Multilayer wiring board

Abstract

To provide a multilayer printed circuit board that can improve the integration density and design flexibility of the printed circuit board. [Solution] The multilayer wiring board comprises at least two stacked wiring boards 1, each wiring board comprising at least two metal layers, through grooves provided in the wiring boards, at least one predetermined element provided in the through grooves, a conductive connection layer 3 provided between two adjacent wiring boards, the conductive connection layer electrically connected to the adjacent wiring boards, and along the thickness direction of the multilayer wiring board, in two adjacent wiring boards, the orthographic projection of at least one predetermined element on a predetermined projection plane on one wiring board at least partially overlaps with the orthographic projection of at least one predetermined element on a predetermined projection plane on the other wiring board, and the predetermined elements are electrically connected via the conductive connection layer.

Description

Technical Field

[0001] The present invention relates to the technical field of wiring boards, and in particular to a multilayer wiring board.

Background Art

[0002] Wiring boards, namely PCB (Printed Circuit Board), have important applications in the field of modern electronic technology. Currently, in the field of high-end electronic manufacturing, embedded packaging technology is an important development direction, the core of which is to embed various elements inside the substrate material, realize the miniaturization of the system, and improve the electrical performance and reliability. However, the embedded wiring boards in the related art have problems such as a single spatial layout form, limited integration density, and insufficient design flexibility, which restrict the further improvement of product performance and functions.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The present invention provides a multilayer wiring board for improving the integration degree of the wiring board and the flexibility of design.

Means for Solving the Problems

[0004] According to one aspect of the present invention, there is provided a multilayer wiring board comprising at least two stacked wiring boards, wherein the wiring board comprises at least two metal layers, a through groove is formed in the wiring board, at least one predetermined element is disposed in the through groove, a conductive connection layer is disposed between two adjacent wiring boards, the conductive connection layer is electrically connected to the adjacent wiring boards, and along the thickness direction of the multilayer wiring board, in two adjacent wiring boards, the orthographic projection of at least one predetermined element on one of the wiring boards on a predetermined projection plane at least partially overlaps with the orthographic projection of at least one predetermined element on the other wiring board on the predetermined projection plane, and the predetermined elements are electrically connected via the conductive connection layer.

[0005] Preferably, a first conductive plating layer is provided on the inner wall of at least one of the through grooves, and the first conductive plating layer is connected to at least one of the metal layers.

[0006] Preferably, the first conductive plating layer of the same through groove includes at least two subconductive plating layers, and the different subconductive plating layers are spaced apart along the circumferential direction of the inner wall of the through groove.

[0007] Preferably, a first insulating layer and a second insulating layer are filled in the through groove, the second insulating layer covers the predetermined element, and the first insulating layer is located between the first conductive plating layer and the second insulating layer.

[0008] Preferably, a gap is formed between two adjacent sub-conductive plating layers, and a third insulating layer is filled into the gap.

[0009] Preferably, the gap extends from the conductive plating layer toward the first insulating layer, at least partially penetrating the first insulating layer, and the third insulating layer fills the gap.

[0010] Preferably, the dimensions of the different sub-conductive plating layers in the same first conductive plating layer are the same.

[0011] Preferably, through holes are provided in the wiring board, a second conductive plating layer is provided in the through holes, and the thickness of the first conductive plating layer is greater than the thickness of the second conductive plating layer.

[0012] Preferably, a dielectric material layer is further provided between two adjacent wiring boards, the dielectric material layer is used to fix the adjacent wiring boards, and the conductive connection layer penetrates the dielectric material layer.

[0013] Preferably, the wiring board comprises a core plate, the at least two metal layers include outer metal layers located on both sides of the core plate, and the predetermined element is electrically connected to at least one of the outer metal layers.

[0014] Preferably, the wiring board comprises at least two layers, including an adjacent first wiring board and a second wiring board, wherein the first wiring board has a first through groove, and a first predetermined element is provided in the first through groove; the second wiring board has a second through groove, and a second predetermined element is provided in the second through groove; the orthographic projections of the first predetermined element and the second predetermined element on predetermined projection planes overlap at least partially along the thickness direction of the multilayer wiring board; and the first predetermined element and the second predetermined element are connected via the conductive connecting layer.

