Laminated chip inductor

Abstract

The utility model discloses a laminated chip inductor which comprises a main body and an outer electrode, the outer electrode is arranged on the outer surface of the main body, the main body comprises a middle wire part, leading-out parts and an insulating part, the middle wire part is arranged between the two leading-out parts, the leading-out parts and the middle wire part are arranged in a stacked mode, and the insulating part is arranged between the two leading-out parts. The insulating parts are arranged between the middle wire parts and between the middle wire parts and the leading-out parts, the middle wire parts are communicated with the outer electrode through the leading-out parts, each leading-out part comprises a coil structure and a leading-out end, and the ratio of the maximum thickness of each leading-out end to the thickness of the coil structure ranges from 2 to 3. And the ratio of the maximum width of the leading-out end to the width of the coil structure is 2-3. The thickness and the width of the leading-out end are increased, so that the contact area between the leading-out end and the outer electrode is increased, the conduction probability between the inner electrode and the outer electrode is improved, and the direct-current resistance characteristic of the inductor and the joint reliability of the leading-out end and the outer electrode under large current are improved.

Description

Technical Field

[0001] This utility model relates to the field of inductor technology, and in particular to a multilayer chip inductor. Background Technology

[0002] The fabrication method of multilayer chip inductors mainly involves printing coils on ferrite or ceramic substrates, stacking multiple coil layers, pressing and sealing the coil layers, sintering the coil layers to obtain a laminate, and finally forming external electrodes at both ends of the sintered laminate. During sintering, the contact area between the coil layer leads and the external electrodes may decrease. Due to the reduced contact area between the leads and the external electrodes, the DC resistance characteristics of the inductor may deteriorate. When a large current flows through the multilayer coil component, the electroplated components in the external electrodes can diffuse into the silver layer, especially Ni, which further reduces the bonding reliability between the leads and the external electrodes. Utility Model Content

[0003] The technical problem to be solved by this utility model is that the DC resistance characteristics of the inductor may be degraded due to the small contact area between the lead-out terminal and the external electrode. When a large current flows through the multilayer coil component, the connection reliability between the lead-out terminal and the external electrode is further reduced.

[0004] To address the aforementioned technical problems, this utility model provides a multilayer chip inductor, comprising a main body and an external electrode. The external electrode is disposed on the outer surface of the main body. The main body includes a central conductor portion, a lead-out portion, and an insulating portion. The central conductor portion is disposed between two of the lead-out portions, and the lead-out portions are stacked with the central conductor portion. The insulating portion is disposed between the central conductor portions and between the central conductor portion and the lead-out portion. The central conductor portion communicates with the external electrode through the lead-out portion. The lead-out portion includes a coil structure and a lead end. The ratio of the maximum thickness of the lead end to the thickness of the coil structure is in the range of 2-3, and the ratio of the maximum width of the lead end to the width of the coil structure is in the range of 2-3.

[0005] Furthermore, the ratio of the maximum thickness of the lead-out end to the thickness of the coil structure is in the range of 2.1-2.5, and the ratio of the maximum width of the lead-out end to the width of the coil structure is in the range of 2.1-2.5.

[0006] Furthermore, the lead-out end includes a lead-out section and a connecting section. The lead-out section is located near the outer boundary of the main body and is connected to the external electrode. One end of the connecting section is connected to the lead-out section, and the other end is connected to the coil structure. The thickness of the lead-out section is the maximum thickness of the lead-out end, the width of the lead-out section is the maximum width of the lead-out end, and the lead-out section occupies 1 / 3 to 1 / 2 of the length of the lead-out end. The thickness of the connecting section is equal to the thickness of the coil structure.

[0007] Furthermore, the thickness of the lead-out section is greater than the thickness of the coil structure; the ratio of the thickness of the lead-out section to the thickness of the connecting section is in the range of 2.1-2.5; the ratio of the width of the lead-out section to the width of the connecting section is in the range of 2.1-2.5.

[0008] Furthermore, the insulating part includes a ferrite sintered body or a ceramic sintered body, and the intermediate conductor part and the lead-out part include a metal sintered body.

[0009] Furthermore, the sintered metal body includes Ag, Al, Ni, Ti, Au, Cu, or Pt.

[0010] Furthermore, the lead-out section, connecting section, and coil structure are all made of the same metal material.

[0011] Furthermore, the lead-out section includes a first layer and a second layer, with the first layer disposed on the second layer. The first layer and the second layer are made of different metal materials, while the second layer, the connecting section, and the coil structure are made of the same metal material.

[0012] Furthermore, the projection of the first layer in the height direction at least partially covers the second layer.

