Structure for current sensing and method of manufacturing the same

Abstract

An IC package structure for current sensing is provided in the present disclosure, including a leadframe composed of a first terminal and a second terminal for measuring a current, a sensing resistor portion positioned between the first terminal and the second terminal and current rectifying portions coupling the first terminal and the second terminal with the sensing resistor portion and leads extending from the sensing resistor portion, and a die mounted on the leadframe and electrically coupled to the leads.

Description

[Technical Field]

[0001] This disclosure generally relates to a structure, and more specifically, to an IC package structure for current sensing and a method of manufacturing the same. [Previous Technology]

[0002] Electronic systems use current measurement to provide various electrical feedback to verify whether the operation of components is within acceptable limits and to detect potential fault conditions. Analyzing the current level in a circuit system helps diagnose undesirable or unexpected operating modes, allowing for corresponding adjustments to enhance reliability or protect system components from damage. Current is typically measured by the voltage drop generated by a sensing element, such as a current sensing resistor (CSR), like a shunt resistor. The magnitude of the current can range widely, from picoamperes (pA) to tens of thousands of amperes (A). In this process, the current sensing resistor collaborates with other components, such as operational amplifiers (OPA), digital-to-analog converters (ADCs), and / or microcontrollers (MCUs), to achieve accurate current sensing.

[0003] In the prior art, current sensing resistors (CSRs) are typically mounted as discrete components on a PCB board, along with other necessary components such as operational amplifiers. In this type of design, the current sensing resistor is coupled to the operational amplifier via wiring on the PCB, which may introduce noise and degrade the signal quality during measurement. Therefore, an RC filter is usually required in the measurement circuit to filter noise, which also complicates the PCB layout and increases the time required for circuit design. Furthermore, since the resistance of the current sensing resistor itself is very small, typically on the order of milliohms (mΩ), the shape of the current path and the location of the current sensing resistor may cause significant resistance deviations, especially when measuring high currents. These deviations may negatively affect the accuracy of current measurements. Therefore, those skilled in the art need to improve existing current sensing component designs to address the above challenges. [Summary of the Invention]

[0004] In view of the shortcomings of the prior art described above, this disclosure presents a novel structure characterized by utilizing a portion of the leadframe within the structure as a current sensing resistor (CSR) required for current measurement. Furthermore, the operational amplifier (OPA) required for current measurement is designed to be integrated into a single die mounted on the leadframe, thereby forming an integrated circuit within the package structure.

[0005] One aspect of this disclosure is to provide a structure for current sensing, comprising: a leadframe including: a first terminal for measuring current; a second terminal located separately from the first terminal; a sensing resistor portion located between the first terminal and the second terminal; a plurality of current rectifying portions located between the first terminal and the sensing resistor portion and between the second terminal and the sensing resistor portion, wherein the current rectifying portions couple the first terminal and the second terminal to the sensing resistor portion; and a plurality of pins extending from the sensing resistor portion; a bare die mounted on the leadframe, wherein the pins are coupled to the bare die; and a molding compound encapsulating the leadframe and the bare die.

[0006] Another aspect of this disclosure is to provide a method of manufacturing a structure for current sensing, comprising: providing a leadframe, wherein the leadframe includes: a first terminal for measuring current; a second terminal for measuring current, wherein the second terminal is different from the first terminal; a sensing resistor portion located between the first terminal and the second terminal; a plurality of current rectifying portions located between the first terminal and the sensing resistor portion and between the second terminal and the sensing resistor portion, respectively, and the current rectifying portions coupling the first terminal and the second terminal to the sensing resistor portion; a plurality of pins extending from the sensing resistor portion; mounting a bare die on the leadframe; electrically coupling the pins to the bare die; and encapsulating the leadframe and the bare die using a molding compound.

[0007] Such and other objects of this disclosure should become more apparent to the reader after reading the detailed description of the preferred embodiments described below with various illustrations and drawings.

