Leadless Pressure Sensor

Abstract

To provide a pressure sensor system that is the pressure sensor system including a pressure sensor die and other components within a compact package having high space efficiency, and allows gas or liquid to reach either side or both sides of the pressure sensor die.SOLUTION: A package includes a base material 200 and a cap 300, and the inside of the package is divided into two chambers by the base material and the cap. The base material includes: a solid bottom layer; a middle layer having a slot or a route; and a top layer having two through holes 214, 218 for providing access to the slot or the route. The cap has two ports 320, 330, the first port is connected with a first chamber 312, and a top face of a pressure sensor die is within the first chamber. The second port 330 is connected with a second chamber 314 and the slot or the route, and the slot or the route is connected with a bottom face of the pressure sensor die.SELECTED DRAWING: Figure 5

Description

[Background technology]

[0001] Pressure sensors find application in a wide variety of products and have become ubiquitous over the past few years. Utilized in automotive, industrial, consumer, medical, and other industries, the demand for pressure sensors is skyrocketing and shows no signs of slowing down.

[0002] This large number and wide variety of uses comes with a wide variety of packaging requirements. Different types of packages for pressure sensor systems have been developed, some of which are based on standard packages such as dual in-line pin (DIP) packages and small outline integrated circuit (SOIC) packages.

[0003] These packages can utilize existing assembly equipment. This allows these packages to be used in mass production applications. However, with these mass productions comes a strong drive to reduce the cost and size of these packages. Thus, in some applications, it may be desirable for the pressure sensor system to be more space efficient. For example, it may be desirable to house the pressure sensor system in a smaller package that consumes less board space.

[0004] The pressure sensor system may include a pressure sensor die as well as other components. The pressure sensor die may include a diaphragm or membrane that may support a Wheatstone bridge or other pressure sensitive structure, where the membrane is at least partially supported by a thicker frame portion. The pressure sensor die may be housed in a package that allows gas or liquid to reach one or both sides of the membrane. This allows the pressure sensor system to be implemented in an absolute, gauge, or differential pressure sensor configuration. Pressure from the gas or liquid may cause the membrane to change shape, which induces a change in the pressure sensitive structure. This change may then be measured to determine the net pressure on the membrane. Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved is to provide a pressure sensor system that includes a pressure sensor die and other components in a compact, space-efficient package that allows gas or liquid to reach either or both sides of the membrane of the pressure sensor die. [Means for solving the problem]

[0006] According to the present invention, a pressure sensor system is provided that includes a package having a layered structure as a mounting substrate. The substrate can include or support electrical traces for electrical interconnection between the pressure sensor die, other components, and circuitry external to the pressure sensor system. The substrate eliminates the need for terminal leads on the package, thereby saving space and cost. The pressure sensor system package can further include a cap attachable to the substrate, which allows the membrane of the pressure sensor die to be pressurized from either the top, bottom, or both sides. A variety of caps with different ports can be attached to the substrate. This provides versatility and allows the pressure sensor system to be configured in absolute, gauge, or differential configurations.

[0007] These and other embodiments of the invention may provide a package substrate having a layered structure or substrate that supports the pressure sensor die and any necessary conditioning electronics, such as application specific integrated circuits (ASICs) and other passive or active components. The substrate may be composed of different cores or layers that are fused together using an adhesive. The cores or layers may be composed of printed circuit board materials such as FR4, ceramic, silicon, plastic, or other materials. These and other embodiments of the invention may provide a three-layer substrate. The substrate may have a solid bottom layer, a middle layer with a slot or passage that runs through part of the length of the layer, and a top layer with two through holes. The cores or layers may be laminated together with the two through holes in the top layer near the ends of the slot or passage in the middle layer. The slots or pathways can be substantially straight, or can be curved or have another shape, for example to avoid or simplify routing traces in the substrate. One or both ends of the slot or pathway can be widened in a dog-bone configuration to simplify alignment of the two through-holes. The resulting substrate has a passageway for conveying a pressure medium (such as a gas or liquid) by allowing the pressure medium to enter the first through-hole, travel the length of the slot or pathway, and exit the second through-hole. The substrate can also have electrical traces and electrical pads.

[0008] These pressure sensor system packages can be constructed by mounting a pressure sensor over one of the through-holes in the substrate, using an adhesive that retains the die and seals between the pressure sensor and the substrate around the through-hole, without the adhesive interfering with the pressure passageway in the substrate. The pressure sensor can then be connected to traces on the surface of the substrate, on the substrate, or supported by the substrate. These traces can communicate electrical inputs and outputs between other electrical components within the pressure sensor system package and circuitry external to the pressure sensor system. Protective materials such as coatings, gels, potting materials, or other substances can be applied to the pressure sensor and other electrical components.