[0013] Furthermore, the ratio of the thickness of the first layer to the thickness of the second layer covering the second layer portion is in the range of 1.1-1.5; the ratio of the width of the first layer to the width of the second layer covering the second layer portion is in the range of 0.5-1.

[0014] Compared with the prior art, the multilayer chip inductor provided in this embodiment of the utility model has the following advantages:

[0015] This embodiment of the invention increases the thickness and width of the lead-out terminals, thereby increasing the contact area between the lead-out terminals and the external electrode. This helps to improve the conductivity between the internal and external electrodes, enhances the DC resistance characteristics of the inductor, and improves the reliability of the connection between the lead-out terminals and the external electrode under high current. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the structure of the multilayer chip inductor provided in this embodiment of the utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the intermediate conductor portion and the insulation portion provided in an embodiment of this utility model;

[0018] Figure 3 This is a schematic diagram of the structure of the lead-out portion and the insulating portion provided in an embodiment of this utility model;

[0019] Figure 4 This is a front view of the lead-out section provided in this embodiment of the utility model;

[0020] In the diagram, 1 is the main body; 11 is the middle conductor section; 111 is the conductor layer; 12 is the lead-out section; 121 is the coil structure; 122 is the lead-out end; 1221 is the lead-out section; 12211 is the first layer; 12212 is the second layer; 1222 is the connecting section; 13 is the insulation part; and 2 is the external electrode. Detailed Implementation

[0021] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0022] like Figures 1 to 3 As shown, this utility model provides a multilayer chip inductor, including a main body 1 and an external electrode 2. The external electrode 2 is disposed on the outer surface of the main body 1 for connecting to a circuit. The main body 1 includes a middle conductor portion 11, a lead-out portion 12, and an insulating portion 13. The middle conductor portion 11 is disposed between two lead-out portions 12, and the lead-out portions 12 and the middle conductor portion 11 are stacked. The insulating portion 13 is disposed between the middle conductor portions 11 and between the middle conductor portion 11 and the lead-out portion 12. The middle conductor portion 11 is connected to the external electrode 2 through the lead-out portion 12. The lead-out portion 12 includes a coil structure 121 and a lead-out end 122. The ratio of the maximum thickness of the lead-out end 122 to the thickness of the coil structure 121 is in the range of 2-3, and the ratio of the maximum width of the lead-out end 122 to the width of the coil structure 121 is in the range of 2-3.

[0023] This embodiment increases the thickness and width of the lead-out terminal 122, thereby increasing the contact area between the lead-out terminal 122 and the external electrode 2. This helps to improve the conductivity between the inner and outer electrodes, improves the DC resistance characteristics of the inductor, and enhances the reliability of the connection between the lead-out terminal 122 and the external electrode 2 under high current.

[0024] Furthermore, this embodiment optimizes the dimensions of the lead-out terminal 122 and the coil structure 121. When the ratio of the maximum thickness of the lead-out terminal 122 to the thickness of the coil structure 121 is greater than 3, the improvement in connection reliability is limited. As the ratio of the maximum thickness of the lead-out terminal 122 to the thickness of the coil structure 121 further increases, the lead-out terminal 122 occupies too much internal space, which is not conducive to the design of high-sensitivity products and is not economical. When the ratio of the maximum thickness of the lead-out terminal 122 to the thickness of the coil structure 121 is less than 2, the increase in the contact area between the lead-out terminal 122 and the external electrode 2 is small, and the increase in the probability of conduction between the internal and external electrodes is not significant. That is, when the ratio of the maximum thickness of the lead-out terminal 122 to the thickness of the coil structure 121 is kept between 2 and 3, the connection reliability can be effectively improved without occupying too much internal space, affecting the design of high-sensitivity products, or causing excessive costs.

[0025] Similarly, when the ratio of the maximum width of the lead-out terminal 122 to the width of the coil structure 121 is greater than 3, the printing cost increases, resulting in insufficient economic efficiency. When the ratio is less than 2, the increase in the contact area between the lead-out terminal 122 and the external electrode 2 is limited, and the increase in the probability of conduction between the internal and external electrodes is not significant. In other words, maintaining the ratio of the maximum width of the lead-out terminal 122 to the width of the coil structure 121 between 2 and 3 can ensure good electrical performance while avoiding unnecessary increases in printing costs.

[0026] Preferably, the ratio of the maximum thickness of the lead-out terminal 122 to the thickness of the coil structure 121 is in the range of 2.1-2.5. When the ratio is greater than 2.5, the improvement in connection reliability is relatively limited. As the ratio further increases, the lead-out terminal 122 occupies too much internal space, which is not conducive to the design of high-sensitivity products and is not economical. When the ratio is less than 2.1, the increase in the contact area between the lead-out terminal 122 and the external electrode 2 is small, and the increase in the probability of conduction between the internal and external electrodes is not significant.

