Molded Semiconductor Module With Bent Metal Terminal

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Power semiconductor modules face challenges with die placement accuracy, gate pad contacting, and contamination issues due to the use of sensitive semiconductor materials like silicon in PCB processing, particularly with laser drilling and FR4 materials.

Innovation Solution

A molded semiconductor module design featuring a semiconductor die attached to a metal block with a bent metal terminal and encapsulated in a molding compound, allowing for improved die placement accuracy and reduced contamination, enabling operation at higher voltages without ion contamination and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If laser drilling is used to form openings in PCB insulator material, then holes can be formed to access electrical contact pads, but semiconductor material becomes contaminated and sensitive to ion damage

Engineering Contradiction:

Improvehole formation processVSAvoidcontamination and ion damage to semiconductor material

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary structure (the molded package with protruding metal terminal) that mediates between the semiconductor die and the PCB drilling process. The metal terminal extends through the molding compound to expose the contact pad, allowing electrical access without requiring direct laser drilling through the semiconductor die itself, thus protecting the semiconductor material from contamination and ion damage while still enabling hole formation in the PCB insulator material

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If traditional embedding process is used with metal block and semiconductor die, then power semiconductor modules can be embedded in PCB, but die placement accuracy is poor and gate pad contacting is problematic

Engineering Contradiction:

Improveembedding capabilityVSAvoiddie placement accuracy and gate pad contacting

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-attaching the metal terminal to the semiconductor die before packaging, and pre-positioning the die on the metal block with accurate alignment. The metal terminal is configured with a specific geometry that facilitates accurate placement and automatic alignment during the embedding process, ensuring precise die placement and reliable gate pad contacting before the module is inserted into the PCB

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the geometric parameters of the metal terminal, specifically configuring it with a bent shape that has a contact region attached to the contact pad and a distal end region that protrudes through the molding compound. This parameter change in the terminal's shape and configuration enables improved placement accuracy and reliable electrical contact while maintaining the embedding capability

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If semiconductor die is directly exposed in PCB embedding, then electrical contact can be made, but the semiconductor material is highly sensitive to contamination from PCB process and ions in FR4

Engineering Contradiction:

Improveelectrical contactVSAvoidcontamination from PCB process and ions in FR4

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces multiple intermediary protective layers: the molding compound encapsulates the semiconductor die to protect it from contamination, while the metal terminal acts as an intermediary conductor that extends through the molding compound to provide electrical access. This intermediary structure allows electrical contact to be made without direct exposure of the semiconductor die to the PCB process environment and ion-containing FR4 material

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If metal terminal is fully encapsulated in molding compound, then semiconductor die is protected, but electrical contact to contact pad is lost

Engineering Contradiction:

Improvesemiconductor die protectionVSAvoidelectrical contact access

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by pre-configuring the metal terminal with a protruding distal end region that extends through the molding compound before packaging. This preliminary configuration ensures that while the semiconductor die is fully protected by the molding compound, the metal terminal's distal end remains accessible for electrical contact, eliminating the need for post-packaging drilling or opening operations

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11404392B1Molded semiconductor module for PCB embedding

Publication Date: 2022.08.02 INFINEON TECHNOLOGIES AG

AI summary

A molded semiconductor module include: a semiconductor die attached to a main surface of a metal block. The die has a metal contact pad at a side of the die facing away from the metal block. A metal terminal has a contact region attached to the metal contact pad of the die, and a distal end region that joins the contact region and is bent upward in a direction away from the metal block such that the distal end region has a free end which terminates at a further distance from the metal block than the contact region. A molding compound encapsulates the die and covers the contact region of the metal terminal. The distal end region of the metal terminal protrudes through a surface of the molding compound that faces a same direction as the side of the die with the metal contact pad.