System and method for improving the robustness of a sensor

Abstract

To provide systems and methods for enhancing robustness of sensors.SOLUTION: A device comprises a substrate, one or more sensors and one or more electrical circuits formed on the substrate, and a metal layer formed over the sensors. The one or more electrical circuits are electrically coupled to at least one of the one or more sensors. The metal layer is positioned over the one or more sensors to provide a barrier.SELECTED DRAWING: Figure 19

Description

Technical Field

[0001] Embodiments of the present invention relate to a system and method for improving the robustness of electrical components. More particularly, embodiments of the present invention relate to a system and method for improving the resistance of electrical components to degradation.

Background Art

[0002] Devices equipped with circuits and sensors are often placed in environments that degrade one or more elements of the device and cause malfunctions in the device's functions. Conventional methods of forming circuits and sensors from metal films and metal foils are insufficient in terms of forming devices with high durability against degradation. Such problems exist in conventional manufacturing methods, and as a result, the durability of the device may decrease and the maintenance cost may increase. Furthermore, in order to improve the durability of the device in conventional methods, the lead time may be lengthened. Also, it may require a great deal of cost to meet the desired size, usable life, and performance characteristics.

Summary of the Invention

[0003] The described device includes a substrate, one or more sensors and one or more electrical circuits formed on the substrate, and a metal layer formed above the sensors. The one or more electrical circuits are electrically connected to at least one of the one or more sensors. The metal layer is formed above the one or more sensors so as to provide a barrier portion.

[0004] Other features and advantages of embodiments of the present invention will become apparent from the accompanying drawings and the following detailed description. Embodiments of the present invention are illustrative and not limited to the accompanying drawings. In the drawings, like elements are denoted by like reference numerals.

Brief Description of the Drawings

[0005]

Figure 1

Figure 2

Figure 3-18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

DETAILED DESCRIPTION OF THE INVENTION

[0006] A system and method for improving the robustness of a device are described below. The device includes sensors and circuits formed using a metal film or metal foil. In various embodiments, the device has sensors that include active and / or passive components integrated in one or more integrated electric circuits. Examples of sensors include RTDs (resistance temperature detectors) (formed from nickel, nickel-chromium, and / or platinum, etc.), thermocouples, strain gauges (formed from constantan, etc.), capacitance sensors, thermocouple arrays, thermistors, sensors, heaters (formed from nichrome, etc.), reference electrodes (formed from silver / silver chloride, etc.), and electrical sensors / stimulation devices such as EKG (electrocardiogram examination method) and medical electronic mapping patches (formed with gold or platinum electrodes). The active and / or passive components include wireless communication components integrated in one or more electric circuits and / or other active and / or passive components. A method for manufacturing a device for improving robustness is also described.

[0007] In some embodiments, one or more electrical circuits are formed on a substrate of a layer separate from passive / active components. The one or more electrical circuits may be electrically connected to one or more passive / active components via, for example, one or more vias extending within an insulating layer. Some embodiments have multiple types of active / passive elements arranged in multiple layers, with the multiple types of elements arranged in separate layers respectively. However, in some embodiments, one or more electrical circuits and one or more types of active / passive components are arranged on the same layer. Active or passive components are formed by methods such as using additive thin films, plating, etching, or coated sensor materials, but are not limited thereto.

[0008] In some embodiments, one or more barrier portions are formed on one or more layers of active / passive elements included in one or more electrical circuits. The barrier portions reduce the amount and / or rate of oxidation of the metal film / foil layer of the electrical circuit, thereby improving the robustness of the one or more electrical circuits. In some embodiments, the barrier portions suppress oxidation by reducing the amount of moisture and / or oxygen that penetrates the metal film / foil layer. The barrier portions reduce the amount of oxidation of the metal layer, maintain the electrical characteristics of the electrical circuit even in harsh environments, and maintain the performance and accuracy of the sensor over a long period.

[0009] FIG. 1 shows an apparatus having a plurality of sensors integrated in an electrical circuit according to one embodiment. Apparatus 100 has a plurality of strain gauge sensors 102 and RTD sensors 104 electrically connected to one or more electrical circuits via a plurality of traces 106. The sensors, electrical circuits, and traces are integrally formed on the same substrate 108 by a similar manufacturing method. Thus, there is no need to add discrete components to the substrate including the electrical circuit, and no mounting pads are required to electrically connect the discrete components to the electrical circuit. Discrete components having packages and contacts for attachment to the substrate require extra space. Further, the packages and mounting pads of discrete components may cause parasitic losses such as capacitance loss and resistance loss, so that the characteristics of the electrical circuit of each device change and the performance of the electrical circuit may degrade from the optimal operating characteristics.

