Optimized planning of quality assurance in SMT and THT production
Electronics production does not end with the successful assembly or soldering of a module. It is only through seamless quality assurance and final testing that an assembled PCB becomes a reliable product that can survive in the field. The following applies: inspection and test processes are not only a guarantee of quality, but also critical bottleneck factors in production planning. This is precisely where PAILOT comes in as an APS solution, intelligently embedding test stations, testers and personnel with specific skillsets into the overall plan.
Quality assurance in the digital production flow
1. automatic optical inspection (AOI) - what, when, why?
AOI (Automated Optical Inspection) is a fundamental component of modern production lines. It checks assemblies for typical faults such as missing components, incorrect positioning or soldering errors. It is not only the application itself that is decisive, but also the time at which the inspection takes place. AOI is often used directly after SMT assembly, but can also be integrated in the THT area or after individual soldering processes, depending on the process design.
In order for the test to be as effective as possible, there are several useful points in the process:
- After solder paste printing (SPI - Solder Paste Inspection): This checks whether the solder paste has been applied correctly and is present in sufficient quantity. Errors at this point often lead to placement or soldering problems later on. The inspection is primarily carried out in-line.
- Before final assembly: A final check ensures that the assembly is undamaged before it is further processed or installed.
2. differences between AOI according to SMT and THT
SMT-AOI:
The focus here is on fine structures, incorrect polarity or missing SMD components. Errors must be detected quickly, otherwise subsequent processes will be blocked.
THT-AOI:
In the THT area, AOI primarily checks solder joints after wave or selective soldering. Due to the higher variance in THT processes, the scheduling of these tests is more complex and time-critical.
3. how PAILOT intelligently plans test stations
PAILOT does not consider AOI test stations in isolation, but integrates them into the overall production flow. The system recognizes when an assembly must be tested and dynamically schedules these stations into the sequence planning. Bottlenecks at test stations are detected at an early stage, rescheduling is automatically simulated and optimally embedded. The result: faults are detected in good time, waiting times are reduced and inspection processes are displayed transparently in the production plan.
End tests as a bottleneck: recognizing, avoiding and planning bottlenecks
1. role of functional tests, ICT & Co.
After AOI and soldering processes comes the supreme discipline: the final tests. Whether in-circuit test (ICT) or other functional tests - these procedures ensure the electrical and functional quality of the assemblies. Without them, there is no release for delivery.
2. why test stations are critical paths
Test stations are usually highly specialized, expensive, only available in limited numbers and sometimes require qualified personnel. This automatically turns them into bottlenecks. Every delay at a test station has a direct impact on the throughput time of the entire production process. Small blockages can quickly have a major impact, especially in high-mix production.
3. use of APS for optimal test planning
PAILOT explicitly includes test stations in the detailed scheduling . By simulating capacities and dependencies, test steps can be scheduled in such a way that they do not become a bottleneck. Bottlenecks can be mitigated by prioritizing or rescheduling other orders. Additional scenarios - such as short-term machine downtimes - can also be calculated and integrated into the planning.
4. KPI-driven optimization of throughput times
An APS such as PAILOT makes it possible not only to schedule inspection and test stations, but also to make their influence on key performance indicators measurable. Typical KPIs are:
Throughput times: Less waiting time in front of test stations.
Adherence to deadlines: Delivery deadlines are met because critical test processes are taken into account at an early stage.
Conclusion
Quality assurance and final tests are indispensable, but they are also critical bottlenecks in electronics production. AOI, ICT (in-circuit test) and functional tests must not be seen as downstream compulsory exercises, but must be an integral part of realistic production planning.
With PAILOT, inspection and test processes are intelligently embedded: AOI stations are scheduled dynamically, test stations are relieved and bottlenecks are actively avoided. This creates a continuous, digital production flow in which quality assurance does not slow things down, but instead increases efficiency and reliability.