[0015] Preferably, the predetermined element comprises at least two connection terminals, the at least two connection terminals being arranged along the thickness direction of the multilayer wiring board, or the at least two connection terminals being arranged along a predetermined direction intersecting the thickness direction of the multilayer wiring board. [Effects of the Invention]

[0016] The multilayer wiring board employed in the technical solution of the embodiment of the present invention comprises at least two stacked wiring boards, each wiring board comprising at least two metal layers, through grooves provided in the wiring boards, at least one predetermined element provided in the through grooves, a conductive connection layer provided between two adjacent wiring boards, and the conductive connection layer electrically connected to the adjacent wiring boards. Along the thickness direction of the multilayer wiring board, in two adjacent wiring boards, the orthographic projection of at least one predetermined element on a predetermined projection plane on one wiring board at least partially overlaps with the orthographic projection of at least one predetermined element on a predetermined projection plane on the other wiring board, and the predetermined elements are electrically connected via the conductive connection layer. The built-in predetermined elements may be arranged in a two-dimensional plane, or further stacked and arranged in three-dimensional space, significantly increasing the number of built-in predetermined elements and integration density within a limited structural space, making full use of the three-dimensional space, and increasing the space utilization rate. Furthermore, 3D stack design enhances the overall design flexibility and scalability of the product, adapting to the design needs of complex circuit architectures and high-density signal transmission, and realizing the development needs of high-function density and high integration. Moreover, the portion of the conductive connection layer for connecting two predetermined elements overlaps with the projection of the two predetermined elements, realizing a vertical interconnection between the two predetermined elements. The electrical connection between the two predetermined elements does not require complex wiring; a vertical interconnection can be achieved simply by using the conductive connection layer, further increasing the integration density of the multilayer printed circuit board.

[0017] It should be understood that the contents described in this section are not intended to indicate key or important features of the embodiments of the present invention, nor do they limit the scope of the present invention. Other features of the present invention can be readily understood from the following specification. [Brief explanation of the drawing]

[0018] To more clearly describe the technical solutions in the embodiments of the present utility model, the following briefly describes the drawings that need to be used in the description of the embodiments. Obviously, the drawings described below only show some embodiments of the present utility model, and a person of ordinary skill in the art can obtain other drawings based on these drawings without any creative effort.

[0019] [Figure 1] This is a schematic structural diagram of a multilayer wiring board according to an embodiment of the present utility model. [Figure 2] This is a plan view of the multilayer wiring board according to the embodiment of the present utility model. [Figure 3] This is a schematic structural diagram of a further multilayer wiring board according to an embodiment of the present utility model. [Figure 4] This is a schematic structural diagram of a further multilayer wiring board according to an embodiment of the present utility model. [Figure 5] This is a schematic structural diagram of a further multilayer wiring board according to an embodiment of the present utility model. [Figure 6] This is a schematic structural diagram of a further multilayer wiring board according to an embodiment of the present utility model. [Figure 7] This is a schematic structural diagram of a further multilayer wiring board according to an embodiment of the present utility model. [Figure 8] This is a schematic structural diagram of a further multilayer wiring board according to an embodiment of the present utility model. [Figure 9] This is a schematic structural diagram of a further multilayer wiring board according to an embodiment of the present utility model. [Figure 10] This is a schematic structural diagram of a product corresponding to the main steps of the method for manufacturing a multilayer wiring board according to an embodiment of the present utility model. [Figure 11] This is a schematic structural diagram of a product corresponding to the main steps of the method for manufacturing a multilayer wiring board according to an embodiment of the present utility model. [Figure 12] This is a schematic structural diagram of a product corresponding to the main steps of the method for manufacturing a multilayer wiring board according to an embodiment of the present utility model. [Figure 13] This is a schematic structural diagram of a product corresponding to the main steps of the method for manufacturing a multilayer wiring board according to an embodiment of the present utility model. [Figure 14] This is a schematic structural diagram of a product corresponding to the main steps of the method for manufacturing a multilayer wiring board according to an embodiment of the present utility model. [Figure 15] This is a schematic diagram of the structure of a product corresponding to the main steps of the manufacturing method for a multilayer wiring board according to an embodiment of the present invention. [Figure 16] This is a schematic diagram of the structure of a product corresponding to the main steps of the manufacturing method for a multilayer wiring board according to an embodiment of the present invention. [Figure 17] This is a schematic diagram of the structure of a product corresponding to the main steps of the manufacturing method for a multilayer wiring board according to an embodiment of the present invention. [Figure 18] This is a schematic diagram of the structure of a product corresponding to the main steps of the manufacturing method for a multilayer wiring board according to an embodiment of the present invention. [Figure 19] This is a schematic diagram of the structure of a product corresponding to the main steps of the manufacturing method for a multilayer wiring board according to an embodiment of the present invention. [Figure 20] This is a schematic diagram of the structure of a product corresponding to the main steps of the manufacturing method for a multilayer wiring board according to an embodiment of the present invention. [Figure 21] This is a schematic diagram of the structure of a product corresponding to the main steps of the manufacturing method for a multilayer wiring board according to an embodiment of the present invention. [Modes for carrying out the invention]

[0020] To allow those skilled in the art to better understand the embodiments of this invention, the technical methods in the embodiments of this invention will be clearly and completely described below in conjunction with the drawings of the embodiments of this invention. Clearly, the embodiments described are not all embodiments, but only a selection of embodiments of this invention. According to the embodiments of this invention, all other embodiments obtained by those skilled in the art without any creative work fall within the scope of protection of this invention.

