Have a technical question, ask 3M's UHM expert Roland Nuiten

Introduction: I hate connectors.  They're big, unreliable, messy, expensive, and introduce crosstalk.  If I could put my whole system on one board I would.  But when the system is spread across hundreds of meters, or even just involves different circuit board technologies or mix-and-match board sets, I need connectors after all.

The specific need I have at the moment is for a board-to-board connector.  The two boards will both be clamped flat to the same aluminum heat sink, so the usual vertical mate board-to-board connectors won't work.  I have about 20 low-speed digital lines, some power supplies, and about 12 x 50 Ohm analog RF signals in the 20 to 200 MHz band, where I need low (-80 dB) crosstalk.  A set of 10 SMA connectors would sort-of work for the analog RF signals; I want to improve on SMA in terms of cost, density, and assembly time, without giving up much in the way of crosstalk.  I hope the low-speed digital and power will come "for free".

I looked at using a single high density connector (Samtec QMS/QFS) but wasn't happy with the amount of board space needed to fan in and fan out.  Two or three smaller connectors would work, but if they are high density, I risk reliability due to assembly tolerances putting stress on the contact area.  Low density connectors have larger antenna areas, which is bad for crosstalk.

Many connectors I have looked at come close.  Maybe I can leverage the current industry excitement about high-speed serial interconnect.  I sense that I need a creative way to relax one key spec, but still get the job done.

   - Larry

Introduction: I hate connectors.  They're big, unreliable, messy, expensive, and introduce crosstalk.  If I could put my whole system on one board I would.  But when the system is spread across hundreds of meters, or even just involves different circuit board technologies or mix-and-match board sets, I need connectors after all.

The specific need I have at the moment is for a board-to-board connector.  The two boards will both be clamped flat to the same aluminum heat sink, so the usual vertical mate board-to-board connectors won't work.  I have about 20 low-speed digital lines, some power supplies, and about 12 x 50 Ohm analog RF signals in the 20 to 200 MHz band, where I need low (-80 dB) crosstalk.  A set of 10 SMA connectors would sort-of work for the analog RF signals; I want to improve on SMA in terms of cost, density, and assembly time, without giving up much in the way of crosstalk.  I hope the low-speed digital and power will come "for free".

I looked at using a single high density connector (Samtec QMS/QFS) but wasn't happy with the amount of board space needed to fan in and fan out.  Two or three smaller connectors would work, but if they are high density, I risk reliability due to assembly tolerances putting stress on the contact area.  Low density connectors have larger antenna areas, which is bad for crosstalk.

Many connectors I have looked at come close.  Maybe I can leverage the current industry excitement about high-speed serial interconnect.  I sense that I need a creative way to relax one key spec, but still get the job done.

   - Larry