Patent Publication Number: US-2023154665-A1

Title: Inductor assembly and manufacturing method for inductor assembly

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present disclosure is a continuation-application of International (PCT) Patent Application No. PCT/CN2020/127010, filed on Nov. 6, 2020, which claims priority to Chinese Patent Application No. 202010645958.1 filed with China National Intellectual Property Administration on Jul. 7, 2020, the contents of which are herein incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the technical field of inductor embedding, in particular to an inductor assembly and a manufacturing method for an inductor assembly. 
     BACKGROUND 
     Hybrid integrated circuits are stepping into a stage of integrating system chips, micro sensors, micro actuators and peripheral film passive components for system packaging. A packaging technology is applied to the system in a unique way, which can reduce the size of the large circuit board connecting many components. The passive components (capacitors, inductors, resistors, etc.) account for 70% to 90% of the number of components in the circuit board and 70% to 80% of the area of the substrate. If the embedded technology of passive components is widely used on the circuit board, the size of a product is expected to be reduced by dozens of times. 
     Nowadays, the inductors are widely used in a design of the circuit board, and a passive filter circuit formed by the inductors mainly plays the role of signal adjusting and wave filtering. An inductor assembly of a power supply occupies more than 40% of the total area of a surface of the power supply, which is not conducive to the miniaturization design of the product. 
     SUMMARY 
     In order to solve the above technical problems, a first technical solution provided in the present disclosure is as following. An inductor assembly is provided and includes a circuit board defining a groove body; a magnetic component embedded in the groove body; and a winding wire, arranged on the magnetic component, surrounding along a thickness direction of the magnetic component, and electrically connected to the circuit board. 
     In order to solve the above technical problems, a second technical solution provided in the present disclosure is as following. An embedded inductor assembly is provided and includes a circuit plate, a magnetic component and a winding wire. The circuit plate includes a first core plate, a second core plate and a third core plate arranged between the first core plate and the second core plate, and the third core plate defines a groove body extending through the third core plate. The magnetic component is embedded in the groove body. The winding wire is arranged on the magnetic component, surrounds along a thickness direction of the magnetic component, and is electrically connected to the circuit board. 
     In order to solve the above technical problems, a second technical solution provided in the present disclosure is as following. A manufacturing method for an inductor assembly is provided and includes: providing a circuit board having a groove body; arranging a winding wire on a magnetic component, the winding wire surrounding the magnetic component along a thickness direction of the magnetic component; and embedding the magnetic component in the groove body and performing a high-temperature pressing, the winding wire is electrically connected to the circuit board. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to make the technical solution described in embodiments of the present disclosure more clearly, the drawings used for the description of the embodiments will be described. Apparently, the drawings in the following description are only some embodiments of the present disclosure. For those skilled in the art, other drawings may be acquired according to the drawings without any creative work. 
         FIG.  1    is a structural schematic view of an inductor assembly according to some embodiments of the present disclosure. 
         FIG.  2    is a structural schematic view of an inductor assembly according to some embodiments of the present disclosure. 
         FIG.  3    is a structural schematic view of a magnetic component according to some embodiments of the present disclosure. 
         FIG.  4    is a structural schematic view of a magnetic component according to some embodiments of the present disclosure. 
         FIG.  5    is a structural schematic view of a magnetic component according to some embodiments of the present disclosure. 
         FIG.  6    is a flowchart of a manufacturing method of the inductor assembly according to some embodiments of the present disclosure. 
         FIG.  7    is a flowchart of a manufacturing method of the inductor assembly according to some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The technical solutions in the embodiments of the present disclosure are clearly and completely described in conjunction with the drawings in the embodiments of the present disclosure. It is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all embodiments. All other embodiments acquired by the ordinary skilled in the art based on the embodiments in the present disclosure without the creative work are all within the scope of the present disclosure. 
