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RF3855

DS110914

7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical

support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.

PCB Solder Mask Pattern

Liquid Photo-Imageable (LPI) solder mask is recommended. The solder mask footprint will match what is shown for the PCB

Metal Land Pattern with a 3mil expansion to accommodate solder mask registration clearance around all pads. The center-

grounding pad shall also have a solder mask clearance. Expansion of the pads to create solder mask clearance can be pro-

vided in the master data or requested from the PCB fabrication supplier.

Thermal Pad and Via Design

The PCB metal land pattern has been designed with a thermal pad that matches the exposed die paddle size on the bottom of

the device.

Thermal vias are required in the PCB layout to effectively conduct heat away from the package. The via pattern has been

designed to address thermal, power dissipation and electrical requirements of the device as well as accommodating routing

strategies.

The via pattern used for the RFMD qualification is based on thru-hole vias with 0.203mm to 0.330mm finished hole size on a

0.5mm to 1.2mm grid pattern with 0.025mm plating on via walls. If micro vias are used in a design, it is suggested that the

quantity of vias be increased by a 4:1 ratio to achieve similar results.

Pin 1

Dimensions in mm.

A = 0.71 x 1.09 (mm) Typ.

B = 1.09 x 0.71 (mm) Typ.

C = 1.73 (mm) Sq.

A

A

A

A

A

B

B

B

A

A

A

A

A

B

B

B

C

3.20 Typ.

0.81 Typ.

0.81 Typ.

1.73 Typ.

0.94 Typ.

1.73 Typ.

1.60 Typ.

0.81 Typ.

1.60 Typ.

Figure 2. PCB Solder Mask (Top View)