Light-emitting-diode (LED) with spherical lens

• US 4,841,344 A
• Filed: 12/07/1987
• Issued: 06/20/1989
• Est. Priority Date: 09/13/1985
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Heinen, Jochen
• Primary Examiner(s): James, Andrew J.
• Assistant Examiner(s): Jackson, Jr., Jerome
• Application Number:
  US07/129,178
• Time in Patent Office: 561 Days
• Field of Search: 357/56, 357/30, 357/17, 350/96.18
• US Class Current: 257/98
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 156/1089 of discrete laminae to single face of additional lamina

Abstract

A light-emitting diode has a lens secured in self-adjusted fashion to a mesa surface of a semiconductor body by means of adhesive. The mesa surface is substantially perpendicular and centered with an emission axis of the light-emitting diode. Preferably, the lens is spherical and the mesa surface has a diameter comparable to or smaller than a diameter of the lens.

Claims

1. A light-emitting diode apparatus, comprising:

spherical lens means for radiation concentration secured to a light-emitting diode by means of adhesive;

said light-emitting diode having a semiconductor body with a luminescent zone which has a shape of a spot;

the luminescent zone being situated closer to one surface of said semiconductor body than an opposite surface thereof;

the opposite surface having a mesa with a circular mesa surface, the circular mesa surface being positioned in adjusted and centered fashion opposite the luminescent zone of the diode;

the spherical lens means being arranged on the circular mesa surface, and being aligned and retained in self-centered fashion on the mesa surface by the adhesive;

a diameter of the circular mesa surface being dimensioned of a comparable size to a diameter of such that the spherical lens is self-centered by a surface tension of the adhesive when viscous in combination with the mesa surface diameter.

2. A light-emitting diode apparatus according to claim 1 wherein the diameter of the circular mesa surface is dimensioned between 1.2 to 0.5 times a diameter of the lens means.

4. A light-emitting diode apparatus according to claim 1 wherein to mesa is an etched mesa.

3. A light-emitting diode apparatus according to claim I wherein the diameter of the circular mesa surface is dimensioned between 0.7 to 0.9 times the diameter of the lens means.

5. A light-emitting diode apparatus, comprising:

a substrate body having a layer at one surface thereof and a luminescent spot zone in a region of a junction between the layer and the substrate body;

at a surface of the substrate body opposite the layer a spherical lens being arranged, said opposite surface being substantially perpendicular to an axis of emission from the luminescent zone through the substrate body;

a mesa structure having a circular mesa surface which is perpendicular to said axis of emission;

the spherical lens being positioned and centered on the mesa surface and symmetrical to said axis of emission from the luminescent spot zone, and being retained thereby adhesive; and

means for self-centering the spherical lens on the mesa surface, said for self-centering comprising a diameter of the circular mesa surface being dimensioned such that through interaction with the adhesive when it is in a viscous condition, the spherical lens is self-centered on the mesa surfaces by surface tension of the adhesive.

6. An apparatus according to claim 5 wherein a diameter of the circular mesa surface is less than a diameter of the spherical lens.