Manufacturing method of high-density inductor and capacitor embedded circuit board and circuit board

Abstract

The embodiment of the invention provides a manufacturing method of a high-density inductor and capacitor embedded circuit board module and a circuit board. The manufacturing method comprises the following steps: providing a core board; cutting the core board to form a cavity on the core board; arranging a plurality of embedded devices in the cavity, wherein the plurality of embedded devices are mutually spaced; filling the cavity with a flowing material at a plurality of positions at the same time so as to fill gaps among the plurality of embedded devices; and baking the core plate to cure the flowable material. The plurality of embedded devices are arranged in the single cavity of the core board, so that the integration level of the circuit board can be improved, and the miniaturization requirement of the circuit board can be met; and on the other hand, the cavity is filled with the flowing material at multiple positions at the same time to fix the multiple embedded devices, the filling amount of the material in unit time can be increased through simultaneous filling at the multiple positions, and the filling uniformity among different areas in the cavity is ensured, so that bubbles or cavities can be prevented from being generated in the flowing material, and the sealing performance of the embedded devices is improved. The stability of the circuit board is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit board packaging, in particular to a manufacturing method of high-density inductance-capacitance embedded circuit board and the circuit board. BACKGROUND

[0002] Embedding multiple inductors / capacitors in a PCB board (Embedded Passive Technology) is a key direction of electronic technology evolution, and its necessity mainly lies in the following five dimensions: high-density integration demand, high-frequency high-speed performance, high reliability, cost and process optimization, and emerging application scenarios. Currently, embedded passive components are the inevitable choice to meet the above-mentioned needs.

[0003] The current mature process is to embed a single capacitor or inductor in a PCB board. There is currently no complete and mature solution for embedding multiple inductors and capacitors in a PCB board. SUMMARY

[0004] The embodiments of the present application provide a manufacturing method of high-density inductance-capacitance embedded circuit board and the circuit board, which can meet the demand of miniaturization of the circuit board and improve the stability of the circuit board.

[0005] The embodiments of the present application provide a manufacturing method of high-density inductance-capacitance embedded circuit board, comprising: providing a core board; cutting the core board to form a cavity on the core board; disposing multiple embedded devices in the cavity, the multiple embedded devices being spaced apart from each other; simultaneously filling flowable material into the cavity at multiple positions to fill gaps between the multiple embedded devices; baking the core board to solidify the flowable material.

[0006] In some embodiments, the core board includes a first side, and the cavity has a first opening located at the first side, and the disposing multiple embedded devices in the cavity comprises: disposing an adhesive layer on the first side of the core board, the adhesive layer covering the first opening; sequentially and spacedly disposing multiple embedded devices on a side of the adhesive layer facing the cavity; After the baking the core board to solidify the flowable material, the method further comprises removing the adhesive layer.

[0007] In some embodiments, the core board further includes a second side opposite to the first side, and the cavity has a second opening located at the second side, and the simultaneously filling flowable material into the cavity at multiple positions comprises: a plurality of exhaust holes are arranged on the adhesive layer, the exhaust holes are located at the gaps between the plurality of embedded devices; a filling device is arranged on the second side of the core plate, the filling device covers the second opening, the filling device has a plurality of spaced filling ports; air in the cavity is extracted through the plurality of exhaust holes, so that a vacuum is formed in the cavity; the cavity is filled with a flowable material through the plurality of filling ports of the filling device at the same time.

[0008] In some embodiments, the core plate includes a substrate and a conductor layer arranged on the substrate, and before the core plate is cut to form a cavity on the core plate, the method further includes: the conductor layer is patterned to form a ring-shaped metal structure around the periphery of the cavity.

[0009] In some embodiments, the core plate is cut to form a cavity on the core plate, including: the core plate is drilled to form a positioning hole on the core plate; milling is performed with the positioning hole as a reference to form a cavity on the core plate.

[0010] Embodiments of the present application also provide a high-density inductance-capacitance embedded circuit board, which is manufactured by the manufacturing method described above, and includes: a core plate, the core plate has a cavity formed thereon; a plurality of embedded devices are arranged in the cavity at intervals, and the gaps between the plurality of embedded devices are filled with solidified flowable material.

[0011] In some embodiments, the plurality of embedded devices include inductance and / or capacitance.

[0012] In some embodiments, the plurality of embedded devices are distributed in an array, and the distance between every two adjacent embedded devices is less than or equal to 0.5 mm.

