Package substrate and manufacturing method therefor

Abstract

Provided in the embodiments of the present disclosure are a package substrate and a manufacturing method therefor. The manufacturing method comprises: by means of etching a metal foil, manufacturing a micron-sized annular recessed cavity having a solid metal column, and filling the annular recessed cavity with a magnetic material to form an embedded magnetic inductor so as to form a first embedded magnetic core layer having the solid metal column; building up layers by means of sputtering a plurality of layers of metal, performing electroplating, laminating dielectric materials, etc. on the first embedded magnetic core layer, performing local etching on an electroplated metal layer by means of patterning to form an annular recessed cavity, and then filling the annular recessed cavity with the magnetic material; and repeating the process to manufacture on different levels a plurality of inductor structures which have the solid metal column and have different thicknesses and sizes.

Description

Packaging substrate and manufacturing method thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present disclosure is based on Chinese patent application CN202410380009.3 filed on March 29, 2024, entitled “Packaging substrate and manufacturing method thereof”, and claims the priority of the patent application, and all the contents disclosed therein are incorporated into the present disclosure by reference. Technical Field

[0003] The embodiments of the present disclosure relate to the technical field of semiconductor packaging, and in particular, to a packaging substrate and a manufacturing method thereof. Background Art

[0004] Inductors are commonly used discrete components in packaging, soldered to substrates for electrical connection. However, they are relatively large and occupy a significant portion of the substrate's surface area. With the advancement of electronic technology, performance requirements for electronic products are increasing, while size requirements are shrinking. High-density integration and miniaturization are inevitable trends in electronic products. Consequently, related technologies face the problem of inductors occupying a significant portion of the substrate's surface area. Summary of the Invention

[0005] The embodiments of the present disclosure provide a packaging substrate and a manufacturing method thereof, which at least solve the problem in the related art that the inductor occupies the area of ​​the substrate surface.

[0006] According to one embodiment of the present disclosure, a method for manufacturing a packaging substrate is provided, comprising: manufacturing a core layer with a metal conductor based on a carrier; manufacturing at least one build-up layer with a metal conductor based on the core layer; wherein the method for manufacturing the core layer and the build-up layer comprises: obtaining the metal conductor while obtaining an annular cavity in the core layer and the build-up layer by etching, wherein the metal conductor is located in the annular cavity; and filling the annular cavity with a magnetic material to obtain the core layer or the build-up layer.

[0007] According to another embodiment of the present disclosure, a packaging substrate is provided, comprising: a core layer, which is manufactured based on a carrier and has a metal conductor; at least one build-up layer, which is manufactured based on the core layer and has a metal conductor; wherein an annular cavity and a metal conductor are provided in the core layer and the build-up layer, the annular cavity and the metal conductor are obtained simultaneously by etching, the metal conductor is located in the annular cavity, and the annular cavity is filled with a magnetic material. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG1 is a flow chart of a method for manufacturing a package substrate according to an embodiment of the present disclosure;

[0009] FIG2 is a process flow chart of a method for manufacturing a package substrate according to an embodiment of the present disclosure;

[0010] FIG3 is a flow chart of a method for manufacturing a first inductor structure according to an embodiment of the present disclosure;

[0011] FIG4 is a flow chart of a method for obtaining a first inductor structure based on an etching operation according to an embodiment of the present disclosure;

[0012] 5 is a flow chart of a method for forming a core layer based on a plurality of first inductor structures according to an embodiment of the present disclosure;

[0013] 6 is a flow chart of a first method for fabricating at least one build-up layer with a metal conductor based on a core layer according to an embodiment of the present disclosure;

[0014] 7 is a flow chart of a second method for fabricating at least one build-up layer with a metal conductor based on a core layer according to an embodiment of the present disclosure;

[0015] FIG8 is a flow chart of a method for manufacturing inductor structures with different inductances according to an embodiment of the present disclosure;

[0016] 9 is a flow chart of a method for disposing a second metal conductor at the position of a first metal conductor according to an embodiment of the present disclosure;

[0017] FIG10 is a flow chart of a method for obtaining a second inductor structure and adding layers according to an embodiment of the present disclosure;

[0018] FIG11 is a schematic diagram of a buried magnetic structure of a package substrate according to an embodiment of the present disclosure;

[0019] FIG12 is a schematic diagram of a packaging structure according to an embodiment of the present disclosure.

[0020] Explanation of the accompanying drawings: 1. Carrier; 2. Core layer; 31. First build-up layer; 32. Second build-up layer; 33. Third build-up layer; 34. Fourth build-up layer; 4. Metal foil layer; 5. First photoresist layer; 6. Annular cavity; 71. First metal conductor; 72. Second metal conductor; 73. Third metal conductor; 8. Magnetic material; 9. Second photoresist layer; 10. Metal protective wall; 11. Dielectric; 12. Conductive layer; 13. Metal conductor layer; 14. Circuit layer; 15. Chip. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and in conjunction with embodiments.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of this disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. The directions such as "upper" and "lower" mentioned below are only used to illustrate the relative positional relationship of the features in conjunction with the drawings, and do not limit the actual positional relationship of the features.

