Electronic Secondary Screening of Components (Second screening) is a critical step in ensuring the quality and reliability of electronic components, particularly in high‑performance applications with stringent reliability requirements, such as military and aerospace systems. This paper examines the automated processes and standards employed in second‑screening laboratories for electronic components.

1. The Purpose and Significance of Secondary Screening
   • Secondary screening is a widely recognized and effective method for ensuring the quality of electronic components. By conducting non‑destructive screening tests, it identifies and removes early‑failure products with latent defects, thereby enhancing the reliability of the entire batch.
   • Secondary screening not only enhances the reliability of component usage but also boosts user confidence.
2. Automated workflow for secondary screening
   • Automated screening machines, leveraging advanced intelligent algorithms and adaptive technologies, can rapidly and accurately sort large volumes of electronic components, thereby enhancing production efficiency and ensuring consistent quality.
   • Automated workflows typically encompass steps such as data acquisition and transmission, filtering, testing, and result analysis, leveraging intelligent automation to enhance both the efficiency and accuracy of assays.
3. Criteria and Items for Secondary Screening
   • Secondary screening typically includes visual inspection, room-temperature initial testing, temperature cycling, and high-temperature aging; the specific test items are selected based on the component type and application requirements.
   • The screening criteria shall be established in accordance with relevant national standards and military‑enterprise standards, such as GJB 360 and GJB 128, to ensure the effectiveness and consistency of the screening process.
4. Quality Control and Management
   • During the secondary screening process, it is essential to strictly adhere to the screening procedures, criteria, and technical requirements to ensure the validity of the screening and the accuracy of the results. These requirements encompass control over screening equipment and the operating environment, as well as the training and certification of personnel.
   • To ensure the reliability of the screening process, all personnel involved must undergo specialized training, hold the requisite certifications, and adhere strictly to established procedures. This includes the ability to analyze and evaluate screening results, thereby enabling accurate assessment of component quality and reliability.
5. Technical Challenges of Secondary Screening
   • With the rapid advancement of electronic components, the complexity and difficulty of secondary screening have increased significantly, particularly in the fields of integrated circuits and very-large-scale integration. These challenges are primarily reflected in the requirements for test equipment and the development of testing procedures, as the swift pace of component innovation demands that testing personnel possess higher technical expertise and greater adaptability to new equipment.
   • Modern screening technologies are continuously evolving, integrating advanced techniques such as machine vision and artificial intelligence. The application of these technologies has significantly enhanced both the accuracy and efficiency of inspections. For instance, machine vision can be employed for visual inspection, while AI enables more sophisticated defect analysis, thereby enabling efficient, intelligent screening of electronic components.
6. Scope of Application for Secondary Screening
   • Secondary screening is widely employed across various electronic components, including discrete semiconductor devices, integrated circuits, and microwave components, with particularly widespread use in the defense and aerospace sectors. In these fields, component‑screening criteria are typically grounded in system‑level reliability and operational‑environment requirements, ensuring both performance and dependability.
   • In the aerospace sector, the single‑use nature of products imposes extremely stringent reliability requirements on electronic components, necessitating rigorous secondary screening. This process encompasses not only component selection and acceptance but also secondary screening and destructive physical analysis—key quality‑control steps designed to ensure product reliability and safety.

In summary, the automated processes and standards for secondary screening of electronic components are critical to ensuring component quality and reliability. By leveraging automation technologies and rigorous standardized procedures, screening efficiency and accuracy can be significantly enhanced, thereby meeting the demanding requirements of high‑performance, high‑reliability applications.

Academic Outline

• The Necessity of Secondary Screening for Electronic Components
  • Secondary screening is an essential measure for ensuring the quality of electronic components.
  • Enhance the confidence of component users.
  • Increase component usage costs
• Scope of Application for Secondary Screening
  • Components that have not undergone any screening.
  • Components that fail to meet the user’s quality requirements after a single screening process.
  • Components requiring verification
  • Special requirements of the complete machine unit
• Projects for secondary screening
  • Visual inspection
  • Initial measurement at room temperature
  • Temperature cycling
  • High-Temperature Dynamic Aging
  • Low-temperature test
  • High-temperature test
  • Sealing Performance Test
  • Final measurement at room temperature
  • X-ray inspection and acoustic microscopy (for imported plastic‑encapsulated integrated circuits)
• Quality Control for Secondary Screening
  • Technical operations方面
    • The design department shall select appropriate secondary screening criteria and test items based on device grade and product requirements.
    • During operation, procedures must be strictly followed in accordance with the relevant standards; the test environment should be controlled, and electrostatic discharge (ESD) protection must be observed.
    • The screening ratio is implemented in accordance with each unit’s regulations; for defense‑industry enterprises, a 100% secondary screening is typically conducted.
• In terms of management
  • The receipt, dispatch, screening, testing, and results of components shall all be meticulously documented to facilitate component traceability. Procurement shall be conducted strictly in accordance with the approved “Qualified Supplier List” and relevant technical documentation.
  • Implement quality oversight and documentation throughout the entire screening and testing process.
• Equipment and Instruments for Secondary Screening
  • High-temperature test chamber
  • Low-temperature test chamber
  • Particle collision equipment
  • Constant-Addition Equipment
  • Leak detection equipment
  • Burn-in board, regulated power supply, test bench, oscilloscope, multimeter
• Technical Requirements for Secondary Screening
  • The screening must be non-destructive.
  • The test stress must not be too low; otherwise, the screening objective cannot be achieved.
  • The screening technical specifications are indispensable technical documents in the screening process.
• Application of Automation Technology in Secondary Screening
  • Automated testing technology enhances testing efficiency.
  • AOI technology is used to detect PCB defects.
  • The design of the automated testing system comprises a hardware platform and a software platform.
• Prevention of Failure in Secondary Screening
  • Follow the secondary screening procedure strictly.
  • Verify the test factors against the applicable standards.
  • Avoid component detection failures caused by improper program settings.
    
    (Note: Some viewpoints are sourced from the internet.)