Inductor element and manufacturing method therefor, and electronic device
By using physical vapor deposition of a metal layer and setting a separator trench in the inductor element, the problems of volume reduction and corrosion of the inductor part caused by electroplating are solved, thereby improving the inductance and electrical performance and simplifying the manufacturing process.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- DONGGUAN SUNLORD ELECTRONICS CO LTD
- Filing Date
- 2025-01-20
- Publication Date
- 2026-07-09
AI Technical Summary
The excessive thickness of the electroplated metal layer in existing inductor components leads to a decrease in the volume ratio of the inductor part, a decrease in electrical characteristics such as inductance, and the electroplating process is prone to corroding the components and leaving residual substances.
A physical vapor deposition metal layer is used as the electrode, and a partition groove is set on it to break it into two parts as lead-out electrodes. Multilayer metal sublayers are combined to improve adhesion and solderability, and avoid the corrosion problem of electroplating.
This increases the volume ratio of the inductor body in the inductor component, improves the inductance and electrical performance, and avoids electroplating residues, thereby improving the durability and reliability of the component.
Smart Images
Figure CN2025073364_09072026_PF_FP_ABST
Abstract
Description
An inductor element and its fabrication method, and an electronic device.
[0001] Related cross-references
[0002] This disclosure claims priority to Chinese Patent Application No. 2024119899963, filed with the Chinese Patent Office on December 31, 2024, entitled "An Inductor Element and Its Preparation Method, Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the field of inductor technology, and in particular to an inductor and its fabrication method, and an electronic device. Background Technology
[0004] In this field, the electrodes of inductor elements are electroplated metal layers, and the thickness of the electroplated metal layer needs to be relatively thick to ensure the continuity of the electroplated metal layer. An excessively thick electroplated layer leads to a decrease in the volume ratio of the inductor part in the inductor element, and a decrease in electrical characteristics such as inductance. Summary of the Invention
[0005] This application discloses an inductor element and its fabrication method, as well as an electronic device, which can increase the volume ratio of the inductor body in the inductor element, thereby increasing the inductance of the inductor element.
[0006] To achieve the above objectives, in a first aspect, embodiments of this application disclose an inductor element, comprising:
[0007] Inductor body, the inductor body having an assembly surface; and
[0008] A physical vapor deposition metal layer is disposed on the assembly surface;
[0009] Wherein, in a direction parallel to the assembly surface, a partition groove is provided between the two ends of the physical vapor deposition metal layer. The partition groove is configured to break the physical vapor deposition metal layer into two parts along the thickness direction of the physical vapor deposition metal layer. One part of the physical vapor deposition metal layer is formed as the first lead electrode of the inductor body, and the other part of the physical vapor deposition metal layer is formed as the second lead electrode of the inductor body.
[0010] In one possible implementation of the first aspect, the physical vapor deposition metal layer includes a plurality of physical vapor deposition metal sub-layers, which are stacked sequentially along a direction away from the inductor body, and the thickness of each physical vapor deposition metal sub-layer is 0.1 μm to 2 μm.
[0011] In one possible implementation of the first aspect, the plurality of said physical vapor deposition metal sublayers are a combination of one or more of an underlayer, a transition layer, or an anti-oxidation layer.
[0012] In a possible implementation of the first aspect, when the number of physical vapor deposition metal sublayers is three, the three physical vapor deposition metal sublayers are the underlayer, the transition layer, and the anti-oxidation layer, and the underlayer, the transition layer, and the anti-oxidation layer are sequentially stacked on the surface of the inductor body in a direction away from the inductor body.
[0013] In one possible implementation of the first aspect, the material of the underlayer is selected from at least one of chromium or titanium;
[0014] And / or, the material of the transition layer contains nickel;
[0015] And / or, the material of the anti-oxidation layer is selected from at least one of silver or tin;
[0016] And / or, the total thickness of the underlayer, the transition layer and the anti-oxidation layer is 0.3 μm to 6 μm.
[0017] In one possible implementation of the first aspect, the dividing groove further extends into a portion of the inductor body in the thickness direction.
