LED filament

US11158611B2 · kind B2 · utility

Assignee

• Osram OLED GMBH · DE

Inventors

• Ee Lian Lee · Balik Pulau, MY
• Tilman Eckert · George Town, MY
• Ralph Bertram · Herzogenrath, DE
• Kok Eng Ng · Bukit Mertajam, MY
• Anuarul Ikhwan Mat Nazri · Bukit Mertajam, MY

Key dates

• Filing date: Jun 8, 2018
• Grant date: Oct 26, 2021
• Expiry date: Jul 1, 2038

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/8514
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

An LED filament is disclosed. In an embodiment an LED filament includes a carrier composed of a material transparent to electromagnetic radiation, two electrical terminals located on the carrier and at least two radiation-emitting semiconductor chips arranged on the carrier, wherein the semiconductor chips are electrically connected to the electrical terminals, wherein undersides of the semiconductor chips are connected by way of an adhesive layer to the carrier, wherein the adhesive layers comprise a first conversion material, wherein the first conversion material is configured to shift at least a portion of a wavelength of radiation from the semiconductor chips, wherein the semiconductor chips comprise a conversion layer on upper sides and on lateral areas, wherein the conversion layers are configured to shift at least a portion of the wavelength of the radiation from the semiconductor chips, wherein a transparent matrix material mixed with a second conversion material covers the semiconductor chips, and wherein sedimented conversion layers with an increased concentration of the second conversion material cover the upper sides and lateral areas of the semiconductor chips.