september 2013 doc id 024163 rev 2 1/6 TN0973 technical note safety application guide for spc56el54xx/spc56el60xx family reference manual addendum introduction this document is an addendum of spc56el54xx/spc56el60xx safety application guide. www.st.com
contents TN0973 2/6 doc id 024163 rev 2 contents 1 purpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 considerations on spc56el54xx/spc56el60xx package and soldering procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1 introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 risk analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2.1 risk item . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2.2 cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2.3 risk evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2.4 item assumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
TN0973 purpose and scope doc id 024163 rev 2 3/6 1 purpose and scope the purpose of this document is to communicate to st customers who intend to integrate spc56el54xx/spc56el60xx in an asil-d item some additional assumptions which shall be met at item level to preserve the spc56el54xx/spc56el60xx integrity. the assumptions described in this document shall be intended as additional assumptions with respect to those communicated in the spc56el54xx/spc56el60xx safety application guide.
considerations on spc56el54xx/spc56el60xx package and soldering procedures TN0973 4/6 doc id 024163 rev 2 2 considerations on spc56el54xx/spc56el60xx package and soldering procedures 2.1 introduction spc56el54xx/spc56el60xx package is composed by ultra low alpha mold compound. measurements report an alpha particle emissivity of 0.00383 0.00056 cp/h/cm 2 . this value has been used in the spc56el54xx/spc56el60xx quantitative safety analyses (see spc56el54xx/spc56el60xx fmeda). in order to ensure that this value does not increase when soldering the device on a board, a risk analysis is made in the following chapter. the conclusions of this analysis report that some caution must take during soldering process in order to avoid package delamination, hence avoiding any contamination from the soldering material to the silicon contained in the plastic package. 2.2 risk analysis 2.2.1 risk item single event upset randomly induced by alpha particle emission from package material 2.2.2 cause a possible cause of silicon contamination is the presence of potentially alpha-emissive soldering material, specifically induced by pb impurities. 2.2.3 risk evaluation assuming that no delamination is present on the package and given the low migration capability of pb particles, the risk of having emissive material on the silicon surface is very low. 2.2.4 item assumption we recommend our customers to avoid active soldering flux and to verify the integrity of packages after board mounting in order to eliminate the possibilit y of package delamination after device mounting on board, therefore eliminating the possibility of silicon contamination by soldering material.
TN0973 revision history doc id 024163 rev 2 5/6 3 revision history table 1. revision history date revision changes 14-feb-2013 1 initial release. 17-sep-2013 2 updated disclaimer.
TN0973 6/6 doc id 024163 rev 2 please read carefully: information in this document is provided solely in connection with st products. stmicroelectronics nv and its subsidiaries (?st ?) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described he rein at any time, without notice. all st products are sold pursuant to st?s terms and conditions of sale. purchasers are solely responsible for the choice, selection and use of the st products and services described herein, and st as sumes no liability whatsoever relating to the choice, selection or use of the st products and services described herein. no license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. i f any part of this document refers to any third party products or services it shall not be deemed a license grant by st for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoev er of such third party products or services or any intellectual property contained therein. unless otherwise set forth in st?s terms and conditions of sale st disclaims any express or implied warranty with respect to the use and/or sale of st products including without limitation implied warranties of merchantability, fitness for a particular purpose (and their equivalents under the laws of any jurisdiction), or infringement of any patent, copyright or other intellectual property right. st products are not designed or authorized for use in: (a) safety critical applications such as life supporting, active implanted devices or systems with product functional safety requirements; (b) aeronautic applications; (c) automotive applications or environments, and/or (d) aerospace applications or environments. where st products are not designed for such use, the purchaser shall use products at purchaser?s sole risk, even if st has been informed in writing of such usage, unless a product is expressly designated by st as being intended for ?automotive, automotive safety or medical? industry domains according to st product design specifications. products formally escc, qml or jan qualified are deemed suitable for use in aerospace by the corresponding governmental agency. resale of st products with provisions different from the statem ents and/or technical features set forth in this document shall immediately void any warranty granted by st for the st product or service described herein and shall not create or extend in any manner whatsoev er, any liability of st. st and the st logo are trademarks or register ed trademarks of st in various countries. information in this document supersedes and replaces all information previously supplied. the st logo is a registered trademark of stmicroelectronics. all other names are the property of their respective owners. ? 2013 stmicroelectronics - all rights reserved stmicroelectronics group of companies australia - belgium - brazil - canada - china - czech republic - finland - france - germany - hong kong - india - israel - ital y - japan - malaysia - malta - morocco - philippines - singapore - spain - swed en - switzerland - united kingdom - united states of america www.st.com
|
