Yuseong gu, South Korea
Yuseong gu, South Korea

Time filter

Source Type

Choi K.-S.,IT Materials and Components Laboratory | Lee H.,IT Materials and Components Laboratory | Bae H.-C.,IT Materials and Components Laboratory | Eom Y.-S.,IT Materials and Components Laboratory | And 4 more authors.
Proceedings - Electronic Components and Technology Conference | Year: 2015

The material designs of the Si interposers are optimized for a 3D RF module. The high resistivity Si wafers are used for the Si interposer fabrication: 1,000 ω·cm ∼ 10,000 ω·cm. To reduce the capacitance and mechanical stress between Cufilled TSV and Si substrate, a polyimide insulation layer is applied as a TSV liner. We designs several types of the transmission line structures and measures their electrical properties. For the 3D interconnection between the Si interposers, fluxing underfill material is developed and used as a pre-applied underfill for the thermocompression bonding process. With these optimizations of materials design of the Si interposers, the microstrip line shows the electrical loss of 0.065 dB/mm at 10 GHz, and the insertion loss of the vertical transition is 0.4 dB at 10 GHz. © 2015 IEEE.


Choi K.-S.,IT Materials and Components Laboratory | Bae H.-E.,IT Materials and Components Laboratory | Bae H.-C.,IT Materials and Components Laboratory | Eom Y.-S.,IT Materials and Components Laboratory
ETRI Journal | Year: 2013

A novel bumping process using solder bump maker is developed for the maskless low-volume solder on pad (SoP) technology of fine-pitch flip chip bonding. The process includes two main steps: one is the aggregation of powdered solder on the metal pads on a substrate via an increase in temperature, and the other is the reflow of the deposited powder to form a low-volume SoP. Since the surface tension that exists when the solder is below its melting point is the major driving force of the solder deposit, only a small quantity of powdered solder adjacent to the pads can join the aggregation process to obtain a uniform, low-volume SoP array on the substrate, regardless of the pad configurations. Through this process, an SoP array on an organic substrate with a pitch of 130 μm is successfully formed. © 2013 ETRI.


Choi K.-S.,IT Materials and Components Laboratory | Lee H.,IT Materials and Components Laboratory | Bae H.-C.,IT Materials and Components Laboratory | Eom Y.-S.,IT Materials and Components Laboratory
Proceedings - Electronic Components and Technology Conference | Year: 2014

Traditionally, ACF (Anisotropic Conductive Adhesive) technology has been used for CoG (Chip-on-Glass) and FoG (Flex-on-Glass) interconnections in display packaging area. The electrical contacts of ACF technology are based on the mechanical contacts between the electrodes on substrates and conductive particles in ACF. As pitches of these interconnections tend to get finer than 30 μm and bonding temperature needs to be decreased because of warpage concerns during the bonding process, a novel interconnection technology for the advanced display systems is necessary. In this paper, a maskless screen printing technology is proposed to form and bond 20 μm-pitch, 52InSn solder interconnections for advanced display systems. InSn solder is selected to decrease the bonding temperature because its melting point is 118 °C. A novel material, called as solder bump maker (SBM) is developed to have InSn solder powder in SBM used for InSn bumping process. The polymer matrix and deoxidizing agent in SBM are carefully designed to make InSn solder powder in SBM wet on Cu or Au electrodes on a substrate during the bumping process. Since InSn solder powder resides only on electrodes on a substrate with temperature variations because of the surface tensions between the solder powder and metal electrodes, a maskless screen printing process can be adopted for the InSn, fine-pitch bumping process. Using a maskless screen printing process with SBM, 20 μm-pitch, InSn solder interconnections on a glass substrate are successfully formed. We, also, developed a no-flow underfill material, name as fluxing underfill, for a bonding material of InSn interconnections. It plays roles of flux and underfill at the same time during the bonding process. The bonding process for 20 μm-pitch, InSn solder interconnections is successfully achieved using fluxing underfill. Its peak temperature of the bonding process is 130 °C. © 2014 IEEE.

Loading IT Materials and Components Laboratory collaborators
Loading IT Materials and Components Laboratory collaborators