MEMS Package And A Method For Manufacturing The Same

• US 20150166335A1
• Filed: 02/26/2015
• Published: 06/18/2015
• Est. Priority Date: 08/13/2009
• Status: Active Grant

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Loeppert, Peter V., Czech, Denise P., Grunert, Lawrence A., Friel, Kurt B., Wang, Qing
• Granted Patent: US 9,399,574 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 7/0061 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81B 7/0064 for protecting against electromagnetic or electrostatic interferences
• CPC Class Codes: B81C 1/00888 Multistep processes involving only mechanical separation, e.g. grooving followed by cleaving
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: B81C 2203/019 characterised by the material or arrangement of seals between parts
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• 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 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/81 using a bump 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 24/16 of an individual bump connector
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 24/48 of an individual wire 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 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 2924/00012 : 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 2924/12042 : LASER
• CPC Class Codes: H01L 2924/1433 : Application-specific integrated circuit [ASIC]
• CPC Class Codes: H01L 2924/1461 : MEMS
• 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 2924/15192 : Resurf arrangement of the internal vias
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

A plurality of MEMS transducer packages is manufactured by placement of a plurality of transducers onto a panel of undivided package substrates, attachment of a plurality of individual covers onto a panel and over the transducers, depositing an epoxy into the channels between the covers, and then singulating the panel into individual MEMS transducer packages.

Claims

1. A method for manufacturing a MEMS transducer package comprising:

attaching a MEMS transducer to a top surface of a substrate;

joining a first plurality of solder pads on a bottom of at least one side of a cup-shaped cover to a corresponding second plurality of solder pads on the top surface of the substrate, such that the transducer is located within an open interior space formed between the top surface of the substrate and the cover, and leaving a gap between the bottom of the at least one side of the cover and the top surface of the substrate;

laterally surrounding the sides of the cover with a dam such that open channels are formed on the top surface of the substrate between the sides of the cover and the dam; and

depositing an epoxy into the channels, substantially filling the channels but not totally covering the cover, where the epoxy is sufficiently viscous to seal the gap between the bottom of the at least one side of the cover and the top surface of the substrate, but will not significantly flow into the interior space.

2. The method of claim 1 where:

the substrate is one of a plurality of substrates interconnected as a panel of undivided substrates;

the transducer is one of a plurality of transducers, and the plurality of transducers is attached to the plurality of substrates, one transducer per substrate;

the cover is one of a plurality of covers, the plurality of covers is joined with the plurality of substrates, one cover per substrate, and additional open channels are formed on the top surface of the substrate between the side wall portions of adjacent covers;

the dam laterally surrounds the sides of the plurality of covers; and

after the epoxy has hardened, the panel is singulated into individual MEMS transducer packages by cutting vertically through the channels and the panel.

3. The method of claim 1 where:

the substrate further comprises a bottom surface and an aperture between the top and bottom surfaces of the substrate; and

attaching the transducer comprises positioning the transducer directly over the aperture.

4. The method of claim 3 where:

the transducer is an acoustic transducer; and

depositing the epoxy comprises acoustically sealing the gap between the bottom of the at least one side of the cover and the top surface of the substrate.

5. The method of claim 1 where:

surrounding the sides of the cover with the dam comprises positioning the dam on a top surface of the periphery of the panel.

6. The method of claim 1 where:

surrounding the sides of the cover with the dam comprises positioning the dam on an outside surface of the periphery of the panel.

7. The method of claim 1 where:

joining the first plurality of solder pads and the second plurality of solder pads comprises using a solder reflow process.

8. The method of claim 1 where:

joining the first plurality of solder pads and the second plurality of solder pads comprises using a conductive adhesive.

9. The method of claim 1 where:

The first plurality of solder pads are distributed over the bottoms of multiple sides of the cover such that when the first plurality of solder pads is joined to the corresponding second plurality of solder pads, there is a uniform gap between the bottoms of the multiple sides of the cover and the top surface of the substrate.

