Surface-mounted devices of light-emitting diodes with small lens

• US 6,610,598 B2
• Filed: 06/20/2002
• Issued: 08/26/2003
• Est. Priority Date: 11/14/2001
• Status: Active Grant

• Current Assignee: Solidlite Corp.
• Original Assignee: Solidlite Corp.
• Inventors: Chen, Hsing
• Primary Examiner(s): Whitehead, Jr., Carl
• Assistant Examiner(s): NGUYEN, THANH T
• Application Number:
  US10/174,817
• Publication Number:
  US 20030089914A1
• Time in Patent Office: 432 Days
• Field of Search: 257/82, 257/95, 257/100, 257/666, 257/676, 257/678, 257/690, 257/710
• US Class Current: 438/666
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/1815 Shape
• CPC Class Codes: H01L 33/54 having a particular shape

Abstract

The present invention is a surface-mounted device of light-emitting diodes (SMD LED) whose component typically has a plane on the surface. Through the calculation of Snell'"'"'s Law, most of light fails to be emitted directly from the component because of the difference in the refractive index of the epoxy resin and the atmosphere (the refractive index of the light in the atmosphere is 1, the refractive index of the epoxy resin is around 1.5). It takes several times of refraction and a waste of brightness to allow the light that fails to be emitted directly a chance to be emitted, while leaving some light that might never be emitted. Therefore, the brightness reduces.

The surface-mounted devices of light-emitting diodes with small lens for the present invention attach several small lens or diffraction lens on the plane surface of the SMD LED. The lens that enlarges the critical angle increases the direct light-emitting opportunity from the light-emitting chip, which in turn increases the brightness of LED. Besides, the plane surface of the component under the vision of naked eyes wards off the influence on the pick and place operation, while prevents the volume of the component from getting large.

Claims

1. Surface-mounted devices of light-emitting diodes with small lens, consisting of:

lead frame or substrate, with electric conducting electrode fitted on it;

light-emitting chip, usually with D.C passing through its positive and negative electrodes to emit light of specific wavelength;

electric conducting wire or material, used for connecting said light-emitting chip and said lead frame or substrate;

encapsulating resin, used for protect said light-emitting chip and electric conducting wire or materials;

with said electric conducting material or adhesive, fix said light-emitting chip on said lead frame or machine plate, then, connecting positive and negative electrodes of said light-emitting chip and electric conducting electrodes on said substrate by welding, next, with molding for encapsulating resin to wrap said light-emitting chip and electric conducting wires into SMD LED characterized with several small lens on surface, with this design to enhance brightness and centralize direction of light.

2. The surface-mounted devices of light-emitting diodes with small lens of claim 1, wherein said small lens can be convex lens arranged in arrays.

3. The surface-mounted devices of light-emitting diodes with small lens of claim 1, wherein said small lens can be convex lens arranged in pillars.

4. The surface-mounted devices of light-emitting diodes with small lens of claim 1, wherein said small lens can be convex lens arranged in concentric circles.

5. The surface-mounted devices of light-emitting diodes with small lens of claim 1, wherein said small lens can be diffraction lens providing diffraction function, such lens offers focusing effect focusing light emitted from each part of component on a same spot to increases brightness.

6. The surface-mounted devices of light-emitting diodes with small lens of claim 1, wherein said small lens can be diamond lens arranged in arrays.

7. The surface-mounted devices of light-emitting diodes with small lens of claim 1, wherein said small lens can be triangular prism.

8. The surface-mounted devices of light-emitting diodes with small lens of claim 1, wherein diameter of said small lens falls between 10˜

200 um and diameter of said small diamond lens falls between 10˜

200 um.