Synopsis:
Automatically generate Lot Genealogy from fab to wafer and assembly test to customer returned material. Enables engineering analysis to be performed across the different manufacturing steps without spending time on finding the data.
Description:
For engineers to comprehend correlations between different test/assembly manufacturing steps having a genealogy at the lot, wafer, and die level assists in these complex sets of analyses. Consider starting with a wafer boat consisting of 25 wafers and 553 die per wafer arriving from your silicon fabrication facility. That lot may be broken up into 3 separate wafer test lots of 8, 8, 9 wafers each with a unique lot name. Each lot may have different ATE, probe cards, and prober equipment.
Subsequently, each test wafer lot will be broken up into assembly lots- they will each run through a set of assembly equipment and then final test (package-level test). Thus, a wafer of 553 die may be split into two assembly lots of 220 and 233 units each. Depending upon your supply chain a single wafer lot (25 wafers) may be shipped to three different OSATs. In this scenario, without a yield management system, locating the data from three different facilities can prove daunting if your product engineers reside 4500 miles away.
Fully automating the collection of data within yieldWerx data allows an engineer to focus on data analysis. Within less than a minute, engineers can analyze parameters across WAT/PCM, wafer probe, assembly, and final test. Providing this level of data management saves engineers days if not weeks of effort. A common use for this module is comprehending yield differences. When yield significantly differs across wafer lots or from specific wafers at final test engineers perform a commonality analysis to discern possible causes. They need to look at all possible causes- equipment, loadboard/probe card, tester version, wafer number, die location. This module makes it easy for engineers to extract lot genealogy data the first step in any commonality analysis.
Where applied:
- Wafer Test
- Final Test
- Customer Field Returns