Molded transformer and production process

Abstract

The invention relates to the technical field of transformers, in particular to a molded transformer and a production process. A molded transformer comprises a top layer, a first magnetic core, an internal circuit layer, a second magnetic core and a bottom layer PCB, and magnetic core installation and connection are achieved through specific structure combination such as a containing cavity and a through hole. And each layer of PCB is provided with a conduction groove and a conductive piece which are connected. A molded transformer production process comprises the steps of material selection, PCB manufacturing, drilling and slotting, magnetic core manufacturing and mounting, assembly gap processing and the like. According to the invention, the electric connection is optimized, the stability is improved, the size is reduced, and the anti-vibration performance is enhanced.

Description

Technical Field

[0001] The present application relates to the technical field of transformers, and in particular to a molded transformer and a production process. Background Art

[0002] Transformers are widely used in drive control in the fields of new energy vehicles, photovoltaic energy storage, and civil appliances. In the field of new energy, transformers can be used in power systems and automation control such as OBC and BMS to transmit control signals, ensure the stability and accuracy of signals to achieve accurate voltage regulation and stable output, ensure the normal operation of the system, and assist in improving system efficiency.

[0003] The traditional wound transformer structure consists of a skeleton, copper wire, and a magnetic core. The copper wire is wound on the skeleton according to the arrangement of the windings, and then the magnetic core is assembled. The parameters can be flexibly adjusted by modifying the copper wire and winding arrangement according to the design requirements. However, the winding arrangement of the copper wire will greatly affect the automation capability of the equipment, and the automation cost is high. In addition, with the development of high-voltage magnetic devices, the insulation capability requirements of magnetic devices are increased. Traditional wound transformers need to use thicker three-layer insulation wires or add additional structures to meet the insulation requirements, making the device structure complex and increasing in size.

[0004] The planar transformer structure integrates the functions of the skeleton and copper wire on the PCB. The transformer as a whole is composed of a PCB and a magnetic core. Compared with the traditional wound transformer, the structure is simpler, easy to automate, and the PCB has strong consistency. The winding is integrated into the PCB, eliminating the requirement for the insulation capacity of the copper wire. Under the same performance requirements, the volume of the PCB transformer is smaller and flatter than that of the wound transformer. However, the magnetic core is exposed on the outside of the PCB and fixed by glue, and the magnetic core is a conductor, so the size of the magnetic core itself cannot be ignored in the insulation distance, occupying a part of the size, so the reduction of the device volume is limited.

[0005] Therefore, based on the above problems, the prior art needs to be improved. Summary of the invention

[0006] The first purpose of the present application is to solve the above technical problems and provide a molded transformer.

[0007] The above technical objectives of the present application are achieved through the following technical solutions: a molded transformer, comprising a top layer PCB, a first magnetic core, an internal circuit layer PCB, a second magnetic core and a bottom layer PCB; a first accommodating cavity is formed between the top layer PCB and the internal circuit layer PCB, and a second accommodating cavity is formed between the bottom layer PCB and the internal circuit layer PCB; a first through hole is provided on the internal circuit layer PCB, and second through holes are provided on opposite sides of the first through hole, and the first accommodating cavity and the second accommodating cavity are conductive; the first magnetic core is provided in the first accommodating cavity, and the second magnetic core is provided in the second accommodating cavity, and the first magnetic core and the second magnetic core are embedded and installed on the internal circuit layer PCB through the first through hole and the second through hole, and the first magnetic core and the second magnetic core are connected through the first through hole and the second through hole.

[0008] By adopting the above technical solution, the magnetic core is embedded in the device, eliminating the influence of the magnetic core size on the insulation distance, and further reducing the size of the device; the external parts are fixed without glue, the structure is integrated, the vibration resistance is strong, and the structure is flat. Through reasonable internal structural design, such as the first accommodating cavity, the second accommodating cavity and the setting of related through holes, the magnetic core can be firmly embedded and installed, which ensures the performance and stability of the transformer, helps it better transmit control signals in the drive control of new energy vehicles, photovoltaic energy storage, civilian home appliances and other fields, ensures the stability and accuracy of the signal to achieve accurate voltage regulation and stable output, ensures the normal operation of the system and helps improve the system efficiency.

[0009] Optionally, a plurality of first conducting grooves are provided on the top layer PCB, a first conductive member is provided in the first conducting groove, and the first conductive member is electrically connected to an internal circuit of the top layer PCB.

[0010] By adopting the above technical solution, by setting a plurality of first conduction grooves on the top layer PCB and setting a first conductive member electrically connected to the internal circuit in the groove, the electrical connection performance of the transformer can be optimized. This makes the current transmission more stable and efficient, reduces signal loss and interference, and thus improves the accuracy and stability of the transformer when transmitting control signals. In practical applications, it helps to improve the driving control effect of the transformer in the fields of new energy vehicles, photovoltaic energy storage, and civilian household appliances, ensures that the system can achieve voltage regulation and stable output more accurately, further guarantees the normal operation of the system and assists in improving the system efficiency.

