Thin film resistor structure

Abstract

This application provides a thin-film resistor structure, specifically comprising: a substrate; a resistive layer disposed on the surface of the substrate; a first electrode and a second electrode disposed at a distance from each other on the resistive layer and electrically connected to the resistive layer respectively; the resistive layer includes a resistance region located between the first electrode and the second electrode; the edges of the opposite sides of the first electrode and the second electrode are bent to form a bent resistance region, the total path length of the resistance region being greater than the longest distance between the two points of the orthographic projection of the first electrode on the surface of the resistive layer, and / or the longest distance between the two points of the orthographic projection of the second electrode on the surface of the resistive layer. This application, through the bent shape of the edges of the first electrode and the second electrode on opposite sides, makes the resistance region also have a bent shape, resulting in a longer total path length; since the width of the resistance region between the two electrodes is substantially equal to the total path length of the resistance region, the width of the resistance region is increased, thereby improving the breakdown resistance of the resistive layer and increasing the power that the thin-film resistor structure can carry.

Description

Technical Field

[0001] This application relates to the fields of thin-film resistors and hybrid integrated circuits, and specifically to a high-power thin-film resistor structure. Background Technology

[0002] As electronic devices become increasingly miniaturized, precise, and integrated, thin-film resistors, as important electronic components, exhibit advantages that thick-film resistors cannot match, such as high precision, high reliability, and high integration. With the ever-increasing demands for electronic device technology, thin-film resistors are widely used in electronic products due to their significant characteristics. Therefore, the fabrication of multifunctional, high-precision, and highly stable thin-film resistors has become an important task in modern thin-film resistor system research.

[0003] In the field of hybrid integrated circuits, thin-film resistors are also widely used. Their high precision, low temperature coefficient, and high stability help hybrid integrated circuits achieve their required functions, which cannot be replaced by other types of resistors.

[0004] Figure 1 and Figure 2 The diagram shows a top and side view of a conventional thin-film resistor fabricated using thin-film technology. The thin-film resistor includes a substrate (03), a resistive layer (02) on the substrate, and electrodes (01) at both ends of the resistive film. In existing thin-film resistor structures, due to the thinness of the thin-film resistive layer, applying a high-power current to both ends of the thin-film resistor can cause overheating and burnout or resistor breakdown, posing a quality hazard. The reasons for this are twofold: firstly, the electrode layer needs to incorporate multiple functions such as conductivity, corrosion resistance, and weldability; the insufficient conductivity of the thin-film resistor electrode material limits the power transmission of the current, resulting in a high temperature of the thin-film resistor electrode; secondly, the thinness of the resistive film makes it prone to breakdown under high power and high current.

[0005] To avoid breakdown of thin-film resistors under high power, thick-film processes using paste as raw material are generally used in the fabrication of high-power, high-precision thin-film resistors. The resulting thin-film resistors typically have a thickness greater than 10µm, which significantly exceeds that of thin-film processes. Furthermore, thin-film resistors prepared using thick-film processes have lower precision, making them difficult to apply in fields requiring high precision (such as sampling resistors for brushed and brushless motors). Utility Model Content

[0006] To address or improve the aforementioned problems in the prior art, this application provides a thin-film resistor structure, which specifically includes: a substrate; a resistor layer disposed on the surface of the substrate; a first electrode and a second electrode disposed at intervals on the resistor layer and electrically connected to the resistor layer respectively; the resistor layer includes a resistance region located between the first electrode and the second electrode; wherein the edges of the opposite sides of the first electrode and the second electrode are bent to form a bent resistance region; the total path length of the resistance region is greater than: the longest distance between two points of the orthographic projection of the first electrode on the surface of the resistor layer, and / or the longest distance between two points of the orthographic projection of the second electrode on the surface of the resistor layer.

[0007] In the aforementioned scheme, the curved shape of the opposite side edges of the first and second electrodes makes the resistance region also curved, resulting in a longer total path length. Since the width of the resistance region between the two electrodes is essentially equal to the total path length of the resistance region, the aforementioned design increases the width of the resistance region, thereby improving the breakdown resistance of the resistance layer and increasing the power that the thin film resistor structure can carry.

