In recent years, most PCB units (having an identical pattern) are manufactured into one single panel to improve the productivity and yield in an automatic part mounting process. So if you are looking at a 20-piece PCB, a panel containing 1 5*4 boards will be produced.
 
Even though there are benefits, one has to consider all the pros and cons of proceeding in this way. Among the 20-piece PCB as mentioned earlier, there is a chance that one or more PCB units of that panel are shown as defective. The defective unit is so called X-out PCB or simply, X-out board. Considering the possible effects that may arise from assembling during the post-production process, it is recommended that “No X-out Allowed” is noted somewhere on your order. Relatively, an order with this high standard level leads us to produce more in order to avoid defectiveness, resulted an average increase of 10%~ 20% added up to your overall sales price. The total sales price will be determined upon reviewed by the numbers of quantities plus the complexity of making PCBs. At a result, it will more than likely differ from every order you place.
 
However, the above only applies to you unless you have a stronger demand of having none x-out boards. If you can accept one or more defective PCB units and all you want is to fulfill the quantity demand, we can send all your PCB units, including the good and defective ones. The only issue you may probably encounter is the inability of the continuous assembling during post production. However, in recent years, a technique for solving this type of issue has been developed and can be seen from most companies offering assembling services with high-tech equipment. You are free to contact us if you are interested to know what companies are able to proceed with such request.
 
The above mentioned are FYI, thank you.