Sensor packaging method and sensor packages
View Patent ↗A method ( 80 ) entails providing ( 82 ) a structure ( 117 ), providing ( 100 ) a controller element ( 102, 24 ), and bonding ( 116 ) the controller element to an outer surface ( 52, 64 ) of the structure. The structure includes a sensor wafer ( 92 ) and a cap wafer ( 94 ). Inner surfaces ( 34, 36 ) of the wafers ( 92, 94 ) are coupled together, with sensors ( 30 ) interposed between the wafers. One wafer ( 94, 92 ) includes a substrate portion ( 40, 76 ) with bond pads ( 42 ) formed on its inner surface ( 34, 36 ). The other wafer ( 94, 92 ) conceals the substrate portion ( 40, 76 ). After bonding, methodology ( 80 ) entails forming ( 120 ) conductive elements ( 60 ) on the element ( 102, 24 ), removing ( 126 ) material sections ( 96, 98, 107 ) from the wafers to expose the bond pads, forming ( 130 ) electrical interconnects ( 56 ), applying ( 134 ) packaging material ( 64 ), and singulating ( 138 ) to produce sensor packages ( 20, 70 ).
1. A method of forming a sensor package comprising:
bonding a sensor wafer, a cap wafer, and at least one controller element together such that a first inner surface of said cap wafer is coupled to a second inner surface of said sensor wafer to form a sensor structure and a bottom side of said at least one controller element is coupled to an outer surface of said sensor structure to form a stacked wafer structure, wherein said sensor wafer includes a plurality of sensors encapsulated by said cap wafer, a first one of said cap wafer and said sensor wafer includes a substrate portion with first bond pads located on a corresponding one of said first and second inner surfaces and a second one of said cap wafer and said sensor wafer conceals said substrate portion, and a top side of said at least one controller element includes control circuitry and second bond pads;
removing a first material section from said second one of said sensor wafer and said cap wafer to expose said substrate portion having said first bond pads;
forming electrical interconnects between said first and second bond pads; and
singulating said stacked wafer structure to produce said sensor package.
2. A method as claimed in claim 1 wherein said bonding operation comprises:
bonding said first inner surface of said cap wafer with said second inner surface of said sensor wafer to form said sensor structure; and
following said bonding of said cap wafer and said sensor wafer, bonding said bottom side of said at least one controller element with said outer surface of said sensor structure to form said stacked wafer structure.
3. A method as claimed in claim 1 wherein said at least one controller element is in the form of a controller wafer having said top side and said bottom side, said top side including a plurality of controller dies, each of said controller dies having said control circuitry and said second bond pads, and wherein:
said bonding operation comprises attaching said bottom side of said controller wafer to said outer surface of said sensor structure such that said each of said controller dies is aligned with one of said sensors; and
said removing operation includes removing a second material section of said controller wafer coinciding with said first material section to expose said substrate portion having said first bond pads.
4. A method as claimed in claim 3 wherein:
for said each of said controller dies aligned with said one of said sensors, said forming operation forms said electrical interconnects between said first and second bond pads; and
said singulating operation is performed following said forming operation to produce a plurality of sensor packages, said sensor package being one of said plurality of sensor packages.
5. A method as claimed in claim 1 wherein said at least one controller element includes a plurality of separate controller dies that are physically detached from one another, each of said separate controller dies having said top side and said bottom side, said top side including said control circuitry and said second bond pads, and said bonding operation comprises attaching said bottom side of each of said separate controller dies to said outer surface of said sensor structure such that said each of said controller dies is aligned with one of said sensors.
6. A method as claimed in claim 5 wherein:
for said each of said controller dies aligned with said one of said sensors, said forming operation forms said electrical interconnects between said first and second bond pads; and
said singulating operation is performed following said forming operation to produce a plurality of sensor packages, said sensor package being one of said plurality of sensor packages.
7. A method as claimed in claim 1 wherein said outer surface of said sensor structure is a second outer surface of said sensor wafer, and said bonding operation comprises attaching said bottom side of said at least one controller element to said second outer surface of said sensor wafer to produce said stacked wafer structure having said sensor wafer positioned between said cap wafer and said at least one controller element.
8. A method as claimed in claim 1 wherein said outer surface of said sensor structure is a first outer surface of said cap wafer, and said bonding operation comprises attaching said bottom side of said at least one controller element to said first outer surface of said cap wafer to produce said stacked wafer structure having said cap wafer positioned between said sensor wafer and said at least one controller element.
