Properties Investigation on Chip-on-Film (COF) Thermosonic Bonding Using Anisotropic Conductive Films (ACFs)
نویسندگان
چکیده
Chip-on-film (COF) technology has been developed for liquid crystal displays (LCD) due to its high yield capability in fine pitch products. In this study, a new COF thermosonic (TS) bonding process using anisotropic conductive adhesive and ultrasonic vibrations will be introduced. Si chips with 16 cylindrical Cu bumps (¤100μm) and polyimide (PI) film substrate with a thickness of 70 μm were prepared. For the bonding condition, the bonding temperature and ultrasonic time were varied from 413 to 453K and from 0.5 to 1 s, respectively. Also, thermocompression (TC) bonding was conducted with a bonding temperature of 453K and bonding time of 8 s to compare it to the bonding characteristics of TS bonding. The shear strength and electrical resistance of COF assemblies were measured to verify the feasibility of COF TS bonding using ACFs. The cross-sectional inspection and fracture surface analysis of COF joints were also conducted using field-emission scanning electron microscopy (FE-SEM). As a result, the mechanical and electrical properties of the COF assembly were improved by increasing the bonding temperature and ultrasonic dwell time. It was also determined that ultrasonic energy has a significant influence in improving the mechanical and electrical properties of the TS COF assembly. [doi:10.2320/matertrans.MB201210]
منابع مشابه
Effects of bonding temperature on the properties and reliabilities of anisotropic conductive films (ACFs) for flip chip on organic substrate application
The effects of bonding temperatures on the composite properties and reliability performances of anisotropic conductive films (ACFs) for flip chip on organic substrates assemblies were studied. As the bonding temperature decreased, the composite properties of ACF, such as water absorption, glass transition temperature (Tg), elastic modulus (E 0) and coefficient of thermal expansion (a), were imp...
متن کاملFlexible Chip-on-Flex (COF) and embedded Chip-in-Flex (CIF) packages by applying wafer level package (WLP) technology using anisotropic conductive films (ACFs)
Due to increasing demand for higher performance, greater flexibility, smaller size, and lighter weight in electronic devices, extensive studies on flexible electronic packages have been carried out. However, there has been little research on flexible packages by wafer level package (WLP) technology using anisotropic conductive films (ACFs) and flex substrates, an innovative packaging technology...
متن کاملStudies on various chip-on-film (COF) packages using ultra fine pitch two-metal layer flexible printed circuits (two-metal layer FPCs)
0026-2714/$ see front matter 2011 Elsevier Ltd. A doi:10.1016/j.microrel.2011.12.020 ⇑ Corresponding author. Tel.: +82 42 350 3375; fax E-mail address: [email protected] (K.-W. Paik). Various fine pitch chip-on-film (COF) packages assembled by (1) anisotropic conductive film (ACF), (2) nonconductive film (NCF), and (3) AuSn metallurgical bonding methods using fine pitch flexible printed circui...
متن کاملFlip Chip Joining on FR-4 Substrate Using ACFs
Anisotropic conductive adhesive films (ACF) were used to attach daisy-chained test chips on FR4 substrates. The feasibility of ACF joining was studied since it is a potential method for fine-pitch bare-die attachment on low-cost organic substrates. Four types of test chips were used, each having a pitch of different size. One of the chips had an area array structure, one had a staggered structu...
متن کاملDynamic strength of anisotropic conductive joints in flip chip on glass and flip chip on flex packages
The work presented in this paper focuses on the behavior of anisotropically conductive film (ACF) joint under the dynamic loading of flip chip on glass (COG) and flip chip on flexible (COF) substrate packages. Impact tests were performed to investigate the key factors that affect the adhesion strength. Scanning electron microscopy (SEM) was used to evaluate the fractography characteristics of t...
متن کامل