A packaging structure and a method of manufacturing the same

Abstract

This invention discloses a packaging structure and its fabrication method. The packaging structure includes: a first sub-board; a photosensitive dielectric layer covering a portion of the first sub-board; the photosensitive dielectric layer including a first groove penetrating the photosensitive dielectric layer, with the surface of the photosensitive dielectric layer away from the first sub-board flush with the exposed portion of the first groove; the first dielectric layer at least covering a portion of the first sub-board; a second sub-board located on the side of the first dielectric layer away from the first sub-board; the second sub-board covering the first dielectric layer; a cavity penetrating from the surface of the second sub-board away from the first sub-board to the photosensitive dielectric layer; and at least one electronic component located within the cavity, electrically connected to the first sub-board through the first groove. This invention can achieve the requirements of high precision, high coplanarity, high quality, and high efficiency for the packaging structure, improving the packaging reliability of electronic components.

Description

Technical Field

[0001] This invention relates to the field of packaging technology, and in particular to a packaging structure and its preparation method. Background Technology

[0002] As electronic products evolve towards miniaturization and high performance, advanced technologies such as System-in-Package (SiP) are widely used, making embedded component technology crucial for improving integration and electrical performance. This technology requires fabricating micron-level grooves at specific locations on the substrate to achieve reliable interconnection between embedded component pins and circuits. The precision of the grooves and the coplanarity of the copper surface, dielectric material, and individual window materials directly affect the yield of subsequent embedded components.

[0003] Since multi-layer stacked embedded packaging technology usually requires a large groove depth, traditional groove cutting methods are limited by the precision capability of mechanical equipment, resulting in poor groove depth control accuracy, with tolerances exceeding 75μm. This makes it impossible to achieve coplanarity and can cause copper surface damage, leading to poor reliability of subsequent embedded components. Summary of the Invention

[0004] This invention provides a packaging structure and its preparation method, which can meet the requirements of high precision, high coplanarity, high quality and high efficiency of the packaging structure, and improve the packaging reliability of electronic components.

[0005] According to one aspect of the present invention, a packaging structure is provided, comprising:

[0006] The first sub-board includes a first surface and a second surface that are disposed opposite to each other.

[0007] A photosensitive medium layer is located on the side of the first surface away from the second surface, and the photosensitive medium layer covers a portion of the first sub-plate; the photosensitive medium layer includes a first groove that penetrates the photosensitive medium layer and exposes a portion of the first surface; the surface of the photosensitive medium layer away from the first sub-plate is flush with the exposed portion of the first surface by the first groove.

[0008] A first dielectric layer is located on the side of the first surface away from the second surface; the first dielectric layer at least covers a portion of the first sub-board;

[0009] The second sub-board is located on the side of the first dielectric layer away from the first sub-board; the second sub-board covers the first dielectric layer;

[0010] The cavity extends from the surface of the second sub-plate away from the first sub-plate to the photosensitive medium layer;

[0011] At least one electronic component is located within the cavity and is electrically connected to the first sub-board via a first groove.

[0012] Based on the above embodiments, optionally, the dimension of the cavity along the first direction is equal to the dimension of the photosensitive dielectric layer along the first direction; or,

[0013] The size of the cavity along the first direction is smaller than the size of the photosensitive dielectric layer along the first direction; the encapsulation structure further includes: a protective structure, which is located between the first dielectric layer and the photosensitive dielectric layer; the first dielectric layer covers the protective structure and part of the first sub-board;

[0014] The first direction is perpendicular to the direction from the first sub-board to the second sub-board.

[0015] Based on the above embodiments, optionally, the protective structure is a single-layer structure, and the material of the protective structure is different from the material of the first sub-board; or, the protective structure includes a seed layer and a first metal layer stacked together, the first metal layer being located on the side of the seed layer away from the first sub-board; the seed layer covers part of the photosensitive medium layer; the first metal layer covers the seed layer;

[0016] The seed layer material includes any one of titanium, tin, nickel, titanium-tungsten alloy, titanium nitride, silicon dioxide, silicon nitride, silicon carbide, polytetrafluoroethylene, amorphous silicon, amorphous boron, and amorphous carbon;

[0017] The material of the first metal layer includes any one of copper, aluminum, and tungsten;

[0018] The material of the photosensitive medium layer is a photosensitive material.

[0019] Based on the above embodiments, optionally, the dimension of the protective structure along the first direction is less than or equal to 5 μm;

[0020] The dimension of the protective structure in the direction from the first sub-plate to the second sub-plate is greater than or equal to 3μm.

[0021] Based on the above embodiments, optionally, the cross-sectional shape of the first groove along the first direction includes at least one of a circle, a triangle, a quadrilateral, and an ellipse.

[0022] Based on the above embodiments, optionally, the first distance between the surface of the photosensitive medium layer away from the first sub-board and the surface of the first sub-board away from the second sub-board is less than the second distance between the surface of the first medium layer away from the first sub-board and the surface of the first sub-board away from the second sub-board.

[0023] Based on the above embodiments, optionally, both the first sub-board and the second sub-board include at least two second metal layers and at least one second dielectric layer, with a second dielectric layer disposed between two adjacent second metal layers;

[0024] The second dielectric layer is provided with at least one blind via, and two adjacent second metal layers are electrically connected through the blind via;

[0025] The second metal layer in the first sub-board that is closest to the second sub-board includes a second groove, which penetrates the second metal layer in the first sub-board that is closest to the second sub-board; the photosensitive dielectric layer fills the second groove and covers a portion of the second metal layer in the first sub-board that is closest to the second sub-board.