[0018] In a possible implementation of the first aspect, the inductor body includes a magnet and a coil, the coil being enclosed within the magnet, the assembly surface being located on the magnet, the coil having two leads, the two leads being electrically connected to a first lead electrode and a second lead electrode, respectively; and in the thickness direction of the magnet, the partition groove extends into the magnet and is spaced apart from the coil.
[0019] In one possible implementation of the first aspect, the magnet includes an insulator and a plurality of magnetic powder particles encapsulated within the insulator;
[0020] And / or, the thickness of the magnet is T1, the thickness of the physical vapor deposition metal layer is T2, and T2 / T1 = 0.05% to 1.09%;
[0021] And / or, in the thickness direction of the magnet, the depth of the partition groove is 30 μm to 50 μm;
[0022] And / or, the thickness of the magnet is 0.5 mm to 0.7 mm.
[0023] Secondly, embodiments of this application disclose a method for fabricating an inductor element as described in the first aspect, comprising the following steps:
[0024] Blocking non-deposition areas: The blocking member is placed on the assembly surface of the inductor body, and in a direction parallel to the assembly surface, the blocking member is at least partially located between the two ends of the assembly surface;
[0025] Physical vapor deposition: The physical vapor deposition metal layer is obtained by performing physical vapor deposition on the assembly surface in a vacuum environment.
[0026] In a possible implementation of the second aspect, the inductor body further includes an end face and a side face, the end face being disposed opposite to the assembly surface, and the side face being connected between the end face and the assembly surface;
[0027] In the step of shielding the non-deposition area, a plurality of inductor bodies are placed side by side into a fixture, the end face of each inductor body is shielded by the fixture, and the side faces of two adjacent inductor bodies are pressed together and shielded.
[0028] Thirdly, embodiments of this application disclose an electronic device, including an inductor as described in the first aspect, or an inductor prepared by the method described in the second aspect.
[0029] Compared with the prior art, the beneficial effects of this application are:
[0030] This application utilizes a physical vapor deposition metal layer as an electrode. The physical vapor deposition metal layer can maintain good film continuity while being relatively thin, thus giving the physical vapor deposition metal layer the characteristics of being thin, dense, having good adhesion, and being solderable.
[0031] This application also provides a partition groove on the physical vapor deposition metal layer. The partition groove is configured to divide the physical vapor deposition metal layer into two parts along the thickness direction of the physical vapor deposition metal layer. One part of the physical vapor deposition metal layer is formed as the first lead electrode of the inductor body, and the other part of the physical vapor deposition metal layer is formed as the second lead electrode of the inductor body. This solves the problem that the physical vapor deposition metal layer is difficult to use as the lead electrode of two different partitions. This allows the inductor element to use a thinner physical vapor deposition metal layer as an electrode, which is beneficial to increase the volume ratio of the inductor body in the inductor element, thereby improving the electrical performance of the inductor element, such as inductance and current. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 is a schematic diagram of the structure of an inductor element disclosed in the first aspect of this application;
[0034] Figure 2 is a partial enlarged view of region I shown in Figure 1;
[0035] Figure 3 is a schematic diagram of the assembly of the inductor and carrier disclosed in the first aspect of this application;
[0036] Figure 4 is a schematic diagram of the operation of the fixture and shielding element in the preparation method disclosed in the second aspect of this application.
[0037] Explanation of reference numerals in the attached drawings: 10, Inductor element; 11, Inductor body; 111, Assembly surface; 112, Magnet; 113, Coil; 114, End face; 115, Side face; 1131, Lead-out terminal; 12, Physical vapor deposition metal layer; 121, Underlayer; 122, Transition layer; 123, Anti-oxidation layer; 13, Separator groove; 14, First lead-out electrode; 15, Second lead-out electrode; Z, Thickness direction of the physical vapor deposition metal layer; Y, Direction parallel to the assembly surface; 20, Carrier; 30, Shielding element; 40, Fixture. Detailed Implementation
[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0039] In this application, the terms "upper," "inner," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.
[0040] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain circumstances to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0041] Furthermore, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0042] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.
