An integrated chip resistor

Abstract

This invention discloses an integrated surface mount resistor, comprising a substrate, with harmonic-shaped resistive layers disposed on both sides of the substrate. The induced magnetic fields generated by the alternating current at the rising and falling edges of the resistive layers cancel each other out. The current flows in opposite directions on the resistive layers on both sides of the substrate, and the two resistive layers together form induced electromagnetic fields with opposite directions. A compensation component is disposed between the two resistive layers. The compensation component includes an insulating shell, an adjustable resistor strip mounted on the inner side of the insulating shell, and a sliding electrode slidably disposed on the outer side of the adjustable resistor strip. A temperature-controlled elastic phase change element is disposed between the sliding electrode and the insulating shell. This design effectively reduces parasitic inductance effects, enabling the surface mount resistor to maintain stable impedance characteristics in high-frequency AC circuits, significantly reducing energy loss and signal distortion caused by induced magnetic fields. The compensation component dynamically compensates for resistance drift caused by temperature changes in the resistive layers, improving the accuracy and reliability of the resistor under wide temperature range conditions.

Description

Technical Field

[0001] This invention relates to the field of resistor technology, and more particularly to an integrated surface mount resistor. Background Technology

[0002] Chip resistors are a basic passive component in surface mount devices. By placing resistive material on an insulating substrate and equipping it with an electrode structure, they enable the regulation of current and the distribution of voltage in a circuit, and are widely used in various electronic devices.

[0003] Currently, thick-film chip resistors are one of the most widely used types on the market. Existing thick-film chip resistors typically use alumina ceramic as the substrate, and a resistive paste (such as ruthenium dioxide-based paste) is printed onto the substrate surface using a screen printing process. After high-temperature sintering, a resistive layer is formed, followed by an insulating protective layer. Terminal electrodes are then fabricated at both ends of the substrate to form a complete chip package structure.

[0004] However, existing surface mount resistors still have the following shortcomings. On the one hand, it is difficult to extend the resistor path and increase the heat dissipation area on a limited substrate area. The current flow direction of traditional surface mount resistors is consistent, making it difficult to effectively suppress parasitic inductance. Under high frequency conditions, there is still a large parasitic inductance, which affects signal integrity. On the other hand, the temperature compensation method of existing resistor layers mainly relies on the temperature coefficient characteristics of the material itself and lacks an active adjustment mechanism. Under wide temperature range operating conditions, the resistance drift is relatively significant. Therefore, in order to solve the above problems, an integrated surface mount resistor is proposed. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing an integrated surface mount resistor.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An integrated surface mount resistor includes a substrate, on both sides of which are provided a harmonic-shaped resistive layer. The induced magnetic fields generated by the alternating current at the rising and falling edges of the resistive layers cancel each other out. The current flows in opposite directions on the resistive layers on both sides of the substrate. The two resistive layers together form an induced electromagnetic field with opposite directions and cancel each other out. A compensation component is provided between the two resistive layers. The compensation component includes an insulating shell, an adjustable resistor strip is installed on the inner side of the insulating shell, a sliding electrode is slidably disposed on the outer side of the adjustable resistor strip, and a temperature-controlled elastic phase change element is disposed between the sliding electrode and the insulating shell.

[0007] The above technical solution further includes: Several harmonic protrusions are fixedly arranged at equal intervals on both sides of the substrate. The several harmonic protrusions are combined to form a continuous harmonic waveform protrusion with fixed amplitude and period. The harmonic protrusions on both sides are symmetrically arranged and extend along the length direction of the substrate.

[0008] The resistive layer is disposed on the harmonic protrusion. At the same cross-sectional position, the current directions of the resistive layers on both sides are opposite and parallel. The induced magnetic fields generated by the resistive layers on both sides are superimposed in opposite directions and cancel each other out.

[0009] An insulating layer is provided on the outside of the resistive layer, and a protective layer is provided on the outside of the insulating layer. Both the insulating layer and the protective layer are provided along the outer contour of the harmonic protrusion, and the harmonic protective layer on both sides of the substrate is used to increase the heat dissipation area.

[0010] The compensation component also includes an adjustment groove formed on the adjustment resistor bar, and a fixed electrode is fixedly provided on the inner wall of the insulating shell. The elastic phase change element is a phase change spring, one end of which is connected to the fixed electrode and the other end is connected to the sliding electrode.

