Work Function Controlled Printed Metal Alloy Pattern Prepared by Using Pressure Annealing Technique
- PDF / 885,418 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 118 Downloads / 149 Views
Work Function Controlled Printed Metal Alloy Pattern Prepared by Using Pressure Annealing Technique Manabu Yoshida, Kouji Suemori, Sei Uemura, Satoshi Hoshino, Noriyuki Takada, Takehito Kodzasa and Toshihide Kamata Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 3058565 Japan ABSTRACT We have developed the pressure annealing technique for fabricating low work function metal pattern on plastic substrate. In general, the difficulty to print conductive low work function metal patterns is caused by the insulating metal oxide layer covering on metal particles included in metal paste. The pressure annealing technique can destruct the metal oxide layer and can form conductive layer on printed metal pattern. Further, we have confirmed that a binary solid solution is easily formed on metal patterns including two kinds of metal particles by using the pressure annealing technique. Changing the composition ratio of the binary metal paste led to the work function control of the pressure-annealed metal patterns. Formation of the binary solid solution was confirmed by using XRD spectra, and work function values were measured by using photoelectron emission spectra. In the case of the binary metal paste of Cu and Zn, we have succeeded in controlling work function from 3.8 eV to 5.0 eV. Since the Cu-Zn paste is composed of relatively low price metals, this would be applicable to large-scale flexible electronic devices. INTRODUCTION In recent years, flexible wiring is the key technology to downsize information appliances and mobile devices. In the wiring technology, the most important issue is process-cost, through-put, quality of products (electrical properties, among others), for fabricating the devices on flexible plastic substrates. In particular, in order to fabricate flexible antennas for wireless communications (e.g. Radio Frequency Identification (RFID)), many issues, which are improvement of electrical properties and efficiency of their production processes, have still remained.[1,2,3] Further, in the global electronics market, lead-free process has become indispensable. With a shift to the lead-free process, we have to look for proper materials and to re-design circuits for adjusting to these materials. The most promising method to solve these issues is the printing process. Employing the printing process will save wasteful production energies and will produce a large amount of electrical circuits effectively. Conventional photolithography process and chemical etching process are a subtractive process while the printing process is an additive process. Therefore, only minimum materials are required in order to produce electrical circuits by using the printing process, in other words, this process is quite resource-saving.[4] However, hightemperature annealing is necessary to decrease resistance of printed conductive patterns by using conductive inks, because metal contacts have to be formed among metal fillers in printed patterns. It i
Data Loading...