[0011] Optionally, a plurality of second conducting grooves are provided on the internal circuit layer PCB, a second conductive member is provided in the second conducting groove, the second conductive member is electrically connected to the internal circuit of the internal circuit layer PCB, and the first conductive member and the second conductive member are connected and arranged.

[0012] By adopting the above technical solution, by setting a plurality of second conducting grooves and corresponding second conductive members on the internal circuit layer PCB, and connecting the first conductive member and the second conductive member, the circuit connection inside the transformer is further optimized. This multi-layer and coherent conductive structure enhances the stability and reliability of current transmission, reduces line resistance, and reduces energy loss. In terms of overall performance, it can more effectively transmit control signals, improve the accuracy and stability of voltage regulation, and help the transformer better realize its functions in application fields such as new energy vehicles, photovoltaic energy storage, and civilian household appliances, ensuring the efficient operation of the system and improving system efficiency and stability.

[0013] Optionally, a plurality of third conducting grooves are provided on the bottom layer PCB, a third conductive member is provided in the third conducting groove, the third conductive member is electrically connected to the internal circuit of the bottom layer PCB, and the second conductive member is connected to the third conductive member.

[0014] By adopting the above technical solution, by setting a plurality of third conducting grooves and third conductive members on the bottom layer PCB, and connecting the second conductive member and the third conductive member, the overall conductive path of the transformer from the top layer to the internal line layer and then to the bottom layer is improved. This helps to further reduce the line impedance, improve the efficiency of power transmission, reduce signal attenuation, and enhance the electrical performance of the transformer in different application scenarios. When the transformer is used in new energy vehicles, photovoltaic energy storage, civilian home appliances and other fields, it can transmit control signals more stably, achieve voltage regulation and stable output more accurately, thereby ensuring the normal operation of the system and improving the overall efficiency and reliability of the system.

[0015] The second purpose of this application is to provide a molded transformer production process.

[0016] A molded transformer production process, producing a molded transformer as described above, comprising: Solid resin and glass fiber are selected to make the core board, and copper foil is evenly covered on the opposite sides of the core board. According to the internal circuit design layout required for the top layer of the transformer, the corresponding circuit is accurately etched on the core board using an etching process, and the core board with etched circuits is pressed with the prepreg to form the top layer PCB; A 10-layer copper-clad circuit board is selected as the raw material, each layer is a core board, the material of the core board is composed of solid resin and glass fiber, and the opposite two sides of the core board are covered with copper foil. For each layer of core board, according to the design requirements of the internal circuit of the transformer, the corresponding circuits are etched on the opposite two sides of the core board, and a prepreg is placed between adjacent core boards. The prepreg covers the entire contact surface of the core board and is used to bond the core board and provide interlayer insulation. The multi-layer core board and the prepreg are pressed together according to the design sequence to form an internal circuit layer PCB; According to the design requirements, CNC drilling or slotting operations are performed on the internal circuit layer PCB to form a first through hole and a second through hole; Prepare the core board material, cover the two opposite sides of the core board with copper foil, etch the corresponding circuit on the core board according to the internal circuit design required for the bottom layer of the transformer, and press the core board with etched circuits with the prepreg to form the bottom layer PCB; According to the design requirements, select appropriate magnetic core materials, and make the first magnetic core and the second magnetic core based on the shape of the internal circuit layer PCB; The first magnetic core is embedded and installed on the internal circuit layer PCB through the first through hole and the second through hole, and the second magnetic core is embedded and installed on the internal circuit layer PCB through the first through hole and the second through hole. The first magnetic core and the second magnetic core clamp the internal circuit layer PCB, and the first magnetic core and the second magnetic core are connected through the first through hole and the second through hole and are wound around the internal circuit layer PCB; Install the manufactured top layer PCB on the internal circuit layer PCB to form a first accommodating cavity for accommodating the first magnetic core, and wrap the first magnetic core with the top layer PCB and the internal circuit layer PCB; install the manufactured bottom layer PCB on the internal circuit layer PCB to form a second accommodating cavity for accommodating the second magnetic core, and wrap the second magnetic core with the bottom layer PCB and the internal circuit layer PCB.

[0017] By adopting the above technical solutions, accurately selecting materials and using etching, pressing and other processes, the quality and performance of each layer of PCB can be ensured, and the accuracy and stability of the internal circuit can be guaranteed, thereby improving the electrical performance of the transformer. Reasonable production and installation of magnetic cores, fitting and connection through specific through holes, and forming a receiving cavity for wrapping can not only effectively fix the magnetic core, but also optimize the coordination between the magnetic core and the PCB, and reduce performance loss caused by magnetic core problems. This production process can realize the integration and compactness of the transformer structure, improve production efficiency and product consistency, and is conducive to ensuring product quality in large-scale production, so that it can be better used in new energy vehicles, photovoltaic energy storage, civilian household appliances and other fields, meet the performance requirements of transformers in different scenarios, and ensure the stable operation of the system.