[0026] According to another aspect of the present invention, a method for preparing an encapsulation structure is provided, comprising:

[0027] A first sub-board is formed; the first sub-board includes a first surface and a second surface disposed opposite to each other;

[0028] A photosensitive medium layer is formed on the side of the first surface away from the second surface; the photosensitive medium layer covers a portion of the first sub-plate; the photosensitive medium layer includes a first groove that penetrates the photosensitive medium layer and exposes a portion of the first surface; the surface of the photosensitive medium layer away from the first sub-plate is flush with the exposed portion of the first surface by the first groove.

[0029] A protective structural material layer is formed on the side of the photosensitive medium layer away from the first sub-plate; the protective structural material layer covers the photosensitive medium layer and the bottom and sidewalls of the first groove;

[0030] A first dielectric material layer is formed on the side of the protective structural material layer away from the first sub-plate; the first dielectric material layer covers a portion of the first sub-plate and the protective structural material layer;

[0031] A second sub-board material layer is formed on the side of the first dielectric material layer away from the first sub-board; the second sub-board material layer covers the first dielectric material layer;

[0032] The protective structural material layer, the first dielectric material layer, and the second sub-plate material layer are processed to form a cavity, thereby forming the first dielectric layer and the second sub-plate; the cavity extends from the surface of the second sub-plate away from the first sub-plate to the photosensitive dielectric layer; the first dielectric layer at least partially covers the first sub-plate; the second sub-plate covers the first dielectric layer;

[0033] At least one electronic component is formed within the cavity, the at least one electronic component is located within the cavity, and the at least one electronic component is electrically connected to the first sub-board through the first groove.

[0034] Based on the above embodiments, optionally, the protective structural material layer, the first dielectric material layer, and the second sub-plate material layer are processed to form a cavity, thereby forming the first dielectric layer and the second sub-plate, including:

[0035] The first dielectric material layer and the second sub-plate material layer are processed to form the first dielectric layer and the second sub-plate. The protective structure material layer is processed to form a cavity, the size of which along the first direction is equal to the size of the photosensitive dielectric layer along the first direction. Alternatively, the first dielectric material layer and the second sub-plate material layer are processed to form the first dielectric layer and the second sub-plate. The protective structure material layer is processed to form a cavity and a protective structure, the size of which along the first direction is smaller than the size of the photosensitive dielectric layer along the first direction. The first dielectric layer covers the protective structure and part of the first sub-plate. The first direction is perpendicular to the direction from the first sub-plate to the second sub-plate.

[0036] Based on the above embodiments, optionally, a protective structural material layer is formed on the side of the photosensitive dielectric layer away from the first sub-plate, including:

[0037] A seed layer is formed on the side of the photosensitive medium layer away from the first daughter plate by a sputtering process; the seed layer covers part of the photosensitive medium layer;

[0038] A first metal layer is formed on the side of the seed layer away from the first daughter plate by an electroplating process, and the first metal layer covers the seed layer.

[0039] The packaging structure provided by the technical solution of this invention includes: a first sub-board, the first sub-board including a first surface and a second surface disposed opposite to each other; a photosensitive dielectric layer covering a portion of the first sub-board; the photosensitive dielectric layer including a first groove, the first groove penetrating the photosensitive dielectric layer and exposing a portion of the first surface; the surface of the photosensitive dielectric layer away from the first sub-board being flush with the exposed portion of the first surface of the first groove; the first dielectric layer at least covering a portion of the first sub-board; a second sub-board covering the first dielectric layer; a cavity penetrating from the surface of the second sub-board away from the first board to the photosensitive dielectric layer; at least one electronic component located in the cavity, and at least one electronic component electrically connected to the first sub-board through the first groove. In this embodiment of the invention, the first groove penetrates the photosensitive dielectric layer and exposes a portion of the first surface; because the height of the photosensitive dielectric layer is controllable, the depth of the first groove can be precisely controlled, greatly improving the slotting accuracy of the packaging structure. The photosensitive dielectric layer is flush with the surface away from the first sub-board, and the exposed portion of the first surface of the first groove is also flush with the first surface. This achieves the coplanarity of the surface of the photosensitive dielectric layer away from the first sub-board and the coplanarity of the first surface exposed at the bottom of the first groove. When at least one electronic component is electrically connected to the first sub-board through the first groove, the unevenness of the height of the photosensitive dielectric layer and the first surface will not affect the reliability of the electrical connection. This improves the packaging quality and production efficiency of the encapsulated structure, and enhances the reliability of the encapsulated structure.

[0040] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of a packaging structure provided in an embodiment of the present invention.

[0043] Figure 2 This is a schematic diagram of another packaging structure provided in an embodiment of the present invention.

[0044] Figure 3 This is a schematic diagram of an intermediate structure of a packaging structure provided in an embodiment of the present invention.

[0045] Figure 4 This is a schematic diagram of the intermediate structure of another packaging structure provided in the embodiments of the present invention.

[0046] Figure 5 This is a top view of the structure of a photosensitive medium layer provided in an embodiment of the present invention.

[0047] Figure 6 This is a flowchart of a method for preparing a packaging structure provided in an embodiment of the present invention.