[0011] The sliding electrode is slidably sleeved on the inner side of the adjustment groove, and the sliding electrode maintains electrical contact with the adjustment resistor strip; When the ambient temperature changes, the phase change spring expands and contracts with the temperature, changing the effective length of the regulating resistor bar connected to the circuit, thereby achieving temperature compensation of the resistance value.

[0012] One end of the resistive layer on one side is electrically connected to a first connecting electrode, and the same end of the resistive layer on the other side is electrically connected to a second connecting electrode. The first connecting electrode is electrically connected to one end of the adjusting resistor strip, and the second connecting electrode is electrically connected to the fixed electrode.

[0013] The first and second connecting electrodes are wrapped with an electrode insulating protective layer, and the insulating shell is fixed to the outside of the electrode insulating protective layer.

[0014] Both sides of the resistive layer are electrically connected to an external electrode at the end away from the insulating shell. The external electrode is bent and extended along the end face of the substrate. The outer side of the external electrode is plated with a nickel plating layer and a tin plating layer from the inside to the outside, forming a surface mount soldering end.

[0015] The harmonic protrusion is a continuous sinusoidal wave structure, and the ratio of the peak height to the wavelength of a single harmonic protrusion is 1:3 to 1:5.

[0016] The present invention has the following beneficial effects: 1. In this invention, the harmonic-shaped resistive layers symmetrically arranged on both sides of the substrate work together with the compensation components to cancel out the induced magnetic fields generated by the alternating current at the rising and falling edges of the resistive layers. At the same time, the current flows in opposite directions on the two resistive layers and the overall induced electromagnetic directions are opposite and cancel each other out. This structure effectively reduces the parasitic inductance effect and reduces energy loss and signal distortion caused by the induced magnetic field.

[0017] 2. In this invention, when the ambient temperature changes, the phase change spring of the compensation component expands and contracts with the temperature, causing the sliding electrode to slide along the adjustment groove to change the effective length of the adjustment resistor strip connected to the circuit. This dynamically compensates for the resistance drift of the resistor layer caused by temperature changes, so that the overall resistance value of the entire chip resistor remains highly stable within the operating temperature range, effectively improving the accuracy and reliability of the resistor under wide temperature range conditions. Attached Figure Description

[0018] Figure 1 This is a top view schematic diagram of the overall structure of an integrated surface mount resistor proposed in this invention; Figure 2 This is a schematic diagram of the overall bottom view structure in this invention; Figure 3 This is a schematic diagram of the first cross-sectional structure of the resistor in this invention; Figure 4 This is a schematic second cross-sectional view of the resistor in this invention; Figure 5 for Figure 3 Enlarged schematic diagram of the structure at point A in the middle; Figure 6 for Figure 3 Enlarged schematic diagram of the structure at point B; Figure 7 for Figure 4 Enlarged schematic diagram of the structure at point C; In the diagram: 1. Protective layer; 10. Tin plating layer; 11. Substrate; 12. Harmonic bump; 13. Insulating layer; 14. Resistive layer; 15. First connecting electrode; 16. Electrode insulating protective layer; 17. Second connecting electrode; 18. External electrode; 19. Nickel plating layer; 2. Insulating shell; 20. Adjusting resistor strip; 21. Adjusting groove; 22. Fixed electrode; 23. Phase change spring; 24. Sliding electrode. Detailed Implementation

[0019] 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.

[0020] Example 1 like Figures 1-7 As shown, the present invention proposes an integrated chip resistor, including a substrate 11, on both sides of the substrate 11, a resistor layer 14 in the shape of a harmonic. The current flows in opposite directions in the rising and falling sections of the harmonic path, and the resulting induced magnetic fields are opposite in direction and cancel each other out. The current flows in opposite directions on the resistor layers 14 on both sides of the substrate 11, and the two resistor layers 14 as a whole form an induced electromagnetic field with opposite directions and cancel each other out. A compensation component is provided between the two resistive layers 14. The compensation component includes an insulating shell 2. An adjustable resistor strip 20 is installed on the inner side of the insulating shell 2. A sliding electrode 24 is slidably provided on the outer side of the adjustable resistor strip 20. A temperature-controlled elastic phase change element is provided between the sliding electrode 24 and the insulating shell 2.

