Granted Patent B2

US 8,304,275 · App. 12/873,195 · Granted Nov 6, 2012

Abstract

Claims (58)

1. A method of making a microelectromechanical systems (MEMS) device comprising:

forming said MEMS device on a substrate, said substrate including a front side and a back side separated from said front side by a thickness of said substrate, said MEMS device being formed on said front side;

removing a portion of said substrate partially surrounding said MEMS device to form a cantilevered substrate platform at which said MEMS device resides, said removing operation including removing at least a section of said portion of said substrate from said front side toward said back side, said at least a section of said portion having a section thickness that is less than said thickness of said substrate;

removing a remainder of said portion of said substrate from said back side toward said front side; and

coupling a cap layer overlying said MEMS device.

2. A method as claimed in claim 1 wherein said removing operation comprises producing said cantilevered substrate platform having an arm extending from said platform, a first end of said arm being fixed to said substrate, and a second end of said arm being fixed to said cantilevered substrate platform, wherein said arm is a sole attachment point of said platform to said substrate.

3. A method of making a microelectromechanical systems (MEMS) device comprising:

forming said MEMS device on a substrate, said substrate including a front side and a back side separated from said front side by a thickness of said substrate, said MEMS device being formed on said front side, and said MEMS device having an active region;

removing a first portion of said substrate partially surrounding said MEMS device to form a cantilevered substrate platform at which said MEMS device resides, said removing operation including removing a second portion of said substrate underlying said active region to form an aperture extending through said substrate to said active region, wherein said removing operation comprises:

performing a first removal process from said front side toward said back side to remove a section of said first portion of said substrate, said section having a section thickness that is less than said thickness of said substrate; and

performing a second removal process from said back side toward said front side to remove a remainder of said first portion to form said cantilevered substrate platform and to concurrently remove said second portion to form said aperture; and

coupling a cap layer overlying said MEMS device.

4. A method of making a microelectromechanical systems (MEMS) device comprising:

forming said MEMS device on a first front side of a first substrate;

removing a first portion of said substrate partially surrounding said MEMS device to form a cantilevered substrate platform at which said MEMS device resides, said removing said first portion comprising:

performing a first removal process from said first front side of said first substrate toward said first back side of said first substrate to remove a section of said first portion, said section having a section thickness that is less than a thickness of said first substrate; and

performing a second removal process from said first back side of said first substrate toward said first front side of said first substrate to remove a remainder of said first portion and to concurrently remove a third portion of said first substrate underlying said active region to form an aperture extending through said first substrate;

providing a second substrate;

removing a second portion of said second substrate to form a second cantilevered substrate platform;

following said second removal process, attaching a second front side of said second substrate to a first back side of said first substrate so that said second cantilevered substrate platform is vertically stacked with said cantilevered substrate platform to form a stacked cantilevered platform structure, wherein said second substrate covers said aperture to form a sealed cavity underlying said active region of said MEMS device; and

coupling a cap layer overlying said MEMS device.

5. A method of making a microelectromechanical systems (MEMS) device comprising:

forming said MEMS device on a first front side of a first substrate;

removing a first portion of said substrate partially surrounding said MEMS device to form a cantilevered substrate platform at which said MEMS device resides; and

providing a second substrate;

removing a second portion of said second substrate to form a second cantilevered substrate platform; and

attaching a second front side of said second substrate to a first back side of said first substrate so that said second cantilevered substrate platform is vertically stacked with said cantilevered substrate platform to form a stacked cantilevered platform structure; and

coupling a cap layer overlying said MEMS device, wherein said removing said first and second portions yields an opening extending through said first and second substrates partially surrounding said stacked cantilevered platform structure, and said method further comprises:

positioning a plug member at a second back side of said second substrate to block said opening;

applying a molding compound to substantially encapsulate said MEMS device and said coupled cap layer, wherein said applying operation is performed following said positioning operation; and

following said applying operation, removing said plug member to expose at least a portion of said opening.

