Metal lining packaging cavity for fluid sensor

Abstract

The invention relates to a metal liner encapsulation cavity for a fluid sensor. In an example, a sensing device (100) includes a semiconductor die (106) including a device side (108) and a fluid sensor (110) in the device side. The device comprises a metal ring (114) forming an opening (121) above the fluid sensor, the metal ring having a top surface (123), a bottom surface (125) and an inner surface (127) extending between the top surface and the bottom surface, and the bottom surface being located on the device side. At least a portion of the inner surface facing the device side is plated with a noble metal (117). The apparatus includes a molding compound (118) covering the semiconductor die and a first portion (115) of the metal ring, where a second portion (116) of the metal ring having the top surface protrudes from the molding compound and provides at least one of a sleeve interface or a tube interface.

Description

Technical Field

[0001] The present application relates to a metal lined packaging cavity for a fluid sensor. Background Art

[0002] An integrated circuit (IC) is formed on a semiconductor die, which is then packaged inside a molding compound to protect the semiconductor die from damage caused by external elements such as moisture, heat, and blunt force. The semiconductor die may also be coupled to a package substrate, such as a lead frame that includes conductive terminals to facilitate communication with electronic devices outside the package. Portions of the conductive terminals are covered by the molding compound, while portions of the conductive terminals are exposed. By coupling the exposed portions of the conductive terminals to electronic devices outside the molding compound, a path is provided for exchanging electrical signals between the circuit within the package and the electronic devices outside the package via the conductive terminals. Some packaged sensor devices or sensor packages may include an IC that includes a fluid sensor formed on a semiconductor die, wherein the fluid sensor may be partially covered by the molding compound. Summary of the invention

[0003] In an example, a sensing device includes a semiconductor die including a device side and a fluid sensor in the device side. The device includes a metal ring that forms an opening above the fluid sensor, the metal ring having a top surface, a bottom surface, and an inner surface extending between the top surface and the bottom surface, and the bottom surface is located on the device side. At least a portion of the inner surface that interfaces with the device side is plated with a noble metal. The device includes a molding compound that covers the semiconductor die and a first portion of the metal ring, wherein a second portion of the metal ring having a top surface protrudes from the molding compound and provides at least one of a sleeve interface or a tube interface.

[0004] In an example, a method for manufacturing a sensing device includes depositing a photoresist layer on a first surface of a semiconductor die, the first surface including a sensor. The method includes exposing and developing the photoresist layer to produce a central photoresist member, an annular photoresist member surrounding the central photoresist member, and an annular cavity between the central photoresist member and the annular photoresist member. The central photoresist member contacts the sensor. The method includes plating a metal ring in the annular cavity, wherein the metal ring includes a first portion having a first lateral thickness and a second portion having a variable lateral thickness. The method includes removing the central photoresist member and the annular photoresist member. The method includes plating a noble metal on at least an inner surface of the abutting first surface of the metal ring. The method includes applying a molding compound to the surface and the metal ring, wherein a top surface of the metal ring is at least partially exposed through the molding compound. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1is a schematic diagram depicting a profile cross-sectional view of a packaged sensor coupled to a tube according to various examples.

[0006] Figure 2 It is a diagram showing the Figure 1 Schematic diagram of the top view of the sensor package and tube.

[0007] Figure 3 is a schematic diagram illustrating an outline cross-sectional view of a sensor package coupled to a substrate according to various examples.

[0008] Figure 4 It is a diagram showing the Figure 3 Schematic diagram of the top view of the sensor package and substrate.

[0009] Figure 5 is a schematic diagram illustrating an outline cross-sectional view of a sensor package coupled to a sleeve according to various examples.

[0010] Figure 6 is a schematic diagram illustrating an outline cross-sectional view of a sensor package coupled to a sleeve according to various examples.

[0011] Figure 7 is a schematic diagram illustrating an outline cross-sectional view of a sensor package coupled to a sleeve according to various examples.

[0012] Figure 8 is a schematic diagram depicting an outline cross-sectional view of a sensor package coupled to a sleeve having electronic circuitry according to various examples.

[0013] Fig. 9 is a schematic diagram depicting an outline cross-sectional view of a sensor package coupled to a plurality of tubes according to various examples.

[0014] Fig.10 is a schematic diagram illustrating a top view of a sensor package and a plurality of tubes according to various examples.

[0015] Fig.11 is a schematic diagram illustrating a perspective view of a sensor package according to various examples.

[0016] Fig.12 It is a diagram showing the Fig.11 Schematic diagram of a top view of the sensor package.

[0017] Fig.13A and Fig. 13B are schematic diagrams illustrating top and perspective views, respectively, of a sensor package having interfaces for multiple tubes according to various examples.

[0018] Fig.14It is a diagram showing the Fig.13A and 13B Schematic diagram of an outline cross-sectional view of a portion of a sensor package.

[0019] Fig.15 is a schematic diagram illustrating a top view of a sensor package having multiple sensors according to various examples.

[0020] Fig.16 It is a diagram showing the Fig.15 Schematic diagram of a perspective view of the sensor package.

[0021] Fig.17 It is a diagram showing the Fig.15 Schematic diagram of an outline cross-sectional view of a portion of the sensor package.

[0022] Fig.18 It is a diagram showing the Fig.15 Schematic diagram of an outline cross-sectional view of a portion of the sensor package.

[0023] Fig.19 is a flow chart of a method for manufacturing a sensor package according to various examples. DETAILED DESCRIPTION

[0024] Some types of sensors are configured to measure various physical properties of the environment, such as temperature, humidity, light, sound, pressure, etc. The sensor can be formed on a semiconductor die, which can be partially encapsulated in a molding compound to form a sensor package. In some cases, the sensor can be directly exposed to the environment to be tested through an opening in the molding compound.

