I. Core Service Capabilities and Hardening Process Analysis

　　1. Military-Grade Standard Compliance Basis

　　Core Implementation Standards:

　　Component Level: Comply with MIL-PRF (Military Performance Specifications), such as MIL-PRF-55342 (Integrated Circuits) and MIL-PRF-19500 (Discrete Semiconductors), ensuring components withstand extreme environments; prioritize "aerospace-grade" and "military-grade" components, rejecting industrial-grade downgrades.

　　Manufacturing and Testing Level: Comply with MIL-STD-883H (Microcircuit Test Methods), MIL-STD-202G (Environmental Testing for Electronic Components), and IPC-A-610 Class 3 (Acceptance Standard for High-Reliability Electronic Components); key processes must be certified to MIL-STD-45662 (Calibration System Requirements).

　　Environmental Protection and Compatibility: Meets MIL-STD-1344A (Thermal Design Specification for Electronic Components in Space Systems) and RoHS 2.0 military exemptions (allowing the use of specific heavy metals in certain military scenarios), and is compatible with military fuels, lubricants, and other chemical environments.

　　2. Core Processes for Harsh Environment Reinforcement

　　PCB Substrate and Structural Reinforcement:

　　Substrate Selection: Employs high Tg (glass transition temperature ≥170℃) FR-4 substrate (for general harsh environments) or polyimide substrate (for extreme temperature scenarios from -269℃ to 400℃), with board thicknesses supporting 0.8mm to 12mm, 2 to 24 layers, and copper foil thickness ≥35μm (to improve current carrying capacity and heat dissipation); ceramic substrates (Al₂O₃/AlN, resistant to high voltage and high temperature) can be selected for special scenarios.

　　Structural Design: Edges are rounded (impact resistance), and the board edges are reinforced with metal frames (such as 6061-T6 aluminum alloy to improve bending strength). Critical areas (such as connector solder joints) are reinforced with ribs to prevent solder joint breakage due to vibration.

　　Component Soldering and Protection Processes:

　　Soldering Process: Lead-free high-temperature solder (melting point ≥217℃, such as SAC305) or high-temperature leaded solder (MIL-SPEC solder, suitable for extreme temperature environments) is used. Reflow soldering temperature profiles are customized according to the component's MIL specifications (e.g., no solder joint cracking after cycling from -55℃ to 125℃). BGA/QFP devices use an "underfill" process (filling with epoxy resin to resist vibration and thermal stress).

　　Conformal Coating:

　　* Silicone Coating (suitable for -60℃~200℃, strong weather resistance, suitable for outdoor/automotive applications);

　　* Acrylic Coating (high insulation, suitable for high humidity/salt spray environments, such as shipboard equipment);

　　* Polyurethane Coating (resistant to chemical corrosion, suitable for oil exploration/chemical equipment);

　　* Coating thickness controlled at 50μm~150μm, critical pins must have exposed test points, coating coverage ≥99%.

　　Reliability Enhancement Design Support:

　　* Derating Design: Component derating is performed according to MIL-STD-810H requirements (e.g., capacitor voltage derating by 30%, resistor power derating by 50%) to avoid parameter drift under extreme environments.

　　* Redundancy Design: Core circuits (e.g., power supply, control unit) employ dual redundancy, and critical components (e.g., MCU, sensors) are backed up to improve fault tolerance.

　　EMC (Electromagnetic Compatibility) Design: Optimize PCB layout in collaboration with clients (e.g., analog/digital ground separation, high-frequency signal shielded routing) to meet MIL-STD-461E/F (military EMC standard), reducing the impact of electromagnetic interference on military equipment.

　　II. Environmental Adaptability and Testing Standards

　　1. Extreme Environment Testing Items (Full-Process Mandatory Testing)

　　High and Low Temperature and Temperature Cycling Testing:

　　High and Low Temperature Storage: -55℃ (low temperature) / 125℃ (high temperature) for 168 hours each, with a 100% pass rate in electrical performance tests after recovery;

　　Temperature Cycling: -55℃ to 125℃ for 500 cycles (transition time ≤ 5 minutes), each cycle consisting of 1 hour of high temperature and 1 hour of low temperature, with no solder joint cracking or component failure after testing.

