CN106170176A - Buried magnetic core circuit board and manufacturing method thereof - Google Patents

Abstract

The invention discloses a circuit board with a buried magnetic core, which comprises a PCB (printed circuit board), a buried groove sunken towards the interior of the PCB and a magnetic core arranged in the buried groove, wherein the PCB comprises a plurality of copper plating layers which are sequentially overlapped from the bottom surface to the top surface of the PCB, and a PP (polypropylene) layer clamped between two adjacent copper plating layers, the copper plating layers comprise conductive through holes penetrating through the copper plating layers, the copper plating layers are more than 8, the copper thickness of each copper plating layer is 0.105mm in 1-6 layers, the magnetic core is buried in 1-8 layers of the PCB, and the top surface of the magnetic core is flush with the top surface of the PCB and is completely exposed out of the PCB. Compared with the prior art, the embedded magnetic core circuit board has stable performance and is suitable for miniaturization and high-density product design. The invention also provides a manufacturing method of the magnetic core embedded circuit board.

Description

Buried magnetic core circuit board and manufacturing method thereof

technical field

The invention relates to a circuit board, in particular to a magnetic core embedded circuit board and a manufacturing method thereof.

Background technique

As the Printed Circuit Board (PCB) industry, also known as the circuit board, enters the system-on-package (SOP) stage, PCB passive device buried technology has also become a hot research topic today. In the adjustment and development of automation progress, PCB is one of the key technologies, and all control systems need PCB as a carrier to realize electrical signal processing.

In related technologies, inductance is widely used in circuit board design. The physical meaning of the inductance through DC and AC resistance is to use the conductive coil to store the energy of the alternating magnetic field. The main function in the circuit is to provide inductive impedance. When cooperating with other related components Complete the corresponding matching, filtering, oscillation and other circuit functions.

Most of the inductors in the power supply part of the PCB need to be mounted manually, the production efficiency is low, and there are risks such as poor solder joints. In addition, the inductance element occupies more than 40% of the surface area of the power board, which is not conducive to the miniaturization and high density of product design.

Therefore, it is necessary to provide a new embedded magnetic core circuit board and its manufacturing method to solve the above technical problems.

Contents of the invention

The purpose of the present invention is to overcome the above technical problems, to provide a buried magnetic core circuit board with stable performance, suitable for miniaturization and high density of product design and its manufacturing method.

An embedded magnetic core circuit board, comprising a PCB main board, an embedding groove recessed to the inside of the PCB main board, and a magnetic core placed in the embedding groove, the PCB main board includes multiple layers from the bottom to the top surface The stacked copper-plated layer and the PP layer sandwiched between two adjacent layers of the copper-plated layer, the copper-plated layer includes a conductive through-hole that runs through it and is copper-plated on its inner side, and the copper-plated layer The layers are greater than 8 layers, and the copper thickness of each layer of the copper plating layer of the 1-6 layers is 0.105mm. The magnetic core is embedded between the copper plating layers of the 1-8 layers of the PCB main board, and the magnetic core The top surface of the core is not higher than the top surface of the PCB main board and is completely exposed to the PCB main board.

Preferably, the magnetic core is annular cylindrical or E-shaped.

Preferably, the size of the embedding groove and the size of the magnetic core differ by ±0.0762 mm.

Preferably, the size of the embedding groove corresponding to the 1-2 layers of the copper plating layer is 0.1016 mm larger than the size of the corresponding position of the magnetic core.

Preferably, the diameter of the conductive through hole is 0.5 mm, and the distance from the embedded groove is at least 0.18 mm.

Preferably, the copper plating thickness of the conductive via hole is greater than 78 μm at a single point.

Preferably, the thickness-to-diameter ratio of the copper plating of the conductive via hole is less than or equal to 11:1.

The present invention also provides a method for manufacturing the above-mentioned embedded magnetic core circuit board, the manufacturing method includes the following steps:

The magnetic core and the PCB main board to be embedded in the magnetic core are provided, and the PCB main board includes a multi-layer copper plating layer stacked sequentially from the bottom to the top surface and the plating layer sandwiched between two adjacent layers. The PP layer between the copper layers, the copper plating layer is greater than 8 layers;

Open the embedding groove, open the embedding groove on the PCB main board from the top surface of the PCB main board to its bottom surface direction, so that the embedding groove extends to the 8th layer of copper plating layer, and makes the embedding groove The size of the difference from the size of the magnetic core is ±0.0762mm;

Paste the metal sheet, attach a layer of metal sheet with an area larger than the area of the top surface of the magnetic core on the top surface of the magnetic core, and make the part of the metal sheet that exceeds the top surface of the magnetic core move away from the The direction of the magnetic core is bent to form a disassembly part;

