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PrEssurE-BA s E d M A ss Fl Ow COntrO ll E r F O r I O n I MP l A nt A PP l ICAt IO ns The 1640 Pressure-based Mass Flow Controller is a metal-sealed instrument designed to meter and control gas flows in low-line pressure applications where thermal mass flow controllers are limited in their ability to accurately measure flow. The 1640 utilizes the principle of sonic flow through an orifice, a condition met when the upstream control pressure is at least twice the downstream pressure. Under these conditions, mass flow is proportional to the control pressure. In the 1640, as illustrated in Figure 1, a Baratron ® capacitance manometer monitors the pressure upstream of the critical orifice. This pressure is proportional to mass flow. The measured pressure is compared in the control electronics to the flow set point. A control signal is then generated to drive the proportional control valve to the conductance required to bring the actual control pressure (flow) into agreement with the flow set point. Features & Benefits Maximize Gas Utilization

  • Control of gas flow at pressures below Torr improves SDS® gas utilization and reduces frequency of source bottle changes Robust
  • Pressure-based flow measurement with Baratron® pressure transducer provides repeatab le flow measurement and control o ver full inlet pressure spectrum
  • Rigorous metal-sealed design and STRIFE testing ensures long ter m reliability Ease-Of-Use
  • Same f ootprint and electrical specifications as ther mal Mass Flow Controllers allo ws for straight forward integration www.MksInst.COM Flow Solutions

Figure 1 — A cross-section view of the 1640 pressure-based Mass Flow Controller. Saf e Delivery System (SDS®) Applications The 1640 was the first MFC to enable SDS gas utilization at source pressures below 10 Torr. Configurations of the 1640 have been designed specifically for the requirements needed for flow control in ion implanters utilizing SDS dopant sources. The SDS source pressure is typically at

650 Torr when the source is full, and drops as the source

gas is extracted. The 1640 PMFC is designed to extract gas below source pressures of 10 Torr (see Figure 2). The

1640 PMFC thus improves source utilization and reduces

the frequency of source bottle changes (see Figure 3). The 1640 for SDS applications is designed to function over the wide SDS source pressure range from 650 Torr to below 10 Torr and provide Full Scale dopant flows as high as 10 sccm. Since flow is controlled by controlling pressure there is not as much pressure coefficient effect as there is with most thermal MFCs. The 1640 is in use today on medium and high current as well as high energy implanters throughout the world. 1640s are also available for high pressure implant gases. PId Control Electronics Proportional Control Valve Baratron Capacitance Manometer Controlled Pressure (P1) Orifice Outlet Pressure (P2) Inlet Pressure Figure 2 — This graph shows pressure drop versus flow rate for two 1640 MFCs: one with 12 sccm Full Scale , the other with 6 sccm Full Scale. Figure 3 — The 1640 design allows for gas extraction to source pressures below 10 Torr depending on flow rate and gas line conductance. A 1640 designed for 6 sccm Full Scale has the potential to extract 5% more SDS source gas than a competitor’s thermal MFC.

Full scale ranges For Implant Applications (N2 equivalent) 2 sccm to 20 sccm Maxim um Operating Inlet Pressure 5 psig Minim um Operating Inlet Pressure (typical) belo w 10 Torr Overpressure l imit 45 psia Contr ol r ange (typical) 5% to 100% of F .S. Flow Accuracy (including non-linearity, hysteresis, and Gas/flo w rate dependent non-repeatability ref erenced to 760 mmHg and 0°C) r epeatability ± 0.2% of F .S. r esolution 0.1% of F .S. temperature Coefficients Zero < 0.02% of F .S./°C Span < 0.2% of Rdg./°C warm-up t ime < 30 min (to within 0.2% of F .S. of steady state performance) Controller s ettling t ime to 100% of F. s < 5 sec (typical per SEMI Guideline E17-91) n ormal Operating temperature r ange 0°C to 50°C Input V oltage r equired Max. current at start-up (first 2 sec) ± 15 VDC (± 5%) @ 200 mA T ypical current at steady state ± 15 VDC (± 5%) @ 100 mA s et Point Command s ignal 0 to 5 VDC from < 20K Ω Output s ignal 0 to 5 VDC into > 10K Ω Output Impedance < 1 Ω Connector types 15-pin T ype “D” wetted Materials Standard w etted components 316L S .S., nickel, Inconel® V alve seat only K el-F®, Chemraz® or Kalrez® (gas/application dependent) l eak Integrity Exter nal (scc/sec He) < 1 x 10-9 Through closed v alve1 1% of F .S. (nitrogen) at 15 psig inlet to atmosphere Fittings Compatible w ith Sw agelok® 4 VCR® Compliance CE 1 To assure no flow-through, a separate positive shut-off valve is required. Saf e Delivery Source (SDS®) The SDS delivers gas based on the differential pressure between the source gas cylinder (at less than 0 psig) and the implanter ion source. An MKS Bar atron pressure transducer with an LDM (Local Display Module) may be used to sense source pressure along with the 1640 pressure-based MFC to control flow.

Dimensional Drawing — Note: Unless otherwise specified, dimensions are nominal values in inches (mm referenced). 1640A XXX 1640 - 1/18 © 2005-2018 MKS Instruments, Inc. All rights reserved. MKS products provided subject to the US Export Regulations. Diversion or transfer contrary to US law is prohibited. Some Baratron® capacitance manometer products may not be exported to many end user countries without both US and local government export licenses under ECCN 2B230. Specifications are subject to change without notice. mksinst™ is a trademark and Baratron® is a registered trademark of MKS registered trademark of Greene, Tweed & Co., Kulpsville, PA. Kel-F® is a registered trademark of 3M Company, Minneapolis, MN. Swagelok® and VCR® are registered trademarks of Swagelok Marketing Co., Solon, OH. SDS® is a registered trademark of Matheson Tri-Gas and ATMI, Inc. Inconel® is a registered trademark of Inco Alloys International, Huntington, WV. Ordering Code Example: 1640AXXX Code Configuration 1640A Pressure Based Mass Flow Controller 1640A MKS will configure the 1640 to meet your specific needs f or gas type and flow rates. Please contact the MKS Applications Engineering Group at (800) 227-8766 with y our requirements and allow them to deter mine an appropriate 1640 configuration. Optional Accessories

750 Baratron Capacitance Manometer

: to monitor the gas source pressure LDM: A local displa y module that, when mounted with the 750, provides a local pressure readout Cabling f or 1640A: CB259-5-10 for 1640 15-pin Type “D” to 246, 247 CB147-1-10 for 1640 15-pin Type “D” to 647 Contact Applications Engineering for shielded cables required for CE Compliance. MKS Instruments, Inc. Global Headquarters

2 Tech Drive, Suite 201

Andover, MA 01810 Tel: 978.645.5500 Tel: 800.227.8766 (in U.S .A.) Web: www .mksinst.com MKS Instruments, Inc. Flow Solutions Six Shattuck Road Andover, MA 01810 Tel: 978.975.2350