These criteria are for components designed with a hole or holes in the lead, a bump on the bottom to assure a good G fillet thickness across most of the bottom, and an attached solder slug to control the amount of solder, and are applicable to termina-
tions on oval or round land patterns.
The top hole of a solder charge termination with two holes is not required to be filled.
Table 8-9 Dimensional Criteria – ButtI Connections – Solder Charged Terminations
Feature Dim.
Class 1 Class 2
Class 3
Maximum Side Overhang A
Not permitted Maximum Toe Overhang
B Not permitted
Minimum End Joint Width C
100 of W Minimum Fillet Height
F Completely fills bottom hole on the termination
Lead Width W
Note 1 Land Width
P Note 1
Note 1: Unspecified parameter or variable in size as determined by design.
1
2 3
Figure 8-139
1. Connector lead 2. Land
3. Solder charge
8.3.8.2 ButtI Connections – Solder Charged Terminations
8-78 IPC-A-610F
July 2014
Target – Class 1,2,3 • No side overhang.
Acceptable – Class 1 • For modified through-hole leads, overhang A less than
25 lead width W, see Figure 8-140. • For solder charged terminations, no side overhang.
Defect – Class 1 • For modified through-hole leads. Overhang A exceeds
25 lead width W, see Figure 8-142. • For solder charged terminations, any side overhang.
Defect – Class 2,3 • Any side overhang A.
A W
Figure 8-140
Figure 8-141
A
Figure 8-142
8.3.8.3 ButtI Connections – Maximum Side Overhang A
8-79 IPC-A-610F
July 2014
These criteria are applicable to both modified through-hole leads and solder-charged terminations. Defect – Class 1,2,3
• Any toe overhang B.
B
Figure 8-143
B
Figure 8-144
8.3.8.4 ButtI Connections – Maximum Toe Overhang B
8-80 IPC-A-610F
July 2014
Target – Class 1,2 • End joint width C is 100 of lead width W.
Acceptable – Class 1,2 • For modified through-hole leads, end joint width C is mini-
mum 75 lead width W, see Figure 8-145. Acceptable – Class 1,2,3
• For solder charged terminations, end joint width C is 100 lead width W.
Defect – Class 1,2 • For modified through-hole leads, end joint width C is less
than 75 lead width W. Defect – Class 3
• For solder charged terminations, end joint width C is less than 100 lead width W.
C W
1
2
Figure 8-145
1. Lead 2. Land
Figure 8-146
8.3.8.5 ButtI Connections – Minimum End Joint Width C
8-81 IPC-A-610F
July 2014
These criteria are applicable only to terminations made with modified through-hole leads. Acceptable – Class 1,2,3
• Wetting is evident.
These criteria are applicable only to terminations made with modified through-hole leads. Acceptable – Class 1,2,3
• Wetted fillet evident. Defect – Class 1,2
• No wetted fillet. • Solder touches package body.
D
Figure 8-147
E
Figure 8-148
8.3.8.6 ButtI Connections – Minimum Side Joint Length D
8-82 IPC-A-610F
July 2014
8.3.8.7 ButtI Connections – Maximum Fillet Height E
Acceptable – Class 1,2 • For modified through-hole leads, fillet height F is minimum
0.5 mm [0.02 in]. Acceptable – Class 1,2,3
• For solder charged terminations, the bottom hole is com- pletely filled with solder.
Defect – Class 1,2 • For modified through-hole leads, fillet height F is less than
0.5 mm [0.02 in]. Defect – Class 1,2,3
• For solder charged terminations, the bottom hole is not completely filled with solder.
F
Figure 8-149
Figure 8-150
8.3.8.8 ButtI Connections – Minimum Fillet Height F
8-83 IPC-A-610F
July 2014
These criteria are applicable only to terminations made with modified through-hole leads. Acceptable – Class 1,,32
• Wetted fillet evident. Defect – Class 1,2,3
• No wetted fillet.
G
Figure 8-151
8.3.8.9 ButtI Connections – Solder Thickness G
8-84 IPC-A-610F
July 2014
Connections formed to the leads of power dissipating components with flat lug leads shall meet the dimensional requirements of
Table 8-10, see Figure 8-153. The design should permit easy inspection of wetting to the wettable surfaces.
Table 8-10 Dimensional Criteria – Flat Lug Leads
Feature Dim.
Class 1 Class 2
Class 3
Maximum Side Overhang A
50 W, Note 1 25 W, Note 1
Not permitted Maximum Toe Overhang
B Note 1
Not permitted Minimum End Joint Width
C 50 W
75 W W
Minimum Side Joint Length D
Note 3 L-M, Note 4
Maximum Fillet Height E
Note 2 G + T + 1 mm [0.04 in]
Minimum Fillet Height F
Note 3 G + T
Solder Fillet Thickness G
Note 3 Lead Length
L Note 2
Maximum Gap M
Note 2 Land Width
P Note 2
Lead Thickness T
Note 2 Lead Width
W Note 2
Flat Unformed Leads, e.g., flat unformed flexible circuitry terminations
Use above criteria except as noted below. Maximum Side Overhang
A 50 W, Note 1
25 W, Note 1 25
Maximum Gap M
Note 2 Notes 1,2
Note 1. Does not violate minimum electrical clearance. Note 2. Unspecified parameter or variable in size as determined by design.
Note 3. Wetted fillet is evident. Note 4. Where the lug is intended to be soldered beneath the component body and the land is designed for the purpose, the lead shows evidence of wetting in
the gap M.
Defect – Class 1,2,3 • Side overhang does not meet Table 8-10, see Figures 8-152
and 8-154.
Figure 8-152
T F
W L
D G
E A
M C
P
Figure 8-153
Figure 8-154
8.3.9 Flat Lug Leads
8-85 IPC-A-610F
July 2014
Connections formed to the termination areas of tall profile components component height is more than twice width or thickness, whichever is less having bottom only terminations
shall meet the dimensional requirements of Table 8-11, see Figure 8-155. Table 8-11 Dimensional Criteria – Tall Profile Components Having Bottom Only Terminations
Feature Dim.
Class 1 Class 2
Class 3
Maximum Side Overhang A
50 W; Notes 1, 4 25 W; Notes 1, 4
Not permitted; Notes 1, 4 Maximum End Overhang
B Notes 1, 4
Not permitted Minimum End Joint Width
C 50 W
75 W W
Minimum Side Joint Length D
Note 3 50 R
75 R Solder Fillet Thickness
G Note 3
TerminationPlating Length R
Note 2 Land Length
S Note 2
Termination Width W
Note 2
Note 1. Does not violate minimum electrical clearance. Note 2. Unspecified parameter or variable in size as determined by design.
Note 3. Wetting is evident. Note 4. As a function of the component design, the termination may not extend to the component edge, and the component body may overhang the PCB land
area.
B D
R S
A C
G W
1 2
3
Figure 8-155
1. Component height 2. Component width