Leadless pressure sensors

Patent metadata

Field	Value
Publication number	US-11519800-B2
Application number	US-201916728490-A
Country	US
Kind code	B2
Filing date	Dec 27, 2019
Priority date	Dec 27, 2019
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

Disclosed are pressure sensors including a die and an application-specific integrated circuit (ASIC) mounted on a top surface of a substrate. The pressure sensor can define an inner volume and a bottom opening configured to abut the substrate. The die and ASIC are mounted on the top surface of the substrate within the inner volume. The substrate defines a first aperture therethrough and the die defines a second aperture therethrough in a direction along an axis perpendicular to the substrate, the first aperture and the second aperture being aligned. Metallic barrier(s) disposed on a bottom surface of the substrate, circumferentially about the first aperture, can be at least partially coated with solder mask to reduce or prevent flow of unwanted materials past the metallic barriers and through the first aperture. The substrate can include electrical connection pads on the bottom surface configured to be in communication with a daughter board.

First claim

The invention claimed is:

1. An apparatus comprising:
a pressure sensor supported on a top surface of a substrate within a sensor housing, wherein the substrate defines an aperture; and
one or more metallic barriers disposed on a bottom surface of the substrate circumferentially about the aperture, at least some of the one or more metallic barriers being at least partially coated with a solder mask,
wherein the one or more metallic barriers comprises a first metallic barrier circumferentially disposed about the aperture and a second metallic barrier circumferentially disposed about the first metallic barrier,
wherein the second metallic barrier is concentric to the first metallic barrier, and
wherein the one or more metallic barriers are configured to solder the substrate of the pressure sensor to a receiving circuit board.

2. The apparatus of claim 1 , wherein the solder mask prevents or reduces flow of matter past the one or more metallic barriers during or after soldering the substrate of the pressure sensor to the receiving circuit board.

3. The apparatus of claim 1 , wherein the pressure sensor comprises a microelectro-mechanical systems (MEMS), the MEMS sensor comprising a deformable membrane and configured to measure a change in conductance related to deformation of the deformable membrane.

4. The apparatus of claim 3 , further comprising:
an application-specific integrated circuit (ASIC) operably coupled to the pressure sensor and configured to measure a pressure, a pressure change, or a differential pressure based upon at least the change in conductance.

5. The apparatus of claim 1 , wherein the first metallic barrier is at least partially coated with the solder mask, and wherein the second metallic barrier forms a pressure seal between the substrate and the receiving circuit board, the second metallic barrier being uncoated by any of the solder mask.

6. The apparatus of claim 5 , wherein at least one of the first metallic barrier and the second metallic barrier comprise a conductive metal or metal alloy comprising one or more of tin, silver, copper, gold, aluminum, calcium, beryllium, rhodium, magnesium, molybdenum, iridium, tungsten, zinc, cobalt, cadmium, nickel, ruthenium, lithium, iron, palladium, tin, selenium, tantalum, niobium, steel, chromium, lead, vanadium, antimony, zirconium, titanium, mercury, or combinations thereof.

7. The apparatus of claim 1 , wherein the substrate is an FR4 substrate.

8. The apparatus of claim 1 , further comprising:
one or more conductive pads configured to be electrically coupled to the receiving circuit board.

9. The apparatus of claim 5 , wherein the pressure sensor is a first pressure sensor and wherein a second pressure sensor is disposed on the bottom side of the substrate such that a differential pressure can be measured as a comparison of pressure measured by the first pressure sensor to pressure measured by the second pressure sensor.

10. The apparatus of claim 1 , wherein the pressure sensor is configured to measure a gauge pressure or a differential pressure up to about 15 bar.

11. The apparatus of claim 1 , wherein the solder mask comprises one of an epoxy liquid that is silkscreened through a pattern onto the substrate, a liquid photoimageable solder mask (LPSM or LPI) ink, or a dry-film photoimageable solder mask (DFSM).