Implementation Method

[0008] Exemplary embodiments of the present disclosure will now be described in detail below, with reference to the accompanying drawings illustrating the described features to enable the reader to understand and achieve the technical effects. The reader will understand that the descriptions herein are by way of illustration only and are not intended to limit the scope of the invention. Various embodiments of the invention and various non-conflicting features thereof can be combined or rearranged in various ways. Modifications, equivalents, or improvements to the invention will be understood by those skilled in the art without departing from the spirit and scope of the disclosure and are intended to be included within the scope of the invention.

[0009] It should be readily understood by the reader that the meanings of "on," "above," and "above" in this case should be interpreted broadly, so that "on" not only means "directly on" something but also includes the meaning of being "on" something with an intervening feature or layer, and "above" or "above" not only means "above" or "above" something but can also include the meaning of being "above" or "above" something without an intervening feature or layer (i.e., directly on something). Furthermore, spatially related terms such as "below," "under," "lower part," "above," and "upper part" may be used herein for descriptive convenience to describe the relationship between one element or feature and one or more other elements or features, as shown in the accompanying drawings.

[0010] As used herein, the term "layer" refers to a portion of material comprising a region having thickness. A layer may extend over the entirety of a structure below or above, or may have a range smaller than that of the structure below or above. Furthermore, a layer may be a region of a homogeneous or heterogeneous continuous structure with a thickness less than that of the continuous structure. For example, a layer may be located between the top and bottom surfaces of a continuous structure or between any horizontal faces at the top and bottom surfaces. A layer may extend horizontally, vertically, and / or along an inclined surface. A substrate may be a layer, which may include one or more layers, and / or may have one or more layers on, above, and / or below it. A layer may include multiple layers. For example, an interconnect layer may include one or more conductor and contact layers (where contacts, interconnects, and / or vias are formed) and one or more dielectric layers.

[0011] Readers can generally understand terms at least partially from their usage in context. For example, depending at least partially on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or it can be used to describe a combination of features, structures, or characteristics in a plural sense. Similarly, depending at least partially on the context, terms such as "a," "an," "the," or "the" can also be understood to convey either a singular or a plural usage. In addition, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather to allow for the presence of additional factors that are not necessarily explicitly described, which also depends at least partially on the context.

[0012] Readers will better understand that when words such as "comprising" and / or "containing" are used in this specification, they expressly define the presence of the stated features, areas, wholes, steps, operations, elements and / or components, but do not preclude the possibility of the presence or addition of one or more other features, areas, wholes, steps, operations, elements, components and / or combinations thereof.

[0013] The embodiments and illustrations below will only be described using a single structure as an example, namely an IC chip unit after packaging and cutting. However, before packaging and cutting, there may be multiple bare dies bonded to a single leadframe and a molding compound covering these bare dies and connectors, and for the sake of simplicity, the PCB board to which the leadframe is connected will not be shown in the figures.

[0014] First, referring to Figure 1, which is a schematic diagram of a current sensing circuit 10 embodied in this disclosure. Generally, a typical current sensing circuit 10 includes a current sensing resistor (CSR) 110, a load 102, an operational amplifier (OPA) 104, an analog-to-digital converter (ADC) 106, and a microcontroller (MCU) 108. In this configuration, the current to be measured is input through one end of the current sensing resistor 110 and output to the main circuit through the other end, where the load 102 is located to regulate the current. In addition, the load 102 can also play a role in providing protection and control functions in an overcurrent protection circuit. If the current flowing through the load 102 exceeds a preset threshold, the current sensor can trigger a circuit breaker or current limiting device, thereby preventing potential damage to the load or circuit.

[0015] Referring again to Figure 1, the other two terminals of the current sensing resistor 110 are coupled to the operational amplifier 104. Specifically, one terminal is coupled to the non-inverting input (+) of the operational amplifier 104, and the other terminal is coupled to the inverting input (-). The operational amplifier 104 is typically designed as a differential amplifier to amplify the voltage difference across the current sensing resistor. The output of the operational amplifier provides the amplified signal to the analog-to-digital converter (ADC) 106. Since the current sensing resistor is typically a low-resistance resistor (in the milliohm range), it generates only a very small voltage when current flows through it. Therefore, the operational amplifier 104 is used to amplify this small voltage to ensure the accuracy of subsequent current measurements.