[0008] Optionally, both the first electrode and the second electrode have a plurality of alternating protrusions and a plurality of recesses; the protrusions of the first electrode are at least partially embedded in the corresponding recesses of the second electrode, and the protrusions of the second electrode are at least partially embedded in the corresponding recesses of the first electrode.

[0009] Optionally, the resistance region has a meandering shape with a consistent width.

[0010] In the aforementioned scheme, the meandering resistance region has a longer total path length, resulting in a wider resistance region and further increasing the power that the thin-film resistor structure can handle. Simultaneously, the resistance region has a consistent width, and the resistance value distribution is relatively linear, facilitating subsequent steps such as laser adjustment.

[0011] Optionally, the thin-film resistor structure further includes a conductive layer; the conductive layer is disposed between the first electrode and the resistor layer, or the conductive layer is disposed between the second electrode and the resistor layer, or two conductive layers spaced apart are disposed between the first electrode and the resistor layer and between the second electrode and the resistor layer, respectively; wherein the orthogonal projection area of ​​the conductive layer on the surface of the resistor layer is greater than or equal to the orthogonal projection area of ​​the corresponding first electrode or second electrode on the surface of the resistor layer.

[0012] In the aforementioned scheme, a conductive layer is added to increase the load capacity of the thin film resistor leads (i.e., the conductive layer above the resistor layer and the electrodes). When a large current is applied to both ends of the electrodes, the added conductive layer can significantly increase the current that the thin film resistor structure can handle, thus preventing the electrodes from overheating or even burning out due to their weak load capacity.

[0013] Optionally, the thin-film resistor structure further includes: a first adhesive layer and / or a second adhesive layer; the first adhesive layer is disposed between the conductive layer and the corresponding resistive layer region, and the second adhesive layer is disposed between the corresponding conductive layer and the first electrode, and between the corresponding conductive layer and the second electrode.

[0014] In the aforementioned scheme, since the conductive layer is usually made of pure metal with weak adhesion, a first adhesive layer and a second adhesive layer are added between the resistive layer, the conductive layer and the electrode layer respectively. This ensures conductivity while improving the bonding force between the film layers and preventing the film layers from falling off.

[0015] Optionally, the first adhesive layer or the second adhesive layer is selected from a chromium metal layer, a titanium metal layer or a nickel metal layer.

[0016] Optionally, the conductive layer has a protrusion facing the substrate; the resistive layer does not cover the area between the protrusion and the substrate.

[0017] Optionally, the thin-film resistor structure further includes a first adhesive layer disposed between the conductive layer and the resistive layer, and between the protrusion of the conductive layer and the substrate.

[0018] The aforementioned protrusion reduces the width of the conductive portion of the resistive layer, allowing the first adhesive layer to directly contact the substrate. The protrusion facing the substrate increases the thickness of the conductive layer, further enhancing the performance of the thin-film resistor in carrying large currents.

[0019] Optionally, the thin-film resistor structure further includes a second adhesive layer, which is disposed between the corresponding conductive layer and the first electrode, and between the corresponding conductive layer and the second electrode.

[0020] Optionally, the thickness of the resistive layer is 0.01 μm to 0.1 μm. Unlike thin-film resistors prepared by thick-film processes, which have a thickness greater than 10 μm, the technical solution in this application uses thin-film processes such as magnetron sputtering to form a thinner resistive layer of 0.01 μm to 0.1 μm, which has higher precision. It can be precisely adjusted using laser or other means, and is suitable for sampling resistors of brushed and brushless motors with high precision requirements. It can also be used as a protection and current-limiting resistor.

[0021] In summary, the thin-film resistor structure provided in this application embodiment has stronger breakdown resistance and stronger current load capacity compared with the prior art, and can effectively avoid problems such as resistor breakdown and resistor overheating burnout that are prone to occur in the prior art. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application or the background art will be described below.

[0023] Figure 1 This is a top view of a thin-film resistor in the prior art, for reference only.

[0024] Figure 2 This is a side view of a thin-film resistor in the prior art, for reference only.