[0013] In some embodiments, the core plate includes a substrate and a conductor layer arranged on the substrate, and the conductor layer forms a ring-shaped metal structure around the periphery of the cavity.

[0014] In some embodiments, the flowable material is resin, and the resin is filled with silica.

[0015] The manufacturing method of the high-density inductance and capacitance embedded circuit board and the circuit board provided by the embodiment of the present application can set multiple embedded devices in a single cavity of the core board, improve the integration of the circuit board, and meet the demand for miniaturization of the circuit board. On the other hand, the flowable material is filled into the cavity at multiple positions to fix the multiple embedded devices, the filling amount of the material per unit time is improved, and the uniformity of the filling in different regions in the cavity is ensured, so that the flowable material is prevented from generating bubbles or cavities, and the stability of the circuit board is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 The flowchart of the manufacturing method of the circuit board of the embodiment of the present application.

[0018] Figure 2 The schematic diagram of the lamination design in the manufacturing method of the circuit board of the embodiment of the present application.

[0019] Figure 3 The schematic diagram of setting the embedded device in the manufacturing method of the circuit board of the embodiment of the present application.

[0020] Figure 4 The schematic diagram of the patterning of the core board in the manufacturing method of the circuit board of the embodiment of the present application.

[0021] Among them, 100, circuit board; 10, core board; 101, base material; 102, conductor layer; 11, cavity; 20, embedded device; 30, flowable material; 40, exhaust hole; 50, gas guide hole. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] The manufacturing method of the circuit board provided by the embodiment of the present application is used to form a circuit board 100, which is a high-density inductance and capacitance embedded circuit board or a high-density inductance and capacitance embedded circuit board module. Referring to Figure 1 , Figure 1This is a schematic flowchart illustrating a method for manufacturing a circuit board according to an embodiment of this application. The manufacturing method includes the following steps: 210, providing 10 core boards; 220, The core board 10 is cut to form a cavity 11 on the core board 10; 230, multiple embedded devices 20 are arranged in the cavity 11, and the multiple embedded devices 20 are spaced apart from each other; 240, simultaneously fill the cavity 11 with fluid material 30 at multiple locations to fill the gaps between multiple embedded devices 20; 250, bake the core board 10 to cure the fluid material 30.

[0024] Please refer to the above. Figures 2 to 4 , Figure 2 This is a schematic diagram of the stacked design in the manufacturing method of this application embodiment. Figure 3 This is a schematic diagram illustrating the installation of an embedded device in the manufacturing method of an embodiment of this application. Figure 4 This is a schematic diagram of the core board patterning in the manufacturing method of this application embodiment.

[0025] Among them, such as Figure 2 As shown, a core board 10 is first provided, specifically a core board 10 with a thickness corresponding to that of the embedded device 20 as the embedding layer. The core board 10 can be a copper-clad laminate, specifically including a substrate 101 and a conductor layer 102 disposed on the substrate 101. The substrate 101 can be FR4 (epoxy fiberglass) or other high-frequency substrates, and the substrate 101 can be used to provide mechanical support; the conductor layer 102 can be electrolytic copper foil.

[0026] Subsequently, as Figure 2 As shown, the core board 10 is cut to form a cavity 11. For example, the cavity 11 can be formed by laser cutting or mechanical cutting.

[0027] Subsequently, as Figure 2 , Figure 3 and Figure 4 As shown, multiple embedded devices 20 are arranged within the cavity 11, spaced apart from each other. For example, the number of embedded devices 20 is greater than or equal to five, and the multiple embedded devices 20 are arranged in an array. The spacing between any two adjacent embedded devices 20 is less than or equal to 0.5 mm. The single-sided length of the area formed by the multiple embedded devices 20 is 0.05-0.2 mm smaller than the single-sided length of the cavity 11. The distribution of the multiple embedded devices 20 is required to be in an array, meaning that the position angle of the multiple embedded devices 20 on the circuit board is only four: 0°, 90°, 180°, and 270°.

