COMBINED PRESSURE AND HUMIDITY SENSOR

• US 20140116122A1
• Filed: 10/25/2013
• Published: 05/01/2014
• Est. Priority Date: 10/25/2012
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH, Robert Bosch Tool Corporation (Robert Bosch GmbH)
• Inventors: Lammel, Gerhard, Feyh, Ando, O'Brien, Gary, Graham, Andrew, Waffenschmidt, Sybille
• Granted Patent: US 10,184,910 B2
• Time in Patent Office: Days
• US Class Current: 73/73
• CPC Class Codes: G01D 3/0365 the undesired influence being measured using a separate sensor, which produces an influence related signal
• CPC Class Codes: G01L 19/0038 being part of the housing other details about the housing G01L19/14
• CPC Class Codes: G01L 19/0092 Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26
• CPC Class Codes: G01L 19/141 Monolithic housings, e.g. molded or one-piece housings
• CPC Class Codes: G01L 19/143 Two part housings
• CPC Class Codes: G01L 19/147 Details about the mounting of the sensor to support or covering means
• CPC Class Codes: G01N 27/041 of a solid body
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/15174 in different layers of the multilayer substrate

Abstract

A sensor device package includes a pressure sensor and a humidity sensor mounted on the same substrate and in the same housing with light protection for the pressure sensor a media opening for gas exchange for the humidity sensor. Light protection and rapid response times are provided through strategic positioning of the media opening, strategic arrangement of the pressure sensor, humidity sensor, and the media opening, and/or the use of opaque materials.

Claims

1. A semiconductor package comprising:

a substrate having an upper surface and a lower surface;

a housing cover having a sidewall portion attached to the substrate and an outer wall portion extending over the upper surface of the substrate, the substrate and the housing cover forming a housing that surrounds and defines an interior volume;

a pressure sensor device supported within the interior volume, the pressure sensor having a top side with including a flexible membrane;

a humidity sensor device supported within the interior volume and including a moisture-sensitive material;

an evaluation circuit device supported within the interior volume and electrically connected to the pressure sensor and the humidity sensor;

a media opening in the housing that enables gas exchange between the interior volume and an exterior of the housing;

wherein the media opening is positioned closer to the moisture-sensitive material of the humidity sensor than the flexible membrane of the pressure sensor, and

wherein the media opening is positioned in the housing at a location that is offset laterally from the pressure sensor device and below the top side of the pressure sensor device with respect to vertical.

2. The package of claim 1, wherein the media opening extends through the sidewall portion of the housing cover,

wherein the top side of the pressure sensor is spaced farther apart from the substrate than an upper extent of the media opening in the sidewall.

3. The package of claim 2, wherein a lower extent of the media opening in the sidewall is spaced farther apart from the substrate than a lower surface of the evaluation circuit.

4. The package of claim 3, wherein the pressure sensor is provided on a first chip and the evaluation circuit is provided on a second chip, and

wherein the first chip is mounted onto the second chip.

5. The package of claim 4, wherein the second chip is electrically connected to the substrate using flip-chip technology.

6. The package of claim 5, wherein the humidity sensor is provided on a third chip, the third chip being mounted to the substrate alongside the first and the second chips, and

wherein the third chip is positioned proximate the media opening and the first and second chips are positioned farther away from the media opening than the third chip.

7. The package of claim 5, wherein the humidity sensor is integrated onto the first chip with the pressure sensor, the humidity sensor being laterally offset from the pressure sensor in the first chip, and

wherein the first chip is positioned with the humidity sensor oriented toward the media opening and the pressure sensor oriented away from the media opening.

8. The package of claim 1, wherein the media opening extends through the substrate directly beneath the humidity sensor device.

9. The package of claim 8, wherein the pressure sensor is provided on a first chip and the evaluation circuit is provided on a second chip, the first chip being mounted on top of the second chip, the second chip being mounted to the substrate,

wherein the humidity sensor is provided on a third chip, the third chip being mounted to the substrate alongside the first and the second chips, and

wherein the humidity sensor is oriented with the moisture-sensitive material facing toward the substrate and positioned above the media opening.

10. The package of claim 9, wherein the third chip is mounted to the substrate using flip-chip technology.

11. A semiconductor package comprising:

a substrate having an upper surface and a lower surface;

a housing cover having a sidewall portion attached to the substrate and an outer wall portion extending over the upper surface of the substrate, the substrate and the housing cover forming a housing that surrounds and defines an interior volume;

a pressure sensor device supported within the interior volume, the pressure sensor having a top side with including a flexible membrane;

a humidity sensor device supported within the interior volume and including a moisture-sensitive material;

an evaluation circuit device supported within the interior volume and electrically connected to the pressure sensor and the humidity sensor;

a media opening in the housing that enables gas exchange between the interior volume and an exterior of the housing;

wherein the media opening is positioned in the housing above the moisture-sensitive material of the humidity sensor, and

wherein an opaque material is provided on the top side of the pressure sensor.

12. The package of claim 11, wherein the opaque material comprises gel mixed an opaque dye.

13. The package of claim 12, wherein the gel comprises an anti-corrosive material.

14. The package of claim 12, wherein the media opening is positioned directly above the moisture-sensitive material of the humidity sensor and has a lateral extent that does not extend over the pressure sensor.

15. A semiconductor package comprising:

a sensor chip having a functional side and including a pressure sensor having a flexible membrane arranged on the functional side of the sensor chip and a humidity sensor having a moisture-sensitive material arranged on the functional side of the sensor chip; and

an evaluation circuit chip having a first side and a second side, the first side and the second side each including electrical connection elements, the electrical connection elements on the first side being electrically connected to the connection elements on the second side by vias;

wherein the sensor chip is electrically connected to the connection contacts on the first side of the evaluation circuit chip with the functional side arranged facing the evaluation circuit chip,

wherein the connection elements on the first side of the evaluation circuit chip space the functional side of the sensor chip apart from the evaluation circuit chip to form a gap therebetween that serves as a media opening for the pressure sensor and the humidity sensor, and

wherein the flexible membrane of the pressure sensor is situated in central position of the functional side of the sensor chip, and

wherein the moisture sensitive material of the humidity sensor is situated between the flexible membrane of the pressure sensor and a side edge of the sensor chip.

16. The package of claim 15, wherein the sensor chip has a backside opposite the functional side, and

wherein the backside is configured as an electromagnetic shield.

17. The package of claim 16, wherein the backside of the sensor chip is highly doped and connected to ground so as to function as a Faraday cage.

18. The package of claim 16, wherein the backside of the sensor chip includes metallic films that are connected to ground so as to function as Faraday cage.

19. The package of claim 16, wherein the backside of the sensor chip includes a silicide layer that is connected to ground so as to function as Faraday cage.