A blog on the repair, operation and calibration of surface analysis systems and components including electron spectrometers, sputter ion guns and vacuum related hardware. Click on the Index tab below to see a list of all posts. Visit our website at http://www.rbdinstruments.com
Category Archives: Operation and Calibration Procedures
Operation and calibration procedures for PHI (Physical Electronics) components
The Hastings RV-16D thermocouple vacuum gauge is used in the Physical Electronics’ (PHI) Auto Valve Control (AVC) to read the vacuum in the load lock and also at the turbo pump. There are two DV-6M thermocouple sensor tubes connected to the back of the AVC and a relay selects which one is routed to the RV-16D vacuum gauge.
The 0 to 10mV output of the RV-16D (also called the “Hockey Puck” ) goes to a comparator circuit in the AVC and is ultimately displayed on a LED segment graph on the AVC remote. One bar on the AVC remote indicates up to air and 5 bars indicates less than 5 X 10-3 Torr.
When the Hockey Puck in the AVC fails, it is usually because one of the DV-6M thermocouple sensor tubes failed and in turn some of the resistors inside the RV-16D overheated. This blog post will show you how to repair the RV-16D by replacing those failed resistors with higher wattage ones that should be able to survive the next time one of the DV-6M gauges fail.
The layout and schematic below show the resistors that usually fail. R 3 is a 15K ohm 2 watt resistor and R 4 is a 100 ohm 1/2 watt resistor.
Failed Resistors on RV-16D
Failed Resistors on RV-16D schematic
It is recommended that when you replace these resistors that you increase the wattage. For the repairs in the photos below, I used a 15K ohm 5 watt resistor and a 100 ohm 2 watt resistor. These resistors are readily available from Digikey, Newark and Mouser.
And since I already had the RV-16D torn apart I also replaced the capacitor C1 with a new one.
TC gauge before repair
TC gauge after repair
When working on the RV-16D be sure to completely unplug the power to the AVC. I recommend pulling the AVC completely out of the electronic rack or vacuum console. The RV-16D is located in the back left hand corner of the AVC. If your RV-16D has the metal cover on it you will need to remove it and either cut it around the wires or un-solder the wires an feed them through the case. Use your cell phone and take some pictures for reference before you un-solder any wires so that you can be sure to put them back in the exact same place. You do not need to replace the cover, the RV-16D will run cooler without it.
One final note. The schematic is not 100% correct as there is a 49 ohm resistor that is tied across the output on most of the RV-16D gauges that I have pulled apart. I think that this resistor replaces R5 and R6 as R6 is not needed since only the 10mV recorder output is used in the PHI AVC. If your RV-16D does not have the 49 ohm resistor, then I recommend that you add one. It will help to stabilize the output.
49 ohm resistor
If you need technical assistance or parts for the AVC or replacement DV-6M tube please contact us by creating a sales ticket here – RBD Portal Sales
Since the AVC was out anyway, I replaced the pots from the RV-16D (R1 , 1 K ohm) and also the bar adjustment pot in the AVC ( R 103 / K6 25 K ohm) to the AVC front panel with 10 turn 2 watt precision potentiometers and also installed an isolated BNC connector to the RV-16D recorder output wires (Blue and black).
This modification makes it much easier to adjust the RV-16D recorder output when you install a new DV-6M tube and to adjust the AVC for 4 bars when the load lock is pump out. The 5th bar on the AVC remote is on a timer and will turn on after the 4th bar stays on for 2 minutes.
With this modification installed it is not necessary to remove the AVC cover to adjust the hockey puck output or the AVC 4th bar.
Installing repaired TC gauge into AVC
Repaired TC gauge inside AVC
10mV and 4th bar
Soldering wires to front panel 10mV and 4th bar potentiometers
The Auto Valve Controller (AVC) is used to open and close valves on PHI surface analysis systems such as the 5000 series XPS and 660 scanning Auger systems. The AVC has a small built in microprocessor and so it also has the ability to protect the user from inadvertently opening a valve out of sequence and dumping the system.
The AVC needs to know that the turbo pump is on before certain valve functions are available. For example the V4 ion gun differential pump valve will not open under any circumstance if the turbo pump is not on.
