Method for embedding semiconductor crystal and PCB

Abstract

The invention discloses a method for embedding a semiconductor crystal and a PCB, and the method for embedding the semiconductor crystal comprises the steps: providing an assembly body wrapped with the semiconductor crystal and at least one core plate; forming at least one through groove of which the size is the same as that of the assembly body on a plate formed by pressing a single core plate or a plurality of core plates; and the assembly body is placed in the through groove, and a layer of prepreg is attached to the surfaces of the two opposite sides of the plate so that the assembly body can be packaged in the plate to form a part to be assembled. Through the method, the PCB with the radioactive ray function is realized.

Description

Technical Field

[0001] The invention relates to the technical field of circuit boards, and in particular to a method for embedding semiconductor crystals and a PCB board. Background Art

[0002] Rays are particle beams or photon beams with specific energy emitted by various radioactive nuclides, or particles such as atoms, electrons, and neutrons during the energy exchange process. Common ones include α rays, β rays, γ rays, X-rays, and neutron rays.

[0003] In scenarios such as medical, industrial control, and security that require exposure to radiation, in order to achieve radiation protection, it is often necessary to use thicker metal plates, such as lead plates, to block X-rays. However, for electronic equipment, it is more difficult to provide radiation protection. Under extreme conditions, radiation may damage electronic equipment or chips.

[0004] Semiconductor crystals have good radiation absorption capabilities. Radiation will generate electron-hole pairs in semiconductors. Since crystals absorb all radiation particle flows and convert them into electrical signals, they cannot be penetrated by radiation and thus have radiation protection. Therefore, how to embed semiconductor crystals into PCB boards to improve product reliability has become a technical problem that needs to be solved. Summary of the invention

[0005] In order to solve the technical problem in the prior art that electronic equipment is easily damaged by radiation, the present application proposes a method for embedding semiconductor crystals and a PCB board.

[0006] In order to solve the above technical problems, the present application provides a method for burying a semiconductor crystal, comprising: providing an assembly wrapped with the semiconductor crystal and at least one core board; opening at least one through groove with the same size as the assembly on a plate formed by pressing a single core board or multiple core boards together; placing the assembly in the through groove, and laminating a layer of semi-cured sheet on the opposite side surfaces of the plate to encapsulate the assembly in the plate to form a part to be assembled.

[0007] Among them, the step of providing an assembly wrapped with the semiconductor crystal specifically includes: providing a core plate with a thickness not less than the thickness of the semiconductor crystal; opening a groove on the core plate, and placing the semiconductor crystal in the groove of the core plate; using glue to fix the semiconductor crystal to the inner wall of the groove to form the assembly; wherein the glue contains a conductive medium.

[0008] Wherein, before placing the assembly in the through groove, the method further comprises: coating four walls of the through groove with a heat insulating material.

[0009] Wherein, the semiconductor crystal includes cadmium telluride or cadmium zinc telluride, and the hardness of the semiconductor crystal is not greater than 3.

[0010] Among them, the step of opening at least one through groove with the same size as the assembly on a plate formed by pressing a single core plate or multiple core plates includes: selecting a core plate with a thickness not less than the thickness of the assembly, and opening a through groove with the same size as the assembly on the core plate; or, pressing multiple core plates into a plate with a thickness not less than the assembly, and opening a through groove with the same size as the assembly on the plate.

[0011] Among them, after the step of placing the assembly in the through groove of the board and laminating a layer of semi-cured sheet on the opposite side surfaces of the board to encapsulate the assembly in the board to form a part to be assembled, it also includes: symmetrically pressing a multi-layer core board on the opposite side surfaces of the part to be assembled to obtain a PCB board with radiation protection function.

