EL SEGUNDO, CA -- Component shortages have led to a traffic pileup in the global electronics supply chain, with major contract manufacturers facing a challenging supply imbalance characterized by tight inventories of parts and finished products and a glut of raw materials, according to research firm iSuppli Corp.

A snapshot of inventory at five of the larger electronic manufacturing service (EMS) providers showed that components and raw materials accounted for nearly 70% of total inventories during the first quarter of 2010, the latest date for which quarterly data are available. In comparison, work-in-process goods made up about 17% of inventories, while finished goods comprised less than 15%, industry analysis from iSuppli shows.

All told, finished goods were at their lowest level since the fourth quarter of 2008 — and the imbalance is likely to persist, according to iSuppli analyst Thomas Dinges.

“iSuppli believes that the current trend — in which electronics inventories are being weighed down by an overwhelmingly large percentage of raw materials — will continue for some time to come, given that more product in kits are waiting to be finished,” he said.

Judging from various earnings calls as well as numerous conversations taking place in the industry, semiconductor companies are citing extended lead times and parts shortages as a major problem, Dinges said.

A quick look at many component samples reveals that lead times have worsened for a wide range of semiconductor discrete devices, with lead times running as much as 100% longer than for the same period last year. The shortest lead times — at 10 weeks as of July—are for connectors, up from five weeks in July 2009. The longest lead times are for rectifiers and small signal discretes, now running at 20 weeks — a full five months compared to 10 weeks last year at this time.

Dinges said that many supply chain industry contacts to whom iSuppli has spoken do not believe the situation is likely to improve until later in the year, even if demand softens in the near term. The difficulties, he said, arise from a combination of seasonality factors and the slow pace in bringing about increased production capacity.

“Given that many suppliers were shuttered during the last years because of financial distress, the shortages have resulted in supply bottlenecks in industries,” Dinges said. “Such shortages — in both parts and raw materials — will only add to the strain of EMS and ODM providers, even if they were to train their efforts at simply maintaining current levels of inventory velocity.”