Standards & Practices
During the design phase, Sigma adheres to the following standards and practices:
- Electronic design and component selection, to meet or exceed specified requirements of Reliability (MTBF)
- Careful selection of components, to ensure long service life, to address obsolescence
- Selection of components of the required grade - MIL / Industrial / Extended Temperature - to meet specified requirements
- PCB fabrication to meet required standards - MIL with Group A / B, or IPC Class 1,2 or 3
- Programmable hardware design and development, meeting DO-254
- Reliability Prediction Analysis, using Parts Stress method, using MIL-HBK-217
- PCB Design, as per MIL-STD-275 / IPC-1701 or equivalent
- PCB level Thermal Analysis
- PCB level High Frequency Signal Integrity Analysis
- Power Integrity Analysis
- Hardare version Control, using GIT and Subversion
- Software Design and Development, to meet required level of quality assurance
- Optional software quality assurance, meeting DO-178 / IEEE 12207
- Optional software coding standards, meeting MISRA C
- Documentation, meeting relevant IEC standards
- Software version Control, using GIT and Subversion
Sigma carefully evaluates its suppliers, based on a number of factors, and maintains a list of approved suppliers, to ensure quality and traceability of its incoming materials. Sigma procures all its items from its approved suppliers. The suppliers are the direct manufacturers, authorised distributors or dealers, international distributors or chains. In case of fabricators, the suppliers are approved, based on sample orders. All incoming items are carefully inspected as per approved plans before usage. Sigma maintains an active "Anti-countefeit policy and procedures meeting AS-5553. The items are stored in controlled environment - anti-static, dust, humidity and temperature controlled area. Component handling meets IPC - 1601.
All production and testing activities are carried out in controlled environment - anti-static, dust, humidity and temperature controlled area. The anti-static facilities are maintained as per ANSI S20-20, and measuements are maintained and recorded as per JED-625.
Sigma also ensures its electronic PCB assemblies are carried out as per IPC J-STD-001, while the inspection of the Electronic assemblies are carried out as per IPC A-610; cable assemblies are carried out and inspected to meet the requirements of IPC A-620.
In-process inspection is carried out at appropriate stages, with route cards and process sheets.
Workmanship records are maintained for each operator to ensure continued quality in PCB assemblies.
After initial design-level testing and board bring-up, cold-tests and warm tests are conducted, followed by formal board-level functional testing, as per approved Accetance Test Procedure (ATP) document. Environmental tests are carried out as per approved AT / QT documents, as per the requirements.
Environmental tests ensure compliance with the following standards (as per requirements):
- MIL-STD-461 for EMI/EMC
- MIL-STD-810 for Environmental Conditions
- IP-65 for enclosure sealing
Sigma has the following environmental chambers and machines:
- Owens (2 Nos.)
- Hot and Cold Chambers, with Humidity Control (3 Nos.)
- Shock and Vibration Shaker machine
- Bump machine
Management and Quality Tools
- Quality Plans
- Risk Management
- Configuration Management
- Root-cause Analysis - 5 Why's, 8D, Fishbone, Fault-tree Analysis
- Data Analysis
- Failure Modes and Effects Analysis (FEMA)
- First-Article Inspection, as per AS 9102