Quality assurance Fiabilité

Reliability is the ability of a product to perform under stated conditions for a specified period of time. Generally, reliability levels are expressed as the probability that a part will fail to function after a specified time interval. The same part will have different probabilities of failure under different use conditions. In the electronics industry, this failure rate over time exhibits characteristics that, when summed, are commonly referred to as the “Bathtub Curve”. This curve is typically divided into the three regions depicted below (Early Failure Rate, Intrinsic Failure Rate, Wear Out Failure Rate).

The specific shape and position of the bathtub curve is dependent on the product design, material, processing and defect density for both die and package. When considering the overall reliability of the product, the intended application(s) and the board/system level manufacturing processes will contribute to the observed reliability. As the knowledge and understanding of all these factors grows, designs and processes can be implemented and improved to ensure a robust and reliable product.

3D PLUS screening module performed on 100% of our Engineering and Space products ought to eliminate early failures, when the Lot Acceptance Test performed on a sampling given by standard is in place to ensure reliable products after time without achieving the wear out zone.

As products can operate in a system for more than twenty years without failing, any test designed to accurately evaluate reliability must utilize accelerated use conditions. This acceleration is achieved through the use of extreme environmental (temperature, humidity, pressure) and operating (voltages, currents) conditions that serve to shorten the overall test times to more manageable levels. Even under accelerated conditions, these tests may take several months to complete.

3D PLUS supplies highly reliable products to its customers using its highly reliable  stacking technology proven since 1995 and with more than 200,000 products in space.

Reliability Testing

Highly Accelerated Stress Test (HAST)

The purpose of this test is to evaluate a plastic packaged component’s ability to withstand harsh environmental conditions with extreme temperature and humidity levels. The parts are stressed to high temperature (110°C) and relative humidity (85%RH) conditions for a defined period (264hours) in a biased state to achieve maximum acceleration (JESD22-A110).

Reliability Qualification Methodology

Methodology to ensure that the requirements for Product Assurance aspects comply with the contractual requirements specified in agreement with the client.

The main objectives are:

  • Ensuring that the products supplied by 3D PLUS in the contractual framework of a project achieve the objective defined mission and that these products are safe, available and reliable,
  • Participating in the project that offers the best cost effectiveness by implementing appropriate product assurance methods,
  • Contributing to project risk management by ensuring, as appropriate, identification, evaluation, prevention and control of risks in accordance with the technical constraints of the project, including the following two points to take into account very early:
    • Electrical, electronic, electromechanical (EEE) components
      The objective associated with EEE components is to ensure that the components meet the requirements of mission accomplishment during the entire life cycle of 3D PLUS product.
    • Materials and Mechanical Component Processes
      The objective associated with materials, Mechanical Components and Processes is to ensure that the use of these satisfy the realization of the mission requirements.

The 3D PLUS Product Assurance Manager make sure the selection, evaluation / qualification has followed ESA ECSS-Q-ST-60-05C and add on  in detail specification. The Product Assurance Manager is in charge to prepare and coordinate  customer source inspection (precap, CSI, Buy Off) and gathering all necessary traceability for the key elements such as:

  • EEE components
  • Materials
  • Mechanical components
  • Product Assurance Manager must ensure that potential suppliers proceed well  and collect all necessary information.

Data Retention Bake (DRB)

This test is used to measure a device’s ability to retain a charge for extended periods of time without applying voltage bias. Stressing at high temperatures (125°C) accelerates any discharge causing the memory state to change.

Electrostatic Discharge (ESD)

Device’s sensitivity is mainly driven by the components’ sensitivity. The 3D PLUS package does not impact ESD Device sensitivity. Human Body Model (HBM) min. value for 3D PLUS catalog products is 2KV (STM 5.1-1998).

Life Test

This test is performed in order to evaluate a device’s ability to be still functional, programmable, erasable, and verifiable after a long time period, which represents end of product life in the “Bathtub Curve” or about more than 12 years for 1000 hours.

