Bubbles After Repair On OCA Machine

[cellularman89]

Hi,

Im getting bubbles after using autoclave to remove them. When I take the lcd out of the autoclave the bubbles will be 100% gone, then slowly come back. Normally the bubbles reappear around the edges and very rarely in the middle section.

MY PROCESS

Im not in a clean room but I keep the room I do the refurbishing in very clean

1. Heat lcd on hotplate at 100 degress for about 5 mins
2. use lcd extractor to pull lcd off the frame
3. use vaccum pump and remove glass using a thin wire
4. clean lcd with a wd40 ( I tried many glue removers and this is by far the best for me )
5. Put oca film mitsubushi onto glass lens with machine like in this video https://www.youtube.com/watch?v=ai8ESBEAVY4
6. I put lcd in lcd mold then lay the glass on top but only press in the middle lightley just enough for the glass to stay on lcd
7. I put into lamination machine, the process is about 2 mins in lamination machine
8. Then I put in autoclave at 6mpa and set to 55 degress for 20 minutes to remove the remaining small bubbles.

Most of the time very small bubbles disappear and then slowly come back minutes later.
--------------------------------------------------------------------------------

Here is what I hear maybe the problems:

1. OCA mitsubishi is for commercial machines and not the smaller machines that I own-- And that Japanese oca is made for small machines ( I never used japanese oca )

2. That dust that slips in is causing the bubbles to reappear.

3. That the glass that im using maybe poor in quality

4. The autoclave is not strong enough ( Even though I adjusted the setting to 10mpa with same result )

5. That the lamination press with glass on lcd in my laminator machine settings are wrong ( I was told not to configure the settings and that they were preset from my supplier )

6. Put the oca in the refrigerator for 15 mins before lamination process ( which I tried and got better results but not good enough )

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

My conclusion is that I tried many different things and get mixed results. Sometimes The bubbles dont come back after refurbish and sometimes it does. Its like 50% chance it will work with no bubbles coming back.

Does any experience person out here have any idea what i maybe doing wrong? Please feel free to give me any suggestions. I would greatly appreciate it.

[cellularman89]

here is a video of machines that I use
https://www.youtube.com/watch?v=SwL5Ku6_6dc

here is a video of the problem Im am having
https://www.youtube.com/watch?v=FLRrBnMU_h8

[benistinc]

I have the same problem in 20% of LCD Right now I'm catching up with the OCA on the LCD and the glass did I catch the OCA on the glass will have better results
I'll be happy to know there is a forum for people who deal in OCA

[cellularman89]

there is a new oca called kn6.uv

This oca had loca in it. after autoclave bubble remover you run uv light on it and the bubbles will never return.

I just purchased some and it will arrive very shortly. I'm very excited to try it

[Arkadi0o0]

Same problem anybody can help

[darkside85]

Yes i'll like to know the right process as well so We All dont make same mistakes thanks guys


Sent from my iPad using Tapatalk

[fun]

	
	

			
				

					Originally Posted by cellularman89
					
				
				
Hi, 

Im getting bubbles after using autoclave to remove them. When I take the lcd out of the autoclave the bubbles will be 100% gone, then slowly come back. Normally the bubbles reappear around the edges and very rarely in the middle section.

MY PROCESS

Im not in a clean room but I keep the room I do the refurbishing in very clean

1. Heat lcd on hotplate at 100 degress for about 5 mins
2. use lcd extractor to pull lcd off the frame
3. use vaccum pump and remove glass using a thin wire
4. clean lcd with a wd40 ( I tried many glue removers and this is by far the best for me )
5. Put oca film mitsubushi onto glass lens with machine like in this video https://www.youtube.com/watch?v=ai8ESBEAVY4
6. I put lcd in lcd mold then lay the glass on top but only press in the middle lightley just enough for the glass to stay on lcd
7. I put into lamination machine, the process is about 2 mins in lamination machine
8. Then I put in autoclave at 6mpa and set to 55 degress for 20 minutes to remove the remaining small bubbles.

Most of the time very small bubbles disappear and then slowly come back minutes later.
--------------------------------------------------------------------------------

Here is what I hear maybe the problems:

1. OCA mitsubishi is for commercial machines and not the smaller machines that I own-- And that Japanese oca is made for small machines ( I never used japanese oca ) 

2. That dust that slips in is causing the bubbles to reappear.

3. That the glass that im using maybe poor in quality 

4. The autoclave is not strong enough ( Even though I adjusted the setting to 10mpa with same result ) 

5. That the lamination press with glass on lcd in my laminator machine settings are wrong ( I was told not to configure the settings and that they were preset from my supplier )

6. Put the oca in the refrigerator for 15 mins before lamination process ( which I tried and got better results but not good enough ) 

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

My conclusion is that I tried many different things and get mixed results. Sometimes The bubbles dont come back after refurbish and sometimes it does. Its like 50% chance it will work with no bubbles coming back.

