A magnetic shielding device

Abstract

This invention discloses a magnetic shielding device, comprising: a substrate, an antimagnetic pad disposed on the substrate, a first antimagnetic sidewall and a second antimagnetic sidewall respectively disposed on opposite sides of the antimagnetic pad, and an antimagnetic cover plate connecting the first and second antimagnetic sidewalls; the included angle between the first and second antimagnetic sidewalls and the antimagnetic pad, and the included angle between the second and third antimagnetic sidewalls and the antimagnetic pad are both less than 90° and greater than or equal to 30°; a magnetic component is located within the space enclosed by the antimagnetic pad, the first and second antimagnetic sidewalls, and the antimagnetic cover plate. Compared with the prior art magnetic shielding devices where the sidewalls are perpendicular to the pad, the magnetic shielding device provided by this invention can effectively improve the shielding efficiency.

Description

Technical Field

[0001] This invention relates to the field of chip packaging technology, and more specifically, to a magnetic shielding device. Background Technology

[0002] Magnetic random access memory (MRAM) uses different orientations of magnetic moments to record data, and it outperforms other storage technologies in terms of high-speed read / write, write cycles, and non-volatility. The data in MRAM is recorded by the relative orientation of the magnetic reference layer and the magnetic free layer. When the two layers are in the same direction, the element is in a low-resistance state (logic 0), and when the two layers are in opposite directions, the element is in a high-resistance state (logic 1). The magnetic free layer is relatively weak, so its magnetic moment direction can be changed in various ways to achieve data writing.

[0003] During the data recording process, the external magnetic field has a significant impact on the stability of the magnetic free layer. Increased magnetic free layer stability leads to higher write voltage, thereby reducing the number of write cycles or causing write errors. Decreased magnetic free layer stability, on the other hand, can cause errors in the data stored in the chip. Therefore, for magnetic random access memory, it is essential to effectively shield the external magnetic field.

[0004] In existing technologies, a high-permeability loop is typically constructed to wrap around the chip, thereby reducing the magnetic field at the chip. However, the shielding efficiency is generally low, making it difficult to meet the shielding requirements under strong magnetic fields (>4000 Oe). Furthermore, existing shielding devices have complex structures and high mass production costs.

[0005] In conclusion, how to improve the shielding effect of magnetic shielding devices is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a magnetic shielding device in which the angle between the first antimagnetic sidewall and the antimagnetic pad and the angle between the second antimagnetic sidewall and the antimagnetic pad are both less than 90° and greater than or equal to 30° during use, so as to improve the shielding efficiency of the magnetic shielding device.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A magnetic shielding device includes: a substrate, an antimagnetic pad disposed on the substrate, a first antimagnetic sidewall and a second antimagnetic sidewall respectively disposed on opposite sides of the antimagnetic pad, and an antimagnetic cover plate connecting the first antimagnetic sidewall and the second antimagnetic sidewall.

[0009] The angle between the first antimagnetic sidewall and the antimagnetic pad, and the angle between the second antimagnetic sidewall and the antimagnetic pad are both less than 90° and greater than or equal to 30°;

[0010] The magnetic component is located within the space enclosed by the antimagnetic pad, the first antimagnetic sidewall, the second antimagnetic sidewall, and the antimagnetic cover plate.

[0011] Preferably, the angle between the first antimagnetic sidewall and the antimagnetic pad is 45° or 60°, and the angle between the second antimagnetic sidewall and the antimagnetic pad is 45° or 60°.

[0012] Preferably, the antimagnetic pad is a pure iron pad or a silicon steel pad;

[0013] The first antimagnetic sidewall is a pure iron sidewall or a silicon steel sidewall;

[0014] The second antimagnetic sidewall is a pure iron sidewall or a silicon steel sidewall;

[0015] The antimagnetic cover plate is a pure iron cover plate or a silicon steel cover plate.

[0016] Preferably, the antimagnetic pad, the first antimagnetic sidewall, the second antimagnetic sidewall, and the antimagnetic cover plate are all prepared using metal powder injection molding technology.

[0017] Preferably, the antimagnetic pad, the first antimagnetic sidewall, and the second antimagnetic sidewall are an integral structure.

[0018] Preferably, the first antimagnetic sidewall, the second antimagnetic sidewall, and the antimagnetic cover plate are an integral structure.

