18

Material Science and Technology of Japan, 59（2022）182～186

Dec. 2022

Regular Paper
Formation of Electroless Plating Film on Smooth Surface ofSyndiotactic Polystyrene Resin
Takehiro IWAMOTO1,2*, Tatsuki HIRANO2 and Mitsuhiro WATANABE 2
1Idemitsu Kosan Co., Ltd., 1-1, Anesakikaigan, Ichihara-City, Chiba, 299-0193, Japan
2Kanto Gakuin University, Materials & Surface Engineering Research Institute, 1162-2, Ogikubo, Odawara-City, Kanagawa, 250-0042, Japan
Received Aug. 24, 2022; accepted Oct. 4, 2022
Abstract
Syndiotactic Polystyrene (SPS) has excellent electrical properties. So it has been strongly expected for SPS to apply
for high frequency circuits. We conducted to form the metallizing layer on smooth surface of the SPS substrate byusing the UV treatment and the electroless plating and examine the effects of crystallinity and containing SEBS forpeel strength. We also investigated the mechanism of the peel strength using FTIR analysis, XPS analysis, TEM
observation and EDS analysis. It was confirmed that the UV treatment and the plating process including the electroless
Cu-Ni plating in the specific conditions on the smooth surface of the SPS substrate that had low crystallinity andcontained SEBS formed the conductivity layer which indicated the practical peel strength. The fracture mode during
the peeling was observed the shift from an interfacial to a cohesive failure according to increaseing SEBS content. The
mixed metal-resin layer at the interface was observed, which would be considered to strengthen the peel strength. We
evaluated to utilize the electroless Cu plating process for the SPS substrate as well.
Keywords: Syndiotactic Polystyrene, SEBS, UV treatment, Electroless plating, Crystallinity, Peel strength1.

Introduction

chromic acid. However, the use of chromic acid has a highHigh speed and large-capacity data transmission is strongly

environmental impact, and surface roughening causes to increase

required due to rapidly increasing electronic devices forthe high-frequency transmission loss. Therefore, with respect totelecommunications, sensors, wireless LAN systems and so on,

the technology to form metallized a conductivity layer, UV

and the high frequency bands in GHz region is widely usedtreatment is a potential process to modify the substrate surface torecently. In such fields, the substrate materials are required

improve adhesion strength without the chemical etching [2-4]. On

excellent electrical properties, such as low dielectric constants andthe other hand, little has been done to examine the metallization

low dielectric dissipation factors (tanδ). Syndiotactic Polystyrene

for the SPS substrates using UV treatment. In this study, we(SPS) is one of the candidate material for the high-frequency

conducted to assess the UV treatment and the electroless plating

applications, exhibiting low dielectric constant and low

on the smooth surface of the SPS substrates, and examine thedissipation factor over wide frequency range [1]. SPS has not only

effects of the resin compositions and the crystalline conditions forexcellent electrical properties but also high heat-resisting

the peel strength.

properties and low water absorption. In general, it is difficult toachieve the practical adhesion between the substrate that consists

2.

of non-polar groups and the metallized conductivity layer made of

2.1 Sample preparationcopper. In that case, it is essential to roughen the surface of theExperimental method
Syndiotactic Polystyrene (SPS) with a weight average

substrate in order to obtain the efficient adhesion due to the anchor

moleculareffect. Chemical etching is generally used for the step using

ethylenebutylene-block-styren) triblock copolymer (SEBS) were

*Corresponding author: takehiro.iwamoto.7440@idemitsu.com(182)

weightof200,000

andpoly(styrene-block-