Improvement of thermoplasticity for s‐BPDA/PDA by copolymerization and blend with novel asymmetric BPDA‐based polyimides

Hasegawa, Masatoshi; Sensui, Nobuyuki; Shindo, Yoichi; Yokota, Rikio

doi:10.1002/(sici)1099-0488(19990901)37:17<2499::aid-polb21>3.3.co;2-7

Cited by 3 publications

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“…Film properties of PEsI systems derived from the TAHQ series with 'rigid' diamines are summarized in Table III. Our previous paper 19 reported that the PEsI film of TAHQ/PDA system exhibited no distinct glass transitions in the DMTA curves (Figure 2a) as often observed in rod-like backbone structures of PI systems (for example, PMDA/PDA 32 and s-BPDA/PDA systems 33,34 ). This is attributed to significantly restricted molecular motion (internal rotation) and a semi-crystalline morphology (a decreased amorphous fraction).…”

Section: Molecular Designmentioning

confidence: 93%

Poly(ester imide)s Possessing Low CTE and Low Water Absorption (II). Effect of Substituents

Hasegawa

Tsujimura

Koseki

et al. 2007

Polym J

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The film properties of a variety of poly(ester imide)s (PEsIs) were evaluated for development of a novel high temperature base film in flexible printed circuit (FPC) boards. In this work, three types of PEsI systems were systematically prepared from the following combinations of monomers: (1) ester-containing tetracarboxylic dianhydrides: hydroquinone bis(trimellitate anhydride) (TAHQ), methyl-substituted TAHQ (M-TAHQ), and methoxy-substituted TAHQ (MeO-TAHQ) with common diamines such as p-phenylenediamine (PDA), (2) common tetracarboxylic dianhydrides such as pyromellitic dianhydride (PMDA) with ester-containing diamines: 4-aminophenyl-4 0 -aminophenylbenzoate (APAB) and methyl-substituted APAB (ATAB), and (3) the TAHQ series with the APAB series. The effects of the substituents on the PEsI film properties and polymerizability were also discussed in this work. The ester-containing monomers used in this work (TAHQ series and the APAB series) were all highly reactive and led to PEsAAs possessing high inherent viscosities ranging 1.09-9.33 dL/g. The incorporation of methyl and methoxy substituents into rigid TAHQ-based PEsI systems caused no significant decrease in T g but allowed molecular motions above the T g s. In some cases, these substituents, in particular, the methoxy group contributed to a significant decrease in water absorption without sacrificing other target properties. For practical FPC application, a flexible diamine was copolymerized into the highly esterified rigid PEsI systems derived from the TAHQ series with the APAB series. One of the PEsI copolymers obtained achieved excellent combined properties: a low CTE (17.8 ppm/K) completely consistent with that of copper foil as a conductive layer, considerably low water absorption (0.47 wt %), a high T g exceeding 360 C, and improved toughness (elongation at break > 40%). Polyimides (PIs) have been widely utilized in a variety of micro-and optoelectronic applications such as flexible printed circuit boards (FPC), chip on film (COF) assembling system, tape automated bonding tapes (TAB), buffer-coating films and interlayer dielectrics for LSI chips, high temperature adhesives, light wave guides for their combined excellent properties, i.e., high glass transition temperatures (T g ), high resistance to chemicals and radiation, relatively low dielectric constants, and good mechanical properties.1-10 The advantages of PI materials are considerably high purity (extremely low contents of metal contaminations and residual monomers and solvents) in the resins, simple fabrication processes, and the ease of structural modifications through copolymerization using various commercially available monomers.FPC, TAB, and COF are fabricated from PI film/Cu foil laminates (flexible copper clad laminates, FCCL or CCL). Adhesive-free FCCL has an advantage in the view point of dimensional stability against heat cycles compared to that using thermally less stable conventional adhesives. This type of FCCL is usually produced by the casting method (thermal imidization after s...

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Section: Molecular Designmentioning

confidence: 93%

Poly(ester imide)s Possessing Low CTE and Low Water Absorption (II). Effect of Substituents

Hasegawa

Tsujimura

Koseki

et al. 2007

Polym J

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“…Thus, s-BPDA/PDA and TPDA/PDA containing these stiff units are also known as low-CTE PIs in contrast to sterically distorted 2,3,3 0 ,4 0 -BPDA (a-BPDA)-derived PIs. [25][26][27] Figure 2 illustrates the backbone structures of typical low-CTE polyimide systems.…”