[0043] In this field, the electrodes of inductors are mostly fabricated by electroplating. This is because electroplating can produce the desired plating structure for surface mount soldering. However, electroplating solutions are generally strong acids or alkalis. Prolonged immersion in acidic or alkaline solutions can corrode inductors, and the plating solution can easily enter micropores and pits within the inductor, causing plating residue to remain inside. Over time, this plating residue continuously corrodes the inductor, leading to a decrease in its electrical performance and reliability. Furthermore, thin electroplated metal layers have poor continuity, making them unsuitable for soldering or resulting in poor solder joints. Therefore, the thickness of the electroplated metal layer must be relatively thick. However, excessively thick plating layers reduce the volume ratio of the inductor portion within the inductor, leading to a decrease in electrical characteristics such as inductance.
[0044] Physical vapor deposition (PVD) is primarily used to deposit films over an entire surface of an object, but it is difficult to use for fabricating electrodes for inductor components. This is because PVD deposits a film over the entire surface, while the two leads of an inductor component need to be separated from each other.
[0045] Based on the above analysis, this application provides an inductor element with a partition groove on a physical vapor deposition (PVD) metal layer. The partition groove is configured to divide the PVD metal layer into two parts along the thickness direction of the PVD metal layer. One part of the PVD metal layer is formed as the first lead electrode of the inductor body, and the other part of the PVD metal layer is formed as the second lead electrode of the inductor body. This solves the problem that the PVD metal layer is difficult to use as the lead electrode for two different partitions, allowing the inductor element to use a thinner PVD metal layer as an electrode. This is beneficial to increasing the volume ratio of the inductor body in the inductor element, thereby increasing the inductance of the inductor element.
[0046] The technical solution of the present invention will now be described in conjunction with the embodiments and accompanying drawings.
[0047] In a first aspect, referring to Figures 1 to 3, embodiments of this application disclose an inductor element 10, including an inductor body 11 and a physical vapor deposition metal layer 12. The inductor body 11 has an assembly surface 111. The physical vapor deposition metal layer 12 is disposed on the assembly surface 111.
[0048] In the direction Y parallel to the assembly surface, a partition groove 13 is provided between the two ends of the physical vapor deposition metal layer 12. The partition groove 13 is configured to divide the physical vapor deposition metal layer 12 into two parts along the thickness direction Z of the physical vapor deposition metal layer. One part of the physical vapor deposition metal layer 12 is formed as the first lead electrode 14 of the inductor body 11, and the other part of the physical vapor deposition metal layer 12 is formed as the second lead electrode 15 of the inductor body 11.
[0049] It should be noted that, referring to Figure 3, the term "assembly surface 111" refers to the side of the inductor body 11 connected to the carrier 20 when the inductor element 10 is assembled on the carrier 20, such as a circuit board. The term "physical vapor deposition metal layer 12" refers to a metal layer fabricated by physical vapor deposition.
[0050] This application utilizes a physical vapor deposition metal layer 12 as an electrode. The physical vapor deposition metal layer 12 can maintain good film continuity while being relatively thin, thereby giving the physical vapor deposition metal layer 12 the characteristics of being thin, dense, having good adhesion, and being solderable.
[0051] This application also provides a partition groove 13 on the physical vapor deposition metal layer 12. The partition groove 13 is configured to divide the physical vapor deposition metal layer 12 into two parts along the thickness direction Z of the physical vapor deposition metal layer. One part of the physical vapor deposition metal layer 12 is formed as the first lead electrode 14 of the inductor body 11, and the other part of the physical vapor deposition metal layer 12 is formed as the second lead electrode 15 of the inductor body 11. This solves the technical problem that the physical vapor deposition metal layer 12 is difficult to use for two kinds of partitioned lead electrodes, so that the inductor element 10 can use a thinner physical vapor deposition metal layer 12 as a lead electrode. This is beneficial to increase the volume ratio of the inductor body 11 in the inductor element 10, thereby improving the electrical performance of the inductor element 10, such as inductance and current.
[0052] In some embodiments, please refer to Figures 1 and 2. The physical vapor deposition metal layer 12 includes a plurality of physical vapor deposition metal sublayers, which are stacked sequentially in a direction away from the inductor body 11.