[0025] Various factors can limit the performance of the sensor package. For example, the molding compound may have a single opening to expose the sensor to the external environment. In the case of a fluid sensor, the sensor can be exposed to one fluid through a single opening at the same time and measure the properties of the fluid. However, another fluid cannot be provided to the sensor for measurement at the same time. On the contrary, if multiple fluids are to be tested, the fluids are tested sequentially. This is a significant limitation on operating efficiency. In addition, the sensor package may include metal components that are exposed to the fluid to be measured or other external elements. Metal components may be prone to corrosion, which may affect the structural or functional integrity of the sensor package. Metal components may also react chemically with the fluid to be measured and may contaminate the fluid or at least affect the accuracy of the measurement. All of this may degrade the performance of the sensor package and is undesirable.

[0026] As described herein, various examples of sensor packages can solve at least some of the above challenges. More specifically, the sensor package described herein includes a plurality of sensors positioned in a cavity lined by a plated metal ring. The metal ring is configured to interface with different structures that provide the fluid, gas or other material to be tested to the sensor. Such structures may include sleeves and tubes. The sleeves and tubes deliver the test material (e.g., fluid, gas) directly to the intended sensor and prevent the test material from reaching unexpected areas, such as other sensors. Therefore, a single package may include any number of sensors, each of which is configured to receive its own test material through pipes, sleeves and other such structures. In addition, the metal ring may be plated with a metal that prevents corrosion caused by exposure to the test material (e.g., fluid). Examples of these sensor packages are now described with reference to the accompanying drawings.

[0027] Figure 1 1 is a profile cross-sectional view of a sensor package 100 having a metal ring interfacing with a tube according to various examples. The tube may provide a test material such as a fluid to a sensor in the sensor package 100. The sensor package 100 may include a die pad 102 and a conductive terminal 104 (e.g., a lead) exposed to an outer surface of the sensor package 100. The sensor package 100 may include a semiconductor die 106, such as a silicon die, coupled to the die pad 102. The die 106 has a device side 108 in which circuitry is formed. For example, circuitry configured to process signals from a sensor 110 may be formed in the device side 108. The sensor 110 may also be positioned in the device side 108, and the sensor 110 may be configured to sense any of a variety of properties of any of a variety of materials (e.g., temperature, viscosity, chemical composition, humidity, light, sound, gas pressure, liquid, environmental conditions, etc.). In an example, the sensor 110 is an ion sensitive field effect transistor (ISFET). The scope of the present specification is not limited to any particular type of sensor 110.

[0028] Wirebonds 112 are coupled to device side 108 (e.g., to contact pads on device side 108) and to conductive terminals 104, thereby establishing a communication path between die 106 and a device external to sensor package 100. A metal ring 114 (e.g., copper) forms an opening 121 around the perimeter of sensor 110. Metal ring 114 may have a cross-section that includes portion 115 and portion 116 above portion 115 (e.g., further away from sensor 110). In an example, portion 115 has a substantially uniform lateral thickness (e.g., thickness along an axis parallel to device side 108), where this thickness may not extend beyond a range of, for example, + / - 10% of a baseline thickness. Portion 116 has a varying lateral thickness, where the maximum lateral thickness is near the bottom of portion 116 (e.g., closest to sensor 110) and the minimum lateral thickness is near the top of portion 116 (e.g., farthest from sensor 110). The lateral thickness of portion 116 varies to include a thickness less than the lateral thickness of portion 115 and a thickness greater than the lateral thickness of portion 115. Metal ring 114 may provide an interface to couple with a tube such as tube 120. The increased lateral thickness of portion 116 may provide a protruding structure (e.g., a hook structure) to facilitate coupling between tube 120 and metal ring and prevent tube 120 from detaching from metal ring 114.

[0029] The metal ring 114 is plated with a noble metal 117 (e.g., gold, palladium, silver, platinum, or other noble metal, or a metal stack such as nickel / gold or nickel / palladium / gold). The metal ring 114 has a top surface 123, a bottom surface 125, and an inner surface 127 extending between the top surface 123 and the bottom surface 125. The bottom surface 125 of the metal ring 114 is coupled to the device side 108 and is therefore not plated, but in some examples, the remaining surface of the metal ring 114 (including at least a portion of the inner surface 123 that interfaces with the device side 108) is plated with the noble metal 117, and in other examples, the surface of the metal ring 114 that is not covered by the molding compound 118 and is not coupled to the device side 108 is plated with the noble metal 117. Such an arrangement can ensure that the metal ring 114 does not react with and contaminate a test material (e.g., a fluid) that may remain at the base of the metal ring 114 and be in physical contact with the sensor 110 for an extended period of time, which can improve the accuracy with which the sensor 110 measures the test material. The molding compound 118 covers the various components of the sensor package 100 as shown and protects the components from external damage, such as through impact, moisture, temperature fluctuations, etc. In addition, portions of the portion 116 (and the top surface 123) protrude from and are exposed to the molding compound 118. Such an arrangement can prevent the molding compound 118 from entering the opening 121 during the molding operation.

