TO5A by National

[bbpcb]

The attached file shows the TO5A package by National.
The Z ( diagonal ) dimension of the pins is 0,97mm ( nominal ) and 1,16 ( worst ).
The distance between pins is 1,7mm
With the landpattern calculator the hole become 1,3 (1,5 )mm.
so the pads must be rectangular or oblong.
So how to choose the correct dimensions of the pads?
Probably the Y dimension must be equal to the hole diameter?
But with 1,5mm hole and pad I've only 0,2mm between them.
Best regards

Bolis Bortolo
BBPCBDesign

[Tom]

Bolis,

What you need to do for these multiple pin TO-220 packages is stagger the pins. I'll attach a sample of a TO-220-7V part that is in our library. The leads of your TO-220-5 are long enough to bend them into a staggered pattern. You need to keep the pad size the same as what the calculator provides in order to carry the sufficient current that this device requires to operate correctly. Of course you will have to mount the part in a vertical position.

[bbpcb]

Yes, I know. With this solution I can mount directly the TO5D package ( staggered version ).
So why National created a non staggered package that must staggered to be mounted?
Best regards

Bolis Bortolo
BBPCBDesign

[Tom]

Bolis,

I don't know why National does what they do. They obviously do not take PCB design into consideration when they develop some of their packages. But, they do make a staggered pin version of the same part that I would recommend. If you have to use the lay-down version I would still stagger the pins instead of creating oval pads that breakout on the sides.