Hi !

Well, actually I even don't think if there is as an oil backstreaming,because my DP has a water cooled cold cap and water cooled cold trap too, but I had to put some lubricant into my chamber. Because, the planetary substrate holder has two ball bearings in the chamber and these needs lubricant. I used a mix of high vacuum grease and some only drops of diffoil 20 ultra. But it is not really good.
I have to try another lubricant, just I dont know what...

My emitter for the glow discharge is about 20mm from the surface last time, before that was 250mm.

The source and substrate distance is 330mm. My best vacuum was ever 2x10-5 torr, this is the system best.

Unfortunatelly the ion source does not work yet. First I have to change my diffusion pump, because the recent pumping speed is too low, it is not enough to operate the ion source too.

Best regards,

Attila

--- In VacuumX@..., Vladimir Chutko<chutko@...> wrote:

Hi Attila,

230 A/s - in my opinion it is too much.....

Anyway I suppose that bad local adhesion is because of a bad cleaning.
If there would be oil backstreaming, oil vapor must cover a whole
surface and there shouldn't be areas with a good adhesion. But things
happen...

140 nm is not a problem. Doing Al mirrors I deposit 100 nm with no
problems. Do you pre-clean your substrate with ion beam?

What is your vacuum? For good layer it must be as low as possible, at
least less than (1-2)x10-5 torr.

Try to decrease deposition rate to 40 - 60 A/s and see what happen.
Maybe it helps.

Best regards,

Vladimir


On 9/8/2011 12:30 PM, Attila wrote:

Hi Vladimir!

Well thank you for the advises!

Yesterday I increased the evaporation rate up to 230 Anstrm/sec(23nm/sec)
The adhesion is much better, but still not passing the tape test.Parts of the layer peals off another parts don't.

Maybe the layer is too thick, because it is 140nm thick. Maybe my precleaning methode is not good. Or could that cause an oil backstreaming from my diffusion pump?


Best regards

Attila

--- In VacuumX@..., Vladimir Chutko<chutko@> wrote:

Hi Attila,

1. Very low evaporation rate. For Al it should be at least tens A/s. I
evaporate Al on a cold substrate at 40 A/s.
2. 4x10-5 torr is not very good for Al. Actually than vacuum is better,
than Al coating is better. It is recommended to evaporate Al at pressure
below 10-5 torr.
3. Cr underlayer strongly improves adhesion.

Best regards,

Vladimir

On 9/2/2011 7:49 AM, Attila wrote:

Hi All,

I ran into a trouble during my evaporation session.
My aluminium coating doesn't pass the tape test for adhesion.

My cleaning methode is:

-First I clean the mirror with isopropanol
- Next I use Balzers substrate cleaner no.1.
-Then the Balzers substrate cleaner no.2 so as the manual said.

After this I immediately put the mirror into the chamber and evacuate to 0.02-0.03 Torr.

Then I let run Argon into the chamber and glow discharge for 15 min.
After this I go down to 6x10-5 Torr, and again let the Argon into the chamber to 0.1 Torr and low discharge at 10Kv and 20mA for another 15 min.
Then evacuate as deep as possible, last time 4x10-5 Torr.
I evaporate aluminium using e-beam at 5 Angstrm per sec. Meantime the optics are turned by the planetary holder.

After this I can let the optic so or make an overcoat of Sio2 or Sio2 and Tio2, doesn't matter the adhesion does not pass the test(bare alu, protected or enhanched does not matter)

What could be wrong?

Or should I apply 10nm of chromium as an adhesive layer?
Just I don't know later how can I strip off the chromium?

Also does not matter the glass type of the substrate.

Thank's for the suggestions.

Attila
The Hun





------------------------------------

Yahoo! Groups Links

------------------------------------

Yahoo! Groups Links

------------------------------------

Yahoo! Groups Links

Hi Attila,

230 A/s - in my opinion it is too much.....

Anyway I suppose that bad local adhesion is because of a bad cleaning.
If there would be oil backstreaming, oil vapor must cover a whole
surface and there shouldn't be areas with a good adhesion. But things
happen...