[0021] Furthermore, terms such as “First,” “Second,” etc., in the specification, claims, and drawings of this invention are for distinguishing similar subjects and are not required to describe a specific order or priority. It should be understood that the data used in this manner may be interchangeable in appropriate circumstances so that the embodiments of this invention described herein can be carried out in an order other than that illustrated or described herein. Also, the terms “includes,” “has,” and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units does not have to be limited to the steps or units explicitly described, and may include other steps or units that are not explicitly described or are specific to these processes, methods, products, or apparatus.

[0022] Figure 1 is a schematic diagram of the structure of a multilayer wiring board according to an embodiment of the present invention, and reference is made to Figure 1. The multilayer wiring board comprises at least two stacked wiring boards 1, each wiring board 1 comprising at least two metal layers, a through groove is provided in the wiring board 1, at least one predetermined element is provided in the through groove, a conductive connection layer 3 is provided between two adjacent wiring boards 1, the conductive connection layer 3 is electrically connected to the wiring boards 1, and along the thickness direction of the multilayer wiring board, in two adjacent wiring boards, the orthographic projection of at least one predetermined element on a predetermined projection plane on one wiring board at least partially overlaps with the orthographic projection of at least one predetermined projection plane on the other wiring board, and the predetermined elements are electrically connected via the conductive connection layer.

[0023] Specifically, each wiring board 1 in the multilayer wiring board may be a PCB, and the wiring board may have a core board. Exemplarily, this embodiment takes the example that the multilayer wiring board includes a first wiring board 11 and a second wiring board 12, and of course, in some embodiments, the number of wiring boards in the multilayer wiring board may be greater than 2. Different wiring boards 1 are arranged in a stack along a third direction Z, where the third direction Z is the thickness direction of the multilayer wiring board.

[0024] The first wiring board 11 comprises a first core board 113, and the second wiring board 12 comprises a second core board 123. At least two metal layers in the wiring board may be located at least partially within the core board. A dielectric layer is provided between two adjacent metal layers, and the material of the dielectric layer may be FR-4, polyimide, polytetrafluoroethylene, or ceramic, etc. The metal layers are used to manufacture the wiring and other components necessary for the wiring board. The wiring board may be a two-layer wiring board, a multilayer wiring board, or a high-density interconnect board, etc.

[0025] In this embodiment, the multilayer wiring board includes a stack of multiple wiring boards, the number of wiring boards may be any number of two or more, for example, three, four, or five, and each wiring board is provided with a through groove, and predetermined elements are further provided within the through groove, so that the multilayer wiring board can be understood as a three-dimensional stacked embedded element group structure. More specifically, at least one first through groove G1 is provided in the first wiring board 11, and at least one second through groove G3 is provided in the second wiring board 12. The through grooves penetrate at least the core board. At least one first predetermined element 117 is provided in the first through groove G1, and at least one second predetermined element 127 is provided in the second through groove G3. The predetermined element 117 is at least partially incorporated into the through groove. The conductive connection layer 3 is used to connect two adjacent wiring boards 1, interconnecting the corresponding metal layers in the two adjacent wiring boards 1 and realizing electrical connection between different wiring boards 1. When two or more predetermined elements are provided within a through groove, the different predetermined elements are arranged in a plane composed of a first direction X and a second direction Y, where the first direction X, the second direction Y, and the third direction Z are perpendicular to each other in pairs.

[0026] In this embodiment, as shown in Figure 1, in two adjacent wiring boards, the orthographic projection of at least one predetermined element on a predetermined projection plane at least partially overlaps with the orthographic projection of at least one predetermined element on the other wiring board on a predetermined projection plane. That is, in two adjacent wiring boards, there is at least one group of through grooves, and the group of through grooves includes one through groove located on one wiring board and one through groove located on the other wiring board. The orthographic projections of the two through grooves on predetermined projection planes at least partially overlap. The conductive connection layer 3 is used to connect portions of the two predetermined elements, overlaps with the projections of the two predetermined elements, and realizes a vertical interconnection between the two predetermined elements. In other words, by providing the conductive connection layer in the region where the two predetermined elements overlap, the connection of the two predetermined elements can be realized by providing the conductive connection layer in such a way that the orthographic projections of the predetermined elements on predetermined projection planes at least partially overlap. In other words, the electrical connection between the two predetermined elements does not require complex wiring, and a vertical interconnection can be achieved simply by using the conductive connection layer 3, further increasing the integration density of the multilayer wiring board. Here, the predetermined projection plane may be any plane perpendicular to the thickness direction of the multilayer wiring board.

