The company, Hexaphone, won the award at the Sherman Theatre in Cardiff on June 17 and will now compete for the UK title on July 1.
Their product is a stand for smart phones and tablets and has already made an impression with business insiders and consumers, securing a patent for their design and a number of deals.
Before the final, at the British Film Institute on the South Bank in London, the year 12 students will be selling their product at Morrisons, Bargoed on Sunday, June 22 from 11am.
The plastic stands are made out of recycled materials and Hexaphone have agreed a deal with Macmillan where the cancer charity will receive 50% of the profits from the sale of the branded product.
Technology teacher, Julie Hovestadt, said: “It’s been an unbelievable few months and winning the wales final is absolutely crazy, it’s great for the school.
“We asked the pupils to support the team, which they have done amazingly. It’s encouraging to pupils throughout the school to get an insight into what these kids have done and realise what they themselves can achieve with hard work.”