Properties of Solvents Used for Electronics

A lot of different types of chemicals are used in electronics manufacturing. A few have come and gone due to obsolescence, handling hazards, cost considerations, and ineffectiveness. Others have been around for the 30+ years (and longer) that I have been in the business. Here is a table of properties of some of the commonly used solvents used in the early 21st century. Please let me know if there are others that should be added.

Note that many of the parameters are highly dependent on temperature. The dielectric constant of acetone, for instance varies from 1.0159 @ 32° F, to 20.7 @77° F, and then back down to 17.7 @ 127° F. Consult manufacturer when precise data is needed at specific temperatures and pressures.

  • Boiling Point - temperature at which a liquid boils at a fixed pressure
  • Flash Point - lowest temperature at which the vapor of a combustible liquid can be made to ignite momentarily in air
  • Auto-Ignition Temperature - temperature at which a material (solid, liquid, or gas) will self-ignite and sustain combustion in air without an external spark or flame
  • Vapor Pressure - pressure exerted by a vapor in equilibrium with its solid or liquid phase
  • Specific Gravity - ratio of the mass of a solid or liquid to the mass of an equal volume of distilled water at 4°C (39°F) or of a gas to an equal volume of air or hydrogen under prescribed conditions of temperature and pressure
  • Viscosity - property that measures a fluid's resistance to flowing
  • Latent Heat of Vaporization - amount of heat required to convert a unit mass of a liquid at its boiling point into vapor without an increase in temperature
Property Acetone Ethanol Isobutanol Isopropanol

(Alcohol)

n(1)-Propanol Methanol sec(2)-Butanol MEK
Boiling Point, °C(°F) 56 (133) 78 (172) 107.9 (226) 82 (180) 97 (207) 64 (147) 99.5 (211) 80 (176)
Flash Point, °C(°F) -9.4 (15) 14 (57) 29 (84) 22 (72) 22 (72) 11 (52) 23 (73) -4.0 (25)
Auto-Ignition Temp, °C(°F) 603 (1118) 426 (799) 440 (824) 433 (812) 433 (812) 470 (878)   400 (752)
Vapor Pressure

@ 20 °C(68 °F), kPa

24.7 5.8 1.17 4.4 18.9 13.0 1.61  
Specific Gravity

@ 20 °C(68 °F)

0.790 0.795 0.803 0.787 0.815 0.792 0.808 0.805
Viscosity

@ 20 °C(68 °F), Pa·s·10-4

3.04 12.2 39.0 24.0 22.6 6.25 36.5  
Molecular Weight 58.08 46.07 74.12 60.09 60.09 32.04 74.12 72.11
Latent Heat of Vaporization, kJ/kg 520 880 618 842 945 1226 605  
Relative Evaporation Rate, CCl4=100 139 31.7 11.7 28.3 21.7 58 15.0  
Dielectric Constant

@ 25 °C (77 °F)

20.7 24.3   18.23 20.1 32.66   18.5
Molecular Formula CH3COCH3 C2H6O C4H10O (CH3)2CHOH C3H8O CH3OH C4H10O CH3COC2H5
                 

MEK = Methyl Ethel Ketone

Source: Electric Materials Handbook, et al