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    Board to board connection

    Hi All,

    First post here - it's good to find a traditional web-based group to post upon.

    For about six months now, I have been attempting to recreate an old add-in board for a computer called the Dragon 64 - a British computer from the early 1980s. I have permission to replicate the board from the original director of the manufacturing company - but I am coming up against hardware reliability issues.

    The board itself is relatively complex - but circuit-wise I am comfortable that everything is sound. I am now on PCB revision 2.2, after numerous mistakes! Where my issue lies is in getting a reliable connection onto the main computer motherboard. As you will see from this link, the board itself is full of ICs - part of the attraction is the retro feel of the board - but more difficult, is the position of the connection onto the motherboard. The connecting area of the board is right at one end - where it says "Dragon 64 SAM Socket". That means quite a shear force on the connectors, even when I add stand-offs at the other end of the board (it's difficult to get it precisely right).

    I have tried using M-M SIL connectors, with DIL sockets then making the connection to the board. They are unreliable. I have tried M-F SIL connectors, with M-M connectors and then DIL sockets - but it is still unreliable. What I am really looking for is a reliable connection - even if that means that the DIL socket on the motherboard needs replacing with something more suitable. I have thought about using wire-wrap DIL sockets, but they are too bulky for the DIL socket on the motherboard - and would basically wreck it.

    Any suggestions please? Right now, the only thing I have found are some much longer SIL connectors from Harwin - and I am awaiting some samples.

    Many Thanks

    John

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    Re: Board to board connection

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    Re: Board to board connection

    Hi - thanks, but this is not really what I am looking for. I need some reasonably stable way of joining directly between the daughterboard and motherboard - with rigid connectors - so that the daughterboard sits just above the motherboard. As I said, I have tried various combinations of SIL and DIL headers/sockets, but none is stable enough.

    I appreciate that using IDC connectors may be more reliable, but that then gives issues with mounting the board inside the computer. And in any case, no matter what I do, I still need to connect into the footprint of a DIL socket on the motherboard.



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    Re: Board to board connection

    What if you used a double pin bus connector, such as the Arduino concept, using plastic spacers to anchor the corners with screws, preferably plastic? It would certainly give more work to remove the daughterboard, but the solution as a whole would be safer.
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    Re: Board to board connection

    Thanks for the response. The double pin bus is an option, but I am not sure using any screws into the existing motherboard is going to work. I've actually decided to modify the daughterboard slightly, and have added a standard IDC connector, as suggested by fouwad. I will then connect into the IC socket using an IDC DIP header, with as short a cable as possible.



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    Re: Board to board connection

    Whats the budget and pin count? Also distance between both boards?
    There are low insertion force board to board connector pairs available.

    Have you tried looking at the Samtec ranges?
    Or DIN41612 with ejection levers.

    You can use an IDC style header with a mating pcb mount socket.
    Please do not PM me questions that are better asked in the PCB forum :)



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    Re: Board to board connection

    You have not mentioned the number of connections to be made between the boards; the more you increase the number of paths on a single connector, the greater the mechanical force necessary to disconnect the (flat) cable, and the greater the chance of damaging it. If you go to the "IDC DIP header" option and if has to be large, consider splitting into smaller connectors.
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