[0012] Among them, after the step of symmetrically pressing the multi-layer core board on the opposite side surfaces of the part to be assembled to obtain a PCB board with radiation protection function, it also includes: arranging components on the bottom surface of the PCB board that overlap with the semiconductor crystal in a direction perpendicular to the PCB board to prevent the components from being damaged by radiation passing through the surface of the PCB board; wherein the bottom surface and the surface are the opposite side surfaces of the PCB board.

[0013] Among them, before the step of symmetrically pressing the multi-layer core board on the opposite side surfaces of the assembly to be assembled, it includes: etching vias on the surface of the semi-cured sheet at positions corresponding to the assembly body, and making a circuit copper layer on the surface of the semi-cured sheet so that the circuit copper layer is electrically connected to the semiconductor crystal through the vias.

[0014] Among them, the step of symmetrically pressing the multi-layer core board on the opposite side surfaces of the part to be assembled also includes: pressing the functional core board on one side surface of the part to be assembled and pressing the ordinary core board on the other side surface; wherein the functional core board is arranged on the side close to the component.

[0015] In order to solve the above technical problems, the present application also provides a PCB board, which includes a board formed by pressing together multiple layers of core boards, wherein at least one through groove is provided in the board, and the through groove is filled with an assembly encapsulating a semiconductor crystal, and semi-cured sheets are adhered to the two surfaces of the board corresponding to the through groove.

[0016] The beneficial effect of the present application is: by first placing the semiconductor crystal in the assembly part, and then placing the assembly part in the through groove of the inner core board of the PCB board, and attaching the semi-cured sheet on the opposite sides of the core board, the assembly wrapped with the semiconductor crystal is encapsulated in the inner board of the PCB board, so that a radiation-resistant PCB board can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of a process flow of an embodiment of a semiconductor crystal embedding method provided in the present application;

[0019] Figure 2 For this application Figure 1 A flowchart of a specific embodiment of step S11;

[0020] Figure 3 A schematic diagram of the process of burying a semiconductor crystal in another specific embodiment of the present application;

[0021] Figure 4 This is a schematic diagram of the structure of an embodiment of a PCB board of the present application;

[0022] Figure 5 This is a schematic structural diagram of a specific embodiment of a PCB board of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "said", and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless otherwise clearly indicated above, and "multiple" generally includes at least two, but does not exclude the inclusion of at least one.

[0025] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0026] It should be understood that the terms "include", "comprises" or any other variations used herein are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "includes..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0027] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The presence of the phrase at each location in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] This application provides a method for embedding a semiconductor crystal. Figure 1 , Figure 1 This is a flow chart of an embodiment of the semiconductor crystal embedding method provided by the present application. Figure 1 As shown, including:

[0030] Step S11: providing an assembly encapsulating a semiconductor crystal and at least a plurality of core boards.

[0031] The assembly can be made of a core board, and the assembly can be made of metals such as copper, aluminum, and iron, or insulating materials such as ceramics and glass, or organic materials such as epoxy resin, which are not specifically limited here. The semiconductor crystal can be a semiconductor crystal composed of cadmium telluride or cadmium zinc telluride and similar substances.

[0032] The core board is the base board of the PCB board, and the PCB board can be formed by pressing multiple core boards together. The core board can specifically include a resin layer and a circuit copper layer located on both sides of the resin layer, which is not specifically limited here.

[0033] Step S11 specifically includes: Steps S21 to S23. Figure 2 , Figure 2 For this application Figure 1 FIG. 1 is a flow chart of a specific embodiment of step S11 in FIG.

[0034] Step S21: Provide a core board having a thickness not less than that of a semiconductor crystal.

[0035] The core board may be the core board in step S11. The core boards include a plurality of core boards, from which a core board having a thickness not less than that of the semiconductor crystal is selected.

[0036] Step S22: Open a groove on the core board and place the semiconductor crystal in the groove of the core board.

[0037] The size of the groove is not less than the size of the semiconductor crystal, so that the semiconductor crystal can be accommodated in the groove.

[0038] Step S23: fix the semiconductor crystal to the inner wall of the groove using glue to form an assembly.

