Microelectronics Low-temperature Fast Packaging Materials Research

Package is an essential process in the production of electronic devices, the package structures should support the chips and protect chips from environment, and it shouldn't affect the electrical performance. Liquid Crystal Display(LCD) is used widely because of its lower cost and better display effect, one of the materials used in the package of LCD is Anisotropic Conductive Film (ACF), but the use of ACF is limited because of its shortage, mainly the high work temperature and the difficulty of preparation. Some new technologies were developed recently for the package of LCD, these technologies use Nonconductive Films(NCF) instead of ACF, the NCF can be cured at lower temperature(160℃) and can be cured fast(several seconds). This technology can reduce the energy consumption and increase the efficiency, so the cost of production can be reduced.This article searched proper epoxy/hardener system for fast technologies first. Several common amines were employed as hardeners, because these hardeners are usually used as fast cure hardeners. The thermo analysis results from DSC and DTG showed that these hardeners can't finish the reaction at given time. Polymercaptan and m-xylylene diamine are effective hardeners at low temperature, they were employed as hardeners in follow-up study. We studied three systems in this article, they were epoxy 332 and polymercaptan (capcure-3800), epoxy 332 and polymercaptan 804, resorcinol diglycidyl ether and m-xylylene diamine, these systems showed good responsivity, the DSC measurements were employed to get the apparent activation energy through non-isothermal and isothermal mode, they were 38.5KJ/mol,38.4 KJ/mol and 62.7 KJ/mol for these three systems, the calculation showed all these three systems can react fast under fast technology conditions.DMA, TMA and DSC were used to characterize the cured resin, the cured epoxy 332 and polymercaptan (capcure-3800) system showed a glass transition temperature at 17.6℃(DSC), the storage modulus was 150MPa(DMA), the coefficients of thermal expansion was 207.8×10-6/℃. The cured epoxy 332 and polymercaptan 804 system showed a glass transition temperature at 47.2℃(DSC), the storage modulus was 500MPa(DMA), the coefficients of thermal expansion was 185.4×10-6/℃. The cured resorcinol diglycidyl ether and m-xylylene diamine showed a glass transition temperature at 74.5℃(DSC), the storage modulus was 2600MPa, the coefficients of thermal expansion corresponding to the glassy and rubbery state are 47.42×10-6/℃ and 175.6×10-6/℃.After the evaluation of common hardeners and epoxies, polymercaptan and epoxy with high activity can be used in fast manufacturing technology. Since the epoxies cured by polymercaptan have lower Tg, which caused higher CTE and lower modulus, we think, polymercaptan with better structure should be explored, such as polymercaptan with more functional groups and heat resistance, so that the cured resin can have proper mechanical property and CTE.