[0009] A cap with one or more ports can be glued or otherwise attached to the substrate. Features of the cap, substrate, or both the cap and substrate can be used to separate the interior of the pressure sensor system into two or more chambers. A first chamber can extend above the pressure sensor die. A separate second chamber can connect to a passage in the substrate, where the passage opening is below the pressure sensor die. Conditioning electronics, if present, can be present in either chamber. The one or more ports can each have at least one opening, where one opening leads to one of the separated chambers. The opening of the port can be at the top of the port, at the side of the port, or a combination thereof. The exterior surface of each port may have a feature, such as a nozzle, that mates with a manifold or tube to form a connection to a pressure source or to the surrounding atmosphere. These nozzles may be smooth, barbed, or have some other form. The port opening passes through the feature, allowing pressure to enter the pressure sensor package. The pressure may be directed through the substrate to the back of the die, or it may be up to a chamber covering the top of the die.

[0010] Electrical signals can be routed to the exterior of the package by traces on or in the surface of the substrate. These traces can be on the top surface of the substrate or the bottom surface of the substrate. If the substrate is made of multiple layers, these traces can be on the top, side, and bottom surfaces of each layer. Vias can be used to route electrical signals through the layers to pads on the bottom of the substrate that are connected to the printed circuit board through solder balls or columns.

[0011] The invention will now be described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view of a portion of a pressure sensor system according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view of a portion of another pressure sensor system according to an embodiment of the present invention. [Diagram 3] 1 is a cross-sectional view of a pressure sensor system according to an embodiment of the present invention. [Figure 4] FIG. 1 is a diagram of a pressure sensor system according to an embodiment of the present invention. [Diagram 5] FIG. 2 is an exploded view of the pressure sensor system according to the embodiment of the present invention. [Figure 6] FIG. 2 is a more detailed view of a substrate according to an embodiment of the present invention. [Figure 7] FIG. 2 is a more detailed view of a substrate according to an embodiment of the present invention. [Figure 8] FIG. 1 is a perspective top view of a pressure sensor system according to an embodiment of the present invention. [Figure 9] FIG. 1 is a diagram of a pressure sensor system according to an embodiment of the present invention. [Figure 10] FIG. 2 is a diagram of another pressure sensor system according to an embodiment of the present invention. [Figure 11] FIG. 2 is a diagram of another pressure sensor system according to an embodiment of the present invention. [Figure 12] FIG. 2 is a diagram of a cap for a pressure sensor system according to an embodiment of the present invention. [Figure 13] FIG. 2 is an exploded view of a cap of the pressure sensor system according to an embodiment of the present invention. [Figure 14] FIG. 2 is a top view of a portion of a pressure sensor system according to an embodiment of the present invention. [Figure 15] FIG. 2 is a top perspective view of a portion of a pressure sensor system according to an embodiment of the present invention. [Figure 16] FIG. 2 is a top view of a substrate according to an embodiment of the present invention. [Figure 17] FIG. 2 is a diagram of another pressure sensor system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1 shows a cross-sectional view of a portion of a pressure sensor system according to an embodiment of the present invention. This figure, as well as the other included figures, are provided for illustrative purposes and do not limit any of the possible embodiments of the present invention or the claims.

[0014] In this example, the substrate 200 can have a passageway 210 formed therein that leads to the backside cavity 130 of the pressure sensor die 100. The passageway 210 can include a first opening 212 in a top surface of the substrate 200. The first opening 212 can be defined by a first through hole 214 that can connect to a second through hole 218 via a slot or via 211. The second through hole 218 can define a second opening 216 and can connect to the backside cavity 130 of the pressure sensor die 100. The substrate 200 can be a multi-layer printed circuit board or can be formed using multiple layers of ceramic, silicon, plastic, or other materials.

[0015] The pressure sensor die 100 may include a membrane 110 supported by a frame 120. The pressure sensor die 100 may further include one or more resistors or transistors (not shown). The one or more resistors or transistors may be disposed at or near the surface of the membrane 110. For example, resistors for a Wheatstone bridge may be formed at or near the surface of the membrane 110.

[0016] The bottom of the frame 120 can be attached to the top surface of the substrate 200. For example, the bottom of the frame 120 can be attached either directly or indirectly to the substrate 200 using an adhesive, a die attachment structure, or a combination of other materials. This attachment can form a seal so that the gas or liquid to be measured does not leak into or out of the backside cavity 130. In this configuration, the pressure sensor die 100 can measure the differential pressure between the pressure at the top surface of the membrane 110 and the top surface of the substrate 200 at the first opening 212.

[0017] In these and other embodiments of the invention, the passages 210 can be formed in a variety of ways. For example, the substrate 200 can be formed from various horizontal layers that can be stacked vertically on top of one another and held together by intervening layers of adhesive or other material. One or more of these layers can include vertical vias that are aligned to form first and second through holes 214 and 218 that align with and provide access to the ends of the slots or passages 211. Some or all of the portions of one or more layers can be removed to form the slots or passages 211. This material can be removed by a router, by etching, or by other techniques. Some or all of the passages 210 can be plated with metal to reduce leakage. Further details of the substrate 200 are shown in Figures 6 and 7 below.