[0039] This step specifically includes using flowing glue to fill the space between the groove and the semiconductor crystal, thereby fixing the semiconductor crystal to the inner wall of the groove after solidification, thereby forming an assembly to be embedded in the PCB board.

[0040] In a further embodiment, it also includes filling the surroundings and top of the semiconductor crystal with glue, and further arranging a cover plate on the top of the groove to package the semiconductor crystal in the core board at one time, which is not limited here.

[0041] The semiconductor crystal at least does not protrude from the surface of the assembly, thereby protecting the semiconductor crystal.

[0042] In a specific embodiment, the glue may contain a conductive medium, so that the glue also has a certain conductivity. When the semiconductor crystal is conductively connected to the core board through glue, and then the core board equipped with the semiconductor crystal is buried in another core board, the semiconductor crystal can be conductively connected to the outer core board of the PCB board through the conductive connection between the core boards, and the weak current generated on the semiconductor crystal after the radiation penetrates can be conducted out, eliminating the adverse effects of the current. It should be noted that the current generated by the radiation passing through the crystal is an effective electrical signal and needs to be transmitted.

[0043] In another specific embodiment, the glue may not contain a conductive medium, and the current may be conducted through other means.

[0044] Step S12: at least one through groove having the same size as the assembly is formed on a single core board or a panel formed by pressing a plurality of core boards together.

[0045] In one embodiment, when the thickness of a core plate is not less than the thickness of the assembly, it is not necessary to press multiple core plates together, and a core plate with the same thickness as the assembly (that is, the first core plate that wraps the semiconductor crystal) can be directly selected as the plate for processing. A first core plate and a second core plate with the same thickness are also selected, and the first core plate is processed (including reducing the cross-sectional area), a groove is made on the first core plate to place the semiconductor crystal to form the assembly, and a through groove is made on the second core plate to place the assembly. The lateral area of ​​the first core plate is smaller than the lateral area of ​​the second core plate.

[0046] In another specific embodiment, when the thickness of the core board is less than the thickness of the assembly, multiple core boards are pressed into a board with a thickness not less than that of the assembly, and a through groove with the same size as the assembly is opened on the board to accommodate the assembly. The thickness of the assembly can be less than the thickness of the board, and when the semi-cured sheet is attached, the excess through groove is filled by the semi-cured sheet during the subsequent pressing of the semi-cured sheet. At least the thickness of the assembly is not greater than the thickness of the board to prevent the assembly from protruding from the through groove and crushing the semiconductor crystal during the subsequent pressing of the semi-cured sheet. The semi-cured sheet is made of PP material and can be pressed. After pressing, the two core boards can be connected.

[0047] Step S13: placing the assembly in the through groove, and attaching a layer of prepreg to the two opposite sides of the plate to encapsulate the assembly in the plate to form a part to be assembled.

[0048] Before this step, or after step S12, a heat insulating material is coated on the four walls of the through groove to prevent the high temperature generated during the pressing process from damaging the semiconductor crystal, thereby achieving high temperature protection for the semiconductor crystal package.

[0049] In this embodiment, the assembly is placed in the through groove, and a layer of prepreg is attached to two opposite sides of the through groove, so that the assembly is encapsulated in the core board.

[0050] In another specific embodiment, before attaching the prepreg, the method further includes: setting a cover plate on one side of the plate close to (or provided with) the semiconductor crystal to encapsulate the semiconductor crystal in the core plate. Alternatively, the cover plate may not be set, and one side of the semiconductor crystal is encapsulated by the prepreg. Since the prepreg has a certain degree of softness (can undergo thermal deformation), the semiconductor crystal is prevented from being scratched by the printed plate.

[0051] The hardness of the semiconductor crystal is not greater than 3. The smaller the hardness, the easier it is to be brittle. In this way, the semiconductor crystal is encapsulated in the core board of the PCB board, thereby avoiding the destruction of the semiconductor crystal during the subsequent processing to form the PCB board.