[0048] Figures 7-13 This is a schematic diagram of the intermediate structure of another packaging structure provided in the embodiments of the present invention. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0050] It should be noted that the terms "first," "second," etc., used in this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0051] This invention provides a packaging structure. Figure 1 This is a schematic diagram of a packaging structure provided in an embodiment of the present invention, for reference. Figure 1 The packaging structure includes:

[0052] First sub-plate 10, the first sub-plate includes a first surface and a second surface disposed opposite to each other; photosensitive medium layer 40, the photosensitive medium layer 40 is located on the side of the first surface away from the second surface, the photosensitive medium layer 40 covers a portion of the first sub-plate 10; the photosensitive medium layer 40 includes a first groove 41, the first groove 41 penetrates the photosensitive medium layer 40, exposing a portion of the first surface; the surface of the photosensitive medium layer 40 away from the first sub-plate 10 is flush with the exposed portion of the first surface of the first groove 41; first medium layer 20, the first medium layer 20 is located on the first sub-plate 10... A sub-board 10 has one side; a first dielectric layer 20 at least partially covers the first sub-board 10; a second sub-board 30 is located on the side of the first dielectric layer 20 away from the first sub-board 10; the second sub-board 30 covers the first dielectric layer 20; a cavity 50 extends from the surface of the second sub-board 30 away from the first sub-board 10 to a photosensitive dielectric layer 40; at least one electronic component 60 is located within the cavity 50 and is electrically connected to the first sub-board 10 through a first groove 41.

[0053] The first sub-board 10 and the second sub-board 30 each include at least two second metal layers 11 and at least one second dielectric layer 12. A second dielectric layer 12 is disposed between two adjacent second metal layers 11. The second dielectric layer 12 can be an insulating dielectric layer or a prepreg. Adjacent second metal layers 11 can be electrically connected through blind vias 13. The number of second metal layers 11 and second dielectric layers 12 included in the first sub-board 10 and the second sub-board 30 can be set according to requirements. The number of layers in the second sub-board 30 can be determined according to the size of the electronic components 60 to be embedded, and can be set as needed. The material of the photosensitive dielectric layer 40 is a photosensitive or photosensitive material. For example, the material of the photosensitive dielectric layer 40 can include photosensitive resin, semiconductor photosensitive material, etc. The embodiments of the present invention do not make specific limitations, and the material can be selected according to cost and requirements.

[0054] The first dielectric layer 20 and the second dielectric layer 12 can be made of the same material, resulting in a simple fabrication process and low material control costs. The cavity 50 can be formed using mechanical depth control and laser etching processes. The size of the cavity 50 can be determined by the size of the electronic component and can be designed according to requirements. At least one electronic component 60 is placed in the cavity 50. The electronic component 60 can include at least one component such as a semiconductor chip, resistor, capacitor, or sensor. Pins of the electronic component 60 can be formed within the first groove 41. These pins can be solder balls, and the electronic component 60 is electrically connected to the first daughter board 10 through these pins. The first groove 41 can be used to form pins electrically connected to the electronic component 60, or it can be used to fill the groove with other materials for other purposes, depending on the actual situation. The electronic component 60 and the photosensitive dielectric layer 40 can also be isolated using the same dielectric material as the first dielectric layer 40. The material of the first dielectric layer 40 is different from that of the photosensitive dielectric layer 40, and the boundary line between the photosensitive dielectric layer 40 and the dielectric layer of different materials can be observed under a metallographic microscope.

[0055] The packaging structure provided in this embodiment of the invention is used in the field of embedded packaging. The electronic component 60 is an embedded component. The electronic component 60 can be designed to be single-sided conductive to achieve unidirectional interconnection; or, the electronic component can be designed to be double-sided conductive to achieve bidirectional interconnection. Figure 2 This is a schematic diagram of another packaging structure provided in an embodiment of the present invention, see reference. Figure 2 , Figure 2 The electronic components 60 are bidirectionally interconnected. Figure 2The encapsulation structure also includes a third daughter board 80, which may include a second metal layer 11 and a second dielectric layer 12. The third daughter board 80 is located on the side of the second daughter board 30 away from the first daughter board 10. The second dielectric layer 12 of the third daughter board 80 fills the area of ​​the cavity 50 except for the area where the electronic component 60 is located, and blind vias are provided in the second dielectric layer 12 of the third daughter board 80 so that the electronic component 60 can be electrically connected to the second metal layer 11 of the third daughter board 80. The electronic component 60 is electrically connected to the first daughter board 10 through the first groove 41, that is, in Figure 2 A third groove is provided in the dielectric layer between the electronic component 60 and the first sub-board 10. The third groove is connected to the first groove 41. The electronic component 60 is electrically connected to the first sub-board through the third groove and the first groove 41, thereby realizing bidirectional interconnection of the electronic components. Figure 2 This is for illustrative purposes only; the specific interconnection method and connecting materials used are not limited. Figure 2 The electronic component 60 can achieve unidirectional interconnection by being electrically connected only to the first daughterboard 10 or only to the third daughterboard 80.

[0056] Specifically, in the existing technology, the cavity 50 can be formed by mechanical depth control and laser grooving processes. The accuracy of grooving depth control is poor, with an error of up to 75μm, resulting in inconsistent grooving dimensions, which affects the reliability of the electrical connection of subsequent electronic components 60; and it will also cause damage to the first surface of the first sub-board 10, resulting in a reduction in the packaging yield of the structure. In this embodiment of the invention, when the photosensitive dielectric layer 40 is formed by laminating the material, the surface of the photosensitive dielectric layer 40 away from the first sub-board 10 can be made flush. At the same time, the height of the photosensitive dielectric layer 40 in the direction from the first sub-board 10 to the second sub-board 30 can be controlled. The photosensitive characteristics of the photosensitive dielectric layer 40 can be used to fabricate the structure of the first groove 41 using circuit technology. The depth of the first groove 41 in the direction from the first sub-board 10 to the second sub-board 30 can be 5μm-30μm. The depth of the first groove 41 is controllable, and the first surface exposed at the bottom of the first groove 41 is flush, so that the accuracy error of the first groove 41 reaches ±5μm, improving the packaging accuracy of the packaging structure and greatly improving the reliability of the subsequent electrical connection of electronic components 60.