[0018] The substrate 200 may also include traces and pads (not shown) that may connect the pressure sensor die 100 to other components on the substrate 200 or elsewhere in the pressure sensor system. Conditioning, processing, or other circuitry, such as ASIC 530 (shown in FIG. 5), may be connected to the pressure sensor die 100, to other components on the substrate 200, or elsewhere in the system. The pressure sensor die 100 may be connected to traces and pads on the substrate 200 and other components using bond wires 1420 (shown in FIG. 14) or other interconnect structures. A cap, such as cap 300 shown in FIG. 3 below, may be attached to the substrate 200 to encapsulate the pressure sensor die 100 to form a pressure sensor system. Either or both of the cap 300 and the substrate 200 can divide the interior of the pressure sensor system into two (or more) chambers, such as a first chamber 312 and a second chamber 314 (shown in FIG. 3). The first through-hole 214 can be located within the first chamber 312, and the top surface of the membrane 110 can reside within the second chamber 314. Ports in the cap can provide access to either or both of the chambers such that the pressure sensor system can be used in an absolute, gauge, or differential pressure sensor configuration.

[0019] 2 illustrates a cross-sectional view of a portion of another pressure sensor system according to an embodiment of the present invention. In this example, a substrate 260 can be formed with a passageway 270 leading to the backside cavity 130 of the pressure sensor die 100. The passageway 270 can include a first opening 272 in a bottom surface of the substrate 260. The first opening 272 can be defined by a first through hole 274, which can be connected to a second through hole 278 through a slot or passage 271 to form the passageway 270. The second through hole 278 can define a second opening 276, which can be connected to the backside cavity 130 of the pressure sensor die 100.

[0020] The pressure sensor die 100 may include a membrane 110 supported by a frame 120. The pressure sensor die 100 may further include one or more resistors or transistors (not shown), which may be disposed at or near a surface of the membrane 110. For example, resistors for a Wheatstone bridge may be formed at or near a surface of the membrane 110.

[0021] The bottom of the frame 120 can be attached to the top surface of the substrate 260. For example, the bottom of the frame 120 can be attached either directly or indirectly to the substrate 260 using an adhesive, a die attach structure, or a combination of other materials. This attachment can form a seal so that the gas or liquid to be measured does not leak into or out of the backside cavity 130. In this configuration, the pressure sensor die 100 can measure the differential pressure between the pressure at the top surface of the membrane 110 and the bottom surface of the substrate 260 at the first opening 272.

[0022] In these and other embodiments of the invention, the passages 270 can be formed in a variety of ways. For example, the substrate 260 can be formed from various horizontal layers that can be stacked vertically on top of one another and held together by intervening layers of adhesive or other material. One of the layers can include a vertical via that forms a first through hole 274, while another layer can include a vertical via that forms a second through hole 278. Some or all of the portions of one or more layers can be removed to form the slots or passages 271. The material can be removed by a router, by etching, or by other techniques. Some or all of the passages 270 can be plated with metal to reduce leakage.

[0023] The substrate 260 may also include traces and pads (not shown) that may connect the pressure sensor die 100 to other components on the substrate 260 or elsewhere in the system. Conditioning, processing, or other circuitry, such as the ASIC 530 (shown in FIG. 5), may be connected to the pressure sensor die 100, to other components on the substrate 260, or elsewhere in the system. The pressure sensor die 100 may be connected to the traces and pads of the substrate 260 and other components using bond wires 1420 (shown in FIG. 14) or other interconnect structures.

[0024] The substrate 260 can divide the pressure sensor device into two (or more) chambers, one substrate 260 above and one substrate 260 below. The chambers can be fitted with nozzles to receive gas or liquid at a pressure. In this case, differential pressure can be measured by the pressure sensor die 100.

[0025] 3 illustrates a cross-sectional view of a pressure sensor system according to an embodiment of the present invention. In this example, a substrate 200 can be formed with a passageway 210 leading to a backside cavity 130 of the pressure sensor die 100. The passageway 210 can include a first opening 212 in a top surface of the substrate 200. The opening can be defined by a first through hole 214 that can connect to a second through hole 218 via a slot or passage 211. The second through hole 218 can define a second opening 216 and can connect to the backside cavity 130 of the pressure sensor die 100. The substrate 200 can be a multi-layered printed circuit board or can be formed using multiple layers of ceramic, silicon, plastic, or other materials.

[0026] The pressure sensor die 100 may include a membrane 110 supported by a frame 120. The pressure sensor die 100 may further include one or more resistors or transistors (not shown). The one or more resistors or transistors may be disposed at or near the surface of the membrane 110. For example, resistors for a Wheatstone bridge may be formed at or near the surface of the membrane 110.

[0027] The bottom of the frame 120 can be attached to the top surface of the substrate 200. For example, the bottom of the frame 120 can be attached either directly or indirectly to the substrate 200 using an adhesive, a die attachment structure, or a combination of other materials. This attachment can form a seal so that the gas or liquid to be measured does not leak into or out of the backside cavity 130. In this configuration, the pressure sensor die 100 can measure the differential pressure between the pressure at the top surface of the membrane 110 and the top surface of the substrate 200 at the first opening 212.

