SRI International has been a certified QML (MIL-PRF-38535) manufacturer for monolithic integrated circuits produced by the Generalized Emulation of Microcircuits (GEM) program since 1997 and all GEM microcircuits are delivered in compliance with the requirements of MIL-PRF-38535. This includes complete traceability, total compliance with customer procurement requirements, and delivery with a certificate of conformance. Adhering to QML requirements ensures the integrity of the system, and the delivery of a highly reliable microcircuit that will work to specifications in rugged military environments.
When a request for an obsolete microcircuit is received, SRI begins its unique Emulation process to manufacture a Form, Fit, Function, and Interface (F3I) compliant microcircuit. Our on-demand manufacturing process significantly reduces the time to deliver a part.
Together with the customer’s procurement specification(s), SRI utilizes other relevant documentation such as catalog datasheets, Original Component Manufacturer (OCM) application notes, Next Higher Assembly (NHA) maintenance manuals, etc. to resolve any ambiguities or omissions in the procurement documentation. An Emulation design specification is created using this documentation augmented by electrical characterization of known good samples of the obsolete microcircuit and physical reverse engineering processes.
Base Wafers and Gate Arrays
SRI has developed a split manufacturing process, in which wafer lots are processed through the majority of the manufacturing flow and held in inventory. This technology is based on gate arrays fabricated with predefined circuit elements (base wafers) which are interconnected by multiple levels of metal conductors (wafer personalization) and minimizes the wafer production time for emulated devices. This approach allows Integrated Circuits (ICs) that were originally manufactured in diverse technologies to be produced from a managed inventory of standardized base wafers. An overview of the SRI Production System for emulating microcircuits is illustrated above.
Design & Layout
Our in-house design center uses a suite of modern CAD tools covering all aspects of chip integration and reliability. Working closely with our co-located Trusted foundry and advanced TCAD tools to model and characterize the fabrication process provides SRI with a unique capability to meet our customers’ requirements. Our digital and analog design capabilities cover a range of technologies (CMOS, BiCMOS, Bipolar, etc...) and feature sizes, from 3.0 μm and below.
Trusted Foundry Fabrication
All parts are manufactured in Princeton, NJ. SRI’s Microcircuit Emulation Wafer DoD Trusted foundry occupies 25,000 square feet at the Princeton, NJ location. The Wafer Fab has ISO 4 and ISO 5 classified cleanrooms. The facility uses the MESA WIP tracking system which enables real-time wafer lot tracking and historical record retrieval. Statistical Process Control (SPC) is implemented in all process areas. SRI maintains all process equipment with OEM trained staff and service contracts.
SRI maintains in-house capability to perform the qualification, screening, and inspection tests for quality level B and Q microcircuits. High performance Automated Test Equipment (ATE) supports parametric and functional testing over the mil temp range for both wafers and packaged parts. All GEM devices are fully screened and QC inspected in accordance with MIL-STD-883 and MIL-PRF-38535.
QML Screening Test
The assembled parts are then individually tested over the full temperature and performance range and verified to meet all requirements of the specification. Screening of package integrity, life test reliability and the full complement of reliability tests are performed in accordance with SRI QML standards following the requirements of MIL-PRF-38535.
Emulated parts are fully traceable and certified to customer procurement requirements, preserving existing configuration control and logistic support. GEM parts are never discontinued and can be manufactured at any time in the future.