[0028] Subsequently, as Figure 2As shown, the flowable material 30 is filled into the cavity 11 at multiple positions to fill the gaps between the multiple embedded devices 20; the flowable material 30 is uniformly filled into the gaps between the multiple embedded devices 20 by screen printing, so as to improve the reliability, electrical performance and space utilization of the circuit board 100, and reduce the deviation of the embedded devices 20. For example, the flowable material 30 can be a resin material, and the process of filling the resin material into the gaps between the multiple embedded devices 20 is a resin mesh filling process, which forms a core plate resin dam design, can control the resin flow area, and reduce the risk of air bubbles. The general resin flowability and shrinkage rate cannot meet the gap filling requirements of embedding multiple embedded devices 20 in a large cavity and the deviation accuracy requirements of the embedded devices 20, so a resin with high flowability, low shrinkage rate, short gel time, high viscosity and other characteristics is required. According to the layout of the multiple embedded devices 20 and the distance between the multiple embedded devices 20 and the inner wall of the cavity 11, a ring array filling area is designed on the core plate 10 to improve the filling amount between the gaps. The gap between the multiple embedded devices 20 is filled with an organic resin material, which can be in a liquid, solid or semi-solid state, and can be filled with silica and other fillers to reduce the CTE (coefficient of thermal expansion) of the resin to within 50, so as to protect the embedded devices 20 from stress damage.

[0029] Finally, the core plate 10 is baked to effectively bake and remove moisture in the core plate 10, so that the flowable material 30 is solidified, and the manufacturing of the circuit board 100 is completed. Specifically, before embedding the multiple embedded devices 20 in the cavity 11, the core plate 10 is baked once to remove moisture in the core plate 10 by baking; then the multiple embedded devices 20 are embedded in the cavity 11, and the flowable material 30 is filled into the cavity 11 at multiple positions to fill the gaps between the multiple embedded devices 20, and the corresponding resin material is filled into the gaps between the multiple embedded devices 20 by using a true hole filling machine; after embedding the multiple embedded devices 20 in the cavity 11, the second baking is performed to solidify the flowable material 30 by baking; finally, the air bubbles and the deviation of the embedded devices 20 are inspected by ultrasonic wave, CT or slicing.

[0030] The present example can improve the integration of the circuit board 100 and meet the demand for miniaturization of the circuit board 100 when manufacturing the circuit board 100 by arranging multiple embedded devices 20 in a single cavity 11 of the core board 10. On the other hand, the multiple embedded devices 20 can be fixed by simultaneously filling the flowable material 30 into the cavity 11 at multiple positions. The simultaneous filling at multiple positions can improve the filling amount of the material per unit time and ensure the uniformity of the filling between different regions in the cavity 11, thereby avoiding the generation of bubbles or cavities in the flowable material 30 and improving the stability of the circuit board 100. The offset accuracy of the embedded devices 20 after embedding and lamination can be ensured, and the signal export can be ensured. Moreover, the subsequent manufacturing process design of the circuit board 100 can not be affected, and mass production operations can be performed. The present example also provides a feasible technical route for embedding other components such as chips in the subsequent process.

[0031] In some embodiments, the core board 10 includes a first side, and the cavity 11 has a first opening located on the first side. The multiple embedded devices 20 are arranged in the cavity 11. Specifically, a sticky layer (e.g., a tape) is first arranged on the first side of the core board 10, and the sticky layer covers the first opening. Then, the multiple embedded devices 20 are sequentially and spacedly arranged on the side of the sticky layer facing the cavity 11 (the embedded devices 20 are embedded into the cavity 11 by a chip mounter according to the data). In this way, the multiple embedded devices 20 are arranged in the cavity 11. Then, the flowable material 30 is filled into the cavity 11 at multiple positions to fill the gaps between the multiple embedded devices 20. Then, the core board 10 is baked to effectively remove the moisture in the core board 10 and solidify the flowable material 30. After the flowable material 30 is solidified, the sticky layer is removed by mechanical scraping or plasma cleaning, and the subsequent process is normally performed according to the data. For example, the flowable material 30 remaining on the surface of the embedded devices 20 is scraped off by a scraping brush to ensure the flatness of the surface of the circuit board 100. For another example, the circuit board 100 is cleaned by spraying a liquid by a plasma instrument to ensure the cleanliness of the circuit board 100. For another example, the sticky layer is manually torn off after being arranged on the circuit board 100 by a machine. In addition, the surface of the embedded devices 20 will inevitably have the flowable material 30 remaining during the processing. Therefore, the surface scraping problem of the embedded devices 20 needs to be solved. A resin protective layer can be uniformly coated on the surface of the core board 10 to protect the embedded devices 20 from being damaged during scraping. By adjusting the scraping parameters, a thin resin protective layer can be left on the surface of the embedded devices 20 to protect the embedded devices 20 without affecting the subsequent lamination.