[0057] During the subsequent cavity formation process, embodiments of the present invention can protect the surface of the photosensitive dielectric layer 40 away from the first sub-board and the first surface exposed at the bottom of the first groove 41 through a protective structure. After the protective structure is removed, the cavity formation process will not damage the surface of the photosensitive dielectric layer 40 away from the first sub-board 10 and the first surface exposed at the bottom of the first groove 41. This achieves the coplanarity of the surface of the photosensitive dielectric layer 40 away from the first sub-board 10 and the first surface exposed at the bottom of the first groove 41. When at least one electronic component 60 is electrically connected to the first sub-board 10 through the first groove 41, the height of the photosensitive dielectric layer 40 and the first surface will not be uneven, affecting the reliability of the electrical connection. This improves the packaging quality and production efficiency of the encapsulated structure.

[0058] The packaging structure provided by the technical solution of this invention includes: a first sub-board 10, which includes a first surface and a second surface disposed opposite to each other; a photosensitive dielectric layer 40 covering a portion of the first sub-board 10; the photosensitive dielectric layer 40 including a first groove 41 penetrating the photosensitive dielectric layer 40 and exposing a portion of the first surface; the surface of the photosensitive dielectric layer 40 away from the first sub-board 10 being flush with the exposed portion of the first surface of the first groove 41 being flush with the first surface; a first dielectric layer 20 at least covering a portion of the first sub-board 10; a second sub-board 30 covering the first dielectric layer 20; a cavity 50 penetrating from the surface of the second sub-board 30 away from the first sub-board 10 to the photosensitive dielectric layer 40; and at least one electronic component 60 located within the cavity 50, and at least one electronic component 60 being electrically connected to the first sub-board 10 through the first groove 41. In this invention, the first groove 41 penetrates the photosensitive dielectric layer 40 and exposes a portion of the first surface; because the height of the photosensitive dielectric layer 40 is controllable, the depth of the first groove 41 can be precisely controlled, greatly improving the slotting accuracy of the packaging structure. The photosensitive dielectric layer 40 is flush with the surface away from the first sub-board 10, and the exposed portion of the first surface of the first groove 41 is also flush with the surface. This achieves the coplanarity of the surface of the photosensitive dielectric layer 40 away from the first sub-board 10 and the coplanarity of the first surface exposed at the bottom of the first groove 41. When at least one electronic component 60 is electrically connected to the first sub-board 10 through the first groove 41, the unevenness of the height of the photosensitive dielectric layer 40 and the first surface will not affect the reliability of the electrical connection. This can improve the packaging quality and production efficiency of the encapsulated structure, and improve the reliability of the encapsulated structure.

[0059] Based on the above embodiments, optionally, refer to Figure 1 The dimension of cavity 50 along the first direction X is equal to the dimension of photosensitive medium layer 40 along the first direction X; or, Figure 3 This is a schematic diagram of an intermediate structure of a packaging structure provided in an embodiment of the present invention, for reference. Figure 3The cavity 50 has a smaller dimension along the first direction X than the photosensitive medium layer 40 along the first direction X; the encapsulation structure also includes a protective structure 70, which is located between the first medium layer 20 and the photosensitive medium layer 40; the first medium layer 20 covers the protective structure 70 and part of the first sub-board 10; wherein the first direction X is perpendicular to the direction of the first sub-board 10 pointing to the second sub-board 30.

[0060] Among them, reference Figure 1 The size of the cavity 50 along the first direction X is equal to the size of the photosensitive medium layer 40 along the first direction X, so that the protective structure 70 can be completely removed when the final structure is formed, thereby achieving that the surface of the photosensitive medium layer 40 away from the first sub-plate 10 is flush, and the exposed part of the first groove 41 is flush with the first surface.

[0061] refer to Figure 3 The cavity 50 has a smaller dimension along the first direction X than the photosensitive medium layer 40 along the first direction X, so that the protective structure 70 will have some residue when the final structure is formed. The dimension of the residual protective structure in the first direction is less than or equal to 5μm. The protective structure 70 can be a single-layer structure or a double-layer structure. When the protective structure is a single-layer structure, it is necessary to ensure that the material of the single-layer structure is different from the material of the metal layer in the first sub-board. When the protective structure is a double-layer structure, the material of the first layer structure of the protective structure 70 that contacts the first sub-board 10 is different from the material of the second metal layer 11 in the first sub-board 10. The material of the second layer structure of the protective structure 70 can be the same as or different from the material of the second metal layer 11. Considering the conditions of satisfying the requirements of manufacturability, production efficiency and cost control, it can be designed independently according to the actual situation, production efficiency and cost control. Since the first layer in both the single-layer and double-layer structures is made of different materials for the second metal layer 11 of the first sub-board 10, selective etching will not damage the second metal layer on the first surface of the first sub-board 10, thereby achieving flush surface of the photosensitive medium layer 40 away from the first sub-board 10, and the exposed portion of the first surface of the first groove 41 is flush.

[0062] In this embodiment of the invention, the size of the cavity 50 along the first direction X is set to be less than or equal to the size of the photosensitive medium layer 40 along the first direction X. Different local structural morphologies can be exhibited by controlling the size of the cavity 50. Alternatively, the size of the cavity 50 along the first direction X can be set to be greater than the size of the photosensitive medium layer 40 along the first direction X. Figure 4 This is a schematic diagram of an intermediate structure of another packaging structure provided in an embodiment of the present invention, for reference. Figure 4 , Figure 4The cavity 50 in the first direction X has a larger dimension than the photosensitive dielectric layer 40 in the first direction X. When the cavity is formed in the subsequent process, since there is no protective structure in the red box area, and due to the instability of the etching process, it will have a concave shape, which will damage the metal layer on the first surface of the first sub-board 10 and affect the reliability of the packaging structure.

