The focus of this work is on interfaces of two-shot molded parts. It is well known that e.g. material combination, process parameters and contact area structures show significant effects on the bond strength of multi-component injection molded parts. It is, among other theories, assumed, that diffusion processes contribute to the adhesion. To get information about the bond strength at various process parameter settings and material combinations a test mold with core back technology was used to produce two-component injection molded tensile test specimens. In the core back process the different materials are injected consecutively, so each component runs through the whole injection molding cycle (two-shot process). Due to this consecutive injection molding processes, a cold interface is generated. This is defined as overmolding of a second melt to a solidified polymer preform. In this paper the influence of the melt temperature of the second component on the interface conditions and bond strength was investigated by Raman spectroscopy and tensile testing. With this combination of measuring methods it was possible to prove a correlation between the melt temperature of the second component, the bond strength and the interdiffusion length over the interface of both materials. A higher melt temperature of the second component caused a longer interdiffusion length, where both materials are present in a mixed phase, resulting in a higher bond strength between the two components. Thus, the diffusion theory was experimentally confirmed. Keywords: injection molding, multi-component, bond strength, interface, interdiffusion