What: On Tuesday, chip-packaging and test-services company Amkor Technology (NASDAQ:AMKR) soared as much as 20.9% after the company reported better-than-expected second-quarter revenue and earnings per share, and published better-than-expected guidance. The stock's gain has pulled back slightly, and shares were trading up about 15.5% as of 1 p.m. EDT.

Image source: Amkor Technology.

So what: Amkor's second-quarter revenue was $917 million, and EPS was $0.02. On average, analysts were expecting the company to report revenue of $876 million and a per-share loss of $0.08. In addition, the company's second-quarter revenue and EPS were both above management's own guidance for the period.

"Strong Android smartphone demand and a quicker recovery at our earthquake-damaged Kumamoto factory were the key drivers of our financial performance for the quarter," said Amkor CEO Steve Kelley in the company's press release for its second-quarter results.

Now what: Importantly, Amkor's projection for Q3 is also better than analysts were anticipating. Management expects third-quarter revenue between $1.01 billion and $1.09 billion, representing growth of 10% to 19% compared to the prior quarter. In addition, management said it expects third-quarter EPS to be between $0.12 and $0.28 -- a significant jump from its EPS of $0.02 in Q2. On average, analysts were expecting third-quarter revenue of $943 million and EPS of $0.06.

Management believes revenue growth will be driven by "the launch of mobile devices across multiple tiers."

Kelley pointed to specific areas promising the greatest expansion: "We expect robust growth in advanced SiP, Greater China and automotive."