From experience in automotive PCB verification, DEKRA iST has converged most of the quality problems of PCB through more critical testing items:
- Connectivity issue
Fig. 1 Cracked Plating Through Hole wall | Fig. 2 Blind Hole cracked at the bottom |
For the abnormal described as above, Thermal Shock Test (TST) could verify PCB’s potential problems caused by sudden exposure to temperature differences, the changing rate of contact resistance would not exceed the standard. As for automotive PCB verifies that in addition to the temperature change conditions, the current is increased to simulate the use state to make the test environment more stringent.
- Insulation Issue
Fig.3 Abnormal Insulation between surface traces |
Fig.4 Conductive Anodic Filament(CAF) between via holes |
The most common acceleration factors to verify for insulation include temperature, moisture and bias; in any kind of test conditions, the main purpose is to verify that the automotive PCB meets the required standard. Each component supplier for automotive PCB has the specifications and methods for the test. It is important to follow the standard and to ensure that your product and process abilities can meet high-reliability requirements; these are the goals of each company.
- Delamination or laminate crack issue
Fig.5 Reflow simulation facility | Fig.6 Delamination image of PCB through SAT |
To verify the delamination of PCB, the reflow simulation test can be used to verify the heat resistance of the PCB. The key parameter of this method is the profile of the temperature of the reflow oven corresponding to the actual board temperature, as for the temperature requirement, IPC and IEC standards or the specification from the component suppliers can be followed. Another important point is the inspection method after reflow simulation, includes visual inspection or SAT (Scanning Acoustic Tomography) could find the abnormal spot, these are for non-destructive analysis. Then the next step could use destructive analysis (Micro-section) find the abnormality and root cause to improve PCB manufacturing process.
As for automotive PCB verification, DEKRA iST is experienced in offering the comprehensive testing services to customer, expertise service and verification methodology planning etc.
To make all your PROBLEMS SOLVED, we provide professional consultant and service.
For more information or service, please feel free to email to 📧 sos@dekra-ist.com