Newly Developed LCP Film Fabricated by Solvent-Casting

Transcription

1 Newly Developed LP Film Fabricated by Solvent-asting Method Sumitomo hemical o., Ltd. IT-Related hemicals Research Laboratory ommercial aromatic liquid-crystalline polymers (hereafter designated as LP), are known to be unable to dissolve in any common organic solvents except for costly fluorinated reagents. Recently, Sumitomo hemical succeeded in the development of innovative LP solvent casting film from its varnish. The casting film exhibits not only low water absorption characteristics, low gas permeability, low dielectric loss at high frequency and high temperature tolerance originated in using LP as a base material, but also high tear strength because of less anisotropic property in comparison to extruded LP films. The LP film by this casting method has many advantages to be applied for the electro devices such as flexible print circuit board, embedded circuit board and so on.

2 Table 1 Physical Properties of Various Themoplastics LP (Type I) PI (Thermotropic) PEEK PES PPS SPS State lassification Melting Point ( ) Tg ( ) Moisture Absorption (%) Flammability UL94 Resistance of Hydrolysis Dielectric onstant 1GHz Dielectric Tangent 1GHz L % V Amorphous % V rystal % V Amorphous % V rystal % V rystal % HB

3 Table 2 Typical LP lassified into Heat-Resistant Group Type L Transition Temp. ( ) Solder Resistance ( ) Molecular Structure I 330 ~ 280 ~ II 280 ~ ~ 270 III ~ 240 ~ 190 H2H2 Fig. 1 LP Melt Injection Molding Solidify rystalline Polymer Schematic representation of injection molding process

4 T Die Extrusion Process F PFP TFP BTFMP H H H F F F F F F F F3 F3 F pentafluorophenol tetrafluorophenol 3,5-bistrifluorometylphenol Fig. 3 Standard solvents for LP Tubular Process ircular Die Fig. 2 LP film fabrication process

5 Type I Type II Fig. 4 H2 H2 Type III onceptual origin of molecular design of LP LP Solution Fig. 5 asting ver As ast Transparent Thermal Treatment rystallization Translucent Dry-up process of LP solvent -casting film Start 3 FDD 1. Scintillator Sample 2 2 Stop 1 22 Na TA Photo-Multiplier 3. onstant Fraction Differential Discriminator 4. Delay 5. Time to Amplitude onverter 6. Multi hannel Analyzer Fig. 6 PALS System 3 4

6 Digital τ 1 τ 2 τ Time (ns) Fig. 7 Typical lifetime spectrum of polymer material for PALS system o-ps Lifetime (ns) (a) Heating Tγ (140 ) Ts(200 ) T β(170 ) Tc(235 ) ooling (a) Positronium (Ps) Ps: Bound state of Positron and Electron similar to hydrogen Temperature ( ) ortho-ps para-ps 20 (b) Heating e + e e + e (b) Pick-off Annihilation ( : Spin Direction) o-ps Intensity (%) ooling Ts(200 ) Fig. 8 o-ps γ + Schematic illustration of positronium (a) and positronium reaction (b) γ 5 Fig Temperature ( ) The temperature dependencies of the ortho-positronium lifetime T3 (a) and intensity I3 (b) of the as-cast film over the high temperature range from 40 to 250 at the heating and cooling rate of 2.5 /h

7 DS mw temperature ( ) no heated sample Fig Temp ( ) DS thermogram of the as-cast film on the 1 st heating process at rate 10 /min. o-ps Lifetime (ns) temperature up temperature down [ ] Storage Modulus (MPa) Temperature ( ) Universal V3.0G TA Instruments Fig [ ] Tan Delta DMA data of the as-cast film on the 1 st heating process at rate 10 /min at frequency 10Hz [ ] Loss Modulus (MPa) o-ps Lifetime (ns) o-ps Lifetime (ns) o-ps Lifetime (ns) Fig. 12 annealed at 200 (30min) annealed at 250 (30min) annealed at 300 (10hrs) temperature up temperature down temperature up temperature down temperature up temperature down The temperature dependencies of the ortho-positronium lifetime T3 of the as-cast film over the high temperature range from 40 to 250 at the heating and cooling rate of 2.5 /h

8 Table 3 Moisture Absorption Property LP Solvent asting Film Polyimide Film 85 / 85%RH 0.1% 1.2% 168Hr Extruded Film No.2 Solvent-asting Film (Annealed at 250 ) No Dielectric onstant PI (25 /45%RH) LP Solvent asting Film (23 /65%RH) TD/MD Ratio : TD : Transverse Direction MD : Machine Direction Fig. 13 Perfect Isotropic Film From Macroscopic View rientation haracteristics measured by Microwave rientationmeter Slit Dielectric Tangent Frequency (Hz) PI (25 /45%RH) LP Solvent asting Film (23 /65%RH) Solvent-asting Tubular Process Tear Propagation Resistance (mn) Fig. 14 Tear property of LP films Fig Frequency (Hz) Dielectric property of LP solvent-casting film

9 Table 4 Solder Resistance sec Melting Point Tg Thermal onductivity Thermal Properties of LP Solvent asting Film LP Solvent asting Film K 300~ mW/K Polyimide Film K > mW/K Table 5 Mechanical Properties of LP Solvent asting Film Tensile Strength (MPa) Tensile Modulus (GPa) Elongation at Break (%) Holding Endurance R=0.38 LP Solvent asting Film Polyimide Film Fig. 16 ur Newly Developed LP solvent-casting film

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