[0010] An apparatus having a plurality of active / passive components integrated in an electrical circuit does not require packages and mounting pads of discrete components that require a large amount of space. Thus, the apparatus according to the embodiments described herein can have smaller dimensions because the integrated active / passive components do not include packages of discrete components and no mounting pads are required. Further, in the apparatus according to the embodiments described herein, no parasitic losses are caused by the mounting pads. Further, since the electrical circuit can be arranged on the substrate to manufacture the active / passive components, the active / passive components and the electrical circuit can be manufactured using similar techniques. As a result, it is possible to improve the performance characteristics and narrow the working range.

[0011] FIG. 2 shows an RTD integrated in an electrical circuit according to one embodiment. The RTD component 202 is integrated into one or more electrical circuits 204 by the methods and the like described herein. Figures 3 to 18 show a process for manufacturing a device having one or more active / passive components integrated on an electrical substrate according to an embodiment. By integrally forming one or more active / passive components with an electrical circuit on the same substrate, the device can be miniaturized compared to conventional devices, such as those that require discrete components to be attached to a circuit board. Further, by integrally forming one or more active / passive components with an electrical circuit on the same substrate, the package can be made smaller. Also, since the device according to the embodiments described herein can be configured as a stand-alone device, the device can be used even in a harsh environment where malfunction or failure may occur in a device not formed as in the present embodiment.

[0012] Figure 3 shows a substrate 302 for forming one or more active / passive components integrated with one or more electrical circuits. The substrate 302 is composed of, for example, stainless steel, copper, polymer film, ceramic, glass, semiconductor, nitinol or other materials, but is not limited thereto. In some embodiments, the substrate 302 is in the form of a roll used in a reel-to-reel manufacturing process.

[0013] Figure 4 shows a substrate with a dielectric layer disposed thereon. Figure 4A is a cross-sectional view of the substrate 302 with the dielectric layer 304 disposed thereon. Figure 4B is a perspective view of the substrate 302 with the dielectric layer 304 disposed thereon. In some embodiments, the dielectric layer 304 is disposed on the substrate 302. In embodiments that do not use a conductive substrate, the placement of the dielectric layer 304 on the substrate 302 may not be required. The dielectric layer 304 includes, but is not limited to, photoresist, polyimide, KMPR, SU-8 or other insulating materials. In some embodiments, the dielectric layer 304 is disposed on the substrate 302 by a coating method (liquid coating or dry film coating). However, the dielectric layer 304 may be formed on the substrate 302 using other methods including methods well known in the art.

[0014] FIG. 5 shows a substrate provided with a dielectric layer patterned according to an embodiment. FIG. 5A is a cross-sectional view of a substrate 302 provided with a dielectric layer 304 patterned according to an embodiment. FIG. 5B is a perspective view of a substrate 302 provided with a dielectric layer 304 patterned according to an embodiment. In some embodiments, a photoresist layer is formed on the dielectric layer 304. In some embodiments, the photoresist is exposed by a photolithography method well-known in the art and developed by a wet etching method well-known in the art. By this patterned photoresist layer, a pattern of the dielectric layer 304 is formed during the dielectric removal process by either wet etching or dry etching. In other embodiments, the dielectric layer 304 is a photosensitive polyimide layer, which is directly patterned by a photolithography method well-known in the art and developed by a wet etching method well-known in the art. In yet another patterning method, unnecessary dielectric is removed by laser ablation.

[0015] FIG. 6 shows a metal layer disposed on a dielectric layer according to an embodiment. FIG. 6A is a cross-sectional view of a metal layer 306 disposed on a dielectric layer 304 according to an embodiment. FIG. 6B is a perspective view of a metal layer 304 disposed on a dielectric layer 304 according to an embodiment. The metal layer 306 is formed on the dielectric layer 304 by methods such as physical vapor deposition, chemical vapor deposition, and electroless chemical vapor deposition, but the method is not limited thereto. In some embodiments, as a first step in forming the metal layer 306, a seed layer is formed on the dielectric layer 304. For example, a seed layer such as nickel chromium is sputtered on the dielectric layer 304. By an electroless chemical vapor deposition method or the like, for example, copper is deposited on the seed layer. In some embodiments, one or more sensors are formed on the dielectric layer 304 using the metal layer 306. In some embodiments, the metal layer 306 is constantan sputtered on the dielectric layer 304 to form one or more strain gauges.

[0016] In some embodiments, the step of forming a sensor on the metal layer 304 includes depositing a photoresist layer on a metal layer such as a constantan layer, and patterning the photoresist layer. The photoresist layer is formed by methods such as liquid slot die, roller coating, spraying, curtain coating, dry film lamination, and screen printing, but the method is not limited thereto. The photoresist is patterned by, for example, photolithography and etching methods well known in the art. Next, a portion of the metal layer 304 exposed by etching a portion of the photoresist layer is etched to form sensors, electrical traces, electrical contacts, and other circuit components. In some embodiments, laser ablation is used to form sensors, electrical traces, electrical contacts, and other circuit components from the metal layer.

