Skyhawk 172/Cutlass 172
Air Traffic Control Fully Certified
Situational Awareness; Communication Breakdown
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Air Traffic Control Issued New Clearance
Procedure; Human Factors
Training on local. South flow VFR conditions. Aircraft X checked on 20 south to land; I told him to enter a left downwind for Runway XX. He never entered the downwind. He flew straight for the airport. Aircraft Y called ready to depart and I cleared him for takeoff Runway XX heading 230. I thought it would take him far enough west to not be a factor. As he got airborne; I called traffic then turned Aircraft X eastbound. Aircraft Y had to turn to a 250 to avoid the conflict. They passed and Aircraft Y got switched to departure. [I] should have turned Aircraft Y to a 270 or held him on the ground.
Tower Controller reported a NMAC between a departing IFR aircraft and an arrival aircraft which was too close.