BANNOCKBURN, IL - The December 90-day moving average shipments of all types of circuit boards rose 8.7% year-on-year, according to the latest poll of U.S. PCB fabricators. Bookings shot up 30.6%, a sharp rebound from November.

The domestic book-to-bill ratio was 1.04, up 0.08 from November. November was marked the first time the indicator had dropped below 1.0 since April 2003, said IPC, which tracks the data.

The ratio is based on data collected by IPC from rigid and flex producers and is calculated by dividing three months worth of orders by sales. A ratio over 1.0 is considered an indicator of rising demand.

Separately, the ratios were 0.93 for rigid PCBs and 1.41 for flexible circuits.

Rigid boards, estimated by IPC to make up 82% of all domestic PCBs, actually slid in December, with shipments falling 1.3% and bookings down 6.1%. Flex sales grew 32%, and bookings rose - no typo - 274%.

For the year rigid shipments rose 16%, bookings 6.6%. Flexible shipments grew 67.4% and bookings were up 104.3%.

For the year, shipments rose 26.5% while bookings jumped 25.4%. For the month, shipments rose 1.6% and bookings 73.4% vs. November.

Flex sales include some value-added services in addition to the bare flex circuits.

In a statement, IPC cautioned that month-to-month comparisons should be made with caution as they may reflect cyclical effects.