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Manufacturing process based on the Pure Additive™ processing


This is the polyimide film used in our substrates.

Special surface treatment has been applied to the polyimide film, making it highly adhesive to our silver ink.

Vastly more heat-resistant when compared to our existing heat-resistant PET film, it allows for the use of conventional lead-free solder and solder paste for parts mounting. Also, using a 25µm substrate, its flex resistance and minimum bending radius are improved over that of the existing 50µm substrate PET.

Our existing heat-resistant PET substrate will remain available in two thicknesses: 50µm and 125µm.

フレキ基板 製造工程 フィルム


A process in which silver ink is printed and the silver ink layer is formed.

By adopting an industrial inkjet printer capable of roll-to-roll printing, silver ink is ejected with high precision as an undercoat layer. The minimum line width/line spacing is 200/200μm as standard but can be pushed to 200/150μm as an option.

From small to large lots, the required quantity can be manufactured rapidly as there is no need for plate-making.


R&D purpose inkjet device (video)
フレキ基板 製造工程 印刷


A process in which heat treatment is applied to the silver ink layer.

The bond between silver particles in the silver ink is weak when printed, making it unsuitable as a base layer for plating.

This is why we apply our own unique heat treatment to strengthen the bond of the silver particles, forming a strong base layer.

A process in which heat treatment is applied to the silver ink layer.


A process in which a copper layer is formed over the silver ink.

At Elephantech, we have established a technology that forms a copper thick-film layer over a silver ink foundation.

When compared to a simple silver ink layer, adding a copper thick-film layer can lower the electrical resistance by more than 2 digits and also enables conventional soldering*.

Automatic plating processing line (Video)
Automatic plating processing line

Solder resist

A process in which the soldermask for the flexible PCB is formed.

Soldermasks are used during soldering to prevent the solder from spreading to unnecessary areas and to maintain insulation between circuits.

By using an industrial purpose inkjet printer that doesn't require plate-making and a special soldermasking ink, the soldermask layer formation process can flexibly handle both rapid prototyping and mass production.

フレキ基板 製造工程 レジスト ピュアアディティブ

Open/short test

We use an equipment called the flying probe to conduct our open/short tests. Two contact pins are moved at high speed to verify that the terminals are connected and that any unintended parts aren't connected. The quality of the product is evaluated by comparing the results with the readings from the circuit board.

A flying probe tester is used for this open short test too, making the tests highly reliable.

Flying probe (Video)
A flying probe tester is used for this open short test too, making the tests highly reliable.


A process in which a circuit is cut out from a rectangular film substrate in a specified shape.

Using our own high-precision alignment technology and shrinkage correction technology during the cutting process, we are able to provide extremely high cut repeatability.

Laser cutting (video)
Laser cutting (video)


The inspection that follows the cut is our final inspection and we check for breakage, short circuits, scratches, and any misalignment of more than 0.2mm between solder mask and pattern.

Other than this final inspection, there are various inspections all along the manufacturing process such as checking for the presence of spreading or chipping in the printed pattern or whether the plating thickness is as specified.

フレキ基板 製造工程 検品


Finished boards are put into bags according to pattern.

フレキ基板 製造工程 発送

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Shifting from "dissolving unnecessary parts" to "printing onto necessary parts"

P-Flex® is a single-face flex PCB manufactured using the Pure Additive™ method. Conventionally, electronic circuits have been manufactured by applying a method known as lithography, in which a thin metallic sheet is first applied to the board surface, and then unrequired sections are melted away.


The Pure Additive™ method (*) developed by Elephantech is a concept completely opposite to what had been used until now, using a proprietary manufacturing technology that prints metal nanoparticles with inkjet only on the necessary parts and grows metals by electroless plating technology.
(* Patent No. 6300213)

Taking the example of printed circuit boards, the conventional manufacturing method was an extremely long process in which copper foil is manufactured, laminated with film (production of CCL), and laminated with photosensitive materials before the desired copper pattern is achieved by dissolving and discarding the copper foil from unnecessary parts by exposure, development and etching.

Our process achieves the desired copper pattern by printing the metal onto film and growing it, not only forgoing the need for copper foil manufacturing and CCL manufacturing processes but also eliminating the need for the etching process to dissolve and discard the copper foil.

By reducing the amount of metal, liquid waste and man-hours, we can lessen manufacturing costs and shorten the lead time.
Elephantech will continue to reduce its environmental burden and contribute to the achievement of SDGs.

P-Flex® manufacturing specifications
Substrate Transparent heat-resistant PET film: 50 µm thick, 125 µm thick
PI (Polyimide) film: 25 µm thick
Line width / spacing 200/200 μm min., 200/150 μm min. (option)
Hole diameter 0.5 mm min.
Outline-pattern spacing 0.3 mm min.
Copper foil thickness 3 μm (please consult us if you require a thickness of more than 3 µm)
Panel size 180 × 270 mm max.
Wiring layer Single-sided
Soldermask coating UV inkjet printing (green) (waterproof graded soldermask coating is possible for special items)
Transparent, black and white soldermask coatings by silkscreen printing for PET substrate are also under development and may be available upon request.
Legend printing UV inkjet printing (white)
Surface finish Oxidation prevention treatment, Electroless nickel gold plating (option)
Outline cutting / Hole drilling Laser cutting
Stiffeners When specifying the thickness of the connector part, film stiffeners can be used to adapt to connectors of 200 µm or 300 µm in total thickness.
Component mounted parts and such can be adapted by using FR4 stiffeners of 0.1, 0.3, 0.5, 1.0, and 1.6mm in thickness.
Other stiffeners, electromagnetic wave shield film, double-sided tape and such are also available.
Inspection Visual inspection + opens/shorts test
contact us

Company information
Name Elephantech Inc.
Establishment January 2014
Address 4-3-8 Hatchobori, Chuo-ku, Tokyo 104-0032, Japan
Capital JPY 310,000,000
Representative Shinya Shimizu, CEO
Business description Development of printed electronics manufacturing technology and provision of related services