     As shown in  FIG.  1   , IG.  1  is a structural schematic view of an inductor assembly according to some embodiments of the present disclosure. The inductor assembly may include a circuit board  11  and a magnetic component  13 . The circuit board  11  may include a groove body  12 , and the magnetic component  13  is arranged in the groove body  12 . When the magnetic component  13  is arranged in the groove body  12 , an axial direction of the magnetic component  13  is substantially perpendicular to a plane at which the circuit board  11  is located. The groove body  12  is arranged on the circuit board without extending through the opposite two surfaces of the circuit board  11 , that is, the groove body  12  is defined between the opposite two surfaces of the circuit board  11 . In some embodiments, the circuit board  11  may include a core plate  111  and a prepreg  112 , the core plate  111  may be a copper-clad plate, which is a basic material for manufacturing the circuit board  11 . The copper-clad plate includes a base substrate and a copper foil coated on the base substrate. The base substrate may be manufactured by combining a plurality of the bonding sheets, and each of the bonding sheets is manufactured by dipping materials such as a paper substrate, a glass-fiber-cloth substrate, a synthetic-fiber-cloth substrate, a non-woven fabric substrate, a composite substrate and so on with resin. The manufactured base substrate is coated with a copper foil on one or two opposite surfaces, and then the base substrate is performed with or subjected to a hot-pressed processing and solidified to manufacture the copper-clad plate. In some embodiments, the copper foils on the two surfaces of the core plate  111  may or may not have a pattern layer  1111 , which is arranged as required and not limited here. The prepreg  112  is an interlayer bonding layer during a lamination. In some embodiments, the prepreg  112  may include resin and reinforcement materials. When manufacturing multilayer circuit boards, a glass fiber cloth is usually used as a reinforcement material. The glass fiber cloth is dipped with resin glue solution and then pre-baked by a heat treatment to manufacture a thin sheet. The prepreg  112  is softened after being heated and pressurized, is solidified after being cooled, and has a viscosity. In a process of high-temperature pressing, adjacent two layers may be bonded by the prepreg  112 . In some embodiments, the circuit board  11  may include three core plates stacked on one another. For example, as shown in  FIG.  1   , the circuit board  11  may include a first core plate  111   a , a second core plate  111   b , and a third core plate  111   c  arranged between the first core plate  111   a  and the second core plate  111   b . The groove body  12  may be defined in the third core plate  111   c , and two opposite ends of the groove body  12  terminate at a surface of the first core plate  111   a  adjacent to the second core plate  111   b  and at a surface of the second core plate  111   b  adjacent to the second core plate  111   b.    
     The magnetic component  13  may be in a shape of a ring, such as a circular ring as shown in  FIG.  3   , a square ring as shown in  FIG.  4   , or other rings in other shapes, which is not limited here. The magnetic component  13  defines an annular part  135  in a middle region of the magnetic component  13 . The annular part  135  may be an inner ring of the magnetic component  13 . 
     A winding wire  131  is arranged on the magnetic component  13  and surrounds the magnetic component  13  along a thickness direction of the magnetic component  13 . The winding wire  131  is made of copper, is formed by electroplating, and has an input end  1311  and an output end  1313 . Each of the input end  1311  and the output end  1313  are connected to a bonding pad. In some embodiments, the number of coils of the winding wire  131  is more than three. In some embodiments, as shown in  FIGS.  3  and  4   , the input end  1311  of the winding wire  131  is connected to a first bonding pad  132 , and the output end  1313  of the winding wire  131  is connected to a second bonding pad  133 . The magnetic component  13  is located in the groove body  12 , and a first insulating layer  14  is arranged between the magnetic component  13  and the groove body  12 . The first insulating layer  14  is filled by the prepreg  112  which melts and flows between the magnetic component  13  and the groove body  12  during a high-temperature pressing. In some embodiments, another first insulating layer  14  may be further arranged in the annular part  135  of the magnetic component  13 , as shown in  FIG.  1   . 
     The circuit board  11  includes the pattern layer  1111 . In some embodiments, the pattern layer  1111  is arranged on a surface of the core plate  111 . After the magnetic component  13  is embedded in the groove body  12 , the winding wire  131  arranged on the magnetic component  13  needs to be electrically connected to the pattern layer  1111  of the circuit board  11 . Therefore, a first blind hole  16  and a second blind hole  17  are defined at positions where the circuit board  11  correspond to the first bonding pad  132  and the second bonding pad  133  respectively. 
