We know that, two triangles are congruent, if the sides and angles of one triangle are equal to the corresponding sides and angles of the other triangle.
Also, criterion for congruence of triangles are SAS (Side-Angle-Side). ASA (Angle-Side-Angle), SSS (Side-side-Side) and RHS (right angle-hypotenuse-side)
So, SSA is not a criterion for congruence of triangles.