[0052] After this step, the method further includes: symmetrically pressing a multilayer core board on the two opposite sides of the assembly to obtain a PCB board with radiation function. Specifically, the semiconductor crystal has a shielding effect on the device passing through it, so that the PCB board has a certain radiation protection function.

[0053] Since weak current will be generated after the radiation penetrates the semiconductor crystal, the step S13 also includes: etching a via hole on the surface of the prepreg at a position corresponding to the assembly, and making a circuit copper layer on the surface of the prepreg away from the assembly, so that the circuit copper layer is electrically connected to the semiconductor crystal through the via hole, thereby conducting the weak current generated on the semiconductor crystal to the outer layer of the PCB board through the circuit copper layer.

[0054] In other embodiments, the circuit copper layer can also be electrically connected to the surface of the core board / board, and then indirectly electrically connected to the semiconductor crystal in the assembly through the core board / board, so as to lead out the weak current on the semiconductor crystal, which is not limited here. In this embodiment, the semiconductor crystal is electrically connected to the surface copper layer of the second core board / board through the assembly.

[0055] This step is followed by: arranging components overlapping with the semiconductor crystal in a direction perpendicular to the PCB board on the bottom surface of the processed PCB board, thereby protecting the components from being damaged by radiation passing through the surface of the PCB board. The bottom surface and the surface are the opposite sides of the PCB board. Specifically, the components that need to be protected from radiation are arranged on a projection plane perpendicular to the semiconductor crystal.

[0056] Furthermore, a plurality of through grooves may be provided in the second core board / board member to place a plurality of assemblies, thereby encapsulating a plurality of semiconductor crystals, thereby providing radiation protection for a plurality of components of a plurality of PCB boards.

[0057] Furthermore, since the components arranged on the side close to the surface of the PCB board do not have radiation protection capabilities, therefore, in the process of symmetrically pressing the multi-layer core boards on the two opposite side surfaces of the part to be assembled, the functional core board can be pressed on one side surface of the part to be assembled, and the ordinary core board can be pressed on the other side surface. Among them, the functional core board (the difference between the functional core board and the ordinary core board is that the functional core board has a multi-layer circuit pattern connected to the component circuit, which is not limited here) is pressed on one side surface of the part to be assembled to form the bottom surface of the PCB board, and the ordinary core board is pressed on the other side surface to form the surface of the PCB board. That is, the above-mentioned components are arranged on the side surface provided with the functional core board.

[0058] This application also provides another method for embedding semiconductor crystals. For details, please refer to Figure 3 , Figure 3 This is a schematic diagram of another specific embodiment of the process of burying a semiconductor crystal in the present application. Figure 3 As shown, including:

[0059] Step S31: Provide a first core board.

[0060] The thickness of the first core plate is greater than the thickness of the semiconductor crystal.

[0061] Step S32: opening a groove on the first core board, and placing a semiconductor crystal in the groove of the first core board.

[0062] Wherein, a plurality of grooves may be provided on the first core plate, and a semiconductor crystal may be placed in each groove. After this step, the method further includes: cutting the first core plate to obtain a plurality of assemblies containing semiconductor crystals.

[0063] Step S33: using glue to fix the first semiconductor crystal to the inner wall of the groove to form an assembly.

[0064] Preferably, the glue is conductive glue.

[0065] Step S34: providing a second core board.

[0066] The second core plate may be a core plate with the same film structure and thickness as the first core plate, or a plate with a different material from the first core plate, or a common plate.

[0067] The second core board is the inner layer board of the PCB board. That is, the basic board for processing the PCB board. A complete PCB board can be formed by laminating multiple layers on the second core board. At least a circuit copper layer is arranged on the second core board.

[0068] Step S35: opening a through groove on the second core plate.

[0069] The through groove passes through the second core plate, and the thickness of the second core plate is not less than the thickness of the assembly.