[0016] Referring again to Figure 1, the analog-to-digital converter (ADC) 106 is responsible for converting the amplified voltage signal with analog properties measured by the current sensing resistor 110 into a digital signal for further processing and analysis by the coupled microcontroller (MCU) 108. The ADC parameters, such as resolution, sampling rate, input range, and signal-to-noise ratio, directly affect the accuracy and response speed of the current measurement. Through precise ADC conversion, the current sensing circuit can achieve high-precision and fast-response current monitoring, providing reliable data for various applications. The main function of the microcontroller 108 is to process the signals from the current sensing resistor 110 and the operational amplifier 104, performing tasks such as current measurement, data calculation, logic control, alarm activation, and circuit protection. Furthermore, the microcontroller 108 supports data transmission through various communication interfaces to provide control outputs for specific operations and allows for flexible configuration of various algorithms through embedded software to achieve the required functions and requirements.

[0017] It should be noted that in this disclosed embodiment, the current sensing resistor 110 and operational amplifier 104 in the current sensing circuit 10 are modularly integrated into a discrete component, such as an IC chip or package structure. This approach is significantly different from the conventional approach. In the conventional approach, the current sensing resistor and operational amplifier are usually mounted on a PCB board as separate discrete components. With the design of the present invention, the current sensing resistor 110 is no longer electrically coupled to the operational amplifier 104 through PCB wiring, thereby minimizing or even eliminating noise in current measurement. Therefore, an RC filter is not required in the current sensing circuit 10.

[0018] Referring to Figure 2, which is a top view schematic diagram of a current sensing resistor 110 in the structure according to an embodiment of the present disclosure. The following description will illustrate how the present disclosure integrates the current sensing resistor 110 and the operational amplifier 104 into a single discrete component.

[0019] The current sensing resistor 110 is part of the lead frame in the disclosed structure and can be specifically applied to an IC package as an IC package structure. As shown in Figure 2, the current sensing resistor 110 is generally composed of a first terminal 112a, a second terminal 112b, a sensing resistor portion 114, and several current rectifying portions (such as 116a and 116b). From a layout perspective, the first terminal 112a and the second terminal 112b are positioned opposite each other in the first direction D1. The sensing resistor portion 114 is located between the first terminal 112a and the second terminal 112b, and the current rectifying portions 116a and 116b are disposed therebetween to couple the two opposite sides of the sensing resistor portion 114 to the first terminal 112a and the second terminal 112b respectively along the first direction D1. The first terminal 112a and the current rectifying portion 116a are preferably symmetrical with the second terminal 112b and the current rectifying portion 116b in the first direction D1. In addition to the first terminal 112a, the second terminal 112b, the sensing resistor portion 114, and the current rectification portions 116a and 116b, the current sensing resistor 110 also includes multiple pins 118a and 118b for outputting sensing signals for amplification. In this embodiment, pins 118a and 118b extend from the same side of the sensing resistor portion 114, for example, in a second direction D2, which is preferably orthogonal to the first direction D1.

[0020] From an operational perspective, the first terminal 112a of the current sensing resistor 110 is coupled to a terminal IN of an external circuit (such as a PCB board), which provides the current I to be measured. The current I flows sequentially along the first direction D1 through the first terminal 112a, the current rectification section 116a, the sensing resistor section 114, and the current rectification section 116b, finally flowing to the other terminal OUT of the external circuit. The first terminal 112a and the second terminal 112b can also be used as output terminals or input terminals, respectively, to detect the current signal. When the current I flows through the sensing resistor section 114, it generates a small voltage drop across the resistor, typically on the order of millivolts (mV). This voltage drop is linearly proportional to the current flowing through the sensing resistor section 114 and is transmitted as an analog signal to the operational amplifier (such as 104 in Figure 1) for amplification via pins 118a and 118b.

