Semiconductor Module Copper Connector Solder Mounting

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Solution Overview

Problem

Conventional semiconductor modules require different manufacturing processes for wire bonding and solder mounting, leading to increased manufacturing time and cost, and lack flexibility in layout and impedance uniformity, particularly for three-phase motors.

Innovation Solution

A semiconductor module and manufacturing method that use a copper connector to joint bare-chip transistors and wiring patterns via solder mounting, allowing for the same process as other surface mounting devices and enabling flexible layout and uniform path lengths, reducing the need for dedicated equipment and improving impedance characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wire bonding is used to joint the emitter of IGBT and copper foil, then electrical connection is achieved, but manufacturing process complexity increases and manufacturing time is extended

Engineering Contradiction:
Improveelectrical connectionVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the wire bonding process with the solder mounting process by using a copper foil with pre-formed through-holes that accept the wire. The wire is inserted through the hole and soldered on both sides, combining electrical connection and mechanical attachment into a single integrated structure that can be manufactured using standard soldering equipment rather than dedicated wire bonding equipment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The copper foil serves multiple functions: it provides the electrical connection path, acts as the bonding substrate for the IGBT emitter, and serves as the mechanical support structure. The through-holes in the copper foil provide both electrical pathways and mechanical anchoring points for the wires, eliminating the need for separate wire bonding equipment.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If wire bonding is used to joint the emitter of IGBT and copper foil, then electrical connection is achieved, but manufacturing cost increases

Engineering Contradiction:
Improveelectrical connectionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the wire bonding process with the solder mounting process by using a copper foil with pre-formed through-holes that accept the wire. The wire is inserted through the hole and soldered on both sides, combining electrical connection and mechanical attachment into a single integrated structure that can be manufactured using standard soldering equipment rather than dedicated wire bonding equipment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a relatively simple copper foil structure with through-holes instead of complex wire bonding equipment. The copper foil acts as a disposable or single-use component in the assembly process, providing the necessary electrical and mechanical functions without requiring expensive dedicated wire bonding machinery.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If conventional layout is used in semiconductor module, then manufacturing is simplified, but impedance uniformity and layout flexibility are reduced

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidlayout flexibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent segments the copper foil into multiple isolated regions or islands, each serving specific electrical connection functions. This segmentation allows independent optimization of each region's position and shape to achieve uniform impedance paths for three-phase motors, while the overall layout can be flexibly adjusted to meet different manufacturing requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different local characteristics to different regions of the copper foil structure. Each copper foil region is designed with specific hole patterns and dimensions optimized for its local electrical and mechanical requirements, allowing simultaneous achievement of impedance uniformity in critical areas and manufacturing flexibility in other areas.

Inventive Principle:
Principle #3Local quality

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 shortens manufacturing time, reduces costs, and enhances the flexibility and uniformity of semiconductor module layouts, improving the impedance characteristics of three-phase motors.

Implementation Method 1

jointing the copper connector (36c) and the wiring pattern (33b) to each other and jointing the copper connector (36c) and the electrode (S, G) of the bare-chip FET (35) to each other by the same process of solder mounting operation

Methodology Applied
Scientific EffectSoldering: Soldering

Data Source

PatentEP2858100B1Semiconductor module and production method for same
Publication Date: 2020.06.10 NSK LTD
  • EP2858100B1 patent drawingFigure 1
  • EP2858100B1 patent drawingFigure 2
  • EP2858100B1 patent drawingFigure 3

AI summary

There is provided a semiconductor module and a method for manufacturing the same which make it possible to joint the electrode of the bare-chip transistor and the wiring pattern on the substrate by solder mounting operation, in the same process of solder mounting operation for mounting the bare-chip transistor or other surface mounting devices on the wiring patterns on the substrate A semiconductor module (30) includes: a plurality of wiring patterns (33a) to (33d) formed on an insulating layer (32); a bare-chip transistor (35) mounted on one wiring pattern (33a) out of the plurality of wiring patterns (33a) to (33d) via a solder (34a); and a copper connector (36a), (36b) constituted of a copper plate for jointing an electrode (S), (G) formed on a top surface of the bare-chip transistor (35) and another wiring pattern (33b), (33c) out of the plurality of wiring patterns (33a) to (33d) via a solder (34a), (34c).