[0023] In this embodiment, a method for manufacturing a package substrate is provided. FIG1 is a process flow chart of the method for manufacturing a package substrate according to an embodiment of the present disclosure, and FIG2 is a flow chart of the method for manufacturing a package substrate according to an embodiment of the present disclosure. As shown in FIG1 and FIG2 , the process includes the following steps:

[0024] Step S201 , manufacturing a core layer 2 with a metal conductor based on the carrier 1 ;

[0025] Step S202, manufacturing at least one build-up layer with a metal conductor based on the core layer 2;

[0026] The method for making the core layer 2 and the build-up layer includes:

[0027] A metal conductor is obtained by etching in the core layer 2 or the build-up layer while obtaining the annular cavity 6, wherein the metal conductor is located in the annular cavity 6;

[0028] The annular cavity 6 is filled with magnetic material 8 to obtain a core layer 2 or a build-up layer.

[0029] In one embodiment, the metal conductor can be a solid metal column, the annular cavity 6 has a size in the micrometer range, and the magnetic material 8 can be in the form of magnetic slurry or magnetic paste. This makes the resulting inductor structure composed of the metal conductor and magnetic material 8 compact and small in size, further resolving the problem of the inductor occupying the substrate surface area encountered in related arts.

[0030] In one embodiment, the height and width of the annular cavity 6 within the core layer 2 or the annular cavity 6 within the build-up layer can be the same or different, thereby changing the volume of the magnetic material 8 disposed within the annular cavity 6 to change the inductance of the resulting inductor structure. The number of build-up layers can be set according to actual conditions and can be one or more layers. The inductor structure within each build-up layer can be connected to the inductor structure within the core layer 2, wherein the inductor structure includes a metal conductor and an annular cavity 6 filled with magnetic material 8. Of course, the inductor structures within adjacent build-up layers can also be interconnected, thereby changing the inductance of the combined inductor structure by changing the height of the inductor structure. Alternatively, there can be multiple inductor structures within the core layer 2 or the build-up layer, and the widths of the multiple inductor structures can be the same or different, thereby changing the inductance of the resulting inductor structure by changing the width. Alternatively, inductor structures at different positions can be connected in series to change the inductance of the resulting inductor structure.

[0031] In an exemplary embodiment, taking the build-up layer as comprising a first build-up layer 31 and a second build-up layer 32, the first build-up layer 31 is located on one side of the core layer 2, and the second build-up layer 32 is located on the side of the core layer 2 facing away from the first build-up layer 31. When multiple metal conductors are present in the core layer 2, the first build-up layer 31, and the second build-up layer 32, an annular cavity 6 is provided outside the metal conductor in the core layer 2, and a magnetic material 8 is disposed within the annular cavity 6 to form a first inductor structure. The one or more metal conductors in the first build-up layer 31 and the second build-up layer 32 are connected to the metal conductor in the core layer 2, thereby providing the inductance of the first inductor structure. Alternatively, an annular cavity 6 is provided on the outer side of one or more metal conductors in the first build-up layer 31, and a magnetic material 8 is provided in the annular cavity 6 to form a second inductor structure. An annular cavity 6 is provided on the outer side of one or more metal conductors in the second build-up layer 32, and a magnetic material 8 is provided in the annular cavity 6 to form a third inductor structure. The first inductor structure is connected to the second inductor structure and the third inductor structure, so as to provide the sum of the inductances of the first inductor structure, the second inductor structure, and the third inductor structure. Alternatively, an annular cavity 6 is not provided on the outer side of one or more metal conductors in the first build-up layer 31, an annular cavity 6 is provided on the outer side of one or more metal conductors in the second build-up layer 32, and a magnetic material 8 is provided in the annular cavity 6 to form a second inductor structure. The first inductor structure is connected to the second inductor structure and one or more metal conductors in the first build-up layer 31, so as to provide the sum of the inductances of the first inductor structure and the second inductor structure. Alternatively, an annular cavity 6 is provided on the outside of one or more metal conductors in the first build-up layer 31, and a magnetic material 8 is provided in the annular cavity 6 to form a second inductor structure. The annular cavity 6 is not provided on the outside of one or more metal conductors in the second build-up layer 32. The first inductor structure is connected to the second inductor structure and the one or more metal conductors in the second build-up layer 32, thereby providing the sum of the inductances of the first and second inductor structures. Therefore, by adopting the above method, the inductance of the obtained inductor structure can be changed. Of course, the above is only an exemplary description, and the number of first build-up layers 31 and second build-up layers 32 can be adjusted according to actual conditions.