[0028] In these and other embodiments of the invention, the passages 210 can be formed in a variety of ways. For example, the substrate 200 can be formed from various horizontal layers that can be stacked vertically on top of one another and held together by intervening layers of adhesive or other material. One or more of these layers can include vertical vias that are aligned to form first and second through holes 214 and 218 that align with and provide access to the ends of the slots or passages 211. Some or all of the portions of one or more layers can be removed to form the slots or passages 211. This material can be removed by a router, by etching, or by other techniques. Some or all of the passages 210 can be plated with metal to reduce leakage. Further details of the substrate 200 are shown in Figures 6 and 7 below.

[0029] The substrate 200 may also include traces and pads (not shown) that may connect the pressure sensor die 100 to other components on the substrate 200 or elsewhere in the system. Conditioning, processing, or other circuitry, such as the ASIC 530 (shown in FIG. 5), may be connected to the pressure sensor die 100, to other components on the substrate 200, or elsewhere in the system. The pressure sensor die 100 may be connected to the traces and pads of the substrate 200 and other components using bond wires 1420 (shown in FIG. 14) or other interconnect structures.

[0030] The cap 300 can be attached to the substrate 200 to form a pressure sensor system. The cap 300 can be attached to the substrate 200 using adhesives, by soldering, or by using other techniques and materials. Either or both of the cap 300 and the substrate 200 can divide the interior of the pressure sensor system into two chambers. In this example, the cap 300 can include an inner wall 310 to divide the interior of the pressure sensor system into two chambers, specifically a first chamber 312 and a second chamber 314. The first through-hole 214 can be disposed in the first chamber 312, and the top surface of the membrane 110 can reside in the second chamber 314. A first port including a first nozzle opening 322 of the first nozzle 320 can provide access to the first chamber 312, and a second port including a second nozzle opening 332 of the second nozzle 330 can provide access to the second chamber 314. This may allow the pressure sensor system to be used in absolute, gauge, or differential pressure sensor configurations. Conditioning, processing, or other circuitry, such as ASIC 530, may be located in either or both of first chamber 312 and second chamber 314. Cap 300 may be formed of plastic, nylon, acrylic, or other materials. Cap 300 may be formed by insert or injection molding, 3D printing, or other techniques.

[0031] FIG. 4 illustrates another pressure sensor system according to an embodiment of the present invention. The pressure sensor system may include a substrate 200 and a cap 300. The cap 300 may further include a first port including a first nozzle 320 having a first nozzle opening 322 and a second port including a second nozzle 330 having a second nozzle opening 332. A first tube or pipe (not shown) may be attached over the first nozzle 320. In the first tube may be a first gas or liquid whose pressure is to be measured. The pressure sensor system may be configured as an absolute pressure sensor by sealing or otherwise closing the second nozzle opening 332 of the second nozzle 330. Alternatively, an absolute pressure sensor die 100 may be used, in which the backside cavity 130 is sealed and has a known pressure, such as a vacuum or other known pressure. The pressure sensor system can be configured as a gauge pressure sensor by allowing the local atmosphere to reach the second nozzle opening 332 of the second nozzle 330. The pressure sensor system can be configured as a differential pressure sensor by attaching a second tube or pipe (not shown) over the second nozzle 330, where a second gas or liquid may be present in the second tube. In this manner, the pressure sensor system can measure the differential pressure between the pressure of the first gas or liquid and the second gas or liquid.

[0032] In this example, the first nozzle 320 and the second nozzle 330 are shown as having a cylindrical shape. In these and other embodiments of the invention, the first nozzle 320 and the second nozzle 330 may include barbs or other structures or features. These barbs or other structures or features may be useful for securing the first and second tubes to the first nozzle 320 and the second nozzle 330. Also, while nozzles designed to fit within tubes or other conduits may be used with the cap 300, other structures may be used. For example, these tubes or other conduits may fit within structures usable with the cap 300.

[0033] FIG. 5 is an exploded view of a pressure sensor system according to an embodiment of the present invention. The cap 300 may include a first nozzle 320 having a first nozzle opening 322 and a second nozzle 330 having a second nozzle opening 332. In this example, the first nozzle 320 and the second nozzle 330 may include a barbed feature. The pressure sensor system may further include a substrate 200. The substrate 200 may include several layers as shown in FIG. 6 and FIG. 7. The substrate 200 may include a first through hole 214 and a second through hole 218. The first through hole 214 may be connected to the second through hole 218 through a slot or passage 211 (shown in FIG. 7) in the substrate 200. The substrate 200 may further include a ribbed portion 230. The ribbed portion 230 may separate the first chamber 312 from the second chamber 314.