     In some embodiments, the first bonding pad  132  and the second bonding pad  133  on the magnetic component  13  may be arranged on a same surface of the magnetic component  13  or on two opposite surfaces of the magnetic component  13 . In some embodiments, when the first bonding pad  132  and the second bonding pad  133  are arranged on the same surface of the magnetic component  13  as shown in  FIGS.  3  and  4   , the first blind hole  16  and the second blind hole  17  may be defined in positions as shown in  FIG.  2   . When the first bonding pad  132  and the second bonding pad  133  are arranged on the two opposite surfaces of the magnetic component  13  respectively, the first blind hole  16  and the second blind hole  17  may be defined in positions as shown in  FIG.  1   . As long as the first blind hole  16  and the second blind hole  17  can electrically connect the input end  1311  and output end  1313  of the winding wire  131  to the pattern layer  1111  of the circuit board  11 , specific positions of the first blind hole  16  and the second blind hole  17  are not limited here. It can be understood that in order to make the first blind hole  16  and the second blind hole  17  conductive, conductive layers  1113  may be arranged on side walls of the first blind hole  16  and the second blind hole  17 . 
     In some embodiments, as shown in  FIG.  5   , the surface of the magnetic component  13  may also be covered or coated with a second insulating layer  19 . The second insulating layer  19  may be made of polyimide, which can protect the magnetic component  13 . The winding wire  131  is arranged on a surface of the second insulating layer  19  by electroplating. 
     In some embodiments, the magnetic component  13  may be made of manganese-zinc alloy and nickel-zinc alloy, etc. The winding wire  131 , the first bonding pad  132 , and the second bonding pad  133  may be made of copper. 
     In the inductor assembly shown in the embodiments, the magnetic component  13  is embedded in the circuit board  11 , the winding wire  131  is arranged on the magnetic component  13 , and the winding wire  131  is electrically connected to the pattern layer  1111  of the circuit board  11 , thereby manufacturing the embedded inductor assembly and realizing a miniaturization of a product. 
     As shown in  FIG.  2   ,  FIG.  2    is a structural schematic view of an inductor assembly according to some embodiments of the present disclosure. Compared with the embodiment shown in  FIG.  1   , a difference is that the inductor assembly in this embodiment may also include a magnetic core  15 . In this embodiment, the magnetic component  13  is substantially annular and defines an annular part  135  in a middle region of the magnetic component  13 . The annular part  135  may be an inner ring of the magnetic component  13 . The circuit board  11  defines a through hole  18  at a position corresponding to an annular part  135  of the magnetic component  13 , the through hole  18  extends through the opposite two surfaces of the circuit board  11  and the first, second, and third core plates, and the magnetic core  15  is inserted into the through hole  18  and flush with the two surfaces of the circuit board  11 , respectively. When the magnetic core  15  is inserted into the through hole  18 , the magnetic core  15  penetrates the annular part  135  of the magnetic component  13 , and the first insulating layer  14  is arranged between the magnetic core  15  and the annular part  135  of the magnetic component  13 , the first insulating layer  14  is arranged between the magnetic core  15  and an inner wall of the annular part  135 . Same as the embodiment as shown in  FIG.  1   , the first insulating layer  14  is the prepreg melts and flowing between the annular part  135  of the magnetic component  13  and the magnetic core  15  during a high-temperature pressing. 
     In some embodiments, the magnetic core  15  is arranged in the middle of the magnetic component  13  to further enhance a magnetic field, thereby improving a performance of the inductor assembly. 
     As shown in  FIG.  6   ,  FIG.  6    is a flowchart of a manufacturing method of the inductor assembly according to some embodiments of the present disclosure. The method may include following operations. 
     Operation S 51  includes: providing a circuit board including a groove body. 
     The circuit board is manufactured by a core plate and a prepreg. When manufacturing the circuit board, the groove body is arranged at a designated position of the circuit board according to a requirement. 
