Multi-die pressure sensor package

• US 9,952,110 B2
• Filed: 03/29/2016
• Issued: 04/24/2018
• Est. Priority Date: 03/29/2016
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Beer, Sebastian, Theuss, Horst
• Primary Examiner(s): DUNLAP, JONATHAN M
• Application Number:
  US15/084,232
• Publication Number:
  US 20170284880A1
• Time in Patent Office: 756 Days
• Field of Search: 7320426, 7320422, 73754, 73 3106, 257787, 257415-416, 257432-433, 257459, 295921, 29595, 438106, 438109
• CPC Class Codes: G01F 15/14 Casings, e.g. of special material
• CPC Class Codes: G01L 19/14 Housings G01L19/0007, G01L19/0084, G01L19/0092, G01L19/04, G01L19/06 take precedence
• CPC Class Codes: G01L 9/0041 Transmitting or indicating the displacement of flexible diaphragms
• CPC Class Codes: H01L 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/92247 the second connecting process involving a wire connector
• CPC Class Codes: H01L 23/3157 Partial encapsulation or coating mask layer used as insulation layer H01L21/31
• CPC Class Codes: H01L 23/4952 the additional leads being a bump or a wire
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• 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 2924/00014 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 2924/15151 the die mounting substrate comprising an aperture, e.g. for underfilling, outgassing, window type wire connections
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/1815 Shape

Abstract

A pressure sensor package includes a pressure sensor having a first side attached to a substrate and a second side opposite the first side, the first side having a pressure inlet aligned with an opening in the substrate, the second side having one or more electrical contacts. A logic die attached to an opposite side of the substrate as the pressure sensor is operable to process signals from the pressure sensor. First electrical conductors connect to the one or more electrical contacts of the pressure sensor. Second electrical conductors connect to one or more electrical contacts of the logic die. A mold compound completely encapsulates the second electrical conductors and at least partly encapsulates the logic die and the first electrical conductors. An open passage in the mold compound is aligned with the opening in the substrate so as to define a pressure port of the pressure sensor package.

Claims

1. A pressure sensor package, comprising:

a substrate having an opening;

a pressure sensor having a first side attached to the substrate and a second side opposite the first side, the first side having a pressure inlet aligned with the opening in the substrate, the second side having one or more electrical contacts;

a logic die attached to an opposite side of the substrate as the pressure sensor and operable to process signals from the pressure sensor;

first electrical conductors connected to the one or more electrical contacts of the pressure sensor;

second electrical conductors connected to one or more electrical contacts of the logic die;

a mold compound completely encapsulating the second electrical conductors and at least partly encapsulating the logic die and the first electrical conductors; and

an open passage in the mold compound which is aligned with the opening in the substrate so as to define a pressure port of the pressure sensor package,

wherein the logic die has an opening aligned with the open passage in the mold compound and the opening in the substrate,

wherein the pressure port of the pressure sensor package is further defined by the opening in the logic die.

2. The pressure sensor package of claim 1, wherein the logic die and the pressure sensor at least partly overlap in a vertical direction perpendicular to the first side of the pressure sensor.

3. The pressure sensor package of claim 1, wherein each sidewall which defines the open passage in the mold compound terminates at a surface of the logic die facing away from the substrate, and wherein each sidewall which defines the opening in the logic die is uncovered by the mold compound.

4. The pressure sensor package of claim 1, wherein each sidewall which defines the open passage in the mold compound terminates at a surface of the substrate to which the logic die is attached, and wherein each sidewall which defines the opening in the logic die is covered by the mold compound.

5. The pressure sensor package of claim 1, wherein the substrate is a circuit board, a ceramic substrate or part of a lead frame.

6. The pressure sensor package of claim 1, wherein the first electrical conductors and the second electrical conductors comprise bond wires.

7. The pressure sensor package of claim 1, further comprising:

a plurality of leads embedded in the mold compound at a first end and protruding out of the mold compound at a second end, the second end of the leads forming external electrical contacts of the pressure sensor package,

wherein the first electrical conductors connect the one or more electrical contacts of the pressure sensor to one or more of the leads,

wherein the second electrical conductors connect the one or more electrical contacts of the logic die to one or more of the leads.

8. The pressure sensor package of claim 7, wherein the first end of the leads terminate in the mold compound at a different level than the substrate so that the first end of the leads and the substrate are vertically offset within the mold compound.

9. The pressure sensor package of claim 1, wherein:

the pressure sensor comprises a first glass substrate attached to the opposite side of the substrate as the logic die and having an opening which forms the pressure inlet, a semiconductor die stacked on the first glass substrate and comprising a membrane, and a second glass substrate stacked on the semiconductor die and comprising a cavity;

the pressure port of the pressure sensor package is further defined by the opening in the first glass substrate;

the opening in the first glass substrate is aligned with the membrane at one side of the membrane so as to permit air flowing into the pressure port to impinge upon the membrane; and

the cavity in the second glass substrate is aligned with the membrane at an opposite side of the membrane as the first glass substrate so as to permit movement of the membrane in response to the air flow.