　　Mechanical Environment Testing:

　　Vibration Test: According to MIL-STD-883H Method 2007.5, frequency 10Hz~2000Hz, acceleration 20g, 1 hour test per axis. After testing, the circuit functioned normally, and no solder joints detached.

　　Impact Test: According to MIL-STD-883H Method 2002.5, half-sine impact, peak acceleration 50g, duration 11ms, 3 impacts per axis. No structural damage or functional failure.

　　Drop Test: Free fall from a height of 1.5 meters onto a concrete surface (1 drop from each of the 6 sides), suitable for scenarios where the equipment is carried by a single soldier.

　　Harsh Environment Testing:

　　* Salt Spray Test: MIL-STD-883H Method 2011.7, 5% NaCl solution, temperature 35℃, 96 hours. No blistering or peeling of the coating, no corrosion of metal parts.

　　* Humidity Test: 95% RH (relative humidity), temperature 40℃, 96 hours. Insulation resistance ≥100MΩ, no leakage.

　　* Dust Test: MIL-STD-810H Method 510.7, talc environment, wind speed 1.5m/s, 24 hours. No blockage of heat dissipation channels, normal function.

　　* Electromagnetic Compatibility (EMC) Test: Passed MIL-STD-461F RS103 (radiated susceptibility), CE102 (conducted emissions), and RE102 (radiated emissions) tests, suitable for strong electromagnetic environments such as radar and communication equipment.

　　2. Testing Process and Report Output

　　100% of all batches undergo basic testing (high and low temperatures, vibration, insulation resistance); 10% are sampled for complete environmental testing (salt spray, EMC, shock).

　　Test reports are output (including raw data and graphs), conforming to MIL-STD-883H test documentation requirements, and supporting third-party re-inspection by the military or customers.

　　III. Applicable Scenarios and Industry Adaptation

　　1. Military Scenarios

　　Individual soldier electronic equipment (e.g., tactical radios, night vision devices, individual soldier computers):

　　Core requirements: lightweight (PCB board weight ≤ 50g), impact and drop resistance, operating temperature -30℃~60℃;

　　Adapted process: polyimide substrate + silicone coating, component selection prioritizes small packages (0201/01005), reinforced lightweight frame design (aluminum alloy material).

　　Shipborne/Airborne Electronic Equipment (e.g., radar control units, navigation modules, weapon fire control systems):

　　Core Requirements: Resistance to salt spray corrosion, resistance to strong vibrations (10g acceleration for shipborne, 15g acceleration for airborne), wide temperature range of -55℃ to 85℃;

　　Adaptive Processes: Acrylic coating + bottom filling process, PCB with thick copper (70μm) design for improved heat dissipation, EMC shielding layer (copper foil wrapping) to reduce electromagnetic interference.

　　Ground Equipment Systems (e.g., tank fire control computers, missile launch control units):

　　Core Requirements: Resistance to dust, resistance to high and low temperature cycling (-40℃ to 105℃), high reliability (MTBF ≥ 10,000 hours);

　　Adaptive Processes: Polyurethane coating + redundant circuit design, heat dissipation using a metal substrate, key components derated by 50%.

　　2. Harsh Civilian Environment Scenarios

　　Aerospace Equipment (Satellite Payload Modules, UAV Flight Control Systems):

　　Core Requirements: Vacuum resistance (1×10⁻⁵Pa), radiation resistance (total dose 100krad), extreme temperature range of -60℃ to 125℃;

　　Suitable Processes: Aerospace-grade components (compliant with MIL-PRF-901D), ceramic substrate + solvent-free coating, no outgassing under vacuum conditions.

　　Oil Exploration and Mining Equipment (Downhole Logging Instruments, Mining Sensors):

　　Core Requirements: High pressure resistance (100MPa), high temperature resistance (150℃), chemical corrosion resistance (oil and gas, slurry);

　　Suitable Processes: Metal casing (316L stainless steel), polyimide substrate + thick coating (150μm), solder joints reinforced with metal encapsulation.

