What is the purpose and effects of substrate prebaking?
Organic substrates, such as BT laminates and polyimides, tend to absorb moisture. Absorbed moisture can volatilize into the adhesive bond line during cure and cause voiding and ultimately decrease reliability performance. To reduce moisture absorption, prebaking of organic substrates is generally recommended, typically 2 to 4 hours at ~100°C (70°C to 125°C) prior to die attach. The substrate should be used within 4 to 6 hours after baking.
