benedict san jose | Kyoto University (original) (raw)

Uploads

Papers by benedict san jose

Embedded and Fan‐Out Wafer and Panel Level Packaging Technologies for Advanced Application Spaces

We prepared a circularly polarized luminescence (CPL) switchable cell by placing together a therm... more We prepared a circularly polarized luminescence (CPL) switchable cell by placing together a thermotropic chiral nematic liquid crystal (N*-LC) cell together with a CPL emitting film from lyotropic chiral di-substituted polyacetylene. In this paper, we present the dynamic switching of CPL from the selective reflection of CPL in a thermotropic N*-LC phase. N*-LCs are excellent organic photonic crystals for the generation of CPL due to their ease of synthesis and external stimuli responsiveness.

We have synthesized and characterized various di-substituted liquid crystalline polyacetylene (di... more We have synthesized and characterized various di-substituted liquid crystalline polyacetylene (di-LCPA) derivatives with chirality, lyotropic liquid crystallinity and photoluminescence. Through the formation of a chiral nematic liquid crystal (N*-LC) phase, we were able to generate circularly polarized luminescence (CPL)on di-LCPA. The highly ordered N*-LC phase of di-LCPA made it possible to exhibit CPL with a high emission dissymmetry factor. The lyotropic LC properties of di-LCPA can be advantageous in the manufacture of electroluminescence (EL) devices since the polymer emissive layer (PEL) of the EL device can be fabricated at room temperature.

2021 IEEE 71st Electronic Components and Technology Conference (ECTC)

The semiconductor industry has entered a new era where monolithic integration cannot achieve the ... more The semiconductor industry has entered a new era where monolithic integration cannot achieve the economic gains of silicon scaling. The role of chiplets is crucial in this new era by enabling cost reduction through the heterogenous integration of various functions and wafer fab technology nodes. Deca's planar M-Series™ surface is ideal for building highly integrated fan-out SoC (System on Chip) structures. Scaling to 2mumathrmm2\mu \mathrm{m}2mumathrmm lines & spaces and multiple redistribution layers (RDL) provides powerful new possibilities for IC designers. Chiplets can now be fabricated using the optimum wafer fab technology node providing the best performance with the most desirable commercial terms. In combination with Adaptive Patterning™, design rules for M-Series provide large via contacts on fine pitch chip interconnects. The scaling of M-Series for chiplets will be presented in this paper. The 2nd generation of M-Series starts with 2mumathrmm2\mu \mathrm{m}2mumathrmm lines & spaces using laser direct imaging (LDI) with up to four layers of Cu RDL delivering die to die interconnect of >200 wires/mm/layer. This breakthrough in high-density routing is achieved on a simple molded chips-first, chips-up structure without the need for complicated bridge chips in substrates. We will also present a breakthrough in device interface density with 20mumathrmm20\mu \mathrm{m}20mumathrmm pitch full array bond pads made possible with Adaptive Patterning (AP). This paper details the M-Series multi-chiplet fan-out structure with four Cu routing layers, all layers include 2mumathrmm2\mu \mathrm{m}2mumathrmm lines & spaces fabricated using LDI and Adaptive Patterning. The M-Series fan-out structure readily supports through-mold Cu posts if a 3D package on package (3D PoP) structure is required.

We synthesized disubstituted liquid crystalline polyacetylene (diLCPA) derivatives bearing 4-nony... more We synthesized disubstituted liquid crystalline polyacetylene (diLCPA) derivatives bearing 4-nonyloxy phenyl groups with lyotropic and thermotropic LC behavior. The poly(diphenylacetylene) main chain structure of the diLCPAs and the chirality induced with either chiral moieties or chiral dopants allow the formation of a highly ordered lyotropic N*-LC phase. Circular dichroism (CD) spectra of the diLCPAs imply that one-handed intrachain helical structures are formed in solution, while interchain helical π-stacking between the polymer main chains are formed in cast film and in the N*-LC state. Absorption dissymmetry factors (g(abs)) in the N*-LC state show values on the order of 10(-1). The N*-LC state facilitates the formation of helically π-stacked structures with a high degree of helical ordering of the diLCPA and is indispensable for the generation of circularly polarized luminescence (CPL) with high emission dissymmetry factors (g(em)) on the order of 10(-1). To the best of our knowledge, this is the highest reported value of CPL achieved for aliphatic, conjugated polymers. As an alternative to the thermotropic N*-LC phase, we have found that the lyotropic N*-LC phase of diLCPA could be promising materials possessing CPL functionality for use in next-generation π-conjugated organic optoelectronic devices, displays, and sensors.

