Designed specifically to meet the exacting requirements of today's semiconductor and industrial processes, the VC-4900 series of vapor flow controllers represent a step forward in the delivery of low vapor pressure liquids. Until now, either a large foot-print mass flow controller or a liquid flow controller was needed to deliver these materials to the process environment. The VC-4900 series vapor controllers enable the delivery of organometallic such as tetraethoxysilane (TEOS), trimethylphosphate(TMP) and trimethylborate (TMB) with pressure drops as low as 6.7kPa(50 Torr). The VC-4900M utilizes metal seals, providing an extra measure of protection for use with highly reactive and corrosive vapors such as titanium tetrachloride (TiC14) and deionized water vapor.

The VC-4900 series uses a large bore sensor, a large valve orifice and high stroke valve to deliver high flows at ultra low pressure drops. With optional remote electronics, operating temperatures of 100°C are possible. For additional flexibility, Tylan General's external heater can also be ordered with the vapor controller.

UltraLow Pressure Drop
The VC-4900 incorporates our large diameter sensor tube, an enlarged valve orifice and a high stroke valve to maximize the conductance of the plumbing. This enables lower pressure drops than a standard MFC. The minimum pressure drop is dependent upon the gas and full scale range of the device. For TEOS, the VC-4900 can flow up to 150 sccm at 50 Torr (86°C) or up to 200 sccm at 60 Torr (90°C). At higher flows, a larger differential pressure is required.

Optional Remote Electronics and Heater
At temperatures over 50°C the electronics should be remoted in order to assure proper performance of the device. The VC-4900 series is available with a remote electronics option to allow for operation to 100°C. The VC-4900 vapor controller is calibrated at the operating temperature, minimizing the calibration shift due to a change in ambient temperature. To prevent condensation of the vaporized liquid in the MFC, it should be heated in excess of 10°C hotter than the vaporizer. This can be aided by the external MFC heater which is available as an option.

Elastomer or Metal Seals
The VC-4900 is available with either VitonTM or Nickel 200 seals. Oxygen and water vapor from the atmosphere diffuse through elastomers, leading to process problems with reactive gases. Our seal technology, which is based upon soft Nickel seals, eliminates this permeation problem. The high leak integrity provides an extra measure of safety when used with toxic gases and the metal seals are compatible with all reactive gases. The seal design makes the vapor controller simple to disassemble and easy to repair.

High Performance 2900 Electronics
The VC-4900, as a member of the 2900 family of flow products, incorporates the 2900 electronics for enhanced process stability. The 2900 electronics provides a balanced power load to minimize common mode rejection problems and greatly reduced flow sensitivity to cable lengths and power supply variations. The VC-4900 has a 20 pin card edge connector and the VC-4901 uses a 15 pin subminiature "D" connector.