Taiwan-based PCB makers, including Unimicron Technology, Tripod Technology, Gold Circuit Electronics (GCE) and Nanya Printed Circuit Board (NPC), will be able to improve their yield rates in the production of any-layer HDI boards in the third quarter after they have ventured into the segment for 2-3 quarters, according to industry sources.

Demand for HDI boards, particularly from the smartphone and tablet PC sectors, is relatively strong for PCB makers for the second half of 2010 following the adoption of HDI boards by Apple's iPhone 4, the sources noted.

Taiwan-based PCB makers Unimicron, Compeq Manufacturing and Tripod as well as Japan-based Ibiden are the supplies of any-layer HDI boards for iPhone 4, while Compeq, GCE, NPC, Austria-based AT&S and Hong Kong-based Oriental Printed Circuit (OPC) are HDI board vendors for iPad tablet PCs, the sources indicated.

While Unimicron has been enjoying a relatively high yield rate in the production of HDI boards, most other Taiwan-based PCB makers saw their yield rates range only between 50-70%, which is unprofitable for makers, the sources commented.

However, the sources indicated that GCE is moving into the advanced manufacturing process for the production of any-layer HDI boards, and is expected to gain more orders. GCE currently has a production capacity of 200,000 square feet of HDI boards a month.

Another maker Unitech Printed Circuit Board plans to ramp up its capacity for any-layer HDI boards by 25% in 2010, while Unimicron is to increase its HDI board capacity to 2.05 million square feet a month by the end of the year, making the company the world's largest HDI board vendor.