Ashley Talbot, 15, was struck by the bus at Maesteg School, Bridgend county, on 10 December.
The Rev Bev Reaney read a written eulogy from Melanie Talbot to about 250 mourners at St Cynfelyn Church in Caerau on Tuesday.
"I am sure he will remain in all our hearts forever," the tribute said.
Ashley, a budding mechanic and motocross fan, was buried at Cymmer Cemetery in Croeserw.
In her eulogy, Ms Talbot said: "Don't get me wrong, Ashley was no angel - but he was our angel.
"Ashley was our son - handsome, funny, and no-one could love him more than we did as a family. "
A coroner's hearing into Ashley's death has been opened and adjourned. A police and health and safety investigation into the incident is continuing.
Ashley was hit by the school minibus as it was being driven to a rugby game by PE teacher Chris Brooks.
The mother of a Maesteg teenager who died after he was hit by a school minibus driven by a teacher described him as "our angel" at his funeral.