[0030] In an example, the tube 120 includes a solid portion 122 and a hollow portion 124 (e.g., an inner cavity) surrounded by the solid portion 122. The end of the tube 120 coupled to the metal ring 114 may have a shape that facilitates such coupling and prevents the tube 120 from being decoupled from the metal ring 114. For example, the end of the tube 120 coupled to the metal ring 114 may include one or more plastic prongs, a press-fit feature, or any other suitable mechanism for coupling with the metal ring 114 and reducing the risk of subsequent detachment from the metal ring 114 that enables the tube 120 to be snapped into place. In addition, as described, the metal ring 114 has a varying lateral thickness (e.g., a portion 115 having a smaller lateral thickness relative to the portion 116), which enables the metal ring 114 to retain the tube 120 after insertion. As shown, once coupled to the metal ring 114, the tube 120 provides the test material (e.g., fluid, gas) to the sensor 110 (e.g., further away from the sensor 110). Similarly, tube 120 can provide a path for test material to be removed from sensor 110. In some examples, tube 120 includes multiple lumens, one lumen for providing test material to sensor 110, and one lumen for removing test material from sensor 110. Any and all such variations are contemplated and are within the scope of this specification. In addition to being coupled to tube 120, metal ring 114 also reduces the risk of fluid leakage into other parts of sensor package 100 (such as into molding compound 118). The noble metal 117 on metal ring 114 reduces corrosion or other wear of metal ring 114 due to fluid, exposure to oxygen, etc. Figure 2 According to each instance Figure 1 Top view of the structure.

[0031] In some examples, sensor package 100 may include flip chip connections to provide electrical connections between die 106 and devices external to the sensor package instead of or in lieu of wire bonds 112. Sensor packages that include both flip chip connections and wire bond connections are also contemplated and within the scope of this description.

[0032] Figure 33 is a cross-sectional view of a sensor package 300 having such a flip chip configuration according to various examples. The sensor package 300 includes a die pad 302 coupled to a semiconductor die 306. The die 306 has a device side 308 in which a circuit system is formed. The sensor package 300 includes a sensor 310 positioned within the device side 308. The sensor 310 can be functionally similar to the sensor 110 described above. The sensor package 300 includes a metal ring 314 (e.g., copper) coupled to the device side 308. As shown, a molding compound 318 covers the various structures of the package 300. The metal ring 314 forms an opening 321 around the perimeter of the sensor 310. The metal ring 314 is plated with a noble metal 316 (e.g., gold, palladium, silver, platinum or other noble metal, or a metal stack such as nickel / gold or nickel / palladium / gold). The metal ring 314 has a top surface 323, a bottom surface 325, and an inner surface 327 extending between the top surface 323 and the bottom surface 325. The bottom surface 325 of the metal ring 314 is coupled to the device side 308 and is therefore not plated, but in some examples, the remaining surface of the metal ring 314 (including at least a portion of the inner surface 327 that interfaces with the device side 308) is plated with the precious metal 316, and in other examples, the surface of the metal ring 314 that is not covered by the molding compound 318 and is not coupled to the device side 308 is plated with the precious metal 316. The size, properties, and function of the metal ring 314 are similar to those of the metal ring 114 described above, and therefore are not repeated in detail here.

[0033] Sensor package 300 may further include metal pillars 320 (e.g., copper) plated with plated metal 322 (e.g., a noble metal such as gold) and metal pillars 324 (e.g., copper) plated with plated metal 326 (e.g., a noble metal such as gold). The metal pillars may provide flip chip connections (or other types of electrical connections) to external components of the sensor package.

[0034] In some examples, metal pillars 320 and 324 are separate pillars and can have a cross-sectional profile similar to metal ring 314. For example, each of the metal pillars can have a top portion (e.g., farther away from device side 308 and sensor 310) and a bottom portion (e.g., closer to device side 308 and sensor 310), wherein the bottom portion has a substantially uniform width and the top portion has a non-uniform width. In some examples, the top portion can have a maximum width near the bottom (e.g., closest to sensor 310) and a minimum width near the top (e.g., farthest from sensor 310). This arrangement can increase the surface area of ​​the metal pillars for making electrical connections to external components (e.g., for soldering).

[0035] exist Figure 3In an example of , metal posts 320 and 324 may form an electrical connection with a PCB 328, which includes metal traces 330 and 332 coupled to metal posts 320 and 324, respectively. More specifically, metal post 320 is coupled to metal trace 330, and metal post 324 is coupled to metal trace 332. In an example, metal traces 330, 332 are copper traces, which may be plated with a plated metal, such as a precious metal (e.g., gold). Metal posts 320, 324 may be coupled to metal traces 330, 332 by means of any suitable technique, such as soldering, anisotropic conductive film (ACF), thermocompression bonding, etc. A non-conductive sealant material 333 (e.g., an elastomeric material) may be positioned between the traces 330, 332 of PCB 328 and cavity 334. Tube 336 may extend through cavity 334 and may be coupled to metal ring 314. Tube 336 may include a solid portion 338 and a hollow portion 340 (e.g., an inner cavity) through which a test material may be provided to sensor 310. The properties and operation of tube 336 may be similar to those of tube 120, and therefore are not repeated in detail herein. Data collected by sensor 310 may be provided to circuitry in die 306, and this circuitry may provide signals to traces 330, 332 with the aid of metal pillars 320, 324. Additional metal pillars may be included. Figure 4 According to each instance Figure 3 Top view of the structure.

