Integrated module and preparation method thereof

Abstract

The invention provides an integrated module and a preparation method thereof, the integrated module comprises an inductance device and a ceramic layer connected on the metal layer, a magnetic body of the inductance device is connected with the metal layer in an embedded manner, and the ceramic layer can be used as a ceramic substrate part so that an electric device can be more conveniently mounted and integrated on the inductance device; moreover, the magnetic body and the metal layer of the inductor device are connected in an embedded manner, so that the contact area between the metal layer and the magnetic body of the inductor device can be increased, and the heat dissipation effect is improved.

Description

Technical Field

[0001] This invention relates to the field of electronic components technology, specifically to an integrated module and its fabrication method. Background Technology

[0002] As the power of electronic devices continues to increase and their size continues to decrease, the application space for various components in electronic devices is becoming increasingly compact. How to reduce the board area occupied by these components has been a problem that the industry has been researching. Inductors are relatively large, and there is a gap between them and other mounted electronic components, resulting in a large board area occupied. For example, CN115707186A discloses an electronic module including an inductor and multiple circuit boards bonded to the inductor using an adhesive layer. At least one of the circuit boards has a first electronic device mounted on it. This application still uses a traditional integration method, and the overall size of the electronic module still needs to be reduced.

[0003] In summary, there is a need to develop a novel integrated module and its fabrication method. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides an integrated module and its preparation method, which provides a new integration method and the integrated module has a small size.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] One objective of this invention is to provide an integrated module, which includes an inductor, wherein a metal layer and a ceramic layer are sequentially disposed on the surface of the magnetic body of the inductor; the magnetic body of the inductor is embeddedly connected to the metal layer, and the metal layer is connected to the ceramic layer.

[0007] Preferably, the bonding between the metal layer and the ceramic layer includes co-firing the metal layer and the ceramic layer together, wherein the metal layer includes a copper layer or an aluminum layer.

[0008] And / or, the magnetic material is embedded in the surface of the metal layer, and the embedding depth is ≥0.05mm, preferably 0.05-0.8mm, such as 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, etc.

[0009] Preferably, a conductive layer is provided on the surface of the ceramic layer away from the metal layer.

[0010] And / or, in the stacking direction of the metal layer and the ceramic layer, heat dissipation through holes are formed on the ceramic layer, which helps to achieve thermal coupling connection between the metal layer and the conductive layer.

[0011] Preferably, the conductive layer is provided with at least one of a power element and a passive element.

[0012] Preferably, the magnetic material and the metal layer form a diffusion layer.

[0013] Preferably, the metal layer is continuously disposed on the side and top surface of the magnetic body, and the ceramic layer includes a plurality of sub-ceramic layers, which are spaced apart on the side and top surface of the magnetic body.

[0014] Preferably, the metal layer is disposed at least on the bottom surface of the magnetic body, and the metal layer is electrically connected to the winding of the inductor.

[0015] A second aspect of this invention provides a method for preparing an integrated module, the method comprising the following steps:

[0016] The inductor blank, metal parts and ceramic parts are stacked in sequence, heat-treated and cooled to obtain the integrated module.

[0017] Preferably, during the heat treatment process, a molten substance similar to an adhesive is formed between the magnetic material and the metal layer to connect the magnetic material and the metal layer. If the metal layer is a copper layer, the adhesive is a Cu-O eutectic liquid; if the metal layer is an aluminum layer, the adhesive can be pure aluminum liquid. That is, as long as the adhesive can help the molten portion of the metal layer surface enter the gap between the metal layer and the magnetic material at the heat treatment temperature, thus facilitating the formation of a locking effect, it is acceptable.

[0018] A third aspect of the present invention provides another method for preparing an integrated module, the method comprising the following:

[0019] (1) Press one of the metal powder or metal parts with soft magnetic powder and winding according to the target position relationship to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is embedded with the metal layer.

[0020] (2) A ceramic layer is placed on the surface of the metal layer away from the magnetic body, and the metal layer and the ceramic layer are connected to obtain an integrated module.

[0021] Preferably, step (1) is performed in any of the following ways;

[0022] Method a: First, the soft magnetic powder and the winding are pre-pressed according to the target position relationship to obtain a pre-pressed magnetic body; then, the metal part is placed on the surface of the pre-pressed magnetic body and pressed under high pressure. After heat treatment, an integrated inductor device is obtained, so that the surface of the magnetic body of the inductor device is embedded and connected to the metal layer.

[0023] Method b: The metal parts, soft magnetic powder and windings are directly pressed under high pressure according to the target position relationship, and then heat-treated to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is interlocked with the metal layer.

[0024] Method c: First, the soft magnetic powder and the winding are pre-pressed according to the target position relationship to obtain a pre-pressed magnetic body; then, the metal powder and the pre-pressed magnetic body are pressed under high pressure according to the target position relationship, and after heat treatment, an integrated inductor device is obtained, so that the surface of the magnetic body of the inductor device is embedded and connected to the metal layer.

