DGC IV calibration

Posted on November 8, 2016 by Randy

Years ago RBD Instruments had our DGC IV manufactured by JC Controls. The DGC IV is basically the same thing as a IG4500.

Although we no longer produce the DGC IV, there are still a few of them in the field. The calibration procedure is listed below.

POTENTIOMETERS LIST

PR7(VREF)Reference Voltage Adjust Direction are with the front

PR4(TC1 Z)TC1 Zero Adjust of the IG4500 facing you.

PR6(TC2 Z)TC2 Zero Adjust N

PR3 TC1 Gain Adjust W –+– E

PR5 TC2 Gain Adjust S

R1(EMIS) Emission Adjust

PR2(ELEC)Electrometer Adjust

Power Supply Tests ( Ground)

Attach Tester box to controller and check voltages on computer or do steps B,C,D,E
Test -15,+15,+5 from 8 Pin Power Connector Pins 2,3,4.
Turn on Ion Gauge
Test +180 V From Grid Pin (Outside) of tube to Ground.
Test +150 V from Grid Pin to Fil Pin (Outside to Inside) of tube.
Check Degas

(1) Reference Voltage Adjustment

Connect DC DVM from R14{E} to ground R31{E}
Turn on IG4500 while holding down the SELECT switch,.
While holding down the SELECT Switch, adjust PR7 (VREF) until the DC voltage is 10.000 ( +/- .001 )
Release Select Switch and Check off Recorder output box
Turn Power off and on, check that all the LED light up, if so check off Digit(LED) Test

(2) TC1 & TC2 Zero Adjustment

Connect TC Cable to TC1 Input on back of IG4500.
Connect a TC tube that is at Atmosphere to the cable.
Connect DC DVM from R26{E} to ground (R31{E})
Adjust PR4(TC1 Z) until DC Voltage is .133 VDC. (+/- .005 )
Do the same with TC2, Using TC2 Input, R33{E} & PR6(TC2 Z).

(3) TC1 & TC2 Gain Adjustment

Connect TC Cable to TC1 Input on Back of IG4500.
Adjust PR3 through the back panel until the main display is the same vacuum as the Test Tube. Because TC Tubes work by Heat, give the tubes time to readjust after the pot is turned.
Do then same with TC2, Using TC2 Input, Bar Graph & PR5.

(4) Emission Adjustment

Use tester box or connect a current meter in series with Pin 3 of J1 ( Power Connector ).
Connect IG cable to unit and a IG Test Tube. Connect the current source to the BNC on the unit.
Turn on power and turn on ion gauge tube. Use current source to get to 10 mA range
Adjust PR1 (EMIS) until you get 10.0 mA (+/- .05) on current meter.
Use current source to switch down to 1 mA range, emission should be 1.00mA on current meter, Record current.

(5) Electrometer Adjustment

A. Connect current source to IG4500, set to 1uA. Turn on Ion Gauge.

B. Adjust PR2 (ELEC) so IG4500 displays 1.0-04.

C. Repeat Step B for 1nA=1.0-08, 100pA=1.0-09.

D. Also record for 10pA, it should be 1.0-10. (+/- 2.0)

(6) Setpoint & EEPROM

A. Check that the relay turn on and off by listening for them to click

B. Use the computer to set the serial number.

C. Turn unit off and on, Check serial number in “Edit Window” by entering =R#

Technical Modes of IG4500

* Enable Adjust Mode

This mode is for turning the System Enables on and off. It is entered by pressing and holding down the [ION] & [SELECT] buttons while turning on the main power . The display will show The Enable Name followed by either On or Off.

IGS Enables

Enable Name	Description
F	Filament Enable ( Display Mode )
Fd	Full Duplex RS-232 Communication
C1	Code 1 enabled – Filament Overdrive
C2	Code 2 enabled – Under Vacuum, No Collector
C3	Code 3 enabled – Over Vacuum
A	Averaging Enabled
E	Emission Ranging Enabled

To Adjust the enables press the [ION] switch to select the different enables and the [DEGAS] switch to change from on to off. The Default for the IG4500 is All enables on.