[0032] In an exemplary embodiment, the first build-up layer 31 or the second build-up layer 32 is produced after the core layer 2 is completed. The metal conductor within the core layer 2 can be obtained simultaneously with the production of the annular cavity 6 within the core layer 2. That is, the annular cavity 6 within the core layer 2 corresponds one-to-one with the metal conductor within the core layer 2. The metal conductor of the first build-up layer 31 can be obtained simultaneously with the production of the annular cavity 6 within the first build-up layer 31. That is, the annular cavity 6 within the first build-up layer 31 corresponds one-to-one with the metal conductor within the first build-up layer 31. The metal conductor of the second build-up layer 32 can be obtained simultaneously with the production of the annular cavity 6 within the second build-up layer 32. That is, the annular cavity 6 within the second build-up layer 32 corresponds one-to-one with the metal conductor within the second build-up layer 32.

[0033] Furthermore, the micron-sized annular cavity 6 is relatively small. Therefore, the resulting inductor structure is relatively small, occupying less internal space on the substrate. Furthermore, due to the flexible configuration and adjustment of the inductor structure, precise control of the inductance can be achieved.

[0034] By using multi-layer buried magnetics, we can obtain inductor structures of various specifications. The inductor structure has strong scalability and can more finely control the inductance to match different voltage regulation requirements. The use of solid metal columns can reduce resistance to achieve optimal performance.

[0035] Through the above steps, due to the use of etching in the core layer 2 and the build-up layer, a metal conductor is obtained at the same time as the annular cavity 6 is obtained, and the metal conductor is located in the annular cavity 6, and then filled with magnetic material 8, and finally the core layer 2 or the build-up layer is obtained. This manufacturing method can effectively hide the inductor in the annular cavity 6, so that it no longer occupies the area of ​​the substrate surface, solving the problems in the related art. Doing so can make the layout of the packaging substrate more flexible and the overall size smaller, meeting the requirements of modern electronic products for lightness, thinness and high performance. Therefore, the manufacturing method provided by the present disclosure effectively solves the problems existing in the related art and promotes the progress and development of inductor packaging substrate technology.

[0036] FIG3 is a flow chart of a method for manufacturing a first inductor structure according to an embodiment of the present disclosure. In one embodiment, as shown in FIG1 and FIG3 , the method for manufacturing the core layer 2 further includes manufacturing the first inductor structure. The method for manufacturing the first inductor structure includes:

[0037] Step S301 , providing a metal foil layer 4 on the surface of the carrier 1 ;

[0038] In an exemplary embodiment, a metal foil layer 4 is adhered to the surface of a carrier 1. The metal foil layer 4 can be made of copper, nickel, or the like. The carrier 1 can be made of a glass plate, FR4 board, or the like to support the metal foil layer 4. As shown in FIG1 , if the carrier 1 is a rectangular parallelepiped, the metal foil layer 4 can also be a rectangular parallelepiped, and the metal foil layer 4 is attached to the upper surface of the carrier 1, but can also be attached to the lower surface of the carrier 1.

[0039] Step S302 , providing a first photoresist layer 5 on the surface of the metal foil layer 4 facing away from the carrier 1 , wherein the first photoresist layer 5 is provided with an annular groove;

[0040] In an exemplary embodiment, the first photoresist layer 5 is a photosensitive film having at least one annular groove disposed therein, wherein the annular groove is the location of the window, i.e., the location of the annular cavity 6. As shown in FIG1 , the first photoresist layer 5 is disposed on the upper surface of the metal foil layer 4.

[0041] Step S303 , etching the metal foil layer 4 to obtain an annular cavity 6 and a metal conductor through an annular groove;

[0042] In an exemplary embodiment, a corrosive solution is used to etch the metal foil layer 4 at the location of the annular groove to form an annular cavity 6. The metal foil layer 4 is retained at the location where the first photoresist layer 5 is attached to form a metal conductor. The metal conductor can be a regular three-dimensional structure such as a cylinder or a square prism, or it can be an "S", "W" or other irregular three-dimensional structure in cross-section, and the configuration can be based on actual conditions.

[0043] Step S304, removing the first photoresist layer 5, and filling the annular cavity 6 with a magnetic material 8;

[0044] In an exemplary embodiment, after the first photoresist layer 5 is separated from the metal foil layer 4, at least one annular cavity 6 is formed in the metal foil layer 4, and a metal conductor is contained in each annular cavity 6. In particular, the metal conductor is located at the center of the annular cavity 6, or the central axis of the metal conductor coincides with the central axis of the annular cavity 6.

[0045] Step S305 : When the magnetic material 8 is solidified, an etching operation is performed to obtain a first inductor structure.

[0046] In one embodiment, the end of the metal conductor facing away from the carrier 1 and the surface of the metal foil layer 4 facing away from the carrier 1 are polished to ensure that the surface of the magnetic material 8 solidified in the annular cavity 6 is at the same height as the surface of the metal conductor. Of course, the first inductor structure can be one or more, and can be arranged according to actual circumstances.