[0027] The multilayer wiring board employed in this embodiment comprises at least two stacked wiring boards, each wiring board comprising at least two metal layers, with through grooves provided in the wiring boards, at least one predetermined element provided within the through grooves, a conductive connection layer provided between two adjacent wiring boards, and the conductive connection layer electrically connected to the adjacent wiring boards. Along the thickness direction of the multilayer wiring board, in two adjacent wiring boards, the orthographic projection of at least one predetermined element on a predetermined projection plane on one wiring board at least partially overlaps with the orthographic projection of at least one predetermined element on a predetermined projection plane on the other wiring board, and the predetermined elements are electrically connected via the conductive connection layer. The built-in predetermined elements may be arranged in a two-dimensional plane, or further stacked and arranged in three-dimensional space, significantly increasing the number and integration density of built-in predetermined elements within a limited structural space, making full use of the three-dimensional space, and increasing the space utilization rate. Furthermore, 3D stack design enhances the overall design flexibility and scalability of the product, adapting to the design needs of complex circuit architectures and high-density signal transmission, and realizing the development needs of high-function density and high integration. Moreover, the portion of the conductive connection layer for connecting two predetermined elements overlaps with the projection of the two predetermined elements, realizing a vertical interconnection between the two predetermined elements. The electrical connection between the two predetermined elements does not require complex wiring; a vertical interconnection can be achieved simply by using the conductive connection layer, further increasing the integration density of the multilayer printed circuit board.

[0028] Preferably, in some embodiments, a first conductive plating layer is provided on the inner wall of at least one through groove, and the first conductive plating layer is connected to at least one metal layer.

[0029] In this embodiment, since each wiring board 1 is provided with a through groove, a predetermined element is further provided within each through groove, and different wiring boards 1 are further stacked. In other words, the built-in predetermined elements can be arranged not only in a two-dimensional plane, but also stacked and arranged in three-dimensional space, significantly increasing the number of built-in predetermined elements and integration density within a limited structural space, making full use of the three-dimensional space and increasing the space utilization rate. Furthermore, the three-dimensional stack design can enhance the flexibility and expandability of the overall product design, adapting to the design needs of complex circuit architectures and high-density signal transmission, and realizing the needs for high-function density and high-integration product development.

[0030] Furthermore, in this embodiment, a first conductive plating layer is provided on the inner wall of at least one through groove. For example, a first first conductive plating layer 112 is provided in the first through groove G1, and a second first conductive plating layer 122 is provided in the second through groove G3. The conductive plating layer is provided along the inner wall of the through groove, and is connected to at least one metal layer, which interconnects the metal layer with other metal layers or connects the metal layer to the outside of the wiring board 1. By providing a conductive plating layer on the inner wall of the through groove, an interconnection structure between metal layers and between metal layers and external lines can be manufactured using the existing through groove structure, eliminating the need to open many more through holes. Consequently, the integration density of the multilayer wiring board can be further improved, and the space utilization rate can be further increased.

[0031] In the above embodiments, the material of the metal layer may be copper. Each metal layer may include plated copper and undercoat copper. If it is necessary to connect a certain metal layer to a conductive plating layer, the metal layer can be extended to the position of the conductive plating layer, and after the conductive plating layer is formed, the metal layer and the conductive plating layer can be electrically connected. Of course, in some embodiments, the first conductive plating layer may not be provided in the through groove.

[0032] Preferably, in some embodiments, the thickness of the wiring board 1 is less than 10 mm.

[0033] Preferably, Figure 2 is a plan view of a multilayer wiring board according to an embodiment of the present invention, and Figure 3 is a schematic structural diagram of a further multilayer wiring board according to an embodiment of the present invention. Referring to Figures 2 and 3, here, for the sake of explanation, this embodiment shows only the structure of the first wiring board. The first conductive plating layer of the same through groove includes at least two subconductive plating layers, and the different subconductive plating layers are spaced apart along the circumferential direction of the inner wall of the through groove.

