Brooks Instrument GF126 - Manual (Page 12)

1-6
GF100 Series
Installation and Operation Manual
X-TMF-GF100-Series-MFC-eng
Part Number: 541B137AAG
March, 2013
Section 1 Introduction
Pressure Transient Insensitivity (PTI)— Included with all GF125 &
GF135 models
Cost and space constraints are driving gas panel designers to remove
point-of-use pressure regulators and pressure monitoring components from
the process design and rely solely on the mass flow controller to accurately
control the process under dynamic pressure conditions. The Brooks GF125
& GF135 (PTI) devices utilize a patented control algorithm that inverts the
pressure signal, compares it to the pre-fluctuation signal and drives real-
time valve position compensation to maintain stable flow. Enhanced
pressure transient is achieved through faster sensing, quicker processing,
and a reduction in internal dead-volume between the sensors and valve
orifice.
Optional High Accuracy (HA)— GF125 model only
The GF125 High Accuracy (HA) is a gas and range specific model for
critical gas process applications requiring the widest working range with
tightest flow control accuracy. A typical application is for multi-step
processes requiring a high flow rate, up to 10 slpm, and a very accurate
low flow rate.
Optional Safe Delivery System (SDS)— GF120 model only
The Safe Delivery System (SDS) enhanced GF120 model is a state-of-the-
art low pressure drop devices for the delivery of sub atmospheric safe
delivery system gases used in Implant and Etch processes. The Brooks
GF120 SDS models are available in full scale flow ranges 4 sccm -1 slpm.
Advanced Thermal Flow Measurement Sensor
Brooks proprietary highly corrosion resistant Hastelloy C-22 sensor with an
enhanced sensor manufacturing and burn in process incorporates a unique
orthogonal sensor mounting orientation to eliminate sensor drift caused by
valve heating effects and eliminates thermal siphoning effects. This unique
sensor configuration includes an optimized temperature profile for gases
prone to thermal decomposition. This design results in:
• Enhanced signal to noise performance for improved accuracy at low
set points
• Superior reproducibility at elevated temperature through new
isothermal packaging and onboard conditioning electronics with
ambient temperature sensing and compensation
• Improved long-term stability
High Purity Flow Path
The Brooks GF Series has an all metal, corrosion resistant Semi F20
compliant wetted flow path with highly corrosion resistant Hastelloy C-22
valve seat and jet orifice. The GF120, GF125 & GF135 devices are
constructed with a 4µ
inch Ra max surface finish while the GF100 is
constructed with a 10µ inch Ra.
• Overall reduced surface area and un-swept volumes for faster dry-down
during purge steps
• Long-term sensor and device stability for maximum yield and throughput