[0047] FIG4 is a flow chart of a method for obtaining a first inductor structure based on an etching operation according to an embodiment of the present disclosure. In one embodiment, as shown in FIG1 and FIG4 , an etching operation is performed when the magnetic material 8 is solidified to obtain the first inductor structure, including:

[0048] Step S401 , providing a second photoresist layer 9 on a surface of the metal foil layer 4 facing away from the carrier 1 , wherein the second photoresist layer 9 is provided with a circular structure covering the first inductor structure, and the radius of the circular structure is larger than the outer diameter of the annular cavity 6 of the first inductor structure;

[0049] In an exemplary embodiment, as shown in FIG1 , the second photoresist layer 9 may be located on the upper surface of the metal foil layer 4. The second photoresist layer 9 has at least one circular structure to cover the metal conductor and the solidified magnetic material 8 in the annular cavity 6 through the circular structure, thereby facilitating etching of the solidified magnetic material 8 and the metal foil layer 4.

[0050] In an exemplary embodiment, the second photoresist layer 9 is a circular structure, and the number of second photoresist layers 9 matches the number of metal conductors, so that one second photoresist layer 9 can be used to protect one metal conductor, thereby improving the flexibility of using the second photoresist layer 9.

[0051] In step S402 , the metal foil layer 4 is etched to form a metal protection wall 10 on the outside of the magnetic material 8 through a circular structure, so as to obtain a first inductor structure.

[0052] In an exemplary embodiment, because the radius of the circular structure is larger than the outer diameter of the annular cavity 6 of the first inductor structure, the circular structure covers a portion of the metal foil layer 4. Therefore, during the secondary etching of the metal foil layer 4, the circular structure protects a portion of the metal foil layer 4 while etching another portion of the metal foil layer 4. The remaining portion of the metal foil layer 4 forms an annular metal protective wall 10, the central axis of which coincides with the central axis of the metal conductor. This allows the metal conductor, the solidified magnetic material 8, and the metal protective wall 10 to form components of the first inductor structure.

[0053] FIG5 is a flow chart of a method for forming a core layer based on a plurality of first inductor structures according to an embodiment of the present disclosure. In one embodiment, as shown in FIG1 and FIG5 , after etching the metal foil layer 4 to form a metal protection wall 10 on the outside of the magnetic material 8 in a circular structure to obtain the first inductor structure, the method further includes:

[0054] In step S501 , a dielectric 11 is disposed between a plurality of first inductor structures to connect the plurality of first inductor structures to form a core layer 2 .

[0055] In an exemplary embodiment, the dielectric 11 can be made of a dielectric material, such as a resin, a filler-containing resin, or an organic resin containing glass fiber. For example, the dielectric 11 can be laminated between multiple first inductor structures to facilitate connecting the multiple first inductor structures together as components of the core layer 2. Of course, the core layer 2 can contain a single inductor structure or multiple first inductor structures. Similarly, if there is only one first inductor structure, the core layer 2 can be formed by laminating the dielectric 11 around the first inductor structure.

[0056] FIG6 is a flow chart of a first method for fabricating at least one build-up layer with a metal conductor based on a core layer according to an embodiment of the present disclosure. In one embodiment, as shown in FIG1 and FIG6 , fabricating at least one build-up layer with a metal conductor based on a core layer 2 includes:

[0057] Step S601 , forming a first build-up layer 31 on the surface of the core layer 2 facing away from the carrier 1 ;

[0058] Step S602, removing the carrier 1; and / or,

[0059] Step S603 : forming a second build-up layer 32 on a surface of the core layer 2 facing away from the first build-up layer 31 .

[0060] In an exemplary embodiment, based on the production requirements, when the build-up layer is produced on the upper surface and / or lower surface of the core layer 2, in order to improve the structural strength of the core layer 2, the carrier 1 can be retained before the first build-up layer 31 is produced. After the first build-up layer 31 is produced, the carrier 1 is removed to obtain a composite structure of the core layer 2 and the first build-up layer 31. Therefore, the first build-up layer 31 can be produced only on one side of the core layer 2. Of course, the number of first build-up layers 31 can be set according to actual conditions so that the core layer 2 is a composite structure with a build-up layer on one side. Of course, after the first build-up layer 31 is already on one side of the core layer 2, the carrier 1 can be removed to produce a second build-up layer 32 on the surface of the core layer 2 away from the first build-up layer 31 (as shown in Figure 1, that is, the original position of the carrier 1, that is, the lower surface of the core layer 2) so that the core layer 2 is a composite structure with a build-up layer on both sides.