[0019] Preferably, the antimagnetic pad is provided with a first groove and a second groove, the first antimagnetic sidewall is inserted into the first groove, and the second antimagnetic sidewall is inserted into the second groove.

[0020] Preferably, the antimagnetic cover plate is provided with a through hole extending through its thickness direction.

[0021] Preferably, the substrate is provided with a plurality of base islands, each base island including a recessed recessed portion, the recessed portion having a recessed depth of 0.5-0.8 mm.

[0022] Preferably, the antimagnetic pad is provided with a recess for mounting the magnetic component.

[0023] Preferably, the surfaces of the antimagnetic pad, the first antimagnetic sidewall, the second antimagnetic sidewall, and the antimagnetic cover plate are all provided with an anti-rust coating and an insulating coating.

[0024] In the process of using the magnetic shielding device provided by the present invention, the antimagnetic pad is first installed on the substrate, and the first and second antimagnetic sidewalls are connected to the antimagnetic pad. The antimagnetic cover plate is connected to the upper part of the first and second antimagnetic sidewalls. The magnetic component is then placed in the space enclosed by the antimagnetic pad, the first and second antimagnetic sidewalls, and the antimagnetic cover plate. During the placement process, the opposite sides of the magnetic component without connecting lines are respectively opposite to the first and second antimagnetic sidewalls.

[0025] During assembly, it is necessary to ensure that the angle between the first antimagnetic sidewall and the antimagnetic pad, and the angle between the second antimagnetic sidewall and the antimagnetic pad are both less than 90° and greater than or equal to 30°. Through multiple tests during use, it can be concluded that the magnetic shielding device provided by this invention can effectively improve the shielding efficiency compared with the magnetic shielding device in the prior art where the sidewall and the pad are perpendicular. Furthermore, the shielding effect is optimal when the angle between the first antimagnetic sidewall and the antimagnetic pad, and the angle between the second antimagnetic sidewall and the antimagnetic pad are both 45°. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a specific embodiment of the magnetic shielding device provided by the present invention.

[0028] Figure 2 for Figure 1 Schematic diagram of the structure of the antimagnetic pad;

[0029] Figure 3 for Figure 1 A schematic diagram of the combined structure of the first antimagnetic sidewall, the second antimagnetic sidewall, and the antimagnetic cover plate;

[0030] Figure 4 This is a schematic diagram of a specific embodiment two of the magnetic shielding device provided by the present invention;

[0031] Figure 5 for Figure 4 Schematic diagram of the structure of the antimagnetic pad;

[0032] Figure 6 for Figure 4 A schematic diagram of the combined structure of the first antimagnetic sidewall, the second antimagnetic sidewall, and the antimagnetic cover plate;

[0033] Figure 7 A comparison chart showing the shielding efficiency of horizontal magnetic fields;

[0034] Figure 8 This is a comparison chart of shielding efficiency for vertical magnetic fields.

[0035] Figure 1-8 middle:

[0036] 1 is the substrate, 2 is the base island, 21 is the recessed part, 3 is the antimagnetic pad, 31 is the first groove, 32 is the second groove, 33 is the recessed part, 4 is the first antimagnetic sidewall, 5 is the second antimagnetic sidewall, 6 is the antimagnetic cover plate, 61 is the through hole, and 7 is the magnetic component. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0038] The core of this invention is to provide a magnetic shielding device in which the angle between the first antimagnetic sidewall and the antimagnetic pad, and the angle between the second antimagnetic sidewall and the antimagnetic pad are both less than 90° and greater than or equal to 30° during use, so as to improve the shielding efficiency of the magnetic shielding device.

[0039] Please refer to Figure 1-8 .

[0040] This specific embodiment discloses a magnetic shielding device, including: a substrate 1, an antimagnetic pad 3 disposed on the substrate 1, a first antimagnetic sidewall 4 and a second antimagnetic sidewall 5 respectively disposed on opposite sides of the antimagnetic pad 3, and an antimagnetic cover plate 6 connecting the first antimagnetic sidewall 4 and the second antimagnetic sidewall 5.

[0041] The angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both less than 90° and greater than or equal to 30°.

[0042] The magnetic component 7 is located within the space enclosed by the antimagnetic pad 3, the first antimagnetic sidewall 4, the second antimagnetic sidewall 5, and the antimagnetic cover plate 6.

