I am using a component with LGA package. Should I use a solid connection or use thermals between pads and GND plane?
If it is an SMT pad, and is meant to go through a commercial reflow oven, don't use thermal relief on the pads. The reflow oven will provide the even heat needed to melt the solder consistently.
This will admittedly make manual rework more difficult, but manufacturers I've worked with are confident enough that reflow will solder everything effectively, that they don't insist on thermal relief on SMT. Given that, I'd prefer to have the solid connection to ground.
Rule of thumb: If it'll be soldered, use thermals. Period.
In my designs I always give my component pads thermals when connecting to a copper pour. Otherwise the heat will be wicked away as I am trying to apply solder (or as it is being reflowed) and you'll get uneven heating, leading to poor solder flow. I do not use thermals on vias, however, because they generally are not soldered. If I plan to use a via as a test point, only then would I give it a thermal connection to the pour because I may need to solder a jumper to it.
Thermal pads for copper to prevent misalignment bridging DFM issues.
Segmented or crosshatch pattern for solder stencil.
Thermal barrel at least 25 um - will need more plating thickness. ( ask supplier)
- optimum final diameter 350 um
- ideal distance from hole to hole (pitch) is 800 um