CMA3000 Assembly Instructions

5

Printed Wiring Board (PWB) Level Guidelines

5.1

PWB layout

Two types of land patterns are generally used for surface mount packages:

1) Non-Solder Mask Defined Pads (NSMD)

2) Solder Mask Defined Pads (SMD).

NSMD pads have an opening which is larger than the pad itself, and SMD pads have a solder

mask opening that is smaller than the metal pad on PWB. NSMD is preferred since the copper

etching process has tighter process control compared to the solder mask process and less solder

mask originated defects. Symmetrical pad and trace designs on the CMA3000 component PWB

area are highly recommended as those would guarantee an optimal component performance.

Moreover, traces should not be routed beneath the CMA3000 component, but to use ground plane

instead in order to optimize immunity to noise coupled from signal lines. Recommended PWB land

pattern and dimensions for the CMA3000 component are presented in Figure 8. Reference layouts

are presented in corresponding product family specifications:

CMA3000 D0X_Product_Family_Specification_8281000 and

CMA3000-A0X_Product_Family_Specification_8282100.

Solder Pad

Copper Pad

Solder Mask

Opening

Trace Width

Non-Solder-Mask

Defined (NMSD)

275 µm

(+0, -25 µm)

375 µm

(+0, -25 µm)

100 µm

(±25 µm)

Figure 8.

Recommended PWB pad layout and dimensions for CMA3000 component.

Subject to changes

TN68

9/18

Rev.09

PRELIMINARY

VTI Technologies Oy

www.vti.fi