** Timer and Control Mode

This Mode displays the timer value from the electrometer circuit. The value is a 6 digit Hexadecimal number. To put it on the 5 digit display either the lower 5 or the upper 5 digits will be displayed depending on if the high digit is a 0 or not. The Units LED’s are used as status LED’s

Display Unit LED’s

LED Name	Status
Torr	25’th Bit of timer
Min	Averaging On
mA	Full Emission On

Mode 8 is entered by turning the Display switch to Emis. , then press the [ION] & [DEGAS] at the same time. The [ION] button will turn the Averaging on & off, you should make sure Averaging is disabled before adjusting it manually or else the controller will probably switch it back. The [DEGAS] button will switch between Full and 1/10 Emission Current.

Longer lifetime ionizer

Posted on October 10, 2016 by Randy

Longer lifetime ionizer for the 04-303 and 06-350 ion source.

Longer-lifetime-ionizer

As many of you know, RBD Instruments’ 04-303 and 06-350 ionizer rebuilds last for an average of 1100 hours of run time. Depending on how much sputtering you do, that can translate into anywhere from 2 months to 3 years between ionizer replacements. But wouldn’t it be nice if they could last longer, such as 2000 hours or more?

Introducing the new long life 04-303 and long life 06-350 ionizer! There are two failure mechanisms related to the ionizers that we have addressed with our new and improved rebuild process. First, as part of the normal operation of the filament, tungsten slowly evaporates onto the base of the ionizer. That coating can cause leakage current between the grid and extractor that shows up as pressure on the 11-065 controller even when no gas is being fed into the source. That ghost pressure current typically shows up towards the end of the filament lifetime cycle. We have addressed this problem by cutting a groove into the ceramic base at the location where the tungsten deposit occurs. That groove will prevent the leakage current from happening when the deposition occurs.

The second improvement that we have implemented is a special low temperature filament wire. Besides running much cooler, the wire evaporation rate is greatly reduced so the deposition rate is also reduced proportionally. Just as with our normal ionizer rebuilds, the filament will hold its shape for the entire filament lifetime, resulting in a very stable and repeatable ion current.

Another benefit of our low temperature wire is that it takes much less filament current to get the same emission current as compared to the normal tungsten wire. As a result, the ion gun controller will also run 20% cooler and operate trouble free longer.

So how long with our new ionizer last? We are projecting between 2000 and 2500 hours but need more data to be able to provide an accurate answer. That is where you can help us. We will be offering a few of our new long-life ionizers at a reduced price and in return we ask that you keep a log of how many hours you get before the ionizer burns out. As that data comes in we will be able to provide an accurate average lifetime.

A longer lifetime ionizer pays for itself by reducing how often you need to vent your chamber for maintenance.

For more information or to place an order, please contact us.

20-622 calibration

Posted on August 17, 2016 by Randy

Below are the DR11 commands use in the 20-622 calibration procedure. The 20-622 electron gun control is used on the Physical Electronics 660 scanning auger systems.

Command Structure

Use DR11 program or RBD 147 diagnostics for computer control.

Function Command/Data (hex)

Beam Voltage 1ddd

Emission 2ddd

Objective Lens 3ddd

Iso. Objective Lens 4ddd

Obj Y 5ddd

Obj X 6ddd

Cond Y 7ddd

Cond X 8ddd

Reset Overcurrent 9ddd

Cond Lens Addd

Notes: – the command and the data are combined in a 16 bit word

– the left-most digit is most significant in address position and data value

– “d” represents a data value in hex

– 000H = 0, 7FFH = 2047 (mid-scale), FFFH = 4095 (max)

Set the CSR (= 1) for proper communication.

Calibration

Beam Voltage and Emission

Take the readings from the High Voltage (HV) Programming connector on the back panel. The Beam Voltage reading is taken from pin A and the Emission reading is taken from pin B. The reference is to chassis ground. Note: the bit number in () indicates the only bit set (=1), for troubleshooting purposes.

Command/Data BV ctrl voltage (V)

1000H .001

1100H (bit 8) .625

1200H (bit 9) 1.25

1400H (bit 10) 2.50

1800H (bit 11) 5.00

1C00H 7.50

1FFFH 10.00

Check for increasing voltage as you enter the following values in sequence: 1000H, 100FH (bits 0-3), 1010H (bit 4), 1020H (bit 5), 1040H (bit 6), 1080H (bit 7).

Command/Data Emission ctrl voltage (V)

2000H .001

2100H (bit 8) .625

2200H (bit 9) 1.25

2400H (bit 10) 2.50

2800H (bit 11) 5.00

2C00H 7.50

2FFFH 10.00

Check for increasing voltage as you enter the following values in sequence: 2000H, 200FH (bits 0-3), 2010H (bit 4), 2020H (bit 5), 2040H (bit 6), 2080H (bit 7).

