Accessing embedded electrical contacts with PCB or other terminals

[Kurtis500]

Hello,

Im needing some help coming up with methods to access embedded copper metal inside a fiberglass panel. What I have is expanded copper that is embedded inside cured fiberglass. I make the fiberglass panels and want to contact the copper with a good and reliable connection. I attached a picture of a panel that is 1/8" thick that has expanded copper foil in the middle. I also attached copper rivets to sections for testing different termination ideas. In the photo you can see where Ive milled to the copper. What I am trying to do is create a reliable embedded copper tab or etc. that I can drill to acess then attach the terminal. Some panels will be thicker so the copper will be deeper down when gaining access. Since I know a lot more about making the panels in compression molding than I do electrical terminations Ive been exploring the pcb world quite a bit, mostly on digikey. My original thoughts were to drill to the copper then simply solder the posts and glue the terminal or pot the solder. Since the panels will undergo some vibration I was looking for a stronger bond, possibly mechanical. I think potting will be strong with epoxy, but a mechanical fastening with potting would be best for long term. I would like to put a threaded post or something in there but the steel molds are .125" apart when closed. Is there a way to use solder as a reliable conection for amperage up to 10A on 110vac and then mechanically fasten the terminal to the board? The more I think about this it seems Im doing exactly the same thing that goes on with pcb's, except I am trying to NOT drill through the panel. Any thoughts would help, I cut-n-pasted the links to some of the products I ordered at digikey.

Thanks!!

https://www.digikey.com/product-detail/en/on-shore-technology-inc/OSTOQ020151/ED2850-ND/1588333
https://www.digikey.com/product-det...corp/0390-0-15-01-08-27-10-0/ED5034-ND/158196
https://www.digikey.com/product-det...orp/0388-0-15-15-08-27-10-0/ED90536-ND/433904
https://www.digikey.com/product-detail/en/phoenix-contact/1778764/277-2315-1-ND/2625585
https://www.digikey.com/product-det...orp/0712-0-33-15-08-27-10-0/ED1361-ND/5176097

 

[shrtrnd]

I'd check the Mill-Max website and see if they have any application data. What you're doing is generally referred to
as a multi-layered printed circuit board (even though you only have one layer, apparently).
What usually happens to make the electrical connection, is that a hole is drilled and a 'socket' pin is pressed into the board; and then
components or connectors (like the ones you linked to), are inserted into the socket and soldered in-place. Sockets that are 'mechanically connected', are pressed into the board, and then crimped in place like a rivet (usually done
by machine to ensure no damage to the socket).
I've replaced many of these, but am not versed in the manufacturing process itself, and I'm sure people at
Mill-Max are.
I'm not sure I understand exactly what you're doing, as your photo shows a copper screen, which would mean that
all of the inserted sockets would be electrically shorted together. Layered boards have the component circuit trace
between the fiberglass to make the connections between the inserted sockets. Not a full (electrically a short-circuit) layer of copper between the fiberglass.
Someone else here may have a better idea of what you're trying to do, and will have more specific input.

 

[Kurtis500]

I'd check the Mill-Max website and see if they have any application data. What you're doing is generally referred to
as a multi-layered printed circuit board (even though you only have one layer, apparently).
What usually happens to make the electrical connection, is that a hole is drilled and a 'socket' pin is pressed into the board; and then
components or connectors (like the ones you linked to), are inserted into the socket and soldered in-place. Sockets that are 'mechanically connected', are pressed into the board, and then crimped in place like a rivet (usually done
by machine to ensure no damage to the socket).
I've replaced many of these, but am not versed in the manufacturing process itself, and I'm sure people at
Mill-Max are.
I'm not sure I understand exactly what you're doing, as your photo shows a copper screen, which would mean that
all of the inserted sockets would be electrically shorted together. Layered boards have the component circuit trace
between the fiberglass to make the connections between the inserted sockets. Not a full (electrically a short-circuit) layer of copper between the fiberglass.
Someone else here may have a better idea of what you're trying to do, and will have more specific input.

Thank you for the reply. For the picture I put a peice of the expanded copper foil in there to show what is in the board. The expanded copper is connected to a rivet which is then embedded into the fiberglass laminates. The expanded copper is cut out and creates and electrode network throughout the composite panel. These are building heaters, so a positive and neutral/negative connection will be needed. The expanded copper resembles electrical traces in a PCB. I can use foil connectors for the copper, but they are too thick in some cases to fit in the molds without being crushed. What you said about the drilling and crimping is probably spot on. Im just not sure a rivet is an 'official' termination to drill and press a socket into. I want to access this from one side and eliminate the drill through. I had thought about riveting a ring terminal to the heater before putting in the compression molding press, but the ring terminal is also thick. The sockets you described, like the ones I linked to, are designed for a specifichole or via, is that right? I would essentialy be making a via with an end mill in the rivet and pressing in the socket. So far, thats as good as I can get with it. i attached a picture of the heater before its placed between layers of fiberglass (SMC) and placed in the press (300 tons). The picture is a sample and the rivet is in top of the picture. Its a larger rivet, but it should help show what im doing, or trying to find a better way to accomplish. I also attached a picture of a cutaway heater embedded in a fiberglass panel.

Thanks again

 

[shrtrnd]

Since you're compressing the copper between two fiberglass boards, and you only want a terminal block or connector on one side of the boards, ....
Why can't you install your electrical connections to the copper BEFORE compressing the two boards together.
Make your electrical connection, just drill the one board you want the electrical connection to protrude through, and
THEN compress the two boards together over the copper. That way you're sure of your electrical connection.
Your wire leads, or posts, or whatever connects to the copper sheet between the fiberglass boards, would protrude
through the one drilled fiberglass board, and then be connected to your electrical connection terminal block.
I'm not well-versed in manufacturing methods, and don't know your temperature range, but you can mount the
terminal block with high-heat epoxy, or you can use Teflon nuts & bolts (drilling both boards) that won't conduct electricity but will hold the terminal block in place. (There are many different types besides the ones you refer to).
If none of this is helpful, maybe others here know of other methods you can use in this application.