[0025] Figure 3 This is a top view schematic diagram of the thin film resistor structure provided in the embodiments of this application;

[0026] Figure 4 yes Figure 3 Schematic diagram of the cross section at point A-A';

[0027] Figure 5 This is another thin-film resistor structure provided in the embodiments of this application. Figure 3 Schematic diagram of the cross section at point A-A';

[0028] Figure 6 This is another thin-film resistor structure provided in the embodiments of this application. Figure 3 A cross-sectional schematic diagram at point A-A' in this embodiment shows that the electrode coverage area is smaller than the corresponding conductive layer.

[0029] Figure 7 This is a schematic diagram of an exemplary fabrication process (first part) of the thin-film resistor structure provided in the embodiments of this application.

[0030] Figure 8 This is a schematic diagram of an exemplary fabrication process of the thin-film resistor structure provided in the embodiments of this application (Part Two).

[0031] The image is labeled as follows:

[0032] 100: substrate;

[0033] 200: Resistor layer; 210: Resistance value area;

[0034] 310: First electrode, 320: Second electrode, 301: Protrusion, 302: Recess;

[0035] 400: Conductive layer; 410: Protrusion;

[0036] 510: First adhesive layer; 520: Second adhesive layer;

[0037] 01: Electrodes in the prior art;

[0038] 02: The resistive layer in existing technology;

[0039] 03: Substrate in the prior art. Detailed Implementation

[0040] In this specification, it will also be understood that when a structure is referred to as being "connected" to other structures relative to them, such as being "connected" to other structures, the structure may be directly connected to or directly coupled to the structure, or there may be an intervening third structure; in addition, in the embodiments of this application, "connection" may specifically be an electrical connection or a structural aspect, such as a connection between layers.

[0041] This application will now be described more fully below with reference to the accompanying drawings. However, this application can be implemented in many different ways and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided herein to make this application more detailed and complete, and to fully convey the scope of this application to those skilled in the art. The same reference numerals denote the same objects throughout the drawings.

[0042] To address the aforementioned problems in the prior art, this application provides a thin-film resistor structure, the top view of which is as follows: Figure 3 As shown, specifically, such as Figure 3 Cross-sectional view at point A-A': Figure 4 As shown, the thin-film resistor structure includes:

[0043] The substrate 100 is located at the bottom of the resistor structure.

[0044] Resistive layer 200 is disposed on the surface of substrate 100, for example Figure 4 The image shows the surface covered on the upper surface of the substrate 100.

[0045] The first electrode 310 and the second electrode 320 are disposed at intervals on the aforementioned resistive layer 200 and are electrically connected to the resistive layer 200 respectively.

[0046] Without considering electrical connections formed by other structures, the first electrode 310 and the second electrode 320 are electrically isolated from each other.

[0047] The resistive layer 200 includes a resistive region 210 located between the first electrode 310 and the second electrode 320. For example... Figure 3 As shown, the resistance region 210 is exposed at the gap between the first electrode 310 and the second electrode 320.

[0048] The edges of the first electrode 310 and the second electrode 320 on opposite sides are bent to form a bent resistance region 210.

[0049] The total path length of the bending of the resistance region 210 is greater than: the longest distance between the two points of the orthographic projection of the first electrode 310 on the surface of the resistive layer 200 (i.e., the distance between the two points that are furthest apart), and / or the longest distance between the two points of the orthographic projection of the second electrode 320 on the surface of the resistive layer 200.

[0050] The aforementioned longest distance between two points refers to the maximum distance between any two points within the range of the orthographic projection formed by the first electrode 310 or the second electrode 320 on the surface of the resistive layer 200.

[0051] It should be understood that the aforementioned opposite sides of the first electrode 310 and the second electrode 320 refer to the side of the first electrode 310 facing the second electrode 320 and the side of the second electrode 320 facing the first electrode 310, i.e. Figure 3 The first electrode 310 and the second electrode 320 are curved in a comb-like shape on their opposite sides. The shape of the opposite sides of the first electrode 310 and the second electrode 320 determines the geometry of the resistance region 210.