[0021] This design allows for the increase of the printed length of the resistor layer 14 by using a sinusoidal harmonic shape on a substrate 11 of fixed length. According to the thick-film resistor formula R=Rs×(L / W) (Rs is the sheet resistance, L is the length, and W is the width), the resistance value of a linear resistor is limited by the substrate size when the substrate length is fixed. To increase the resistance value, the lines must be printed extremely finely, but fine lines printed by screen printing are prone to breakage, jagged edges, or uneven film thickness. The sinusoidal design allows for the easy achievement of high resistance values ​​by extending the physical length while maintaining sufficient linewidth, avoiding process scrap due to excessively narrow linewidth.

[0022] Furthermore, the rated power of a resistor is positively correlated with its effective heat dissipation area. The sinusoidal path is longer than a straight line, and the waveform bends outward, which significantly increases the total surface area of ​​the resistor layer. More importantly, in conjunction with the harmonic protrusions 12 on both sides of the substrate and the wave profile of the protective layer 1, the heat source is evenly distributed over the wide area of ​​the substrate. This reduces the heat flux density per unit area, thereby allowing the resistor to withstand greater transient impact power and significantly improving power stability under long-term loading.

[0023] Furthermore, the initial resistance tolerance of thick-film printing is typically between ±15% and ±20%, usually requiring laser cutting of the resistor element for fine-tuning. For short, straight resistors, laser cutting off a small section results in a large rate of resistance change, making precise control difficult. In contrast, sine waves have an extremely long total length; during laser cutting, the portion removed is a very small proportion of the total length, resulting in a very precise increase in resistance with each cut, significantly improving the yield rate.

[0024] Furthermore, under the same operating current conditions, the current flows through a longer resistance path, resulting in a corresponding decrease in current density per unit cross-sectional area. A lower current density means reduced electron wind impact on the conductive particles within the resistor, which significantly suppresses resistance drift under high loads, extending the resistor's lifespan and long-term stability.

[0025] Furthermore, conventional wire-wound resistors often have high parasitic inductance due to frequent reversals of the current direction. In this design, however, the rising and falling edges of the sine wave are used to generate reverse induced magnetic fields that cancel each other out.

[0026] Furthermore, during the operation of the resistor, changes in ambient temperature can cause the resistance value of the resistor layer 14 to drift. Through the compensation component, when the ambient temperature rises, the phase change spring 23 is heated and elongates, pushing the sliding electrode 24 to slide along the adjustment groove 21, increasing the effective resistance strip length connected to the circuit; when the ambient temperature drops, the phase change spring 23 contracts, causing the sliding electrode 24 to slide in the opposite direction, reducing the effective resistance strip length connected to the circuit.

[0027] Example 2 like Figures 1-7 As shown, based on Embodiment 1, in this embodiment, a plurality of harmonic protrusions 12 are fixedly arranged at equal intervals on both sides of the substrate 11. The plurality of harmonic protrusions 12 are combined to form a continuous harmonic waveform protrusion with fixed amplitude and period. The harmonic protrusions 12 on both sides are symmetrically arranged and extend along the length direction of the substrate 11.

[0028] An insulating layer 13 is provided on the outer side of the resistive layer 14, and a protective layer 1 is provided on the outer side of the insulating layer 13. Both the insulating layer 13 and the protective layer 1 are provided along the outer contour of the harmonic protrusion 12, and the harmonic protective layer 1 on both sides of the substrate 11 is used to increase the heat dissipation area.

[0029] Both ends of the resistive layers 14 away from the insulating shell 2 are electrically connected to external electrodes 18. The external electrodes 18 are bent and extended along the end face of the substrate 11. The outer side of the external electrodes 18 is plated with a nickel plating layer 19 and a tin plating layer 10 from the inside to the outside, forming the solder end for surface mounting.

[0030] Furthermore, a resistive layer 14 covers the harmonic protrusions 12 disposed on both sides of the substrate 11. The harmonic protrusions 12 are sinusoidal continuous structures with a single peak height to wavelength ratio of 1:3 to 1:5, extending along the length of the substrate 11 and arranged at equal intervals, with the harmonic protrusions 12 on both sides symmetrically arranged. When alternating current flows along the harmonic-shaped resistive layer 14, the current generates induced magnetic fields in opposite directions at the rising and falling edges of each harmonic cycle.

