Water-processable resist

Fig. 138 Poly(vinyl alcohol)-based water processable resists...

Another approach that has been reported for making water-processable resists is via polymeric quaternary pyridinium salts (VIII), which are made light sensitive by reaction with an aldehyde. ... 

It can be seen that in this example the largest resistance, the controlling film, is that of the air, 1/U 1 /Aajr, he. U hiur, and so the air film controls the overall heat transfer process. If we wish to increase the overall rate of heat transfer by increasing U, we should look at the dominating resistance, the air film, and try to reduce it, e.g. by increasing the air-side velocity. Reducing the water film resistance has very little effect upon U. 

The manufacturing process and properties of polybutene-1 are comparable to PP. Compared to the aliphatic hydrocarbons, this material is not as inert as PE and PP. Its high burst strength and tear strength are very advantageous for the manufacture of hot water pipes (resistant up to 95 °C). 

We next examine a simplified expression for the total water vapor resistance that often adequately describes diffusion of water vapor from the sites of evaporation in cell walls to the turbulent air surrounding a leaf and is useful for considering diffusion processes in general. We will consider the case in which nearly all of the water vapor moves out across the lower epidermis and when cuticular transpiration is negligible. By Equations 8.11 and 8.12, the total resistance then is... 

The Overall process of reduction of an alkene to an alkane, or of reduction of an alkyne to either an al-kene or an alkane, via hydroboration requires that the intermediate organoborane be protonolyzed (Section 3.10.1.1). However, simple trialkylboranes are remarkably resistant to hydrolysis. For example, trimethylborane gives only 69% of hydroxydimethylborane after 7 h at 180 °C with 1 equiv. of water. Similar resistance is shown to alcohols, phenols and amines, and even mineral acids do not completely protonolyze trialkylboranes with any ease. Thus, aqueous or anhydrous hydrogen bromide removes only one alkyl group from tributylborane after reflux for 1 h. ... 

C), anhydride formation proceeds in the exposed area while PTBMA in the unexposed regions remains intact. After this high temperature process, the PTBMA resist film is flood-exposed and baked at <150 °C, which converts PTBMA to poly (methacrylic acid) in the initially unexposed areas. This entire process renders the unexposed area more polar (carboxylic acid) than the exposed area (anhydride), allowing negative imaging with aqueous base [121]. This concept has been later employed in the design of water-castable and water-developable resist [346]. 

Fig. 140 Oxazoline-based water processable negative resists...

Fig. 142 Vinyl ether-based water processable positive resist...

Although the original KTFR resist based on 2,6-bis(4-azidobenzal)-4-methyl-cyclohexanone in poly(cA-isoprene) rubber resin that dominated the IC industry between 1957 and 1972 was organic solvent developed, in the 1980s, water-processable azide resists were described by Nonogaki and co-workers. These... 

PROPERTIES OF SPECIAL INTEREST Good abrasion resistance low flammability and emission of smoke and toxic gases low water absorption resistance to hydrolysis, wear, solvents, radiation, and high-temperature steam ease of processing and excellent thermal stability and mechanical properties at high temperatures. 

In another invention, plasticizers are prepared from a mixture of acids (acrylic, maleic, and fumaric) and alcohols having 6 to 18 carbon atoms. Mono and diesters are obtained during manufacturing process. The composition of stock is controlled to obtain plasticizer which has good electrical insulation properties, water extraction resistance, and fogging resistance. ... 

The MB deionisers are designed to produce demineralised water with resistivity >16.0 Mf2-cm (conductivity <0.063 pS/cm). All operating modes — service, standby, and regeneration — are controlled by the PLC, which opens and closes the pneumatic valves and the corresponding solenoid valves. The process operating conditions are given in Section 4.2. Valve operations are detailed in Table 4.4. 

---