Phosphorus Information Memo

Notification to Linear Technology Customers

Subject: Phosphorus Based Flame Retardant in Mold Compounds

Plastic mold compound manufacturers have historically included small amounts of bromine and antimony compounds as a flame retardant in order to comply with UL94V-0 flammability rating. A few years ago there began an initiative in the industry to make the mold compounds more "environmentally friendly" by eliminating the bromine and antimony compounds; while maintaining UL rating equivalency. To that end, one mold compound manufacturer introduced for sale a compound series (i.e., EMExxxxU), which replaced bromine and antimony compounds with elemental (red) phosphorus. This compound formulation was made available to any IC manufacturer or Assembly Subcontractor who wished to convert.

It is, and has been, Linear Technology's policy that any change we deem as major (e.g., mold compound change) be extensively evaluated and qualified before any manufacturing change is implemented. Therefore, in late CY2000, Linear Technology began an extensive evaluation of a mold compound containing an elemental (red) phosphorus based flame retardant. As a result of this evaluation, Linear Technology Corporation determined that this type of mold compound DID NOT meet our high standards of quality and reliability. In early CY2001, the findings of our evaluation were available to the mold compound manufacturer and we have subsequently learned that the EMExxxxU series of compound has been withdrawn from the market.

During the past few months we have been receiving customer inquires as to whether Linear Technology Corporation has ever used an elemental (red) phosphorus based flame retardant mold compound. Through this notification we wish to assure all our customers that Linear Technology Corporation has never approved and has never sold products which incorporate an elemental (red) phosphorus based flame retardant mold compound.

If there are any questions, please contact:

Dwight Somersett
Director of Reliability 
Linear Technology Corporation
408-432-1900 ext. 2427
408-434-0507 (fax)

Naib Girn
Director of Quality Assurance 
Linear Technology Corporation
408-432-1900 ext. 2519
408-434-0507 (fax)