Fabrication of a stainless steel shadow mask using batch mode micro-EDM

Abstract

A metal shadow mask for organic thin-film transistors (OTFTs) has been fabricated by batch mode electro-discharge machining (EDM). Batch mode microelectro-discharge machining method was applied for productivity improvement. Negative electrode with multiple holes (3 9 3 or 4 9 4) was fabricated using a single tool electrode. With the negative electrode, 3 9 3 and 4 9 4 tool electrode arrays are EDMed; 6 9 6 and 16 9 16 square hole array masks were batch mode EDMed with the fabricated multi-electrodes arrays. With 4 9 4 electrode array, the productivity is improved to five times of that in the case using a single electrode. Source and drain electrodes of OTFTs were successfully patterned on a pentacene active layer through the mask, and the fabricated pentacene TFTs had good output characteristics.

Advancement in Ultrasonic Vibration and Magnetic Field Assisted Micro-Edm Process: An Overview

“…So, there is a provision of industrial applications of products, features fabricated by micro-EDM process. Promising applications are not only restricted to the machining of hard materials for micro moulds and cutting tools but also to the production of difficult to make structures such as fuel injection nozzles [14], spinneret holes for synthetic fibres, electronic and optical devices, micromechatronic actuator parts and micro tools for fabricating these devices [15,17]. Micro spherical styli for micro CMM's probing heads are fabricated by hybrid gluing and assembling process on micro EDM [18].…”

“…A batch mode fabrication process of stainless steel shadow mask with high aspect ratio and high resolution for OTFTs is developed. This stainless steel shadow mask could be used as a patterning method to fabricate pentacene TFTs [15]. Kerosene is used as dielectric for batch production of stainless steel mass micro holes.…”

Macro Scale Arrayed Structure Fabrication using Reverse EDM

“…Yi et al [8] fabricated the high aspect-ratio shadow mask for organic thin film transistors (OTFTs) on stainless steel and achieved impressive productivity improvement by using batch mode µ-EDM. Zeng et al [9] explored and assessed the ultrasonic vibration assisted µ-EDM as an alternative to LIGA for fabrication of microelectrode array (3x3) of diameter 30 μm and observed theimprovement in surface finish and productivity.…”

Flow Field Simulation of Ultrasonic Vibration Assisted EDM of Holes Array

“…Tong et al reported that micro-holes drilling were implemented for micro-holes array with high consistency accuracy by a tangential feed WEDG method [4]. Yi et al fabricated a metal shadow mask by batch mode electro-discharge machining, and improved the productivity to five times of that in the case of using a single tool electrode [5]. Wang et al proposes a threedimensional model of flow field with liquid, gas, and solid phases for machining gap in EDM to investigate the mechanisms of debris and bubble movement in the machining gap during consecutive-pulse discharge [6].…”