On the other hand, leadless devices — common types include QFNs [quad flat no leads] and LGA [land grid array] package styles — pursue miniaturization through a different route. Rather
than attach to the board with any extended legs or leads,
these devices make contact using solder “bumps” on the
bottom of the component package. The place you will most
often see these types of SMTs will be where very flat
structure heights are required, such as in handheld devices
or where a lot of heat dissipation is necessary.
However, the price of this compactness is that both of
these component types are consequently difficult to place
for hobbyists for single devices when there is no stencil
printing involved. In addition, these packages generally
Roboticists need a plethora of skills to create and construct their
automatons. Knowing how to solder is a major part of moving from
simple kits into the realm of advanced circuits and chassis.
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Figure 2. Make sure the apertures of the stencil are properly
aligned on the part.
Figure 3. Don't worry if there's a little excess paste on the stencil.
It can be easily wiped off with a lint free cloth.
Figure 4. If using a brush to apply alcohol, be careful not to scratch
Figure 5. Make sure that the apertures are well aligned before
you fully stick the stencil down.