[0021] Referring again to Figure 2, the current rectification sections (such as 116a and 116b) are located between the sensing resistor section 114, the first terminal 112a, and the second terminal 112b. The current rectification sections 116a and 116b are located on opposite sides of the sensing resistor section 114 in the first direction D1, and these two current rectification sections 116a and 116b are preferably perfectly aligned in the first direction D1. Since different shaped current paths in the current sensing resistor 110 result in different current densities and effective resistances, the current rectification sections 116a and 116b are designed to direct the current I flowing through the sensing resistor section 114 towards the first direction D1, thereby eliminating the influence of the aforementioned current paths.

[0022] Furthermore, as shown in Figure 2, the widths of the current rectifier sections 116a and 116b in the second direction D2 are intentionally designed to be narrower than those of the sensing resistor section 114. This design helps to rectify the current I passing through the current rectifier sections 116a and 116b, thereby minimizing resistance deviations during measurement, especially when the measured current is very large, thus significantly improving the accuracy of current measurement. This is a major advantage of the circuit design disclosed herein.

[0023] Referring now to Figure 3, which is a top view schematic diagram of a current sensing resistor in another embodiment of the structure according to this disclosure. This embodiment is largely similar to the previous embodiment, except that the ratio of the length L1 of the current rectifying portions 116a and 116b in the first direction D1 to the width W1 of the current rectifying portions 116a and 116b in the second direction D2 is greater than that in the previous embodiment. This design further minimizes resistance deviation during measurement. In terms of the dimensions of each component in the current sensing resistor 110, the ratio of the length L1 of the current rectifying portions 116a and 116b in the first direction D1 to the width W1 in the second direction D2 is preferably greater than 0.02, and more particularly greater than 0.03. The ratio of the width W1 of the current rectifying portions 116a and 116b in the second direction D2 to the width W2 of the sensing resistor portion 114 is preferably less than 0.9, and more particularly less than 0.8.

[0024] Referring now to Figure 4, which is a top view schematic diagram of a current sensing resistor in a structure according to yet another embodiment of the present disclosure. This embodiment is largely similar to the previous embodiment, except that pins 118a and 118b extend from two opposite sides of the sensing resistor portion 114 in a second direction D2, rather than from the same side. This design further minimizes resistance deviation during measurement because the sensing signal is output from two opposite sides, avoiding mutual interference between them.

[0025] Referring now to Figure 5, which is a perspective view of the sensing resistor portion 114 and the current rectifier portions 116a / 116b of the current sensing resistor according to the embodiment of this disclosure. In addition to the width ratio of the current rectifier portions 116a / 116b to the sensing resistor portion 114, the cross-sectional area of ​​these portions in the first direction D1 can also rectify the current flowing through the sensing resistor, minimizing resistance deviation during measurement. As shown in Figure 5, the cross-sectional area A1 of the current rectifier portions 116a / 116b is intentionally designed to be smaller than the cross-sectional area A2 of the sensing resistor portion 114. This design, similar to the width ratio of the aforementioned portions, further enhances the rectification effect when current flows through the current rectifier portions 116a and 116b, thereby minimizing resistance deviation and significantly improving the accuracy of current measurement. The thickness of the current rectifier portions 116a / 116b in the vertical direction is preferably (but not necessarily) designed to be equal to the thickness of the sensing resistor portion 114.

[0026] Referring now to Figures 6A and 6B, which are respectively a top view and an isometric view of a leadframe 100 and a bare die 120 in the structure described in the embodiments disclosed herein. The current sensing resistor 110 is integrated into the leadframe 100 of the structure. As shown in Figures 6A and 6B, all the aforementioned current sensing resistor 110 portions, including the first terminal 112a, the second terminal 112b, the current rectification portions 116a / 116b, the sensing resistor portion 114, and the pins 118a / 118b, are part of the leadframe 100. The current to be measured is supplied from the terminal IN of an external circuit (such as a PCB board) and flows sequentially along the first direction D1 through the first terminal 112a, the current rectification portion 116a, the sensing resistor portion 114, and the current rectification portion 116b, finally flowing to the other terminal OUT of the external circuit. When current flows through the sensing resistor section 114, a small voltage drop is generated. This voltage drop is transmitted as a sensing signal to the bare die 120 mounted on the leadframe 100. This sensing signal is transmitted through pins 118a and 118b, and each pin is coupled to a corresponding terminal (such as a pad, not shown) on the bare die 120.