[0063] Based on the above embodiments, optionally, refer to Figure 3 The protective structure 70 is a single-layer structure, and the material of the protective structure 70 is different from the material of the first sub-board 10; or, the protective structure 70 includes a seed layer 71 and a first metal layer 72 stacked together, the first metal layer 72 being located on the side of the seed layer 71 away from the first sub-board 10; the seed layer 71 covers part of the photosensitive medium layer 40; the first metal layer 72 covers the seed layer 71; the material of the seed layer 71 includes any one of titanium, tin, nickel, titanium-tungsten alloy, titanium nitride, silicon dioxide, silicon nitride, silicon carbide, polytetrafluoroethylene, amorphous silicon, amorphous boron, and amorphous carbon; the material of the first metal layer 72 includes any one of copper, aluminum, and tungsten.

[0064] The material of the single-layer protective structure 70 is different from the material of the first sub-plate 10, that is, the material of the single-layer structure is different from the material of the metal layer in the first sub-plate 10; for example, the material of the single-layer structure may include any one of titanium, tin, nickel, titanium-tungsten alloy, titanium nitride, silicon dioxide, silicon nitride, silicon carbide, polytetrafluoroethylene, amorphous silicon, amorphous boron and amorphous carbon.

[0065] When the protective structure 70 is a double-layer structure, the material of the seed layer 71 is different from the material of the first sub-plate 10. The material of the first metal layer can be different from or the same as the material of the second metal layer of the first sub-plate 10. The material of the seed layer includes any one of titanium, tin, nickel, titanium-tungsten alloy, titanium nitride, silicon dioxide, silicon nitride, silicon carbide, polytetrafluoroethylene, amorphous silicon, amorphous boron and amorphous carbon. The material of the first metal layer includes any one of copper, aluminum and tungsten.

[0066] In one preferred embodiment, the seed layer 71 of the protective structure is made of titanium, and the first metal layer 72 is made of copper. Considering the cost and processing efficiency of titanium, the titanium layer is made to a thickness of only 0.2 μm, and the rest is made of electroplated copper, which saves costs and improves production efficiency.

[0067] Based on the above embodiments, optionally, refer to Figure 3 The dimension of the protective structure 70 along the first direction X is less than or equal to 5 μm; the dimension of the protective structure 70 along the direction from the first sub-plate 10 to the second sub-plate 30 is greater than or equal to 3 μm.

[0068] The protective structure 70 has a dimension of less than or equal to 5 μm along the first direction X, meaning the cavity 50 has a dimension of less than or equal to 5 μm along the first direction X. Depending on the size of the cavity, different local structural features can be exhibited, ensuring that the first groove 41 and the photosensitive medium layer 40 are not damaged. The protective structure 70 has a dimension of greater than or equal to 3 μm along the direction from the first sub-plate 10 to the second sub-plate 30. This dimension depends on the precision of the device opening the cavity 50 and can be designed independently, with a minimum dimension of 3 μm. The protective structure 70 can protect the metal layer and photosensitive medium layer 40 of the first sub-plate 10 exposed by the first groove 41 from damage.

[0069] Based on the above embodiments, optionally, Figure 5 This is a top view of the structure of a photosensitive medium layer provided in an embodiment of the present invention, with reference to... Figure 5 The cross-sectional shape of the first groove 41 along the first direction X includes at least one of a circle, a triangle, a quadrilateral, and an ellipse.

[0070] In this process, a first groove 41 is fabricated in the photosensitive dielectric layer 40 using circuit technology. The shape of the first groove 41 can match the shape of the pins of the electronic components. The first groove 41 of any shape can be fabricated. If the packaging structure needs to package multiple electronic components with different pins, then the first groove 41 can be set with different shapes to match the pins of different electronic components.

[0071] Based on the above embodiments, optionally, refer to Figure 1 The first distance D1 between the surface of the photosensitive medium layer 40 away from the first sub-plate 10 and the surface of the first sub-plate 10 away from the second sub-plate 30 is less than the second distance D2 between the surface of the first medium layer 20 away from the first sub-plate 10 and the surface of the first sub-plate 10 away from the second sub-plate 30.

[0072] Wherein, the first distance D1 is less than the second distance D2, such that the surface of the photosensitive dielectric layer 40 away from the first sub-board 10 is lower than the surface of the first dielectric layer 20 away from the first sub-board 10. When forming the pins of the electronic components in the first groove 41 in the photosensitive dielectric layer 40, electrical connections between the pins and the second metal layer 11 in the first sub-board 10 or the second sub-board 30 caused by process errors can be avoided, thus preventing the reliability of the device from being affected. The first dielectric layer 20 is only a connection bridge for embedded electronic components, and the number of layers in the first sub-board 10 and the second sub-board 30 can be set according to requirements.

[0073] Based on the above embodiments, optionally, refer to Figure 1The first sub-board 10 and the second sub-board 30 each include at least two second metal layers 11 and at least one second dielectric layer 12, with a second dielectric layer 12 disposed between two adjacent second metal layers 11; the second dielectric layer 12 is provided with at least one blind via 13, and two adjacent second metal layers 11 are electrically connected through the blind via 13; the second metal layer 11 of the first sub-board 10 adjacent to the second sub-board 30 includes a second groove 14, which penetrates the second metal layer 11 of the first sub-board 10 adjacent to the second sub-board 30; the photosensitive dielectric layer 40 fills the second groove 14 and covers a portion of the second metal layer 11 of the first sub-board 10 adjacent to the second sub-board 30.

