Page 78 - Kingbright 2022-2023 catalog

TECHNICAL NOTES

17. When placing reverse-mount LEDs, the nozzle must not place IPC/JEDEC J-STD-020 Moisture Sensitivity Levels
pressure on the part. Refer to the figures below, pressure on the Floor Life
LED will cause the LED to bend and potentially cause delamination Level
Time Conditions
or cracking between the component PCB and the epoxy lens. The
1 Unlimited ≤30°C / 85% RH
damaged LED will be more prone to failure after undergoing 2 1 year ≤30°C / 60% RH
high-temperature reflow soldering process. 2a 4 weeks ≤30°C / 60% RH
3 168 hours ≤30°C / 60% RH
4 72 hours ≤30°C / 60% RH
5 48 hours ≤30°C / 60% RH
5a 24 hours ≤30°C / 60% RH
6 Time on Label (TOL) ≤30°C / 60% RH
3. If the Humidity Indicator Card (HIC)’s 10 % mark has changed, or the
LEDs have not been used within the floor life specified, they should be
baked with the following conditions to reset the floor life:

Type Temperature Humidity Bake Time
Proper SMD placement. Nozzle does not press down on When still in carrier tape 60±3°C <5%RH 100H
the LED. When out of carrier tape 110°C / 10H
* Not more than once
4. Do not store LEDs in an environment where high humidity or acidic/
basic chemicals are present, as they will degrade the LED’s metallic
surfaces.
5. LED leadframe and soldering pads (cathode and anode) are plated
with gold, tin, or other metals. Under long-term exposure to open air,
the exposed pins and pads may become oxidized causing poor
solderability. Therefore opened but unused parts must be stored in
sealed containers. Suggest to store unused parts in the original
moisture barrier bag.
Pressure from the nozzle can cause structural damage 6. Moisture control for components already mounted on PCB: If the PCB
to the LED. will not undergo additional reflow soldering or high-temperature
processes, then no special treatment is required for the mounted
moisture-sensitive SMD components. If the PCB will undergo multiple
reflow soldering or other high-temperature processes, including
rework, then the SMD component's cumulative exposure time until the
final high-temperature process must be controlled to within the
specified time limit.
For Through-Hole Products
1. Avoid continued exposure to the condensing moisture environment
and keep the product away from rapid transitions in ambient
temperature.
Consider using wider nozzles with diameter greater 2. LEDs should be stored with temperature ≤30°C and relative humidity
than the PCB hole opening. This will prevent pressure < 60%.
damage during placement. 3. Product in the original sealed package is recommended to be
assembled within 72 hours of opening. Product in opened package for
Storage Control more than a week should be baked for 30 (+10/-0) hours at 85 ~
For SMD Products 100°C.
1. Before a sealed moisture barrier bag (MBB) is opened, contained 4. The LED leadframe surface is plated with silver. When the leadframe is
LEDs shall be kept in an environment with temperature below 40°C stored under high-humidity environments, or exposed to certain
and humidity below 90% RH. MBB shall be kept sealed until LEDs chemical elements or gases, the surface may become discolored.
contained in the bag are ready to be used. Once MBB is opened, it Please maintain the cleanliness of the storage environment.
shall be stored in an environment with temperature range of 5. If the storage conditions do not meet specification standards, the
5°C~30°C and humidity below 60% RH. component pins may become oxidized requiring re-plating and
2. After the MBB has been opened, the LEDs should be used according re-sorting before use. Suggest customers consume LEDs as soon as
to the floor life specified in the table below. possible, and avoid long-term storage of large inventories.
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