[0027] Referring again to Figures 6A and 6B, the operational amplifier used for current measurement (e.g., 104 shown in Figure 1) is integrated into a die 120. This die 120 is mounted on a leadframe 100 and forms part of the structure disclosed herein, allowing the current sensing resistor 110 and the operational amplifier 104 to be combined into a discrete component (such as a chip). The sensing signal transmitted through pins 118a and 118b is amplified by the operational amplifier 104 in the die 120, generating an amplified signal suitable for subsequent processing and analysis. This amplified signal is then output to external circuitry (e.g., a PCB) via additional pins 119 of the leadframe 100, which are coupled to the die 120. This amplified signal can then be processed or analyzed by other components mounted on the PCB, such as the analog-to-digital converter 106 and the microcontroller 108 shown in Figure 1. With this design, the current sensing resistor is no longer electrically coupled to the operational amplifier 104 via PCB wiring, as is common in traditional designs, thereby minimizing or even eliminating noise in the measurement. Therefore, an RC filter is no longer needed in the current sensing circuit. Furthermore, the sensing signal is transmitted via pins 118a / 118b, which extend in the second direction D2 on the same side of the sensing resistor portion 114. Therefore, the bare die 120 is located on the side of the sensing resistor portion 114 in the second direction D2, which is orthogonal to the current path in the first direction D1.

[0028] Furthermore, in another embodiment of this disclosure, pins 118a / 118b can be coupled to the bare die 120 via other components. For example, as shown in Figure 6C, pins 118a / 118b are initially coupled to resistors 121a / 121b for adjusting the sense voltage before being wired to the bare die 120.

[0029] Furthermore, in another embodiment of this disclosure, pins 118a / 118b can be configured in an L-shape to route to an external RC filter circuit to meet custom requirements, rather than being directly coupled to the bare die 120. For example, as shown in Figure 6D, each pin 118a / 118b is L-shaped and divided into two segments 123a / 123b and 125a / 125b. One segment, 123a and 125a, is coupled to one end of the resistor R in the RC filter circuit, while the other segment, 123b and 125b, is coupled to the other end of the resistor R and one end of the capacitor C in the RC filter circuit. Finally, the wiring is routed back to the bare die 120.

[0030] Referring now to Figures 7A and 7B, a top view and an isometric view, respectively, of the leadframe 100 and the die 120 in another embodiment of the present disclosure are shown. This embodiment differs from the previous embodiment in that the die 120 is located above the sensing resistor portion 114 of the current sensing resistor. In this design, as shown in Figures 7A and 7B, an isolation layer 130 is required between the die 120 and the leadframe for electrical isolation. Furthermore, it should be noted that in this embodiment, the pins 118a / 118b extend from opposite sides of the sensing resistor portion 114, unlike the previous embodiment where the pins extend from the same side. Moreover, in this embodiment, the pins 118a / 118b are preferably offset from each other in the first direction D1. To electrically couple the pins 118a / 118b extending from the sensing resistor portion 114 in the second direction D2, conductors 122a / 122b (such as copper wires) are also formed on the isolation layer 130 to connect the bare die 120 to the lead frame below. The conductors 122a / 122b can also extend from both sides of the bare die 120 along the second direction D2. Furthermore, vias 124a / 124b are formed in the isolation layer 130 to couple the conductors 122a / 122b to the pins 118a / 118b below. This design further reduces resistance variations in current measurement because the pins 118a / 118b are located on opposite sides of the current sensing resistor and offset from each other in the first direction D1, thereby avoiding mutual interference of the sensing signals. The signal amplified by the bare die 120 can be output to an external circuit, such as a PCB board, via additional conductive traces (not shown) on the isolation layer 130 and additional pins 119 of the lead frame 100. This amplified signal can then be processed or analyzed by other components mounted on the PCB, such as the analog-to-digital converter 106 and the microcontroller 108, as shown in Figure 1.

