I hoped someone wold reply to your posting.
I know that C-Ply ...and other materials arebeing used in such applications but I guess the companies involved with spacetech are prohibited from disclosing information.
Generally, the embedded capacitance materials has become progressively thinner.
-Down to a few microns.
Its obvious that the thinner the dielectric, the larger the risk for break donw during ESD.
I would imagine that for space use, the somewhat thicker dielectrics are used.
It is strange that you haven't received any documentation from 3M.
The manufacturers of these materails are the onces who takes the materials through certification and they can generally provide you with very detailed reliability data and certification documentation. -And one would think that they have an interest to make you convinced :-)
I have a 3M contact that might be helpful - email me for contact details. (firstname.lastname@example.org )
You can also try other material vendors:
We have used 3M C-Ply in a trial design, but not for space application. Based on my experiences with all major fabs in China, there is no OEMs use embedded capacitive material in lot production, only a few of Telecom vendors do trial designs. Becasue it's high costs, they don't expect use it in lot production.
Good day Per:
Thanks for your reply.
We (I) have looked at the DuPont Interra and the OakMitsui materials. The latter says that its material was used on the Beagle, but it is not clear from the articles if that material was not the embedded resistor product. The resistance to using other vendor's embedded capacitance material is the cost of approving another board house as a qualified vendor. (For those of you reading this: the vendor must be space level production certified and we have to do an on-site cert.) There is also a material licensing fee that they charge and 3M's C-Ply does not have. None of these problems are show stoppers, just a pain to have to go through.
Getting the UL listing documents is no problem but I bet that 3M did not do the space qualification, the OEM probably did. That means that 3M may not have the paperwork. We are just trying to get the name of any space based project so that we or our customer can make contact with team responsible for the hardware. Most of the 3M papers that are posted to the WEB have Joel Peiffer's name on these and we have made contact with him. If you have another point of contact and you can share it, please send it to me.
We (I) have danced around this application for years. For aerospace designs we have always fallen back to thin laminates and Kapton. But this project must have low electrical noise and have any radiating fields nulled. So this type material seems to be called for.
I understand that 10% or 12% of the cell phones are now using this type of material. Some of those must be built in China.
Thanks to both of you,
Yes. a few of high-end mobile use embeded material. Motorola have used embedded capacitative and resistative material yeas ago and it indeeded manafactured by Wus (Kunshan plant, China). In China, 3M have a team dedicated to market C-Ply, they visit frequently the OEMS and PCB Plant, but cost is the barrier to adopt it to neally all OEMS.
Good day Per:
We are having a project review with our customer and they have fear of de-lamination (of all things?) of the embedded capacitance material and want us to insert 450 caps onto the board. I must admit that I don't know what a third of those caps are going to do for a living, but what ever. We will spread the resonance frequencies the best we can and go with it. Not at this meeting but there was a question about dielectric breakdown. I don't see it as as any different than the discrete capacitors soldered to the board. Our standard stack-up practices will null the fields so we don't see any problem there.
Joel Peiffer at 3M has been helpful but it looks like he is not able to supply documentation to the needs of our customer. Most users would be satisfied with 3M's help.
Have fun and thanks
I posted a few links in your MUG thread.
The C-PLY material is just now going thorough NASA tests and wont be finished until some time next year by the looks of it. They have a PDF in there Tech section that you can download about it.
Now as others have stated, most designers can not talk about it due to regulations (ITAR and such). But the FAB houses can provide you with some of the information that you are looking for. The one that is most popular with our customers is the ZBC-2000 material. It has been approved for use with most of the laminitis and prepregs out there, so you may want to take a look at it.
As for the space qualification, off gassing and radiation susceptibility are the 2 biggest issues with space designs. So if the the embedded capacitance material you want to use is halogen free and has been approved for use with the laminate and prepreg that you want to use, you will probably be OK with the off gassing. The next issue you will have to over come, is the the radiation susceptibility test, this you will have to go through any how to get your design qualified for space use. So it might not be an issue if your customer is going to have the design qualified any way.