Microencapsulation
rule
Dodge has the capability to coat very small particles — from 5-100 microns
 

 

Vapor Phase Deposition is a physical method of encapsulation by which the core material (solid) is placed in a coating chamber under high vacuum. The coating is a special dimer that is first vaporized under high vacuum, once under the high vacuum the dimer molecule is "cracked" in a furnace, forming free radicals. The free radicals then move into the coating chamber reforming/polymerizing onto the surface of the core material/substrate forming a good conformal wall.
 

Parylene Coating Process:

Parylene is the generic name for members of a unique family of thermoplastic polymers that are formed on surfaces exposed to a rarified gas in a vacuum.

Parylene Dimer

The parylene process is often used to protect electronic parts from moisture and corrosion.

In 1982 the Ronald T. Dodge Company began utilizing the Parylene process to coat small particles, and in 1985 received their first patent for the microencapsulation of electro- luminescent (ZnS) phosphors.

 

Parylene's Limitations

Parylene's Advantages


 

 
Parylene N
 
 
Parylene C
 
 
Parylene D 
 

The first in the series is poly-para-xylylene, a completely linear, highly crystalline material.  
 
 
 
 
 

Is the same as Parylene N but modified by the substitution of a Cl atom for one of the aromatic H.

 
 
 
 
 

Is the same as Parylene N but modified by the substitution of two Cl atom for one of the aromatic H.

 

Parylene Process

 

 

Conformal Coating

 

Non Conformal Coating

Conformal coating Non-conformal coating
       
  Conformal coating cross-section