Slim Transformer Core Structure to Prevent Curing Warpage

Solution Overview

Problem

Slim transformers experience core shrinkage during the curing process of a bonding agent, leading to thickness defects and non-ideal heat generation due to the formation of gaps between core components.

Innovation Solution

The transformer design includes a core unit with upper and lower cores featuring flat plate-shaped bodies and protruding legs, where the thickness of the protruding portions is optimized relative to the body portions to maintain an optimal rear surface thickness, preventing warpage during bonding and operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the thickness of the flat plate-shaped body is reduced to secure physical cross-sectional area for windings, then the transformer achieves a slim profile, but heat generation occurs from the rear surface during operation

Engineering Contradiction:

Improvethickness of transformer bodyVSAvoidheat generation from rear surface

Core Design Contradiction:

Volume of moving objectVSTemperature

Solution Approach 1:

The core structure is designed with different thickness characteristics in different regions: the body portion has a first thickness while the protruding portion has a second thickness that is 5-15 μm greater. This local thickness variation ensures that the rear surface maintains adequate thickness for heat dissipation while the overall transformer profile remains slim, preventing excessive heat generation from the rear surface during operation.

Inventive Principle:

Principle #3Local quality

2Volume of moving object

If the thickness of the core is reduced for a slim transformer design, then the transformer achieves compact dimensions, but shrinkage of the core occurs during the curing process of the bonding agent causing thickness defects

Engineering Contradiction:

Improvethickness of coreVSAvoidthickness uniformity during bonding agent curing

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The core is designed with a protruding portion that extends in the thickness direction from the body portion. This protruding structure is configured to contact the opposing core before the bonding agent is applied, establishing a mechanical stop that prevents shrinkage-induced gaps during the bonding agent curing process. The preliminary geometric configuration compensates for the shrinkage that occurs during manufacturing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The core structure is designed with different thickness characteristics in different regions: the body portion has a first thickness while the protruding portion has a second thickness that is 5-15 μm greater. This local thickness variation ensures that the rear surface maintains adequate thickness for heat dissipation while the overall transformer profile remains slim, preventing excessive heat generation from the rear surface during operation.

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If gaps are formed between upper core and lower core during bonding agent curing, then the transformer structure accommodates shrinkage, but thickness defects occur and non-ideal heat generation results

Engineering Contradiction:

Improvecore structure stability during bondingVSAvoidthickness uniformity

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The core is designed with a protruding portion that extends in the thickness direction from the body portion. This protruding structure is configured to contact the opposing core before the bonding agent is applied, establishing a mechanical stop that prevents shrinkage-induced gaps during the bonding agent curing process. The preliminary geometric configuration compensates for the shrinkage that occurs during manufacturing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The core structure is designed with different thickness characteristics in different regions: the body portion has a first thickness while the protruding portion has a second thickness that is 5-15 μm greater. This local thickness variation ensures that the rear surface maintains adequate thickness for heat dissipation while the overall transformer profile remains slim, preventing excessive heat generation from the rear surface during operation.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP4645352A1Transformer and power supply device using same

Publication Date: 2025.11.05 LG INNOTEK CO LTD

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Figure 2A
Figure 2B~3

AI summary

The present invention relates to a transformer and a power supply device using same, the transformer being capable of reducing the occurrence of defects due to a core shrinkage phenomenon during a curing process of a bonding liquid. The transformer according to the present invention may comprise: a core part including an upper core and a lower core which are coupled to face each other; and a bobbin which is at least partially disposed between the upper core and the lower core, wherein the upper core and the lower core comprises: a body part in the form of a flat plate; and a plurality of legs formed by protrusion parts protruding from the body part in a thickness direction and extending along one axial direction, and the protrusion parts form a predetermined proportional relationship with the body part and have different thicknesses, so that the thicknesses of the protrusion parts and rear surfaces of the upper core and the lower core can be designed at an optimal ratio, and thus the occurrence of a warpage phenomenon of the cores can be prevented during a curing process after bonding and during operation.