1. Field of the Invention
The present invention relates generally to a method of modeling the assembly of a product to increase the production or manufacturing yield thereof, and more particularly pertains to a method of modeling the assembly of a product constructed from a plurality of components, each of which is produced in multiple manufacturing lots, to increase the production yield of electronic products having acceptable performance characteristics. The subject invention is particularly applicable to the assembly of an electronic product assembled from a plurality of electronic components.
2. Discussion of the Prior Art
Traditionally in the military electronics manufacturing business, major electronic assemblies such as electronic modules, circuit boards, etc. are designed such that any individual component of the major assembly can be replaced by another component of the same part number that meets the component technical specifications, with no impact on the ability of the major assembly to meet the overall or top performance specification requirements of the assembly. The tolerance build-up within an electronic assembly is normally analyzed during the design phase, and component tolerances are designed and specified to ensure interchangeability. In some instances, a tolerance build-up can occur as a result of a suboptimum combination of components that yields an out of specification final product. When an electronic assembly uses a series of components which could cause a deviation from overall or top performance of the assembly specifications, trimming components are usually introduced, and during final testing, the required value of the trimming component (e.g., resistor, capacitor) is determined and inserted therein.
In the military electronics manufacturing business, the requirement for interchangeable components has been dictated by the requirements of the government for maintenance and spare components. This allows equipment to be repaired by military personnel at various maintenance levels within the military services without concern for a component selection process, which would otherwise require measuring a series of component parts until one is located that yields acceptable performance specifications.
Moreover, in the assembly of electronic products, increased automation and improved manufacturing equipment and techniques can also increase production yields, and increased inspection, testing and burn-in can further improve production yields despite faulty components. A reduction of yield due to tolerance build-up can be addressed by tightening tolerances on individual components or by understanding a priori, the nature and magnitude of the tolerance build-up problem in a given manufacturing run, and taking steps to minimize the yield of unacceptable products caused by a mismatch of components. In many instances, a traditional approach of simply tightening the tolerances of the individual components in the product can be a very costly undertaking which is not particularly cost effective.