9. A method as claimed in claim 1 wherein said at least one controller element includes bump pads formed on said top side, and said method further comprises forming conductive elements on said bump pads following said bonding operation.
10. A method as claimed in claim 1 wherein said removing operation is performed following said bonding operation.
11. A method as claimed in claim 1 further comprising:
applying a packaging material over said top side of said at least one controller element to encapsulate said control circuitry and said electrical interconnects; and
performing said singulating operation following said applying operation.
12. A method as claimed in claim 1 further comprising mounting a sensor die on said top side of said at least one controller element following said bonding operation.
13. A method of forming a sensor package comprising:
bonding a sensor wafer, a cap wafer, and at least one controller element together such that a first inner surface of said cap wafer is coupled to a second inner surface of said sensor wafer to form a sensor structure and a bottom side of said at least one controller element is coupled to an outer surface of said sensor structure to form a stacked wafer structure, wherein said sensor wafer includes a plurality of sensors encapsulated by said cap wafer, a first one of said cap wafer and said sensor wafer includes a substrate portion with first bond pads located on a corresponding one of said first and second inner surfaces and a second one of said cap wafer and said sensor wafer conceals said substrate portion, and a top side of said at least one controller element includes control circuitry and second bond pads;
removing a first material section from said second one of said sensor wafer and said cap wafer to expose said substrate portion having said first bond pads;
forming electrical interconnects between said first and second bond pads following said bonding and removing operations;
applying a packaging material over said top side of said at least one controller element to encapsulate said control circuitry and said electrical interconnects; and
following said applying operation, singulating said stacked wafer structure to produce said sensor package.
14. A method as claimed in claim 13 wherein said removing operation is performed following said bonding operation.
15. A method of forming a sensor package comprising:
bonding a sensor wafer, a cap wafer, and at least one controller element together such that a first inner surface of said cap wafer is coupled to a second inner surface of said sensor wafer to form a sensor structure and a bottom side of said at least one controller element is coupled to an outer surface of said sensor structure to form a stacked wafer structure, wherein said sensor wafer includes a plurality of sensors encapsulated by said cap wafer, a first one of said cap wafer and said sensor wafer includes a substrate portion with first bond pads located on a corresponding one of said first and second inner surfaces and a second one of said cap wafer and said sensor wafer conceals said substrate portion, and a top side of said at least one controller element includes control circuitry and second bond pads, wherein said bonding operation comprises:
bonding said first inner surface of said cap wafer with said second inner surface of said sensor wafer to form said sensor structure; and
following said bonding of said cap wafer and said sensor wafer, bonding said bottom side of said at least one controller element with said outer surface of said sensor structure to form said stacked wafer structure;
following said bonding operation, removing a first material section from said second one of said sensor wafer and said cap wafer to expose said substrate portion having said first bond pads;
forming electrical interconnects between said first and second bond pads; and
singulating said stacked wafer structure to produce said sensor package.
16. A method as claimed in claim 15 wherein said at least one controller element is in the form of a controller wafer having said top side and said bottom side, said top side including a plurality of controller dies, each of said controller dies having said control circuitry and said second bond pads, and wherein:
said bonding operation comprises attaching said bottom side of said controller wafer to said outer surface of said sensor structure such that said each of said controller dies is aligned with one of said sensors; and
said removing operation includes removing a second material section of said controller wafer coinciding with said first material section to expose said substrate portion having said first bond pads.
17. A method as claimed in claim 15 wherein said at least one controller element includes a plurality of separate controller dies that are physically detached from one another, each of said separate controller dies having said top side and said bottom side, said top side including said control circuitry and said second bond pads, and said bonding operation comprises attaching said bottom side of each of said separate controller dies to said outer surface of said sensor structure such that said each of said controller dies is aligned with one of said sensors.
18. A method as claimed in claim 15 wherein said outer surface of said sensor structure is a second outer surface of said sensor wafer, and said bonding operation comprises attaching said bottom side of said at least one controller element to said second outer surface of said sensor wafer to produce said stacked wafer structure having said sensor wafer positioned between said cap wafer and said at least one controller element.
19. A method as claimed in claim 15 wherein said outer surface of said sensor structure is a first outer surface of said cap wafer, and said bonding operation comprises attaching said bottom side of said at least one controller element to said first outer surface of said cap wafer to produce said stacked wafer structure having said cap wafer positioned between said sensor wafer and said at least one controller element.
20. A method as claimed in claim 15 wherein said at least one controller element includes bump pads formed on said top side, and said method further comprises forming conductive elements on said bump pads following said bonding operation.