PCB Assembly Considerations
1. Insert the sensor and all
other electrical components
into PCB.
2. Insert the LED into the
assembly clip and bend the
leads 90 degrees.
3. Insert the LED/clip
assembly into PCB.
4. Wave Solder the entire
assembly in a no-wash
solder process utilizing
solder fixture. The solder
fixture is needed to protect
the sensor during the solder
process. It also sets the
correct sensor-to-PCB
distance as the lead
shoulders do not normally
rest on the PCB surface.
The fixture should be
designed to expose the
sensor leads to solder while
shielding the optical
aperture from direct solder
contact.
5. Place the lens onto the base
plate.
6. Remove the protective
kapton tape from optical
aperture of the sensor. Care
must be taken to keep
contaminants from entering
the aperture. Recommend
not to place the PCB facing
up during the entire mouse
assembly process.
Recommend to hold the PCB
first vertically for the
kapton removal process.
7. Insert PCB assembly over
the lens onto the base plate
aligning post to retain PCB
assembly. The sensor
aperture ring should self-
align to the lens.
8. The optical position
reference for the PCB is set
by the base plate and lens.
Note that the PCB motion
due to button presses must
be minimized to maintain
optical alignment.
9. Install mouse top case.
There
MUST
be a feature in
the top case to press down
onto the clip to ensure all
components are interlocked
to the correct vertical
height.
Design considerations for improved
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
Agilent supplied IGES file and
ADNS-3120-001 lens.
ADNS-3040
Power and control
VDD
AVDD
NCS
SCLK
Serial Port and Registers
GND
AGND
SHTDWN
Image Array
MOSI
MISO
MOTION
DSP
Oscillator
XY_LED
LED Drive
Typical Distance
Creepage
Clearance
LED
Millimeters
16.0
2.1
Figure 6. Block diagram of ADNS-3040 optical mouse sensor
Clip
Sensor
PCB
Lens / Light Pipe
Base Plate
Surface
Figure 7. Sectional view of PCB assembly highlighting optical mouse components
Note
that the lens material is polycarbonate and therefore, cyanoacrylate based adhesives or other adhesives that may damage the lens should
NOT
be used.
5
AGILENT [ AGILENT TECHNOLOGIES, LTD. ]