[0053] Since the physical vapor deposition metal sublayers are all thin, this application can deposit multiple physical vapor deposition metal sublayers while still enabling the inductor body 11 to have a high volume ratio. At the same time, by setting different characteristics for each physical vapor deposition metal sublayer, the physical vapor deposition metal layer 12 can have a variety of composite characteristics.
[0054] It should be noted that if the thickness of the physical vapor deposition (PVD) metal sublayer is less than 0.1 μm, the continuity and density of the PVD metal sublayer will be poor, and it will be easily oxidized. If the thickness of the PVD metal sublayer is greater than 2 μm, the film stress will be high, and the adhesion will be poor. Preferably, the thickness of each PVD metal sublayer is 0.1 μm to 2 μm, including any value within this thickness range, such as 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, or 2 μm. PVD metal sublayers within this thickness range exhibit good continuity, high film density, good oxidation resistance, low film stress, and high adhesion.
[0055] Optionally, the multiple physical vapor deposition metal sublayers are a combination of one or more of the following: an underlayer 121, a transition layer 122, or an anti-oxidation layer 123.
[0056] For example, the number of physical vapor deposition metal sublayers is two layers, which are a base layer and a transition layer stacked sequentially in the direction away from the inductor body; or, the two physical vapor deposition metal sublayers are a transition layer or an anti-oxidation layer stacked sequentially in the direction away from the inductor body.
[0057] The underlayer 121 is well bonded to the assembly surface 111 to enhance the adhesion of the entire physical vapor deposition metal layer 12. Preferably, the material of the underlayer 121 is selected from at least one of chromium or titanium. The inventors have found that chromium and titanium have high ionic kinetic energy, which allows them to bond well with the inductor element 10 during physical vapor deposition, especially when the assembly surface 111 is insulated; chromium and titanium can still bond with the insulated assembly surface 111 and the film continuity is good. Chromium and titanium also have low synchronous resistivity, giving the inductor element 10 the advantage of low DC resistance.
[0058] The transition layer 122 has high-temperature resistance, thus providing solderability. Preferably, the transition layer 122 is made of nickel. The nickel-based transition layer 122 can withstand high temperatures even at a relatively thin thickness, thereby making the inductor element 10 solderable.
[0059] The anti-oxidation layer 123 serves to prevent the physical vapor deposition metal layer 12 from being oxidized, thereby enabling the physical vapor deposition metal layer 12 to better bond with the circuit board during soldering and reducing solder rejection. Preferably, the anti-oxidation layer 123 is made of at least one of silver or tin. Anti-oxidation layers 123 made of silver and tin can maintain good oxidation resistance even with a relatively thin thickness.
[0060] Preferably, as shown in Figures 1 and 2, when the number of physical vapor deposition metal sublayers is three, the three physical vapor deposition metal sublayers are an underlayer 121, a transition layer 122, and an anti-oxidation layer 123, which are stacked sequentially on the surface of the inductor body 11 in a direction away from the inductor body 11.
[0061] Based on the above analysis, the physical vapor deposition metal layer 12, composed of the successively stacked base layer 121, transition layer 122, and anti-oxidation layer 123, will have the characteristics of good adhesion, solderability, and oxidation resistance. This allows the inductor element 10 to bond better with solder during soldering, which is beneficial for improving the connection strength after soldering.
[0062] More preferably, the total thickness of the underlayer 121, the transition layer 122, and the anti-oxidation layer 123 is 0.3μm to 6μm, including any value within this thickness range, such as 0.3μm, 2μm, 4μm, or 6μm, so that the underlayer 121, the transition layer 122, and the anti-oxidation layer 123 all have high film continuity, while the overall thickness is relatively thin, which can make the volume ratio of the inductor body 11 relatively high.
[0063] In some embodiments, referring to Figures 1 and 2, the partition groove 13 extends into a portion of the inductor body 11 along its thickness direction. In this embodiment, the thickness direction of the inductor body 11 is the same as the thickness direction Z of the physical vapor deposition metal layer.