Advanced Functional Materials

NanoScience and Technology, 2014

Advanced Functional Materials, 2014

Angewandte Chemie (International ed. in English), Jan 26, 2014

The circularly polarized luminescence (CPL) of chiral disubstituted liquid-crystalline polyacetyl... more The circularly polarized luminescence (CPL) of chiral disubstituted liquid-crystalline polyacetylene (di-LCPA) can be dynamically switched and amplified from left- to right-handed CPL and vice versa through the selective transmission of CPL across a thermotropic chiral nematic liquid crystal (N*-LC) phase. By combining a chiral di-LCPA CPL-emitting film with an N*-LC cell and tuning the selective reflection band of the N*-LC phase to coincide with the CPL emission band, a CPL-switchable cell was constructed. The phase change induced by the thermotropic N*-LC cell by varying the temperature leads to a change in the selective transmission of CPL, which enables the dynamic switching and amplification of CPL. It is anticipated that CPL-switchable devices might find applications in switchable low-threshold lasers and optical memory devices.

Polymer Chemistry, Royal Chemical Society, Feb 6, 2013

Herein, we review the recent progress in advanced functionalities of liquid crystalline polyacety... more Herein, we review the recent progress in advanced functionalities of liquid crystalline polyacetylenes
(LCPAs). We focus on properties and functionalities that include (i) electrical anisotropy, (ii) linearly
polarised luminescence (LPL), and (iii) circularly polarised luminescence (CPL). In Section 2, monosubstituted
LCPAs are macroscopically aligned by magnetic force, which results in enhancement of the
electrical conductivity by two orders of magnitude. In Section 3, di-substituted LCPAs are
macroscopically aligned using a rubbing technique to exhibit LPL with notable dichroic ratios. In Section
4, lyotropic di-substituted LCPAs are induced with chiral moieties or chiral dopants, leading to the
formation of a N*-LC phase. The high degree of helical ordering in the N*-LC phase is indispensable for
the generation of CPL with a large value of the dissymmetry factor in emission (gem).

Journal of the American Chemical Society, Nov 14, 2012

"We synthesized disubstituted liquid crystalline polyacetylene (diLCPA) derivatives bearing 4-non... more "We synthesized disubstituted liquid crystalline polyacetylene (diLCPA) derivatives bearing 4-nonyloxy phenyl groups with lyotropic and thermotropic LC behavior. The poly(diphenylacetylene) main chain structure of the diLCPAs and the chirality induced with either chiral moieties or chiral dopants allow the formation of a highly ordered lyotropic N*-LC phase. Circular dichroism (CD) spectra of the diLCPAs imply that one-handed intrachain helical structures are formed in solution, while interchain helical π-stacking between the polymer main chains are formed in cast film and in the N*-LC state. Absorption dissymmetry factors (gabs) in the N*-LC state show values on the order of 10−1. The N*-LC state facilitates the formation of helically π-stacked structures with a high degree of helical ordering of the diLCPA and is indispensable for the generation of circularly polarized luminescence (CPL) with high emission dissymmetry factors (gem) on the order of 10−1. To the best of our knowledge, this is the highest reported value of CPL achieved for aliphatic, conjugated polymers. As an alternative to the thermotropic N*-LC phase, we have found that the lyotropic N*-LC phase of diLCPA could be promising materials possessing CPL functionality for use in next-generation π-conjugated organic optoelectronic devices, displays, and sensors."

Macromolecules, Jul 29, 2011

We synthesized disubstituted liquid crystalline polyacetylene (di-LCPA) derivatives by polymerizi... more We synthesized disubstituted liquid crystalline polyacetylene (di-LCPA) derivatives by polymerizing acetylene derivatives consisting of LC moieties either directly or indirectly attached to the main chain through flexible alkyl spacers. The di-LCPA derivatives show either enantiotropically thermotropic LC or lyotropic LC behavior. The origin of emission of substituted PAs, with respect to their substituents and structure, was elucidated. Depending on the substituents of the side chains, the polymers exhibit blue (470485 nm) and green (500-540 nm) photoluminescence (PL) in chloroform and in cast film. The di-LCPA derivatives weremacroscopically aligned using rubbing technique, and the aligned structures of the polymers are characterized in terms of main chain and side chain type alignments through XRD measurements. The emission color and
alignment direction toward an external force in the di-LCPA derivatives are crucially determined by both the linkage forms (direct or indirect attachment) between the main chain and side chains and the molecular moieties (alkyl or aromatic moiety) of the side chains. The macroscopically aligned films of the polymers exhibit linearly polarized photoluminescence (LPL) with notable dichroic ratios. We fabricate multilayer electroluminescence (EL) devices using the polymers as the emissive polymer layer that emit 480 nm light with promising EL properties. We emphasize that although substituted PA derivatives are usually nonluminescent, the di-LCPA derivatives emit intense fluorescence with notable linear dichroism, and they could be promising for optically anisotropic luminescent materials.