[0032] In some embodiments, as shown in FIG. 6, the cavity 11 has a first opening located on the first side of the core board 10. The multiple embedded devices 20 are arranged in the cavity 11. Specifically, a sticky layer (e.g., a tape) is first arranged on the first side of the core board 10, and the sticky layer covers the first opening. Then, the multiple embedded devices 20 are sequentially and spacedly arranged on the side of the sticky layer facing the cavity 11 (the embedded devices 20 are embedded into the cavity 11 by a chip mounter according to the data). In this way, the multiple embedded devices 20 are arranged in the cavity 11. Then, the flowable material 30 is filled into the cavity 11 at multiple positions to fill the gaps between the multiple embedded devices 20. Then, the core board 10 is baked to effectively remove the moisture in the core board 10 and solidify the flowable material 30. After the flowable material 30 is solidified, the sticky layer is removed by mechanical scraping or plasma cleaning, and the subsequent process is normally performed according to the data. For example, the flowable material 30 remaining on the surface of the embedded devices 20 is scraped off by a scraping brush to ensure the flatness of the surface of the circuit board 100. For another example, the circuit board 100 is cleaned by spraying a liquid by a plasma instrument to ensure the cleanliness of the circuit board 100. For another example, the sticky layer is manually torn off after being arranged on the circuit board 100 by a machine. In addition, the surface of the embedded devices 20 will inevitably have the flowable material 30 remaining during the processing. Therefore, the surface scraping problem of the embedded devices 20 needs to be solved. A resin protective layer can be uniformly coated on the surface of the core board 10 to protect the embedded devices 20 from being damaged during scraping. By adjusting the scraping parameters, a thin resin protective layer can be left on the surface of the embedded devices 20 to protect the embedded devices 20 without affecting the subsequent lamination. Figure 2 and Figure 3As shown, the core plate 10 further comprises a second side opposite to the first side, the cavity 11 has a second opening on the second side, and the flowable material 30 is filled into the cavity 11 at multiple positions at the same time, specifically, first, a plurality of exhaust holes 40 are arranged on the adhesive layer (for example, the exhaust holes 40 are drilled on the adhesive layer according to the design by using a laser drilling machine, and in addition, a laser drilling air guide hole 50 is designed on the second side of the core plate 10 to facilitate air communication up and down during vacuumizing, so as to avoid the formation of air bubbles in the gaps between the plurality of embedded devices 20), and the exhaust holes 40 are located at the gaps between the plurality of embedded devices 20, so that the flowable material 30 can be filled in the gaps to avoid air bubbles. Subsequently, a filling device is arranged on the second side of the core plate 10, the filling device covers the second opening, and the filling device has a plurality of spaced filling ports, so that the flowable material 30 can be filled into the gaps between the plurality of embedded devices 20 through the filling device. When the flowable material 30 is filled, first, the machine is used to extract the air in the cavity 11 through the plurality of exhaust holes 40, so as to form a vacuum in the cavity 11; and finally, the flowable material 30 is filled into the cavity 11 through the plurality of filling ports of the filling device at the same time, specifically, the flowable material 30 is filled into the gaps between the plurality of embedded devices 20, and the gaps between the embedded devices 20 and the cavity 11.

[0033] In some embodiments, as shown in Figure 2 and Figure 4 The core plate 10 comprises a substrate 101 and a conductor layer 102 arranged on the substrate 101, and the conductor layer 102 can be a copper foil, for example, an electrolytic copper foil. Before step 220, that is, before the core plate 10 is cut to form the cavity 11 on the core plate 10, the conductor layer 102 is patterned (for example, the conductor layer 102 can be patterned by exposure, etching and the like to form a circuit pattern), so that the conductor layer 102 forms an annular metal structure, and the annular metal structure is arranged around the periphery of the cavity 11, specifically, a copper sheet with a width of 0.1-0.5 mm and a thickness greater than or equal to 0.01 mm is designed at a position 0.5 mm inward from the boundary of the cavity 11, so as to facilitate the control of the flow area of the flowable material 30. In addition, the pattern can be browned to improve the recognition, for example, the surface is treated by a chemical agent to improve the surface roughness. Baking and curing + roughening can improve the bonding force of the flowable material 30, so as to ensure that the flowable material 30 can be normally cured and does not affect the subsequent process.

