Recommendation on PCB assembly

ECMF06-6AM16

12/16

Doc ID 022284 Rev 2

5

Recommendation on PCB assembly

5.1

Stencil opening design

1.

General recommendation on stencil opening design

a)

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

Figure 19.

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 central exposed pad: Opening to footprint ratio is 50%.

c)

Stencil opening for leads: Opening to footprint ratio is 90%.

Figure 20.

Recommended stencil window position

L

T

W

Aspect Ratio

W

T

-----

1,5



=

Aspect Area

LW



2T L

W

+



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

0,66



=

180 µm

200 µm

10 µm

30 µm

Stencil window

Footprint

0.40

0.60

0.20

3.00

1.75