[0036] In some examples, the sleeve may be adapted to replace the tube and the PCB to provide and retrieve test materials to and from the sensor package, and to provide and retrieve data signals from the sensor package. Figure 55 is a cross-sectional view of a sensor package 500 configured to be coupled to such a sleeve according to various examples. The sensor package 500 includes a die pad 502 and a conductive terminal 504 (e.g., a lead). The sensor package 500 includes a semiconductor die 506 coupled to the die pad 502. The device side 508 of the die 506 includes a circuit system that is configured to process a signal provided by a sensor 510. The sensor 510 can be functionally similar to the sensor 110 described above. The wirebond 512 couples the circuit system on the device side 508 (e.g., a contact pad on the device side 508 coupled to the circuit system) to the conductive terminal 504. A metal ring 514 (e.g., composed of copper) surrounds the sensor 510. In an example, the metal ring 514 is plated with a plated metal 516 (e.g., a precious metal such as gold). As shown, a molding compound 518 covers the various structures of the sensor package 500. The plated metal 516 may cover all surfaces of the metal ring 514 except the surface coupled to the device side 508. In other examples, the plated metal 516 only covers the surface of the metal ring 514 that is not covered by the molding compound 518 and is not coupled to the device side 508. The metal ring 514 surrounds the sensor 510 and the cavity 520. The sleeve 522 is positioned above the sensor package 500. The sleeve 522 can be made of any suitable material. The sleeve 522 includes a fluid channel 524 that terminates at the cavity 526. As shown, the cavities 520 and 526 are aligned to facilitate the exchange of test materials (e.g., fluid) between the fluid channel 524 and the cavity 520 (e.g., the sensor 510). An adhesive 528 (e.g., a two-component epoxy or a UV-cured adhesive) can couple the sleeve 522 to the molding compound 518. In an example, a variety of adhesives may be applicable. In an example, an elastomeric gasket may be used to form a seal between the sleeve 522 and the plated metal 516. In operation, a test material is provided to the sensor 510 via the fluid channel 524 of the sleeve 522. The sensor 510 collects data about the properties of the test material, and the circuit system in the die 506 processes this data. The circuit system can communicate with devices external to the sensor package 500 through the bond wires 512 and the conductive terminals 504. The properties and functionality of the metal ring 514 are similar to those of the metal ring 114, and therefore will not be described in detail here.

[0037] In some examples, the bond wires of sensor package 500 may be replaced with metal traces formed on the sleeve. Figure 66 is a profile cross-sectional view of a sensor package 600 configured to be coupled to a sleeve having such metal traces according to various examples. In an example, the sensor package 600 includes a die pad 602. The sensor package 600 includes a semiconductor die 606 coupled to the die pad 602. The device side 608 of the die 606 includes a circuit system that is configured to process a signal provided by a sensor 610. The sensor 610 can be functionally similar to the sensor 110 described above. A metal ring 614 (e.g., composed of copper) surrounds the sensor 610. In an example, the metal ring 614 is plated with a noble metal 616 (e.g., gold, palladium, silver, platinum or other noble metal, or a metal stack such as nickel / gold or nickel / palladium / gold). As shown, a molding compound 618 covers the various structures of the sensor package 600. The plated metal 616 can cover all surfaces of the metal ring 614 except the surface coupled to the device side 608. In other examples, the plated metal 616 covers only the surface of the metal ring 614 that is not covered by the molding compound 618 and is not coupled to the device side 608. The sensor package 600 also includes a metal pillar 617 (e.g., copper) plated with a plated metal 619 (e.g., a noble metal such as gold) and a metal pillar 621 (e.g., copper) plated with a plated metal 623 (e.g., a noble metal such as gold). The metal pillars 617, 621 may have the same Figure 3 The metal pillars 320 and 324 have similar structures and shapes.

[0038] Metal ring 614 surrounds sensor 610 and cavity 620. In some instances, as shown, microfluidic channel 624 extends laterally from cavity 620. Sleeve 625 is positioned above sensor package 600. Sleeve 625 can be made of any suitable material. Sleeve 625 includes fluid channel 626 that terminates at cavity 627. As shown, cavities 620, 627 are aligned to facilitate test material (e.g., fluid) exchange between fluid channel 626 and cavity 620 (e.g., sensor 610). Metal traces 628, 630 (e.g., copper plated with a precious metal such as gold) are formed on sleeve 625 and coupled to metal posts 617, 621. Metal traces 628, 630 may be coupled to other circuit systems, traces, solder bumps, etc. that are not explicitly shown. Signals may be exchanged between circuitry on die 606 and devices or circuitry coupled to metal traces 628, 630 by means of metal pillars 617, 621 and metal traces 628, 630. Adhesive 632 (e.g., anisotropic conductive film (ACF)) may couple sleeve 625 to molding compound 618. In an example, a variety of adhesives may be applicable. In an example, metal traces 628, 630 may be coupled to metal pillars 617, 621, respectively, by a suitable adhesive such as solder or ACF.

[0039] In operation, a test material is provided to the sensor 610 via the fluid channel 626 of the sleeve 625. The sensor 610 collects data about the properties of the test material, and the circuitry in the die 606 processes this data. The circuitry can communicate with devices external to the sensor package 600 through the metal pillars 617, 621 and the metal traces 628, 630.

[0040] In some examples, the metal rings and metal pillars may have shapes different from those described above. For example, each metal ring may have a uniform lateral thickness over its entire height. Similarly, each metal pillar may have a uniform lateral thickness over its entire height. Figure 7 and 8 They were shown Figure 5 and 6 The structure of the present invention comprises a metal ring and a metal column having such a uniform lateral thickness. Specifically, Figure 7 7 is a cross-sectional view of a sensor package 700 coupled to a sleeve configured to provide test material to the packaged sensor according to various examples. In addition to the metal ring 514 having a uniform lateral thickness throughout its entire height, Figure 7 The structure and Figure 5 The structure is the same. Figure 8 8 is a cross-sectional view of a sensor package 800 coupled to a sleeve configured to provide test material to the packaged sensor and to exchange data signals with the sensor package according to various examples. In addition to the metal ring 614 and each of the metal pillars 617 and 621 having a uniform lateral thickness throughout their respective heights, Figure 8 The structure and Figure 6 The structure is the same.