[0034] In some embodiments, the core plate 10 is cut to form the cavity 11, specifically, the core plate 10 is drilled to form a positioning hole on the core plate 10; and the positioning hole is used as a reference to mill a groove (for example, the cavity 11 is milled by a CCD machine) to form the cavity 11 on the core plate 10.

[0035] The embodiment of the present application further provides a high-density inductance-capacitance embedded circuit board 100, which can be applied to devices or systems such as power supply, control system, frequency converter and the like.

[0036] The circuit board 100 is manufactured by the manufacturing method in the above embodiment, and as shown in Figure 2 、 Figure 3 and Figure 4 , the circuit board 100 comprises a core board 10 and a plurality of embedded devices 20.

[0037] During installation, first, the cavity 11 is formed on the core board 10; the core board 10 can be a copper-clad board, and specifically comprises a base material 101 and a conductor layer 102 arranged on the base material 101; the base material 101 can be a single-layer circuit board or a multi-layer circuit board, and the base material 101 comprises at least one conductor layer 102, and the conductor layer 102 is formed with a circuit pattern. The base material 101 is formed with one cavity 11. The cavity 11 can be formed by laser cutting or mechanical cutting and the like. The shape, size and depth of the cavity 11 can be set according to requirements. In actual application, the cavity 11 can be a square cavity, and penetrates through the base material 101.

[0038] Subsequently, the plurality of embedded devices 20 are arranged at intervals in the cavity 11; the embedded devices 20 can be functional modules such as chips, antennas and the like, or electronic elements such as resistors, capacitors, inductors and the like. The plurality of embedded devices 20 are arranged in the cavity 11, and the plurality of embedded devices 20 are arranged at intervals. For example, the number of the embedded devices 20 is greater than or equal to five, and the plurality of embedded devices 20 are distributed in an array, and the interval between every two adjacent embedded devices 20 is less than or equal to 0.5 mm. The area formed by the plurality of embedded devices 20 has a single-side length which is 0.05-0.2 mm less than the single-side length of the cavity 11, and the distribution of the plurality of embedded devices 20 requires an array, i.e. the position angle of the plurality of embedded devices 20 in the circuit board is only 0°, 90°, 180° and 270°.

[0039] The gap between the plurality of embedded devices 20 is filled with the cured flowable material 30; specifically, the flowable material 30 is filled into the cavity 11 at multiple positions at the same time to fill the gap between the plurality of embedded devices 20; specifically, the flowable material 30 is uniformly filled into the gap between the plurality of embedded devices 20 by screen printing, so as to improve the reliability, electrical performance and space utilization of the circuit board 100, and reduce the deviation of the embedded devices 20. For example, the flowable material 30 can be a resin material, and the process of filling the gap between the plurality of embedded devices 20 with the resin material is a resin plug-in plate process, which forms a core plate resin dam design, can realize control of resin flow area, and reduce the risk of air bubbles. Among them, the general resin flowability and shrinkage rate cannot meet the gap filling requirements of embedding the plurality of embedded devices 20 in the large cavity and the deviation accuracy requirements of the embedded devices 20, so it is necessary to select a resin with high flowability, low shrinkage rate, short gel time, high viscosity and the like. Among them, according to the layout of the plurality of embedded devices 20 and the distance between the plurality of embedded devices 20 and the inner wall of the cavity 11, a ring array filling area is designed on the core plate 10 to improve the filling amount between the gaps. The gap between the plurality of embedded devices 20 is filled with an organic resin material, which can be in a liquid, solid or semi-solid state, and can be filled with silica and other fillers inside to reduce the CTE (coefficient of thermal expansion) of the resin to within 50, thereby protecting the embedded devices 20 from stress damage.