[0017] FIG. 7 shows a strain gauge 308 formed on a dielectric layer 304 according to an embodiment. FIG. 7A is a cross-sectional view of the strain gauge 308 formed on the dielectric layer 304 according to an embodiment. FIG. 7B is a perspective view of the strain gauge 308 formed on the dielectric layer 304 according to an embodiment. The metal layer 306 formed on the dielectric layer 304 is patterned and etched by methods well known in the art. For example, a photoresist is formed on the metal layer 306 by methods well known in the art. The photoresist is patterned and etched by the methods described herein.

[0018] FIG. 8 shows a second dielectric layer formed on a strain gauge according to one embodiment. FIG. 8A is a cross-sectional view of a second dielectric layer 310 formed on a strain gauge 308 according to one embodiment. FIG. 8B is a perspective view of a second dielectric layer 310 formed on a strain gauge 308 according to one embodiment. After forming one or more sensors on the first dielectric layer 304 by the method described herein, a second dielectric layer 310 is formed on the one or more sensors thus formed. By laminating the second dielectric layer 310 after the one or more sensors are formed, the sensors can be isolated from other structures formed in subsequent processes, so that the sensors can be protected from damage in subsequent processing steps of the device. In some embodiments, the second dielectric layer 310 is a polyimide layer formed by the method described herein or the like.

[0019] FIG. 9 shows a substrate 302 provided with a second dielectric layer patterned according to one embodiment. FIG. 9A is a cross-sectional view of a substrate provided with a second dielectric layer 310 patterned according to one embodiment. FIG. 9B is a perspective view of a substrate 302 provided with a second dielectric layer 310 patterned according to one embodiment. The second dielectric layer 310 is patterned by photolithography methods well known in the art or the like, and developed by wet etching methods well known in the art or the like.

[0020] FIG. 10 shows a second metal layer 312 formed on a second dielectric layer 310 according to an embodiment. FIG. 10A is a cross-sectional view of the second metal layer 312 formed on the second dielectric layer 310 according to an embodiment. FIG. 10B is a perspective view of the second metal layer 312 formed on the second dielectric layer 310 according to an embodiment. The second metal layer 312 is formed on the second dielectric layer 310 by methods such as physical vapor deposition, chemical vapor deposition, and electroless chemical vapor deposition, but the methods are not limited thereto. In some embodiments, as an initial step in forming a metal layer such as the second metal layer 312, a seed layer is formed on the dielectric layer. For example, a seed layer such as nickel chromium is sputtered on the dielectric layer. Copper, for example, is deposited on the seed layer by electroless chemical vapor deposition or electroplating. In some embodiments, one or more traces, vias, and electrical circuits are formed using the second metal layer 312. For example, the second metal layer 312 may have traces and vias for interconnecting one or more sensors already formed on the substrate or to be formed later and connecting one or more sensors to other electrical circuits. FIG. 11 shows traces, electrical circuits, and vias formed from a metal layer using a method according to an embodiment. FIG. 11A is a cross-sectional view of traces, electrical circuits, and vias formed from a metal layer using a method according to an embodiment. FIG. 11B is a perspective view of traces, electrical circuits, and vias formed from a metal layer using a method according to an embodiment. In some embodiments, the second metal layer 312 is patterned to include one or more sensors, another dielectric layer is formed over the second sensor layer, and another metal layer is formed to include traces, electrical circuits, and / or vias. Thus, those skilled in the art will understand that any number of dielectric layers and patterned metal layers can be formed to include any number and type of sensors and electrical circuits by the methods described herein and the like.

[0021] FIG. 12 shows a third dielectric layer 314 disposed on a patterned metal layer according to one embodiment. FIG. 12A is a cross-sectional view of a third dielectric layer 314 disposed on a patterned metal layer according to one embodiment. FIG. 12B is a perspective view of a third dielectric layer 314 disposed on a patterned metal layer according to one embodiment. The third dielectric layer 314 is formed by the methods described herein and the like. For example, the third dielectric layer 314 is a polyimide layer.

[0022] FIG. 13 shows a third dielectric layer 314 patterned to include one or more openings 316. FIG. 13A is a cross-sectional view of a third dielectric layer 314 patterned to include one or more openings 316. FIG. 13B is a perspective view of a third dielectric layer 314 patterned to include one or more openings 316. The dielectric layer is patterned by the methods described herein and the like. In some embodiments, one or more openings 316 are formed in the dielectric layer, such that a portion of the dielectric layer is removed and one or more of the traces, vias, and electrical circuits are exposed. Such openings are used, for example, to interconnect one or more electrical circuits and / or sensors with other electrical circuits and / or other sensors formed by the methods described herein and the like.

