Last year five junior Saints, including Packman, helped England to the title in Madrid with a final win over Ireland, while in 2011 a further four were involved as England reached the showpiece.
Only Exeter can match the Saints' total of four players in the travelling squad.
Their 2013 tilt begins at 7pm on Friday, when they take on Portugal in Grenoble and with a majority of the squad involved in wins over the Six Nations period - including the Saints quartet - head coach John Fletcher is hopeful of a positive campaign.
"We've got a good squad for this tournament but we know that it will be a challenge," he said. "We're missing a few lads; Alfie Barron, Max Clark, Brett Herron and Will Owen are injured unfortunately, but it gives an opportunity for guys to come in and impress.
"Our aim is to build on the recent performances against Scotland and Wales and improve through the three games"
ENGLAND UNDER-18 SQUAD FOR 2013 FIRA/AER CHAMPIONSHIPS
Andrew Boyce (Worcester Warriors & Kings Worcester)
Andrew Hughes (Sale Sharks & Hartpury College)
Charlie Ewels (Bath Rugby & Bryanston School)
Charlie Hewitt (Exeter Chiefs & Ivybridge College)
Lewis Boyce (Leeds Carnegie & Prince Henry's Grammar)
Jack Walker (Leeds Carnegie & Prince Henry's Grammar)
James Chisholm (Harlequins & Brighton College)
Jordan Onjoaife (Northampton Saints & Stowe School)
Josh Peters (Northampton Saints & Oundle School)
Matt Bolwell (Exeter Chiefs & Truro College)
Luke Chapman (Exeter Chiefs & Truro College)
Neale Farthing (Leicester Tigers & Wyggeston & Queen Elizabeth College)
Paul Hill (Leeds Carnegie & Prince Henry's Grammar)
Sam James (Saracens & Bishops Stortford)
George Perkins (Saracens & Oaklands College)
Howard Packman (Northampton Saints & Moulton College)
James Mitchell (Sale Sharks & Lymm School)
Josh Sharp (Saracens & Oaklands College)
Josh Skelcey (Northampton Saints & Moulton College)
Louis Clayton-Molloy (London Wasps & Harrow School)
Nick Tompkins (Saracens & Oaklands College)
Stuart Townsend (Exeter Chiefs & Ivybridge College)
Tom Fowlie (London Irish & St Pauls Catholic College)
Tom Howe (London Wasps & Shiplake College)
Lucas Slowik (Bristol Rugby & Filton College)
Rory Jennings (Bath Rugby & Bryanston School)