[0064] If the separator groove 13 extends only along the thickness direction Z of the physical vapor deposition metal layer, that is, the depth of the separator groove 13 is equal to the thickness of the physical vapor deposition metal layer 12, the separator groove 13 will be shallow due to the thinness of the physical vapor deposition metal layer 12, which is not conducive to the discharge of solder balls generated during soldering. Therefore, in this embodiment, the separator groove 13 extends into a portion of the inductor body 11 to increase its depth. The deeper separator groove 13 is beneficial for the discharge of solder balls during soldering. Furthermore, before physical vapor deposition is performed on the inductor body 11, the separator groove 13 on the inductor body 11 also helps to position the shielding component, so that the shielding component is accurately shielded in the non-deposition area.
[0065] Furthermore, the inductor body 11 includes a magnet 112 and a coil 113. The coil 113 is enclosed within the magnet 112, and the assembly surface 111 is located on the magnet 112. The coil 113 has two leads 1131, which are electrically connected to a first lead electrode 14 and a second lead electrode 15, respectively. In the thickness direction of the magnet 112, a partition groove 13 extends into the magnet 112 and is spaced apart from the coil 113. The partition groove 13 can be formed on the magnet 112 during the molding process, for example, by using a mold to create the partition groove on the magnet. Alternatively, the partition groove can be formed after the magnet 112 has been molded by removing a portion of the material from the magnet 112.
[0066] Furthermore, the magnet 112 includes an insulator and a plurality of magnetic powder particles encapsulated within the insulator. The insulator may be, for example, an epoxy resin insulator or a silicone resin insulator. Of course, the insulator can also be made of other materials. The magnetic powder particles may be, for example, magnetite, iron-silicon-aluminum magnetic powder, iron-silicon magnetic powder, or iron-nickel-molybdenum magnetic powder.
[0067] It is understood that the assembly surface 111 on the magnet 112 is an insulating surface. If an electroplating method is used to electroplat a metal layer on the insulating surface, it is necessary to first cover the insulating surface with silver paste before electroplating, which is a complex and costly process. However, this application utilizes physical vapor deposition to directly deposit a physical vapor deposition metal layer 12 on the insulating surface, thereby simplifying the manufacturing process, and the physical vapor deposition metal layer 12 has strong adhesion to the insulating surface.
[0068] Preferably, the thickness of the magnet 112 is T1, and the thickness of the physical vapor deposition metal layer 12 is T2, where T2 / T1 = 0.05% to 1.09%, including any value within this range, such as 0.05%, 0.1%, 0.5%, 0.7%, or 1.09%. Within this thickness range, the physical vapor deposition metal layer 12 is relatively thin but still has good film continuity and density, the magnet 112 has a larger volume fraction, and the inductor 10 has better electrical performance, such as higher inductance.
[0069] It is understandable that if the depth of the separator groove 13 is less than 30 μm, it may not be able to separate the physical vapor deposition metal layer 12, and the solder ball removal effect will be poor. If the depth of the separator groove 13 is greater than 50 μm, the portion of the separator groove 13 extending into the magnet 112 will be too deep, the volume fraction of the magnet 112 in the inductor element 10 will decrease, and the electrical performance of the inductor element 10 will be affected. Preferably, in the thickness direction of the magnet 112, the depth of the separator groove 13 is 30 μm to 50 μm, including any value within this depth range, such as 30 μm, 40 μm, or 50 μm. The separator groove 13 within this depth range can effectively separate the physical vapor deposition metal layer 12, efficiently remove solder balls during soldering, and also allow the magnet 112 to have a high volume fraction in the inductor element 10.
[0070] Preferably, the thickness T1 of the magnet 112 is 0.5 mm to 0.7 mm, including any value within this thickness range, such as 0.5 mm, 0.6 mm, or 0.7 mm. The inductor 10 fabricated with a magnet 112 of this thickness range is a thin inductor 10. Because this application utilizes a thinner physical vapor deposition metal layer 12 in conjunction with a thinner magnet 112, the thinner magnet 112 still has a high volume fraction in the inductor 10, resulting in excellent electrical performance of the inductor 10. Simultaneously, the overall thickness of the inductor 10 remains relatively thin, making the thin inductor 10 beneficial for the miniaturization of electronic devices.