140 nm is not a problem. Doing Al mirrors I deposit 100 nm with no
problems. Do you pre-clean your substrate with ion beam?

What is your vacuum? For good layer it must be as low as possible, at
least less than (1-2)x10-5 torr.

Try to decrease deposition rate to 40 - 60 A/s and see what happen.
Maybe it helps.

Best regards,

Vladimir


On 9/8/2011 12:30 PM, Attila wrote:

Hi Vladimir!

Well thank you for the advises!

Yesterday I increased the evaporation rate up to 230 Anstr?m/sec(23nm/sec)
The adhesion is much better, but still not passing the tape test.Parts of the layer peals off another parts don't.

Maybe the layer is too thick, because it is 140nm thick. Maybe my precleaning methode is not good. Or could that cause an oil backstreaming from my diffusion pump?


Best regards

Attila

--- In VacuumX@..., Vladimir Chutko<chutko@> wrote:

Hi Attila,

1. Very low evaporation rate. For Al it should be at least tens A/s. I
evaporate Al on a cold substrate at 40 A/s.
2. 4x10-5 torr is not very good for Al. Actually than vacuum is better,
than Al coating is better. It is recommended to evaporate Al at pressure
below 10-5 torr.
3. Cr underlayer strongly improves adhesion.

Best regards,

Vladimir

On 9/2/2011 7:49 AM, Attila wrote:

Hi All,

I ran into a trouble during my evaporation session.
My aluminium coating doesn't pass the tape test for adhesion.

My cleaning methode is:

-First I clean the mirror with isopropanol
- Next I use Balzers substrate cleaner no.1.
-Then the Balzers substrate cleaner no.2 so as the manual said.

After this I immediately put the mirror into the chamber and evacuate to 0.02-0.03 Torr.

Then I let run Argon into the chamber and glow discharge for 15 min.
After this I go down to 6x10-5 Torr, and again let the Argon into the chamber to 0.1 Torr and low discharge at 10Kv and 20mA for another 15 min.
Then evacuate as deep as possible, last time 4x10-5 Torr.
I evaporate aluminium using e-beam at 5 Angstr?m per sec. Meantime the optics are turned by the planetary holder.

After this I can let the optic so or make an overcoat of Sio2 or Sio2 and Tio2, doesn't matter the adhesion does not pass the test(bare alu, protected or enhanched does not matter)

What could be wrong?

Or should I apply 10nm of chromium as an adhesive layer?
Just I don't know later how can I strip off the chromium?

Also does not matter the glass type of the substrate.

Thank's for the suggestions.

Attila
The Hun





------------------------------------

Yahoo! Groups Links

------------------------------------

Yahoo! Groups Links

?

@Thomas

The pump is new. Is a break-in period required before the best vacuum is reached. Right now, I only have about 2 hrs running time on it.

Bruce

--- In VacuumX@..., Thomas Janstrom wrote:
>
> Have you baked the fittings sensor etc. while pumping down? Might get
> you a bit further down, but if it's holding vacuum then it's not going
> to be the magic bullet.
>
> Oh yeah is the pump brand new or older?
>
> Thomas.
>
>
>

Hi Attila,

230 A/s - in my opinion it is too much.....

Anyway I suppose that bad local adhesion is because of a bad cleaning.
If there would be oil backstreaming, oil vapor must cover a whole
surface and there shouldn't be areas with a good adhesion. But things
happen...

140 nm is not a problem. Doing Al mirrors I deposit 100 nm with no
problems. Do you pre-clean your substrate with ion beam?

What is your vacuum? For good layer it must be as low as possible, at
least less than (1-2)x10-5 torr.

Try to decrease deposition rate to 40 - 60 A/s and see what happen.
Maybe it helps.

