Data Sheet

ADRF5420

APPLICATIONS INFORMATION

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Rev. 0 | 13 of 14

DIE ASSEMBLY

The ADRF5420 complies with the standard RoHS reflow assembly

process and can be assembled together with other surface-mount-

ed technology (SMT) components in the same reflow cycle. The

PCB must incorporate fiduicials close to the device to get the best

pick and place accuracy.

The top copper layer of the PCB is designed for optimum RF

performance, and the solder mask and paste mask layers are

designed for optimum assembly yield. The ground pads are drawn

as solder mask defined. The signal pads are drawn as pad defined.

The same solder mask and paste mask design is used for both

pads. Alternatively, the ADRF5420 can be assembled without ap-

plying a solder paste on the PCB. If no solder paste is applied, the

device must be dipped into flux prior to placement on the PCB.

Reflow Assembly with Solder Paste

Solder mask openings of 175µm in a square shape are recom-

mended for the signal and RF pads, and solder mask openings of

150µm in a square shape are recommended for the GND pads.

Solder mask thickness must not exceed 50µm. Paste mask is

drawn circular with a 150µm diameter. Using a stencil with 2mil

thickness and no aperture reduction yields the optimum paste mask

print. The device does not need any flux dipping during the pick and

place process.

Figure 20. Recommended Footprint for Solder Paste

Reflow Assembly with Flux Dipping

Solder mask openings in a circular shape and 130µm in diameter

are recommended. Solder mask thickness must not exceed 50µm.

Solder paste is not applied. The device is dipped into flux prior to

placement on the board.

Figure 21. Recommended Footprint for Flux Dip Assembly

Assembly Durability

The device is a bumped die. The bump composition is copper (Cu)

pillar with a plated tin (Sn) and silver (Ag) solder-cap, which forms

the device interconnect to PCB when it is attached with reflow. The

integrity of the interconnect structures and solder joints are compro-

mised by the accumulated stress over temperature due to a mis-

match of the thermomechanical properties of the different materials

in the complete assembly of the user hardware. The ADRF5420

fulfills the JEDEC JED47L requirements under the JESD22-A104

Condition J (0-100C) for 2300 temperature cycles while mounted

on a 0.75mm thick laminate PCB, which is assembled using solder

paste reflow and without any underfill material applied. Users must

qualify their hardware for the environmental conditions aligned with

their end-use requirements because differences in PCB properties

and design, varied number of temperature cycles, soak and dwell

times, and changes in temperature range, can affect thermome-

chanical results. Note that using a proper underfill adhesive signifi-

cantly improves the integrity of the device assembly by reducing the

stress exposed to the interconnect structures and solder joints.