[0027] Similarly, the ratio of the maximum width of the lead-out terminal 122 to the width of the coil structure 121 ranges from 2.1 to 2.5. When the ratio is greater than 2.5, the printing cost increases relatively, resulting in poor economic efficiency. When the ratio is less than 2.1, the increase in the contact area between the lead-out terminal 122 and the external electrode 2 is limited, and the increase in the probability of conduction between the internal and external electrodes is not significant.

[0028] Understandably, the intermediate conductor section 11 includes a plurality of stacked conductor layers 111, with adjacent conductor layers 111 isolated from each other by an insulation section 13.

[0029] Furthermore, the lead-out end 122 includes a lead-out section 1221 and a connecting section 1222. The lead-out section 1221 is located near the outer boundary of the main body 1 and is connected to the external electrode 2. One end of the connecting section 1222 is connected to the lead-out section 1221, and the other end is connected to the coil structure 121. The thickness of the lead-out section 1221 is the maximum thickness of the lead-out end 122, the width of the lead-out section 1221 is the maximum width of the lead-out end 122, and the lead-out section 1221 occupies 1 / 3 to 1 / 2 of the length of the lead-out end 122. The thickness of the connecting section 1222 is equal to the thickness of the coil structure 121.

[0030] In this embodiment, the lead-out section 1221, being the thickest and widest part of the lead-out terminal 122, increases the contact area with the external electrode 2, thereby reducing contact resistance and improving DC resistance characteristics. The larger contact area allows for a higher probability of conduction between the internal and external electrodes, ensuring effective current transmission, especially under high current conditions, effectively improving connection reliability. Furthermore, the lead-out section 1221 occupies 1 / 3 to 1 / 2 of the length of the lead-out terminal 122, better distributing external pressure and preventing stress concentration at a single point. This prevents breakage or failure due to excessive current or mechanical impact. By setting the thickness of the connecting section 1222 to match that of the coil structure 121, a continuous and robust path is ensured from the coil structure 121 to the lead-out section 1221 and then to the external electrode 2, enhancing the overall mechanical stability of the structure.

[0031] Furthermore, the thickness of the lead-out section 1221 is greater than the thickness of the coil structure 121. In this embodiment, by making the lead-out section 1221 thicker, the contact area between the lead-out section 1221 and the external electrode 2 can be increased, thereby reducing contact resistance and improving DC resistance characteristics. Under high current conditions, the thicker lead-out section 1221 can better withstand the heat and stress brought by the current, improve the reliability of the connection, and prevent overheating or material diffusion (such as Ni diffusion into the silver layer).

[0032] The ratio of the thickness of the lead-out section 1221 to the thickness of the connecting section 1222 ranges from 2.1 to 2.5. If the lead-out section 1221 is not thick enough, it may not be able to effectively increase the contact area with the external electrode 2, resulting in insignificant improvement in DC resistance characteristics and affecting reliability under high current. An excessively thick lead-out section 1221 will occupy too much internal space, affecting the design layout of other components; at the same time, it may lead to insufficient economic efficiency, as it requires more materials and potentially more complex processing techniques. In other words, the above ratio range ensures that the lead-out section 1221 is thick enough to provide good electrical and mechanical performance, while the connecting section 1222 maintains an appropriate thickness to maintain consistency with the coil structure 121. In addition, while ensuring performance improvement, it minimizes the occupation of internal space, ensures a compact design, and controls manufacturing costs.

[0033] The ratio of the width of the lead-out section 1221 to the width of the connecting section 1222 ranges from 2.1 to 2.5. If the width of the lead-out section 1221 is insufficient, the effect of increasing the contact area is limited, and the probability of conduction between the inner and outer electrodes will not significantly improve, which is detrimental to improving the electrical performance of the product. An excessively wide lead-out section 1221 not only increases printing costs but may also lead to challenges in product design, such as difficulty in achieving a compact design or the need for additional space to accommodate a wider lead-out section 122, thus affecting the overall economy and design flexibility. In other words, the above-mentioned ratio range, by widening the lead-out section 1221, further increases the contact area with the outer electrode 2, improves the probability of conduction, enhances current conduction efficiency, and the wider lead-out section 1221 also provides better mechanical support, making the connection between the lead-out section 1221 and the outer electrode 2 more stable.

