Surface Treatment – Plating

Metallization on Hard-to-plate Materials

In response to the development of communications technology, the design of electronic products is significantly changing. Along with that, various basic materials for electronic products are being developed and started to be used to satisfy diversified requirements. We are happy to serve our customers by forming a metal film on promising materials in the field of electronics.

Inorganic materials: Glass, Ceramics
Organic materials: ABS, Liquid crystal polymer, Cycloolefin polymer, Nylon, etc.

1. Plating on Glass

Our wet plating process can be used for both wafers and panels.
Available size: Wafer ≦12", Panel ≦500mmx500mm

Since our wet plating process does not require etching of the surface of the glass, the smoothness of the glass can be maintained and fine patterns can be formed. The front and rear patterns are firmly connected through the through glass vias (TGV).

Our wet plating process enables forming a metal film on various TGV shapes in one batch. A strong conductive film can be formed even inside the TGVs with a high aspect ratio, which is difficult to realize by the dry process.

Since our wet plating process does not require etching, a conductive and/or reflection film can be formed on the inner and/or outer surface of special shape materials such as glass tubes.

Our wet plating process enables forming of a uniform conductive film on resin powder and glass powder of several μm to tens of μm in diameter.

2. Metallization (Plating) on Ceramics

Plating of Ni/Sn, Ni/Au, Ni/Ag, etc. is available on the Ag-metallized (printed) ceramics.

Proven Applications

Touch panel

Interposer

Image sensor

LED

High-frequency antenna

RF device

Examples of Promising Applications

5G remote (online) surgery

5G vehicular communication

Plating on Minute and Small Parts

Electronics components are being required to be downsized and multifunctional to cope with the development of smart phones, tablets, automobiles, and robots. It is also required to improve the production efficiency and quality stability of the electronics components. Koto has the technology to plate on minute parts as well as the proven barrel plating technology on small components. We are happy to receive small-lot prototype orders not to mention large quantity orders where we plate as many parts as possible at one time.

Plating type

Nickel Plating

Features ・Whitish silver finish
・High corrosion resistance
・Proper hardness (Matte: approx. HV 200, Semi-bright or bright finishes: approx. HV 500)
・Stress: Normally, tensile stress
・Changes in bath composition, additive concentration, and electrolysis condition can add flexibility to and reduce stress in films. Films can have a wide range of physical and mechanical properties.
Bath types ・Matte nickel plating bath (Watts bath)
・Semi-bright nickel plating bath (Watts bath)
・Wood's nickel strike bath
・Nickel sulfamate bath
Process of manufacture ・Barrel plating
・Rack plating
Uses Corrosion prevention and undercoat for gold plating for the hermetic seals (steels) used in electronics components for automobiles, aircrafts and pressure sensors.

Gold Plating

Features Gold plating in general
・High corrosion resistance
・Good electrodeposition property
・Low contact resistance, Good electrification characteristic, Easy soldering
・Hard gold plating
 Au:99.7%, Approx. Hv 200, Good wear resistance
・Soft gold plating
 Au:99.99%, Approx. Hv 80, Good bondability
Bath types ・Strike gold plating (Acid bath)
・Hard gold plating (Acid bath, For contact materials and connectors)
・Soft gold plating (Middle bath, For bonding)
Process of manufacture ・Barrel plating
・Rack plating
・Selective gold plating using in-house-designed machine
Uses Bonding of hermetic seals used in electronics for automobiles, aircrafts and pressure sensors as well as finish plating for connectors.
In-house-designed selective gold plating machine is used for plating.

Copper Plating

Features ・High corrosion resistance
・Soft and easily spreadable
・High conductivity of heat and electricity
・Widely used as an undercoat for various platings
Bath types ・Strong alkaline bath
・Acid bath
・Pyrophosphate bath
Process of manufacture ・Rack plating
・Barrel plating
・Hook plating
Uses Copper plating is widely used for various materials. A suitable bath type will be selected according to the usage. Copper plating can be used for the materials of electronic substrates and to improve designability.

Electroless Nickel Plating

Features ・Unlike electroplating, power supply not needed
・Contact on a substrate not needed
・Uniform deposition
・High coating hardness, Good wear resistance
(After Ni-P plating: Approx. Hv 500, After heat treatment: Approx. Hv 1000, After Ni-B plating: Approx. Hv 700 to 800)
・Less pinholes than those by electroplating
・Stress: Normally, compressive stress
・Good solderability and bondability (Ni-B)
Bath types ・Electroless nickel-phosphorus plating bath (Middle phosphorus bath)
・Electroless nickel-boron plating bath
・Electroless nickel-phosphorus plating bath (Lead-free bath)
・Electroless nickel-boron plating bath (Lead-free bath)
Process of manufacture ・Barrel plating
・Rack plating
・Others
Uses Corrosion prevention and undercoat for gold plating for the hermetic seals used in electronics components for automobiles, aircrafts and pressure sensors.

Electroless Gold Plating

Features ・High corrosion resistance
・Good electrodeposition property
・Low contact resistance, Good electrification characteristic, Easy soldering
・Electric contact not needed
・Applicable to the high-density wiring of electronic components
Bath types ・Displacement electroless gold plating bath
・Thick plating type displacement electroless gold plating bath
・Autocatalytic electroless gold plating bath
Process of manufacture ・Barrel plating
・Rack plating
・Others
Uses Plating on the connectors of direct view filament display for aerospace.

Tin Plating

Features ・Good solderability
・Bath type selectable corresponding to material
・High lubricity
・Environmentally friendly, Compliant with applicable laws and regulations
・Less likely to develop whiskers
Bath types ・Neutral tin plating bath
・Acidic tin plating bath
Process of manufacture ・Barrel plating
Uses Plating on the contacting points of capacitors and inductors.

In addition to the above types of plating, solder plating and Ag plating are available. We are happy to suggest you the best plating options to respond to your requirements.

Processing Line, Equipment, Analysis

Our equipment and plating line can handle your requirements from beaker testing for a small amount of sample material to plating on a large material.

Analysis, Inspection

List of Equipment and Facility
Film hardness tester / Adhesion strength tester / Particle counter / Pilot line / Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) / Scanning Electron Microscope (SEM) / Digital microscope / High Accelerated Stress Test (HAST) chamber / Solder checker / X-ray fluorescence film thickness meter / He leak detector / Cyclic Voltammetry Stripping (CVS) analyzer / Spectrophotometer / High power UV irradiation equipment / Box furnace

Click here for inquiries about each department and product