[0018] Optionally, the steps after forming the top layer PCB, the inner circuit layer PCB and the bottom layer PCB include: Performing CNC drilling or slotting operations on the top layer PCB to form a plurality of first conducting slots; Performing CNC drilling or slotting operations on the internal circuit layer PCB to form a plurality of second conducting slots; Performing CNC drilling or slotting operations on the bottom layer PCB to form a plurality of third conducting slots; A first conductive member is arranged in the first conductive groove, a second conductive member is arranged in the second conductive groove, and a third conductive member is arranged in the third conductive groove. The first conductive member, the second conductive member and the third conductive member are subjected to copper deposition and electroplating to form electrodes, and the electrodes are connected to corresponding internal circuits.

[0019] By adopting the above technical solution, CNC drilling or grooving operations are performed on each layer of PCB and conductive parts are set, which can further optimize the electrical connection between each layer of PCB and improve the efficiency and stability of signal transmission. Copper deposition and electroplating treatment form electrodes, which enhance the conductivity, ensure good connection between electrodes and internal circuits, and reduce signal loss and energy loss. This precise processing and treatment method helps to improve the overall electrical performance of the transformer, so that it can more accurately transmit control signals in application fields such as new energy vehicles, photovoltaic energy storage, and civilian appliances, achieve stable voltage regulation and output, and ensure efficient operation of the system.

[0020] Optionally, the steps after wrapping the second magnetic core with the bottom layer PCB and the inner circuit layer PCB include: When the manufactured top layer PCB is mounted on the internal circuit layer PCB or the manufactured bottom layer PCB is mounted on the internal circuit layer PCB, an assembly gap is reserved according to the design and size tolerance of the transformer to avoid interference fit.

[0021] By adopting the above technical solution, the reserved assembly gap can avoid interference fit, effectively prevent the core cracking and PCB deformation caused by excessive extrusion of components, and ensure the integrity and stability of each component of the transformer. It helps to improve the production yield of the transformer and reduce production costs. At the same time, during long-term use, it can maintain the stability of the transformer's performance, ensure its reliable operation in application fields such as new energy vehicles, photovoltaic energy storage, and civilian appliances, reduce the risk of failure caused by structural damage, and extend the service life of the transformer.

[0022] Optionally, the steps after reserving an assembly gap according to the design and dimensional tolerance of the transformer include: Add polypropylene powder in the assembly gap; The top layer PCB, the first magnetic core, the internal circuit layer PCB, the second magnetic core and the bottom layer PCB, which have been installed and have polypropylene powder added in the assembly gap, are heat-pressed. During the heat-pressing process, the polypropylene powder melts, fills the designed assembly gap and expels trapped air, ensuring that the components are tightly combined without trapped air.

[0023] By adopting the above technical solution, adding polypropylene powder in the assembly gap and performing hot pressing treatment, the powder can be melted to fill the gap and expel the air, which can further enhance the tightness of the combination between the components and improve the overall structural strength and stability of the transformer. This tight combination helps to reduce the loosening or displacement of components caused by vibration or other external factors, and ensure the performance reliability of the transformer in various working environments. At the same time, the structure without air retention can avoid the problem of electrical performance degradation caused by the presence of air, such as partial discharge, thereby improving the electrical performance of the transformer and ensuring its stable and efficient operation in application fields such as new energy vehicles, photovoltaic energy storage, and civilian household appliances.

[0024] In summary, this application has at least the following beneficial effects: 1. The magnetic core is embedded inside the device, eliminating the influence of the core size on the insulation distance and further reducing the size of the device; 2. The external parts are fixed without glue and adopt an integrated structural design to enhance the anti-vibration performance of the device; 3. The flat structure design makes the transformer more compact and improves the power density. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a molded transformer; Figure 2 It is an exploded view of a molded transformer; Figure 3 is a cross-sectional view of a molded transformer; Figure 4 It is a flow chart of the steps of the molded transformer production process.

[0026] Reference numerals

[0027] 1. Top layer PCB; 2. First magnetic core; 3. Internal circuit layer PCB; 4. Second magnetic core; 5. Bottom layer PCB; 6. First accommodating cavity; 7. Second accommodating cavity; 8. First through hole; 9. Second through hole; 10. First conducting groove; 11. First conductive member; 12. Second conducting groove; 13. Second conductive member; 14. Third conducting groove; 15. Third conductive member. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with the accompanying drawings.