[0043] During processing, the antimagnetic pad 3 can be made of pure iron or silicon steel, preferably DT4C pure iron; the first antimagnetic sidewall 4 can be made of pure iron or silicon steel, preferably DT4C pure iron; the second antimagnetic sidewall 5 can be made of pure iron or silicon steel, preferably DT4C pure iron; the antimagnetic cover plate 6 can be made of pure iron or silicon steel, preferably DT4C pure iron; of course, the antimagnetic pad 3, the first antimagnetic sidewall 4, the second antimagnetic sidewall 5 and the antimagnetic cover plate 6 can also be made of other materials that meet the requirements, which will not be elaborated here.

[0044] Preferably, the antimagnetic pad 3, the first antimagnetic sidewall 4, the second antimagnetic sidewall 5, and the antimagnetic cover plate 6 are all prepared using metal powder injection molding technology. During the preparation process, the antimagnetic pad 3, the first antimagnetic sidewall 4, and the second antimagnetic sidewall 5 can be prepared as a single piece, or the first antimagnetic sidewall 4, the second antimagnetic sidewall 5, and the antimagnetic cover plate 6 can be prepared as a single piece, so as to reduce the number of parts and preparation steps and reduce costs.

[0045] In the process of using the magnetic shielding device provided in this specific embodiment, the antimagnetic pad 3 needs to be installed on the substrate 1 first, and the first antimagnetic sidewall 4 and the second antimagnetic sidewall 5 are both connected to the antimagnetic pad 3. The antimagnetic cover plate 6 is connected to the upper part of the first antimagnetic sidewall 4 and the second antimagnetic sidewall 5. The magnetic component 7 is placed in the space enclosed by the antimagnetic pad 3, the first antimagnetic sidewall 4, the second antimagnetic sidewall 5 and the antimagnetic cover plate 6. During the placement process, the opposite sides of the magnetic component 7 without connecting lines are respectively opposite to the first antimagnetic sidewall 4 and the second antimagnetic sidewall 5.

[0046] During assembly, it is necessary to ensure that the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both less than 90° and greater than or equal to 30°. Through multiple tests during use, it can be concluded that the magnetic shielding device provided in this specific embodiment can effectively improve the shielding efficiency compared with the magnetic shielding device in the prior art where the sidewall and the pad are perpendicular. Furthermore, the shielding effect is optimal when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 45°.

[0047] Preferably, the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3 can be 45° or 60°, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 can be 45° or 60°.

[0048] Specific shielding efficiency such as Figure 7 , Figure 8 As shown, where Figure 7This is a comparison chart of shielding efficiency for horizontal magnetic fields. The vertical axis represents shielding efficiency, and the horizontal axis represents magnetic field strength, in Oe. Square markers represent cases where the sidewall and cover plate are combined in a circular shape. Circular markers represent cases where the angles between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and between the second antimagnetic sidewall 5 and the antimagnetic pad 3, are both 45°. Upright triangle markers represent cases where the angles between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and between the second antimagnetic sidewall 5 and the antimagnetic pad 3, are both 60°. Inverted triangle markers represent cases where the angles between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and between the second antimagnetic sidewall 5 and the antimagnetic pad 3, are both 90°. The chart shows that at a magnetic field strength of 1500 Oe, the highest shielding efficiency is achieved when the angles between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and between the second antimagnetic sidewall 5 and the antimagnetic pad 3, are both 45°. The shielding efficiency is higher when the angle between the magnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 60°, than when the sidewall and cover plate are combined in a circular shape. The shielding efficiency is worst when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 90°. Under a magnetic field of 2000 Oe, the shielding efficiency is highest when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 45°. The shielding efficiency is highest when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 60°, than when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 90°. The shielding efficiency is worst when the sidewall and cover plate are combined in a circular shape.

[0049] like Figure 8The figure shows a comparison of shielding efficiency for vertical magnetic fields. The vertical axis represents shielding efficiency, and the horizontal axis represents magnetic field strength, in units of Oe. Square markers represent cases where the sidewall and cover plate are combined in a circular shape. Circular markers represent cases where the angles between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and between the second antimagnetic sidewall 5 and the antimagnetic pad 3, are both 45°. Upright triangle markers represent cases where the angles between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and between the second antimagnetic sidewall 5 and the antimagnetic pad 3, are both 60°. Inverted triangle markers represent cases where the angles between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and between the second antimagnetic sidewall 5 and the antimagnetic pad 3, are both 90°. As can be seen from the figure, at a magnetic field strength of 1500 Oe, the highest shielding efficiency is achieved when the angles between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and between the second antimagnetic sidewall 5 and the antimagnetic pad 3, are both 45°. The shielding efficiency is higher when the combination of the sidewall and cover plate is circular than when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 60°. The shielding efficiency is worst when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 90°. Under a magnetic field of 2000 Oe, the shielding efficiency is highest when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 45°. The shielding efficiency is higher when the combination of the sidewall and cover plate is circular than when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 60°. The shielding efficiency is worst when the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 90°.