[0025] Method d: Metal powder, soft magnetic powder and winding are directly pressed under high pressure according to the target position relationship, and then heat treated to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is embedded and connected with the metal layer.

[0026] Preferably, in step (1), the soft magnetic powder includes at least one of iron-silicon-aluminum powder, iron-silicon powder, iron-nickel powder, iron-cobalt powder, iron-molybdenum powder, amorphous nanocrystalline powder, or carbonyl iron powder.

[0027] And / or, in step (2), the raw material of the ceramic layer includes at least one of mullite, Al2O3, Si3N4, AlN, ZTA, ATZ, TiO2, ZrO2, MgO, CaO or CaCO3.

[0028] Preferably, the high-pressure pressing pressure is 12-24 t / m. 2 For example, 12t / m 2 13t / m 2 14t / m 2 15t / m 2 16t / m 2 17t / m 2 18t / m 2 19t / m 2 20t / m 2 21t / m 2 22t / m 2 Or 24t / m 2 The preferred value is 16-22 t / cm. 2 .

[0029] And / or, after sequentially undergoing high-pressure pressing and heat treatment, a diffusion layer is formed between the magnetic material and the metal layer. It should be noted that regardless of whether the metal component used in method a or method b, or the metal powder used in method c or method d, a metal layer will ultimately be formed; this is not intended to cause ambiguity.

[0030] Preferably, in method a or method c, the pre-compression pressure is 2-10 t / cm.2 For example, 2t / cm 2 4t / cm 2 5t / cm 2 6t / cm 2 7t / cm 2 8t / cm 2 9t / cm 2 or 10t / cm 2 The preferred values ​​are 5-10 t / cm. 2 The pre-pressing pressure is less than the high-pressure pressing pressure, and is used to pre-form the shape of the inductor.

[0031] Preferably, in step (2), after the high-temperature sintering, in the stacking direction of the metal layer and the ceramic layer, heat dissipation through holes are first opened on the ceramic layer, and then a conductive layer is formed on the upper surface of the ceramic layer; further, according to the circuit design, the circuit, bare electrical components, and plastic encapsulation are sequentially performed on the upper surface of the conductive layer to obtain an integrated module.

[0032] Preferably, the metal layer in step (1) is an aluminum layer or a copper layer, and step (2) includes using DAB or DBC process to place a ceramic layer with alumina pre-formed on the connecting surface on the surface of the metal layer, and sintering it so that the metal layer and the ceramic layer are co-fired and connected.

[0033] Compared with existing technical solutions, the present invention has at least the following beneficial effects:

[0034] This invention provides an integrated module and its fabrication method. The integrated module includes an inductor with its magnetic body and a metal layer interlocked. It also includes a ceramic layer disposed on the metal layer, which can serve as a ceramic substrate to facilitate the integration of the electrical components onto the inductor. Furthermore, the interlocked connection between the magnetic body of the inductor and the metal layer increases the contact area between the metal layer and the magnetic body of the inductor, thereby improving heat dissipation. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the integrated module in a specific embodiment of the present invention;

[0036] Figure 2 yes Figure 1 A schematic diagram of the structure of a medium-sized integrated inductor;

[0037] Figure 3 yes Figure 2 An explosion diagram;

[0038] In the diagram, 1-metal layer; 2-ceramic layer; 3-conductive layer; 4-molding layer; 5-electrical component; 6-magnetic body; 7-winding. Detailed Implementation

[0039] It should be understood that in the description of this invention, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0040] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0042] This invention provides an integrated module, such as... Figure 1 As shown, the integrated module includes an inductor, with a metal layer 1 and a ceramic layer 2 sequentially disposed on the surface of the inductor; the magnetic body 6 of the inductor is embedded in the metal layer 1, and the metal layer 1 is connected to the ceramic layer 2.

[0043] It is understood that an inductor includes a magnetic body 6 and a winding 7, mostly disposed inside the magnetic body 6. The winding can be a single-turn coil or a multi-turn coil. The inductor can be an inductor or a transformer.

[0044] It is understood that the magnetic body 1 includes a main body and an extension body connected to the main body and extending beyond the bottom surface of the main body, with the winding 3 exposed from the end of the extension body. There are at least two windings 3, with at least two windings 2 spaced apart along the length of the main body, and the heat transfer element covering the width side of the main body.

[0045] In this embodiment, the magnetic body 6 of the inductor in the integrated module is embeddedly connected to the metal layer 1, and a ceramic layer 2 is connected to the metal layer 1. The metal layer 1 serves as a connecting layer to connect the magnetic body 6 and the ceramic layer 2, and the ceramic layer 2 can serve as a ceramic substrate portion, making it easier to integrate the electrical device 5 onto the inductor. Furthermore, the embedded connection between the magnetic body 6 of the inductor and the metal layer 1 increases the contact area between the metal layer 1 and the magnetic body of the inductor, improving heat dissipation.

