The objective of this study is to experimentally investigate the heat transfer enhancement by delta winglet vortex generators for air cooling in the entrance region of an in-line array of electronic modules. The study has been carried out when the winglet pairs are placed in front of all modules with attack angles of 10, 15 and 20 degrees. Each module has dimensions of 1.8 cm x 5.8 cm x 0.6 cm and generates heat at 5 W. The adiabatic heat transfer coefficients and the thermal wake functions for the modules with and without the generators are considered at different values of Reynolds number. It could be seen that the vortex generators could enhance the adiabatic heat transfer coefficients and reduce the thermal wake function and the module temperature significantly. Moreover, the correlations to predict the heat transfer data when the vortex generators are integrated have been developed. The temperatures of the modules in each row could be predicted from these correlations, and the results agree very well with the experimental data.