[0071] Secondly, embodiments of this application disclose a method for fabricating an inductor element as described in the first aspect, comprising the following steps:
[0072] Blocking non-deposition areas: The blocking element is placed on the assembly surface of the inductor body, and in a direction parallel to the assembly surface, the blocking element is at least partially located between the two ends of the assembly surface;
[0073] Physical vapor deposition: Physical vapor deposition is performed on the assembly surface in a vacuum environment to obtain a physical vapor deposited metal layer.
[0074] As shown in Figure 4, in this fabrication method, before the physical vapor deposition (PVD) step, a shielding element 30 is used to shield between the two ends of the assembly surface 111. The shielding element 30 can be, for example, a mask, a shielding sheet, or a shielding film. In the subsequent PVD step, the metal deposited in the non-deposition area is only plated onto the shielding element, thereby forming a separating groove on the non-deposition area to separate the PVD metal layers. This solves the problem that PVD is difficult to fabricate two mutually separated lead electrodes, allowing the inductor to use a thinner PVD metal layer as an electrode. This is beneficial for increasing the volume ratio of the inductor body in the inductor, thereby improving the inductance of the inductor.
[0075] Compared to electroplating, this fabrication method leaves no electroplating residue on the inductor element, reducing rust and corrosion of the magnet and improving the durability and reliability of the inductor element. This method also allows for the direct deposition of a physical vapor deposition metal layer on the insulating assembly surface, thus removing material limitations on the inductor body. Furthermore, the first and second leads can be designed in various shapes, broadening the application range of the inductor element.
[0076] In some embodiments, as shown in FIG4, the inductor body 11 further includes an end face 114 and a side face 115, the end face 114 being disposed opposite to the assembly surface 111, and the side face 115 being connected between the end face 114 and the assembly surface 111.
[0077] In the step of shielding the non-deposition area, multiple inductor bodies 11 are placed side by side into the fixture 40, the end face 114 of each inductor body 11 is shielded by the fixture 40, and the side faces 115 of two adjacent inductor bodies 11 are pressed together and shielded.
[0078] In the electroplating process of related technologies, especially in barrel plating, the inductor bodies are prone to chipping due to collisions. This chipping can further cause plating creep, resulting in poor appearance of the inductor element and increasing the risk of short circuits during assembly due to potential connections with other devices. In contrast, this application utilizes a fixture to fix the inductor body, reducing collisions during plating and thus minimizing chipping. Furthermore, this application uses a fixture 40 to shield the end face 114 of the inductor body 11, and the sides 115 of adjacent inductor bodies 11 are pressed together to prevent metal deposition in non-deposition areas, resulting in a better appearance of the inductor element and reducing the risk of short circuits during assembly.
[0079] In some embodiments, prior to the step of shielding the non-deposited area, the preparation method further includes the following steps:
[0080] Surface treatment: Argon gas is introduced into a negative pressure and heating environment, and a bias voltage is applied to ionize the argon gas to form argon ions. Argon ions are used to bombard the assembly surface to remove oxides on the assembly surface and to treat the assembly surface.
[0081] Optionally, in the surface treatment step, the vacuum degree of the negative pressure environment is (3.5~4.5)×10. -3 Pa, the heating environment temperature is 110℃~130℃, the applied bias voltage is 450V~550V, and the processing time is 5min~10min.
[0082] After surface treatment, impurities such as oxides on the assembly surface are removed, which improves its surface activity and adhesion to the target material. As a result, when a thinner physical vapor deposition metal layer is deposited subsequently, the physical vapor deposition metal layer still has high adhesion and film continuity.
[0083] In some embodiments, the physical vapor deposition step includes:
[0084] Deposit the base layer on the assembly surface;
[0085] A transition layer is deposited on the side of the inductor body that is away from the substrate.
[0086] An anti-oxidation layer is deposited on the side of the transition layer away from the inductor body.
[0087] This physical vapor deposition (PVD) process involves sequentially depositing an underlayer, a transition layer, and an anti-oxidation layer to form a PVD metal layer. This PVD metal layer exhibits good adhesion, solderability, and oxidation resistance. During soldering, the inductor component bonds better with solder, thus improving the post-soldering connection strength.
