Thin Film Circuits

Features

A thin film circuit is fabricated by sputtering, photolithography, plating as well as other standard semiconductor process. Film resistor, film inductor, film conductor and other distributed circuit components are integrated in one ceramic substrate. The features of the thin film circuits are as follows:

  • High integrity and small size
  • High precision of the line, excellent component performance
  • Excellent temperature and frequency characteristic, working frequency up to millimeter wave band

Applications

  • Communications applications: Microwave & millimeter wave communications, Optical communications and Telecommunications
  • LED power lighting applications
  • Sensors applications
  • Medical imaging applications
  • Biotech applications

Product types

Lange couplers            Power dividers             Filters       

Transmission line         Circulators                   Isolators

 Resistors                     Attenuators                  Heat sinks

Overview

Product metal layers

Thin Film Fabrication Technology

Al2O3 , AlN, BeO, Sapphire, quartz and hi-K dielectrics
 Wide selection of material and metallization
 Accurately controlled dimensions and tolerances
 Hollow plated vias
 Plating and etching facilities
 Extensive dicing and laser machining facilities

Substrate Type and Specifications

Substrate MaterialPurityA Surface
Roughness
B Surface
Roughness
Dielectric
Constant
Thermal
Conductivity
Dissipation Factor
(Loss Tangent)
%µ"µ"@1MHzW/mK@1MHz
Asfired Alumina (Al2O3)99.6339.9±126.90.0001
Polished Alumina (Al2O3)99.611 or 129.9±126.90.0001
Aluminum Nitride (AlN)98338.61700.0001
Beryllium Oxide (BeO)99.53106.52700.0004
Sapphire (A/C plane—Al2O3)1001110-0.00086
Quartz (SiO2)100114.4-1.5E-5

Metalizations

Metallization
System
Applicationcomponent
Attachment
Method
Typical
thickness range
Max. use
temperature
TiW(Ti)/Pt/AuStandard thin film metal
system for conductors
Au/Sn,Au/Si,
Au/Ge
Eutectic;Epoxy
TaN:25–100Ω /sq
TiW(Ti):500–800Å
Au:0.5–5µm,
typical = 3µm
425℃
TaN/TiW(Ti)/AuStandard thin film metal
system for conductors with
resistor layer
380℃
TiW(Ti)/Ni/AuConductor applications that
require Pb/Sn soldering
Au/Sn,Au/Si,
Au/Ge
Eutectic;Pb/Sn;
Epoxy
TaN:25–100Ω /sq
TiW(Ti):500–800Å
Ni:1000–10000Å
Au:0.5–5µm,
typical = 3µm
350℃
TaN/TiW(Ti)/Ni/AuConductor with resistor layer
applications that require
Pb/Sn soldering
350℃
TaN/TiW (Ti)/Au/
Cu/Ni/Au
High current &low loss
applications
Au/Sn,Au/Si,
Au/Ge
Eutectic;Pb/Sn
TaN:25–100Ω /sq
TiW(Ti):500–800Å
Au:0.2–1µm
Cu:0.5–12µm
Ni:0.5–2µm
Au:0.5-5µm
350℃

Standard Dimensions and Tolerance

*Aspect ratio is defined as: Dv/Ts. Where
Dv = Diameter of the via (thru hole)
Ts = Thickness of the substrate

ProjectSpecificationsTypical
Imperial unitsThe Metric System
FeaturesOverall circuit size tolerance:±1mil±25µm
Diced features:±1mil±25µm
Minimum distance from the diced edge:1mil25µm
Laser machined features:±2mil±50µm
Minimum distance from the laser
machined edge:
2mil50µm
ConductorMinimum line width:0.8mil20µm
Minimum gap:0.4mil10µm
Dimensional tolerance on critical areas:±0.1mil±2.5µm
Dimensional tolerance on noncritical
areas:
±0.2mil±5µm
Metal thickness tolerance:±20%
ResistorMinimum length and width of resistors2×2mil50×50µm
Resistor tolerance:±10%/±5%/±1%
Watts density:≥3.8mW/mil2≥6W/mm2
Vias*Via hole diameter aspect ratio: ≥0.6
Via hole diameter tolerance:±2mil±50µm
Minimum annular ring around metalized
cutout:
4mil100µm
Minimum via hole spacing:One diameter
Filled material:Hollow plated vias
Au/Cu solid filled
vias
SlotMetallization pullback:±2mil±50µm
Metalized edge wrap minimum recess:4mil100µm
Minimum radius: 2mil50µm

Photomasks Requirements

 Auto CAD .DWG or .DXF files
 Gerber photo plotter data
 DPF files
 DCF files

Documentation requirements

 Product structures with different
meanings such as conductive tapes, resistors, mounting holes, grounding holes, product outlines, etc. must be drawn using different
levels.
 Each layer of graphics must be closed without overlapping intersections and color
filling.
  Drawing ratio 1:1, unit of imperial or metric
  The following parameters are indicated in the drawings

Material & Thickness
Size of substrates
Quantity
Metal system on both sides
Sheet resistance
Tolerance of resistors
Die attach method
Tolerance of line widths