[0074] In this embodiment, the vertical projection of the first groove 41 on the second surface of the first sub-board can overlap with the vertical projection of the blind via on the second surface of the first sub-board, thereby enabling electrical connection. The portions of the first sub-board 10 and the second sub-board 30 that contact the first dielectric layer 20 are both second metal layers 11, on which conductive lines can be fabricated. The number of layers in the first sub-board 10 and the second sub-board 30 can be set according to requirements; in either the first sub-board 10 or the second sub-board 30, the total number of second metal layers 11 is one more than the total number of second dielectric layers; this embodiment of the invention does not impose specific limitations. For example, in... Figure 1 In the first sub-board 10, there are two second metal layers 11 and one second dielectric layer 12, with the second dielectric layer 12 located between the two second metal layers 11; the second sub-board 30 includes three second metal layers 11 and two second dielectric layers 12, with one second dielectric layer 12 disposed between two adjacent second metal layers 11.

[0075] Based on the above embodiments, this invention provides a method for preparing a packaging structure, used to prepare the packaging structure described in any embodiment of this invention. Figure 6 This is a flowchart of a method for preparing a packaging structure according to an embodiment of the present invention. Figures 7-13 This is a schematic diagram of an intermediate structure of another packaging structure provided in an embodiment of the present invention, for reference. Figure 6 The preparation methods include:

[0076] S110, Form a first sub-board; the first sub-board includes a first surface and a second surface that are disposed opposite to each other.

[0077] Among them, reference Figure 7The first sub-board 10 includes at least two second metal layers 11 and at least one second dielectric layer 12, with a second dielectric layer 12 disposed between two adjacent second metal layers 11. The second dielectric layer 12 has at least one blind via 13, and adjacent second metal layers 11 are electrically connected through the blind via 13. The second metal layer 11 closest to the second sub-board 30 in the first sub-board 10 includes a second groove 14, which penetrates the second metal layer 11 closest to the second sub-board 30 in the first sub-board 10. A second metal layer 11 can be formed on one surface of the second dielectric layer 12, with a blind via 13 formed in the second dielectric layer. Then, a second metal layer 11 is formed on the other surface opposite to the first surface, filling the blind via 13, and the second groove 14 is etched into the second metal layer 11 on the other surface.

[0078] S120, A photosensitive medium layer is formed on the side of the first surface away from the second surface; the photosensitive medium layer covers a portion of the first sub-plate; the photosensitive medium layer includes a first groove, the first groove penetrates the photosensitive medium layer and exposes a portion of the first surface; the surface of the photosensitive medium layer away from the first sub-plate is flush with the first surface exposed by the first groove.

[0079] Among them, reference Figure 8 First, a photosensitive medium material layer 401 can be formed through a lamination process. This photosensitive medium material layer is a photosensitive material, and its thickness can be controlled, making the thickness of the photosensitive medium material layer 401 controllable. Then, the photosensitive medium material layer 401 can be etched using circuit processing, thereby forming… Figure 9 The photosensitive dielectric layer 40 has a structure including a first groove 41. The cross-sectional shape of the first groove 40 along a first direction includes at least one of a circle, a triangle, a quadrilateral, and an ellipse.

[0080] S130, A protective structural material layer is formed on the side of the photosensitive medium layer away from the first sub-plate; the protective structural material layer covers the photosensitive medium layer and the bottom and sidewalls of the first groove.

[0081] Among them, reference Figure 10The protective structural material layer may include a seed layer 71 and a first metal layer 72 stacked together, with the first metal layer 72 located on the side of the seed layer 71 away from the first sub-plate 10. The seed layer 71 is made of any one of titanium, tin, nickel, titanium-tungsten alloy, titanium nitride, silicon dioxide, silicon nitride, silicon carbide, polytetrafluoroethylene, amorphous silicon, amorphous boron, and amorphous carbon. The first metal layer 72 is made of any one of copper, aluminum, and tungsten. The protective structural material layer can be a two-layer structure formed using sputtering and electroplating processes, or it can be prepared using other processes. If the protective structural material layer is a single-layer structure, it can be formed using sputtering or electroplating processes. The material of the protective structural material layer 701 is different from the material of the first sub-plate 10; specifically, the material of the protective structural material layer 701 is different from the material of the second metal layer 11 of the first sub-plate 10.

[0082] S140. A first dielectric material layer is formed on the side of the protective structural material layer away from the first sub-plate; the first dielectric material layer covers a portion of the first sub-plate and the protective structural material layer.

[0083] S150, a second sub-board material layer is formed on the side of the first dielectric material layer away from the first sub-board; the second sub-board material layer covers the first dielectric material layer.

[0084] Among them, reference Figure 11 A first dielectric material 201 and a second sub-board material layer 301 are formed by a lamination process. The second sub-board material layer 301 includes at least two second metal layers 11 and at least one second dielectric layer 12, with a second dielectric layer 12 disposed between two adjacent second metal layers 11; the second dielectric layer 12 is provided with at least one blind hole 13, and two adjacent second metal layers 11 are electrically connected through the blind hole 13.

[0085] S160. The protective structural material layer, the first dielectric material layer, and the second sub-plate material layer are processed to form a cavity, forming the first dielectric layer and the second sub-plate; the cavity extends from the surface of the second sub-plate away from the first sub-plate to the photosensitive dielectric layer; the first dielectric layer at least partially covers the first sub-plate; the second sub-plate covers the first dielectric layer.