Condenser and Objective Lenses

A 200 ohm 2W 10-turn potentiometer must be connected to the Objective Fine Adjustment connector on the back before checking the voltages (Unless it is connected in the electronics bay) . Connect pin D to the pot wiper and connect pins A and C to the pot limits (either order). Set the pot to midway (5 turns for a 10-turn pot).

Note: the bit number in () indicates the only bit set (=1), for troubleshooting purposes. The voltages across the resistors (RX) are taken behind the front panel.

Iso. Objective

Command/Data R1-R6 Voltage (V)

4000H .016

4100H (bit 8) .304

4200H (bit 9) .610

4400H (bit 10) 1.22

4600H 1.83

4800H (bit 11) 2.44

4A00H 3.05

4C00H 3.66

4F00H 4.58

4FFFH 4.88

Check for increasing voltage as you enter the following values in sequence: 4000H, 400FH (bits 0-3), 4010H (bit 4), 4020H (bit 5), 4040H (bit 6), 4080H (bit 7).

Objective

Command/Data R7-R10 Voltage (V)

3000H .021

3100H (bit 8) .322

3200H (bit 9) .645

3400H (bit 10) 1.29

3600H 1.94

3800H (bit 11) 2.58

3A00H 3.23

3C00H 3.88

3F00H 4.85

3FFFH 5.17

Check for increasing voltage as you enter the following values in sequence: 3000H, 300FH (bits 0-3), 3010H (bit 4), 3020H (bit 5), 3040H (bit 6), 3080H (bit 7).

Condenser

Command/Data R11-R14 Voltage (V)

A000H .018

A100H (bit 8) .469

A200H (bit 9) .939

A400H (bit 10) 1.88

A600H 2.82

A800H (bit 11) 3.76

AA00H 4.70

AC00H 5.64

AF00H 7.05

AFFFH 7.50

Check for increasing voltage as you enter the following values in sequence: A000H, A00FH (bits 0-3), A010H (bit 4), A020H (bit 5), A040H (bit 6), A080H (bit 7).

Steering

Check for proper centering of the voltages at the Objective and Condenser Steering connector on the back panel.

Command/Data Between pins, Voltage (V)

57FFH F&H, 0V +/- .4V Obj. Y

67FFH E&G, 0V +/- .4V Obj. X

77FFH B&D, 0V +/- .4V Cond. Y

87FFH A&C, 0V +/- .4V Cond. X

20-622 System Test

It is possible for a 20-620 or 20-622 to work on the bench but not focus properly on a system. That is because on the bench the Objective and ISO Objective supplies are tested separately but on the system the objective coil is actually two coils which are tied together. So one of the objective supplies may cave in when connected to the objective coil. You can do a quick test by measuring the voltage across the current resistors behind the front panel of the 20-622 or 20-620.

Voltages for the 20-622 are listed below. The 20-620 should show a similar trend.

20-622 3kV Beam voltage, COND set to 35%, OBJ set to 74.49%, and Objective fine pot set to midrange.

COND	.856
OBJ	3.68
ISO OBJ	3.69

20-622 5kV Beam voltage, COND set to 35%, OBJ set to 83.49%, and Objective fine pot set to midrange.

COND	1.076
OBJ	3.85
ISO OBJ	3.47

20-622 Coil voltage supply test points

There are three coil voltage supplies in the 20-622:

Condenser 30V DC

Objective 34.5V DC

Isolated Objective 40V DC

To measure the supplies, remove the 4 screws on the 20-622 front panel and drop the front panel down (it is on a hinge).

There are three fuses visible on the front center of the heat sink assembly.

The top fuse is the Condenser supply, and it has a value of 1.5A slow blow. Measure from either side of the fuse to the chassis and there should be approximately 30 V DC when the 20-622 main power is turned ON.

The center fuse is the Objective supply, and it has a value of 2A slow blow. Measure from either side of the fuse to the chassis and there should be approximately 34.5 V DC when the 20-622 main power is turned ON.

The bottom fuse is the isolated Objective supply, and it has a value of 2.5A slow blow. Measure from either side of the fuse to the ISO Objective test point (white wire) near the far-right hand current sense resistors. There be approximately 40 V DC when the 20-622 main power is turned ON.

The picture below shows the ISO Objective test point location.