[0031] Furthermore, if the waveform is too gentle (the ratio is too small), the effect of this local reverse current will be weakened, affecting the effect of canceling parasitic inductance. A ratio of 1:3 to 1:5 ensures that the waveform has sufficient undulation. If the waveform is steeper (the larger the ratio), the potential difference between the resistive layer and the substrate will be greater, and the parasitic capacitance will be more significant. At the same time, this ratio range also takes into account the feasibility of screen printing process and avoids distortion of printed patterns due to excessively steep peaks.

[0032] Furthermore, since the current directions of the two resistive layers 14 are opposite and parallel, and the harmonic protrusions 12 are symmetrically arranged, the induced magnetic fields generated on both sides at the same cross-sectional location are opposite in direction. According to the law of electromagnetic induction, the opposite induced magnetic fields cancel each other out after being superimposed in space, thereby significantly reducing the parasitic inductance effect when the resistor is working.

[0033] Furthermore, the protective layer 1 itself mainly serves an insulating function. Meanwhile, the harmonic protective layer 1 on both sides of the substrate 11 adopts a wavy profile, which significantly increases the contact area with air compared to a planar structure, effectively improving heat dissipation efficiency and ensuring that the Joule heat generated by the resistor under high current operating conditions can be dissipated in a timely manner.

[0034] Furthermore, when the external circuit is connected to AC power through the external electrode 18, the current flows along the resistive layers 14 on both sides of the substrate 11. The external electrode 18 bends and extends along the end face of the substrate 11, and its outer side is plated with a nickel plating layer 19 and a tin plating layer 10 from the inside to the outside, forming the solder end for surface mounting; Furthermore, the nickel plating layer 19 is used to improve the heat resistance during welding and prevent ion migration, while the tin plating layer 10 serves as a solderable layer to ensure good solderability. The current flows into the resistive layer 14 on one side of the substrate 11 through an external electrode 18, flows through the compensation assembly, passes through the resistive layer 14 on the other side, and flows out from the external electrode 18 on that side. Furthermore, the substrate 11 is made of 96% aluminum oxide ceramic material, which has good electrical insulation and high-temperature thermal conductivity; Furthermore, the resistive layer 14 is formed by printing and sintering resistive pastes such as ruthenium dioxide.

[0035] Furthermore, the current directions of the two resistive layers 14 are opposite and parallel at the same cross-sectional position of the substrate 11. One end of one resistive layer 14 is electrically connected to one end of the adjusting resistor strip 20 through the first connecting electrode 15, and the same end of the other resistive layer 14 is electrically connected to the fixed electrode 22 through the second connecting electrode 17, thereby forming a complete current loop.

[0036] Furthermore, the outer sides of the first connecting electrode 15 and the second connecting electrode 17 are covered with an electrode insulating protective layer 16, and the insulating shell 2 is fixed to the outer side of the electrode insulating protective layer 16.

[0037] The compensation component also includes an adjustment groove 21 formed on the adjustment resistor bar 20, a fixed electrode 22 fixedly disposed on the inner wall of the insulating shell 2, and an elastic phase change element, which is a phase change spring 23. One end of the phase change spring 23 is connected to the fixed electrode 22, and the other end is connected to the sliding electrode 24. The phase change spring 23 is disposed at the end of the adjustment resistor bar 20 away from the first connecting electrode 15.

[0038] The sliding electrode 24 is slidably sleeved on the inner side of the adjustment groove 21, and the sliding electrode 24 maintains electrical contact with the adjustment resistor bar 20; When the ambient temperature changes, the phase change spring 23 expands and contracts with the temperature, changing the effective length of the regulating resistor bar 20 connected to the circuit, thereby achieving temperature compensation of the resistance value.

[0039] Furthermore, the ring compensation component is connected to the circuit, and the adjusting resistor strip 20 is connected in series with the two resistor layers 14. The compensation component changes the value of the variable part in the total series resistance, thereby offsetting the drift of the resistor layer 14 itself. The sheet resistance and temperature coefficient of resistance of the thick film resistor are affected by the material system composition. The resistance of the resistor layer 14 formed by sintering ruthenium dioxide resistor paste will change accordingly as the temperature rises.

[0040] Furthermore, when the ambient temperature rises, the phase change spring 23 stretches due to heat, pushing the sliding electrode 24 to slide along the adjustment groove 21, increasing the effective resistance bar length connected to the circuit; when the ambient temperature drops, the phase change spring 23 contracts, causing the sliding electrode 24 to slide in the opposite direction, reducing the effective resistance bar length connected to the circuit.