[0046] In some embodiments, a conductive layer 3 is disposed on a surface of the ceramic layer 2 away from the metal layer 1, and heat dissipation vias are formed on the ceramic layer 2 in the stacking direction of the metal layer 1 and the ceramic layer 2. Figure 1 (Not shown in the image) This facilitates thermal coupling between the metal layer 1 and the conductive layer 2. An electrical device 5 can be further disposed on the upper surface of the conductive layer 3 and encapsulated by a molding compound 4. The heat from the electrical device 5 is transferred to the metal layer 1 through the conductive layer 3, and then further transferred to the metal layer 1 and the inductor for heat dissipation.

[0047] It should be noted that after the inductor is connected to the circuit board via its winding leads, if a space is formed beneath the magnetic material, and electrical components connected to the circuit board can be installed within this space, then the metal layer on the upper surface of the inductor can extend further to the side of the inductor, or, as... Figure 1 As shown, the metal layer on the upper surface of the inductor can extend further to the side and lower surface of the inductor, so that the electrical components in the accommodating space are electrically connected to the metal layer.

[0048] It should be noted that, Figure 2 and Figure 3 It shows Figure 1 The structural relationship of the integrated inductor device shows that, on the one hand, the metal layer 1 on the upper surface of the magnetic body 6 extends further to the side and lower surface of the magnetic body 6, which helps to install electrical components in the space below the magnetic body 6. On the other hand, the position of the winding pin of the magnetic body 6 is further extended to form a magnetic body shielding section, which can cover the winding pin as much as possible by the magnetic body shielding section, reducing the exposed surface of the winding pin, thereby shielding the electrical components located below the magnetic body 6 and reducing signal interference.

[0049] It is understandable that, since the shielding section extends beyond the bottom surface of the magnetic body 6, the winding 7, after being connected to the circuit board, can form an accommodating space 4. After the winding 7 protrudes from the end of the shielding section onto the magnetic body 6, different connection methods can be used with the circuit board depending on the length of the exposed portion of the winding 7, i.e., the length of the winding pins exposed beyond the shielding section. If the exposed portion of the winding 7 is short, or when it is flush with the end face of the shielding section, it can be directly connected to the surface of the circuit board using a surface mount method. When the exposed portion of the winding 7 is long, a connection hole is provided on the circuit board, and the winding 7 is inserted into the connection hole, allowing the winding 7 and the circuit board to be connected using a plug-in connection method. Of course, in some embodiments, the shielding section may not be included; this is not specifically limited here.

[0050] In some implementations, the metal layer includes a copper layer or an aluminum layer.

[0051] In some embodiments, the magnetic material is embedded in the surface of the metal layer, and the embedding depth is ≥0.05mm, preferably 0.05-0.8mm, such as 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, etc.

[0052] It should be noted that the number of heat dissipation through holes in this invention is greater than or equal to one. As for the size, density, etc. of the heat dissipation through holes, those skilled in the art can reasonably set them according to the actual situation. The thermal coupling connection achieved through the heat dissipation through holes can be either a non-contact thermal coupling connection or a contact thermal coupling connection filled with thermally conductive material.

[0053] In some embodiments, the metal layer 1 can be continuously disposed on the side and top surface of the magnetic body 6, and the ceramic layer 2 includes a plurality of sub-ceramic layers, which are spaced apart on the side and top surface of the magnetic body 6. Alternatively, the metal layer 1 can be disposed on opposite sides of the magnetic body 6; or the metal layer 1 can be disposed at least on the bottom surface of the magnetic body 6, and the metal layer 1 is electrically connected to the winding 7 of the inductor. Of course, the position of the metal layer 1 on the outer surface of the magnetic body 6 can be selected according to the actual situation, and no specific limitation is made here.

[0054] In one aspect, the present invention provides a method for fabricating an integrated module, which can be used to fabricate the integrated module in any of the above embodiments. In a specific embodiment, the present invention provides a method for fabricating an integrated module, the method comprising the following steps:

[0055] The inductor blank, metal parts and ceramic parts are stacked in sequence, heat-treated and cooled to obtain the integrated module.

[0056] The method for preparing an integrated module according to an embodiment of the present invention can simultaneously achieve the interlocking connection between the magnetic body and the metal layer in the integrated module, as well as the co-firing connection between the metal layer and the ceramic layer through one-step heat treatment. The operation is simple and saves time and effort.

