February_EDFA_Digital

edfas.org 51 ELECTRONIC DEVICE FAILURE ANALYSIS | VOLUME 21 NO. 1 compared to two-component glob topsystems. Thisblack, heat curable compound has a flowable paste consistency well suited for glob top, chip coating, and bonding appli- cations. EP17HTND-CCM meets NASA low outgassing specifications and is serviceable from -80 to +600°F [-62 to +316°C]. This adhesive forms high strength bonds to a wide variety of similar/dissimilar substrates such as metals, ceramics, plastics, composites, and various circuit board materials. EP17HTND-CCM is thermally conductive and electri- cally nonconductive even upon exposure to hostile envi- ronmental conditions. It has a high volume resistivity of more than 1015 ohm-cm at 75°F and over 1012 ohm-cm at 400°F. Its thermal conductivity is 9-10 BTU•in/ft 2 •hr•°F [1.4423 W/(m•K)] at 75°F. Also noteworthy is the ability to resist many chemicals including acids, bases, salts, fuels, oils, and many solvents. Formulated for various electronic applications, EP17HTND-CCM cures readily in 1-2 hours at 350°F with a relatively low exotherm upon curing. It can be dis- pensed from a syringe, either manually or with an auto- matic dispenser. Master Bond EP17HTND-CCM is avail- able for use in common syringe sizes ranging from 10 to 30 cc. For storage, simple refrigeration at 40 ° to 45°F is recommended. For more information, visit masterbond.com. FILM ADDRESSES ELECTRICAL SHORTS Ultra-finepitchassemblies are increasingly requiredby high-resolution display electronic devices. In this context, display driver interconnection technology is an important challenge for advancing display electronics. Now, with a novel thermoplastic anchoring polymer layer structure, scientists have moved one step closer to achieving ultra-fine resolution for displays. By effectively preventing the movement of conductive particles, this innovative structure can considerably enhance the ultra- fine pitch interconnection. It is believed that this film can be applied to a wide range of large OLED panels, mobile devices, and VR equipment, among other applications. Researchers led by Professor Kyung-Wook Paik in the KAIST Department of Materials in Korea have developed a novel anchoring polymer layer structure that can effec- tively prevent themovement of conductive particles at the time of the bonding process of the anisotropic conductive films (ACFs). Thenovel structurewill considerably enhance the capture rate of conductive particles, thereby tackling electrical short issues encountered in the ultra-fine pitch assembly process. Master Bond’s low outgassing UV cured black epoxy paste. The research team at KAIST was led by Prof. Kyung-Wook Paik (right). At the time of the ultra-fine pitch bonding process, the conductive particles of traditional ACFs tend to agglomer- ate between bumps and lead to electrical short circuits. Therefore, higher tensile strength anchoring polymer layers integrated with conductive particles were added to the ACFs to resolve the electrical short issue induced by the free movement of conductive particles. This was done to effectively suppress themovement of conductive particles. Nylonwas usedby the researchers tocreateaone-layer film with incorporated and well distributed conductive particles. It was observed that the nylon’s higher tensile strength fully prevented conductive particle movement, increasing the conductive particle capture rate from just 33% in conventional ACFs to 90%. During chip-on-glass assembly, the nylon films did not display any short circuit issues. Further, during the ultra- fine pitch applications, they also exhibited high reliability and excellent electrical conductivity. A prototype of the filmhas been completed by Paik’s teamwith support from a domestic company, H&S High-Tech, and the Innopolis Foundation. For more information, visit www.kaist.ac.kr.