User Guide

PAMS
UIF Module DU8
NHB–3
Technical Documentation
Original 26/97
Page 5–3
Introduction
NOTE! UIM (User Identity Module) = SIM (Subscriber Identity Module)
DU8C UI–module ismade for HD851 project. It is used also in HD851EFR prod-
uct. UI–module is based on GSM/PCN UI–module DU8. Two capacitors pads
added for 18pF capacitors (2320041) from microphone pins to ground. Reason
why capacitors are added is noise to microphone audio in certain situations.
Also some changes are done for reability and productivity reasons. DU8C UI–
module is for NOKIA1 design. Final product use only one 18pF capacitor be-
tween microphone pins.
Technical Outline
Mechanics
The module is made from a single flexible printed circuit board – loaded with all
the parts for the User Interface Module. A flexible circuit was used for a num-
ber of reasons:
– The material is only 0.3 mm thick – so the phone’s height buildup can be
kept to a minimum.
– The Volume keys, SIM interface and microphone wiring can be folded to fit
in the phone during assembly – since the circuit is flexible.
– Connection from the UIF to the main circuit board can be made with a fold-
ing termination.
The major mechanical parts on the UIF assembly include the following:
– Display Module:– LCD, Heat seal, LCD driver TAB circuit and Light guide.
– Main Keydome assembly: Adhesive film holding 20 metal dome clickers
– Volume & Power Keydome assemblies: Adhesive film (2 films for Style 1)
holding 3 (2 + 1 for Style 1) domes for Vol Up, Vol Down & Power Key.
– Acoustic Components: microphone, speaker, buzzer.