So, how does the AVC know that the turbo pump is on? The Up to Air relay in the AVC auto valve controller is energized by a voltage from the turbo pump controller.
Up to Air relay inside AVC
When the AVC was designed PHI used Balzers (now Pfeifers) turbo pumps which had a 240 VAC output voltage when the turbo pump controller was ON. So, the Up to Air relay in most AVCs has a 240VAC coil.
Fast forward to today and some of those original Balzers/Pfeifers turbo pumps and controllers are now obsolete. So when one of those controllers fails, it needs to be replaced with a new state of the art turbo pump and controller.
These days most turbo pump controllers have a 24 V DC output voltage that can be used to control the AVC up to air relay. Both Edwards and Pfeifers have low cost replacement packages that are 4.5” CF flange mounted and also dry pumped backed. See information on those pumps at the bottom of this post.
The direct replacement 24 V DC Up to Air relay is Grainger part number 1YCZ6. This relay is the same form factor as the original Up to Air relay only it has a 24V DC coil instead of a 240 VAC coil.
24V up to air relay
Updating an AVC to this relay is a simple two-step process;
Replace the Up to Air relay in the AVC
Connect the Up to Air cable to the new turbo pump controller.
To replace the Up to Air relay in the AVC first make sure that all valves are closed and that the turbo pump is OFF.
Turn OFF the AVC and also unplug the power from the back of the AVC control. Depending on your system configuration the AVC is located in the front left hand side of the electronics console, or in the back of the vacuum console.
If the solenoid manifold is located on top of the AVC, remove the screws that hold the manifold to the cover and then remove the cover from the AVC. You should be able to move the solenoid manifold towards the back of the AVC and not need to unplug the wire bulkhead connector. Just balance the manifold on the edge of the AVC chassis.
If your AVC has the solenoid manifold mounted on the back of the AVC, then just remove the AVC cover.
Slide the AVC out enough so that you can get at the screws which mount the Up to Air relay to the side of the AVC. The Up to Air relay is located on the right hand side of the AVC chassis.
Make a drawing or use your phone and take a picture of the connections to the Up to Air relay to make sure that you put the connectors on the same way when you install the new relay. Remove the 240 VAC Up to Air relay bracket and install the new 24V DC relay.
Reattach the relay bracket to the side of the AVC.
Reattach the cover and solenoid manifold.
Reattach the power cord and slide the AVC back in.
Next, you need to attach the Up to Air cable to the new turbo pump controller. Refer to the turbo pump manual for information on how to make that connection. There will be a Setpoint output or some kind of external status connection that provides 24V DC when the turbo pump is ON.
Note the polarity of the wires on the Up to Air cable. On the end that plugs into the back of the AVC, the larger connector is the negative (ground) wire and the smaller one is the positive (+24V) connector. There are only two wires in the Up to Air cable. Red is positive and Black is ground.
If your turbo pump controller has some other voltage for the status signal (such as 12V or 5 V DC) then you will need to find a version of the Up to Air relay with that same voltage.
Once the new Up to Air relay modification is complete then you should hear the V5 vent solenoid click when the turbo pump is turned ON.
The V5 vent valve is designed to vent the turbo pump in order to prevent back-streaming of oil vapors into the system in the event of a system dump. When the AVC was first designed the backing pumps were all rotary vane mechanical pumps that used oil.
New state-of-the-art turbo pumps are typically backed with a dry pump and also have built in vent valves. If your new turbo pump is also dry backed (both of the turbo pumps listed below are then you do not need the V5 vent function.
The V5 vent valve was mounted on the rough side of the old turbo pump. If your new turbo pump is dry backed all you need to do to disable the V5 vent valve is to close the little needle valve that is either on the V5 vent valve itself or on the solenoid manifold near the V5 vent solenoid. (The largest solenoid is V1 and then you count out from there, V2, V3….)
If your new turbo pump is backed with a rotary vane oil pump then the V5 vent valve still needs to be connected to the rough line. The V5 needle valve is set to 1/4 turn CCW from the fully closed (full CW) position.
In addition, you want to make sure that the mechanical pump turns OFF when the turbo pump is turned OFF. If you need help with that contact RBD Instruments.
