Optoelectronic structural element

• US 6,376,902 B1
• Filed: 01/31/2000
• Issued: 04/23/2002
• Est. Priority Date: 07/29/1997
• Status: Expired due to Term

• Current Assignee: OSRAM GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Arndt, Karlheinz
• Primary Examiner(s): CLARK, JASMINE JHIHAN B
• Application Number:
  US09/494,771
• Time in Patent Office: 813 Days
• Field of Search: 257/678, 257/99, 257/100, 257/81, 257/82, 257/431, 257/432, 257/433
• US Class Current: 257/678
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/642 characterized by the shape
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

An optoelectronic structural element in which an optoelectronic chip is attached to a chip carrier part of a lead frame. The lead frame has a connection part disposed at a distance from the chip carrier part, and which is electrically conductively connected with an electrical contact of the optoelectronic chip. The chip carrier part presents a number of external connections for improved conduction of heat away from the chip. The external connections project from a casing and at a distance from each other.

Claims

1. An optoelectronic surface-mountable structural element (SMD), comprising:

a lead frame having a chip carrier part, external connections, and a connection part disposed at a distance from said chip carrier part, at least three of said external connections being heat-conducting connections thermally conductively connected to said chip carrier part;

an optoelectronic chip heat-conductively connected to said chip carrier part of said lead frame, said optoelectronic chip having an electrical contact electrically conductively connected to said connection part; and

a casing having a foundation encasing said optoelectronic chip and a part of said lead frame, said foundation having a first main surface and an outward facing second main surface disposed opposite said first main surface, said external connections and said connection part project outside of said casing, said external connections and said connection part being bent outside of said foundation toward said outward-facing second main surface of said foundation and in a further course being further bent one of below said foundation toward a center of said outward-facing second main surface and away from said foundation for forming rocker-shaped connection stumps, said at least three of said external connections projecting from said casing on at least two sides of said casing at different places at a distance from each other, said heat-conducting connections as seen in a top view of said lead frame projecting from said casing on at least two sides and starting from said chip carrier part run toward the outside in a stellate form within said casing and separately from each other.

2. The optoelectronic structural element according to claim 1, wherein said connection part has an external connection that is narrower than said external connections connected to said chip carrier part.

3. The optoelectronic structural element according to claim 1, including at least one cooling fin connected to said chip carrier part for conducting heat away from said chip carrier part, said at least one cooling fin projecting on a side surface of said casing on which said connection part and said external connections do not project.

4. The optoelectronic structural element according to claim 1, wherein said casing is formed completely of a radiation-permeable material.

5. The optoelectronic structural element according to claim 1, wherein said casing has a recess formed therein and an emission-permeable window part disposed in said recess.

6. The optoelectronic structural element according to claim 5, wherein said foundation is formed of an emission-impermeable material, said chip carrier part is partially encased by said foundation, and said optoelectronic chip is disposed in said recess.

7. The optoelectronic structural element according to claim 5, wherein said recess has a cross-section widening in its course from inside said casing toward an outside of said casing.

8. The optoelectronic structural element according to claim 7, wherein said foundation has inner surfaces defining said recess and said inner surfaces are reflectors for an emission transmitted by said optoelectronic chip and an emission to be received by said optoelectronic chip.

9. An optoelectronic surface-mountable structural element (SMD), comprising:

a lead frame having a chip carrier part, external connections, and a first and second connection part disposed at a distance from said chip carrier part, at least two of said external connections being heat-conducting connections thermally conductively connected to said chip carrier part;

a first and a second optoelectronic chip heat-conductively connected to said chip carrier part of said lead frame, said first optoelectronic chip having an electric contact electrically conductively connected to said first connection part and said second optoelectronic chip having an electrical contact electrically conductively connected to said second connection part; and

a casing having a foundation encasing said first optoelectronic chip, said second optoelectronic chip, and a part of said lead frame, said foundation having a first main surface and an outward facing second main surface disposed opposite said first main surface, said external connections, said first connection part, and said second connection part project outside of said casing, and said external connections, said first connection part, and said second connection part being bent outside of said foundation toward said outward facing second main surface of said foundation and in a further course being further bent one of below said foundation toward a center of said outward-facing second main surface and away from said foundation, said at least two of said external connections projecting from said casing on two opposite sides of said casing, said heat-conducting connections as seed from a top view of said lead frame projecting from said casing on two opposite sides and starting from said chip carrier part extend in opposite directions toward the outside;

said first connection part and said second connection part as seen from the top view of said lead frame being disposed on opposite sides of said chip carrier part, extend in opposite directions and project from said casing at two opposite sides.