[0029] In this embodiment, refer to Figure 1-Figure 3A molded transformer includes a top layer PCB1, a first magnetic core 2, an internal circuit layer PCB3, a second magnetic core 4 and a bottom layer PCB5. A first accommodating cavity 6 is formed between the top layer PCB1 and the internal circuit layer PCB3, and a second accommodating cavity 7 is formed between the bottom layer PCB5 and the internal circuit layer PCB3. A first through hole 8 is provided on the internal circuit layer PCB3, and second through holes 9 are provided on opposite sides of the first through hole 8. The first accommodating cavity 6 and the second accommodating cavity 7 are connected; the first magnetic core 2 is provided in the first accommodating cavity 6, and the second magnetic core 4 is provided in the second accommodating cavity 7. The first magnetic core 2 and the second magnetic core 4 are respectively mounted on the internal circuit layer PCB3 through the first through hole 8 and the second through hole 9, and the first magnetic core 2 and the second magnetic core 4 are connected through the first through hole 8 and the second through hole 9, which achieves the effect of significantly improving the compactness and reliability of the transformer structure, making the transformer more widely and reliably used in the fields of new energy vehicles, photovoltaic energy storage, etc.

[0030] Specifically, the top layer PCB1 includes a core board and a prepreg. The core board is made of solid resin and glass fiber, and its upper and lower surfaces are covered with copper foil. During the manufacturing process, the circuit design of the core board is completed by etching the entire piece of material, and a complete circuit is formed on the upper and lower surfaces of the core board. The prepreg is used to bond and isolate the core board to ensure interlayer insulation. For example, the bottom of the core board can be made of standard FR-4 material, and the copper foil is 35μm thick. The material selection of the prepreg can be determined according to actual needs, and common ones are FR-4 or CEM materials. In this way, the top layer PCB1 is lightweight and planar.

[0031] In addition, the internal circuit layer PCB3 also includes a core board and a semi-cured sheet. The core board is also composed of solid resin and glass fiber, and its upper and lower surfaces are covered with copper foil. The circuit design of the core board is completed by etching the entire piece of material during the manufacturing process. The semi-cured sheet between the core boards is used to bond adjacent core boards and provide interlayer insulation. Specifically, in this embodiment, it is preferred to have 10 layers of core boards, the thickness of the core board is selected to be 1.0 mm, and the thickness of the copper foil is 35 μm to ensure excellent conductive properties. At the same time, the thickness of the semi-cured sheet is usually around 0.15 mm, which ensures good bonding and insulation effects. The connection between the core board and the semi-cured sheet is completed by hot pressing to ensure a tight and reliable connection. A first through hole 8 is hollowed out in the center of the internal circuit layer PCB3, and a long second through hole 9 is hollowed out on both sides of the first through hole 8 on the internal circuit layer PCB3.

[0032] Reference Figure 2The first magnetic core 2 and the second magnetic core 4 have the same structure and are made of materials such as ferrite or sendust alloy according to design requirements. The first magnetic core 2 is installed and embedded on the internal circuit layer PCB3 through the first through hole 8 to ensure that the magnetic core is installed firmly and does not shift. The second magnetic core 4 is also installed and embedded on the other side of the internal circuit layer PCB3 through the first through hole 8. The main bodies of the first magnetic core 2 and the second magnetic core 4 cooperate to clamp the internal circuit layer PCB3 to ensure the compactness and reliability of the overall structure. The first magnetic core 2 and the second magnetic core 4 are installed in abutment with each other in the first channel, and at the same time, the first magnetic core 2 and the second magnetic core 4 extend into the second through hole 9 at a position relative to the second through hole 9, so that the first magnetic core 2 and the second magnetic core 4 are installed in abutment with each other in the second through hole 9, forming an "8"-shaped structure.

[0033] Reference Figure 3 During assembly, the internal circuit layer PCB3 is the core component and is located between the top layer PCB1 and the bottom layer PCB5. The top layer PCB1 is thermally pressed with the internal circuit layer PCB3 to form a first accommodating cavity 6 for accommodating the first magnetic core 2. The bottom layer PCB5 is thermally pressed with the internal circuit layer PCB3 in the same way to form a second accommodating cavity 7 for accommodating the second magnetic core 4. Therefore, the structure of the entire molded transformer is very compact and reliable, which is not only convenient for automated production, but also significantly improves its application value and reliability in the field of new energy.

[0034] The implementation principle of this embodiment is: by embedding the magnetic core in the internal circuit layer PCB3, the influence of the magnetic core on the insulation distance is avoided, so that the device volume is further reduced. The integrated design after the structure is simplified also enhances the vibration resistance of the device. At the same time, the flattened structure improves the overall compactness and heat dissipation performance, and improves the stability and reliability of the transformer in the application.

[0035] Reference Figure 1 The top layer PCB1 also includes a plurality of first conducting grooves 10, in which a first conductive member 11 is disposed, and the first conductive member 11 is electrically connected to the internal circuit of the top layer PCB1. Specifically, the function of the first conductive member 11 is to achieve the connection between the external circuit and the internal circuit. The first conductive member 11 is usually made of conductive materials such as copper columns or copper sheets, and is connected to the internal circuit of the top layer PCB1 through the first conductive member 11. Thus, a good electrical connection between the external PCBA and the internal circuit layer PCB3 is achieved, ensuring the transmission accuracy of the signal.

