ASTM E431-96(2022)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E431 − 96 (Reapproved 2022)
Standard Guide to
Interpretation of Radiographs of Semiconductors and
Related Devices
This standard is issued under the fixed designation E431; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Significance and Use
1.1 This guide provides illustrations of radiographs of 4.1 Illustrations provided in this guide are intended for use
semiconductors and related devices. Low powered transistors
as references to aid in interpreting film or nonfilm images
(through the TO-11 case configuration), diodes, low-power resulting from x-ray examinations (see Table 1) to ascertain
rectifiers, power devices, and integrated circuits are illustrated
quality of assembly and workmanship.
with common assembly features. Particular areas of construc-
4.2 Required attributes of the design features or other
tion are featured for these devices detailing critical points of
construction details are not provided but are to be established
design or assembly.
as mutually agreed upon by manufacturers and users of these
1.2 This standard does not purport to address all of the
devices. Many devices share common assembly features; thus,
safety concerns, if any, associated with its use. It is the
these interpretations can be used for components not illus-
responsibility of the user of this standard to establish appro-
trated.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
5. Use of Illustrations
1.3 This international standard was developed in accor-
5.1 The illustrations in this guide are for use in interpreting
dance with internationally recognized principles on standard-
radiographs of semiconductors and related devices. They
ization established in the Decision on Principles for the
provide reference points and information on the critical areas
Development of International Standards, Guides and Recom-
of such devices. These points must be clearly resolved in the
mendations issued by the World Trade Organization Technical
radiographs being interpreted. The radiographs to be inter-
Barriers to Trade (TBT) Committee.
preted must comply with the requirements of Practice E801 to
2. Referenced Documents ensure suitable image quality with minimal distortion. Addi-
tional information on the application of radiographic tech-
2.1 ASTM Standards:
niques to semiconductors and electronic components may be
E801 Practice for Controlling Quality of Radiographic Ex-
found in Test Method E1161.
amination of Electronic Devices
E1161 Practice for Radiographic Examination of Semicon-
5.2 The illustrations in this guide may also be used to
ductors and Electronic Components
interpret the radioscopic images of semiconductors and related
E1255 Practice for Radioscopy
devices when using radioscopic techniques. The radioscopic
E1316 Terminology for Nondestructive Examinations
images to be interpreted must comply with the requirements of
Practice E801 to ensure suitable image quality with minimal
3. Terminology
distortion. Additional information on the application of radio-
3.1 Definitions of terms used in these reference illustrations
scopic techniques may be found in Test Method E1161 and
may be found in Terminology E1316, Section D.
Practice E1255.
This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-
6. Description
tive Testing and is the direct responsibility of Subcommittee E07.02 on Reference
Radiological Images.
6.1 Description of irregularities and applicable figures are
Current edition approved Oct. 1, 2022. Published October 2022. Originally
shown in Table 1.
approved in 1971. Last previous edition approved in 2016 as E431 – 96(2016). DOI:
10.1520/E0431-96R22.
7. Keywords
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
7.1 electronic devices; nondestructive testing; radiographs;
Standards volume information, refer to the standard’s Document Summary page on
radiography; reference illustrations; semiconductors; x-ray
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E431 − 96 (2022)
TABLE 1 Irregularity Description and Figure References
Figure
Item and Irregularity Expressed as
Reference
Transistors, low-power (TO-11 and smaller packages)
Extraneous matter Any material contained in the semiconductor device that is not necessary for its manufacture or 1
operation.
Internal lead irregularities, bond-to-post connection Leads extending beyond attachment points at either end. Allowable extension should be stated in 2(a)
wire diameters.
Slack leads deviate from a straight line between attachment points. Allowable deviation should 2(b)
be stated in wire diameters.
Internal lead clearance is the distance between the edge of the chip and lead wire. Allowable 2(c)
clearance should be stated in wire diameters.
Post-position irregularities Allowable deviations of the post from its intended (design) position may be specified as minimum 3
angle made by the post and header, or as clearance between post and post or post and case
expressed in terms of post diameter.
Getter-position irregularities In crimp-type devices, deviations of the getter ring from its intended (design) position are stated 4(a)
relative to the crimp. In noncrimp-type devices, deviations of the getter ring from its intended 4(b)
(design) position are stated as the angle between the actual and intended positions.
Mounting paste Mounting-paste buildup or expulsion, or both, is an excessive amount of material used to mount 5
the semiconductor element on the header. Allowable excess should be measured relative to
the surfaces, clearances, and shape of the deposit.
Post-connection solder or gold paste Post-connection solder or gold-paste buildup is an excessive amount of such material at the 6
termination. Excess is measured relative to the diameter at the attachment point and by the
deposit shape.
Diodes and low-power rectifiers (whisker-type)
Extraneous matter Any material contained in the cav
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