Circuit board design

Generally It is designed by your engineer, using computer software to draw a good picture. Then pass it to the manufacturer of the board. They will make the board according to the drawings you provide. First let him send a few samples. For fear that your engineers in the design of the problem. So take the prototype back to try to do first. After the finished product to take to the test. Waiting for the test results out and then notify the manufacturer to do the board officially started. If you do not take the look back to try. Problems are counted on your own, the cost and other technical things can not be estimated. In the production process if found in too many bad boards can call the manufacturer rework. First of all, that is not a design problem.