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72 SMT007 MAGAZINE I JANUARY 2023 for prototype packaged devices. Die design- ers are oen pushed to validate the perfor- mance of their new designs as quickly as pos- sible. e time-to-market is oen paramount. OSATs' infrastructure and geographical loca- tion make it challenging for them to support quick-turn prototyping for U.S.-based semi- conductor design firms. With the availability of open molded plastic packages, companies with flexible assembly operations can provide the support needed. Meeting MSL Requirements e JEDEC moisture sensitivity level (MSL) rating is a key characteristic of plastic encap- sulated micro-circuits (PEMs) that defines the storage and handling constraints during the manufacturing process for a particular PEM product. e MSL rating also determines the preconditioning stress level for the package reliability tests that are performed to qualify a PEM product for release to production. e joint IPC/JEDEC J-STD-020E Mois- ture/Reflow Sensitivity Classification for Non- Hermetic Solid-State Surface-Mount Devices standard is used to determine what classifica- tion level should be used for initial reliability qualification. Once identified, the PEMs can be properly packed, stored and handled to avoid subsequent thermal and mechanical damage during the assembly solder reflow attachment and/or repair operation. e standard establishes the period in which a moisture-sensitive device can be exposed to ambient room temperature. MSL floor life rat- ings are shown in Table 1. e definition of "floor life" is the allowable time storage at ≤ 30°C, 60% RH before degradation occurs. A Real-World Example As noted earlier, OCPP is an attractive option for production when no onshore sources are available for a particular plastic package assembly, and lead time and Interna- tional Traffic in Arms Regulations (ITAR) con- straints prohibit offshore assembly. When avi- onics ASIC provider Device Engineering Inc. (DEI) ran into this problem, QP Technologies' OCPP approach was an effective solution for DEI's crucial production schedule, reliability requirements, and ITAR supply constraints. DEI sought out OCPP technology as a solu- tion for production assembly of its 64-lead thin QFP (TQFP) 10 mm x 10 mm ePad prod- uct when its prior onshore assembly provider ceased doing business, in turn, creating a chal- lenge for DEI's customer. Once DEI was able to source a quantity of suitable dummy IC packages (containing no die) from an offshore supplier, QP Technologies converted them to OCPP, developing the assembly process and materials that achieve DEI's required package performance. e IC was characterized for MSL, as deter- mined by J-STD-020, and qualified via envi- ronmental stress-based accelerated reliability tests. e IC was qualified in the end product and has entered production. To find the right process for DEI's specifica- tions, QP Technologies experimented to eval- uate various OCPP types and configurations. First, 64-lead TQFP packages were opened Table 1: MSL definition