[0034] The cap 300 can be attached to the substrate 200 using an adhesive or epoxy layer 510. The adhesive or epoxy layer 510 can be applied along the top surface of the rib-like portion 230. The pressure sensor die 100 can include a backside cavity 130 (shown in FIG. 3). The pressure sensor die 100 can be attached to the substrate 200 such that the second through-hole 218 is aligned with the backside cavity 130. The frame 120 (shown in FIG. 3) of the pressure sensor die 100 can be directly or indirectly attached to the top surface of the substrate 200. The ASIC 530 can perform calculations, calibrations, or other functions related to the pressure sensor system. Appropriate firmware and software can operate on the ASIC 530. The ASIC 530 can be located in the second chamber 314 or the ASIC 530 can be located in the first chamber 312. Other components such as resistors, bypass capacitors, etc. may be included in either the first chamber 312 or the second chamber 314. The pressure sensor die 100 and ASIC 530 may be attached to each other or to other components internal or external to the pressure sensor system via bond wires 1420 (shown in FIG. 14 ) and traces (not shown) on or in the surface of the substrate 200.

[0035] The bottom surface (not shown) of the cap 300 may include a groove (not shown) corresponding to the rib-like portion 230. This allows the cap 300 to be attached to the substrate 200 in a tongue-and-groove manner. The bottom surface of the cap 300 may otherwise be substantially flat. In this case, the height of the rib-like portion 230 may be sufficient to accommodate the height of the pressure sensor die 100 and the ASIC 530, as well as the bond wires 1420 and other components that may be present. Alternatively, the bottom surface of the cap 300 may include one or more recesses to accommodate the height of these components. These one or more recesses may be shaped to correspond to the first chamber 312 and the second chamber 314, or may have other shapes.

[0036] 6 is a more detailed view of a substrate according to an embodiment of the present invention. The substrate 200 may include a top layer 234 having a first through hole 214 and a second through hole 218. A second or middle layer 236 may include a slot or passage 211 (shown in FIG. 7) connecting the first through hole 214 and the second through hole 218. A third or bottom layer 238 may be a solid layer. A ribbed portion 230 may be disposed on a top surface of the top layer 234. The ribbed portion 230 may include an outer portion 232 and an inner portion 231. The inner portion 231 may separate the first chamber 312 from the second chamber 314. The top layer 234, middle layer 236, bottom layer 238, and ribbed portion 230 may be formed of plastic, ceramic, silicon, printed circuit board material such as FR4, or other materials, and may be laminated or otherwise attached to one another using epoxy, adhesive, or other materials.

[0037] 7 is a more detailed view of a substrate according to an embodiment of the present invention. The substrate 200 may include a top layer 234 having a first through hole 214 and a second through hole 218. The second or middle layer 236 may include a slot or path 211 connecting the first through hole 214 and the second through hole 218. The slot or path 211 may be substantially straight or may be curved or have another shape, for example to avoid or simplify routing traces in the substrate 200. One or both ends of the slot or path 211 may be widened in a dog-bone configuration to simplify alignment of the first through hole 214 and the second through hole 218. The third or bottom layer 238 may be a solid layer. The ribbed portion 230 may be disposed on the top surface of the top layer 234. The top layer 234, middle layer 236, bottom layer 238, and ribbed portion 230 may be formed of plastic, ceramic, silicon, printed circuit board material such as FR4, or other materials, and may be laminated or otherwise attached to one another using epoxy, adhesive, or other materials.

[0038] Traces (not shown) may be formed on the top, bottom, and side surfaces of the top layer 234, the middle layer 236, the bottom layer 238, and the ribbed portion 230. These traces may be connected together using vias (not shown) through the top layer 234, the middle layer 236, the bottom layer 238, and the ribbed portion 230. Contacts, such as pads 1410 (shown in FIG. 14) and leadless contacts 910 (shown in FIG. 9), may be supported by the substrate 200 and may be connected to these traces.

[0039] In these and other embodiments of the invention, one or more of these layers may be omitted. For example, the rib-like portion 230 may be omitted, especially if the bottom surface of the cap 300 does not include a groove. In these and other embodiments of the invention, the bottom layer 238 may be omitted, especially if another packaging or substrate structure (not shown) of the middle layer 236 is used below. The top layer 234 and the middle layer 236 may be combined, for example if the slot or passage 211 of the middle layer 236 is replaced with a groove on the bottom surface of the top layer 234, in which case the groove extends from the first through hole 214 to the second through hole 218. One or more intervening layers may be included. These layers may include additional through holes and slots or passages. For example, the passage from the first through hole 214 to the second through hole 218 may include another layer having a slot or passage forming part of the passage from the first through hole 214 to the second through hole 218. These layers may further include additional through holes as necessary to complete the passageways.

[0040] 8 shows a perspective top view of a pressure sensor system according to an embodiment of the present invention. The cap 300 may include a first nozzle 320 having a first nozzle opening 322 and a second nozzle 330 having a second nozzle opening 332. The substrate 200 may include a ribbed portion 230 that may be used to form a seal with the cap 300 and to separate the first chamber 312 from the second chamber 314. The first through-hole 214 of the substrate 200 may be located in the first chamber 312, while the second through-hole 218 (shown in FIG. 7) may be located in the second chamber 314 and below the pressure sensor die 100. The ASIC 530 may be located in the second chamber 314, but the ASIC 530 may be located in the first chamber 312 or elsewhere in or associated with the pressure sensor system.