[0088] Thirdly, embodiments of this application disclose an electronic device, including an inductor as described in the first aspect, or an inductor prepared by the method described in the second aspect. This electronic device may be, for example, a computer, a mobile phone, or an in-vehicle infotainment system.
[0089] The technical solution of the present invention will be described below with reference to the embodiments.
[0090] Example 1
[0091] The method for fabricating the inductor provided in this embodiment includes the following steps:
[0092] Surface treatment: under a vacuum degree of 4×10 -3 Argon gas is introduced into a negative pressure and heating environment with a pressure of 120°C and a pressure of 500V to ionize the argon gas and form argon ions. The assembly surface is bombarded with argon ions for 7 minutes to remove oxides on the assembly surface and to treat the assembly surface.
[0093] Non-deposition area shielding: Multiple inductor bodies are placed side by side in a fixture, with the end faces of each inductor body shielded by the fixture, and the sides of two adjacent inductor bodies pressed together to shield each other. The shielding element is placed on the assembly surface of the inductor body, and in a direction parallel to the assembly surface, the shielding element is at least partially located between the two ends of the assembly surface.
[0094] Physical Vapor Deposition (PVD): PVD is performed on the assembly surface in a vacuum environment. A 0.6 μm thick chromium layer is deposited on the assembly surface as a base layer. A 0.8 μm thick nickel layer is deposited on the side of the base layer facing away from the inductor body as a transition layer. A 0.6 μm thick silver layer is deposited on the side of the transition layer facing away from the inductor body as an anti-oxidation layer, thus fabricating the inductor element. In this inductor element, the base layer, transition layer, and anti-oxidation layer constitute the PVD metal layer. A separation groove is formed on the shielding area of the assembly surface by a shielding component. The separation groove breaks the PVD metal layer into two parts along the thickness direction of the PVD metal layer. One part of the PVD metal layer forms the first lead electrode of the inductor body, and the other part of the PVD metal layer forms the second lead electrode of the inductor body.
[0095] Example 2
[0096] The only difference between this embodiment and Embodiment 1 is that:
[0097] The base layer is made of titanium and is 0.7 μm thick. The anti-oxidation layer is 0.5 μm thick.
[0098] Comparative Example
[0099] The fabrication method of the inductor provided in the comparative example includes the following steps:
[0100] Using the same inductor body as in Example 1, a 15μm thick copper layer is electroplated on the assembly surface of the inductor body as a base layer, and a 5μm thick nickel layer is electroplated on the side of the base layer away from the inductor body as a transition layer. Finally, a 10μm thick tin layer is electroplated on the side of the transition layer away from the inductor body as an anti-oxidation layer to obtain an inductor element.
[0101] The inductors prepared in each embodiment and comparative example were tested below. The test results are shown in Table 1.
[0102] Table 1: Test Results of Inductor Components
[0103] As shown in Table 1, in terms of electrical performance, the inductance and current of Examples 1 and 2 are improved compared with the comparative example, and the resistance is not much different. This indicates that in the inductor obtained by the preparation method of this application, the volume ratio of the magnet is increased by depositing a thin physical vapor deposition metal layer as the lead electrode. After the volume ratio of the magnet is increased, the inductance and current of the inductor are improved.
[0104] Regarding peel strength, the peel strength of Examples 1 and 2 is comparable to that of the comparative example, indicating that the inductor of this application can still have comparable peel strength with a thicker electroplated metal electrode even with a thinner physical vapor deposition metal layer.
[0105] Regarding corrosion resistance, the electroplating solution used in the comparative example process has a corrosive effect on the inductor body, and the inductor element prepared in the comparative example has electroplating residue. However, the inductor elements prepared in Examples 1 and 2 have no electroplating residue. As a result, the salt spray test time of Examples 1 and 2 is significantly improved compared with the comparative example, indicating that the corrosion resistance of the inductor elements in Examples 1 and 2 is significantly improved compared with the comparative example.
