I am finishing up a prototype board using the A6282ELP led driver. This is a 24 pin TSSOP package with an exposed thermal pad on the bottom (but one that doesn't go to the very end edge of the chip).
This low side chip regulates the current to each LED so you don't need series resistors. It is recommended to keep the LED driver voltage low enough such that Vds on the chip fets is between 1 and 3V. Easy since I am using an efficient buck regulator and can set the LED driver voltage to whatever I want....except I am using RGB leds where the red led drop is significantly less than the blue and green elements. I predict having to use a LED voltage of around 4.5V, meaning the Vds on the red led driver fets will be around 2.3V. At 50mA per channel average current and using 12 of the 16 channels in my design, I get a package power dissipation of around 1.38 watts plus about .12 watts for the rest of the chip electronics...so around 1.5W. (note I could use series resistors on just the red channel lines to the leds, except that there is no standard in the industry on these PLC6 RGB LED packages so I don't know which pins will actually be red if the supplier changes!)
Sorry for the wall of text, but wanted to provide a background to the question.
1.5W seems a fair amount of heat for such a tiny package and I plan on using a layout with thermal vias to a large ground plane. The question I have is how do you guys hand solder these type of parts ensuring good contact of the "exposed pad" underneath the TSSOP 24 pin chip to the circuit board landing? I won't be using an oven, so I guess solder paste is out. I could design the top landing pad to be large enough that it sticks out a little on each side of the chip and then try to wick solder under the chip across this pad or I could try to wick solder through the thermal vias from the underside, or
Thanks for any suggestions!