Soft collars and special pillows
BMJ Group Medical Reference
There's no good-quality research to show that wearing a soft collar around your neck can reduce your pain and stiffness.
There's also no evidence that using special pillows to support your neck will work. One small study looked at special pillows and found they didn't help with neck pain.  Another found that special pillows weren't any better than ordinary pillows. 
It might be worth trying to sleep with only one or two pillows to support your neck at night. And you could try improving your neck posture without using a supportive collar. But we didn't find any research on whether these things help reduce neck pain.
For references related to Neck pain click here