[0023] FIG. 14 shows a gold plating pad 318 formed according to one embodiment. FIG. 14A is a cross-sectional view of the gold plating pad 318 formed according to one embodiment. FIG. 14B is a perspective view of the gold plating pad 318 formed according to one embodiment. In some embodiments, one or more portions of the exposed metal layer are gold plated. For example, gold plating is applied to one or more portions to form electrical contacts. The metal layer 312 is gold plated using one or more film formation methods and patterning methods such as the methods described herein. FIG. 15 shows a gold plating pad 320 formed on a substrate. The gold plating pad 320 is formed on a surface of the substrate opposite to the surface on which one or more dielectric layers and a patterned metal layer are disposed. FIG. 15A is a cross-sectional view showing the gold plating pad 320 formed on the surface of the substrate opposite to the surface on which one or more dielectric layers and a patterned metal layer are disposed. FIG. 15B is a perspective view showing the gold plating pad 320 formed on the surface of the substrate opposite to the surface on which one or more dielectric layers and a patterned metal layer are disposed. The gold plating pad 320 is formed using one or more film formation methods and patterning methods such as the methods described herein. In such an embodiment, the substrate 302 is a metal layer, and the gold plating pad 320 formed on the substrate is used to form one or more ground terminals and / or negative terminals for one or more electrical circuits and / or one or more sensors that are already formed or will be formed later in the device.

[0024] FIG. 16 shows a patterned substrate layer 322 according to an embodiment. FIG. 16A is a cross-sectional view of the patterned substrate layer 322 according to an embodiment. FIG. 16B is a perspective view of the patterned substrate layer 322 (top and bottom surfaces) according to an embodiment. The substrate is patterned using the methods described herein, for example, methods related to patterning metal layers. Also, the substrate may be patterned by laser ablation methods and the like well-known in the art. In some embodiments, the substrate is patterned to perform at least one of forming at least a part of one or more circuits and forming the device into a desired shape. Examples of the desired shape include, but are not limited to, the shape of a package, the shape of an attachment, forming holes for attaching hardware, and forming other mechanical features. In some embodiments, patterning includes forming a texture or pattern on the substrate using a patterning method such as the methods described herein.

[0025] FIG. 17 shows a device formed to include mechanical features 324 according to an embodiment. In some embodiments, the device is patterned or shaped to have mechanical features 324, which enable the achievement of desired mechanical properties and / or incorporation into a system. For example, the substrate is bent into a reinforcing rail shape or formed by other methods. Other mechanical features 324 may include one or more weld points for fixing the device to a system or for fixing another device or circuit to the substrate. Further, the substrate may be patterned by the methods described herein to include one or more high-surface-area adhesive attachment features to increase the adhesive force of the adhesive applied to the substrate. By applying the adhesive to the substrate, one or more components can be attached or the device can be attached to the system.

[0026] Figure 18 shows a formed device of one embodiment. The formed device may have one or more types of sensors such as the sensors described herein. The various sensors may form different sensors on the same layer or on different layers by the methods described herein or the like. The formed device may also have one or more contact pads for attaching discrete components to the device, for example, to complete one or more electrical circuits formed on the device. Further, the one or more contact pads may be configured to electrically connect the formed device to another system. In some embodiments, the one or more electrical circuits formed on the device include an electrical circuit configured as a wireless communication circuit or a part thereof. For example, the device may include one or more coils, antennas, inductors, capacitors, stub elements, or other elements of a wireless communication circuit.

[0027] In some embodiments, the one or more electrical circuits may be formed to include traces and other features having a line spacing in the range of, for example, 8 to 12 microns. In other embodiments, the range of the line spacing is 12 to 50 microns. However, those skilled in the art will understand that the line spacing may be larger or smaller than this.

[0028] In some embodiments, a temperature sensor according to one embodiment is configured as a resistance thermometer electrically connected to a first electrical trace and a second electrical trace. The temperature sensor is configured as a meandering line disposed on a dielectric layer. The meandering line is electrically connected to the first electrical trace at a first end of the meandering line and electrically connected to the second electrical trace at a second end.

[0029] In some embodiments, the substrate is attached to the web of a reel-to-reel manufacturing process to form one or more sensors and / or electrical circuits described herein. In the reel-to-reel manufacturing process, any metal layer, any dielectric layer, and one or more sensors and electrical circuits are formed and patterned by methods and the like described herein.

[0030] FIG. 19 shows an apparatus 1900 formed by an embodiment of the manufacturing process described with reference to FIGS. 3 - 18. In some embodiments, the apparatus 1900 includes active and / or passive components integrated into one or more integrated electrical circuits. For example, the sensors are RTDs (resistance temperature detectors), thermocouples, strain gauges, capacitance sensors, thermopile arrays, thermistors, heaters, reference electrodes, or electrical sensors / stimulation devices such as electrocardiogram examinations and medical electronic mapping patches.