[0041] exist Figure 8 In some examples, the metal ring 614 has a top surface 823, a bottom surface 825, and an inner surface 827 extending between the top surface 823 and the bottom surface 825. The bottom surface 825 of the metal ring 614 is coupled to the device side 608 and is therefore not plated, but in some examples, the remaining surface of the metal ring 614 (including at least a portion of the inner surface 827 that interfaces with the device side 608) is plated with the precious metal 616, and in other examples, the surface of the metal ring 614 that is not covered by the molding compound 618 and is not coupled to the device side 608 is plated with the precious metal 616.

[0042] Additionally, in some examples, the sensor package 800 includes Figure 6632 in a different configuration. In this configuration, adhesive 632 may be an ACF, in which case current may flow vertically between metal pillar 617 and metal trace 628, but not horizontally between metal pillar 617 and a fluid flowing through cavity 627. Similarly, adhesive 632 (e.g., an ACF) may facilitate current flow vertically between metal pillar 621 and metal trace 630, but not horizontally between metal pillar 621 and a fluid flowing through cavity 627. Similarly, adhesive 632 blocks current from flowing horizontally between metal pillars 614, 616 and a fluid flowing through cavity 627.

[0043] Fig. 9 9 is a cross-sectional view of a sensor package 900 having a microfluidic channel according to various examples, wherein the microfluidic channel is configured to provide a test material between a first tube and a second tube coupled to a metal ring of the sensor package. Specifically, the sensor package 900 includes a die pad 902 and a conductive terminal 904 (e.g., a lead). The sensor package 900 includes a die 906 having a device side 908 in which a circuit system is formed. The sensor package 900 includes a sensor 910 having properties similar to those of the sensor 110 described above, which properties are not repeated here. A wire bond 912 couples a contact pad on the device side 908 to the conductive terminal 904.

[0044] The sensor package 900 includes a metal ring 914 (e.g., copper) that has been plated with a plated metal 916 (e.g., a precious metal such as gold). The properties of the metal ring 914 are similar to the properties of the metal ring 114 described above, and therefore are not repeated here. As shown, the sensor package 900 may also include a molding compound 918 covering the various structures of the sensor package 900. The microfluidic channel 920 fluidically connects the cavity 922 and the cavity 924, wherein the sensor 910 is exposed to the microfluidic channel 920. Therefore, the sensor 910 is configured to evaluate the properties of a test material that can flow through the microfluidic channel 920 between the cavities 922 and 924. The metal ring 914 surrounds the cavity 924, and the metal ring 926 (e.g., copper) surrounds the cavity 922. The metal ring 926 is plated with a precious metal 928 (e.g., gold, silver, platinum or other precious metal, or a metal stack such as nickel / gold or nickel / palladium / gold). A metal ring 930 (eg, copper) also surrounds cavity 922 and is positioned between cavity 922 and metal ring 926. Metal ring 930 is plated with a noble metal 932 (eg, gold, silver, platinum or other noble metal, or a metal stack such as nickel / gold or nickel / palladium / gold).

[0045] exist Fig. 9In some examples, the metal ring 926 has a top surface 923, a bottom surface 925, and an inner surface 927 extending between the top surface 923 and the bottom surface 925. The bottom surface 925 of the metal ring 926 is coupled to the device side 908 and is therefore not plated, but in some examples, the remaining surface of the metal ring 926 (including at least a portion of the inner surface 927 that interfaces with the device side 908) is plated with the precious metal 928, and in other examples, the surface of the metal ring 926 that is not covered by the molding compound 918 and is not coupled to the device side 908 is plated with the precious metal 928.

[0046] exist Fig. 9 In some examples, the metal ring 930 has a top surface 929, a bottom surface 931, and an inner surface 933 extending between the top surface 929 and the bottom surface 931. The bottom surface 931 of the metal ring 930 is coupled to the device side 908 and is therefore not plated, but in some examples, the remaining surface of the metal ring 930 (including at least a portion of the inner surface 933 that interfaces with the device side 908) is plated with the precious metal 932, and in other examples, the surface of the metal ring 930 that is not covered by the molding compound 918 and is not coupled to the device side 908 is plated with the precious metal 932.

[0047] The metal rings 926, 930 are configured to couple to a tube 934 having a solid portion 935 and a hollow portion 936 (e.g., an inner cavity). In some examples, the end of the tube 934 closest to the sensor package 900 can be molded to "snap" and lock between the metal rings 926, 930. In an example, when the tube 934 is coupled to the sensor package 900, the tube 934 and / or the sensor package 900 can be heated, and thus the tube 934 can change its shape or can melt to fuse with the metal rings 926, 930. When cooled, the risk of the tube 934 being decoupled from the sensor package 900 can be reduced. The end of the solid portion 935 that is coupled to the metal rings 926, 930 can be molded to couple to the metal rings 926, 930, such as using one or more plastic prongs, press-fit features, etc. that allow the tube 934 to snap into place. Similarly, a tube 938 including a solid portion 939 and a hollow portion 940 (e.g., an inner cavity) can be coupled to the metal ring 914, and the end of the solid portion 939 coupled to the metal ring 914 can be molded to include one or more plastic prongs, press-fit features, etc. that allow the tube 938 to snap into place, thereby facilitating coupling to the metal ring 914. In operation, a test material (e.g., a fluid) flows through one of the tubes 934, 938, into the microfluidic channel 920, across the sensor 910, and out of the other tube 934, 938. Fig.10 According to each instance Fig. 9 Top view of the structure.

