Welwyn Components Ltd Microelectronics Why Use Microelectronics? - PDF document

Welwyn Components Ltd Microelectronics

Why Use Microelectronics? Braking resistors/Heaters Power & Control High Power High Density & Reliability High Frequency

Thick Film Circuit 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.

Technologies  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

 Component Attach Technologies  Solder Surface Mount  Polymer Component and die attach  Vacuum soldering (Power Die Attach) upto 400 o C  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

Microelectronics Assembly  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.

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

MCM Engine Management Characteristics  High Temperature Co-fired Ceramic (HTCC)  Chip and Wire (>1000 bonds)  High Density – Reduced size and Weight  Hermetically sealed Function  Engine mounted • Engine management (FADEC)  Qualified –55 o C to +150 o C • Custom ASIC - CPU, SRAM, EPROM,  Extended high temperature approval Oscillator testing –55 o C to +205 o C. • Hi Reliability >20yrs life  Completed 1000 hours +205 o C  Completed 100 cycles –55 o C to 205 o C

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 -55 o C to +150 o C • • 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 -40 o C to +95 o C • 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 @ -40 o C to +110 o C • 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 Design for high temperature l environment 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 l 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