The affordably priced turbo pumps below can replace the original Balzers TPU 040 thru TPU 062 turbo pumps on older PHI surface analysis systems. If you order one, make sure that you order it with a 4.5” CF flange. A 4.5” CF flange will make it easier to adapt the new turbo to the existing vacuum connections.
If you get one of the Pfeiffer Cubes then this is the cable that you will need to connect to the Up to Air connector on the back of the AVC – Digikey PN A120881-ND made by TE and the TE PN is 22730001-1
This post will show how to replace the 10-610 monochromator X-ray source anode and filaments. The 10-610 monochromator X-ray source is used in conjunction with the 10-410 or 10-420 monochromator. When replacing the anode you should also replace both filaments and the deionizer cartridge (located in the 16-0XX heat exchanger).
Once the anode and filaments have been replaced the vacuum chamber needs to be baked out and the new filament and anode need to be out gassed and conditioned. The monochromator may also need to be adjusted slightly to optimize the counts with the new anode and filaments.
Please read the entire procedure first, then watch the picture slideshow at the bottom of the post.
Anode replacement procedure
Vent the chamber.
Remove the water lines from the source.
Remove the safety cover from the source (3 screws).
Remove the high voltage cable
Remove the sixteen 5/16” bolts on the 6” flange and remove 10-610 mono source from the monochromator.
Next, remove the screw that connects the ground wire to the manifold.
Remove the Teflon block from the source base (2 spline cap head screws).
Remove the Teflon block from the source base. Twist it as you slide it off the anode.
Loosen the nut on the high voltage connector (3/4” open end wrench) and remove the high voltage connector.
Remove the silicone rubber insulator and spring. The spring makes electrical contact between the high voltage connector and the anode flange.
Remove the three spline cap head screws that hold the base to the flange and remove base from the flange. Note, this is optional as the base can stay on for bake out.
Remove the two screws that hold the filament cover on and remove the filament cover.
Remove the two screws that hold the filament cover support on and remove the filament cover support. Note the position of the covers as you take them out as they need to go back the same way.
Remove the 6 cap head screws that hold the anode to the base and lift the old anode out of the source housing.
Separate the old anode from the anode flange.
Install a new O-ring on the new anode bottom and slide the anode flange into the new anode. There are 4 O-rings in the anode kit. The anode flange forces the cooling water to the tip of the anode.
Use a new copper gasket and mount the new anode onto the anode flange. Use care as you slide the anode in not to touch the sides of the anode housing (like the old game Operation). The anode surface is coated with a thin layer of aluminum on a copper substrate. Any contact with the top of the anode surface can cause little dents in the anode surface that can cause arc points. Tighten the 6 cap head screws very lightly as the anode will need to be adjusted.
Using plastic tweezers or needle nose pliers, carefully rotate the anode until it is parallel to the filament housing. The idea is that the anode should be parallel to the anode housing and also centered so that there is a maximum and equal distance between the anode and the housing in order to prevent arcing.
Once the anode is parallel, tighten the six cap head screws on the base all the way down.
center the anode
Next, if necessary loosen the 4 screws on the copper pedestal and move it to center the anode for maximum distance between the anode and the filament housing. If available, you can use the anode alignment tool to help center the anode and then tighten the 4 screws on the base of the copper pedestal.
anode alignment tool
The anode surface should be the same level as the fence that is between the filaments and the anode. If not loosen the spline head cap screw that secures the filament housing to the copper pedestal. You can use the anode alignment tool, a straight edge or just eye ball it.
Filament replacement procedure
The filaments are coated with Yttrium so that they can provide sufficient electrons for emission at a lower filament operating current. Be careful when handling the filaments so that you do not knock off any of the coating on the filaments.
Loosen the filament clamp screws on the large 7mm (diffused) area filament and remove the old filament. Note that the large 7mm filament is closest to the filament connector and wires.
Carefully insert the new filament into the filament clamps and lightly tighten them. The filament should be centered with respect to the anode and the top of the filament should be even with the top of the filament cavity (level with the anode guard). It should also be parallel to the anode guard and centered in the filament cavity. If not, remove the filament and carefully bend the legs as needed. Once the filament height and centering is correct, firmly tighten the filament clamp screws.
Repeat this procedure for the small 2mm (focused) filament.
