Si510/511

Rev. 1.2

21

10. PCB Land Pattern: 3.2 x 5 mm, 4-pin

Figure 9 illustrates the 3.2 x 5 mm PCB land pattern for the Si510/511. Table 19 lists the values for the dimensions

shown in the illustration.

Figure 9. Si510/511 PCB Land Pattern

Table 19. PCB Land Pattern Dimensions (mm)

Dimension

(mm)

C1

2.60

E2.54

X1

1.35

Y1

1.70

Notes:

General

1.

All dimensions shown are in millimeters (mm) unless otherwise noted.

2.

Dimensioning and Tolerancing is per the ANSI Y14.5M-1994 specification.

3.

This Land Pattern Design is based on the IPC-7351 guidelines.

4.

All dimensions shown are at Maximum Material Condition (MMC). Least Material Condition

(LMC) is calculated based on a Fabrication Allowance of 0.05 mm.

Solder Mask Design

5.

All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder

mask and the metal pad is to be 60 µm minimum, all the way around the pad.

Stencil Design

6.

A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be

used to assure good solder paste release.

7.

The stencil thickness should be 0.125 mm (5 mils).

8.

The ratio of stencil aperture to land pad size should be 1:1.

Card Assembly

9.

A No-Clean, Type-3 solder paste is recommended.

10.

The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for

Small Body Components.