[0034] Specifically, regarding the through grooves of the conductive plating layer, the conductive plating layer can be divided into at least two mutually insulated sub-conductive plating layers. For example, it can be divided into a first sub-conductive plating layer 1121 and a second sub-conductive plating layer 1122, with the different sub-conductive plating layers insulated from each other. The different sub-conductive plating layers can function as interconnection structures between different metal layers. By dividing the same conductive plating layer into multiple sub-conductive plating layers, the number of through holes required for the wiring board can be further reduced, and the integration density of the wiring board can be further improved. Since predetermined elements are provided within the through grooves, the dimensions of the through grooves are correspondingly large, and the dimensions of the corresponding conductive plating layers are also large. It is easy to divide the conductive plating layer into multiple sub-conductive plating layers, and each sub-conductive plating layer has sufficient dimensions, and the sub-conductive plating layers have low resistance.

[0035] Preferably, referring to Figures 1 to 3, a first insulating layer 1191 and a second insulating layer 1192 are filled in the through groove, the second insulating layer 1192 covers a predetermined element, and the first insulating layer 1191 is located between the first conductive plating layer 112 and the second insulating layer 1192.

[0036] Specifically, the first insulating layer 1191 and the second insulating layer 1192 are formed in different steps. The materials for the first insulating layer 1191 and the second insulating layer 1192 are not limited and should be suitable for insulating and bonding the corresponding structures. The first insulating layer 1191 is used to isolate the conductive plating layer 112 from a predetermined element. After forming the conductive plating layer 112, the first insulating layer 1191 is formed first, and then the predetermined element is placed in the cavity formed by the first insulating layer 1191. After the predetermined element is placed in the corresponding position, the second insulating layer 1192 is further filled to fix the predetermined element in place. In this embodiment, by providing two insulating layers, the first insulating layer 1191 and the second insulating layer 1192, insulation between the predetermined element and the conductive plating layer can be ensured, as well as the precise positioning of the predetermined element.

[0037] Preferably, a gap is formed between two adjacent sub-conductive plating layers, and a third insulating layer is filled into the gap. Specifically, after forming a conductive plating layer in the through groove, holes can be made in the conductive plating layer to create a sub-conductive plating layer and a gap located between the sub-conductive plating layers. The gap is filled with a third insulating layer, insulating and isolating the corresponding sub-conductive plating layer.

[0038] More preferably, in some embodiments, the gap penetrates the first insulating layer 1191 at least partially from the conductive plating layer toward the first insulating layer 1191, and the third insulating layer fills the gap. The portion of the third insulating layer located in the gap is defined as the third insulating sublayer. Specifically, after forming a conductive plating layer in the through groove, the material for the first insulating layer 1191 is first completely filled into the through groove, and then the hole is opened a second time to form the first insulating layer 1191. When the hole is opened a second time, a gap is synchronously formed that penetrates the conductive plating layer and the first insulating layer 1191. In this case, the gap completely penetrates the first insulating layer 1191, and at this time, the conductive plating layer is divided into multiple sub-conductive plating layers. After that, a predetermined element is placed in the corresponding position, and then the second insulating layer 1192 is filled to fix the predetermined element. In this embodiment, by providing the second insulating layer 1192 and filling the gap, the process flow can be simplified and the production efficiency of the multilayer wiring board can be increased.

[0039] Preferably, in some embodiments, the material of the third insulating layer may be different from the material of the second insulating layer, or the material of the third insulating layer may be the same as the material of the second insulating layer.

[0040] Preferably, in some embodiments, the material of the first insulating layer 1191 is the same as the material of the second insulating layer 1192, and by setting it in this way, material costs can be reduced. Of course, the materials of the first insulating layer 1191 and the second insulating layer 1192 may be different.

[0041] Preferably, in some embodiments, the first insulating layer on different wiring boards may be the same or different, and the second insulating layer on different wiring boards may be the same or different.

[0042] Preferably, in some embodiments, the dimensions of different sub-conductive plating layers within the same conductive plating layer are the same. Specifically, in this embodiment, one conductive plating layer is uniformly divided into multiple sub-conductive plating layers. That is, in a cross-section of a plane composed of a first direction X and a second direction Y, the perimeters of the different sub-conductive plating layers are the same, the electrical performance of the different sub-conductive plating layers is similar, and the stability of the electrical performance of the multilayer wiring board can be ensured.

[0043] Preferably, the shape of the through groove may be circular or rectangular. In some embodiments, if there is only one predetermined element in the through groove, the shape of the through groove may be the same as the shape of the predetermined element. For example, if the predetermined element is circular, the shape of the through groove is circular, and if the predetermined element is rectangular, the shape of the through groove is rectangular. The predetermined element is located at the center of the through groove, and in this case, the distance between the predetermined element and the inner wall of the through groove is the same in all cases, which can improve the stability of the operation of the predetermined element.

[0044] Preferably, the predetermined element may be a capacitor, inductor, resistor, resonator, heat sink, or control IC.

