THE IDEAL CAPACITOR
The non-ideal characteristics of a real capacitor can be ignored at low
frequencies. Physical size imparts inductance to the capacitor and
dielectric and metal electrodes result in resistive losses, but these often
are of negligible effect on the circuit. At the very high frequencies of radio
communication (>100MHz) and satellite systems (>1GHz), these effects
become important. Recognizing that a real capacitor will exhibit inductive
and resistive impedances in addition to capacitance, the ideal capacitor for
these high frequencies is an ultra low loss component which can be fully
characterized in all parameters with total repeatability from unit to unit.
Until recently, most high frequency/microwave capacitors were based on
fired-ceramic (porcelain) technology. Layers of ceramic dielectric material
and metal alloy electrode paste are interleaved and then sintered in a
high temperature oven. This technology exhibits component variability in
dielectric quality (losses, dielectric constant and insulation resistance),
variability in electrode conductivity and variability in physical size (affecting
inductance). An alternate thin-film technology has been developed which
virtually eliminates these variances. It is this technology which has been fully
incorporated into Accu-P® and Accu-P® to provide high frequency capacitors
exhibiting truly ideal characteristics.
The main features of Accu-P® may be summarized as follows:
• High purity of electrodes for very low and repeatable ESR.
• Highly pure, low-K dielectric for high breakdown field, high insulation
resistance and low losses to frequencies above 40GHz.
• Very tight dimensional control for uniform inductance, unit to unit.
• Very tight capacitance tolerances for high frequency signal
applications.
This accuracy sets apart these Thin-Film capacitors from ceramic capacitors
so that the term Accu has been employed as the designation for this series
of devices, an abbreviation for “accurate.”
THIN-FILM TECHNOLOGY
Thin-film technology is commonly used in producing semiconductor devices.
In the last two decades, this technology has developed tremendously, both
in performance and in process control. Today’s techniques enable line
definitions of below 1μm, and the controlling of thickness of layers at 100Å
(10-2μm). Applying this technology to the manufacture of capacitors has
enabled the development of components where both electrical and physical
properties can be tightly controlled.
The thin-film production facilities at KYOCERA AVX consist of:
• Class 1000 clean rooms, with working areas under laminar-flow hoods
of class 100, (below 100 particles per cubic foot larger than 0.5μm).
• High vacuum metal deposition systems for high-purity
electrode construction.
• Photolithography equipment for line definition down to 2.0μm
accuracy.
• Plasma-enhanced CVD for various dielectric depositions
(CVD=Chemical Vapor Deposition).
• High accuracy, microprocessor-controlled dicing saws for
chip separation.
• High speed, high accuracy sorting to ensure strict tolerance adherence.
ACCU-P® TECHNOLOGY
The use of very low-loss dielectric materials, silicon dioxide and silicon
oxynitride, in conjunction with highly conductive electrode metals results
in low ESR and high Q. These high-frequency characteristics change
at a slower rate with increasing frequency than for ceramic microwave
capacitors.
Because of the thin-film technology, the above-mentioned frequency
characteristics are obtained without significant compromise of properties
required for surface mounting.
The main Accu-P® properties are:
• Internationally agreed sizes with excellent dimensional control.
• Ultra small size chip capacitors (1005) are available.
• Ultra tight capacitance tolerances.
• Low ESR at VHF, UHF and microwave frequencies.
• Enhanced RF power handling capablity.
• High stability with respect to time, temperature, frequency and voltage
variation.
• Nickel/solder-coated terminations to provide excellent solderability
and leach resistance.
ACCU-P® FEATURES
Accu-P® meets the fast-growing demand for low-loss (high-Q) capacitors for
use in surface mount technology especially for the mobile communications
market, such as cellular radio of 450 and 900 MHz, UHF walkie-talkies, UHF
cordless telephones to 2.3 GHz, low noise blocks at 11-12.5 GHz and for
other VHF, UHF and microwave applications.
Accu-P® is currently unique in its ability to offer very low capacitance values
(0.05pF) and very tight capacitance tolerances (±0.01pF).
• The RF power handling capability of the Accu-P® allows for its usage in
both small signal and RF power applications.
• Thin Film Technology guarantees minimal batch to batch variability of
parameters at high frequency.
• Inspection test and quality control procedures in accordance with
ISO 9001, CECC, IECQ and USA MIL Standards yield products of the
highest quality.
• Hand soldering Accu-P®: Due to their construction utilizing relatively
high thermal conductivity materials, Accu-P’s have become the
preferred device in R & D labs and production environments where
hand soldering is used.
APPLICATIONS
• Cellular Communications
• CT2/PCN (Cordless
Telephone/Personal Comm.
Networks)
• Satellite TV
• Cable TV
• GPS (Global Positioning
Systems)
• Vehicle Location Systems
• Vehicle Alarm Systems
• Paging
• Military
Communications
• Radar Systems
• Video Switching
• Test & Measurements
• Filters
• VCO’s
• Matching Networks
• RF Amplifiers
012521
Thin-Film RF/Microwave Capacitor Technology
Thin-Film Technology
Accu-P® Series
APPROVALS
• ISO 9001
• IATF 16949:2016