The issue is unfamiliarity; you can make really thin films, it surface treats well for metalization, and the dielectric properties are superb. Did I mention the high tensile and Tg? Unfortunately, no-one is going to set up a film line to produce it for caps unless there's a market demand from the electronics industry, and in that sector, the material is almost unknown.
You probably nailed it - so went polycarbonate capacitor grade film. what is the cost relative to BOPP?
More, but a whole lot less than PTFE or polysulfone. Figure $2.50-$3 per pound for the grades useful to do caps.
That is probably the main issue (market size). There are specific application out there for film caps that existing materials don't really fill the bill - but there is no real large market segment.
I may have come across too strong but thanks for the support. I have thick skin 🙂
I will give my knowledge where ever possible, regardless if its received well or not.
I have made some statement that contain good information - you might already have that knowledge, but others might not.
This subject is very complex and can not be answered in a few short posts on a forum. there is no easy answer to your question
If you would like to discuss any of these subject in more detail, by all means ask a question --
"how some caps have features (apart from the standard electrical properties) which mean they sound better in audio circuits" - the short answer is all of the above. As I mentioned in one of my other posts, the audio business is very subjective. I've been simply trying to point out that not all capacitors are made the same regardless of what they look like or for that matter, even if the OEM specification look the same.
I've been trying to give knowledge of construction, materials, etc to give a broad understanding of film capacitors. I will continue to do so - if information is below you, then why comment. If its above you, by all means let me know and I will try to explain it so that you understand. I do not need a forum to justify my knowledge - I was the original founder of this company, sold it, went on to more of a materials back ground, and came back to manage and grow the company.
Allow me to ask one question - in film capacitors, what characteristics effects ESR?
Correct - lead type/style/size effect ESR
Any other comments? There are no less than 8 to 10 characteristics
Any other comments? There are no less than 8 to 10 characteristics
Are you familiar with Kelvin connection caps? Suppression Devices in England makes a line of those.
What about real foil vs. metallized?
Copper foil vs. aluminum foil?
Dielectricum (dielectric losses?)
Karsten 🙂
Copper foil vs. aluminum foil?
Dielectricum (dielectric losses?)
Karsten 🙂
I'll see if I can do a sketch later or a photo. Basically, you have multiple leads in each end which are attached at a single point to the (probably) thermal spray zinc. Very useful for power supplies.
Yes - electrode thickness effects ESR. Typical foil thickness is 5 um and metalized ranges from 500 to 1000 angstroms.
Foil type also has an effect - aluminum, tin, and copper all have different resistances
Dielectric losses - very good - correct
Any others??
Exactly - this is one of the manufacturing techniques I've been getting beat up on.
Metalized film uses an arc spray technique - more of a mechanical bond, no so much of a solder bond, but rather an impacting into the end of the winding. It can be further effected by the materials used for the arc spray.
The, how are the leads attached? Resistance welded or soldered?
How about the foils?
Iv'e heard of "stacked film" type of capacitors; how does this type of construction stack up when compared to wound caps in regards to ESL / ESR?
oooh, that was bad😱
oooh, that was bad😱
thanks to Sy and Capman57
Being a audio\music lover \ tech guy, I have bought many of the audio caps and have found the sound difference a worthwhile. But some are out of reach price wise to do much see if you like it testing. So knowing what makes a cap sound better or do a better job in a given app: power supply, x-over, signal path, by-pass , is of interest. going on what people say on the net is ok but most don't always have a good ear for upper hi-end audio.
Also if you know some of the ultra hi-end ones, Duelund, Jantzen, Mundorf
is there a justifiable reason for the high price. I have some of them and do enjoy the difference, so maybe that is the only reason needed. But as a tech I do like to know I am buying better product.
thanks
jjacks4x
Being a audio\music lover \ tech guy, I have bought many of the audio caps and have found the sound difference a worthwhile. But some are out of reach price wise to do much see if you like it testing. So knowing what makes a cap sound better or do a better job in a given app: power supply, x-over, signal path, by-pass , is of interest. going on what people say on the net is ok but most don't always have a good ear for upper hi-end audio.
Also if you know some of the ultra hi-end ones, Duelund, Jantzen, Mundorf
is there a justifiable reason for the high price. I have some of them and do enjoy the difference, so maybe that is the only reason needed. But as a tech I do like to know I am buying better product.
thanks
jjacks4x
Stacked film is actually manufactured similar to wound film - actually almost exactly the same. The are wound on large oval shape mandrels than pressed and diced to size. The real difference would be cross section vs. length - if the stacked has a higher ration of cross-section vs. length, the ESR would be better.
oops - gave up one of my answers of what effects ESR & ESL
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