Film is extruded in T dies, then rolled up.
Converters do the metallizing, slitting and printing along with other processes, for them the jumbo rolls are the raw material.
Do the math again, I feel 0.5 micron is too thin, most packaging film are way thicker.
Calculate the mechanical strength needed to move air at a particular power level, in dB if needed.
Read up on screen printing, and how the screens are prepared using fine mesh, and adhesive coats, and so on.
Converters do the metallizing, slitting and printing along with other processes, for them the jumbo rolls are the raw material.
Do the math again, I feel 0.5 micron is too thin, most packaging film are way thicker.
Calculate the mechanical strength needed to move air at a particular power level, in dB if needed.
Read up on screen printing, and how the screens are prepared using fine mesh, and adhesive coats, and so on.
Based on previous experiments 0.5 microns is my preferred thickness. I just want to take it up a notch and try to make a more professionally finished version with finer, thinner traces.
The plan is to make it utilize as little power as possible using as many coil turns as possible.
It's difficult for me to say whether or not 0.07mm is too thin but I can always make it thicker if needed.
Silkscreen etch resist ink on aluminum layer already Factory applied , think metallized Polyester or Mylar raw material to make standard capacitors, "somebody" must sell it, worst case ask some Capacitor Factory to sell you some roll leftovers..
Very thin layers of each, yet ¨designed to carry significant current, it´s not only a decorative or optical (mirror) aluminum layer.
Typical etch resist is a Tar based ink, which resists both acid and alkaline etchants, then is removed with solvents, even plain kerosene ("paraffin" inn some weird English speaking Countries
)
I use it all the time for my own PCBs, on Aluminum you would use lye/sodium hydroxide solution.
Ferric perchloride can be used but is dirty, messy and comparatively expensive, while lye is clean, cheap and disposable, and even Nature friendly, it will clean your drainpipes and later self neutralize by absobing CO2 from the atmosphere, what´s not to like?
https://www.nazdar.com/en-us/P/3144/182034PC-Black-Etch-Resist-Screen-Ink
https://www.nazdar.com/en-us/P/4331/16935PC-Etch--Plating-Resist-Black
https://leessupply.com/collections/nazdar/products/nazdar-182034pc-etch-resist-screen-ink
"This resist withstands not only most plating solutions but can be used as a solvent strippable resist with alkaline etchants"
167 bucks a gallon; a quart or half quart will last you years
Very thin layers of each, yet ¨designed to carry significant current, it´s not only a decorative or optical (mirror) aluminum layer.
Typical etch resist is a Tar based ink, which resists both acid and alkaline etchants, then is removed with solvents, even plain kerosene ("paraffin" inn some weird English speaking Countries
)I use it all the time for my own PCBs, on Aluminum you would use lye/sodium hydroxide solution.
Ferric perchloride can be used but is dirty, messy and comparatively expensive, while lye is clean, cheap and disposable, and even Nature friendly, it will clean your drainpipes and later self neutralize by absobing CO2 from the atmosphere, what´s not to like?
https://www.nazdar.com/en-us/P/3144/182034PC-Black-Etch-Resist-Screen-Ink
https://www.nazdar.com/en-us/P/4331/16935PC-Etch--Plating-Resist-Black
https://leessupply.com/collections/nazdar/products/nazdar-182034pc-etch-resist-screen-ink
"This resist withstands not only most plating solutions but can be used as a solvent strippable resist with alkaline etchants"
167 bucks a gallon; a quart or half quart will last you years
Handling the film without wrinkles through all this needs practice, and a natural ability...some people are clumsy.
The film is cheap, and like I said, get an excess quantity to play with.
Search for metallized film, not Mylar, which is a trade mark.
And decide what thickness is needed, box sticking tape here is 30 microns base with 10 to 20 microns adhesive layer, and it is pretty thin.
The film is cheap, and like I said, get an excess quantity to play with.
Search for metallized film, not Mylar, which is a trade mark.
And decide what thickness is needed, box sticking tape here is 30 microns base with 10 to 20 microns adhesive layer, and it is pretty thin.
Yes, you make your pattern on the silkscreen (think of how they make t-shirt printing screens). Then you print that pattern on the mylar. The printing ink becomes the resist when you etch. You then remove the ink with a solvent and you are done. The advantage is that you can make a bunch of diaphragms from a single silkscreen design.
A converter takes big rolls of materhail and processes them. For example metalizing or cutting down and winding one big roll of film onto smaller rolls. The places I'm familiar with only go down to 1/2 mil (12 microns). Anything smaller than that is hard to find, and it typically capacitor films.
Since you are loading up the diaphragm with lots of metal, are you sure it's worth it to use super thin mylar? I'd start with a 1/2 mil and get your processes tuned and experiment with your design. You can get it cheaply and in smallish quantities (two things that super thin films aren't). Also 1/2 mill mylar is super rugged and can handle some abuse. I have some 1.2um film that I've used as dust covers for quads, and it's a total nightmare to work with. One inadvertant touch and you start over. And I'm no stranger to mylar, I use 3um film all the time.
