A study is reported of the fracture mechanics of metal-to-ceramic laminates (Al2O3/Nb, Si3N4/Zr) produced by solid-state bonding. The bond quality of notched bend and tension specimens is described in terms of a stress intensity factor K ICV, which is evaluated in the same way as for isotropic material. K ICV is measured as functions of the microstructure of the constituents, the metal layer thickness, the environmental conditions and the test temperature. At very high test temperatures where plastic flow occurs, the J-integral was used for bond quality characterization. For the linear elastic case, the J-value is compared with the stress intensity concept K ICV. In contrast to the behaviour of a bulk ceramic material, the J-value increases with increasing test temperature if a thick metal layer (3 mm) is used.