[0061] FIG7 is a flow chart of a second method for fabricating at least one build-up layer with a metal conductor based on the core layer 2 according to an embodiment of the present disclosure. In one embodiment, as shown in FIG1 and FIG7 , fabricating at least one build-up layer with a metal conductor based on the core layer 2 includes:

[0062] Step S701, removing carrier 1;

[0063] Step S702: fabricating a first build-up layer 31 on the surface of the core layer 2, and / or,

[0064] Step S703 , forming a second build-up layer 32 on a surface away from the first build-up layer 31 .

[0065] In an exemplary embodiment, based on manufacturing requirements, the carrier 1 may be removed first to facilitate the fabrication of the first build-up layer 31 on one side of the core layer 2. Of course, to improve the efficiency of fabricating the build-up layers, the first build-up layer 31 and the second build-up layer 32 may be fabricated on either side of the core layer 2 after the carrier 1 is removed. It should be noted that the fabrication of the first build-up layer 31 and the second build-up layer 32 may be performed simultaneously, or the second build-up layer 32 may be fabricated after the first build-up layer 31 is fabricated.

[0066] FIG8 is a flow chart of a method for manufacturing inductor structures with different inductances according to an embodiment of the present disclosure. In one embodiment, as shown in FIG1 and FIG8 , the method includes:

[0067] Step S801, disposing a second metal conductor 72 at the position of the first metal conductor 71;

[0068] In step S802, a third metal conductor 73 is provided at the position of the second metal conductor 72 to connect the first metal conductor 71 with the second metal conductor 72, and to connect the second metal conductor 72 with the third metal conductor 73; wherein the first metal conductor 71 is located in the core layer 2, and the second metal conductor 72 and the third metal conductor 73 are located in different build-up layers.

[0069] In an exemplary embodiment, the second metal conductor 72 and the third metal conductor 73 are merely exemplary descriptions. There may be only one or more second metal conductors 72 and third metal conductors 73 respectively, and they may be provided according to specific circumstances.

[0070] In one embodiment, a third metal conductor 73 may also be provided at a position of the first metal conductor 71 away from one end of the second metal conductor 72, so that one end of the first metal conductor 71 is connected to the second metal conductor 72, and the other end of the first metal conductor 71 is connected to the third metal conductor 73, thereby forming a connection path among the first metal conductor 71, the second metal conductor 72, and the third metal conductor 73.

[0071] In one embodiment, the method further comprises:

[0072] A second inductor structure is provided on one side of the first inductor structure;

[0073] A third inductor structure is provided on the other side of the first inductor structure so that the magnetic materials 8 in the annular cavities 6 of the first inductor structure, the second inductor structure and the third inductor structure are connected and the metal conductors are connected;

[0074] The first inductor structure, the second inductor structure and the third inductor structure include a metal conductor and an annular cavity 6 filled with a magnetic material 8 .

[0075] Therefore, the inductance of the obtained inductor structure can be changed by changing the height and size of the annular cavity 6 or stacking multiple annular cavities.

[0076] FIG9 is a flow chart of a method for disposing a second metal conductor in place of a first metal conductor according to an embodiment of the present disclosure. In one embodiment, as shown in FIG1 and FIG9 , disposing a second metal conductor 72 in place of a first metal conductor 71 includes:

[0077] Step S901, providing a conductive layer 12 on the surface of the core layer 2;

[0078] In an exemplary embodiment, after the core layer 2 is formed, a conductive layer 12 is first provided on one side of the core layer 2 in order to form the first build-up layer 31 on the other side of the core layer 2. The conductive layer 12 is provided to facilitate electrical conduction and protect the magnetic material. The conductive layer 12 can be formed by sputtering, chemical plating, or other methods.

[0079] Step S902, providing a metal conductor layer 13 on the surface of the conductive layer 12;

[0080] In an exemplary embodiment, based on the number of metal conductor layers 13 required, pattern transfer is performed on the conductive layer 12 to obtain the locations where the metal conductor layers 13 are to be placed, and the metal conductor layers 13 are placed at the locations. The metal conductor layers 13 can be formed by electroplating or other methods.

[0081] In step S903 , the metal conductor layer 13 is etched to obtain a second metal conductor 72 , so as to connect the first metal conductor 71 and the second metal conductor 72 .

[0082] In an exemplary embodiment, under the condition that the first metal conductor 71 and the second metal conductor 72 are connected, since the purpose of providing part of the second metal conductor 72 is to facilitate the first metal conductor 71 of the core layer 2 to communicate with the external chip 15 through the second metal conductor 72, part of the second metal conductor 72 does not need to be further processed, and the end of the second metal conductor 72 facing away from the core layer 2 can be made higher than the surface of the first build-up layer 31 facing away from the core layer 2. Another part of the second metal conductor 72 is to make a second inductor structure, so it is necessary to etch the metal conductor layer 13 to obtain the second metal conductor 72 needed to support the second inductor structure. Figure 10 is a flow chart of a method for obtaining a second inductor structure and a build-up layer according to an embodiment of the present disclosure. In one embodiment, as shown in Figures 1 and 10, the metal conductor layer 13 is etched to obtain the second metal conductor 72, so that after the first metal conductor 71 and the second metal conductor 72 are connected, it includes:

[0083] Step S1001, when there are multiple second metal conductors 72, removing the conductive layer 12;

[0084] In an exemplary embodiment, the conductive layer 12 may be removed using aqueous etching or plasma etching.