[0057] It should be noted that if the metal part is copper, the heat treatment temperature is 1065-1083℃ or 1083.4℃, such as 1065℃, 1067℃, 1068℃, 1070℃, 1071℃, 1073℃, 1075℃, 1077℃, 1079℃, 1080℃, or 1083℃, etc. If the metal part is aluminum, the heat treatment temperature is 640-660℃, such as 640℃, 645℃, 650℃, 655℃, or 660℃, etc. That is, the heat treatment temperature is related to the material of the metal part and is set based on the melting point of the metal layer bonding surface material. This allows the surface of the metal part to partially melt, which is more conducive to the tight connection between the metal part and the magnetic body green body and the ceramic layer, thereby forming an interlocking copper layer and aluminum layer on the magnetic body, and directly bonding the copper layer or aluminum layer with the ceramic layer formed by the ceramic part.

[0058] Preferably, during the heat treatment process, a molten substance similar to an adhesive is formed between the magnetic material and the metal part to connect the magnetic material and the metal part. If the metal part is copper, the adhesive is a Cu-O eutectic liquid or copper liquid; if the metal part is aluminum, the adhesive can be pure aluminum liquid. That is, as long as the adhesive can help the molten portion of the metal part surface enter the gap between the metal layer and the magnetic material at the heat treatment temperature, thus facilitating the formation of a locking effect, it is acceptable.

[0059] Preferably, during the heat treatment process, a molten body similar to an adhesive is formed between the metal part and the ceramic part to connect the ceramic part and the metal part. If the metal part is copper, the adhesive is Cu-O eutectic liquid or copper liquid. If the metal part is aluminum, the adhesive can be pure aluminum liquid, thereby directly bonding copper and aluminum to the ceramic part.

[0060] Understandably, to facilitate the bonding between the ceramic and metal layers, an aluminum oxide layer can be pre-formed on the ceramic layer to increase the wettability of the metal and ceramic layers, thereby increasing the bonding strength between them. Alternatively, Cu2O can be pre-formed on the copper.

[0061] In another specific embodiment, the present invention provides a method for preparing an integrated module, the method comprising the following steps:

[0062] (1) Press one of the metal powder or metal parts with soft magnetic powder and winding according to the target position relationship to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is connected to the metal layer in an interlocking manner.

[0063] (2) A ceramic layer is placed on the surface of the metal layer away from the direction of the magnetic body, and the metal layer and the ceramic layer are connected to obtain an integrated module.

[0064] The method for fabricating the integrated module described in this invention first obtains an integrated inductor device through pressing, thereby embedding the magnetic surface of the inductor device with a metal layer. Then, it uses high-temperature sintering to co-fire the metal layer with a ceramic layer. This two-step method of "pressing first, then high-temperature sintering" is more conducive to controlling the tight connection between the layers. It is understood that using an embedding connection between the magnetic body and the metal layer, and bonding the ceramic layer to the metal layer, provides a new integration method. Furthermore, the integration of the module does not use organic materials, avoiding the simple integration method of traditional adhesive bonding, effectively improving the lifespan of the integrated module and reducing its overall size.

[0065] It should be noted that in step (1), the soft magnetic powder needs to be insulated from at least one of the windings to ensure that only the windings conduct electricity during subsequent operation. For example, the soft magnetic powder is first coated with insulation, and the prepared insulated soft magnetic powder is then placed together with the windings in the mold cavity for pressing. The soft magnetic powder in the magnetic body of the integrated inductor device is bonded together with the insulating material.

[0066] In some implementations, step (1) is performed in any of the following ways;

[0067] Method a: First, the soft magnetic powder and the winding are pre-pressed according to the target position relationship to obtain a pre-pressed magnetic body; then, the metal part is placed on the surface of the pre-pressed magnetic body and pressed under high pressure to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is interlocked with the metal layer.

[0068] Optionally, an adhesive is applied between the surfaces of the metal part and the pre-pressed magnetic body. The adhesive may be the same as or different from the insulating material coating the soft magnetic powder. The adhesive is at least one of epoxy resin, PVB resin, polyacrylic acid resin, or PVA resin. Applying the adhesive to the target location of the pre-pressed magnetic body before bonding the metal part to its surface effectively prevents misalignment between the metal part and the pre-pressed magnetic body during high-pressure pressing.

[0069] Method b: The metal parts, soft magnetic powder and windings are directly pressed under high pressure according to the target position relationship, and then heat-treated to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is interlocked with the metal layer.

[0070] One method involves first placing the metal part in the mold cavity, laying a first layer of soft magnetic powder, then placing the winding on the first layer of soft magnetic powder, and then laying a second layer of soft magnetic powder before high-pressure pressing to obtain a magnetic body and a metal part integrated on the magnetic body. No specific limitations are made here.

[0071] Method c: First, the soft magnetic powder and the winding are pre-pressed according to the target position relationship to obtain a pre-pressed magnetic body; then, the metal powder and the pre-pressed magnetic body are pressed under high pressure according to the target position relationship, and after heat treatment, an integrated inductor device is obtained, so that the surface of the magnetic body of the inductor device is interlocked with the metal layer.

