Semiconductor radiation source and light curing device

• US 20070228392A1
• Filed: 03/23/2007
• Published: 10/04/2007
• Est. Priority Date: 04/03/2006
• Status: Abandoned Application

• Current Assignee: Ivoclar Vivadent AG
• Original Assignee: Ivoclar Vivadent AG
• Inventors: Plank, Wolfgang, Senn, Bruno
• Application Number:
  US11/728,239
• Publication Number:
  US 20070228392A1
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: A61C 19/003 Apparatus for curing resins by radiation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/00014 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 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements
• CPC Class Codes: H01L 33/648 the elements comprising fluids, e.g. heat-pipes

Abstract

A semiconductor radiation source has a base body on which at least two LED chips are directly mounted and are fitted to the base body using a thermally conductive connection. At least one printed circuit board is mounted on the base body and extends from the centrally arranged LED chips to the outside, in particular to the peripheral region of the base body, and projects, in particular, into free areas which extend laterally beside the chips or between the latter.

Claims

1. A semiconductor radiation source for curing light-polymerizable materials comprising:

a base body (22);

at least two centrally arranged LED chips directly mounted to the base body using a thermally conductive connection;

at least one printed circuit board (46) mounted on the base body and which extends from the centrally arranged LED chips to the outside, in particular to the peripheral region of the base body (22).

2. The radiation source as claimed in claim 1, wherein the printed circuit board (46) projects into free areas which extend laterally beside the chips.

3. The radiation source as claimed in claim 1, wherein the printed circuit board (46) runs beside the chips but not between the chips and the optical axis (60) of the radiation source.

4. The radiation source as claimed in claim 1, wherein a first LED chip (12) is arranged on an optical axis (60) and a plurality of several LED chips (14, 16, 18, 20) are radially arranged outside the first LED chip (12), in particular in such a manner that they are symmetrical with respect to one another and surround the LED chip (12) in the manner of a cross or star.

5. The radiation source as claimed in claim 1, wherein four further LED chips (14, 16, 18, 20) surround the first LED chip (12).

6. The radiation source as claimed in claim 1, wherein the LED chips are arranged in the central region of the base body (22) such that they are adjacent to one another, that is to say without the printed circuit board (46) between them.

7. The radiation source as claimed in claim 1, wherein the printed circuit board (46) surrounds the LED chips.

8. The radiation source as claimed in claim 1, wherein the LED chips and the printed circuit board (46) essentially have the same height.

9. The radiation source as claimed in claim 1, wherein connecting areas (70, 72) of conductor tracks (47) of the printed circuit board (46) are connected to the LED chips via bonding connections, in particular.

10. The radiation source as claimed in claim 1, wherein the LED chips are directly mounted on the base body (22), if appropriate using a thermally conductive adhesive, and the printed circuit board (46) is, in particular, adhesively bonded to the base body (22).

11. The radiation source as claimed in claim 1, wherein the printed circuit board (46) has an epoxy resin base, has at least one conductor track (47) at least on one side, is coated with copper, in particular, and is connected by through-plating.

12. The radiation source as claimed in claim 1, wherein a reflector element (24) which is arranged at least between two mutually adjacent LED chips.

13. The radiation source as claimed in claim 12, wherein a reflector element (24) which extends between two LED chips has two reflecting areas (26, 28) which run essentially obliquely, each reflecting area reflecting radiation emanating from the adjacent LED chip.

14. The radiation source as claimed in claim 13, wherein the reflecting areas (26, 28), when viewed in the direction of the optical axis (60), essentially extend in a manner corresponding to the height of the printed circuit board (46) or project beyond the printed circuit board (46).

15. The radiation source as claimed in claim 12, wherein a plurality of reflector elements (24) are connected to one another so as to form a grating reflector (30).

16. The radiation source as claimed in claim 15, wherein the LED chips are held in the grating reflector (30), and wherein the grating reflector is supported on the base body (22) and/or the printed circuit board (46) and/or the LED chips.

17. The radiation source as claimed in claim 2, wherein reflector elements (24) extend between the lateral free areas (34, 36) and the LED chips and support the LED chips.

18. The radiation source as claimed in claim 1, wherein radiation absorbers are connected, in particular, to the base body (22) using thermally conductive connections extend between a centrally located LED chip (12) and external LED chips (14, 16, 18, 20), in particular the external LED chips (14, 16, 18, 20), and the printed circuit board (46).

19. The radiation source as claimed in claim 18, wherein the radiation absorbers are simultaneously of heat-insulating design and are composed of ceramic, in particular.

20. The radiation source as claimed in claim 18 wherein the radiation absorbers extend at least over the width of the LED chips (14, 16, 18, 20) and, in particular, have a greater height than the LED chips (14, 16, 18, 20), preferably approximately 1.5 to 5 times the height, and particularly preferably approximately twice the height, of the LED chips (14, 16, 18, 20).

21. The radiation source as claimed in claim 1, wherein a cover lens (40) is arranged in the beam path downstream of the LED chips and a spacer (42) for said lens is of essentially tubular or annular design, and wherein the spacer (42) is at least partially supported on the printed circuit board (46) and/or the base body (22).

22. The radiation source as claimed in claim 21, wherein at least one conductor track of the printed circuit board (46) runs through under a spacer (42) and, in particular, runs from outside the spacer (42) to inside the spacer.

23. The radiation source as claimed in claim 20 wherein a closed space (82) which has a transparent or translucent, liquid or gelatinous substance, in particular silicone gel or a potting compound, extends between the LED chips, the spacer (42) and the cover lens (40).

24. The radiation source as claimed in claim 23, wherein the substance has phosphorus particles.

25. The radiation source as claimed in claim 21, wherein a converging lens (52) whose diameter is, in particular, larger than the diameter of a cover lens (40) is arranged in the beam path downstream of the cover lens (40).

26. The radiation source as claimed in claim 21, wherein a reflector (50) is arranged at a distance from the LED chips in front of the latter, that is to say downstream of the latter in the beam path, and/or is also arranged, in particular, downstream of a cover lens (40) in the beam path.

27. The radiation source as claimed in claim 26, wherein a light guide is arranged in the beam path downstream of the reflector (50).

28. The radiation source as claimed in claim 1, wherein series resistors (84) which can be adjusted, in particular, and are freely accessible for adjustment are arranged on the printed circuit board (46) outside the spacer (42).

29. The radiation source as claimed in claim 1, wherein the first LED chip (12) and the further LED chips (14, 16, 18, 20) emit light at different wavelengths, in particular at 400 to 430 nm, on the one hand, and at 450 to 480 nm, on the other hand.

30. The radiation source as claimed in claim 1, wherein the first chip (12) and the further chips (14, 16, 18, 20) can be switched on and off at the same time or at different times.

31. The radiation source as claimed in claim 1, wherein the first LED chip (12) emits light at 400 to 430 nm and the further LED chips (14, 16, 18, 20) emit light at 450 to 480 nm.

32. The light curing device as claimed in claim 1 wherein the light curing device has a housing (54) on which the converging lens (52) is supported.