Fundamental Technology


Functional Film Formation

Functional films including resistive film, sensor film, electrode and protective films are formed with film-forming methodologies such as screen printing, sputtering, CVD, non-electrolytic & electrolytic plating combined with our proprietary material blending ratios.
We are capable of forming nickel-chrome ultra-high-precision film and platinum film which is used in high-precision temperature sensors.

Electrical discharge observed in sputtering

Product design

Thermal Design

When an electrical current flows, resistors generate heat.
For the use in high-temperature environment and when applying high power, the construction of the component has to be designed in consideration of heat resistance and heat dissipation properties, which we do by employing materials with high heat-resistance characteristics and establishing heat dissipation paths.
Also, we conduct simulations to analyze the heat generation under transient phenomena such as inrush current to design product construction in consideration of dynamic characteristics.

Microstructural design

In addition to designing microscopic patterns with photolithography technology, we also use high-precision screen printing to create fine patterns.
Additionally, we possess technologies for designing and fabricating multilayered structure of fine-line patterns within an LTCC substrate.
These technologies are also utilized in the manufacturing of 0201mm-size micro miniature chip resistors.


Package Design

For the purpose of properly protecting functional layers electrically, mechanically and environmentally, just like IC package, it is possible to encapsulate multiple elements in a package with the use of thermoset resin or thermoplastic resins.
Packaged products featuring metal terminals have the advantage of exhibiting high reliability characteristics under temperature cycle tests.

High-density Mounting

With the use of an LTCC substrate as an interposer or a package, elements developed by customers can be embedded within the substrate.
For the high-density placement of electronic components, we use highly integrated mounting package using glass-epoxy substrates, alumina substrates and LTCC substrates. As terminals, SOP, BGA and LGA are available. We also have the capability to downsize multi-chip modules (MCM).


Accelerated Tests

We are determining the life prediction of our products with the use of constant-temperature bath, constant-temperature constant-humidity bath, pressure cooker, thermal shock device, etc.
Also we possess the technology to predict with accelerated tests the changes in product characteristics under exposure to severe temperature and humidity conditions.
In addition, we possess unique knowhow for accelerated tests to evaluate anti-sulfur characteristics.

Chemical・Physical Analysis

To ensure compliance to the RoHS regulations, despite being an electronic components manufacturer, we have a testing and calibration laboratory accredited with ISO/IEC17025, which enable us to internally analyze RoHS 6 substances and issue certifications.
We possess a wide range of physical analysis devices such as FIB-SEM(*1), X-ray CT(*2) and ICP-AES(*3) to allow us to analyze characteristics of products and materials and conduct failure analysis.

  1. This is a device to cut out a microscopic area then observe and analyze it.
  2. This is a device to three-dimensionally observe the inside of a test specimen with an X-ray.
  3. This is a device to measure infinitesimal amounts of element content inside of a test specimen.

Observation of a cross section of the interface between nickel and copper layers after being cut and processed with FIB (Upper layer is copper.)


Multi-cavity Structure/Dimensional Precision

Excellent shrinkage control in sintering process makes the creation of high-precision multistage cavities possible to realize sensor package and interposer.
To achieve even greater dimensional precision, polishing of the top and end surfaces are the options we can offer.



Temperature Measurement

For temperature measurement, there are contact methods like thermocouple and non-contact methods like thermography to discern in-plate temperature distribution. To correctly measure the temperature of a small area, optimization of wire diameter of thermocouple and lens resolution of thermography is necessary. KOA has accumulated a variety of know-how for temperature measurement.

1005mm chip resistor and thermocouple

Resistance Measurement

For measuring resistance values, 2-terminal and 4-terminal methods are well-known. But for the measurement of ultra-low-value, ultra-high-value and miniature resistors, insulation properties of terminal cable, the layout of measuring terminals, and measuring environment (e.g. humidity and noise) greatly influence the results.
We have the capability to establish a system of precisely measuring resistance values suited to each product.


Materials Formulation

We are capable of designing materials that enable resistors to deliver prescribed ohmic values, temperature coefficient of resistance, and durability and environmental characteristics.
Our proprietary materials technologies allow our LTCC substrates to achieve high dimensional precision.

Green sheet, which is the base material for LTCC substrate

Material development

Resistive materials developed in-house realize current-sense resistors with low temperature coefficient of resistance and temperature sensors and resistors with superior anti-surge properties.
Our materials developed in-house make possible varistors high in Maximum energy and low in leakage current.