[0031] In some embodiments, the sensor 1922 is formed on a substrate 1912 on which a first dielectric layer 1910 is laminated. The substrate 1912 is composed of, for example, but not limited to, stainless steel, copper, polymer film, ceramic, glass, semiconductor, nitinol, or other materials. In some embodiments, the substrate 1912 is a thin metal film / foil having a thickness in the range of 50 - 100 microns. However, those skilled in the art will understand that the thickness of the substrate 1912 may be greater or less than this.

[0032] The first dielectric layer 1910 is formed on the substrate 1912 by the above-described film-forming method. The first dielectric layer 1910 includes, but is not limited to, photoresist, polyimide, KMPR, SU-8, or other insulating materials. In some embodiments, the first dielectric layer 1910 is patterned using a photoresist layer formed on the first dielectric layer 1910. In other embodiments, the first dielectric layer 1910 is a photosensitive polyimide layer that is directly patterned using a photolithography method. In one embodiment, the thickness of the first dielectric layer 1910 is, for example, in the range of 5 to 10 microns. However, those skilled in the art will understand that the thickness of the first dielectric layer 1910 may be greater than or less than this value.

[0033] In some embodiments, a metal layer 1908 is formed on the first dielectric layer 1910. For example, the metal layer 1908 is a copper layer laminated on a nickel-chromium seed layer sputtered on the first dielectric layer 1910, or a constantan layer sputtered on the first dielectric layer 1910, but is not limited thereto. In some embodiments, one or more sensors are formed on the dielectric layer using the metal layer 1908. For example, the sensor is an RTD (resistance temperature detector), thermocouple, strain gauge, capacitance sensor, thermocouple array, thermistor, heater, reference electrode, or an electrical sensor / stimulation device such as an electrocardiogram examination or a medical electronic mapping patch. In some embodiments, the sensor 1922 is a quarter-bridge strain gauge that determines strain based on the resistance measured at one or more terminals. In one embodiment, the sensor 1922 has a voltage terminal 1920 that receives an input voltage, and main terminals 1926 and redundant terminals 1924 that acquire two measured values of the resistance of the entire quarter-bridge circuit.

[0034] In some embodiments, the second dielectric layer 1906 is formed over one or more sensors 1922 formed in the metal layer 1908. By laminating the second dielectric layer 1906 after one or more sensors 1922 are formed, the sensors 1922 can be isolated from other structures formed in subsequent processes, so that the sensors 1922 can be protected from being damaged in subsequent processing steps of the device 1900. In some embodiments, the second dielectric layer 1906 is a polyimide layer formed using methods described herein and the like. In one embodiment, the second dielectric layer 1906 is patterned using photolithography methods well known in the art and the like, and developed by wet etching methods well known in the art and the like. In one embodiment, the thickness of the second dielectric layer 1906 ranges from 5 to 10 microns. However, those skilled in the art will understand that the thickness of the second dielectric layer 1906 may be greater or less than this.

[0035] In some embodiments, the second metal layer 1904 is formed over the second dielectric layer 1906. The second metal layer 1904 is a barrier portion disposed above the sensors 1922 formed in the metal layer 1908. In some embodiments, the barrier portion constituted by the second metal layer 1904 suppresses the penetration of moisture and / or oxygen from the external environment to the sensors 1922 formed in the metal layer 1904, thereby preventing oxidation of the sensor material. To improve the durability and robustness of the sensors 1922, the second metal layer covers the surface of the sensors 1922 and reduces the portions not covered in the sensors 1922 and / or the portions exposed to the external environment. The second metal layer 1904 is, for example, a sputtered copper chromium layer, a sputtered chromium layer, or a copper plating layer.

[0036] In some embodiments, the second metal layer 1904 not only forms a barrier to prevent oxidation, but also forms one or more traces, vias, and electrical circuits. For example, the second metal layer 1904 may have traces and vias for interconnecting one or more sensors 1922 that are already formed or will be formed later on the substrate 1912 and connecting the one or more sensors 1922 to other electrical circuits. In some embodiments, the second metal layer 1904 is patterned to include one or more sensors, another dielectric layer is formed over the second sensor layer, and another metal layer is formed to include traces, electrical circuits, and / or vias. In one embodiment, the thickness of the second metal layer 1904 is, for example, 12 microns. However, those skilled in the art will understand that the thickness of the second metal layer 1904 may be greater or less than this.

[0037] In some embodiments, a third dielectric layer 1902 is formed over the second metal layer 1904. The third dielectric layer 1902 is formed by methods described herein, etc. The third dielectric layer 1902 is, for example, a polyimide layer, but is not limited thereto. In one embodiment, the thickness of the third dielectric layer 1902 is in the range of, for example, 5 to 10 microns. However, those skilled in the art will understand that the thickness of the third dielectric layer 1902 may be greater or less than this. Also, those skilled in the art will understand that the effects described herein can also be achieved by arrangements of metal layers and dielectric layers different from the embodiments.

