replace one floor of a 3D np array by a 2D numpy array

Question

I'm trying to "replace one floor of a 3D np array by a 2D numpy array"

this is my code, but I'm pretty sure there is a better way :

import numpy as np
w,h = 2,5
board_2D = np.random.randint(1, 5, size=(h, w))
board_3D = np.arange(h*w*4).reshape(4,h,w)
print(board_3D)

z= 1
for y in range(h):
    for x in range(w):
        board_3D[z,y,x] = board_2D[y,x]

print(board_3D)