[0072] Optionally, an adhesive is first applied to the target position of the pre-pressed magnetic body, and then metal powder is bonded to the surface of the pre-pressed magnetic body to form a metal powder layer before high-pressure pressing. The adhesive is at least one of PVB resin, polyacrylic acid resin or PVA resin, and the thickness of the metal powder layer is 0.05-0.15 mm, such as 0.05 mm, 0.07 mm, 0.09 mm, 0.10 mm, 0.11 mm, 0.13 mm or 0.15 mm.

[0073] Method d: Metal powder, soft magnetic powder and winding are directly pressed under high pressure according to the target position relationship, and then heat treated to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is embedded and connected with the metal layer.

[0074] For example, according to the target position relationship, metal powder and soft magnetic powder are sequentially laid in the mold cavity to form a first metal powder layer and a first soft magnetic powder layer, respectively. Then, a winding is placed on the first soft magnetic powder layer, and soft magnetic powder and metal powder are sequentially laid on the winding to form a second soft magnetic powder layer and a second metal powder layer, respectively, so that the first metal powder layer and the second metal powder layer are connected, and the resulting whole is subjected to high pressure pressing.

[0075] For example, a pre-pressed magnetic material can be placed into a mold cavity, and then metal powder can be filled into the mold cavity before high-pressure pressing. When it is only necessary to press the metal powder onto the same surface of the pre-pressed magnetic material, for example, the pre-pressed magnetic material can be placed upside down into the mold cavity, that is, the bottom surface of the pre-pressed magnetic material is close to the opening of the mold cavity; then the metal powder is filled into the mold cavity and covers the bottom surface of the pre-pressed magnetic material before high-pressure pressing. Alternatively, if it is necessary to press the metal powder onto different surfaces of the pre-pressed magnetic material, the orientation of the pre-pressed magnetic material can be changed, and multiple metal powder fillings and multiple high-pressure pressings can be performed.

[0076] It should be noted that in methods a, b, c, and d of the present invention, high-pressure pressing can be either room-temperature pressing or heated high-pressure pressing. Heated high-pressure pressing has the function of hot pressing pre-pressed magnetic materials or sintering metal powders.

[0077] It should be noted that in methods a, b, c, and d of this invention, the heat treatment includes one or more of curing and annealing processes. It can have at least one function: stress relief, curing, and sintering the metal powder together. The heat treatment can include a single heat treatment or multiple heat treatments, which can be selected according to the actual situation. For example, a single annealing or curing process can be performed, in which stress can be relieved and the metal powder can be sintered together. When multiple heat treatments are performed, the temperatures of the multiple heat treatments can also be different. For example, annealing, impregnation, and curing can be performed after high-pressure pressing; wherein, annealing and curing are both heat treatment steps, and the temperature of the annealing process is higher than the temperature of the curing process.

[0078] It should be noted that both method a and method c described in this invention are two-step methods of "pre-pressing followed by high-pressure pressing," which facilitates precise control in the design of the target structure. Furthermore, the pre-pressing pressure is lower than the high-pressure pressing pressure, and is used to pre-form the shape of the inductor device.

[0079] For the pre-pressing operation, a first layer of soft magnetic powder can be laid in the mold cavity, then the winding can be placed on the first layer of soft magnetic powder, and a second layer of soft magnetic powder can be laid on the winding for pre-pressing to obtain a pre-pressed magnetic body. Alternatively, the soft magnetic powder can be pre-pressed to obtain multiple magnetic body blanks, and then the winding can be assembled with the multiple magnetic body blanks according to a predetermined relationship to obtain a pre-pressed magnetic body with windings. Or, the soft magnetic powder can be pre-pressed to obtain multiple magnetic body blanks, and then the winding can be assembled with the multiple magnetic body blanks according to a predetermined relationship before pressing to obtain a pre-pressed magnetic body with windings.

[0080] It should be noted that method b or method d described in this invention are both one-step methods of "direct high-pressure pressing", which are simple to operate, convenient and quick, and can also achieve the goal of integrating metal parts with magnetic bodies.

[0081] In some embodiments, in step (1), the soft magnetic powder includes at least one of iron-silicon-aluminum powder, iron-silicon powder, iron-nickel powder, iron-cobalt powder, iron-molybdenum powder, amorphous nanocrystalline powder, or carbonyl iron powder.

[0082] In some embodiments, in step (2), the raw material for the ceramic layer includes at least one of mullite, Al2O3, Si3N4, AlN, ZTA, ATZ, TiO2, ZrO2, MgO, CaO, or CaCO3.