Best regards,

Vladimir


On 9/8/2011 12:30 PM, Attila wrote:

Hi Vladimir!

Well thank you for the advises!

Yesterday I increased the evaporation rate up to 230 Anstr?m/sec(23nm/sec)
The adhesion is much better, but still not passing the tape test.Parts of the layer peals off another parts don't.

Maybe the layer is too thick, because it is 140nm thick. Maybe my precleaning methode is not good. Or could that cause an oil backstreaming from my diffusion pump?


Best regards

Attila

--- In VacuumX@..., Vladimir Chutko<chutko@> wrote:

Hi Attila,

1. Very low evaporation rate. For Al it should be at least tens A/s. I
evaporate Al on a cold substrate at 40 A/s.
2. 4x10-5 torr is not very good for Al. Actually than vacuum is better,
than Al coating is better. It is recommended to evaporate Al at pressure
below 10-5 torr.
3. Cr underlayer strongly improves adhesion.

Best regards,

Vladimir

On 9/2/2011 7:49 AM, Attila wrote:

Hi All,

I ran into a trouble during my evaporation session.
My aluminium coating doesn't pass the tape test for adhesion.

My cleaning methode is:

-First I clean the mirror with isopropanol
- Next I use Balzers substrate cleaner no.1.
-Then the Balzers substrate cleaner no.2 so as the manual said.

After this I immediately put the mirror into the chamber and evacuate to 0.02-0.03 Torr.

Then I let run Argon into the chamber and glow discharge for 15 min.
After this I go down to 6x10-5 Torr, and again let the Argon into the chamber to 0.1 Torr and low discharge at 10Kv and 20mA for another 15 min.
Then evacuate as deep as possible, last time 4x10-5 Torr.
I evaporate aluminium using e-beam at 5 Angstr?m per sec. Meantime the optics are turned by the planetary holder.

After this I can let the optic so or make an overcoat of Sio2 or Sio2 and Tio2, doesn't matter the adhesion does not pass the test(bare alu, protected or enhanched does not matter)

What could be wrong?

Or should I apply 10nm of chromium as an adhesive layer?
Just I don't know later how can I strip off the chromium?

Also does not matter the glass type of the substrate.

Thank's for the suggestions.

Attila
The Hun





------------------------------------

Yahoo! Groups Links

------------------------------------

Yahoo! Groups Links

Have you baked the fittings sensor etc. while pumping down? Might get
you a bit further down, but if it's holding vacuum then it's not going
to be the magic bullet.

Oh yeah is the pump brand new or older?

Thomas.


On 8/09/2011 11:33 PM, trikeflight wrote:

Thanks Gomez --

FYI, I bought a Viot 2-stage rotary vacuum pump (2.75 lpm) for some
plasma experiments. To check out the pump's ultimate performance, I
mounted a TIF9450D Digital Micron Gauge directly on the pump's 3/8"
brass input port (with an isolation ball valve). With fresh oil and
clean brass fittings, I am able to pump down to about 200 microns Hg
after several out-gassing cycles lasting about an hour. It appears
that 200 microns is the floor for this setup. With the ball valve
shut, the small sensor chamber leaks only a few microns a day, so I
know I have a tight chamber. This pump has an "ultimate vacuum" rating
of about 15 microns, so I am trying to determine if my mediocre vacuum
level of 200 microns is due to my inexperience with vacuum systems or
if this performance is "normal" for an inexpensive 2-stage rotary
vacuum pump. Comments and suggestions are welcome.

Bruce

--- In VacuumX@... <mailto:VacuumX%40yahoogroups.com>,
Gomez Addams <gomez@> wrote:

On Sep 6, 2011, at 9:57 PM, trikeflight wrote:

The specifications for several two-stage, rotary vacuum pumps list
an "ultimate vacuum rating" of around 15-20 microns Hg. Has anyone
come close to these vacuum pressures with one of these commercial
pumps? If so, what pump make/model and what type of pressure sensor
did you use?

