Measurement methods for curing properties of resin considering process condition and effects on package

Today, the semiconductor device is used in all kinds of electronic equipment that we are usually using. And, it can be said that most of the function is realized by the integrated circuit in the silicon chip. The silicon chip is very delicate. Therefore, it has to be packaged by resin material to protect from the external environment and to let the heat of the chip go outside efficiently. Recently, space-saving (being smaller, thinner and lighter) is strongly required. Reducing the thickness has been requested for all parts in the package such as silicon chip, substrate and package layer. And the packaging structure is shifted from BGA to CSP, WL-CSP. As a result, the weight of silicon layer in the whole package decreases, and the influence of the deformation of the resin have been growing. In addition, it becomes easy to warp because the flexural rigidity became small as the semiconductor part thinned. Then the influence of the warp caused by the curing deformation of the resin began to appear remarkably further more. A lot of researches have been conducted for the resin behavior after the curing process before now, but very few investigations were focused on the mechanical behavior during the curing process. Several measurement methods for the curing shrinkage of the resin in the condition that constraining for the resin is almost free, have been developed. However the resin property given by the conventional measuring methods doesn´t coincide with the behavior of the actual packaging. The authors have found that the shrinkage behavior of the packaging resin is greatly affected by the constraint condition, especially during the curing process. The purposes of this study are to propose the measuring method of property of the resin considering the process condition and to verify the results from experimental and analytical models. Finally, it is shown that the behavior of packaging process can be accurately estimated by using proposed method. As the research metho- , a three point bending vehicle was used to measure the Young´s modulus of the curing resin and an optical digital image correlation method was used for the measurement of shrinkage deformation. The concrete method is shown below. First, the change of the Young´s modulus of aluminum board is measured while heating it along the temperature profile. Next, after the resin is spread on the aluminum board, the change of the Young´s modulus of the aluminum board and resin is measured while heating it along the temperature profile. Then the one that the change of the Young´s modulus of the aluminum was subtracted from the change of the Young´s modulus of the aluminum and the resin, is assumed to be a change in the Young´s Modulus under curing of the resin. Next, the thermal deformation of the resin to which filler is added in the vicinity of the glass metastasis point after curing, can be forecasted and evaluated. Moreover, it is thought that the warp of the semiconductor parts when encapsulation and mounting are done at the same time can be forecast, and be evaluated by using thermal deformation and the mechanical properties after and while curing. In addition, the forecast becomes possible as for the thermal deformation of various resins to which filler is added. And, it is thought the warp of the semiconductor part is widely forecast, and it is appreciable. As a result, it turned out that the amount of the curing deformation affected greatly by the mechanical constraint condition for the resin. Therefore, it has been understood to have to use the curing property with considering the real packaging conditions. The validity of the measured curing property was verified, and the influence on the package was evaluated. This study can contribute to diversification and improved quality of the semiconductor device.