Method for operating an optoelectronic semiconductor device and optoelectronic semiconductor device

Patent metadata

Field	Value
Publication number	US-11388798-B2
Application number	US-202017264241-A
Country	US
Kind code	B2
Filing date	Sep 15, 2020
Priority date	Sep 19, 2019
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A method for operating an optoelectronic semiconductor device. The semiconductor device includes a first optoelectronic semiconductor chip for generating, for example, blue light, an optional second optoelectronic semiconductor chip for generating, for example, green light, and a third optoelectronic semiconductor chip for generating, for example, red light. The semiconductor device also includes a driver unit which supplies the semiconductor chips with current during operation. The third semiconductor chip is operated on the basis of a temperature-brightness characteristic curve stored in the driver unit. The temperature-brightness characteristic curve is configured for a minimum color location deviation over an intended operating temperature range, relative to at least one reference color location.

First claim

The invention claimed is:

1. A method for operating an optoelectronic semiconductor device,
wherein
the semiconductor device comprises a first optoelectronic semiconductor chip for generating light of a first color and a third optoelectronic semiconductor chip for generating light of a third color,
the semiconductor device comprises a driver unit which supplies the semiconductor chips with current during operation,
the third semiconductor chip is operated on the basis of a temperature-brightness characteristic curve stored in the driver unit,
the temperature-brightness characteristic curve is configured for a minimum color location deviation over an intended operating temperature range with respect to at least one reference color location,
the temperature-brightness characteristic curve for the third semiconductor chip slopes less steeply towards higher temperatures than a curve designed for constant brightness over the operating temperature range, and
the semiconductor device is free of phosphors.

2. The method according to claim 1 ,
wherein the first semiconductor chip is configured to generate blue light and the third semiconductor chip is configured to generate red light, and the semiconductor device further comprises a second optoelectronic semiconductor chip for generating green light.

3. The method according to claim 1 ,
wherein the operating temperature range is from 0° C. or less to 100° C. or more with respect to a temperature of an active zone of the third semiconductor chip,
wherein the reference color location or at least one of the reference color locations is located at coordinates 0.31; 0.33 in the CIE-xy standard chromaticity diagram with a tolerance of at most 0.1 units.

4. The method according to claim 1 ,
wherein the temperature-brightness characteristic curve for the third semiconductor chip is configured for a minimum color location deviation to at least three different reference color locations,
wherein the reference color locations in the CIE-xy standard chromaticity diagram pairwise comprise a distance to each other of at least 0.1 units.

5. The method according to claim 4 ,
wherein the reference color locations are weighted differently when determining the temperature-brightness characteristic curve.

6. The method according to claim 1 ,
wherein in determining the temperature-brightness characteristic curve
a brightness for the third semiconductor chip is determined for each temperature sampling point, so that the respective reference color location is hit as accurately as possible, and
interpolation is carried out between the temperature sampling points in order to obtain the temperature-brightness characteristic curve.

7. The method according to claim 2 ,
wherein the first and the second semiconductor chip are controlled with respect to their brightness in accordance with a temperature-independent characteristic curve.

8. The method according to claim 1 ,
in which the temperature-brightness characteristic curve is non-linear.

9. The method according to claim 1 ,
wherein the temperature-brightness characteristic comprises a smaller slope at any point than the curve designed for constant brightness over the operating temperature range.

10. The method according to claim 1 ,
wherein the temperature-brightness characteristic curve slopes increasingly more steeply towards higher temperatures,
wherein a change in slope of the temperature-brightness characteristic curve towards higher temperatures decreases so that a first derivative of the temperature-brightness characteristic curve towards higher temperatures tends towards zero.

11. The method according to claim 1 ,
wherein the semiconductor chips are mounted on a common carrier,
wherein the driver unit is an application specific integrated circuit and comprises a temperature sensor.

12. The method according to claim 2 ,
wherein the first and second semiconductor chips are each based on the AlInGaN material system and the third semiconductor chip is based on the AlInGaP material system.

13. The method according to claim 1 ,
wherein dominant wavelengths of the semiconductor chips at a temperature of 25° C. are in the following ranges, wherein a color saturation of an emission of the semiconductor chips is at least 0.8 each:
first semiconductor chip, between 455 nm and 475 nm, inclusive,
second semiconductor chip, between 515 nm and 535 nm inclusive, and
third semiconductor chip, between 610 nm and 630 nm, inclusive.

14. The method according to claim 1 ,
wherein the driver unit drives each semiconductor chip by pulse width modulation, and the driver unit comprises a separate current output for each of the semiconductor chips, so that an emission color of the semiconductor device is adjustable.

15. An optoelectronic semiconductor device comprising:
a first optoelectronic semiconductor chip for generating blue light,
a second optoelectronic semiconductor chip for generating green light,
a third optoelectronic semiconductor chip for generating red light
a driver unit which supplies the semiconductor chips with current independently from each other during operation, and
a carrier which is a heat sink and on which the semiconductor chips and the driver unit are mounted together,
wherein the driver unit is configured to operate the third semiconductor chip based on a temperature-brightness characteristic curve stored in the driver unit, and the temperature-brightness characteristic is configured for a minimum color location deviation over an intended operating temperature range with respect to at least one reference color location, wherein the temperature-brightness characteristic curve for the third semiconductor chip slopes less steeply toward higher temperatures than a curve configured for constant brightness over the operating temperature range, and wherein the optoelectronic semiconductor device is free of phosphors.

16. The optoelectronic semiconductor device according to claim 15 , which is configured for vehicle interior lighting system of a vehicle, wherein the car interior lighting system has an adjustable emission color.

17. A method for operating an optoelectronic semiconductor device, wherein
the semiconductor device comprises a first optoelectronic semiconductor chip for generating light of a first color and a third optoelectronic semiconductor chip for generating light of a third color,
the semiconductor device comprises a driver unit which supplies the semiconductor chips with current during operation,
the third semiconductor chip is operated on the basis of a temperature-brightness characteristic curve stored in the driver unit,
the temperature-brightness characteristic curve is configured for a minimum color location deviation over an intended operating temperature range with respect to at least one reference color location,
the temperature-brightness characteristic curve for the third semiconductor chip slopes less steeply towards higher temperatures than a curve designed for constant brightness over the operating temperature range,
the operating temperature range is from 0° C. or less to 100° C. or more with respect to a temperature of an active zone of the third semiconductor chip, and
the reference color location or at least one of the reference color locations is located at coordinates 0.31; 0.33 in the CIE-xy standard chromaticity diagram with a tolerance of at most 0.1 units.

Assignees

• Osram Opto Semiconductors Gmbh

Inventors

• Moritz Martin
• Stigler Sebastian
• Hiller Uli
• Höflinger Benjamin

Classifications

• H10W90/00

  Package configurations · CPC title

• H10H20/825

  containing nitrogen, e.g. GaN · CPC title

• B60Q3/74 Primary

  for overall compartment lighting; for overall compartment lighting in combination with specific lighting, e.g. room lamps with reading lamps (general lighting mounted on specific fittings B60Q3/20; general lighting for mass transit vehicles B60Q3/43) · CPC title

• B60Q3/80

  Circuits; Control arrangements (for dashboards B60Q3/16; for mass transit vehicles B60Q3/47) · CPC title

• H05B45/18

  using temperature feedback · CPC title