• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 80 subscribers
  • Views 742 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

MSP430F5510: RGC package, thermal pad

Oba
Mastermind 18065 points

Part Number: MSP430F5510

Hello,

 

I have two questions for MSP430F5510 RGC package.

 

1.

Are thermal pad and terminal pins on the exact same plane?

 

2.

I would like to know minimum requirement for percentage of exposed thermal pad joint area to PCB to keep thermal performance.

SLUA271 application note that the datasheet mentions at the package mechanical data page says like the below on P11.

 

“Typically, the solder-paste coverage is approximately 50% to 70% of the pad area (see Figure 11).”

 

From this descritpin, is it OK to think the minimum requirent is 50%?

 

Regards,

Oba

 

  • 0
    Guru 326060 points

    1. Probably; but in any case, the package drawing in the datasheet guarantees that the difference would be less than 50 µm.
    2. The example stencil design in the datasheet mentions a 72% coverage. In any case, surface tension will increase the actual amount of coverage; the stencil coverage is smaller to prevent excess solder.
      Typically, the PCB's copper is much thinner than the solder, so the latter is unlikely to be the largest source of thermal resistance. In other words, it does not really matter much, and 50 % would be fine. (Section 5.6 of the datasheet mentions that θJC(BOTTOM) was measured with an actual coverage of 100 %.)

  • 0
    TI__Guru**** 223517 points

    Hello Oba,

    Both of Clemens' points are correct, and as the MSP430 is a low-power MCU family the thermal considerations are less strict than with other high-performance microcontrollers/processors.

    Regards,
    Ryan

**Attention** This is a public forum