[0040] The core plate 10 is baked to effectively bake and remove moisture in the core plate 10, so that the flowable material 30 is cured, and the manufacturing of the circuit board 100 is completed. Specifically, before embedding the plurality of embedded devices 20 in the cavity 11, the core plate 10 is baked once to remove moisture in the core plate 10 by baking; then the plurality of embedded devices 20 are embedded in the cavity 11, and the flowable material 30 is filled into the cavity 11 at multiple positions at the same time to fill the gap between the plurality of embedded devices 20, and the corresponding resin material is filled into the gap between the plurality of embedded devices 20 by using a true hole plugging machine; after embedding the plurality of embedded devices 20 in the cavity 11, the second baking is performed to cure the flowable material 30 by baking; finally, the air bubbles and the deviation of the embedded devices 20 are inspected by ultrasonic wave, CT or slicing The example can improve the integration of the circuit board 100 and meet the demand of miniaturization of the circuit board 100 when the circuit board 100 is manufactured, and the plurality of embedded devices 20 are arranged in the single cavity 11 of the core board 10; on the other hand, the flowable material 30 is filled into the cavity 11 at multiple positions to fix the plurality of embedded devices 20, the filling amount of the material per unit time can be improved when the cavity 11 is filled at multiple positions, and the uniformity of filling between different areas in the cavity 11 is ensured, so that the bubbles or cavities in the flowable material 30 can be avoided, and the stability of the circuit board 100 is improved; the offset accuracy of the embedded device 20 after embedding and laminating can be ensured, and the signal export is ensured; moreover, the subsequent manufacturing process design of the circuit board 100 is not affected, and mass production operation can be performed; and a feasible technical route is provided for subsequent embedding of other components such as chips.

[0041] The principles and implementation manners of the present application are described by using specific examples in the present application, and the above description of the examples is only used to help understand the present application. Meanwhile, according to the idea of the present application, the specific implementation manners and application ranges will be changed by those skilled in the art, and the above description of the specification should not be understood as the limitation of the present application.

Claims

1. A method of manufacturing a high-density embedded inductor-capacitor circuit board, characterized by comprising: The method comprises: providing a core board; cutting the core board to form a cavity on the core board; arranging a plurality of embedded devices in the cavity, the plurality of embedded devices being spaced apart from each other; simultaneously filling the cavity with a flowable material at a plurality of positions to fill gaps between the plurality of embedded devices; and baking the core board to solidify the flowable material.

2. The production method according to claim 1, characterized by The core board comprises a first side, and the cavity has a first opening on the first side, and the arranging a plurality of embedded devices in the cavity comprises: arranging an adhesive layer on the first side of the core board, the adhesive layer covering the first opening; sequentially and spacedly arranging the plurality of embedded devices on a side of the adhesive layer facing the cavity; and after the baking the core board to solidify the flowable material, further comprising removing the adhesive layer.

3. The production method according to claim 2, wherein The core board further comprises a second side opposite to the first side, and the cavity has a second opening on the second side, and the simultaneously filling the cavity with a flowable material at a plurality of positions comprises: arranging a plurality of exhaust holes on the adhesive layer, the exhaust holes being located at the gaps between the plurality of embedded devices; arranging a filling device on the second side of the core board, the filling device covering the second opening, the filling device having a plurality of spaced filling ports; evacuating air in the cavity through the plurality of exhaust holes to form a vacuum in the cavity; and simultaneously filling the cavity with the flowable material through the plurality of filling ports of the filling device.

4. The production method according to any one of claims 1 to 3, characterized by, The core board comprises a substrate and a conductor layer arranged on the substrate, and before the cutting the core board to form a cavity on the core board, the method further comprises: patterning the conductor layer to form a ring-shaped metal structure around a periphery of the cavity.

5. The production method according to any one of claims 1 to 3, characterized by, The cutting the core board to form a cavity on the core board comprises: drilling a positioning hole on the core board; and milling a groove on the core board based on the positioning hole to form the cavity.

6. A high density embedded inductance capacitance circuit board, characterized by, The circuit board is manufactured by the manufacturing method of any one of claims 1 to 5, and the circuit board comprises: a core board having a cavity formed thereon; a plurality of embedded devices arranged in the cavity and spaced apart from each other, and gaps between the plurality of embedded devices being filled with solidified flowable material.

7. The circuit board of claim 6, wherein The plurality of embedded devices comprises inductors and / or capacitors.

8. The circuit board of claim 6, wherein, The plurality of embedded devices are arranged in an array, and a distance between every two adjacent embedded devices is less than or equal to 0.5 mm.

9. The circuit board of claim 6, wherein, The core board comprises a substrate and a conductor layer arranged on the substrate, and the conductor layer forms a ring-shaped metal structure around a periphery of the cavity.

10. The circuit board of claim 6, wherein, The flowable material is a resin, and the resin is filled with silica.

Images