[0085] Step S1002 , disposing a dielectric 11 between the plurality of second metal conductors 72 to connect the plurality of second metal conductors 72 ;

[0086] In an exemplary embodiment, the purpose of pouring the medium 11 is to connect the plurality of second metal conductors 72 into an integral structure after the medium 11 is cured.

[0087] Step S1003, etching an annular cavity 6 in the second metal conductor 72;

[0088] In an exemplary embodiment, because a portion of the second metal conductor 72 needs to be formed into a second inductor structure, the portion of the second metal conductor 72 needs to be etched to etch the outer peripheral surface of the portion of the second metal conductor 72, so as to form an annular cavity 6 between the remaining second metal conductor 72 and the dielectric 11. Of course, if the second metal conductor 72 is a single one, the conductive layer 12 can also be removed first, and then the dielectric 11 is pressed around the single second metal conductor 72, and then the annular cavity 6 is etched in the second metal conductor 72.

[0089] Step S1004 : Fill the annular cavity 6 with a magnetic material 8 so that the magnetic material 8 surrounds the second metal conductor 72 , thereby obtaining a second inductor structure and a build-up layer.

[0090] In an exemplary embodiment, a magnetic material 8 is filled in an annular cavity 6 etched in the second metal conductor 72, so that the magnetic material 8 surrounds the second metal conductor 72, so that the second metal conductor 72 and the solidified magnetic material 8 serve as components of the second inductor structure, and further, multiple second inductor structures, the metal conductor layer 13 that has not been etched, and the solidified medium 11 serve as components of the build-up layer.

[0091] It should be noted that the above description uses the manufacturing process of the second metal conductor 72 as an example. Of course, the manufacturing process of the third metal conductor 73 is similar and will not be described in detail here. After the first build-up layer 31 of the first layer is completed, the first build-up layer 31 of the second layer can be continued to be manufactured on the first build-up layer 31 of the first layer, and the first build-up layer 31 of the third layer can be continued to be manufactured on the first build-up layer 31 of the second layer, and so on, until the required number of first build-up layers 31 is obtained. After the second build-up layer 32 of the first layer is completed, the second build-up layer 32 of the second layer can be continued to be manufactured on the second build-up layer 32 of the first layer, and the second build-up layer 32 of the third layer can be continued to be manufactured on the second build-up layer 32 of the second layer, and so on, until the required number of second build-up layers 32 is obtained.

[0092] In one embodiment, the method further comprises:

[0093] A circuit layer 14 is provided at one end of the second inductor structure facing away from the core layer 2 .

[0094] In one exemplary embodiment, the provision of a circuit layer 14 not only facilitates communication between the second inductor structure and external devices, but also allows second inductor structures located at different locations to be connected in series to obtain an inductor structure that meets the requirements. Of course, the circuit layer 14 can also be provided only at the end of a second inductor structure facing away from the core layer 2, allowing the second inductor structure to communicate with an external chip 15. Similarly, the circuit layer 14 can also be provided at the end of the third inductor structure facing away from the core layer 2, but this will not be discussed further here.

[0095] It should be noted that the numbering of the above steps is only for the convenience of describing the steps, and the order of the numbers is not necessarily used to describe a specific order or sequence.

[0096] In this embodiment, a packaging substrate is also provided, which is obtained based on the above-mentioned embodiment.

[0097] FIG11 is a schematic diagram of a buried magnetic structure of a package substrate according to an embodiment of the present disclosure; as shown in FIG11 , the package substrate includes:

[0098] A core layer 2, made based on the carrier 1 and having a metal conductor;

[0099] at least one build-up layer, fabricated based on the core layer 2 and having a metal conductor;

[0100] Among them, an annular cavity 6 and a metal conductor are provided in the core layer 2 and the build-up layer. The annular cavity 6 and the metal conductor are obtained simultaneously by etching. The metal conductor is located in the annular cavity 6, and the annular cavity 6 is filled with magnetic material 8.

[0101] In one embodiment, the packaging substrate further includes:

[0102] The first metal conductor 71 is disposed in the core layer 2;

[0103] The second metal conductor 72 is disposed in the first build-up layer 31;

[0104] A third metal conductor 73 is disposed in the second build-up layer 32;

[0105] The build-up layer includes a first build-up layer 31 and / or a second build-up layer 32 , and the first metal conductor 71 is connected to the second metal conductor 72 and / or the third metal conductor 73 .

[0106] In one embodiment, the annular cavity 6 of the core layer 2 and the annular cavity 6 of the build-up layer have different heights and widths.

