NEW YORK (CNNMoney) -- You've never heard of Irish-born entrepreneur Liam Casey, but you're probably carrying a gadget with parts or accessories made by Casey's manufacturing company, PCH International.
Silicon Valley insiders call him "Mr. China." He carries three iPhones -- one each for his American, Irish, and Chinese phone lines -- but doesn't have an actual home. Instead, he lives in hotels around the world, traveling constantly as he juggles supply-chain logistics for some of the world's most demanding gadgetmakers. Last week's itinerary: New York, Hong Kong, China, London, and Ireland.
Casey is tight-lipped about his client roster, but Apple's 2011 supplier list has PCH's name on it, and a source with knowledge of Square's manufacturing operations says PCH manufactured the early versions of the mobile payment device.
So how did someone who grew up in a small town in Ireland -- and who still doesn't speak Chinese -- become the high-tech industry's man-on-the-ground in Asia?
It started with a year off.
After working in the garment industry for a decade, Casey moved to California, where he worked for a trading company whose business was centered around computer components.
"I saw a huge opportunity when I looked at what they were doing, importing components from Asia into the U.S.," Casey says. "It was extremely complex and it was very confusing."
That's when he hatched the idea for PCH International, named after the Pacific Coast Highway.
Casey spent two years getting to know the factories in China and making connections.
"It was a challenge at first, but once you actually built the relationship, the trust with people -- they were very helpful," he says. "The Chinese people are very ambitious and entrepreneurial, and they want to do business for you."
Robert Brunner, a former industrial design director at Apple who now runs his own product design firm, describes Casey as the "go to" guy for entrepreneurs trying to navigate the Asian supply chain. Brunner's firm, Ammunition Group, frequently uses PCH to manufacture its designs.
"I'm amazed at how many times I go see a company and Liam comes up," he says.
PCH's edge is its vast network of connections and its "factory-agnostic" approach, Brunner says. Instead of running its own manufacturing plant, PCH will typically work with a collection of partners, playing to the strengths of different local factories.
"When an opportunity comes up, he can figure out who the right people are to build it," Brunner says.
Casey's clients include some of the tech industry's largest and most iconic companies, but last year, he launched a new "PCH Accelerator" program to help smaller companies navigate the Chinese manufacturing process.
Julia Hu, who built an iPhone-based silent alarm clock called Lark, was the program's guinea pig. A Stanford-trained engineer, Hu had a device concept but little idea how to turn her paper design into a working prototype.
"I had spent about nine months looking for the right partner because I realized how critical it was," she says. Casey's name kept coming up, so she shot him an email. He replied almost instantly and arranged to meet with Hu just two days later.
The partnership clicked, and the device PCH helped Hu build was impressive enough to get on Apple's radar. The company signed on as a Lark retailer, featuring the silent alarm on its Apple (AAPL, Fortune 500) store shelves.
"Without Liam, Lark would definitely not be where it was right now -- or will be in a few years," Hu says. "Liam is just one of the most genuine and capable people, who really bridges that gap of bringing an idea to reality."
Casey is looking to build a lot more bridges. He's starting in on an aggressive expansion plan.
Earlier this month PCH acquired engineering and product development firm Lime Labs, a small but influential incubator. Its cofounder, Kurt Dammermann, is the former director of product development for Design Within Reach and previously worked on Apple's iPod development team. The acquisition gives PCH a prototype lab in San Francisco and a team of skilled designers and engineers to run it.
The company is also ramping up globally. Last week, PCH announced that it intends to expand its staff from its current 1,300 employees to 3,000.
Casey -- who tends to answer emails within nanoseconds -- is moving with his usual urgency. He wants to have all of the new hires on board by mid-August.
"We're really excited at the moment because hardware is getting popular again," Casey says. "People stopped making things about 10 to 15 years ago. They're starting to get inquisitive and curious again." 
