IPC-7527.pdf - 第12页
Defect – Class 1, 2, 3 • Solder paste deposit has connected with adjacent pad (Figure 5-15). • Paste deposit (D) is of f pad >25% (A) in X and/or Y direction (Figures 5-14 through 5-16). • Solder deposit not in single…
5.1.2 Misregistration of Solder Paste Deposits
Target – Class 1, 2, 3
• Paste deposit is centered on solder pad (Figures 5-6 and
5-7).
• The paste deposit appears as one single block (unless
segmented by design).
• All solder balls have contact to the solder paste deposit.
Acceptable – Class 1, 2, 3
• Paste deposit (D) is off pad <25% (A) in X and/or Y
direction (Figures 5-8 through 5-13).
Figure 5-6 Centered Deposit
Figure 5-7 Centered Deposit
Figure 5-8 Offset – Acceptable
Figure 5-9 Offset – Acceptable
Figure 5-10 Offset – Acceptable
Figure 5-11 Offset – Acceptable
May 2012 IPC-7527
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Defect – Class 1, 2, 3
• Solder paste deposit has connected with adjacent pad
(Figure 5-15).
• Paste deposit (D) is off pad >25% (A) in X and/or Y
direction (Figures 5-14 through 5-16).
• Solder deposit not in single block (except by design).
• Solder balls that do not contact the solder paste deposit.
Figure 5-12 Offset – Acceptable
Figure 5-13 Offset – Acceptable
Figure 5-14 Offset – Defect
Figure 5-15 Shorting – Defect
Figure 5-16 Offset – Defect
IPC-7527 May 2012
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5.1.3 Solder Paste Deposit – Area It may be necessary
to use a measurement system to evaluate this factor. See
Section 4, MEASUREMENT OF SOLDER PASTE
DEPOSITS.
Target – Class 1, 2, 3
• Coverage = 100% of stencil aperture (Figures 5-17 and
5-18).
Process Indicator – Class 1, 2, 3
• Coverage 75% of stencil aperture (Figures 5-19 and
5-20).
Defect – Class 1, 2, 3
• Coverage <50% of stencil aperture (Figure 5-21).
Figure 5-17 Area – Target
Figure 5-18 Area – Target
Figure 5-19 Area – Acceptable
Figure 5-20 Area – Acceptable
Figure 5-21 Area – Defect
May 2012 IPC-7527
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