Solder crack failures on LED assemblies
How new Insulated Metal Substrates can help improve reliability
The key to achieving good reliability and requisite service lifetimes in modern electronic devices has long been associated with the quality of the solder joints used in assembling components onto substrates. Originally, the electronics industry used leaded components with through hole mounting and solder joints that were much larger than are found today. The solders were also typically made of tin and lead, in compositions that had both modest melting points and good mechanical properties.
However, progress in the electronics industry has always been characterised by ever greater levels of integration and miniaturisation that have seen the move from leaded components to the use of surface mount technology and increasing numbers of connections being required to fit into smaller and smaller areas on a circuit board or substrate. As a result, the actual volumes of solder used to form the individual solder joints has been significantly diminished, e.g. in area array packaging.
Also, since 2006, the electronics industry has been forced to move away
from the use of tin-lead based solders for environmental and health
The new lead-free solders, such as the commonly employed SAC alloys,
typically have higher melting points, can form different intermetallic
compounds and have mechanical properties that may impact solder
joint reliability when compared to conventional tin-lead solders.