IPC-SM-782A 表面安装设计和焊盘设计标准(带BGA).pdf - 第120页
6.0 TOLERANCE AND SOLDER JOINT ANALYSIS Figure 4 provides an analysis of tolerance assumptions and resultant solder joints based on the land pattern dimensions shown in Figure 3. Tolerances for the component dimensions, …
5.0 LAND PATTERN DIMENSIONS
Figure 3 provides the land pattern dimensions for SOIC com-
ponents. These numbers represent industry consensus on the
best dimensions based on empirical knowledge of fabricated
land patterns.
In the table, the dimensions shown are at maximum material
condition (MMC). The least material condition (LMC) should
not exceed the fabrication (F) allowance shown on page 4.
The LMC and the MMC provide the limits for each dimension.
The dotted line in Figure 3 shows the grid placement court-
yard which is the area required to place land patterns and
their respective components in adjacent proximity without
interference or shorting. Numbers in the table represent the
number of grid elements (each element is 0.5 by 0.5 mm) in
accordance with the international grid detailed in IEC publica-
tion 97.
RLP No.
Component
Identifier Z (mm) G (mm) X (mm)
Y (mm) C (mm) D (mm) E (mm)
Placement Grid
(No. Grid
Elements)
ref ref ref ref
300A S08 7.40 3.00 0.60 2.20 5.20 3.81 1.27 16x12
301A S08W 11.40 7.00 0.60 2.20 9.20 3.81 1.27 24x12
302A S014 7.40 3.00 0.60 2.20 5.20 7.62 1.27 16x20
303A S014W 11.40 7.00 0.60 2.20 9.20 7.62 1.27 24x20
304A S016 7.40 3.00 0.60 2.20 5.20 8.89 1.27 16x22
305A S016W 11.40 7.00 0.60 2.20 9.20 8.89 1.27 24x22
306A S020W 11.40 7.00 0.60 2.20 9.20 11.43 1.27 24x28
307A S024W 11.40 7.00 0.60 2.20 9.20 13.97 1.27 24x32
308A S024X 13.00 8.60 0.60 2.20 10.80 13.97 1.27 28x32
309A S028W 11.40 7.00 0.60 2.20 9.20 16.51 1.27 24x38
310A S028X 13.00 8.60 0.60 2.20 10.80 16.51 1.27 28x38
311A S032W 11.40 7.00 0.60 2.20 9.20 19.05 1.27 24x44
312A S032X 13.00 8.60 0.60 2.20 10.80 19.05 1.27 28x44
313A S036W 11.40 7.00 0.60 2.20 9.20 21.59 1.27 24x48
314A S036X 13.00 8.60 0.60 2.20 10.80 21.59 1.27 28x48
Figure 3 SOIC land pattern dimensions
x
GZ
Y
E
D
C
Grid
placement
courtyard
IPC-782-9-1-3
IPC-SM-782A
Subject
SOIC
Date
5/96
Section
9.1
Revision
A
Page3of4
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ
6.0 TOLERANCE AND SOLDER JOINT ANALYSIS
Figure 4 provides an analysis of tolerance assumptions and
resultant solder joints based on the land pattern dimensions
shown in Figure 3. Tolerances for the component dimensions,
the land pattern dimensions (fabrication tolerances on the
interconnecting substrate), and the component placement
equipment accuracy are all taken into consideration.
Figure 4 provides the solder joint minimums for toe, heel, and
side fillets, as discussed in Section 3.3. The tolerances are
addressed in a statistical mode, and assume even distribution
of the tolerances for component, fabrication, and placement
accuracy.
Individual tolerances for fabrication (‘‘F’’) and component
placement equipment accuracy (‘‘P’’) are assumed to be as
given in the table. These numbers may be modified based on
user equipment capability or fabrication criteria. Component
tolerance ranges (C
L
,C
S
, and C
W
) are derived by subtracting
minimum from maximum dimensions given in Figure 2. The
user may also modify these numbers, based on experience
with their suppliers. Modification of tolerances may result in
alternate land patterns (patterns with dimensions other than
the IPC registered land pattern dimensions).
The dimensions for minimum solder fillets at the toe, heel, or
side (J
T
,J
H
,J
S
) have been determined based on industry
empirical knowledge and reliability testing. Solder joint
strength is greatly determined by solder volume. An observ-
able solder fillet is necessary for evidence of proper wetting.
Thus, the values in the table usually provide for a positive sol-
der fillet. Nevertheless, the user may increase or decrease the
minimum value based on process capability.
RLP No.
