Microstructuring of polymer films by inkjet etching

Abstract

The inkjet printing (IJP) technique is generally used as tool for positioning small quantities of a liquid material on a target substrate. An interesting application of IJP is inkjet etching that consists of the deposition of drops of solvent or solvent mixtures onto a soluble polymer layer. This technique allows one to structure the polymer film and to change the shape, from concave to convex, by varying the mixing ratio of the solvents. In this work, the structuring of some polymeric layers (polyimide and polystyrene) by solvents [N-methyl-2-pyrrolidone (NMP) and toluene (TOL)] and a solvent mixture (TOL-NMP) at different mixing ratios were studied, and the effect of the printing parameters on the microstructural profile was investigated. Some applications in optoelectronic devices are described.

The effect of droplet ejection frequency on the dimensions of inkjet-etched micro-via holes in poly4(-vinyl phenol) thin films

“…However, it can be inferred that a low frequency was employed, which may explain these contrasting observations. Impacts of other parameters on the dimensions and appearances of the generated pattern in different polymer/solvent or particles/solvent systems have also been investigated [16][17][18][19][20][21][22][23]. Nonetheless, few studies focus on the interrelationship between droplet ejection frequency, the number of drops and the resulting via hole dimensions, which is significant in studying this inkjet-etching via hole formation technique and its feasibility for micro-via production in printed electronics applications.…”

A mechanism of the penetration limit for producing holes in poly(4-vinyl phenol) films by inkjet etching

“…The occurrence of the coffee ring effect is generally unfavourable for printing of functional materials, such as for conductive tracks, as the inhomogeneous material deposition inhibits the conductivity of the structure [11]. Interestingly however, several investigations of deliberately utilizing the coffee ring effect as a means of generating structural patterns in various polymers have also been reported [12][13][14][15][16]. These polymer patterning investigations can be potentially useful in some structural or functional applications.…”

The impact of substrate temperature on the size and aspect ratio of inkjet-dissolved via holes in thin poly(4-vinyl phenol) dielectric layers

“…Inkjet, as a digitally driven and non-contact printing method, has been used for various electronics manufacturing applications, such as transistor and organic light-emitting diode (OLED) fabrication, [1][2][3][4][5] polymer structural patterning, [6][7][8][9][10][11][12] microlenses, [13][14][15] and other fields over the last decade as printed electronics has attracted great interest both in academia and in industrial application. One recently emerged investigation is the use of inkjet printing as a subtractive etching process rather than an additive manufacturing technique, which is what inkjet printing is usually utilized for.…”