From my limited experience and a lot of reading, those ultimate
pressures apply to a brand new pump fresh from the factory, with brand
new oil of the best available sort, dead-headed with a sensor at the
port (obviously).

And it will only do that after perhaps a hundred hours of break-in,
but only for the first 1,000 hours of operation maybe much less
depending on the design.

This is kind of a hand-wave estimate from memory tho. Why? Do you
want to try to achieve a moderately high vacuum without a high vacuum
pump? Doing so nearly always puts you on the edge of the mechanical
pump's performance, and will lead to tears as soon as it no longer
performs at its peak.

Hi Vladimir!

Well thank you for the advises!

Yesterday I increased the evaporation rate up to 230 Anstrm/sec(23nm/sec)
The adhesion is much better, but still not passing the tape test.Parts of the layer peals off another parts don't.

Maybe the layer is too thick, because it is 140nm thick. Maybe my precleaning methode is not good. Or could that cause an oil backstreaming from my diffusion pump?


Best regards

Attila

--- In VacuumX@..., Vladimir Chutko<chutko@...> wrote:

Hi Attila,

1. Very low evaporation rate. For Al it should be at least tens A/s. I
evaporate Al on a cold substrate at 40 A/s.
2. 4x10-5 torr is not very good for Al. Actually than vacuum is better,
than Al coating is better. It is recommended to evaporate Al at pressure
below 10-5 torr.
3. Cr underlayer strongly improves adhesion.

Best regards,

Vladimir

On 9/2/2011 7:49 AM, Attila wrote:

Hi All,

I ran into a trouble during my evaporation session.
My aluminium coating doesn't pass the tape test for adhesion.

My cleaning methode is:

-First I clean the mirror with isopropanol
- Next I use Balzers substrate cleaner no.1.
-Then the Balzers substrate cleaner no.2 so as the manual said.

After this I immediately put the mirror into the chamber and evacuate to 0.02-0.03 Torr.

Then I let run Argon into the chamber and glow discharge for 15 min.
After this I go down to 6x10-5 Torr, and again let the Argon into the chamber to 0.1 Torr and low discharge at 10Kv and 20mA for another 15 min.
Then evacuate as deep as possible, last time 4x10-5 Torr.
I evaporate aluminium using e-beam at 5 Angstrm per sec. Meantime the optics are turned by the planetary holder.

After this I can let the optic so or make an overcoat of Sio2 or Sio2 and Tio2, doesn't matter the adhesion does not pass the test(bare alu, protected or enhanched does not matter)

What could be wrong?

Or should I apply 10nm of chromium as an adhesive layer?
Just I don't know later how can I strip off the chromium?

Also does not matter the glass type of the substrate.

Thank's for the suggestions.

Attila
The Hun





------------------------------------

Yahoo! Groups Links

------------------------------------

Yahoo! Groups Links

I got one more thing to add. I have a dual diff pump with Dow 704 oil in it and a really really really tiny leak in the left pump. This puts a tiny flow of air into the left pump that results in a carry of vapor into the tank and eventually into my right diff pump ( then to dump ). All this said, I also failed the tape test for a long time. I believe it was because of the high voltage cleaning system.

The HV plasma was incinerating the oil vapor and putting a kind of soot on the surfaces. When I stopped using the HV cleaning system I stopped having the soot problem and my coatings started sticking way better.

You may not have the leak like I do, but if there is any ( and I mean any ) hydrocarbons in your chamber, then when you fire up your HV you are going to make soot. You may not see it but it is there. That may ( only guessing here ) be what is adding to the adhesion issue.

The deeper the vacuum the farther away the emitters can be. I suggest moving the emitters closer to the mirror. My bud ( that never calls me anymore ) James Lerch has his emitters about 3" from the mirror surface. He has awesome adhesion. I have to have my emitters no farther than 18" or my coatings will come right off.