[0038] FIG. 20 shows an exemplary embodiment of a sensor 2000 including a boundary protection feature 2002. In some embodiments, the boundary protection feature 2002 is an additional annular portion formed on the outer periphery of the sensor 2000 and is composed of an inactive sensor material. The boundary protection feature 2002 includes, but is not limited to, a metallic material (e.g., constantan). In some embodiments, the boundary protection feature 2002 functions as a sacrificial anode that prevents moisture from entering the circuit 2004 of the sensor 2000 and is destroyed prior to the metal components inside the sensor 2000. In some embodiments, the sensor 2000 is formed on the metal layer of the device described herein. The sensor 2000 is formed by the method described herein and the like.

[0039] FIG. 21 is a cross-sectional view of a device 2100 having a barrier portion that improves the robustness of the device 2100 according to an embodiment. The device 2100 includes a substrate 2102 and a first dielectric layer 2114 formed on the substrate 2102. In some embodiments, the substrate 2102 is a stainless steel film / foil, and the first dielectric layer 2114 includes, but is not limited to, photoresist, polyimide, KMPR, SU-8, or other insulating materials. A first metal layer 2104 is formed on the first dielectric layer 2114. In some embodiments, the first metal layer 2104 is patterned to form a sensor in the first metal layer 2104. In one embodiment, the sensor is a strain gauge. The first metal layer 2104 has a boundary barrier portion 2106 formed on the outer periphery of the sensor. In some embodiments, the boundary barrier portion 2106 is an additional annular portion of an inactive sensor material made of, for example, constantan or other metallic materials. The boundary barrier portion 2106 is formed in the first dielectric layer 2114 around the outer surface of the sensor. The boundary barrier portion 2106 is disposed on the outer periphery of the sensor and functions as a physical barrier to prevent moisture from entering the sensor formed in the first metal layer 2104. Further, the boundary barrier portion 2106 functions as a sacrificial anode that oxidizes prior to the sensor material in the presence of moisture / air.

[0040] In one embodiment, the apparatus 2100 has a second dielectric layer 2112 formed on the first metal layer 2104. The second dielectric layer 2112 insulates and / or isolates the first metal layer 2104 from other active / inactive layers of the apparatus 2100. In one embodiment, a second metal layer 2108 is formed on the second dielectric layer 2112. The second metal layer 2108 is, but not limited to, a layer of copper plated on the second dielectric layer 2112 above the first metal layer 2104. In some embodiments, the second metal layer 2108 is plated on the second dielectric layer 2112 by methods described herein or the like. The second metal layer 2108 is disposed above the sensor formed in the first metal layer 2104 and functions as a physical barrier to seal the metal sensor material from the penetration of moisture and oxygen.

[0041] In some embodiments, the second metal layer 2108 is, but not limited to, a thermally conductive material such as copper plating. Since the second metal layer 2108 has thermal conductivity, the barrier provides a heat dissipation effect, as a result of which the temperature is dispersed across the entire surface of the sensor. This heat dissipation effect improves the accuracy of sensors that sense temperature or sensors whose performance changes with temperature. For example, the resistance of the wires included in an electrical circuit integrated with a strain gauge (such as a quarter-bridge strain gauge) or a temperature sensor (such as a resistance temperature detector) changes with temperature. Therefore, the second metal layer 2108 improves the performance of the sensor by equalizing the temperature at the sensor surface. In one embodiment, the apparatus 2100 includes a third dielectric layer 2110 formed on the second metal layer 2108.

[0042] FIG. 22 is a cross-sectional view of an apparatus 2200 having a barrier portion for improving the robustness of the apparatus 2200 according to one embodiment. The apparatus 2200 includes a substrate 2202 and a first dielectric layer 2212 formed on the substrate 2202. In some embodiments, the substrate 2202 is a stainless steel film / foil, and the first dielectric layer 2212 includes, but is not limited to, photoresist, polyimide, KMPR, SU-8, or other insulating materials. A first metal layer 2204 is formed on the first dielectric layer 2212. In some embodiments, the first metal layer 2204 is patterned to form sensors in the first metal layer 2204. In one embodiment, the sensor is a strain gauge. The first metal layer 2204 has a boundary barrier portion 2206 formed on the outer periphery of the sensor. In some embodiments, the boundary barrier portion 2206 is an additional annular portion made of an inactive sensor material such as, for example, constantan or other metal materials. The boundary barrier portion 2206 is formed around the outer surface of the sensor on the first dielectric layer 2212. The boundary barrier portion 2206 is disposed on the outer periphery of the sensor and functions as a physical barrier to prevent moisture from entering the sensor formed in the first metal layer 2204. Further, the boundary barrier portion 2206 functions as a sacrificial anode that oxidizes prior to the sensor material in the presence of moisture / air.