[0045] Preferably, Figure 4 is a schematic diagram of the structure of a further multilayer wiring board according to an embodiment of the present invention, and refer to Figure 4. Through holes G2 are further provided in the wiring board, a second conductive plating layer G21 is provided in the through holes G2, and the thickness of the first conductive plating layer is greater than the thickness of the second conductive plating layer G21. Specifically, the through-hole G2 is not used to house a predetermined element, but is used solely as an interconnection structure to achieve interconnection between different metal layers. The dimensions of the through-hole G2 are small, and the thickness of the corresponding second conductive plating layer G21 only needs to meet the usual required thickness. In this embodiment, the dimensions of the through-groove are large, providing sufficient space to house a thick first conductive plating layer, which can then be used to transmit large currents. This eliminates the need to add through-holes to the wiring board for transmitting large currents, further improving the integration density of the wiring board.

[0046] Preferably, refer to Figures 1 and 4. A dielectric material layer 2 is further provided between two adjacent wiring boards, and the dielectric material layer 2 is used to fix the adjacent wiring boards 1, and the conductive connection layer 3 penetrates the dielectric material layer 2. Specifically, the dielectric material layer 2 acts as an adhesive to the wiring board 1, fixing two adjacent wiring boards 1 into a single structure. The dielectric material layer 2 may be a prepreg or build-up film, etc. The thickness of the dielectric material layer 2 is less than 500 μm to ensure the effect of high-density stacking. The material of the conductive connection layer 3 may be plated copper, tin balls, sintered metal paste, etc.

[0047] Preferably, continuing to refer to Figures 1 and 4, in some embodiments, the at least two metal layers include outer metal layers located on both sides of the core plate, and a given element is connected to at least one outer metal layer. Specifically, the first wiring board 11 comprises a first outer metal layer 111 and a second outer metal layer 115, and the second wiring board 12 comprises a third outer metal layer 121 and a fourth outer metal layer 125. The outer metal layers are the outermost metal layers of the wiring board and may be bare metal layers or, of course, non-bare metal layers. The outer metal layers can be used to attach surface elements, etc. The outer metal layers can be bonded to the core board by a crimping method. A corresponding crimping material layer is further provided between the outer metal layers and the core board, and the insulating material between the crimping material layer and two adjacent metal layers on the core board may be the same or different. For example, the second outer metal layer 115 and the first core board 113 are crimped together via a first crimping material layer 114, and the fourth outer metal layer 125 and the second core board 123 are crimped together via a second crimping material layer 124. Of course, in some embodiments, the wiring board may not have an outer metal layer and may consist only of a core plate. In another embodiment, the number of outer metal layers on each side of the wiring board is not limited and may be one layer, at least two layers, etc.

[0048] Preferably, in some embodiments, the outer metal layer is connected to a core plate or a predetermined element via a connecting structure that penetrates the crimping material layer. The second outer metal layer 115 is connected to the first predetermined element 117 via the first connecting structure 118, and the fourth outer metal layer 125 is connected to the second predetermined element 127 via the second connecting structure 128.

[0049] Preferably, in some embodiments, the through groove can penetrate only the core plate, and the crimping material layer can cover the through groove. The thickness of a given element may be less than the thickness of the through groove, in which case the given element can be connected to the outer metal layer via a corresponding connection structure.

[0050] Preferably, in some embodiments, the thickness of a predetermined element may be greater than or equal to the thickness of the through groove.

[0051] Preferably, Figure 5 is a schematic diagram of the structure of a further multilayer wiring board according to an embodiment of the present invention, and Figure 6 is a schematic diagram of the structure of a further multilayer wiring board according to an embodiment of the present invention, with reference to Figures 1, 5, and 6. The predetermined element comprises at least two connection terminals, the at least two connection terminals being arranged along the thickness direction of the multilayer wiring board, or the at least two connection terminals being arranged along a predetermined direction intersecting the thickness direction of the multilayer wiring board. Specifically, the first predetermined element 117 is provided with a first connection terminal 1171, and the second predetermined element 127 is provided with a second connection terminal 1271. The connection terminals of the same predetermined element may be arranged in the third direction Z, as shown in Figure 1, or in a direction intersecting the third direction Z, as shown in Figure 5. In this embodiment, they are arranged in the first direction X as an example. Of course, the predetermined direction may be the second direction Y, or a direction that forms a certain angle with the third direction Z, etc. The arrangement direction of the connection terminals on different wiring boards may be the same or different. As shown in Figure 6, the connection terminals on the second wiring board 12 are arranged in the third direction Z, and the connection terminals on the first wiring board 11 are arranged in the first direction X.