[0041] This pressure sensor system can be used as a differential pressure sensor. In this configuration, a first gas or liquid can be applied to a first nozzle 320 through a first tube or pipe (not shown). The first gas or liquid can flow through a first nozzle opening 322 into a first chamber 312. The first gas or liquid can flow through a first through hole 214, a slot or passage 211 (shown in FIG. 7), a second through hole 218 (shown in FIG. 7) into a backside cavity 130 (shown in FIG. 3) of the pressure sensor die 100, where the first gas or liquid can exert a force on the bottom surface of the membrane 110. A second gas or liquid can be applied to a second nozzle 330 through a second tube or pipe (not shown). The second gas or liquid can flow through a second nozzle opening 332 into a second chamber 314, where the second gas or liquid can exert a force on the top surface of the membrane 110. The pressure sensor system may also be used as a gauge pressure sensor, where either the first nozzle opening 322 or the second nozzle opening 332 may be exposed to ambient conditions. The pressure sensor system may also be used as an absolute pressure sensor, where either the first nozzle opening 322 or the second nozzle opening 332 may be sealed, while the unsealed nozzle opening may have the gas or liquid to be measured applied to it. Alternatively, an absolute pressure sensor die 100 may be used, where the backside cavity 130 is sealed and has a known pressure, such as a vacuum or other known pressure.

[0042] The substrate 200 may include leadless contacts that can be soldered to a substrate or other suitable substrate in a device employing a pressure sensor system according to an embodiment of the present invention. The use of leadless contacts can conserve substrate space in the device. In the above examples, the substrate 200 is shown as having a square shape, but the substrate 200 may alternatively have a rectangular or other shape. Examples of pressure sensor systems employing such substrates are shown in the following figures.

[0043] 9 illustrates another pressure sensor system according to an embodiment of the present invention. In this example, the cap 300 may include a first nozzle 320 having a first nozzle opening 322. The substrate 200 may include a leadless contact 910. The leadless contact 910 may be plated and soldered to a board or other suitable substrate.

[0044] 10 illustrates another pressure sensor system according to an embodiment of the present invention. In this example, a cap 300 may include a first nozzle 320 having a first nozzle opening 322 and a second nozzle 330 having a second nozzle opening 332. In this example, the first nozzle 320 and the second nozzle 330 are shown as having barbs. The cap 300 may be attached to a substrate 200 that may include leadless contacts 910. The leadless contacts 910 may be plated and soldered to a board or other suitable substrate.

[0045] 11 illustrates another pressure sensor system according to an embodiment of the present invention. In this example, a cap 300 may include a first nozzle 320 having a first nozzle opening 322 and a second nozzle 330 having a second nozzle opening 332. The first nozzle 320 and the second nozzle 330 are shown as having a cylindrical shape. The cap 300 may be attached to a substrate 200 that may include a leadless contact 910. The leadless contact 910 may be plated and soldered to a board or other suitable substrate.

[0046] In these and other embodiments of the invention, the first chamber 312 may be separated from the second chamber 314 by a portion of either the cap 300 or the substrate 200 or both. In the example of Figure 4, a ribbed portion 230 (shown in Figure 4) may at least partially divide the interior of the pressure sensor system into the first chamber 312 and the second chamber 314. In the example below, the substrate 200 may have a relatively flat surface, and a feature of the cap 300, such as an interior wall, may be used to at least partially divide the interior of the pressure sensor system.

[0047] 12 illustrates a cap for a pressure sensor system according to an embodiment of the present invention. This cap can be used as the cap 300 in the pressure sensor system of FIG. 10 or as the cap 300 in other pressure sensor systems according to these and other embodiments of the present invention. The cap 300 can include an inner wall 310 separating a first chamber 312 from a second chamber 314. The cap 300 can include a first nozzle 320 for providing access to the first chamber 312 and a second nozzle 330 for providing access to the second chamber 314. As shown in subsequent figures, the cap 300 can be attached to a substantially flat substrate 200 using an adhesive or epoxy.

[0048] FIG. 13 illustrates an exploded view of a pressure sensor system according to an embodiment of the present invention. The cap 300 may include a first nozzle 320 having a first nozzle opening 322, and a second nozzle 330 having a second nozzle opening 332. The cap 300 may be attached to the top surface of the substrate 200 using an epoxy or adhesive layer 1300. A die attach structure 522 may be used to affix the pressure sensor die 100 to the top surface of the substrate 200. In particular, the second through hole 218 may be aligned with the opening 524 of the die attach structure 522 and the backside cavity 130 of the pressure sensor die 100 (shown in FIG. 3). A die attach structure 532 may be used to affix the ASIC 530 to the top surface of the substrate 200. The substrate 200 may further include a first through hole 214 and a slot or via 211 (shown in FIG. 16 ) for connecting the first through hole 214 to a second through hole 218. Leadless contacts 910 can be used to connect the pressure sensor die 100 and the ASIC 530 to components and devices external to the pressure sensor system.

