WS2813

Intelligent control LED

integrated light source

7 / 8

http://www.world-semi.com

2.3. Management after unpacking

It’s recommend to perform SMT assembly as soon as possible after opening the moisture-proof bag, and reflow

soldering should be completed within 4 hours after SMT assembly; for the remaining LEDs, they should be

re-packed in seal package and placed in moisture-proof cabinet (Please note that it’s necessary to rebake at

“

70℃-75℃/48 hours” before next SMT process).

3. Dehumidification Operation (Non-leakage of air, baking temperature:70℃-75℃)

a. MD within 2 weeks, baking time: 24 hours.

b. MD exceeds 2 weeks, baking time: 48 hours.

It’s necessary to do moisture-proof treatment when the secondary reflow carried out that followed the first reflow.

It can’t be more than 2 hours to be exposed at condition of “<30℃/60%RH” and dehumification operation is

requested for a longer interval reflow. For instance, place in a drying box or a container with desiccant, and

dehumidify it before the secondary reflow(Low temperature baking operation:

70℃-75℃, ≥12 hours).

5. SMT Reflow

Refer to the parameters listed below, the experimental results prove that the TOP SMD LED meets the JEDEC

J-STD-020C standards. As a general guideline, it is recommended to follow the SMT reflow temperature curve

recommended by the solder paste manufacturer.

Remarks: 1. These general guidelines may not apply to all PCB designs and reflow soldering configurations.

2. All temperatures referred are measured on the surface of the package body.

Curve Description

Lead-free

Reflow

The lowest preheat temperature (Tsmin)

150℃

The highest preheat temperature (Tsmax)

200℃

Preheating time (Tsmin to Tsmax) (ts)

60-180 S

Average rate of temperature rise (Tsmax to Tp)

<3℃/S

LIQUID REGION temperature (TL)

217℃

LIQUID REGION Holding Time (tL)

60-150 S

Peak Temperature (Tp)

240℃

High Temperature Region(Tp=-5℃) Holding

Time (tp)

<10 S

Cooling Rate

<6℃/S

Room Temperature to Peak Holding Time

<6 min