[0041] Furthermore, the compensation component dynamically adjusts the total resistance value of the series-connected circuit according to temperature changes, thereby offsetting the resistance drift of the resistor layer 14 caused by temperature changes, and keeping the overall resistance value of the entire chip resistor stable within the operating temperature range.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated surface mount resistor, comprising a substrate (11), characterized in that, Both sides of the substrate (11) are provided with harmonic-shaped resistor layers (14). The induced magnetic fields generated by the alternating current at the rising and falling edges of the resistor layers (14) cancel each other out. The current flows in opposite directions on the resistor layers (14) on both sides of the substrate (11). The two resistor layers (14) together form an induced electromagnetic field with opposite directions and cancel each other out. A compensation component is provided between the two resistive layers (14). The compensation component includes an insulating shell (2). An adjusting resistor strip (20) is installed on the inner side of the insulating shell (2). A sliding electrode (24) is slidably provided on the outer side of the adjusting resistor strip (20). A temperature-controlled elastic phase change element is provided between the sliding electrode (24) and the insulating shell (2).

2. An integrated surface mount resistor according to claim 1, characterized in that, The substrate (11) has several harmonic protrusions (12) fixedly arranged at equal intervals on both sides. The several harmonic protrusions (12) are combined to form a continuous harmonic waveform with fixed amplitude and period. The harmonic protrusions (12) on both sides are symmetrically arranged and extend along the length direction of the substrate (11).

3. An integrated surface mount resistor according to claim 1, characterized in that, The resistive layer (14) is disposed on the harmonic protrusion (12). At the same cross-sectional position, the current directions of the two resistive layers (14) are opposite and parallel. The induced magnetic fields generated by the two resistive layers (14) are superimposed in opposite directions and cancel each other out.

4. An integrated surface mount resistor according to claim 1, characterized in that, An insulating layer (13) is provided on the outside of the resistive layer (14), and a protective layer (1) is provided on the outside of the insulating layer (13). Both the insulating layer (13) and the protective layer (1) are provided along the outer contour of the harmonic protrusion (12), and the harmonic protective layer (1) on both sides of the substrate (11) is used to increase the heat dissipation area.

5. An integrated surface mount resistor according to claim 1, characterized in that, The compensation component also includes an adjustment groove (21) opened on the adjustment resistor bar (20), and a fixed electrode (22) is fixedly provided on the inner wall of the insulating shell (2). The elastic phase change element is a phase change spring (23), one end of the phase change spring (23) is connected to the fixed electrode (22), and the other end is connected to the sliding electrode (24).

6. An integrated surface mount resistor according to claim 5, characterized in that, The sliding electrode (24) is slidably sleeved on the inner side of the adjustment groove (21), and the sliding electrode (24) maintains electrical contact with the adjustment resistor bar (20); When the ambient temperature changes, the phase change spring (23) expands and contracts with the temperature, changing the effective length of the regulating resistor strip (20) connected to the circuit, thereby achieving temperature compensation of the resistance value.

7. An integrated surface mount resistor according to claim 1, characterized in that, One end of the resistive layer (14) on one side is electrically connected to a first connecting electrode (15), and the same end of the resistive layer (14) on the other side is electrically connected to a second connecting electrode (17). The first connecting electrode (15) is electrically connected to one end of the adjusting resistor strip (20), and the second connecting electrode (17) is electrically connected to the fixed electrode (22).

8. An integrated surface mount resistor according to claim 7, characterized in that, The first connecting electrode (15) and the second connecting electrode (17) are wrapped with an electrode insulating protective layer (16), and the insulating shell (2) is fixed on the outside of the electrode insulating protective layer (16).

9. An integrated surface mount resistor according to claim 1, characterized in that, Both sides of the resistive layer (14) are electrically connected to an external electrode (18) at the end away from the insulating shell (2). The external electrode (18) is bent and extended along the end face of the substrate (11). The outer side of the external electrode (18) is plated with a nickel plating layer (19) and a tin plating layer (10) from the inside to the outside, forming a surface mount soldering end.

10. An integrated surface mount resistor according to claim 2, characterized in that, The harmonic protrusion (12) is a continuous sinusoidal wave structure, and the ratio of the peak height to the wavelength of a single harmonic protrusion (12) is 1:3 to 1:5.

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