External Lead Finish for Plastic Packages For plastic packages, National Semiconductor offers two primary lead finishes: solder plate and solder dip. The component lead finish serves as a protective coating to prevent oxidation of the lead base material prior to use. The lead finish will ensure the leads are solderable for board mount applications as well as provide long term protection against lead corrosion. The lead finish composition and thickness is dependent on the package type and the applications in which the package is used. SOLDER BALL SOLDER PLATE GOLD FLASH For National's plastic packages, the most common lead finish is electroplated solder. Solder plating provides a uniform coating conforming to the shape of the lead. A tin-lead alloy plating is used and the typical composition is approximately 85% tin and 15% lead. A plating thickness of 200 microinches minimum is required. The laminate based CSP packages are supplied with gold plated pads ( 0.5 micron nominal gold over 5 micron nickel ) and meet the solderability requirements after 8 hr steam ageing. For either lead finish, the cleaning and plating or dipping process is designed such that the component meets solderability requirements after 8 hours steam aging. The following table is provided as a reference to determine which lead finish is used for each plastic package type offered at National Semiconductor. SOLDER DIP A solder dip lead finish is applied to plastic pin grid array packages (PPGA) and selected molded dual in-line packages (MDIP). Typical solder dip composition for application to MDIPs is a eutectic alloy of approximately 60% tin and 40% lead. The PPGA external lead finish is approximately 90% tin and 10% lead. A thickness of 200 microinches minimum is required and is measured at the major flat of the lead. Tin-lead eutectic solder balls with a composition of 63 tin and 37 lead are specified for array based packages ( FBGA,EBGA,SBGA,PBGA ) . Depending on the type of package , the solder ball diameters vary from 0.13 mm to 0.6 mm and the pitch varies from 0.5 to 1.27 mm with details specified in the relevant market outline drawings. Lead Finish for Plastic Packages Package Type Package External (Code) Designator Lead Finish M; MA Solder Plate M; MA Solder Plate Small Outline Transistor (SOT) Small Outline Package -- EIAJ and JEDEC (SOP) Shrink Small Outline Package -- EIAJ and JEDEC (SSOP) ME; MQ; MS Solder Plate Very Small Outline Package (VSOP) M; MA Solder Plate Thin Small Outline Package (TSOP) MB Solder Plate Thin Shrink Small Outline Package (TSSOP) MT Solder Plate N; NA Solder Plate Molded Dual-In-Line Package (MDIP) or Solder Dip Plastic Pin Grid Array (PPGA) UP Solder Dip Plastic Leaded Chip Carrier (PLCC) V; VA Solder Plate Plastic Quad Flat Pack (PQFP) V (xx) Solder Plate C; P; PA; R; RA; Solder Plate Plastic Transistor Outline Package (TO) RC; T; TA; TS; Z Laminated Plastic Chip Scale Package (CSP) SLB Gold Flash Laminated Plastic Fine Pitch Ball Grid Array (FBGA) SLC Solder Ball Enhanced Ball Grid Array (EBGA) Super Ball Grid Array (SBGA) (c) 2000 National Semiconductor Corporation MS011799 UCK Solder Ball UBC; UCC; UCD; UCG; UDB; UFD Solder Ball www.national.com External Lead Finish for Plastic Packages August 1999 External Lead Finish for Plastic Packages Lead Finish for Plastic Packages (Continued) Package Type Package External (Code) Designator Lead Finish UBA; UBB; UBD; UBE; UCB; UCE; UDA; UDC; UDD; UEA; UFA; UFB; UFC Solder Ball BPA Solder Ball Plastic Ball Grid Array (PBGA) micro-SMD LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Francais Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: sea.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.