Method for fabricating a transducer package with the transducer die unsupported by a substrate

• US 7,790,492 B1
• Filed: 08/18/2009
• Issued: 09/07/2010
• Est. Priority Date: 06/13/2009
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: MWM Acoustics LLC (Samsung Electronics Co. Ltd.)
• Inventors: McAteer, Jeffrey Phillip, Baumhauer, John Charles Jr., Michel, Alan Dean, Welsh, Christopher Todd, Barber, Joshua R.
• Primary Examiner(s): Brewster; William M.
• Application Number:
  US12/583,364
• Time in Patent Office: 385 Days
• Field of Search: 438/51, 438/126, 438/669, 257/E23.133
• US Class Current: 438/51
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0271 Resonators; ultrasonic resonators
• 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 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48237 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/83 using a layer connector
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/00014 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 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

A transducer package fabrication process is provided, the completed transducer package achieving a thin package profile. The fabrication process utilizes an encapsulation material to eliminate the need for a transducer support substrate, the encapsulation material isolating the terminal pads from one another while holding the transducer and signal processing IC in position.

Claims

1. A method of fabricating a transducer package, said method comprising the steps of:

applying a layer of an adhesive film to a production panel;

bonding a sheet of terminal pad material to said layer of adhesive film;

defining a plurality of terminal pad sets on said sheet of terminal pad material, wherein each of said terminal pad sets corresponds to one of a plurality of transducer packages;

removing excess terminal pad material from said sheet of terminal pad material, wherein excess terminal pad material is defined as terminal pad material other than the terminal pad material comprising said plurality of terminal pad sets;

attaching a signal processing integrated circuit (IC) to each of said plurality of transducer packages;

bonding a MEMS transducer to said layer of adhesive film through a transducer window within each of said plurality of terminal pad sets;

electrically connecting said MEMS transducer to said signal processing IC for each of said plurality of transducer packages;

electrically connecting said signal processing IC to said terminal pad set for each of said plurality of transducer packages;

positioning a production dam on said production panel, said production dam comprised of a plurality of encapsulation apertures, wherein each of said plurality of encapsulation apertures surround at least a portion of each of said terminal pad sets corresponding to said plurality of transducer packages;

pouring encapsulation material into said plurality of encapsulation apertures;

removing said production dam;

attaching a cover to each of said plurality of transducer packages; and

separating said plurality of transducer packages from said production panel and into a plurality of individual transducer packages.

2. The method of claim 1, further comprising the step of selecting a heat releasable adhesive for said adhesive film.

3. The method of claim 1, further comprising the step of selecting a copper sheet for said sheet of terminal pad material.

4. The method of claim 1, wherein a photo-etching process is used during said defining and excess terminal pad material removing steps.

5. The method of claim 1, further comprising the step of plating said plurality of terminal pad sets prior to said signal processing IC attaching step.

6. The method of claim 1, further comprising the step of plating said plurality of terminal pad sets with a metal material.

7. The method of claim 1, further comprising the step of plating said plurality of terminal pad sets with a material selected from the group consisting of tin and tin alloys, wherein said plating step is performed prior to said signal processing IC attaching step.

8. The method of claim 1, said signal processing IC attaching step further comprising the step of bonding said signal processing IC to an upper terminal pad surface for each of said plurality of transducer packages.

9. The method of claim 1, said signal processing IC attaching step further comprising the step of bonding said signal processing IC to said layer of adhesive film through an IC bonding window within each of said plurality of terminal pad sets.

10. The method of claim 1, wherein said encapsulation material pouring step further comprises the step of pouring sufficient encapsulation material into each of said plurality of encapsulation apertures to extend to approximately two thirds the height of said MEMS transducer.

11. The method of claim 1, further comprising the step of heating said encapsulation material to a preset temperature for a preset period of time, wherein said heating step is performed prior to said production dam removing step, and wherein said heating step accelerates encapsulation material curing.

12. The method of claim 11, further comprising the steps of selecting a preset temperature of at least 50°

C. and selecting a preset period of time of at least 3 hours.

13. The method of claim 1, further comprising the step of selecting a material for said cover from the group consisting of metals, conductive plastics, conductive composites, and non-conductive materials coated with at least one conductive layer.

14. The method of claim 1, further comprising the step of selecting a metal for said cover from the group of metals consisting of steel, tin-plated steel, copper, brass, nickel, aluminum, tin-plated aluminum, and copper-plated aluminum.

15. The method of claim 1, further comprising the step of fabricating a port within said cover.

16. The method of claim 15, further comprising the step of offsetting and displacing said port relative to said MEMS transducer.

17. The method of claim 15, wherein said port fabricating step is performed prior to said cover attaching step.

18. The method of claim 1, said cover attaching step further comprising the step of soldering an edge of said cover to a peripheral portion of at least one terminal pad of each of said plurality of terminal pad sets.

19. The method of claim 18, wherein said peripheral portion of said at least one terminal pad of each of said plurality of terminal pad sets is covered by said production dam during said production dam positioning step.

20. The method of claim 1, said separating step further comprising the step of releasing said plurality of transducer packages from said production panel.

21. The method of claim 20, said releasing step further comprising the step of heating said production panel and said plurality of transducer packages to a preset adhesive film release temperature.

22. The method of claim 1, further comprising the step of adding a protective cap to said MEMS transducer prior to said step of bonding said MEMS transducer to said layer of adhesive film, wherein said protective cap covers an aperture of said MEMS transducer.