[0043] In one embodiment, device 2200 has a second dielectric layer 2210 formed on a first metal layer 2204. The second dielectric layer 2210 insulates and / or isolates the first metal layer 2204 from other active / inactive layers of device 2200. In one embodiment, a second metal layer 2208 is formed on the second dielectric layer 2210. In some embodiments, the second metal layer 2208 is a sputtered layer. The second metal layer 2208 is, but not limited to, a sputtered chromium layer, a sputtered nickel chromium layer, or a sputtered copper chromium layer. In some embodiments, the second metal layer 2208 is sputtered on the second dielectric layer 2210 by methods described herein and the like. The second metal layer 2208 is disposed to cover the upper surface of the sensor formed in the first metal layer 2204. In some embodiments, the side surfaces of the device, including the side surfaces of the sensor, the side surfaces of the second dielectric layer 2210, and the side surfaces of the first dielectric layer 2212, are entirely covered by the second metal layer 2208 up to the substrate 2202. The second metal layer 2208 covers the first metal layer 2204 and / or the side surfaces of the device to form a physical barrier that prevents moisture and oxygen from penetrating from the external environment of device 2200 to the sensor.

[0044] In some embodiments, the second metal layer 2208 includes an antistatic component. Examples of the antistatic component include, but are not limited to, chromium compounds, chromium complexes (e.g., chromium complexes containing carboxylic acids), and chromium salts. By having the antistatic component in the second metal layer 2208, the barrier portion formed above the sensor can protect the electrical circuit from electrostatic discharge. The sensor is charged by the charged electrical circuit and / or other components of the sensor. When the charged sensor comes into contact with other charged objects (e.g., other electrical components or humans), static electricity is discharged and enters the sensor. When static electricity enters the sensor, the performance of the sensor is inhibited (e.g., noise that affects accuracy is generated, or the calibration of the sensor is disturbed). If the voltage of the static electricity discharged into the sensor is high, the electrical circuit integrated in the sensor may be damaged by the static electricity. The antistatic component of the second metal layer 2208 suppresses and removes the accumulation of static electricity in the sensor and the electrostatic discharge when the sensor comes into contact with other charged objects, thereby improving the durability, reliability, and performance of the sensor.

[0045] FIG. 23 shows an example of a process for improving the robustness of a sensor. In 2302, a metal layer is formed on a substrate. The substrate is, for example, a thin film / foil made of stainless steel, copper, polymer film, ceramic, glass, semiconductor, nitinol, and other materials, but is not limited thereto. In some embodiments, one or more dielectric layers are formed on the substrate between the substrate and the metal layer. The metal layer is a layer of copper formed on a nickel chromium seed layer sputtered on a dielectric layer formed on the substrate, or a layer of constantan sputtered on a dielectric layer formed on the substrate, but is not limited thereto. The metal layer is formed on the substrate by the methods described herein and the like.

[0046] At 2304, one or more sensors are formed using a metal layer. For example, the sensor can be an RTD (resistance temperature detector), thermocouple, strain gauge, capacitance sensor, thermocouple array, thermistor, heater, reference electrode, or an electrical sensor / stimulation device such as an electrocardiogram examination or a medical electronic mapping patch. The sensor is formed on the metal layer by methods described herein, etc. At 2306, if necessary, boundary features are formed around one or more sensors. Examples of boundary features include, but are not limited to, additional annular portions made of an inactive material (such as constantan or other sensor materials). The boundary feature functions as a sacrificial anode to prevent moisture intrusion into the sensor and prevent corrosion.

[0047] At 2308, a second metal layer is formed over the metal layer. In some embodiments, one or more dielectric layers are formed on the metal layer to achieve insulation of the first metal layer and separation between the first and second metal layers. The second metal layer can be, but is not limited to, a copper plating layer and a sputtered chromium layer, etc. The second metal layer is formed on the first metal layer using methods including the techniques described herein. The second metal layer is disposed over one or more sensors formed in the first metal layer, covering the sensors and forming a barrier portion to prevent moisture and / or oxygen from penetrating to the sensors. In some embodiments, the second metal layer has thermal conductivity, providing a heat dissipation effect that evenly disperses the temperature across the sensor and improves the performance of the sensor. In some embodiments, the second metal layer has an antistatic component that protects the sensor from electrostatic discharge, resulting in improved durability, reliability, and performance of the sensor.

[0048] Although described in connection with these embodiments, those skilled in the art will recognize that changes can be made in the aspects and details without departing from the spirit and scope of the invention.

