Light emitting diode assembly having integrated electrostatic discharge protection

• US 5,914,501 A
• Filed: 08/27/1998
• Issued: 06/22/1999
• Est. Priority Date: 08/27/1998
• Status: Expired due to Term

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.), Philips Lumileds Lighting Company LLC (Apollo Global Management, Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Antle, William K., Stewart, James W., Lam, Michael K.
• Primary Examiner(s): Ngo, Ngan V.
• Application Number:
  US09/141,389
• Time in Patent Office: 299 Days
• Field of Search: 257/79, 257/84, 257/99
• US Class Current: 257/99
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48139 with an intermediate bond, e.g. continuous wire daisy chain
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• 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 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H05B 45/40 Details of LED load circuits
• CPC Class Codes: H05B 47/20 Responsive to malfunctions or to light source life; for protection
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A light-emitting diode assembly incorporates a power shunting element that provides electrical over-stress protection to a light-emitting diode (LED) and prevents damage to the LED from electrostatic discharge (ESD). The power shunting element is coupled in parallel to the LED within the LED assembly and protects the LED by diverting electrical current from the LED and limiting the voltage across the LED to a clamp voltage when a threshold voltage across the LED is exceeded.

Claims

1. A light-emitting diode assembly, comprising:

a light-emitting diode having a first electrical contact and a second electrical contact;

a package having a first electrode coupled to the first electrical contact and a second electrode coupled to the second electrical contact, the first electrode and the second electrode for receiving an applied voltage;

a power shunting element coupled to the first electrical contact and the second electrical contact, shunting electrical current from the light-emitting diode when the applied voltage exceeds a threshold voltage.

2. The light-emitting diode assembly of claim 1 wherein the power shunting element includes a back-to-back configuration of voltage clamping devices.

3. The light-emitting diode assembly of claim 2 wherein the back-to-back configuration of voltage clamping devices includes at least one zener diode.

4. The light-emitting diode assembly of claim 2 wherein the back-to-back configuration of voltage clamping devices includes at least one transient voltage suppressor.

5. The light-emitting diode assembly of claim 1 wherein the first electrode has a first mounting site accommodating the light-emitting diode and a second mounting site for accommodating the power shunt element, the coupling between the second electrical contact and the power shunting element provided by the first electrode.

6. The light-emitting diode assembly of claim 5 wherein the power shunting element includes a back-to-back configuration of voltage clamping devices.

7. The light-emitting diode assembly of claim 6 wherein the back-to-back configuration of voltage clamping devices includes at least one zener diode.

8. The light-emitting diode assembly of claim 6 wherein the back-to-back configuration of voltage clamping devices includes at least one transient voltage suppressor.

9. The light-emitting diode assembly of claim 1 wherein the power shunting element has a bottom surface attached to the first electrode and a top surface having a first terminal and a second terminal, the first electrical contact of the light-emitting diode coupled to the first terminal and the second electrical contact of the light-emitting diode coupled to the second terminal using flip-chip soldering.

10. The light-emitting diode assembly of claim 9 wherein the power shunting element includes a back-to-back configuration of voltage clamping devices.

11. The light-emitting diode assembly of claim 10 wherein the back-to-back configuration of voltage clamping devices includes at least one zener diode.

12. The light-emitting diode assembly of claim 10 wherein the back-to-back configuration of voltage clamping devices includes at least one transient voltage suppressor.