| Summary: | 碩士 === 國立虎尾科技大學 === 光電與材料科技研究所 === 100 === Abstract
This study focused on the chip bonding in the electronic assembling process and self-designed a shear stress measurement system to measure the bonding force between LED chip and substrate, which utilized the linear movement principle to drive the platform by an air pump. We placed a substrate attached with a chip on the platform and adjusted the cylinder head of the thrust meter to the chip front. The air inlet control switch opened and activated the air pump to push forward the lever in order to push the chip on the platform toward the cylinder head. At the moment the chip being pushed away from the substrate, we could obtain the shear stress value for the chip to peel off the substrate by the thrust meter indicator. Thus, in the flip-chip package bonding process, we used the self-developed shear stress measurement system to test the selected silver paste solidification, aluminum-germanium-tin eurectic bonding and tin paste solidification.
The chip size used in the experiment is 1x1mm, while the substrate size is 2x2mm and made of glass. The substrate surface was cleaned using solvent and deionized water and then we placed a small amount of silver paste in the center before placing the LED chip on it. A slight pressure was applied to bond the chip and the substrate with the silver paste. Several samples were made and moved to the oven for solidification according to different temperature and time conditions. Regarding the aluminum-germanium-tin eurectic bonding, we firstly electroplated a thin aluminum-germanium-tin film on both the chip and the substrate, which were then bonded using heat-bonding. The experiment was proceeded in different proportions of aluminum-germanium-tin and temperature to segregate different sample sets. Regarding the tin paste solidification, we bonded the chip with the substrate using heat-bonding and created different samples under the condition of fixed temperature but different times.
The samples derived from the above three bonding procedures were measured the shear stress by the shear stress measurement system. All numeral data is analyzed and compared with the microscope-observed result for the reference of packaging process and equipment deficiency improvement.
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