[0086] Among them, reference Figure 12 The material of the second and first dielectric layers can be removed first using a segmented grooving method. This method combines mechanical depth control with laser ablation, which can improve processing efficiency. (Reference) Figure 13 Then, a selective etching process is used to remove the protective structural material layer.

[0087] Optionally, the first distance between the surface of the photosensitive medium layer away from the first sub-board and the surface of the first sub-board away from the second sub-board is less than the second distance between the surface of the first medium layer away from the first sub-board and the surface of the first sub-board away from the second sub-board.

[0088] S170. At least one electronic component is formed in the cavity, the at least one electronic component is located in the cavity, and the at least one electronic component is electrically connected to the first sub-board through the first groove.

[0089] At least one electronic component can be formed inside the cavity through a welding process.

[0090] The packaging structure fabrication method provided by the technical solution of this invention involves a first groove penetrating the photosensitive dielectric layer and exposing a portion of the first surface. Because the height of the photosensitive dielectric layer is controllable, the depth of the first groove can be precisely controlled, greatly improving the slotting accuracy of the packaging structure. The surface of the photosensitive dielectric layer away from the first sub-board is flush, and the exposed portion of the first surface of the first groove is also flush, achieving coplanarity of the surface of the photosensitive dielectric layer away from the first sub-board and the coplanarity of the first surface exposed at the bottom of the first groove. When at least one electronic component is electrically connected to the first sub-board through the first groove, the unevenness of the height of the photosensitive dielectric layer and the first surface will not affect the reliability of the electrical connection, thereby improving the packaging quality and production efficiency of the packageable structure and enhancing its reliability. This invention, by fabricating a composite structure of a photosensitive dielectric layer and a protective structural material layer, overcomes the physical limits of mechanical depth control, achieving the advanced packaging requirements for high precision, high coplanarity, high quality, and high efficiency. It is applicable to both entire boards and localized areas, and can achieve the aforementioned standards for slotting depth control accuracy. The final structure can be customized according to actual product requirements, retaining the shape of the first groove, filling the first groove, embedding electronic components, etc., and has a wide range of practical applications.

[0091] Based on the above embodiments, optionally, the protective structural material layer, the first dielectric material layer, and the second sub-plate material layer are processed to form a cavity, thereby forming the first dielectric layer and the second sub-plate, including:

[0092] The first dielectric material layer and the second sub-plate material layer are processed to form the first dielectric layer and the second sub-plate. The protective structure material layer is processed to form a cavity, the size of which along the first direction is equal to the size of the photosensitive dielectric layer along the first direction. Alternatively, the first dielectric material layer and the second sub-plate material layer are processed to form the first dielectric layer and the second sub-plate. The protective structure material layer is processed to form a cavity and a protective structure, the size of which along the first direction is smaller than the size of the photosensitive dielectric layer along the first direction. The first dielectric layer covers the protective structure and part of the first sub-plate. The first direction is perpendicular to the direction from the first sub-plate to the second sub-plate.

[0093] In the process of forming the cavity, the first dielectric layer, and the second sub-plate, if the dimension of the cavity along the first direction is equal to the dimension of the photosensitive dielectric layer along the first direction, the materials of the second dielectric layer and the first dielectric layer can be removed first by a segmented grooving method, and then the protective structural material layer can be completely removed using a selective etching process to form... Figure 1 The structure in the middle. Alternatively, when forming the cavity, the first dielectric layer, and the second sub-plate, if the size of the cavity along the first direction is smaller than the size of the photosensitive dielectric layer along the first direction, the material of the second dielectric layer and the first dielectric layer can be removed first by a segmented grooving method, and then a portion of the protective structure material layer can be removed using a selective etching process to form a protective structure, thereby forming Figure 3 The structure has a dimension of less than or equal to 5 μm along the first direction; and a dimension of greater than or equal to 3 μm along the direction from the first sub-plate to the second sub-plate.

[0094] Based on the above embodiments, optionally, a protective structural material layer is formed on the side of the photosensitive medium layer away from the first sub-board, including: forming a seed layer on the side of the photosensitive medium layer away from the first sub-board by a sputtering process; the seed layer covering a portion of the photosensitive medium layer; and forming a first metal layer on the side of the seed layer away from the first sub-board by an electroplating process, the first metal layer covering the seed layer.

[0095] The above method is used to prepare a two-layer protective structure, which includes a seed layer and a first metal layer stacked together. The first metal layer is located on the side of the seed layer away from the first daughter plate. The seed layer partially covers the photosensitive dielectric layer, and the first metal layer covers the seed layer. Sputtering and electroplating processes are used, which are mature and simple.

[0096] The method for preparing the packaging structure provided in this embodiment of the invention has the same beneficial effects as the packaging structure described in any embodiment of the invention.

[0097] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and no limitation is imposed herein.