     The core plate is the copper-clad plate, which is a basic material for manufacturing the circuit board  11 . The copper-clad plate includes a base substrate and a copper foil coated on the base substrate. The base substrate may be manufactured by combining a plurality of the bonding sheets, and each of the bonding sheets is manufactured by dipping materials such as a paper substrate, a glass-fiber-cloth substrate, a synthetic-fiber-cloth substrate, a non-woven fabric substrate, a composite substrate and so on with resin. The manufactured base substrate is coated with a copper foil on one or two opposite surfaces, and then the base substrate is performed with or subjected to a hot-pressed processing and solidified to manufacture the copper-clad plate. In some embodiments, the copper foils on the two surfaces of the core plate may or may not have a pattern layer, which is arranged as required and not limited here. The prepreg is an interlayer bonding layer during a lamination. In some embodiments, the prepreg may include resin and reinforcement materials. When manufacturing multilayer circuit boards, a glass fiber cloth is usually used as a reinforcement material. The glass fiber cloth is dipped with resin glue solution and then pre-baked by a heat treatment to manufacture a thin sheet. The prepreg is softened after being heated and pressurized, is solidified after being cooled, and has a viscosity. In a process of high-temperature pressing, adjacent two layers may be bonded by the prepreg. 
     Operation S 52  includes: arranging a winding wire on a magnetic component. The winding wire surrounds the magnetic component along a thickness direction of the magnetic component. 
     The magnetic component may be in a shape of a ring such as a circular ring or a square ring, which is not limited here. The winding wire may be arranged on the magnetic component and surrounds the magnetic component. In some embodiments, the metal winding wire surrounding the magnetic component is formed by electroplating around the magnetic component. In some embodiments, the winding wire starts to wind along the thickness direction of the magnetic component. 
     Operation S 53  includes: embedding the magnetic component in the groove body and performing a high-temperature pressing. The winding wire is electrically connected to the circuit board. 
     The operation of the embedding the magnetic component in the groove body and performing the high-temperature pressing in some embodiments includes: preparing the core plate and the prepreg and defining the groove body in the core plate, placing the magnetic component in the groove body, stacking the core plate and prepreg as required, and performing the high-temperature pressing. In the process of the high-temperature pressing, the prepreg melts and forms a first insulating layer, and then fill a gap between the magnetic component and the groove body. 
     The manufacturing method for the inductor assembly as shown in this embodiment is to manufacture the embedded inductor assembly, thereby realizing the miniaturization of the product. 
     As shown in  FIG.  7   ,  FIG.  7    is a flowchart of the manufacturing method of the inductor assembly according to some embodiments of the present disclosure. Compared with the embodiment as shown in  FIG.  6   , a difference is that this embodiment as shown in  FIG.  7    may include following operations. 
     Operation S 61  includes: arranging a second insulating layer on the magnetic component. 
     The magnetic component is coated with the second insulating layer. In some embodiments, the second insulating layer material is made of polyimide, and the material of magnetic component is one or any combination of a manganese-zinc alloy and a nickel-zinc alloy. 
     Operation S 62  includes: electroplating the second insulating layer to form a winding wire surrounding along a thickness direction of the magnetic component. 
     The surface of the second insulating layer is electroplated to form the winding wire surrounding the magnetic component. In some embodiments, the winding wire includes an input end and an output end, and the winding wire surrounds the magnetic component along the thickness direction of the magnetic component. In some embodiments, the number of coils of the winding wire  131  is more than three. 
     Operation S 63  includes: arranging a first bonding pad connected to the input end of the winding and a second bonding pad connected to the output end of the winding wire on the surface of the magnetic component substantially perpendicular to the thickness direction. 
     The first bonding pad connected to the input end and the second bonding pad connected to the output end are arranged at positions where the input end and the output end of the magnetic component are located. In some embodiments, the first bonding pad and the second bonding pad may be manufactured simultaneously in the process of manufacturing the winding wire by electroplating. 
     Operation S 64  includes: defining a through hole on the circuit board at a position corresponding to an annular part of the magnetic component. 
     In some embodiments, after the magnetic component is embedded in the circuit board, the through hole extending through the circuit board is arranged on the circuit board at a position corresponding to the annular part of the magnetic component. A diameter of the through hole is smaller than a diameter of the annular part of the magnetic component. 
