Betsi Cadwaladr health board has been awarded Â£500,000 for the unit at Glan Clwyd Hospital in Bodelwyddan.
It has already received Â£1.4m for electrical infrastructure upgrades and to pay for an extra transport incubator for transferring critically-ill babies.
The Sub Regional Neonatal Intensive Care Centre (SuRNICC) is due to open in two years' time.
Health Minister Mark Drakeford said: "We have now taken a further step that will help the health board to develop the final business case for the SuRNICC through which we want to provide the best possible standards of care for mothers and babies across north Wales."
Tina Donnelly, director of the Royal College Nurses in Wales, said: "Neonatal care across Wales has been an area of specific concern to the RCN. The government has listened to the evidence-based advice of health care organisations, service users, clinicians and independent advisers.
"This is excellent news for mothers and babies because there is a commitment to providing a safe and effective neonatal service in north Wales."
Plans to develop a new neo-natal baby care unit in north Wales have been approved by the Welsh Government.