[0052] In alternative embodiments, such as Figure 4 As shown, the resistive layer 200 completely covers the area of ​​the substrate 100 directly below the first electrode 310 and the second electrode 320.

[0053] In another alternative embodiment, such as Figure 5 As shown, the resistive layer 200 only covers a portion of the substrate 100 region directly below the first electrode 310 and the second electrode 320.

[0054] In an alternative embodiment, the total path length of the bending of the resistance region 210 is greater than the length of the long side of the minimum circumscribed rectangle of either the first electrode 310 or the second electrode 320.

[0055] by Figure 3 For example, Figure 3 The long side of the smallest circumscribed rectangle of the first electrode 310 coincides with the top edge of the first electrode 310, the two short sides coincide with the left and right side edges of the first electrode 310 respectively, and the lower long side is tangent to the rounded corner of the lower convex part of the first electrode 310. Thus, the smallest circumscribed rectangle of the first electrode 310 is formed, and the length of the long side of the smallest circumscribed rectangle is the same as the horizontal length of the first electrode 310 in the figure.

[0056] It should be understood that the total path length mentioned in the foregoing embodiments refers to, for example, Figure 3 The curved resistance region 210 shown in the figure represents the path length along its centerline from one end to the other; in other words, it is equivalent to the length of the curved resistance region 210 after it has been "straightened out." For example... Figure 1 As shown, in the prior art, the edge of the resistance region adjacent to electrode 01 is a straight line and does not have a curve. Therefore, the width of the resistance region in the prior art depends on the width of the two electrodes 01 (along...). Figure 1The width of the longitudinal direction cannot exceed the longest distance between the two points of the orthographic projection formed by either electrode on the surface of the resistive layer. In the aforementioned embodiment of this application, the resistance region 210 also has a curved shape due to the curved shape of the opposite side edges of the first and second electrodes, giving it a longer total path length. Since the width of the resistance region (the area where the resistive layer actually provides resistance) between the two electrodes is substantially equal to the total path length of the resistance region 210, the aforementioned design increases the width of the resistance region, thereby improving the breakdown resistance of the resistive layer 200 and increasing the power that the thin film resistive structure in the embodiment can carry.

[0057] In a typical embodiment, an electrode layer is disposed above the resistive layer 200, i.e., on the side of the resistive layer 200 facing away from the substrate. The first electrode 310 and the second electrode 320 originate from the same electrode layer formed in the same process. By means of, for example, wet etching, gaps are etched into the electrode layer to expose a portion of the underlying resistive layer 200 (i.e., the resistance region 210). The aforementioned gaps separate the electrode layer into two electrically isolated parts, i.e., forming the first electrode 310 and the second electrode 320.

[0058] In a typical embodiment, such as Figure 3 As shown, the edges of the first electrode 310 and the second electrode 320 that are opposite to each other, namely the edge of the first electrode 310 toward the second electrode 320 (and also toward the resistance region 210), and the edge of the second electrode 320 toward the first electrode 310 (and also toward the resistance region 210), have matching and complementary shapes, for example, each recess on the edge of the first electrode 310 corresponds to each protrusion on the edge of the second electrode 320.

[0059] In a typical embodiment, such as Figure 3 As shown, the shapes of the first electrode 310 and the second electrode 320 are centrally symmetrical. In other words, after rotating the second electrode 320 180° around its thickness direction, its shape can coincide with that of the first electrode 310.

[0060] In an optional embodiment, the resistance region 210 is in the shape of a snake, a wave, or the like.

[0061] In an optional embodiment, the first electrode 310 and the second electrode 320 are formed above the resistive layer 200, that is, above the upper surface of the resistive layer 200 on the side facing away from the substrate, or are partially or completely embedded in the resistive layer 200. Regardless of the arrangement, the first electrode 310 and the second electrode 320 need to have a reliable electrical connection with the resistive layer 200.

