Printed Circuit Board
Obejective
Printed Circuit Board is plated with Gold layers so that the surface of key pads can last with good conductivity, meaning key pad surface will not be oxidized with gold layer. Everybody knows gold is really expensive, the same for its raw materials. As the manufacturer for the Printed Circuit Board, we only want to plate the gold with the least thickness allowed by customer. The customer specification is 0.05 to 0.08 micrometer for gold layer. We aim to plate the gold layer just marginally larger than 0.05 micrometer. Considering the error possibly introduced by the measuring system of gold thickness, even marginally pass the specification, the products may be rejected by customer. To avoid such risk, the decision is made to contact customer to do a comparison between two measuring systems owned by our company and customer to see whether the two measuring system would give the same conclusion for pass or fail for the products we ship to customer. Lets name the measuring systems as below:
Measuring system A( abbreviated as MSA): Customers CMI 900
Measuring system B( abbreviated as MSB): Our companys CMI 900
The hypothesis planned to make is, if we can prove with statistical significance that the two measure systems can give out the equal results, we can ship those marginal pass products to our customer without causing any trouble for both customer and us. Otherwise, we need establish the correlation between the two measuring systems or get suppliers of the measuring system to improve the measuring system. In the worst case, we need to buy a new measuring system to support this business need.