[0083] In some implementations, the high-pressure pressing pressure is 12-24 t / m. 2 For example, 12t / m 2 13t / m 214t / m 2 15t / m 2 16t / m 2 17t / m 2 18t / m 2 19t / m 2 20t / m 2 21t / m 2 22t / m 2 Or 24t / m 2 The preferred value is 16-22 t / cm. 2 .

[0084] In some embodiments, the metal part undergoes high-pressure pressing and heat treatment in sequence, causing a diffusion layer to form on the surface of the metal part in contact with the magnetic body. It should be noted that regardless of whether the metal part used in method a or method b, or the metal powder used in method c or method d, a metal layer will eventually be formed; this is not intended to cause ambiguity.

[0085] It should be noted that, depending on the actual situation, by adjusting the high-pressure pressing time, heat treatment temperature, and time, a diffusion layer can be formed on the surface where the magnetic material contacts the copper sheet. This diffusion layer can be an alloy layer, such as a copper-iron alloy, used to increase the connection strength between the copper sheet and the magnetic material. To form the diffusion layer, the temperature only needs to be greater than or equal to the thermal diffusion temperature between the metal part and the soft magnetic powder, while being lower than the melting point of the metal part. The specific high-pressure pressing time and temperature vary depending on the composition of the soft magnetic powder and the thickness of the diffusion layer. If the formation of a diffusion layer is not required, heat treatment can be performed after high-pressure pressing. This heat treatment is carried out in an inert gas atmosphere, such as nitrogen, and the heat treatment temperature is lower than the thermal diffusion temperature between the metal part and the magnetic material, thereby eliminating the stress caused by high-pressure pressing. The heat treatment of this invention can release the internal stress generated after high-pressure pressing. Furthermore, insulation treatment after the heat treatment step can form an insulating layer on the exposed surfaces of the metal part and the magnetic material, or it can form an insulating layer only on the exposed surface of the magnetic material. In the prior art, when using adhesive bonding to connect metal parts, it is necessary to first spray insulation on the outer surface of the magnetic body and then apply adhesive to bond the metal parts. However, the insulation treatment of the present invention is carried out after high-pressure pressing. Therefore, when spraying insulation, the outer surface of the metal parts is not insulated, or the outer surface of the metal parts is exposed after insulation treatment to ensure heat dissipation.

[0086] In some implementations, in method a or method c, the pre-compression pressure is 2-10 t / cm. 2 For example, 2t / cm 2 4t / cm 2 5t / cm 2 6t / cm 27t / cm 2 8t / cm 2 9t / cm 2 or 10t / cm 2 The preferred values ​​are 5-10 t / cm. 2 The pre-pressing pressure is less than the high-pressure pressing pressure, and is used to pre-form the shape of the inductor.

[0087] Optionally, in method a or method b, the metal part is prepared by casting a slurry containing metal powder, or by stamping or cutting a metal sheet.

[0088] Optionally, in method a or method b, the metal part is a copper sheet; the copper sheet is prepared by casting copper powder slurry, or the copper sheet is obtained by stamping or cutting copper plate; if the copper sheet is prepared by casting copper powder slurry, the copper powder particle size in the copper powder slurry is 20-200 mesh, such as 20 mesh, 50 mesh, 70 mesh, 100 mesh, 120 mesh, 150 mesh, 160 mesh, 180 mesh or 200 mesh, etc., and the binder in the copper powder slurry is at least one of PVB resin, polyacrylic acid resin or PVA resin.

[0089] In this embodiment of the invention, if the metal part is directly made from a pre-formed copper plate stamped or cut into copper sheets, which does not contain copper powder particles, the copper sheet is not easily deformed under high pressure and the degree of fitting is small; if the metal part is made from a copper sheet prepared by casting of copper powder slurry, which contains copper powder particles, it is easier to deform during high pressure and the degree of fitting is large; moreover, the copper sheet prepared by casting can be either formed into a sheet body and cut into a predetermined shape using the casting process, or it can be directly formed into a predetermined shape using the casting process.

[0090] Optionally, in method c or method d, the metal powder is a composite powder, which can be a physical mixture of metal powders of different materials or a coating of metal powders of different materials.

[0091] Optionally, in method c or method d, the metal powder is copper powder, or a composite powder of copper powder and graphite powder.

[0092] If the metal powder is copper powder, and a single copper powder with a single particle size is used, the single particle size is larger than the average particle size of the soft magnetic powder. The particle size of the single copper powder is 20-300 mesh, such as 20 mesh, 50 mesh, 70 mesh, 100 mesh, 120 mesh, 150 mesh, 160 mesh, 180 mesh, 200 mesh, 220 mesh, 250 mesh, 260 mesh, 280 mesh, etc., and the ratio of the single particle size of the single copper powder to the average particle size of the soft magnetic powder is greater than 5. Because the average diameter of the single copper powder is larger than the average diameter of the soft magnetic powder, the copper powder can be easily plastically deformed during high-pressure pressing, causing the copper powder to plastically deform and connect together. Furthermore, the plastic deformation of the copper powder particles near the magnetic body can easily cover the soft magnetic powder particles at the connection point. The depth of the magnetic body embedded in the copper powder particles is greater than or equal to 0.05 mm.