[0031] Referring now to Figure 8, an isometric view of a structure for current sensing according to an embodiment of this disclosure is shown. In this disclosure, components including the lead frame 100 and the bare die 120 are encapsulated within a molding compound 132 to form this structure. As shown in Figure 8, portions such as the first terminal 112a, the second terminal 112b, and the pin 119 are exposed from the molding compound 132 for electrical connection to external circuitry (such as a current source, load, or PCB board).

[0032] Referring now to Figure 9, a manufacturing process diagram of a structure for current sensing according to an embodiment of the present disclosure is shown. Based on the foregoing embodiments, the present disclosure also proposes a method for manufacturing a structure specifically designed for current sensing.

[0033] As shown in Figure 9, in step S1, a leadframe (e.g., 100 in Figure 6B) is first provided as the basic structure for the packaged component. The leadframe is typically made from a metal material (such as copper or iron-nickel alloy) through processes such as stamping or etching. Its main function is to provide mechanical support for the die and to serve as an electrical connection medium between the die and the PCB board. After the leadframe is prepared, in step S2, the die (e.g., 120 in Figure 6B) is mounted onto the leadframe. The die can be precisely mounted onto the leadframe using an automated die bonding machine to ensure accurate positioning. Furthermore, in step S3, a thermally conductive or conductive adhesive is typically applied to the designated mounting area of ​​the leadframe to promote heat dissipation and electrical connection, especially for electrically connecting the die to the pins extending from the sensing resistor portion of the leadframe (e.g., 118a / 118b in Figure 6B). After the bare die is securely mounted and electrically coupled to the leadframe, in step S4, the leadframe and the bare die are encapsulated in a molding compound (such as 132 in Figure 8) to form the final structure disclosed herein. The molding compound protects the chip from environmental influences and maintains the stability of the electrical connection. In the molding step, the leadframe and the bare die bonded to it are placed in a mold, where they are injection molded under high temperature and pressure using materials such as plastic or epoxy resin to form a molding compound that completely encapsulates the bare die and the lead or wiring, while exposing the terminals for external connection. Subsequently, a dicing process may be performed, dividing the entire package into multiple independent package units. The above description is only a preferred embodiment of the present invention, and all equivalent variations and modifications made within the scope of the claims of this invention should be considered within the scope of this invention. [Simplified Explanation of the Diagram]

[0034] Figure 1 is a schematic diagram of a current sensing circuit according to an embodiment of the present disclosure; Figure 2 is a top view of a current sensing resistor in the structure according to an embodiment of the present disclosure; Figure 3 is a top view of a current sensing resistor in the structure according to another embodiment of the present disclosure; Figure 4 is a top view of a current sensing resistor in the structure according to yet another embodiment of the present disclosure; Figure 5 is a perspective view of the sensing resistor portion and the current rectification portion in the current sensing resistor according to an embodiment of the present disclosure; Figure 6A is a top view of a leadframe and a bare die in the structure according to an embodiment of the present disclosure; Figure 6B is an isometric perspective view of the leadframe and the bare die in Figure 6A; Figure 6C is a top view of a leadframe and a bare die in the structure according to another embodiment of the present disclosure; Figure 6D is a top view of a leadframe and a bare die in the structure according to yet another embodiment of the present disclosure; Figure 7A is a top view of a leadframe and a bare die in the structure according to another embodiment of the present disclosure; Figure 7B is an isometric perspective view of the leadframe and the bare die in Figure 7A; Figure 8 is a perspective view of the structure for current measurement according to an embodiment of the present disclosure; Figure 9 is a flowchart of the manufacturing method of the structure for current measurement according to an embodiment of the present disclosure. It should be noted that all illustrations in this specification are for illustrative purposes only. For clarity and convenience, the dimensions and scale of the components in the illustrations may be exaggerated or reduced. Generally, the same reference numerals in the figures are used to indicate corresponding or similar element features in modified or different embodiments.

Claims

1. A structure for current sensing, comprising: A leadframe includes: a first terminal for measuring current; a second terminal located separately from the first terminal; a sensing resistor portion located between the first terminal and the second terminal; a plurality of current rectifying portions located between the first terminal and the sensing resistor portion and between the second terminal and the sensing resistor portion, wherein the current rectifying portions couple the first terminal and the second terminal to the sensing resistor portion; and a plurality of pins extending from the sensing resistor portion; a bare die mounted on the leadframe, wherein the pins are coupled to the bare die; and a molding compound encapsulating the leadframe and the bare die.

