2019 · 11 citations · 1 references
EngineeringIntegrated CircuitsEnergy-efficient Induction HeatingInterconnect (Integrated Circuits)Wafer Scale ProcessingInnovative Packaging TechniquesHomogeneous HeatingAdvanced Packaging (Semiconductors)Thermal AnalysisThermodynamicsCopper-tin Slid BondingElectronic PackagingMaterials ScienceMaterials EngineeringElectrical EngineeringChip AttachmentHeat TransferMicroelectronicsRapid Induction HeatingAdvanced PackagingChip-scale PackageHigh Temperature MaterialsMicrofabricationApplied PhysicsMems Wafer-level PackagingThermal Engineering
Innovative packaging techniques are essential for the development of new microsystems. To integrate different materials into one package, the thermal stress on the devices has to be minimized. This paper presents a method for selective and energy-efficient induction heating of Cu-Sn layers to support and enhance the bonding process at wafer-level. Technological challenges include the inductor design for homogeneous heating, the use of high-frequency electromagnetic fields up to frequencies of f = 2.0 MHz, and the integration of the induction equipment into an industrial wafer bonder. Infrared thermography imaging was used to characterize the selective heat generation with very fast heating rates of ΔT > 150 K/s. Consequently, the wafer bonding process could be performed in t <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">bond</sub> = 120.0 s by applying a low pressure of p = 2.2 MPa.
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