Electronic

SEMICONDUCTOR IQI'sSEMICONDUCTOR IQIs JEM semiconductor IQI's are manufactured to meet the exacting standards of ASTM E 801, MIL-STD-883, and MIL-STD-750 for controlling the quality of radiographic testing of electronic devices for internal discontinuities and extraneous material within cavities or encapsulated materials. Eight separate IQI's are specified by the standards, each IQI with different stainless steel shim thicknesses and lead particle sizes.

ASTM E 801: Electronic IQI's are fabricated of clear acrylic plastic with Stainless Steel covers, lead particles (spheres), tungsten wires and lead identification numbers, as show in the accompanying drawing.

The stainless steel covers serve as shims. The IQI's are used in such a manner as to simulate as closely as possible the device being examined. To accomplish this, a set of eight IQI's is specified. These provide a range of cover thickness (of stainless steel shims) that is radiologically equivalent to the range of devices from glass diodes or plastic-encapsulated circuits (IQI # 1) to large power or hybrid circuit devices (IQI # 8).

Wire size increases with shim thickness. Higher power devices are radiologically compatible with the thicker coverings, because they use interconnecting wire's that are large. Small signal devices are compatible with thin coverings. Particle size is normally independent of device type, so these remain constant.

Image Quality Indicator for Electron Devices
Fig. 1 Image Quality Indicator for Electron Devices.

Dimensions, in. (mm)
a. 0.187 ( 4.750) f. 1.00 (25.40) k. 1.125 (28.575)
b. 0.375 ( 9.525) g. 0.375 ( 9.525) l. 1.313 (33.350)
c. 0.500 (12.700) h. 0.500 (12.700) m. 1.50 (38.10)
d. 0.625 (15.875) i. 0.625 (15.875) n. 0.125 ( 3.175)
e. 0.813 (20.650) j. 0938 (23.825) p. 0.250 ( 6.350)


Particle Diameter, in. (mm)
G. 0.015 (0.381) J. 0.006 (0.152)
H. 0.010 (0.254) K. 0.004 (0.102)
I. 0.008 (0.203) L. 0.002 (0.051)


Shim and Wire Specifications
Shim thickness,
in. (mm)
Wire diameters, in. (mm)
A B C D E F
0
0
0.002
(0.051)
0.001
(0.025)
0.0005
(0.0127)
0.0005
(0.0127)
0.001
(0.025)
0.002
(0.051)
0.002
(0.051)
0.002
(0.051)
0.001
(0.025)
0.0005
(0.0127)
0.0005
(0.0127)
0.001
(0.025)
0.002
(0.051)
0.005
(0.127)
0.002
(0.051)
0.001
(0.025)
0.0005
(0.0127)
0.0005
(0.0127)
0.001
(0.025)
0.002
(0.051)
0.007
(0.178)
0.002
(0.051)
0.001
(0.025)
0.0005
(0.0127)
0.0005
(0.0127)
0.001
(0.025)
0.002
(0.051)
0.010
(0.254)
0.003
(0.076)
0.002
(0.051)
0.001
(0.025)
0.001
(0.025)
0.002
(0.051)
0.003
(0.076)
0.015
(0.381)
0.003
(0.076)
0.002
(0.051)
0.001
(0.025)
0.001
(0.025)
0.002
(0.051)
0.003
(0.076)
0.025
(0.635)
0.005
(0.127)
0.003
(0.076)
0.002
(0.051)
0.002
(0.051)
0.003
(0.076)
0.005
(0.127)
0.035
(0.889)
0.005
(0.127)
0.003
(0.076)
0.002
(0.051)
0.002
(0.051)
0.003
(0.076)
0.005
(0.127)