[0093] If the metal powder is copper powder, and a mixture of copper powder with a first particle size and a second particle size is used, the first particle size is larger than the average particle size of the soft magnetic powder, and the second particle size is smaller than the average particle size of the soft magnetic powder. The first particle size is larger than the average diameter of the soft magnetic powder particles, and the second particle size is smaller than the average diameter of the soft magnetic powder particles. This increases the density of the copper powder while maintaining the same thickness, thus increasing the density of the metal part formed under high pressure. Furthermore, the copper powder with the second particle size, being smaller than the average diameter of the soft magnetic powder particles, can also form between the soft magnetic powder particles, further increasing the contact area between the metal part and the magnetic material. Specifically, the first particle size is 20-200 mesh, and the particle size of the single copper powder is 20-300 mesh, such as 20 mesh, 50 mesh, 70 mesh, 100 mesh, 120 mesh, 150 mesh, 160 mesh, 180 mesh, 200 mesh, 220 mesh, 250 mesh, 260 mesh, 280 mesh, etc., and the ratio of the first particle size to the average particle size of the soft magnetic powder is greater than 5.

[0094] If the metal powder is a composite powder of copper powder and graphite powder, a physical mixture of copper powder and graphite powder can be used, or a core-shell composite powder with a copper layer wrapped around the graphite powder can be used. Since graphite powder is a highly thermally conductive powder, its thermal conductivity is not only greater than that of copper powder, but it is also easily deformed under high pressure, thereby further increasing the thermal conductivity of the metal parts.

[0095] It should be noted that when the metal part is prepared by casting metal powder slurry or by pressing metal powder, preferably, the subsequent heat treatment process also has the function of sintering the metal powder together, and the organic adhesive in the metal part prepared by casting metal powder is removed during the heat treatment process.

[0096] Understandably, to ensure the metal powders are firmly bonded together even at lower heat treatment temperatures, the slurry also includes nanoscale metal powders, such as silver powder, which melt at lower temperatures. Of course, when the insulating material in the magnetic material can withstand higher temperatures, the metal powders can be directly sintered together at a higher annealing temperature. That is, in one specific application, high-pressure pressing involves heating and high-pressure pressing followed by a heat treatment to solidify the insulating material in the magnetic material, and the metal powders are sintered and bonded together to form a metal part embedded in the magnetic material, wherein the metal part formed in this way has porosity. In another specific application, high-pressure pressing is performed at room temperature, followed by a heat treatment to anneal the soft magnetic powders together to form a magnetic powder core, and the metal powders are sintered and bonded together to form a metal part embedded in the magnetic material.

[0097] In some embodiments, in step (2), after high-temperature sintering, in the stacking direction of the metal layer and the ceramic layer, heat dissipation through holes are first opened on the ceramic layer, and then a conductive layer is formed on the upper surface of the ceramic layer; further, according to the circuit design, the circuit, bare electrical components, and plastic encapsulation are sequentially performed on the upper surface of the conductive layer to obtain an integrated module.

[0098] In some embodiments, step (1) is an aluminum layer or a copper layer, and step (2) includes using a DAB or DBC process to place a ceramic layer with alumina pre-formed on the bonding surface on the surface of the metal layer and sintering it so that the metal layer and the ceramic layer are co-fired and bonded.

[0099] It should be noted that the conductive layer of the present invention includes a conductive copper layer and a conductive aluminum layer. If the conductive layer is a conductive copper layer, the DBC process is adopted, specifically including: forming a copper oxygen-containing eutectic liquid between the ceramic layer and the copper plate; reacting the copper oxygen-containing eutectic liquid with the ceramic substrate at 1065-1083°C to generate CuAlO2 or CuAl2O4 phase; and connecting the ceramic substrate and the conductive layer together after cooling. If the conductive layer is a conductive aluminum layer, those skilled in the art can choose to directly utilize the wettability of the aluminum plate to achieve the connection between the ceramic layer and the aluminum layer, or choose to form a layer of copper on the aluminum plate and utilize the copper-aluminum eutectic to achieve the connection between the ceramic layer and the aluminum layer, depending on the actual situation.

[0100] In summary, the present invention provides an integrated module and its fabrication method. The integrated module includes an inductor with its magnetic body and a metal layer interlocked, and a ceramic layer disposed on the metal layer in a co-fired manner. The ceramic layer can serve as a ceramic substrate to facilitate the installation and integration of the electrical device onto the inductor. Furthermore, the interlocked connection between the magnetic body of the inductor and the metal layer increases the contact area between the metal layer and the magnetic body of the inductor, greatly improving the heat dissipation effect.