[0036] Specifically, the internal circuit layer PCB3 also includes a plurality of second conducting grooves 12, in which a second conductive member 13 is provided, and the second conductive member 13 is electrically connected to the internal circuit of the internal circuit layer PCB3. The first conductive member 11 is connected to the second conductive member 13 to form a complete external and internal circuit connection system. The design of the second conductive member 13 enables good connection between different layers on the internal circuit layer PCB3, thereby ensuring current continuity. The material selection of the second conductive member 13 should also be consistent with that of the first conductive member 11 to ensure the stability and reliability of the connection.

[0037] The bottom layer PCB5 also includes a plurality of third conducting grooves 14, in which a third conductive member 15 is disposed, and the third conductive member 15 is electrically connected to the internal circuit of the bottom layer PCB5. The second conductive member 13 and the third conductive member 15 are connected and arranged. Specifically, the connection between the bottom layer PCB5 and other layers is made through the third conductive member 15, so as to ensure the continuity of the current between the layers. The design of the third conductive member 15 is similar to that of the first conductive member 11 and the second conductive member 13, and is intended to ensure the reliability and stability of the connection.

[0038] The implementation principle of this embodiment is: by setting a conductive groove and a conductive member between the top layer, the internal circuit layer PCB3 and the bottom layer PCB5, the external PCBA is connected to the internal PCB. To this end, this application mainly adopts the following technical solutions: the magnetic core is effectively connected to the internal circuit, the signal is embedded in the PCB board, and the transmission accuracy and reliability are formed.

[0039] Reference Figure 4 , a molded transformer production process, producing any of the above molded transformers, comprising: S1: Select solid resin and glass fiber to make a core board, evenly cover the copper foil on the opposite sides of the core board, design the layout according to the internal circuit required by the top layer of the transformer, use the etching process to accurately etch the corresponding circuit on the core board, and press the core board with the etched circuit with the prepreg to form the top layer PCB1; Specifically, suitable solid resin and glass fiber are selected as the materials for making the core board. According to the established process requirements, these materials are processed into core boards with certain specifications and performance. Then, copper foil is evenly covered on the surfaces of the opposite sides of the core board to ensure that the copper foil fits tightly with the core board. Next, the core board is finely processed using an etching process according to the internal circuit design layout required for the top layer of the transformer. The etching process requires strict control of process parameters to ensure that the circuit that meets the design requirements is accurately etched on the core board. Finally, the core board with etched circuits is pressed together with the prepreg according to a specific process sequence and conditions. By applying appropriate pressure and temperature, the core board and the prepreg are tightly combined to form the top layer PCB1.

[0040] S2: 10 layers of copper clad circuit boards are selected as raw materials, each layer is a core board, the material of the core board is composed of solid resin and glass fiber, and the surfaces of the opposite sides of the core board are covered with copper foil. For each layer of core board, according to the design requirements of the internal circuit of the transformer, the corresponding circuits are etched on the surfaces of the opposite sides of the core board, and prepregs are placed between adjacent core boards. The prepregs cover the entire contact surface of the core board and are used to bond the core boards and provide interlayer insulation. The multi-layer core boards and prepregs are pressed together according to the design sequence to form the internal circuit layer PCB3; Specifically, 10 layers of copper-clad circuit boards are selected as raw materials, and it is confirmed that each layer meets the requirements of the core board. The materials are solid resin and glass fiber and the surfaces on both sides are covered with copper foil. For each layer of core board, according to the precise design requirements of the internal circuit of the transformer, professional equipment and processes are used to etch the corresponding circuits on the opposite sides of the core board. A semi-cured sheet is placed between adjacent core boards to ensure that it completely covers the contact surface of the core board to achieve good bonding and provide reliable interlayer insulation. After that, the multi-layer core board and the semi-cured sheet are pressed together in a pre-designed order. During the pressing process, parameters such as pressure, temperature and time must be strictly controlled to ensure that the layers are tightly combined to finally form the internal circuit layer PCB3.

[0041] S3: According to the design requirements, CNC drilling or slotting operations are performed on the internal circuit layer PCB3 to form a first through hole 8 and a second through hole 9; Specifically, according to the predetermined design requirements, prepare the corresponding CNC drilling equipment or slotting tools. Place the internal circuit layer PCB3 accurately on the processing equipment to ensure that its position is fixed and meets the processing accuracy requirements. Then, according to the position, size and other parameters of the first through hole 8 and the second through hole 9 specified in the design drawings, start the CNC drilling program or perform the slotting operation. During the drilling process, it is necessary to accurately control the parameters such as the speed and feed rate of the drill bit to ensure that the drilled through hole has accurate size, smooth surface and no burrs. For the slotting operation, the movement trajectory and cutting depth of the tool must also be strictly controlled to ensure that the shape and size of the slot meet the design requirements. Through these operations, the first through hole 8 and the second through hole 9 are accurately formed on the internal circuit layer PCB3.

