Systems and methods for vertically stacking a sensor on an integrated circuit chip

• US 8,476,720 B2
• Filed: 06/29/2011
• Issued: 07/02/2013
• Est. Priority Date: 06/29/2011
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Liu, Chia-Ming
• Primary Examiner(s): Tran, Minh-Loan T
• Assistant Examiner(s): Erdem, Fazli
• Application Number:
  US13/172,604
• Publication Number:
  US 20130001709A1
• Time in Patent Office: 734 Days
• Field of Search: 257/415, 257/777, 257/E21.001, 257/E29.324
• US Class Current: 257/415
• CPC Class Codes: B81C 1/0023 Packaging together an electronic processing unit die and a micromechanical structure die MEMS packages B81B7/0032; MEMS packaging processes B81C1/00261
• CPC Class Codes: H01L 2224/131 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/32145 the bodies being stacked
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 24/13 of an individual bump connector
• CPC Class Codes: H01L 24/16 of an individual bump connector
• CPC Class Codes: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• 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 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/0665 Epoxy resin
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H05K 1/0201 Thermal arrangements, e.g. for cooling, heating or preventing overheating
• CPC Class Codes: H05K 1/181 : associated with surface mounted components
• CPC Class Codes: H05K 2201/10083 : Electromechanical or electro-acoustic component, e.g. microphone
• CPC Class Codes: H05K 2201/10151 : Sensor
• CPC Class Codes: H05K 2201/10515 : Stacked components
• CPC Class Codes: H05K 2201/10537 : Attached components
• CPC Class Codes: H05K 2203/041 : Solder preforms in the shape of solder balls soldering leadless components having an array of bottom contacts H05K3/3436
• CPC Class Codes: H05K 3/3431 : Leadless components
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

A sensing unit package with reduced size and improved thermal sensing capabilities. An exemplary package includes a printed circuit board with a plurality of electrical traces, an application-specific integrated circuit (Analog ASIC) chip, and a micromachined sensor formed on a microelectromechanical system (MEMS) die. The Analog ASIC chip is electrically and mechanically attached to the printed circuit board. The MEMS die is in direct electrical communication with only a portion of the electrical traces of the printed circuit board and is mechanically and thermally attached directly to the Analog ASIC chip. A thermally conducting compound is located between the MEMS die and the Analog ASIC chip. One or more solder balls electrically attach the Analog ASIC chip to the printed circuit board and one or more solder traces electrically attach the MEMS die to the printed circuit board.

Claims

1. A sensing unit comprising:

a printed circuit board comprising a plurality of electrical traces;

an application-specific integrated circuit (ASIC) chip being electrically and mechanically attached to the printed circuit board;

a micromachined sensor formed on a microelectromechanical system (MEMS) die being in direct electrical communication with only a portion of the electrical traces of the printed circuit board and being mechanically and thermally attached directly to the ASIC chip;

a nonelectrical epoxy connected to the ASIC chip and the printed circuit board;

one or more solder balls, wherein the ASIC chip is electrically attached to the printed circuit board using the one or more solder balls, wherein the nonelectrical epoxy surrounds the solder balls; and

one or more solder traces configured to electrically attach a lead on a surface of the MEMS die to the printed circuit board, wherein the surface of the MEMS die faces the ASIC chip and the printed circuit board.

2. The unit of claim 1, wherein the sensor comprises at least one of an accelerometer or an angular rate sensor.

3. The unit of claim 1, wherein the MEMS die is a leadless chip carrier (LCC) package.

4. The unit of claim 1, wherein the MEMS die is a wafer-level chip-scale package (WLCSP).

5. The unit of claim 1, further comprising a thermally conducting compound located between the MEMS die and the ASIC chip.

6. The unit of claim 5, wherein the thermally conducting compound is at least one of an adhesive compound or an epoxy.

7. A method comprising:

electrically and mechanically attaching an application-specific integrated circuit (ASIC) chip directly to a printed circuit board using solder balls surrounded by non-conductive epoxy;

only mechanically and thermally attaching a micromachined sensor formed on a microelectromechanical system (MEMS) die to the ASIC chip; and

electrically attaching the sensor directly with only a portion of electrical traces located on the printed circuit board using one or more solder traces extending from a side of the MEMS die closest to the ASIC chip and the printed circuit board,

wherein attaching the ASIC chip comprises injecting the non-conductive epoxy after the ASIC chip is attached to the printed circuit board.