[0107] In one embodiment, the first metal conductor 71 , the second metal conductor 72 , and the third metal conductor 73 have different heights and widths.

[0108] In an exemplary embodiment, the core layer 2 and the build-up layer can each have only one or multiple annular cavities 6. Since the height and width of the annular cavities 6 in the core layer 2 or the build-up layer can be the same or different, the length and width of the magnetic material disposed within the annular cavities 6 can be different, thereby adjusting the inductance of the resulting inductor structure. Similarly, since the number, height, and width of the first metal conductors 71, the second metal conductors 72, and the third metal conductors 73 can be the same or different, the number of build-up layers can be multiple, and the second metal conductors 72 and the third metal conductors 73 can be located in different build-up layers. By connecting different first metal conductors 71, second metal conductors 72, and third metal conductors 73, the inductance of the resulting inductor structure can be adjusted by changing the height and width of the metal conductors, thereby providing greater freedom and flexibility.

[0109] FIG12 is a schematic diagram of a packaging structure according to an embodiment of the present disclosure. In one embodiment, as shown in FIG12 , the packaging structure includes a chip 15 and the above-mentioned packaging substrate. The packaging substrate includes a core layer 2, a first build-up layer 31, a second build-up layer 32, a third build-up layer 33, and a fourth build-up layer 34. The first build-up layer 31 is located on one side of the core layer 2, the second build-up layer 32 is located on the side of the core layer 2 facing away from the first build-up layer 31, the third build-up layer 33 is located on the side of the first build-up layer 31 facing away from the core layer 2, and the fourth build-up layer 34 is located on the side of the second build-up layer 32 facing away from the core layer 2. The first metal conductor 71 is located in the core layer 2, the second metal conductor 72 is located in the first build-up layer 31, and the third metal conductor 73 is located in the second build-up layer 32. The second metal conductor 72 is connected to the first metal conductor 71, and the first metal conductor 71 is connected to the third metal conductor 73. Of course, there can be multiple first metal conductors 71, second metal conductors 72, and third metal conductors 73. Some of these first metal conductors 71, second metal conductors 72, and third metal conductors 73 have an annular cavity 6 disposed outside them, and magnetic material is placed inside the annular cavity 6 to form an inductor structure. Other first metal conductors 71, second metal conductors 72, and third metal conductors 73 do not have an annular cavity 6 disposed outside them. Therefore, the connections of the first metal conductors 71, second metal conductors 72, and third metal conductors 73 can be freely combined based on the required inductance. Furthermore, metal conductors are also present within the third build-up layer 33 and the fourth build-up layer 34, but these metal conductors do not have an annular cavity 6 disposed outside them. The metal conductor within the third build-up layer 33 is connected to the second metal conductor 72. The metal conductor within the fourth build-up layer 34 is connected to the third metal conductor 73. The circuit layer 14 within the first build-up layer 31 or the second build-up layer 32 can connect two or more adjacent second metal conductors 72 in series. Therefore, by connecting different inductor structures in series, different inductance requirements can be achieved. The metal conductors in the third build-up layer 33 are connected to the ports of the chip 15 through one or more electrical conductors, so as to achieve the effect of communication between the packaging substrate and the chip 15 .

[0110] In summary, the method for manufacturing the packaging substrate of the embodiment of the present disclosure can be summarized. The method for manufacturing the packaging substrate includes: etching a metal foil to make a micron-sized annular cavity with a solid metal column, filling the annular cavity with a magnetic material to form a buried magnetic inductor, so as to form a first buried magnetic core layer with a solid metal column; by sputtering multiple layers of metal, electroplating, laminating dielectric materials, etc. on the first buried magnetic core layer to increase the layer, and by graphic processing, the electroplated metal layer is partially etched to form an annular cavity and then filled with magnetic material; repeating the above process to realize the production of multiple inductor structures of different thicknesses and sizes with solid metal columns at different levels in the packaging substrate, forming a packaging substrate with a multi-layer buried magnetic stacking structure in some / all positions.

[0111] Therefore, the following technical effects can be achieved:

[0112] 1. The multi-layer buried magnetic structure realizes multiple specifications of inductors and strong scalability: by making and stacking cavities of different thicknesses and sizes with solid metal pillars at different levels in the multi-layer structure, and then filling the cavities with magnetic material 8, the inductor height can be increased by continuing to add layers to improve the inductor inductance, more refined inductance control, matching different voltage regulation requirements, and achieving performance optimization.

[0113] 2. High-density inductor integration: Based on the filling of magnetic materials, micron-level cavity filling can be achieved, and a variety of inductor specifications can be formed without multi-layer winding to further optimize space utilization.

[0114] 3. Improve the performance and reliability of the inductor structure: In the embedded inductor structure, the magnetic material 8 is filled in the concave cavity outside the solid electroplated metal column. The solid metal column reduces current interference, improves the inductor performance, and enhances heat dissipation while avoiding the use of resin to fill the hole to improve the reliability of the structure.