[0050] like Figure 1-3 As shown, in another specific embodiment, a first groove 31 and a second groove 32 can be provided in the antimagnetic pad 3. The first antimagnetic sidewall 4 is inserted into the first groove 31 and the second antimagnetic sidewall 5 is inserted into the second groove 32. This is beneficial to increase the contact area between the first antimagnetic sidewall 4, the second antimagnetic sidewall 5 and the antimagnetic pad 3 or the antimagnetic cover plate 6, thereby reducing the leakage of magnetic flux at the contact surface and improving the magnetic shielding efficiency.

[0051] Preferably, the depth of the first groove 31 and the second groove 32 is 0.3-0.5mm.

[0052] Preferably, the bottom of the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the bottom of the second antimagnetic sidewall 5 and the antimagnetic pad 3 are bonded together with an adhesive, with a gap of less than or equal to 30 micrometers.

[0053] like Figure 3As shown, the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 45°. Compared with the case where the angle between the first antimagnetic sidewall 4 and the antimagnetic pad 3, and the angle between the second antimagnetic sidewall 5 and the antimagnetic pad 3 are both 90°, the shielding efficiency can be improved by about 10%.

[0054] The antimagnetic pad 3 is provided with a recess 33 for mounting the magnetic component 7. The pins of the magnetic component 7 are connected by a connecting wire. Only a few pins in the middle of the substrate 1 are wired to avoid the lead wire from contacting the first antimagnetic sidewall 4 and the second antimagnetic sidewall 5.

[0055] like Figure 1 As shown, the substrate 1 has several base islands 2, each including a recessed recessed portion 21 with a depth of 0.5-0.8 mm, which is much greater than the recessed depth of ordinary base islands 2 in the prior art, thus reducing the height difference between the leads of the magnetic component 7 and the wire bonding leads. A DT4C pure iron antimagnetic pad 3 is placed on the base island 2, with a thickness of 0.6-0.9 mm. The antimagnetic pad 3 has a square recessed portion 33 in the middle with a depth of 0.05-0.1 mm, used to position the magnetic component 7.

[0056] like Figure 3 As shown, the thickness of the antimagnetic cover plate 6 of DT4C pure iron is 0.3mm-0.9mm, and the antimagnetic cover plate 6 is provided with a through hole 61 extending through its thickness direction, which facilitates the flow of molding compound through the through hole 61 during the molding process. The first antimagnetic sidewall 4, the second antimagnetic sidewall 5, and the antimagnetic cover plate 6 of DT4C pure iron are an integral structure, and the thickness of both the first antimagnetic sidewall 4 and the second antimagnetic sidewall 5 is 0.6-1.2mm.

[0057] like Figure 1 As shown, after the magnetic component 7 is installed, the distance between the magnetic component 7 and the antimagnetic cover plate 6 is 0.5-0.6mm to prevent contact with the top of the antimagnetic cover plate 6 during the wire bonding process.

[0058] In another specific embodiment, such as Figure 4-6 As shown, base island 2 does not undergo special sinking treatment. The DT4C pure iron antimagnetic pad 3 is approximately 0.3mm thick and has a shape like... Figure 5 As shown, the thickness of the antimagnetic cover plate 6 of DT4C pure iron is 0.6-1.2mm. This configuration can reduce costs compared to the above embodiments.

[0059] Based on the above embodiments, before encapsulation, the first antimagnetic sidewall 4, the second antimagnetic sidewall 5, the antimagnetic gasket 3, and the antimagnetic cover plate 6 need to undergo rust removal, electroplating for rust prevention, and insulation treatment. DT4C pure iron is prone to rusting in natural environments, therefore rust removal and electroplating for rust prevention are required. To prevent short circuits caused by the lead wires touching the shielding structure during wire bonding, the shielding structure also needs insulation treatment.