     Operation S 65  includes: arranging a magnetic core in the through hole and filling first insulating layer between the magnetic core and the magnetic component. 
     The magnetic core is arranged in the through hole. In some embodiments, after the magnetic core is arranged in the through hole, in order to ensure that the magnetic core is adhered to the circuit board, the circuit board is performed with or subjected to the high-temperature pressing. At this time, the prepreg melts and fills a gap between the magnetic core and the magnetic component to form the first insulating layer. 
     Operation S 66  includes: defining a first blind hole at a position of the circuit board corresponding to the first bonding pad, and defining a second blind hole at a position of the circuit board corresponding to the second bonding pad. 
     In some embodiments, after the magnetic core is arranged, the first blind hole is defined at the position of the circuit board corresponding to the first bonding pad, and the second blind hole is defined at the position of the circuit board corresponding to the second bonding pad. The first blind hole and the second blind hole are configured to electrically connect the pattern layer arranged on the circuit board to the input end and the output end of the winding wire. In some embodiments, the positions of the first blind hole and the second blind hole may be determined according to the positions of the first bonding pad and the second bonding pad. The first blind hole and the second blind hole may be arranged on a same side of the circuit board or opposite two sides of the circuit board, which is not limited here. 
     Operation S 67  includes: arranging a conductive layer in the first blind hole to electrically connect the input end of the winding wire to the pattern layer and arranging a conductive layer in the second blind hole to electrically connect the output end of the winding wire to the pattern layer. 
     In order to enable the first blind hole and the second blind hole to have a conductivity, after the first blind hole and the second blind hole are manufactured, the conductive layers are arranged on side walls of the first blind hole and the second blind hole. 
     An inductor assembly is provided and includes a circuit board defining a groove body; a magnetic component embedded in the groove body; and a winding wire, arranged on the magnetic component, surrounding along a thickness direction of the magnetic component, and electrically connected to the circuit board. 
     In some embodiments, the inductor assembly further includes a magnetic core. The magnetic component is substantially in shape of a ring, an axial direction of the magnetic core is substantially perpendicular to a plane direction where the circuit board is located, the circuit board defines a through hole corresponding to an annular part of the magnetic component, the magnetic core is inserted into the through hole and is flush with two opposite surfaces of the circuit board. First insulating layers are filled between the magnetic core and the magnetic component, and between the magnetic component and the groove body. 
     In some embodiments, a first bonding pad and a second bonding pad are arranged on a surface of the magnetic component substantially perpendicular to the thickness direction of the circuit board, the first bonding pad is electrically connected to an input end of the winding wire, and the second bonding pad is electrically connected to an output end of the winding wire. 
     In some embodiments, a first blind hole is defined at position of the circuit board corresponding to the first bonding pad, and a second blind hole is defined at a position of the circuit board corresponding to the second bonding pad. A pattern layer is arranged on the circuit board, and conductive layers are arranged on side walls of the first blind hole and the second blind hole. The first bonding pad is electrically connected to the pattern layer through the second blind hole to electrically connect the input end of the winding wire to the pattern layer. The second bonding pad is electrically connected to the pattern layer through the second blind hole to electrically connect the output end of the winding wire to the pattern layer. 
     In some embodiments, the first bonding pad and the second bonding pad are located on a same surface of the magnetic component. Or the first bonding pad and the second bonding pad are located on opposite two surfaces of the magnetic component, respectively. 
     In some embodiments, the through hole extends through the circuit board. 
     In some embodiments, a diameter of the through hole is less a diameter of the annular part of the magnetic component. 
     In some embodiments, the magnetic component is in a shape of a ring, and defines an annular part in a middle region of the magnetic component. A first insulating layer is arranged in the annular part and arranged between the magnetic component and the groove body. 
     In some embodiments, the groove body is defined between the opposite two surfaces of the circuit board. 
     In some embodiments, a second insulating layer is coated on the magnetic component, the winding wire is located on a surface of the second insulating layer, and the winding wire is made of copper. 
