Measurement technique of shrinkage ratio and stress value of epoxy resin

Continuous measurement of shrinkage rate of thermosetting resin

Several electronic components mounted on semiconductor packages are used for communication devices such as mobile phones and laptop computers. In these semiconductor packages, an epoxy resin, which is a thermosetting resin, is used to seal the integrated circuit (IC) chip. Filling and curing the epoxy resin between the IC chip and the printed circuit board plays an important role in securing the strength and reliability of the electronic components.


Epoxy resins are generally accompanied by changes such as crosslinking density and volumetric shrinkage due to chemical reaction during the process of curing from a viscous fluid, and occurrence of residual stress and strain inside the material after curing. These changes may cause defects such as strength reduction and deformation of the semiconductor package, therefore, it is important to characterize the mechanism of thermal stress and deformation behavior generated in the curing process. Widely used curing process of various functional adhesives involves hybrid products combining UV curing and thermal curing.


It is not an exaggeration to say that all industries such as electricity, devices, automobiles, building construction benefits from coating film formation, such as the mentioned curing processes various functional adhesives. In order to maintain international competitiveness and continue to supply high quality products, it is necessary to reduce yield, stabilize production efficiency, and lower product cost.


In line with this, it is necessary to accurately establish the shrinkage rate, shrinkage stress and change over time of resin coating the thin film. Conventional methods use viscoelasticity measuring device to measure the shrinkage ratio from the volumetric change before and after shrinkage of the resin (i.e., underwater displacement method described in JIS K 7112, etc.). There has never been a method to simply and substantially measure a trace amount of highly functional resin continuously. A device called Custron (Cure Shrinkage and Stress Analysis System) is a device that can continuously measure the curing shrinkage rate and stress of a resin in a trace amount.


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