[0042] S4: prepare core board materials, cover the surfaces of the core board on two opposite sides with copper foil, etch corresponding circuits on the core board according to the internal circuit design required for the bottom layer of the transformer, and press the core board with etched circuits with the prepreg to form the bottom layer PCB5; Specifically, prepare the core board material that meets the requirements and ensure that it has suitable physical and chemical properties. Then, evenly cover the copper foil on the opposite sides of the core board so that the copper foil fits tightly to the core board. Next, according to the internal circuit design required for the bottom layer of the transformer, use professional etching technology to accurately etch the corresponding circuit on the core board. The etching process requires strict control of process parameters to ensure the accuracy and quality of the circuit. Finally, the core board with etched circuits is pressed together with the prepreg according to specific process requirements. By applying appropriate pressure and temperature, the two are tightly combined to form the bottom layer PCB5.

[0043] S5: According to the design requirements, a suitable magnetic core material is selected, and the first magnetic core 2 and the second magnetic core 4 are manufactured based on the shape of the internal circuit layer PCB 3; Specifically, the design requirements are carefully studied to clarify the performance requirements for the core material, such as magnetic permeability, saturation magnetic flux density, etc. Then, materials that meet the requirements are selected from a variety of core materials. Next, based on the shape of the internal circuit layer PCB3, precise processing techniques such as cutting, grinding, sintering, etc. (select appropriate processes based on the characteristics of the core material) are used to make the first core 2 and the second core 4. During the production process, the dimensional accuracy is strictly controlled to ensure that the core and the internal circuit layer PCB3 can be perfectly matched to achieve the best electromagnetic coupling effect.

[0044] S6: The first magnetic core 2 is embedded and installed on the internal circuit layer PCB3 through the first through hole 8 and the second through hole 9, and the second magnetic core 4 is embedded and installed on the internal circuit layer PCB3 through the first through hole 8 and the second through hole 9. The first magnetic core 2 and the second magnetic core 4 clamp the internal circuit layer PCB3, and the first magnetic core 2 and the second magnetic core 4 are connected through the first through hole 8 and the second through hole 9 and are wound around the internal circuit layer PCB3; Specifically, align the first magnetic core 2 with the first through hole 8 and the second through hole 9 on the internal circuit layer PCB3, and slowly and accurately embed the first magnetic core 2 into the through hole to ensure that the magnetic core and the through hole are tightly matched to achieve embedded installation. Similarly, operate the second magnetic core 4 so that it is accurately embedded on the internal circuit layer PCB3 through the corresponding first through hole 8 and second through hole 9. During the installation process, it is necessary to ensure that the positions of the first magnetic core 2 and the second magnetic core 4 are correct so that they can effectively clamp the internal circuit layer PCB3. Then, through the structural design of the first through hole 8 and the second through hole 9, the first magnetic core 2 and the second magnetic core 4 are connected, and the magnetic core and the circuit on the internal circuit layer PCB3 form a suitable winding relationship to meet the electromagnetic performance requirements of the transformer.

[0045] S7: Install the manufactured top layer PCB1 on the internal circuit layer PCB3 to form a first accommodating cavity 6 for accommodating the first magnetic core 2, and wrap the first magnetic core 2 with the top layer PCB1 and the internal circuit layer PCB3; install the manufactured bottom layer PCB5 on the internal circuit layer PCB3 to form a second accommodating cavity 7 for accommodating the second magnetic core 4, and wrap the second magnetic core 4 with the bottom layer PCB5 and the internal circuit layer PCB3.

[0046] Specifically, after the first magnetic core 2 is embedded and installed on the internal circuit layer PCB3, the prepared top layer PCB1 is accurately placed on top of the internal circuit layer PCB3, ensuring that the edges of the two are aligned, and then fixed by a specific connection method (such as welding, snap-fitting or gluing, etc., depending on the design), thereby forming a first accommodating cavity 6, so that the top layer PCB1 and the internal circuit layer PCB3 tightly wrap the first magnetic core 2. Similarly, after the second magnetic core 4 is embedded and installed on the internal circuit layer PCB3, the prepared bottom layer PCB5 is placed under the internal circuit layer PCB3 and fixed to form a second accommodating cavity 7, and the second magnetic core 4 is wrapped by the bottom layer PCB5 and the internal circuit layer PCB3. During the installation process, attention should be paid to the position accuracy and connection firmness of each component.

[0047] The steps after forming the top layer PCB1, the inner circuit layer PCB3 and the bottom layer PCB5 include: Performing CNC drilling or slotting operations on the top layer PCB1 to form a plurality of first conducting slots 10; Performing CNC drilling or slotting operations on the internal circuit layer PCB3 to form a plurality of second conducting slots 12; Performing CNC drilling or slotting operations on the bottom layer PCB5 to form a plurality of third conducting slots 14; A first conductive member 11 is disposed in the first conductive groove 10, a second conductive member 13 is disposed in the second conductive groove 12, and a third conductive member 15 is disposed in the third conductive groove 14. The first conductive member 11, the second conductive member 13 and the third conductive member 15 are subjected to copper deposition and electroplating treatment to form electrodes, and the electrodes are connected to corresponding internal circuits.

