Pressure sensor with integrated structure

• US 7,401,521 B2
• Filed: 06/09/2004
• Issued: 07/22/2008
• Est. Priority Date: 06/13/2003
• Status: Active Grant

• Current Assignee: Sicpa Holding SA
• Original Assignee: Telecom Italia S.p.A.
• Inventors: Bellini, Paolo, Conta, Renato
• Primary Examiner(s): Allen; Andre J.
• Application Number:
  US10/559,936
• Publication Number:
  US 20060137461A1
• Time in Patent Office: 1,504 Days
• Field of Search: 737/21, 737/27, 737/25, 737/54, 737/06, 737/56
• US Class Current: 73/706
• CPC Class Codes: G01L 19/0627 Protection against aggressive medium in general
• CPC Class Codes: G01L 19/147 Details about the mounting of the sensor to support or covering means
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/00014 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 2924/10155 being other than a cuboid
• CPC Class Codes: H01L 2924/181 Encapsulation

Abstract

Pressure sensor with an integrated structure comprising a support (33, 133, 233) and a silicon die (11), which lies substantially on the same plane as the upper surface (37, 137, 237) of the support and is integrated in a seat (34, 134, 234) made in the thickness of the support. On the inside face (23) of the die (11), in contact with the fluid the pressure of which has to be measured, is a protective layer.

Claims

1. Pressure sensor with an integrated structure comprising:

a silicon die, having an upper surface including at least an upper edge and an inner face, and an outer surface on which piezoresistors are comprised, wherein at least the inner face of the die is in contact with a fluid the pressure of which is to be measured;

a support having an upper surface, a thickness and a recessed seat in the thickness, the recessed seat adapted to receive the entire die, wherein the recessed seat and the die have the same profile; and

a container including the support;

wherein said die is integrated into the recessed seat in the thickness of the support.

2. Pressure sensor with integrated structure according to claim 1 wherein the support further comprises a lower surface, and the recessed seat passes through the support from the upper surface to the lower surface.

3. Pressure sensor with integrated structure according to claim 1, further comprising a step on the inner surface of the container, the step enabling improved gluing of the support.

4. Pressure sensor with integrated structure according to claim 1:

wherein the upper edge of the die is substantially coplanar with the upper surface of the support.

5. Pressure sensor with integrated structure according to claim 1:

wherein on the inner face of the die, in contact with the fluid the pressure of which is to be measured, is a layer of protection made from at least one of chromium, tantalum, silicon, or carbide alloys.

6. Pressure sensor with integrated structure according to claim 1:

further comprising a step on the inside of the seat, running along an edge of the seat, in the vicinity of the upper surface of the support.

7. Pressure sensor with integrated structure according to claim 6 wherein the upper edge of the die is in abutment with the step.

8. Pressure sensor with integrated structure according to claim 7:

wherein the surface of the part of the step, that is in contact with the upper edge of the die, is less than the surface of the upper edge itself.

9. Pressure sensor with integrated structure according to claim 1:

further comprising a step on the inside of the seat, running along an edge of the seat, in the vicinity of the lower surface of the support.

10. Pressure sensor with integrated structure according to claim 9:

wherein the upper edge of the die is substantially coplanar with the upper surface of the support.

11. Pressure sensor with integrated structure according to claim 9:

wherein the outer face of the die is in abutment with the step.

12. Pressure sensor with an integrated structure according to claim 1, wherein the support further comprises a lower surface, and wherein the pressure sensor further comprises an electronic circuit built on the lower surface of the support, said electronic circuit being connected through bonding wires to the piezoresistors on the outer face of the die.

13. Pressure sensor with an integrated structure according to claim 1, wherein the support further comprises a lower surface, and wherein the pressure sensor further comprises a silicone resin layer coated on the lower surface of the support, said layer being capable of following deformations of the die.

14. Pressure sensor with an integrated structure according to claim 1, further comprising a container being suitable for putting the die in contact with the fluid the pressure of which is to be measured.