In recent years, domestic MCUs have blossomed everywhere. With the increase of manufacturers, a good way to enhance the competitiveness of their own MCUs is to "get on board", and an important prerequisite for getting on board is to pass AECQ100 certification. The overall certification testing process is divided into different testing groups by AECQ100 for different categories, and each testing group has different testing items:

Although these test items may seem cluttered, all testing standards and methods have detailed documentation, such as AEC-Q100-001 Bond Line Shear Stress Test and AEC-Q100-002 Human Body Mode Electrostatic Discharge Test.
Temperature level: AECQ100 divides the device into five levels from 0 to 4:
Level 0: Environmental working temperature range -40 ℃ -150 ℃
Level 1: Environmental working temperature range -40 ℃ -125 ℃
Level 2: Environmental working temperature range -40 ℃ -105 ℃
Level 3: Environmental working temperature range -40 ℃ -85 ℃
Level 4: Environmental working temperature range: 0 ℃ -70 ℃
In the AECQ100 vehicle certification process diagram, it can be seen that many experiments require room temperature or high/low temperature testing before and after.

1. Developed by third-party certification agencies or Fabless
Generally speaking, it is recommended to seek third-party certification agencies for AECQ100 vehicle specification certification. These agencies have the ability to develop ATE environments and can provide LB board design, program development, and more. However, based on the ATE development experience of other projects I have previously encountered, there is a lack of progress control in institutional development due to various communication issues such as lack of understanding of chips. Therefore, it is recommended that Fabless's own FT engineers carry out the development.
2. Heat flow hood or three temperature sorting machine
Many tests before and after the experiment are conducted at high and low temperatures. In the preliminary preparation, it is necessary to determine whether to use a three temperature sorting machine or a heat flow hood for the three temperature test. The three temperature sorting machine has a fast speed and saves manpower. After the completion of AECQ100, the environment can also be used for three temperature testing in the testing plant. The KIT procurement cycle during early development is particularly long, requiring preparation in advance and incurs significant costs. The heat flow hood is relatively convenient, and in the early stage, only LB and three temperature SOCKET need to be purchased. However, during the three temperature test, the heat flux hood needs to be manually tested, and the intermediate testing time is longer.
3. LB design considerations
If you design and develop your own LB board and choose to use a heat flux hood for three temperature testing. A few small details to pay attention to:
1) Before designing the LB board, it is necessary to obtain the size of the heat flux cover from the mechanism in advance. Do not place any other components on the front side of the heat flux cover, except for the socket. Try to place the components on the north side of the chip to reduce the impact of temperature on other components.
2) When selecting components, the LB board should operate at three temperatures, so attention should be paid to the temperature range of resistance and capacitance. The capacitance should be selected based on different temperatures, X7R/X5R. If there is a crystal oscillator, choose one that has AECQ100 certification and meets the temperature range. The same applies to other components.
3) Select high-temperature resistant PI material (polyimide) board with a thickness of>=3mm (to avoid bending LB under high temperature of the heat flow hood), and plated with hard gold.
4. Different testing programs are used for room temperature and high/low temperature. Many SPECs will undergo significant changes at room temperature and high/low temperature, especially in terms of simulation. It is advisable not to use the same testing program.

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