When Does a BGA Chip Need to Be Baked?

Ball Grid Array (BGA) chips are high-performance integrated circuits widely used in electronic devices. These chips feature a unique three-dimensional structure, with numerous spherical solder balls arranged in a specific grid pattern on the bottom of the package. The working principle of BGA chips is based on the surface tension of the solder balls. During the soldering process, the solder balls melt, and their surface tension keeps the package in the correct position on the circuit board until the solder cools and solidifies. This process achieves automatic alignment, simplifying the soldering process and improving the reliability and success rate of soldering. BGA packaging offers several advantages, such as high interconnect density and high integration. It can provide more pins within the same package area, significantly enhancing the functionality of the chip. BGA chips are widely used in high-performance electronic devices like computers, mobile phones, and servers, providing key support for their high-performance operation.

When BGA Chips Need Baking

• When Moisture-Affected: BGA chips can easily absorb moisture from the air during storage or transportation. When moisture is present inside the chip, it can vaporize and expand during high-temperature processes like reflow soldering. This can cause the chip to swell, deform, and even experience "popcorn" effects, leading to various internal defects that affect performance and lifespan.

• Beyond the Controlled Time Limit: If BGA components exceed their controlled time limit, even if they are still sealed, they may have absorbed moisture over time due to prolonged exposure to the environment. Baking is necessary to remove this moisture.

• When Vacuum Packaging Fails or After Opening: If the vacuum packaging of BGA chips fails, or if the humidity indicator card shows a humidity level beyond the specified value after opening, it indicates that the chip has likely absorbed a certain amount of moisture. Baking is required to remove this moisture.

• Bulk and Non-Vacuum Packaged: For BGA chips that are bulk packaged without vacuum protection, they are more susceptible to moisture absorption due to direct contact with the external environment. These chips typically need to be baked before use to remove any moisture.

The Purpose of Baking

• Moisture Removal: Heating the chip causes the internal moisture to evaporate and escape, reducing the moisture content. This prevents issues during subsequent high-temperature processes, such as soldering, where moisture can lead to poor solder joint quality.

• Enhanced Soldering Quality: A dry chip allows for better solder joint formation during soldering. The solder can more effectively wet the pads and chip leads, reducing defects like cold solder joints and improving the electrical and mechanical strength of the soldering.

• Increased Chip Reliability: Removing moisture slows down the rate of internal chemical reactions in the chip, such as corrosion between metallization lines and leakage. This reduces the risk of chip failure and enhances long-term stability and reliability.

• Stress Reduction: During baking, the moisture inside the chip evaporates, reducing the internal stress caused by vaporization. The appropriate temperature can also allow the internal material molecules of the chip to rearrange, releasing stress and preventing cracking, thereby improving mechanical properties.

Application Fields

• Electronic Manufacturing Industry: In the production of electronic products such as computers, mobile phones, tablets, and servers, BGA chips, as core components, usually need to be baked before soldering to ensure soldering quality and improve product yield and reliability.

• Semiconductor Packaging and Testing Industry: During the chip packaging process, BGA chips need to be baked before and after packaging to prevent moisture damage. Baking during storage and transportation after packaging can also prevent moisture absorption.

• Electronic Repair Industry:When repairing circuit boards with BGA chips, such as replacing chips or repairing faulty boards, the circuit board and chips need to be baked first to remove moisture before soldering. This prevents moisture-related soldering issues or chip damage during repair.

• Aerospace, Automotive Electronics, and Other High-Reliability Fields: In these fields, where the reliability of electronic products is extremely important, BGA chips must undergo strict baking treatment before use to ensure normal operation in harsh environments and prevent chip failures that could cause safety accidents.

Suitable Ovens for Baking

• Hot Air Circulation Oven: This type of oven uses a hot air circulation system to maintain uniform temperature inside, making it suitable for baking most BGA chips. Its advantages include low cost, easy operation, and simple maintenance. However, it may not be ideal for chips that require extremely precise temperature control and uniformity.

• Vacuum oven: Baking in a vacuum environment lowers the boiling point of moisture, making it easier to evaporate while preventing oxidation. The baking effect is good, but the equipment is costly, and the operation is complex, with high environmental requirements.

• Nitrogen-filled oven:By filling the oven with nitrogen, an inert gas environment is created, which prevents chip oxidation and facilitates moisture removal. This type of oven is suitable for baking chips that are sensitive to oxidation, but the cost of using nitrogen is high, and additional supply equipment is needed.

In the electronics industry, the baking process is an essential step to ensure the performance and reliability of BGA chips. By removing moisture from the chips through baking, various defects caused by moisture vaporization during soldering can be effectively prevented. This enhances the mechanical and electrical properties of the chips. Baking is indispensable in fields such as electronic manufacturing, semiconductor packaging and testing, electronic repair, and high-reliability areas like aerospace and automotive electronics. In practice, the appropriate oven should be selected based on different situations.