[0062] Regarding the influence of the aforementioned curved, serpentine, or wavy resistance region 210 on the resistance value of the thin-film resistor product, refer to the formula R=ρL / DT, where ρ is resistivity, L is resistor length, D is resistor width, and T is resistive layer thickness. The serpentine pattern of the resistance region 210, in combination with the curved shape of the first and second electrodes, can increase the width D of the thin-film resistor per unit area (i.e., the length of the corresponding serpentine or wavy resistance region 210, more accurately, the total path length). The larger D is, the smaller the resistance R, thus resulting in extremely low resistance in the resistive portion, meeting the requirements for small resistance.

[0063] In the foregoing embodiments, the substrate 100 is used to provide mechanical support and an insulating base for the device, and its material can be selected from, but is not limited to, alumina ceramic (Al2O3), silicon (Si), glass, quartz or aluminum nitride (AlN).

[0064] In the foregoing embodiments, the resistive layer 200 may be selected from, but is not limited to, nickel-chromium alloy (NiCr, such as 80 / 20 Ni / Cr), tantalum nitride (TaN), chromium silicon oxide (Cr-Si-O), titanium (Ti), titanium tungsten (TiW) or other metal oxides (such as SnO2, In2O3).

[0065] In the aforementioned embodiments, the resistive layer 200 is formed by a thin film process.

[0066] In the aforementioned embodiment, the resistive layer 200 is formed by magnetron sputtering.

[0067] In the foregoing embodiments, the resistive layer 200, particularly the aforementioned resistance region 210, is patterned, for example by laser cutting or ablation, the pattern being used to fine-tune the resistance value to achieve the desired precision.

[0068] In a preferred embodiment, such as Figure 3 As shown, the edges of the first electrode 310 and the second electrode 320 each have a plurality of alternating protrusions 301 and a plurality of recesses 302; the protrusions 301 of the first electrode 310 are at least partially embedded in the corresponding recesses 302 of the second electrode 320, and the protrusions 301 of the second electrode 320 are at least partially embedded in the corresponding recesses 302 of the first electrode 310.

[0069] In an alternative embodiment, the width of the recess 302 is three times that of the protrusion 301, so that the formed resistance region 210 has a consistent width.

[0070] In a preferred embodiment, the corners of the recess 302 and the ends of the protrusion 301 are rounded with the same radius.

[0071] In another representation, the first electrode 310 and the second electrode 320 are comb-shaped with the same shape. The "comb teeth" of the two electrodes, i.e., the aforementioned protrusions 301, are inserted into the resistance region 210 from both sides in an alternating manner on the orthographic projection of the surface of the resistance region 210, so that the resistance region 210 has a curved shape. Obviously, this design significantly increases the path length of the resistance region 210, that is, increases the width of the resistance region, and avoids the risk of the resistance layer 200 being broken down.

[0072] Preferably, such as Figure 3 As shown, the resistance region 210 has a meandering shape with a consistent width.

[0073] Preferably, the resistance region 210 has a regularly extending meandering shape.

[0074] In the aforementioned embodiments, the regularly meandering resistance region has a longer total path length, resulting in a wider resistance region and further increasing the power that the thin-film resistor structure can handle. Simultaneously, the resistance region 210 has a consistent width, and the resistance value changes linearly, facilitating subsequent steps such as laser adjustment.

[0075] To address the problem in existing technologies where the insufficient conductivity of thin-film resistor electrode materials limits current transmission power, leading to overheating and burnout of the thin-film resistor, in a preferred embodiment, such as... Figure 4 As shown, the thin-film resistor structure further includes: a conductive layer 400 disposed between the first electrode 310 and the resistor layer 200, or a conductive layer 400 disposed between the second electrode 320 and the resistor layer 200, or two spaced conductive layers 400 disposed between the first electrode 310 and the resistor layer 200, and between the second electrode 320 and the resistor layer 200, respectively.

[0076] In a typical embodiment, similar to the aforementioned electrode layer, the conductive layer 400 is also subjected to, for example, wet etching to expose the underlying resistive layer 200 and form a resistance region 210, such as... Figure 4 As shown.

[0077] In a typical embodiment, the electrode layer and the conductive layer 400 are etched simultaneously using the same process.

