Correlations between process, material and quality characteristics and the reliability of solder joints

The reliability of solder joints is an important part of the quality of SMT-Boards. Accelerated reliability tests (e.g. thermal shock or others) are a possibility to test this important property. These tests are destroying tests. So it is not possible to use such tests for the characterization of the reliability of produced SMT-Boards. The IPC 610 E [1] contains a lot of quality characteristics with a deep correlation between the value of the characteristic and the reliability of the related solder joint. The measurement of such characteristics during the production of the boards enables a characterization of the reliability of the produced solder joints. The paper shows the results of some investigations and experiments performed to determine the dependencies between the measured quality characteristics and reliability.