I find that a wipe with really really thin slurry of CeO and a damp soft cloth does wonders to get a surface hungry for aluminum ice.


Drew in soggy Florida.

ps.......... totally unrelated......... I got the 1000 amp transformer hooked up to the tantalum box finally and it is under the XMS-1 thickness monitor control. I am going to try for over-coat again this weekend.


-----------------------------------------------------------------------------------------------

On Thu, Sep 8, 2011 at 3:30 PM, Attila <schneyolo@...> wrote:

Hi Vladimir!

Well thank you for the advises!

Yesterday I increased the evaporation rate up to 230 Anstrm/sec(23nm/sec)
The adhesion is much better, but still not passing the tape test.Parts of the layer peals off another parts don't.

Maybe the layer is too thick, because it is 140nm thick. Maybe my precleaning methode is not good. Or could that cause an oil backstreaming from my diffusion pump?

Best regards

Attila

?

Thanks Gomez --

FYI, I bought a Viot 2-stage rotary vacuum pump (2.75 lpm) for some plasma experiments. To check out the pump's ultimate performance, I mounted a TIF9450D Digital Micron Gauge directly on the pump's 3/8" brass input port (with an isolation ball valve). With fresh oil and clean brass fittings, I am able to pump down to about 200 microns Hg after several out-gassing cycles lasting about an hour. It appears that 200 microns is the floor for this setup. With the ball valve shut, the small sensor chamber leaks only a few microns a day, so I know I have a tight chamber. This pump has an "ultimate vacuum" rating of about 15 microns, so I am trying to determine if my mediocre vacuum level of 200 microns is due to my inexperience with vacuum systems or if this performance is "normal" for an inexpensive 2-stage rotary vacuum pump. Comments and suggestions are welcome.

Bruce

--- In VacuumX@..., Gomez Addams wrote:
>
>
> On Sep 6, 2011, at 9:57 PM, trikeflight wrote:
>
> > The specifications for several two-stage, rotary vacuum pumps list
> > an "ultimate vacuum rating" of around 15-20 microns Hg. Has anyone
> > come close to these vacuum pressures with one of these commercial
> > pumps? If so, what pump make/model and what type of pressure sensor
> > did you use?
>
> From my limited experience and a lot of reading, those ultimate
> pressures apply to a brand new pump fresh from the factory, with brand
> new oil of the best available sort, dead-headed with a sensor at the
> port (obviously).
>
> And it will only do that after perhaps a hundred hours of break-in,
> but only for the first 1,000 hours of operation maybe much less
> depending on the design.
>
> This is kind of a hand-wave estimate from memory tho. Why? Do you
> want to try to achieve a moderately high vacuum without a high vacuum
> pump? Doing so nearly always puts you on the edge of the mechanical
> pump's performance, and will lead to tears as soon as it no longer
> performs at its peak.
>

Hi Attila,

1. Very low evaporation rate. For Al it should be at least tens A/s. I
evaporate Al on a cold substrate at 40 A/s.
2. 4x10-5 torr is not very good for Al. Actually than vacuum is better,
than Al coating is better. It is recommended to evaporate Al at pressure
below 10-5 torr.
3. Cr underlayer strongly improves adhesion.

Best regards,

Vladimir

On 9/2/2011 7:49 AM, Attila wrote:

Hi All,

I ran into a trouble during my evaporation session.
My aluminium coating doesn't pass the tape test for adhesion.

My cleaning methode is:

-First I clean the mirror with isopropanol
- Next I use Balzers substrate cleaner no.1.
-Then the Balzers substrate cleaner no.2 so as the manual said.

After this I immediately put the mirror into the chamber and evacuate to 0.02-0.03 Torr.

Then I let run Argon into the chamber and glow discharge for 15 min.
After this I go down to 6x10-5 Torr, and again let the Argon into the chamber to 0.1 Torr and low discharge at 10Kv and 20mA for another 15 min.
Then evacuate as deep as possible, last time 4x10-5 Torr.
I evaporate aluminium using e-beam at 5 Angstr?m per sec. Meantime the optics are turned by the planetary holder.

