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405nm Laser Polygon Mirror Scanning

rajhlinux

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From my (exceedingly limited) knowledge on lithography, the exposure is energy-dependent, not power dependent. Yes? Even with a 50% attenuation, doubling power or doubling exposure time negates this, yes?

I too don't have much knowledge with lithography (hence why I'm asking question in a laser/optic forum) but, yes, exposure is energy dependent. The datasheet for the photoresist specifically tells the optimal energy exposure to be in the range of 50-200 mJ/cm2.

I could increase the laser power to output more light energy to compensate the lens attenuation, common sense tells me that this should work in theory... but then again who knows.

Here is the link for the UV sensitive Dupont photoresist:
dupont.com/content/dam/dupont/amer/us/en/products/ei-transformation/documents/DEC-Riston-200-DataSheet.pdf
 



Encap

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From my (exceedingly limited) knowledge on lithography, the exposure is energy-dependent, not power dependent. Yes? Even with a 50% attenuation, doubling power or doubling exposure time negates this, yes?
Good point and rational question but the OP hasn't got a clue or experience in any aspect of the real world of what he wants to do--only a daydream about it so....
Not to mention the difficulties of doing anything to copper with lasers--copper has some of the worst reflection issues of any material and best thermal conductivity + many alloys of copper are a bio- hazard ex: toxic fumes of beryllium oxide from beryllium-copper alloys make heavy metal poisoning look like the common cold.
I guess I'll just wait for the HP printer LSU to arrive (about two weeks...:cry:)...
Meanwhile I can study about building the laser's driver module for switching it.

In post #1 you say "Anyone here ... can tell me how I can make my own F-Theta lens used specifically for 405nm lasers?
(Yes, I know many factors must be know such as the polygon mirror size and scanning distance etc... etc)"
If not a joke and you have the skills, capability and equipment to make your own optics/lenses, have you not made the magic lens you want that does not exist, that nobody makes, needs, or wants?

The likelihood of making an ultra high precision LDI device for fabricating PCBs at home from $22 worth of rubbish used laser printer parts and a 405nm diode are probably zero for several reasons as you have no real world idea of or experience in what you are attempting. Only what you are are imagining which only exists in your imagination. Everything "me too" thing is possible in imagination - not so with real world constraints.

Other people have been attempting the same thing since 2011 from your links with limited success. If it could be done successfully easily, it would have been done a hundred times over and there would instructions on how to do same on the internet an if actually worthwhile be a hobbyist DIY unit available in the marketplace complete at a reasonable price capable what you are daydreaming about.

Give it a try if you have to, however, don't be surprised or disappointed if the results are very poor of even total failure as in this YT video of a 1W output diode attempt to do roughly the same thing:
 
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rajhlinux

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Good point and rational question but the OP hasn't got a clue or experience in any aspect of the real world of what he wants to do--only a daydream about it so....
Not to mention the difficulties of doing anything to copper with lasers--copper has some of the worst reflection issues of any material + many alloys of copper are a bio- hazard ex: toxic fumes of beryllium oxide from beryllium-copper alloys make heavy metal poisoning look like the common cold.


In post #1 you say "Anyone here ... can tell me how I can make my own F-Theta lens used specifically for 405nm lasers?
(Yes, I know many factors must be know such as the polygon mirror size and scanning distance etc... etc)"
If not a joke and you have the skills, capability and equipment to make your own optics/lenses, have you not made the magic lens you want that does not exist, that nobody makes, needs, or wants?

The likelihood of making an ultra high precision LDI device for fabricating PCBs at home from $22 worth of garbage dump rubbish laser printer parts and a 405nm diode are probably zero for several reasons as you have no real world idea of or experience in what you are attempting nor any related real world aspects. Only what you are are imagining which only exists in your imagination.

Other people have been attempting the same thing since 2011 from your links with little if any success. If it could be done successfully, it would have been done already, many times over and there would be a hobbyist unit available in the marketplace complete at a reasonable price capable what you are daydreaming about.

Give it a try if you have to, however, don't be surprised or disappointed if the results are very poor of even total failure as in this YT video of a 1W output diode attempt to do roughly the same thing:

Obviously you're too dumb to comprehend anything. There's always a troll in a forum thats crashing this thread and thats you. Go back up the tree and go eat a banana monkey. I'm here talking with intelligent people to get some ideas.

Someone needs to stop you from trolling around. Just because someone ask "hey how can I build xyz" doesn't mean everything will be built from the get-go. I'm just asking questions to get an overall idea.

Just because you're such a complete illiterate, arrogant fool doesn't mean the rest of the population is.

I don't need to feed you the sources of how intelligent people was able to make precision PCB using low cost laser "garbage", it has been done and proved and I'm here to replicate it for my own needs. Get lost fool.
 

Cyparagon

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Page 4 lists exposure range as 45-100mJ/cm², so this is easily attained by varying exposure time and/or power. I don't see a relation between efficacy and wavelength though. You'd want to be sure 405nm is effective at all. There may be a better color for all I know.


...precision PCB using low cost laser "garbage", it has been done and proved...

Why are these individuals not being consulted? They're clearly more equipped to offer design ideas than we are.

Not to mention the difficulties of doing anything to copper with lasers--copper has some of the worst reflection issues of any material

I think you missed the part where this is a lithography project, not direct etching. Ablation of the copper layer is not the mechanism at play.
 