[0070] Step S36: placing the assembly into the through groove of the second core plate.

[0071] The second core board may be provided with a plurality of through slots, so that a plurality of assemblies can be placed on the second core board, thereby expanding the radiation protection area of ​​the second core board, that is, expanding the radiation protection area of ​​the formed PCB board.

[0072] Step S37: prepregs are arranged on the opposite side surfaces of the through groove to encapsulate the assembly in the second core board to form a part to be assembled.

[0073] Among them, the semi-cured sheet is made of PP material, which can be thermally dissolved when heated, thereby bonding the multi-layer core board.

[0074] Step S38: symmetrically pressing the multi-layer core board on the two opposite sides of the assembly to obtain a PCB board with radiation protection function.

[0075] Step S39: Arrange components on one side of the PCB board that overlap with the semiconductor crystal in the vertical projection direction.

[0076] It is used to realize radiation protection of components. Specifically, components are placed on the bottom surface of the PCB board, so as to prevent radiation on the surface of the PCB board from penetrating the PCB board and causing radiation interference to the components on the bottom surface of the PCB board.

[0077] This application also provides a PCB board, please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of an embodiment of a PCB board of this application. Figure 4 As shown, the PCB board includes a board 41 formed by laminating multiple core boards, and at least one through slot 411 is provided in the board 41, and an assembly 402 covering a semiconductor crystal 401 is placed in the through slot 411. Prepregs 42 are respectively attached to the two opposite surfaces of the board 41 corresponding to the through slot 411. The assembly 402 is encapsulated in the through slot 411 of the board 41 through the prepreg 42, so that the semiconductor crystal 401 is placed in the through slot 411 of the PCB board, and the semiconductor crystal 401 is encapsulated and buffered by the assembly 402.

[0078] Furthermore, a heat insulating material 410 is coated around the through groove 411 , and the heat insulating material 410 is used to cover the assembly 402 to prevent the high temperature generated during the pressing process from damaging the semiconductor crystal 401 , thereby further providing a high temperature resistant buffer for the packaging of the semiconductor crystal 401 .

[0079] Furthermore, the present application also provides a complete PCB board. Figure 4 The PCB board in the picture is a semi-processed PCB board. Figure 5 , Figure 5 This is a schematic diagram of the structure of a specific embodiment of the PCB board of this application. Figure 5As shown, the surfaces of the prepreg sheets 42 on opposite sides of the plate 41 are respectively pressed with multi-layer core boards 43 to form a PCB board 40 of a specific thickness. Among them, a component 44 corresponding to the semiconductor crystal 401 is arranged on one side surface (that is, the bottom surface) of the PCB board 40. Specifically, the component 44 overlaps with the semiconductor crystal 401 on the vertical projection plane, that is, the component 44 is optimally located directly below the vertical projection plane of the semiconductor crystal 401, so that the semiconductor crystal 401 can shield the rays incident on the component 44.

[0080] Specifically, the multilayer core board 43 of the semiconductor crystal 401 on the side of the board 41 close to the component 44 includes at least a plurality of functional core boards, such as L7-L8, L9-L10, etc. It should be noted that the symbol "L" in the figure represents the circuit copper layer in the PCB board, and L1-L14 represents the first layer of circuit copper layer to the fourteenth layer of circuit copper layer in the PCB board, and one layer of copper layer can be a core board. In this specific embodiment, an ordinary core board is set on the side of the board 41 away from the component 44, and a functional core board and an ordinary core board are set on the side of the board 41 close to the component 44. In another specific embodiment, a plurality of functional core boards can also be set on the side of the board 41 away from the component 44, that is, the multilayer core board 43 is completely symmetrical. In this specific embodiment, a functional core board can be set on one side of the board 41 first, and then the board 41 is symmetrically pressed with an ordinary core board, which is not limited here.

