The US Semiconductor Industry Association’s book-to-bill ratio fell to 1.17 in June from a revised figure of 1.25 reported for May, after eighth consecutive months of increases. The decrease in the ratio was due primarily to a big rise in June’s shipment rate, reflecting higher booking rates experienced during the past few months, but the order level also now appears to be falling off slightly. Book-to-bill ratios for May and April were both revised downward to 1.25 and 1.21 from 1.26 and 1.22, respectively. The book-to-bill ratio is computed by dividing three-month average bookings in the semiconductor industry by three-month average billings. The three-month average US market orders, for June totalled $980m, a 4.2% decrease from the May figure. Three-month average shipments through June amounted to $835.4m, up 3% on the May figure. At $933.4m, June shipments were 18.2% up on the shipment rate for May. The last time billings were higher was in November 1984, when shipments reached $940.5m. Analysts seemed relatively unconcerned about the drop, mostly attributing it to a typical summer slow-down. Commenting on the figures the chip association’s ever-bullish said Andrew Procassini commented The industry’s business indicators continue to show that a strong recovery is in progress. If the industry is able to sustain the current annualised shipment run rate, US market sales will exceed $10,000m for 1987 – the highest level since the boom year of 1984.