부산대학교 도서관

Unit Level Traceability (ULT) is the ‘State of the Art’ automation system. As the name implied, it is a revolutionize game changer in today advanced manufacturing environment that leapfrog manufacturing system through the adoption of SEMI standard protocol integration and machine upgrade among the key processes. The ULT system concurrently enables process tracking chronology encompasses wafer identification, die coordinate (from wafer map), material batch, machine history as well as lots and strips movement history. This comprehensive traceability system also coincides with the Automotive standard compliances [1]. ULT capability set up requires additional pre-assembly steps for strip marking in which every strip has unique Strip Identification (ID) and its respective assembly strip map. Information Technology (IT) server to machine integration with strip map download and upload communication will enable real-time transmission of process information along assembly flow. At marking process, final unique unit level code will be marked [2] on top of the assembled product according to the downloaded strip map. Upon completion of production cycle, the finished products will flow down to the subsequent test process in which the test handler will read the product unique marked code and transmits it together with the post test data log to the centralized ULT database system. Therefore, high level of traceability data is available in case unexpected quality issue or high-test fallouts happened. ULT retention data provides quick traceability by pinpointing the root cause of the failed products and accurately isolate the defective batches product. Although significant investment requires to drive ULT implementation such as production machineries upgrade and modification, IT system integration and server upgrade, it definitely provides immerse benefits for today's advanced manufacturing line especially OSAT providers.