We consider a homogenization problem for the Laplace operator posed in a bounded domain of the upper half-space, a part of its boundary being in contact with the plane $$\{x_3=0\}$$
{
x
3
=
0
}
. On this part, the boundary conditions alternate from Neumann to nonlinear-Robin, being of Dirichlet type outside. The nonlinear-Robin boundary conditions are imposed on small regions periodically placed along the plane and contain a Robin parameter that can be very large. We provide all the possible homogenized problems, depending on the relations between the three parameters: period $$\varepsilon $$
ε
, size of the small regions $$r_\varepsilon $$
r
ε
and Robin parameter $$\beta (\varepsilon )$$
β
(
ε
)
. In particular, we address the convergence, as $$\varepsilon $$
ε
tends to zero, of the solutions for the critical size of the small regions $$r_\varepsilon =O(\varepsilon ^{ 2})$$
r
ε
=
O
(
ε
2
)
. For certain $$\beta (\varepsilon )$$
β
(
ε
)
, a nonlinear capacity term arises in the strange term which depends on the macroscopic variable and allows us to extend the usual capacity definition to semilinear boundary conditions.