A method for testing the die-attach quality of a photovoltaic cell assembly, in particular, for electrical inline monitoring of a photovoltaic cell die-attach quality during the manufacturing of a concentrator photovoltaic module, comprises the steps of providing a photovoltaic cell assembly comprising at least one photovoltaic cell, in particular, a concentrator photovoltaic cell, attached to a heat sink, injecting a current into the photovoltaic cell assembly, measuring the voltage across the photovoltaic cell during the current injection, and determining the relative voltage drop over the duration of the current injection, whereby insufficiently bonded photovoltaic cell assemblies can be identified and screened.