Inductive Components


5. Planar Transformer


Feature

Low leakage inductance and low winding AC resistance are more easily achievable; High consistency between components, the low profile nature.


Application

There are mechanical benefits that aid the development of more efficient power converter products; be ideal for many power circuit applications; high current connections can be made more easily.

General Technical Data

Transformers can be produced for all types of SMPS circuits. Other electrical characteristics can be supplied on request.

Input voltage: 12 VAC to 240/400 VAC
Output voltage: 3 VDC to 60 VDC
Rating: up to 5000 W
Frequency: 50 kHz to 1 MHz
Efficiency: typically 98%
Insulation: 4 kV (prim.-to-sec.)
Safety margins: 6 to 8 mm (prim.-to-sec.)
Ambient temperature: -40℃to + 130℃
Weight: from 23g for 100W power output
Height: from 10 mm
Multilayer: up to 20 layers, typical 8-12 layers


Production

The way how ECL makes and tests the planar transformer in production:
1) Place pins to the assembly fixture;
2) Put the lower halve of the core to the assembly fixture;
3) Put the PCB assembly;
4) Close the assembly fixture;
5) Solder the pins and the PCB assembly;
6) Put the upper halve of the core;
7) Close the assembly fixture;
8) Curing;


Test Requirement

Other than the traditional inductance, leakage, capacitance and hipot tests, the followings are additional tests for planar transformers:
1) Co-planarity Check (usually < 0.004")
2) Thermal Shock (depends on customer requirement)
3) Solderability
4) IR Reflow Test