10. The optoelectronic structural element according to claim 9, wherein said first optoelectronic chip and said second optoelectronic chip emit differently colored light.

11. The optoelectronic structural element according to claim 9, wherein said first connection part and said second connection part each have an external connection that is narrower than said external connections connected to said chip carrier part.

12. The optoelectronic structural element according to claim 9, wherein said casing is formed completely of a radiation-permeable material.

13. The optoelectronic structural element according to claim 9, wherein said casing has a recess formed therein and an emission-permeable window part disposed in said recess.

14. The optoelectronic structural element according to claim 13, wherein said foundation is formed of an emission-impermeable material, said chip carrier part is partially encased by said foundation, and said first optoelectronic chip and said second optoelectronic are disposed in said recess.

15. The optoelectronic structural element according to claim 14, wherein said recess has a cross-section widening in its course from inside said casing toward an outside of said casing.

16. The optoelectronic structural element according to claim 15, wherein said foundation has inner surfaces defining said recess and said inner surfaces are reflectors for an emission transmitted by said first optoelectronic chip and said second optoelectronic chip and an emission to be recieved by said first optoelectronic chip and said second optoelectronic chip.

17. An optoelectronic surface-mountable, laterally emitting structural element (SMD), comprising:

a lead frame having a chip carrier part, external connections, and a connection part disposed at a distance from said chip carrier part, at least two of said external connections being heat-conducting connections thermally conductively connected to said chip carrier part;

an optoelectronic chip-heat conductively connected to said chip carrier part of said lead frame, said optoelectronic chip having an electrical contact electrically conductively connected to said connection part; and

a casing having a foundation encasing said optoelectronic chip and a part of said lead frame, said foundation having a first main surface and an outward facing second main surface disposed opposite said first main surface, said external connections and said connection part project outside of said casing, said external connection and said connection part being bent outside of said foundation toward said outward-facing second main surface of said foundation and in a further course being further beng toward a center of said outward facing second main surface, said at least two of said external connections and said connection part projecting from said casing at a same side of said casing at different places at a distance from each other, said heat-conducting connections as seen in a top view of said lead frame projecting from said casing on the same side and starting from said chip carrier part run toward the outside in different directions and break in said further course in a same directions within said casing, said connection part being disposed between said two heat-conduction connections.

18. The optoelectronic structural element according to claim 17, wherein said connection part has an external connection that is narrower than said external connections connected to said chip carrier part.

19. The optoelectronic structural element according to claim 17, including at least one cooling fin connected to said chip carrier part for conducting heat away from said chip carrier part, said at least one cooling fin projecting on a side surface of said casing on which said connection part and said external connections do not project.

20. The optoelectronic structural element according to claim 17, wherein said casing is found completely of a radiation-permeable material.

21. The optoelectronic structural element according to claim 17, wherein said casing has a recess formed therein and an emission-permeable window part disposed in said recess.

22. The optoelectronic structural element according to claim 21, wherein said foundation is formed on an emission-impermeable material, said chip carrier part is partially encased by said foundation, and said optoelectronic chip is disposed in said recess.

23. The optoelectronic structural element according to claim 21, wherein said recess has a cross-section widening in its course from inside said casing toward an outside of said casing.

24. The optoelectronic structural element according to claim 23, wherein said foundation has inner surfaces defining said recess and said inner surfaces are reflectors for an emission transmitted by said optoelectronic chip and an emission to be received by said optoelectronic chip.