dm00077307

TN0983
Technical note
Safety application guide for SPC56xL70xx/RPC56xL70xx family
reference manual addendum
Introduction
This document is an addendum of SPC56xL70xx/RPC56xL70xx Safety Application Guide.
March 2016
DocID024257 Rev 3
1/6
www.st.com
6
Contents
TN0983
Contents
1
Purpose and scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
Considerations on SPC56xL70xx/RPC56xL70xx package and
soldering procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3
2/6
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
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DocID024257 Rev 3
TN0983
1
Purpose and scope
Purpose and scope
The purpose of this document is to communicate to ST customers who intend to integrate
SPC56xL70xx/RPC56xL70xx in an ASIL-D Item some additional assumptions which shall
be met at item level to preserve the SPC56xL70xx/RPC56xL70xx integrity. The
assumptions described in this document shall be intended as additional assumptions with
respect to those communicated in the SPC56xL70xx/RPC56xL70xx Safety Application
Guide.
DocID024257 Rev 3
3/6
6
Considerations on SPC56xL70xx/RPC56xL70xx package and soldering procedures
2
Considerations on SPC56xL70xx/RPC56xL70xx
package and soldering procedures
2.1
Introduction
TN0983
SPC56xL70xx/RPC56xL70xx package is composed by Ultra Low Alpha mold compound.
Measurements report an alpha particle emissivity of 0.00383 ± 0.00056 cp/h/cm2.
This value has been used in the SPC56xL70xx/RPC56xL70xx quantitative safety analyses
(see SPC56xL70xx/RPC56xL70xx 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
caution must be taken 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 possibility of package delamination
after device mounting on board, therefore eliminating the possibility of silicon contamination
by soldering material.
4/6
DocID024257 Rev 3
TN0983
3
Revision history
Revision history
Table 1. Document revision history
Date
Revision
Changes
14-Feb-2013
1
Initial release.
17-Sep-2013
2
Updated disclaimer.
15-Mar-2016
3
Added RPC56xL70xx device family.
DocID024257 Rev 3
5/6
6
TN0983
IMPORTANT NOTICE – PLEASE READ CAREFULLY
STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and
improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on
ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order
acknowledgement.
Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or
the design of Purchasers’ products.
No license, express or implied, to any intellectual property right is granted by ST herein.
Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product.
ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners.
Information in this document supersedes and replaces information previously supplied in any prior versions of this document.
© 2016 STMicroelectronics – All rights reserved
6/6
DocID024257 Rev 3
Similar pages