ASTM E431-96(2016)

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Designation: E431 − 96 (Reapproved 2011) E431 − 96 (Reapproved 2016)
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
1.1 This guide provides illustrations of radiographs of semiconductors and related devices. Low powered transistors (through
the TO-11 case configuration), diodes, low-power rectifiers, power devices, and integrated circuits are illustrated with common
assembly features. Particular areas of construction are featured for these devices detailing critical points of design or assembly.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E801 Practice for Controlling Quality of Radiological Examination of Electronic Devices
E1161 Practice for Radiologic Examination of Semiconductors and Electronic Components
E1255 Practice for Radioscopy
E1316 Terminology for Nondestructive Examinations
3. Terminology
3.1 Definitions of terms used in these reference illustrations may be found in Terminology E1316, Section D.
4. Significance and Use
4.1 Illustrations provided in this guide are intended for use as references to aid in interpreting film or nonfilm images resulting
from x-ray examinations (see Table 1) to ascertain quality of assembly and workmanship.
4.2 Required attributes of the design features or other construction details are not provided but are to be established as mutually
agreed upon by manufacturers and users of these devices. Many devices share common assembly features; thus, these
interpretations can be used for components not illustrated.
5. Use of Illustrations
5.1 The illustrations in this guide are for use in interpreting radiographs of semiconductors and related devices. They provide
reference points and information on the critical areas of such devices. These points must be clearly resolved in the radiographs
being interpreted. The radiographs to be interpreted must comply with the requirements of Practice E801 to ensure suitable image
quality with minimal distortion. Additional information on the application of radiographic techniques to semiconductors and
electronic components may be found in Test Method E1161.
5.2 The illustrations in this guide may also be used to interpret the radioscopic images of semiconductors and related devices
when using radioscopic techniques. The radioscopic images to be interpreted must comply with the requirements of Practice E801
to ensure suitable image quality with minimal distortion. Additional information on the application of radioscopic techniques may
be found in Test Method E1161 and Practice E1255.
This guide is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.02 on Reference
Radiological Images.
Current edition approved Dec. 1, 2011June 1, 2016. Published March 2012June 2016. Originally approved in 1971. Last previous edition approved in 20072011 as
E431 - 96(2007).(2011). DOI: 10.1520/E0431-96R11.10.1520/E0431-96R16.
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 Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
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E431 − 96 (2016)
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 cavity of the device that is not part of its design and not required 7(a)
for its manufacture or operation. 7(b)
7(c)
Whisker irregularities Any whisker malformation from its intended shape caused by compression. Allowable 8(a)
compression is stated as a percentage of design length.
Whisker cross-sectional—area deviations are stated as a percentage of cross sect
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