4-545
RF3220
Rev A1 050822
PCB Design Requirements
PCB Surface Finish
The PCB surface finish used for RFMD’s qualification process is electroless nickel, immersion gold. Typical thickness is
3
μinch to 8μinch gold over 180μinch nickel.
PCB Land Pattern Recommendation
PCB land patterns are based on IPC-SM-782 standards when possible. The pad pattern shown has been developed and
tested for optimized assembly at RFMD; however, it may require some modifications to address company specific
assembly processes. The PCB land pattern has been developed to accommodate lead and package tolerances.
PCB Metal Land Pattern
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 provided 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 bot-
tom 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.
A = 0.90 x 0.28 (mm) Typ.
B = 0.28 x 0.90 (mm) Typ.
C = 1.10 (mm) Sq.
Pin 1
B
B
B
B
B
B
A
A
A
A
A
A
C
Dimensions in mm.
1.00 Typ.
0.50 Typ.
0.50 Typ.
0.77 Typ.
0.50 (mm)
0.77 Typ.
0.50
1.00 Typ.
Figure 1. PCB Metal Land Pattern (Top View)
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