[0048] Specifically, after forming each layer of PCB, firstly, the top layer PCB1 is subjected to CNC drilling or slotting equipment, and the operation is performed according to the design parameters to form a plurality of first conductive grooves 10. Similarly, the internal circuit layer PCB3 and the bottom layer PCB5 are respectively subjected to corresponding operations to form the second conductive groove 12 and the third conductive groove 14. Then, the first conductive member 11 is accurately placed in the first conductive groove 10, the second conductive member 13 is placed in the second conductive groove 12, and the third conductive member 15 is placed in the third conductive groove 14. Afterwards, these conductive members are subjected to copper deposition and electroplating treatment, and the process conditions are strictly controlled so that the copper layer is uniformly deposited on the surface of the conductive member and electroplated, thereby forming an electrode, ensuring that the electrode is well connected with the corresponding internal circuit to meet the electrical performance requirements.

[0049] The steps after wrapping the second magnetic core 4 with the bottom layer PCB 5 and the inner circuit layer PCB 3 include: When the manufactured top layer PCB1 is mounted on the internal circuit layer PCB3 or the manufactured bottom layer PCB5 is mounted on the internal circuit layer PCB3, an assembly gap is reserved according to the design and size tolerance of the transformer to avoid interference fit.

[0050] Specifically, after the second magnetic core 4 is wrapped by the bottom layer PCB5 and the internal circuit layer PCB3, when the prepared top layer PCB1 or bottom layer PCB5 is installed on the internal circuit layer PCB3, the design requirements and dimensional tolerances of the transformer must be strictly followed. Use precision measuring tools to determine the appropriate assembly gap size to ensure that there will be no interference fit during the installation process. Through precise positioning and installation processes, a uniform and required assembly gap is reserved between each layer of PCB to ensure that the transformer will not be damaged due to excessive squeezing between components during subsequent use, and also provide suitable space conditions for subsequent processing steps.

[0051] Among them, the steps after the assembly gap is reserved according to the design and size tolerance of the transformer include: Add polypropylene powder in the assembly gap; The top layer PCB1, the first magnetic core 2, the internal circuit layer PCB3, the second magnetic core 4 and the bottom layer PCB5, which have been installed and have polypropylene powder added in the assembly gap, are subjected to heat pressing. During the heat pressing process, the polypropylene powder melts, fills the designed assembly gap and expels retained air, ensuring that the components are tightly combined and no air is retained.

[0052] Specifically, before reserving the assembly gap, polypropylene powder is evenly added to each component so that the polypropylene powder is added in the assembly gap. Make sure that the amount of powder added meets the design requirements to ensure that there is enough material to fill the gap during the subsequent hot pressing process. Next, the top layer PCB1, the first magnetic core 2, the internal circuit layer PCB3, the second magnetic core 4 and the bottom layer PCB5 that have been installed and added with polypropylene powder are hot pressed. During the hot pressing process, parameters such as temperature, pressure and time are strictly controlled to melt the polypropylene powder by heat. The melted polypropylene powder can fully fill the designed assembly gap, and at the same time, the retained air is discharged under pressure to ensure that the components are tightly combined without air retention. This can improve the structural stability and electrical performance of the transformer and reduce problems such as local discharge that may be caused by the presence of air.

[0053] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A molded transformer, characterized in that: The invention comprises a top layer PCB (1), a first magnetic core (2), an internal circuit layer PCB (3), a second magnetic core (4) and a bottom layer PCB (5); a first accommodating cavity (6) is formed between the top layer PCB (1) and the internal circuit layer PCB (3), and a second accommodating cavity (7) is formed between the bottom layer PCB (5) and the internal circuit layer PCB (3); a first through hole (8) is provided on the internal circuit layer PCB (3), and second through holes (9) are provided on opposite sides of the first through hole (8), and the first accommodating cavity (6) and the second accommodating cavity (7) are connected; the first magnetic core (2) is arranged in the first accommodating cavity (6), and the second magnetic core (4) is arranged in the second accommodating cavity (7); the first magnetic core (2) and the second magnetic core (4) are mounted on the internal circuit layer PCB (3) by means of the first through hole (8) and the second through hole (9), and the first magnetic core (2) and the second magnetic core (4) are connected by means of the first through hole (8) and the second through hole (9).

2. A molded transformer according to claim 1, characterized in that: A plurality of first conducting grooves (10) are provided on the top layer PCB (1), a first conductive member (11) is provided in each of the first conducting grooves (10), and the first conductive member (11) is electrically connected to an internal circuit of the top layer PCB (1).

3. A molded transformer according to claim 2, characterized in that: The internal circuit layer PCB (3) is provided with a plurality of second conducting grooves (12), a second conductive member (13) is provided in the second conducting groove (12), the second conductive member (13) is electrically connected to the internal circuit of the internal circuit layer PCB (3), and the first conductive member (11) and the second conductive member (13) are connected.