[0115] The foregoing description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that various modifications and variations of the present disclosure are possible. Any modifications, equivalent substitutions, or improvements made within the principles of the present disclosure shall be included within the scope of protection of the present disclosure.

Claims

1. A method for manufacturing a packaging substrate, comprising: Producing a core layer with a metal conductor based on the carrier; Making at least one build-up layer with a metal conductor based on the core layer; The method for manufacturing the core layer and the build-up layer includes: The metal conductor is obtained by etching in the core layer and the build-up layer while obtaining an annular cavity, wherein the metal conductor is located in the annular cavity; The annular cavity is filled with magnetic material to obtain the core layer or the build-up layer.

2. The method according to claim 1, wherein The method for manufacturing the core layer further includes manufacturing a first inductor structure, and the method for manufacturing the first inductor structure includes: Disposing a metal foil layer on the surface of the carrier; A first photoresist layer is provided on the surface of the metal foil layer facing away from the carrier, wherein the first photoresist layer is provided with an annular groove; etching the metal foil layer to obtain the annular cavity and the metal conductor through the annular groove; removing the first photoresist layer and filling the annular cavity with a magnetic material; When the magnetic material is solidified, an etching operation is performed to obtain the first inductor structure.

3. The method according to claim 2, wherein: When the magnetic material is solidified, an etching operation is performed to obtain the first inductor structure, including: A second photoresist layer is provided on a surface of the metal foil layer facing away from the carrier, wherein the second photoresist layer is provided with a circular structure covering the first inductor structure, and the radius of the circular structure is larger than the outer diameter of the annular cavity of the first inductor structure; The metal foil layer is etched to form a metal protection wall on the outer side of the magnetic material through the circular structure, so as to obtain the first inductor structure.

4. The method according to claim 3, wherein: After etching the metal foil layer to form a metal protection wall on the outer side of the magnetic material through the circular structure to obtain the first inductor structure, the method further includes: A medium is provided between the plurality of first inductance structures to connect the plurality of first inductance structures to form the core layer.

5. The method according to claim 1, wherein Producing at least one build-up layer with a metal conductor based on the core layer, comprising: Fabricating a first build-up layer on a surface of the core layer facing away from the carrier; removing the carrier; and / or, The second build-up layer is fabricated on a surface of the core layer facing away from the first build-up layer.

6. The method according to claim 1, wherein Producing at least one build-up layer with a metal conductor based on the core layer, comprising: removing the carrier; Producing a first build-up layer on the surface of the core layer, and / or, A second build-up layer is fabricated on a surface facing away from the first build-up layer.

7. The method according to claim 1, wherein include: Disposing a second metal conductor at the position of the first metal conductor; Disposing a third metal conductor at the position of the second metal conductor so that the first metal conductor is connected to the second metal conductor, and so that the second metal conductor is connected to the third metal conductor; The first metal conductor is located in the core layer, and the second metal conductor and the third metal conductor are located in different build-up layers.

8. The method according to claim 7, wherein: Arranging a second metal conductor at the position of the first metal conductor comprises: Disposing a conductive layer on the surface of the core layer; Disposing a metal conductor layer on the surface of the conductive layer; The metal conductor layer is etched to obtain the second metal conductor, so that the second metal conductor is connected to the first metal conductor.

9. The method according to claim 8, wherein The metal conductor layer is etched to obtain a second metal conductor, so that the second metal conductor is connected to the first metal conductor, and the method further comprises: In the case where there are multiple second metal conductors, removing the conductive layer; Disposing a medium between the plurality of second metal conductors to connect the plurality of second metal conductors; Etching an annular cavity in the second metal conductor; The annular cavity is filled with magnetic material so that the magnetic material surrounds the second metal conductor, thereby obtaining a second inductor structure and the build-up layer.

10. The method according to claim 9, wherein: Also includes: A circuit layer is provided at one end of the second inductor structure away from the core layer.

11. A packaging substrate, comprising: The core layer is made based on the carrier and has a metal conductor; at least one build-up layer, manufactured based on the core layer and having a metal conductor; An annular cavity and a metal conductor are provided in the core layer and the build-up layer. The annular cavity and the metal conductor are obtained simultaneously by etching. The metal conductor is located in the annular cavity, and the annular cavity is filled with magnetic material.

12. The package substrate according to claim 11, wherein: include: a first metal conductor, disposed in the core layer; a second metal conductor disposed in the first build-up layer; a third metal conductor disposed in the second build-up layer; The build-up layer includes the first build-up layer and / or the second build-up layer, and the first metal conductor is connected to the second metal conductor and / or the third metal conductor.

13. The package substrate according to claim 11, wherein: include: The annular concave cavity of the core layer and the annular concave cavity of the build-up layer have different heights and widths.

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