Molded-Via Power Module Package for Stress-Reduced Press-Fit Connections
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Solution Overview
Problem
Power device modules face increasing performance requirements in size, electrical, thermal, mechanical, reliability, and fatigue, as well as assembly and external connection challenges, particularly in automotive and industrial applications, where existing solutions often lead to stress-induced mechanical damage and reliability issues.
Innovation Solution
The implementation of a power module with a press-fit pin coupler and a resilient substrate featuring plated-through holes, allowing for solder-less mounting and reducing mechanical stress, which includes a mold body with a through-mold via exposing the plated-through holes for external access and connection, enabling reliable electrical connections without damaging the encapsulating material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional soldering or press-fit connections are used to mount power device modules to substrates, then electrical connections can be established, but mechanical stress is induced that can cause damage to the encapsulating mold material and lead to reliability issues
Solution Approach 1:
The patent introduces a resilient substrate as an intermediary component between the power device module and the host substrate. This substrate features plated-through holes that provide mechanical compliance and stress absorption, acting as a mediator that decouples the rigid connection from the encapsulated power device, thereby reducing mechanical stress while maintaining reliable electrical connections
2Strength
If the mold body is made rigid to protect the encapsulated components, then mechanical protection is improved, but accessibility for external connections becomes difficult
Solution Approach 1:
The patent segments the connection interface by providing dedicated through-mold vias in the encapsulating mold material. These vias create localized access points that allow press-fit pins to penetrate the rigid mold body and establish connections with the power device leads, maintaining overall mold integrity while enabling external accessibility
3Ease of manufacture
If press-fit pins are used for mounting to reduce assembly complexity, then ease of assembly is improved, but mechanical stress on the mold body increases
Solution Approach 1:
The resilient substrate serves as a stress-absorbing intermediary between the press-fit pins and the rigid mold body. When press-fit pins are inserted into the plated-through holes of the resilient substrate, the compliant material absorbs and distributes the insertion stress, preventing concentration of forces on the mold body while maintaining the simplicity of press-fit assembly
Data Source
AI summary
A module includes an assembly of a semiconductor device die, a lead frame connected to the semiconductor device die, and a substrate connected to the lead frame. The substrate includes at least one plated-through hole (PTH). A mold body encapsulates the assembly. The mold body includes a through-mold via (TMV) aligned with a portion of the substrate including the at least one PTH. The PTH is exposed in the TMV to an environment outside the mold body and is physically accessible from outside the mold body through the TMV.