　　Polar Scientific Expeditions and Outdoor Equipment (Polar Weather Stations, Outdoor Monitoring Terminals):

　　Core Requirements: Resistance to ultra-low temperatures (-60℃), resistance to strong ultraviolet radiation (UVB radiation), and resistance to ice and snow impact;

　　Suitable Processes: Silicone coating (UV resistant), low-temperature toughness solder (melting point 183℃), PCB edge anti-icing design.

　　IV. Key Aspects of Cooperation and Quality Control

　　1. Cooperation Process and Confidentiality Management

　　Early Design Collaboration:

　　Sign a confidentiality agreement (NDA) and establish a dedicated project team (restricting personnel access to sensitive information);

　　Jointly conduct DFM (Design for Manufacturability) and DfR (Design for Reliability) reviews, providing reinforcement process suggestions (e.g., component layout avoiding stress concentration areas, wiring considering the coefficient of thermal expansion);

　　Provide component alternatives (e.g., compliant replacements of scarce military-grade components, ensuring consistent performance and compliance with MIL standards).

　　Order and Production Control:

　　Order Confirmation: Clearly define military standard versions, environmental testing requirements, and delivery cycles (military-grade PCBA cycles are typically 2-4 weeks, including testing time);

　　Production Environment: Closed cleanroom (Class 10000), ESD protection meets ANSI/ESD S20.20 standards, and production personnel hold military production qualification certificates;

　　Progress Tracking: Regularly synchronize production progress (e.g., component procurement, soldering, testing stages), and provide real-time data feedback for key milestones (e.g., environmental testing initiation/completion).

　　2. Quality Control and Traceability

　　Component Traceability:

　　Component Procurement: Procurement is only from original manufacturers or authorized distributors (e.g., Avnet, Arrow's military division), obtaining COC (Certificate of Conformity) and MIL standard certification documents;

　　Traceability Management: Establish a system linking "component batch number - production work order - test report," allowing traceability to the source of components, soldering parameters, and test data for each PCBA, with a retention period of ≥10 years (meeting military equipment lifecycle requirements). Full-process quality control:

　　* **Incoming Quality Control (IQC):** 100% component visual inspection and parameter testing (e.g., capacitance, inductance, semiconductor reverse leakage current), conforming to MIL-STD-883H Method 2000;

　　* **In-Process Quality Control (IPQC):** 20% sampling inspection of each process (welding, coating, reinforcement), focusing on solder joint quality (X-Ray 100% inspection of BGA/QFP solder joints) and coating thickness (laser thickness gauge);

　　* **Final Quality Control (FQC):** 100% PCBA undergoes electrical performance testing (ICT+FCT), insulation resistance testing, and full visual inspection. 10% sampling undergoes complete environmental testing. Non-conforming products are immediately isolated and root cause analysis is initiated (8D report).

　　Certification and Qualification Guarantee:

　　System Certification: Certified by ISO 9001 (Quality Management), AS9100 (Aerospace Quality Management), and MIL-STD-790 (Reliability Engineering);

　　Testing Qualification: The laboratory is CNAS (China National Accreditation Service for Conformity Assessment) certified, or collaborates with third-party military product testing organizations (such as the China Aeronautical Integrated Technology Research Institute) to ensure authoritative and valid test results.

　　3. After-Sales and Support Services

　　Warranty Period: Provides a 1-5 year warranty (customized according to the equipment lifecycle). During the warranty period, any process issues (such as solder joint cracking or coating peeling) will be reworked or remanufactured free of charge;

　　Fault Analysis: Analysis will be initiated within 24 hours of receiving fault feedback, and a fault report (including failure mode, root cause, and corrective measures) will be provided;

　　Long-Term Support: Provides PCBA maintenance recommendations (such as regular coating integrity checks and cleaning of heat dissipation channels) and adapts to equipment upgrade needs (such as process improvements and component updates).