Step 10: Attach the cells to the backing
Using a blank piece of paper, create a template by tracing the outline of the backing constructed in step 6 onto the piece of paper. The outline will be used to position the cells onto the backing.
Carefully slide the template under the solar cells and position them within the outline as you want them mounted on the backing. Leave enough space on all sides to attach the clear plastic cover and for the two wires that will be soldered to the cells.
Apply a dab of adhesive about the size of a nickel to the back of each cell. You want enough to adhese the cells to the backing, but not enough to squirt out the sides, nor so much that the cells end up sitting up high off the backing--they need to be close against the backing to fit well under the plastic cover.
Hold the backing over the cells and, using the template outline as a guide, gently press the backing onto the cells. The cells are in danger of breaking in the step, so be gentle but firm. Pull up the backing, hopefully with the cells stuck on, and flip it over. You can do some repositioning and make certain that each cell is well pressed into the backing.