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I am preparing to start work on designing a board that uses a component in a PowerFLAT 5x6 package (the component is a power Schottky rectifier, part STPS30M100DJF from STMicroelectronics). The datasheet is here: http://www.st.com/web/en/resource/technical/document/datasheet/CD00255467.pdf

Altium Designer (the software I am using to design the board) does not have a land pattern for the PowerFLAT 5x6 package so I am having to create it from scratch. However, looking at the footprint in the datasheet I am still missing a few critical dimensions. I contacted STMicroelectronics but have not received a response. I'm wondering if anyone has the information shown in red in the below image?

Missing dimensions

Most of the land pattern is done, I'm just missing the information needed to put on the side tabs. Thanks!

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  • \$\begingroup\$ I'm lazy; I probably would've laid out a plain square pad for it: 5.35mm x 4.33mm \$\endgroup\$
    – Nick Williams
    Commented Feb 27, 2015 at 13:36
  • \$\begingroup\$ If I was just designing this board for myself I probably would have done the same, but this is to be a professional board and needs the actual land pattern shown in the image \$\endgroup\$
    – DerStrom8
    Commented Feb 27, 2015 at 13:37
  • \$\begingroup\$ Looks like "PowerFLAT 5x6" is a bit of a standard. I've been able to find other ICs in this package but they don't reveal much more info. Maybe you could find another IC in the "PowerFLAT 5x6" package with the info you need. \$\endgroup\$
    – Nick Williams
    Commented Feb 27, 2015 at 13:42
  • \$\begingroup\$ I've gone though a few but it seems like this particular diode is one of the only components that has the tabs on the side. Most only have them on the top and bottom. \$\endgroup\$
    – DerStrom8
    Commented Feb 27, 2015 at 13:43
  • \$\begingroup\$ And it seems like ST really doesn't want to give the dimensions for the components that DO have the tabs =P \$\endgroup\$
    – DerStrom8
    Commented Feb 27, 2015 at 13:46

2 Answers 2

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There is no point in following the intracacies of the package exactly. ST probably didn't give the exact locations of the tabs because you're not supposed to care. Worrying about the radius of curvature you ask about is really silly.

I would put a rectangle around the whole thing and be done with it. You want the pad to be a little bigger than the pin anyway. I usually add 10 to 20 mils to the pad past the edge of the pin, especially for external edges where I might want to put a scope probe or a soldering iron there.

The only issue in this case for a enclosing rectangle is that the surface tension at top will pull the package somewhat, and that may pull the four pins at bottom partially off their pads. There are several ways to address this. You can add the three indentations at the top so that there is no place for suface tension to pull from. You can add a little at the bottom of the rectangle to balance the forces. You can add a little to the top of the four pads to leave room for some upwards pulling.

In any case, this is not as big a problem as you are making it. You are over-thinking this.

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  • \$\begingroup\$ Asking for the radius of the corners was just one of those "While you're at it" things. I currently have it set to 5% and it looks fine, so I'm not too worried about it. I'm really just looking for the tab dimensions. My supervisor specifically requested we follow the land pattern in the datasheet which is why I am not simply placing a 5.35x6.29mm square pad. \$\endgroup\$
    – DerStrom8
    Commented Feb 27, 2015 at 14:20
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I was able to cross-reference with a few other datasheets and eventually someone showed me a component in the same package, but this one had the dimensions. Here they are:

Dimensions

The component is different so this one has the split down the center, but the outside edges and tabs should be correct. This was taken from the following datasheet:

http://www.st.com/web/en/resource/technical/document/datasheet/DM00040099.pdf

Hopefully this will help someone else out too.

EDIT: Further update-- I heard back from STMicroelectronics and they have provided a very detailed land pattern for the PowerFLAT 5x6. Here it is:

Land Pattern

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