SMX1J

Recommendation on PCB assembly

Doc ID 16180 Rev 3

7/11

4

Recommendation on PCB assembly

4.1

Stencil opening design

1.

General recommendation on stencil opening design

a)

Stencil opening dimensions: L (Length), W (Width), T (Thickness).

Figure 14.

Stencil opening dimensions

b)

General design rule

Stencil thickness (T) = 75 ~ 125 µm

2.

Reference design

a)

Stencil opening thickness: 100 µm

b)

Stencil opening for leads: Opening to footprint ratio - between 65% and 70%.

Figure 15.

Recommended stencil windows position

L

T

W

Aspect Ratio

W

T

-----

1.5

≥

=

Aspect Area

LW

×

2T L

W

+

()

----------------------------

0.66

≥

=

550 µm

360 µm

135µm

95 µm

Footprint

Stencil window

Footprint

T=100 µm

0.83

0.55

1.72

0.62

135µm

95 µm