Sheldon
A converter takes big rolls of materhail and processes them. For example metalizing or cutting down and winding one big roll of film onto smaller rolls. The places I'm familiar with only go down to 1/2 mil (12 microns). Anything smaller than that is hard to find, and it typically capacitor films.
Since you are loading up the diaphragm with lots of metal, are you sure it's worth it to use super thin mylar? I'd start with a 1/2 mil and get your processes tuned and experiment with your design. You can get it cheaply and in smallish quantities (two things that super thin films aren't). Also 1/2 mill mylar is super rugged and can handle some abuse. I have some 1.2um film that I've used as dust covers for quads, and it's a total nightmare to work with. One inadvertant touch and you start over. And I'm no stranger to mylar, I use 3um film all the time.
Sheldon
Dude, this thread seems to be about planar speakers, I think.
Tell us how you will use a transformer to make a speaker diaphragm vibrate...
https://soundbridge.io/planar-magnetic-speakers/
Magnepan speakers, or 'Maggies':
https://en.wikipedia.org/wiki/Magnepan
Tell us how you will use a transformer to make a speaker diaphragm vibrate...
https://soundbridge.io/planar-magnetic-speakers/
Magnepan speakers, or 'Maggies':
https://en.wikipedia.org/wiki/Magnepan
Copied from the Wilipedia article:
Mylar film, 0.0005" (12.5 μm) thick, is suspended in front of the magnet structure about 1/16" (1.6 mm) away from the magnets. Aluminum wires or film are then glued to the mylar. Only aluminum was used: copper has two-thirds the resistance of aluminum, which would make the speakers either much larger or much more difficult to drive.
The wire is glued to the mylar with 3M 77 spray adhesive, then sealed with 3M Fastbond 30NF (Magnepan used to use Milloxane to seal, but no more)
That should be enough guidance for you to start...
Mylar film, 0.0005" (12.5 μm) thick, is suspended in front of the magnet structure about 1/16" (1.6 mm) away from the magnets. Aluminum wires or film are then glued to the mylar. Only aluminum was used: copper has two-thirds the resistance of aluminum, which would make the speakers either much larger or much more difficult to drive.
The wire is glued to the mylar with 3M 77 spray adhesive, then sealed with 3M Fastbond 30NF (Magnepan used to use Milloxane to seal, but no more)
That should be enough guidance for you to start...
If it's a headphone, there seems to be some precedent. Since the OP has provided little info other than some goals that seem odd to most of us, maybe he's not trying to build what we are thinking (or maybe he's off in the weeds, I can't tell). That doesn't make the task of working with such fragile materials any easier though.
Without a clearer idea of what the end goal is, it's difficult to help.
https://www.stereophile.com/content/technologically-impressive-lcd-4-planar-magnetic-headphone"Diaphragm - Audeze characterizes their LCD-4 diaphragm as "nano-grade". The actual dimension is proprietary, but Sankar told me it was sub-0.5 microns thick."
Without a clearer idea of what the end goal is, it's difficult to help.
https://www.stereophile.com/content/technologically-impressive-lcd-4-planar-magnetic-headphone"Diaphragm - Audeze characterizes their LCD-4 diaphragm as "nano-grade". The actual dimension is proprietary, but Sankar told me it was sub-0.5 microns thick."
I am skeptical, a 1.5T strength magnetic field from permanent magnets is mentioned for those headphones.
That is super cooled with Helium MRI territory, and quite unhealthy to be wearing a device with such a strong magnetic field...at least that is my opinion.
Searched for how strong that can be, a result was:
"The magnet field produced by the magnet in a 1.5T MRI machine is 15,000 gauss, meaning the magnet in a 1.5T scanner is 30,000 times stronger than that produced by the Earth. The scanner uses this strength to align the hydrogen nuclei and produce the images for a MRI exam.31-Jan-2019"
That is super cooled with Helium MRI territory, and quite unhealthy to be wearing a device with such a strong magnetic field...at least that is my opinion.
Searched for how strong that can be, a result was:
"The magnet field produced by the magnet in a 1.5T MRI machine is 15,000 gauss, meaning the magnet in a 1.5T scanner is 30,000 times stronger than that produced by the Earth. The scanner uses this strength to align the hydrogen nuclei and produce the images for a MRI exam.31-Jan-2019"
Last edited:
Dude, (1) you missed noticing my word "historic" and you may not know much audio history (hint: you should google "Delta ribbon" or "Apogee"), (2) you seem deficient in technical imagination, and/or (3) you may not know how soldering guns work
Speakers in the planar/ribbon family make intriguing DIY projects because the results can be great. I've been tinkering with DIY ESLs (including direct drive amps) for almost 50 years and recently ribbons. But the industrial techniques of preparing the films posted in this thread seems daunting to me.
So an alternative that seems a whole lot easier is to use unmodified films but to modify the impedance seen by the amp by means of a transformer. The impedance ratio in a soldering gun might resemble that needed in a planar driver.
... as I said too succinctly for some readers in my previous post. Might be a helpful idea or maybe not a useful idea at all.
B.
Last edited: