BNC connector mouting hole

[rameshrai]

BNC connector mounting hole

Hi,

I have a supplied pcb footprint of a BNC connector (files attached). In that footprint design, I don't understand (1) why pads are used along with drill holes for the mounting? and (2) how did they calculate the X and Y size(i guess this is the pad surrounding the mounting hole) as 129.92 mils given that the hole size is 79.74mils?



thanks

 

[pradeep.g.belchada]

the hole size can be edited as per your bnc sample

 

[FvM]

Obviously the mounting clips are intended to be soldered, thus use throughplated holes with surrounding pad, designed as any soldered thoughplated pad. The pad diameter seems reasonable, but can be varied over a wide range.

The footprint editor mask is almost self-explanatory, but you can ask the Altium manual in case of doubt.

 

[rameshrai]

Hi,
I thought this was just for mounting purpose and therefore didn't think of plated through hole. I thought(seems I have misunderstood) plated through holes are required only for signal passage(?).

about the pad diameter size(129.92 mils)? how was this size derived? (129.92-79.74)~ 50 mils is the pad angular size used here but how?

thanks

 

[Mattylad]

(1) why pads are used along with drill holes for the mounting?

Not only are these for mounting and holding the connector on place but they may also be used for the grounding pins.

A physical pin used to locate in the correct position and when soldered to keep it there.

 

[rameshrai]

are all pads numbered 2 for grounding purpose? should they be connected to ground?

thanks

 

[FvM]

Typically yes, but depending on your application. Review the datasheet about the circuit, particularly the ground bypass capacitor.

In my understanding, grounding the pin also creates a ground path to the front panel which may be wanted or unwanted.

In any case. the pins should be soldered to fix the part.

 

[rameshrai]

thanks for help

I haven't still understood the pad size calculation. This is not mentioned in the datasheet.

 

[FvM]

Right, pad size isn't discussed in the datasheet. You can conclude that there aren't any specific requirements for the part. So standard pad/hole relations according to your PCB technology apply. Nothing particularly related to BNC connectors.