[0052] Preferably, in some embodiments, predetermined elements of two adjacent multilayer wiring boards are electrically connected. The predetermined elements can be connected to the corresponding outer metal layer, and then interconnection between the outer metal layers of different wiring boards 1 is realized via a conductive connection layer 3. In this embodiment, by providing a connection between the predetermined elements and the outer metal layer, structures such as series connection and parallel connection of predetermined elements on different wiring boards 1 can be realized.

[0053] As shown in Figure 7, Figure 7 is a schematic diagram of the structure of a further multilayer wiring board according to an embodiment of the present invention. In this embodiment, the connection terminals of the first predetermined element 117 that are far from the second wiring board 12 are connected to the connection terminals of the second predetermined element 127 that are close to the first wiring board 11, and the connection terminals of the first predetermined element 117 that are close to the second wiring board 12 are connected to the connection terminals of the second predetermined element 127 that are far from the first wiring board 11. In other words, the first predetermined element 117 and the second predetermined element 127 are connected in parallel.

[0054] As shown in Figure 8, Figure 8 is a schematic diagram of the structure of a further multilayer wiring board according to an embodiment of the present invention. In this embodiment, one connection terminal of the first predetermined element 117 is connected to one connection terminal of the second predetermined element 127 by a first conductive plating layer, a metal layer, and through holes, etc., and the other connection terminal of the first predetermined element 117 is insulated from the other connection terminal of the second predetermined element 127. In other words, the first predetermined element 117 and the second predetermined element 127 are connected in series.

[0055] Of course, as shown in Figure 9, Figure 9 is a schematic diagram of the structure of a further multilayer wiring board according to an embodiment of the present invention. In this embodiment, the arrangement direction of the connection terminals of the first predetermined element 117 is different from the arrangement direction of the connection terminals of the second predetermined element 127. The first predetermined element 117 and the second predetermined element 127 are still connected in series or in parallel by the first conductive plating layer, metal layer, through holes, etc.

[0056] Preferably, continuing to refer to Figures 1, 7 to 9, the orthographic projections of the first predetermined element 117 and the second predetermined element 127 on a predetermined projection plane overlap at least partially along the thickness direction of the multilayer wiring board, i.e., along the third direction Z, and the first predetermined element 117 and the second predetermined element 127 are connected via a conductive connection layer. Specifically, when it is necessary to electrically connect the first predetermined element 117 and the second predetermined element 127, they can be arranged so that their orthographic projections overlap at least partially, and in this case, the projections between the two corresponding through grooves also overlap at least partially. In the external metal layer, electrical connection between the two predetermined elements can be achieved with simpler wiring. Furthermore, the overlapping installation of the predetermined elements can further reduce the wiring board area occupied by the entire predetermined element, thereby further improving the integration density.

[0057] For illustrative purposes, a method for manufacturing a multilayer printed circuit board will be briefly described below. Figures 10 to 21 are schematic diagrams of the product structure corresponding to the main steps of the method for manufacturing a multilayer printed circuit board according to an embodiment of the present invention. As shown in Figures 10 to 21, first, as shown in Figure 10, one base printed circuit board is provided, that is, a core board is provided. In this embodiment, the first core board 113 is used as an example. The first printed circuit board and the second printed circuit board can be manufactured synchronously.

[0058] Subsequently, as shown in Figure 11, a foundation penetration hole is made in the wiring board, that is, a penetration groove G1 is first made.

[0059] Subsequently, as shown in Figure 12, the through-hole is subjected to a metallization treatment. Specifically, processes such as electroless copper plating or thick plating are performed on the through-groove G1 to form an electrolytic copper plating layer on the inner wall of the through-groove G1, i.e., a conductive plating layer is formed.

[0060] Subsequently, as shown in Figure 13, the material for the first insulating layer 1191 is filled into the through groove G1, and the material for the first insulating layer 1191 is, for example, hole-filling ink. After filling is complete, a hardening treatment is performed, and the surface of the wiring board is polished to be flush with the surface by a polishing process to ensure surface flatness.

[0061] Subsequently, as shown in Figure 14, holes are made to form cavities corresponding to the second insulating layer. At this time, the conductive plating layer can be synchronously divided into a sub-conductive plating layer. In this case, gaps are formed in both the first insulating layer 1191 and the conductive plating layer.

[0062] Subsequently, as shown in Figure 15, the temporary carrier 4 is attached to the bottom of the wiring board and used to mount the predetermined elements later.

[0063] Subsequently, as shown in Figure 16, the predetermined elements are precisely attached to the temporary carrier 4, and at this time, the predetermined elements are precisely aligned.