Section: Imidization-induced In-plane Orientation Relating To Pi Chaimentioning

confidence: 99%

Low-CTE Polyimides Derived from 2,3,6,7-Naphthalenetetracarboxylic Dianhydride

Hasegawa

Horii

2007

Polym J

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ABSTRACT:2,3,6,7-naphthalenetetracarboxylic dianhydride (NTDA) showed high reactivity in the polymerization of polyimide precursors [poly(amic acid)s (PAAs)] with various aromatic and cycloaliphatic diamines with an exception of trans-1,4-cyclohexanediamine (CHDA). On the other hand, another isomer 1,4,5,8-NTDA did not allow the formation of high molecular weight PAAs. The poor reactivity of 1,4,5,8-NTDA is probably attributed to the more stable six-membered anhydride structure. The polyimide (PI) films derived from 2,3,6,7-NTDA with some diamines possessing stiff/linear structures, i.e., p-phenylenediamine (PDA), 4-aminophenyl-4 0 -aminobenzoate (APAB), and 2,2 0 -bis(trifluoromethyl)benzidine (TFMB) exhibited no distinct glass transitions on the dynamic mechanical thermal analysis or a considerably high T g exceeding 400 C, extremely low CTE values close to that of silicon wafer or lower, and relatively low degrees of water absorption simultaneously in addition to excellent thermal stability. A polyimide system derived from 2,3,6,7-NTDA and 4,4 0 -oxydianiline (4,4 0 -ODA) achieved a low CTE approximate to that of copper foil (20.0 ppm K À1 ) in spite of the presence of flexible ether linkages in the structure while retaining excellent film toughness (elongation at break > 80%). The low CTE characteristics observed probably results from the longer naphthaldiimide mesogenic unit which acts more effectively for the imidization-induced in-plane orientation. The properties of 2,3,6,7-NTDA-based PIs were compared with those of PIs derived from a fixed diamine with different dianhydrides, i.e., pyromellitic dianhydride (PMDA) and 3,3 0 ,4,4 0 -biphenyltetracarboxylic dianhydride (s-BPDA) to elucidate the merits of the use of 2,3,6,7-NTDA. The results revealed that 2,3,6,7-NTDA is a useful monomer for lowering both CTE and water absorption and enhancing T g . [doi:10.1295/polymj.PJ2006234] KEY WORDS Polyimides / 2,3,6,7-Naphthalenetetracarboxylic Dianhydride / 1,4,5,8-Naphthalenetetracarboxylic Dianhydride / Low Linear Coefficient of Thermal Expansion (CTE) / Low Water Absorption / Polyimides (PIs) have been widely utilized in a variety of micro-and optoelectronic applications such as the substrates for flexible printed circuit (FPC) and tape automated bonding (TAB), buffer-coating films and interlayer dielectrics for LSI chips, high temperature adhesives, light wave guides for their combined excellent properties, i.e., high glass transition temperatures (T g ), high resistance to chemicals and radiation, relatively low dielectric constants (K or "), and good mechanical properties.1-10 The advantages of PI materials are considerably high purity in the resins, simple production processes, and the ease of structural modifications through copolymerization using various commercially available monomers.Recently, the demands of PIs for the FPC applications have been increasing more and more in the world. Particularly, adhesive-free PI film/Cu laminates (flexible copper clad laminates, FCCL) for FPC fabrications, where the ...

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“…In addition, large differences have been observed in the coefficients of thermal expansion (CTE) and the glass transition temperatures (Tg) among these isomers. [2,3] When a precursor is changed from a poly(amic acid) (PAA) to a poly(amide alkylester) (PAE), the volatile component eliminated during imidization changes from water to alcohols. Miwa et al [4] have reported that the CTEs of PI films prepared from PAEs increase as their alkyl chain lengths increase.…”

Section: Introductionmentioning

confidence: 99%

Effects of Structural Isomerism and Precursor Structures on Thermo-optic Coefficients of BPDA/PDA Polyimide Films

Matsumura¹,

Terui²,

Andò³

et al. 2007

J. Photopol. Sci. Technol.

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The effects of the structural isomerism and the alkyl side-chain lengths in the precursors of BPDA/PDA polyimide (PI) on the temperature dependence of the refractive indices (i.e. thermo-optical coefficients) have been investigated. The PIs were formed on Si substrates by thermal curing of a) poly(amic acid)s (PAA) derived from three isomers (s-, a-, and i-) of biphenyltetracarboxylic acid dianhydride (BPDA) and p-diminobenzene (PDA) and b) poly(amide alkylester)s (PAEs) having methyl-, n-propyl-, n-pentyl-, and n-octyl side chains. The TO coefficients of PIs increase as the average refractive indices and thermal expansion coefficients increase, which can be well explained with the derivative form of the Lorentz-Lorenz formula. The absolute values of TO coefficients for s-BPDA/PDA are smaller than those expected from their refractive indices, which is due to the dense molecular packing and the small coefficient of thermal expansion. Significantly larger TO coefficients were observed for the PI films prepared from PAEs than that from PAA, indicating that the larger volatile components (alcohols) eliminated during thermal imidization cause loose molecular packing in the former PIs. The use of structural isomers and chemical modification of precursors are effective to control the TO coefficients and their anisotropies in BPDA/PDA films.Keywords / polyimide / optical properties / thermo-optic coefficient / refractive index / molecular packing / structural isomerism / thermal expansion /

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Improvement of thermoplasticity for s‐BPDA/PDA by copolymerization and blend with novel asymmetric BPDA‐based polyimides

Cited by 3 publications

References 0 publications

Poly(ester imide)s Possessing Low CTE and Low Water Absorption (II). Effect of Substituents

Poly(ester imide)s Possessing Low CTE and Low Water Absorption (II). Effect of Substituents

Low-CTE Polyimides Derived from 2,3,6,7-Naphthalenetetracarboxylic Dianhydride

Effects of Structural Isomerism and Precursor Structures on Thermo-optic Coefficients of BPDA/PDA Polyimide Films

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