Precision and/or high performance SMD caps

peranders · 17th February 2003, 08:17 AM

Hi!

I'm looking for polypropylene "compatible" SMD caps. I gather that polyester is the only material so far. Anyone who knows more?

Steve Eddy · 17th February 2003, 08:31 AM

Quote:

Originally posted by peranders
Hi!

I'm looking for polypropylene "compatible" SMD caps. I gather that polyester is the only material so far. Anyone who knows more?

Not sure what you mean by "compatable." But other than polyester there's also stacked polyphenylene sulfide (PPS) and polyehtylene napthalate (PEN) films available.

se

peranders · 17th February 2003, 08:40 AM

Polyphenylene sulfide poped into my mind after my post, but the second one I have heard but not rescently.

I'm looking good caps equally good as polypropylene and also 5% or better.

pinkmouse · 17th February 2003, 08:55 AM

I am currently trying Wima SMD2200 polyester caps, too early to give an opinion yet, but for those that follow such things, they seem to be completely non-magnetic

mirlo · 17th February 2003, 09:22 AM

Panasonic makes PPS caps in SMD style.

I typed "panasonic PPS" into google; got this:

http://www.digikey.com/scripts/us/dk...9&Cat=30409424

Is PPS really as good as polypropylene? I think the panasonic PPS caps are rated to have about twice the DF as PP. Still probably better than polyester!

jackinnj · 17th February 2003, 02:21 PM

PEN is one of the best vapor barrier resins availabe. It's a little more difficult to make than PET (polyester terephthalate -- which we think of as DuPont's mylar.)

At some point PEN may replace glass in packaging of consummable -- it's lighter weight, unbreakable, excellent vapor barrier properties, recyclable etc. If this ever happens it would be a boon to the price of high quality SMD capacitors.

BrianL · 18th February 2003, 12:41 AM

I have talked to WIMA folk about PPS. It
would appear to have properties as good as
or better than Polypropylene. Temperature
coefficient is better. They stopped short
of saying it would be better for critical
sample/hold circuits. In my experience a
cap that works well in critical S/H applications
works well for audio.

The problem with SMT film caps is that
the plastic melts when they get hot. This
instantly limits your choices for film
dielectrics.

I don't know anything about PEN, though
the Panasonic pages in Digi-key would
suggest that PPS is the better of the two.

I'd give PPS a try, but be VERY careful
with your soldering technique.

peranders · 23rd February 2003, 05:09 PM

I think I will use "Metallized polyphenylene sulphide (PPS) SMD", Evox Rifa for my SMD headphone project with OPA134/OPA627 and BUF634 (all SMD). The capacitor is for input coupling otherwise the amp will be DC coupled.
http://www.elfa.se/elfa/produkter/se/20/2023233.htm

ALW · 23rd February 2003, 06:26 PM

PPS caps are very good, but please heed this warning.

When I was involved in desiging an 800MHz transceiver some time ago, we used these for the first time.

The prototype boards (hand soldered) experienced lots of failures in the PPS caps, some latent.

These components reflow well, but you need tight temperature / time control to fit them by hand - be quick and you'll be OK.

Andy.

peranders · 23rd February 2003, 07:30 PM

Quote:

Originally posted by ALW
When I was involved in desiging an 800MHz transceiver some time ago, we used these for the first time.

Why did you choose this particular type? Why not ceramic of some sort?

17th February 2003, 08:17 AM	#1
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	Precision and/or high performance SMD caps Hi! I'm looking for polypropylene "compatible" SMD caps. I gather that polyester is the only material so far. Anyone who knows more? __________________ /Per-Anders (my first name) or P-A as my friends call me

17th February 2003, 08:40 AM	#3
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	Polyphenylene sulfide poped into my mind after my post, but the second one I have heard but not rescently. I'm looking good caps equally good as polypropylene and also 5% or better. __________________ /Per-Anders (my first name) or P-A as my friends call me

17th February 2003, 08:55 AM	#4
pinkmouse diyAudio Moderator Join Date: Apr 2002 Location: Chatham, England	I am currently trying Wima SMD2200 polyester caps, too early to give an opinion yet, but for those that follow such things, they seem to be completely non-magnetic __________________ Al I conceive of nothing, in religion, science or philosophy, that is more than the proper thing to wear, for a while. Charles Fort

17th February 2003, 02:21 PM	#6
jackinnj diyAudio Member Join Date: Apr 2002 Location: Llanddewi Brefi, NJ	OT- Polyethylene Napthalate PEN is one of the best vapor barrier resins availabe. It's a little more difficult to make than PET (polyester terephthalate -- which we think of as DuPont's mylar.) At some point PEN may replace glass in packaging of consummable -- it's lighter weight, unbreakable, excellent vapor barrier properties, recyclable etc. If this ever happens it would be a boon to the price of high quality SMD capacitors.

18th February 2003, 12:41 AM	#7
BrianL diyAudio Member Join Date: Mar 2002 Location: USA	I have talked to WIMA folk about PPS. It would appear to have properties as good as or better than Polypropylene. Temperature coefficient is better. They stopped short of saying it would be better for critical sample/hold circuits. In my experience a cap that works well in critical S/H applications works well for audio. The problem with SMT film caps is that the plastic melts when they get hot. This instantly limits your choices for film dielectrics. I don't know anything about PEN, though the Panasonic pages in Digi-key would suggest that PPS is the better of the two. I'd give PPS a try, but be VERY careful with your soldering technique. __________________ bel


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

17th February 2003, 09:22 AM	#5
mirlo diyAudio Member Join Date: Jul 2002 Location: San Diego	Panasonic makes PPS caps in SMD style. I typed "panasonic PPS" into google; got this: http://www.digikey.com/scripts/us/dk...9&Cat=30409424 Is PPS really as good as polypropylene? I think the panasonic PPS caps are rated to have about twice the DF as PP. Still probably better than polyester!

23rd February 2003, 06:26 PM	#9
ALW diyAudio Member Join Date: Jun 2001 Location: UK	PPS caps PPS caps are very good, but please heed this warning. When I was involved in desiging an 800MHz transceiver some time ago, we used these for the first time. The prototype boards (hand soldered) experienced lots of failures in the PPS caps, some latent. These components reflow well, but you need tight temperature / time control to fit them by hand - be quick and you'll be OK. Andy.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
high precision high voltage supply	nhuwar	Planars & Exotics	13	12th February 2007 09:24 AM
high performance but cheap amp	rulezzz	Solid State	7	15th May 2004 04:30 PM
Precision polypropylene 1% caps - any good?	peranders	Parts	44	16th March 2003 05:31 PM
PEH169 RIFA High performance computer grade caps	peranders	Swap Meet	4	26th November 2002 01:54 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read