10. The method of claim 1 where:

the cover further comprises an inner surface with respect to the cup shape and an outer surface with respect to the cup shape;

the outer surface of the cover comprises a flat top surface that is substantially perpendicular to the sides of the cover;

the top surface of the cover comprises a third plurality of solder pads; and

an electrical pathway connects one of the third plurality of solder pads and one of the first plurality of solder pads;

where joining the first plurality of solder pads and the second plurality of solder comprises creating an electrical connection between one of the third plurality of solder pads and one of the second plurality of solder pads.

11. The method of claim 10 where:

the electrical pathway comprises a via between the top surface of the cover and the inner surface of the cover and a metal trace on the inner surface of the cover.

12. The method of claim 10 where:

the electrical pathway comprises a via between the top surface of the cover and a conductive inner layer within the cover.

13. The method of claim 10 where:

the electrical pathway comprises a metal trace on the top surface of the cover and a side of the outer surface of the cover.

14. The method of claim 13 where:

depositing the epoxy into the channels further comprises partially covering the metal trace on the side of the outer surface of the cover to protect the metal trace from physical damage and unwanted electrical contact.

15. The method of claim 10 where:

the cover further comprises a first layer of conductive material that is electrically connected to one pad of the first plurality of solder pads and to one pad of the third plurality of solder pads; and

the substrate further comprises a second layer of conductive material that is electrically connected to one pad of the second plurality of solder pads;

where joining the first plurality of solder pads and the second plurality of solder comprises creating an electrical connection between the first layer of conductive material and the second layer of conductive material to form a shield that protects the transducer from electromagnetic interference.

16. The method of claim 15 where:

the first layer of conductive material is located on the inner surface of the cover.

17. The method of claim 15 where:

the first layer of conductive material is located in a layer within the cover.

18. A method of manufacturing a plurality of MEMS transducer packages comprising:

mechanically attaching a plurality of MEMS transducers to a plurality of package substrates, one transducer to one substrate, where;

the substrates are interconnected in a single undivided flat panel,

each substrate comprises a top surface and a bottom surface,

the top surface of each substrate comprises a first plurality of solder pads along the periphery of the top surface of each substrate, and

each transducer is attached to the top surface of each substrate;

positioning a plurality of individual covers onto the plurality of package substrates, one cover to one substrate, where;

each cover comprises a top portion that is parallel to each substrate,

each cover comprises a plurality of side portions extending downward from the top surface of the cover towards the top surface of the substrate,

each side portion comprises a bottom surface comprising a second plurality of solder pads arranged such that when each cover is positioned onto the corresponding substrate, the first set of solder pads aligns with the second set of solder pads,

an internal cavity is formed under each cover, bounded by the substrate, the side portions of the cover, and the top portion of the cover,

the transducer is located within the internal cavity, and

a plurality of channels are formed between adjacent covers;

affixing the plurality of covers to the plurality of substrates;

attaching a dam to the periphery of the panel, the dam surrounding the plurality of covers and forming additional channels between the dam and adjacent covers;

depositing an epoxy into the channels, where the epoxy is sufficiently viscous to seal any gaps between the bottom surfaces of the side portions of each cover and the top surface of the corresponding substrate, but will not significantly flow into each internal cavity; and

vertically cutting through each of the channels to create individual MEMS transducer packages, where each package has one cover and one substrate.

19. The method of claim 18 where:

the substrate further comprises an aperture between the top and bottom surfaces of the substrate;

the transducer is an acoustic transducer;

attaching the transducer comprises positioning the transducer directly over the aperture; and

depositing the epoxy comprises acoustically sealing the gap between the bottom of the at least one side of the cover and the top surface of the substrate.

20. The method of claim 18 where:

the top surface of the cover comprises a third plurality of solder pads; and

an electrical pathway connects one of the third plurality of solder pads and one of the second plurality of solder pads;

where joining the first plurality of solder pads and the second plurality of solder comprises creating an electrical connection between one of the third plurality of solder pads and one of the first plurality of solder pads.