The size of 纸箱 is basically equal to纸板箱，but there are a litter difference between the material they used, the material of 纸箱 maybe more soft than 纸板箱. The material of 纸板箱 is same as 硬纸盒, but the size of 硬纸盒 is small.

They do have different,not in size,but they have different in material. 纸箱 is the total name of the box which is made by paper. While "纸板箱" is the box which is made by corrugated paper, and "硬纸盒" is the box which is made by hardborad.