[0078] In alternative embodiments, such as Figure 4 or Figure 5 As shown, the projected area of ​​the conductive layer 400 on the surface of the resistive layer 200 is equal to the projected area of ​​the corresponding first electrode 310 or second electrode 320 on the surface of the resistive layer 200.

[0079] In another alternative embodiment, such as Figure 6As shown, the projected area of ​​the conductive layer 400 on the surface of the resistive layer 200 is greater than the projected area of ​​the corresponding first electrode 310 or second electrode 320 on the surface of the resistive layer 200.

[0080] The conductive layer 400 is used to increase the load capacity of the two electrodes. When a large current is applied to the first electrode 310 and the second electrode 320, the conductive layer 400 connected to the electrodes can reduce the equivalent resistance of the current path between the electrodes and the resistive layer 200. Overall, it can significantly increase the load current of the thin film resistive structure and prevent the electrodes from burning out due to weak load capacity.

[0081] Referring to the formula R=ρL / DT, where ρ is resistivity, L is resistor length, D is resistor width, and T is resistive layer thickness, the increased conductive layer has a lower resistivity ρ, which significantly reduces the overall electrode lead-out resistance, thereby greatly improving the current load capacity of the electrode leads and preventing the electrode from burning out due to excessive current. Besides using low-resistivity materials to improve current load capacity, increasing the thickness D of the conductive layer (400mm) increases the cross-sectional area of ​​the electrode, which also contributes to improving load capacity.

[0082] In an optional embodiment, the conductive layer 400 may be made of a material with low resistivity ρ, such as gold (Au), silver (Ag), copper (Cu), or aluminum (Al).

[0083] In alternative embodiments, such as Figure 4 As shown, the thin-film resistor structure further includes: a first adhesive layer 510 and / or a second adhesive layer 520; the first adhesive layer 510 is disposed between the conductive layer 400 and the corresponding resistive layer 200, and the second adhesive layer 520 is disposed between the conductive layer 400 and the corresponding first electrode 310, and between the conductive layer 400 and the corresponding second electrode 320.

[0084] In a typical embodiment, such as Figure 4 As shown, for the non-resistance region 210 of the resistor structure, from bottom to top, it consists of substrate 100, resistor layer 200, first adhesive layer 510, conductive layer 400, second adhesive layer 520, and electrode layer (first electrode 310 or second electrode 320).

[0085] In a typical embodiment, such as Figure 4 As shown, for the area corresponding to the resistance value region 210 on the resistor structure, from bottom to top, there are substrate 100 and resistor layer 200, that is, the cutout above resistor layer 200.

[0086] In an optional embodiment, the aforementioned cutout is provided with a protective layer (e.g., filled or covered).

[0087] In a typical embodiment, the first adhesive layer 510 and the second adhesive layer 520 are etched together in the same steps as the aforementioned electrode layer and conductive layer to expose the underlying resistive layer 200 and form a resistance region 210.

[0088] In an optional embodiment, the first adhesive layer 510 and the second adhesive layer 520 may be made of the same material or different materials.

[0089] In an optional embodiment, both the first adhesive layer 510 and the second adhesive layer 520 can be metals, such as chromium (Cr), titanium (Ti), and nickel (Ni).

[0090] In the aforementioned embodiments, since the conductive layer 400 can be selected as a pure metal layer with weak adhesion, by adding a first adhesive layer 510 and a second adhesive layer 520 between the resistive layer 200, the conductive layer 400 and the electrode respectively, the bonding force between each film layer is improved while ensuring conductivity, thus preventing the film layer from falling off.

[0091] In an optional embodiment, the first adhesive layer 510 or the second adhesive layer 520 is selected from a chromium metal layer, a titanium metal layer or a nickel metal layer formed using an evaporation coating apparatus.

[0092] To further enhance the load capacity of the electrodes, in a typical embodiment, such as Figure 5 As shown, the edge of the resistive layer 200 is sloped to expose the substrate 100 below, while the conductive layer 400 has a protrusion 410 (the area below the dashed line in the conductive layer 400) facing the substrate 100. The protrusion 410 can extend toward the exposed portion of the substrate 100; that is, the resistive layer 200 does not cover the area between the protrusion 410 and the substrate 100.