2. The structure for current sensing as described in claim 1, wherein the pins extend in a second direction, and the width of the current rectifying portion in the second direction is smaller than the width of the first terminal in the second direction and smaller than the width of the second terminal in the second direction.

3. The structure for current sensing as described in claim 1, wherein the pins extend in a second direction and the width of the current rectifying portion in the second direction is smaller than the width of the sensing resistor portion in the second direction.

4. The structure for current sensing as described in claim 1, wherein the second terminal is opposite to the first terminal in a first direction, the pins extend from the sensing resistor portion in a second direction, and the ratio of the length of the current rectifying portion in the first direction to the width in the second direction is greater than 0.

02.

5. The current sensing structure as described in claim 1, wherein the pins extend from the sensing resistor portion in a second direction, and the ratio of the width of the current rectifying portion in the second direction to the width of the sensing resistor portion is less than 0.

9.

6. The structure for current sensing as described in claim 1, wherein the second terminal is opposite to the first terminal in a first direction, and the cross-sectional area of ​​the current rectifying portion in the first direction is smaller than the cross-sectional area of ​​the sensing resistor portion in the first direction.

7. The structure for current sensing as described in claim 1, wherein the bare die includes an operational amplifier circuit.

8. The structure for current sensing as described in claim 7, wherein the pins are respectively coupled to the bare die.

9. The structure for current sensing as described in claim 1, wherein the pins extend from the sensing resistor portion in a second direction, and the pins extend from two opposite sides of the sensing resistor portion in the second direction.

10. The structure for current sensing as described in claim 9, wherein the second terminal is opposite to the first terminal in a first direction, and the pins are offset from each other in the first direction.

11. The current sensing structure as described in claim 1 further includes an isolation layer located between the bare die and the lead frame, wherein the pins are electrically coupled to the bare die through vias extending through the isolation layer.

12. The structure for current sensing as described in claim 1, wherein the first terminal and the second terminal of the lead frame are symmetrical with respect to the sensing resistor portion.

13. The structure for current sensing as described in claim 1, wherein the second terminal is opposite to the first terminal in a first direction, and the current rectifying portions are aligned in the first direction.

14. A method for manufacturing a structure for current sensing, comprising: A leadframe is provided, comprising: a first terminal for measuring current; a second terminal for measuring current, wherein the second terminal is different from the first terminal; a sensing resistor portion located between the first terminal and the second terminal; a plurality of current rectifying portions located between the first terminal and the sensing resistor portion and between the second terminal and the sensing resistor portion, respectively, and the current rectifying portions coupling the first terminal and the second terminal to the sensing resistor portion; a plurality of pins extending from the sensing resistor portion; mounting a bare die on the leadframe; electrically coupling the pins to the bare die; and encapsulating the leadframe and the bare die using a molding compound.

15. The method of manufacturing a current sensing structure as described in claim 14 further includes forming an isolation layer on the leadframe, wherein the isolation layer is located between the bare die and the leadframe.

16. The method of manufacturing a current sensing structure as described in claim 15 further includes forming vias in the isolation layer, and the pins being electrically coupled to the bare die through the vias extending through the isolation layer.

17. A method of manufacturing a current sensing structure as described in claim 14, wherein the pins extend from the sensing resistor portion in a second direction, and the width of the current rectifying portion in the second direction is smaller than the width of the first terminal in the second direction and smaller than the width of the second terminal in the second direction.

18. A method of manufacturing a current sensing structure as described in claim 14, wherein the pins extend from the sensing resistor portion in a second direction, and the width of the current rectifying portion in the second direction is smaller than the width of the sensing resistor portion in the second direction.

19. A method of manufacturing a structure for current sensing as described in claim 14, wherein the bare die includes an operational amplifier circuit.

20. A method of manufacturing a current sensing structure as described in claim 14, wherein the pins extend from the sensing resistor portion and the pins extend from two opposite sides of the sensing resistor portion in a second direction.

Images