Semiconductor Package Interconnects via Laser-Melted Metal Powder
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Solution Overview
Problem
Conventional semiconductor package assembly manufacturing techniques are complex, time-consuming, and prone to connectivity failures due to fragile bonds, requiring pre-designed connecting elements and resulting in high R DS(on) characteristics, limiting the performance of leaded/leadless power/MCD packages or power modules.
Innovation Solution
A method involving the formation of connection elements through layer-by-layer deposition and solidification of metal powder using laser radiation, eliminating the need for pre-designed components and allowing for flexible control of layer thickness and density, reducing material stresses and R DS(on) characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wire bonds or ribbon bonds are used to connect semiconductor die structures with lead frame terminals, then electrical and mechanical connection is achieved, but the process becomes complex, time-consuming, and the bonds are fragile and prone to connectivity failures
Solution Approach 1:
The patent merges the connection element formation with the semiconductor package manufacturing process itself. Instead of using separate pre-manufactured wire bonds or ribbon bonds that require additional mounting steps, the connection elements are directly formed within the mold cavity during the molding process, integrating multiple functions into a single manufacturing step.
Solution Approach 2:
The connection elements are formed in-situ within the mold cavity, allowing the molding process to automatically create the electrical and mechanical connections between the semiconductor die structure and lead frame terminals. This eliminates the need for separate handling and mounting of pre-manufactured connecting elements.
2Productivity
If pre-designed and pre-manufactured connecting elements are used, then electrical connection is established, but the manufacturing process becomes cumbersome and time-consuming due to additional handling steps
Solution Approach 1:
The patent combines the formation of connection elements with the molding process by providing mold inserts that define the shape and position of connection elements directly in the mold cavity. This integration eliminates separate steps for preparing and mounting pre-manufactured connecting elements.
Solution Approach 2:
The mold inserts are pre-configured with the desired connection element geometry and positioning before the molding process begins. This preliminary preparation allows connection elements to be formed correctly during the molding process without requiring subsequent adjustment or mounting operations.
3Reliability
If conventional bonding techniques are used, then electrical connection is achieved, but the R DS(on) is high which limits performance
Solution Approach 1:
The patent uses metal powder with uniform composition and properties to form the connection elements. This homogeneity ensures consistent electrical properties throughout the connection element, reducing resistance and improving overall electrical performance compared to conventional bonded connections.
Solution Approach 2:
The connection elements are formed from metal powder that can be combined with bonding agents or other materials to create composite structures with optimized electrical and mechanical properties, achieving lower R DS(on) while maintaining connection reliability.
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 approach simplifies the manufacturing process, reduces connectivity failures, extends the life span of semiconductor packages, and lowers R DS(on) by forming a uniform metal layer interface, thereby enhancing the performance and reliability of leaded/leadless power/MCD packages or power modules.
Implementation Method 1
selectively melting, with laser light radiation, the layer of metal powder to form a metal layer
Implementation Method 2
selectively melting, with laser light radiation, the layer of metal powder to form a metal layer
Data Source
Figure 1
Figure 2a~2b
Figure 3a~3b
AI summary
A method for manufacturing a leaded/leadless power/MCD package or power module is proposed with less complex and less time-consuming process steps, and wherein the connecting elements being implemented are of a simple design with reduced RDS(on) characteristic. It comprises the sub-steps i1) providing a lead frame, and providing in step i2) at least one semiconductor die structure on the lead frame. The step i-3) of forming one or more connection elements between the at least one semiconductor die structures and the at least two terminals of the lead frame comprises at least one forming sequence of the sub steps of i3-1) of providing a layer of a metal powder such that the metal powder is in contact with the at least one semiconductor die structure and one of the at least two terminals of the lead frame; and sub-step i3-2) of selectively melting with laser light radiation, the layer of the metal powder to form a metal layer. In a final step ii) the at least one semiconductor die structure, the one or more connection elements and the plurality of terminals are encapsulated with a molding resin leaving at least a portion of at least two terminals exposed, thereby forming at least one encapsulated semiconductor package assembly.