6

Assembly Recommendations

1. Insert the sensor package and all other electrical

components into the application PCB.

2. Wave-solder the entire assembly in a no-wash

soldering process utilizing a solder fixture. The solder

fixture is needed to protect the sensor during the

solder process. The fixture should be designed to

expose the sensor leads to solder while shielding the

optical aperture from direct solder contact.

NOTE: Sensor package does not support IR reflow

soldering process.

3. Place the lens onto the base plate. Care must be taken

to avoid contamination on the optical surfaces.

4. Remove the protective kapton tapes from the optical

aperture of the sensor and VCSEL respectively. Care

must be taken to keep contaminants from entering the

aperture.

5. Insert the PCB assembly over the lens onto the base

plate. The sensor package should self-align to the lens.

The optical position reference for the PCB is set by the

base plate and lens. The alignment guide post of the

lens locks the lens and sensor package together. Note

that the PCB motion due to button presses must be

minimized to maintain optical alignment.

6. Optional: The lens can be permanently locked to the

sensor package by melting the lens’ guide posts over

the sensor with heat staking process. Press down with

a force value of between 500gf - 1kgf to ensure good

mating between lens and sensor package. The gap

between the lens and sensor after heat stake process

must be less than 80 micron.

7. Install the mouse top case. There must be a feature in

the top case (or other area) to press down onto the

sensor to ensure the sensor and lenses are interlocked

to the correct vertical height.

8. Susceptibility of VCSEL to Delamination Failure. The

moisture sensitive component VCSEL device is not

handled in accordance with the MSL 3 requirements

an increased chance of VCSEL failure is present.

Design Considerations for Improving ESD Performance

For improved electrostatic discharge performance, typical

creepage and clearance distance are shown in the table

below. Assumption: base plate construction as per the

PixArt supplied 3D model file when use with the lens. The

lens can be sealed (i.e. glued) to the base plate. Note that

the lens material is polycarbonate and therefore, cyanoac-

rylate based adhesives or other adhesives that may dam-

age the lens should NOT be used.

Typical Distance

In millimeters (mm)

Creepage

7.12

Clearance

3.80

Figure 5. Block diagram of sensor

Sensor

NCS

SCLK

MOTION

MOSI

MISO

LASER_NEN

XY_LASER

-VCSEL

AGND

VDD3

VDD3

VDD1.8

VDDIO

DGND

+VCSEL

Image

Oscillator

LASER Drive

VCSEL

Regulatory Requirements

 Passes FCC B and worldwide analogous emission limits

when assembled into a mouse and following

PixArt

recommendations.

 Passes IEC-1000-4-3 radiated susceptibility level

when assembled into a mouse following

PixArt

recommendations.

 Passes IEC-61000-4-2 Electrostatic Discharge Immunity

Test (ESD) and provides sufficient ESD creepage/

clearance distance to withstand discharge up to 15kV

when assembled into a mouse according to usage

instructions above.

 Passes IEC/EN 60825-1 Eye Safety Class 1 when

operating with the laser output power pre-calibrated

by

PixArt Imaging without external hardware and

software control of laser current.

All rights strictly reserved any portion in this paper shall not be reproduced, copied or transformed to any other forms without permission.

PixArt Imaging Inc.