Application Notes
5. Humidity Control Of PCB-Mounted Parts
If the moisture-sensitive SMD parts will not undergo further reflow or other high-temperature
processes, then no special treatment is required. However, if the PCB assembly requires further
reflow or other high-temperature process, including rework, then the mounted SMD’s exposure time
should continue to accumulate against the MSL limit, unless the board is kept in a dry environ ment
(<5% RH).If the exposure time exceeds the MSL limit, the board and part must be baked dry to reset
the exposure time before undergoing further reflow.
Installation and Usage
If the part’s silicone lens extends beyond the board’s edge after installation, proper protection
Should be made (such as covers) to prevent accidental impact or stress on the exposed lens that
would cause damage or detachment. The silicone lens may withstand up to 1.5-newton in shear
force when properly mounted.If external protection is not available, strongly suggest following these
handling procedures to prevent damage:
1. When the PCB assembly is handled or transported after reflow soldering, care must be taken to
prevent accidental contact or impact on the exposed silicone lens.
2. When the PCB assembly is installed into the casing or panel, care must be taken to maintain
sufficient clearance for the lens.
3. Do not subject the silicone lens to outside impact or friction.
Cleaning
1. Do not use unknown chemicals or acidic solvents to clean the part. Please check to insure the
cleaning solvent will notcorode epoxy resin, silicone resin, silver plating, and other component
materials before using.
2. Kingbright suggests ethanol as a safe solvent for use with the surface mount devices. Softly wipe
away any surface partcles,avoiding excessive force scratching the surface or damaging the struc-
tures. Then place down and allow to naturally dry under room temperature conditions before further
use. Do not soak the component in the solvent.
SPEC NO: DSAN3491
APPROVED: Wynec
REV NO: V.4B
DATE: SEP/22/2016
DRAWN: W.Q.Zhong
PAGE: 7 OF 7
CHECKED: Allen Liu
ERP: 1102015727
KINGBRIGHT [ KINGBRIGHT CORPORATION ]