Tolerance
Assumptions (mm)
Solder Joint
Toe (mm) Heel (mm) Side (mm)
FPC
L
J
T
min J
T
max C
S
J
H
min J
H
max C
W
J
S
min J
S
max
300A 0.10 0.10 0.40 0.59 0.80 1.29 0.13 0.78 0.18 0.02 0.14
301A 0.10 0.10 0.65 0.37 0.70 1.39 0.23 0.93 0.18 0.02 0.14
302A 0.10 0.10 0.40 0.59 0.80 1.29 0.13 0.78 0.18 0.02 0.14
303A 0.10 0.10 0.65 0.37 0.70 1.39 0.23 0.93 0.18 0.02 0.14
304A 0.10 0.10 0.40 0.59 0.80 1.29 0.13 0.78 0.18 0.02 0.14
305A 0.10 0.10 0.65 0.37 0.70 1.39 0.23 0.93 0.18 0.02 0.14
306A 0.10 0.10 0.65 0.37 0.70 1.39 0.23 0.93 0.18 0.02 0.14
307A 0.10 0.10 0.35 0.37 0.56 0.80 0.60 1.01 0.15 0.02 0.12
308A 0.10 0.10 0.36 0.40 0.60 0.81 0.56 0.97 0.15 0.02 0.12
309A 0.10 0.10 0.35 0.37 0.56 0.80 0.60 1.01 0.15 0.02 0.12
310A 0.10 0.10 0.36 0.40 0.60 0.81 0.56 0.97 0.15 0.02 0.12
311A 0.10 0.10 0.35 0.37 0.56 0.80 0.60 1.01 0.15 0.02 0.12
312A 0.10 0.10 0.36 0.40 0.60 0.81 0.56 0.97 0.15 0.02 0.12
313A 0.10 0.10 0.35 0.37 0.56 0.80 0.60 1.01 0.15 0.02 0.12
314A 0.10 0.10 0.36 0.40 0.60 0.81 0.56 0.97 0.15 0.02 0.12
Figure 4 Tolerance and solder joint analysis
Zmax
Lmin
▼
▼
▼
▼
1
/2 T
T
J
T
min
Smax
J
H
min
1
/2 T
H
Xmax
▼
▼
Toe Fillet
▼
▼
▼
Heel Fillet
Side Fillet
▼
▼
▼
▼
▼
J
T
max
J
H
max
J
S
min
▼
▼
▼
▼
▼
▼
▼
▼
▼
▼
▼
▼
▼
▼
▼
Gmin
▼
1
/2 T
S
J
S
max
▼
▼
▼
Wmin
▼
IPC-782-9-1-4
IPC-SM-782A
Subject
SOIC
Date
5/96
Section
9.1
Revision
A
Page4of4
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ
1.0 SCOPE
This subsection provides the component and land pattern
dimensions for small outline integrated circuits (SSOIC com-
ponents) with gullwing leads. Basic construction of the SSOIC
device is also covered. At the end of this subsection is a list-
ing of the tolerances and target solder joint dimensions used
to arrive at the land pattern dimensions.
2.0 APPLICABLE DOCUMENTS
See Section 9.0 and the following for documents applicable to
this subsection.
2.1 Electronic Industries Association
JEDEC Publication 95
Registered and Standard Outlines for
Solid State and Related Products, ‘‘Small Outline Gullead, 12
mm Body, 0.80 mm lead Spacing,’’ Outline M0-117, issue
‘‘A,’’ and ‘‘Shrink Small Outline Package Family, 7.62 mm
body, 0.635 mm,’’ Outline MO-018, issue ‘‘A’’
Application for copies should be addressed to:
Global Engineering Documents
1990 M Street N.W.,
Washington,DC
3.0 COMPONENT DESCRIPTIONS
These components are all on 0.635 mm pitch, and are avail-
able in wide body (7.50 mm) and extra wide body (12.00 mm)
sizes, ranging from 48 to 64 pins.
3.1 Basic Construction
See Figure 1. Basic construction
consists of a plastic body and metallic leads.
3.1.1 Termination Materials
Leads should be solder-
coated with a tin/lead alloy. The solder should contain
between 58 to 68% tin. Solder may be applied to the termi-
nation by hot dipping or by plating from solution. Plated sol-
der terminations should be subjected to a post-plating reflow
operation to fuse the solder. The tin/lead finish should be at
least 0.00075 mm [0.0003 in] thick.
3.1.2 Marking
All parts shall be marked with a part number
and ‘‘Pin 1’’ location. ‘‘Pin 1’’ location may be molded into the
plastic body.
3.1.3 Carrier Package Format
Bulk rods, 24 mm tape/
8–12 mm pitch is preferred for best handling. Tube carriers
are also used.
3.1.4 Resistance to Soldering
Parts should be capable of
withstanding ten cycles through a standard reflow system
operating at 215°C. Each cycle shall consist of 60 seconds
exposure at 215°C. Parts must also be capable of withstand-
ing a minimum of 10 seconds immersion in molten solder at
260°C.
IPC-782-9-2-1
Figure 1 SSOIC construction
IPC-SM-782
Surface Mount Design
and Land Pattern Standard
Date
5/96
Section
9.2
Revision
A
Subject
SSOIC
Page1of4
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