Claims

1. An apparatus comprising: a substrate; a first dielectric layer formed on the substrate and patterned to expose a portion of the substrate; a first metal layer disposed on the first dielectric layer, the first metal layer being patterned to form one or more sensors therein, the first metal layer having boundary features disposed around the one or more sensors, the boundary features being sacrificial anodes that are destroyed in the presence of moisture or oxygen to prevent corrosion of the one or more sensors; a second dielectric layer formed over the one or more sensors of the first metal layer; a second metal layer disposed over the second dielectric layer, the second metal layer having one or more electrical circuits electrically connected to at least one of the one or more sensors formed in the first metal layer via the second dielectric layer; The apparatus, wherein the second metal layer is disposed above the first metal layer and configured to provide a physical barrier covering the one or more sensors.

2. The apparatus according to claim 1, wherein the physical barrier is configured to prevent moisture or oxygen from penetrating to the sensors.

3. The apparatus according to claim 1, wherein the second metal layer is copper plating.

4. The apparatus according to claim 3, wherein the copper plating provides a heat dissipation effect that disperses heat above the upper surfaces of the one or more sensors.

5. The apparatus according to claim 1, wherein the second metal layer comprises sputtered chromium.

6. The apparatus according to claim 5, wherein the sputtered chromium comprises one or more antistatic components that reduce electrostatic discharge.

7. The apparatus according to claim 1, wherein the boundary features are physical barrier portions configured to prevent the ingress of moisture into the one or more sensors.

8. The apparatus according to claim 1, wherein at least one of the one or more sensors is a resistance temperature detector.

9. The apparatus according to claim 1, wherein at least one of the one or more sensors comprises an array of multiple resistance temperature detectors.

10. The apparatus according to claim 1, wherein at least one of the one or more sensors is a pressure sensor.

11. The device according to claim 10, wherein the pressure sensor is a strain gauge.

12. The device according to claim 10, wherein the pressure sensor is a capacitance sensor.

13. A sensor, comprising: a substrate; a first dielectric layer disposed on the substrate, the first dielectric layer being patterned to expose a part of the substrate; a first metal layer disposed on the first dielectric layer, the first metal layer having one or more sensor components formed thereon; a second dielectric layer formed at least above the one or more sensor components; a second metal layer disposed above the second dielectric layer, the second metal layer having one or more electrical circuits and vias for electrically connecting the one or more electrical circuits to at least one of the one or more sensor components formed on the first metal layer through the second dielectric layer; a boundary feature disposed around the one or more sensor components, the boundary feature being a sacrificial anode that is destroyed in the presence of moisture or oxygen to prevent corrosion of the one or more sensor components.

14. The sensor according to claim 13, wherein the boundary feature is an additional annular portion made of a metal material having the same composition as the first metal layer.

15. The sensor according to claim 13, wherein the boundary feature prevents ingress of moisture into the one or more sensor components.

16. A method for improving the robustness of a sensor, comprising: disposing a first dielectric layer above a substrate, the first dielectric layer being patterned to expose a part of the substrate; forming a first metal layer on the first dielectric layer; forming one or more sensors on the first metal layer; forming a boundary feature around the one or more sensors, the boundary feature being a sacrificial anode that is destroyed in the presence of moisture or oxygen to prevent corrosion of the one or more sensors; forming a second dielectric layer above the one or more sensors of the first metal layer; Forming a second metal layer above the second dielectric layer, wherein the second metal layer is disposed above the one or more sensors, thereby forming a barrier portion that prevents moisture or oxygen from penetrating to the one or more sensors, and the second metal layer includes one or more electrical circuits and vias for electrically connecting the one or more electrical circuits to at least one of the one or more sensors formed in the first metal layer via the second dielectric layer.

17. The apparatus according to claim 1, wherein the second metal layer includes one or more sensors formed in the second metal layer.

18. The apparatus according to claim 1, further comprising a third metal layer disposed above the second metal layer.

19. The apparatus according to claim 18, further comprising an insulating layer disposed between the second metal layer and the third metal layer.

20. The apparatus according to claim 18, wherein the third metal layer has one or more electrical circuits and at least one or more sensors, and the third metal layer is disposed above the second metal layer and configured to provide a physical barrier portion.

21. An apparatus, a substrate, a first metal layer disposed on the substrate and having one or more electrical circuits, the first metal layer having boundary features disposed around the one or more electrical circuits, the boundary features being sacrificial anodes that are destroyed in the presence of moisture or oxygen to prevent corrosion of the one or more electrical circuits, a first dielectric layer formed on the substrate, the first dielectric layer being patterned to expose a portion of the substrate, a second dielectric layer formed above the one or more electrical circuits of the first metal layer and a plurality of portions of the first dielectric layer, a second metal layer disposed above the second dielectric layer and having at least one of the one or more electrical circuits, a third metal layer disposed above the second metal layer and configured to provide a physical barrier portion covering the one or more electrical circuits.

Images