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Microelectronics & JEDEC Standards

microchip on a printed circuit board

Microchips, also known as integrated circuits or ICs, are tiny, self-contained electronic devices consisting of millions to billions of miniaturized transistors, resistors, and capacitors etched onto semiconductor material, usually silicon. They make everything from smartphones and computers, to household appliances like washing machines and refrigerators, possible. Cutting-edge microprocessors, memory chips, and microcontrollers are driving advances in Artificial Intelligence (AI), robotics, and data processing, allowing for increasingly complex computing tasks.

But for all of the powerful technologies unlocked by integrated circuits, they have a vulnerability which necessitates careful handling to keep them viable. Microchips and other surface-mount devices (SMDs) are sensitive to moisture primarily because their polymer-based encapsulation materials (such as epoxy molding compounds) are hygroscopic and can absorb water from the atmosphere. Even relatively low levels of ambient humidity, when exposure time exceeds specified limits, can lead to moisture absorption in SMDs that may result in catastrophic failure.

The primary danger to be avoided is moisture-induced damage from affected SMDs during the high heat solder reflow process wherein SMDs are affixed to printed circuit boards (PCBs). When an SMD has absorbed moisture from the air, the rapid temperature spike (up to 260°C) causes that trapped water to instantly turn into superheated steam, which causes the package to crack or burst. This is commonly known as the “Popcorn Effect.” Related hazards include internal delamination, bond wire damage, and solderability issues.

These issues are preventable thanks to the industry standards set forth by JEDEC, a consortium of semiconductor and microelectronics manufacturers, in conjunction with IPC. Specifically, IPC/JEDEC J-STD-020 classifies surface-mount devices by Moisture Sensitivity Level (MSL) and IPC/JEDEC J-STD-033 clarifies the materials and procedures required for proper handling, packing, shipping, and use of moisture-sensitive SMDs.

Procedural Considerations by MSL

The level of packaging and handling rigor depends on the Moisture Sensitivity Level (MSL) assigned to each type of component per J-STD-020.

  • MSL 1: No dry-pack required; not sensitive to moisture-induced failure.
  • MSL 2 to 5a: Must be dry-packed with desiccant and humidity indicator card. Each level has a specific "floor life" (allowable exposure time to ambient air) ranging from one year (MSL 2) to 24 hours (MSL 5a) at ≤30°C/60% RH.
  • MSL 6: Highly sensitive; dry-packing is required but often insufficient, and parts must be baked immediately before use.

Most semiconductor products are rated MSL 3 or higher.

chart of MSL levels

Dry Packaging Components

Flexible Packaging: Moisture Barrier Bags (MBB)

Flexible packaging for moisture-sensitive devices (MSDs) must meet specific technical requirements detailed in IPC/JEDEC J-STD-033 to ensure a minimum shelf life of 12 months.

  • Material Standards: Bags must comply with MIL-PRF-81705, Type I for flexibility, ESD protection, and puncture resistance.
  • Water Vapor Transmission Rate (WVTR): The bag's permeability must be extremely low, specifically ≤0.0310 g/m² (or 0.002 g/100 in²) over 24 hours at 40°C.
  • Sealing: Bags must be heat-sealed. Vacuum sealing is common but requires a visual inspection to ensure the bag's integrity is maintained without punctures.

Desiccant Requirements

Desiccants are placed inside the MBB to absorb residual moisture and any moisture that permeates the bag over time.

  • Quality Standard: Desiccants must meet or exceed MIL-D-3464, Type II (non-dusting) requirements.
  • Sizing: The amount of desiccant must be specifically sized to the bag's surface area and the intended shelf life.
  • "Active" Status: Only fresh or newly baked desiccant (renewed to original specs) is considered "active" and suitable for dry-packing.

Monitoring with Humidity Indicator Cards (HIC)

Every dry-pack must include a Humidity Indicator Card to alert the end user if the internal environment has been compromised.

  • Indicator Spots: Modern cards (Type 1 or 2) typically feature spots for 5%, 10%, and 60% relative humidity (RH).
  • Critical Thresholds: The amount of desiccant must be specifically sized to the bag's surface area and the intended shelf life.
    • If the 10% spot turns pink (or the indicated color for "wet"), the components may require baking before use.
    • If the 60% spot indicates exposure, the HIC must be discarded because its accuracy for lower readings is no longer guaranteed.
chart of MSL levels

Reel of SMDs on a strip, vacuum sealed in MBB