A photoinitiator‐free photosensitive polyimide with low dielectric constant

Abstract

A series of photoinitiator-free photosensitive polyimides (PSPIs) with lower dielectric constants have been synthesized by reaction of fluorine aromatic diamine, 2,2 0 -bis(3-amino-4-hydroxyphenyl)hexafluoropropane diamine (AHHFP) with 3,3 0 ,4,4 0 -benzophenonetetracarboxylic dianhydride (BTDA) and a mixture of various mole ratios of 3,3 0 ,4,4 0 -benzophenonetetracarboxylic dianhydride (BTDA) and 4,4 0 -(hexafluoroisopropylidene)diphthalic anhydride (6FDA) by using solution polycondensation reaction at room temperature and further imidization at 180 C. These aromatic polyimides were further acrylated via a reaction with acryloyl chlroride in the presence of triethyl amine to produce negative photoinitiator-free PSPIs. All the photoinitiator-free photosensitive polyimides were characterized by FTIR and NMR while their morphologhy was evaluated by X-ray diffractions study. These newly synthesized PSPIs were evaluated to determine their electrical, thermal, and photolithographic properties. The PSPI (AHHFP-BTDA-6FDA [1 : 0.5 : 0.5]) with high mole ratio of 6FDA showed lower dielectric constants of 2.420 at 1 kHz and 2.170 at 1 MHz in capacitance and optical methods, respectively. Further, the acrylated AHHFP-BTDA showed the highest photosensitivity than other PSPIs.

Synthesis and properties of the novel polyimides containing cyano and biphenyl moieties

“…30,31 Both H-PIs and CN-PIs have good performance in terms of the dielectric loss (<0.01 at 1 MHz). As for the volume resistivity, H-PIs and CN-PIs are both more than 10 10 Ω·cm at 1000 Hz and more than 10 6 Ω·cm at 10 6 Hz, which fully demonstrated their good insulation performance.…”

“…Some functional moieties, such as trifluoromethyl (–CF 3 ), sulfonic acid (–SO 3 H), hydroxyl (–OH), and ethynyl groups, were introduced into the PI backbones to enhance the performance of gas permeability, dielectric property, transparency, proton conducting ability, and thermo-mechanical integrity. 3,10 –13…”

Structure‐Property Relationship of Polyimide Fibers with High Tensile Strength and Low Dielectric Constant by Introducing Benzimidazole and Trifluoromethyl Units

“…[21] However, most PI fibers available on the market possess the relatively high dielectric constant of 3.5. [22] Since fluorine atoms exhibit strong electronegativity and low electric polarity, it has been recognized as an efficient approach to produce PI fibers possessing a low dielectric constant by introducing trifluoromethyl groups into the polymer chains. [23][24][25] Zhang and co-workers introduced 2,2′-bis-(trifluoromethyl)-4,4′-diaminobiphenyl (TFMB), a novel fluorinated monomer, to a BPDA/4,4′-oxydianiline backbone to prepare aerogel with an excellently comprehensive performance.…”

“…[ 22 ] Since fluorine atoms exhibit strong electronegativity and low electric polarity, it has been recognized as an efficient approach to produce PI fibers possessing a low dielectric constant by introducing trifluoromethyl groups into the polymer chains. [ 23–25 ] Zhang and co‐workers introduced 2,2′‐bis‐(trifluoromethyl)‐4,4′‐diaminobiphenyl (TFMB), a novel fluorinated monomer, to a BPDA/4,4′‐oxydianiline backbone to prepare aerogel with an excellently comprehensive performance. [ 26 ] The resulting polyimide aerogels displayed low dielectric constant and loss tangents in the range of 1.29–1.33 and 0.001–0.004, respectively.…”

Solvent‐resistant ultrafine nonwoven fibrous membranes by ultraviolet‐assisted electrospinning of organo‐soluble photosensitive polyimide resin

“…In addition, owing to the self-sensitivity of this PSPI, its shrinkage and weight loss were much reduced in the absence of extra photosensitizers, which made it perform as an appropriate candidate for ES. 37,38 The PSPI showed as a negative mechanism whose exposed area experienced photo induced crosslinking then became insoluble in organic solvents. [39][40][41] The synthesis of the PI resin and the morphology of the fibers were studied.…”