DocID025079 Rev 2

13/17

ECMF02-2HSMX6

Recommendation on PCB assembly

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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 29. 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 is 90%.

4.2

Solder paste

1.

Use halide-free flux, qualification ROL0 according to ANSI/J-STD-004.

2.

“No clean” solder paste recommended.

3.

Offers a high tack force to resist component displacement during PCB movement.

4.

Use solder paste with fine particles: powder particle size 20-45 µm.

L

T

W

Aspect Ratio

W

T

-----

1.5

≥

=

Aspect Area

LW

×

2T L

W

+

()

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

0.66

≥

=