Advanced Machinery for Electronics Manufacturers | SEIKA Machinery, Inc.

McDry Ultra-Low Humidity Storage Cabinets

Moisture Absorption and Dehumidification Data

Data on moisture absorption and dehumidification of an IC package
IC Package Moisture Absorption and Dehumidification Data Pretreatment: 24-hour baking at +125°C 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-033B.1)
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)
Example of low-humidity storage of laminated PCB

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
PBGA carrier board PBGA

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.

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