There are strong reasons for choosing Para Tech Coating, Inc. as your Parylene business partner. We work closely with each customer to meet their business objectives, and offer industry proven technology advantages such as those described below.

Predictable Coating Cycles

PTC systems use a proprietary deposition sequence (Figure 1) that is based on time and temperature alone and does not depend on chamber pressure fluctuations related to the flow of monomer gas. This advanced PTC process control methodology has been refined over more than 30 years of operation, and is not available from any other Parylene coating supplier.

In the PTC process, the thermal excursions and coating bursts of the traditional deposition approach are avoided, along with unpredictable cycle length. Time/temperature control results in film of superior clarity and uniformity, and allows for a known cycle length, predictable production scheduling and superior customer service.

Figure 1 - PTC coating systems deposit Parylene film using a stepped time and temperature process under microprocessor control in accordance with a recipe based on the volume of vaporized dimer and the chamber load. Process cycle time is fixed and predictable, and this method enhances both film quality and coating productivity.

In conventional Parylene deposition systems, the sublimating temperature is controlled by a chamber vacuum sensor, which cycles periodically. As a result, both the vacuum level and monomer flow rate oscillate in a sine wave pattern, making the coating cycles unpredictable in length and introducing significant process inefficiency (see Figure 2).

Figure 2 -
The conventional Parylene deposition cycle used by other coating suppliers depends on a pressure sensor in the vacuum chamber to control the rate of dimer pyrolysis. This results in the cyclical application of monomer gas to the vacuum chamber, and unpredictable process timing.

Patented Tangential Flow Design

PTC’s coating quality also benefits from the company’s patented tangential flow chamber design (Figure 3). In this proprietary coating process the monomer gas is introduced into the deposition chamber tangentially and flows around the periphery of the chamber. Parts to be coated are rotated in the counter direction to aid dispersion of the gas. This technique eliminates the need for diverting baffles, enhances uniformity and reduces dimer waste, resulting in competitive pricing and faster turnaround times.

Figure 3 - The PTC tangential flow method of introducing monomer gas to the vacuum chamber enhances the uniformity of gas dispersion. Since there are no baffles to clean, system maintenance is simplified.

Patented Asymmetrical Design for Tumble Coating

PTC’s Parylene tumble coating method is highly efficient for processing small, non-fixtured components as it reduces parts handling and allows simultaneous coating of multiple part types. The patented asymmetrical chamber design ensures constant product motion for superior Parylene uniformity. PTC’s range of tumble coating equipment offers optimal user flexibility and the largest production capacity system in the industry (Figure 4).

Figure 4 - Tumble Coat illustration

Patented Fixture Design

A patented PTC fixture design controls the flow of monomer gas as it enters the coating chamber, enhancing diffusion and uniformity, directing the gas to substrates and reducing the amount of dimer required to achieve desired coating results. Variable aperture plates at the bottom of the fixture stack are pre-adjusted according to the volume and geometry of the coating load, and a load-specific skirt of aluminum foil is placed around the base of the structure to further direct monomer flow.