While the LPC11U37 was designed for standard breakaway headers, it can also accomodate mating boards designed for DIP sockets or direct PCB insertion.
For DIP sockets use machined pins like the Samtec TS-1XX-T-AX series
Those pins have a smaller cross section that is closer to the pins of a DIP24 part (0.018" round vs 0.022" x 0.012" rectangular).
LPC11U37
Standard DIP24 package spec
Machine pin compatible with DIP24 socket
Alternate for DIP24 socket
Pin specs for the alternates, 0.18" round
Standard PCB layout for DIP24
Standard 0.025" sq breakaway header
