IPC-TM-650 EN 2022 试验方法1.pdf - 第298页

Figure 7 Corne rs Supports R1 R1 R2 Supporting Jacks or Blocks Figure 8 Highest Point M easurement Measure at This Point Measure at This Point R2 R2 R1 IPC-TM-650 Page 5 of 5

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Figure 5 Measurement of Twist
R
A
C
D
B
R = Highest
Point of Board
Shim under raised
corner of A.
B, C, and D touching
Datum Surface. Only
one corner may be
physically restrained.
Figure 6 Sample Placement
R2 Lowest
Corners
R2 R2
R1
Raised Parallel
Surfaces
IPC-TM-650
Page 4 of 5
Figure 7 Corners Supports
R1 R1
R2
Supporting Jacks or Blocks
Figure 8 Highest Point Measurement
Measure at
This Point
Measure at
This Point
R2
R2
R1
IPC-TM-650
Page 5 of 5
None
Figure 1
Figure 2
Page 1 of 2