Temperature Cycle (TC)

This test is used to measure a product’s sensitivity to thermal stresses due to differences in expansion and contraction characteristics of the die and package materials by repeated alternating temperature dwells between high (+125°C) and low (–55°C) temperature extremes.

Reliability Modeling

Failure rates for 3D PLUS products are typically calculated based on test data with acceleration factors based on the Arrhenius Model for thermal acceleration. The other model, Coffin-Manson (temperature cycling) may be used for specific applications or customer concerns.

Failure Rate

Failure rate is the frequency with which an engineered system or component fails, expressed in failures per unit of time.

In practice, the Mean Time Between Failures (MTBF= 1/λ) is often reported instead of the failure rate.

The Failures In Time (FIT) rate of a device is the number of failures that can be expected in one billion (109) device-hours of operation

This is valid and useful if the failure rate may be assumed constant – often used for complex units / systems, electronics – and is a general agreement in some reliability standards (Military and Aerospace). It does in this case only relate to the flat region of the bathtub curve, also called the “useful life period”.

Reliability Calculation

The reliability behavior of each module is characterized by using the MIL-HDBK-217F + N2 standard based on model for Overall Hybrid Part, the UTE standard C 80-810 dated July, 2000 for Failure Rate Calculation, and by taking into account the following documents:
Supplier qualification report
3D PLUS evaluation / qualification database and 3D PLUS background
3D thermal analysis output (see § VIII thermal management)
Customer specification (module environment, module reliability requirement, …)
Thus the 3D Module reliability assessment can be validated by the customer before the manufacturing.

Reliability Monitoring

Once a year, 3D PLUS’s Quality releases representative quality data of products subjected previously to the stress tests for reliability qualification. These data are gathered from one year of manufacturing testing. This release is completed to ensure that the reliability of 3D PLUS stacking technology continues to meet the assigned goals since its initial qualification in 1995.
These data are accumulated over several years to determine reliability trends in manufacturing, design rules, and assembly processes. Additionally, these data allow customers to predict the expected reliability performance of their overall system (3300-5709: Qualification results for 3D PLUS products).
collect all necessary information.


3D PLUS modules are designed to support harsh environments proved by both environmental and mechanical tests.

The table below lists some tests successfully withstood by 3D PLUS modules.

Stress Conditions Test method
Thermal Cycling
Extended Thermal Cycles 500cycles -55° to 125°C MIL-STD-883 M1010 Cond.B
Extended Thermal Cycles 500cycles -65° to 150°C MIL-STD-883 M1010 Cond.C
Thermal Cycles under vacuum 10^-6 torr Specific
10 cycles -40°C/+70°C
Temperature storage
Low Temp Storage -130°C Specific
High Temp Storage 2000hrs / 150°C MIL-STD-883 M1008
High Temp Operating under pressure 1000hrs / 150°C / 1000bars Specific
Endurance Testing
Dynamic Life Test 2000hrs / +125°C MIL-STD-883 M1015
Power Cycling 30K cycles on/off Specific
120s on (+110°C)
60s off (+40°C)
Resistance to Humidity
THB Test 1000hrs +85°C/85%RH MIL-STD-202 M103
HAST 264hrs / +110°C JEDEC STD 22TMA110
Salt Atmosphere 24hrs MIL-STD-883 M1009 Cond.
(industrial varnished modules) AJESD22-A107-A Cond.A
Mechanical Resistance
Mechanical shock Y1 / 0.5ms / 1500g MIL-STD-883 M2002 Cond.B
Peak Acceleration 40 000g Specific
Sine Vibrations 20Hz – 2000Hz MIL-STD-883 M2007 Cond.A
Peak acceleration 20g/3axes
Packaging Tests
Lead Integrity MIL-STD-883 M2004
Solderability MIL-STD-883 M2003
Marking permanency MIL-STD-883 M2015
Electrical Sensitivity Discharge
ESD Human Body Model ESD JS001-2014