Moisture-sensitive devices (MSDs) are electronic devices that are sensitive to the presence of moisture and can be easily damaged by them. These devices include but are not limited to, integrated circuits, semiconductors, and other electronic components. The proper management of MSDs is crucial for ensuring they function correctly and have a long lifespan. This article will discuss the best practices for managing moisture-sensitive devices better.
The IPC (International Printed Circuit Association) is a trade association that sets standards for the electronics industry, including standards for moisture-sensitive devices (MSDs). The IPC standard for MSDs is IPC/JEDEC J-STD-033B.1, titled “Handling, Packing, Shipping, and Use of Moisture/Reflow Sensitive Surface Mount Devices.”
Understanding Moisture Sensitivity
Before discussing the management of moisture-sensitive devices, it is crucial to understand the concept of moisture sensitivity. Moisture sensitivity is the measure of a device’s susceptibility to damage caused by exposure to moisture. This susceptibility can be measured by the device’s moisture sensitivity level (MSL). MSL is a standardized rating system that ranges from MSL 1 to MSL 6, with MSL 1 being the least sensitive and MSL 6 being the most sensitive.
Proper storage is one of the most critical aspects of managing moisture-sensitive devices. MSDs should be stored in a dry, controlled environment free from moisture. The ideal storage conditions for MSDs are a temperature of 25 degrees Celsius (77 degrees Fahrenheit) or lower and a relative humidity of 60% or lower. If these conditions cannot be met, it is essential to use desiccants or other moisture-absorbing materials to keep the moisture levels low.
It is also important to note that MSDs should not be stored for long periods. The longer the storage period, the greater the risk of moisture damage. Therefore, it is recommended to use MSDs as soon as possible after receiving them.
The standard defines floor life as the time a moisture-sensitive device can be exposed to the atmosphere after it has been removed from its original packaging and before it must be soldered or processed.
Shelf life is twhena moisture-sensitive device can be stored before it must be soldered or processed.
Proper packaging and handling of moisture-sensitive devices are also crucial for longevity. MSDs should be packaged in moisture-barrier bags (MBBs) specifically designed to protect the devices from moisture. These bags have a moisture vapour transmission rate (MVTR) of less than 0.1 g/m2 per day, providing an effective barrier against moisture.
When handling MSDs, it is essential to avoid exposing them to moisture. This means avoiding contact with liquids, not handling the devices with damp hands, and not handling the devices in humid environments. It is also essential to avoid exposing MSDs to extreme temperatures, as this can also cause damage.
MSDs should be inspected for any moisture damage, such as discolouration, corrosion, or swelling. The device should be considered damaged and not used if any of these signs are present.
Testing of MSDs is also crucial for ensuring that they are functioning correctly. This includes testing for proper voltage, current, and resistance. If any of these tests reveal an issue, the device should be considered damaged and should not be used.
Managing moisture-sensitive devices in a better way requires a combination of proper storage, packaging, and handling, as well as inspection and testing. By following these best practices, you can ensure that your MSDs function correctly and have a long lifespan. Remember, moisture sensitivity measures a device’s susceptibility to damage caused by exposure to moisture, and proper management is crucial for avoiding damage.