[0048] Fig.111 is a perspective view of a sensor package 1100 having a plated sealing surface and a plated metal ring surrounding the sensor according to various examples. In an example, the sensor package 1100 includes a molding compound 1102, a sensor 1104 coupled to a semiconductor die (not explicitly shown) within the sensor package 1100, and a conductive terminal 1106 (e.g., a lead) also coupled to the semiconductor die within the sensor package 1100. The sensor 1104 can be similar to the sensor 110 and therefore will not be described in detail herein. The sensor package 1100 includes a plated metal ring 1107 (e.g., composed of copper and plated with a precious metal such as gold). The plated metal ring 1107 surrounds the sensor 1104. A plated area 1108 (e.g., a precious metal such as gold) can be located on the top surface of the molding compound 1102 and can be adjacent to the plated metal ring 1107. The sensor package 1100 can include an o-ring 1110 positioned on the plated area 1108 and surrounding the sensor 1104. O-ring 1110 facilitates coupling with a structure (such as a sleeve) that can provide test material (e.g., fluid) to and / or retrieve test material (e.g., fluid) from sensor 1104, and further because o-ring 1110 helps facilitate a secure seal to reduce the risk of test material leaking into damage-prone areas of sensor package 1100. Plated area 1108 is beneficial because it prevents any test material (e.g., fluid) that has escaped from within the confines of o-ring 1110 from damaging other portions of sensor package 1100 (e.g., by penetrating into the porous top surface of molding compound 1102). Fig.12 is a top view of a sensor package 1100 according to various examples.

[0049] In some instances, the sensor package may include multiple sensors (e.g., a multi-dimensional array of sensors), each sensor surrounded by its own one or more metal rings, and wherein each metal ring is coupled to a tube or sleeve to provide test material to one or more corresponding sensors and / or retrieve test material from the corresponding sensor. Fig.13A1 is a top view of a sensor package 1300 having a plurality of metal rings that surround a plurality of sensors and are configured to be coupled to a plurality of tubes that provide a test material to the sensors according to various examples. Specifically, the sensor package 1300 includes a molding compound 1302 covering a semiconductor die 1304 that includes an array of sensors 1305 (e.g., similar to sensor 110) embedded within the die 1304. Each sensor 1305 may be positioned between a pair of metal rings 1306, wherein one of the metal rings 1306 is configured to provide a test material (e.g., a fluid) to the corresponding sensor 1305, and the other metal ring 1306 is configured to retrieve the test material from the corresponding sensor 1305. By including an array of sensors 1305 and a pair of metal rings 1306 for each of the sensors 1305, and further by coupling a separate tube and / or sleeve fluid channel to each metal ring, a large number of different test materials may be tested simultaneously. Thus, the sensor package 1300 provides an efficient technical solution for testing a large number of test materials simultaneously. Sensor package 1300 includes contact pads 1308 positioned along the periphery of die 1304 and conductive terminals 1312 (e.g., leads) positioned along the periphery of molding compound 1302. Wirebonds 1314 couple contact pads 1308 to respective conductive terminals 1312. In some examples, wirebonds 1314 may be replaced with wirebonds as in flip chip packaging. Figure 6 and 8 The metal pillars are similar to the metal pillars. Fig. 13B yes Fig.13A perspective view of the structure.

[0050] Fig.14 1 is a schematic cross-sectional view of a portion of a sensor package 1300 according to various examples. As shown, a sensor 1305 is embedded within a die 1304 and fluidically coupled to a cavity 1400 surrounded by a metal ring 1306 via a microfluidic channel 1401. The microfluidic channel 1401 is also fluidically coupled to another of the metal rings 1306 (e.g., Fig.13A A cavity surrounded by one of the metal rings 1306 shown in FIG. Fig.14 The metal ring 1306 shown in FIG. 1 is plated with a plated metal 1402 (e.g., a precious metal such as gold). A tube 1403 having a solid portion 1404 and a hollow portion 1406 (e.g., an inner cavity) is coupled to the metal ring 1306 (e.g., using one or more plastic prongs, a press fit structure, etc. at the end of the tube 1403 coupled to the metal ring 1306).

[0051] In operation, a test material (e.g., fluid) is provided to the microfluidic channel 1401 via tube 1403. As the test material flows through the microfluidic channel 1401, the sensor 1305 senses a property of the test material. The test material then exits the sensor package 1300 via another tube 1403 coupled to an adjacent metal ring 1306. The circuitry in the die 1304 processes the signal received from the sensor 1305 and provides an output signal via bond wires 1314 and conductive terminals 1312 (e.g., to another device coupled to the conductive terminals 1312 via metal traces on a PCB).

[0052] The scope of the present description is not limited to packages having a circular metal ring. The metal ring may include any of a variety of shapes, such as an oblong metal ring. Fig.15 1 is a top view of a sensor package 1500 having a plurality of oblong metal rings that surround a plurality of sensors and are configured to be coupled to a sleeve that provides a test material to the sensors according to various examples. Specifically, the sensor package 1500 includes a semiconductor die 1504 and contact pads 1506 positioned along the periphery of the die 1504. At least some of the contact pads 1506 include metal pillars 1508 (which may be plated with a plated metal 1509 (e.g., a precious metal such as gold)) that are configured to establish an electrical path with other components (e.g., a sleeve, a PCB, etc.), as described below. The following reference may be used to Fig.19 The metal pillars 1508 and the oblong metal rings 1510 are formed by using the photolithography and plating techniques described herein. The sensor package 1500 includes a plurality of oblong metal rings 1510 that form a cavity 1514 (e.g., a fluid channel). The oblong metal rings 1510 may be plated with a plated metal 1512 (e.g., a precious metal such as gold). The cavity 1514 includes a test material input region 1516, a test material output region 1518, and a sensor 1520. In an example, the sensor 1520 is similar to the sensor 110 and therefore is not described in detail herein. As described below, a test material (e.g., a fluid) is deposited at or near the test material input region 1516, sensed by the sensor 1520 when the test material flows to the test material output region 1518, and removed from the cavity 1514 at or near the test material output region 1518. Fig.16 yes Fig.15 perspective view of the structure.

