IPC-SM-782A-表面贴装焊盘图形设计标准.pdf.pdf - 第84页
4.0 COMPONENT DIMENSIONS Figure 2 provides the component dimensions for tantalum capacitors. Component Identifier (mm) L (mm) S (mm) W1 (mm) W2 (mm) T (mm) H1 (mm) H2 (mm) min max min max min max min max min max min max 3…
1.0 SCOPE
Microminiature leadless devices are available to the circuit
designer in rectangular form for discrete components such as
tantalum capacitors.
This subsection provides the component and land pattern
dimensions for tantalum capacitors along with an analysis of
tolerance and solder joint assumptions used to arrive at the
land pattern dimensions. Basic construction of the inductor is
also covered.
2.0 APPLICABLE DOCUMENTS
See Section 8.0 for documents applicable to the subsections.
3.0 COMPONENT DESCRIPTIONS
A variety of values exist for tantalum capacitors. The following
sections describe the most common types.
3.1 Basic Construction See Figure 1.
3.1.1 Termination Materials End terminations 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 0.0075 mm [0.0003 in] thick.
The termination shall be symmetrical, and shall not have nod-
ules lumps, protrusions, etc., that compromise the symmetry
or dimensional tolerances of the part. The end termination
shall cover the ends of the components, and shall extend out
to the top and bottom of the component.
Most common termination materials include palladium-silver
alloy, silver, and gold. Solder finish applied over precious
metal electrodes shall have a diffusion-barrier layer between
the electrode metallization and the solder finish. The barrier
layer should be nickel or an equivalent diffusion barrier, and
should be at least 0.00125 mm [0.00005 in] thick.
3.1.2 Marking Parts are available with or without marked
capacitance values.
3.1.3 Carrier Package Format Bulk rods, 8 mm tape/4
mm pitch is preferred for best handling. Tape and reel speci-
fications provide additional requirements.
3.1.4 Resistance to Soldering Parts should be capable of
withstanding five 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-782-8-4-1
Figure 1 Tantalum capacitor construction
or
IPC-SM-782
Surface Mount Design
and Land Pattern Standard
Date
5/96
Section
8.4
Revision
A
Subject
Tantalum Capacitors
Page1of4
4.0 COMPONENT DIMENSIONS
Figure 2 provides the component dimensions for tantalum capacitors.
Component
Identifier (mm)
L (mm) S (mm) W1 (mm) W2 (mm) T (mm)
H1
(mm)
H2
(mm)
min max min max min max min max min max min max
3216 3.00 3.40 0.80 1.74 1.17 1.21 1.40 1.80 0.50 1.10 0.70 1.80
3528 3.30 3.70 1.10 2.04 2.19 2.21 2.60 3.00 0.50 1.10 0.70 2.10
6032 5.70 6.30 2.50 3.54 2.19 2.21 2.90 3.50 1.00 1.60 1.00 2.80
7343 7.00 7.60 3.80 4.84 2.39 2.41 4.00 4.60 1.00 1.60 1.00 3.10
Figure 2 Tantalum capacitor component dimensions
S
L
H
1
H
2
W
1
W
2
T
2 Places
IPC-782-8-4-2
IPC-SM-782
Subject
Tantalum Capacitors
Date
5/96
Section
8.4
Revision
A
Page2of4
5.0 LAND PATTERN DIMENSIONS
Figure 3 provides the land pattern dimensions for tantalum
capacitors. These numbers represent industry consensus on
the best dimensions based on empirical knowledge of fabri-
cated 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
(mm) Z (mm) G (mm) X (mm)
Y (mm) C (mm)
Placement Grid
(No. of Grid Elements)ref ref
180A 3216 4.80 0.80 1.20 2.00 2.80 6x12
181A 3528 5.00 1.00 2.20 2.00 3.00 8x12
182A 6032 7.60 2.40 2.20 2.60 5.00 8x18
183A 7343 9.00 3.80 2.40 2.60 6.40 10x20
Figure 3 Tantalum capacitor land pattern dimensions
▼
▼
▼
▼
▼
▼
▼
▼
▼
C
G
Z
X
Y
Grid
placement
courtyard
▼
IPC-782-8-4-3
IPC-SM-782
Subject
Tantalum Capacitors
Date
5/96
Section
8.4
Revision
A
Page3of4