[0081] The beneficial effect of the present application is: by first placing the semiconductor crystal in the assembly part, and then placing the assembly part in the through groove of the inner core board of the PCB board, and attaching the semi-cured sheet on the opposite sides of the core board, the assembly wrapped with the semiconductor crystal is encapsulated in the inner board of the PCB board, so that a radiation-resistant PCB board can be obtained.

[0082] The above are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for embedding a semiconductor crystal, characterized in that: include: Providing an assembly encapsulating the semiconductor crystal and at least one core board; At least one through groove having the same size as the assembly is provided on a single core plate or a plate formed by pressing a plurality of core plates together; The assembly is placed in the through groove, and a layer of prepreg is attached to the surfaces of two opposite sides of the plate, so as to encapsulate the assembly in the plate to form a part to be assembled.

2. The method for burying a semiconductor crystal according to claim 1, characterized in that: The step of providing an assembly encapsulating the semiconductor crystal specifically comprises: providing a core plate having a thickness not less than that of the semiconductor crystal; A groove is formed on the core plate, and the semiconductor crystal is placed in the groove of the core plate; The semiconductor crystal is fixed to the inner wall of the groove by glue to form the assembly; wherein the glue contains a conductive medium.

3. The method for burying a semiconductor crystal according to claim 1, characterized in that: Before placing the assembly into the through slot, the method further comprises: The four walls of the through groove are coated with heat insulating material.

4. The method for burying a semiconductor crystal according to claim 1, characterized in that: The semiconductor crystal includes cadmium telluride or cadmium zinc telluride, and the hardness of the semiconductor crystal is not greater than 3.

5. The method for burying a semiconductor crystal according to claim 1, characterized in that: The step of providing at least one through groove having the same size as the assembly on a single core plate or a plate formed by pressing a plurality of core plates comprises: Select a core plate with a thickness not less than that of the assembly, and open a through groove with the same size as the assembly on the core plate; or, A plurality of core plates are pressed into a plate member with a thickness not less than that of the assembly, and a through groove having the same size as that of the assembly is opened on the plate member.

6. The method for burying a semiconductor crystal according to claim 1, characterized in that: After the step of placing the assembly in the through groove of the plate and attaching a layer of prepreg to the two opposite sides of the plate to encapsulate the assembly in the plate to form a part to be assembled, the method further includes: The multi-layer core boards are symmetrically pressed on the two opposite side surfaces of the part to be assembled to obtain a PCB board with radiation protection function.

7. The method for burying a semiconductor crystal according to claim 6, characterized in that: After the step of symmetrically pressing the multi-layer core board on the two opposite sides of the assembly to obtain the PCB board with radiation protection function, the method further includes: Components overlapping with the semiconductor crystal in a direction perpendicular to the PCB are arranged on the bottom surface of the PCB to prevent the components from being damaged by radiation passing through the surface of the PCB; wherein the bottom surface and the surface are opposite side surfaces of the PCB.

8. The method for burying a semiconductor crystal according to claim 6, characterized in that: Before the step of symmetrically pressing the multi-layer core panels on the two opposite sides of the part to be assembled, the method includes: A via hole is etched on the surface of the prepreg at a position corresponding to the assembly, and a circuit copper layer is formed on the surface of the prepreg, so that the circuit copper layer is electrically connected to the semiconductor crystal through the via hole.

9. The method for burying a semiconductor crystal according to claim 7, characterized in that: The step of symmetrically pressing the multi-layer core board on the two opposite side surfaces of the part to be assembled also includes: A functional core board is pressed onto one side surface of the part to be assembled, and an ordinary core board is pressed onto the other side surface; wherein the functional core board is arranged on the side close to the components.

10. A PCB board, characterized in that: The PCB board includes a board formed by laminating multiple core boards, wherein at least one through groove is arranged in the board, and the through groove is filled with an assembly encapsulating a semiconductor crystal, and semi-cured sheets are attached to the two surfaces of the board corresponding to the through groove.

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