Purpose The purpose of this study is to offer the advanced leadless leadframe package which achieve small form factor and high thermal and electrical performance, according to the continuous market requirement. Because of demand and trends, new package structures that can accommodate many pins (I/Os) while maintaining the excellent thermal and electrical properties of the leadframe package was studied. Different from conventional leadframe and laminate packages, it must have the large-exposed pad for thermal dissipation and design flexibility to deploy signal, ground and power selectively. Design/methodology/approach In this study, the routable molded leadframe (rtMLF®) package applying the pre-resin MLF substrate was introduced. The structural advantages, in terms of design flexibility, were checked by adopting the specific electrical feature. Also, the excellence of thermal and electrical performance was confirmed by simulation. The sample was manufactured, and its package robustness was validated by reliability test. Findings rtMLF package that enables one layer substrate but routable pattern on top layer differently from existing leadframe package was developed and studied if it overcome the limitations of leadframe and laminate products. Asymmetric land layout was designed and special features to keep electrical interference was applied to prove design flexibility. The thermal and electrical simulation has been executed to check the advantages. And key differentiations were identified. Finally, actual sample was manufactured, and structural robustness was validated by package level and board level reliability. Originality/value The differentiation of new semiconductor package was introduced and its excellence was verified by electrical and thermal simulation as well as reliability test. It is expected to be adopted for alternative solutions not covered by the existing products.