Maxell - Electro Fine Forming (EF2) Technology

EF2 Technology English

What is Electro Forming?


With a surge of downsizing, the high function of the electronic equipment, as for the exact processing technique found to electronic parts, it becomes more and more important factor in an advanced technology industry.

Especially by high density integration and expansion of small electronic devices such as handheld device, high precision and high density implementation of the parts are highly demanded.

Electro Fine Forming (EF²) of Maxell have been developed as a technique corresponding to this.

It is the high precision process technology that combined "STAY LAND" which equalize electroforming density and control the board thickness freely with "PAREX" which enhance graphic mode.

Electro Forming (EF²) will take a role as the pivot of new innovation including precision electronic parts in future in various fields.


Principle of electroforming

When the metal which is to be electroformed on the anode side is put into the sulfamic acid nickel liquid at a adequate temperature, allocate matrix such as stainless steel towards the cathode side and apply electronic current, the metal of the anode side gradually melt and form the patterns with the non conductor film on the surface of matrix that become apertures.

STAY LAND technique

Stay Land Technology imeage

The volume of the electrodeposited metal in proportion to the quantity of flowing electricity and equal to electrodeposited qty per unit area.

Therefore, it is electrodeposited thinly in a large area and thickly in a small area.

Based on this principle, the electrocoating quantity can be reduced by setting Land of STAY on the part to be electroformed.

Performance cost comparison

Materials Mainly Ni·Cu (Au·Ag) All materials which can corrode Almost all materials
Aperture width
(Aspect ratio)

(Max. 2)
Less than plate thickness are impossible

(Depends on materials, a kind of the laser)
Aperture dimensional accuracy
*In the case of under 100µm of plate thickness


Plate thickness accuracy Thin product: Thin product (It is hard to obtain it.): △ Thin product (It is hard to obtain it.): △
Thick product: △ Approximately +/-5% of plate thickness (Depends on pattern) Thick product: ○ Approximately +/-5% of plate thickness Thick product: ○ Approximately +/-5% of plate thickness
Cost Thin product: Cheap
Thick product: High
Cheap A price greatly changes
(Depends on the number of the pattern)


1. Enables forming apertures smaller than board

2. Highly precise aperture dimensions (+/-5% lower than of plate thickness: Possible by specifications as for +/-1µm or less)

3. Excellent Cross-section

4. High hardness (about HV500)

5. Flexible control of plate thickness

Comparison of the production process (EF2&Etching)

Solution by the EF² technology

EF2 applications

Application of EF² of Maxell spreads broadly in a semiconductor and the electronic field.

<Applied product example of EF²>

1. Stencil

· For printing and For solder ball mounting

· Hybrid stencil for OLED

· Special 2 steps stencil "AVP stencil"

2. Lead frame

· Transcription Lead of Electroforming Method "TLEM"

3. Precision Parts

· Wafer Bumping

· Test wafer

· Nozzle/Filter for Inkjet printer

· Molding

· Precision gear

<Rule of thumb to apply EF²>

•Materials less than stock thickness 300µm that high dimensional accuracy is required by aperture width or rib width.

Page top