Install the filament cover base and cover. Note that the little cut out goes over the 2mm filament.
Condition the anode and filaments procedure
Once the new anode and filaments have been installed onto the 10-610 monochromator X-ray source, the source needs to be baked out and then outgassed and conditioned.
First, bake out the system.
Next, outgas the filaments
Finally, condition the anode
Bake out the system
Follow the bake out procedure in the PHI manual or search for the RBD Techspot blog- Bake-out procedure to improve base vacuum.
The O-rings on the mono source, HV connector and silicone rubber insulator and Teflon block are all removed from the 10-610 mono source before bake out. After bake out, use a little bit of vacuum grease on the O-rings to help provide a tight water seal when the Teflon block is replaced.
Replace the deionizer cartridge in the 16-0XX heat exchanger. PHI recommends that the deionizer cartridge be replaced each time the anode is replaced to help make sure that the water does not react with the anode.
Outgas the filaments
Prior to outgassing the filaments the system should have been baked out and the mono source housing and water lines reassembled. The deionizer cartridge should also have been replaced. The system should be cool and the base pressure in the low 10-9 to low 10-10 Torr range.
The filaments need to be initially outgassed slowly in order to prevent warping and also to set them.
Select the Outgas/ACT mode on the X-ray source controller.
Select the 2mm focused filament and ramp the current up to 5 amps in increments of .5 amps over a period of 2 to 5 minutes. Wait for the outgassing to subside somewhat as indicated by the ion gauge.
Set the 2mm focused filament current to zero amps and then repeat the procedure with the 7mm diffused filament. Once up to 5 amps, let the 7mm diffused filament sit there for 4 to 8 hours or until the base vacuum returns to the low 10-9 Torr range. Then set the filament current to zero and turn off the Outgas/ACT mode on the X-ray source controller.
Degas the Anode
Set the beam voltage to 500V and turn it on.
On the X-ray source controller, select the Outgas/ACT mode
Select the 2mm focused filament (Mg filament on a 32-095/6)
Slowly increase the amps to 3.5 and then monitor the anode current (emission current) meter.
VERY SLOWY increase the filament current until you get 1mA of emission current. Do not exceed 5 amps of filament current. Do not exceed 2mA of emission current.
Monitor the ion gauge vacuum reading and wait until the outgassing comes back down then slowly increase the beam voltage to 1 kV. If necessary reduce the filament current to keep the emission below 2mA.
In steps of 500V bring the high voltage up to 10kV while adjusting the filament current as needed to keep the emission current below 2mA. Do this over a period of 30 minutes to several hours, depending on how much the anode outgasses. For best results keep the vacuum in the chamber in the low 10-9 Torr range. The higher the pressure from outgassing, the more likely an arc will occur.
Once the anode has been outgassed to 10kV, turn the filament current to zero and set the high voltage to zero. Then switch to the other filament and repeat the procedure.
Condition the high voltage
Make sure that the Out/Act button is OFF and that the filament current is set to zero on both filaments.
SLOWLY bring the high voltage up to 10kV while monitoring the vacuum chamber ion gauge.
Step the high voltage up increments of 500V until you get to 16.5kV. When you see some signs of outgassing (the pressure in the vacuum chamber will come up) then back down the high voltage a little bit and wait until the vacuum recovers.
Once you are able to get to 16.5 kV with no arcing, let the anode sit there for at least 20 minutes.
The X-ray source is now ready for normal operation. For best results, start at a low power and kV such as 100 watts and 10kV. You can step up both the power and the kV over a period of a few hours based on how much outgassing you see when operating in this mode. Once you are up to full power of 300 watts and 15kv the X-ray source can be brought up to full power quickly.
Note that the maximum power that should be applied to the 2mm focused filament is 350 watts and the maximum power that should be applied to the 7mm diffused filament is 600 watts. Personally I do not recommend more than 300 watts on either anode. If you can get by with a lower wattage (such as 250) then both the filaments and anode will last longer.
It is also recommended that you inspect the 10-610 mono anode any time you vent your chamber for maintenance, or at least once a year. If you see indications of melting in the center of the anode you should replace the anode. Otherwise it will eventually develop a water leak and cause potentially catastrophic damage to system components and substantial downtime.