] In an optional embodiment of the present invention, the ceramic ball 18 is a ball of equal diameter, and the diameter tolerance of the ball of equal diameter is less than 10 μm.

[0074] Specifically, in this embodiment of the invention, since the ceramic balls 18 are of uniform diameter, the diameter of the ceramic balls 18 in the same batch is consistent, with a tolerance within 10 μm. The uniform diameter arrangement allows all ceramic balls 18 to form a direct contact structure with the upper and lower bottom surfaces (including the bottom of the magnetic element and the surface of the conductive pad) that are bonded and fixed, which can maximize the heat dissipation performance of the heat-conducting structure.

[0075] In an optional embodiment of the present invention, the diameter of the ceramic ball 18 is in the range of 0.2mm-0.5mm.

[0076] Specifically, in the thermally conductive and insulating heat dissipation structure at the bottom of the magnetic device 19 in this embodiment of the invention, the presence of the ceramic ball 18 mainly serves two purposes. First, utilizing the high thermal conductivity of the ceramic ball 18, a thermally conductive bridge structure is formed between the bottom of the magnetic device 19 and the thickened area 16 of the conductive strip coating on the surface of the ceramic-based conductive strip locally thickened substrate 15, acting as a thermally conductive microchannel and significantly improving the heat dissipation performance of the magnetic device 19. Second, it serves to adjust the insulating distance between the magnetic device 19 and the surface of the ceramic-based conductive strip locally thickened substrate 15. Due to the presence of the ceramic ball 18, the magnetic device 19 cannot be directly pressed downwards onto the surface of the ceramic-based conductive strip locally thickened substrate 15, and an insulating isolation layer with the same diameter as the ceramic ball 18 is formed between the bottom of the magnetic device 19 and the thickened area 16 of the conductive strip coating on the surface of the ceramic-based conductive strip locally thickened substrate 15.

[0077] Based on the above mechanism of action, the diameter of the ceramic balls 18 mixed into the thermally conductive fixing adhesive can be selected according to the insulation capability required by the product. According to the technical characteristics of this type of hybrid integrated circuit power supply product, the typical selectable ball diameter range is between 0.2mm and 0.5mm.

[0078] Based on the above embodiments of the present invention, another embodiment of the present invention provides a method for fabricating a ceramic-based conductive strip locally thickened substrate, used to fabricate the ceramic-based conductive strip locally thickened substrate described in the above embodiments, with reference to... Figure 6 , Figure 6This is a schematic flowchart illustrating a method for fabricating a ceramic-based conductive strip locally thickened substrate according to an embodiment of the present invention. The method for fabricating the ceramic-based conductive strip locally thickened substrate includes:

[0079] S101: Apply an electroplated masking layer to a co-fired multilayer ceramic plate.

[0080] S102: Thicken the copper plating on the conductive strips and pads of co-fired multilayer ceramic plates that require high current.

[0081] S103: Remove the electroplating masking layer.

[0082] S104: Chemical plating is performed on co-fired multilayer ceramic plates, sequentially plating nickel, palladium, and gold.

[0083] S105: Remove electroplating connection wires from co-fired multilayer ceramic plates.

[0084] Based on the above embodiments of the present invention, another embodiment of the present invention also provides a method for manufacturing a high power density power supply, used to manufacture the high power density power supply described in the above embodiments, referencing... Figure 7 , Figure 7 This is a schematic flowchart illustrating a method for manufacturing a high-power-density power supply according to an embodiment of the present invention. The method for manufacturing the high-power-density power supply includes:

[0085] S201: A metal housing 11, a ceramic-based conductive strip locally thickened substrate 15, a thermally conductive fixing layer 17, a ceramic ball 18, a magnetic device 19, and a metal cover plate 20 are provided; the metal housing 11 and the metal cover plate 20 form a cavity; the ceramic-based conductive strip locally thickened substrate 15, the thermally conductive fixing layer 17, the ceramic ball 18, and the magnetic device 19 are located in the cavity; the ceramic-based conductive strip locally thickened substrate 15 includes at least one conductive strip plating thickened area 16 on the surface of the side opposite to the bottom of the metal housing 11.

[0086] S202: The ceramic-based conductive strip locally thickened substrate 15 is welded to the bottom of the metal shell 11.

[0087] S203: Power components 21 are assembled on the thickened conductive strip coating area 16 of the ceramic-based conductive strip locally thickened substrate 15, and signal components 22 are assembled on other areas of the ceramic-based conductive strip locally thickened substrate 15. The other areas are non-conductive strip coating thickened areas.

