Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


EPTSSOP

Lex WW

#7301

EPTSSOP | 19 July, 2001

Can anyone tell me the significance of the EPTSSOP (Exposed Pad Thin Shrink Small Outline Package)? From the drawing it appears to be just a 28-pin TSSOP. Are there any special sensitivities / requirements during PCB assembly? Please help.

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#7302

EPTSSOP | 19 July, 2001

You're correct, but you need to take it a little bit further. Installed correctly, ExposedPad� TSSOP IC packages significantly increase the thermal efficiency of power constrained standard TSSOP packages. This can increase heat dissipation by as much as 150%.

So to dissipate the increased power, you need to solder the exposed pad [read ... heatsink] to something that will absorb the heat spewing forth from this device. Look at page 6 of http://www.amkor.com/services/electrical/RF_Wireless/Package_Options_for_Wireless_Portable_Apps.pdf to better visualize what's going on with this device.

This is an Amkor proprietary package design. So after you read the paper; root around their site, find some good stuff, and report back to us.

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Lex WW

#7315

EPTSSOP | 21 July, 2001

Dave, thank you for the pointer. The Amkor site covered most of the basics, from the package design to assembly guidelines. If you have any further tips on assembling this package, I'd much appreciate it. Thanks again..

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#7317

EPTSSOP | 21 July, 2001

No. There's nothing fancy. You need enough solder on the exposed pad for a good thermal connection, but not so much to lift the comonent off the TSSOP pads. We reduce the aperture for the pad, dunno 85%, with four windows [but it doesn't matter how you do it]. You can experiment with dummy components. Practical has 'em and probably Top Line and the others do, also. [Oh, and when you call Practical, tell 'em "Thank you very kindly for supporting SMTnet. It's the best dang forum on the planet." Er, words to that effect.]

Gogetem!!

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