Dual-Sided Power Semiconductor Package Without Topside Grinding

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional power semiconductor packages with top side only cooling suffer from inconsistent thermal performance due to tilted copper blocks, increased manufacturing costs, and reduced thermal efficiency from thicker thermal interface materials required to accommodate warpage.

Innovation Solution

A molded semiconductor package design featuring a semiconductor die, substrate, leads, heat sink clip, and molding compound, where the leads and heat sink clip protrude from opposing faces of the molding compound edge, eliminating the need for topside thinning and ensuring consistent double-sided cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a grinding method is used to expose a copper block at the package top side, then double sided cooling is achieved, but manufacturing cost increases due to added steps of grinding, taping, etc.

Engineering Contradiction:

Improvethermal resistanceVSAvoidmanufacturing cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

Instead of grinding the package top side to expose the copper block, the patent inverts the approach by designing the copper block to protrude through the molding compound. This eliminates the need for grinding operations while achieving the same double-sided cooling effect, thereby reducing manufacturing cost and process complexity.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The copper block is pre-positioned and designed to protrude through the molding compound during the packaging process itself, rather than requiring subsequent grinding operations. This preliminary action integrates the heat dissipation structure formation into the main packaging process, eliminating additional manufacturing steps.

Inventive Principle:

Principle #10Preliminary action

2Temperature

If a grinding method is used to expose a copper block, then double sided cooling is achieved, but the exposed cooling surfaces become inconsistent due to tilt of the copper block

Engineering Contradiction:

Improvethermal resistanceVSAvoidcooling surface consistency

Core Design Contradiction:

TemperatureVSManufacturing precision

Solution Approach 1:

Rather than attempting to grind the copper block flat after it has been tilted during assembly, the patent inverts the approach by designing the copper block to protrude through the molding compound in its tilted state. This accepts the tilt as part of normal manufacturing tolerances and achieves consistent cooling surfaces without requiring precise flatness control.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the parameter of copper block orientation from requiring precise flatness (grinded surface) to allowing controlled tilt (protruding surface). By accepting a range of tilt angles within manufacturing tolerances, the system achieves consistent thermal performance without the need for precision grinding operations.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If conventional packaging is used, then manufacturing is simpler, but warpage of the circuit board occurs which requires thicker thermal interface material

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidthermal performance

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent segments the heat dissipation function into two independent paths: one through the substrate to the circuit board, and another through the protruding copper block directly to the heat sink. This segmentation allows the thermal interface material to be thinner since it only needs to compensate for minor warpage, not the full extent of board deformation, thereby improving thermal performance while maintaining manufacturing simplicity.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design achieves improved thermal performance with consistent cooling surfaces, reduced manufacturing costs by eliminating grinding steps, and thinner thermal interface materials, enhancing overall system thermal efficiency.

Implementation Method 1

a heat sink clip thermally coupled to the pad

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a molding compound encapsulating the semiconductor die, part of the leads, part of the heat sink clip, and at least part of the substrate

Methodology Applied

Scientific EffectEncapsulation:

Data Source

PatentUS12334414B2Power semiconductor device with dual heat dissipation structures

Publication Date: 2025.06.17 INFINEON TECHNOLOGIES AG

AI summary

A molded semiconductor package includes: a semiconductor die; a substrate attached to a first side of the semiconductor die; a plurality of leads electrically connected to a second side of the semiconductor die opposite the first side; a heat sink clip thermally coupled to a pad at the second side of the semiconductor die; and a molding compound encapsulating the die, part of the leads, part of the heat sink clip, and at least part of the substrate. The molding compound has a first main side, a second main side opposite the first main side and at which the substrate is disposed, and an edge extending between the first main side and the second main side. The leads protrude from opposing first and second faces of the edge of the molding compound. The heat sink clip protrudes from opposing third and fourth faces of the edge of the molding compound.