[0088] S204: Mix the ceramic balls 18 into the thermally conductive fixing adhesive in a certain proportion and stir evenly.

[0089] S205: Using thermally conductive adhesive mixed with the ceramic ball 18, fix the magnetic device 19 onto the thickened area 16 of the conductive strip coating.

[0090] S206: Apply a certain amount of pressure and rub back and forth to make the ceramic balls 18 at the bottom of the magnetic device 19 arranged in a single layer.

[0091] Specifically, by applying a certain amount of pressure and rubbing back and forth, the ceramic balls 18 at the bottom can be made into a single layer through the compression of the magnetic device 19. In order to ensure that a relatively dense single layer of ceramic balls 18 can be formed at the interface between the magnetic device 19 and the locally thickened substrate 15 of the ceramic base conductive strip when the magnetic device 19 is rubbed and compressed back and forth, the proportion of ceramic balls 18 mixed with thermally conductive fixing adhesive needs to be controlled: First, if the proportion of ceramic balls 18 is too high, during the assembly of the magnetic device 19, due to the high viscosity of the mixed adhesive, the magnetic device 19 cannot be compressed downwards to a position close to the surface pads of the locally thickened substrate 15 of the ceramic base conductive strip through friction and compression, or a single layer of ceramic balls 18 cannot be formed at the bottom of the magnetic device 19. There may be multiple layers of ceramic balls 18 stacked together at the bottom, which not only reduces the heat dissipation performance of the magnetic device 19, but also increases the height of the product to a certain extent. Secondly, if the proportion of ceramic balls 18 is too low, after a single layer of ceramic balls 18 is formed at the bottom of the magnetic device 19, the number of heat dissipation microchannels formed between the magnetic device 19 and the locally thickened substrate 15 of the ceramic base conductive strip is very limited due to the scarcity of ceramic balls 18, resulting in very limited improvement on the heat dissipation performance of the magnetic device 19.

[0092] S207: As Figure 8 As shown, Figure 8 This is a schematic diagram of the curing of a counterweight for a magnetic device provided in an embodiment of the present invention. A counterweight block 31 is added to the surface of the magnetic device 19 to cure the thermally conductive fixing adhesive, forming the thermally conductive fixing layer 17 with the ceramic ball 18.

[0093] Specifically, when the magnetic device 19 is attached to the surface of the locally thickened ceramic substrate 15, the thermally conductive adhesive is still in a flowable state because it has not yet been cured. Through the extrusion and friction described in the above steps, a single layer of ceramic spheres 18 can be formed at the bottom of the magnetic device 19. If no measures are taken to directly cure the magnetic device 19, due to the expansion, contraction, and flow of the adhesive during the curing process, it cannot be guaranteed that the ceramic spheres 18, the magnetic device 19, and the substrate surface pads will remain in contact after curing. Therefore, in the manufacturing method of this application, a counterweight 31 of a certain weight is stacked on top of the magnetic device 19 to cure it. Because the weight of the counterweight 31 is continuously applied during the curing process, it can be guaranteed that after curing, the ceramic spheres 18, the magnetic device 19, and the substrate surface pads will remain in basic contact, ultimately forming the thermally conductive microchannel structure mentioned in this application.

[0094] S208: Perform sealing welding based on the metal cover plate 20.

[0095] After the metal cover plate 20 is welded, the product can be sealed.

[0096] As described above, the high power density power supply and its manufacturing method provided by the present invention, based on a co-fired multilayer ceramic plate, form at least one thickened conductive strip plating region 16 by thickening the surface conductive strip and pads. This creates a substrate structure that can achieve high wiring and packaging density while also meeting the requirements for high current overcurrent. Simultaneously, by setting a heat dissipation microchannel at the bottom of the main heat-generating magnetic component 19, which has a heat dissipation bottleneck, the thermal resistance between the magnetic component 19 and the locally thickened ceramic substrate 15 is significantly reduced while maintaining the bonding strength and insulation capability. This solves the bottleneck problem of poor heat dissipation performance of heat-generating magnetic components in the prior art, significantly improving the current density and power density of this type of product, and meeting the further miniaturization design requirements of this type of product.