[0053] As described above, sensor package 1500 is configured to be coupled to a structure such as a sleeve or tube to receive a test material. Fig.17 1 is a cross-sectional view of a sensor package 1500 coupled to such a structure according to various examples. The cross section is taken along Fig.15More specifically, the sensor package 1500 is coupled to a sleeve 1522 having a fluid channel 1524 terminating in a cavity 1526 that interfaces with a cavity 1528 surrounded by the metal ring 1510. The sleeve 1522 may include a plurality of such fluid channels 1524 and a plurality of test material output regions 1518. Fig.15 The plurality of metal rings 1510 shown in FIG. 15 are interfaced with the cavity 1526. An adhesive layer 1530 can couple the sleeve 1522 to the sensor package 1500. In some examples, the sensor 1520 can be positioned within or adjacent to a microfluidic channel.

[0054] Fig.18 Provides Fig.15 Another cross-sectional view of the structure. The cross section is taken along the Fig.15 1508. The metal ring 1510 and metal pillar 1508 shown are intercepted. Fluid channel 1531 provides a test material (e.g., a fluid) to cavity 1532, which provides the test material to fluid channel 1534. Fluid channel 1534 interfaces with cavity 1514, and the test material flows through the combination of fluid channel 1534 and cavity 1514. As the test material flows, sensor 1520 (e.g., in some instances, the sensor may be located in or near a microfluidic channel) detects a property of the test material. The test material exits through cavity 1526 and fluid channel 1524. Circuitry in die 1504 receives a signal from sensor 1520 and processes the signal. Circuitry provides a signal to metal pillar 1508 via contact pad 1506. In turn, metal pillar 1508 provides a signal to metal traces 1542 and 1544 formed on sleeve 1522. Metal traces 1542 and 1544 may be coupled to Fig.18 Other devices or components not explicitly shown.

[0055] Fig.191 is a flow chart of a method 1900 for manufacturing a sensor package having a metal ring according to various examples, the metal ring being configured to be coupled to a tube that provides a test material (e.g., a fluid) to a sensor in the sensor package. Specifically, the method 1900 includes depositing a photoresist layer on a first surface of a semiconductor die, wherein the first surface includes a sensor (1902). The method 1900 includes exposing and developing the photoresist layer to produce a central photoresist member, an annular photoresist member surrounding the central photoresist member, and an annular cavity between the central photoresist member and the annular photoresist member (1904). The central photoresist member contacts the sensor (1904). The method 1900 further includes plating a metal ring in the annular cavity (1906). After the annular cavity has been filled, plating continues. The metal ring includes a first portion having a first lateral thickness, which is formed by plating in the annular cavity; and a second portion having a variable lateral thickness, which is formed by continuing to plate after the annular cavity has been filled (1906). As plating continues, the second portion may form a tapered shape, similar to an arch with a flat bottom. Plating that continues after the annular cavity has been filled may continue until the second portion has achieved a target thickness profile. The method 1900 also includes removing the central photoresist member and the annular photoresist member (1908). The method 1900 includes plating a precious metal on at least the inner surface of the abutting first surface of the metal ring after removing the central photoresist member and the annular photoresist member and before applying the molding compound (1910). The method 1900 includes applying the molding compound to the surface and the metal ring (1912). The top surface of the metal ring is at least partially exposed through the molding compound (1912). Similar to the above reference Fig.19 The described techniques may be used to form metal pillars 1508 (eg, Fig.15 ). To form such a metal pillar 1508, the photoresist layer of (1902) is exposed and developed to form a single photoresist member having a cavity having a substantially circular horizontal cross-section. The cavity may be positioned above the contact pad 1506. Plating is performed within the cavity to form a first portion of the metal pillar 1508, and after filling the cavity, plating may continue to form a second portion of the metal pillar 1508. Continuing plating after filling the cavity naturally produces a dome-shaped second portion having a rounded surface and a flat bottom.

[0056] In this specification, the term "coupled" may encompass connections, communications, or signal paths that enable a functional relationship consistent with this description. For example, if device A generates a signal to control device B to perform an action, then: (a) in a first instance, device A is coupled to device B through a direct connection; or (b) in a second instance, device A is coupled to device B through an intermediate component C, provided that the intermediate component C does not change the functional relationship between device A and device B, so that device B is controlled by device A via the control signal generated by device A.

[0057] A device "configured to" perform a task or function may be configured (e.g., programmed and / or hardwired) to perform the function when manufactured by a manufacturer, and / or may be configured (or reconfigurable) by a user after manufacture to perform the function and / or other additional or alternative functions. The configuration may be performed through firmware and / or software programming of the device, through the construction and / or layout of hardware components and interconnection of the device, or a combination thereof.

[0058] In this specification, unless otherwise stated, "about," "approximately," or "substantially" preceding a parameter means within a + / -10% range of the parameter. Modifications may be made in the described examples, and other examples may be made within the scope of the claims.

Claims

1. A sensing device, comprising: a semiconductor die comprising a device side and a fluid sensor in the device side; a metal ring forming an opening above the fluid sensor, the metal ring having a top surface, a bottom surface, and an inner surface extending between the top surface and the bottom surface, the bottom surface being located on the device side, and at least a portion of the inner surface abutting the device side being plated with a precious metal; and A molding compound covers the semiconductor die and a first portion of the metal ring, wherein a second portion of the metal ring having the top surface protrudes from the molding compound and provides at least one of a sleeve interface or a tube interface.