[0093] In the foregoing embodiments, for example, in the magnetron sputtering step, the film-forming area or range of the resistive layer 200 can be limited so that the edge of the resistive layer 200 forms a slope, exposing the substrate 100 below. In subsequent steps, the aforementioned protrusion 410 is formed on the area of ​​the substrate 100 not covered by the resistive layer 200, and the entire conductive layer 400 continues to be formed on top.

[0094] from Figure 5 As can be easily seen in the cross-sectional view shown, the aforementioned protrusion 410 reduces the width of the conductive portion (the portion connected to the conductive layer) of the resistive layer 200, allowing part of the first adhesive layer 510 to directly contact the substrate 100. The protrusion 410 facing the substrate 100 increases the thickness of the conductive layer 400, thereby enhancing the performance of the thin film resistor in carrying large currents without increasing the thickness of the thin film resistor structure.

[0095] In an embodiment, such as Figure 5As shown, the conductive layer 400 with protrusion 410 is connected to the sloping side edge of the resistive layer 200 and to a portion of the top surface of the resistive layer 200 (or indirectly connected by an adhesive layer).

[0096] In a preferred embodiment, such as Figure 5 As shown, the resistor structure also includes a first adhesive layer 510, which is disposed between the conductive layer 400 and the resistive layer 200, and between the protrusion 410 of the conductive layer 400 and the substrate 100. The conductive layer 400 with protrusions 410 has a complex shape, which weakens its adhesion. By adding the first adhesive layer 510 between the conductive layer 400 and the resistive layer 200, the adhesion between the conductive layer 400 and the resistive layer 200 is enhanced.

[0097] One side of the first adhesive layer 510 is connected to the sloping side edge of the resistive layer 200 and a portion of the top surface of the resistive layer 200, while the other side is connected to the conductive layer 400 with protrusions 410.

[0098] For the same considerations as the aforementioned embodiments, for the embodiment of the conductive layer 400 with protrusion 410, the resistor structure may further include a second adhesive layer 520, which is disposed between the conductive layer 400 and the corresponding first electrode 310, and between the conductive layer 400 and the corresponding second electrode 320.

[0099] In a typical embodiment, the thickness of the resistive layer 200 is 0.01 μm to 0.1 μm. Unlike thin-film resistors prepared by thick-film processes, which have a thickness greater than 10 μm, the thin-film resistor structure of this application has strong breakdown resistance and stronger current carrying capacity. Therefore, the technical solution in this application can use thin-film processes such as magnetron sputtering to form a thinner resistive layer of 0.01 μm to 0.1 μm, resulting in higher precision of the thin-film resistor structure. It can be precisely adjusted using methods such as lasers, making it suitable for sampling resistors of brushed and brushless motors with high precision requirements. It can also be used as a protection and current-limiting resistor.

[0100] To provide a more complete disclosure of the technical solution of this application, the following exemplary embodiment provides a fabrication process for the aforementioned thin-film resistor structure, such as... Figure 7 As shown, it includes:

[0101] 1. Provide substrate;

[0102] 2. A resistive layer is sputtered onto the substrate using a magnetron sputtering machine;

[0103] 3. Prepare the adhesive layer, conductive layer, and electrode layer using an evaporation coating machine;

[0104] like Figure 8 As shown, it includes:

[0105] 4. Using the wet etching method, a mask is applied, and the electrode layers to be retained (i.e., the first electrode 310 and the second electrode 320) are covered with photoresist using an exposure machine. The resistive layer is etched out using an etching solution to expose the resistive film pattern.

[0106] 5. Laser trimming: A laser trimming machine is used to trim the exposed resistive layer with a laser to obtain the desired resistance value.

[0107] 6. Dicing: Using dicing equipment to produce individual thin-film resistor products.

[0108] In summary, the thin-film resistor structure provided in the foregoing embodiments has the following beneficial effects:

[0109] 1. By adopting a special serpentine resistance region structure and comb-shaped electrodes, the width of the resistance section is the same as the length of the serpentine resistance region. This significantly increases the width of the resistance section, improves the breakdown resistance of the thin film resistor structure, and avoids breakdown of the thin film resistor structure when subjected to high power and high current.

