presensitized pcbs come with a similar green coating although it appears they are much thicker. you may want to try 2 coats or slower spin. I use clear slides then lay them under glass directly on the boards similar to 1:1 printing a photo negative. the angle of the walls can be controlled to some degree by using a wider light source and varying the distance of the source to control the angle of the light rays
Thanks for the video! May I ask why only the Aluminum on tip of the photo resist gets lift off and the ones that arent on dont get etched? and is the reason why positive pr is not good for lift off is because angle is tilted outside of the middle aluminum, causing it to be deposited there?
Beautiful work - this and your previous one on sputter-coating. When you've got the sputter gun working well, you have to do up some CAD drawings - this is something I thought on making ages ago! Unfortunately I'd then need to make a proper vacuum chamber to go with it ;-) Have you noticed any temperature effects on the quartz thickness monitor? I remember using one that started giving a reading, just because of radiant heating from the filament and not because any material was being deposited. The resist looks like the stuff that comes on pre-sensitised PCBs - it's green to start with and then changes to a gray-blue colour (hard to tell because of the coppery colour underneath). I never understood spin coating - why is the coating thickness uniform, and why doesn't it just all fly off, leaving a lump in the middle. I guess it's getting a balance between speed, viscosity, and evaporation rate.
The reason is doesn't all spin off is because the layer closest to the glass actually has an electrochemical bond, so to speak. Water and many other liquids will do this. The layer of water that is directly touching the glass actually ends up with a slight charge separation. If you want to know more about this, check out Ben's videos on the plasma formed by high-pressure water... pretty sure he goes into more depth on the same topic in his fritted glass electro-pump (the one with no moving parts, just uses electrostatic fields to move water using this charge separation I mentioned).
With that machine you could make high performance capacitors with only a few grams of gold vapour and some other material like boron or selenium? Each layer in the capacitor only a few atoms thick. A capacitor like that would revolutionize the battery industry.
You say you can do multiple layers because you're not using an etchant, but that sodium hydroxide you're using as a developer will quite happily act as an etchant too. It eats through Aluminium like it's no-one's business. edit: oh, you mentioned you switched to Sodium Metasilicate.
"I don't know what chemical this is, but it is green"
next week. Ben makes a mass spectrometer from a pen lid, some glue, and glitter.
Anyone else would use a glitter-glue pen, but that's just too pre-fabricated.
Well he did it, did not use a pen tho, used a coper tube and needles ots of needles
I honestly can't get enough of your videos!
same
Yep, I only understand bits but it really pushes me to learn more than anything
Yet another video where I have no idea what is going on, but I can't stop watching!
Again, I never know what you're talking about, but I am always captivated by your videos.
I aspire to have a workshop 1/100th as cool as yours one day...
FYI, sodium metasilicate is available from the hardware store as "TSP substitute".
_FYI, sodium metasilicate is available from the hardware store as "TSP substitute"._
Yeah, less than 5% mixed with a lot of other shit.
presensitized pcbs come with a similar green coating although it appears they are much thicker. you may want to try 2 coats or slower spin. I use clear slides then lay them under glass directly on the boards similar to 1:1 printing a photo negative. the angle of the walls can be controlled to some degree by using a wider light source and varying the distance of the source to control the angle of the light rays
Amazingly interesting, as always!
1.75% strength sodium bicarbonate is also an excellent developer for aqueous developed photoresists
Thanks for the video!
May I ask why only the Aluminum on tip of the photo resist gets lift off and the ones that arent on dont get etched?
and is the reason why positive pr is not good for lift off is because angle is tilted outside of the middle aluminum, causing it to be deposited there?
Could you put a list of machines, and chemical products you have used to make this LCD please in the description ????
"It's green". Haha! Was that an intentional or an unintentional Star Trek reference?
Plz tell me out to remove the deposited aluminium without disturbing the silicon dioxide.
i believe the greenish photoresist is based on potassium dichromate
Beautiful work - this and your previous one on sputter-coating. When you've got the sputter gun working well, you have to do up some CAD drawings - this is something I thought on making ages ago! Unfortunately I'd then need to make a proper vacuum chamber to go with it ;-)
Have you noticed any temperature effects on the quartz thickness monitor? I remember using one that started giving a reading, just because of radiant heating from the filament and not because any material was being deposited.
The resist looks like the stuff that comes on pre-sensitised PCBs - it's green to start with and then changes to a gray-blue colour (hard to tell because of the coppery colour underneath).
I never understood spin coating - why is the coating thickness uniform, and why doesn't it just all fly off, leaving a lump in the middle. I guess it's getting a balance between speed, viscosity, and evaporation rate.
The reason is doesn't all spin off is because the layer closest to the glass actually has an electrochemical bond, so to speak. Water and many other liquids will do this. The layer of water that is directly touching the glass actually ends up with a slight charge separation. If you want to know more about this, check out Ben's videos on the plasma formed by high-pressure water... pretty sure he goes into more depth on the same topic in his fritted glass electro-pump (the one with no moving parts, just uses electrostatic fields to move water using this charge separation I mentioned).
After deposition of aluminium should not we bake the sample?
With that machine you could make high performance capacitors with only a few grams of gold vapour and some other material like boron or selenium? Each layer in the capacitor only a few atoms thick. A capacitor like that would revolutionize the battery industry.
donde puedo conseguir ese producto fotoresistente
Just awsome!
great video!
(As always)
When I grow up I wanna be like you >:3
Hey can we give you ideas inventions
You say you can do multiple layers because you're not using an etchant, but that sodium hydroxide you're using as a developer will quite happily act as an etchant too. It eats through Aluminium like it's no-one's business.
edit: oh, you mentioned you switched to Sodium Metasilicate.
this is so interesting
ferrite chloride i do belive
Be cool if made a mistake while doing this that made something even better, mistakes can sometimes be exciting haha