2. The sensing device of claim 1, wherein the metal ring comprises copper. The sensing device of claim 1 , wherein the noble metal comprises gold.

4. The sensing device of claim 1, wherein the second portion has a uniform lateral thickness and provides the sleeve interface.

5. The sensing device of claim 4, further comprising a sleeve coupled to the sleeve interface by an insulating adhesive layer, the sleeve comprising a fluid channel.

6. The sensing device of claim 5, wherein the metal ring is electrically coupled to a conductive trace on the sleeve.

7. A sensing device according to claim 1, wherein the second portion includes a first sub-portion and a second sub-portion, the first sub-portion is closer to the fluid sensor than the second sub-portion, the first sub-portion has a first lateral thickness, and the second sub-portion has a second lateral thickness exceeding the first lateral thickness.

8. The sensing device of claim 7, further comprising a sleeve coupled to the sleeve interface by an insulating adhesive layer, the sleeve comprising a fluid channel. 9 . The sensing device of claim 7 , wherein the second lateral thickness gradually decreases from a bottom surface of the second sub-portion to a top surface of the second sub-portion.

10. The sensing device of claim 7, further comprising a tube coupled to the metal ring.

11. The sensing device of claim 1 , wherein the noble metal is a first noble metal, and the sensing device comprises: a metal pillar protruding from the molding compound and plated with a second noble metal and coupled to the circuitry of the semiconductor die; and A conductive trace is coupled to the metal post. 12 . The sensing device of claim 11 , wherein the metal pillar comprises a first portion and a second portion, the first portion being closer to the semiconductor die than the second portion, the first portion having a first width, and the second portion having a second width greater than the first width.

13. The sensing device of claim 1, wherein the fluid sensor comprises an ion sensitive field effect transistor (ISFET).

14. The sensing device of claim 1, wherein a horizontal cross-section of the metal ring has an oblong shape.

15. The sensing device of claim 1, wherein a horizontal cross-section of the metal ring has a circular shape.

16. A sensing system comprising: a semiconductor die comprising a device side and a fluid sensor in the device side; a first metal ring forming an opening configured to be in fluid communication with the fluid sensor, the first metal ring having a first top surface, a first bottom surface, and a first inner surface extending between the first top surface and the first bottom surface, the first bottom surface being located on the device side, and at least a portion of the first inner surface abutting the device side being plated with a first precious metal; a second metal ring surrounding the first metal ring, the second metal ring having a second top surface, a second bottom surface, and a second inner surface extending between the second top surface and the second bottom surface, the second bottom surface being located on the device side, and at least a portion of the second inner surface being plated with a second precious metal; and A molding compound covers the semiconductor die and a first portion of the second metal ring, wherein a second portion of the second metal ring having the second top surface protrudes from the molding compound.

17. The sensing system of claim 16, wherein the second portion comprises a first sub-portion and a second sub-portion, the first sub-portion being closer to the fluid sensor than the second sub-portion, the first sub-portion having a first lateral thickness, and the second sub-portion having a second lateral thickness exceeding the first lateral thickness; and The first metal ring includes a third portion and a fourth portion, the third portion is closer to the fluid sensor than the fourth portion, the third portion has a third lateral thickness, and the fourth portion has a fourth lateral thickness exceeding the third lateral thickness.

18. The sensing system of claim 17, wherein the second lateral thickness is variable and comprises a thickness that exceeds the first lateral thickness and is less than the first lateral thickness.

19. The sensing system of claim 17, wherein the second lateral thickness gradually decreases from a proximal end closest to the fluid sensor to a distal end farthest from the fluid sensor.

20. The sensing system of claim 16, further comprising a tube including a flange coupled to the first and second metal rings.

21. The sensing system of claim 16, further comprising a printed circuit board (PCB) comprising a conductive trace, wherein the conductive trace contacts the second metal ring.

22. The sensing system of claim 16, further comprising: a sleeve coupled to the molding compound via an insulating adhesive layer; and A conductive material is coupled to the first metal ring and the second metal ring.

23. A sensing system according to claim 16, wherein the opening is a first opening, and the sensing system includes a third metal ring, the third metal ring forming a second opening configured to be connected to the fluid of the fluid sensor, wherein the third metal ring includes a first portion and a second portion, the molding compound covers the first portion of the third metal ring, and the second portion of the third metal ring having a third top surface protrudes from the molding compound.

24. The sensing system of claim 23, further comprising a tube coupled to the third metal ring.

25. A method for manufacturing a sensing device, comprising: depositing a photoresist layer on a first surface of a semiconductor die, the first surface comprising a sensor; exposing and developing the photoresist layer to produce a central photoresist member, an annular photoresist member surrounding the central photoresist member, and an annular cavity between the central photoresist member and the annular photoresist member, the central photoresist member contacting the sensor; Plating a metal ring in the annular cavity, the metal ring comprising a first portion having a first lateral thickness and a second portion having a variable lateral thickness; removing the central photoresist component and the annular photoresist component; Plating a precious metal on at least the inner surface of the metal ring that abuts the first surface; and A molding compound is applied to the surface and the metal ring, with a top surface of the metal ring at least partially exposed through the molding compound.

26. The method of claim 25, wherein plating the metal ring comprises: performing a plating process to fill the annular cavity with a plating metal; and The plating process continues after the annular cavity is filled with plating metal.

27. The method of claim 25, further comprising plating the noble metal on the metal ring after removing the central photoresist member and the annular photoresist member and before applying the molding compound.

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