FUNDAMENTALSOF VACUUMTECHNOLOGY - UAIC

1 B5 fundamentals OFVACUUM TECHNOLOGYF undamentals of Vacuum Technology1 fundamentals ofVacuum Technologyrevised and compiled byDr. Walter Umrathwith contributions fromDr. Hermann Adam , Alfred Bolz, Hermann Boy, Heinz Dohmen, Karl Gogol, Dr. Wolfgang Jorisch, Walter M nning, Dr. Hans-J rgen Mundinger, Hans-Dieter Otten, Willi Scheer, Helmut Seiger, Dr. Wolfgang Schwarz, Klaus Stepputat, Dieter Urban,Heinz-Josef Wirtzfeld, Heinz-Joachim ZenkerFundamentals of Vacuum Technology2 PrefaceAgreat deal has transpired since the final reprint of the previous edition ofFundamentals of Vacuum Technology appeared in 1987. LEYBOLD has inthe meantime introduced a number of new developments in the field. Theseinclude the dry-running ALL ex chemicals pump, the COOLVAC-FIRST cryopump systems with quick regeneration feature, turbomolecular pumpswith magnetic bearings, the A-Series vacuum gauges, the TRANSPECTORand XPR mass spectrometer transmitters, leak detectors in the ULseries,and the ECOTEC 500 leak detector for refrigerants and many other , the present edition of the fundamentals goes into much greaterdetail on some topics.

2 Among these are residual gas analyses at lowpressures, measurement of low pressures, pressure monitoring, open- andclosed-loop pressure control, and leaks and their detection. Included for thefirst time are the sections covering the devices used to measure and controlthe application of coatings and uses for vacuum technology in the coatingprocess. Naturally LEYBOLD s Vacuum Technology Training Center atCologne was dependent on the invaluable support of numerous associatesin collating the literature on hand and preparing new sections; I would liketo expressly thank all those individuals at this juncture. Aspecial word ofappreciation is due the Communications Department for its professionalcontribution in preparing this document for publishing. Regrettably Adam, who at one time compiled the very first version of the fundamentals , did not live to see the publication of this edition. Thoughhe had been in retirement for many years, he nonetheless labored over thecorrections and editing of this current edition until shortly before his hope that this volume will enjoy a response as favorable as the Walter UmrathCologne, August, 1998 Preface3 fundamentals of Vacuum of pumping process.

3 Of the most usual pumping processes .. of gases (dry processes) .. of gases and vapors (wet processes) .. processes .. of an oil-free (hydrocarbon-free) vacuum .. vacuum working Techniques .. of a vacuum chamber and determination of pump sizes .. of a vacuum chamber (without additional sources of gas or vapor) .. of a chamber in the rough vacuum region .. of a chamber in the high vacuum region .. of a chamber in the medium vacuum region .. of a suitable backing pump .. of pump-down time from nomograms .. of a chamber where gases and vapors are evolved .. of pumps for drying processes .. and their seals .. of suitable valves .. locks and seal-off fittings .. measurement, monitoring, control and regulation .. of low-pressure measurement .. gauges with pressure reading that is independentof the type of gas .. vacuum gauges .. vacuum gauges .. vacuum gauges .. diaphragm vacuum gauge .. diaphragm vacuum gauges .. diaphragm gauges .. (mercury) vacuum gauges.

4 Vacuum gauges .. vacuum gauges (according to McLeod) .. gauges with gas-dependent pressure reading .. rotor gauge (SRG) (VISCOVAC) .. conductivity vacuum gauges .. vacuum gauges .. ionization vacuum gauges(Penning vacuum gauges) .. ionization vacuum gauges .. and calibration; DKD, PTB national standards .. of fundamental pressure measurement methods(as standard methods for calibrating vacuum gauges .. monitoring,control and regulation invacuum systems .. of pressure monitoring and control .. protection, monitoring and control of vacuum systems .. regulation and control in rough and mediumvacuum systems .. regulation in high and ultrahigh vacuum systems .. of applications with diaphragm controllers ..93 Table of physics Quantities, their symbols, units of measure and definitions .. terms and concepts in vacuum technology .. air .. laws and models .. theory .. gas theory .. pressure ranges in vacuum technology and their characterization.)

5 Of flow and conductance .. of flow .. conductance values .. for piping and openings .. values for other elements .. Generation .. pumps: Asurvey .. displacement vacuum pumps .. pumps .. sealed rotary displacement pumps .. ring pumps .. sealed rotary displacement pumps .. vane pumps (TRIVAC A, TRIVAC B, TRIVAC E, SOGEVAC) .. plunger pumps (E-Pumps) .. pumps .. gas ballast .. compressing rotary displacement pumps .. pumps .. pumps .. pumps with internal compression for the semiconductor industry ( DRYVAC Series ) .. pump without internal compression for chemistry applications ( ALL ex ) .. for oil-sealed rotary displacement pumps .. pumps .. (Oil) Diffusion pumps .. vapor ejector pumps .. fluids .. fluid backstreaming and its suppression (Vapor barriers, baffles) .. jet pumps and steam ejectors .. pumps .. pumps .. pumps .. pumps .. pumps .. evaporable getter pumps (NEG pumps) .. of cryopump .. cold head and its operating principle.

