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Moisture Absorption and Dehumidification Data


Data on moisture absorption and dehumidification of an IC package


↑ Click on the above graph for magnification.




 
 

  Pretreatment: 24-hour baking at +125ºC

Measurement condition

(1) Component stored in ambient environment(30 degrees C, 85%RH) for 25 hours.
(2) Dehumidification: The component is stored in a McDry cabinet at 5%RH for 150 hours.
(3) The component was baked and then stored in McDry at 5%RH. (Example of storage in a dry box at 5% RH specified by the new IPC/JEDEC J-STD-033D)

Example of low-humidity storage of laminated PCB

Multi-layered PCBs absorb moisture at a faster rate as they become thinner. Layer break off and blistering will occur during reflow if the moisture content of the PCB exceeds 0.2% (weight.) Store laminated PCBs in an ultra-low humidity dry box.

PCB (Glass-epoxy substrate)
  Sample: 6-layered laminated PCB
Dimensions: 50 x 100 x 1t (mm)
Measurement condition
Pretreatment: Baked for 24 hours at 125℃
Humidification: Steamed for 2 hours
Dehumidification: Stored in McDry box at 5% RH



PBGA carrier board
 
 
  Test Conditions

Pretreatment: 24-hour bake at +125℃


(1) Component stored in ambient environment(30 degrees C, 85%RH) for 25 hours.
(2) After process (1), the component is stored in McDry cabinet(5%RH) for 150 hours.
(3) Stored in McDry cabinet(5% RH) after baking.




Data on moisture absorption and dehumidification of chip LEDs

Experiment Data on moisture absorption and dehumidification of chip LEDs
 

Example: LED3025 (3.0mmx2.5mmxt1.3mm) floor life 168h Pretreatment: 48 hour-Baking Process at +60C tle (LED makers' baking guideline)


(1) Chip LED stored in ambient environment (30°C, 60% RH) for 168 hours.
(2) After 11 hours of storage in this environment, it was left for 13 hours in a dry box at <3% RH. This process was repeated 5 times from Monday to Friday and left for 61 hours in a dry box at <3% RH.
(3) After baking, the LED chip was stored in a dry cabinet capable of maintaining 3%RH.

(This is a similar condition with an LED chip that is stored in a dry cabinet right after opening a moisture barrier bag.)