[0064] Subsequently, as shown in Figure 17, the cavity is filled with a material corresponding to the second insulating layer to achieve firm fixation between the predetermined element and the wiring board. In this case, both the gap formed in the conductive plating layer and the gap formed in the first insulating layer are filled by the second insulating layer.

[0065] Subsequently, the temporary carriers are removed as shown in Figure 18. These temporary carriers can be removed by methods such as chemical dissolution, mechanical exfoliation, or thermal release.

[0066] Subsequently, as shown in Figure 19, the metal layer is patterned to produce a predetermined circuit pattern, completing the production of the inner layer and preliminary outer layer circuits. Subsequently, as shown in Figure 20, the core plate, the crimping material layer, and the outer metal layer are crimped together to build up the wiring board and facilitate subsequent track expansion and interconnection.

[0067] Subsequently, as shown in Figure 21, laser blind vias are created in the crimping material layer to construct vertical interconnection paths between the surface lines (i.e., lines in the outer metal layer), the inner line lines, and predetermined elements. Then, metallization and plating are performed on the blind vias. After that, the outer metal layer is patterned to form the surface circuit, and the manufacturing of the first and second wiring boards is completed after this process.

[0068] Subsequently, as shown in Figure 1, different wiring boards are stacked, crimped, and electrically connected. Using a Transient Liquid Phase Sintering (TLPS) process, a conductive metal paste (as a conductive connection layer) and a prepreg (as a dielectric material layer) are placed between the first and second wiring boards, and a crimping and sintering process is performed to integrally bond the two, forming a high-density three-dimensional stacked embedded wiring board. In this embodiment, the first predetermined element and the second predetermined element are connected in series via the conductive connection layer, and the first outer metal layer and the second outer metal layer are connected via the conductive connection layer.

[0069] It should be understood that steps can be rearranged, added, or deleted using the various forms of flows described above. For example, each step described in this invention may be executed in parallel, sequentially, or in a different order, and the invention is not limited thereto, as long as the desired results of the technical solution disclosed herein are achieved.

[0070] The specific embodiments described above do not limit the scope of protection of the present invention. Those skilled in the art will understand that various modifications, combinations, subcombinations, and substitutions are possible based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should all be included within the scope of protection of the present invention.

Claims

1. The device comprises at least two stacked wiring boards, each wiring board comprising at least two metal layers, a through groove is provided in the wiring board, at least one predetermined element is provided in the through groove, a conductive connection layer is provided between two adjacent wiring boards, and the conductive connection layer is electrically connected to the adjacent wiring boards. Along the thickness direction of the multilayer wiring board, in two adjacent wiring boards, the orthographic projection of at least one predetermined element on a predetermined projection plane in one wiring board at least partially overlaps with the orthographic projection of at least one predetermined element on a predetermined projection plane in the other wiring board, and the predetermined elements are electrically connected via the conductive connecting layer. A multilayer wiring board characterized by the following features.

2. A first conductive plating layer is provided on the inner wall of at least one of the through grooves, and the first conductive plating layer is connected to at least one of the metal layers. The multilayer wiring board according to claim 1.

3. The first conductive plating layer of the same through groove includes at least two subconductive plating layers, and the different subconductive plating layers are spaced apart along the circumferential direction of the inner wall of the through groove. The multilayer wiring board according to claim 2, characterized in that it is a multilayer wiring board.

4. A first insulating layer and a second insulating layer are filled into the through groove, the second insulating layer covers the predetermined element, and the first insulating layer is located between the first conductive plating layer and the second insulating layer. The multilayer wiring board according to claim 3.

5. A gap is formed between two adjacent sub-conductive plating layers, and a third insulating layer is filled into the gap. The multilayer wiring board according to feature 4.

6. The gap extends from the first conductive plating layer toward the first insulating layer, at least partially penetrating the first insulating layer, and the third insulating layer fills the gap. The multilayer wiring board according to claim 5.

7. The dimensions of the different sub-conductive plating layers in the same first conductive plating layer are the same. The multilayer wiring board according to claim 3.

8. A dielectric material layer is further provided between two adjacent wiring boards, the dielectric material layer is used to fix the adjacent wiring boards, and the conductive connection layer penetrates the dielectric material layer. The multilayer wiring board according to claim 1.

9. The wiring board comprises a core plate, the at least two metal layers include outer metal layers located on both sides of the core plate, and the predetermined element is electrically connected to at least one of the outer metal layers. The multilayer wiring board according to claim 1.

10. The predetermined element comprises at least two connection terminals, the at least two connection terminals being arranged along the thickness direction of the multilayer wiring board, or the at least two connection terminals being arranged along a predetermined direction intersecting the thickness direction of the multilayer wiring board. The multilayer wiring board according to claim 1.

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