Investigations were carried out on etching behaviour of an engineering polymer Kapton-H (4-4'-oxydiphenylene pyromellitimide). Kapton-H samples were subjected to etching in 4N NaOH at 400 °C and at 500 °C temperatures in pristine as well as irradiated form. Irradiation of pristine Kapton-H specimen was done using 75 MeV/nucleon O+ ion beam of fluence 1.875 x a trillion ions/cm2. The specimen was exposed to etchant for a period of 150 minutes. The effect of etching was observed as half layer thickness removed. Thickness measurements were made at etching cycles of 15 minutes each. It was observed that temperature and the irradiation has their effect on etching behaviour of Kapton-H. Study showed that the temperature results in the increased average bulk etch rate. The average bulk etch rate was also observed to increase with the irradiation of the sample.
Table of Contents
CHAPTER 1 INTRODUCTION
1.1 KAPTON-H
1.1.1 Synthesis
1.1.2 Important properties
1.2 ETCHING MECHANISM OF KAPTON-H
1.3 LITERATURE REVIEW
CHAPTER 2 METHODOLOGY
CHAPTER 3 RESULTS AND DISCUSSION
3.1 RESULTS AND DISCUSSION
Research Objectives and Key Topics
The primary objective of this research is to investigate the surface chemical etching behavior of the engineering polymer Kapton-H, specifically analyzing the impact of temperature and ion-beam irradiation on the bulk etch rate.
- Surface chemical etching characteristics of pristine versus irradiated polyimide.
- Effects of etching temperature (40°C and 50°C) on Kapton-H.
- Influence of 75 MeV/nucleon O+ ion beam irradiation on etching behavior.
- Analysis of material removal mechanisms and etch induction variations.
- Evaluation of average bulk etch rates for industrial and micro-filter applications.
Excerpt from the Book
1.1 Kapton-H
Polyimides constitute an important class of materials because of their many desirable characteristics viz. excellent mechanical properties, low dielectric constant , low relative permittivity, high breakdown voltage, low dielectric loss over a wide range of frequency, good polarization, good processing capability, wear resistance, radiation resistance, inertness to solvents, good adhesion properties, low thermal expansion, good hydrolytic stability and long term stability. Because of these traits, polyimides have found applications in a host of technologies as inter-metal dielectric, high temperature adhesive, photoresist etc. the applications of polyimides range from aerospace to microelectronics besides optoelectronics and composites.
The synthesis of an aromatic polyimide was first reported in 1908 but it was not until the late 1950s that DuPont developed a successful commercial route to high molecular weight polyimide. DuPont introduced the first commercial polyimide in the late 1960s.since then the field has blossomed and there has been a high tempo of R & D activity in synthesizing an array of polyimides with requisite properties for a given application and in devising new methods of characterization.
The oxydianiline (ODA) - pyromellitic dianhydride (PMDA) polyimide, with a commercial name Kapton-H, attracted the attention of researchers over other polyimides because ether structure of ODA would enhance possibilities for a moulding resin. Soon it was discovered that the ODA based polymers had real potential for moulding, superior toughness and hydrolytic stability as compared to other polyimide which were MPD (m-phenylene diamine) and PPD (p-phenylene diamine) based. Therefore Kapton-H polyimide, which is superior to other polyimides, has been used in the present investigations. Poly(4-4’ oxydiphenylene pyromellitimide), chemical name of Kapton-H, is available in thin film form in standard thickness of 7.5, 12.5 ,25 ,50 ,75 and 125 m.
Summary of Chapters
CHAPTER 1 INTRODUCTION: This chapter provides an overview of Kapton-H, its chemical properties, synthesis, and established etching mechanisms, while reviewing existing literature on track detectors.
CHAPTER 2 METHODOLOGY: This section details the experimental procedures, including sample preparation, irradiation with O+ ion beams, and the specific conditions used for NaOH etching.
CHAPTER 3 RESULTS AND DISCUSSION: This chapter presents the experimental findings regarding the variation in half-layer thickness removed and discusses how irradiation and temperature influence the average bulk etch rates of Kapton-H.
Keywords
Kapton-H, Polyimide, Chemical etching, Bulk etch rate, NaOH, Ion irradiation, Polymer, Surface degradation, Micro-pores, Thermal stability, Etching mechanism, Material science, Thin films, Hydrolysis, Etch induction
Frequently Asked Questions
What is the primary subject of this publication?
This work explores the surface chemical etching behavior of the engineering polymer Kapton-H in both pristine and high-energy ion-irradiated forms using NaOH as an etchant.
What are the core thematic areas discussed in the book?
The core themes include polymer chemistry, the impact of high-energy heavy ion radiation on polymer structures, and the kinetics of chemical etching in electronics and micro-filter development.
What is the central research question?
The study aims to determine how temperature changes and O+ ion irradiation modify the surface etching rates of Kapton-H, contributing to more precise material processing.
Which scientific methods were applied during the study?
The researchers utilized thin-film etching, ion-beam irradiation via a PELLETRON facility, and thickness measurements taken via a dial gauge to calculate bulk etch rates.
What topics are covered in the main section of the book?
The main section covers the chemical structure of polyimides, the step-by-step hydrolytic etching mechanism with NaOH, and the quantitative analysis of how temperature and irradiation increase etch rates.
Which keywords best characterize this research?
Key terms include Kapton-H, Chemical Etching, Bulk Etch Rate, NaOH, Ion Irradiation, and Micro-filter fabrication.
How does the etchant temperature influence the etch rate?
The study concludes that the average bulk etch rate increases with higher temperatures, likely due to increased solubility of reaction products like carboxylate salts and bond cleavage.
How does ion irradiation affect the etching process of Kapton-H?
Irradiation generally enhances the bulk etch rate due to the breaking of chemical linkages; however, it also induces changes in crystallinity that can affect the reaction over time.
What role does the etching induction time play in this research?
The research notes that discrepancies in etch induction times can complicate sub-microscopic track event analysis, necessitating careful measurement of the etched thickness over time cycles.
What practical application is mentioned for this research?
The study is specifically relevant to the development of micro-pore nuclear track filters where precise material subtraction is required.
- Citar trabajo
- Deep Shikha (Autor), 2009, Chemical Etching Behaviour of a Polyimide, Múnich, GRIN Verlag, https://www.grin.com/document/307138
