I realized that if I create two UV's in the Blender, Unity automatically reads the first UV channel as "Base" and the second as "lightmap".
And bumpmap?
I created Difuse, Normal Map (Bump) and Lightmap in Blender, each one with its respective UV map channel. Consequently, now in Unity, I need to use the channels Base, Bump and the lightmap of "Lightmapped / Bumped Diffuse" shader. How should I organize my UV's in the blender so that the unity read each one for each channel of the shader? The Unity reads more than two UV channels of blender? How does this reading of the relationship between Blender's UV's and shaders channels of Unity?