Polyimide Upilex

Recently Yamaoka and Miyata carried out the reactor irradiation at 20 K on two kinds of aromatic polyimides, Upilex-S and Upilex-R [51]. The stress-strain curves of irradiated Upilex-S films are depicted in Fig. 7. No essential changes in both elastic modulus and yield strength were observed for Upilex-S after irradiation up to 8 x 106 Gy, although a slight decrease of the ultimate elongation was detected. A similar tendency was found in the reactor irradiation of Upilex-R at 20 K, in spite of the fact that its structural unit of the main chain is different from that of Upilex-S. These results indicate that a homologue of aromatic polyimides exhibits the excellent radiation stability even at cryogenic temperatures as well as at ambient temperature. 

Figure 4. Absorption coefficients at 308 nm for polyimide/PTFE blends predicted using a rule of mixtures relationship for polyimide dopant concentrations (weight fraction of polyimide) up to 5.0%. Calculated values of a blend over the full range of polyimide concentrations, from neat PTFE to neat polyimide (Upilex-S film), are given in the inset.

Kapton resin (5) (113) and Upilex (6) resin (114) are sold as films, partially polymerized resin coating solutions, and sinterable powders. Allied Signal also offers Apical polyimide film. 

Figure 5.21 a shows an SEM micrograph (in cross section) of a feature ablated in doped PTFE, specifically 0.5% polyimide, at 12 J/cm2. The ablated feature is well defined and exhibits a smooth wall profile, typical of all blends having more than 0.1% (wt/wt) polyimide. The sidewall profiles of the less heavily doped blends are extremely vertical, having less taper than typically observed for more heavily doped PTFE films, e.g., 1.0 and 5.0% (Figures 5.21b and 5.21c, respectively) or Upilex-S polyimide, (Figure 5.21d). Ablation rates for a variety of PI-PTFE blends [0.2-5% polyimide (wt/wt) and neat polyimide] at 248 nm and 308 nm are shown in Figures 5.22 and 5.23, respectively.78...

Commonly accepted practice restricts the term to plastics that serve engineering purposes and can be processed and reprocessed by injection and extrusion methods. This excludes the so-called specialty plastics, eg, fluorocarbon polymers and infusible film products such as Kapton and Upilex polyimide film, and thermosets including phenolics, epoxies, urea—formaldehydes, and silicones, some of which have been termed engineering plastics by other authors (4) (see Elastomers, synthetic-fluorocarbon elastomers Fluorine compounds, organic-tetrafluoroethylene copolymers with ethylene Phenolic resins Epoxy resins Amino resins and plastics). 

Methods. Polyamic acid in NMP was spin-coated onto a Si or Quartz wafer (diameter = 2.25 inches) coated with Cr, and then cured to polyimide at 400 °C. The purpose of the 500-750-A-thick layer of chromium is to enhance wettability and to give good reflectance to the Quartz wafer. Kapton H (PMDA-ODA) and Upilex S (BPDA-PDA) films were employed for gravimetric analysis. Around 5-um thick layers were used to measure the thickness change. The 100-1000-A-thick layers were employed to obtain XPS and ER IR spectra. The samples for contact angle measurement, XPS and ER IR were dried under vacuum at ambient temperature for 12-24 h and the samples for gravimetric analysis were dried at 85 °C for 12 h. The samples for film thickness measurement were fully re-cured to polyimide. 

Starting materials and solvents were purchased from Aldrich Chemical Co. acetonitrile (ACN), N,N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP) were obtained anhydrous in Sure/Seal bottles and used as received. The polyamic acid of PMDA-ODA (2545 Pyralin) was supplied by DuPont. The soluble polyimide XU-218, derived from 3,3, 4,4 -benzophenone tetracarboxylic dianhydride (BTDA) and diamino-1,1,3-trimethyl-3-phenylindan isomers (DAPI) was purchased from Ciba-Geigy Corp. The acetylene terminated imide oligomer powder (Thermid MC-600) derived from BTDA, aminophenylacetylene, and 1,3-bis (2-aminophenoxy) benzene (APB) was obtained from National Starch and Chemical Company. Kapton Type II (PMDA-ODA) films were obtained from DuPont Co., Apical polyimide films were obtained from Allied Corp., and Upilex Type-S and Type-R polyimide films derived from 3,3, 4,4 -biphenyl tetracarboxylic dianhydride (BPDA) plus p-phenylenediamine (PDA) and ODA, respectively were obtained from ICI Americas Inc. 

Reduction of Upilex-R polyimide films in a solution containing 0.05 M anthracene (15 percent radical-anion) / 0.1 M TBAFB / NMP results in a broad visible absorbance (blue colored films) with a maximum at about 625 nm as shown in Figure 3. Since the potential of the anthracene couple is quite negative, BPDA-polymers can accept two electrons per imide unit which may contribute to the broad absorbance response for the reduced films. 

From Table 11-1 we can see that mica creates higher parasitic capacitances despite a lower K, and that is clearly attributable to the smaller thickness of insulator typically required. The same happens when we use some of the modern, expensive, and yet popular polyimide (not polyamide ) insulators which are excellent thermal conductors, but are also very thin. These can be recognized by their typically amber color, and they come in various brand names like Kapton, Kinel, Upilex, Upimol, Vespel, and so on. 

Figure 5 displays the ITPD curves determined at 90 °C of PEEK, PES, and PPS films [27]. Both sulfur-containing polymer films exhibit a pronounced charge drain-off within the first 180 min and hence cannot be considered as electret materials. PEEK, on the other hand, shows a moderate surface potential decay and maintains around 50% charge after 24 h at 90°C. The charge storage characteristics of commercial polyimides and polyetherimide (Ultem 1000) films at 90 °C are displayed in Fig. 6. Kapton HN (PI) films lose almost the complete surface potential within 24 h, exhibiting a steep decay in the first minutes. Upilex R renders better results, since its potential decay is moderate and after 24 h around 45% of the applied charge...

Base dielectrics Conductor materials Copper-clad laminates Coverlay Adhesive sheets Polyimide films (Kapton K, E, EN, KJ Apical NP, FP Upilex S) Liquid polyimide resin, PEN film, LCP films Ultra-thin copper foils, sputtered copper, copper alloys, stainless steel foil Adhesiveless laminates (cast type, sputtered/plated type, laminated type) Photoimageable coverlay (PIC) (dry film type, liquid ink type) Hot-melt polyimide film... 

Several newer polyimide films such as Upilex S , Kapton E , and Apical NP and FP have been commercialized to satisfy the requirements for increased dimensional stability. 

Flexible substrates Traditional polyimide films (Kapton H , Apical AVTm) New polyimide films (Kapton E , Apical HP , Upilex S )... 

Another family of aromatic polyimides is produced from the condensation reaction between biphenyl tetra carboxylic dianhydride (BPDA) and aromatic diamines such as ODA and p-phenylene diamine, PDA. The polyimides BPDA-ODA and BPDA-PDA are available from Ube Industries under the Upilex R and S trademarks, respectively. Their T s are reported to be >400°C. Structures appear in Fig. 1.29. 

Figure 13 Repeating units of commercial polyimide films Kapton and Apical 93, Upilex R 94, Upilex S 95, Novax 96 + 93, and Regulus 97.

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