[0049] A first nozzle opening 322 of the first nozzle 320 can receive a first gas or liquid. The first gas or liquid can pass through the first chamber 312 (shown in FIG. 12 ) and enter the first through-hole 214 of the substrate 200. The first gas or liquid can continue through the slot or passage 211 in the substrate 200 and exit the second through-hole 218, where the first gas or liquid can exert a force on the bottom surface of the membrane 110. A second nozzle opening 332 of the second nozzle 330 can receive a second gas or liquid. The second gas or liquid can pass through the second nozzle opening 332 and enter the second chamber 314 (shown in FIG. 12 ), where the second gas or liquid can exert a force on the top surface of the membrane 110. As discussed above, the pressure sensor system can thus operate as a differential pressure sensor. The pressure sensor system can alternatively operate as a gauge pressure sensor by exposing either the first nozzle opening 322 or the second nozzle opening 332 to ambient conditions. The pressure sensor system can also operate as an absolute pressure sensor by sealing either the first nozzle opening 322 or the second nozzle opening 332. Alternatively, an absolute pressure sensor die 100 can be used, where the backside cavity 130 is sealed and has a known pressure, such as a vacuum or other known pressure.

[0050] FIG. 14 is a top view of a portion of a pressure sensor system according to an embodiment of the present invention. In this example, the pressure sensor die 100 can be attached to the top surface of the substrate 200 using a die attach structure 522. The pressure sensor die 100 can be positioned to cover the second through hole 218 of the substrate 200. The ASIC 530 can be attached to the top surface of the substrate 200 using a die attach structure 532. Bond wires 1420 can form electrical connections between either or both of the pressure sensor die 100 and the ASIC 530 to pads 1410. The pads 1410 can be connected to the leadless contacts 910 (shown in FIG. 10 ) or other components on the substrate 200 using traces (not shown) on or in the substrate 200. The traces can be formed on the top, bottom, and side surfaces of the layers used to form the substrate 200. These traces may be connected together using vias (not shown) through the layers of substrate 200. Contacts, such as pads 1410 (shown in FIG. 14) and leadless contacts 910 (shown in FIG. 9), may be supported by substrate 200 and may be connected to these traces.

[0051] FIG. 15 shows a top perspective view of a pressure sensor system according to an embodiment of the present invention. A cap 300 may include a first nozzle 320 having a first nozzle opening 322 and a second nozzle 330 having a second nozzle opening 332. An inner wall 310 of the cap 300 may separate a first chamber 312 from a second chamber 314. The first through hole 214 may be connected to a second through hole 218 of the substrate 200 via a slot or passage 211 (shown in FIG. 16). The pressure sensor die 100 may be attached to a top surface of the substrate 200 using a die attachment structure 522. An ASIC 530 may be attached to a top surface of the substrate 200 using a die attachment structure 532.

[0052] 16 is a top view of a substrate according to an embodiment of the present invention. Substrate 200 may include leadless contacts 910. First through-holes 214 may be connected to second through-holes 218 via internal slots or vias 211. Pads 1410 may be electrically connected to leadless contacts 910 using traces (not shown) on or at the surface of substrate 200. Substrate 200 may further include rib-like portions 230 as shown in FIG. 7.

[0053] 17 illustrates another pressure sensor system according to an embodiment of the present invention. A cap 300 can include a first nozzle 320 having a first nozzle opening 322, and a second nozzle 330 having a second nozzle opening 332. The cap 300 can be attached to a substrate 200. A pin 1720 can include a lead 1710, which can be clipped, soldered, or otherwise attached to a trace (not shown) on the substrate 200. The lead 1710 can be a spring-type structure or part of a spring-type structure that pinches and grips the substrate 200, or is soldered or otherwise attached to a trace on the substrate 200. For example, the lead 1710 can be clipped, soldered, or otherwise attached to a trace on the substrate 200, along with a similar lead (not shown) underneath the substrate and attached to the pin 1720. The leads 1710 can be formed as part of the pin 1720, with the leads underneath the substrate 200, or the leads 1710 can be formed separately and attached to the pin 1720, for example by spot welding or laser welding, or a combination of these techniques can be used. In this manner, embodiments of the present invention can provide a dual in-line package (DIP) pressure sensor system.

[0054] In these and other embodiments of the invention, the substrate 200 and the substrate 260 can be formed of a printed circuit board material such as FR4, ceramic, silicon, plastic, or other materials. In these and other embodiments of the invention, the substrate 200, the substrate 260, and the cap 300 can be formed of plastic, nylon, laser direct structuring (LDS) material, acrylic, or other materials or combinations of materials. The substrate 200, the substrate 260, and the cap 300 can be formed by insert or injection molding, 3D printing, or other techniques. In these and other embodiments of the invention, the substrate 200 and the substrate 260 can be replaced by subassemblies, silicon wafers, printed circuit boards, or other structures. They can be formed of ceramic, silicon, printed circuit board materials such as FR4, silicon, or other materials or combinations of materials.