[0060] Preferably, the surfaces of the antimagnetic pad 3, the first antimagnetic sidewall 4, the second antimagnetic sidewall 5, and the antimagnetic cover plate 6 are all provided with an anti-rust coating and an insulating coating.

[0061] The magnetic shielding device provided in this application has a simple packaging process, and the alignment and bonding steps can be easily integrated into the normal chip packaging process. Packaging companies do not need to purchase additional packaging equipment during the packaging process. The antimagnetic cover plate 6 and the antimagnetic pad 3 are prepared using metal powder injection molding (MIM) technology, which is easy to mass-produce and has low cost. Figure 1-3 The structure in the illustrated embodiment achieves a shielding efficiency of 77%@2650Gs for vertical magnetic fields and 69%@2650Gs and 55%@4000Gs for horizontal magnetic fields. A more optimized structure can achieve a shielding efficiency of over 70%@4000Gs.

[0062] The terms "first" and "second" in the first groove 31 and second groove 32, first antimagnetic sidewall 4 and second antimagnetic sidewall 5 mentioned in this application are only for distinguishing different positions and do not indicate any order.

[0063] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Any combination of all embodiments provided by this invention is within the scope of protection of this invention and will not be elaborated upon here.

[0064] The magnetic shielding device provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A magnetic shielding device, characterized in that, include: The substrate (1), the antimagnetic pad (3) disposed on the substrate (1), the first antimagnetic sidewall (4) and the second antimagnetic sidewall (5) respectively disposed on opposite sides of the antimagnetic pad (3), and the antimagnetic cover plate (6) connecting the first antimagnetic sidewall (4) and the second antimagnetic sidewall (5). The angle between the first antimagnetic sidewall (4) and the antimagnetic pad (3), and the angle between the second antimagnetic sidewall (5) and the antimagnetic pad (3) are both less than 90° and greater than or equal to 30°; The magnetic component (7) is located within the space enclosed by the antimagnetic pad (3), the first antimagnetic sidewall (4), the second antimagnetic sidewall (5), and the antimagnetic cover plate (6); The antimagnetic pad (3) is provided with a first groove (31) and a second groove (32), the first antimagnetic sidewall (4) is inserted into the first groove (31), and the second antimagnetic sidewall (5) is inserted into the second groove (32).

2. The magnetic shielding device according to claim 1, characterized in that, The angle between the first antimagnetic sidewall (4) and the antimagnetic pad (3) is 45° or 60°, and the angle between the second antimagnetic sidewall (5) and the antimagnetic pad (3) is 45° or 60°.

3. The magnetic shielding device according to claim 1, characterized in that, The antimagnetic pad (3) is a pure iron pad or a silicon steel pad; The first antimagnetic sidewall (4) is a pure iron sidewall or a silicon steel sidewall; The second antimagnetic sidewall (5) is a pure iron sidewall or a silicon steel sidewall; The antimagnetic cover plate (6) is a pure iron cover plate or a silicon steel cover plate.

4. The magnetic shielding device according to claim 3, characterized in that, The antimagnetic pad (3), the first antimagnetic sidewall (4), the second antimagnetic sidewall (5), and the antimagnetic cover plate (6) are all prepared using metal powder injection molding technology.

5. The magnetic shielding device according to claim 4, characterized in that, The antimagnetic pad (3), the first antimagnetic sidewall (4), and the second antimagnetic sidewall (5) are an integral structure.

6. The magnetic shielding device according to claim 4, characterized in that, The first antimagnetic sidewall (4), the second antimagnetic sidewall (5), and the antimagnetic cover plate (6) are an integral structure.

7. The magnetic shielding device according to any one of claims 1-6, characterized in that, The antimagnetic cover plate (6) is provided with a through hole (61) extending through its thickness direction.

8. The magnetic shielding device according to any one of claims 1-6, characterized in that, The substrate (1) is provided with a plurality of base islands (2), each base island (2) including a recessed recessed portion (21) with a recessed depth of 0.5-0.8 mm.

9. The magnetic shielding device according to claim 8, characterized in that, The antimagnetic pad (3) is provided with a recess (33) for mounting the magnetic component (7).

10. The magnetic shielding device according to any one of claims 1-6, characterized in that, The surfaces of the antimagnetic pad (3), the first antimagnetic sidewall (4), the second antimagnetic sidewall (5), and the antimagnetic cover plate (6) are all provided with an anti-rust coating and an insulating coating.

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