Control of under-fill using an encapsulant for a dual-sided ball grid array package

Disclosed herein are methods of fabricating a packaged radio-frequency (RF) device. The disclosed methods use an encapsulant on solder balls to control the distribution of an under-fill material between one or more components and a packaging substrate. The encapsulant can be used in the ball attach process. The fluxing agent leaves behind a material that encapsulates the base of each solder ball. The encapsulant forms an obtuse angle with the substrate surface and with the ball surface. This reduces the tendency of the under-fill material to wick around the solder balls by capillary action which can prevent or limit the capillary under-fill material from flowing onto or contacting other components. Accordingly, the disclosed technologies control under-fill for dual-sided ball grid array packages using an encapsulant on the solder balls.