Dual Heat Dissipation Semiconductor Package Without Top-Side Grinding
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Solution Overview
Problem
Conventional power semiconductor packages with top-side cooling face issues such as tilted copper blocks leading to inconsistent cooling surfaces and increased costs due to grinding processes, which result in reduced thermal performance when attached to a circuit board.
Innovation Solution
A molded semiconductor package design featuring a semiconductor die with a substrate and heat sink clip thermally coupled to a pad, encapsulated in a molding compound, where the heat sink clip protrudes from opposing faces of the compound edge, providing double-sided cooling without the need for top-side thinning, and leads protrude from the compound edge for attachment to a circuit board.
Engineering Contradictions & Design Principles
Engineering 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 the copper block tilt leads to inconsistent exposed cooling surfaces
Solution Approach 1:
Instead of grinding the package top side to expose the copper block (conventional approach), the patent inverts the approach by having the heat sink clip protrude from the molding compound edge. This eliminates the need for grinding and ensures consistent cooling surfaces without tilt-related inconsistencies.
Solution Approach 2:
The patent transitions from top-side-only cooling to dual-sided cooling by extending the heat sink clip functionality to protrude from the edge of the molding compound. This dimensional change allows heat dissipation from both sides of the package, achieving 50% lower thermal resistance.
2Temperature
If a grinding method is used to expose a copper block, then double sided cooling is achieved, but the overall cost of the package increases due to added steps
Solution Approach 1:
The patent eliminates the conventional grinding process by inverting the approach: instead of removing material to expose the copper block, the heat sink clip is designed to protrude directly from the molding compound edge. This simplifies manufacturing and reduces costs while achieving the same dual-sided cooling effect.
Solution Approach 2:
The patent extracts the unnecessary grinding step from the manufacturing process. By designing the heat sink clip to protrude from the molding compound edge, the complex steps of grinding, taping, and other post-processing operations are eliminated, reducing both cost and complexity.
3Ease of manufacture
If the package uses conventional top side cooling only, then manufacturing is simpler, but thermal performance is reduced when attached to a circuit board
Solution Approach 1:
The patent enhances thermal performance by adding a second cooling dimension. The heat sink clip protrudes from the edge of the molding compound, enabling dual-sided heat dissipation. This maintains manufacturing simplicity while significantly improving thermal performance compared to top-side-only cooling.
Solution Approach 2:
The heat sink clip serves multiple functions: it provides mechanical support, electrical connection, and dual-sided thermal management. This multi-functionality achieves superior thermal performance without complicating the manufacturing process, as the same component structure fulfills multiple roles.
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 enhances thermal performance by ensuring consistent cooling surfaces and reducing manufacturing costs, while maintaining effective heat dissipation through the heat sink clip and substrate, thus improving the overall thermal efficiency of the system.
Implementation Method 1
a heat sink clip thermally coupled to the pad
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
Data Source
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 pad at a second side of the semiconductor die opposite the first side; a heat sink clip thermally coupled to the pad; and a molding compound encapsulating the semiconductor 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.