[0101] The present invention has been illustrated with the above embodiments to illustrate its detailed structural features. However, the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0102] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0103] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0104] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. An integrated module, characterized in that, The integrated module includes an inductor, and a metal layer and a ceramic layer are sequentially disposed on the surface of the magnetic body of the inductor; the magnetic body of the inductor is embeddedly connected to the metal layer, and the metal layer is connected to the ceramic layer.

2. The integrated module according to claim 1, characterized in that, The metal layer is co-fired with the ceramic layer, and the metal layer includes a copper layer or an aluminum layer. And / or, the magnetic material is embedded in the surface of the metal layer, and the embedding depth is ≥0.05mm.

3. The integrated module according to claim 1 or 2, characterized in that, A conductive layer is disposed on the ceramic layer on a surface away from the metal layer; And / or, in the stacking direction of the metal layer and the ceramic layer, heat dissipation through holes are formed on the ceramic layer.

4. The integrated module according to claim 3, characterized in that, The conductive layer is provided with at least one of a power element and a passive element.

5. The integrated module according to claim 1, characterized in that, The magnetic material and the metal layer form a diffusion layer.

6. The integrated module according to claim 3, characterized in that, The metal layer is continuously disposed on the side and top surface of the magnetic body, and the ceramic layer includes a plurality of sub-ceramic layers, which are spaced apart on the side and top surface of the magnetic body.

7. The integrated module according to claim 1, characterized in that, The metal layer is disposed at least on the bottom surface of the magnetic body, and the metal layer is electrically connected to the winding of the inductor.

8. A method for preparing an integrated module, characterized in that, The preparation method includes the following: The inductor blank, metal parts and ceramic parts are stacked in sequence, heat-treated and cooled to obtain the integrated module.

9. A method for preparing an integrated module, characterized in that, The preparation method includes the following: (1) Press one of the metal powder or metal parts with soft magnetic powder and winding according to the target position relationship to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is connected to the metal layer in an interlocking manner. (2) A ceramic layer is placed on the surface of the metal layer away from the magnetic body, and the metal layer and the ceramic layer are connected to obtain an integrated module.

10. The preparation method according to claim 9, characterized in that, Step (1) can be performed using any of the following methods; Method a: First, the soft magnetic powder and the winding are pre-pressed according to the target position relationship to obtain a pre-pressed magnetic body; then, the metal part is placed on the surface of the pre-pressed magnetic body and pressed under high pressure, and after heat treatment, an integrated inductor device is obtained, so that the surface of the magnetic body of the inductor device is embedded and connected to the metal layer. Method b: The metal parts, soft magnetic powder and windings are directly pressed under high pressure according to the target position relationship, and then heat-treated to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is embedded and connected to the metal layer. Method c: First, the soft magnetic powder and the winding are pre-pressed according to the target position relationship to obtain a pre-pressed magnetic body; then, the metal powder and the pre-pressed magnetic body are high-pressure pressed according to the target position relationship, and after heat treatment, an integrated inductor device is obtained, so that the surface of the magnetic body of the inductor device is embedded and connected to the metal layer. Method d: Metal powder, soft magnetic powder and winding are directly pressed under high pressure according to the target position relationship, and then heat treated to obtain an integrated inductor device, so that the surface of the magnetic body of the inductor device is embedded and connected with the metal layer.

11. The preparation method according to claim 9 or 10, characterized in that, In step (1), the soft magnetic powder includes at least one of iron-silicon-aluminum powder, iron-silicon powder, iron-nickel powder, iron-cobalt powder, iron-molybdenum powder, amorphous nanocrystalline powder, or carbonyl iron powder; And / or, in step (2), the raw material of the ceramic layer includes at least one of mullite, Al2O3, Si3N4, AlN, ZTA, ATZ, TiO2, ZrO2, MgO, CaO or CaCO3.

12. The preparation method according to claim 10, characterized in that, The high-pressure pressing pressure is 12-24 t / m. 2 ; And / or, after being subjected to high-pressure pressing and heat treatment in sequence, the magnetic body and the metal layer form a diffusion layer.

13. The preparation method according to claim 10 or 12, characterized in that, In method a or method c, the pre-compression pressure is 2-10 t / cm. 2 .

14. The preparation method according to claim 9 or 10, characterized in that, In step (2), after the high-temperature sintering, in the stacking direction of the metal layer and the ceramic layer, heat dissipation through holes are first opened on the ceramic layer, and then a conductive layer is formed on the upper surface of the ceramic layer.

15. The preparation method according to claim 9 or 10, characterized in that, The metal layer in step (1) is an aluminum layer or a copper layer. Step (2) includes using DAB or DBC process to place a ceramic layer with alumina pre-formed on the connecting surface on the surface of the metal layer and sintering it so that the metal layer and the ceramic layer are co-fired and connected.

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