Does any experience person out here have any idea what i maybe doing wrong? Please feel free to give me any suggestions. I would greatly appreciate it.
			
		

You said what using WD40 for cleaning glue. Do you clean LCD with ISOPROPANOL before to apply OCA?
I'm very new to this too and thank you for this tread.

[cellularman89]

Here is what I do for cleaning lcd.

After glass seperation I spray wd40 on the lcd to weaken the oca then I use a plastic pry tool to peel off the oca. Then I use a cottom anti static cloth with 99% isoprohel alcolhol to remove the wd40 from lcd.

[cellularman89]

Also what machine are you guys using? Are they the 3 in 1 machine or do you use the laminator and bubble remover seperate?

[bajinchi]

Hi Guys,

I was lucky to get here, as I was looking information related with OCA equipment and I just read this thread.

Actually I do LOCA repairs, struggling a lot with LCDs with BACKLIGHT but the work can be done.

So, trying to help here, I found this 3M document about OCA, that maybe can help to fix the bubbles problem showing up after their removal.


I can´t post the PDF as I have less than 10 posts, so google this and it should be the first hit:

Optically Clear CEF TB qxd - 3M


And now the highlights I think are important here to solve this out:


Step 1: Baking

Samples can be baked at 85°C for 2-5 hours, depending on the plastic thickness; the thicker the plastic, the longer it takes to remove moisture

Are you guys “baking” the OCA before using them to remove moisture from it? Or it can be from the recently cleaned LCD and the moisture came from it? Or both? Or his step can´t be applied to the OCA sheet as it can melt?



Step 2: Lamination

In the document is made by hand with a roller…



Step 3: Autoclave

Temperature: 30-60°C

Pressure: 70-100 PSI

Duration: 20-60 minutes

I thought that there is vacuum inside the autoclave, not pressure… am I correct?

cellularman89 in process #8 do this at 55ºC by 20 minutes at 6MPA (no idea what MPA is…yet) Maybe a new setting to try?


Step 4: Durability

This step is meant for customers who would like to determine the effect of long term device exposure to high temperature and high humidity. Most moisture absorbing substrates (e.g. PC and PMMA) fail this process because they outgas at high temperature and high humidity creating bubble in the assembly. Step 1 above is implemented to improve outgassing problem.
Here is a typical accelerated process condition.

Temperature: 60°C
Humidity: 90% R. H.
Duration:12-72 hours

This should be to have in consideration if bubbles appear after the de-bubbling process? Weird... but it points back to Step #1 of the document...



Maybe someone with these tools can help to try this new settings described in this document recommendations and let us know if it helps?



Thank you guys.

[cellularman89]

Originally Posted by Arkadi0o0

Same problem anybody can help

Hi, try to lower mpa pressusre on autoclave to 40 and put 50 degrees temp and let it stay for 30 mins.

How are you laminating the glass to oca? By automatic machine or semi or manual?

[GSMsurgeon]

iam using loca not @ any problem..except small things some times..coming out some loca in home button..clean it many times then will be ok(with experiance) never tryed oca sticker

[barba14]

hello i have another kind of problem, i bought an lcd separator machine for separate the lcd from frame, but they didn't work good because they broke my lcd...anyone can help me??

[bajinchi]

Originally Posted by cellularman89

Hi, try to lower mpa pressusre on autoclave to 40 and put 50 degrees temp and let it stay for 30 mins.

How are you laminating the glass to oca? By automatic machine or semi or manual?

Hi cellularman89, did you solve the problem with this settings?

Thanks

[cellularman89]

Originally Posted by bajinchi

Hi cellularman89, did you solve the problem with this settings?

Thanks

I believe so. The problem I was having was bubbles would come back after an hour or so. But I changed the lamination process from 2 mins to 5 seconds, and I also was not laying the oca on the glass correctly bc I was not using the machine that aids you in laying the oca on the glass correclty. After I laid oca on glass good and changed lamination settings then I got no bubble return.

also another thing to note is after lamination process do not press on glass to try and squeeze out the air bubbles. Let the autoclave do that. I use to press on the glass after lamination to try and squeeze the big bubbles out so the autoclave wouldnt have to remove big bubbles, but I had better sucess rate with no hard pressing