After this I can let the optic so or make an overcoat of Sio2 or Sio2 and Tio2, doesn't matter the adhesion does not pass the test(bare alu, protected or enhanched does not matter)

What could be wrong?

Or should I apply 10nm of chromium as an adhesive layer?
Just I don't know later how can I strip off the chromium?

Also does not matter the glass type of the substrate.

Thank's for the suggestions.

Attila
The Hun





------------------------------------

Yahoo! Groups Links

On Sep 6, 2011, at 9:57 PM, trikeflight wrote:

The specifications for several two-stage, rotary vacuum pumps list
an "ultimate vacuum rating" of around 15-20 microns Hg. Has anyone
come close to these vacuum pressures with one of these commercial
pumps? If so, what pump make/model and what type of pressure sensor
did you use?

From my limited experience and a lot of reading, those ultimate
pressures apply to a brand new pump fresh from the factory, with brand
new oil of the best available sort, dead-headed with a sensor at the
port (obviously).

And it will only do that after perhaps a hundred hours of break-in,
but only for the first 1,000 hours of operation maybe much less
depending on the design.

This is kind of a hand-wave estimate from memory tho. Why? Do you
want to try to achieve a moderately high vacuum without a high vacuum
pump? Doing so nearly always puts you on the edge of the mechanical
pump's performance, and will lead to tears as soon as it no longer
performs at its peak.

Hi All,

I ran into a trouble during my evaporation session.
My aluminium coating doesn't pass the tape test for adhesion.

My cleaning methode is:

-First I clean the mirror with isopropanol
- Next I use Balzers substrate cleaner no.1.
-Then the Balzers substrate cleaner no.2 so as the manual said.

After this I immediately put the mirror into the chamber and evacuate to 0.02-0.03 Torr.

Then I let run Argon into the chamber and glow discharge for 15 min.
After this I go down to 6x10-5 Torr, and again let the Argon into the chamber to 0.1 Torr and low discharge at 10Kv and 20mA for another 15 min.
Then evacuate as deep as possible, last time 4x10-5 Torr.
I evaporate aluminium using e-beam at 5 Angstrm per sec. Meantime the optics are turned by the planetary holder.

After this I can let the optic so or make an overcoat of Sio2 or Sio2 and Tio2, doesn't matter the adhesion does not pass the test(bare alu, protected or enhanched does not matter)

What could be wrong?

Or should I apply 10nm of chromium as an adhesive layer?
Just I don't know later how can I strip off the chromium?

Also does not matter the glass type of the substrate.

Thank's for the suggestions.

Attila
The Hun





------------------------------------

Yahoo! Groups Links

Greetings,
I was given this site by one of your fine members.
I have for sale 3 one pound (poind) bottles of this oil. It was part of a lost freight sale. I will sell 1, 2 or 3 jars to the highest bidder on 09-03-2011 at 7pm central.

All three jars are factory sealed and have a lot # 38040B Dated 03-29-2010.

These jars sell retail for $2400 and dealer wholesale cost is $1850 each.
You may start the bidding at whatever you think is fair. In your bid please let me know if it's for 1, 2 or 3 jars.

BRAYCO 815Z, Wide Temp Lubricating Oil, 1 poind bottle.
Wide Temperature Range Perfluorinated Polyether Lubricating Oil.
Compatible with rocket propellants and oxidizers
1 pound jar.

Item #: 27090-AEBT
Manufacturer: Castrol Industrial
I will send you a picture if needed.

Thanks for your time.
Please send your bid to trouba@... by 9-3-11 7pm central

I've been working on a high vacuum project that should make it easy for almost anyone to copy with only basic hand tools. The links are to the fusor site where I spend most of my time ranting about how easy building stuff can be. Maybe someone here will find the information useful.