IPx6 Rated Surface Mount LED
Application Note 5487
1. Introduction
The LED has been used in variable-message signs and full-
color display applications for years. Its popularity in such
applications stems from the vibrant and wide color gamut
that it produces, its long operating lifetime, and its ex-
ceptional brightness which makes it suitable for outdoor
viewing. The common LED package used in outdoor sign
and display applications has typically been the through-
hole package, due to its robust package design, high
optical efficiency and shapeable radiation pattern.
Thanks to the advancement of surface mount LED
package design and materials in recent years, coupled
with the progress in LED die efficiency, surface mount
LED packaging can now deliver the required brightness
for outdoor sign and display applications. In order to fully
enable their potential for use in harsh outdoor environ-
ments, Avago has developed a series of surface mount
tricolor packages with high reliability and durability
that fully satisfy the requirements for outdoor applica-
tions. With our patented package design and proprietary
material, these packages comply with IPX6 coding per IEC
60529 standard for protection against water.
The objective of this Application Note is to provide users a
general understanding of the IPX6 coding, its advantages
as well as precautions needed when using these LEDs.
2. Reference Documents
IEC 60529: Degree of protection provided by enclosure
(IP Code)
This standard provides a summarized definition of ingress
protection (IP) code designations and the test require-
ments with which a package must comply to qualify for a
specific IP coding.
3. What is IP code?
IP code is used to determine the degree of ingress pro-
tection provided by an enclosure against solid foreign
objects (first characteristic numeral), ingress of water
(second characteristic numeral) and hazardous parts
(additional letter). Since surface mount LED packages are a
complete solid without air gap, the ingress of solid objects
(such as dust or dirt) is of less concern. As such, this appli-
cation note focuses mainly on the ingress of water within
the surface mount package.
3.1 IP Code Delineation
IP X X X X
Supplementary Information
Supplement letter (optional), with letters H, M, S, W
--
Additional letter (optional), with letters A, B, C, D
Protection against ingress of water with harmful effects
Second characteristic numeral, with (numerals 0 to 8 or letter X)
Protection against ingress of solid foreign object
First characteristic numeral, with (numerals 0 to 6 or letter X)
3.2 Description of IP code against ingress of water (second characteristic numeral)
IP code
IPX 0
IPX 1
IPX 2
IPX 3
IPX 4
IPX 5
IPX 6
IPX 7
IPX 8
Description for degree of protection
Non-protected
Protected against vertically falling water drops
Protected against vertically falling water drops when enclosure tilted up to 15°
Protected against spraying water
Protected against splashing water
Protected against water jets
Protected against powerful water jets
Protected against the effects of temporary immersion in water
Protected against the effects of continuous immersion in water
4. Benefits of IPX6-rated LED packages
Common surface mount LED packages, especially those
with silicone encapsulation, require additional protection
commonly in the form of a transparent cover on top of
the LED or LED panel to shield off direct water exposure.
The cover also acts as a protection against dust accumula-
tion on the silicone surface. Prolonged exposure to water
without protection on such LED packages might lead to
premature LED failures.
In contrast, Avago’s IPX6-rated surface mount LED
packages are capable of withstanding direct exposed to
the outdoor environment where rainfall, condensation,
mist or water splashes can come in direct contact with
the LED surface. Moreover, sign and display makers can
now design their products without a transparent plastic
cover when using Avago’s LED with IPX6 rating. This
directly reduces the material and assembly costs of the
end product as well as eliminating the unwanted reflec-
tion from the plastic cover.
LED packages are IPX6 rated. It is recommended that the
water pressure be kept below 30kPa to avoid exerting too
much pressure on the LED surface.
6. Precautions
Avago surface mount LED packages have metal leads pro-
truding from the polymer body. These leads act as electrical
terminals to the package and are meant to be soldered onto a
printed circuit board. Although packages that are IPX6 rated
are protected against powerful water jets, it is necessary to
protect the leads and the solder joints from being exposed
to the environment. If left unprotected, such exposure may
lead to corrosion, shorts, leakage or breakdowns.
After having been in contact with water, small globules of
water might remain on the LED surface. These small globules,
acting just like lenses, might slightly affect the optical per-
formance of the LED package. However, the effect is not
permanent and will disappear as the water dries off.
Although these IPX6-rated LED packages are protected
against exposure to water, the soft silicone encapsulation is
still susceptible to external mechanical stress which may lead
to unwanted catastrophic failure. It is therefore necessary to
observe appropriate precautions as listed in Avago applica-
tion note AN 5288 when handling these devices.
Avago’s IPX6 rated LED
Electronic grade potting
material
5. Cleaning
Surface mount LED packages with silicone encapsula-
tion generally attract dust and dirt due to their surface
tackiness. To clean the LED surface when this happens,
water can be sprayed directly on the LED panel, as these
Outdoor environment
Printed circuit board
For product information and a complete list of distributors, please go to our web site:
www.avagotech.com
Avago, Avago Technologies, and the A logo are trademarks of Avago Technologies in the United States and other countries.
Data subject to change. Copyright © 2005-2010 Avago Technologies. All rights reserved.
AV02-2678EN - November 4, 2010
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