Fixing the magnetic core, placing the magnetic core in the embedding groove, and fixing the magnetic core in the embedding groove through a lamination process with a pressure of 290-295 PSI;

Disassembling the metal sheet, tearing off the metal sheet through the disassembly part to remove the glue pasted on its surface, so that the top surface of the magnetic core is completely exposed;

Opening through holes, opening a plurality of through holes on the PCB main board, so that a plurality of through holes are arranged around the magnetic core, and the minimum distance between the through holes and the magnetic core is 0.18mm;

Copper plating on the through hole, copper plating in the through hole to form the conductive through hole, electrically connecting the conductive through hole to form a magnetic core winding, the thickness of copper plating at a single point is greater than 78 μm, and the buried magnetic core circuit is obtained plate.

Compared with the related art, the embedded magnetic core circuit board and its manufacturing method provided by the present invention embed the magnetic core inside the PCB main board, thereby improving the production efficiency of the manual mounting process, and thus eliminating the need for soldering. problem, avoiding the problem of poor solder joints, and improving the reliability of the resulting performance. The embedded structure saves a lot of area on the PCB surface of the power board, which is conducive to the miniaturization and high density of product design.

Description of drawings

Fig. 1 is the structural representation of buried magnetic core circuit board of the present invention;

Fig. 2 is a flow chart of the manufacturing method of the embedded magnetic core circuit board of the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Please refer to FIG. 1 , which is a schematic structural diagram of a buried magnetic core circuit board according to the present invention. The embedded magnetic core circuit board 10 provided by the present invention includes a PCB main board 1 , an embedding groove 2 recessed into the PCB main board 1 , and a magnetic core 3 placed in the embedding groove 2 .

The PCB main board 1 includes a multi-layer copper plating layer 11 stacked sequentially from the bottom to the top surface and a PP layer 12 sandwiched between two adjacent layers of the copper plating layer 11 for forming the copper plating layer 11. Insulation between layers 11. The copper plating layer 11 includes a conductive through hole 111 penetrating through it and plated with copper inside, for realizing the communication between the copper plating layers 11 . The copper plating layer 11 is more than 8 layers, and the copper thickness of the copper plating layer 11 in each layer of 1 to 6 layers is 0.105 mm. The magnetic core 3 is embedded in the 1 to 8 layers of the PCB main board 1, and the The top surface of the magnetic core 3 is not higher than the top surface of the PCB main board 1 and is completely exposed to the PCB main board 1 .

Specifically, the magnetic core 3 is annular cylindrical or E-shaped.

In this embodiment, the diameter of the conductive via 111 is 0.5 mm, and the distance from the conductive via 111 to the embedding groove 2 is at least 0.18 mm. The copper plating thickness of the conductive via 111 is greater than 75 μm at a single point. The thickness-to-diameter ratio of the copper plating of the conductive via hole 111 is less than or equal to 11:1.

The size of the embedding groove 2 is different from the size of the magnetic core 3 by ±0.0762mm. While meeting the requirements of smooth embedding, the glue filling is reduced as much as possible. The position of the embedding groove 2 corresponding to the first to second layers of the copper plating layer 11 is larger than the size of the corresponding position of the magnetic core 3 by 0.1016 mm. This structure prevents the influence of burrs and improves the product qualification rate .

Please refer to FIG. 2 , which is a flow chart of the manufacturing method of the embedded magnetic core circuit board of the present invention. The present invention also provides a method for manufacturing the above-mentioned embedded magnetic core circuit board, the method includes the following steps:

Step S1, providing the magnetic core 3 and the PCB main board 1 to be embedded in the magnetic core, the PCB main board 1 includes a multi-layer copper plating layer 11 stacked sequentially from the bottom to the top surface and interposed between For the PP layer 12 between two adjacent layers of the copper plating layer 11, the copper plating layer 11 is more than 8 layers.

Step S2, setting up an embedding groove, opening the embedding groove 2 on the PCB main board 1 from the top surface of the PCB main board 1 to its bottom surface, so that the embedding groove 2 extends to the eighth copper plating layer, And make the difference between the size of the embedding groove 2 and the size of the magnetic core 3 by ±0.0762 mm.

