Inorganic-Organic Hybrid Polymers as Photo-Patternable Dielectrics for Multilayer Microwave Circuits

Abstract

Inorganic-organic hybrid polymers (ORMOCE®s) combine very good optical and dielectricproperties in the frequency range up to 1 MHz (εr = 3.1 and tanδ = 0.004, both at 1 MHz). Thisis particularly promising for electro-optical (e/o) applications. Multi-layer microwave circuits forhigh frequency applications up to 100 GHz demand extraordinary material properties such as alow permittivity εr < 3 and a dielectric loss tanδ of about 10-3. For low-cost processing, direct UVpatterning would be particularly advantageous. Additionally, the material should be thermallystable at least up to temperatures around 300°C.We have developed a series of novel ORMOCE® materials for high frequency applications.Using these ORMOCE®s, thick film coatings (up to 150 m) can be produced and directlypatterned by UV lithography with sufficiently high resolution. The synthesis has been carried outusing styrene-substituted organosilanes and silanediols as precursors reacted by simplified solgel-processing in combination with organic cross-linking of polymerizable organic functions.The materials have been characterized at high frequencies up to 40 GHz, exhibiting verypromising dielectric properties of εr = 2.5 and tanδ = 0.0035.

Inorganic–Organic Hybrid Polymers for Information Technology: from Planar Technology to 3D Nanostructures

“…This flexibility enables one to tailor their properties to the application. [3,4] Specially synthesized ORMOCER s are used in optical connections or waveguides, micro-optics, and electro-optical applications. [5] The refractive index can be tuned over a wide range by mixing various resins.…”

“…They are stable up to about 355 C in an oxygen atmosphere and 415 C in nitrogen. [4] 2. Material Properties ORMOCER coatings are usually prepared by hydrolysis/ polycondensation reactions (sol-gel processing) from alkoxysilane precursors, followed by an organic cross-linking of the inorganic-oxidic units by organically polymerizable groups.…”

Impact of photoinitiators on the photopolymerization and the optical properties of inorganic–organic hybrid polymers

“…This flexibility enables one to tailor their properties as recommended by the application. [3][4][5][6] Upon sol-gel processing of alkoxysilane precursors, inorganic-oxidic nanoscale structural units ͑0.7-1 nm͒ 7 are formed which are organically modified. As organic polymerizable unit, typically acryl or styryl functionalities are used which account for the negative resist behavior of the hybrid resins.…”

“…Although the materials have been established already for a variety of applications, [1][2][3][4][5][6] there has been little effort so far to correlate their processing, i.e., their photochemical or thermal treatment, to their physical properties such as, e.g., optical properties. In this letter, the influence of the UV initiator concentration on the degree of conversion of the methacrylic side chain ͑henceforth referred to as degree of polymeriza-tion͒ within a hybrid polymer model system is followed by Fourier-transform infrared spectroscopy ͑FTIR͒ spectroscopy.…”