Using protective cups to fabricate light emitting semiconductor packages
View Patent ↗A method of manufacturing a light emitting semiconductor package on a semiconductor wafer 252 which includes a plurality of light emitting devices 254 residing on or in a surface of the semiconductor wafer, the method comprising the steps of: forming at least one first hollow cap 256 , each first hollow cap 256 formed to provide: a central portion 260 and first perimeter walls extending from the perimeter edge of the central portion with the free edges of the first perimeter walls adapted to be bonded to the surface of the semiconductor wafer 252 to provide a first cavity; at least one region 258 of the central portion 260 which is substantially transparent or translucent to electromagnetic radiation; aligning the at least one first cap with a corresponding at least one light emitting device using a tool having the same coefficient of thermal expansion as the wafer; bonding the at least one first hollow cap 256 to the semiconductor wafer 252 , the central portion overlying at least one of the plurality of light emitting devices 254 ; and, separating the semiconductor wafer 252 with bonded caps 256 into light emitting semiconductor packages 250.
1. A method of fabricating a light emitting semiconductor packages from a semiconductor wafer comprising a plurality of light emitting devices manufactured on or in the wafer surface, the method comprising the steps of:
(B) forming at least one first hollow cap, each first hollow cap formed to provide:
(1) a central portion and first perimeter walls extending from the perimeter edge of the central portion with the free edges of the first perimeter walls adapted to be bonded to the surface of the semiconductor wafer to provide a first cavity;
(2) at least one region of the central portion which is substantially transparent or translucent to electromagnetic radiation emitted by the light emitting devices;
(C) aligning the at least one first cap with a corresponding at least one light emitting device using a tool having the same coefficient of thermal expansion as the wafer;
(D) bonding the at least one first hollow cap to the semiconductor wafer, the central portion overlying at least one of the corresponding light emitting devices; and
(E) separating the semiconductor wafer with bonded caps into light emitting semiconductor packages.
2. The method as claimed in claim 1 , wherein the first hollow cap is formed by molding a sheet.
3. The method as claimed in claim 2 , wherein infrared radiation is used to heat the sheet to facilitate molding.
4. The method as claimed in claim 2 , wherein the sheet is a plastic sheet.
5. The method as claimed in claim 1 , wherein one or more elongate lenses are formed on the lower surface of the central portion of the first hollow cap.
6. The method as claimed in claim 5 , wherein the one or more elongate lenses are formed by a mold wafer disposed with one or more depressions in the surface of the mold wafer.
7. The method as claimed in claim 1 , wherein more than one second hollow cap is bonded to the semiconductor wafer on the surface opposite the bonded first hollow cap.
8. The method as claimed in claim 7 , wherein the wafer is separated by etching the wafer between the second hollow caps.
9. The method as claimed in claim 1 , wherein the at least one region refracts the electromagnetic radiation emitted by the at least one device.
10. The method as claimed in claim 1 , wherein the cap is further formed to include at least one attachment means for attaching an electromagnetic radiation transmitting cable or fiber to the cap, whereby at least some electromagnetic radiation emitted from the at least one device passes through said at least one region into the cable or fiber.
11. The method as claimed in claim 1 , wherein more than one region of the central portion is formed, each region of the central portion associated with at least one light emitting device.
12. The method as claimed in claim 1 , wherein the tool used for aligning the at least one first hollow cap with respect to the corresponding at least one light emitting device is also used in the step of forming the at least one first hollow cap.