[0110] 2. By adding a conductive layer between the resistive layer and the electrode, the resistivity from the electrode to the resistive layer is reduced, which improves the current load capacity of the electrodes at both ends of the thin film resistor, thereby preventing the electrodes from burning out due to high power and high current load.

[0111] 3. Compared with high-power thin-film resistors fabricated by existing thick-film processes, the high-power thin-film resistor structure provided in this application can be prepared by thin-film processes, such as forming a resistive layer by sputtering, which makes the precision of the thin-film resistor structure higher. It can be used as a sampling resistor for brushed and brushless motors with high precision requirements, and can also be used as a protection and current limiting resistor.

[0112] The above description is only a partial embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A thin film resistive structure, characterized by, include: substrate(100); A resistive layer (200) is disposed on the surface of the substrate (100); The first electrode (310) and the second electrode (320) are disposed at intervals on the resistive layer (200) and are electrically connected to the resistive layer (200) respectively; The resistive layer (200) includes a resistance region (210) located between the first electrode (310) and the second electrode (320); The edges of the first electrode (310) and the second electrode (320) on opposite sides are bent to form the bent resistance region (210). The total path length of the resistance region (210) is greater than: The longest distance between the two points of the orthographic projection of the first electrode (310) onto the surface of the resistive layer (200), and / or The longest distance between the two points of the orthographic projection of the second electrode (320) onto the surface of the resistive layer (200).

2. The sheet resistance structure of claim 1, wherein, The first electrode (310) and the second electrode (320) each have a plurality of alternating protrusions (301) and a plurality of recesses (302). The protrusion (301) of the first electrode (310) is at least partially embedded in the corresponding recess (302) of the second electrode (320), and the protrusion (301) of the second electrode (320) is at least partially embedded in the corresponding recess (302) of the first electrode (310).

3. The sheet resistance structure of claim 2, wherein, The resistance region (210) has a meandering shape with a consistent width.

4. The sheet resistance structure according to any one of claims 1 to 3, wherein It also includes a conductive layer (400); The conductive layer (400) is disposed between the first electrode (310) and the resistive layer (200), or, The conductive layer (400) is disposed between the second electrode (320) and the resistive layer (200), or, The two conductive layers (400) spaced apart are respectively disposed between the first electrode (310) and the resistive layer (200), and between the second electrode (320) and the resistive layer (200); Wherein, the positive projection area of ​​the conductive layer (400) on the surface of the resistive layer (200) is greater than or equal to the positive projection area of ​​the corresponding first electrode (310) or second electrode (320) on the surface of the resistive layer (200).

5. The sheet resistance structure of claim 4, wherein, It also includes a first adhesive layer (510) and / or a second adhesive layer (520); The first adhesive layer (510) is disposed between the conductive layer (400) and the corresponding resistive layer (200); The second adhesive layer (520) is disposed between the corresponding conductive layer (400) and the first electrode (310), and between the corresponding conductive layer (400) and the second electrode (320).

6. The sheet resistance structure of claim 5, wherein, The first adhesive layer (510) or the second adhesive layer (520) is selected from a chromium metal layer, a titanium metal layer or a nickel metal layer.

7. The sheet resistance structure of claim 4, wherein, The conductive layer (400) has a protrusion (410) facing the substrate (100). The resistive layer (200) does not cover the area between the protrusion (410) and the substrate (100).

8. The sheet resistance structure of claim 7, wherein, It also includes a first adhesive layer (510) disposed between the conductive layer (400) and the resistive layer (200), and between the protrusion (410) of the conductive layer (400) and the substrate (100).

9. The sheet resistance structure of claim 8, wherein, It also includes a second adhesive layer (520), which is disposed between the corresponding conductive layer (400) and the first electrode (310), and between the corresponding conductive layer (400) and the second electrode (320).

10. The sheet resistance structure according to any one of claims 1 to 3, wherein The thickness of the resistive layer (200) is 0.01 μm to 0.1 μm.

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