Welwyn Components Ltd Microelectronics Why Use Microelectronics? - - PDF document

Welwyn Components Ltd Microelectronics

Why Use Microelectronics?

High Power High Frequency High Density & Reliability Power & Control Braking resistors/Heaters

Thick Film Ink Systems

• Printing – Firing - Lasering
• Gold, Silver, High and low Temperature

Copper.

• Resistor Printing directly in circuit.
• Aspect ratio to 0.1mm track and gap width,

+/- 0.03mm registration.

• Automatic printing machines cassette to

cassette process.

• Automatic Laser trimming and continuity

testing.

• Clean-room facility operating on 3 shifts.

Thick Film Circuit

• Substrates
• Thick film on 96% alumina or

aluminium nitride

• Directly bonded copper (DBC)
• Active metal braise on aluminium

nitride & silicon nitride

• High/Low temperature co-fired

ceramic (HTCC/LTCC)

• Steel
• Aluminium
• Thin film
• FR4

Technologies

• Component Attach
• Solder Surface Mount
• Polymer Component and die attach
• Vacuum soldering (Power Die Attach)

upto 400oC

• Wire Bonding
• Fine wire Au 17um to 33um
• Fine wire Al 25um to 33um
• Large diameter Al >125um
• Packaging
• Hermetic sealing
• Projection weld & Seam Seal
• Ceramic lidding
• Glob-top / Silicon conformal coat

Technologies

• Clean-room assembly operations.
• Automated die bonding and wire bonding

by pattern recognition.

• Re-flow soldering and real time x-ray for

void detection.

• Aluminium fine wire bonding for high

density signal and control circuits.

• Large diameter Aluminium wire bonding

for power circuits.

• Hermetic sealing in inert atmosphere.
• Leak detection.
• Automatic test facilities.

Microelectronics Assembly

Test, Burn-In and Screening Facilities.

Test

• Two General Purpose ATEs in Chip&Wire Clean Room.
• One reduced capability, DC only, ATE.
• One General Purpose ATE for one high volume product.
• Two ATEs for surface mount hybrids.
• One tray pack system – measure, accept/reject, pack.
• One PIC program/test XYZ system.

Screening:

• Temperature cycling
• Constant acceleration
• Burnin
• Fine & Gross Leak Test
• Pin D
• Bump
• Limited range vibration

Characteristics

• High Temperature Co-fired Ceramic

(HTCC)

• Chip and Wire (>1000 bonds)
• High Density – Reduced size and

Weight

• Hermetically sealed
• Engine mounted
• Qualified –55oC to +150oC
• Extended high temperature approval

testing –55oC to +205 oC.

• Completed 1000 hours +205oC
• Completed 100 cycles –55oC to 205 oC

Function

• Engine management (FADEC)
• Custom ASIC - CPU, SRAM, EPROM,

Oscillator

• Hi Reliability >20yrs life

MCM Engine Management

MCM (Linear) Engine Management – Civil Aviation

Function

• 3 Precision instrumentation

amplifiers

• High common mode rejection
• Precision gain
• 3 Precision voltage references
• General purpose comparator

Characteristics

• High operating temperature -55oC to +150oC
• Engine mounted
• Thin Film provides high accuracy and stability.
• Active Trimming to <0.01% tolerance.
• High precision and accuracy achieved with low cost Commercial Off

The Shelf Components.

• Easily redesigned if amplifiers or reference become obsolete

DC/DC Converter – Civil Aviation

Function:

• 3 Fixed DC Outputs from 14 to

36VDC

• 28 Watts
• Flight computer System
• Self Monitoring
• Self Diagnostics

Characteristics:

• Mixed power and control circuits.
• High reliability >20 years life proven through extreme temperature

cycling (>3,000 cycles) and HALT testing.

• Operating temperature -40oC to +95oC
• High packing density.
• Relatively low cost.

Safety Critical Fuse

Function:

• 10 amps continuous current carrying capacity
• Fuse activation by external contol
• Fusing time <5 second @ -40oC to +110oC

Current applications:

• Wing ice protections system, heater circuit protection (787

Dreamliner)

• Engine de-icing (Joint Strike Fighter) heater protection

Power MCM – Civil Aviation

Function

• Part of Wing Ice Protection System
• Switching controls power to wing tip
• r engine heaters (up to 5 amps

continuous without heatsinking).

• Used in conjunction with thick film

solder fuse protection device Characteristics

• Each module contains 8 MOSFETs with low Rdson (<138m Ohm)
• High packing density and low assembly cost (35mm x 20mm)
• Good thermal management
• High reliability

Sonar Transducer Power Driver – Naval Systems

Function

• H Bridge MOSFET Switch to

control power to sonar antenna

• Intelligent switch with ASIC control

and MOSFET drivers. Characteristics

• Each module contains 4

MOSFETs with low Rdson, drivers and control ASIC

• Uses mixed technologies
• Good thermal management
• High reliability

Flight Controls

• Steel Dynamic Braking Resistors
• For Aileron, Elevator and Rudder Actuation
• Increased power dissipation by the use of bottom and top

heatsinking

• Low profile, Low Weight
• Design-ins on:
• Airbus A400M
• A330 MRTT
• Boeing 787 EBACS

Power Resistor – Motor Speed Control

l

Design for high temperature environment

l

Design for high reliability

l

Low Profile, fits in motor housing

l

0.7 Ohm Resistance

l

Curved shape to fit in housing

l

Test requirement

Duty Cycle Number Power On Off Cycles 300W 3 10 100 100W 10 10 50,000

AlN Heater – Toner Fusing

Function:

• Instantaneous heating with individual

control of 3 discrete segements

• 210°C in 2 seconds (1kW)
• Precision Temperature Control

Characteristics:

• Large size printing
• AlN
• Hi thermal Conductivity
• Resistance to thermal shock
• Developed Inks with Fraunhofer Institute

Hi Frequency Telecommunications

Function:

• Frequencies up to 38GHz
• Hi Reliability
• Direct feed to antenna
• Small Package size

Characteristics:

• Low loss at high frequency
• Gold based ink
• 0.38mm thick substrate down to 0.1% tolerance
• Good thermal management
• Precise track definition

Automotive – Mass air-flow sensor

Industrial – Ink jet print head

Military & Avionics

Industrial – Power module