[0034] Furthermore, the insulating part 13 includes a ferrite sintered body or a ceramic sintered body. Ferrite, understandably, is a material with high permeability and low loss characteristics. As the insulating part 13, the ferrite sintered body provides excellent electrical insulation performance while supporting effective magnetic field concentration, thus improving inductor efficiency. It is easy to process and mold, has relatively low cost, and exhibits excellent magnetic properties at high frequencies, helping to reduce eddy current losses and hysteresis losses. Ceramic materials typically possess extremely high heat resistance and chemical stability, as well as excellent electrical insulation properties. When used as the insulating part 13, the ceramic sintered body ensures effective isolation between coil layers, prevents short circuits, and can withstand high-temperature environments. Its high mechanical strength, good thermal and chemical stability make it suitable for applications requiring long-term stability and high reliability.

[0035] The intermediate conductor portion 11 and the lead-out portion 12 include a metal sintered body, which combines the good conductivity of metal with a certain mechanical strength. As the material of the intermediate conductor portion 11 and the lead-out portion 12, the metal sintered body can provide the necessary mechanical support and connection strength while maintaining good conductivity.

[0036] Furthermore, the sintered metal body includes Ag, Al, Ni, Ti, Au, Cu, or Pt.

[0037] Understandably, the metal sintered body in this embodiment is formed by sintering one of silver (Ag), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), or platinum (Pt), and the performance of the intermediate conductor portion 11 and the lead-out portion 12 can be optimized according to specific needs. For example, using silver can significantly reduce contact resistance, while adding nickel can improve mechanical strength and corrosion resistance.

[0038] Furthermore, the lead-out section 1221, the connecting section 1222, and the coil structure 121 are all made of the same metal material.

[0039] Understandably, using the same metal material in this embodiment reduces compatibility issues between different materials, avoids process complexity and potential quality problems caused by material differences, and simplifies supply chain management, reduces inventory types, and may lower procurement costs. Furthermore, using the same material ensures uniform conductivity throughout the current path (from the lead to the coil structure), reducing contact and interface resistance, thereby improving DC resistance characteristics. This metal material can be one of Ag, Al, Ni, Ti, Au, Cu, or Pt, preferably Ag.

[0040] like Figure 4 As shown, the lead-out section 1221 includes a first layer 12211 and a second layer 12212. The first layer 12211 is disposed on the second layer 12212. The first layer 12211 and the second layer 12212 are made of different metal materials. The second layer 12212, the connecting section 1222 and the coil structure 121 are made of the same metal material.

[0041] Understandably, this embodiment can improve DC resistance characteristics by selecting a material with better conductivity as the first layer 12211, thereby reducing the contact resistance between the lead-out section 1221 and the external electrode 2. The selection of the material for the first layer 12211 can be optimized based on its compatibility with the material of the external electrode 2 to ensure optimal electrical connection, especially under high current conditions. Furthermore, using different materials for the first layer 12211 and the second layer 12212 allows for different coefficients of thermal expansion and other physical properties, helping to disperse stress and reduce mechanical stress concentration caused by temperature changes. Using the same metal material for the second layer 12212, the connecting section 1222, and the coil structure 121 reduces compatibility issues between different materials and avoids process complexity and potential quality problems caused by material differences.

[0042] If the second layer 12212 has the same metal as the coil structure 121, which is Ag, the metal of the first layer 12211 can be one of aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu), or platinum (Pt).

[0043] Furthermore, the projection of the first layer 12211 in the height direction at least covers a portion of the second layer 12212, that is, the first layer 12211 at least covers a portion of the second layer 12212. By making the first layer 12211 and the second layer 12212 partially overlap, a larger contact area between them can be ensured, thereby reducing the contact resistance and improving the DC resistance characteristics. The larger contact area also helps to increase the probability of conduction between the inner and outer electrodes, especially under high current conditions, which enhances the bonding reliability between the lead-out terminal 122 and the outer electrode 2.

[0044] Furthermore, the ratio of the thickness of the first layer 12211 covering the second layer 12212 to the thickness of the second layer 12212 is in the range of 1.1-1.5. This can increase the contact area with the external electrode 2, thereby reducing contact resistance and improving DC resistance characteristics. Appropriately increasing the thickness of the first layer 12211 can provide additional mechanical support without affecting the overall design compactness, preventing delamination or breakage caused by external stress or temperature changes. If the ratio of the thickness of the first layer 12211 covering the second layer 12212 to the thickness of the second layer 12212 is less than 1.1, the first layer 12211 may not be thick enough, which may not effectively increase the contact area and reduce the contact resistance. Insufficient mechanical support makes it susceptible to stress. If the ratio of the thickness of the first layer 12211 covering the second layer 12212 to the thickness of the second layer 12212 is greater than 1.5, the first layer 12211 will be too thick, occupying too much internal space, affecting the design layout of other components, and may lead to increased costs and unnecessary weight.