10. The pressure sensor package of claim 1, wherein:

the pressure sensor comprises a semiconductor die attached to the opposite side of the substrate as the logic die and having a membrane and a recessed region;

the pressure port of the pressure sensor package is further defined by the recessed region of the semiconductor die; and

the recessed region of the semiconductor die is aligned with the membrane so as to permit air flowing into the pressure port to impinge upon the membrane.

11. The pressure sensor package of claim 1, further comprising a silicone gel covering the pressure sensor and part of the first electrical conductors, the silicone gel being interposed between the mold compound and the pressure sensor.

12. A method of manufacturing a pressure sensor package, the method comprising:

attaching a first side of a pressure sensor to a substrate which has an opening, the pressure sensor having a second side opposite the first side, the first side having a pressure inlet aligned with the opening in the substrate, the second side having one or more electrical contacts;

attaching a logic die to an opposite side of the substrate as the pressure sensor, the logic die operable to process signals from the pressure sensor;

connecting first electrical conductors to the one or more electrical contacts of the pressure sensor;

connecting second electrical conductors to one or more electrical contacts of the logic die;

completely encapsulating the second electrical conductors and at least partly encapsulating the logic die and the first electrical conductors in a mold compound;

forming an open passage in the mold compound which is aligned with the opening in the substrate so as to define a pressure port of the pressure sensor package; and

aligning an opening in the logic die with the open passage in the mold compound and the opening in the substrate,

wherein the pressure port of the pressure sensor package is further defined by the opening in the logic die.

13. The method of claim 12, wherein mold compound is formed such that each sidewall which defines the open passage in the mold compound extends to and terminates at a surface of the logic die facing away from the substrate and each sidewall which defines the opening in the logic die is uncovered by the mold compound.

14. The method of claim 12, wherein mold compound is formed such that each sidewall which defines the open passage in the mold compound extends to and terminates at a surface of the substrate to which the logic die is attached and each sidewall which defines the opening in the logic die is covered by the mold compound.

15. The method of claim 12, further comprising:

embedding a plurality of leads in the mold compound at a first end and such that the leads protrude out of the mold compound at a second end, the second end of the leads forming external electrical contacts of the pressure sensor package;

connecting the one or more electrical contacts of the pressure sensor to one or more of the leads via the first electrical conductors; and

connecting the one or more electrical contacts of the logic die to one or more of the leads via the second electrical conductors.

16. The method of claim 12, wherein attaching the first side of the pressure sensor to the substrate comprises:

attaching a first glass substrate of the pressure sensor to the opposite side of the substrate as the logic die, the first glass substrate having an opening which forms the pressure inlet, the pressure sensor further having a semiconductor die stacked on the first glass substrate and comprising a membrane, and a second glass substrate stacked on the semiconductor die and comprising a cavity,

wherein the pressure port of the pressure sensor package is further defined by the opening in the first glass substrate,

wherein the first glass substrate is attached to the opposite side of the substrate as the logic die such that the opening in the first glass substrate is aligned with the membrane at one side of the membrane so as to permit air flowing into the pressure port to impinge upon the membrane, and the cavity in the second glass substrate is aligned with the membrane at an opposite side of the membrane as the first glass substrate so as to permit movement of the membrane in response to the air flow.

17. The method of claim 12, wherein the pressure sensor comprises a semiconductor die attached to the opposite side of the substrate as the logic die and having a membrane and a recessed region, wherein the pressure port of the pressure sensor package is further defined by the recessed region of the semiconductor die, the method further comprising:

aligning the recessed region of the semiconductor die with the membrane so as to perms air flowing into the pressure port to impinge upon the membrane.

18. The method of claim 12, further comprising:

covering the pressure sensor and part of the first electrical conductors with a silicone gel, the silicone gel being interposed between the mold compound and the pressure sensor.

19. A pressure sensor package, comprising:

a substrate having an opening;

a pressure sensor having a first side attached to the substrate and a second side opposite the first side, the first side having a pressure inlet aligned with the opening in the substrate, the second side having one or more electrical contacts;

a logic die attached to an opposite side of the substrate as the pressure sensor and operable to process signals from the pressure sensor;

first electrical conductors connected to the one or more electrical contacts of the pressure sensor;

second electrical conductors connected to one or more electrical contacts of the logic die;

a mold compound in direct contact with and completely covering the second electrical conductors and the one or more electrical contacts of the logic die, and at least partly encapsulating the first electrical conductors; and

an open passage in the mold compound which is aligned with the opening in the substrate so as to define a pressure port of the pressure sensor package.