Thermal diffusivity of aromatic polyimide thin films by temperature wave analysis

Abstract

Thermal diffusivity of alkali and silver halide crystals as a function of temperature J. Appl. Phys. 109, 033516 (2011); 10.1063/1.3544444 Thermal conductivity/diffusivity of Nd 3 + doped Gd V O 4 , Y V O 4 , Lu V O 4 , and Y 3 Al 5 O 12 by temperature wave analysisThe heat transport properties of aromatic polyimide thin films have become more important in the use for the electric insulation in the microelectronic devices with highly integrated circuits. The various kinds of measuring methods have been applied to obtain the anisotropic thermal conductivity and thermal diffusivity of thin films, however, if the specimens are soft and transparent, the conventional methodology requires highly advanced technology in preparing the specimens for the measurement and the results obtained vary widely. The purpose of this study is to apply the temperature wave analysis ͑TWA͒ method to measure the thermal diffusivity of thin films and spin-coated layers of aromatic polyimide in the thickness direction at various temperatures. The TWA is an absolute method to determine the thermal diffusivity by using the phase shift of temperature wave. We have performed measurements on the five different chemical structures of aromatic polyimide, including polyimide isoindoloquinazolinedione ͑PIQ͒, pyromellitic dianhydride and 4 , 4Ј-oxydianiline ͑PMDA/ODA͒, 3,3Ј ,4,4Ј,-biphenyltetracarboxylic dianhydride and p-phenylenediamine ͑BPDA/PPDA͒, 3,3Ј ,4,4Ј-biphenyltetracarboxylic dianhydride and 4,4Ј-oxydianiline ͑BPDA/ODA͒, and 3 , 3Ј ,4,4Ј-benzophenonetetracarboxylic dianhydride and 3,3Ј-diaminobenzophenone ͑BTDA/DAB͒. As a result, thermal diffusivity of thin films in a thickness range from 0.1 to 300 m at a temperature range from 10 to 570 K is obtained. The thickness dependence of thermal diffusivity of spin-coated layers of PIQ exhibits a good coincidence with the tendency of molecular anisotropy observed by attenuated total reflection Fourier transform infrared spectroscopy. In the low temperature below 20 K the amorphous PMDA/ ODA film exhibits a substantial increase, which can be understood by considering the phonon mean free path of amorphous systems as first noted by Kittel for inorganic glasses. The glass transition of BTDA/DAB is observed as a rapid decrease of thermal diffusivity. The results indicate the availability of TWA for the present needs of accurate but simple measuring technique to determine the thermal diffusivity of thin polymer films, which is strongly dependent on the chemical and anisotropic structures.

Effects of Orientational Relaxation of Polymer Chains Induced by Isotropic Particles on the Enhanced Thermal Conductivity of AlN-filled Polyimide Films

“…The TC  of sBPOD, on the other hand, is relatively high because a larger proportion of PI chains contributes to heat propagation in the out-of-plane direction. It is confirmed by the fact that reported in-plane TD (TD // ) of sBPPD and sBPOD are approximately 5-fold and 2-fold of their TD  , respectively [9].…”

“…It has been reported that the major factors contributing to TC of PIs are (1) the chemical structure of the repeating unit, (2) the orientation of chains, and (3) the degree of molecular packing [8][9][10]. In dielectric materials, heat is transferred via quantized lattice vibrations called 'phonons'.…”

Enhanced Thermal Conductivity in Polyimide/Silver Particle Composite Films Based on Spontaneous Formation of Thermal Conductive Paths

“…Out-of-plane thermal diffusivity (D  ) of pristine and composite films was measured using a temperature wave analyzer (ai-phase mobile 1u) at room temperature [6,7]. The applied voltage was 1.8 V, and the film thicknesses were 25−100 μm.…”

Enhancement of Thermal Diffusivity in Phase-Separated Bismaleimide/Poly(ether imide) Composite Films Containing Needle-Shaped ZnO Particles

“…The thermal expansion behaviors of PI film BPADA-SDA, and copolymers) were evaluated by Shimadzu TMA-60 (Shimadzu, K a fixed load of 1.5 g and a heating rate of 10 °C/min. Differential scanning c Shimadzu DSC-60, Shimadzu, Kyoto, Japan) was used to monitor the cross-linkin The temperature was raised from room temperature to 300 °C at a heating rate thermal diffusivities along the out-of-plane direction (D ⏊ ) of PI and BMI/PI com measured at room temperature using an AC temperature wave analyzer (ai-Ph phase Co. Ltd., Tokyo, Japan) [11,12]. Each film was measured ten times at differ value of pristine BPADA-MPD film is lower than that of pristine TF film because of the flexible ether and bent m-phenylene linkages in its main chain, which coincides well with the analysis proposed in our previous study [22].…”

“…The mal diffusivities along the out-of-plane direction (D ⏊ ) of PI and BMI/PI composite films were sured at room temperature using an AC temperature wave analyzer (ai-Phase mobile 1u, aise Co. Ltd., Tokyo, Japan) [11,12]. Each film was measured ten times at different locations, and ) of PI and BMI/PI composite films were measured at room temperature using an AC temperature wave analyzer (ai-Phase mobile 1u, ai-phase Co. Ltd., Tokyo, Japan) [11,12]. Each film was measured ten times at different locations, and the average value was adopted as the experimental value.…”