Parylene Coating Blog by Diamond-MT

A Guide to Parylene Temperatures

Posted by Sean Horn on Fri, Dec 07, 2018 @ 07:30 AM

A specialized chemical vapor deposition (CVD) process attaches conformal coatings composed parylene (XY) to substrates.  CVD uniformly encapsulates all exposed substrate surfaces as a gaseous monomer; completely eliminating wet coatings’ liquid phase and need for post-deposition curing.  Synthesizing in-process, CVD polymerization requires careful monitoring of temperature levels throughout

Beneficial thermal properties of XY protective coatings include reliable performance through an exceptional range of temperatures.  Parylene is available in variety of material formats, prominently Types C, N, F, D and AH-4.  Each has a particular range of properties that determine its optimal uses.  Types C and N exhibit faster deposition rates than other parylenes, making them useful for a wider range of coating functions.  However, operating temperature is a significant determinant of use:  Much depends on chemical composition. 

  • Used more frequently than other XY varietals, Parylene C is a poly-monochoro para-xylene.  It is a carbon-hydrogen combination material, with one chlorine group per repeat-unit on its main-chain phenyl ring.  In oxygen-dominated atmospheres, C conformal films regularly provide reliable assembly security at temperatures of 100° C (212° F/water’s boiling point) for 100,000 hours (approximately 10 years).  C is suggested for use in operating environments reflecting these temperature conditions.  Chemical, corrosive gas, moisture, and vapor permeability remain consistently low.  C generates exceptional vacuum stability, registering only 0.12% total weight-loss (TWL) at 49.4° C/10-6 torr (1 torr = 1/760 SAP (standard atmospheric pressure, 1 mm Hg).   C can also be effective at temperatures below zero, to -165º C.
  • With a completely linear chemical format, Parylene N is the most naturally-occurring of the parylene series.  Used less regularly than Type C, N is highly crystalline; each molecule consists of a carbon-hydrogen combination.  N’s melting point of 420° C is greater than most other XY types.  Vacuum stability is high, registering TWL-levels of 0.30% at 49.4° C, and 10-6 torr.  These properties encourage higher temperature applications.  Compared to other XY varietals, N’s low dielectric constant/dissipation values also recommend uses with assemblies and parts subjected to higher levels of unit vibration during operation.  N’s electrical/physical properties are not noticeably impacted by cycling from -270º C to room temperature, adding to its versatility.  
  •  Parylene F has fluorine atoms on its aromatic ring.  Possessing aliphatic -CH2- chemistry, F’s superior thermal stability is attributed to this aliphatic C-F bond, compared to Type C’s C-C bond.   Better thermal stability, and reduced electrical charge/dielectric constant expand its use for ILD (inner layer dielectric) applications, such as those for ULSI (ultra large-scale integration), where a single chip can incorporate a million or more circuit elements.   F is a good choice for many microelectromechanical systems (MEMS)/nanotech (NT) solutions. 
  • Originating from the same monomer as Type C, Parylene D’s chemical composition contains two atoms of chlorine in place of two hydrogen atoms.  Like Type C, D conformal films can perform at 134° C (273° F), dependably securing assembly performance in oxygen-dominated environs for 10 years, at a constant 100° C.  Parylene F resists higher operating temperatures and UV light better than C or N.  
  • Parylene AF-4’s melting point is greater than 500° C.  It survives at higher temperatures/UV-exposure better than other parylenes for long durations because it possesses CF2 units, situated between its polymer-chain rings.  
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Tags: parylene, parylene properties, parylene temperature, parylene C, parylene f, parylene d, parylene af-4

Paralene, Paralyne, or Parylene: Correctly Spelling and Using This Superior Conformal Coating

Posted by Sean Horn on Fri, Dec 01, 2017 @ 08:01 AM

Accidentally discovered in 1947, by chemist Michael Szwarc, the polymer parylene originally bore his name, and was known for a brief period known as Szwarcite. Working to thermally decompose the solvent p-xylene at temperatures exceeding 1000 °C, Szwarc identified the monomer para-xylylene di-iodide as the only product resulting when para-xylylene was reacted with iodine.

