[labnetwork] Oxford Wafer Jam/Break

[Michael Perry]

Hi Long,
Justin is likely to be right, as steve says, he knows his stuff. If its been failing for some time though it can also start to burn out one of the other transistors. Any that are discolored replace. Its sometimes easier to just snip the legs off and solder a new one to the legs to minimise risk of damage to pcb. Or if you want to future proof it, stick some sockets in there. Really common problem on oipt LL's. keep a batch on 450's and 550's as spares. They can fail as well.

mike

________________________________
From: labnetwork <labnetwork-bounces at mtl.mit.edu> on behalf of Paolini, Steven <spaolini at cns.fas.harvard.edu>
Sent: 22 June 2022 17:06
To: Moreau, Justin <Justin_Moreau at uml.edu>; Chang, Long <lvchang at Central.UH.EDU>; labnetwork at mtl.mit.edu <labnetwork at mtl.mit.edu>
Subject: Re: [labnetwork] Oxford Wafer Jam/Break

CAUTION: This e-mail originated outside the University of Southampton.

Long,

  I misinterpreted your message yesterday. It would be wise to take Justin’s advice, he is the top dog when it comes to Oxford equipment.

Steve



Steve Paolini

Principal Equipment Engineer

Harvard University Center for Nanoscale Systems

11 Oxford St.

Cambridge, MA 02138

617- 496- 9816

spaolini at cns.fas.harvard.edu

www.cns.fas.harvard.edu



From: labnetwork <labnetwork-bounces at mtl.mit.edu> On Behalf Of Moreau, Justin
Sent: Wednesday, June 22, 2022 7:59 AM
To: Chang, Long <lvchang at Central.UH.EDU>; labnetwork at mtl.mit.edu
Subject: Re: [labnetwork] Oxford Wafer Jam/Break



Hi Long



By jamming does the handler just stall?

I don’t think adding more time or removing PR from your wafer edge will help.

I suspect one of the handling sensors isn’t made, you have a mechanical bind (ff feedthrough, gearbox, linear bearing) or you have a failing drive transistor.



Looking at your image- Slit valve is open, clamp is up, lift is up, arm is extended



Is your “arm out”sensor made? If no you should adjust the arm out sensor.



If the arm out sensor is made. Check for a mechanical bind-  Remove the mounting plate that holds the motor and gearbox assy. You can then try and rotate the ferrofluid feedthrough shaft by hand.

If you can rotate, you don’t have a bind.



This looks like a Blue PLC control system so it would likely be the Q4 transistor on the LL control card that’s the problem. Its mounted just below the LL chamber. It can overheat and intermittently work. Q4 controls the drive back into the LL.

It will also discolor so it should be easy to spot. You can replace it with a ZTX450 NPN.







Hope this helps

















[University of Massachusetts Lowell]

Justin Moreau

Sr. Lab Manager, Nanofabrication Core

CORE RESEARCH FACILITIES

ETIC

E: Justin_Moreau at uml.edu<mailto:Justin_Moreau at uml.edu>

T: 978-934-3615





From: labnetwork <labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu>> On Behalf Of Chang, Long
Sent: Tuesday, June 21, 2022 2:51 PM
To: labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Subject: [labnetwork] Oxford Wafer Jam/Break



This e-mail originated from outside the UMass Lowell network.

________________________________

Hi Guys,



After etching through 380um of Silicon, the loading arm would get jammed during unloading, see photo. The problem was fixed by adding a 15min step to do nothing step to allow the clamp to cool down before unloading. Now the problem is back and the plan is to increase the cool down time until it stops jamming. Is there a better way to avoid this problem? Should the PR on the wafer edge be removed?



Thanks,

Long

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