ANSI/GEIA STD-0008-2011电子元件降额标准

    1 PURPOSE

   
This document is generated to provide an industry standard for derating of electronic components. For the purposes of this document, the following definitions apply:

   
1.1 Definitions

   
Controlled/Uncontrolled – See paragraph 3 herein.

   
Derate – To reduce the rating(s) of a component to improve its reliability or to permit operation at high ambient temperatures.

   
Derating – The reduction in rating of a component.

   
Derating limits – The maximum nominal stresses that a component is allowed to experience in an application. The Derating Limits are always less than the component’s rated maximum stresses.

   
 

   
1.2 Scope

   
This Standard specifies the minimum derating requirements for using electronic components in moderately severe environments. These environments are assumed to include Airborne Inhabited Cargo (AIC), Airborne Inhabited Fighter (AIF), Ground Mobile (GM), and Naval Sheltered (NS) environments specified in MIL-HDBK-217. This Standard is intended to supersede the derating limits contained in Defense Standardization Program Office (DSPO) Standardization Directive SD-18, Naval Standard TE000-AB-GTP-010, and Air Force ESD-TR-85-148. It is intended that a future revision of this Standard will include additional requirements for derating for other environments (e.g. Airborne Uninhabited Cargo). Since this Standard specifies the minimum derating requirements, (sub)contractors may derate in excess of these requirements. This Standard is not intended for use in space or launch system applications, which have their own existing derating standards, and shall not be used for such applications unless specifically allowed by contract.

   
1.3 Use of this Standard

   
It is intended that this Standard be called out in contractual documents, and that the call-out specify what to do in case the derating limits herein cannot be met in certain cases.

   
1.3.1 Sample contract language:

   
“The (sub)contractor shall derate electronic components in accordance with GEIA-STD-0008. In the event the (sub)contractor intends to exceed a derating limit, the (sub)contractor shall obtain customer approval of that exception.”

   
NOTE: JEP149 may be used as the basis of the engineering evaluations, which include the component supplier in determining alternate derating criteria that will meet the application reliability requirements. The customer may want to grant blanket approval of all derating exceptions that are successfully addressed by JEP149 engineering evaluations.

   
1.4 Components not addressed in this standard

   
When a component is being used that is not addressed by this standard, the user is strongly encouraged to contact the appropriate TechAmerica chairperson (G-12 Chair for solid state components, G-11 Chair for passive components) from the www.techamerica.org website (under “Committees”, “Systems Standards and Technology Committee” for determination of a value to be used and included in the next revision of this Standard.