6 Refrigerator cryopump .. of gases to cold surfaces .. speed and position of the cryopanels .. quantities of a cryopump ..57 Table of of gas at low pressures using mass spectrometry .. review .. quadrupole mass spectrometer (TRANSPECTOR) .. of the sensor .. normal (open) ion source .. quadrupole separation system .. measurement system (detector) .. admission and pressure adaptation .. valve .. converter .. ion source (CIS) .. gas monitor (AGM) .. values in mass spectrometry (specifications) .. width (resolution) .. range .. detectable partial pressure .. detectable partial pressure ratio (concentration) .. range .. on surfaces and amenability to bake-out .. spectra .. and fundamental problems in gas analysis .. pressure measurement .. gas analysis .. gas analysis .. SQX software (DOS) for stand-alone operation(1 MS plus, 1 PC, RS 232) .. software MQX (1 to 8 MS plus 1 PC, RS 485) .. software Transpector-Ware for Windows .. software TranspectorView.

7 Pressure regulation ..1095 Leaks and their detection .. of leaks .. rate, leak size, mass flow .. standard helium leak rate .. equations .. and definitions .. detection methods without a leak detector unit .. rise test .. drop test .. test using vacuum gauges which are sensitiveto the type of gas .. immersion test .. test .. box check bubble .. 85 test .. vacuum test .. with chemical reactions and dye penetration .. detectors and how they work .. Halogen leak detectors (HLD 4000, D-Tek) .. detectors with mass spectrometers (MS) .. operating principle for a MSLD .. limit, background, gas storage in oil (gas ballast), floating zero-point suppression .. leak detectors; test leaks .. detectors with quadrupole mass spectrometer (ECOTEC II) .. leak detectors with 180 sector mass spectrometer(UL200, UL500) .. and counter-flow leak detectors .. flow operation .. to vacuum systems .. constants .. values / Specifications for the leak detector.

8 Detection techniques using helium leak detectors .. technique (local leak test) .. technology (local leak testing using the positive pressure method) .. envelope test (integral leak test) .. test test specimen pressurized with helium ..123a) Envelope test with concentration measurement and subsequent leak rate calculation ..123b) Direct measurement of the leak rate with the leak detector (rigid envelope) .. test with test specimen evacuated ..123a) Envelope = plastic tent ..123b) Rigid envelope .. Bombing test, Storage under pressure .. leak testing ..1246 Thin film controllers and control units with quartzoscillators .. principles of coating thickness measurement with quartz oscillators .. shape of quartz oscillator crystals .. measurement .. Z match technique .. active oscillator .. mode-lock oscillator .. Z match technique .. thickness regulation .. instrument variants ..1317 Application of vacuum technology for coating techniques.

9 Coating technique .. sources .. evaporators (boats, wires etc.) .. beam evaporators (electron guns) .. sputtering .. vapor deposition .. coating technology/coating systems .. of parts .. coating ..135 Table of coatings .. coating .. for producing data storage disks ..1378 Instructions for vacuum equipment operation .. of faults where the desired ultimate pressure is not achieved or is achieved too slowly .. of vacuum vessels and eliminatingcontamination .. operating information for vacuum pumps .. rotary vacuum pumps(Rotary vane pumps and rotary piston pumps) .. consumption, oil contamination, oil change .. of the pump oil when handling aggressive vapors . when pumping various chemical substances .. defects while pumping with gas ballast Potential sources of error where the required ultimate pressure is not achieved .. pumps .. operating instructions, installation and commissioning .. change, maintenance work .. in case of operational disturbances.

10 Pumps .. operating instructions .. and vapor-jet vacuum pumps .. the pump fluid and cleaning the pump .. errors with diffusion and vapor-jet pumps .. pumps .. of adsorption capacity .. the molecular sieve .. sublimation pumps .. pumps .. on working with vacuum gauges .. on installing vacuum sensors .. at the measurement system and its removal . influence of magnetic and electrical fields .. , power pack, measurement systems .. , formulas, nomograms, diagrams and symbols ..147 Tab IPermissible pressure units including the torr and its conversion ..147 Tab IIConversion of pressure units ..147 Tab IIIMean free path ..147 Tab IVCompilation of important formulas pertaining to the kinetic theory of gases ..148 Tab VImportant values ..148 Tab VIConversion of pumping speed (volume flow rate) units ..149 Tab VIIC onversion of throughput(a,b)QpV units; leak rate units ..149 Tab VIIIC omposition of atmospheric air ..150 Tab IXPressure ranges used in vacuum technology and their characteristics.