OCTOBER 2024
PEM
Integra offers a comprehensive range of PEM Qual evaluation services designed to meet the diverse needs of our clients. Our services include detailed screening processes to ensure the highest standards of quality, along with rigorous qualification procedures that verify the reliability and performance of the products.
Our Construction Analysis is thorough, providing insights into the build and integrity of electronic packages. Additionally, we conduct Destructive Physical Analysis (DPA) and Failure Analysis (FA) to identify and address potential weaknesses or failures within the products. Our evaluation capabilities extend to all types of Electrical, Electronic, and Electromechanical (EEE) products. This includes, but is not limited to, Discretes (transistors and diodes), Passives (ex: resistors and capacitors), Linear devices, various types of Memory, FPGAs, SERDES, and Microcontrollers. We also screen and qualify Analog-to-Digital (A/D) and Digital-to-Analog (D/A) converters, Inductors, Magnetics, and much more to ensure comprehensive coverage of your electronic component testing needs.
Q: What is a PEM?
A: Plastic encapsulated IC’s or Microcircuits are commonly referred to as PEMs. Plastic encapsulated Transistors and Diodes are typically referenced as PETs and PEDs respectively.
Q: Why do companies use PEMs?
A: The main reasons are:
- Primarily to lower costs and accelerate time to market because:
- Higher volume/more cost-effective production
- Shorter lead times – many products off-the-shelf
- Greater product variety
- Mechanically more rugged
- Lighter weight - available in smaller/thinner packages
Q: What are the potential concerns with PEMs in an Aerospace and Defense system?
A: The main potential concerns are:
- PEMs have predominately been designed for commercial and industrial applications – not Aerospace and Defense (A&D).
- Higher military temperature ranges are not generally available (except EP)
- Typical PEMs are COTs and screening by OCM are not always as stringent as A&D end applications require.
- Qualifications are typically at the inception of product release and is not lot-by-lot.
- Qualifications are typically not sequential as used by A&D.
- Reliability of plastic packages could vary dramatically from supplier to supplier.
- Copper bond wire PEMS are known to have Reliability concerns if not properly manufactured
Q: What are typical PEM failure modes?
A: Typical failure modes are
- CTE mismatch between molding compound and mase material as well as
- Pop corning of plastic package
- Delamination
- Die attach voids
- Cracked package & cracked die
- Wire breaks & wire lift
- Corrosion
- Contamination
- Moisture ingression / Current leakage
- Cracked passivation
Q: What are some key considerations in a PEM qual plan?
A: Perform a detailed construction analysis or DPA on package before the qual. You will learn a lot of package weakness data before start of qual. Canned qual plans can be a good start but additional device specific information such as application and original data from the manufacturer will help.
Q: What are some PEM qual plans?
A: Some of the plans:
- SAE Standards
- AS6294/1 for Space PEMs and AS9294/2 for Military PEMs
- AS6294/3 for Space PEDs and AS6294/4 for Military PEDs
- NASA Standards
- PEM-INST-001 (NASA Goddard)
- MSFC-STD-3012 (Marshal Space Flight Center)
- Mil Std
- MIL-PRF-38535: General Specification for Integrated Circuits (Microcircuits)
- Class N
- Class P
- Class Y (Flip Chip)
- MIL-PRF-38534: General Specification for Hybrids
- MIL-PRF-38535: General Specification for Integrated Circuits (Microcircuits)
- AEC (Automotive)
- AEC- Q100 – Microcircuits Quals
- AEC - Q101: Discrete Semiconductor Quals
- AEC-Q006: Copper Bond Wire Quals
Q: What is an example of a PEM Qual Plan?
A: The following is an example of a PEM Qual Plan
- External visual and serialization: Qty=32
- Baseline SAM: Qty: 32
- Pre-Conditioning: Qty=32
- Moisture soak per appropriate MSL Level
- Reflow
- Electrical Testing at 25°C, min and max operating temp; Qty=32
- Sub-Group 1 Qual: Qty=22
- 125C Life Test for 1000 or 1500 hours
- Electrical testing at 25°C, min and max operating temp
- Temp Cycle; 200 or 500 cycles
- Electrical testing at 25°C, min and max operating temp
- SAM: 22 units
- DPA: 5 units
- Subgroup 2 Qual: Qty: 10
- Biased or unbiased HAST; 96 hours at 130°C/85%RH
- Electrical testing at 25°C, min and max operating temp
Integra has performed thousands of PEM Quals covering nearly all packages from hundreds of suppliers.