PCB Assembly Test:
Given the same test cost, circuit board testing will affect the defect rate and yield indicator. For example, if the defect rate is high, automatic testing for diagnosis is more economical. However, to use an automatic tester, test contact points for all nodes on the circuit board are required. This means at least one node of each wiring network needs to be connected to the automatic tester. On the other hand, if the defect rate is low, manual diagnosis is needed, which takes more time but reduces the impact on yield. The node test rate may be less than 100%. In theory, with a very low defect rate, a 0% node test rate can be allowed, but in reality, a simple pass or fail test is essential. Using dedicated test connectors can simplify the process.
Factors affecting the node test rate include:
1. Defect rate
2. Judgment ability
3. Yield rate
4. Circuit board area
5. Circuit board layers
6. Cost
When determining the node test rate in circuit board wiring design, balancing multiple factors is essential for manual fault-finding, and its impact on circuit board yield. Full node testing is preferred unless there are no defects in the assembly.
Realizing that once the circuit board design is completed and the test plan is implemented, reducing costs is primarily based on reducing the defect rate. Therefore, analyzing defect reports, correcting and preventing defects is crucial. Building strong relationships with sub-suppliers to reduce component and circuit board problems, as well as streamlining production processes, are also important.
Before assembling wiring, a rework strategy must be developed, especially for multilayer PCBs. Reworking inner layer conductors is complex, requiring special tools and precision. Circuit board manufacturers need to thoroughly test products to avoid the complexities of reworking installed components. Following SMT component rules is crucial, as removing components can weaken pad adhesion and cause warping.
The rework strategy involves dismantling and reinstalling components, considering test through-holes, land shapes, and assembly details. Tools for rework and repair must have the necessary capabilities to complete tasks effectively.
Given the same test cost, circuit board testing will affect the defect rate and yield indicator. For example, if the defect rate is high, automatic testing for diagnosis is more economical. However, to use an automatic tester, test contact points for all nodes on the circuit board are required. This means at least one node of each wiring network needs to be connected to the automatic tester. On the other hand, if the defect rate is low, manual diagnosis is needed, which takes more time but reduces the impact on yield. The node test rate may be less than 100%. In theory, with a very low defect rate, a 0% node test rate can be allowed, but in reality, a simple pass or fail test is essential. Using dedicated test connectors can simplify the process.
Factors affecting the node test rate include:
1. Defect rate
2. Judgment ability
3. Yield rate
4. Circuit board area
5. Circuit board layers
6. Cost
When determining the node test rate in circuit board wiring design, balancing multiple factors is essential for manual fault-finding, and its impact on circuit board yield. Full node testing is preferred unless there are no defects in the assembly.
Realizing that once the circuit board design is completed and the test plan is implemented, reducing costs is primarily based on reducing the defect rate. Therefore, analyzing defect reports, correcting and preventing defects is crucial. Building strong relationships with sub-suppliers to reduce component and circuit board problems, as well as streamlining production processes, are also important.
Before assembling wiring, a rework strategy must be developed, especially for multilayer PCBs. Reworking inner layer conductors is complex, requiring special tools and precision. Circuit board manufacturers need to thoroughly test products to avoid the complexities of reworking installed components. Following SMT component rules is crucial, as removing components can weaken pad adhesion and cause warping.
The rework strategy involves dismantling and reinstalling components, considering test through-holes, land shapes, and assembly details. Tools for rework and repair must have the necessary capabilities to complete tasks effectively.