Step S3, attaching a metal sheet, attaching a layer of metal sheet (not shown) with an area larger than the area of the top surface of the magnetic core 3 on the top surface of the magnetic core 3, and making the metal sheet exceed the A part of the top surface of the magnetic core 3 is bent in a direction away from the magnetic core 3 to form a dismounting part;

Step S4, fixing the magnetic core, placing the magnetic core 3 in the embedding groove 2, and fixing the magnetic core 3 in the embedding groove 2 through a lamination process with a pressure of 290-295 PSI;

Step S5, disassembling the metal sheet, tearing off the metal sheet through the disassembly part to remove the glue attached to its surface, so that the top surface of the magnetic core 3 is completely exposed;

Step S6, opening through holes, opening a plurality of through holes on the PCB main board 1, so that a plurality of through holes are arranged around the magnetic core 3, and the minimum distance between the through holes and the magnetic core 3 is 0.18 mm;

Step S7, through-hole copper plating, copper plating in the through-hole to form the conductive through-hole 111, electrically connecting the conductive through-hole 111 to form a magnetic core winding, the thickness of copper plating at a single point is greater than 78 μm, and the obtained The embedded magnetic core circuit board 10 is described.

Compared with the related technology, the embedded magnetic core circuit board provided by the present invention embeds the magnetic core inside the PCB main board, thereby eliminating the manual mounting process, improving production efficiency, and thus eliminating the problem of welding. The problem of poor solder joints is avoided, and the resulting reliable performance is improved. The embedded structure saves a lot of area on the PCB surface of the power board, which is conducive to the miniaturization and high density of product design.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process conversion made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technologies fields, all of which are equally included in the scope of patent protection of the present invention.

Claims (8)

1. bury a magnetic core wiring board, including PCB main board, being embedded into groove and being placed in described embedding to described PCB main board inner recess Bury the magnetic core in groove, it is characterised in that described PCB main board include multilamellar by its bottom surface to the end face successively folded copper plate set and folder Being located at the PP layer between copper plate described in adjacent two layers, described copper plate includes running through thereon and the most copper-plated conduction Through hole, described copper plate is more than 8 layers, and the copper thickness of 1～6 layer every layer described copper plate is 0.105mm, and described magnetic core is embedded in described Between 1～8 layer of described copper plate of PCB main board, the end face of described magnetic core is not higher than the end face of described PCB main board and exposes completely In described PCB main board.

The most according to claim 1 bury magnetic core wiring board, it is characterised in that described magnetic core is circular cylindrical or E type.

The most according to claim 1 bury magnetic core wiring board, it is characterised in that described in be embedded into the size of groove and described magnetic core Size difference ± 0.0762mm.

The most according to claim 3 bury magnetic core wiring board, it is characterised in that described in be embedded into the described copper plate of correspondence of groove The position of 1～2 layer, its size 0.1016mm bigger than the size of the correspondence position of described magnetic core.

The most according to claim 1 bury magnetic core wiring board, it is characterised in that the aperture of described conductive through hole is 0.5mm, its The distance being embedded into groove described in Ju Li is at least 0.18mm.

The most according to claim 1 bury magnetic core wiring board, it is characterised in that described conductive through hole copper facing thickness single-point is more than 78μm。

The most according to claim 1 bury magnetic core wiring board, it is characterised in that the copper-plated radius-thickness ratio of described conductive through hole is less than Or equal to 11:1.

8. the manufacture method burying magnetic core wiring board as described in claim 1-8 any one, it is characterised in that this manufacture Method comprises the steps:

Described magnetic core is provided and waits to imbed the described PCB main board of described magnetic core, described PCB main board include multilamellar by its bottom surface to top The face folded copper plate set successively and the PP layer being located in described in adjacent two layers between copper plate, described copper plate is more than 8 layers；

Offer and be embedded into groove, by the end face of described PCB main board to its direction, bottom surface offer on described PCB main board described in be embedded into groove, Be embedded into groove described in making and be extended down to the 8th layer of copper plate, and the size of the size and described magnetic core being embedded into groove described in making differ ± 0.0762mm；

Be sticked foil, and the aspect that is sticked by the end face of described magnetic core amasss the foil more than described magnetic core top surface area, And make the part beyond described magnetic core end face of described foil be bent to form disassembling part to the direction away from described magnetic core；

Magnetic core is fixed, described magnetic core is placed in described in be embedded in groove, and by laminating technology that pressure is 290～295PSI by institute State magnetic core be fixed on described in be embedded in groove；

Dismounting foil, is removed described foil by described disassembling part and is sticked at the glue on its surface to remove, make institute State magnetic core end face to expose completely；

Offer through hole, described PCB main board is offered multiple through hole so that multiple through holes are arranged around described magnetic core, and make institute Stating through hole apart from the minimum range of described magnetic core is 0.18mm；

Through hole copper facing, in described through hole, copper facing forms described conductive through hole, described conductive through hole is electrically connected to form magnetic core around Line, copper facing thickness single-point be more than 78 μm, prepare described in bury magnetic core wiring board.