     An embedded inductor assembly is provided and includes a circuit board, a magnetic component and a winding wire. The circuit board includes a first core plate, a second core plate and a third core plate arranged between the first core plate and the second core plate, and the third core plate defines a groove body extending through the third core plate. The magnetic component is embedded in the groove body. The winding wire is arranged on the magnetic component, surrounds along a thickness direction of the magnetic component, and is electrically connected to the circuit board. 
     In some embodiments, the inductor assembly further includes a magnetic core. The magnetic component is substantially in shape of a ring, an axial direction of the magnetic core is substantially perpendicular to a plane direction where the circuit board is located, the circuit board defines a through hole corresponding to an annular part of the magnetic component, the through hole extends through the first, second, and third core plates, the magnetic core is inserted into the through hole and is flush with two opposite surfaces of the circuit board. First insulating layers are filled between the magnetic core and the magnetic component, and between the magnetic component and the groove body. 
     In some embodiments, a first bonding pad and a second bonding pad are arranged on a surface of the magnetic component substantially perpendicular to the thickness direction of the circuit board, the first bonding pad is electrically connected to an input end of the winding wire, and the second bonding pad is electrically connected to an output end of the winding wire. 
     In some embodiments, a first blind hole is defined at position of the circuit board corresponding to the first bonding pad, and a second blind hole is defined at a position of the circuit board corresponding to the second bonding pad. A pattern layer is arranged on the circuit board, and conductive layers are arranged on side walls of the first blind hole and the second blind hole. The first bonding pad is electrically connected to the pattern layer through the second blind hole to electrically connect the input end of the winding wire to the pattern layer. The second bonding pad is electrically connected to the pattern layer through the second blind hole to electrically connect the output end of the winding wire to the pattern layer. 
     In some embodiments, the first bonding pad and the second bonding pad are located on a same surface of the magnetic component. Or the first bonding pad and the second bonding pad are located on opposite two surfaces of the magnetic component, respectively. 
     In some embodiments, the groove body is defined between the opposite two surfaces of the circuit board. 
     In some embodiments, a second insulating layer is coated on the magnetic component, the winding wire is located on a surface of the second insulating layer, and the winding wire is made of copper. 
     A manufacturing method for an inductor assembly is provided and includes: providing a circuit board having a groove body; arranging a winding wire on a magnetic component, the winding wire surrounding the magnetic component along a thickness direction of the magnetic component; and embedding the magnetic component in the groove body and performing a high-temperature pressing, the winding wire is electrically connected to the circuit board. 
     In some embodiments, the embedding the magnetic component in the groove body and performing a high-temperature pressing, includes: defining a through hole on the circuit board at a position corresponding to an annular part of the magnetic component; and arranging a magnetic core in the through hole and filling a first insulating layer between the magnetic core and the magnetic component; the magnetic component is substantially in shape of a ring; the arranging a winding wire on a magnetic component, includes: arranging a second insulating layer on the magnetic component; electroplating the second insulating layer to form the winding wire surrounding along the thickness direction of the magnetic component; and arranging a first bonding pad connecting to an input end of the winding wire and a second bonding pad connecting to an output end of the winding wire on a surface of the magnetic component substantially perpendicular to the thickness direction. 
     In some embodiments, the circuit board includes a pattern layer; after the embedding the magnetic component in the groove body and performing a high-temperature pressing, the manufacturing method further includes: defining a first blind hole on the circuit board at a position corresponding to the first bonding pad, and defining a second blind hole at the position of the circuit board corresponding to the second bonding pad; and arranging a conductive layer in the first blind hole to connect the input end of the winding wire to the pattern layer and arranging a conductive layer in the second blind hole to electrically connect the output end of the winding wire to the pattern layer. 
     The inductor assembly and the manufacturing method for the inductor assembly provided in some embodiments of the present disclosure realize the manufacturing of the embedded inductor assembly and the miniaturization of the product by defining the groove body in the circuit board, embedding the magnetic component in the groove body, and arranging the winding wires on the magnetic component. 
     Above embodiments are only some embodiments of the present disclosure, and can not be understood as limitation of scope of the present disclosure. Any equivalent structure or equivalent process transformation made by using the description of the present disclosure and the drawings, or contents of the present disclosure directly or indirectly applied in other related technical fields, are equally included in the scope of the present disclosure.