SENSOR DEVICE WITH FLIP-CHIP DIE AND INTERPOSER

• US 20200131026A1
• Filed: 10/30/2018
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Inventors: Doraisamy, Stanley Job, Lye, Meng Kong, Mohd Sukemi, Norazham
• Granted Patent: US 10,787,361 B2
• Time in Patent Office: Days
• CPC Class Codes: B60C 23/02 Signalling devices actuated by tyre pressure hand-held tyre pressure gauges G01L17/00
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 2207/098 Arrangements not provided for in groups B81B2207/092 - B81B2207/097
• CPC Class Codes: B81B 7/0061 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 1/00309 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81C 2203/0154 Moulding a cap over the MEMS device
• CPC Class Codes: B81C 2203/0792 Forming interconnections between the electronic processing unit and the micromechanical structure
• CPC Class Codes: G01L 19/0069 from the sensor to its support
• CPC Class Codes: G01L 19/0654 against moisture or humidity
• CPC Class Codes: G01L 19/141 Monolithic housings, e.g. molded or one-piece housings
• CPC Class Codes: G01L 19/148 Details about the circuit board integration, e.g. integrated with the diaphragm surface or encapsulation
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48145 the bodies being stacked
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/10155 : being other than a cuboid
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape

Abstract

A semiconductor sensor device includes a lead frame flag having a vent hole, an interposer mounted on the flag and having a vent hole in fluid communication with the vent hole of the flag, and a sensor die having an active region. The sensor die is mounted on and electrically connected to the interposer in a flip-chip manner such that the vent hole of the interposer is in fluid communication with the active region of the sensor die. Bond wires electrically connect the interposer to one or more other components of the device. A molding compound covers the sensor die, the interposer, and the bond wires. The sensor die may be a pressure-sensing (P-cell) die, and the device may also include a micro-controller unit (MCU) die and an acceleration-sensing (G-cell) die, for tire pressure monitoring applications.

Claims

1. A semiconductor sensor device, comprising:

a lead frame flag having a vent hole;

an interposer mounted on the lead frame flag and having a vent hole in fluid communication with the vent hole of the lead frame flag;

a sensor die having an active region, wherein the sensor die is mounted on and electrically connected to the interposer in a flip-chip manner such that the vent hole of the interposer is in fluid communication with the active region of the sensor die;

bond wires electrically connecting the interposer to one or more other components of the device; and

molding compound encapsulating the sensor die, the interposer, and the bond wires.

2. The device of claim 1, wherein the sensor die is a pressure-sensing die having a pressure-sensitive active region, and wherein the vent hole of the interposer is in fluid communication with the active region of the pressure-sensing die to enable the pressure-sensing die to sense ambient atmospheric pressure outside of the device.

3. The device of claim 1, wherein the vent holes of the lead frame flag and the interposer are aligned with each other and with the active region of the sensor die.

4. The device of claim 1, further comprising a micro control unit (MCU) die mounted on the lead frame flag, and electrically connected to the interposer with one or more of the bond wires, and wherein the MCU die is covered by the molding compound.

5. The device of claim 4, further comprising an acceleration-sensing die electrically connected to the MCU die and covered by the molding compound.

6. The device of claim 1, wherein the lead frame flag functions as a lid for the device.

7. The device of claim 1, wherein all the bond wires in the device are covered by the molding compound.

8. The device of claim 1, wherein the active region of the sensor die is not covered by a pressure-sensitive gel.

9. A method of assembling a semiconductor sensor device, the method comprising:

mounting an interposer having a vent hole on a lead frame flag having a vent hole such that the interposer vent hole is in fluid communication with the lead frame flag vent hole;

mounting a sensor die on the interposer in a flip-chip manner, wherein the sensor die has an active region, and wherein the vent hole of the interposer is in fluid communication with the active region of the sensor die;

electrically connecting the interposer to one or more other components of the device using bond wires; and

applying molding compound to encapsulate the sensor die, the interposer, and the bond wires.

10. The method of claim 9, wherein the sensor die is a pressure-sensing die having a pressure-sensitive active region, and the vent hole of the interposer is in fluid communication with the active region of the pressure-sensing die to enable the pressure-sensing die to sense ambient atmospheric pressure outside of the device.

11. The method of claim 9, wherein the vent holes of the lead frame flag and the interposer are aligned with each other and with the active region of the sensor die.

12. The method of claim 9, further comprising:

mounting an MCU die on the lead frame flag;

electrically connecting the MCU die to the interposer; and

covering the MCU die with the molding compound.

13. The method of claim 12, further comprising electrically connecting an acceleration-sensing die to the MCU die, wherein the acceleration-sensing die is covered by the molding compound.

14. The method of claim 9, wherein the lead frame flag functions as a lid for the device.

15. The method of claim 9, wherein all the bond wires of the device are covered by the molding compound.

16. The method of claim 9, wherein the active region of the sensor die is not covered by a pressure-sensitive gel.