BANNOCKBURN, IL - The 90-day moving average shipments of all types of circuit boards fell 4.5% year-on-year in March, according to the latest poll of U.S. PCB fabricators. Bookings fell 10%, continuing their first-quarter slog.

A large percentage of the production includes boards built offshore and distributed by North American vendors. According to IPC, which takes the poll, 30% of the shipments reported were produced offshore, down three points from February.

The domestic book-to-bill ratio dropped 0.03 points to 1.05, remaining above 1.0 for the fourth month in a row. 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.

The ratio for rigid PCBs was flat at 1.04, while that of flexible circuits dropped 0.16 points to 1.07.

Rigid board shipments, estimated by IPC to make up 75% of all domestic PCBs, were down 9% in March vs. a year ago. Bookings were down 2.7% for the month. Flex sales grew 21.3%, but bookings fell 35.9%. Value-added services made up 55% of the shipment value of flex circuits.

Year-to-date flex bookings are down 2.3% and shipments are up 29.5%. Rigid shipments are down 4.6% and bookings are off 4.8%. Shipments of all boards are up just 1% and bookings are down 4.3%.

Sequentially, combined shipments were up 7.1% over February, while bookings were up 8.3%. Rigid shipments were up 8.7% and bookings climbed 11.1% sequentially. Flex shipments were up 0.6% and bookings were down 4.8% against revised February numbers.

Seventy percent of PCB shipments reported were domestically produced. Domestic production accounted for 75% of rigid PCB and 47% of flexible circuit shipments in March, IPC said.

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