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Tags: parylene, parylene C, parylene process, parylene deposition

Cost of Parylene Dimer

Posted by Sean Horn on Fri, Apr 07, 2017 @ 07:32 AM

Perhaps the most reliable of the conformal coatings, parylene (para-xylylene di-iodide) is also one of the more expensive coating options.  Production costs typically encompass three primary expense categories -- raw materials, labor, and lot volume.  Of the three, labor expenses are generally the most costly, but raw materials can add significantly to production overhead; materials’ costs can be largely attributed to the raw parylene dimer required to make conformal coatings.   

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Tags: parylene, parylene C, parylene af-4, parylene n, parylene dimer

Types of Parylene

Posted by Sean Horn on Fri, Mar 10, 2017 @ 07:34 AM

          Applied in a gaseous form to component surfaces through a chemical vapor deposition (CVD) process, parylene (Poly-para-xylylene) films protect printed circuit boards (PCBs) and similar electrical assemblies.  Gaseous CVD application supports efficient coating of complex component surfaces characterized by crevices, exposed internal areas, or sharp edges.  Depending on the specific use, parylene conformal coatings can be effective in the range of 0.1 - 76 microns' thickness, far finer than competing coating materials.  Equally as strong, adaptable and versatile parylene protects substrates with

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Tags: parylene, parylene C, parylene n, parylene f, parylene d, parylene af-4

Different Types of Parylene

Posted by Sean Horn on Fri, Oct 07, 2016 @ 07:30 AM

Parylene Varietals:  Matching Material to Purpose

A common generic name for Poly-para-xylylene, parylene forms a protective plastic film when applied to substrate surfaces.  Application is achieved through a chemical vapor deposition (CVD) process in a vacuum, as a gas to targeted substrate surfaces.

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Tags: parylene, parylene C, parylene n, parylene f, parylene af-4, parylene applications, parylene cost

Parylene C vs Parylene F

Posted by Sean Horn on Fri, Jun 03, 2016 @ 07:30 AM

Parylene C is the most widely used parylene type for conformal coatings.  It is classified as a poly-monochoro para-xylene, produced from dimer material, with one chlorine group per repeat unit on its main-chain phenyl ring.  As a conformal coating, Type C can be deposited at room temperature via CVD.  The resulting film exhibits low chemical, moisture, and vapor permeability, making it particularly useful where protection is needed from corrosive gases.  C’s alliance of electrical and physical properties distinguish it uses from those Parylene F, a consequence of their different chemical composition; F has a fluorine atom on its benzene ring, in contrast to C’s chlorine atom. 

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Tags: parylene, parylene C, parylene f

5 Common Misconceptions of Parylene

Posted by Sean Horn on Wed, Mar 11, 2015 @ 09:11 AM

In the course of our business applying parylene to a range of different products, our clients ask many questions. They also have a few consistent misconceptions. Here are the five biggest ones -- and the facts to clear things up.

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Tags: parylene, parylene C, parylene adhesion, parylene n

Parylene C vs Parylene N

Posted by Sean Horn on Tue, Feb 17, 2015 @ 11:07 AM

Parylene and It's Uses

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Tags: parylene, parylene C, parylene n

5 Key Properties of Parylene

Posted by Sean Horn on Tue, Jan 07, 2014 @ 09:42 AM

Since its discovery in the 1940s, Parylene has skyrocketed to prominence as an ideal conformal coating choice for a range of applications. Given its unique blend of properties, it might seem like an unparalleled conformal coating option. In many ways, it is. Here are five key properties of Parylene that differentiate it from the rest.

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Tags: parylene, parylene C, parylene properties

Parylene and MEMS Technology

Posted by Sean Horn on Mon, Jun 18, 2012 @ 07:52 AM

In the past decade, the use of Parylene as a structural material in microelectromechanical systems (MEMS) devices has attracted significant attention.  Parylene C, known for its biocompatibility, is widely used in implantable medical devices.  Parylene C is also compatible with MEMS microfabrication processes.

WHAT ARE MEMS?

Microelectromechanical systems (MEMS) is the technology of very small devices; it merges at the nano-scale into nanoelectromechanical systems (NEMS) and nanotechnology.  MEMS are made up of components between 1 to 100 micrometres in size (i.e. 0.001 to 0.1 mm), and MEMS devices generally range in size from 20 micrometres (20 millionths of a metre) to a millimetre (i.e. 0.02 to 1.0 mm). They usually consist of a central unit that processes data (the microprocessor) and several components that interact with the outside such as microsensors.

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Tags: parylene, parylene deposition, parylene conformal coating, parylene thickness, parylene C, conformal coating thickness, Parylene and MEMS, MEMS