[0097] The above provides a detailed description of a high power density power supply and its manufacturing method provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

[0098] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0099] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that elements inherent to a process, method, article, or apparatus that comprises a list of elements, or elements inherent to such processes, methods, articles, or apparatus, are also included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0100] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high power density power supply characterized by, The high-power-density power supply comprises a metal shell and a metal cover plate, which form a cavity; a ceramic-based conductive band locally thickened substrate, a heat-conductive fixing layer, ceramic balls and a magnetic device in the cavity; The ceramic-based conductive band locally thickened substrate is welded to the bottom of the metal shell, and the surface of the side of the ceramic-based conductive band locally thickened substrate away from the bottom of the metal shell comprises at least one conductive band plating thickened area; the ceramic-based conductive band locally thickened substrate is a co-fired multilayer ceramic plate and a plating thickened structure on one side of the co-fired multilayer ceramic plate, and the area where the plating thickened structure is located is the conductive band plating thickened area; The magnetic device is fixed on the conductive band plating thickened area through the heat-conductive fixing layer; The ceramic balls are distributed between the magnetic device and the conductive band plating thickened area, and the ceramic balls are located in the heat-conductive fixing layer; The upper top surface of the ceramic ball is in contact with the magnetic device, and the lower top surface of the ceramic ball is in contact with the conductive band plating thickened area, so as to form a heat dissipation microchannel between the magnetic device and the conductive band plating thickened area.

2. The high power density power supply of claim 1, wherein, The co-fired multilayer ceramic plate is an HTCC plate or an LTCC plate.

3. The high power density power supply of claim 1, wherein, The plating thickened structure comprises a copper layer, a nickel layer, a palladium layer and a gold layer which are sequentially stacked, and the copper layer is arranged adjacent to the co-fired multilayer ceramic plate.

4. The high power density power supply of claim 3, wherein, The thickness of the copper layer ranges from 30 μm to 50 μm.

5. The high power density power supply of claim 1, wherein, The magnetic device comprises a pot-shaped transformer and / or a pot-shaped inductor.

6. The high power density power supply of claim 1, wherein, The material of the ceramic ball comprises an aluminum nitride material.

7. The high power density power supply of claim 1, wherein, The ceramic ball is an equal-diameter ball. The diameter tolerance of the equal-diameter ball is less than 10 μm.

8. The high power density power supply of claim 1, wherein, The diameter of the ceramic ball ranges from 0.2 mm to 0.5 mm.

9. A method of manufacture, characterized by, The manufacturing method is used for manufacturing the ceramic-based conductive band locally thickened substrate of any one of claims 1-8, and the manufacturing method comprises the following steps: coating an electroplating shielding layer on the co-fired multilayer ceramic plate; thickening the conductive band and the pad on the co-fired multilayer ceramic plate which need to pass large current by electroplating copper; removing the electroplating shielding layer; carrying out chemical plating on the co-fired multilayer ceramic plate, and sequentially plating nickel, palladium and gold; removing the electroplated connecting wires of the co-fired multilayer ceramic plate.

10. A method of manufacture, characterized by, The manufacturing method is used for manufacturing the high-power-density power supply of any one of claims 1-8, and the manufacturing method comprises the following steps: providing a metal shell, a ceramic-based conductive band locally thickened substrate, a heat-conductive fixing layer, ceramic balls, a magnetic device and a metal cover plate; the metal shell and the metal cover plate form a cavity; the ceramic-based conductive band locally thickened substrate, the heat-conductive fixing layer, the ceramic balls and the magnetic device are located in the cavity; the surface of the side of the ceramic-based conductive band locally thickened substrate away from the bottom of the metal shell comprises at least one conductive band plating thickened area; welding the ceramic-based conductive band locally thickened substrate to the bottom of the metal shell; assembling power-type components on the conductive band plating thickened area of the ceramic-based conductive band locally thickened substrate, and assembling signal-type components on other areas of the ceramic-based conductive band locally thickened substrate; the other areas are non-conductive band plating thickened areas. Mix the ceramic balls into the heat-conducting fixing glue in a certain proportion and stir them evenly; Use the heat-conducting fixing glue mixed with the ceramic balls to fix the magnetic device on the thickened area of the conductive strip plating; Apply a certain extrusion force and rub back and forth so that the ceramic balls at the bottom of the magnetic device are arranged in a single layer; Increase the counterweight on the surface of the magnetic device, solidify the heat-conducting fixing glue, and form the heat-conducting fixing layer with the ceramic balls; Based on the metal cover plate, perform a sealing welding process.

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