PCBA test fixture classification and inspection standards
1. The ICT test mainly includes the on/off, voltage and current values and fluctuation curves, amplitude, and noise of the circuit.
2. The FCT test requires IC program firing, simulates the function of the entire PCBA board, finds problems in the hardware and software, and equips with the necessary production fixtures and test stands.
3. The fatigue test is mainly to sample the PCBA board, and perform high-frequency and long-term operation of the function to observe whether there is a failure and judge the probability of the test failure, so as to feedback the working performance of the PCBA board in the electronic product.
4. The test under the harsh environment is mainly to expose the PCBA board to the limit value of temperature, humidity, drop, splashing water and vibration, and obtain the test result of the random sample, so as to infer the reliability of the entire PCBA board batch product.
5. The aging test is mainly to energize the PCBA board and electronic products for a long time, keep their work and observe whether there is any failure failure. After the aging test, the electronic products can be sold in batches.
Standard disadvantages of quality inspection:
1. Severe shortcomings (indicated by CR): Any shortcomings that are harmful to the human body or the machine or endanger life safety, such as: safety compliance / burning machine / electric shock.
2. the main shortcomings (indicated by MA): may cause product damage, functional abnormalities or the shortcomings of the product's service life due to materials.
3. minor shortcomings (indicated by MI): does not affect the product function and service life, some flaws in appearance and minor defects or differences in the assembly of the mechanism.
PCBA board inspection conditions:
1. In order to prevent contamination of components or components, gloves or finger cots with full EOS/ESD protection must be selected and the electrostatic ring should be worn. The light source is a white fluorescent lamp. The light intensity must be above 100 Lux and clearly visible within 10 seconds.
2.inspection method: the object to be inspected is placed about 40cm from the eyes, up and down 45o, with a visual or triple magnifying glass inspection.
3. Inspection and judgment criteria: (Sampling according to QS9000 C=0 AQL=0.4% sampling level; if the customer has special requirements, it is judged according to the customer's acceptance criteria)
4. Sampling plan: MIL-STD-105E LEVEL II normal single sampling
5. the criteria: serious shortcomings (CR) AQL 0%
6. the main shortcomings (MA) AQL 0.4%
7. minor disadvantages (MI) AQL 0.65%