IPC-SM-782A 表面安装设计和焊盘设计标准(带BGA).pdf - 第80页

4.0 COMPONENT DIMENSIONS Figure 2 provides the component dimensions for inductors. 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 max max 2012 Chip 1…

1.0 SCOPE

Microminiature leadless devices are available to the circuit

designer in rectangular form for discrete components such as

inductors.

This subsection provides the component and land pattern

dimensions for inductors, 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 cov-

ered.

2.0 APPLICABLE DOCUMENTS

See Section 8.0 for documents applicable to the subsections.

3.0 COMPONENT DESCRIPTIONS

A variety of values exist for inductors. The following sections

describe the most common types.

3.1 Basic Construction

At the time of publication, there

was no industry standard document for leadless inductors.

The dimensions were taken from manufacturer’s catalogs, but

only when at least two component vendors manufacture the

same package. However, the same inductor value may not be

available in the same package from the two manufacturers.

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

inductance 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-782-8-3-1

Figure 1 Inductor construction

Ferrite

Chip

▼

Precision wire—wound Molded

External electrode

▼

IPC-SM-782

Surface Mount Design

and Land Pattern Standard

Date

8/93

Section

8.3

Revision Subject

Inductors

Page1of4

电子技术应用　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

4.0 COMPONENT DIMENSIONS

Figure 2 provides the component dimensions for inductors.

Component

Identiﬁer (mm)

L (mm) S (mm) W1 (mm) W2 (mm) T (mm)

(mm)

min max min max min max min max min max max max

2012 Chip 1.70 2.30 1.10 1.76 0.60 1.20 — — 0.10 0.30 1.20 —

3216 Chip 2.90 3.50 1.90 2.63 1.30 1.90 — — 0.20 0.50 1.90 —

4516 Chip 4.20 4.80 2.60 3.53 0.60 1.20 — — 0.30 0.80 1.90 —

2825 Prec. w/w 2.20 2.80 0.90 1.62 1.95 2.11 2.10 2.54 0.37 0.65 2.29 0.07

3225 Prec. w/w 2.90 3.50 0.90 1.83 1.40 1.80 — — 0.50 1.00 2.00 0.50

4532 Prec. w/w 4.20 4.80 2.20 3.13 3.00 3.40 — — 0.50 1.00 2.80 0.50

5038 Prec. w/w 4.35 4.95 2.81 3.51 2.46 2.62 3.41 3.81 0.51 0.77 3.80 0.76

3225/3230 Molded 3.00 3.40 1.60 2.18 1.80 2.00 2.30 2.70 0.40 0.70 2.40 0.51

4035 Molded 3.81 4.32 0.81 1.60 1.20 1.50 2.92 3.18 1.20 1.50 2.67 1.27

4532 Molded 4.20 4.80 2.30 3.15 2.00 2.20 3.00 3.40 0.65 0.95 3.40 0.50

5650 Molded 5.30 5.50 3.30 4.32 3.80 4.20 4.70 5.30 0.50 1.00 5.80 1.00

8530 Molded 8.25 8.76 5.25 6.04 1.20 1.50 2.92 3.18 1.20 1.50 2.67 1.27

Figure 2 Inductor component dimensions

Chip Precision wire - wound Molded

▼

IPC-782-8-3-2

IPC-SM-782

Subject

Inductors

Date

8/93

Section

8.3

Revision

Page2of4

电子技术应用　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

5.0 LAND PATTERN DIMENSIONS

Figure 3 provides the land pattern dimensions for inductors.

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 mate-rial 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)

C (mm) Y (mm)

Placement Grid

(No. Grid Elements)ref ref

160 2012 Chip 3.00 1.00 1.00 2.00 1.00 4x8

161 3216 Chip 4.20 1.80 1.60 3.00 1.20 6x10

162 4516 Chip 5.80 2.60 1.00 4.20 1.60 4x12

163 2825 Prec 3.80 1.00 2.40 2.40 1.40 6x10

164 3225 Prec 4.60 1.00 2.00 2.80 1.80 6x10

165 4532 Prec 5.80 2.20 3.60 4.00 1.80 8x14

166 5038 Prec 5.80 3.00 2.80 4.40 1.40 8x14

167 3225/3230 Molded 4.40 1.20 2.20 2.80 1.60 6x10

168 4035 Molded 5.40 1.00 1.40 3.20 2.20 8x12

169 4532 Molded 5.80 1.80 2.40 3.80 2.00 8x14

170 5650 Molded 6.80 3.20 4.00 5.00 1.80 12x16

171 8530 Molded 9.80 5.00 1.40 7.40 2.40 8x22

Figure 3 Inductor land pattern dimensions

▼

Grid

placement

courtyard

▼

IPC-782-8-3-3

IPC-SM-782

Subject

Inductors

Date

8/93

Section

8.3

Revision

Page3of4

电子技术应用　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