6. A method of making a microelectromechanical systems (MEMS) device comprising:

forming said MEMS device and bondwire pads on a substrate, said bondwire pads being electrically coupled with said MEMS device via traces;

removing a portion of said substrate partially surrounding said MEMS device to form a cantilevered substrate platform at which said MEMS device resides;

coupling a cap layer overlying said MEMS device;

exposing said bondwire pads of said MEMS device out of said cap layer;

electrically interconnecting said bondwire pads with an integrated circuit die via conductive interconnects; and

applying a molding compound to substantially encapsulate said MEMS device and said coupled cap layer, said cap layer preventing said molding compound from contacting said MEMS device, and said applying operation concurrently encapsulating said integrated circuit die, said conductive interconnects, said bondwire pads, said MEMS device, and said cap layer with said molding compound.

7. A method as claimed in claim 6 wherein:

said forming operation forms multiple MEMS devices and bondwire pads on said substrate to form a panel of MEMS devices, wherein a distinct set of said bondwire pads is electrically coupled with one each of said multiple MEMS devices;

said removing operation removes said portion of said substrate surrounding said MEMS devices to form multiple cantilevered substrate platforms, at least one of said MEMS devices residing upon one each of said cantilevered substrate platforms;

said cap layer overlies said multiple MEMS devices;

said exposing operation exposes said bondwire pads for said each of said multiple MEMS devices; and

said method further comprises separating said multiple MEMS devices of said panel to form individual MEMS devices, said MEMS device being one of said multiple MEMS devices.

8. An assembly comprising:

a substrate having a cantilevered substrate platform formed therein, said cantilevered substrate platform including an arm extending from said platform, wherein a first end of said arm is fixed to said substrate, and a second end of said arm is fixed to said cantilevered substrate platform, said arm being a sole attachment point of said platform to said substrate;

a microelectromechanical (MEMS) device residing on said cantilevered substrate platform, said MEMS device including bondwire pads formed on said substrate and traces formed on said arm, said traces electrically coupling said bondwire pads with said MEMS device;

an integrated circuit die interconnected with said bondwire pads via conductive interconnects;

a cap layer overlying said MEMS device; and

a molding compound substantially encapsulating said integrated circuit die, said conductive interconnects, said bondwire pads, said MEMS device, and said cap layer, wherein said cap layer prevents said molding compound from contacting said MEMS device.

9. An assembly as claimed in claim 8 wherein said substrate is a first substrate, said MEMS device is formed on a front side of said first substrate, and said assembly further comprises a second substrate attached to a back side of said first substrate, said second substrate including a second cantilevered substrate platform that is vertically stacked with said cantilevered substrate platform to form a stacked cantilevered platform structure.

10. An assembly as claimed in claim 9 wherein:

said MEMS device includes an active region;

said first substrate includes an aperture underlying said active region and extending through said first substrate to said active region; and

said second substrate is attached to said first substrate such that said second cantilevered substrate platform covers said aperture to form a sealed cavity underlying said active region of said MEMS device.

11. A method of packaging a microelectromechanical systems (MEMS) assembly, said MEMS assembly including a MEMS device formed in a cantilevered substrate platform and a cap layer overlying said MEMS device, said cantilevered substrate platform having an arm extending from said platform, a first end of said arm being fixed to said substrate, a second end of said arm being fixed to said cantilevered substrate platform, and said arm being a sole attachment point of said platform to said substrate, bondwire pads electrically coupled with said MEMS device and exposed out of said cap layer, and said method comprising:

electrically interconnecting said bondwire pads with an integrated circuit die via conductive interconnects; and

following said electrically interconnecting operation, applying a molding compound to substantially encapsulate said integrated circuit die, said conductive interconnects, and said MEMS assembly, said cap layer preventing said molding compound from contacting said MEMS device.

Assignments (29)