How to Perform Chip Baking Treatment

In the electronics manufacturing industry, chips, as core components, have performance and reliability that directly impact the quality and lifespan of the entire electronic device. During manufacturing, transportation, and storage, chips are inevitably exposed to environmental humidity, leading to the absorption of a certain amount of moisture internally. If not effectively removed, this moisture can rapidly vaporize during subsequent high-temperature processes (such as reflow soldering or SMT soldering), generating internal pressure that may compromise the chip's structural integrity and electrical performance.

The chip baking process employs a scientific approach to effectively remove internal moisture and volatile substances, ensuring the chip's stability and reliability in subsequent high-temperature stages. This treatment significantly reduces the risk of chip failure due to moisture absorption, extends the chip's service life, and enhances the overall performance of the electronic device.

I.Chip Baking Standards

Chip baking standards are primarily based on the Moisture Sensitivity Level (MSL) and specific storage and usage environments. Generally, for materials with an MSL of Level 2 or higher, baking is required under the following conditions: if the humidity indicator card reads above 20% RH when the package is opened, if the exposure time of the unpackaged chip exceeds the specified limit, if the chip is not stored in a dry cabinet with less than 20% RH as required, or if more than one year has passed since the sealing date.

The specific baking time and temperature depend on the chip's MSL and material properties. For example, for certain materials, baking can be performed in a low-temperature oven at 40℃ ± 5℃ with less than 5% RH for 192 hours, or in an oven at 125℃ ± 5℃ for 24 hours. IC baking time is typically 3 hours, followed by a 2-hour temperature recovery period.

II.Chip Baking Process

1. Pre-Baking Preparation:​​

• Open the component's outer packaging and check the reading on the humidity indicator card.
• Verify that the storage environment meets requirements, typically around 25℃ with relative humidity less than 40%.
• Record information such as the date, time, part number, and location of the chips for subsequent tracking and management.

2. Parameter Control:

• Select the appropriate baking temperature and time based on the chip's MSL and material characteristics.
• During baking, maintain the oven humidity below 5% RH to ensure effective removal of internal moisture.

3. Equipment Requirements:

• Ensure the oven's temperature and humidity control systems are calibrated and capable of accurately maintaining the set parameters.
• Perform regular maintenance and inspections on the oven to ensure proper operation.

4. Operational Considerations:

• Strictly observe Electrostatic Discharge (ESD) precautions when placing chips into or removing them from the oven. Personnel should wear ESD footwear or heel straps and a grounded wrist strap.
• Check whether trays, tubes, reel tapes, and other packaging materials can withstand the baking temperature to avoid damage caused by heat-sensitive packaging.
• Moisture-sensitive components are typically limited to a maximum of two baking cycles. After baking, they should be used as soon as possible to prevent re-absorption of moisture.

5.Post-Baking Handling:​​

• After baking is complete, allow the oven to cool sufficiently before removing the chips. Chips should be removed within one hour after the oven temperature reaches room temperature to prevent thermal shock.
• Upon removal, record the date and time, and verify the chip's appearance and performance against the recorded information to ensure the baking process caused no damage.

III.Applicable Oven Types

1. Nitrogen Purged Ovens:These ovens introduce nitrogen to reduce oxygen levels, minimizing oxidation reactions. They are suitable for oxidation-sensitive chips, effectively protecting the chip surface.

2. High-temperature ovens:Suitable for shorter baking cycles (e.g., 24 hours) at higher temperatures (e.g., 125℃). These ovens often feature rapid heating and cooling capabilities to improve efficiency.

3. Clean oxygen-free ovens:Ideal for chips requiring an extremely controlled baking environment, such as precision electronic components and semiconductor chips. By purging with an inert gas (like nitrogen), they create a high-temperature, low-oxygen, and particle-free environment, effectively preventing contamination and oxidation during baking.

4. Vacuum ovens:Used in specific cases, such as when removing internal organic contaminants or enhancing baking efficiency. These ovens reduce internal pressure through vacuum pumping, accelerating moisture evaporation and organic compound decomposition.

Chip baking is a critical step in the electronics manufacturing process. Strict adherence to baking standards and procedures effectively enhances chip reliability and performance, ensuring stability and consistency in subsequent production stages. Selecting the appropriate oven type and paying attention to operational details are essential for achieving efficient and safe baking. In practice, baking conditions should be adjusted flexibly according to the specific chip requirements and application scenarios to achieve optimal results.