Claims

1. A substrate (200) comprising a plurality of layers and having a passageway (210), the passageway (210) comprising: a first through hole (214) in a first layer (234) of said substrate (200); A second through hole (218) in the substrate (200); and a substrate (200) having a passage (211) in a second layer (236) of the substrate (200) connecting the first through hole (214) to the second through hole (218); a pressure sensor die (100) attached to the first layer (234) of the substrate (200) so as to cover the second through hole (218); a cap (300) covering the pressure sensor die (100) attached to the substrate (200), the cap (300) having a first port (320) and a second port (330); A pressure sensor system comprising: the cap (300) and the substrate (200) form a first chamber (312) and a second chamber (314) within the pressure sensor system, the first port (320) communicating with the first chamber (312) to provide a first pathway into the first chamber (312), and the second port (330) communicating with the second chamber (314) to provide a second pathway into the second chamber (314); The pressure sensor system, wherein the substrate (200) comprises a raised rib (230) for separating the first chamber (312) from the second chamber (314).

2. 2. The pressure sensor system of claim 1, wherein the pressure sensor die (100) comprises a membrane (110), and the second through hole (218) defines a second opening (216) in a top surface of the substrate (200), the second opening (216) being below the membrane (110) of the pressure sensor die (100).

3. 3. The pressure sensor system of claim 2, wherein the first through hole (214) is in the first layer (234) of the substrate (200) and defines a first opening (212) in the top surface of the substrate (200).

4. 2. The pressure sensor system of claim 1, wherein the plurality of layers includes the first layer (234), the second layer (236), and a third layer (238), the second layer (236) being on the third layer (238), the first layer (234) being on the second layer (236), the second layer (236) being attached to the third layer (238) using an adhesive, and the first layer (234) being attached to the second layer (236) using an adhesive.

5. A substrate (200) comprising a passageway (210) from a first opening (212) in a top surface of the substrate (200) to a second opening (216) in the top surface of the substrate (200); a pressure sensor die (100) attached to the substrate (200) so as to cover the second opening (216); a cap (300) attached to the substrate (200) such that the pressure sensor die (100) is encapsulated by the cap (300) and the substrate (200); A pressure sensor system comprising: the cap (300) and the substrate (200) form a first chamber (312) and a second chamber (314) within the pressure sensor system, the first opening (212) is within the first chamber (312), the second opening (216) and the pressure sensor die (100) are within the second chamber (314); The pressure sensor system, wherein the substrate (200) comprises a raised rib (230) for separating the first chamber (312) from the second chamber (314).

6. 6. The pressure sensor system of claim 5, wherein the cap (300) provides access to the first chamber (312) and the second chamber (314), the cap (300) comprising a first nozzle (320) for providing access to the first chamber (312) and a second nozzle (330) for providing access to the second chamber (314).

7. 6. The pressure sensor system of claim 1, wherein the raised rib (230) includes an outer portion (232) surrounding the first chamber (312) and the second chamber (314) and an inner portion (231) for separating the first chamber (312) from the second chamber (314).

8. A substrate (200) for a pressure sensor system, comprising: a solid bottom layer (238); a middle layer (236) having passages (211) attached to the solid bottom layer (238); a top layer (234) attached to the intermediate layer (236) and having a first through hole (214) extending from a top surface of the top layer (234) to a bottom surface of the top layer (234) and aligned with the pathway (211), and a second through hole (218) extending from the top surface of the top layer (234) to the bottom surface of the top layer (234) and aligned with the pathway (211), wherein the first through hole (214), the second through hole (218), and the pathway (211) form a passage (210) through the substrate (200); The substrate (200) for the pressure sensor system comprises: a rib layer attached to said top layer (234) and at least partially defining a first chamber (312) and a second chamber (314); The substrate (200) for the pressure sensor system, wherein the rib layer is formed from the same material as the solid bottom layer (238), the middle layer (236) and the top layer (234).

9. 9. The substrate (200) for a pressure sensor system of claim 8, wherein the rib layer includes an outer portion (232) surrounding the first chamber (312) and the second chamber (314) and an inner portion (231) for separating the first chamber (312) from the second chamber (314).

10. The substrate (200) comprises the first chamber (312) at least partially defined by the rib layer, and the second chamber (314) at least partially defined by the rib layer; The first chamber (312) is in communication with the passage (211) via the first through hole (214); 9. The substrate (200) for a pressure sensor system according to claim 8, wherein the second chamber (314) is in communication with the passage (211) via the second through hole (218).

11. A substrate (200) for a pressure sensor system as described in any one of claims 8 to 10, wherein the rib layer is configured such that an adhesive layer (510) is applied along the top surface of the rib layer.

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