[0045] The ratio of the width of the first layer 12211 covering the second layer 12212 to the width of the second layer 12212 is between 0.5 and 1. This ensures sufficient contact area to improve the conductivity probability between the inner and outer electrodes, especially under high current conditions, enhancing the bonding reliability between the lead-out section 1221 and the outer electrode 2. If the ratio of the width of the first layer 12211 covering the second layer 12212 to the width of the second layer 12212 is less than 0.5, the first layer 12211 may be too narrow, resulting in insufficient contact area and failing to significantly improve the conductivity probability between the inner and outer electrodes, also affecting the mechanical connection strength. If the ratio of the width of the first layer 12211 covering the second layer 12212 to the width of the second layer 12212 is greater than 1, the first layer 12211 may be wider than the second layer 12212, increasing printing costs and potentially causing challenges in product design, such as difficulty in achieving a compact design.

[0046] In summary, this utility model embodiment provides a multilayer chip inductor, which increases the contact area between the lead-out terminal 122 and the external electrode 2 by increasing the thickness and width of the lead-out terminal 122, thereby increasing the probability of conduction between the inner and outer electrodes, improving the DC resistance characteristics of the inductor, and enhancing the reliability of the connection between the lead-out terminal 122 and the external electrode 2 under high current.

[0047] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A multilayer chip inductor, characterized in that, The device includes a main body and an outer electrode. The outer electrode is disposed on the outer surface of the main body. The main body includes a middle conductor portion, a lead-out portion, and an insulating portion. The middle conductor portion is disposed between two lead-out portions, and the lead-out portions are stacked with the middle conductor portion. The insulating portion is disposed between the middle conductor portions and between the middle conductor portion and the lead-out portion. The middle conductor portion is connected to the outer electrode through the lead-out portion. The lead-out portion includes a coil structure and a lead-out end. The ratio of the maximum thickness of the lead-out end to the thickness of the coil structure is in the range of 2-3, and the ratio of the maximum width of the lead-out end to the width of the coil structure is in the range of 2-3.

2. The multilayer chip inductor according to claim 1, characterized in that, The ratio of the maximum thickness of the lead-out end to the thickness of the coil structure is in the range of 2.1-2.5, and the ratio of the maximum width of the lead-out end to the width of the coil structure is in the range of 2.1-2.

5.

3. The multilayer chip inductor according to claim 1, characterized in that, The lead-out end includes a lead-out section and a connecting section. The lead-out section is located near the outer boundary of the main body and is connected to the external electrode. One end of the connecting section is connected to the lead-out section, and the other end is connected to the coil structure. The thickness of the lead-out section is the maximum thickness of the lead-out end, and the width of the lead-out section is the maximum width of the lead-out end. The lead-out section occupies 1 / 3 to 1 / 2 of the length of the lead-out end. The thickness of the connecting section is equal to the thickness of the coil structure.

4. The multilayer chip inductor according to claim 3, characterized in that, The thickness of the lead-out section is greater than the thickness of the coil structure; the ratio of the thickness of the lead-out section to the thickness of the connecting section is in the range of 2.1-2.5; the ratio of the width of the lead-out section to the width of the connecting section is in the range of 2.1-2.

5.

5. The multilayer chip inductor according to claim 3, characterized in that, The insulating part includes a ferrite sintered body or a ceramic sintered body, and the intermediate conductor part and the lead-out part include a metal sintered body.

6. The multilayer chip inductor according to claim 5, characterized in that, The sintered metal body includes Ag, Al, Ni, Ti, Au, Cu, or Pt.

7. The multilayer chip inductor according to claim 6, characterized in that, The lead-out section, connecting section, and coil structure are all made of the same metal material.

8. The multilayer chip inductor according to claim 6, characterized in that, The lead-out section includes a first layer and a second layer, with the first layer disposed on the second layer. The first layer and the second layer are made of different metal materials, while the second layer, the connecting section, and the coil structure are made of the same metal material.

9. The multilayer chip inductor according to claim 8, characterized in that, The projection of the first layer in the height direction covers at least a portion of the second layer.

10. The multilayer chip inductor according to claim 9, characterized in that, The ratio of the thickness of the first layer to the thickness of the second layer covering the second layer portion is in the range of 1.1-1.5; the ratio of the width of the first layer to the width of the second layer covering the second layer portion is in the range of 0.5-1.

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