[0098] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for preparing a packaging structure, characterized in that, include: A first sub-board is formed; the first sub-board includes a first surface and a second surface disposed opposite to each other; A photosensitive medium layer is formed on the side of the first surface away from the second surface; The photosensitive medium layer covers a portion of the first sub-plate; the photosensitive medium layer includes a first groove that penetrates the photosensitive medium layer and exposes a portion of the first surface; the surface of the photosensitive medium layer away from the first sub-plate is flush with the exposed portion of the first surface. A protective structural material layer is formed on the side of the photosensitive medium layer away from the first sub-plate; the protective structural material layer covers the photosensitive medium layer and the bottom and sidewalls of the first groove; A first dielectric material layer is formed on the side of the protective structural material layer away from the first sub-plate; The first dielectric material layer covers a portion of the first sub-board and the protective structural material layer; A second sub-board material layer is formed on the side of the first dielectric material layer away from the first sub-board; The second sub-board material layer covers the first dielectric material layer; The protective structural material layer, the first dielectric material layer, and the second sub-plate material layer are processed to form a cavity, thereby forming the first dielectric layer and the second sub-plate; the cavity extends from the surface of the second sub-plate away from the first sub-plate to the photosensitive dielectric layer; the first dielectric layer at least partially covers the first sub-plate; the second sub-plate covers the first dielectric layer. At least one electronic component is formed within the cavity, the at least one electronic component is located within the cavity, and the at least one electronic component is electrically connected to the first sub-board through the first groove.

2. The preparation method according to claim 1, characterized in that, Processing the protective structural material layer, the first dielectric material layer, and the second sub-plate material layer to form a cavity, thereby forming the first dielectric layer and the second sub-plate, includes: The first dielectric material layer and the second sub-plate material layer are processed to form a first dielectric layer and a second sub-plate. The protective structure material layer is processed to form a cavity, the dimension of which along a first direction is equal to the dimension of which along the first direction is the same as that of which the photosensitive dielectric layer is. Alternatively, the first dielectric material layer and the second sub-plate material layer are processed to form a first dielectric layer and a second sub-plate. The protective structure material layer is processed to form a cavity and a protective structure, the dimension of which along the first direction is smaller than that of which along the first direction is the same as that of which the photosensitive dielectric layer is. The first dielectric layer covers the protective structure and part of the first sub-plate. The first direction is perpendicular to the direction from which the first sub-plate points to the second sub-plate.

3. The preparation method according to claim 1, characterized in that, A protective structural material layer is formed on the side of the photosensitive dielectric layer away from the first sub-plate, comprising: A seed layer is formed on the side of the photosensitive medium layer away from the first sub-plate by a sputtering process; the seed layer covers a portion of the photosensitive medium layer; A first metal layer is formed on the side of the seed layer away from the first daughter plate by an electroplating process, and the first metal layer covers the seed layer.

4. A packaging structure, prepared using the packaging structure preparation method as described in any one of claims 1-3, characterized in that, include: The first sub-board includes a first surface and a second surface disposed opposite to each other; A photosensitive medium layer is located on the side of the first surface away from the second surface, and the photosensitive medium layer covers a portion of the first sub-plate; the photosensitive medium layer includes a first groove that penetrates the photosensitive medium layer and exposes a portion of the first surface; the surface of the photosensitive medium layer away from the first sub-plate is flush with the exposed portion of the first surface by the first groove. A first dielectric layer is located on the side of the first surface away from the second surface; the first dielectric layer at least covers a portion of the first sub-board. The second sub-board is located on the side of the first dielectric layer away from the first sub-board; the second sub-board covers the first dielectric layer; A cavity extending from the surface of the second sub-plate away from the first sub-plate to the photosensitive medium layer; At least one electronic component is located within the cavity and is electrically connected to the first sub-board via the first groove.

5. The packaging structure according to claim 4, characterized in that, The dimension of the cavity along the first direction is equal to the dimension of the photosensitive medium layer along the first direction; or, The dimension of the cavity along the first direction is smaller than the dimension of the photosensitive medium layer along the first direction; The encapsulation structure further includes: a protective structure located between the first dielectric layer and the photosensitive dielectric layer; the first dielectric layer covers the protective structure and a portion of the first sub-board; Wherein, the first direction is perpendicular to the direction from the first sub-board to the second sub-board.

6. The packaging structure according to claim 5, characterized in that, The protective structure is a single-layer structure, and the material of the protective structure is different from that of the first sub-board; or, the protective structure includes a seed layer and a first metal layer stacked together, the first metal layer being located on the side of the seed layer away from the first sub-board; the seed layer covers a portion of the photosensitive medium layer; the first metal layer covers the seed layer; The seed layer material includes any one of titanium, tin, nickel, titanium-tungsten alloy, titanium nitride, silicon dioxide, silicon nitride, silicon carbide, polytetrafluoroethylene, amorphous silicon, amorphous boron, and amorphous carbon. The material of the first metal layer includes any one of copper, aluminum, and tungsten; The material of the photosensitive medium layer is a photosensitive material.

7. The packaging structure according to claim 5, characterized in that, The dimension of the protective structure along the first direction is less than or equal to 5 μm; The dimension of the protective structure along the direction from the first sub-plate to the second sub-plate is greater than or equal to 3 μm.

8. The packaging structure according to claim 4, characterized in that, The cross-sectional shape of the first groove along the first direction includes at least one of a circle, a triangle, a quadrilateral, and an ellipse.

9. The packaging structure according to claim 4, characterized in that, The first distance between the surface of the photosensitive medium layer away from the first sub-plate and the surface of the first sub-plate away from the second sub-plate is less than the second distance between the surface of the first medium layer away from the first sub-plate and the surface of the first sub-plate away from the second sub-plate.

10. The packaging structure according to claim 4, characterized in that, Both the first sub-board and the second sub-board include at least two second metal layers and at least one second dielectric layer, with a second dielectric layer disposed between two adjacent second metal layers; The second dielectric layer is provided with at least one blind via, and two adjacent second metal layers are electrically connected through the blind via; The second metal layer in the first sub-board that is closest to the second sub-board includes a second groove, the second groove penetrating the second metal layer in the first sub-board that is closest to the second sub-board; the photosensitive dielectric layer fills the second groove and covers a portion of the second metal layer in the first sub-board that is closest to the second sub-board.

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