A question about a connector with staggered pins

Question

I have ribbon cable which uses a staggered male IDC connector, which plugs into a corresponding staggered female PCB mount connector.

The following image shows the cable plugged in to the PCB connector.

The female connector is Wurth 690367180872 which looks like this:

^{Image sourced from manufacturers website}

I want to solder it on a stripboard. But the pins on the PCB connector are on a staggered grid as can be seen from the datasheet:

I have a couple of questions about this connector. Firstly, why are the pins staggered? Secondly, is it possible to solder this connector on to stripboard?

Answer 1

The staggering potentially gives easier signal routing on a custom PCB (not stripboard), but it also makes the mechanicals of the connector internals easier.

For prototyping use they can often be made to fit normal stripboard with a bit of "persuasion".

However, the default socket for 0.05" IDC cable is a dual row 0.1" connector which is a trivial fit for stripboard. I would suggest you use such a socket instead.

Answer 2

As stated in the other answers, there is nothing about the term "PCB Mount" that indicates a particular arrangement of the pins on any given grid. The term simply means the connector can be soldered to a PCB assuming the appropriate footprint is used.

The staggered footprint simply lines up the pins with the individual wires in the ribbon cable which are on a 1.27mm pitch. Doing this is a choice the manufacturer made in order to make a more compact connector.

The more common 2.54mm pitch regular grid connectors are physically larger in order to accommodate additional metal elements in order to map the splice terminals onto a grid.

You have three options available to you, depending on whether this is a prototype or a more permanent setup.

1. For a simple one-off prototype, you can most likely just bend the legs of the socket to match the strip board. Using a pair of plyers, gently kink one row 0.635mm one way, and the other row 0.635mm in the opposite way to line them up on grid. You should be able to then push the connector into the strip board and solder it in place.

2. For a permanent setup, you could consider designing a PCB (they are cheap to produce now-a-days) rather than using strip board. On the PCB use the correct staggered connector.

3. As an alternative, consider if possible replacing the connector altogether. You can simply cut off the existing connector, and attach a new IDC connector which uses a stripboard friendly rectangular grid such as those shown in @Davide's answer. The PCB mount mating connector for those uses a stripboard friendly grid.

Answer 3

That is a "Mini-flex connector" (made by a few manufacturers.)

Why are the pins staggered?

The PCB terminals are staggered because the ribbon cable has half the pitch and half the rows of the PCB terminals. The cable has a 0.05 inch pitch in one row and the PCB terminals have a pitch of 0.1 inch and are in two rows.

If the PCB terminals had been in one row, then they would not be staggered, but the PCB pads would have to be spaced 0.05 inch, which would not leave enough space on the PCB for pads.

Having said that, there are connectors that offset the contacts by 0.025 inch one way or the other way so that the two rows of PCB terminals are in a regular grid. If you are able to replace that connector, use an IDC bump connector (my site).

{My pictures}

And can it be soldered on a stripboard?

Not directly.

Answer 4

Simply put, "standard" prototyping strip board, veroboard, and breadboard style generic pcbs are designed with 0.1" / 2.54mm throughhole spacing. This is a standard built from years of throughhole inline packages, and before the spread of cheap mass produced designed circuits.

You would not be able to use that specific pcb mounted connector on one of those standard strip boards, without modifying the board, modifying the connector, or replacing either.

0.05" pcb development boards are available if you really want to use that specific connector without modifying one. Or you can order breakout boards that convert 0.05 to 0.1 spacing.

0.05" is not an uncommon pin spacing for higher density connectors and parts. You can get them in throughhole even now, brand new from various manufacturers, but they also make them in surface mount options.