In semiconductor manufacturing, IC packaging is crucial for protecting chips and ensuring their performance and reliability. It involves encapsulating chips with specialized materials and processes to form complete integrated circuit components, shielding them from environmental factors like moisture, dust, and chemicals while providing electrical connections and heat dissipation paths. The quality of IC packaging directly impacts the chip's lifespan and dependability.
I. Roles of IC Packaging Baking
1.Moisture and Volatile Removal: Chips may absorb water and other volatiles during manufacturing, storage, and transport. These impurities can cause bubbling and welding defects during high - temperature soldering, affecting the circuit board's stability and longevity. Baking effectively eliminates these substances, reducing welding risks.
2.Improved Soldering Quality: Baking activates the active ingredients in solder paste, enhancing solder wetting and ensuring a smoother soldering process. It also preheats components, reducing thermal shock and stress during soldering, thereby improving soldering reliability.
3.Oxidation Prevention: Oxides on chip surfaces and pads can reduce metal activity and impair soldering. Baking minimizes oxidation on component and pad surfaces, ensuring good metal contact during soldering.
4.Cleaning and Decontamination: High - temperature baking removes oils, dust, and other contaminants from components and PCBs, lowering the risk of poor soldering.
5.Performance Enhancement: Baking relieves internal chip stresses, reducing microcrack and defect formation. This improves the chip's conductivity and durability. For some MOS devices, baking also boosts carrier mobility and lifetime.
II. IC Packaging Baking Process
1.Preheating: Chips are heated to a preset temperature in a preheating furnace to prepare for sintering, reducing the risk of defects like bubbles and cracks during this process.
2.Sintering: High - temperature sintering promotes material crystallization and bonding within the chip, forming the desired structure. Sintering conditions (temperature, time, atmosphere) significantly affect the chip's structure and properties.
3.Cooling: After sintering, chips are removed from the furnace and cooled to room temperature.
4.Cleaning: Chips are cleaned in deionized water to remove residues and contaminants, ensuring a clean surface.
During baking, parameters like temperature, time, and atmosphere must be strictly controlled. Pre - baking, chips undergo ultrasonic cleaning and vacuum drying. Post - baking, chips should be promptly removed and surface oxides eliminated to maintain normal electrical performance.
III. Applications of IC Packaging Baking
1.Consumer Electronics: In devices like smartphones, tablets, and laptops, baking removes chip moisture and volatiles, improves soldering quality, and prevents oxidation, ensuring product stability and lifespan.
2.Automotive Electronics: With growing automotive intelligence and electrification, chips in automotive electronic systems require high reliability. Baking enhances chip durability and environmental resistance, ensuring proper system operation in diverse conditions.
3.Industrial Control: In industrial automation and smart manufacturing, control devices and sensors need high - reliability chips. Baking boosts chip performance and reliability, meeting the stringent demands of industrial environments.
4.Aerospace: Aerospace electronics demand extremely high reliability. Baking removes chip impurities and stresses, enhancing radiation and high - temperature resistance, and ensuring reliable system operation in harsh conditions.
IV. Common IC Packaging Ovens
1.Nitrogen - filled Oxidation - free Oven: Designed for semiconductor chip baking and encapsulation curing, it uses nitrogen to prevent chip oxidation and improve product quality.
2.Nitrogen - charged Precision Oven: By introducing nitrogen and controlling hot - air circulation, it provides uniform chip heating with precise temperature control and oxidation prevention, suitable for high - temperature - and atmosphere - sensitive applications.
3.Vacuum Oven: Ideal for removing internal chip gaps and moisture, vacuum baking lowers the boiling points of water and volatiles, facilitating their removal. The vacuum environment also prevents oxidation and contamination.
4.Programmable Oven: With accurate temperature and time programming, it automatically adjusts parameters based on preset curves, making it suitable for highly automated and intelligent baking processes.
IC packaging and baking processes are vital in semiconductor manufacturing, significantly impacting chip performance, reliability, and lifespan. IC packaging protects chips from external damage and provides electrical connections and heat dissipation, while baking further ensures packaging quality and chip stability. Baking enhances product performance by eliminating internal chip stresses, reducing defects, and improving conductivity and durability.