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rajhlinux

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Page 4 lists exposure range as 45-100mJ/cm², so this is easily attained by varying exposure time and/or power. I don't see a relation between efficacy and wavelength though. You'd want to be sure 405nm is effective at all. There may be a better color for all I know.




Why are these individuals not being consulted? They're clearly more equipped to offer design ideas than we are.



I think you missed the part where this is a lithography project, not direct etching. Ablation of the copper layer is not the mechanism at play.

You're obviously the individual I primarily seeked for in this forum who actually understands and reads people's post correctly.

Dupont has another document for their photoresist which states that the photoresist is sensitive to the wavelength around 300-450nm, at page 5:

dupont.com/content/dam/dupont/amer/us/en/products/ei-transformation/documents/DEC-Riston_GeneralProcessingGuide.pdf

It also sates that the best optimal wavelength is around 350-380nm. (I'll try to find a laser for this wavelength range, but 405nm is fine and can easily be purchased in the market).

To make things more interesting, Dupont also sells another series of photoresist which is specfically designed for lasers (LDI).
The photoresist which everyone got their hands on at home is not specifically designed for lasers (LDI) but for UV light exposure units.
It really doesn't make any difference between the two types of photoresists, but only matters when resolution and accuracy comes to play. The average person doesn't make PCBs at home which uses QFN, FPGA, BGA chips which has hundreds if not thousands of 0.2 - 0.8mm pins, since it requires state of the art LDI machines for exposing the photoresist at that level of precision traces or expensive PCB Transparent film laser printers which uses UV units for exposure.
Transparent film laser printing UV exposure is an old proven technology which is being deprecated in the advance PCB industry in favor for LDI. But "LDI" is also an old techonolgy too, which is coming back to life in the modern world now since lasers now are low cost, advanced and accessible. All of the big players in the PCB manufacturing who uses LDI, uses "galvo LDI". ("galvo LDI" is hella old technology, which is also getting advanced)

All in all, 30 years ago galvo LDI costed an arm and a leg, now 30 years into the future to the coming year "2021", galvo LDI still costs an arm and a leg. People like "encap" only knows galvo LDI, because they live in a rock (I don't blame COVID for it). Maybe the concept of galvo LDI is so much easier to understand and comprehend than other scanning technologies.

But...
There are individuals who realized the potential of "lasers", "hardware" and "polygon mirrors" available to the current consumer market, and made ~$100 "LDI" technology with mind blowing resolution of ~0.1mm traces. (Without the need of precision galvo scanning motors)

One of the open source projects is called "LDgraphy", here's the website:
github.com/hzeller/ldgraphy

The creator did a phenomenal job for explaining and documenting everything so that anyone can build it and also gave some ideas how to further improve their open source LDI project..
It's unbelievable how no external lens was used and 0.1mm trace accuracy can be achieved.

For my needs I need 0.07mm PCB traces (which shouldn't be a big deal to achieve). But anyhow I guess I'll shoot the creator a message for how I can achieve 0.07mm. I was assuming maybe, perhaps theres smatter people in a laser/optic forum which can give "free" simple ideas in how to use external lens to achieve 0.07mm.
 
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Alaskan

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I wish this forum had the ability to have visitors request support like this through first making a small donation. When I first joined, I made a 35 dollar donation, thinking that would buy me some good will for answers, and all that happened is whips upside the head and shoulders with wet noodles for wanting to be spoon fed :p

This web page has some info on the subject of measuring a small spot size, which isn't want you want, but maybe there is something useful for you:
Maybe we need a Spoon Feeding section where people can come and ask questions or be ignored, depending upon who feels generous with their time. Spoon feeding should not be free, beyond a certain point, but some amount is OK in my mind, but with a donation to support the forum, bring your questions!
 

rajhlinux

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I wish this forum had the ability to have visitors request support like this through first making a small donation. When I first joined, I made a 35 dollar donation, thinking that would buy me some good will for answers, and all that happened is whips upside the head and shoulders with wet noodles for wanting to be spoon fed :p

This web page has some info on the subject of measuring a small spot size, which isn't want you want, but maybe there is something useful for you:

Maybe we need a Spoon Feeding section where people can come and ask questions or be ignored, depending upon who feels generous with their time. Spoon feeding should not be free, beyond a certain point, but some amount is OK in my mind, but with a donation to support the forum, bring your questions!

I'm reading about Gaussian beam...

That is a good idea, I'll donate to this forum. Hopefully that will change the minds of the experts in this forum to discuss about valid improvements of an open source project. I'll donate to both this forum and to "LDgraphy".

But honestly I have the mind of a business man. I totally agree with the concept "money talks" and it solves complex projects and problems.

You're completely right, there needs to be a "spoon feeding section", so that serious people can pay effectively for world class solutions/answers/advice.
You never know, there could be a PhD optics photonics engineering expert just getting ready to go bed but right before closing eyes, read's the "spoon feeding section" on this forum to cover the following morning's Starbuck's premium expresso shot. :coffee:

Something tells me Mr."encap" is getting a bit too hungry and wild here...
 

Unown (WILD)

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Encap means well. He's a good guy once you get to know him. This forum has been subjected to a lot of trolling and sometimes feel distain for new members (myself included at times) asking for help. I don't mean to do it but it does happen.
 




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