Semi equipment book-to-bill continues trend of improvement North America-based manufacturers of semiconductor equipment posted $253 million in orders in April 2009 (on a three-month average basis) and a book-to-bill ratio of 0.65 according to the April 2009 Book-to-Bill Report published today by SEMI. A book-to-bill of 0.65 means that $65 worth of orders were received for every $100 of product billed for the month.The three-month average of worldwide bookings in April 2009 was $253 million. The bookings figure is three percent greater than the final March 2009 level of $245.6 million, and about 77 percent less than the $1.09 billion in orders posted in April 2008.The three-month average of worldwide billings in April 2009 was $389.9 million. The billings figure is 11 percent less than the final March 2009 level of $438.3 million, and about 71 percent less than the April 2008 billings ...