Development of Bonding Process Technology for MLCB Electric Components

Lithium-ion batteries are currently the most widely used battery technology. However, due to the use of liquid electrolytes, they have some safety issues such as the risk of ignition and explosion. To overcome these limitations of conventional lithium-ion batteries, multi-layer ceramic batteries (MLCBs) have been emerged as a promising next-generation alternative. Since MLCBs are miniaturized batteries, they are gaining attention as replacements for lithium-ion batteries in various industries, including wearable devices and medical equipment. However, in order to apply MLCBs to various electronic devices and modules, they must be packaged accordingly. Therefore, this study focuses on the bonding process technology for mounting MLCB electric components onto substrates. Using a surface mount technology (SMT) process, bonding was conducted under various process conditions, including solder paste-types, solder quantities, and bonding methods. After the bonding process, characteristics of the bonded joints, such as voids and fillet formation, were analyzed to compare the joint properties under different conditions. From results in this study, the L3-2 condition, which was performed at 160 W for 5 seconds with laser soldering, was analyzed a relatively low void fraction and the formation of appropriate fillet.