12. A method of manufacturing a pressure sensor assembly, the method comprising:
providing a sensor housing disposed on a substrate, an aperture being defined through the substrate;
providing a pressure sensor supported on a top surface of the substrate within the sensor housing;
disposing one or more metallic barriers onto a bottom surface of the substrate circumferentially about the aperture, the one or more metallic barriers being at least partially coated with a solder mask,
wherein the one or more metallic barriers comprises a first metallic barrier circumferentially disposed about the aperture and a second metallic barrier circumferentially disposed about the first metallic barrier, and
wherein the second metallic barrier is concentric to the first metallic barrier; and
soldering, using the one or more metallic barriers, the substrate of the pressure sensor to a receiving circuit board.

13. The method of claim 12 , wherein, once the substrate has been soldered to the receiving circuit board, the solder mask is configured to prevent or reduce matter flowing past the one or more metallic barriers during or after soldering the substrate of the pressure sensor to the receiving circuit board.

14. The method of claim 12 , wherein the pressure sensor comprises a microelectro-mechanical systems (MEMS), the MEMS comprising a deformable membrane and configured to measure a change in conductance related to deformation of the deformable membrane.

15. The method of claim 14 , further comprising:
providing an application-specific integrated circuit (ASIC) operably coupled to the pressure sensor and configured to measure a pressure, a pressure change, or a differential pressure based upon at least the change in conductance.

16. The method of claim 12 , wherein the substrate is an FR4 substrate, and wherein the first metallic barrier is at least partially coated with the solder mask, and wherein the second metallic barrier forms a pressure seal between the FR4 substrate and the receiving circuit board, the second metallic barrier being uncoated by any of the solder mask.

17. The method of claim 12 , wherein the one or more metallic barriers comprise a conductive metal or metal alloy comprising one or more of tin, silver, copper, gold, aluminum, calcium, beryllium, rhodium, magnesium, molybdenum, iridium, tungsten, zinc, cobalt, cadmium, nickel, ruthenium, lithium, iron, palladium, tin, selenium, tantalum, niobium, steel, chromium, lead, vanadium, antimony, zirconium, titanium, mercury, or combinations thereof.

18. The method of claim 12 , wherein the pressure sensor is configured to measure a gauge pressure or a differential pressure up to about 15 bar.

19. The method of claim 12 , wherein the solder mask comprises one of an epoxy liquid that is silkscreened through a pattern onto the substrate, a liquid photoimageable solder mask (LPSM or LPI) ink, or a dry-film photoimageable solder mask (DFSM).

20. A pressure sensor comprising:
a substrate defining a first aperture therethrough;
a sensor assembly supported on a top surface of the substrate and defining an inner volume;
a pressure sense die defining a second aperture therethrough, the pressure sense die disposed on the top surface of the substrate such that the first and second apertures are at least partially aligned;
a microelectro-mechanical systems (MEMS) sensor supported on the top surface of the substrate within the inner volume, the MEMS sensor comprising a deformable membrane and configured to measure a change in conductance related to deformation of the deformable membrane;
an application-specific integrated circuit (ASIC) operably coupled to the MEMS sensor and configured to measure a pressure, a pressure change, or a differential pressure based upon at least the change in conductance; and
one or more metallic barriers disposed on a bottom surface of the substrate circumferentially about the first aperture, the one or more metallic barriers being at least partially coated with a solder mask,
wherein the one or more metallic barriers comprises a first metallic barrier circumferentially disposed about the first aperture and a second metallic barrier circumferentially dispo

Assignees

• Honeywell Int Inc

Inventors

• B Manjesh Kumar
• Bradley Alistair David
• Fribley Josh M
• Sreeramu Sudheer Beligere
• Vadlamudi Sathish

Classifications

• G01L19/0069

  from the sensor to its support · CPC title

• G01L7/102 Primary

  construction or mounting of capsules · CPC title

• B81B2201/0264

  Pressure sensors · CPC title

• G01L19/04

  Means for compensating for effects of changes of temperature {, i.e. other than electric compensation} · CPC title

• G01L9/065

  with temperature compensating means (non electric temperature compensating means G01L19/04) · CPC title