Welwyn Components LtdMicroelectronics

Why Use Microelectronics?

High Power

High FrequencyHigh 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 AviationFunction• 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 AviationFunction:• 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 FuseFunction:• 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

or 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

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Design for high reliabilityl

Low Profile, fits in motor housing l

0.7 Ohm Resistancel

Curved shape to fit in housing

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Test requirement

Duty Cycle NumberPower On Off Cycles300W 3 10 100100W 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