Unlock instant, AI-driven research and patent intelligence for your innovation.

Zener diode protection network in substrate for LEDs connected in series

A zener diode and light emitting diode technology, applied in the use of semiconductor lamps, electrical components, circuits, etc., can solve the problems of insufficient surface area of ​​zener diode silicon

Active Publication Date: 2015-11-25
LUMILEDS HLDG BV
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, when the LED die is in a small footprint (eg 1mm 2 ) are connected in series on the silicon substrate within the die, the silicon surface area under the die for forming the zener diode may be insufficient according to the design rules in principle for good transient voltage protection of the LED

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Zener diode protection network in substrate for LEDs connected in series
  • Zener diode protection network in substrate for LEDs connected in series
  • Zener diode protection network in substrate for LEDs connected in series

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0027] As a preliminary matter, LEDs were formed on a growth substrate. In the example used, the LEDs are GaN-based LEDs, such as AlInGaN or InGaN LEDs, which are used to generate UV by green light. Typically, a relatively thick n-type GaN layer is grown on a sapphire growth substrate using conventional techniques. Relatively thick GaN layers typically include a low temperature nucleation layer and one or more additional layers to provide a low defect lattice structure for the n-type cladding layer and active layer. Then, one or more n-type cladding layers are formed over the thick n-type layer, followed by the active layer, one or more p-type cladding layers, and a p-type contact layer (for metallization).

[0028] For flip-chip, portions of the p-layer and active layer are etched away to expose the n-layer for metallization. In this way, the p-contact and n-contact are on the same side of the chip and can be electrically attached directly to the substrate contact pads. Cu...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A transient voltage suppressor circuit is disclosed for a plurality (N) of LEDs connected in series. Only one zener diode is created for connection to each node between LEDs, and a pair of zener diodes (the end zener diodes) are connected to the two pins (anode and cathode pads) of the series string. Therefore, only N+1 zener diodes are used. The end zener diodes (Q1 and Qn+1) effectively create back-to-back zener diodes across the two pins since the zener diodes share a common p+ substrate. The n+ regions of the end zener diodes Q1 and Qn+1 have the highest breakdown voltage requirement and must be placed relatively far apart. Adjacent n+ regions of the intermediate zener diodes have a much lower breakdown voltage requirement so may be located close together. The zener diodes may be placed within a very small footprint or can be larger for better suppressor performance.

Description

technical field [0001] The present invention relates to light emitting diodes (LEDs), and in particular to providing a zener diode network for protecting series connected LEDs from high voltage transients. Background technique [0002] It is common to protect LEDs from electrostatic discharge (ESD) or other high voltage transients by connecting back-to-back Zener diodes in parallel with the LEDs. If the reverse voltage across the LED is higher than the Zener breakdown voltage, the current is bypassed to the power supply through the Zener diode and the LED is protected. Such a protection circuit is called a transient voltage suppressor (TVS). [0003] It is common to interconnect the LED dies in series so that each LED drops the forward voltage and the LEDs operate at the same current. It is more efficient to generate high voltage and low current than high current and low voltage. Such series connections are common in high brightness applications such as lighting and backl...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H05B33/08H05B44/00
CPCH05B33/083H01L25/0753H01L25/167H05B33/089Y02B20/341H01L2224/16225H01L2924/0002H05B45/48Y02B20/30H05B45/54H05B45/50H01L2924/00
Inventor Y.韦W.D.科林斯三世D.斯泰格瓦尔德
Owner LUMILEDS HLDG BV