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IECQ System Specification Structure

I. Specification Hierarchy
Standards and Specifications for use under the IECQ System consist of the following levels:
  • Basic Specifications
  • Generic Specifications
  • Sectional Specifications
  • Blank Detail Specifications
  • Detail Specifications
  (1) Basic Specifications
The main categories of the Basic Specifications include the general requirements and special items and material of different component families. In addition to some special items, the scope of the Basic Specifications includes the following items:
  • Basic environmental tests, for example IEC publication 60068.
  • Sampling procedures, for example IEC publication 60410.
  • SI units, for example ISO 1000.
  • Series of preferred values, for example IEC publication 60063 and ISO 3.
  • Requirements for identification, marking, dating, etc
(2) Generic Specifications and Sectional Specifications
Generic Specifications are applicable to a family of electronic components. They shall contain, or give direct reference to, the terms, definitions, symbols, test methods, and information relating to the inspection peculiar to the family. They may also include test sequences used for the quality assessment in this family, and standard series of values for ratings or characteristics.
Where substantial parts of the above information are peculiar to particular sub-families of components, they may be issued separately in sectional specifications. Generic and/or sectional specifications include the flowing principal informations :
A. General and identification
  • Scope
  • Related documents
  • Terminology
  • Letter symbols and abbreviations
  • Graphical symbols
  • Marking of component and package
B. Quality assessment aspects
  • Primary stage of manufacture
  • Structurally similar components
  • Qualification approval requirements
  • Capability approval requirements
  • Quality conformance inspection
  • Alternative test methods
  • Delayed deliveries
  • Unchecked parameters
C. Tests and methods of measurement
  • Visual inspection
  • Dimensional inspection
  • Environmental tests
  • Methods of measuring characteristics
  • Endurance tests

(3) Blank Detail Specifications
Blank Detail Specifications are used to ensure a uniform, presentation of detail specifications and are derived from the requirements of the generic or sectional specifications. They list the technical criteria which are necessary and sufficient to assess the quality of a component and may specify some of the conditions under which the tests are carried out.
The blank detail specification, when completed by a specification writer in accordance with the specific requirements for a particular component, becomes a detail specification.

(4) Detail Specifications
Detail Specifications are applicable to a particular electronic component or a range of electronic components. They contain or refer to all information required for identification and quality assessment of that component or range of components under the IECQ. In the way, the relevant specification (detail specification together with all relevant parts from the sectional, generic and basic levels) is complete and sufficient for inspection purposes.
Detail specifications include the following information :
  • Dimensional characteristics
  • Related documents
  • Electrical characteristics and limiting values
  • Ordering information
  • Additional information
  • Marking
  • Technical requirements for inspection
II . Component Grouping
@ (1)Component family :
For the purpose of specifications, electronic components are divided into families based on their function. Refer to Section "The Scope of the IECQ System".
@ (2)Component sub-family :
Families may be divided into sub-families on the basis of function or technology or both, according to the composition of the family. For example, fixed resistors may be divided into low power, high power and precision, or into composition, film and wirewound, or into normal and high stability.
@ (3)Groups :
Sub-families may be further divided into smaller groups which have a common test schedule with similar inspection conditions and criteria but differing in values for the ratings, characteristics and test requirements and in the requirements for the degree of quality assurance.
III. Specification Structures
@ (1) 2-level System
A 2-level System is sometimes appropriate when the family contains very few component types. In this case there is no generic specification and all the relevant information is included in the detail specification, either in full or by reference to an appropriate basic specification (column 6).
(2) 3-level System
A 3-level System may have variants according to the position of the quality conformance inspection test schedule :
  • the schedule may appear directly in the detail specification (column 5).
  • alternatively , the schedule may appear in an associated blank detail specification (column 4).
(3) 4-level System:
A 4-level System, which is often used, is an extension of the 3-level System by the inclusion of the information relevant to a sub-family in sectional specification (column 3).
IV. Expanding the Standards Base
  Accordingly, in recent years the IECQ System has extended its assessment activities so as to offer hospitality to the documents of any organization having a recognized standards-making function. The single limiting factor is that formal recognition must be accorded by the Management Committee.
The listing immediately below summarizes the bodies of standards and specifications, current and potential, now eligible for inclusion or consideration by IECQ.
Examples of standards bodies:
International : IEC, ISO, ITU
Regional : CENELEC
National : ANSI, BSI, JSA, MIL, UTE, VDE

Illustration of possible specification structures

Column 1 Column 2 Column 3 Column 4 Column 5 Column 6
Applicable to Examples of information to be included Possible division of contents
between the different levels


Two or more component
families or sub-families
  • Assessment system rules
  • Inspection rules
  • Environmental test methods
  • Sampling plans
  • Identification rules
  • Marking standards
  • Dimensional Standards
  • Terminology standards
  • Symbol standards
  • Preferred number series
Basic specification
Component family
  • Specific terminology
  • Specific symbols
  • Specific units
  • Preferred values
  • Marking
  • Quality assessment procedures
  • Test and measurement methods
Generic Generic Generic(2) Detail(3)
Component sub-family
  • Additional terms
  • Additional test methods
  • Selection of tests
  • Preferred values for:
    - characteristics
    - ratings(1)
    - test severities
    - dimensions
  • Qualification approval and/or
    capability procedures
Groups of types having a common test schedule
  • Quality conformance test schedule
  • Inspection requirements
  • Information common to a number of types
Blank detail Blank detail Detail(3) Detail(3)
Individual type
  • Individual values specific information completed quality conformance test schedule
Detail Detail @ @
1) In this guide "ratings" means rated values or limiting values as appropriate.
2) May include instructions for the writing of detail specifications.
3) These detail specification may only be prepare by technical committees of the IEC or the Rules of Procedure,  IECQ QC  001002.