M4T28-BR12SH, M4T32-BR12SH
MECHANICAL INFORMATION
Electrical connection to the SOIC is made through
four pins that connect to the four press fitted sock-
ets at each end of the SOIC. Critical contact points
between the pins and sockets are gold-plated to
resist oxidation. Internally, each socket contains
six independent contact fingers to form redundant
connections between the two components. These
sockets were designed with high point contact
force to provide the lowest possible contact resis-
tance. The SNAPHAT
®
top also incorporates four
molded-in retaining clips which hold onto the ends
of the SOIC insuring mechanical and electrical
connection even under severe mechanical shock
and vibration. The combined SOIC and SNAPHAT
Figure 3. SNAPHAT Insertion/Extraction Forces
15
assembly can sustain shock levels in excess of
100 g without separating. This package also pass-
es variable frequency testing in accordance with
MIL-STD-883, method 2007.2, condition A.
Figure 3 illustrates the affect of repeated insertion
and extraction of the SNAPHAT top to the SOIC.
The force required to extract the SNAPHAT, and
then to re-insert it, reduces each time. After four or
five extractions, the reduction starts to become
unnoticeable and the force required remains at a
fairly constant figure. Typically, though, the
SNAPHAT will only need to be extracted and re-
inserted once in its lifetime.
12.5
Average Insertion
Average Extraction
10
Force (pounds)
7.5
5
2.5
0
1
2
3
4
5
6
7
8
9
10
AI02526
Number of Extractions
5/12
STMICROELECTRONICS [ STMICROELECTRONICS ]