4. A molded transformer according to claim 3, characterized in that: The bottom layer PCB (5) is provided with a plurality of third conductive grooves (14), a third conductive member (15) is provided in the third conductive groove (14), the third conductive member (15) is electrically connected to the internal circuit of the bottom layer PCB (5), and the second conductive member (13) and the third conductive member (15) are connected.

5. A molded transformer production process, characterized in that: Producing a molded transformer as claimed in any one of claims 1 to 4, comprising: Select solid resin and glass fiber to make a core board, evenly cover the surfaces of two opposite sides of the core board with copper foil, design a layout according to the internal circuit required by the top layer of the transformer, accurately etch the corresponding circuit on the core board using an etching process, and press the core board with the etched circuit with a prepreg to form a top layer PCB (1); A 10-layer copper-clad circuit board is selected as a raw material, each layer is a core board, the material of the core board is composed of solid resin and glass fiber, and the surfaces of the opposite sides of the core board are covered with copper foil. For each layer of the core board, according to the design requirements of the internal circuit of the transformer, the corresponding circuits are etched on the surfaces of the opposite sides of the core board, and a prepreg is placed between adjacent core boards. The prepreg covers the entire contact surface of the core board and is used to bond the core board and provide interlayer insulation. The multi-layer core board and the prepreg are pressed together according to the design sequence to form an internal circuit layer PCB (3); According to design requirements, CNC drilling or slotting operations are performed on the internal circuit layer PCB (3) to form a first through hole (8) and a second through hole (9); Prepare core board material, cover the two opposite sides of the core board with copper foil, etch corresponding circuits on the core board according to the internal circuit design required for the bottom layer of the transformer, and press the core board with etched circuits with the prepreg to form a bottom layer PCB (5); According to design requirements, a suitable magnetic core material is selected, and a first magnetic core (2) and a second magnetic core (4) are manufactured based on the shape of the internal circuit layer PCB (3); The first magnetic core (2) is embedded and installed on the internal circuit layer PCB (3) through the first through hole (8) and the second through hole (9); the second magnetic core (4) is embedded and installed on the internal circuit layer PCB (3) through the first through hole (8) and the second through hole (9); the first magnetic core (2) and the second magnetic core (4) clamp the internal circuit layer PCB (3); the first magnetic core (2) and the second magnetic core (4) are connected through the first through hole (8) and the second through hole (9) and are wound around the internal circuit layer PCB (3); The manufactured top layer PCB (1) is mounted on the internal circuit layer PCB (3) to form a first accommodating cavity (6) for accommodating a first magnetic core (2), and the first magnetic core (2) is wrapped by the top layer PCB (1) and the internal circuit layer PCB (3); the manufactured bottom layer PCB (5) is mounted on the internal circuit layer PCB (3) to form a second accommodating cavity (7) for accommodating a second magnetic core (4), and the second magnetic core (4) is wrapped by the bottom layer PCB (5) and the internal circuit layer PCB (3).

6. A molded transformer production process according to claim 5, characterized in that: The steps after forming the top layer PCB (1), the inner circuit layer PCB (3) and the bottom layer PCB (5) include: Performing CNC drilling or slotting operations on the top layer PCB (1) to form a plurality of first conducting slots (10); Performing numerical control drilling or slotting operations on the internal circuit layer PCB (3) to form a plurality of second conducting slots (12); Performing CNC drilling or slotting operations on the bottom layer PCB (5) to form a plurality of third conducting slots (14); A first conductive member (11) is arranged in the first conductive groove (10), a second conductive member (13) is arranged in the second conductive groove (12), and a third conductive member (15) is arranged in the third conductive groove (14). The first conductive member (11), the second conductive member (13) and the third conductive member (15) are subjected to copper deposition and electroplating treatment to form electrodes, and the electrodes are connected to corresponding internal circuits.

7. A molded transformer production process according to claim 5, characterized in that: The steps after wrapping the second magnetic core (4) with the bottom layer PCB (5) and the inner circuit layer PCB (3) include: When the manufactured top layer PCB (1) is mounted on the internal circuit layer PCB (3) or the manufactured bottom layer PCB (5) is mounted on the internal circuit layer PCB (3), an assembly gap is reserved according to the design and dimensional tolerance of the transformer to avoid interference fit.

8. A molded transformer production process according to claim 7, characterized in that: The steps after the assembly clearance is reserved according to the design and dimensional tolerance of the transformer include: Add polypropylene powder in the assembly gap; The top layer PCB (1), the first magnetic core (2), the internal circuit layer PCB (3), the second magnetic core (4) and the bottom layer PCB (5) which have been installed and have polypropylene powder added in the assembly gap are subjected to heat pressing. During the heat pressing process, the polypropylene powder melts, fills the designed assembly gap and discharges the trapped air, ensuring that the components are tightly combined without trapped air.

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