Properties of room temperature bonded and UV cured temporary bonding adhesive for ultra-thin wafer's handling

With the development of advanced packaging towards more complex heterogeneous integration, larger package carrier, thinner chip and smaller package size, the new temporary bonding material and technology is required, such as lower bonding temperature, higher heat resistance, lower warpage and less/no cleaning solvent. Herein, a novel temporary bonding and de-bonding (TBDB) material has been developed and the properties of room temperature bonded and ultraviolet (UV) cured temporary bonding adhesive for ultra-thin wafer's handling is introduced. The curing process with UV light could be completed within 30 seconds which successfully improves the production efficiency and reduces energy consumption. Besides, as the bonding material is liquid, it is easy to flow without any residual stress during the bonding process. Then, low TTV and warpage of the bonding pair has also been observed, the results of ultrasonic scanning microscope shows there is no failure can be found between the interfaces of the bonding pair. The UV curing characteristic was investigated by photo-DSC and the heat resistance was investigated by TGA. It shows the 5% weight loss temperature of the material is more than 320 °C. At last, after de-bonded, the cured bonding material on the device wafer can be easily removed by adhesive tape without any other cleaning process proved by energy dispersive X-ray spectroscopy (EDS).