Method of providing an optoelectronic element with a non-protruding lens

• US 20030132495A1
• Filed: 01/03/2003
• Published: 07/17/2003
• Est. Priority Date: 03/10/1998
• Status: Active Grant

• Current Assignee: James P. Coffin IV, Michael A. Mills
• Original Assignee: James P. Coffin IV, Michael A. Mills
• Inventors: Coffin, James P. IV, Mills, Michael A.
• Granted Patent: US 7,067,893 B2
• Time in Patent Office: Days
• US Class Current: 257/433
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: B29C 45/14655 connected to or mounted on a carrier, e.g. lead frame
• CPC Class Codes: B29C 45/401 Ejector pin constructions or mountings
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• 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 24/45 of an individual wire connector
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01077 Iridium [Ir]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/12043 Photo diode
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/1815 Shape
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: H01L 33/54 : having a particular shape
• CPC Class Codes: Y10S 425/808 : Lens mold

Abstract

An optoelectronic component has a lens that is formed in the surface of an encapsulant surrounding a semiconductor diode element. With respect to emitters, the lens reduces internal reflection and reduces dispersion to increase overall efficiency. With respect to detectors, the lens focuses photons on the active area of the detector, increasing detector sensitivity, which allows a detector having a reduced size and reduced cost for a given application. The lens portion of the encapsulant is generally nonprotruding from the surrounding portions of the encapsulant reducing contact surface pressure caused by the optoelectronic component. This non-protruding lens is particularly useful in pulse oximetry sensor applications. The lens is advantageously formed with a contoured-tip ejector pin incorporated into the encapsulant transfer mold, and the lens shape facilitates mold release.

Claims

1. An optoelectronic method comprising the steps of:

providing a generally planar surface at a predefined distance from an optoelectronic element;

defining a light transmissive region of said surface within the critical angle of said element; and

contouring said surface within said transmissive region without exceeding said predefined distance so as to create a non-protruding lens for said element.

2. The optoelectronic method of claim 1, wherein said transmissive region has a circular cross-section.

3. The optoelectronic method of claim 2, wherein said contouring step comprises forming a flat surface element.

4. The optoelectronic method of claim 3, wherein said contouring step further comprises forming an arcuate surface element.

5. The optoelectronic method of claim 2, wherein said contouring step comprises forming a spherical surface element.

6. The optoelectronic method of claim 2, wherein said contouring step comprises forming a parabolic surface element.

7. The optoelectronic method of claim 1, comprising the further step of shaping a surrounding region adjacent said transmissive region.

8. The optoelectronic method of claim 7, wherein said shaping step comprises forming a sidewall defining a trough disposed around said transmissive region.