[0106] Regarding storage performance, since the inductor in the comparative example was corroded during the electroplating process and there was still electroplating residue on the inductor in the comparative example, while the preparation process of Examples 1 and 2 had little impact on the inductor, the inductor was made without electroplating residue, thus extending the storage shelf life of Examples 1 and 2 by 4 months compared to the comparative example.
[0107] In summary, the inductor components prepared using the methods provided in the embodiments of this application exhibit improved electrical performance, peel strength, corrosion resistance, and storage performance compared to the comparative components prepared using electroplating processes.
[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. An inductor element, characterized in that, include: An inductor body, the inductor body having an assembly surface; as well as A physical vapor deposition metal layer is disposed on the assembly surface; Wherein, in a direction parallel to the assembly surface, a partition groove is provided between the two ends of the physical vapor deposition metal layer. The partition groove is configured to break the physical vapor deposition metal layer into two parts along the thickness direction of the physical vapor deposition metal layer. One part of the physical vapor deposition metal layer is formed as the first lead electrode of the inductor body, and the other part of the physical vapor deposition metal layer is formed as the second lead electrode of the inductor body.
2. The inductor element according to claim 1, characterized in that, The physical vapor deposition metal layer includes multiple physical vapor deposition metal sub-layers, which are stacked sequentially in a direction away from the inductor body, and the thickness of each physical vapor deposition metal sub-layer is 0.1μm to 2μm.
3. The inductor element according to claim 2, characterized in that, The multiple physical vapor deposition metal sublayers are a combination of one or more of the following: an underlayer, a transition layer, or an anti-oxidation layer.
4. The inductor element according to claim 3, characterized in that, When the number of physical vapor deposition metal sublayers is three, the three physical vapor deposition metal sublayers are the underlayer, the transition layer and the anti-oxidation layer, and the underlayer, the transition layer and the anti-oxidation layer are sequentially stacked on the surface of the inductor body in a direction away from the inductor body.
5. The inductor element according to claim 3, characterized in that, The material of the base layer is selected from at least one of chromium or titanium; And / or, the material of the transition layer contains nickel; And / or, the material of the anti-oxidation layer is selected from at least one of silver or tin; And / or, the total thickness of the underlayer, the transition layer and the anti-oxidation layer is 0.3 μm to 6 μm.
6. The inductor element according to any one of claims 1 to 5, characterized in that, In the thickness direction of the inductor body, the dividing groove also extends into the inductor body.
7. The inductor element according to claim 6, characterized in that, The inductor body includes a magnet and a coil. The coil is enclosed in the magnet. The assembly surface is located on the magnet. The coil has two leads, which are electrically connected to the first lead electrode and the second lead electrode, respectively. In the thickness direction of the magnet, the partition groove extends into the magnet and is spaced apart from the coil.
8. The inductor element according to claim 7, characterized in that, The magnet includes an insulator and a plurality of magnetic powder particles encapsulated within the insulator; And / or, the thickness of the magnet is T1, the thickness of the physical vapor deposition metal layer is T2, and T2 / T1 = 0.05% to 1.09%; And / or, in the thickness direction of the magnet, the depth of the partition groove is 30 μm to 50 μm; And / or, the thickness of the magnet is 0.5 mm to 0.7 mm.
9. A method for preparing an inductor element as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Blocking non-deposition areas: The blocking member is placed on the assembly surface of the inductor body, and in a direction parallel to the assembly surface, the blocking member is at least partially located between the two ends of the assembly surface; Physical vapor deposition: The physical vapor deposition metal layer is obtained by performing physical vapor deposition on the assembly surface in a vacuum environment.
10. The preparation method according to claim 9, characterized in that, The inductor body also includes an end face and a side face, the end face being disposed opposite to the assembly surface, and the side face being connected between the end face and the assembly surface; In the step of shielding the non-deposition area, a plurality of inductor bodies are placed side by side into a fixture, the end face of each inductor body is shielded by the fixture, and the side faces of two adjacent inductor bodies are pressed together and shielded.
11. An electronic device, characterized in that, It includes the inductor element as described in any one of claims 1 to 8, or the inductor element prepared by the preparation method as described in claim 9 or 10.